feat: bind socket to a particular device

cmd/config.go

@@ -63,6 +63,10 @@ type serverConfig struct {
 		User     string `json:"user"`
 		Password string `json:"password"`
 	} `json:"socks5_outbound"`
+	SocketConfig struct {
+		BindAddress  string `json:"bind_address"`
+		BindToDevice string `json:"bind_to_device"`
+	} `json:"socket_config"`
 }
 
 func (c *serverConfig) Speed() (uint64, uint64, error) {

cmd/server.go

@@ -15,6 +15,7 @@ import (
 	"github.com/tobyxdd/hysteria/pkg/core"
 	"github.com/tobyxdd/hysteria/pkg/obfs"
 	"github.com/tobyxdd/hysteria/pkg/pmtud_fix"
+	"github.com/tobyxdd/hysteria/pkg/sockopt"
 	"github.com/tobyxdd/hysteria/pkg/transport"
 	"github.com/yosuke-furukawa/json5/encoding/json5"
 	"io"
@@ -163,6 +164,33 @@ func server(config *serverConfig) {
 		}
 		transport.DefaultServerTransport.SOCKS5Client = ob
 	}
+	// socket settings
+	if config.SocketConfig.BindToDevice != "" {
+		iface, err := net.InterfaceByName(config.SocketConfig.BindToDevice)
+		if err != nil {
+			logrus.WithFields(logrus.Fields{
+				"error": err,
+			}).Fatal("Failed to get bind_to_device")
+		}
+		transport.DefaultServerTransport.Intf = iface
+		sockopt.BindDialer(transport.DefaultServerTransport.Dialer, iface)
+	}
+	if config.SocketConfig.BindAddress != "" {
+		ip := net.ParseIP(config.SocketConfig.BindAddress)
+		if ip == nil {
+			logrus.WithFields(logrus.Fields{
+				"error": err,
+			}).Fatal("Failed to parse bind_address")
+		}
+		transport.DefaultServerTransport.Dialer.LocalAddr = &net.TCPAddr{
+			IP:   ip,
+			Port: 0,
+		}
+		transport.DefaultServerTransport.LocalAddrUDP = &net.UDPAddr{
+			IP:   ip,
+			Port: 0,
+		}
+	}
 	// ACL
 	var aclEngine *acl.Engine
 	if len(config.ACL) > 0 {

go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/spf13/viper v1.11.0
 	github.com/txthinking/socks5 v0.0.0-20220212043548-414499347d4a
 	github.com/yosuke-furukawa/json5 v0.1.1
+	golang.org/x/sys v0.0.0-20220412211240-33da011f77ad
 )
 
 require (
@@ -66,7 +67,6 @@ require (
 	golang.org/x/crypto v0.0.0-20220411220226-7b82a4e95df4 // indirect
 	golang.org/x/mod v0.5.0 // indirect
 	golang.org/x/net v0.0.0-20220412020605-290c469a71a5 // indirect
-	golang.org/x/sys v0.0.0-20220412211240-33da011f77ad // indirect
 	golang.org/x/text v0.3.7 // indirect
 	golang.org/x/tools v0.1.6-0.20210726203631-07bc1bf47fb2 // indirect
 	golang.org/x/xerrors v0.0.0-20220411194840-2f41105eb62f // indirect

pkg/sockopt/sockopt.go

@@ -0,0 +1,23 @@
+package sockopt
+
+import (
+	"net"
+	"syscall"
+)
+
+//https://github.com/v2fly/v2ray-core/blob/4e247840821f3dd326722d4db02ee3c237074fc2/transport/internet/config.pb.go#L420-L426
+
+func BindDialer(d *net.Dialer, intf *net.Interface) {
+	d.Control = func(network, address string, c syscall.RawConn) error {
+		return bindRawConn(network, c, intf)
+	}
+}
+
+func BindUDPConn(network string, conn *net.UDPConn, intf *net.Interface) error {
+	c, err := conn.SyscallConn()
+	if err != nil {
+		return err
+	}
+
+	return bindRawConn(network, c, intf)
+}

pkg/sockopt/sockopt_linux.go

@@ -0,0 +1,16 @@
+package sockopt
+
+import (
+	"net"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+func bindRawConn(network string, c syscall.RawConn, bindIface *net.Interface) error {
+	return c.Control(func(fd uintptr) {
+		if bindIface != nil {
+			unix.BindToDevice(int(fd), bindIface.Name)
+		}
+	})
+}

pkg/sockopt/sockopt_others.go

@@ -0,0 +1,10 @@
+//go:build !linux
+
+package sockopt
+
+import (
+	"net"
+	"syscall"
+)
+
+func bindRawConn(network string, c syscall.RawConn, bindIface *net.Interface) error { return nil }

pkg/transport/server.go

@@ -8,6 +8,7 @@ import (
 	"github.com/tobyxdd/hysteria/pkg/conns/udp"
 	"github.com/tobyxdd/hysteria/pkg/conns/wechat"
 	"github.com/tobyxdd/hysteria/pkg/obfs"
+	"github.com/tobyxdd/hysteria/pkg/sockopt"
 	"github.com/tobyxdd/hysteria/pkg/utils"
 	"net"
 	"strconv"
@@ -20,6 +21,8 @@ type ServerTransport struct {
 	PrefEnabled   bool
 	PrefIPv6      bool
 	PrefExclusive bool
+	LocalAddrUDP  *net.UDPAddr
+	Intf          *net.Interface
 }
 
 // AddrEx is like net.TCPAddr or net.UDPAddr, but with additional domain information for SOCKS5.
@@ -164,10 +167,17 @@ func (st *ServerTransport) ListenUDP() (PUDPConn, error) {
 	if st.SOCKS5Client != nil {
 		return st.SOCKS5Client.ListenUDP()
 	} else {
-		conn, err := net.ListenUDP("udp", nil)
+		conn, err := net.ListenUDP("udp", st.LocalAddrUDP)
 		if err != nil {
 			return nil, err
 		}
+		if st.Intf != nil {
+			err = sockopt.BindUDPConn("udp", conn, st.Intf)
+			if err != nil {
+				conn.Close()
+				return nil, err
+			}
+		}
 		return &udpConnPUDPConn{
 			Conn: conn,
 		}, nil