feat: initial tracing support (#1623)

vendor/google.golang.org/grpc/internal/backoff/backoff.go

@@ -0,0 +1,73 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package backoff implement the backoff strategy for gRPC.
+//
+// This is kept in internal until the gRPC project decides whether or not to
+// allow alternative backoff strategies.
+package backoff
+
+import (
+	"time"
+
+	grpcbackoff "google.golang.org/grpc/backoff"
+	"google.golang.org/grpc/internal/grpcrand"
+)
+
+// Strategy defines the methodology for backing off after a grpc connection
+// failure.
+type Strategy interface {
+	// Backoff returns the amount of time to wait before the next retry given
+	// the number of consecutive failures.
+	Backoff(retries int) time.Duration
+}
+
+// DefaultExponential is an exponential backoff implementation using the
+// default values for all the configurable knobs defined in
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+var DefaultExponential = Exponential{Config: grpcbackoff.DefaultConfig}
+
+// Exponential implements exponential backoff algorithm as defined in
+// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
+type Exponential struct {
+	// Config contains all options to configure the backoff algorithm.
+	Config grpcbackoff.Config
+}
+
+// Backoff returns the amount of time to wait before the next retry given the
+// number of retries.
+func (bc Exponential) Backoff(retries int) time.Duration {
+	if retries == 0 {
+		return bc.Config.BaseDelay
+	}
+	backoff, max := float64(bc.Config.BaseDelay), float64(bc.Config.MaxDelay)
+	for backoff < max && retries > 0 {
+		backoff *= bc.Config.Multiplier
+		retries--
+	}
+	if backoff > max {
+		backoff = max
+	}
+	// Randomize backoff delays so that if a cluster of requests start at
+	// the same time, they won't operate in lockstep.
+	backoff *= 1 + bc.Config.Jitter*(grpcrand.Float64()*2-1)
+	if backoff < 0 {
+		return 0
+	}
+	return time.Duration(backoff)
+}

vendor/google.golang.org/grpc/internal/balancer/gracefulswitch/gracefulswitch.go

@@ -0,0 +1,384 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package gracefulswitch implements a graceful switch load balancer.
+package gracefulswitch
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/balancer/base"
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/resolver"
+)
+
+var errBalancerClosed = errors.New("gracefulSwitchBalancer is closed")
+var _ balancer.Balancer = (*Balancer)(nil)
+
+// NewBalancer returns a graceful switch Balancer.
+func NewBalancer(cc balancer.ClientConn, opts balancer.BuildOptions) *Balancer {
+	return &Balancer{
+		cc:    cc,
+		bOpts: opts,
+	}
+}
+
+// Balancer is a utility to gracefully switch from one balancer to
+// a new balancer. It implements the balancer.Balancer interface.
+type Balancer struct {
+	bOpts balancer.BuildOptions
+	cc    balancer.ClientConn
+
+	// mu protects the following fields and all fields within balancerCurrent
+	// and balancerPending. mu does not need to be held when calling into the
+	// child balancers, as all calls into these children happen only as a direct
+	// result of a call into the gracefulSwitchBalancer, which are also
+	// guaranteed to be synchronous. There is one exception: an UpdateState call
+	// from a child balancer when current and pending are populated can lead to
+	// calling Close() on the current. To prevent that racing with an
+	// UpdateSubConnState from the channel, we hold currentMu during Close and
+	// UpdateSubConnState calls.
+	mu              sync.Mutex
+	balancerCurrent *balancerWrapper
+	balancerPending *balancerWrapper
+	closed          bool // set to true when this balancer is closed
+
+	// currentMu must be locked before mu. This mutex guards against this
+	// sequence of events: UpdateSubConnState() called, finds the
+	// balancerCurrent, gives up lock, updateState comes in, causes Close() on
+	// balancerCurrent before the UpdateSubConnState is called on the
+	// balancerCurrent.
+	currentMu sync.Mutex
+}
+
+// swap swaps out the current lb with the pending lb and updates the ClientConn.
+// The caller must hold gsb.mu.
+func (gsb *Balancer) swap() {
+	gsb.cc.UpdateState(gsb.balancerPending.lastState)
+	cur := gsb.balancerCurrent
+	gsb.balancerCurrent = gsb.balancerPending
+	gsb.balancerPending = nil
+	go func() {
+		gsb.currentMu.Lock()
+		defer gsb.currentMu.Unlock()
+		cur.Close()
+	}()
+}
+
+// Helper function that checks if the balancer passed in is current or pending.
+// The caller must hold gsb.mu.
+func (gsb *Balancer) balancerCurrentOrPending(bw *balancerWrapper) bool {
+	return bw == gsb.balancerCurrent || bw == gsb.balancerPending
+}
+
+// SwitchTo initializes the graceful switch process, which completes based on
+// connectivity state changes on the current/pending balancer. Thus, the switch
+// process is not complete when this method returns. This method must be called
+// synchronously alongside the rest of the balancer.Balancer methods this
+// Graceful Switch Balancer implements.
+func (gsb *Balancer) SwitchTo(builder balancer.Builder) error {
+	gsb.mu.Lock()
+	if gsb.closed {
+		gsb.mu.Unlock()
+		return errBalancerClosed
+	}
+	bw := &balancerWrapper{
+		gsb: gsb,
+		lastState: balancer.State{
+			ConnectivityState: connectivity.Connecting,
+			Picker:            base.NewErrPicker(balancer.ErrNoSubConnAvailable),
+		},
+		subconns: make(map[balancer.SubConn]bool),
+	}
+	balToClose := gsb.balancerPending // nil if there is no pending balancer
+	if gsb.balancerCurrent == nil {
+		gsb.balancerCurrent = bw
+	} else {
+		gsb.balancerPending = bw
+	}
+	gsb.mu.Unlock()
+	balToClose.Close()
+	// This function takes a builder instead of a balancer because builder.Build
+	// can call back inline, and this utility needs to handle the callbacks.
+	newBalancer := builder.Build(bw, gsb.bOpts)
+	if newBalancer == nil {
+		// This is illegal and should never happen; we clear the balancerWrapper
+		// we were constructing if it happens to avoid a potential panic.
+		gsb.mu.Lock()
+		if gsb.balancerPending != nil {
+			gsb.balancerPending = nil
+		} else {
+			gsb.balancerCurrent = nil
+		}
+		gsb.mu.Unlock()
+		return balancer.ErrBadResolverState
+	}
+
+	// This write doesn't need to take gsb.mu because this field never gets read
+	// or written to on any calls from the current or pending. Calls from grpc
+	// to this balancer are guaranteed to be called synchronously, so this
+	// bw.Balancer field will never be forwarded to until this SwitchTo()
+	// function returns.
+	bw.Balancer = newBalancer
+	return nil
+}
+
+// Returns nil if the graceful switch balancer is closed.
+func (gsb *Balancer) latestBalancer() *balancerWrapper {
+	gsb.mu.Lock()
+	defer gsb.mu.Unlock()
+	if gsb.balancerPending != nil {
+		return gsb.balancerPending
+	}
+	return gsb.balancerCurrent
+}
+
+// UpdateClientConnState forwards the update to the latest balancer created.
+func (gsb *Balancer) UpdateClientConnState(state balancer.ClientConnState) error {
+	// The resolver data is only relevant to the most recent LB Policy.
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return errBalancerClosed
+	}
+	// Perform this call without gsb.mu to prevent deadlocks if the child calls
+	// back into the channel. The latest balancer can never be closed during a
+	// call from the channel, even without gsb.mu held.
+	return balToUpdate.UpdateClientConnState(state)
+}
+
+// ResolverError forwards the error to the latest balancer created.
+func (gsb *Balancer) ResolverError(err error) {
+	// The resolver data is only relevant to the most recent LB Policy.
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return
+	}
+	// Perform this call without gsb.mu to prevent deadlocks if the child calls
+	// back into the channel. The latest balancer can never be closed during a
+	// call from the channel, even without gsb.mu held.
+	balToUpdate.ResolverError(err)
+}
+
+// ExitIdle forwards the call to the latest balancer created.
+//
+// If the latest balancer does not support ExitIdle, the subConns are
+// re-connected to manually.
+func (gsb *Balancer) ExitIdle() {
+	balToUpdate := gsb.latestBalancer()
+	if balToUpdate == nil {
+		return
+	}
+	// There is no need to protect this read with a mutex, as the write to the
+	// Balancer field happens in SwitchTo, which completes before this can be
+	// called.
+	if ei, ok := balToUpdate.Balancer.(balancer.ExitIdler); ok {
+		ei.ExitIdle()
+		return
+	}
+	gsb.mu.Lock()
+	defer gsb.mu.Unlock()
+	for sc := range balToUpdate.subconns {
+		sc.Connect()
+	}
+}
+
+// UpdateSubConnState forwards the update to the appropriate child.
+func (gsb *Balancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	gsb.currentMu.Lock()
+	defer gsb.currentMu.Unlock()
+	gsb.mu.Lock()
+	// Forward update to the appropriate child.  Even if there is a pending
+	// balancer, the current balancer should continue to get SubConn updates to
+	// maintain the proper state while the pending is still connecting.
+	var balToUpdate *balancerWrapper
+	if gsb.balancerCurrent != nil && gsb.balancerCurrent.subconns[sc] {
+		balToUpdate = gsb.balancerCurrent
+	} else if gsb.balancerPending != nil && gsb.balancerPending.subconns[sc] {
+		balToUpdate = gsb.balancerPending
+	}
+	gsb.mu.Unlock()
+	if balToUpdate == nil {
+		// SubConn belonged to a stale lb policy that has not yet fully closed,
+		// or the balancer was already closed.
+		return
+	}
+	balToUpdate.UpdateSubConnState(sc, state)
+}
+
+// Close closes any active child balancers.
+func (gsb *Balancer) Close() {
+	gsb.mu.Lock()
+	gsb.closed = true
+	currentBalancerToClose := gsb.balancerCurrent
+	gsb.balancerCurrent = nil
+	pendingBalancerToClose := gsb.balancerPending
+	gsb.balancerPending = nil
+	gsb.mu.Unlock()
+
+	currentBalancerToClose.Close()
+	pendingBalancerToClose.Close()
+}
+
+// balancerWrapper wraps a balancer.Balancer, and overrides some Balancer
+// methods to help cleanup SubConns created by the wrapped balancer.
+//
+// It implements the balancer.ClientConn interface and is passed down in that
+// capacity to the wrapped balancer. It maintains a set of subConns created by
+// the wrapped balancer and calls from the latter to create/update/remove
+// SubConns update this set before being forwarded to the parent ClientConn.
+// State updates from the wrapped balancer can result in invocation of the
+// graceful switch logic.
+type balancerWrapper struct {
+	balancer.Balancer
+	gsb *Balancer
+
+	lastState balancer.State
+	subconns  map[balancer.SubConn]bool // subconns created by this balancer
+}
+
+func (bw *balancerWrapper) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	if state.ConnectivityState == connectivity.Shutdown {
+		bw.gsb.mu.Lock()
+		delete(bw.subconns, sc)
+		bw.gsb.mu.Unlock()
+	}
+	// There is no need to protect this read with a mutex, as the write to the
+	// Balancer field happens in SwitchTo, which completes before this can be
+	// called.
+	bw.Balancer.UpdateSubConnState(sc, state)
+}
+
+// Close closes the underlying LB policy and removes the subconns it created. bw
+// must not be referenced via balancerCurrent or balancerPending in gsb when
+// called. gsb.mu must not be held.  Does not panic with a nil receiver.
+func (bw *balancerWrapper) Close() {
+	// before Close is called.
+	if bw == nil {
+		return
+	}
+	// There is no need to protect this read with a mutex, as Close() is
+	// impossible to be called concurrently with the write in SwitchTo(). The
+	// callsites of Close() for this balancer in Graceful Switch Balancer will
+	// never be called until SwitchTo() returns.
+	bw.Balancer.Close()
+	bw.gsb.mu.Lock()
+	for sc := range bw.subconns {
+		bw.gsb.cc.RemoveSubConn(sc)
+	}
+	bw.gsb.mu.Unlock()
+}
+
+func (bw *balancerWrapper) UpdateState(state balancer.State) {
+	// Hold the mutex for this entire call to ensure it cannot occur
+	// concurrently with other updateState() calls. This causes updates to
+	// lastState and calls to cc.UpdateState to happen atomically.
+	bw.gsb.mu.Lock()
+	defer bw.gsb.mu.Unlock()
+	bw.lastState = state
+
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		return
+	}
+
+	if bw == bw.gsb.balancerCurrent {
+		// In the case that the current balancer exits READY, and there is a pending
+		// balancer, you can forward the pending balancer's cached State up to
+		// ClientConn and swap the pending into the current. This is because there
+		// is no reason to gracefully switch from and keep using the old policy as
+		// the ClientConn is not connected to any backends.
+		if state.ConnectivityState != connectivity.Ready && bw.gsb.balancerPending != nil {
+			bw.gsb.swap()
+			return
+		}
+		// Even if there is a pending balancer waiting to be gracefully switched to,
+		// continue to forward current balancer updates to the Client Conn. Ignoring
+		// state + picker from the current would cause undefined behavior/cause the
+		// system to behave incorrectly from the current LB policies perspective.
+		// Also, the current LB is still being used by grpc to choose SubConns per
+		// RPC, and thus should use the most updated form of the current balancer.
+		bw.gsb.cc.UpdateState(state)
+		return
+	}
+	// This method is now dealing with a state update from the pending balancer.
+	// If the current balancer is currently in a state other than READY, the new
+	// policy can be swapped into place immediately. This is because there is no
+	// reason to gracefully switch from and keep using the old policy as the
+	// ClientConn is not connected to any backends.
+	if state.ConnectivityState != connectivity.Connecting || bw.gsb.balancerCurrent.lastState.ConnectivityState != connectivity.Ready {
+		bw.gsb.swap()
+	}
+}
+
+func (bw *balancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return nil, fmt.Errorf("%T at address %p that called NewSubConn is deleted", bw, bw)
+	}
+	bw.gsb.mu.Unlock()
+
+	sc, err := bw.gsb.cc.NewSubConn(addrs, opts)
+	if err != nil {
+		return nil, err
+	}
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) { // balancer was closed during this call
+		bw.gsb.cc.RemoveSubConn(sc)
+		bw.gsb.mu.Unlock()
+		return nil, fmt.Errorf("%T at address %p that called NewSubConn is deleted", bw, bw)
+	}
+	bw.subconns[sc] = true
+	bw.gsb.mu.Unlock()
+	return sc, nil
+}
+
+func (bw *balancerWrapper) ResolveNow(opts resolver.ResolveNowOptions) {
+	// Ignore ResolveNow requests from anything other than the most recent
+	// balancer, because older balancers were already removed from the config.
+	if bw != bw.gsb.latestBalancer() {
+		return
+	}
+	bw.gsb.cc.ResolveNow(opts)
+}
+
+func (bw *balancerWrapper) RemoveSubConn(sc balancer.SubConn) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return
+	}
+	bw.gsb.mu.Unlock()
+	bw.gsb.cc.RemoveSubConn(sc)
+}
+
+func (bw *balancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resolver.Address) {
+	bw.gsb.mu.Lock()
+	if !bw.gsb.balancerCurrentOrPending(bw) {
+		bw.gsb.mu.Unlock()
+		return
+	}
+	bw.gsb.mu.Unlock()
+	bw.gsb.cc.UpdateAddresses(sc, addrs)
+}
+
+func (bw *balancerWrapper) Target() string {
+	return bw.gsb.cc.Target()
+}

vendor/google.golang.org/grpc/internal/balancerload/load.go

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Package balancerload defines APIs to parse server loads in trailers. The
+// parsed loads are sent to balancers in DoneInfo.
+package balancerload
+
+import (
+	"google.golang.org/grpc/metadata"
+)
+
+// Parser converts loads from metadata into a concrete type.
+type Parser interface {
+	// Parse parses loads from metadata.
+	Parse(md metadata.MD) interface{}
+}
+
+var parser Parser
+
+// SetParser sets the load parser.
+//
+// Not mutex-protected, should be called before any gRPC functions.
+func SetParser(lr Parser) {
+	parser = lr
+}
+
+// Parse calls parser.Read().
+func Parse(md metadata.MD) interface{} {
+	if parser == nil {
+		return nil
+	}
+	return parser.Parse(md)
+}

vendor/google.golang.org/grpc/internal/binarylog/binarylog.go

@@ -0,0 +1,189 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package binarylog implementation binary logging as defined in
+// https://github.com/grpc/proposal/blob/master/A16-binary-logging.md.
+package binarylog
+
+import (
+	"fmt"
+	"os"
+
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/grpcutil"
+)
+
+// Logger is the global binary logger. It can be used to get binary logger for
+// each method.
+type Logger interface {
+	GetMethodLogger(methodName string) MethodLogger
+}
+
+// binLogger is the global binary logger for the binary. One of this should be
+// built at init time from the configuration (environment variable or flags).
+//
+// It is used to get a MethodLogger for each individual method.
+var binLogger Logger
+
+var grpclogLogger = grpclog.Component("binarylog")
+
+// SetLogger sets the binary logger.
+//
+// Only call this at init time.
+func SetLogger(l Logger) {
+	binLogger = l
+}
+
+// GetLogger gets the binary logger.
+//
+// Only call this at init time.
+func GetLogger() Logger {
+	return binLogger
+}
+
+// GetMethodLogger returns the MethodLogger for the given methodName.
+//
+// methodName should be in the format of "/service/method".
+//
+// Each MethodLogger returned by this method is a new instance. This is to
+// generate sequence id within the call.
+func GetMethodLogger(methodName string) MethodLogger {
+	if binLogger == nil {
+		return nil
+	}
+	return binLogger.GetMethodLogger(methodName)
+}
+
+func init() {
+	const envStr = "GRPC_BINARY_LOG_FILTER"
+	configStr := os.Getenv(envStr)
+	binLogger = NewLoggerFromConfigString(configStr)
+}
+
+// MethodLoggerConfig contains the setting for logging behavior of a method
+// logger. Currently, it contains the max length of header and message.
+type MethodLoggerConfig struct {
+	// Max length of header and message.
+	Header, Message uint64
+}
+
+// LoggerConfig contains the config for loggers to create method loggers.
+type LoggerConfig struct {
+	All      *MethodLoggerConfig
+	Services map[string]*MethodLoggerConfig
+	Methods  map[string]*MethodLoggerConfig
+
+	Blacklist map[string]struct{}
+}
+
+type logger struct {
+	config LoggerConfig
+}
+
+// NewLoggerFromConfig builds a logger with the given LoggerConfig.
+func NewLoggerFromConfig(config LoggerConfig) Logger {
+	return &logger{config: config}
+}
+
+// newEmptyLogger creates an empty logger. The map fields need to be filled in
+// using the set* functions.
+func newEmptyLogger() *logger {
+	return &logger{}
+}
+
+// Set method logger for "*".
+func (l *logger) setDefaultMethodLogger(ml *MethodLoggerConfig) error {
+	if l.config.All != nil {
+		return fmt.Errorf("conflicting global rules found")
+	}
+	l.config.All = ml
+	return nil
+}
+
+// Set method logger for "service/*".
+//
+// New MethodLogger with same service overrides the old one.
+func (l *logger) setServiceMethodLogger(service string, ml *MethodLoggerConfig) error {
+	if _, ok := l.config.Services[service]; ok {
+		return fmt.Errorf("conflicting service rules for service %v found", service)
+	}
+	if l.config.Services == nil {
+		l.config.Services = make(map[string]*MethodLoggerConfig)
+	}
+	l.config.Services[service] = ml
+	return nil
+}
+
+// Set method logger for "service/method".
+//
+// New MethodLogger with same method overrides the old one.
+func (l *logger) setMethodMethodLogger(method string, ml *MethodLoggerConfig) error {
+	if _, ok := l.config.Blacklist[method]; ok {
+		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
+	}
+	if _, ok := l.config.Methods[method]; ok {
+		return fmt.Errorf("conflicting method rules for method %v found", method)
+	}
+	if l.config.Methods == nil {
+		l.config.Methods = make(map[string]*MethodLoggerConfig)
+	}
+	l.config.Methods[method] = ml
+	return nil
+}
+
+// Set blacklist method for "-service/method".
+func (l *logger) setBlacklist(method string) error {
+	if _, ok := l.config.Blacklist[method]; ok {
+		return fmt.Errorf("conflicting blacklist rules for method %v found", method)
+	}
+	if _, ok := l.config.Methods[method]; ok {
+		return fmt.Errorf("conflicting method rules for method %v found", method)
+	}
+	if l.config.Blacklist == nil {
+		l.config.Blacklist = make(map[string]struct{})
+	}
+	l.config.Blacklist[method] = struct{}{}
+	return nil
+}
+
+// getMethodLogger returns the MethodLogger for the given methodName.
+//
+// methodName should be in the format of "/service/method".
+//
+// Each MethodLogger returned by this method is a new instance. This is to
+// generate sequence id within the call.
+func (l *logger) GetMethodLogger(methodName string) MethodLogger {
+	s, m, err := grpcutil.ParseMethod(methodName)
+	if err != nil {
+		grpclogLogger.Infof("binarylogging: failed to parse %q: %v", methodName, err)
+		return nil
+	}
+	if ml, ok := l.config.Methods[s+"/"+m]; ok {
+		return NewTruncatingMethodLogger(ml.Header, ml.Message)
+	}
+	if _, ok := l.config.Blacklist[s+"/"+m]; ok {
+		return nil
+	}
+	if ml, ok := l.config.Services[s]; ok {
+		return NewTruncatingMethodLogger(ml.Header, ml.Message)
+	}
+	if l.config.All == nil {
+		return nil
+	}
+	return NewTruncatingMethodLogger(l.config.All.Header, l.config.All.Message)
+}

vendor/google.golang.org/grpc/internal/binarylog/binarylog_testutil.go

@@ -0,0 +1,42 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// This file contains exported variables/functions that are exported for testing
+// only.
+//
+// An ideal way for this would be to put those in a *_test.go but in binarylog
+// package. But this doesn't work with staticcheck with go module. Error was:
+// "MdToMetadataProto not declared by package binarylog". This could be caused
+// by the way staticcheck looks for files for a certain package, which doesn't
+// support *_test.go files.
+//
+// Move those to binary_test.go when staticcheck is fixed.
+
+package binarylog
+
+var (
+	// AllLogger is a logger that logs all headers/messages for all RPCs. It's
+	// for testing only.
+	AllLogger = NewLoggerFromConfigString("*")
+	// MdToMetadataProto converts metadata to a binary logging proto message.
+	// It's for testing only.
+	MdToMetadataProto = mdToMetadataProto
+	// AddrToProto converts an address to a binary logging proto message. It's
+	// for testing only.
+	AddrToProto = addrToProto
+)

vendor/google.golang.org/grpc/internal/binarylog/env_config.go

@@ -0,0 +1,208 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package binarylog
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// NewLoggerFromConfigString reads the string and build a logger. It can be used
+// to build a new logger and assign it to binarylog.Logger.
+//
+// Example filter config strings:
+//   - "" Nothing will be logged
+//   - "*" All headers and messages will be fully logged.
+//   - "*{h}" Only headers will be logged.
+//   - "*{m:256}" Only the first 256 bytes of each message will be logged.
+//   - "Foo/*" Logs every method in service Foo
+//   - "Foo/*,-Foo/Bar" Logs every method in service Foo except method /Foo/Bar
+//   - "Foo/*,Foo/Bar{m:256}" Logs the first 256 bytes of each message in method
+//     /Foo/Bar, logs all headers and messages in every other method in service
+//     Foo.
+//
+// If two configs exist for one certain method or service, the one specified
+// later overrides the previous config.
+func NewLoggerFromConfigString(s string) Logger {
+	if s == "" {
+		return nil
+	}
+	l := newEmptyLogger()
+	methods := strings.Split(s, ",")
+	for _, method := range methods {
+		if err := l.fillMethodLoggerWithConfigString(method); err != nil {
+			grpclogLogger.Warningf("failed to parse binary log config: %v", err)
+			return nil
+		}
+	}
+	return l
+}
+
+// fillMethodLoggerWithConfigString parses config, creates TruncatingMethodLogger and adds
+// it to the right map in the logger.
+func (l *logger) fillMethodLoggerWithConfigString(config string) error {
+	// "" is invalid.
+	if config == "" {
+		return errors.New("empty string is not a valid method binary logging config")
+	}
+
+	// "-service/method", blacklist, no * or {} allowed.
+	if config[0] == '-' {
+		s, m, suffix, err := parseMethodConfigAndSuffix(config[1:])
+		if err != nil {
+			return fmt.Errorf("invalid config: %q, %v", config, err)
+		}
+		if m == "*" {
+			return fmt.Errorf("invalid config: %q, %v", config, "* not allowed in blacklist config")
+		}
+		if suffix != "" {
+			return fmt.Errorf("invalid config: %q, %v", config, "header/message limit not allowed in blacklist config")
+		}
+		if err := l.setBlacklist(s + "/" + m); err != nil {
+			return fmt.Errorf("invalid config: %v", err)
+		}
+		return nil
+	}
+
+	// "*{h:256;m:256}"
+	if config[0] == '*' {
+		hdr, msg, err := parseHeaderMessageLengthConfig(config[1:])
+		if err != nil {
+			return fmt.Errorf("invalid config: %q, %v", config, err)
+		}
+		if err := l.setDefaultMethodLogger(&MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
+			return fmt.Errorf("invalid config: %v", err)
+		}
+		return nil
+	}
+
+	s, m, suffix, err := parseMethodConfigAndSuffix(config)
+	if err != nil {
+		return fmt.Errorf("invalid config: %q, %v", config, err)
+	}
+	hdr, msg, err := parseHeaderMessageLengthConfig(suffix)
+	if err != nil {
+		return fmt.Errorf("invalid header/message length config: %q, %v", suffix, err)
+	}
+	if m == "*" {
+		if err := l.setServiceMethodLogger(s, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
+			return fmt.Errorf("invalid config: %v", err)
+		}
+	} else {
+		if err := l.setMethodMethodLogger(s+"/"+m, &MethodLoggerConfig{Header: hdr, Message: msg}); err != nil {
+			return fmt.Errorf("invalid config: %v", err)
+		}
+	}
+	return nil
+}
+
+const (
+	// TODO: this const is only used by env_config now. But could be useful for
+	// other config. Move to binarylog.go if necessary.
+	maxUInt = ^uint64(0)
+
+	// For "p.s/m" plus any suffix. Suffix will be parsed again. See test for
+	// expected output.
+	longMethodConfigRegexpStr = `^([\w./]+)/((?:\w+)|[*])(.+)?$`
+
+	// For suffix from above, "{h:123,m:123}". See test for expected output.
+	optionalLengthRegexpStr      = `(?::(\d+))?` // Optional ":123".
+	headerConfigRegexpStr        = `^{h` + optionalLengthRegexpStr + `}$`
+	messageConfigRegexpStr       = `^{m` + optionalLengthRegexpStr + `}$`
+	headerMessageConfigRegexpStr = `^{h` + optionalLengthRegexpStr + `;m` + optionalLengthRegexpStr + `}$`
+)
+
+var (
+	longMethodConfigRegexp    = regexp.MustCompile(longMethodConfigRegexpStr)
+	headerConfigRegexp        = regexp.MustCompile(headerConfigRegexpStr)
+	messageConfigRegexp       = regexp.MustCompile(messageConfigRegexpStr)
+	headerMessageConfigRegexp = regexp.MustCompile(headerMessageConfigRegexpStr)
+)
+
+// Turn "service/method{h;m}" into "service", "method", "{h;m}".
+func parseMethodConfigAndSuffix(c string) (service, method, suffix string, _ error) {
+	// Regexp result:
+	//
+	// in:  "p.s/m{h:123,m:123}",
+	// out: []string{"p.s/m{h:123,m:123}", "p.s", "m", "{h:123,m:123}"},
+	match := longMethodConfigRegexp.FindStringSubmatch(c)
+	if match == nil {
+		return "", "", "", fmt.Errorf("%q contains invalid substring", c)
+	}
+	service = match[1]
+	method = match[2]
+	suffix = match[3]
+	return
+}
+
+// Turn "{h:123;m:345}" into 123, 345.
+//
+// Return maxUInt if length is unspecified.
+func parseHeaderMessageLengthConfig(c string) (hdrLenStr, msgLenStr uint64, err error) {
+	if c == "" {
+		return maxUInt, maxUInt, nil
+	}
+	// Header config only.
+	if match := headerConfigRegexp.FindStringSubmatch(c); match != nil {
+		if s := match[1]; s != "" {
+			hdrLenStr, err = strconv.ParseUint(s, 10, 64)
+			if err != nil {
+				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
+			}
+			return hdrLenStr, 0, nil
+		}
+		return maxUInt, 0, nil
+	}
+
+	// Message config only.
+	if match := messageConfigRegexp.FindStringSubmatch(c); match != nil {
+		if s := match[1]; s != "" {
+			msgLenStr, err = strconv.ParseUint(s, 10, 64)
+			if err != nil {
+				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
+			}
+			return 0, msgLenStr, nil
+		}
+		return 0, maxUInt, nil
+	}
+
+	// Header and message config both.
+	if match := headerMessageConfigRegexp.FindStringSubmatch(c); match != nil {
+		// Both hdr and msg are specified, but one or two of them might be empty.
+		hdrLenStr = maxUInt
+		msgLenStr = maxUInt
+		if s := match[1]; s != "" {
+			hdrLenStr, err = strconv.ParseUint(s, 10, 64)
+			if err != nil {
+				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
+			}
+		}
+		if s := match[2]; s != "" {
+			msgLenStr, err = strconv.ParseUint(s, 10, 64)
+			if err != nil {
+				return 0, 0, fmt.Errorf("failed to convert %q to uint", s)
+			}
+		}
+		return hdrLenStr, msgLenStr, nil
+	}
+	return 0, 0, fmt.Errorf("%q contains invalid substring", c)
+}

