295 lines
8.5 KiB
Go
295 lines
8.5 KiB
Go
// Copyright 2018 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package proto
|
|
|
|
import (
|
|
"google.golang.org/protobuf/encoding/protowire"
|
|
"google.golang.org/protobuf/internal/encoding/messageset"
|
|
"google.golang.org/protobuf/internal/errors"
|
|
"google.golang.org/protobuf/internal/flags"
|
|
"google.golang.org/protobuf/internal/genid"
|
|
"google.golang.org/protobuf/internal/pragma"
|
|
"google.golang.org/protobuf/reflect/protoreflect"
|
|
"google.golang.org/protobuf/reflect/protoregistry"
|
|
"google.golang.org/protobuf/runtime/protoiface"
|
|
)
|
|
|
|
// UnmarshalOptions configures the unmarshaler.
|
|
//
|
|
// Example usage:
|
|
//
|
|
// err := UnmarshalOptions{DiscardUnknown: true}.Unmarshal(b, m)
|
|
type UnmarshalOptions struct {
|
|
pragma.NoUnkeyedLiterals
|
|
|
|
// Merge merges the input into the destination message.
|
|
// The default behavior is to always reset the message before unmarshaling,
|
|
// unless Merge is specified.
|
|
Merge bool
|
|
|
|
// AllowPartial accepts input for messages that will result in missing
|
|
// required fields. If AllowPartial is false (the default), Unmarshal will
|
|
// return an error if there are any missing required fields.
|
|
AllowPartial bool
|
|
|
|
// If DiscardUnknown is set, unknown fields are ignored.
|
|
DiscardUnknown bool
|
|
|
|
// Resolver is used for looking up types when unmarshaling extension fields.
|
|
// If nil, this defaults to using protoregistry.GlobalTypes.
|
|
Resolver interface {
|
|
FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error)
|
|
FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error)
|
|
}
|
|
|
|
// RecursionLimit limits how deeply messages may be nested.
|
|
// If zero, a default limit is applied.
|
|
RecursionLimit int
|
|
}
|
|
|
|
// Unmarshal parses the wire-format message in b and places the result in m.
|
|
// The provided message must be mutable (e.g., a non-nil pointer to a message).
|
|
func Unmarshal(b []byte, m Message) error {
|
|
_, err := UnmarshalOptions{RecursionLimit: protowire.DefaultRecursionLimit}.unmarshal(b, m.ProtoReflect())
|
|
return err
|
|
}
|
|
|
|
// Unmarshal parses the wire-format message in b and places the result in m.
|
|
// The provided message must be mutable (e.g., a non-nil pointer to a message).
|
|
func (o UnmarshalOptions) Unmarshal(b []byte, m Message) error {
|
|
if o.RecursionLimit == 0 {
|
|
o.RecursionLimit = protowire.DefaultRecursionLimit
|
|
}
|
|
_, err := o.unmarshal(b, m.ProtoReflect())
|
|
return err
|
|
}
|
|
|
|
// UnmarshalState parses a wire-format message and places the result in m.
|
|
//
|
|
// This method permits fine-grained control over the unmarshaler.
|
|
// Most users should use Unmarshal instead.
|
|
func (o UnmarshalOptions) UnmarshalState(in protoiface.UnmarshalInput) (protoiface.UnmarshalOutput, error) {
|
|
if o.RecursionLimit == 0 {
|
|
o.RecursionLimit = protowire.DefaultRecursionLimit
|
|
}
|
|
return o.unmarshal(in.Buf, in.Message)
|
|
}
|
|
|
|
// unmarshal is a centralized function that all unmarshal operations go through.
|
|
// For profiling purposes, avoid changing the name of this function or
|
|
// introducing other code paths for unmarshal that do not go through this.
