1. added darwin mpath context implementation

Author: vikulin

src/core/link_mpath_darwin.go

@@ -0,0 +1,33 @@
+//go:build darwin
+// +build darwin
+
+package core
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// WARNING: This context is used both by net.Dialer and net.Listen in tcp.go
+
+func (t *linkMPATH) tcpContext(network, address string, c syscall.RawConn) error {
+	var control error
+	var recvanyif error
+
+	control = c.Control(func(fd uintptr) {
+		// sys/socket.h: #define	SO_RECV_ANYIF	0x1104
+		recvanyif = unix.SetsockoptInt(int(fd), syscall.SOL_SOCKET, 0x1104, 1)
+	})
+
+	switch {
+	case recvanyif != nil:
+		return recvanyif
+	default:
+		return control
+	}
+}
+
+func (t *linkMPATH) getControl(sintf string) func(string, string, syscall.RawConn) error {
+	return t.tcpContext
+}