1 files changed, 68 insertions, 0 deletions
diff --git a/server/sockopt_linux.go b/server/sockopt_linux.go
index d1b08ace..cbe461d4 100644
--- a/server/sockopt_linux.go
+++ b/server/sockopt_linux.go
@@ -20,10 +20,78 @@ import (
 	"fmt"
 	"net"
 	"os"
+	"strings"
 	"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(l *net.TCPListener, address string, key string) error {
+	t, _ := buildTcpMD5Sig(address, key)
+	fi, err := l.File()
+	defer fi.Close()
+	if err != nil {
+		return err
+	}
+	if l, err := net.FileListener(fi); err == nil {
+		defer l.Close()
+	}
+	_, _, e := syscall.Syscall6(syscall.SYS_SETSOCKOPT, fi.Fd(),
+		uintptr(syscall.IPPROTO_TCP), uintptr(TCP_MD5SIG),
+		uintptr(unsafe.Pointer(&t)), unsafe.Sizeof(t), 0)
+	if e > 0 {
+		return e
+	}
+	return nil
+}
+
+func SetTcpTTLSockopts(conn *net.TCPConn, ttl int) error {
+	level := syscall.IPPROTO_IP
+	name := syscall.IP_TTL
+	if strings.Contains(conn.RemoteAddr().String(), "[") {
+		level = syscall.IPPROTO_IPV6
+		name = syscall.IPV6_UNICAST_HOPS
+	}
+	fi, err := conn.File()
+	defer fi.Close()
+	if err != nil {
+		return err
+	}
+	if conn, err := net.FileConn(fi); err == nil {
+		defer conn.Close()
+	}
+	return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(int(fi.Fd()), level, name, ttl))
+}
+
 func DialTCPTimeoutWithMD5Sig(host string, port int, localAddr, key string, msec int) (*net.TCPConn, error) {
 	var family int
 	var ra, la syscall.Sockaddr