forwarder: add the ability to specify local ip. #48

conf.go

@@ -191,10 +191,9 @@ func usage() {
 	fmt.Fprintf(os.Stderr, "  lha: Latency based High Availability mode\n")
 	fmt.Fprintf(os.Stderr, "\n")
 
-	fmt.Fprintf(os.Stderr, "Forwarder option scheme: FORWARD_URL[#OPTIONS]\n")
+	fmt.Fprintf(os.Stderr, "Forwarder option scheme: FORWARD_URL#OPTIONS\n")
-	fmt.Fprintf(os.Stderr, "  Available options for forwarders:\n")
+	fmt.Fprintf(os.Stderr, "  priority: set the priority of that forwarder, default:0\n")
-	fmt.Fprintf(os.Stderr, "    priority: set the priority of that forwarder, default:0\n")
+	fmt.Fprintf(os.Stderr, "  e.g.:\n")
-	fmt.Fprintf(os.Stderr, "  Examples:\n")
 	fmt.Fprintf(os.Stderr, "    socks5://1.1.1.1:1080#priority=100\n")
 	fmt.Fprintf(os.Stderr, "    vmess://[security:]uuid@host:port?alterID=num#priority=200\n")
 	fmt.Fprintf(os.Stderr, "\n")

dns/client.go

@@ -129,7 +129,7 @@ func (c *Client) exchange(qname string, reqBytes []byte, preferTCP bool) (server
 
 	// if we are resolving the dialer's domain, then use Direct to avoid denpency loop
 	if strings.Contains(dialer.Addr(), qname) {
-		dialer = proxy.Direct
+		dialer = proxy.Default
 	}
 
 	// If client uses udp and no forwarders specified, use udp

proxy/dialer.go

@@ -45,7 +45,7 @@ func DialerFromURL(s string, dialer Dialer) (Dialer, error) {
 	}
 
 	if dialer == nil {
-		dialer = Direct
+		dialer = Default
 	}
 
 	c, ok := dialerMap[strings.ToLower(u.Scheme)]

proxy/direct.go

@@ -6,20 +6,33 @@ import (
 	"github.com/nadoo/glider/common/log"
 )
 
-// direct proxy
-type direct struct{}
-
 // Direct proxy
-var Direct = &direct{}
+type Direct struct {
+	*net.Dialer
+}
 
-func (d *direct) Addr() string { return "DIRECT" }
+// Default dialer
+var Default = &Direct{Dialer: &net.Dialer{}}
 
-func (d *direct) Dial(network, addr string) (net.Conn, error) {
+// NewDirect returns a Direct dialer
+func NewDirect(localip string) *Direct {
+	d := &net.Dialer{LocalAddr: &net.TCPAddr{
+		IP:   net.ParseIP(localip),
+		Port: 0,
+	}}
+	return &Direct{Dialer: d}
+}
+
+// Addr returns forwarder's address
+func (d *Direct) Addr() string { return "DIRECT" }
+
+// Dial connects to the address addr on the network net
+func (d *Direct) Dial(network, addr string) (net.Conn, error) {
 	if network == "uot" {
 		network = "udp"
 	}
 
-	c, err := net.Dial(network, addr)
+	c, err := d.Dialer.Dial(network, addr)
 	if err != nil {
 		return nil, err
 	}
@@ -31,8 +44,9 @@ func (d *direct) Dial(network, addr string) (net.Conn, error) {
 	return c, err
 }
 
-func (d *direct) DialUDP(network, addr string) (net.PacketConn, net.Addr, error) {
+// DialUDP connects to the given address
-	pc, err := net.ListenPacket(network, "")
+func (d *Direct) DialUDP(network, addr string) (net.PacketConn, net.Addr, error) {
+	pc, err := net.ListenPacket(network, d.Dialer.LocalAddr.String())
 	if err != nil {
 		log.F("ListenPacket error: %s", err)
 		return nil, nil, err
@@ -42,4 +56,5 @@ func (d *direct) DialUDP(network, addr string) (net.PacketConn, net.Addr, error)
 	return pc, uAddr, err
 }
 
-func (d *direct) NextDialer(dstAddr string) Dialer { return d }
+// NextDialer returns the next dialer
+func (d *Direct) NextDialer(dstAddr string) Dialer { return d }

proxy/forwarder.go

@@ -19,12 +19,19 @@ type Forwarder struct {
 	failures    uint32
 	MaxFailures uint32 //maxfailures to set to Disabled
 	latency     int64
+	localip     string // local ip address
 }
 
 // ForwarderFromURL parses `forward=` command value and returns a new forwarder
 func ForwarderFromURL(s string) (f *Forwarder, err error) {
+	f = &Forwarder{}
+
 	ss := strings.Split(s, "#")
-	var d Dialer
+	if len(ss) > 1 {
+		err = f.parseOption(ss[1])
+	}
+
+	var d Dialer = NewDirect(f.localip)
 	for _, url := range strings.Split(ss[0], ",") {
 		d, err = DialerFromURL(url, d)
 		if err != nil {
@@ -32,19 +39,12 @@ func ForwarderFromURL(s string) (f *Forwarder, err error) {
 		}
 	}
 
-	f = NewForwarder(d)
+	f.Dialer = d
-	if len(ss) > 1 {
+	f.addr = d.Addr()
-		err = f.parseOption(ss[1])
-	}
 
 	return f, err
 }
 
-// NewForwarder returns a new forwarder
-func NewForwarder(dialer Dialer) *Forwarder {
-	return &Forwarder{Dialer: dialer, addr: dialer.Addr()}
-}
-
 func (f *Forwarder) parseOption(option string) error {
 	query, err := url.ParseQuery(option)
 	if err != nil {
@@ -58,6 +58,8 @@ func (f *Forwarder) parseOption(option string) error {
 	}
 	f.Priority = int(priority)
 
+	f.localip = query.Get("localip")
+
 	return err
 }
 

proxy/server.go

@@ -39,7 +39,7 @@ func ServerFromURL(s string, dialer Dialer) (Server, error) {
 	}
 
 	if dialer == nil {
-		dialer = Direct
+		dialer = Default
 	}
 
 	c, ok := serverMap[strings.ToLower(u.Scheme)]

strategy/strategy.go

@@ -38,7 +38,7 @@ func NewDialer(s []string, c *Config) proxy.Dialer {
 	}
 
 	if len(fwdrs) == 0 {
-		return proxy.Direct
+		return proxy.Default
 	}
 
 	if len(fwdrs) == 1 {