XPlus obfs & don't frag

pkg/utils/df_linux.go

@@ -0,0 +1,21 @@
+package utils
+
+import (
+	"net"
+	"syscall"
+)
+
+func SetDontFragment(conn *net.UDPConn) error {
+	rawConn, err := conn.SyscallConn()
+	if err != nil {
+		return err
+	}
+	var err1, err2 error
+	err1 = rawConn.Control(func(fd uintptr) {
+		err2 = syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IP, syscall.IP_MTU_DISCOVER, syscall.IP_PMTUDISC_PROBE)
+	})
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}