vendor/google.golang.org/grpc/internal/binarylog/method_logger.go

@@ -0,0 +1,435 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package binarylog
+
+import (
+	"net"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes"
+	binlogpb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+type callIDGenerator struct {
+	id uint64
+}
+
+func (g *callIDGenerator) next() uint64 {
+	id := atomic.AddUint64(&g.id, 1)
+	return id
+}
+
+// reset is for testing only, and doesn't need to be thread safe.
+func (g *callIDGenerator) reset() {
+	g.id = 0
+}
+
+var idGen callIDGenerator
+
+// MethodLogger is the sub-logger for each method.
+type MethodLogger interface {
+	Log(LogEntryConfig)
+}
+
+// TruncatingMethodLogger is a method logger that truncates headers and messages
+// based on configured fields.
+type TruncatingMethodLogger struct {
+	headerMaxLen, messageMaxLen uint64
+
+	callID          uint64
+	idWithinCallGen *callIDGenerator
+
+	sink Sink // TODO(blog): make this plugable.
+}
+
+// NewTruncatingMethodLogger returns a new truncating method logger.
+func NewTruncatingMethodLogger(h, m uint64) *TruncatingMethodLogger {
+	return &TruncatingMethodLogger{
+		headerMaxLen:  h,
+		messageMaxLen: m,
+
+		callID:          idGen.next(),
+		idWithinCallGen: &callIDGenerator{},
+
+		sink: DefaultSink, // TODO(blog): make it plugable.
+	}
+}
+
+// Build is an internal only method for building the proto message out of the
+// input event. It's made public to enable other library to reuse as much logic
+// in TruncatingMethodLogger as possible.
+func (ml *TruncatingMethodLogger) Build(c LogEntryConfig) *binlogpb.GrpcLogEntry {
+	m := c.toProto()
+	timestamp, _ := ptypes.TimestampProto(time.Now())
+	m.Timestamp = timestamp
+	m.CallId = ml.callID
+	m.SequenceIdWithinCall = ml.idWithinCallGen.next()
+
+	switch pay := m.Payload.(type) {
+	case *binlogpb.GrpcLogEntry_ClientHeader:
+		m.PayloadTruncated = ml.truncateMetadata(pay.ClientHeader.GetMetadata())
+	case *binlogpb.GrpcLogEntry_ServerHeader:
+		m.PayloadTruncated = ml.truncateMetadata(pay.ServerHeader.GetMetadata())
+	case *binlogpb.GrpcLogEntry_Message:
+		m.PayloadTruncated = ml.truncateMessage(pay.Message)
+	}
+	return m
+}
+
+// Log creates a proto binary log entry, and logs it to the sink.
+func (ml *TruncatingMethodLogger) Log(c LogEntryConfig) {
+	ml.sink.Write(ml.Build(c))
+}
+
+func (ml *TruncatingMethodLogger) truncateMetadata(mdPb *binlogpb.Metadata) (truncated bool) {
+	if ml.headerMaxLen == maxUInt {
+		return false
+	}
+	var (
+		bytesLimit = ml.headerMaxLen
+		index      int
+	)
+	// At the end of the loop, index will be the first entry where the total
+	// size is greater than the limit:
+	//
+	// len(entry[:index]) <= ml.hdr && len(entry[:index+1]) > ml.hdr.
+	for ; index < len(mdPb.Entry); index++ {
+		entry := mdPb.Entry[index]
+		if entry.Key == "grpc-trace-bin" {
+			// "grpc-trace-bin" is a special key. It's kept in the log entry,
+			// but not counted towards the size limit.
+			continue
+		}
+		currentEntryLen := uint64(len(entry.GetKey())) + uint64(len(entry.GetValue()))
+		if currentEntryLen > bytesLimit {
+			break
+		}
+		bytesLimit -= currentEntryLen
+	}
+	truncated = index < len(mdPb.Entry)
+	mdPb.Entry = mdPb.Entry[:index]
+	return truncated
+}
+
+func (ml *TruncatingMethodLogger) truncateMessage(msgPb *binlogpb.Message) (truncated bool) {
+	if ml.messageMaxLen == maxUInt {
+		return false
+	}
+	if ml.messageMaxLen >= uint64(len(msgPb.Data)) {
+		return false
+	}
+	msgPb.Data = msgPb.Data[:ml.messageMaxLen]
+	return true
+}
+
+// LogEntryConfig represents the configuration for binary log entry.
+type LogEntryConfig interface {
+	toProto() *binlogpb.GrpcLogEntry
+}
+
+// ClientHeader configs the binary log entry to be a ClientHeader entry.
+type ClientHeader struct {
+	OnClientSide bool
+	Header       metadata.MD
+	MethodName   string
+	Authority    string
+	Timeout      time.Duration
+	// PeerAddr is required only when it's on server side.
+	PeerAddr net.Addr
+}
+
+func (c *ClientHeader) toProto() *binlogpb.GrpcLogEntry {
+	// This function doesn't need to set all the fields (e.g. seq ID). The Log
+	// function will set the fields when necessary.
+	clientHeader := &binlogpb.ClientHeader{
+		Metadata:   mdToMetadataProto(c.Header),
+		MethodName: c.MethodName,
+		Authority:  c.Authority,
+	}
+	if c.Timeout > 0 {
+		clientHeader.Timeout = ptypes.DurationProto(c.Timeout)
+	}
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_HEADER,
+		Payload: &binlogpb.GrpcLogEntry_ClientHeader{
+			ClientHeader: clientHeader,
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	if c.PeerAddr != nil {
+		ret.Peer = addrToProto(c.PeerAddr)
+	}
+	return ret
+}
+
+// ServerHeader configs the binary log entry to be a ServerHeader entry.
+type ServerHeader struct {
+	OnClientSide bool
+	Header       metadata.MD
+	// PeerAddr is required only when it's on client side.
+	PeerAddr net.Addr
+}
+
+func (c *ServerHeader) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_HEADER,
+		Payload: &binlogpb.GrpcLogEntry_ServerHeader{
+			ServerHeader: &binlogpb.ServerHeader{
+				Metadata: mdToMetadataProto(c.Header),
+			},
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	if c.PeerAddr != nil {
+		ret.Peer = addrToProto(c.PeerAddr)
+	}
+	return ret
+}
+
+// ClientMessage configs the binary log entry to be a ClientMessage entry.
+type ClientMessage struct {
+	OnClientSide bool
+	// Message can be a proto.Message or []byte. Other messages formats are not
+	// supported.
+	Message interface{}
+}
+
+func (c *ClientMessage) toProto() *binlogpb.GrpcLogEntry {
+	var (
+		data []byte
+		err  error
+	)
+	if m, ok := c.Message.(proto.Message); ok {
+		data, err = proto.Marshal(m)
+		if err != nil {
+			grpclogLogger.Infof("binarylogging: failed to marshal proto message: %v", err)
+		}
+	} else if b, ok := c.Message.([]byte); ok {
+		data = b
+	} else {
+		grpclogLogger.Infof("binarylogging: message to log is neither proto.message nor []byte")
+	}
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_MESSAGE,
+		Payload: &binlogpb.GrpcLogEntry_Message{
+			Message: &binlogpb.Message{
+				Length: uint32(len(data)),
+				Data:   data,
+			},
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	return ret
+}
+
+// ServerMessage configs the binary log entry to be a ServerMessage entry.
+type ServerMessage struct {
+	OnClientSide bool
+	// Message can be a proto.Message or []byte. Other messages formats are not
+	// supported.
+	Message interface{}
+}
+
+func (c *ServerMessage) toProto() *binlogpb.GrpcLogEntry {
+	var (
+		data []byte
+		err  error
+	)
+	if m, ok := c.Message.(proto.Message); ok {
+		data, err = proto.Marshal(m)
+		if err != nil {
+			grpclogLogger.Infof("binarylogging: failed to marshal proto message: %v", err)
+		}
+	} else if b, ok := c.Message.([]byte); ok {
+		data = b
+	} else {
+		grpclogLogger.Infof("binarylogging: message to log is neither proto.message nor []byte")
+	}
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_MESSAGE,
+		Payload: &binlogpb.GrpcLogEntry_Message{
+			Message: &binlogpb.Message{
+				Length: uint32(len(data)),
+				Data:   data,
+			},
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	return ret
+}
+
+// ClientHalfClose configs the binary log entry to be a ClientHalfClose entry.
+type ClientHalfClose struct {
+	OnClientSide bool
+}
+
+func (c *ClientHalfClose) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type:    binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_HALF_CLOSE,
+		Payload: nil, // No payload here.
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	return ret
+}
+
+// ServerTrailer configs the binary log entry to be a ServerTrailer entry.
+type ServerTrailer struct {
+	OnClientSide bool
+	Trailer      metadata.MD
+	// Err is the status error.
+	Err error
+	// PeerAddr is required only when it's on client side and the RPC is trailer
+	// only.
+	PeerAddr net.Addr
+}
+
+func (c *ServerTrailer) toProto() *binlogpb.GrpcLogEntry {
+	st, ok := status.FromError(c.Err)
+	if !ok {
+		grpclogLogger.Info("binarylogging: error in trailer is not a status error")
+	}
+	var (
+		detailsBytes []byte
+		err          error
+	)
+	stProto := st.Proto()
+	if stProto != nil && len(stProto.Details) != 0 {
+		detailsBytes, err = proto.Marshal(stProto)
+		if err != nil {
+			grpclogLogger.Infof("binarylogging: failed to marshal status proto: %v", err)
+		}
+	}
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_TRAILER,
+		Payload: &binlogpb.GrpcLogEntry_Trailer{
+			Trailer: &binlogpb.Trailer{
+				Metadata:      mdToMetadataProto(c.Trailer),
+				StatusCode:    uint32(st.Code()),
+				StatusMessage: st.Message(),
+				StatusDetails: detailsBytes,
+			},
+		},
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	if c.PeerAddr != nil {
+		ret.Peer = addrToProto(c.PeerAddr)
+	}
+	return ret
+}
+
+// Cancel configs the binary log entry to be a Cancel entry.
+type Cancel struct {
+	OnClientSide bool
+}
+
+func (c *Cancel) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type:    binlogpb.GrpcLogEntry_EVENT_TYPE_CANCEL,
+		Payload: nil,
+	}
+	if c.OnClientSide {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
+	} else {
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
+	}
+	return ret
+}
+
+// metadataKeyOmit returns whether the metadata entry with this key should be
+// omitted.
+func metadataKeyOmit(key string) bool {
+	switch key {
+	case "lb-token", ":path", ":authority", "content-encoding", "content-type", "user-agent", "te":
+		return true
+	case "grpc-trace-bin": // grpc-trace-bin is special because it's visiable to users.
+		return false
+	}
+	return strings.HasPrefix(key, "grpc-")
+}
+
+func mdToMetadataProto(md metadata.MD) *binlogpb.Metadata {
+	ret := &binlogpb.Metadata{}
+	for k, vv := range md {
+		if metadataKeyOmit(k) {
+			continue
+		}
+		for _, v := range vv {
+			ret.Entry = append(ret.Entry,
+				&binlogpb.MetadataEntry{
+					Key:   k,
+					Value: []byte(v),
+				},
+			)
+		}
+	}
+	return ret
+}
+
+func addrToProto(addr net.Addr) *binlogpb.Address {
+	ret := &binlogpb.Address{}
+	switch a := addr.(type) {
+	case *net.TCPAddr:
+		if a.IP.To4() != nil {
+			ret.Type = binlogpb.Address_TYPE_IPV4
+		} else if a.IP.To16() != nil {
+			ret.Type = binlogpb.Address_TYPE_IPV6
+		} else {
+			ret.Type = binlogpb.Address_TYPE_UNKNOWN
+			// Do not set address and port fields.
+			break
+		}
+		ret.Address = a.IP.String()
+		ret.IpPort = uint32(a.Port)
+	case *net.UnixAddr:
+		ret.Type = binlogpb.Address_TYPE_UNIX
+		ret.Address = a.String()
+	default:
+		ret.Type = binlogpb.Address_TYPE_UNKNOWN
+	}
+	return ret
+}

vendor/google.golang.org/grpc/internal/binarylog/sink.go

@@ -0,0 +1,170 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package binarylog
+
+import (
+	"bufio"
+	"encoding/binary"
+	"io"
+	"sync"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	binlogpb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
+)
+
+var (
+	// DefaultSink is the sink where the logs will be written to. It's exported
+	// for the binarylog package to update.
+	DefaultSink Sink = &noopSink{} // TODO(blog): change this default (file in /tmp).
+)
+
+// Sink writes log entry into the binary log sink.
+//
+// sink is a copy of the exported binarylog.Sink, to avoid circular dependency.
+type Sink interface {
+	// Write will be called to write the log entry into the sink.
+	//
+	// It should be thread-safe so it can be called in parallel.
+	Write(*binlogpb.GrpcLogEntry) error
+	// Close will be called when the Sink is replaced by a new Sink.
+	Close() error
+}
+
+type noopSink struct{}
+
+func (ns *noopSink) Write(*binlogpb.GrpcLogEntry) error { return nil }
+func (ns *noopSink) Close() error                       { return nil }
+
+// newWriterSink creates a binary log sink with the given writer.
+//
+// Write() marshals the proto message and writes it to the given writer. Each
+// message is prefixed with a 4 byte big endian unsigned integer as the length.
+//
+// No buffer is done, Close() doesn't try to close the writer.
+func newWriterSink(w io.Writer) Sink {
+	return &writerSink{out: w}
+}
+
+type writerSink struct {
+	out io.Writer
+}
+
+func (ws *writerSink) Write(e *binlogpb.GrpcLogEntry) error {
+	b, err := proto.Marshal(e)
+	if err != nil {
+		grpclogLogger.Errorf("binary logging: failed to marshal proto message: %v", err)
+		return err
+	}
+	hdr := make([]byte, 4)
+	binary.BigEndian.PutUint32(hdr, uint32(len(b)))
+	if _, err := ws.out.Write(hdr); err != nil {
+		return err
+	}
+	if _, err := ws.out.Write(b); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (ws *writerSink) Close() error { return nil }
+
+type bufferedSink struct {
+	mu             sync.Mutex
+	closer         io.Closer
+	out            Sink          // out is built on buf.
+	buf            *bufio.Writer // buf is kept for flush.
+	flusherStarted bool
+
+	writeTicker *time.Ticker
+	done        chan struct{}
+}
+
+func (fs *bufferedSink) Write(e *binlogpb.GrpcLogEntry) error {
+	fs.mu.Lock()
+	defer fs.mu.Unlock()
+	if !fs.flusherStarted {
+		// Start the write loop when Write is called.
+		fs.startFlushGoroutine()
+		fs.flusherStarted = true
+	}
+	if err := fs.out.Write(e); err != nil {
+		return err
+	}
+	return nil
+}
+
+const (
+	bufFlushDuration = 60 * time.Second
+)
+
+func (fs *bufferedSink) startFlushGoroutine() {
+	fs.writeTicker = time.NewTicker(bufFlushDuration)
+	go func() {
+		for {
+			select {
+			case <-fs.done:
+				return
+			case <-fs.writeTicker.C:
+			}
+			fs.mu.Lock()
+			if err := fs.buf.Flush(); err != nil {
+				grpclogLogger.Warningf("failed to flush to Sink: %v", err)
+			}
+			fs.mu.Unlock()
+		}
+	}()
+}
+
+func (fs *bufferedSink) Close() error {
+	fs.mu.Lock()
+	defer fs.mu.Unlock()
+	if fs.writeTicker != nil {
+		fs.writeTicker.Stop()
+	}
+	close(fs.done)
+	if err := fs.buf.Flush(); err != nil {
+		grpclogLogger.Warningf("failed to flush to Sink: %v", err)
+	}
+	if err := fs.closer.Close(); err != nil {
+		grpclogLogger.Warningf("failed to close the underlying WriterCloser: %v", err)
+	}
+	if err := fs.out.Close(); err != nil {
+		grpclogLogger.Warningf("failed to close the Sink: %v", err)
+	}
+	return nil
+}
+
+// NewBufferedSink creates a binary log sink with the given WriteCloser.
+//
+// Write() marshals the proto message and writes it to the given writer. Each
+// message is prefixed with a 4 byte big endian unsigned integer as the length.
+//
+// Content is kept in a buffer, and is flushed every 60 seconds.
+//
+// Close closes the WriteCloser.
+func NewBufferedSink(o io.WriteCloser) Sink {
+	bufW := bufio.NewWriter(o)
+	return &bufferedSink{
+		closer: o,
+		out:    newWriterSink(bufW),
+		buf:    bufW,
+		done:   make(chan struct{}),
+	}
+}

vendor/google.golang.org/grpc/internal/buffer/unbounded.go

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2019 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package buffer provides an implementation of an unbounded buffer.
+package buffer
+
+import "sync"
+
+// Unbounded is an implementation of an unbounded buffer which does not use
+// extra goroutines. This is typically used for passing updates from one entity
+// to another within gRPC.
+//
+// All methods on this type are thread-safe and don't block on anything except
+// the underlying mutex used for synchronization.
+//
+// Unbounded supports values of any type to be stored in it by using a channel
+// of `interface{}`. This means that a call to Put() incurs an extra memory
+// allocation, and also that users need a type assertion while reading. For
+// performance critical code paths, using Unbounded is strongly discouraged and
+// defining a new type specific implementation of this buffer is preferred. See
+// internal/transport/transport.go for an example of this.
+type Unbounded struct {
+	c       chan interface{}
+	mu      sync.Mutex
+	backlog []interface{}
+}
+
+// NewUnbounded returns a new instance of Unbounded.
+func NewUnbounded() *Unbounded {
+	return &Unbounded{c: make(chan interface{}, 1)}
+}
+
+// Put adds t to the unbounded buffer.
+func (b *Unbounded) Put(t interface{}) {
+	b.mu.Lock()
+	if len(b.backlog) == 0 {
+		select {
+		case b.c <- t:
+			b.mu.Unlock()
+			return
+		default:
+		}
+	}
+	b.backlog = append(b.backlog, t)
+	b.mu.Unlock()
+}
+
+// Load sends the earliest buffered data, if any, onto the read channel
+// returned by Get(). Users are expected to call this every time they read a
+// value from the read channel.
+func (b *Unbounded) Load() {
+	b.mu.Lock()
+	if len(b.backlog) > 0 {
+		select {
+		case b.c <- b.backlog[0]:
+			b.backlog[0] = nil
+			b.backlog = b.backlog[1:]
+		default:
+		}
+	}
+	b.mu.Unlock()
+}
+
+// Get returns a read channel on which values added to the buffer, via Put(),
+// are sent on.
+//
+// Upon reading a value from this channel, users are expected to call Load() to
+// send the next buffered value onto the channel if there is any.
+func (b *Unbounded) Get() <-chan interface{} {
+	return b.c
+}

vendor/google.golang.org/grpc/internal/channelz/funcs.go

@@ -0,0 +1,789 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package channelz defines APIs for enabling channelz service, entry
+// registration/deletion, and accessing channelz data. It also defines channelz
+// metric struct formats.
+//
+// All APIs in this package are experimental.
+package channelz
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sort"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+const (
+	defaultMaxTraceEntry int32 = 30
+)
+
+var (
+	db    dbWrapper
+	idGen idGenerator
+	// EntryPerPage defines the number of channelz entries to be shown on a web page.
+	EntryPerPage  = int64(50)
+	curState      int32
+	maxTraceEntry = defaultMaxTraceEntry
+)
+
+// TurnOn turns on channelz data collection.
+func TurnOn() {
+	if !IsOn() {
+		db.set(newChannelMap())
+		idGen.reset()
+		atomic.StoreInt32(&curState, 1)
+	}
+}
+
+// IsOn returns whether channelz data collection is on.
+func IsOn() bool {
+	return atomic.CompareAndSwapInt32(&curState, 1, 1)
+}
+
+// SetMaxTraceEntry sets maximum number of trace entry per entity (i.e. channel/subchannel).
+// Setting it to 0 will disable channel tracing.
+func SetMaxTraceEntry(i int32) {
+	atomic.StoreInt32(&maxTraceEntry, i)
+}
+
+// ResetMaxTraceEntryToDefault resets the maximum number of trace entry per entity to default.
+func ResetMaxTraceEntryToDefault() {
+	atomic.StoreInt32(&maxTraceEntry, defaultMaxTraceEntry)
+}
+
+func getMaxTraceEntry() int {
+	i := atomic.LoadInt32(&maxTraceEntry)
+	return int(i)
+}
+
+// dbWarpper wraps around a reference to internal channelz data storage, and
+// provide synchronized functionality to set and get the reference.
+type dbWrapper struct {
+	mu sync.RWMutex
+	DB *channelMap
+}
+
+func (d *dbWrapper) set(db *channelMap) {
+	d.mu.Lock()
+	d.DB = db
+	d.mu.Unlock()
+}
+
+func (d *dbWrapper) get() *channelMap {
+	d.mu.RLock()
+	defer d.mu.RUnlock()
+	return d.DB
+}
+
+// NewChannelzStorageForTesting initializes channelz data storage and id
+// generator for testing purposes.
+//
+// Returns a cleanup function to be invoked by the test, which waits for up to
+// 10s for all channelz state to be reset by the grpc goroutines when those
+// entities get closed. This cleanup function helps with ensuring that tests
+// don't mess up each other.
+func NewChannelzStorageForTesting() (cleanup func() error) {
+	db.set(newChannelMap())
+	idGen.reset()
+
+	return func() error {
+		cm := db.get()
+		if cm == nil {
+			return nil
+		}
+
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer cancel()
+		ticker := time.NewTicker(10 * time.Millisecond)
+		defer ticker.Stop()
+		for {
+			cm.mu.RLock()
+			topLevelChannels, servers, channels, subChannels, listenSockets, normalSockets := len(cm.topLevelChannels), len(cm.servers), len(cm.channels), len(cm.subChannels), len(cm.listenSockets), len(cm.normalSockets)
+			cm.mu.RUnlock()
+
+			if err := ctx.Err(); err != nil {
+				return fmt.Errorf("after 10s the channelz map has not been cleaned up yet, topchannels: %d, servers: %d, channels: %d, subchannels: %d, listen sockets: %d, normal sockets: %d", topLevelChannels, servers, channels, subChannels, listenSockets, normalSockets)
+			}
+			if topLevelChannels == 0 && servers == 0 && channels == 0 && subChannels == 0 && listenSockets == 0 && normalSockets == 0 {
+				return nil
+			}
+			<-ticker.C
+		}
+	}
+}
+
+// GetTopChannels returns a slice of top channel's ChannelMetric, along with a
+// boolean indicating whether there's more top channels to be queried for.
+//
+// The arg id specifies that only top channel with id at or above it will be included
+// in the result. The returned slice is up to a length of the arg maxResults or
+// EntryPerPage if maxResults is zero, and is sorted in ascending id order.
+func GetTopChannels(id int64, maxResults int64) ([]*ChannelMetric, bool) {
+	return db.get().GetTopChannels(id, maxResults)
+}
+
+// GetServers returns a slice of server's ServerMetric, along with a
+// boolean indicating whether there's more servers to be queried for.
+//
+// The arg id specifies that only server with id at or above it will be included
+// in the result. The returned slice is up to a length of the arg maxResults or
+// EntryPerPage if maxResults is zero, and is sorted in ascending id order.
+func GetServers(id int64, maxResults int64) ([]*ServerMetric, bool) {
+	return db.get().GetServers(id, maxResults)
+}
+
+// GetServerSockets returns a slice of server's (identified by id) normal socket's
+// SocketMetric, along with a boolean indicating whether there's more sockets to
+// be queried for.
+//
+// The arg startID specifies that only sockets with id at or above it will be
+// included in the result. The returned slice is up to a length of the arg maxResults
+// or EntryPerPage if maxResults is zero, and is sorted in ascending id order.
+func GetServerSockets(id int64, startID int64, maxResults int64) ([]*SocketMetric, bool) {
+	return db.get().GetServerSockets(id, startID, maxResults)
+}
+
+// GetChannel returns the ChannelMetric for the channel (identified by id).
+func GetChannel(id int64) *ChannelMetric {
+	return db.get().GetChannel(id)
+}
+
+// GetSubChannel returns the SubChannelMetric for the subchannel (identified by id).
+func GetSubChannel(id int64) *SubChannelMetric {
+	return db.get().GetSubChannel(id)
+}
+
+// GetSocket returns the SocketInternalMetric for the socket (identified by id).
+func GetSocket(id int64) *SocketMetric {
+	return db.get().GetSocket(id)
+}
+
+// GetServer returns the ServerMetric for the server (identified by id).
+func GetServer(id int64) *ServerMetric {
+	return db.get().GetServer(id)
+}
+
+// RegisterChannel registers the given channel c in the channelz database with
+// ref as its reference name, and adds it to the child list of its parent
+// (identified by pid). pid == nil means no parent.
+//
+// Returns a unique channelz identifier assigned to this channel.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterChannel(c Channel, pid *Identifier, ref string) *Identifier {
+	id := idGen.genID()
+	var parent int64
+	isTopChannel := true
+	if pid != nil {
+		isTopChannel = false
+		parent = pid.Int()
+	}
+
+	if !IsOn() {
+		return newIdentifer(RefChannel, id, pid)
+	}
+
+	cn := &channel{
+		refName:     ref,
+		c:           c,
+		subChans:    make(map[int64]string),
+		nestedChans: make(map[int64]string),
+		id:          id,
+		pid:         parent,
+		trace:       &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
+	}
+	db.get().addChannel(id, cn, isTopChannel, parent)
+	return newIdentifer(RefChannel, id, pid)
+}
+
+// RegisterSubChannel registers the given subChannel c in the channelz database
+// with ref as its reference name, and adds it to the child list of its parent
+// (identified by pid).
+//
+// Returns a unique channelz identifier assigned to this subChannel.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterSubChannel(c Channel, pid *Identifier, ref string) (*Identifier, error) {
+	if pid == nil {
+		return nil, errors.New("a SubChannel's parent id cannot be nil")
+	}
+	id := idGen.genID()
+	if !IsOn() {
+		return newIdentifer(RefSubChannel, id, pid), nil
+	}
+
+	sc := &subChannel{
+		refName: ref,
+		c:       c,
+		sockets: make(map[int64]string),
+		id:      id,
+		pid:     pid.Int(),
+		trace:   &channelTrace{createdTime: time.Now(), events: make([]*TraceEvent, 0, getMaxTraceEntry())},
+	}
+	db.get().addSubChannel(id, sc, pid.Int())
+	return newIdentifer(RefSubChannel, id, pid), nil
+}
+
+// RegisterServer registers the given server s in channelz database. It returns
+// the unique channelz tracking id assigned to this server.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterServer(s Server, ref string) *Identifier {
+	id := idGen.genID()
+	if !IsOn() {
+		return newIdentifer(RefServer, id, nil)
+	}
+
+	svr := &server{
+		refName:       ref,
+		s:             s,
+		sockets:       make(map[int64]string),
+		listenSockets: make(map[int64]string),
+		id:            id,
+	}
+	db.get().addServer(id, svr)
+	return newIdentifer(RefServer, id, nil)
+}
+
+// RegisterListenSocket registers the given listen socket s in channelz database
+// with ref as its reference name, and add it to the child list of its parent
+// (identified by pid). It returns the unique channelz tracking id assigned to
+// this listen socket.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterListenSocket(s Socket, pid *Identifier, ref string) (*Identifier, error) {
+	if pid == nil {
+		return nil, errors.New("a ListenSocket's parent id cannot be 0")
+	}
+	id := idGen.genID()
+	if !IsOn() {
+		return newIdentifer(RefListenSocket, id, pid), nil
+	}
+
+	ls := &listenSocket{refName: ref, s: s, id: id, pid: pid.Int()}
+	db.get().addListenSocket(id, ls, pid.Int())
+	return newIdentifer(RefListenSocket, id, pid), nil
+}
+
+// RegisterNormalSocket registers the given normal socket s in channelz database
+// with ref as its reference name, and adds it to the child list of its parent
+// (identified by pid). It returns the unique channelz tracking id assigned to
+// this normal socket.
+//
+// If channelz is not turned ON, the channelz database is not mutated.
+func RegisterNormalSocket(s Socket, pid *Identifier, ref string) (*Identifier, error) {
+	if pid == nil {
+		return nil, errors.New("a NormalSocket's parent id cannot be 0")
+	}
+	id := idGen.genID()
+	if !IsOn() {
+		return newIdentifer(RefNormalSocket, id, pid), nil
+	}
+
+	ns := &normalSocket{refName: ref, s: s, id: id, pid: pid.Int()}
+	db.get().addNormalSocket(id, ns, pid.Int())
+	return newIdentifer(RefNormalSocket, id, pid), nil
+}
+
+// RemoveEntry removes an entry with unique channelz tracking id to be id from
+// channelz database.
+//
+// If channelz is not turned ON, this function is a no-op.
+func RemoveEntry(id *Identifier) {
+	if !IsOn() {
+		return
+	}
+	db.get().removeEntry(id.Int())
+}
+
+// TraceEventDesc is what the caller of AddTraceEvent should provide to describe
+// the event to be added to the channel trace.
+//
+// The Parent field is optional. It is used for an event that will be recorded
+// in the entity's parent trace.
+type TraceEventDesc struct {
+	Desc     string
+	Severity Severity
+	Parent   *TraceEventDesc
+}
+
+// AddTraceEvent adds trace related to the entity with specified id, using the
+// provided TraceEventDesc.
+//
+// If channelz is not turned ON, this will simply log the event descriptions.
+func AddTraceEvent(l grpclog.DepthLoggerV2, id *Identifier, depth int, desc *TraceEventDesc) {
+	// Log only the trace description associated with the bottom most entity.
+	switch desc.Severity {
+	case CtUnknown, CtInfo:
+		l.InfoDepth(depth+1, withParens(id)+desc.Desc)
+	case CtWarning:
+		l.WarningDepth(depth+1, withParens(id)+desc.Desc)
+	case CtError:
+		l.ErrorDepth(depth+1, withParens(id)+desc.Desc)
+	}
+
+	if getMaxTraceEntry() == 0 {
+		return
+	}
+	if IsOn() {
+		db.get().traceEvent(id.Int(), desc)
+	}
+}
+
+// channelMap is the storage data structure for channelz.
+// Methods of channelMap can be divided in two two categories with respect to locking.
+// 1. Methods acquire the global lock.
+// 2. Methods that can only be called when global lock is held.
+// A second type of method need always to be called inside a first type of method.
+type channelMap struct {
+	mu               sync.RWMutex
+	topLevelChannels map[int64]struct{}
+	servers          map[int64]*server
+	channels         map[int64]*channel
+	subChannels      map[int64]*subChannel
+	listenSockets    map[int64]*listenSocket
+	normalSockets    map[int64]*normalSocket
+}
+
+func newChannelMap() *channelMap {
+	return &channelMap{
+		topLevelChannels: make(map[int64]struct{}),
+		channels:         make(map[int64]*channel),
+		listenSockets:    make(map[int64]*listenSocket),
+		normalSockets:    make(map[int64]*normalSocket),
+		servers:          make(map[int64]*server),
+		subChannels:      make(map[int64]*subChannel),
+	}
+}
+
+func (c *channelMap) addServer(id int64, s *server) {
+	c.mu.Lock()
+	s.cm = c
+	c.servers[id] = s
+	c.mu.Unlock()
+}
+
+func (c *channelMap) addChannel(id int64, cn *channel, isTopChannel bool, pid int64) {
+	c.mu.Lock()
+	cn.cm = c
+	cn.trace.cm = c
+	c.channels[id] = cn
+	if isTopChannel {
+		c.topLevelChannels[id] = struct{}{}
+	} else {
+		c.findEntry(pid).addChild(id, cn)
+	}
+	c.mu.Unlock()
+}
+
+func (c *channelMap) addSubChannel(id int64, sc *subChannel, pid int64) {
+	c.mu.Lock()
+	sc.cm = c
+	sc.trace.cm = c
+	c.subChannels[id] = sc
+	c.findEntry(pid).addChild(id, sc)
+	c.mu.Unlock()
+}
+
+func (c *channelMap) addListenSocket(id int64, ls *listenSocket, pid int64) {
+	c.mu.Lock()
+	ls.cm = c
+	c.listenSockets[id] = ls
+	c.findEntry(pid).addChild(id, ls)
+	c.mu.Unlock()
+}
+
+func (c *channelMap) addNormalSocket(id int64, ns *normalSocket, pid int64) {
+	c.mu.Lock()
+	ns.cm = c
+	c.normalSockets[id] = ns
+	c.findEntry(pid).addChild(id, ns)
+	c.mu.Unlock()
+}
+
+// removeEntry triggers the removal of an entry, which may not indeed delete the entry, if it has to
+// wait on the deletion of its children and until no other entity's channel trace references it.
+// It may lead to a chain of entry deletion. For example, deleting the last socket of a gracefully
+// shutting down server will lead to the server being also deleted.
+func (c *channelMap) removeEntry(id int64) {
+	c.mu.Lock()
+	c.findEntry(id).triggerDelete()
+	c.mu.Unlock()
+}
+
+// c.mu must be held by the caller
+func (c *channelMap) decrTraceRefCount(id int64) {
+	e := c.findEntry(id)
+	if v, ok := e.(tracedChannel); ok {
+		v.decrTraceRefCount()
+		e.deleteSelfIfReady()
+	}
+}
+
+// c.mu must be held by the caller.
+func (c *channelMap) findEntry(id int64) entry {
+	var v entry
+	var ok bool
+	if v, ok = c.channels[id]; ok {
+		return v
+	}
+	if v, ok = c.subChannels[id]; ok {
+		return v
+	}
+	if v, ok = c.servers[id]; ok {
+		return v
+	}
+	if v, ok = c.listenSockets[id]; ok {
+		return v
+	}
+	if v, ok = c.normalSockets[id]; ok {
+		return v
+	}
+	return &dummyEntry{idNotFound: id}
+}
+
+// c.mu must be held by the caller
+// deleteEntry simply deletes an entry from the channelMap. Before calling this
+// method, caller must check this entry is ready to be deleted, i.e removeEntry()
+// has been called on it, and no children still exist.
+// Conditionals are ordered by the expected frequency of deletion of each entity
+// type, in order to optimize performance.
+func (c *channelMap) deleteEntry(id int64) {
+	var ok bool
+	if _, ok = c.normalSockets[id]; ok {
+		delete(c.normalSockets, id)
+		return
+	}
+	if _, ok = c.subChannels[id]; ok {
+		delete(c.subChannels, id)
+		return
+	}
+	if _, ok = c.channels[id]; ok {
+		delete(c.channels, id)
+		delete(c.topLevelChannels, id)
+		return
+	}
+	if _, ok = c.listenSockets[id]; ok {
+		delete(c.listenSockets, id)
+		return
+	}
+	if _, ok = c.servers[id]; ok {
+		delete(c.servers, id)
+		return
+	}
+}
+
+func (c *channelMap) traceEvent(id int64, desc *TraceEventDesc) {
+	c.mu.Lock()
+	child := c.findEntry(id)
+	childTC, ok := child.(tracedChannel)
+	if !ok {
+		c.mu.Unlock()
+		return
+	}
+	childTC.getChannelTrace().append(&TraceEvent{Desc: desc.Desc, Severity: desc.Severity, Timestamp: time.Now()})
+	if desc.Parent != nil {
+		parent := c.findEntry(child.getParentID())
+		var chanType RefChannelType
+		switch child.(type) {
+		case *channel:
+			chanType = RefChannel
+		case *subChannel:
+			chanType = RefSubChannel
+		}
+		if parentTC, ok := parent.(tracedChannel); ok {
+			parentTC.getChannelTrace().append(&TraceEvent{
+				Desc:      desc.Parent.Desc,
+				Severity:  desc.Parent.Severity,
+				Timestamp: time.Now(),
+				RefID:     id,
+				RefName:   childTC.getRefName(),
+				RefType:   chanType,
+			})
+			childTC.incrTraceRefCount()
+		}
+	}
+	c.mu.Unlock()
+}
+
+type int64Slice []int64
+
+func (s int64Slice) Len() int           { return len(s) }
+func (s int64Slice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s int64Slice) Less(i, j int) bool { return s[i] < s[j] }
+
+func copyMap(m map[int64]string) map[int64]string {
+	n := make(map[int64]string)
+	for k, v := range m {
+		n[k] = v
+	}
+	return n
+}
+
+func min(a, b int64) int64 {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func (c *channelMap) GetTopChannels(id int64, maxResults int64) ([]*ChannelMetric, bool) {
+	if maxResults <= 0 {
+		maxResults = EntryPerPage
+	}
+	c.mu.RLock()
+	l := int64(len(c.topLevelChannels))
+	ids := make([]int64, 0, l)
+	cns := make([]*channel, 0, min(l, maxResults))
+
+	for k := range c.topLevelChannels {
+		ids = append(ids, k)
+	}
+	sort.Sort(int64Slice(ids))
+	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= id })
+	count := int64(0)
+	var end bool
+	var t []*ChannelMetric
+	for i, v := range ids[idx:] {
+		if count == maxResults {
+			break
+		}
+		if cn, ok := c.channels[v]; ok {
+			cns = append(cns, cn)
+			t = append(t, &ChannelMetric{
+				NestedChans: copyMap(cn.nestedChans),
+				SubChans:    copyMap(cn.subChans),
+			})
+			count++
+		}
+		if i == len(ids[idx:])-1 {
+			end = true
+			break
+		}
+	}
+	c.mu.RUnlock()
+	if count == 0 {
+		end = true
+	}
+
+	for i, cn := range cns {
+		t[i].ChannelData = cn.c.ChannelzMetric()
+		t[i].ID = cn.id
+		t[i].RefName = cn.refName
+		t[i].Trace = cn.trace.dumpData()
+	}
+	return t, end
+}
+
+func (c *channelMap) GetServers(id, maxResults int64) ([]*ServerMetric, bool) {
+	if maxResults <= 0 {
+		maxResults = EntryPerPage
+	}
+	c.mu.RLock()
+	l := int64(len(c.servers))
+	ids := make([]int64, 0, l)
+	ss := make([]*server, 0, min(l, maxResults))
+	for k := range c.servers {
+		ids = append(ids, k)
+	}
+	sort.Sort(int64Slice(ids))
+	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= id })
+	count := int64(0)
+	var end bool
+	var s []*ServerMetric
+	for i, v := range ids[idx:] {
+		if count == maxResults {
+			break
+		}
+		if svr, ok := c.servers[v]; ok {
+			ss = append(ss, svr)
+			s = append(s, &ServerMetric{
+				ListenSockets: copyMap(svr.listenSockets),
+			})
+			count++
+		}
+		if i == len(ids[idx:])-1 {
+			end = true
+			break
+		}
+	}
+	c.mu.RUnlock()
+	if count == 0 {
+		end = true
+	}
+
+	for i, svr := range ss {
+		s[i].ServerData = svr.s.ChannelzMetric()
+		s[i].ID = svr.id
+		s[i].RefName = svr.refName
+	}
+	return s, end
+}
+
+func (c *channelMap) GetServerSockets(id int64, startID int64, maxResults int64) ([]*SocketMetric, bool) {
+	if maxResults <= 0 {
+		maxResults = EntryPerPage
+	}
+	var svr *server
+	var ok bool
+	c.mu.RLock()
+	if svr, ok = c.servers[id]; !ok {
+		// server with id doesn't exist.
+		c.mu.RUnlock()
+		return nil, true
+	}
+	svrskts := svr.sockets
+	l := int64(len(svrskts))
+	ids := make([]int64, 0, l)
+	sks := make([]*normalSocket, 0, min(l, maxResults))
+	for k := range svrskts {
+		ids = append(ids, k)
+	}
+	sort.Sort(int64Slice(ids))
+	idx := sort.Search(len(ids), func(i int) bool { return ids[i] >= startID })
+	count := int64(0)
+	var end bool
+	for i, v := range ids[idx:] {
+		if count == maxResults {
+			break
+		}
+		if ns, ok := c.normalSockets[v]; ok {
+			sks = append(sks, ns)
+			count++
+		}
+		if i == len(ids[idx:])-1 {
+			end = true
+			break
+		}
+	}
+	c.mu.RUnlock()
+	if count == 0 {
+		end = true
+	}
+	s := make([]*SocketMetric, 0, len(sks))
+	for _, ns := range sks {
+		sm := &SocketMetric{}
+		sm.SocketData = ns.s.ChannelzMetric()
+		sm.ID = ns.id
+		sm.RefName = ns.refName
+		s = append(s, sm)
+	}
+	return s, end
+}
+
+func (c *channelMap) GetChannel(id int64) *ChannelMetric {
+	cm := &ChannelMetric{}
+	var cn *channel
+	var ok bool
+	c.mu.RLock()
+	if cn, ok = c.channels[id]; !ok {
+		// channel with id doesn't exist.
+		c.mu.RUnlock()
+		return nil
+	}
+	cm.NestedChans = copyMap(cn.nestedChans)
+	cm.SubChans = copyMap(cn.subChans)
+	// cn.c can be set to &dummyChannel{} when deleteSelfFromMap is called. Save a copy of cn.c when
+	// holding the lock to prevent potential data race.
+	chanCopy := cn.c
+	c.mu.RUnlock()
+	cm.ChannelData = chanCopy.ChannelzMetric()
+	cm.ID = cn.id
+	cm.RefName = cn.refName
+	cm.Trace = cn.trace.dumpData()
+	return cm
+}
+
+func (c *channelMap) GetSubChannel(id int64) *SubChannelMetric {
+	cm := &SubChannelMetric{}
+	var sc *subChannel
+	var ok bool
+	c.mu.RLock()
+	if sc, ok = c.subChannels[id]; !ok {
+		// subchannel with id doesn't exist.
+		c.mu.RUnlock()
+		return nil
+	}
+	cm.Sockets = copyMap(sc.sockets)
+	// sc.c can be set to &dummyChannel{} when deleteSelfFromMap is called. Save a copy of sc.c when
+	// holding the lock to prevent potential data race.
+	chanCopy := sc.c
+	c.mu.RUnlock()
+	cm.ChannelData = chanCopy.ChannelzMetric()
+	cm.ID = sc.id
+	cm.RefName = sc.refName
+	cm.Trace = sc.trace.dumpData()
+	return cm
+}
+
+func (c *channelMap) GetSocket(id int64) *SocketMetric {
+	sm := &SocketMetric{}
+	c.mu.RLock()
+	if ls, ok := c.listenSockets[id]; ok {
+		c.mu.RUnlock()
+		sm.SocketData = ls.s.ChannelzMetric()
+		sm.ID = ls.id
+		sm.RefName = ls.refName
+		return sm
+	}
+	if ns, ok := c.normalSockets[id]; ok {
+		c.mu.RUnlock()
+		sm.SocketData = ns.s.ChannelzMetric()
+		sm.ID = ns.id
+		sm.RefName = ns.refName
+		return sm
+	}
+	c.mu.RUnlock()
+	return nil
+}
+
+func (c *channelMap) GetServer(id int64) *ServerMetric {
+	sm := &ServerMetric{}
+	var svr *server
+	var ok bool
+	c.mu.RLock()
+	if svr, ok = c.servers[id]; !ok {
+		c.mu.RUnlock()
+		return nil
+	}
+	sm.ListenSockets = copyMap(svr.listenSockets)
+	c.mu.RUnlock()
+	sm.ID = svr.id
+	sm.RefName = svr.refName
+	sm.ServerData = svr.s.ChannelzMetric()
+	return sm
+}
+
+type idGenerator struct {
+	id int64
+}
+
+func (i *idGenerator) reset() {
+	atomic.StoreInt64(&i.id, 0)
+}
+
+func (i *idGenerator) genID() int64 {
+	return atomic.AddInt64(&i.id, 1)
+}

