Move a few things around

common.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"net"
 	"time"
 )
 
@@ -22,6 +23,16 @@ var (
 	TimeoutMax             = 5 * time.Second
 )
 
+type ServerInfo struct {
+	MagicQuery         [8]byte
+	ServerPk           [32]byte
+	SharedKey          [32]byte
+	CryptoConstruction CryptoConstruction
+	Timeout            time.Duration
+	UDPAddr            *net.UDPAddr
+	TCPAddr            *net.TCPAddr
+}
+
 func HasTCFlag(packet []byte) bool {
 	return packet[2]&2 == 2
 }

dnscrypt-proxy.go

@@ -20,6 +20,79 @@ type Proxy struct {
 	serversInfo     []ServerInfo
 }
 
+func main() {
+	log.SetFlags(0)
+	_ = NewProxy("127.0.0.1:5399", "212.47.228.136:443", "E801:B84E:A606:BFB0:BAC0:CE43:445B:B15E:BA64:B02F:A3C4:AA31:AE10:636A:0790:324D", "2.dnscrypt-cert.fr.dnscrypt.org")
+}
+
+func NewProxy(listenAddrStr string, serverAddrStr string, serverPkStr string, providerName string) Proxy {
+	proxy := Proxy{minQuestionSize: InitialMinQuestionSize}
+	if _, err := rand.Read(proxy.proxySecretKey[:]); err != nil {
+		log.Fatal(err)
+	}
+	curve25519.ScalarBaseMult(&proxy.proxyPublicKey, &proxy.proxySecretKey)
+	proxy.fetchServerInfo(serverAddrStr, serverPkStr, providerName)
+	proxy.udpListener(listenAddrStr)
+	return proxy
+}
+
+func (proxy *Proxy) adjustMinQuestionSize() {
+	if MaxDNSPacketSize-proxy.minQuestionSize < proxy.minQuestionSize {
+		proxy.minQuestionSize = MaxDNSPacketSize
+	} else {
+		proxy.minQuestionSize *= 2
+	}
+}
+
+func (proxy *Proxy) udpListener(listenAddrStr string) error {
+	clientPc, err := net.ListenPacket("udp", listenAddrStr)
+	if err != nil {
+		return err
+	}
+	defer clientPc.Close()
+	fmt.Printf("Now listening to %v [UDP]\n", listenAddrStr)
+	for {
+		buffer := make([]byte, MaxDNSPacketSize)
+		length, clientAddr, err := clientPc.ReadFrom(buffer)
+		if err != nil {
+			return err
+		}
+		packet := buffer[:length]
+		go func() {
+			proxy.processIncomingUDPQuery(&proxy.serversInfo[0], packet, clientAddr, clientPc)
+		}()
+	}
+}
+
+func (proxy *Proxy) processIncomingUDPQuery(serverInfo *ServerInfo, packet []byte, clientAddr net.Addr, clientPc net.PacketConn) {
+	if len(packet) < MinDNSPacketSize {
+		return
+	}
+	encrypted, clientNonce := proxy.Crypt(serverInfo, packet)
+	pc, err := net.DialUDP("udp", nil, serverInfo.UDPAddr)
+	if err != nil {
+		return
+	}
+	defer pc.Close()
+	pc.SetDeadline(time.Now().Add(serverInfo.Timeout))
+	pc.Write(encrypted)
+
+	encrypted = make([]byte, MaxDNSPacketSize)
+	length, err := pc.Read(encrypted)
+	if err != nil {
+		return
+	}
+	encrypted = encrypted[:length]
+	packet, err = proxy.Decrypt(serverInfo, encrypted, clientNonce)
+	if err != nil {
+		return
+	}
+	clientPc.WriteTo(packet, clientAddr)
+	if HasTCFlag(packet) {
+		proxy.adjustMinQuestionSize()
+	}
+}
+
 func (proxy *Proxy) fetchServerInfo(serverAddrStr string, serverPkStr string, providerName string) {
 	serverPublicKey, err := hex.DecodeString(strings.Replace(serverPkStr, ":", "", -1))
 	if err != nil || len(serverPublicKey) != ed25519.PublicKeySize {
@@ -48,82 +121,3 @@ func (proxy *Proxy) fetchServerInfo(serverAddrStr string, serverPkStr string, pr
 	}
 	proxy.serversInfo = append(proxy.serversInfo, serverInfo)
 }
-
-func NewProxy(listenAddrStr string, serverAddrStr string, serverPkStr string, providerName string) Proxy {
-	proxy := Proxy{minQuestionSize: InitialMinQuestionSize}
-	if _, err := rand.Read(proxy.proxySecretKey[:]); err != nil {
-		log.Fatal(err)
-	}
-	curve25519.ScalarBaseMult(&proxy.proxyPublicKey, &proxy.proxySecretKey)
-	proxy.fetchServerInfo(serverAddrStr, serverPkStr, providerName)
-	clientPc, err := net.ListenPacket("udp", listenAddrStr)
-	if err != nil {
-		log.Fatal(err)
-	}
-	defer clientPc.Close()
-	fmt.Printf("Now listening to %v [UDP]\n", listenAddrStr)
-	for {
-		buffer := make([]byte, MaxDNSPacketSize)
-		length, clientAddr, err := clientPc.ReadFrom(buffer)
-		if err != nil {
-			break
-		}
-		packet := buffer[:length]
-		go func() {
-			proxy.processIncomingQuery(&proxy.serversInfo[0], packet, clientAddr, clientPc)
-		}()
-	}
-	return proxy
-}
-
-type ServerInfo struct {
-	MagicQuery         [8]byte
-	ServerPk           [32]byte
-	SharedKey          [32]byte
-	CryptoConstruction CryptoConstruction
-	Timeout            time.Duration
-	UDPAddr            *net.UDPAddr
-	TCPAddr            *net.TCPAddr
-}
-
-func (proxy *Proxy) adjustMinQuestionSize() {
-	if MaxDNSPacketSize-proxy.minQuestionSize < proxy.minQuestionSize {
-		proxy.minQuestionSize = MaxDNSPacketSize
-	} else {
-		proxy.minQuestionSize *= 2
-	}
-}
-
-func (proxy *Proxy) processIncomingQuery(serverInfo *ServerInfo, packet []byte, clientAddr net.Addr, clientPc net.PacketConn) {
-	if len(packet) < MinDNSPacketSize {
-		return
-	}
-	encrypted, clientNonce := proxy.Crypt(serverInfo, packet)
-	pc, err := net.DialUDP("udp", nil, serverInfo.UDPAddr)
-	if err != nil {
-		return
-	}
-	defer pc.Close()
-	pc.SetDeadline(time.Now().Add(serverInfo.Timeout))
-	pc.Write(encrypted)
-
-	encrypted = make([]byte, MaxDNSPacketSize)
-	length, err := pc.Read(encrypted)
-	if err != nil {
-		return
-	}
-	encrypted = encrypted[:length]
-	packet, err = proxy.Decrypt(serverInfo, encrypted, clientNonce)
-	if err != nil {
-		return
-	}
-	clientPc.WriteTo(packet, clientAddr)
-	if HasTCFlag(packet) {
-		proxy.adjustMinQuestionSize()
-	}
-}
-
-func main() {
-	log.SetFlags(0)
-	_ = NewProxy("127.0.0.1:5399", "212.47.228.136:443", "E801:B84E:A606:BFB0:BAC0:CE43:445B:B15E:BA64:B02F:A3C4:AA31:AE10:636A:0790:324D", "2.dnscrypt-cert.fr.dnscrypt.org")
-}