Feature: use native syscall to bind interface on Linux and macOS

component/dialer/bind_darwin.go

@@ -0,0 +1,46 @@
+package dialer
+
+import (
+	"net"
+	"syscall"
+)
+
+func bindIfaceToDialer(dialer *net.Dialer, ifaceName string) error {
+	iface, err := net.InterfaceByName(ifaceName)
+	if err != nil {
+		return err
+	}
+
+	dialer.Control = func(network, address string, c syscall.RawConn) error {
+		return c.Control(func(fd uintptr) {
+			switch network {
+			case "tcp4", "udp4":
+				syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IP, syscall.IP_BOUND_IF, iface.Index)
+			case "tcp6", "udp6":
+				syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IPV6, syscall.IPV6_BOUND_IF, iface.Index)
+			}
+		})
+	}
+
+	return nil
+}
+
+func bindIfaceToListenConfig(lc *net.ListenConfig, ifaceName string) error {
+	iface, err := net.InterfaceByName(ifaceName)
+	if err != nil {
+		return err
+	}
+
+	lc.Control = func(network, address string, c syscall.RawConn) error {
+		return c.Control(func(fd uintptr) {
+			switch network {
+			case "tcp4", "udp4":
+				syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IP, syscall.IP_BOUND_IF, iface.Index)
+			case "tcp6", "udp6":
+				syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IPV6, syscall.IPV6_BOUND_IF, iface.Index)
+			}
+		})
+	}
+
+	return nil
+}