vendor/google.golang.org/grpc/internal/channelz/id.go

@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import "fmt"
+
+// Identifier is an opaque identifier which uniquely identifies an entity in the
+// channelz database.
+type Identifier struct {
+	typ RefChannelType
+	id  int64
+	str string
+	pid *Identifier
+}
+
+// Type returns the entity type corresponding to id.
+func (id *Identifier) Type() RefChannelType {
+	return id.typ
+}
+
+// Int returns the integer identifier corresponding to id.
+func (id *Identifier) Int() int64 {
+	return id.id
+}
+
+// String returns a string representation of the entity corresponding to id.
+//
+// This includes some information about the parent as well. Examples:
+// Top-level channel: [Channel #channel-number]
+// Nested channel:    [Channel #parent-channel-number Channel #channel-number]
+// Sub channel:       [Channel #parent-channel SubChannel #subchannel-number]
+func (id *Identifier) String() string {
+	return id.str
+}
+
+// Equal returns true if other is the same as id.
+func (id *Identifier) Equal(other *Identifier) bool {
+	if (id != nil) != (other != nil) {
+		return false
+	}
+	if id == nil && other == nil {
+		return true
+	}
+	return id.typ == other.typ && id.id == other.id && id.pid == other.pid
+}
+
+// NewIdentifierForTesting returns a new opaque identifier to be used only for
+// testing purposes.
+func NewIdentifierForTesting(typ RefChannelType, id int64, pid *Identifier) *Identifier {
+	return newIdentifer(typ, id, pid)
+}
+
+func newIdentifer(typ RefChannelType, id int64, pid *Identifier) *Identifier {
+	str := fmt.Sprintf("%s #%d", typ, id)
+	if pid != nil {
+		str = fmt.Sprintf("%s %s", pid, str)
+	}
+	return &Identifier{typ: typ, id: id, str: str, pid: pid}
+}

vendor/google.golang.org/grpc/internal/channelz/logging.go

@@ -0,0 +1,79 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+var logger = grpclog.Component("channelz")
+
+func withParens(id *Identifier) string {
+	return "[" + id.String() + "] "
+}
+
+// Info logs and adds a trace event if channelz is on.
+func Info(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtInfo,
+	})
+}
+
+// Infof logs and adds a trace event if channelz is on.
+func Infof(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtInfo,
+	})
+}
+
+// Warning logs and adds a trace event if channelz is on.
+func Warning(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtWarning,
+	})
+}
+
+// Warningf logs and adds a trace event if channelz is on.
+func Warningf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtWarning,
+	})
+}
+
+// Error logs and adds a trace event if channelz is on.
+func Error(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprint(args...),
+		Severity: CtError,
+	})
+}
+
+// Errorf logs and adds a trace event if channelz is on.
+func Errorf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+	AddTraceEvent(l, id, 1, &TraceEventDesc{
+		Desc:     fmt.Sprintf(format, args...),
+		Severity: CtError,
+	})
+}

vendor/google.golang.org/grpc/internal/channelz/types.go

@@ -0,0 +1,722 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/credentials"
+)
+
+// entry represents a node in the channelz database.
+type entry interface {
+	// addChild adds a child e, whose channelz id is id to child list
+	addChild(id int64, e entry)
+	// deleteChild deletes a child with channelz id to be id from child list
+	deleteChild(id int64)
+	// triggerDelete tries to delete self from channelz database. However, if child
+	// list is not empty, then deletion from the database is on hold until the last
+	// child is deleted from database.
+	triggerDelete()
+	// deleteSelfIfReady check whether triggerDelete() has been called before, and whether child
+	// list is now empty. If both conditions are met, then delete self from database.
+	deleteSelfIfReady()
+	// getParentID returns parent ID of the entry. 0 value parent ID means no parent.
+	getParentID() int64
+}
+
+// dummyEntry is a fake entry to handle entry not found case.
+type dummyEntry struct {
+	idNotFound int64
+}
+
+func (d *dummyEntry) addChild(id int64, e entry) {
+	// Note: It is possible for a normal program to reach here under race condition.
+	// For example, there could be a race between ClientConn.Close() info being propagated
+	// to addrConn and http2Client. ClientConn.Close() cancel the context and result
+	// in http2Client to error. The error info is then caught by transport monitor
+	// and before addrConn.tearDown() is called in side ClientConn.Close(). Therefore,
+	// the addrConn will create a new transport. And when registering the new transport in
+	// channelz, its parent addrConn could have already been torn down and deleted
+	// from channelz tracking, and thus reach the code here.
+	logger.Infof("attempt to add child of type %T with id %d to a parent (id=%d) that doesn't currently exist", e, id, d.idNotFound)
+}
+
+func (d *dummyEntry) deleteChild(id int64) {
+	// It is possible for a normal program to reach here under race condition.
+	// Refer to the example described in addChild().
+	logger.Infof("attempt to delete child with id %d from a parent (id=%d) that doesn't currently exist", id, d.idNotFound)
+}
+
+func (d *dummyEntry) triggerDelete() {
+	logger.Warningf("attempt to delete an entry (id=%d) that doesn't currently exist", d.idNotFound)
+}
+
+func (*dummyEntry) deleteSelfIfReady() {
+	// code should not reach here. deleteSelfIfReady is always called on an existing entry.
+}
+
+func (*dummyEntry) getParentID() int64 {
+	return 0
+}
+
+// ChannelMetric defines the info channelz provides for a specific Channel, which
+// includes ChannelInternalMetric and channelz-specific data, such as channelz id,
+// child list, etc.
+type ChannelMetric struct {
+	// ID is the channelz id of this channel.
+	ID int64
+	// RefName is the human readable reference string of this channel.
+	RefName string
+	// ChannelData contains channel internal metric reported by the channel through
+	// ChannelzMetric().
+	ChannelData *ChannelInternalMetric
+	// NestedChans tracks the nested channel type children of this channel in the format of
+	// a map from nested channel channelz id to corresponding reference string.
+	NestedChans map[int64]string
+	// SubChans tracks the subchannel type children of this channel in the format of a
+	// map from subchannel channelz id to corresponding reference string.
+	SubChans map[int64]string
+	// Sockets tracks the socket type children of this channel in the format of a map
+	// from socket channelz id to corresponding reference string.
+	// Note current grpc implementation doesn't allow channel having sockets directly,
+	// therefore, this is field is unused.
+	Sockets map[int64]string
+	// Trace contains the most recent traced events.
+	Trace *ChannelTrace
+}
+
+// SubChannelMetric defines the info channelz provides for a specific SubChannel,
+// which includes ChannelInternalMetric and channelz-specific data, such as
+// channelz id, child list, etc.
+type SubChannelMetric struct {
+	// ID is the channelz id of this subchannel.
+	ID int64
+	// RefName is the human readable reference string of this subchannel.
+	RefName string
+	// ChannelData contains subchannel internal metric reported by the subchannel
+	// through ChannelzMetric().
+	ChannelData *ChannelInternalMetric
+	// NestedChans tracks the nested channel type children of this subchannel in the format of
+	// a map from nested channel channelz id to corresponding reference string.
+	// Note current grpc implementation doesn't allow subchannel to have nested channels
+	// as children, therefore, this field is unused.
+	NestedChans map[int64]string
+	// SubChans tracks the subchannel type children of this subchannel in the format of a
+	// map from subchannel channelz id to corresponding reference string.
+	// Note current grpc implementation doesn't allow subchannel to have subchannels
+	// as children, therefore, this field is unused.
+	SubChans map[int64]string
+	// Sockets tracks the socket type children of this subchannel in the format of a map
+	// from socket channelz id to corresponding reference string.
+	Sockets map[int64]string
+	// Trace contains the most recent traced events.
+	Trace *ChannelTrace
+}
+
+// ChannelInternalMetric defines the struct that the implementor of Channel interface
+// should return from ChannelzMetric().
+type ChannelInternalMetric struct {
+	// current connectivity state of the channel.
+	State connectivity.State
+	// The target this channel originally tried to connect to.  May be absent
+	Target string
+	// The number of calls started on the channel.
+	CallsStarted int64
+	// The number of calls that have completed with an OK status.
+	CallsSucceeded int64
+	// The number of calls that have a completed with a non-OK status.
+	CallsFailed int64
+	// The last time a call was started on the channel.
+	LastCallStartedTimestamp time.Time
+}
+
+// ChannelTrace stores traced events on a channel/subchannel and related info.
+type ChannelTrace struct {
+	// EventNum is the number of events that ever got traced (i.e. including those that have been deleted)
+	EventNum int64
+	// CreationTime is the creation time of the trace.
+	CreationTime time.Time
+	// Events stores the most recent trace events (up to $maxTraceEntry, newer event will overwrite the
+	// oldest one)
+	Events []*TraceEvent
+}
+
+// TraceEvent represent a single trace event
+type TraceEvent struct {
+	// Desc is a simple description of the trace event.
+	Desc string
+	// Severity states the severity of this trace event.
+	Severity Severity
+	// Timestamp is the event time.
+	Timestamp time.Time
+	// RefID is the id of the entity that gets referenced in the event. RefID is 0 if no other entity is
+	// involved in this event.
+	// e.g. SubChannel (id: 4[]) Created. --> RefID = 4, RefName = "" (inside [])
+	RefID int64
+	// RefName is the reference name for the entity that gets referenced in the event.
+	RefName string
+	// RefType indicates the referenced entity type, i.e Channel or SubChannel.
+	RefType RefChannelType
+}
+
+// Channel is the interface that should be satisfied in order to be tracked by
+// channelz as Channel or SubChannel.
+type Channel interface {
+	ChannelzMetric() *ChannelInternalMetric
+}
+
+type dummyChannel struct{}
+
+func (d *dummyChannel) ChannelzMetric() *ChannelInternalMetric {
+	return &ChannelInternalMetric{}
+}
+
+type channel struct {
+	refName     string
+	c           Channel
+	closeCalled bool
+	nestedChans map[int64]string
+	subChans    map[int64]string
+	id          int64
+	pid         int64
+	cm          *channelMap
+	trace       *channelTrace
+	// traceRefCount is the number of trace events that reference this channel.
+	// Non-zero traceRefCount means the trace of this channel cannot be deleted.
+	traceRefCount int32
+}
+
+func (c *channel) addChild(id int64, e entry) {
+	switch v := e.(type) {
+	case *subChannel:
+		c.subChans[id] = v.refName
+	case *channel:
+		c.nestedChans[id] = v.refName
+	default:
+		logger.Errorf("cannot add a child (id = %d) of type %T to a channel", id, e)
+	}
+}
+
+func (c *channel) deleteChild(id int64) {
+	delete(c.subChans, id)
+	delete(c.nestedChans, id)
+	c.deleteSelfIfReady()
+}
+
+func (c *channel) triggerDelete() {
+	c.closeCalled = true
+	c.deleteSelfIfReady()
+}
+
+func (c *channel) getParentID() int64 {
+	return c.pid
+}
+
+// deleteSelfFromTree tries to delete the channel from the channelz entry relation tree, which means
+// deleting the channel reference from its parent's child list.
+//
+// In order for a channel to be deleted from the tree, it must meet the criteria that, removal of the
+// corresponding grpc object has been invoked, and the channel does not have any children left.
+//
+// The returned boolean value indicates whether the channel has been successfully deleted from tree.
+func (c *channel) deleteSelfFromTree() (deleted bool) {
+	if !c.closeCalled || len(c.subChans)+len(c.nestedChans) != 0 {
+		return false
+	}
+	// not top channel
+	if c.pid != 0 {
+		c.cm.findEntry(c.pid).deleteChild(c.id)
+	}
+	return true
+}
+
+// deleteSelfFromMap checks whether it is valid to delete the channel from the map, which means
+// deleting the channel from channelz's tracking entirely. Users can no longer use id to query the
+// channel, and its memory will be garbage collected.
+//
+// The trace reference count of the channel must be 0 in order to be deleted from the map. This is
+// specified in the channel tracing gRFC that as long as some other trace has reference to an entity,
+// the trace of the referenced entity must not be deleted. In order to release the resource allocated
+// by grpc, the reference to the grpc object is reset to a dummy object.
+//
+// deleteSelfFromMap must be called after deleteSelfFromTree returns true.
+//
+// It returns a bool to indicate whether the channel can be safely deleted from map.
+func (c *channel) deleteSelfFromMap() (delete bool) {
+	if c.getTraceRefCount() != 0 {
+		c.c = &dummyChannel{}
+		return false
+	}
+	return true
+}
+
+// deleteSelfIfReady tries to delete the channel itself from the channelz database.
+// The delete process includes two steps:
+//  1. delete the channel from the entry relation tree, i.e. delete the channel reference from its
+//     parent's child list.
+//  2. delete the channel from the map, i.e. delete the channel entirely from channelz. Lookup by id
+//     will return entry not found error.
+func (c *channel) deleteSelfIfReady() {
+	if !c.deleteSelfFromTree() {
+		return
+	}
+	if !c.deleteSelfFromMap() {
+		return
+	}
+	c.cm.deleteEntry(c.id)
+	c.trace.clear()
+}
+
+func (c *channel) getChannelTrace() *channelTrace {
+	return c.trace
+}
+
+func (c *channel) incrTraceRefCount() {
+	atomic.AddInt32(&c.traceRefCount, 1)
+}
+
+func (c *channel) decrTraceRefCount() {
+	atomic.AddInt32(&c.traceRefCount, -1)
+}
+
+func (c *channel) getTraceRefCount() int {
+	i := atomic.LoadInt32(&c.traceRefCount)
+	return int(i)
+}
+
+func (c *channel) getRefName() string {
+	return c.refName
+}
+
+type subChannel struct {
+	refName       string
+	c             Channel
+	closeCalled   bool
+	sockets       map[int64]string
+	id            int64
+	pid           int64
+	cm            *channelMap
+	trace         *channelTrace
+	traceRefCount int32
+}
+
+func (sc *subChannel) addChild(id int64, e entry) {
+	if v, ok := e.(*normalSocket); ok {
+		sc.sockets[id] = v.refName
+	} else {
+		logger.Errorf("cannot add a child (id = %d) of type %T to a subChannel", id, e)
+	}
+}
+
+func (sc *subChannel) deleteChild(id int64) {
+	delete(sc.sockets, id)
+	sc.deleteSelfIfReady()
+}
+
+func (sc *subChannel) triggerDelete() {
+	sc.closeCalled = true
+	sc.deleteSelfIfReady()
+}
+
+func (sc *subChannel) getParentID() int64 {
+	return sc.pid
+}
+
+// deleteSelfFromTree tries to delete the subchannel from the channelz entry relation tree, which
+// means deleting the subchannel reference from its parent's child list.
+//
+// In order for a subchannel to be deleted from the tree, it must meet the criteria that, removal of
+// the corresponding grpc object has been invoked, and the subchannel does not have any children left.
+//
+// The returned boolean value indicates whether the channel has been successfully deleted from tree.
+func (sc *subChannel) deleteSelfFromTree() (deleted bool) {
+	if !sc.closeCalled || len(sc.sockets) != 0 {
+		return false
+	}
+	sc.cm.findEntry(sc.pid).deleteChild(sc.id)
+	return true
+}
+
+// deleteSelfFromMap checks whether it is valid to delete the subchannel from the map, which means
+// deleting the subchannel from channelz's tracking entirely. Users can no longer use id to query
+// the subchannel, and its memory will be garbage collected.
+//
+// The trace reference count of the subchannel must be 0 in order to be deleted from the map. This is
+// specified in the channel tracing gRFC that as long as some other trace has reference to an entity,
+// the trace of the referenced entity must not be deleted. In order to release the resource allocated
+// by grpc, the reference to the grpc object is reset to a dummy object.
+//
+// deleteSelfFromMap must be called after deleteSelfFromTree returns true.
+//
+// It returns a bool to indicate whether the channel can be safely deleted from map.
+func (sc *subChannel) deleteSelfFromMap() (delete bool) {
+	if sc.getTraceRefCount() != 0 {
+		// free the grpc struct (i.e. addrConn)
+		sc.c = &dummyChannel{}
+		return false
+	}
+	return true
+}
+
+// deleteSelfIfReady tries to delete the subchannel itself from the channelz database.
+// The delete process includes two steps:
+//  1. delete the subchannel from the entry relation tree, i.e. delete the subchannel reference from
+//     its parent's child list.
+//  2. delete the subchannel from the map, i.e. delete the subchannel entirely from channelz. Lookup
+//     by id will return entry not found error.
+func (sc *subChannel) deleteSelfIfReady() {
+	if !sc.deleteSelfFromTree() {
+		return
+	}
+	if !sc.deleteSelfFromMap() {
+		return
+	}
+	sc.cm.deleteEntry(sc.id)
+	sc.trace.clear()
+}
+
+func (sc *subChannel) getChannelTrace() *channelTrace {
+	return sc.trace
+}
+
+func (sc *subChannel) incrTraceRefCount() {
+	atomic.AddInt32(&sc.traceRefCount, 1)
+}
+
+func (sc *subChannel) decrTraceRefCount() {
+	atomic.AddInt32(&sc.traceRefCount, -1)
+}
+
+func (sc *subChannel) getTraceRefCount() int {
+	i := atomic.LoadInt32(&sc.traceRefCount)
+	return int(i)
+}
+
+func (sc *subChannel) getRefName() string {
+	return sc.refName
+}
+
+// SocketMetric defines the info channelz provides for a specific Socket, which
+// includes SocketInternalMetric and channelz-specific data, such as channelz id, etc.
+type SocketMetric struct {
+	// ID is the channelz id of this socket.
+	ID int64
+	// RefName is the human readable reference string of this socket.
+	RefName string
+	// SocketData contains socket internal metric reported by the socket through
+	// ChannelzMetric().
+	SocketData *SocketInternalMetric
+}
+
+// SocketInternalMetric defines the struct that the implementor of Socket interface
+// should return from ChannelzMetric().
+type SocketInternalMetric struct {
+	// The number of streams that have been started.
+	StreamsStarted int64
+	// The number of streams that have ended successfully:
+	// On client side, receiving frame with eos bit set.
+	// On server side, sending frame with eos bit set.
+	StreamsSucceeded int64
+	// The number of streams that have ended unsuccessfully:
+	// On client side, termination without receiving frame with eos bit set.
+	// On server side, termination without sending frame with eos bit set.
+	StreamsFailed int64
+	// The number of messages successfully sent on this socket.
+	MessagesSent     int64
+	MessagesReceived int64
+	// The number of keep alives sent.  This is typically implemented with HTTP/2
+	// ping messages.
+	KeepAlivesSent int64
+	// The last time a stream was created by this endpoint.  Usually unset for
+	// servers.
+	LastLocalStreamCreatedTimestamp time.Time
+	// The last time a stream was created by the remote endpoint.  Usually unset
+	// for clients.
+	LastRemoteStreamCreatedTimestamp time.Time
+	// The last time a message was sent by this endpoint.
+	LastMessageSentTimestamp time.Time
+	// The last time a message was received by this endpoint.
+	LastMessageReceivedTimestamp time.Time
+	// The amount of window, granted to the local endpoint by the remote endpoint.
+	// This may be slightly out of date due to network latency.  This does NOT
+	// include stream level or TCP level flow control info.
+	LocalFlowControlWindow int64
+	// The amount of window, granted to the remote endpoint by the local endpoint.
+	// This may be slightly out of date due to network latency.  This does NOT
+	// include stream level or TCP level flow control info.
+	RemoteFlowControlWindow int64
+	// The locally bound address.
+	LocalAddr net.Addr
+	// The remote bound address.  May be absent.
+	RemoteAddr net.Addr
+	// Optional, represents the name of the remote endpoint, if different than
+	// the original target name.
+	RemoteName    string
+	SocketOptions *SocketOptionData
+	Security      credentials.ChannelzSecurityValue
+}
+
+// Socket is the interface that should be satisfied in order to be tracked by
+// channelz as Socket.
+type Socket interface {
+	ChannelzMetric() *SocketInternalMetric
+}
+
+type listenSocket struct {
+	refName string
+	s       Socket
+	id      int64
+	pid     int64
+	cm      *channelMap
+}
+
+func (ls *listenSocket) addChild(id int64, e entry) {
+	logger.Errorf("cannot add a child (id = %d) of type %T to a listen socket", id, e)
+}
+
+func (ls *listenSocket) deleteChild(id int64) {
+	logger.Errorf("cannot delete a child (id = %d) from a listen socket", id)
+}
+
+func (ls *listenSocket) triggerDelete() {
+	ls.cm.deleteEntry(ls.id)
+	ls.cm.findEntry(ls.pid).deleteChild(ls.id)
+}
+
+func (ls *listenSocket) deleteSelfIfReady() {
+	logger.Errorf("cannot call deleteSelfIfReady on a listen socket")
+}
+
+func (ls *listenSocket) getParentID() int64 {
+	return ls.pid
+}
+
+type normalSocket struct {
+	refName string
+	s       Socket
+	id      int64
+	pid     int64
+	cm      *channelMap
+}
+
+func (ns *normalSocket) addChild(id int64, e entry) {
+	logger.Errorf("cannot add a child (id = %d) of type %T to a normal socket", id, e)
+}
+
+func (ns *normalSocket) deleteChild(id int64) {
+	logger.Errorf("cannot delete a child (id = %d) from a normal socket", id)
+}
+
+func (ns *normalSocket) triggerDelete() {
+	ns.cm.deleteEntry(ns.id)
+	ns.cm.findEntry(ns.pid).deleteChild(ns.id)
+}
+
+func (ns *normalSocket) deleteSelfIfReady() {
+	logger.Errorf("cannot call deleteSelfIfReady on a normal socket")
+}
+
+func (ns *normalSocket) getParentID() int64 {
+	return ns.pid
+}
+
+// ServerMetric defines the info channelz provides for a specific Server, which
+// includes ServerInternalMetric and channelz-specific data, such as channelz id,
+// child list, etc.
+type ServerMetric struct {
+	// ID is the channelz id of this server.
+	ID int64
+	// RefName is the human readable reference string of this server.
+	RefName string
+	// ServerData contains server internal metric reported by the server through
+	// ChannelzMetric().
+	ServerData *ServerInternalMetric
+	// ListenSockets tracks the listener socket type children of this server in the
+	// format of a map from socket channelz id to corresponding reference string.
+	ListenSockets map[int64]string
+}
+
+// ServerInternalMetric defines the struct that the implementor of Server interface
+// should return from ChannelzMetric().
+type ServerInternalMetric struct {
+	// The number of incoming calls started on the server.
+	CallsStarted int64
+	// The number of incoming calls that have completed with an OK status.
+	CallsSucceeded int64
+	// The number of incoming calls that have a completed with a non-OK status.
+	CallsFailed int64
+	// The last time a call was started on the server.
+	LastCallStartedTimestamp time.Time
+}
+
+// Server is the interface to be satisfied in order to be tracked by channelz as
+// Server.
+type Server interface {
+	ChannelzMetric() *ServerInternalMetric
+}
+
+type server struct {
+	refName       string
+	s             Server
+	closeCalled   bool
+	sockets       map[int64]string
+	listenSockets map[int64]string
+	id            int64
+	cm            *channelMap
+}
+
+func (s *server) addChild(id int64, e entry) {
+	switch v := e.(type) {
+	case *normalSocket:
+		s.sockets[id] = v.refName
+	case *listenSocket:
+		s.listenSockets[id] = v.refName
+	default:
+		logger.Errorf("cannot add a child (id = %d) of type %T to a server", id, e)
+	}
+}
+
+func (s *server) deleteChild(id int64) {
+	delete(s.sockets, id)
+	delete(s.listenSockets, id)
+	s.deleteSelfIfReady()
+}
+
+func (s *server) triggerDelete() {
+	s.closeCalled = true
+	s.deleteSelfIfReady()
+}
+
+func (s *server) deleteSelfIfReady() {
+	if !s.closeCalled || len(s.sockets)+len(s.listenSockets) != 0 {
+		return
+	}
+	s.cm.deleteEntry(s.id)
+}
+
+func (s *server) getParentID() int64 {
+	return 0
+}
+
+type tracedChannel interface {
+	getChannelTrace() *channelTrace
+	incrTraceRefCount()
+	decrTraceRefCount()
+	getRefName() string
+}
+
+type channelTrace struct {
+	cm          *channelMap
+	createdTime time.Time
+	eventCount  int64
+	mu          sync.Mutex
+	events      []*TraceEvent
+}
+
+func (c *channelTrace) append(e *TraceEvent) {
+	c.mu.Lock()
+	if len(c.events) == getMaxTraceEntry() {
+		del := c.events[0]
+		c.events = c.events[1:]
+		if del.RefID != 0 {
+			// start recursive cleanup in a goroutine to not block the call originated from grpc.
+			go func() {
+				// need to acquire c.cm.mu lock to call the unlocked attemptCleanup func.
+				c.cm.mu.Lock()
+				c.cm.decrTraceRefCount(del.RefID)
+				c.cm.mu.Unlock()
+			}()
+		}
+	}
+	e.Timestamp = time.Now()
+	c.events = append(c.events, e)
+	c.eventCount++
+	c.mu.Unlock()
+}
+
+func (c *channelTrace) clear() {
+	c.mu.Lock()
+	for _, e := range c.events {
+		if e.RefID != 0 {
+			// caller should have already held the c.cm.mu lock.
+			c.cm.decrTraceRefCount(e.RefID)
+		}
+	}
+	c.mu.Unlock()
+}
+
+// Severity is the severity level of a trace event.
+// The canonical enumeration of all valid values is here:
+// https://github.com/grpc/grpc-proto/blob/9b13d199cc0d4703c7ea26c9c330ba695866eb23/grpc/channelz/v1/channelz.proto#L126.
+type Severity int
+
+const (
+	// CtUnknown indicates unknown severity of a trace event.
+	CtUnknown Severity = iota
+	// CtInfo indicates info level severity of a trace event.
+	CtInfo
+	// CtWarning indicates warning level severity of a trace event.
+	CtWarning
+	// CtError indicates error level severity of a trace event.
+	CtError
+)
+
+// RefChannelType is the type of the entity being referenced in a trace event.
+type RefChannelType int
+
+const (
+	// RefUnknown indicates an unknown entity type, the zero value for this type.
+	RefUnknown RefChannelType = iota
+	// RefChannel indicates the referenced entity is a Channel.
+	RefChannel
+	// RefSubChannel indicates the referenced entity is a SubChannel.
+	RefSubChannel
+	// RefServer indicates the referenced entity is a Server.
+	RefServer
+	// RefListenSocket indicates the referenced entity is a ListenSocket.
+	RefListenSocket
+	// RefNormalSocket indicates the referenced entity is a NormalSocket.
+	RefNormalSocket
+)
+
+var refChannelTypeToString = map[RefChannelType]string{
+	RefUnknown:      "Unknown",
+	RefChannel:      "Channel",
+	RefSubChannel:   "SubChannel",
+	RefServer:       "Server",
+	RefListenSocket: "ListenSocket",
+	RefNormalSocket: "NormalSocket",
+}
+
+func (r RefChannelType) String() string {
+	return refChannelTypeToString[r]
+}
+
+func (c *channelTrace) dumpData() *ChannelTrace {
+	c.mu.Lock()
+	ct := &ChannelTrace{EventNum: c.eventCount, CreationTime: c.createdTime}
+	ct.Events = c.events[:len(c.events)]
+	c.mu.Unlock()
+	return ct
+}

vendor/google.golang.org/grpc/internal/channelz/types_linux.go

@@ -0,0 +1,51 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// SocketOptionData defines the struct to hold socket option data, and related
+// getter function to obtain info from fd.
+type SocketOptionData struct {
+	Linger      *unix.Linger
+	RecvTimeout *unix.Timeval
+	SendTimeout *unix.Timeval
+	TCPInfo     *unix.TCPInfo
+}
+
+// Getsockopt defines the function to get socket options requested by channelz.
+// It is to be passed to syscall.RawConn.Control().
+func (s *SocketOptionData) Getsockopt(fd uintptr) {
+	if v, err := unix.GetsockoptLinger(int(fd), syscall.SOL_SOCKET, syscall.SO_LINGER); err == nil {
+		s.Linger = v
+	}
+	if v, err := unix.GetsockoptTimeval(int(fd), syscall.SOL_SOCKET, syscall.SO_RCVTIMEO); err == nil {
+		s.RecvTimeout = v
+	}
+	if v, err := unix.GetsockoptTimeval(int(fd), syscall.SOL_SOCKET, syscall.SO_SNDTIMEO); err == nil {
+		s.SendTimeout = v
+	}
+	if v, err := unix.GetsockoptTCPInfo(int(fd), syscall.SOL_TCP, syscall.TCP_INFO); err == nil {
+		s.TCPInfo = v
+	}
+}

vendor/google.golang.org/grpc/internal/channelz/types_nonlinux.go

@@ -0,0 +1,43 @@
+//go:build !linux
+// +build !linux
+
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"sync"
+)
+
+var once sync.Once
+
+// SocketOptionData defines the struct to hold socket option data, and related
+// getter function to obtain info from fd.
+// Windows OS doesn't support Socket Option
+type SocketOptionData struct {
+}
+
+// Getsockopt defines the function to get socket options requested by channelz.
+// It is to be passed to syscall.RawConn.Control().
+// Windows OS doesn't support Socket Option
+func (s *SocketOptionData) Getsockopt(fd uintptr) {
+	once.Do(func() {
+		logger.Warning("Channelz: socket options are not supported on non-linux environments")
+	})
+}

vendor/google.golang.org/grpc/internal/channelz/util_linux.go

@@ -0,0 +1,37 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+import (
+	"syscall"
+)
+
+// GetSocketOption gets the socket option info of the conn.
+func GetSocketOption(socket interface{}) *SocketOptionData {
+	c, ok := socket.(syscall.Conn)
+	if !ok {
+		return nil
+	}
+	data := &SocketOptionData{}
+	if rawConn, err := c.SyscallConn(); err == nil {
+		rawConn.Control(data.Getsockopt)
+		return data
+	}
+	return nil
+}

vendor/google.golang.org/grpc/internal/channelz/util_nonlinux.go

@@ -0,0 +1,27 @@
+//go:build !linux
+// +build !linux
+
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package channelz
+
+// GetSocketOption gets the socket option info of the conn.
+func GetSocketOption(c interface{}) *SocketOptionData {
+	return nil
+}

vendor/google.golang.org/grpc/internal/credentials/credentials.go

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import (
+	"context"
+)
+
+// requestInfoKey is a struct to be used as the key to store RequestInfo in a
+// context.
+type requestInfoKey struct{}
+
+// NewRequestInfoContext creates a context with ri.
+func NewRequestInfoContext(ctx context.Context, ri interface{}) context.Context {
+	return context.WithValue(ctx, requestInfoKey{}, ri)
+}
+
+// RequestInfoFromContext extracts the RequestInfo from ctx.
+func RequestInfoFromContext(ctx context.Context) interface{} {
+	return ctx.Value(requestInfoKey{})
+}
+
+// clientHandshakeInfoKey is a struct used as the key to store
+// ClientHandshakeInfo in a context.
+type clientHandshakeInfoKey struct{}
+
+// ClientHandshakeInfoFromContext extracts the ClientHandshakeInfo from ctx.
+func ClientHandshakeInfoFromContext(ctx context.Context) interface{} {
+	return ctx.Value(clientHandshakeInfoKey{})
+}
+
+// NewClientHandshakeInfoContext creates a context with chi.
+func NewClientHandshakeInfoContext(ctx context.Context, chi interface{}) context.Context {
+	return context.WithValue(ctx, clientHandshakeInfoKey{}, chi)
+}

vendor/google.golang.org/grpc/internal/credentials/spiffe.go

@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package credentials defines APIs for parsing SPIFFE ID.
+//
+// All APIs in this package are experimental.
+package credentials
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"net/url"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+var logger = grpclog.Component("credentials")
+
+// SPIFFEIDFromState parses the SPIFFE ID from State. If the SPIFFE ID format
+// is invalid, return nil with warning.
+func SPIFFEIDFromState(state tls.ConnectionState) *url.URL {
+	if len(state.PeerCertificates) == 0 || len(state.PeerCertificates[0].URIs) == 0 {
+		return nil
+	}
+	return SPIFFEIDFromCert(state.PeerCertificates[0])
+}
+
+// SPIFFEIDFromCert parses the SPIFFE ID from x509.Certificate. If the SPIFFE
+// ID format is invalid, return nil with warning.
+func SPIFFEIDFromCert(cert *x509.Certificate) *url.URL {
+	if cert == nil || cert.URIs == nil {
+		return nil
+	}
+	var spiffeID *url.URL
+	for _, uri := range cert.URIs {
+		if uri == nil || uri.Scheme != "spiffe" || uri.Opaque != "" || (uri.User != nil && uri.User.Username() != "") {
+			continue
+		}
+		// From this point, we assume the uri is intended for a SPIFFE ID.
+		if len(uri.String()) > 2048 {
+			logger.Warning("invalid SPIFFE ID: total ID length larger than 2048 bytes")
+			return nil
+		}
+		if len(uri.Host) == 0 || len(uri.Path) == 0 {
+			logger.Warning("invalid SPIFFE ID: domain or workload ID is empty")
+			return nil
+		}
+		if len(uri.Host) > 255 {
+			logger.Warning("invalid SPIFFE ID: domain length larger than 255 characters")
+			return nil
+		}
+		// A valid SPIFFE certificate can only have exactly one URI SAN field.
+		if len(cert.URIs) > 1 {
+			logger.Warning("invalid SPIFFE ID: multiple URI SANs")
+			return nil
+		}
+		spiffeID = uri
+	}
+	return spiffeID
+}