|
|
func (o UnmarshalOptions) unmarshal(b []byte, m protoreflect.Message) (out protoiface.UnmarshalOutput, err error) {
|
|
if o.Resolver == nil {
|
|
o.Resolver = protoregistry.GlobalTypes
|
|
}
|
|
if !o.Merge {
|
|
Reset(m.Interface())
|
|
}
|
|
allowPartial := o.AllowPartial
|
|
o.Merge = true
|
|
o.AllowPartial = true
|
|
methods := protoMethods(m)
|
|
if methods != nil && methods.Unmarshal != nil &&
|
|
!(o.DiscardUnknown && methods.Flags&protoiface.SupportUnmarshalDiscardUnknown == 0) {
|
|
in := protoiface.UnmarshalInput{
|
|
Message: m,
|
|
Buf: b,
|
|
Resolver: o.Resolver,
|
|
Depth: o.RecursionLimit,
|
|
}
|
|
if o.DiscardUnknown {
|
|
in.Flags |= protoiface.UnmarshalDiscardUnknown
|
|
}
|
|
out, err = methods.Unmarshal(in)
|
|
} else {
|
|
o.RecursionLimit--
|
|
if o.RecursionLimit < 0 {
|
|
return out, errors.New("exceeded max recursion depth")
|
|
}
|
|
err = o.unmarshalMessageSlow(b, m)
|
|
}
|
|
if err != nil {
|
|
return out, err
|
|
}
|
|
if allowPartial || (out.Flags&protoiface.UnmarshalInitialized != 0) {
|
|
return out, nil
|
|
}
|
|
return out, checkInitialized(m)
|
|
}
|
|
|
|
func (o UnmarshalOptions) unmarshalMessage(b []byte, m protoreflect.Message) error {
|
|
_, err := o.unmarshal(b, m)
|
|
return err
|
|
}
|
|
|
|
func (o UnmarshalOptions) unmarshalMessageSlow(b []byte, m protoreflect.Message) error {
|
|
md := m.Descriptor()
|
|
if messageset.IsMessageSet(md) {
|
|
return o.unmarshalMessageSet(b, m)
|
|
}
|
|
fields := md.Fields()
|
|
for len(b) > 0 {
|
|
// Parse the tag (field number and wire type).
|
|
num, wtyp, tagLen := protowire.ConsumeTag(b)
|
|
if tagLen < 0 {
|
|
return errDecode
|
|
}
|
|
if num > protowire.MaxValidNumber {
|
|
return errDecode
|
|
}
|
|
|
|
// Find the field descriptor for this field number.
|
|
fd := fields.ByNumber(num)
|
|
if fd == nil && md.ExtensionRanges().Has(num) {
|
|
extType, err := o.Resolver.FindExtensionByNumber(md.FullName(), num)
|
|
if err != nil && err != protoregistry.NotFound {
|
|
return errors.New("%v: unable to resolve extension %v: %v", md.FullName(), num, err)
|
|
}
|
|
if extType != nil {
|
|
fd = extType.TypeDescriptor()
|
|
}
|
|
}
|
|
var err error
|
|
if fd == nil {
|
|
err = errUnknown
|
|
} else if flags.ProtoLegacy {
|
|
if fd.IsWeak() && fd.Message().IsPlaceholder() {
|
|
err = errUnknown // weak referent is not linked in
|
|
}
|
|
}
|
|
|
|
// Parse the field value.
|
|
var valLen int
|
|
switch {
|
|
case err != nil:
|
|
case fd.IsList():
|
|
valLen, err = o.unmarshalList(b[tagLen:], wtyp, m.Mutable(fd).List(), fd)
|
|
case fd.IsMap():
|
|
valLen, err = o.unmarshalMap(b[tagLen:], wtyp, m.Mutable(fd).Map(), fd)
|
|
default:
|
|
valLen, err = o.unmarshalSingular(b[tagLen:], wtyp, m, fd)
|
|
}
|
|
if err != nil {
|
|
if err != errUnknown {
|
|
return err
|
|
}
|
|
valLen = protowire.ConsumeFieldValue(num, wtyp, b[tagLen:])
|
|
if valLen < 0 {
|
|
return errDecode
|
|
}
|
|
if !o.DiscardUnknown {
|
|
m.SetUnknown(append(m.GetUnknown(), b[:tagLen+valLen]...))
