Misc fixes

- Set LBEstimator to true by default
- Shuffle the servers list at startup
- Add the server name to the query log

dnscrypt-proxy/config.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"math/rand"
 	"net/http"
 	"net/url"
 	"os"
@@ -115,6 +116,7 @@ func newConfig() Config {
 		NetprobeTimeout:          60,
 		OfflineMode:              false,
 		RefusedCodeInResponses:   false,
+		LBEstimator:              true,
 	}
 }
 
@@ -519,6 +521,10 @@ func (config *Config) loadSources(proxy *Proxy) error {
 		}
 		proxy.registeredServers = append(proxy.registeredServers, RegisteredServer{name: serverName, stamp: stamp})
 	}
+	rand.Shuffle(len(proxy.registeredServers), func(i, j int) {
+		proxy.registeredServers[i], proxy.registeredServers[j] = proxy.registeredServers[j], proxy.registeredServers[i]
+	})
+
 	return nil
 }
 

dnscrypt-proxy/crypto.go

@@ -2,9 +2,10 @@ package main
 
 import (
 	"bytes"
-	"crypto/rand"
+	crypto_rand "crypto/rand"
 	"crypto/sha512"
 	"errors"
+	"math/rand"
 
 	"github.com/jedisct1/dlog"
 	"github.com/jedisct1/xsecretbox"
@@ -59,7 +60,7 @@ func ComputeSharedKey(cryptoConstruction CryptoConstruction, secretKey *[32]byte
 
 func (proxy *Proxy) Encrypt(serverInfo *ServerInfo, packet []byte, proto string) (sharedKey *[32]byte, encrypted []byte, clientNonce []byte, err error) {
 	nonce, clientNonce := make([]byte, NonceSize), make([]byte, HalfNonceSize)
-	rand.Read(clientNonce)
+	crypto_rand.Read(clientNonce)
 	copy(nonce, clientNonce)
 	var publicKey *[PublicKeySize]byte
 	if proxy.ephemeralKeys {

dnscrypt-proxy/main.go

@@ -1,8 +1,11 @@
 package main
 
 import (
+	crypto_rand "crypto/rand"
+	"encoding/binary"
 	"flag"
 	"fmt"
+	"math/rand"
 	"os"
 	"sync"
 
@@ -26,6 +29,10 @@ func main() {
 	dlog.Init("dnscrypt-proxy", dlog.SeverityNotice, "DAEMON")
 	os.Setenv("GODEBUG", os.Getenv("GODEBUG")+",tls13=1")
 
+	seed := make([]byte, 8)
+	crypto_rand.Read(seed)
+	rand.Seed(int64(binary.LittleEndian.Uint64(seed[:])))
+
 	pwd, err := os.Getwd()
 	if err != nil {
 		dlog.Fatal("Unable to find the path to the current directory")

dnscrypt-proxy/plugin_query_log.go

@@ -82,14 +82,15 @@ func (plugin *PluginQueryLog) Eval(pluginsState *PluginsState, msg *dns.Msg) err
 		year, month, day := now.Date()
 		hour, minute, second := now.Clock()
 		tsStr := fmt.Sprintf("[%d-%02d-%02d %02d:%02d:%02d]", year, int(month), day, hour, minute, second)
-		line = fmt.Sprintf("%s\t%s\t%s\t%s\t%s\t%dms\n", tsStr, clientIPStr, StringQuote(qName), qType, returnCode, requestDuration/time.Millisecond)
+		line = fmt.Sprintf("%s\t%s\t%s\t%s\t%s\t%dms\t%s\n", tsStr, clientIPStr, StringQuote(qName), qType, returnCode, requestDuration/time.Millisecond,
+			StringQuote(pluginsState.serverName))
 	} else if plugin.format == "ltsv" {
 		cached := 0
 		if pluginsState.cacheHit {
 			cached = 1
 		}
-		line = fmt.Sprintf("time:%d\thost:%s\tmessage:%s\ttype:%s\treturn:%s\tcached:%d\tduration:%d\n",
-			time.Now().Unix(), clientIPStr, StringQuote(qName), qType, returnCode, cached, requestDuration/time.Millisecond)
+		line = fmt.Sprintf("time:%d\thost:%s\tmessage:%s\ttype:%s\treturn:%s\tcached:%d\tduration:%d\tserver:%s\n",
+			time.Now().Unix(), clientIPStr, StringQuote(qName), qType, returnCode, cached, requestDuration/time.Millisecond, StringQuote(pluginsState.serverName))
 	} else {
 		dlog.Fatalf("Unexpected log format: [%s]", plugin.format)
 	}

dnscrypt-proxy/plugins.go

@@ -75,6 +75,7 @@ type PluginsState struct {
 	requestEnd             time.Time
 	cacheHit               bool
 	returnCode             PluginsReturnCode
+	serverName             string
 }
 
 func InitPluginsGlobals(pluginsGlobals *PluginsGlobals, proxy *Proxy) error {
@@ -163,10 +164,11 @@ func NewPluginsState(proxy *Proxy, clientProto string, clientAddr *net.Addr, sta
 	}
 }
 