vendor/google.golang.org/grpc/internal/credentials/syscallconn.go

@@ -0,0 +1,58 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package credentials
+
+import (
+	"net"
+	"syscall"
+)
+
+type sysConn = syscall.Conn
+
+// syscallConn keeps reference of rawConn to support syscall.Conn for channelz.
+// SyscallConn() (the method in interface syscall.Conn) is explicitly
+// implemented on this type,
+//
+// Interface syscall.Conn is implemented by most net.Conn implementations (e.g.
+// TCPConn, UnixConn), but is not part of net.Conn interface. So wrapper conns
+// that embed net.Conn don't implement syscall.Conn. (Side note: tls.Conn
+// doesn't embed net.Conn, so even if syscall.Conn is part of net.Conn, it won't
+// help here).
+type syscallConn struct {
+	net.Conn
+	// sysConn is a type alias of syscall.Conn. It's necessary because the name
+	// `Conn` collides with `net.Conn`.
+	sysConn
+}
+
+// WrapSyscallConn tries to wrap rawConn and newConn into a net.Conn that
+// implements syscall.Conn. rawConn will be used to support syscall, and newConn
+// will be used for read/write.
+//
+// This function returns newConn if rawConn doesn't implement syscall.Conn.
+func WrapSyscallConn(rawConn, newConn net.Conn) net.Conn {
+	sysConn, ok := rawConn.(syscall.Conn)
+	if !ok {
+		return newConn
+	}
+	return &syscallConn{
+		Conn:    newConn,
+		sysConn: sysConn,
+	}
+}

vendor/google.golang.org/grpc/internal/credentials/util.go

@@ -0,0 +1,52 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package credentials
+
+import (
+	"crypto/tls"
+)
+
+const alpnProtoStrH2 = "h2"
+
+// AppendH2ToNextProtos appends h2 to next protos.
+func AppendH2ToNextProtos(ps []string) []string {
+	for _, p := range ps {
+		if p == alpnProtoStrH2 {
+			return ps
+		}
+	}
+	ret := make([]string, 0, len(ps)+1)
+	ret = append(ret, ps...)
+	return append(ret, alpnProtoStrH2)
+}
+
+// CloneTLSConfig returns a shallow clone of the exported
+// fields of cfg, ignoring the unexported sync.Once, which
+// contains a mutex and must not be copied.
+//
+// If cfg is nil, a new zero tls.Config is returned.
+//
+// TODO: inline this function if possible.
+func CloneTLSConfig(cfg *tls.Config) *tls.Config {
+	if cfg == nil {
+		return &tls.Config{}
+	}
+
+	return cfg.Clone()
+}

vendor/google.golang.org/grpc/internal/envconfig/envconfig.go

@@ -0,0 +1,62 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package envconfig contains grpc settings configured by environment variables.
+package envconfig
+
+import (
+	"os"
+	"strconv"
+	"strings"
+)
+
+var (
+	// TXTErrIgnore is set if TXT errors should be ignored ("GRPC_GO_IGNORE_TXT_ERRORS" is not "false").
+	TXTErrIgnore = boolFromEnv("GRPC_GO_IGNORE_TXT_ERRORS", true)
+	// AdvertiseCompressors is set if registered compressor should be advertised
+	// ("GRPC_GO_ADVERTISE_COMPRESSORS" is not "false").
+	AdvertiseCompressors = boolFromEnv("GRPC_GO_ADVERTISE_COMPRESSORS", true)
+	// RingHashCap indicates the maximum ring size which defaults to 4096
+	// entries but may be overridden by setting the environment variable
+	// "GRPC_RING_HASH_CAP".  This does not override the default bounds
+	// checking which NACKs configs specifying ring sizes > 8*1024*1024 (~8M).
+	RingHashCap = uint64FromEnv("GRPC_RING_HASH_CAP", 4096, 1, 8*1024*1024)
+)
+
+func boolFromEnv(envVar string, def bool) bool {
+	if def {
+		// The default is true; return true unless the variable is "false".
+		return !strings.EqualFold(os.Getenv(envVar), "false")
+	}
+	// The default is false; return false unless the variable is "true".
+	return strings.EqualFold(os.Getenv(envVar), "true")
+}
+
+func uint64FromEnv(envVar string, def, min, max uint64) uint64 {
+	v, err := strconv.ParseUint(os.Getenv(envVar), 10, 64)
+	if err != nil {
+		return def
+	}
+	if v < min {
+		return min
+	}
+	if v > max {
+		return max
+	}
+	return v
+}

vendor/google.golang.org/grpc/internal/envconfig/observability.go

@@ -0,0 +1,36 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package envconfig
+
+import "os"
+
+const (
+	envObservabilityConfig     = "GRPC_GCP_OBSERVABILITY_CONFIG"
+	envObservabilityConfigFile = "GRPC_GCP_OBSERVABILITY_CONFIG_FILE"
+)
+
+var (
+	// ObservabilityConfig is the json configuration for the gcp/observability
+	// package specified directly in the envObservabilityConfig env var.
+	ObservabilityConfig = os.Getenv(envObservabilityConfig)
+	// ObservabilityConfigFile is the json configuration for the
+	// gcp/observability specified in a file with the location specified in
+	// envObservabilityConfigFile env var.
+	ObservabilityConfigFile = os.Getenv(envObservabilityConfigFile)
+)

vendor/google.golang.org/grpc/internal/envconfig/xds.go

@@ -0,0 +1,92 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package envconfig
+
+import (
+	"os"
+)
+
+const (
+	// XDSBootstrapFileNameEnv is the env variable to set bootstrap file name.
+	// Do not use this and read from env directly. Its value is read and kept in
+	// variable XDSBootstrapFileName.
+	//
+	// When both bootstrap FileName and FileContent are set, FileName is used.
+	XDSBootstrapFileNameEnv = "GRPC_XDS_BOOTSTRAP"
+	// XDSBootstrapFileContentEnv is the env variable to set bootstrap file
+	// content. Do not use this and read from env directly. Its value is read
+	// and kept in variable XDSBootstrapFileContent.
+	//
+	// When both bootstrap FileName and FileContent are set, FileName is used.
+	XDSBootstrapFileContentEnv = "GRPC_XDS_BOOTSTRAP_CONFIG"
+)
+
+var (
+	// XDSBootstrapFileName holds the name of the file which contains xDS
+	// bootstrap configuration. Users can specify the location of the bootstrap
+	// file by setting the environment variable "GRPC_XDS_BOOTSTRAP".
+	//
+	// When both bootstrap FileName and FileContent are set, FileName is used.
+	XDSBootstrapFileName = os.Getenv(XDSBootstrapFileNameEnv)
+	// XDSBootstrapFileContent holds the content of the xDS bootstrap
+	// configuration. Users can specify the bootstrap config by setting the
+	// environment variable "GRPC_XDS_BOOTSTRAP_CONFIG".
+	//
+	// When both bootstrap FileName and FileContent are set, FileName is used.
+	XDSBootstrapFileContent = os.Getenv(XDSBootstrapFileContentEnv)
+	// XDSRingHash indicates whether ring hash support is enabled, which can be
+	// disabled by setting the environment variable
+	// "GRPC_XDS_EXPERIMENTAL_ENABLE_RING_HASH" to "false".
+	XDSRingHash = boolFromEnv("GRPC_XDS_EXPERIMENTAL_ENABLE_RING_HASH", true)
+	// XDSClientSideSecurity is used to control processing of security
+	// configuration on the client-side.
+	//
+	// Note that there is no env var protection for the server-side because we
+	// have a brand new API on the server-side and users explicitly need to use
+	// the new API to get security integration on the server.
+	XDSClientSideSecurity = boolFromEnv("GRPC_XDS_EXPERIMENTAL_SECURITY_SUPPORT", true)
+	// XDSAggregateAndDNS indicates whether processing of aggregated cluster
+	// and DNS cluster is enabled, which can be enabled by setting the
+	// environment variable
+	// "GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER" to
+	// "true".
+	XDSAggregateAndDNS = boolFromEnv("GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER", true)
+
+	// XDSRBAC indicates whether xDS configured RBAC HTTP Filter is enabled,
+	// which can be disabled by setting the environment variable
+	// "GRPC_XDS_EXPERIMENTAL_RBAC" to "false".
+	XDSRBAC = boolFromEnv("GRPC_XDS_EXPERIMENTAL_RBAC", true)
+	// XDSOutlierDetection indicates whether outlier detection support is
+	// enabled, which can be disabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_ENABLE_OUTLIER_DETECTION" to "false".
+	XDSOutlierDetection = boolFromEnv("GRPC_EXPERIMENTAL_ENABLE_OUTLIER_DETECTION", true)
+	// XDSFederation indicates whether federation support is enabled, which can
+	// be enabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_XDS_FEDERATION" to "true".
+	XDSFederation = boolFromEnv("GRPC_EXPERIMENTAL_XDS_FEDERATION", false)
+
+	// XDSRLS indicates whether processing of Cluster Specifier plugins and
+	// support for the RLS CLuster Specifier is enabled, which can be enabled by
+	// setting the environment variable "GRPC_EXPERIMENTAL_XDS_RLS_LB" to
+	// "true".
+	XDSRLS = boolFromEnv("GRPC_EXPERIMENTAL_XDS_RLS_LB", false)
+
+	// C2PResolverTestOnlyTrafficDirectorURI is the TD URI for testing.
+	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv("GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI")
+)

vendor/google.golang.org/grpc/internal/grpclog/grpclog.go

@@ -0,0 +1,126 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package grpclog (internal) defines depth logging for grpc.
+package grpclog
+
+import (
+	"os"
+)
+
+// Logger is the logger used for the non-depth log functions.
+var Logger LoggerV2
+
+// DepthLogger is the logger used for the depth log functions.
+var DepthLogger DepthLoggerV2
+
+// InfoDepth logs to the INFO log at the specified depth.
+func InfoDepth(depth int, args ...interface{}) {
+	if DepthLogger != nil {
+		DepthLogger.InfoDepth(depth, args...)
+	} else {
+		Logger.Infoln(args...)
+	}
+}
+
+// WarningDepth logs to the WARNING log at the specified depth.
+func WarningDepth(depth int, args ...interface{}) {
+	if DepthLogger != nil {
+		DepthLogger.WarningDepth(depth, args...)
+	} else {
+		Logger.Warningln(args...)
+	}
+}
+
+// ErrorDepth logs to the ERROR log at the specified depth.
+func ErrorDepth(depth int, args ...interface{}) {
+	if DepthLogger != nil {
+		DepthLogger.ErrorDepth(depth, args...)
+	} else {
+		Logger.Errorln(args...)
+	}
+}
+
+// FatalDepth logs to the FATAL log at the specified depth.
+func FatalDepth(depth int, args ...interface{}) {
+	if DepthLogger != nil {
+		DepthLogger.FatalDepth(depth, args...)
+	} else {
+		Logger.Fatalln(args...)
+	}
+	os.Exit(1)
+}
+
+// LoggerV2 does underlying logging work for grpclog.
+// This is a copy of the LoggerV2 defined in the external grpclog package. It
+// is defined here to avoid a circular dependency.
+type LoggerV2 interface {
+	// Info logs to INFO log. Arguments are handled in the manner of fmt.Print.
+	Info(args ...interface{})
+	// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
+	Infoln(args ...interface{})
+	// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
+	Infof(format string, args ...interface{})
+	// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
+	Warning(args ...interface{})
+	// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
+	Warningln(args ...interface{})
+	// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
+	Warningf(format string, args ...interface{})
+	// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+	Error(args ...interface{})
+	// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+	Errorln(args ...interface{})
+	// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+	Errorf(format string, args ...interface{})
+	// Fatal logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatal(args ...interface{})
+	// Fatalln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatalln(args ...interface{})
+	// Fatalf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatalf(format string, args ...interface{})
+	// V reports whether verbosity level l is at least the requested verbose level.
+	V(l int) bool
+}
+
+// DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
+// DepthLoggerV2, the below functions will be called with the appropriate stack
+// depth set for trivial functions the logger may ignore.
+// This is a copy of the DepthLoggerV2 defined in the external grpclog package.
+// It is defined here to avoid a circular dependency.
+//
+// # Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
+type DepthLoggerV2 interface {
+	// InfoDepth logs to INFO log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	InfoDepth(depth int, args ...interface{})
+	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	WarningDepth(depth int, args ...interface{})
+	// ErrorDepth logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	ErrorDepth(depth int, args ...interface{})
+	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	FatalDepth(depth int, args ...interface{})
+}

vendor/google.golang.org/grpc/internal/grpclog/prefixLogger.go

@@ -0,0 +1,81 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpclog
+
+import (
+	"fmt"
+)
+
+// PrefixLogger does logging with a prefix.
+//
+// Logging method on a nil logs without any prefix.
+type PrefixLogger struct {
+	logger DepthLoggerV2
+	prefix string
+}
+
+// Infof does info logging.
+func (pl *PrefixLogger) Infof(format string, args ...interface{}) {
+	if pl != nil {
+		// Handle nil, so the tests can pass in a nil logger.
+		format = pl.prefix + format
+		pl.logger.InfoDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	InfoDepth(1, fmt.Sprintf(format, args...))
+}
+
+// Warningf does warning logging.
+func (pl *PrefixLogger) Warningf(format string, args ...interface{}) {
+	if pl != nil {
+		format = pl.prefix + format
+		pl.logger.WarningDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	WarningDepth(1, fmt.Sprintf(format, args...))
+}
+
+// Errorf does error logging.
+func (pl *PrefixLogger) Errorf(format string, args ...interface{}) {
+	if pl != nil {
+		format = pl.prefix + format
+		pl.logger.ErrorDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	ErrorDepth(1, fmt.Sprintf(format, args...))
+}
+
+// Debugf does info logging at verbose level 2.
+func (pl *PrefixLogger) Debugf(format string, args ...interface{}) {
+	if !Logger.V(2) {
+		return
+	}
+	if pl != nil {
+		// Handle nil, so the tests can pass in a nil logger.
+		format = pl.prefix + format
+		pl.logger.InfoDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	InfoDepth(1, fmt.Sprintf(format, args...))
+}
+
+// NewPrefixLogger creates a prefix logger with the given prefix.
+func NewPrefixLogger(logger DepthLoggerV2, prefix string) *PrefixLogger {
+	return &PrefixLogger{logger: logger, prefix: prefix}
+}

vendor/google.golang.org/grpc/internal/grpcrand/grpcrand.go

@@ -0,0 +1,74 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package grpcrand implements math/rand functions in a concurrent-safe way
+// with a global random source, independent of math/rand's global source.
+package grpcrand
+
+import (
+	"math/rand"
+	"sync"
+	"time"
+)
+
+var (
+	r  = rand.New(rand.NewSource(time.Now().UnixNano()))
+	mu sync.Mutex
+)
+
+// Int implements rand.Int on the grpcrand global source.
+func Int() int {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Int()
+}
+
+// Int63n implements rand.Int63n on the grpcrand global source.
+func Int63n(n int64) int64 {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Int63n(n)
+}
+
+// Intn implements rand.Intn on the grpcrand global source.
+func Intn(n int) int {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Intn(n)
+}
+
+// Int31n implements rand.Int31n on the grpcrand global source.
+func Int31n(n int32) int32 {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Int31n(n)
+}
+
+// Float64 implements rand.Float64 on the grpcrand global source.
+func Float64() float64 {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Float64()
+}
+
+// Uint64 implements rand.Uint64 on the grpcrand global source.
+func Uint64() uint64 {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Uint64()
+}

vendor/google.golang.org/grpc/internal/grpcsync/event.go

@@ -0,0 +1,61 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package grpcsync implements additional synchronization primitives built upon
+// the sync package.
+package grpcsync
+
+import (
+	"sync"
+	"sync/atomic"
+)
+
+// Event represents a one-time event that may occur in the future.
+type Event struct {
+	fired int32
+	c     chan struct{}
+	o     sync.Once
+}
+
+// Fire causes e to complete.  It is safe to call multiple times, and
+// concurrently.  It returns true iff this call to Fire caused the signaling
+// channel returned by Done to close.
+func (e *Event) Fire() bool {
+	ret := false
+	e.o.Do(func() {
+		atomic.StoreInt32(&e.fired, 1)
+		close(e.c)
+		ret = true
+	})
+	return ret
+}
+
+// Done returns a channel that will be closed when Fire is called.
+func (e *Event) Done() <-chan struct{} {
+	return e.c
+}
+
+// HasFired returns true if Fire has been called.
+func (e *Event) HasFired() bool {
+	return atomic.LoadInt32(&e.fired) == 1
+}
+
+// NewEvent returns a new, ready-to-use Event.
+func NewEvent() *Event {
+	return &Event{c: make(chan struct{})}
+}

vendor/google.golang.org/grpc/internal/grpcsync/oncefunc.go

@@ -0,0 +1,32 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcsync
+
+import (
+	"sync"
+)
+
+// OnceFunc returns a function wrapping f which ensures f is only executed
+// once even if the returned function is executed multiple times.
+func OnceFunc(f func()) func() {
+	var once sync.Once
+	return func() {
+		once.Do(f)
+	}
+}

vendor/google.golang.org/grpc/internal/grpcutil/compressor.go

@@ -0,0 +1,47 @@
+/*
+ *
+ * Copyright 2022 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import (
+	"strings"
+
+	"google.golang.org/grpc/internal/envconfig"
+)
+
+// RegisteredCompressorNames holds names of the registered compressors.
+var RegisteredCompressorNames []string
+
+// IsCompressorNameRegistered returns true when name is available in registry.
+func IsCompressorNameRegistered(name string) bool {
+	for _, compressor := range RegisteredCompressorNames {
+		if compressor == name {
+			return true
+		}
+	}
+	return false
+}
+
+// RegisteredCompressors returns a string of registered compressor names
+// separated by comma.
+func RegisteredCompressors() string {
+	if !envconfig.AdvertiseCompressors {
+		return ""
+	}
+	return strings.Join(RegisteredCompressorNames, ",")
+}

vendor/google.golang.org/grpc/internal/grpcutil/encode_duration.go

@@ -0,0 +1,63 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import (
+	"strconv"
+	"time"
+)
+
+const maxTimeoutValue int64 = 100000000 - 1
+
+// div does integer division and round-up the result. Note that this is
+// equivalent to (d+r-1)/r but has less chance to overflow.
+func div(d, r time.Duration) int64 {
+	if d%r > 0 {
+		return int64(d/r + 1)
+	}
+	return int64(d / r)
+}
+
+// EncodeDuration encodes the duration to the format grpc-timeout header
+// accepts.
+//
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
+func EncodeDuration(t time.Duration) string {
+	// TODO: This is simplistic and not bandwidth efficient. Improve it.
+	if t <= 0 {
+		return "0n"
+	}
+	if d := div(t, time.Nanosecond); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "n"
+	}
+	if d := div(t, time.Microsecond); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "u"
+	}
+	if d := div(t, time.Millisecond); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "m"
+	}
+	if d := div(t, time.Second); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "S"
+	}
+	if d := div(t, time.Minute); d <= maxTimeoutValue {
+		return strconv.FormatInt(d, 10) + "M"
+	}
+	// Note that maxTimeoutValue * time.Hour > MaxInt64.
+	return strconv.FormatInt(div(t, time.Hour), 10) + "H"
+}

vendor/google.golang.org/grpc/internal/grpcutil/grpcutil.go

@@ -0,0 +1,20 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package grpcutil provides utility functions used across the gRPC codebase.
+package grpcutil

vendor/google.golang.org/grpc/internal/grpcutil/metadata.go

@@ -0,0 +1,40 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import (
+	"context"
+
+	"google.golang.org/grpc/metadata"
+)
+
+type mdExtraKey struct{}
+
+// WithExtraMetadata creates a new context with incoming md attached.
+func WithExtraMetadata(ctx context.Context, md metadata.MD) context.Context {
+	return context.WithValue(ctx, mdExtraKey{}, md)
+}
+
+// ExtraMetadata returns the incoming metadata in ctx if it exists.  The
+// returned MD should not be modified. Writing to it may cause races.
+// Modification should be made to copies of the returned MD.
+func ExtraMetadata(ctx context.Context) (md metadata.MD, ok bool) {
+	md, ok = ctx.Value(mdExtraKey{}).(metadata.MD)
+	return
+}

vendor/google.golang.org/grpc/internal/grpcutil/method.go

@@ -0,0 +1,88 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import (
+	"errors"
+	"strings"
+)
+
+// ParseMethod splits service and method from the input. It expects format
+// "/service/method".
+func ParseMethod(methodName string) (service, method string, _ error) {
+	if !strings.HasPrefix(methodName, "/") {
+		return "", "", errors.New("invalid method name: should start with /")
+	}
+	methodName = methodName[1:]
+
+	pos := strings.LastIndex(methodName, "/")
+	if pos < 0 {
+		return "", "", errors.New("invalid method name: suffix /method is missing")
+	}
+	return methodName[:pos], methodName[pos+1:], nil
+}
+
+// baseContentType is the base content-type for gRPC.  This is a valid
+// content-type on it's own, but can also include a content-subtype such as
+// "proto" as a suffix after "+" or ";".  See
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
+// for more details.
+const baseContentType = "application/grpc"
+
+// ContentSubtype returns the content-subtype for the given content-type.  The
+// given content-type must be a valid content-type that starts with
+// "application/grpc". A content-subtype will follow "application/grpc" after a
+// "+" or ";". See
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
+// more details.
+//
+// If contentType is not a valid content-type for gRPC, the boolean
+// will be false, otherwise true. If content-type == "application/grpc",
+// "application/grpc+", or "application/grpc;", the boolean will be true,
+// but no content-subtype will be returned.
+//
+// contentType is assumed to be lowercase already.
+func ContentSubtype(contentType string) (string, bool) {
+	if contentType == baseContentType {
+		return "", true
+	}
+	if !strings.HasPrefix(contentType, baseContentType) {
+		return "", false
+	}
+	// guaranteed since != baseContentType and has baseContentType prefix
+	switch contentType[len(baseContentType)] {
+	case '+', ';':
+		// this will return true for "application/grpc+" or "application/grpc;"
+		// which the previous validContentType function tested to be valid, so we
+		// just say that no content-subtype is specified in this case
+		return contentType[len(baseContentType)+1:], true
+	default:
+		return "", false
+	}
+}
+
+// ContentType builds full content type with the given sub-type.
+//
+// contentSubtype is assumed to be lowercase
+func ContentType(contentSubtype string) string {
+	if contentSubtype == "" {
+		return baseContentType
+	}
+	return baseContentType + "+" + contentSubtype
+}

vendor/google.golang.org/grpc/internal/grpcutil/regex.go

@@ -0,0 +1,31 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcutil
+
+import "regexp"
+
+// FullMatchWithRegex returns whether the full text matches the regex provided.
+func FullMatchWithRegex(re *regexp.Regexp, text string) bool {
+	if len(text) == 0 {
+		return re.MatchString(text)
+	}
+	re.Longest()
+	rem := re.FindString(text)
+	return len(rem) == len(text)
+}

vendor/google.golang.org/grpc/internal/internal.go

@@ -0,0 +1,160 @@
+/*
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package internal contains gRPC-internal code, to avoid polluting
+// the godoc of the top-level grpc package.  It must not import any grpc
+// symbols to avoid circular dependencies.
+package internal
+
+import (
+	"context"
+	"time"
+
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+var (
+	// WithHealthCheckFunc is set by dialoptions.go
+	WithHealthCheckFunc interface{} // func (HealthChecker) DialOption
+	// HealthCheckFunc is used to provide client-side LB channel health checking
+	HealthCheckFunc HealthChecker
+	// BalancerUnregister is exported by package balancer to unregister a balancer.
+	BalancerUnregister func(name string)
+	// KeepaliveMinPingTime is the minimum ping interval.  This must be 10s by
+	// default, but tests may wish to set it lower for convenience.
+	KeepaliveMinPingTime = 10 * time.Second
+	// ParseServiceConfig parses a JSON representation of the service config.
+	ParseServiceConfig interface{} // func(string) *serviceconfig.ParseResult
+	// EqualServiceConfigForTesting is for testing service config generation and
+	// parsing. Both a and b should be returned by ParseServiceConfig.
+	// This function compares the config without rawJSON stripped, in case the
+	// there's difference in white space.
+	EqualServiceConfigForTesting func(a, b serviceconfig.Config) bool
+	// GetCertificateProviderBuilder returns the registered builder for the
+	// given name. This is set by package certprovider for use from xDS
+	// bootstrap code while parsing certificate provider configs in the
+	// bootstrap file.
+	GetCertificateProviderBuilder interface{} // func(string) certprovider.Builder
+	// GetXDSHandshakeInfoForTesting returns a pointer to the xds.HandshakeInfo
+	// stored in the passed in attributes. This is set by
+	// credentials/xds/xds.go.
+	GetXDSHandshakeInfoForTesting interface{} // func (*attributes.Attributes) *xds.HandshakeInfo
+	// GetServerCredentials returns the transport credentials configured on a
+	// gRPC server. An xDS-enabled server needs to know what type of credentials
+	// is configured on the underlying gRPC server. This is set by server.go.
+	GetServerCredentials interface{} // func (*grpc.Server) credentials.TransportCredentials
+	// DrainServerTransports initiates a graceful close of existing connections
+	// on a gRPC server accepted on the provided listener address. An
+	// xDS-enabled server invokes this method on a grpc.Server when a particular
+	// listener moves to "not-serving" mode.
+	DrainServerTransports interface{} // func(*grpc.Server, string)
+	// AddGlobalServerOptions adds an array of ServerOption that will be
+	// effective globally for newly created servers. The priority will be: 1.
+	// user-provided; 2. this method; 3. default values.
+	AddGlobalServerOptions interface{} // func(opt ...ServerOption)
+	// ClearGlobalServerOptions clears the array of extra ServerOption. This
+	// method is useful in testing and benchmarking.
+	ClearGlobalServerOptions func()
+	// AddGlobalDialOptions adds an array of DialOption that will be effective
+	// globally for newly created client channels. The priority will be: 1.
+	// user-provided; 2. this method; 3. default values.
+	AddGlobalDialOptions interface{} // func(opt ...DialOption)
+	// ClearGlobalDialOptions clears the array of extra DialOption. This
+	// method is useful in testing and benchmarking.
+	ClearGlobalDialOptions func()
+	// JoinDialOptions combines the dial options passed as arguments into a
+	// single dial option.
+	JoinDialOptions interface{} // func(...grpc.DialOption) grpc.DialOption
+	// JoinServerOptions combines the server options passed as arguments into a
+	// single server option.
+	JoinServerOptions interface{} // func(...grpc.ServerOption) grpc.ServerOption
+
+	// WithBinaryLogger returns a DialOption that specifies the binary logger
+	// for a ClientConn.
+	WithBinaryLogger interface{} // func(binarylog.Logger) grpc.DialOption
+	// BinaryLogger returns a ServerOption that can set the binary logger for a
+	// server.
+	BinaryLogger interface{} // func(binarylog.Logger) grpc.ServerOption
+
+	// NewXDSResolverWithConfigForTesting creates a new xds resolver builder using
+	// the provided xds bootstrap config instead of the global configuration from
+	// the supported environment variables.  The resolver.Builder is meant to be
+	// used in conjunction with the grpc.WithResolvers DialOption.
+	//
+	// Testing Only
+	//
+	// This function should ONLY be used for testing and may not work with some
+	// other features, including the CSDS service.
+	NewXDSResolverWithConfigForTesting interface{} // func([]byte) (resolver.Builder, error)
+
+	// RegisterRLSClusterSpecifierPluginForTesting registers the RLS Cluster
+	// Specifier Plugin for testing purposes, regardless of the XDSRLS environment
+	// variable.
+	//
+	// TODO: Remove this function once the RLS env var is removed.
+	RegisterRLSClusterSpecifierPluginForTesting func()
+
+	// UnregisterRLSClusterSpecifierPluginForTesting unregisters the RLS Cluster
+	// Specifier Plugin for testing purposes. This is needed because there is no way
+	// to unregister the RLS Cluster Specifier Plugin after registering it solely
+	// for testing purposes using RegisterRLSClusterSpecifierPluginForTesting().
+	//
+	// TODO: Remove this function once the RLS env var is removed.
+	UnregisterRLSClusterSpecifierPluginForTesting func()
+
+	// RegisterRBACHTTPFilterForTesting registers the RBAC HTTP Filter for testing
+	// purposes, regardless of the RBAC environment variable.
+	//
+	// TODO: Remove this function once the RBAC env var is removed.
+	RegisterRBACHTTPFilterForTesting func()
+
+	// UnregisterRBACHTTPFilterForTesting unregisters the RBAC HTTP Filter for
+	// testing purposes. This is needed because there is no way to unregister the
+	// HTTP Filter after registering it solely for testing purposes using
+	// RegisterRBACHTTPFilterForTesting().
+	//
+	// TODO: Remove this function once the RBAC env var is removed.
+	UnregisterRBACHTTPFilterForTesting func()
+)
+
+// HealthChecker defines the signature of the client-side LB channel health checking function.
+//
+// The implementation is expected to create a health checking RPC stream by
+// calling newStream(), watch for the health status of serviceName, and report
+// it's health back by calling setConnectivityState().
+//
+// The health checking protocol is defined at:
+// https://github.com/grpc/grpc/blob/master/doc/health-checking.md
+type HealthChecker func(ctx context.Context, newStream func(string) (interface{}, error), setConnectivityState func(connectivity.State, error), serviceName string) error
+
+const (
+	// CredsBundleModeFallback switches GoogleDefaultCreds to fallback mode.
+	CredsBundleModeFallback = "fallback"
+	// CredsBundleModeBalancer switches GoogleDefaultCreds to grpclb balancer
+	// mode.
+	CredsBundleModeBalancer = "balancer"
+	// CredsBundleModeBackendFromBalancer switches GoogleDefaultCreds to mode
+	// that supports backend returned by grpclb balancer.
+	CredsBundleModeBackendFromBalancer = "backend-from-balancer"
+)
+
+// RLSLoadBalancingPolicyName is the name of the RLS LB policy.
+//
+// It currently has an experimental suffix which would be removed once
+// end-to-end testing of the policy is completed.
+const RLSLoadBalancingPolicyName = "rls_experimental"

vendor/google.golang.org/grpc/internal/metadata/metadata.go

@@ -0,0 +1,120 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package metadata contains functions to set and get metadata from addresses.
+//
+// This package is experimental.
+package metadata
+
+import (
+	"fmt"
+	"strings"
+
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/resolver"
+)
+
+type mdKeyType string
+
+const mdKey = mdKeyType("grpc.internal.address.metadata")
+
+type mdValue metadata.MD
+
+func (m mdValue) Equal(o interface{}) bool {
+	om, ok := o.(mdValue)
+	if !ok {
+		return false
+	}
+	if len(m) != len(om) {
+		return false
+	}
+	for k, v := range m {
+		ov := om[k]
+		if len(ov) != len(v) {
+			return false
+		}
+		for i, ve := range v {
+			if ov[i] != ve {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// Get returns the metadata of addr.
+func Get(addr resolver.Address) metadata.MD {
+	attrs := addr.Attributes
+	if attrs == nil {
+		return nil
+	}
+	md, _ := attrs.Value(mdKey).(mdValue)
+	return metadata.MD(md)
+}
+
+// Set sets (overrides) the metadata in addr.
+//
+// When a SubConn is created with this address, the RPCs sent on it will all
+// have this metadata.
+func Set(addr resolver.Address, md metadata.MD) resolver.Address {
+	addr.Attributes = addr.Attributes.WithValue(mdKey, mdValue(md))
+	return addr
+}
+
+// Validate returns an error if the input md contains invalid keys or values.
+//
+// If the header is not a pseudo-header, the following items are checked:
+// - header names must contain one or more characters from this set [0-9 a-z _ - .].
+// - if the header-name ends with a "-bin" suffix, no validation of the header value is performed.
+// - otherwise, the header value must contain one or more characters from the set [%x20-%x7E].
+func Validate(md metadata.MD) error {
+	for k, vals := range md {
+		// pseudo-header will be ignored
+		if k[0] == ':' {
+			continue
+		}
+		// check key, for i that saving a conversion if not using for range
+		for i := 0; i < len(k); i++ {
+			r := k[i]
+			if !(r >= 'a' && r <= 'z') && !(r >= '0' && r <= '9') && r != '.' && r != '-' && r != '_' {
+				return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", k)
+			}
+		}
+		if strings.HasSuffix(k, "-bin") {
+			continue
+		}
+		// check value
+		for _, val := range vals {
+			if hasNotPrintable(val) {
+				return fmt.Errorf("header key %q contains value with non-printable ASCII characters", k)
+			}
+		}
+	}
+	return nil
+}
+
+// hasNotPrintable return true if msg contains any characters which are not in %x20-%x7E
+func hasNotPrintable(msg string) bool {
+	// for i that saving a conversion if not using for range
+	for i := 0; i < len(msg); i++ {
+		if msg[i] < 0x20 || msg[i] > 0x7E {
+			return true
+		}
+	}
+	return false
+}

vendor/google.golang.org/grpc/internal/pretty/pretty.go

@@ -0,0 +1,82 @@
+/*
+ *
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package pretty defines helper functions to pretty-print structs for logging.
+package pretty
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+
+	"github.com/golang/protobuf/jsonpb"
+	protov1 "github.com/golang/protobuf/proto"
+	"google.golang.org/protobuf/encoding/protojson"
+	protov2 "google.golang.org/protobuf/proto"
+)
+
+const jsonIndent = "  "
+
+// ToJSON marshals the input into a json string.
+//
+// If marshal fails, it falls back to fmt.Sprintf("%+v").
+func ToJSON(e interface{}) string {
+	switch ee := e.(type) {
+	case protov1.Message:
+		mm := jsonpb.Marshaler{Indent: jsonIndent}
+		ret, err := mm.MarshalToString(ee)
+		if err != nil {
+			// This may fail for proto.Anys, e.g. for xDS v2, LDS, the v2
+			// messages are not imported, and this will fail because the message
+			// is not found.
+			return fmt.Sprintf("%+v", ee)
+		}
+		return ret
+	case protov2.Message:
+		mm := protojson.MarshalOptions{
+			Multiline: true,
+			Indent:    jsonIndent,
+		}
+		ret, err := mm.Marshal(ee)
+		if err != nil {
+			// This may fail for proto.Anys, e.g. for xDS v2, LDS, the v2
+			// messages are not imported, and this will fail because the message
+			// is not found.
+			return fmt.Sprintf("%+v", ee)
+		}
+		return string(ret)
+	default:
+		ret, err := json.MarshalIndent(ee, "", jsonIndent)
+		if err != nil {
+			return fmt.Sprintf("%+v", ee)
+		}
+		return string(ret)
+	}
+}
+
+// FormatJSON formats the input json bytes with indentation.
+//
+// If Indent fails, it returns the unchanged input as string.
+func FormatJSON(b []byte) string {
+	var out bytes.Buffer
+	err := json.Indent(&out, b, "", jsonIndent)
+	if err != nil {
+		return string(b)
+	}
+	return out.String()
+}

