initial commit

common/net/dialer/dialer.go

@@ -0,0 +1,144 @@
+package dialer
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"syscall"
+	"time"
+
+	"github.com/go-gost/core/logger"
+)
+
+var (
+	DefaultNetDialer = &NetDialer{
+		Timeout: 30 * time.Second,
+	}
+)
+
+type NetDialer struct {
+	Interface string
+	Timeout   time.Duration
+	DialFunc  func(ctx context.Context, network, addr string) (net.Conn, error)
+	Logger    logger.Logger
+}
+
+func (d *NetDialer) Dial(ctx context.Context, network, addr string) (net.Conn, error) {
+	if d == nil {
+		d = DefaultNetDialer
+	}
+	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)
+	}
+	logger.Default().Infof("interface: %s %v/%s", ifceName, ifAddr, network)
+
+	switch network {
+	case "udp", "udp4", "udp6":
+		if addr == "" {
+			var laddr *net.UDPAddr
+			if ifAddr != nil {
+				laddr, _ = ifAddr.(*net.UDPAddr)
+			}
+
+			return net.ListenUDP(network, laddr)
+		}
+	case "tcp", "tcp4", "tcp6":
+	default:
+		return nil, fmt.Errorf("dial: unsupported network %s", network)
+	}
+	netd := net.Dialer{
+		Timeout:   d.Timeout,
+		LocalAddr: ifAddr,
+		Control: func(network, address string, c syscall.RawConn) error {
+			var cerr error
+			err := c.Control(func(fd uintptr) {
+				cerr = bindDevice(fd, ifceName)
+			})
+			if err != nil {
+				return err
+			}
+			if cerr != nil {
+				return cerr
+			}
+			return nil
+		},
+	}
+	return netd.DialContext(ctx, network, addr)
+}
+
+func parseInterfaceAddr(ifceName, network string) (ifce string, addr net.Addr, err error) {
+	if ifceName == "" {
+		return
+	}
+
+	ip := net.ParseIP(ifceName)
+	if ip == nil {
+		var ife *net.Interface
+		ife, err = net.InterfaceByName(ifceName)
+		if err != nil {
+			return
+		}
+		var addrs []net.Addr
+		addrs, err = ife.Addrs()
+		if err != nil {
+			return
+		}
+		if len(addrs) == 0 {
+			err = fmt.Errorf("addr not found for interface %s", ifceName)
+			return
+		}
+		ip = addrs[0].(*net.IPNet).IP
+		ifce = ifceName
+	} else {
+		ifce, err = findInterfaceByIP(ip)
+		if err != nil {
+			return
+		}
+	}
+
+	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 findInterfaceByIP(ip net.IP) (string, error) {
+	ifces, err := net.Interfaces()
+	if err != nil {
+		return "", err
+	}
+	for _, ifce := range ifces {
+		addrs, _ := ifce.Addrs()
+		if len(addrs) == 0 {
+			continue
+		}
+		for _, addr := range addrs {
+			ipAddr, _ := addr.(*net.IPNet)
+			if ipAddr == nil {
+				continue
+			}
+			// logger.Default().Infof("%s-%s", ipAddr, ip)
+			if ipAddr.IP.Equal(ip) {
+				return ifce.Name, nil
+			}
+		}
+	}
+	return "", nil
+}