|
|
}
|
|
}
|
|
b = b[tagLen+valLen:]
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (o UnmarshalOptions) unmarshalSingular(b []byte, wtyp protowire.Type, m protoreflect.Message, fd protoreflect.FieldDescriptor) (n int, err error) {
|
|
v, n, err := o.unmarshalScalar(b, wtyp, fd)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
switch fd.Kind() {
|
|
case protoreflect.GroupKind, protoreflect.MessageKind:
|
|
m2 := m.Mutable(fd).Message()
|
|
if err := o.unmarshalMessage(v.Bytes(), m2); err != nil {
|
|
return n, err
|
|
}
|
|
default:
|
|
// Non-message scalars replace the previous value.
|
|
m.Set(fd, v)
|
|
}
|
|
return n, nil
|
|
}
|
|
|
|
func (o UnmarshalOptions) unmarshalMap(b []byte, wtyp protowire.Type, mapv protoreflect.Map, fd protoreflect.FieldDescriptor) (n int, err error) {
|
|
if wtyp != protowire.BytesType {
|
|
return 0, errUnknown
|
|
}
|
|
b, n = protowire.ConsumeBytes(b)
|
|
if n < 0 {
|
|
return 0, errDecode
|
|
}
|
|
var (
|
|
keyField = fd.MapKey()
|
|
valField = fd.MapValue()
|
|
key protoreflect.Value
|
|
val protoreflect.Value
|
|
haveKey bool
|
|
haveVal bool
|
|
)
|
|
switch valField.Kind() {
|
|
case protoreflect.GroupKind, protoreflect.MessageKind:
|
|
val = mapv.NewValue()
|
|
}
|
|
// Map entries are represented as a two-element message with fields
|
|
// containing the key and value.
|
|
for len(b) > 0 {
|
|
num, wtyp, n := protowire.ConsumeTag(b)
|
|
if n < 0 {
|
|
return 0, errDecode
|
|
}
|
|
if num > protowire.MaxValidNumber {
|
|
return 0, errDecode
|
|
}
|
|
b = b[n:]
|
|
err = errUnknown
|
|
switch num {
|
|
case genid.MapEntry_Key_field_number:
|
|
key, n, err = o.unmarshalScalar(b, wtyp, keyField)
|
|
if err != nil {
|
|
break
|
|
}
|
|
haveKey = true
|
|
case genid.MapEntry_Value_field_number:
|
|
var v protoreflect.Value
|
|
v, n, err = o.unmarshalScalar(b, wtyp, valField)
|
|
if err != nil {
|
|
break
|
|
}
|
|
switch valField.Kind() {
|
|
case protoreflect.GroupKind, protoreflect.MessageKind:
|
|
if err := o.unmarshalMessage(v.Bytes(), val.Message()); err != nil {
|
|
return 0, err
|
|
}
|
|
default:
|
|
val = v
|
|
}
|
|
haveVal = true
|
|
}
|
|
if err == errUnknown {
|
|
n = protowire.ConsumeFieldValue(num, wtyp, b)
|
|
if n < 0 {
|
|
return 0, errDecode
|
|
}
|
|
} else if err != nil {
|
|
return 0, err
|
|
}
|
|
b = b[n:]
|
|
}
|
|
// Every map entry should have entries for key and value, but this is not strictly required.
|
|
if !haveKey {
|
|
key = keyField.Default()
|
|
}
|
|
if !haveVal {
|
|
switch valField.Kind() {
|
|
case protoreflect.GroupKind, protoreflect.MessageKind:
|
|
default:
|
|
val = valField.Default()
|
|
}
|
|
}
|
|
mapv.Set(key.MapKey(), val)
|
|
return n, nil
|
|
}
|
|
|
|
// errUnknown is used internally to indicate fields which should be added
|
|
// to the unknown field set of a message. It is never returned from an exported
|
|
// function.
|
|
var errUnknown = errors.New("BUG: internal error (unknown)")
|
|
|
|
var errDecode = errors.New("cannot parse invalid wire-format data")
|