vendor/google.golang.org/grpc/internal/resolver/config_selector.go

@@ -0,0 +1,167 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package resolver provides internal resolver-related functionality.
+package resolver
+
+import (
+	"context"
+	"sync"
+
+	"google.golang.org/grpc/internal/serviceconfig"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/resolver"
+)
+
+// ConfigSelector controls what configuration to use for every RPC.
+type ConfigSelector interface {
+	// Selects the configuration for the RPC, or terminates it using the error.
+	// This error will be converted by the gRPC library to a status error with
+	// code UNKNOWN if it is not returned as a status error.
+	SelectConfig(RPCInfo) (*RPCConfig, error)
+}
+
+// RPCInfo contains RPC information needed by a ConfigSelector.
+type RPCInfo struct {
+	// Context is the user's context for the RPC and contains headers and
+	// application timeout.  It is passed for interception purposes and for
+	// efficiency reasons.  SelectConfig should not be blocking.
+	Context context.Context
+	Method  string // i.e. "/Service/Method"
+}
+
+// RPCConfig describes the configuration to use for each RPC.
+type RPCConfig struct {
+	// The context to use for the remainder of the RPC; can pass info to LB
+	// policy or affect timeout or metadata.
+	Context      context.Context
+	MethodConfig serviceconfig.MethodConfig // configuration to use for this RPC
+	OnCommitted  func()                     // Called when the RPC has been committed (retries no longer possible)
+	Interceptor  ClientInterceptor
+}
+
+// ClientStream is the same as grpc.ClientStream, but defined here for circular
+// dependency reasons.
+type ClientStream interface {
+	// Header returns the header metadata received from the server if there
+	// is any. It blocks if the metadata is not ready to read.
+	Header() (metadata.MD, error)
+	// Trailer returns the trailer metadata from the server, if there is any.
+	// It must only be called after stream.CloseAndRecv has returned, or
+	// stream.Recv has returned a non-nil error (including io.EOF).
+	Trailer() metadata.MD
+	// CloseSend closes the send direction of the stream. It closes the stream
+	// when non-nil error is met. It is also not safe to call CloseSend
+	// concurrently with SendMsg.
+	CloseSend() error
+	// Context returns the context for this stream.
+	//
+	// It should not be called until after Header or RecvMsg has returned. Once
+	// called, subsequent client-side retries are disabled.
+	Context() context.Context
+	// SendMsg is generally called by generated code. On error, SendMsg aborts
+	// the stream. If the error was generated by the client, the status is
+	// returned directly; otherwise, io.EOF is returned and the status of
+	// the stream may be discovered using RecvMsg.
+	//
+	// SendMsg blocks until:
+	//   - There is sufficient flow control to schedule m with the transport, or
+	//   - The stream is done, or
+	//   - The stream breaks.
+	//
+	// SendMsg does not wait until the message is received by the server. An
+	// untimely stream closure may result in lost messages. To ensure delivery,
+	// users should ensure the RPC completed successfully using RecvMsg.
+	//
+	// It is safe to have a goroutine calling SendMsg and another goroutine
+	// calling RecvMsg on the same stream at the same time, but it is not safe
+	// to call SendMsg on the same stream in different goroutines. It is also
+	// not safe to call CloseSend concurrently with SendMsg.
+	SendMsg(m interface{}) error
+	// RecvMsg blocks until it receives a message into m or the stream is
+	// done. It returns io.EOF when the stream completes successfully. On
+	// any other error, the stream is aborted and the error contains the RPC
+	// status.
+	//
+	// It is safe to have a goroutine calling SendMsg and another goroutine
+	// calling RecvMsg on the same stream at the same time, but it is not
+	// safe to call RecvMsg on the same stream in different goroutines.
+	RecvMsg(m interface{}) error
+}
+
+// ClientInterceptor is an interceptor for gRPC client streams.
+type ClientInterceptor interface {
+	// NewStream produces a ClientStream for an RPC which may optionally use
+	// the provided function to produce a stream for delegation.  Note:
+	// RPCInfo.Context should not be used (will be nil).
+	//
+	// done is invoked when the RPC is finished using its connection, or could
+	// not be assigned a connection.  RPC operations may still occur on
+	// ClientStream after done is called, since the interceptor is invoked by
+	// application-layer operations.  done must never be nil when called.
+	NewStream(ctx context.Context, ri RPCInfo, done func(), newStream func(ctx context.Context, done func()) (ClientStream, error)) (ClientStream, error)
+}
+
+// ServerInterceptor is an interceptor for incoming RPC's on gRPC server side.
+type ServerInterceptor interface {
+	// AllowRPC checks if an incoming RPC is allowed to proceed based on
+	// information about connection RPC was received on, and HTTP Headers. This
+	// information will be piped into context.
+	AllowRPC(ctx context.Context) error // TODO: Make this a real interceptor for filters such as rate limiting.
+}
+
+type csKeyType string
+
+const csKey = csKeyType("grpc.internal.resolver.configSelector")
+
+// SetConfigSelector sets the config selector in state and returns the new
+// state.
+func SetConfigSelector(state resolver.State, cs ConfigSelector) resolver.State {
+	state.Attributes = state.Attributes.WithValue(csKey, cs)
+	return state
+}
+
+// GetConfigSelector retrieves the config selector from state, if present, and
+// returns it or nil if absent.
+func GetConfigSelector(state resolver.State) ConfigSelector {
+	cs, _ := state.Attributes.Value(csKey).(ConfigSelector)
+	return cs
+}
+
+// SafeConfigSelector allows for safe switching of ConfigSelector
+// implementations such that previous values are guaranteed to not be in use
+// when UpdateConfigSelector returns.
+type SafeConfigSelector struct {
+	mu sync.RWMutex
+	cs ConfigSelector
+}
+
+// UpdateConfigSelector swaps to the provided ConfigSelector and blocks until
+// all uses of the previous ConfigSelector have completed.
+func (scs *SafeConfigSelector) UpdateConfigSelector(cs ConfigSelector) {
+	scs.mu.Lock()
+	defer scs.mu.Unlock()
+	scs.cs = cs
+}
+
+// SelectConfig defers to the current ConfigSelector in scs.
+func (scs *SafeConfigSelector) SelectConfig(r RPCInfo) (*RPCConfig, error) {
+	scs.mu.RLock()
+	defer scs.mu.RUnlock()
+	return scs.cs.SelectConfig(r)
+}

vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go

@@ -0,0 +1,458 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package dns implements a dns resolver to be installed as the default resolver
+// in grpc.
+package dns
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	grpclbstate "google.golang.org/grpc/balancer/grpclb/state"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal/backoff"
+	"google.golang.org/grpc/internal/envconfig"
+	"google.golang.org/grpc/internal/grpcrand"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+// EnableSRVLookups controls whether the DNS resolver attempts to fetch gRPCLB
+// addresses from SRV records.  Must not be changed after init time.
+var EnableSRVLookups = false
+
+var logger = grpclog.Component("dns")
+
+// Globals to stub out in tests. TODO: Perhaps these two can be combined into a
+// single variable for testing the resolver?
+var (
+	newTimer           = time.NewTimer
+	newTimerDNSResRate = time.NewTimer
+)
+
+func init() {
+	resolver.Register(NewBuilder())
+}
+
+const (
+	defaultPort       = "443"
+	defaultDNSSvrPort = "53"
+	golang            = "GO"
+	// txtPrefix is the prefix string to be prepended to the host name for txt record lookup.
+	txtPrefix = "_grpc_config."
+	// In DNS, service config is encoded in a TXT record via the mechanism
+	// described in RFC-1464 using the attribute name grpc_config.
+	txtAttribute = "grpc_config="
+)
+
+var (
+	errMissingAddr = errors.New("dns resolver: missing address")
+
+	// Addresses ending with a colon that is supposed to be the separator
+	// between host and port is not allowed.  E.g. "::" is a valid address as
+	// it is an IPv6 address (host only) and "[::]:" is invalid as it ends with
+	// a colon as the host and port separator
+	errEndsWithColon = errors.New("dns resolver: missing port after port-separator colon")
+)
+
+var (
+	defaultResolver netResolver = net.DefaultResolver
+	// To prevent excessive re-resolution, we enforce a rate limit on DNS
+	// resolution requests.
+	minDNSResRate = 30 * time.Second
+)
+
+var customAuthorityDialler = func(authority string) func(ctx context.Context, network, address string) (net.Conn, error) {
+	return func(ctx context.Context, network, address string) (net.Conn, error) {
+		var dialer net.Dialer
+		return dialer.DialContext(ctx, network, authority)
+	}
+}
+
+var customAuthorityResolver = func(authority string) (netResolver, error) {
+	host, port, err := parseTarget(authority, defaultDNSSvrPort)
+	if err != nil {
+		return nil, err
+	}
+
+	authorityWithPort := net.JoinHostPort(host, port)
+
+	return &net.Resolver{
+		PreferGo: true,
+		Dial:     customAuthorityDialler(authorityWithPort),
+	}, nil
+}
+
+// NewBuilder creates a dnsBuilder which is used to factory DNS resolvers.
+func NewBuilder() resolver.Builder {
+	return &dnsBuilder{}
+}
+
+type dnsBuilder struct{}
+
+// Build creates and starts a DNS resolver that watches the name resolution of the target.
+func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+	host, port, err := parseTarget(target.Endpoint(), defaultPort)
+	if err != nil {
+		return nil, err
+	}
+
+	// IP address.
+	if ipAddr, ok := formatIP(host); ok {
+		addr := []resolver.Address{{Addr: ipAddr + ":" + port}}
+		cc.UpdateState(resolver.State{Addresses: addr})
+		return deadResolver{}, nil
+	}
+
+	// DNS address (non-IP).
+	ctx, cancel := context.WithCancel(context.Background())
+	d := &dnsResolver{
+		host:                 host,
+		port:                 port,
+		ctx:                  ctx,
+		cancel:               cancel,
+		cc:                   cc,
+		rn:                   make(chan struct{}, 1),
+		disableServiceConfig: opts.DisableServiceConfig,
+	}
+
+	if target.URL.Host == "" {
+		d.resolver = defaultResolver
+	} else {
+		d.resolver, err = customAuthorityResolver(target.URL.Host)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	d.wg.Add(1)
+	go d.watcher()
+	return d, nil
+}
+
+// Scheme returns the naming scheme of this resolver builder, which is "dns".
+func (b *dnsBuilder) Scheme() string {
+	return "dns"
+}
+
+type netResolver interface {
+	LookupHost(ctx context.Context, host string) (addrs []string, err error)
+	LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error)
+	LookupTXT(ctx context.Context, name string) (txts []string, err error)
+}
+
+// deadResolver is a resolver that does nothing.
+type deadResolver struct{}
+
+func (deadResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (deadResolver) Close() {}
+
+// dnsResolver watches for the name resolution update for a non-IP target.
+type dnsResolver struct {
+	host     string
+	port     string
+	resolver netResolver
+	ctx      context.Context
+	cancel   context.CancelFunc
+	cc       resolver.ClientConn
+	// rn channel is used by ResolveNow() to force an immediate resolution of the target.
+	rn chan struct{}
+	// wg is used to enforce Close() to return after the watcher() goroutine has finished.
+	// Otherwise, data race will be possible. [Race Example] in dns_resolver_test we
+	// replace the real lookup functions with mocked ones to facilitate testing.
+	// If Close() doesn't wait for watcher() goroutine finishes, race detector sometimes
+	// will warns lookup (READ the lookup function pointers) inside watcher() goroutine
+	// has data race with replaceNetFunc (WRITE the lookup function pointers).
+	wg                   sync.WaitGroup
+	disableServiceConfig bool
+}
+
+// ResolveNow invoke an immediate resolution of the target that this dnsResolver watches.
+func (d *dnsResolver) ResolveNow(resolver.ResolveNowOptions) {
+	select {
+	case d.rn <- struct{}{}:
+	default:
+	}
+}
+
+// Close closes the dnsResolver.
+func (d *dnsResolver) Close() {
+	d.cancel()
+	d.wg.Wait()
+}
+
+func (d *dnsResolver) watcher() {
+	defer d.wg.Done()
+	backoffIndex := 1
+	for {
+		state, err := d.lookup()
+		if err != nil {
+			// Report error to the underlying grpc.ClientConn.
+			d.cc.ReportError(err)
+		} else {
+			err = d.cc.UpdateState(*state)
+		}
+
+		var timer *time.Timer
+		if err == nil {
+			// Success resolving, wait for the next ResolveNow. However, also wait 30 seconds at the very least
+			// to prevent constantly re-resolving.
+			backoffIndex = 1
+			timer = newTimerDNSResRate(minDNSResRate)
+			select {
+			case <-d.ctx.Done():
+				timer.Stop()
+				return
+			case <-d.rn:
+			}
+		} else {
+			// Poll on an error found in DNS Resolver or an error received from ClientConn.
+			timer = newTimer(backoff.DefaultExponential.Backoff(backoffIndex))
+			backoffIndex++
+		}
+		select {
+		case <-d.ctx.Done():
+			timer.Stop()
+			return
+		case <-timer.C:
+		}
+	}
+}
+
+func (d *dnsResolver) lookupSRV() ([]resolver.Address, error) {
+	if !EnableSRVLookups {
+		return nil, nil
+	}
+	var newAddrs []resolver.Address
+	_, srvs, err := d.resolver.LookupSRV(d.ctx, "grpclb", "tcp", d.host)
+	if err != nil {
+		err = handleDNSError(err, "SRV") // may become nil
+		return nil, err
+	}
+	for _, s := range srvs {
+		lbAddrs, err := d.resolver.LookupHost(d.ctx, s.Target)
+		if err != nil {
+			err = handleDNSError(err, "A") // may become nil
+			if err == nil {
+				// If there are other SRV records, look them up and ignore this
+				// one that does not exist.
+				continue
+			}
+			return nil, err
+		}
+		for _, a := range lbAddrs {
+			ip, ok := formatIP(a)
+			if !ok {
+				return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+			}
+			addr := ip + ":" + strconv.Itoa(int(s.Port))
+			newAddrs = append(newAddrs, resolver.Address{Addr: addr, ServerName: s.Target})
+		}
+	}
+	return newAddrs, nil
+}
+
+func handleDNSError(err error, lookupType string) error {
+	if dnsErr, ok := err.(*net.DNSError); ok && !dnsErr.IsTimeout && !dnsErr.IsTemporary {
+		// Timeouts and temporary errors should be communicated to gRPC to
+		// attempt another DNS query (with backoff).  Other errors should be
+		// suppressed (they may represent the absence of a TXT record).
+		return nil
+	}
+	if err != nil {
+		err = fmt.Errorf("dns: %v record lookup error: %v", lookupType, err)
+		logger.Info(err)
+	}
+	return err
+}
+
+func (d *dnsResolver) lookupTXT() *serviceconfig.ParseResult {
+	ss, err := d.resolver.LookupTXT(d.ctx, txtPrefix+d.host)
+	if err != nil {
+		if envconfig.TXTErrIgnore {
+			return nil
+		}
+		if err = handleDNSError(err, "TXT"); err != nil {
+			return &serviceconfig.ParseResult{Err: err}
+		}
+		return nil
+	}
+	var res string
+	for _, s := range ss {
+		res += s
+	}
+
+	// TXT record must have "grpc_config=" attribute in order to be used as service config.
+	if !strings.HasPrefix(res, txtAttribute) {
+		logger.Warningf("dns: TXT record %v missing %v attribute", res, txtAttribute)
+		// This is not an error; it is the equivalent of not having a service config.
+		return nil
+	}
+	sc := canaryingSC(strings.TrimPrefix(res, txtAttribute))
+	return d.cc.ParseServiceConfig(sc)
+}
+
+func (d *dnsResolver) lookupHost() ([]resolver.Address, error) {
+	addrs, err := d.resolver.LookupHost(d.ctx, d.host)
+	if err != nil {
+		err = handleDNSError(err, "A")
+		return nil, err
+	}
+	newAddrs := make([]resolver.Address, 0, len(addrs))
+	for _, a := range addrs {
+		ip, ok := formatIP(a)
+		if !ok {
+			return nil, fmt.Errorf("dns: error parsing A record IP address %v", a)
+		}
+		addr := ip + ":" + d.port
+		newAddrs = append(newAddrs, resolver.Address{Addr: addr})
+	}
+	return newAddrs, nil
+}
+
+func (d *dnsResolver) lookup() (*resolver.State, error) {
+	srv, srvErr := d.lookupSRV()
+	addrs, hostErr := d.lookupHost()
+	if hostErr != nil && (srvErr != nil || len(srv) == 0) {
+		return nil, hostErr
+	}
+
+	state := resolver.State{Addresses: addrs}
+	if len(srv) > 0 {
+		state = grpclbstate.Set(state, &grpclbstate.State{BalancerAddresses: srv})
+	}
+	if !d.disableServiceConfig {
+		state.ServiceConfig = d.lookupTXT()
+	}
+	return &state, nil
+}
+
+// formatIP returns ok = false if addr is not a valid textual representation of an IP address.
+// If addr is an IPv4 address, return the addr and ok = true.
+// If addr is an IPv6 address, return the addr enclosed in square brackets and ok = true.
+func formatIP(addr string) (addrIP string, ok bool) {
+	ip := net.ParseIP(addr)
+	if ip == nil {
+		return "", false
+	}
+	if ip.To4() != nil {
+		return addr, true
+	}
+	return "[" + addr + "]", true
+}
+
+// parseTarget takes the user input target string and default port, returns formatted host and port info.
+// If target doesn't specify a port, set the port to be the defaultPort.
+// If target is in IPv6 format and host-name is enclosed in square brackets, brackets
+// are stripped when setting the host.
+// examples:
+// target: "www.google.com" defaultPort: "443" returns host: "www.google.com", port: "443"
+// target: "ipv4-host:80" defaultPort: "443" returns host: "ipv4-host", port: "80"
+// target: "[ipv6-host]" defaultPort: "443" returns host: "ipv6-host", port: "443"
+// target: ":80" defaultPort: "443" returns host: "localhost", port: "80"
+func parseTarget(target, defaultPort string) (host, port string, err error) {
+	if target == "" {
+		return "", "", errMissingAddr
+	}
+	if ip := net.ParseIP(target); ip != nil {
+		// target is an IPv4 or IPv6(without brackets) address
+		return target, defaultPort, nil
+	}
+	if host, port, err = net.SplitHostPort(target); err == nil {
+		if port == "" {
+			// If the port field is empty (target ends with colon), e.g. "[::1]:", this is an error.
+			return "", "", errEndsWithColon
+		}
+		// target has port, i.e ipv4-host:port, [ipv6-host]:port, host-name:port
+		if host == "" {
+			// Keep consistent with net.Dial(): If the host is empty, as in ":80", the local system is assumed.
+			host = "localhost"
+		}
+		return host, port, nil
+	}
+	if host, port, err = net.SplitHostPort(target + ":" + defaultPort); err == nil {
+		// target doesn't have port
+		return host, port, nil
+	}
+	return "", "", fmt.Errorf("invalid target address %v, error info: %v", target, err)
+}
+
+type rawChoice struct {
+	ClientLanguage *[]string        `json:"clientLanguage,omitempty"`
+	Percentage     *int             `json:"percentage,omitempty"`
+	ClientHostName *[]string        `json:"clientHostName,omitempty"`
+	ServiceConfig  *json.RawMessage `json:"serviceConfig,omitempty"`
+}
+
+func containsString(a *[]string, b string) bool {
+	if a == nil {
+		return true
+	}
+	for _, c := range *a {
+		if c == b {
+			return true
+		}
+	}
+	return false
+}
+
+func chosenByPercentage(a *int) bool {
+	if a == nil {
+		return true
+	}
+	return grpcrand.Intn(100)+1 <= *a
+}
+
+func canaryingSC(js string) string {
+	if js == "" {
+		return ""
+	}
+	var rcs []rawChoice
+	err := json.Unmarshal([]byte(js), &rcs)
+	if err != nil {
+		logger.Warningf("dns: error parsing service config json: %v", err)
+		return ""
+	}
+	cliHostname, err := os.Hostname()
+	if err != nil {
+		logger.Warningf("dns: error getting client hostname: %v", err)
+		return ""
+	}
+	var sc string
+	for _, c := range rcs {
+		if !containsString(c.ClientLanguage, golang) ||
+			!chosenByPercentage(c.Percentage) ||
+			!containsString(c.ClientHostName, cliHostname) ||
+			c.ServiceConfig == nil {
+			continue
+		}
+		sc = string(*c.ServiceConfig)
+		break
+	}
+	return sc
+}

vendor/google.golang.org/grpc/internal/resolver/passthrough/passthrough.go

@@ -0,0 +1,64 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package passthrough implements a pass-through resolver. It sends the target
+// name without scheme back to gRPC as resolved address.
+package passthrough
+
+import (
+	"errors"
+
+	"google.golang.org/grpc/resolver"
+)
+
+const scheme = "passthrough"
+
+type passthroughBuilder struct{}
+
+func (*passthroughBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+	if target.Endpoint() == "" && opts.Dialer == nil {
+		return nil, errors.New("passthrough: received empty target in Build()")
+	}
+	r := &passthroughResolver{
+		target: target,
+		cc:     cc,
+	}
+	r.start()
+	return r, nil
+}
+
+func (*passthroughBuilder) Scheme() string {
+	return scheme
+}
+
+type passthroughResolver struct {
+	target resolver.Target
+	cc     resolver.ClientConn
+}
+
+func (r *passthroughResolver) start() {
+	r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint()}}})
+}
+
+func (*passthroughResolver) ResolveNow(o resolver.ResolveNowOptions) {}
+
+func (*passthroughResolver) Close() {}
+
+func init() {
+	resolver.Register(&passthroughBuilder{})
+}

vendor/google.golang.org/grpc/internal/resolver/unix/unix.go

@@ -0,0 +1,74 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package unix implements a resolver for unix targets.
+package unix
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/internal/transport/networktype"
+	"google.golang.org/grpc/resolver"
+)
+
+const unixScheme = "unix"
+const unixAbstractScheme = "unix-abstract"
+
+type builder struct {
+	scheme string
+}
+
+func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) {
+	if target.URL.Host != "" {
+		return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.URL.Host)
+	}
+
+	// gRPC was parsing the dial target manually before PR #4817, and we
+	// switched to using url.Parse() in that PR. To avoid breaking existing
+	// resolver implementations we ended up stripping the leading "/" from the
+	// endpoint. This obviously does not work for the "unix" scheme. Hence we
+	// end up using the parsed URL instead.
+	endpoint := target.URL.Path
+	if endpoint == "" {
+		endpoint = target.URL.Opaque
+	}
+	addr := resolver.Address{Addr: endpoint}
+	if b.scheme == unixAbstractScheme {
+		// We can not prepend \0 as c++ gRPC does, as in Golang '@' is used to signify we do
+		// not want trailing \0 in address.
+		addr.Addr = "@" + addr.Addr
+	}
+	cc.UpdateState(resolver.State{Addresses: []resolver.Address{networktype.Set(addr, "unix")}})
+	return &nopResolver{}, nil
+}
+
+func (b *builder) Scheme() string {
+	return b.scheme
+}
+
+type nopResolver struct {
+}
+
+func (*nopResolver) ResolveNow(resolver.ResolveNowOptions) {}
+
+func (*nopResolver) Close() {}
+
+func init() {
+	resolver.Register(&builder{scheme: unixScheme})
+	resolver.Register(&builder{scheme: unixAbstractScheme})
+}

vendor/google.golang.org/grpc/internal/serviceconfig/serviceconfig.go

@@ -0,0 +1,180 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package serviceconfig contains utility functions to parse service config.
+package serviceconfig
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"google.golang.org/grpc/balancer"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	externalserviceconfig "google.golang.org/grpc/serviceconfig"
+)
+
+var logger = grpclog.Component("core")
+
+// BalancerConfig wraps the name and config associated with one load balancing
+// policy. It corresponds to a single entry of the loadBalancingConfig field
+// from ServiceConfig.
+//
+// It implements the json.Unmarshaler interface.
+//
+// https://github.com/grpc/grpc-proto/blob/54713b1e8bc6ed2d4f25fb4dff527842150b91b2/grpc/service_config/service_config.proto#L247
+type BalancerConfig struct {
+	Name   string
+	Config externalserviceconfig.LoadBalancingConfig
+}
+
+type intermediateBalancerConfig []map[string]json.RawMessage
+
+// MarshalJSON implements the json.Marshaler interface.
+//
+// It marshals the balancer and config into a length-1 slice
+// ([]map[string]config).
+func (bc *BalancerConfig) MarshalJSON() ([]byte, error) {
+	if bc.Config == nil {
+		// If config is nil, return empty config `{}`.
+		return []byte(fmt.Sprintf(`[{%q: %v}]`, bc.Name, "{}")), nil
+	}
+	c, err := json.Marshal(bc.Config)
+	if err != nil {
+		return nil, err
+	}
+	return []byte(fmt.Sprintf(`[{%q: %s}]`, bc.Name, c)), nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+//
+// ServiceConfig contains a list of loadBalancingConfigs, each with a name and
+// config. This method iterates through that list in order, and stops at the
+// first policy that is supported.
+//   - If the config for the first supported policy is invalid, the whole service
+//     config is invalid.
+//   - If the list doesn't contain any supported policy, the whole service config
+//     is invalid.
+func (bc *BalancerConfig) UnmarshalJSON(b []byte) error {
+	var ir intermediateBalancerConfig
+	err := json.Unmarshal(b, &ir)
+	if err != nil {
+		return err
+	}
+
+	var names []string
+	for i, lbcfg := range ir {
+		if len(lbcfg) != 1 {
+			return fmt.Errorf("invalid loadBalancingConfig: entry %v does not contain exactly 1 policy/config pair: %q", i, lbcfg)
+		}
+
+		var (
+			name    string
+			jsonCfg json.RawMessage
+		)
+		// Get the key:value pair from the map. We have already made sure that
+		// the map contains a single entry.
+		for name, jsonCfg = range lbcfg {
+		}
+
+		names = append(names, name)
+		builder := balancer.Get(name)
+		if builder == nil {
+			// If the balancer is not registered, move on to the next config.
+			// This is not an error.
+			continue
+		}
+		bc.Name = name
+
+		parser, ok := builder.(balancer.ConfigParser)
+		if !ok {
+			if string(jsonCfg) != "{}" {
+				logger.Warningf("non-empty balancer configuration %q, but balancer does not implement ParseConfig", string(jsonCfg))
+			}
+			// Stop at this, though the builder doesn't support parsing config.
+			return nil
+		}
+
+		cfg, err := parser.ParseConfig(jsonCfg)
+		if err != nil {
+			return fmt.Errorf("error parsing loadBalancingConfig for policy %q: %v", name, err)
+		}
+		bc.Config = cfg
+		return nil
+	}
+	// This is reached when the for loop iterates over all entries, but didn't
+	// return. This means we had a loadBalancingConfig slice but did not
+	// encounter a registered policy. The config is considered invalid in this
+	// case.
+	return fmt.Errorf("invalid loadBalancingConfig: no supported policies found in %v", names)
+}
+
+// MethodConfig defines the configuration recommended by the service providers for a
+// particular method.
+type MethodConfig struct {
+	// WaitForReady indicates whether RPCs sent to this method should wait until
+	// the connection is ready by default (!failfast). The value specified via the
+	// gRPC client API will override the value set here.
+	WaitForReady *bool
+	// Timeout is the default timeout for RPCs sent to this method. The actual
+	// deadline used will be the minimum of the value specified here and the value
+	// set by the application via the gRPC client API.  If either one is not set,
+	// then the other will be used.  If neither is set, then the RPC has no deadline.
+	Timeout *time.Duration
+	// MaxReqSize is the maximum allowed payload size for an individual request in a
+	// stream (client->server) in bytes. The size which is measured is the serialized
+	// payload after per-message compression (but before stream compression) in bytes.
+	// The actual value used is the minimum of the value specified here and the value set
+	// by the application via the gRPC client API. If either one is not set, then the other
+	// will be used.  If neither is set, then the built-in default is used.
+	MaxReqSize *int
+	// MaxRespSize is the maximum allowed payload size for an individual response in a
+	// stream (server->client) in bytes.
+	MaxRespSize *int
+	// RetryPolicy configures retry options for the method.
+	RetryPolicy *RetryPolicy
+}
+
+// RetryPolicy defines the go-native version of the retry policy defined by the
+// service config here:
+// https://github.com/grpc/proposal/blob/master/A6-client-retries.md#integration-with-service-config
+type RetryPolicy struct {
+	// MaxAttempts is the maximum number of attempts, including the original RPC.
+	//
+	// This field is required and must be two or greater.
+	MaxAttempts int
+
+	// Exponential backoff parameters. The initial retry attempt will occur at
+	// random(0, initialBackoff). In general, the nth attempt will occur at
+	// random(0,
+	//   min(initialBackoff*backoffMultiplier**(n-1), maxBackoff)).
+	//
+	// These fields are required and must be greater than zero.
+	InitialBackoff    time.Duration
+	MaxBackoff        time.Duration
+	BackoffMultiplier float64
+
+	// The set of status codes which may be retried.
+	//
+	// Status codes are specified as strings, e.g., "UNAVAILABLE".
+	//
+	// This field is required and must be non-empty.
+	// Note: a set is used to store this for easy lookup.
+	RetryableStatusCodes map[codes.Code]bool
+}

vendor/google.golang.org/grpc/internal/status/status.go

@@ -0,0 +1,176 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package status implements errors returned by gRPC.  These errors are
+// serialized and transmitted on the wire between server and client, and allow
+// for additional data to be transmitted via the Details field in the status
+// proto.  gRPC service handlers should return an error created by this
+// package, and gRPC clients should expect a corresponding error to be
+// returned from the RPC call.
+//
+// This package upholds the invariants that a non-nil error may not
+// contain an OK code, and an OK code must result in a nil error.
+package status
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes"
+	spb "google.golang.org/genproto/googleapis/rpc/status"
+	"google.golang.org/grpc/codes"
+)
+
+// Status represents an RPC status code, message, and details.  It is immutable
+// and should be created with New, Newf, or FromProto.
+type Status struct {
+	s *spb.Status
+}
+
+// New returns a Status representing c and msg.
+func New(c codes.Code, msg string) *Status {
+	return &Status{s: &spb.Status{Code: int32(c), Message: msg}}
+}
+
+// Newf returns New(c, fmt.Sprintf(format, a...)).
+func Newf(c codes.Code, format string, a ...interface{}) *Status {
+	return New(c, fmt.Sprintf(format, a...))
+}
+
+// FromProto returns a Status representing s.
+func FromProto(s *spb.Status) *Status {
+	return &Status{s: proto.Clone(s).(*spb.Status)}
+}
+
+// Err returns an error representing c and msg.  If c is OK, returns nil.
+func Err(c codes.Code, msg string) error {
+	return New(c, msg).Err()
+}
+
+// Errorf returns Error(c, fmt.Sprintf(format, a...)).
+func Errorf(c codes.Code, format string, a ...interface{}) error {
+	return Err(c, fmt.Sprintf(format, a...))
+}
+
+// Code returns the status code contained in s.
+func (s *Status) Code() codes.Code {
+	if s == nil || s.s == nil {
+		return codes.OK
+	}
+	return codes.Code(s.s.Code)
+}
+
+// Message returns the message contained in s.
+func (s *Status) Message() string {
+	if s == nil || s.s == nil {
+		return ""
+	}
+	return s.s.Message
+}
+
+// Proto returns s's status as an spb.Status proto message.
+func (s *Status) Proto() *spb.Status {
+	if s == nil {
+		return nil
+	}
+	return proto.Clone(s.s).(*spb.Status)
+}
+
+// Err returns an immutable error representing s; returns nil if s.Code() is OK.
+func (s *Status) Err() error {
+	if s.Code() == codes.OK {
+		return nil
+	}
+	return &Error{s: s}
+}
+
+// WithDetails returns a new status with the provided details messages appended to the status.
+// If any errors are encountered, it returns nil and the first error encountered.
+func (s *Status) WithDetails(details ...proto.Message) (*Status, error) {
+	if s.Code() == codes.OK {
+		return nil, errors.New("no error details for status with code OK")
+	}
+	// s.Code() != OK implies that s.Proto() != nil.
+	p := s.Proto()
+	for _, detail := range details {
+		any, err := ptypes.MarshalAny(detail)
+		if err != nil {
+			return nil, err
+		}
+		p.Details = append(p.Details, any)
+	}
+	return &Status{s: p}, nil
+}
+
+// Details returns a slice of details messages attached to the status.
+// If a detail cannot be decoded, the error is returned in place of the detail.
+func (s *Status) Details() []interface{} {
+	if s == nil || s.s == nil {
+		return nil
+	}
+	details := make([]interface{}, 0, len(s.s.Details))
+	for _, any := range s.s.Details {
+		detail := &ptypes.DynamicAny{}
+		if err := ptypes.UnmarshalAny(any, detail); err != nil {
+			details = append(details, err)
+			continue
+		}
+		details = append(details, detail.Message)
+	}
+	return details
+}
+
+func (s *Status) String() string {
+	return fmt.Sprintf("rpc error: code = %s desc = %s", s.Code(), s.Message())
+}
+
+// Error wraps a pointer of a status proto. It implements error and Status,
+// and a nil *Error should never be returned by this package.
+type Error struct {
+	s *Status
+}
+
+func (e *Error) Error() string {
+	return e.s.String()
+}
+
+// GRPCStatus returns the Status represented by se.
+func (e *Error) GRPCStatus() *Status {
+	return e.s
+}
+
+// Is implements future error.Is functionality.
+// A Error is equivalent if the code and message are identical.
+func (e *Error) Is(target error) bool {
+	tse, ok := target.(*Error)
+	if !ok {
+		return false
+	}
+	return proto.Equal(e.s.s, tse.s.s)
+}
+
+// IsRestrictedControlPlaneCode returns whether the status includes a code
+// restricted for control plane usage as defined by gRFC A54.
+func IsRestrictedControlPlaneCode(s *Status) bool {
+	switch s.Code() {
+	case codes.InvalidArgument, codes.NotFound, codes.AlreadyExists, codes.FailedPrecondition, codes.Aborted, codes.OutOfRange, codes.DataLoss:
+		return true
+	}
+	return false
+}

