support specify multiple interfaces

common/net/dialer/dialer.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"strings"
 	"syscall"
 	"time"
 
@@ -24,28 +25,10 @@ type NetDialer struct {
 	Timeout   time.Duration
 	DialFunc  func(ctx context.Context, network, addr string) (net.Conn, error)
 	Logger    logger.Logger
+	deadline  time.Time
 }
 
-func (d *NetDialer) Dial(ctx context.Context, network, addr string) (net.Conn, error) {
+func (d *NetDialer) dialOnce(ctx context.Context, network, addr, ifceName string, ifAddr net.Addr, log logger.Logger) (net.Conn, error) {
-	if d == nil {
-		d = DefaultNetDialer
-	}
-	if d.Timeout <= 0 {
-		d.Timeout = DefaultTimeout
-	}
-
-	log := d.Logger
-	if log == nil {
-		log = logger.Default()
-	}
-
-	ifceName, ifAddr, err := parseInterfaceAddr(d.Interface, network)
-	if err != nil {
-		return nil, err
-	}
-	if d.DialFunc != nil {
-		return d.DialFunc(ctx, network, addr)
-	}
 	if ifceName != "" {
 		log.Debugf("interface: %s %v/%s", ifceName, ifAddr, network)
 	}
@@ -89,7 +72,7 @@ func (d *NetDialer) Dial(ctx context.Context, network, addr string) (net.Conn, e
 		return nil, fmt.Errorf("dial: unsupported network %s", network)
 	}
 	netd := net.Dialer{
-		Timeout:   d.Timeout,
+		Deadline:  d.deadline,
 		LocalAddr: ifAddr,
 		Control: func(network, address string, c syscall.RawConn) error {
 			return c.Control(func(fd uintptr) {
@@ -109,8 +92,76 @@ func (d *NetDialer) Dial(ctx context.Context, network, addr string) (net.Conn, e
 	return netd.DialContext(ctx, network, addr)
 }
 
-func parseInterfaceAddr(ifceName, network string) (ifce string, addr net.Addr, err error) {
+func (d *NetDialer) Dial(ctx context.Context, network, addr string) (conn net.Conn, err error) {
+	if d == nil {
+		d = DefaultNetDialer
+	}
+	if d.Timeout <= 0 {
+		d.Timeout = DefaultTimeout
+	}
+
+	if d.DialFunc != nil {
+		return d.DialFunc(ctx, network, addr)
+	}
+
+	log := d.Logger
+	if log == nil {
+		log = logger.Default()
+	}
+
+	ifces := strings.Split(d.Interface, ",")
+	d.deadline = time.Now().Add(d.Timeout)
+	for _, ifce := range ifces {
+		strict := strings.HasSuffix(ifce, "!")
+		ifce = strings.TrimSuffix(ifce, "!")
+		var ifceName string
+		var ifAddrs []net.Addr
+		ifceName, ifAddrs, err = parseInterfaceAddr(ifce, network)
+		if err != nil && strict {
+			return
+		}
+
+		for _, ifAddr := range ifAddrs {
+			conn, err = d.dialOnce(ctx, network, addr, ifceName, ifAddr, log)
+			if err == nil {
+				return
+			}
+
+			log.Debugf("dial %s %v@%s failed: %s", network, ifAddr, ifceName, err)
+
+			if strict &&
+				!strings.Contains(err.Error(), "no suitable address found") &&
+				!strings.Contains(err.Error(), "mismatched local address type") {
+				return
+			}
+
+			if time.Until(d.deadline) < 0 {
+				return
+			}
+		}
+	}
+
+	return
+}
+
+func ipToAddr(ip net.IP, network string) (addr net.Addr) {
+	port := 0
+	switch network {
+	case "tcp", "tcp4", "tcp6":
+		addr = &net.TCPAddr{IP: ip, Port: port}
+		return
+	case "udp", "udp4", "udp6":
+		addr = &net.UDPAddr{IP: ip, Port: port}
+		return
+	default:
+		addr = &net.IPAddr{IP: ip}
+		return
+	}
+}
+
+func parseInterfaceAddr(ifceName, network string) (ifce string, addr []net.Addr, err error) {
 	if ifceName == "" {
+		addr = append(addr, nil)
 		return
 	}
 
@@ -130,27 +181,21 @@ func parseInterfaceAddr(ifceName, network string) (ifce string, addr net.Addr, e
 			err = fmt.Errorf("addr not found for interface %s", ifceName)
 			return
 		}
-		ip = addrs[0].(*net.IPNet).IP
 		ifce = ifceName
+		for _, addr_ := range addrs {
+			if ipNet, ok := addr_.(*net.IPNet); ok {
+				addr = append(addr, ipToAddr(ipNet.IP, network))
+			}
+		}
 	} else {
 		ifce, err = findInterfaceByIP(ip)
 		if err != nil {
 			return
 		}
+		addr = []net.Addr{ipToAddr(ip, network)}
 	}
 
-	port := 0
+	return
-	switch network {
-	case "tcp", "tcp4", "tcp6":
-		addr = &net.TCPAddr{IP: ip, Port: port}
-		return
-	case "udp", "udp4", "udp6":
-		addr = &net.UDPAddr{IP: ip, Port: port}
-		return
-	default:
-		addr = &net.IPAddr{IP: ip}
-		return
-	}
 }
 
 func findInterfaceByIP(ip net.IP) (string, error) {