1 files changed, 45 insertions, 0 deletions
diff --git a/server/sockopt.go b/server/sockopt.go
new file mode 100644
index 00000000..10b3c186
--- /dev/null
+++ b/server/sockopt.go
@@ -0,0 +1,45 @@
+package server
+
+import (
+	"net"
+	"syscall"
+	"unsafe"
+)
+
+const (
+	TCP_MD5SIG = 14
+)
+
+type tcpmd5sig struct {
+	ss_family uint16
+	ss        [126]byte
+	pad1      uint16
+	keylen    uint16
+	pad2      uint32
+	key       [80]byte
+}
+
+func buildTcpMD5Sig(address string, key string) (tcpmd5sig, error) {
+	t := tcpmd5sig{}
+	addr := net.ParseIP(address)
+	if addr.To4() != nil {
+		t.ss_family = syscall.AF_INET
+		copy(t.ss[2:], addr.To4())
+	} else {
+		t.ss_family = syscall.AF_INET6
+		copy(t.ss[6:], addr.To16())
+	}
+
+	t.keylen = uint16(len(key))
+	copy(t.key[0:], []byte(key))
+
+	return t, nil
+}
+
+func SetTcpMD5SigSockopts(fd int, address string, key string) error {
+	t, _ := buildTcpMD5Sig(address, key)
+	_, _, e := syscall.Syscall6(syscall.SYS_SETSOCKOPT, uintptr(fd),
+		uintptr(syscall.IPPROTO_TCP), uintptr(TCP_MD5SIG),
+		uintptr(unsafe.Pointer(&t)), unsafe.Sizeof(t), 0)
+	return e
+}