vendor/google.golang.org/grpc/internal/syscall/syscall_linux.go

@@ -0,0 +1,112 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package syscall provides functionalities that grpc uses to get low-level operating system
+// stats/info.
+package syscall
+
+import (
+	"fmt"
+	"net"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/unix"
+	"google.golang.org/grpc/grpclog"
+)
+
+var logger = grpclog.Component("core")
+
+// GetCPUTime returns the how much CPU time has passed since the start of this process.
+func GetCPUTime() int64 {
+	var ts unix.Timespec
+	if err := unix.ClockGettime(unix.CLOCK_PROCESS_CPUTIME_ID, &ts); err != nil {
+		logger.Fatal(err)
+	}
+	return ts.Nano()
+}
+
+// Rusage is an alias for syscall.Rusage under linux environment.
+type Rusage = syscall.Rusage
+
+// GetRusage returns the resource usage of current process.
+func GetRusage() *Rusage {
+	rusage := new(Rusage)
+	syscall.Getrusage(syscall.RUSAGE_SELF, rusage)
+	return rusage
+}
+
+// CPUTimeDiff returns the differences of user CPU time and system CPU time used
+// between two Rusage structs.
+func CPUTimeDiff(first *Rusage, latest *Rusage) (float64, float64) {
+	var (
+		utimeDiffs  = latest.Utime.Sec - first.Utime.Sec
+		utimeDiffus = latest.Utime.Usec - first.Utime.Usec
+		stimeDiffs  = latest.Stime.Sec - first.Stime.Sec
+		stimeDiffus = latest.Stime.Usec - first.Stime.Usec
+	)
+
+	uTimeElapsed := float64(utimeDiffs) + float64(utimeDiffus)*1.0e-6
+	sTimeElapsed := float64(stimeDiffs) + float64(stimeDiffus)*1.0e-6
+
+	return uTimeElapsed, sTimeElapsed
+}
+
+// SetTCPUserTimeout sets the TCP user timeout on a connection's socket
+func SetTCPUserTimeout(conn net.Conn, timeout time.Duration) error {
+	tcpconn, ok := conn.(*net.TCPConn)
+	if !ok {
+		// not a TCP connection. exit early
+		return nil
+	}
+	rawConn, err := tcpconn.SyscallConn()
+	if err != nil {
+		return fmt.Errorf("error getting raw connection: %v", err)
+	}
+	err = rawConn.Control(func(fd uintptr) {
+		err = syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, unix.TCP_USER_TIMEOUT, int(timeout/time.Millisecond))
+	})
+	if err != nil {
+		return fmt.Errorf("error setting option on socket: %v", err)
+	}
+
+	return nil
+}
+
+// GetTCPUserTimeout gets the TCP user timeout on a connection's socket
+func GetTCPUserTimeout(conn net.Conn) (opt int, err error) {
+	tcpconn, ok := conn.(*net.TCPConn)
+	if !ok {
+		err = fmt.Errorf("conn is not *net.TCPConn. got %T", conn)
+		return
+	}
+	rawConn, err := tcpconn.SyscallConn()
+	if err != nil {
+		err = fmt.Errorf("error getting raw connection: %v", err)
+		return
+	}
+	err = rawConn.Control(func(fd uintptr) {
+		opt, err = syscall.GetsockoptInt(int(fd), syscall.IPPROTO_TCP, unix.TCP_USER_TIMEOUT)
+	})
+	if err != nil {
+		err = fmt.Errorf("error getting option on socket: %v", err)
+		return
+	}
+
+	return
+}

vendor/google.golang.org/grpc/internal/syscall/syscall_nonlinux.go

@@ -0,0 +1,77 @@
+//go:build !linux
+// +build !linux
+
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package syscall provides functionalities that grpc uses to get low-level
+// operating system stats/info.
+package syscall
+
+import (
+	"net"
+	"sync"
+	"time"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+var once sync.Once
+var logger = grpclog.Component("core")
+
+func log() {
+	once.Do(func() {
+		logger.Info("CPU time info is unavailable on non-linux environments.")
+	})
+}
+
+// GetCPUTime returns the how much CPU time has passed since the start of this
+// process. It always returns 0 under non-linux environments.
+func GetCPUTime() int64 {
+	log()
+	return 0
+}
+
+// Rusage is an empty struct under non-linux environments.
+type Rusage struct{}
+
+// GetRusage is a no-op function under non-linux environments.
+func GetRusage() *Rusage {
+	log()
+	return nil
+}
+
+// CPUTimeDiff returns the differences of user CPU time and system CPU time used
+// between two Rusage structs. It a no-op function for non-linux environments.
+func CPUTimeDiff(first *Rusage, latest *Rusage) (float64, float64) {
+	log()
+	return 0, 0
+}
+
+// SetTCPUserTimeout is a no-op function under non-linux environments.
+func SetTCPUserTimeout(conn net.Conn, timeout time.Duration) error {
+	log()
+	return nil
+}
+
+// GetTCPUserTimeout is a no-op function under non-linux environments.
+// A negative return value indicates the operation is not supported
+func GetTCPUserTimeout(conn net.Conn) (int, error) {
+	log()
+	return -1, nil
+}

vendor/google.golang.org/grpc/internal/transport/bdp_estimator.go

@@ -0,0 +1,141 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"sync"
+	"time"
+)
+
+const (
+	// bdpLimit is the maximum value the flow control windows will be increased
+	// to.  TCP typically limits this to 4MB, but some systems go up to 16MB.
+	// Since this is only a limit, it is safe to make it optimistic.
+	bdpLimit = (1 << 20) * 16
+	// alpha is a constant factor used to keep a moving average
+	// of RTTs.
+	alpha = 0.9
+	// If the current bdp sample is greater than or equal to
+	// our beta * our estimated bdp and the current bandwidth
+	// sample is the maximum bandwidth observed so far, we
+	// increase our bbp estimate by a factor of gamma.
+	beta = 0.66
+	// To put our bdp to be smaller than or equal to twice the real BDP,
+	// we should multiply our current sample with 4/3, however to round things out
+	// we use 2 as the multiplication factor.
+	gamma = 2
+)
+
+// Adding arbitrary data to ping so that its ack can be identified.
+// Easter-egg: what does the ping message say?
+var bdpPing = &ping{data: [8]byte{2, 4, 16, 16, 9, 14, 7, 7}}
+
+type bdpEstimator struct {
+	// sentAt is the time when the ping was sent.
+	sentAt time.Time
+
+	mu sync.Mutex
+	// bdp is the current bdp estimate.
+	bdp uint32
+	// sample is the number of bytes received in one measurement cycle.
+	sample uint32
+	// bwMax is the maximum bandwidth noted so far (bytes/sec).
+	bwMax float64
+	// bool to keep track of the beginning of a new measurement cycle.
+	isSent bool
+	// Callback to update the window sizes.
+	updateFlowControl func(n uint32)
+	// sampleCount is the number of samples taken so far.
+	sampleCount uint64
+	// round trip time (seconds)
+	rtt float64
+}
+
+// timesnap registers the time bdp ping was sent out so that
+// network rtt can be calculated when its ack is received.
+// It is called (by controller) when the bdpPing is
+// being written on the wire.
+func (b *bdpEstimator) timesnap(d [8]byte) {
+	if bdpPing.data != d {
+		return
+	}
+	b.sentAt = time.Now()
+}
+
+// add adds bytes to the current sample for calculating bdp.
+// It returns true only if a ping must be sent. This can be used
+// by the caller (handleData) to make decision about batching
+// a window update with it.
+func (b *bdpEstimator) add(n uint32) bool {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.bdp == bdpLimit {
+		return false
+	}
+	if !b.isSent {
+		b.isSent = true
+		b.sample = n
+		b.sentAt = time.Time{}
+		b.sampleCount++
+		return true
+	}
+	b.sample += n
+	return false
+}
+
+// calculate is called when an ack for a bdp ping is received.
+// Here we calculate the current bdp and bandwidth sample and
+// decide if the flow control windows should go up.
+func (b *bdpEstimator) calculate(d [8]byte) {
+	// Check if the ping acked for was the bdp ping.
+	if bdpPing.data != d {
+		return
+	}
+	b.mu.Lock()
+	rttSample := time.Since(b.sentAt).Seconds()
+	if b.sampleCount < 10 {
+		// Bootstrap rtt with an average of first 10 rtt samples.
+		b.rtt += (rttSample - b.rtt) / float64(b.sampleCount)
+	} else {
+		// Heed to the recent past more.
+		b.rtt += (rttSample - b.rtt) * float64(alpha)
+	}
+	b.isSent = false
+	// The number of bytes accumulated so far in the sample is smaller
+	// than or equal to 1.5 times the real BDP on a saturated connection.
+	bwCurrent := float64(b.sample) / (b.rtt * float64(1.5))
+	if bwCurrent > b.bwMax {
+		b.bwMax = bwCurrent
+	}
+	// If the current sample (which is smaller than or equal to the 1.5 times the real BDP) is
+	// greater than or equal to 2/3rd our perceived bdp AND this is the maximum bandwidth seen so far, we
+	// should update our perception of the network BDP.
+	if float64(b.sample) >= beta*float64(b.bdp) && bwCurrent == b.bwMax && b.bdp != bdpLimit {
+		sampleFloat := float64(b.sample)
+		b.bdp = uint32(gamma * sampleFloat)
+		if b.bdp > bdpLimit {
+			b.bdp = bdpLimit
+		}
+		bdp := b.bdp
+		b.mu.Unlock()
+		b.updateFlowControl(bdp)
+		return
+	}
+	b.mu.Unlock()
+}

vendor/google.golang.org/grpc/internal/transport/controlbuf.go

@@ -0,0 +1,998 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"runtime"
+	"strconv"
+	"sync"
+	"sync/atomic"
+
+	"golang.org/x/net/http2"
+	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/status"
+)
+
+var updateHeaderTblSize = func(e *hpack.Encoder, v uint32) {
+	e.SetMaxDynamicTableSizeLimit(v)
+}
+
+type itemNode struct {
+	it   interface{}
+	next *itemNode
+}
+
+type itemList struct {
+	head *itemNode
+	tail *itemNode
+}
+
+func (il *itemList) enqueue(i interface{}) {
+	n := &itemNode{it: i}
+	if il.tail == nil {
+		il.head, il.tail = n, n
+		return
+	}
+	il.tail.next = n
+	il.tail = n
+}
+
+// peek returns the first item in the list without removing it from the
+// list.
+func (il *itemList) peek() interface{} {
+	return il.head.it
+}
+
+func (il *itemList) dequeue() interface{} {
+	if il.head == nil {
+		return nil
+	}
+	i := il.head.it
+	il.head = il.head.next
+	if il.head == nil {
+		il.tail = nil
+	}
+	return i
+}
+
+func (il *itemList) dequeueAll() *itemNode {
+	h := il.head
+	il.head, il.tail = nil, nil
+	return h
+}
+
+func (il *itemList) isEmpty() bool {
+	return il.head == nil
+}
+
+// The following defines various control items which could flow through
+// the control buffer of transport. They represent different aspects of
+// control tasks, e.g., flow control, settings, streaming resetting, etc.
+
+// maxQueuedTransportResponseFrames is the most queued "transport response"
+// frames we will buffer before preventing new reads from occurring on the
+// transport.  These are control frames sent in response to client requests,
+// such as RST_STREAM due to bad headers or settings acks.
+const maxQueuedTransportResponseFrames = 50
+
+type cbItem interface {
+	isTransportResponseFrame() bool
+}
+
+// registerStream is used to register an incoming stream with loopy writer.
+type registerStream struct {
+	streamID uint32
+	wq       *writeQuota
+}
+
+func (*registerStream) isTransportResponseFrame() bool { return false }
+
+// headerFrame is also used to register stream on the client-side.
+type headerFrame struct {
+	streamID   uint32
+	hf         []hpack.HeaderField
+	endStream  bool               // Valid on server side.
+	initStream func(uint32) error // Used only on the client side.
+	onWrite    func()
+	wq         *writeQuota    // write quota for the stream created.
+	cleanup    *cleanupStream // Valid on the server side.
+	onOrphaned func(error)    // Valid on client-side
+}
+
+func (h *headerFrame) isTransportResponseFrame() bool {
+	return h.cleanup != nil && h.cleanup.rst // Results in a RST_STREAM
+}
+
+type cleanupStream struct {
+	streamID uint32
+	rst      bool
+	rstCode  http2.ErrCode
+	onWrite  func()
+}
+
+func (c *cleanupStream) isTransportResponseFrame() bool { return c.rst } // Results in a RST_STREAM
+
+type earlyAbortStream struct {
+	httpStatus     uint32
+	streamID       uint32
+	contentSubtype string
+	status         *status.Status
+	rst            bool
+}
+
+func (*earlyAbortStream) isTransportResponseFrame() bool { return false }
+
+type dataFrame struct {
+	streamID  uint32
+	endStream bool
+	h         []byte
+	d         []byte
+	// onEachWrite is called every time
+	// a part of d is written out.
+	onEachWrite func()
+}
+
+func (*dataFrame) isTransportResponseFrame() bool { return false }
+
+type incomingWindowUpdate struct {
+	streamID  uint32
+	increment uint32
+}
+
+func (*incomingWindowUpdate) isTransportResponseFrame() bool { return false }
+
+type outgoingWindowUpdate struct {
+	streamID  uint32
+	increment uint32
+}
+
+func (*outgoingWindowUpdate) isTransportResponseFrame() bool {
+	return false // window updates are throttled by thresholds
+}
+
+type incomingSettings struct {
+	ss []http2.Setting
+}
+
+func (*incomingSettings) isTransportResponseFrame() bool { return true } // Results in a settings ACK
+
+type outgoingSettings struct {
+	ss []http2.Setting
+}
+
+func (*outgoingSettings) isTransportResponseFrame() bool { return false }
+
+type incomingGoAway struct {
+}
+
+func (*incomingGoAway) isTransportResponseFrame() bool { return false }
+
+type goAway struct {
+	code      http2.ErrCode
+	debugData []byte
+	headsUp   bool
+	closeConn error // if set, loopyWriter will exit, resulting in conn closure
+}
+
+func (*goAway) isTransportResponseFrame() bool { return false }
+
+type ping struct {
+	ack  bool
+	data [8]byte
+}
+
+func (*ping) isTransportResponseFrame() bool { return true }
+
+type outFlowControlSizeRequest struct {
+	resp chan uint32
+}
+
+func (*outFlowControlSizeRequest) isTransportResponseFrame() bool { return false }
+
+// closeConnection is an instruction to tell the loopy writer to flush the
+// framer and exit, which will cause the transport's connection to be closed
+// (by the client or server).  The transport itself will close after the reader
+// encounters the EOF caused by the connection closure.
+type closeConnection struct{}
+
+func (closeConnection) isTransportResponseFrame() bool { return false }
+
+type outStreamState int
+
+const (
+	active outStreamState = iota
+	empty
+	waitingOnStreamQuota
+)
+
+type outStream struct {
+	id               uint32
+	state            outStreamState
+	itl              *itemList
+	bytesOutStanding int
+	wq               *writeQuota
+
+	next *outStream
+	prev *outStream
+}
+
+func (s *outStream) deleteSelf() {
+	if s.prev != nil {
+		s.prev.next = s.next
+	}
+	if s.next != nil {
+		s.next.prev = s.prev
+	}
+	s.next, s.prev = nil, nil
+}
+
+type outStreamList struct {
+	// Following are sentinel objects that mark the
+	// beginning and end of the list. They do not
+	// contain any item lists. All valid objects are
+	// inserted in between them.
+	// This is needed so that an outStream object can
+	// deleteSelf() in O(1) time without knowing which
+	// list it belongs to.
+	head *outStream
+	tail *outStream
+}
+
+func newOutStreamList() *outStreamList {
+	head, tail := new(outStream), new(outStream)
+	head.next = tail
+	tail.prev = head
+	return &outStreamList{
+		head: head,
+		tail: tail,
+	}
+}
+
+func (l *outStreamList) enqueue(s *outStream) {
+	e := l.tail.prev
+	e.next = s
+	s.prev = e
+	s.next = l.tail
+	l.tail.prev = s
+}
+
+// remove from the beginning of the list.
+func (l *outStreamList) dequeue() *outStream {
+	b := l.head.next
+	if b == l.tail {
+		return nil
+	}
+	b.deleteSelf()
+	return b
+}
+
+// controlBuffer is a way to pass information to loopy.
+// Information is passed as specific struct types called control frames.
+// A control frame not only represents data, messages or headers to be sent out
+// but can also be used to instruct loopy to update its internal state.
+// It shouldn't be confused with an HTTP2 frame, although some of the control frames
+// like dataFrame and headerFrame do go out on wire as HTTP2 frames.
+type controlBuffer struct {
+	ch              chan struct{}
+	done            <-chan struct{}
+	mu              sync.Mutex
+	consumerWaiting bool
+	list            *itemList
+	err             error
+
+	// transportResponseFrames counts the number of queued items that represent
+	// the response of an action initiated by the peer.  trfChan is created
+	// when transportResponseFrames >= maxQueuedTransportResponseFrames and is
+	// closed and nilled when transportResponseFrames drops below the
+	// threshold.  Both fields are protected by mu.
+	transportResponseFrames int
+	trfChan                 atomic.Value // chan struct{}
+}
+
+func newControlBuffer(done <-chan struct{}) *controlBuffer {
+	return &controlBuffer{
+		ch:   make(chan struct{}, 1),
+		list: &itemList{},
+		done: done,
+	}
+}
+
+// throttle blocks if there are too many incomingSettings/cleanupStreams in the
+// controlbuf.
+func (c *controlBuffer) throttle() {
+	ch, _ := c.trfChan.Load().(chan struct{})
+	if ch != nil {
+		select {
+		case <-ch:
+		case <-c.done:
+		}
+	}
+}
+
+func (c *controlBuffer) put(it cbItem) error {
+	_, err := c.executeAndPut(nil, it)
+	return err
+}
+
+func (c *controlBuffer) executeAndPut(f func(it interface{}) bool, it cbItem) (bool, error) {
+	var wakeUp bool
+	c.mu.Lock()
+	if c.err != nil {
+		c.mu.Unlock()
+		return false, c.err
+	}
+	if f != nil {
+		if !f(it) { // f wasn't successful
+			c.mu.Unlock()
+			return false, nil
+		}
+	}
+	if c.consumerWaiting {
+		wakeUp = true
+		c.consumerWaiting = false
+	}
+	c.list.enqueue(it)
+	if it.isTransportResponseFrame() {
+		c.transportResponseFrames++
+		if c.transportResponseFrames == maxQueuedTransportResponseFrames {
+			// We are adding the frame that puts us over the threshold; create
+			// a throttling channel.
+			c.trfChan.Store(make(chan struct{}))
+		}
+	}
+	c.mu.Unlock()
+	if wakeUp {
+		select {
+		case c.ch <- struct{}{}:
+		default:
+		}
+	}
+	return true, nil
+}
+
+// Note argument f should never be nil.
+func (c *controlBuffer) execute(f func(it interface{}) bool, it interface{}) (bool, error) {
+	c.mu.Lock()
+	if c.err != nil {
+		c.mu.Unlock()
+		return false, c.err
+	}
+	if !f(it) { // f wasn't successful
+		c.mu.Unlock()
+		return false, nil
+	}
+	c.mu.Unlock()
+	return true, nil
+}
+
+func (c *controlBuffer) get(block bool) (interface{}, error) {
+	for {
+		c.mu.Lock()
+		if c.err != nil {
+			c.mu.Unlock()
+			return nil, c.err
+		}
+		if !c.list.isEmpty() {
+			h := c.list.dequeue().(cbItem)
+			if h.isTransportResponseFrame() {
+				if c.transportResponseFrames == maxQueuedTransportResponseFrames {
+					// We are removing the frame that put us over the
+					// threshold; close and clear the throttling channel.
+					ch := c.trfChan.Load().(chan struct{})
+					close(ch)
+					c.trfChan.Store((chan struct{})(nil))
+				}
+				c.transportResponseFrames--
+			}
+			c.mu.Unlock()
+			return h, nil
+		}
+		if !block {
+			c.mu.Unlock()
+			return nil, nil
+		}
+		c.consumerWaiting = true
+		c.mu.Unlock()
+		select {
+		case <-c.ch:
+		case <-c.done:
+			return nil, errors.New("transport closed by client")
+		}
+	}
+}
+
+func (c *controlBuffer) finish() {
+	c.mu.Lock()
+	if c.err != nil {
+		c.mu.Unlock()
+		return
+	}
+	c.err = ErrConnClosing
+	// There may be headers for streams in the control buffer.
+	// These streams need to be cleaned out since the transport
+	// is still not aware of these yet.
+	for head := c.list.dequeueAll(); head != nil; head = head.next {
+		hdr, ok := head.it.(*headerFrame)
+		if !ok {
+			continue
+		}
+		if hdr.onOrphaned != nil { // It will be nil on the server-side.
+			hdr.onOrphaned(ErrConnClosing)
+		}
+	}
+	// In case throttle() is currently in flight, it needs to be unblocked.
+	// Otherwise, the transport may not close, since the transport is closed by
+	// the reader encountering the connection error.
+	ch, _ := c.trfChan.Load().(chan struct{})
+	if ch != nil {
+		close(ch)
+	}
+	c.trfChan.Store((chan struct{})(nil))
+	c.mu.Unlock()
+}
+
+type side int
+
+const (
+	clientSide side = iota
+	serverSide
+)
+
+// Loopy receives frames from the control buffer.
+// Each frame is handled individually; most of the work done by loopy goes
+// into handling data frames. Loopy maintains a queue of active streams, and each
+// stream maintains a queue of data frames; as loopy receives data frames
+// it gets added to the queue of the relevant stream.
+// Loopy goes over this list of active streams by processing one node every iteration,
+// thereby closely resemebling to a round-robin scheduling over all streams. While
+// processing a stream, loopy writes out data bytes from this stream capped by the min
+// of http2MaxFrameLen, connection-level flow control and stream-level flow control.
+type loopyWriter struct {
+	side      side
+	cbuf      *controlBuffer
+	sendQuota uint32
+	oiws      uint32 // outbound initial window size.
+	// estdStreams is map of all established streams that are not cleaned-up yet.
+	// On client-side, this is all streams whose headers were sent out.
+	// On server-side, this is all streams whose headers were received.
+	estdStreams map[uint32]*outStream // Established streams.
+	// activeStreams is a linked-list of all streams that have data to send and some
+	// stream-level flow control quota.
+	// Each of these streams internally have a list of data items(and perhaps trailers
+	// on the server-side) to be sent out.
+	activeStreams *outStreamList
+	framer        *framer
+	hBuf          *bytes.Buffer  // The buffer for HPACK encoding.
+	hEnc          *hpack.Encoder // HPACK encoder.
+	bdpEst        *bdpEstimator
+	draining      bool
+
+	// Side-specific handlers
+	ssGoAwayHandler func(*goAway) (bool, error)
+}
+
+func newLoopyWriter(s side, fr *framer, cbuf *controlBuffer, bdpEst *bdpEstimator) *loopyWriter {
+	var buf bytes.Buffer
+	l := &loopyWriter{
+		side:          s,
+		cbuf:          cbuf,
+		sendQuota:     defaultWindowSize,
+		oiws:          defaultWindowSize,
+		estdStreams:   make(map[uint32]*outStream),
+		activeStreams: newOutStreamList(),
+		framer:        fr,
+		hBuf:          &buf,
+		hEnc:          hpack.NewEncoder(&buf),
+		bdpEst:        bdpEst,
+	}
+	return l
+}
+
+const minBatchSize = 1000
+
+// run should be run in a separate goroutine.
+// It reads control frames from controlBuf and processes them by:
+// 1. Updating loopy's internal state, or/and
+// 2. Writing out HTTP2 frames on the wire.
+//
+// Loopy keeps all active streams with data to send in a linked-list.
+// All streams in the activeStreams linked-list must have both:
+// 1. Data to send, and
+// 2. Stream level flow control quota available.
+//
+// In each iteration of run loop, other than processing the incoming control
+// frame, loopy calls processData, which processes one node from the activeStreams linked-list.
+// This results in writing of HTTP2 frames into an underlying write buffer.
+// When there's no more control frames to read from controlBuf, loopy flushes the write buffer.
+// As an optimization, to increase the batch size for each flush, loopy yields the processor, once
+// if the batch size is too low to give stream goroutines a chance to fill it up.
+func (l *loopyWriter) run() (err error) {
+	// Always flush the writer before exiting in case there are pending frames
+	// to be sent.
+	defer l.framer.writer.Flush()
+	for {
+		it, err := l.cbuf.get(true)
+		if err != nil {
+			return err
+		}
+		if err = l.handle(it); err != nil {
+			return err
+		}
+		if _, err = l.processData(); err != nil {
+			return err
+		}
+		gosched := true
+	hasdata:
+		for {
+			it, err := l.cbuf.get(false)
+			if err != nil {
+				return err
+			}
+			if it != nil {
+				if err = l.handle(it); err != nil {
+					return err
+				}
+				if _, err = l.processData(); err != nil {
+					return err
+				}
+				continue hasdata
+			}
+			isEmpty, err := l.processData()
+			if err != nil {
+				return err
+			}
+			if !isEmpty {
+				continue hasdata
+			}
+			if gosched {
+				gosched = false
+				if l.framer.writer.offset < minBatchSize {
+					runtime.Gosched()
+					continue hasdata
+				}
+			}
+			l.framer.writer.Flush()
+			break hasdata
+		}
+	}
+}
+
+func (l *loopyWriter) outgoingWindowUpdateHandler(w *outgoingWindowUpdate) error {
+	return l.framer.fr.WriteWindowUpdate(w.streamID, w.increment)
+}
+
+func (l *loopyWriter) incomingWindowUpdateHandler(w *incomingWindowUpdate) error {
+	// Otherwise update the quota.
+	if w.streamID == 0 {
+		l.sendQuota += w.increment
+		return nil
+	}
+	// Find the stream and update it.
+	if str, ok := l.estdStreams[w.streamID]; ok {
+		str.bytesOutStanding -= int(w.increment)
+		if strQuota := int(l.oiws) - str.bytesOutStanding; strQuota > 0 && str.state == waitingOnStreamQuota {
+			str.state = active
+			l.activeStreams.enqueue(str)
+			return nil
+		}
+	}
+	return nil
+}
+
+func (l *loopyWriter) outgoingSettingsHandler(s *outgoingSettings) error {
+	return l.framer.fr.WriteSettings(s.ss...)
+}
+
+func (l *loopyWriter) incomingSettingsHandler(s *incomingSettings) error {
+	if err := l.applySettings(s.ss); err != nil {
+		return err
+	}
+	return l.framer.fr.WriteSettingsAck()
+}
+
+func (l *loopyWriter) registerStreamHandler(h *registerStream) error {
+	str := &outStream{
+		id:    h.streamID,
+		state: empty,
+		itl:   &itemList{},
+		wq:    h.wq,
+	}
+	l.estdStreams[h.streamID] = str
+	return nil
+}
+
+func (l *loopyWriter) headerHandler(h *headerFrame) error {
+	if l.side == serverSide {
+		str, ok := l.estdStreams[h.streamID]
+		if !ok {
+			if logger.V(logLevel) {
+				logger.Warningf("transport: loopy doesn't recognize the stream: %d", h.streamID)
+			}
+			return nil
+		}
+		// Case 1.A: Server is responding back with headers.
+		if !h.endStream {
+			return l.writeHeader(h.streamID, h.endStream, h.hf, h.onWrite)
+		}
+		// else:  Case 1.B: Server wants to close stream.
+
+		if str.state != empty { // either active or waiting on stream quota.
+			// add it str's list of items.
+			str.itl.enqueue(h)
+			return nil
+		}
+		if err := l.writeHeader(h.streamID, h.endStream, h.hf, h.onWrite); err != nil {
+			return err
+		}
+		return l.cleanupStreamHandler(h.cleanup)
+	}
+	// Case 2: Client wants to originate stream.
+	str := &outStream{
+		id:    h.streamID,
+		state: empty,
+		itl:   &itemList{},
+		wq:    h.wq,
+	}
+	return l.originateStream(str, h)
+}
+
+func (l *loopyWriter) originateStream(str *outStream, hdr *headerFrame) error {
+	// l.draining is set when handling GoAway. In which case, we want to avoid
+	// creating new streams.
+	if l.draining {
+		// TODO: provide a better error with the reason we are in draining.
+		hdr.onOrphaned(errStreamDrain)
+		return nil
+	}
+	if err := hdr.initStream(str.id); err != nil {
+		return err
+	}
+	if err := l.writeHeader(str.id, hdr.endStream, hdr.hf, hdr.onWrite); err != nil {
+		return err
+	}
+	l.estdStreams[str.id] = str
+	return nil
+}
+
+func (l *loopyWriter) writeHeader(streamID uint32, endStream bool, hf []hpack.HeaderField, onWrite func()) error {
+	if onWrite != nil {
+		onWrite()
+	}
+	l.hBuf.Reset()
+	for _, f := range hf {
+		if err := l.hEnc.WriteField(f); err != nil {
+			if logger.V(logLevel) {
+				logger.Warningf("transport: loopyWriter.writeHeader encountered error while encoding headers: %v", err)
+			}
+		}
+	}
+	var (
+		err               error
+		endHeaders, first bool
+	)
+	first = true
+	for !endHeaders {
+		size := l.hBuf.Len()
+		if size > http2MaxFrameLen {
+			size = http2MaxFrameLen
+		} else {
+			endHeaders = true
+		}
+		if first {
+			first = false
+			err = l.framer.fr.WriteHeaders(http2.HeadersFrameParam{
+				StreamID:      streamID,
+				BlockFragment: l.hBuf.Next(size),
+				EndStream:     endStream,
+				EndHeaders:    endHeaders,
+			})
+		} else {
+			err = l.framer.fr.WriteContinuation(
+				streamID,
+				endHeaders,
+				l.hBuf.Next(size),
+			)
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (l *loopyWriter) preprocessData(df *dataFrame) error {
+	str, ok := l.estdStreams[df.streamID]
+	if !ok {
+		return nil
+	}
+	// If we got data for a stream it means that
+	// stream was originated and the headers were sent out.
+	str.itl.enqueue(df)
+	if str.state == empty {
+		str.state = active
+		l.activeStreams.enqueue(str)
+	}
+	return nil
+}
+
+func (l *loopyWriter) pingHandler(p *ping) error {
+	if !p.ack {
+		l.bdpEst.timesnap(p.data)
+	}
+	return l.framer.fr.WritePing(p.ack, p.data)
+
+}
+
+func (l *loopyWriter) outFlowControlSizeRequestHandler(o *outFlowControlSizeRequest) error {
+	o.resp <- l.sendQuota
+	return nil
+}
+
+func (l *loopyWriter) cleanupStreamHandler(c *cleanupStream) error {
+	c.onWrite()
+	if str, ok := l.estdStreams[c.streamID]; ok {
+		// On the server side it could be a trailers-only response or
+		// a RST_STREAM before stream initialization thus the stream might
+		// not be established yet.
+		delete(l.estdStreams, c.streamID)
+		str.deleteSelf()
+	}
+	if c.rst { // If RST_STREAM needs to be sent.
+		if err := l.framer.fr.WriteRSTStream(c.streamID, c.rstCode); err != nil {
+			return err
+		}
+	}
+	if l.draining && len(l.estdStreams) == 0 {
+		return errors.New("finished processing active streams while in draining mode")
+	}
+	return nil
+}
+
+func (l *loopyWriter) earlyAbortStreamHandler(eas *earlyAbortStream) error {
+	if l.side == clientSide {
+		return errors.New("earlyAbortStream not handled on client")
+	}
+	// In case the caller forgets to set the http status, default to 200.
+	if eas.httpStatus == 0 {
+		eas.httpStatus = 200
+	}
+	headerFields := []hpack.HeaderField{
+		{Name: ":status", Value: strconv.Itoa(int(eas.httpStatus))},
+		{Name: "content-type", Value: grpcutil.ContentType(eas.contentSubtype)},
+		{Name: "grpc-status", Value: strconv.Itoa(int(eas.status.Code()))},
+		{Name: "grpc-message", Value: encodeGrpcMessage(eas.status.Message())},
+	}
+
+	if err := l.writeHeader(eas.streamID, true, headerFields, nil); err != nil {
+		return err
+	}
+	if eas.rst {
+		if err := l.framer.fr.WriteRSTStream(eas.streamID, http2.ErrCodeNo); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (l *loopyWriter) incomingGoAwayHandler(*incomingGoAway) error {
+	if l.side == clientSide {
+		l.draining = true
+		if len(l.estdStreams) == 0 {
+			return errors.New("received GOAWAY with no active streams")
+		}
+	}
+	return nil
+}
+
+func (l *loopyWriter) goAwayHandler(g *goAway) error {
+	// Handling of outgoing GoAway is very specific to side.
+	if l.ssGoAwayHandler != nil {
+		draining, err := l.ssGoAwayHandler(g)
+		if err != nil {
+			return err
+		}
+		l.draining = draining
+	}
+	return nil
+}
+
+func (l *loopyWriter) closeConnectionHandler() error {
+	// Exit loopyWriter entirely by returning an error here.  This will lead to
+	// the transport closing the connection, and, ultimately, transport
+	// closure.
+	return ErrConnClosing
+}
+
+func (l *loopyWriter) handle(i interface{}) error {
+	switch i := i.(type) {
+	case *incomingWindowUpdate:
+		return l.incomingWindowUpdateHandler(i)
+	case *outgoingWindowUpdate:
+		return l.outgoingWindowUpdateHandler(i)
+	case *incomingSettings:
+		return l.incomingSettingsHandler(i)
+	case *outgoingSettings:
+		return l.outgoingSettingsHandler(i)
+	case *headerFrame:
+		return l.headerHandler(i)
+	case *registerStream:
+		return l.registerStreamHandler(i)
+	case *cleanupStream:
+		return l.cleanupStreamHandler(i)
+	case *earlyAbortStream:
+		return l.earlyAbortStreamHandler(i)
+	case *incomingGoAway:
+		return l.incomingGoAwayHandler(i)
+	case *dataFrame:
+		return l.preprocessData(i)
+	case *ping:
+		return l.pingHandler(i)
+	case *goAway:
+		return l.goAwayHandler(i)
+	case *outFlowControlSizeRequest:
+		return l.outFlowControlSizeRequestHandler(i)
+	case closeConnection:
+		return l.closeConnectionHandler()
+	default:
+		return fmt.Errorf("transport: unknown control message type %T", i)
+	}
+}
+
+func (l *loopyWriter) applySettings(ss []http2.Setting) error {
+	for _, s := range ss {
+		switch s.ID {
+		case http2.SettingInitialWindowSize:
+			o := l.oiws
+			l.oiws = s.Val
+			if o < l.oiws {
+				// If the new limit is greater make all depleted streams active.
+				for _, stream := range l.estdStreams {
+					if stream.state == waitingOnStreamQuota {
+						stream.state = active
+						l.activeStreams.enqueue(stream)
+					}
+				}
+			}
+		case http2.SettingHeaderTableSize:
+			updateHeaderTblSize(l.hEnc, s.Val)
+		}
+	}
+	return nil
+}
+
+// processData removes the first stream from active streams, writes out at most 16KB
+// of its data and then puts it at the end of activeStreams if there's still more data
+// to be sent and stream has some stream-level flow control.
+func (l *loopyWriter) processData() (bool, error) {
+	if l.sendQuota == 0 {
+		return true, nil
+	}
+	str := l.activeStreams.dequeue() // Remove the first stream.
+	if str == nil {
+		return true, nil
+	}
+	dataItem := str.itl.peek().(*dataFrame) // Peek at the first data item this stream.
+	// A data item is represented by a dataFrame, since it later translates into
+	// multiple HTTP2 data frames.
+	// Every dataFrame has two buffers; h that keeps grpc-message header and d that is actual data.
+	// As an optimization to keep wire traffic low, data from d is copied to h to make as big as the
+	// maximum possible HTTP2 frame size.
+
+	if len(dataItem.h) == 0 && len(dataItem.d) == 0 { // Empty data frame
+		// Client sends out empty data frame with endStream = true
+		if err := l.framer.fr.WriteData(dataItem.streamID, dataItem.endStream, nil); err != nil {
+			return false, err
+		}
+		str.itl.dequeue() // remove the empty data item from stream
+		if str.itl.isEmpty() {
+			str.state = empty
+		} else if trailer, ok := str.itl.peek().(*headerFrame); ok { // the next item is trailers.
+			if err := l.writeHeader(trailer.streamID, trailer.endStream, trailer.hf, trailer.onWrite); err != nil {
+				return false, err
+			}
+			if err := l.cleanupStreamHandler(trailer.cleanup); err != nil {
+				return false, nil
+			}
+		} else {
+			l.activeStreams.enqueue(str)
+		}
+		return false, nil
+	}
+	var (
+		buf []byte
+	)
+	// Figure out the maximum size we can send
+	maxSize := http2MaxFrameLen
+	if strQuota := int(l.oiws) - str.bytesOutStanding; strQuota <= 0 { // stream-level flow control.
+		str.state = waitingOnStreamQuota
+		return false, nil
+	} else if maxSize > strQuota {
+		maxSize = strQuota
+	}
+	if maxSize > int(l.sendQuota) { // connection-level flow control.
+		maxSize = int(l.sendQuota)
+	}
+	// Compute how much of the header and data we can send within quota and max frame length
+	hSize := min(maxSize, len(dataItem.h))
+	dSize := min(maxSize-hSize, len(dataItem.d))
+	if hSize != 0 {
+		if dSize == 0 {
+			buf = dataItem.h
+		} else {
+			// We can add some data to grpc message header to distribute bytes more equally across frames.
+			// Copy on the stack to avoid generating garbage
+			var localBuf [http2MaxFrameLen]byte
+			copy(localBuf[:hSize], dataItem.h)
+			copy(localBuf[hSize:], dataItem.d[:dSize])
+			buf = localBuf[:hSize+dSize]
+		}
+	} else {
+		buf = dataItem.d
+	}
+
+	size := hSize + dSize
+
+	// Now that outgoing flow controls are checked we can replenish str's write quota
+	str.wq.replenish(size)
+	var endStream bool
+	// If this is the last data message on this stream and all of it can be written in this iteration.
+	if dataItem.endStream && len(dataItem.h)+len(dataItem.d) <= size {
+		endStream = true
+	}
+	if dataItem.onEachWrite != nil {
+		dataItem.onEachWrite()
+	}
+	if err := l.framer.fr.WriteData(dataItem.streamID, endStream, buf[:size]); err != nil {
+		return false, err
+	}
+	str.bytesOutStanding += size
+	l.sendQuota -= uint32(size)
+	dataItem.h = dataItem.h[hSize:]
+	dataItem.d = dataItem.d[dSize:]
+
+	if len(dataItem.h) == 0 && len(dataItem.d) == 0 { // All the data from that message was written out.
+		str.itl.dequeue()
+	}
+	if str.itl.isEmpty() {
+		str.state = empty
+	} else if trailer, ok := str.itl.peek().(*headerFrame); ok { // The next item is trailers.
+		if err := l.writeHeader(trailer.streamID, trailer.endStream, trailer.hf, trailer.onWrite); err != nil {
+			return false, err
+		}
+		if err := l.cleanupStreamHandler(trailer.cleanup); err != nil {
+			return false, err
+		}
+	} else if int(l.oiws)-str.bytesOutStanding <= 0 { // Ran out of stream quota.
+		str.state = waitingOnStreamQuota
+	} else { // Otherwise add it back to the list of active streams.
+		l.activeStreams.enqueue(str)
+	}
+	return false, nil
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

