For #1, support for specified a network interface

Makefile

@@ -15,10 +15,10 @@ client: build kill
 	sudo $(PWD)/sower -f conf/sower.toml -logtostderr
 
 server: build kill
-	$(PWD)/sower -n QUIC -logtostderr -v 1
+	$(PWD)/sower -n TCP -logtostderr -v 1
 
 run: build kill
-	$(PWD)/sower -n QUIC -logtostderr -v 1  &
+	$(PWD)/sower -n TCP -logtostderr -v 1  &
 	sudo $(PWD)/sower -f conf/sower.toml -logtostderr &
 	@sleep 1
 	curl 127.0.0.1

conf/sower.toml

@@ -1,10 +1,11 @@
-net_type="QUIC"
+net_type="TCP"
+cipher="AES_128_GCM"
 password="12345678"
 server_port="5533"
 server_addr="remote-server:5533" # replce it to remote server
-dns_server="114.114.114.114"
-# client_ip="192.168.0.1"
-# clear_dns_cache="sudo killall -HUP mDNSResponder"
+dns_server="223.5.5.5"           # Alibaba public dns
+client_ip="127.0.0.1"
+# clear_dns_cache="killall -HUP mDNSResponder"
 blocklist=[
     "*.google.com", # google
     "*.google.com.hk",

dns/dns.go

@@ -12,7 +12,7 @@ import (
 
 const colon = byte(':')
 
-func StartDNS(dnsServer string) {
+func StartDNS(dnsServer, listenIP string, ipNet net.IP) {
 	dns.HandleFunc(".", func(w dns.ResponseWriter, r *dns.Msg) {
 		// *Msg r has an TSIG record and it was validated
 		if r.IsTsig() != nil && w.TsigStatus() == nil {
@@ -30,17 +30,17 @@ func StartDNS(dnsServer string) {
 		}
 
 		if len(conf.Conf.BlockList) == 0 {
-			bestTry(w, r, domain, dnsServer)
+			bestTry(w, r, domain, dnsServer, ipNet)
 		} else {
-			manual(w, r, domain, dnsServer)
+			manual(w, r, domain, dnsServer, ipNet)
 		}
 	})
 
-	server := &dns.Server{Addr: ":53", Net: "udp"}
+	server := &dns.Server{Addr: listenIP + ":53", Net: "udp"}
 	glog.Fatalln(server.ListenAndServe())
 }
 
-func bestTry(w dns.ResponseWriter, r *dns.Msg, domain, dnsServer string) {
+func bestTry(w dns.ResponseWriter, r *dns.Msg, domain, dnsServer string, ipNet net.IP) {
 	msg, _ := dns.Exchange(r, dnsServer+":53")
 	if msg == nil {
 		return
@@ -63,16 +63,16 @@ func bestTry(w dns.ResponseWriter, r *dns.Msg, domain, dnsServer string) {
 
 	if _, err := net.DialTimeout("tcp", ip+":http", time.Second); err != nil {
 		glog.V(2).Infoln(ip+":80", err)
-		w.WriteMsg(localA(r, domain))
+		w.WriteMsg(localA(r, domain, ipNet))
 		return
 	}
 	w.WriteMsg(msg)
 }
 
-func manual(w dns.ResponseWriter, r *dns.Msg, domain, dnsServer string) {
+func manual(w dns.ResponseWriter, r *dns.Msg, domain, dnsServer string, ipNet net.IP) {
 	if rule.Match(strings.TrimSuffix(domain, ".")) {
 		glog.V(2).Infof("match %s suss", domain)
-		w.WriteMsg(localA(r, domain))
+		w.WriteMsg(localA(r, domain, ipNet))
 		return
 	}
 
@@ -100,12 +100,12 @@ func manual(w dns.ResponseWriter, r *dns.Msg, domain, dnsServer string) {
 	}
 }
 
-func localA(r *dns.Msg, domain string) *dns.Msg {
+func localA(r *dns.Msg, domain string, localIP net.IP) *dns.Msg {
 	m := new(dns.Msg)
 	m.SetReply(r)
 	m.Answer = []dns.RR{&dns.A{
 		Hdr: dns.RR_Header{Name: domain, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 20},
-		A:   conf.Conf.ClientIPNet,
+		A:   localIP,
 	}}
 	return m
 }

main.go

@@ -14,7 +14,7 @@ func main() {
 	if conf.ServerAddr == "" {
 		proxy.StartServer(conf.NetType, conf.ServerPort, conf.Cipher, conf.Password)
 	} else {
-		go dns.StartDNS(conf.DnsServer)
-		proxy.StartClient(conf.NetType, conf.ServerAddr, conf.Cipher, conf.Password)
+		go dns.StartDNS(conf.DnsServer, conf.ClientIP, conf.ClientIPNet)
+		proxy.StartClient(conf.NetType, conf.ServerAddr, conf.Cipher, conf.Password, conf.ClientIP)
 	}
 }

proxy/client.go

@@ -14,8 +14,8 @@ type Client interface {
 	Dial(server string) (net.Conn, error)
 }
 
-func StartClient(netType, server, cipher, password string) {
-	var connCh = listenLocal([]string{":80", ":443"})
+func StartClient(netType, server, cipher, password, listenIP string) {
+	var connCh = listenLocal(listenIP, []string{":80", ":443"})
 
 	var client Client
 	switch netType {
@@ -47,11 +47,11 @@ func StartClient(netType, server, cipher, password string) {
 	}
 }
 
-func listenLocal(ports []string) <-chan net.Conn {
+func listenLocal(listenIP string, ports []string) <-chan net.Conn {
 	connCh := make(chan net.Conn, 10)
 	for i := range ports {
 		go func(port string) {
-			ln, err := net.Listen("tcp", port)
+			ln, err := net.Listen("tcp", listenIP+port)
 			if err != nil {
 				glog.Fatalln(err)
 			}
@@ -59,7 +59,7 @@ func listenLocal(ports []string) <-chan net.Conn {
 			for {
 				conn, err := ln.Accept()
 				if err != nil {
-					glog.Errorln("accept", port, "fail:", err)
+					glog.Errorln("accept", listenIP+port, "fail:", err)
 					continue
 				}