-func (pluginsState *PluginsState) ApplyQueryPlugins(pluginsGlobals *PluginsGlobals, packet []byte) ([]byte, error) {
+func (pluginsState *PluginsState) ApplyQueryPlugins(pluginsGlobals *PluginsGlobals, packet []byte, serverName *string) ([]byte, error) {
 	if len(*pluginsGlobals.queryPlugins) == 0 && len(*pluginsGlobals.loggingPlugins) == 0 {
 		return packet, nil
 	}
+	pluginsState.serverName = *serverName
 	pluginsState.action = PluginsActionForward
 	msg := dns.Msg{}
 	if err := msg.Unpack(packet); err != nil {

dnscrypt-proxy/proxy.go

@@ -1,9 +1,9 @@
 package main
 
 import (
+	crypto_rand "crypto/rand"
 	"io"
 	"io/ioutil"
-	"math/rand"
 	"net"
 	"os"
 	"sync/atomic"
@@ -68,7 +68,7 @@ type Proxy struct {
 
 func (proxy *Proxy) StartProxy() {
 	proxy.questionSizeEstimator = NewQuestionSizeEstimator()
-	if _, err := rand.Read(proxy.proxySecretKey[:]); err != nil {
+	if _, err := crypto_rand.Read(proxy.proxySecretKey[:]); err != nil {
 		dlog.Fatal(err)
 	}
 	curve25519.ScalarBaseMult(&proxy.proxyPublicKey, &proxy.proxySecretKey)
@@ -332,7 +332,7 @@ func (proxy *Proxy) processIncomingQuery(serverInfo *ServerInfo, clientProto str
 		return
 	}
 	pluginsState := NewPluginsState(proxy, clientProto, clientAddr, start)
-	query, _ = pluginsState.ApplyQueryPlugins(&proxy.pluginsGlobals, query)
+	query, _ = pluginsState.ApplyQueryPlugins(&proxy.pluginsGlobals, query, &serverInfo.Name)
 	if len(query) < MinDNSPacketSize || len(query) > MaxDNSPacketSize {
 		return
 	}
@@ -461,6 +461,6 @@ func (proxy *Proxy) processIncomingQuery(serverInfo *ServerInfo, clientProto str
 
 func NewProxy() Proxy {
 	return Proxy{
-		serversInfo: ServersInfo{lbStrategy: DefaultLBStrategy, lbEstimator: true},
+		serversInfo: NewServersInfo(),
 	}
 }

dnscrypt-proxy/serversInfo.go

@@ -70,6 +70,10 @@ type ServersInfo struct {
 	lbEstimator       bool
 }
 
+func NewServersInfo() ServersInfo {
+	return ServersInfo{lbStrategy: DefaultLBStrategy, lbEstimator: true, registeredServers: make([]RegisteredServer, 0)}
+}
+
 func (serversInfo *ServersInfo) registerServer(proxy *Proxy, name string, stamp stamps.ServerStamp) error {
 	newRegisteredServer := RegisteredServer{name: name, stamp: stamp}
 	serversInfo.Lock()
@@ -175,9 +179,10 @@ func (serversInfo *ServersInfo) estimatorUpdate(candidate int) {
 		serversInfo.inner[candidate], serversInfo.inner[0] = serversInfo.inner[0], serversInfo.inner[candidate]
 		partialSort = true
 		dlog.Debugf("New preferred candidate: %v (rtt: %v vs previous: %v)", serversInfo.inner[0].Name, candidateRtt, currentBestRtt)
-	} else if candidateRtt >= currentBestRtt*4.0 {
+	} else if candidateRtt > 0 && candidateRtt >= currentBestRtt*4.0 {
 		if time.Since(serversInfo.inner[candidate].lastActionTS) > time.Duration(1*time.Minute) {
 			serversInfo.inner[candidate].rtt.Add(MinF(MaxF(candidateRtt/2.0, currentBestRtt*2.0), candidateRtt))
+			dlog.Debugf("Giving a new chance to candidate [%s], setting its RTT from %v to %v (best: %v)", serversInfo.inner[candidate].Name, candidateRtt, serversInfo.inner[candidate].rtt.Value(), currentBestRtt)
 			partialSort = true
 		}
 	}