vendor/google.golang.org/grpc/internal/transport/defaults.go

@@ -0,0 +1,55 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"math"
+	"time"
+)
+
+const (
+	// The default value of flow control window size in HTTP2 spec.
+	defaultWindowSize = 65535
+	// The initial window size for flow control.
+	initialWindowSize             = defaultWindowSize // for an RPC
+	infinity                      = time.Duration(math.MaxInt64)
+	defaultClientKeepaliveTime    = infinity
+	defaultClientKeepaliveTimeout = 20 * time.Second
+	defaultMaxStreamsClient       = 100
+	defaultMaxConnectionIdle      = infinity
+	defaultMaxConnectionAge       = infinity
+	defaultMaxConnectionAgeGrace  = infinity
+	defaultServerKeepaliveTime    = 2 * time.Hour
+	defaultServerKeepaliveTimeout = 20 * time.Second
+	defaultKeepalivePolicyMinTime = 5 * time.Minute
+	// max window limit set by HTTP2 Specs.
+	maxWindowSize = math.MaxInt32
+	// defaultWriteQuota is the default value for number of data
+	// bytes that each stream can schedule before some of it being
+	// flushed out.
+	defaultWriteQuota              = 64 * 1024
+	defaultClientMaxHeaderListSize = uint32(16 << 20)
+	defaultServerMaxHeaderListSize = uint32(16 << 20)
+)
+
+// MaxStreamID is the upper bound for the stream ID before the current
+// transport gracefully closes and new transport is created for subsequent RPCs.
+// This is set to 75% of 2^31-1. Streams are identified with an unsigned 31-bit
+// integer. It's exported so that tests can override it.
+var MaxStreamID = uint32(math.MaxInt32 * 3 / 4)

vendor/google.golang.org/grpc/internal/transport/flowcontrol.go

@@ -0,0 +1,215 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"fmt"
+	"math"
+	"sync"
+	"sync/atomic"
+)
+
+// writeQuota is a soft limit on the amount of data a stream can
+// schedule before some of it is written out.
+type writeQuota struct {
+	quota int32
+	// get waits on read from when quota goes less than or equal to zero.
+	// replenish writes on it when quota goes positive again.
+	ch chan struct{}
+	// done is triggered in error case.
+	done <-chan struct{}
+	// replenish is called by loopyWriter to give quota back to.
+	// It is implemented as a field so that it can be updated
+	// by tests.
+	replenish func(n int)
+}
+
+func newWriteQuota(sz int32, done <-chan struct{}) *writeQuota {
+	w := &writeQuota{
+		quota: sz,
+		ch:    make(chan struct{}, 1),
+		done:  done,
+	}
+	w.replenish = w.realReplenish
+	return w
+}
+
+func (w *writeQuota) get(sz int32) error {
+	for {
+		if atomic.LoadInt32(&w.quota) > 0 {
+			atomic.AddInt32(&w.quota, -sz)
+			return nil
+		}
+		select {
+		case <-w.ch:
+			continue
+		case <-w.done:
+			return errStreamDone
+		}
+	}
+}
+
+func (w *writeQuota) realReplenish(n int) {
+	sz := int32(n)
+	a := atomic.AddInt32(&w.quota, sz)
+	b := a - sz
+	if b <= 0 && a > 0 {
+		select {
+		case w.ch <- struct{}{}:
+		default:
+		}
+	}
+}
+
+type trInFlow struct {
+	limit               uint32
+	unacked             uint32
+	effectiveWindowSize uint32
+}
+
+func (f *trInFlow) newLimit(n uint32) uint32 {
+	d := n - f.limit
+	f.limit = n
+	f.updateEffectiveWindowSize()
+	return d
+}
+
+func (f *trInFlow) onData(n uint32) uint32 {
+	f.unacked += n
+	if f.unacked >= f.limit/4 {
+		w := f.unacked
+		f.unacked = 0
+		f.updateEffectiveWindowSize()
+		return w
+	}
+	f.updateEffectiveWindowSize()
+	return 0
+}
+
+func (f *trInFlow) reset() uint32 {
+	w := f.unacked
+	f.unacked = 0
+	f.updateEffectiveWindowSize()
+	return w
+}
+
+func (f *trInFlow) updateEffectiveWindowSize() {
+	atomic.StoreUint32(&f.effectiveWindowSize, f.limit-f.unacked)
+}
+
+func (f *trInFlow) getSize() uint32 {
+	return atomic.LoadUint32(&f.effectiveWindowSize)
+}
+
+// TODO(mmukhi): Simplify this code.
+// inFlow deals with inbound flow control
+type inFlow struct {
+	mu sync.Mutex
+	// The inbound flow control limit for pending data.
+	limit uint32
+	// pendingData is the overall data which have been received but not been
+	// consumed by applications.
+	pendingData uint32
+	// The amount of data the application has consumed but grpc has not sent
+	// window update for them. Used to reduce window update frequency.
+	pendingUpdate uint32
+	// delta is the extra window update given by receiver when an application
+	// is reading data bigger in size than the inFlow limit.
+	delta uint32
+}
+
+// newLimit updates the inflow window to a new value n.
+// It assumes that n is always greater than the old limit.
+func (f *inFlow) newLimit(n uint32) {
+	f.mu.Lock()
+	f.limit = n
+	f.mu.Unlock()
+}
+
+func (f *inFlow) maybeAdjust(n uint32) uint32 {
+	if n > uint32(math.MaxInt32) {
+		n = uint32(math.MaxInt32)
+	}
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	// estSenderQuota is the receiver's view of the maximum number of bytes the sender
+	// can send without a window update.
+	estSenderQuota := int32(f.limit - (f.pendingData + f.pendingUpdate))
+	// estUntransmittedData is the maximum number of bytes the sends might not have put
+	// on the wire yet. A value of 0 or less means that we have already received all or
+	// more bytes than the application is requesting to read.
+	estUntransmittedData := int32(n - f.pendingData) // Casting into int32 since it could be negative.
+	// This implies that unless we send a window update, the sender won't be able to send all the bytes
+	// for this message. Therefore we must send an update over the limit since there's an active read
+	// request from the application.
+	if estUntransmittedData > estSenderQuota {
+		// Sender's window shouldn't go more than 2^31 - 1 as specified in the HTTP spec.
+		if f.limit+n > maxWindowSize {
+			f.delta = maxWindowSize - f.limit
+		} else {
+			// Send a window update for the whole message and not just the difference between
+			// estUntransmittedData and estSenderQuota. This will be helpful in case the message
+			// is padded; We will fallback on the current available window(at least a 1/4th of the limit).
+			f.delta = n
+		}
+		return f.delta
+	}
+	return 0
+}
+
+// onData is invoked when some data frame is received. It updates pendingData.
+func (f *inFlow) onData(n uint32) error {
+	f.mu.Lock()
+	f.pendingData += n
+	if f.pendingData+f.pendingUpdate > f.limit+f.delta {
+		limit := f.limit
+		rcvd := f.pendingData + f.pendingUpdate
+		f.mu.Unlock()
+		return fmt.Errorf("received %d-bytes data exceeding the limit %d bytes", rcvd, limit)
+	}
+	f.mu.Unlock()
+	return nil
+}
+
+// onRead is invoked when the application reads the data. It returns the window size
+// to be sent to the peer.
+func (f *inFlow) onRead(n uint32) uint32 {
+	f.mu.Lock()
+	if f.pendingData == 0 {
+		f.mu.Unlock()
+		return 0
+	}
+	f.pendingData -= n
+	if n > f.delta {
+		n -= f.delta
+		f.delta = 0
+	} else {
+		f.delta -= n
+		n = 0
+	}
+	f.pendingUpdate += n
+	if f.pendingUpdate >= f.limit/4 {
+		wu := f.pendingUpdate
+		f.pendingUpdate = 0
+		f.mu.Unlock()
+		return wu
+	}
+	f.mu.Unlock()
+	return 0
+}

vendor/google.golang.org/grpc/internal/transport/handler_server.go

@@ -0,0 +1,477 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// This file is the implementation of a gRPC server using HTTP/2 which
+// uses the standard Go http2 Server implementation (via the
+// http.Handler interface), rather than speaking low-level HTTP/2
+// frames itself. It is the implementation of *grpc.Server.ServeHTTP.
+
+package transport
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"golang.org/x/net/http2"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/peer"
+	"google.golang.org/grpc/stats"
+	"google.golang.org/grpc/status"
+)
+
+// NewServerHandlerTransport returns a ServerTransport handling gRPC from
+// inside an http.Handler, or writes an HTTP error to w and returns an error.
+// It requires that the http Server supports HTTP/2.
+func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats []stats.Handler) (ServerTransport, error) {
+	if r.ProtoMajor != 2 {
+		msg := "gRPC requires HTTP/2"
+		http.Error(w, msg, http.StatusBadRequest)
+		return nil, errors.New(msg)
+	}
+	if r.Method != "POST" {
+		msg := fmt.Sprintf("invalid gRPC request method %q", r.Method)
+		http.Error(w, msg, http.StatusBadRequest)
+		return nil, errors.New(msg)
+	}
+	contentType := r.Header.Get("Content-Type")
+	// TODO: do we assume contentType is lowercase? we did before
+	contentSubtype, validContentType := grpcutil.ContentSubtype(contentType)
+	if !validContentType {
+		msg := fmt.Sprintf("invalid gRPC request content-type %q", contentType)
+		http.Error(w, msg, http.StatusUnsupportedMediaType)
+		return nil, errors.New(msg)
+	}
+	if _, ok := w.(http.Flusher); !ok {
+		msg := "gRPC requires a ResponseWriter supporting http.Flusher"
+		http.Error(w, msg, http.StatusInternalServerError)
+		return nil, errors.New(msg)
+	}
+
+	st := &serverHandlerTransport{
+		rw:             w,
+		req:            r,
+		closedCh:       make(chan struct{}),
+		writes:         make(chan func()),
+		contentType:    contentType,
+		contentSubtype: contentSubtype,
+		stats:          stats,
+	}
+
+	if v := r.Header.Get("grpc-timeout"); v != "" {
+		to, err := decodeTimeout(v)
+		if err != nil {
+			msg := fmt.Sprintf("malformed grpc-timeout: %v", err)
+			http.Error(w, msg, http.StatusBadRequest)
+			return nil, status.Error(codes.Internal, msg)
+		}
+		st.timeoutSet = true
+		st.timeout = to
+	}
+
+	metakv := []string{"content-type", contentType}
+	if r.Host != "" {
+		metakv = append(metakv, ":authority", r.Host)
+	}
+	for k, vv := range r.Header {
+		k = strings.ToLower(k)
+		if isReservedHeader(k) && !isWhitelistedHeader(k) {
+			continue
+		}
+		for _, v := range vv {
+			v, err := decodeMetadataHeader(k, v)
+			if err != nil {
+				msg := fmt.Sprintf("malformed binary metadata %q in header %q: %v", v, k, err)
+				http.Error(w, msg, http.StatusBadRequest)
+				return nil, status.Error(codes.Internal, msg)
+			}
+			metakv = append(metakv, k, v)
+		}
+	}
+	st.headerMD = metadata.Pairs(metakv...)
+
+	return st, nil
+}
+
+// serverHandlerTransport is an implementation of ServerTransport
+// which replies to exactly one gRPC request (exactly one HTTP request),
+// using the net/http.Handler interface. This http.Handler is guaranteed
+// at this point to be speaking over HTTP/2, so it's able to speak valid
+// gRPC.
+type serverHandlerTransport struct {
+	rw         http.ResponseWriter
+	req        *http.Request
+	timeoutSet bool
+	timeout    time.Duration
+
+	headerMD metadata.MD
+
+	closeOnce sync.Once
+	closedCh  chan struct{} // closed on Close
+
+	// writes is a channel of code to run serialized in the
+	// ServeHTTP (HandleStreams) goroutine. The channel is closed
+	// when WriteStatus is called.
+	writes chan func()
+
+	// block concurrent WriteStatus calls
+	// e.g. grpc/(*serverStream).SendMsg/RecvMsg
+	writeStatusMu sync.Mutex
+
+	// we just mirror the request content-type
+	contentType string
+	// we store both contentType and contentSubtype so we don't keep recreating them
+	// TODO make sure this is consistent across handler_server and http2_server
+	contentSubtype string
+
+	stats []stats.Handler
+}
+
+func (ht *serverHandlerTransport) Close(err error) {
+	ht.closeOnce.Do(func() {
+		if logger.V(logLevel) {
+			logger.Infof("Closing serverHandlerTransport: %v", err)
+		}
+		close(ht.closedCh)
+	})
+}
+
+func (ht *serverHandlerTransport) RemoteAddr() net.Addr { return strAddr(ht.req.RemoteAddr) }
+
+// strAddr is a net.Addr backed by either a TCP "ip:port" string, or
+// the empty string if unknown.
+type strAddr string
+
+func (a strAddr) Network() string {
+	if a != "" {
+		// Per the documentation on net/http.Request.RemoteAddr, if this is
+		// set, it's set to the IP:port of the peer (hence, TCP):
+		// https://golang.org/pkg/net/http/#Request
+		//
+		// If we want to support Unix sockets later, we can
+		// add our own grpc-specific convention within the
+		// grpc codebase to set RemoteAddr to a different
+		// format, or probably better: we can attach it to the
+		// context and use that from serverHandlerTransport.RemoteAddr.
+		return "tcp"
+	}
+	return ""
+}
+
+func (a strAddr) String() string { return string(a) }
+
+// do runs fn in the ServeHTTP goroutine.
+func (ht *serverHandlerTransport) do(fn func()) error {
+	select {
+	case <-ht.closedCh:
+		return ErrConnClosing
+	case ht.writes <- fn:
+		return nil
+	}
+}
+
+func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) error {
+	ht.writeStatusMu.Lock()
+	defer ht.writeStatusMu.Unlock()
+
+	headersWritten := s.updateHeaderSent()
+	err := ht.do(func() {
+		if !headersWritten {
+			ht.writePendingHeaders(s)
+		}
+
+		// And flush, in case no header or body has been sent yet.
+		// This forces a separation of headers and trailers if this is the
+		// first call (for example, in end2end tests's TestNoService).
+		ht.rw.(http.Flusher).Flush()
+
+		h := ht.rw.Header()
+		h.Set("Grpc-Status", fmt.Sprintf("%d", st.Code()))
+		if m := st.Message(); m != "" {
+			h.Set("Grpc-Message", encodeGrpcMessage(m))
+		}
+
+		if p := st.Proto(); p != nil && len(p.Details) > 0 {
+			stBytes, err := proto.Marshal(p)
+			if err != nil {
+				// TODO: return error instead, when callers are able to handle it.
+				panic(err)
+			}
+
+			h.Set("Grpc-Status-Details-Bin", encodeBinHeader(stBytes))
+		}
+
+		if md := s.Trailer(); len(md) > 0 {
+			for k, vv := range md {
+				// Clients don't tolerate reading restricted headers after some non restricted ones were sent.
+				if isReservedHeader(k) {
+					continue
+				}
+				for _, v := range vv {
+					// http2 ResponseWriter mechanism to send undeclared Trailers after
+					// the headers have possibly been written.
+					h.Add(http2.TrailerPrefix+k, encodeMetadataHeader(k, v))
+				}
+			}
+		}
+	})
+
+	if err == nil { // transport has not been closed
+		// Note: The trailer fields are compressed with hpack after this call returns.
+		// No WireLength field is set here.
+		for _, sh := range ht.stats {
+			sh.HandleRPC(s.Context(), &stats.OutTrailer{
+				Trailer: s.trailer.Copy(),
+			})
+		}
+	}
+	ht.Close(errors.New("finished writing status"))
+	return err
+}
+
+// writePendingHeaders sets common and custom headers on the first
+// write call (Write, WriteHeader, or WriteStatus)
+func (ht *serverHandlerTransport) writePendingHeaders(s *Stream) {
+	ht.writeCommonHeaders(s)
+	ht.writeCustomHeaders(s)
+}
+
+// writeCommonHeaders sets common headers on the first write
+// call (Write, WriteHeader, or WriteStatus).
+func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) {
+	h := ht.rw.Header()
+	h["Date"] = nil // suppress Date to make tests happy; TODO: restore
+	h.Set("Content-Type", ht.contentType)
+
+	// Predeclare trailers we'll set later in WriteStatus (after the body).
+	// This is a SHOULD in the HTTP RFC, and the way you add (known)
+	// Trailers per the net/http.ResponseWriter contract.
+	// See https://golang.org/pkg/net/http/#ResponseWriter
+	// and https://golang.org/pkg/net/http/#example_ResponseWriter_trailers
+	h.Add("Trailer", "Grpc-Status")
+	h.Add("Trailer", "Grpc-Message")
+	h.Add("Trailer", "Grpc-Status-Details-Bin")
+
+	if s.sendCompress != "" {
+		h.Set("Grpc-Encoding", s.sendCompress)
+	}
+}
+
+// writeCustomHeaders sets custom headers set on the stream via SetHeader
+// on the first write call (Write, WriteHeader, or WriteStatus).
+func (ht *serverHandlerTransport) writeCustomHeaders(s *Stream) {
+	h := ht.rw.Header()
+
+	s.hdrMu.Lock()
+	for k, vv := range s.header {
+		if isReservedHeader(k) {
+			continue
+		}
+		for _, v := range vv {
+			h.Add(k, encodeMetadataHeader(k, v))
+		}
+	}
+
+	s.hdrMu.Unlock()
+}
+
+func (ht *serverHandlerTransport) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
+	headersWritten := s.updateHeaderSent()
+	return ht.do(func() {
+		if !headersWritten {
+			ht.writePendingHeaders(s)
+		}
+		ht.rw.Write(hdr)
+		ht.rw.Write(data)
+		ht.rw.(http.Flusher).Flush()
+	})
+}
+
+func (ht *serverHandlerTransport) WriteHeader(s *Stream, md metadata.MD) error {
+	if err := s.SetHeader(md); err != nil {
+		return err
+	}
+
+	headersWritten := s.updateHeaderSent()
+	err := ht.do(func() {
+		if !headersWritten {
+			ht.writePendingHeaders(s)
+		}
+
+		ht.rw.WriteHeader(200)
+		ht.rw.(http.Flusher).Flush()
+	})
+
+	if err == nil {
+		for _, sh := range ht.stats {
+			// Note: The header fields are compressed with hpack after this call returns.
+			// No WireLength field is set here.
+			sh.HandleRPC(s.Context(), &stats.OutHeader{
+				Header:      md.Copy(),
+				Compression: s.sendCompress,
+			})
+		}
+	}
+	return err
+}
+
+func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream), traceCtx func(context.Context, string) context.Context) {
+	// With this transport type there will be exactly 1 stream: this HTTP request.
+
+	ctx := ht.req.Context()
+	var cancel context.CancelFunc
+	if ht.timeoutSet {
+		ctx, cancel = context.WithTimeout(ctx, ht.timeout)
+	} else {
+		ctx, cancel = context.WithCancel(ctx)
+	}
+
+	// requestOver is closed when the status has been written via WriteStatus.
+	requestOver := make(chan struct{})
+	go func() {
+		select {
+		case <-requestOver:
+		case <-ht.closedCh:
+		case <-ht.req.Context().Done():
+		}
+		cancel()
+		ht.Close(errors.New("request is done processing"))
+	}()
+
+	req := ht.req
+
+	s := &Stream{
+		id:             0, // irrelevant
+		requestRead:    func(int) {},
+		cancel:         cancel,
+		buf:            newRecvBuffer(),
+		st:             ht,
+		method:         req.URL.Path,
+		recvCompress:   req.Header.Get("grpc-encoding"),
+		contentSubtype: ht.contentSubtype,
+	}
+	pr := &peer.Peer{
+		Addr: ht.RemoteAddr(),
+	}
+	if req.TLS != nil {
+		pr.AuthInfo = credentials.TLSInfo{State: *req.TLS, CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.PrivacyAndIntegrity}}
+	}
+	ctx = metadata.NewIncomingContext(ctx, ht.headerMD)
+	s.ctx = peer.NewContext(ctx, pr)
+	for _, sh := range ht.stats {
+		s.ctx = sh.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
+		inHeader := &stats.InHeader{
+			FullMethod:  s.method,
+			RemoteAddr:  ht.RemoteAddr(),
+			Compression: s.recvCompress,
+		}
+		sh.HandleRPC(s.ctx, inHeader)
+	}
+	s.trReader = &transportReader{
+		reader:        &recvBufferReader{ctx: s.ctx, ctxDone: s.ctx.Done(), recv: s.buf, freeBuffer: func(*bytes.Buffer) {}},
+		windowHandler: func(int) {},
+	}
+
+	// readerDone is closed when the Body.Read-ing goroutine exits.
+	readerDone := make(chan struct{})
+	go func() {
+		defer close(readerDone)
+
+		// TODO: minimize garbage, optimize recvBuffer code/ownership
+		const readSize = 8196
+		for buf := make([]byte, readSize); ; {
+			n, err := req.Body.Read(buf)
+			if n > 0 {
+				s.buf.put(recvMsg{buffer: bytes.NewBuffer(buf[:n:n])})
+				buf = buf[n:]
+			}
+			if err != nil {
+				s.buf.put(recvMsg{err: mapRecvMsgError(err)})
+				return
+			}
+			if len(buf) == 0 {
+				buf = make([]byte, readSize)
+			}
+		}
+	}()
+
+	// startStream is provided by the *grpc.Server's serveStreams.
+	// It starts a goroutine serving s and exits immediately.
+	// The goroutine that is started is the one that then calls
+	// into ht, calling WriteHeader, Write, WriteStatus, Close, etc.
+	startStream(s)
+
+	ht.runStream()
+	close(requestOver)
+
+	// Wait for reading goroutine to finish.
+	req.Body.Close()
+	<-readerDone
+}
+
+func (ht *serverHandlerTransport) runStream() {
+	for {
+		select {
+		case fn := <-ht.writes:
+			fn()
+		case <-ht.closedCh:
+			return
+		}
+	}
+}
+
+func (ht *serverHandlerTransport) IncrMsgSent() {}
+
+func (ht *serverHandlerTransport) IncrMsgRecv() {}
+
+func (ht *serverHandlerTransport) Drain() {
+	panic("Drain() is not implemented")
+}
+
+// mapRecvMsgError returns the non-nil err into the appropriate
+// error value as expected by callers of *grpc.parser.recvMsg.
+// In particular, in can only be:
+//   - io.EOF
+//   - io.ErrUnexpectedEOF
+//   - of type transport.ConnectionError
+//   - an error from the status package
+func mapRecvMsgError(err error) error {
+	if err == io.EOF || err == io.ErrUnexpectedEOF {
+		return err
+	}
+	if se, ok := err.(http2.StreamError); ok {
+		if code, ok := http2ErrConvTab[se.Code]; ok {
+			return status.Error(code, se.Error())
+		}
+	}
+	if strings.Contains(err.Error(), "body closed by handler") {
+		return status.Error(codes.Canceled, err.Error())
+	}
+	return connectionErrorf(true, err, err.Error())
+}

vendor/google.golang.org/grpc/internal/transport/http_util.go

@@ -0,0 +1,412 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"bufio"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"math"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+	"unicode/utf8"
+
+	"github.com/golang/protobuf/proto"
+	"golang.org/x/net/http2"
+	"golang.org/x/net/http2/hpack"
+	spb "google.golang.org/genproto/googleapis/rpc/status"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+const (
+	// http2MaxFrameLen specifies the max length of a HTTP2 frame.
+	http2MaxFrameLen = 16384 // 16KB frame
+	// https://httpwg.org/specs/rfc7540.html#SettingValues
+	http2InitHeaderTableSize = 4096
+)
+
+var (
+	clientPreface   = []byte(http2.ClientPreface)
+	http2ErrConvTab = map[http2.ErrCode]codes.Code{
+		http2.ErrCodeNo:                 codes.Internal,
+		http2.ErrCodeProtocol:           codes.Internal,
+		http2.ErrCodeInternal:           codes.Internal,
+		http2.ErrCodeFlowControl:        codes.ResourceExhausted,
+		http2.ErrCodeSettingsTimeout:    codes.Internal,
+		http2.ErrCodeStreamClosed:       codes.Internal,
+		http2.ErrCodeFrameSize:          codes.Internal,
+		http2.ErrCodeRefusedStream:      codes.Unavailable,
+		http2.ErrCodeCancel:             codes.Canceled,
+		http2.ErrCodeCompression:        codes.Internal,
+		http2.ErrCodeConnect:            codes.Internal,
+		http2.ErrCodeEnhanceYourCalm:    codes.ResourceExhausted,
+		http2.ErrCodeInadequateSecurity: codes.PermissionDenied,
+		http2.ErrCodeHTTP11Required:     codes.Internal,
+	}
+	// HTTPStatusConvTab is the HTTP status code to gRPC error code conversion table.
+	HTTPStatusConvTab = map[int]codes.Code{
+		// 400 Bad Request - INTERNAL.
+		http.StatusBadRequest: codes.Internal,
+		// 401 Unauthorized  - UNAUTHENTICATED.
+		http.StatusUnauthorized: codes.Unauthenticated,
+		// 403 Forbidden - PERMISSION_DENIED.
+		http.StatusForbidden: codes.PermissionDenied,
+		// 404 Not Found - UNIMPLEMENTED.
+		http.StatusNotFound: codes.Unimplemented,
+		// 429 Too Many Requests - UNAVAILABLE.
+		http.StatusTooManyRequests: codes.Unavailable,
+		// 502 Bad Gateway - UNAVAILABLE.
+		http.StatusBadGateway: codes.Unavailable,
+		// 503 Service Unavailable - UNAVAILABLE.
+		http.StatusServiceUnavailable: codes.Unavailable,
+		// 504 Gateway timeout - UNAVAILABLE.
+		http.StatusGatewayTimeout: codes.Unavailable,
+	}
+	logger = grpclog.Component("transport")
+)
+
+// isReservedHeader checks whether hdr belongs to HTTP2 headers
+// reserved by gRPC protocol. Any other headers are classified as the
+// user-specified metadata.
+func isReservedHeader(hdr string) bool {
+	if hdr != "" && hdr[0] == ':' {
+		return true
+	}
+	switch hdr {
+	case "content-type",
+		"user-agent",
+		"grpc-message-type",
+		"grpc-encoding",
+		"grpc-message",
+		"grpc-status",
+		"grpc-timeout",
+		"grpc-status-details-bin",
+		// Intentionally exclude grpc-previous-rpc-attempts and
+		// grpc-retry-pushback-ms, which are "reserved", but their API
+		// intentionally works via metadata.
+		"te":
+		return true
+	default:
+		return false
+	}
+}
+
+// isWhitelistedHeader checks whether hdr should be propagated into metadata
+// visible to users, even though it is classified as "reserved", above.
+func isWhitelistedHeader(hdr string) bool {
+	switch hdr {
+	case ":authority", "user-agent":
+		return true
+	default:
+		return false
+	}
+}
+
+const binHdrSuffix = "-bin"
+
+func encodeBinHeader(v []byte) string {
+	return base64.RawStdEncoding.EncodeToString(v)
+}
+
+func decodeBinHeader(v string) ([]byte, error) {
+	if len(v)%4 == 0 {
+		// Input was padded, or padding was not necessary.
+		return base64.StdEncoding.DecodeString(v)
+	}
+	return base64.RawStdEncoding.DecodeString(v)
+}
+
+func encodeMetadataHeader(k, v string) string {
+	if strings.HasSuffix(k, binHdrSuffix) {
+		return encodeBinHeader(([]byte)(v))
+	}
+	return v
+}
+
+func decodeMetadataHeader(k, v string) (string, error) {
+	if strings.HasSuffix(k, binHdrSuffix) {
+		b, err := decodeBinHeader(v)
+		return string(b), err
+	}
+	return v, nil
+}
+
+func decodeGRPCStatusDetails(rawDetails string) (*status.Status, error) {
+	v, err := decodeBinHeader(rawDetails)
+	if err != nil {
+		return nil, err
+	}
+	st := &spb.Status{}
+	if err = proto.Unmarshal(v, st); err != nil {
+		return nil, err
+	}
+	return status.FromProto(st), nil
+}
+
+type timeoutUnit uint8
+
+const (
+	hour        timeoutUnit = 'H'
+	minute      timeoutUnit = 'M'
+	second      timeoutUnit = 'S'
+	millisecond timeoutUnit = 'm'
+	microsecond timeoutUnit = 'u'
+	nanosecond  timeoutUnit = 'n'
+)
+
+func timeoutUnitToDuration(u timeoutUnit) (d time.Duration, ok bool) {
+	switch u {
+	case hour:
+		return time.Hour, true
+	case minute:
+		return time.Minute, true
+	case second:
+		return time.Second, true
+	case millisecond:
+		return time.Millisecond, true
+	case microsecond:
+		return time.Microsecond, true
+	case nanosecond:
+		return time.Nanosecond, true
+	default:
+	}
+	return
+}
+
+func decodeTimeout(s string) (time.Duration, error) {
+	size := len(s)
+	if size < 2 {
+		return 0, fmt.Errorf("transport: timeout string is too short: %q", s)
+	}
+	if size > 9 {
+		// Spec allows for 8 digits plus the unit.
+		return 0, fmt.Errorf("transport: timeout string is too long: %q", s)
+	}
+	unit := timeoutUnit(s[size-1])
+	d, ok := timeoutUnitToDuration(unit)
+	if !ok {
+		return 0, fmt.Errorf("transport: timeout unit is not recognized: %q", s)
+	}
+	t, err := strconv.ParseInt(s[:size-1], 10, 64)
+	if err != nil {
+		return 0, err
+	}
+	const maxHours = math.MaxInt64 / int64(time.Hour)
+	if d == time.Hour && t > maxHours {
+		// This timeout would overflow math.MaxInt64; clamp it.
+		return time.Duration(math.MaxInt64), nil
+	}
+	return d * time.Duration(t), nil
+}
+
+const (
+	spaceByte   = ' '
+	tildeByte   = '~'
+	percentByte = '%'
+)
+
+// encodeGrpcMessage is used to encode status code in header field
+// "grpc-message". It does percent encoding and also replaces invalid utf-8
+// characters with Unicode replacement character.
+//
+// It checks to see if each individual byte in msg is an allowable byte, and
+// then either percent encoding or passing it through. When percent encoding,
+// the byte is converted into hexadecimal notation with a '%' prepended.
+func encodeGrpcMessage(msg string) string {
+	if msg == "" {
+		return ""
+	}
+	lenMsg := len(msg)
+	for i := 0; i < lenMsg; i++ {
+		c := msg[i]
+		if !(c >= spaceByte && c <= tildeByte && c != percentByte) {
+			return encodeGrpcMessageUnchecked(msg)
+		}
+	}
+	return msg
+}
+
+func encodeGrpcMessageUnchecked(msg string) string {
+	var sb strings.Builder
+	for len(msg) > 0 {
+		r, size := utf8.DecodeRuneInString(msg)
+		for _, b := range []byte(string(r)) {
+			if size > 1 {
+				// If size > 1, r is not ascii. Always do percent encoding.
+				fmt.Fprintf(&sb, "%%%02X", b)
+				continue
+			}
+
+			// The for loop is necessary even if size == 1. r could be
+			// utf8.RuneError.
+			//
+			// fmt.Sprintf("%%%02X", utf8.RuneError) gives "%FFFD".
+			if b >= spaceByte && b <= tildeByte && b != percentByte {
+				sb.WriteByte(b)
+			} else {
+				fmt.Fprintf(&sb, "%%%02X", b)
+			}
+		}
+		msg = msg[size:]
+	}
+	return sb.String()
+}
+
+// decodeGrpcMessage decodes the msg encoded by encodeGrpcMessage.
+func decodeGrpcMessage(msg string) string {
+	if msg == "" {
+		return ""
+	}
+	lenMsg := len(msg)
+	for i := 0; i < lenMsg; i++ {
+		if msg[i] == percentByte && i+2 < lenMsg {
+			return decodeGrpcMessageUnchecked(msg)
+		}
+	}
+	return msg
+}
+
+func decodeGrpcMessageUnchecked(msg string) string {
+	var sb strings.Builder
+	lenMsg := len(msg)
+	for i := 0; i < lenMsg; i++ {
+		c := msg[i]
+		if c == percentByte && i+2 < lenMsg {
+			parsed, err := strconv.ParseUint(msg[i+1:i+3], 16, 8)
+			if err != nil {
+				sb.WriteByte(c)
+			} else {
+				sb.WriteByte(byte(parsed))
+				i += 2
+			}
+		} else {
+			sb.WriteByte(c)
+		}
+	}
+	return sb.String()
+}
+
+type bufWriter struct {
+	buf       []byte
+	offset    int
+	batchSize int
+	conn      net.Conn
+	err       error
+}
+
+func newBufWriter(conn net.Conn, batchSize int) *bufWriter {
+	return &bufWriter{
+		buf:       make([]byte, batchSize*2),
+		batchSize: batchSize,
+		conn:      conn,
+	}
+}
+
+func (w *bufWriter) Write(b []byte) (n int, err error) {
+	if w.err != nil {
+		return 0, w.err
+	}
+	if w.batchSize == 0 { // Buffer has been disabled.
+		return w.conn.Write(b)
+	}
+	for len(b) > 0 {
+		nn := copy(w.buf[w.offset:], b)
+		b = b[nn:]
+		w.offset += nn
+		n += nn
+		if w.offset >= w.batchSize {
+			err = w.Flush()
+		}
+	}
+	return n, err
+}
+
+func (w *bufWriter) Flush() error {
+	if w.err != nil {
+		return w.err
+	}
+	if w.offset == 0 {
+		return nil
+	}
+	_, w.err = w.conn.Write(w.buf[:w.offset])
+	w.offset = 0
+	return w.err
+}
+
+type framer struct {
+	writer *bufWriter
+	fr     *http2.Framer
+}
+
+func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, maxHeaderListSize uint32) *framer {
+	if writeBufferSize < 0 {
+		writeBufferSize = 0
+	}
+	var r io.Reader = conn
+	if readBufferSize > 0 {
+		r = bufio.NewReaderSize(r, readBufferSize)
+	}
+	w := newBufWriter(conn, writeBufferSize)
+	f := &framer{
+		writer: w,
+		fr:     http2.NewFramer(w, r),
+	}
+	f.fr.SetMaxReadFrameSize(http2MaxFrameLen)
+	// Opt-in to Frame reuse API on framer to reduce garbage.
+	// Frames aren't safe to read from after a subsequent call to ReadFrame.
+	f.fr.SetReuseFrames()
+	f.fr.MaxHeaderListSize = maxHeaderListSize
+	f.fr.ReadMetaHeaders = hpack.NewDecoder(http2InitHeaderTableSize, nil)
+	return f
+}
+
+// parseDialTarget returns the network and address to pass to dialer.
+func parseDialTarget(target string) (string, string) {
+	net := "tcp"
+	m1 := strings.Index(target, ":")
+	m2 := strings.Index(target, ":/")
+	// handle unix:addr which will fail with url.Parse
+	if m1 >= 0 && m2 < 0 {
+		if n := target[0:m1]; n == "unix" {
+			return n, target[m1+1:]
+		}
+	}
+	if m2 >= 0 {
+		t, err := url.Parse(target)
+		if err != nil {
+			return net, target
+		}
+		scheme := t.Scheme
+		addr := t.Path
+		if scheme == "unix" {
+			if addr == "" {
+				addr = t.Host
+			}
+			return scheme, addr
+		}
+	}
+	return net, target
+}

vendor/google.golang.org/grpc/internal/transport/networktype/networktype.go

@@ -0,0 +1,46 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package networktype declares the network type to be used in the default
+// dialer. Attribute of a resolver.Address.
+package networktype
+
+import (
+	"google.golang.org/grpc/resolver"
+)
+
+// keyType is the key to use for storing State in Attributes.
+type keyType string
+
+const key = keyType("grpc.internal.transport.networktype")
+
+// Set returns a copy of the provided address with attributes containing networkType.
+func Set(address resolver.Address, networkType string) resolver.Address {
+	address.Attributes = address.Attributes.WithValue(key, networkType)
+	return address
+}
+
+// Get returns the network type in the resolver.Address and true, or "", false
+// if not present.
+func Get(address resolver.Address) (string, bool) {
+	v := address.Attributes.Value(key)
+	if v == nil {
+		return "", false
+	}
+	return v.(string), true
+}

vendor/google.golang.org/grpc/internal/transport/proxy.go

@@ -0,0 +1,142 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"bufio"
+	"context"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+)
+
+const proxyAuthHeaderKey = "Proxy-Authorization"
+
+var (
+	// The following variable will be overwritten in the tests.
+	httpProxyFromEnvironment = http.ProxyFromEnvironment
+)
+
+func mapAddress(address string) (*url.URL, error) {
+	req := &http.Request{
+		URL: &url.URL{
+			Scheme: "https",
+			Host:   address,
+		},
+	}
+	url, err := httpProxyFromEnvironment(req)
+	if err != nil {
+		return nil, err
+	}
+	return url, nil
+}
+
+// To read a response from a net.Conn, http.ReadResponse() takes a bufio.Reader.
+// It's possible that this reader reads more than what's need for the response and stores
+// those bytes in the buffer.
+// bufConn wraps the original net.Conn and the bufio.Reader to make sure we don't lose the
+// bytes in the buffer.
+type bufConn struct {
+	net.Conn
+	r io.Reader
+}
+
+func (c *bufConn) Read(b []byte) (int, error) {
+	return c.r.Read(b)
+}
+
+func basicAuth(username, password string) string {
+	auth := username + ":" + password
+	return base64.StdEncoding.EncodeToString([]byte(auth))
+}
+
+func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, backendAddr string, proxyURL *url.URL, grpcUA string) (_ net.Conn, err error) {
+	defer func() {
+		if err != nil {
+			conn.Close()
+		}
+	}()
+
+	req := &http.Request{
+		Method: http.MethodConnect,
+		URL:    &url.URL{Host: backendAddr},
+		Header: map[string][]string{"User-Agent": {grpcUA}},
+	}
+	if t := proxyURL.User; t != nil {
+		u := t.Username()
+		p, _ := t.Password()
+		req.Header.Add(proxyAuthHeaderKey, "Basic "+basicAuth(u, p))
+	}
+
+	if err := sendHTTPRequest(ctx, req, conn); err != nil {
+		return nil, fmt.Errorf("failed to write the HTTP request: %v", err)
+	}
+
+	r := bufio.NewReader(conn)
+	resp, err := http.ReadResponse(r, req)
+	if err != nil {
+		return nil, fmt.Errorf("reading server HTTP response: %v", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		dump, err := httputil.DumpResponse(resp, true)
+		if err != nil {
+			return nil, fmt.Errorf("failed to do connect handshake, status code: %s", resp.Status)
+		}
+		return nil, fmt.Errorf("failed to do connect handshake, response: %q", dump)
+	}
+
+	return &bufConn{Conn: conn, r: r}, nil
+}
+
+// proxyDial dials, connecting to a proxy first if necessary. Checks if a proxy
+// is necessary, dials, does the HTTP CONNECT handshake, and returns the
+// connection.
+func proxyDial(ctx context.Context, addr string, grpcUA string) (conn net.Conn, err error) {
+	newAddr := addr
+	proxyURL, err := mapAddress(addr)
+	if err != nil {
+		return nil, err
+	}
+	if proxyURL != nil {
+		newAddr = proxyURL.Host
+	}
+
+	conn, err = (&net.Dialer{}).DialContext(ctx, "tcp", newAddr)
+	if err != nil {
+		return
+	}
+	if proxyURL != nil {
+		// proxy is disabled if proxyURL is nil.
+		conn, err = doHTTPConnectHandshake(ctx, conn, addr, proxyURL, grpcUA)
+	}
+	return
+}
+
+func sendHTTPRequest(ctx context.Context, req *http.Request, conn net.Conn) error {
+	req = req.WithContext(ctx)
+	if err := req.Write(conn); err != nil {
+		return fmt.Errorf("failed to write the HTTP request: %v", err)
+	}
+	return nil
+}

vendor/google.golang.org/grpc/internal/transport/transport.go

@@ -0,0 +1,823 @@
+/*
+ *
+ * Copyright 2014 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package transport defines and implements message oriented communication
+// channel to complete various transactions (e.g., an RPC).  It is meant for
+// grpc-internal usage and is not intended to be imported directly by users.
+package transport
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal/channelz"
+	"google.golang.org/grpc/keepalive"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/resolver"
+	"google.golang.org/grpc/stats"
+	"google.golang.org/grpc/status"
+	"google.golang.org/grpc/tap"
+)
+
+// ErrNoHeaders is used as a signal that a trailers only response was received,
+// and is not a real error.
+var ErrNoHeaders = errors.New("stream has no headers")
+
+const logLevel = 2
+
+type bufferPool struct {
+	pool sync.Pool
+}
+
+func newBufferPool() *bufferPool {
+	return &bufferPool{
+		pool: sync.Pool{
+			New: func() interface{} {
+				return new(bytes.Buffer)
+			},
+		},
+	}
+}
+
+func (p *bufferPool) get() *bytes.Buffer {
+	return p.pool.Get().(*bytes.Buffer)
+}
+
+func (p *bufferPool) put(b *bytes.Buffer) {
+	p.pool.Put(b)
+}
+
+// recvMsg represents the received msg from the transport. All transport
+// protocol specific info has been removed.
+type recvMsg struct {
+	buffer *bytes.Buffer
+	// nil: received some data
+	// io.EOF: stream is completed. data is nil.
+	// other non-nil error: transport failure. data is nil.
+	err error
+}
+
+// recvBuffer is an unbounded channel of recvMsg structs.
+//
+// Note: recvBuffer differs from buffer.Unbounded only in the fact that it
+// holds a channel of recvMsg structs instead of objects implementing "item"
+// interface. recvBuffer is written to much more often and using strict recvMsg
+// structs helps avoid allocation in "recvBuffer.put"
+type recvBuffer struct {
+	c       chan recvMsg
+	mu      sync.Mutex
+	backlog []recvMsg
+	err     error
+}
+
+func newRecvBuffer() *recvBuffer {
+	b := &recvBuffer{
+		c: make(chan recvMsg, 1),
+	}
+	return b
+}
+
+func (b *recvBuffer) put(r recvMsg) {
+	b.mu.Lock()
+	if b.err != nil {
+		b.mu.Unlock()
+		// An error had occurred earlier, don't accept more
+		// data or errors.
+		return
+	}
+	b.err = r.err
+	if len(b.backlog) == 0 {
+		select {
+		case b.c <- r:
+			b.mu.Unlock()
+			return
+		default:
+		}
+	}
+	b.backlog = append(b.backlog, r)
+	b.mu.Unlock()
+}
+
+func (b *recvBuffer) load() {
+	b.mu.Lock()
+	if len(b.backlog) > 0 {
+		select {
+		case b.c <- b.backlog[0]:
+			b.backlog[0] = recvMsg{}
+			b.backlog = b.backlog[1:]
+		default:
+		}
+	}
+	b.mu.Unlock()
+}
+
+// get returns the channel that receives a recvMsg in the buffer.
+//
+// Upon receipt of a recvMsg, the caller should call load to send another
+// recvMsg onto the channel if there is any.
+func (b *recvBuffer) get() <-chan recvMsg {
+	return b.c
+}
+
+// recvBufferReader implements io.Reader interface to read the data from
+// recvBuffer.
+type recvBufferReader struct {
+	closeStream func(error) // Closes the client transport stream with the given error and nil trailer metadata.
+	ctx         context.Context
+	ctxDone     <-chan struct{} // cache of ctx.Done() (for performance).
+	recv        *recvBuffer
+	last        *bytes.Buffer // Stores the remaining data in the previous calls.
+	err         error
+	freeBuffer  func(*bytes.Buffer)
+}
+
+// Read reads the next len(p) bytes from last. If last is drained, it tries to
+// read additional data from recv. It blocks if there no additional data available
+// in recv. If Read returns any non-nil error, it will continue to return that error.
+func (r *recvBufferReader) Read(p []byte) (n int, err error) {
+	if r.err != nil {
+		return 0, r.err
+	}
+	if r.last != nil {
+		// Read remaining data left in last call.
+		copied, _ := r.last.Read(p)
+		if r.last.Len() == 0 {
+			r.freeBuffer(r.last)
+			r.last = nil
+		}
+		return copied, nil
+	}
+	if r.closeStream != nil {
+		n, r.err = r.readClient(p)
+	} else {
+		n, r.err = r.read(p)
+	}
+	return n, r.err
+}
+
+func (r *recvBufferReader) read(p []byte) (n int, err error) {
+	select {
+	case <-r.ctxDone:
+		return 0, ContextErr(r.ctx.Err())
+	case m := <-r.recv.get():
+		return r.readAdditional(m, p)
+	}
+}
+
+func (r *recvBufferReader) readClient(p []byte) (n int, err error) {
+	// If the context is canceled, then closes the stream with nil metadata.
+	// closeStream writes its error parameter to r.recv as a recvMsg.
+	// r.readAdditional acts on that message and returns the necessary error.
+	select {
+	case <-r.ctxDone:
+		// Note that this adds the ctx error to the end of recv buffer, and
+		// reads from the head. This will delay the error until recv buffer is
+		// empty, thus will delay ctx cancellation in Recv().
+		//
+		// It's done this way to fix a race between ctx cancel and trailer. The
+		// race was, stream.Recv() may return ctx error if ctxDone wins the
+		// race, but stream.Trailer() may return a non-nil md because the stream
+		// was not marked as done when trailer is received. This closeStream
+		// call will mark stream as done, thus fix the race.
+		//
+		// TODO: delaying ctx error seems like a unnecessary side effect. What
+		// we really want is to mark the stream as done, and return ctx error
+		// faster.
+		r.closeStream(ContextErr(r.ctx.Err()))
+		m := <-r.recv.get()
+		return r.readAdditional(m, p)
+	case m := <-r.recv.get():
+		return r.readAdditional(m, p)
+	}
+}
+
+func (r *recvBufferReader) readAdditional(m recvMsg, p []byte) (n int, err error) {
+	r.recv.load()
+	if m.err != nil {
+		return 0, m.err
+	}
+	copied, _ := m.buffer.Read(p)
+	if m.buffer.Len() == 0 {
+		r.freeBuffer(m.buffer)
+		r.last = nil
+	} else {
+		r.last = m.buffer
+	}
+	return copied, nil
+}
+
+type streamState uint32
+
+const (
+	streamActive    streamState = iota
+	streamWriteDone             // EndStream sent
+	streamReadDone              // EndStream received
+	streamDone                  // the entire stream is finished.
+)
+
+// Stream represents an RPC in the transport layer.
+type Stream struct {
+	id           uint32
+	st           ServerTransport    // nil for client side Stream
+	ct           *http2Client       // nil for server side Stream
+	ctx          context.Context    // the associated context of the stream
+	cancel       context.CancelFunc // always nil for client side Stream
+	done         chan struct{}      // closed at the end of stream to unblock writers. On the client side.
+	doneFunc     func()             // invoked at the end of stream on client side.
+	ctxDone      <-chan struct{}    // same as done chan but for server side. Cache of ctx.Done() (for performance)
+	method       string             // the associated RPC method of the stream
+	recvCompress string
+	sendCompress string
+	buf          *recvBuffer
+	trReader     io.Reader
+	fc           *inFlow
+	wq           *writeQuota
+
+	// Callback to state application's intentions to read data. This
+	// is used to adjust flow control, if needed.
+	requestRead func(int)
+
+	headerChan       chan struct{} // closed to indicate the end of header metadata.
+	headerChanClosed uint32        // set when headerChan is closed. Used to avoid closing headerChan multiple times.
+	// headerValid indicates whether a valid header was received.  Only
+	// meaningful after headerChan is closed (always call waitOnHeader() before
+	// reading its value).  Not valid on server side.
+	headerValid bool
+
+	// hdrMu protects header and trailer metadata on the server-side.
+	hdrMu sync.Mutex
+	// On client side, header keeps the received header metadata.
+	//
+	// On server side, header keeps the header set by SetHeader(). The complete
+	// header will merged into this after t.WriteHeader() is called.
+	header  metadata.MD
+	trailer metadata.MD // the key-value map of trailer metadata.
+
+	noHeaders bool // set if the client never received headers (set only after the stream is done).
+
+	// On the server-side, headerSent is atomically set to 1 when the headers are sent out.
+	headerSent uint32
+
+	state streamState
+
+	// On client-side it is the status error received from the server.
+	// On server-side it is unused.
+	status *status.Status
+
+	bytesReceived uint32 // indicates whether any bytes have been received on this stream
+	unprocessed   uint32 // set if the server sends a refused stream or GOAWAY including this stream
+
+	// contentSubtype is the content-subtype for requests.
+	// this must be lowercase or the behavior is undefined.
+	contentSubtype string
+}
+
+// isHeaderSent is only valid on the server-side.
+func (s *Stream) isHeaderSent() bool {
+	return atomic.LoadUint32(&s.headerSent) == 1
+}
+
+// updateHeaderSent updates headerSent and returns true
+// if it was alreay set. It is valid only on server-side.
+func (s *Stream) updateHeaderSent() bool {
+	return atomic.SwapUint32(&s.headerSent, 1) == 1
+}
+
+func (s *Stream) swapState(st streamState) streamState {
+	return streamState(atomic.SwapUint32((*uint32)(&s.state), uint32(st)))
+}
+
+func (s *Stream) compareAndSwapState(oldState, newState streamState) bool {
+	return atomic.CompareAndSwapUint32((*uint32)(&s.state), uint32(oldState), uint32(newState))
+}
+
+func (s *Stream) getState() streamState {
+	return streamState(atomic.LoadUint32((*uint32)(&s.state)))
+}
+
+func (s *Stream) waitOnHeader() {
+	if s.headerChan == nil {
+		// On the server headerChan is always nil since a stream originates
+		// only after having received headers.
+		return
+	}
+	select {
+	case <-s.ctx.Done():
+		// Close the stream to prevent headers/trailers from changing after
+		// this function returns.
+		s.ct.CloseStream(s, ContextErr(s.ctx.Err()))
+		// headerChan could possibly not be closed yet if closeStream raced
+		// with operateHeaders; wait until it is closed explicitly here.
+		<-s.headerChan
+	case <-s.headerChan:
+	}
+}
+
+// RecvCompress returns the compression algorithm applied to the inbound
+// message. It is empty string if there is no compression applied.
+func (s *Stream) RecvCompress() string {
+	s.waitOnHeader()
+	return s.recvCompress
+}
+
+// SetSendCompress sets the compression algorithm to the stream.
+func (s *Stream) SetSendCompress(str string) {
+	s.sendCompress = str
+}
+
+// Done returns a channel which is closed when it receives the final status
+// from the server.
+func (s *Stream) Done() <-chan struct{} {
+	return s.done
+}
+
+// Header returns the header metadata of the stream.
+//
+// On client side, it acquires the key-value pairs of header metadata once it is
+// available. It blocks until i) the metadata is ready or ii) there is no header
+// metadata or iii) the stream is canceled/expired.
+//
+// On server side, it returns the out header after t.WriteHeader is called.  It
+// does not block and must not be called until after WriteHeader.
+func (s *Stream) Header() (metadata.MD, error) {
+	if s.headerChan == nil {
+		// On server side, return the header in stream. It will be the out
+		// header after t.WriteHeader is called.
+		return s.header.Copy(), nil
+	}
+	s.waitOnHeader()
+
+	if !s.headerValid {
+		return nil, s.status.Err()
+	}
+
+	if s.noHeaders {
+		return nil, ErrNoHeaders
+	}
+
+	return s.header.Copy(), nil
+}
+
+// TrailersOnly blocks until a header or trailers-only frame is received and
+// then returns true if the stream was trailers-only.  If the stream ends
+// before headers are received, returns true, nil.  Client-side only.
+func (s *Stream) TrailersOnly() bool {
+	s.waitOnHeader()
+	return s.noHeaders
+}
+
+// Trailer returns the cached trailer metedata. Note that if it is not called
+// after the entire stream is done, it could return an empty MD. Client
+// side only.
+// It can be safely read only after stream has ended that is either read
+// or write have returned io.EOF.
+func (s *Stream) Trailer() metadata.MD {
+	c := s.trailer.Copy()
+	return c
+}
+
+// ContentSubtype returns the content-subtype for a request. For example, a
+// content-subtype of "proto" will result in a content-type of
+// "application/grpc+proto". This will always be lowercase.  See
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
+// more details.
+func (s *Stream) ContentSubtype() string {
+	return s.contentSubtype
+}
+
+// Context returns the context of the stream.
+func (s *Stream) Context() context.Context {
+	return s.ctx
+}
+
+// Method returns the method for the stream.
+func (s *Stream) Method() string {
+	return s.method
+}
+
+// Status returns the status received from the server.
+// Status can be read safely only after the stream has ended,
+// that is, after Done() is closed.
+func (s *Stream) Status() *status.Status {
+	return s.status
+}
+
+// SetHeader sets the header metadata. This can be called multiple times.
+// Server side only.
+// This should not be called in parallel to other data writes.
+func (s *Stream) SetHeader(md metadata.MD) error {
+	if md.Len() == 0 {
+		return nil
+	}
+	if s.isHeaderSent() || s.getState() == streamDone {
+		return ErrIllegalHeaderWrite
+	}
+	s.hdrMu.Lock()
+	s.header = metadata.Join(s.header, md)
+	s.hdrMu.Unlock()
+	return nil
+}
+
+// SendHeader sends the given header metadata. The given metadata is
+// combined with any metadata set by previous calls to SetHeader and
+// then written to the transport stream.
+func (s *Stream) SendHeader(md metadata.MD) error {
+	return s.st.WriteHeader(s, md)
+}
+
+// SetTrailer sets the trailer metadata which will be sent with the RPC status
+// by the server. This can be called multiple times. Server side only.
+// This should not be called parallel to other data writes.
+func (s *Stream) SetTrailer(md metadata.MD) error {
+	if md.Len() == 0 {
+		return nil
+	}
+	if s.getState() == streamDone {
+		return ErrIllegalHeaderWrite
+	}
+	s.hdrMu.Lock()
+	s.trailer = metadata.Join(s.trailer, md)
+	s.hdrMu.Unlock()
+	return nil
+}
+
+func (s *Stream) write(m recvMsg) {
+	s.buf.put(m)
+}
+
+// Read reads all p bytes from the wire for this stream.
+func (s *Stream) Read(p []byte) (n int, err error) {
+	// Don't request a read if there was an error earlier
+	if er := s.trReader.(*transportReader).er; er != nil {
+		return 0, er
+	}
+	s.requestRead(len(p))
+	return io.ReadFull(s.trReader, p)
+}
+
+// tranportReader reads all the data available for this Stream from the transport and
+// passes them into the decoder, which converts them into a gRPC message stream.
+// The error is io.EOF when the stream is done or another non-nil error if
+// the stream broke.
+type transportReader struct {
+	reader io.Reader
+	// The handler to control the window update procedure for both this
+	// particular stream and the associated transport.
+	windowHandler func(int)
+	er            error
+}
+
+func (t *transportReader) Read(p []byte) (n int, err error) {
+	n, err = t.reader.Read(p)
+	if err != nil {
+		t.er = err
+		return
+	}
+	t.windowHandler(n)
+	return
+}
+
+// BytesReceived indicates whether any bytes have been received on this stream.
+func (s *Stream) BytesReceived() bool {
+	return atomic.LoadUint32(&s.bytesReceived) == 1
+}
+
+// Unprocessed indicates whether the server did not process this stream --
+// i.e. it sent a refused stream or GOAWAY including this stream ID.
+func (s *Stream) Unprocessed() bool {
+	return atomic.LoadUint32(&s.unprocessed) == 1
+}
+
+// GoString is implemented by Stream so context.String() won't
+// race when printing %#v.
+func (s *Stream) GoString() string {
+	return fmt.Sprintf("<stream: %p, %v>", s, s.method)
+}
+
+// state of transport
+type transportState int
+
+const (
+	reachable transportState = iota
+	closing
+	draining
+)
+
+// ServerConfig consists of all the configurations to establish a server transport.
+type ServerConfig struct {
+	MaxStreams            uint32
+	ConnectionTimeout     time.Duration
+	Credentials           credentials.TransportCredentials
+	InTapHandle           tap.ServerInHandle
+	StatsHandlers         []stats.Handler
+	KeepaliveParams       keepalive.ServerParameters
+	KeepalivePolicy       keepalive.EnforcementPolicy
+	InitialWindowSize     int32
+	InitialConnWindowSize int32
+	WriteBufferSize       int
+	ReadBufferSize        int
+	ChannelzParentID      *channelz.Identifier
+	MaxHeaderListSize     *uint32
+	HeaderTableSize       *uint32
+}
+
+// ConnectOptions covers all relevant options for communicating with the server.
+type ConnectOptions struct {
+	// UserAgent is the application user agent.
+	UserAgent string
+	// Dialer specifies how to dial a network address.
+	Dialer func(context.Context, string) (net.Conn, error)
+	// FailOnNonTempDialError specifies if gRPC fails on non-temporary dial errors.
+	FailOnNonTempDialError bool
+	// PerRPCCredentials stores the PerRPCCredentials required to issue RPCs.
+	PerRPCCredentials []credentials.PerRPCCredentials
+	// TransportCredentials stores the Authenticator required to setup a client
+	// connection. Only one of TransportCredentials and CredsBundle is non-nil.
+	TransportCredentials credentials.TransportCredentials
+	// CredsBundle is the credentials bundle to be used. Only one of
+	// TransportCredentials and CredsBundle is non-nil.
+	CredsBundle credentials.Bundle
+	// KeepaliveParams stores the keepalive parameters.
+	KeepaliveParams keepalive.ClientParameters
+	// StatsHandlers stores the handler for stats.
+	StatsHandlers []stats.Handler
+	// InitialWindowSize sets the initial window size for a stream.
+	InitialWindowSize int32
+	// InitialConnWindowSize sets the initial window size for a connection.
+	InitialConnWindowSize int32
+	// WriteBufferSize sets the size of write buffer which in turn determines how much data can be batched before it's written on the wire.
+	WriteBufferSize int
+	// ReadBufferSize sets the size of read buffer, which in turn determines how much data can be read at most for one read syscall.
+	ReadBufferSize int
+	// ChannelzParentID sets the addrConn id which initiate the creation of this client transport.
+	ChannelzParentID *channelz.Identifier
+	// MaxHeaderListSize sets the max (uncompressed) size of header list that is prepared to be received.
+	MaxHeaderListSize *uint32
+	// UseProxy specifies if a proxy should be used.
+	UseProxy bool
+}
+
+// NewClientTransport establishes the transport with the required ConnectOptions
+// and returns it to the caller.
+func NewClientTransport(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose func(GoAwayReason)) (ClientTransport, error) {
+	return newHTTP2Client(connectCtx, ctx, addr, opts, onClose)
+}
+
+// Options provides additional hints and information for message
+// transmission.
+type Options struct {
+	// Last indicates whether this write is the last piece for
+	// this stream.
+	Last bool
+}
+
+// CallHdr carries the information of a particular RPC.
+type CallHdr struct {
+	// Host specifies the peer's host.
+	Host string
+
+	// Method specifies the operation to perform.
+	Method string
+
+	// SendCompress specifies the compression algorithm applied on
+	// outbound message.
+	SendCompress string
+
+	// Creds specifies credentials.PerRPCCredentials for a call.
+	Creds credentials.PerRPCCredentials
+
+	// ContentSubtype specifies the content-subtype for a request. For example, a
+	// content-subtype of "proto" will result in a content-type of
+	// "application/grpc+proto". The value of ContentSubtype must be all
+	// lowercase, otherwise the behavior is undefined. See
+	// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
+	// for more details.
+	ContentSubtype string
+
+	PreviousAttempts int // value of grpc-previous-rpc-attempts header to set
+
+	DoneFunc func() // called when the stream is finished
+}
+
+// ClientTransport is the common interface for all gRPC client-side transport
+// implementations.
+type ClientTransport interface {
+	// Close tears down this transport. Once it returns, the transport
+	// should not be accessed any more. The caller must make sure this
+	// is called only once.
+	Close(err error)
+
+	// GracefulClose starts to tear down the transport: the transport will stop
+	// accepting new RPCs and NewStream will return error. Once all streams are
+	// finished, the transport will close.
+	//
+	// It does not block.
+	GracefulClose()
+
+	// Write sends the data for the given stream. A nil stream indicates
+	// the write is to be performed on the transport as a whole.
+	Write(s *Stream, hdr []byte, data []byte, opts *Options) error
+
+	// NewStream creates a Stream for an RPC.
+	NewStream(ctx context.Context, callHdr *CallHdr) (*Stream, error)
+
+	// CloseStream clears the footprint of a stream when the stream is
+	// not needed any more. The err indicates the error incurred when
+	// CloseStream is called. Must be called when a stream is finished
+	// unless the associated transport is closing.
+	CloseStream(stream *Stream, err error)
+
+	// Error returns a channel that is closed when some I/O error
+	// happens. Typically the caller should have a goroutine to monitor
+	// this in order to take action (e.g., close the current transport
+	// and create a new one) in error case. It should not return nil
+	// once the transport is initiated.
+	Error() <-chan struct{}
+
+	// GoAway returns a channel that is closed when ClientTransport
+	// receives the draining signal from the server (e.g., GOAWAY frame in
+	// HTTP/2).
+	GoAway() <-chan struct{}
+
+	// GetGoAwayReason returns the reason why GoAway frame was received, along
+	// with a human readable string with debug info.
+	GetGoAwayReason() (GoAwayReason, string)
+
+	// RemoteAddr returns the remote network address.
+	RemoteAddr() net.Addr
+
+	// IncrMsgSent increments the number of message sent through this transport.
+	IncrMsgSent()
+
+	// IncrMsgRecv increments the number of message received through this transport.
+	IncrMsgRecv()
+}
+
+// ServerTransport is the common interface for all gRPC server-side transport
+// implementations.
+//
+// Methods may be called concurrently from multiple goroutines, but
+// Write methods for a given Stream will be called serially.
+type ServerTransport interface {
+	// HandleStreams receives incoming streams using the given handler.
+	HandleStreams(func(*Stream), func(context.Context, string) context.Context)
+
+	// WriteHeader sends the header metadata for the given stream.
+	// WriteHeader may not be called on all streams.
+	WriteHeader(s *Stream, md metadata.MD) error
+
+	// Write sends the data for the given stream.
+	// Write may not be called on all streams.
+	Write(s *Stream, hdr []byte, data []byte, opts *Options) error
+
+	// WriteStatus sends the status of a stream to the client.  WriteStatus is
+	// the final call made on a stream and always occurs.
+	WriteStatus(s *Stream, st *status.Status) error
+
+	// Close tears down the transport. Once it is called, the transport
+	// should not be accessed any more. All the pending streams and their
+	// handlers will be terminated asynchronously.
+	Close(err error)
+
+	// RemoteAddr returns the remote network address.
+	RemoteAddr() net.Addr
+
+	// Drain notifies the client this ServerTransport stops accepting new RPCs.
+	Drain()
+
+	// IncrMsgSent increments the number of message sent through this transport.
+	IncrMsgSent()
+
+	// IncrMsgRecv increments the number of message received through this transport.
+	IncrMsgRecv()
+}
+
+// connectionErrorf creates an ConnectionError with the specified error description.
+func connectionErrorf(temp bool, e error, format string, a ...interface{}) ConnectionError {
+	return ConnectionError{
+		Desc: fmt.Sprintf(format, a...),
+		temp: temp,
+		err:  e,
+	}
+}
+
+// ConnectionError is an error that results in the termination of the
+// entire connection and the retry of all the active streams.
+type ConnectionError struct {
+	Desc string
+	temp bool
+	err  error
+}
+
+func (e ConnectionError) Error() string {
+	return fmt.Sprintf("connection error: desc = %q", e.Desc)
+}
+
+// Temporary indicates if this connection error is temporary or fatal.
+func (e ConnectionError) Temporary() bool {
+	return e.temp
+}
+
+// Origin returns the original error of this connection error.
+func (e ConnectionError) Origin() error {
+	// Never return nil error here.
+	// If the original error is nil, return itself.
+	if e.err == nil {
+		return e
+	}
+	return e.err
+}
+
+// Unwrap returns the original error of this connection error or nil when the
+// origin is nil.
+func (e ConnectionError) Unwrap() error {
+	return e.err
+}
+
+var (
+	// ErrConnClosing indicates that the transport is closing.
+	ErrConnClosing = connectionErrorf(true, nil, "transport is closing")
+	// errStreamDrain indicates that the stream is rejected because the
+	// connection is draining. This could be caused by goaway or balancer
+	// removing the address.
+	errStreamDrain = status.Error(codes.Unavailable, "the connection is draining")
+	// errStreamDone is returned from write at the client side to indiacte application
+	// layer of an error.
+	errStreamDone = errors.New("the stream is done")
+	// StatusGoAway indicates that the server sent a GOAWAY that included this
+	// stream's ID in unprocessed RPCs.
+	statusGoAway = status.New(codes.Unavailable, "the stream is rejected because server is draining the connection")
+)
+
+// GoAwayReason contains the reason for the GoAway frame received.
+type GoAwayReason uint8
+
+const (
+	// GoAwayInvalid indicates that no GoAway frame is received.
+	GoAwayInvalid GoAwayReason = 0
+	// GoAwayNoReason is the default value when GoAway frame is received.
+	GoAwayNoReason GoAwayReason = 1
+	// GoAwayTooManyPings indicates that a GoAway frame with
+	// ErrCodeEnhanceYourCalm was received and that the debug data said
+	// "too_many_pings".
+	GoAwayTooManyPings GoAwayReason = 2
+)
+
+// channelzData is used to store channelz related data for http2Client and http2Server.
+// These fields cannot be embedded in the original structs (e.g. http2Client), since to do atomic
+// operation on int64 variable on 32-bit machine, user is responsible to enforce memory alignment.
+// Here, by grouping those int64 fields inside a struct, we are enforcing the alignment.
+type channelzData struct {
+	kpCount int64
+	// The number of streams that have started, including already finished ones.
+	streamsStarted int64
+	// Client side: The number of streams that have ended successfully by receiving
+	// EoS bit set frame from server.
+	// Server side: The number of streams that have ended successfully by sending
+	// frame with EoS bit set.
+	streamsSucceeded int64
+	streamsFailed    int64
+	// lastStreamCreatedTime stores the timestamp that the last stream gets created. It is of int64 type
+	// instead of time.Time since it's more costly to atomically update time.Time variable than int64
+	// variable. The same goes for lastMsgSentTime and lastMsgRecvTime.
+	lastStreamCreatedTime int64
+	msgSent               int64
+	msgRecv               int64
+	lastMsgSentTime       int64
+	lastMsgRecvTime       int64
+}
+
+// ContextErr converts the error from context package into a status error.
+func ContextErr(err error) error {
+	switch err {
+	case context.DeadlineExceeded:
+		return status.Error(codes.DeadlineExceeded, err.Error())
+	case context.Canceled:
+		return status.Error(codes.Canceled, err.Error())
+	}
+	return status.Errorf(codes.Internal, "Unexpected error from context packet: %v", err)
+}

vendor/google.golang.org/grpc/internal/xds_handshake_cluster.go

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package internal
+
+import (
+	"google.golang.org/grpc/attributes"
+	"google.golang.org/grpc/resolver"
+)
+
+// handshakeClusterNameKey is the type used as the key to store cluster name in
+// the Attributes field of resolver.Address.
+type handshakeClusterNameKey struct{}
+
+// SetXDSHandshakeClusterName returns a copy of addr in which the Attributes field
+// is updated with the cluster name.
+func SetXDSHandshakeClusterName(addr resolver.Address, clusterName string) resolver.Address {
+	addr.Attributes = addr.Attributes.WithValue(handshakeClusterNameKey{}, clusterName)
+	return addr
+}
+
+// GetXDSHandshakeClusterName returns cluster name stored in attr.
+func GetXDSHandshakeClusterName(attr *attributes.Attributes) (string, bool) {
+	v := attr.Value(handshakeClusterNameKey{})
+	name, ok := v.(string)
+	return name, ok
+}