frpc: support ip4p

client/ip4p.go

@@ -0,0 +1,36 @@
+// Copyright 2022 hev, r@hev.cc
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"net"
+)
+
+func lookupIP4P(addr string, port int) (string, int) {
+	ips, err := net.LookupIP(addr)
+	if err == nil {
+		for _, ip := range ips {
+			if len(ip) == 16 {
+				if ip[0] == 0x20 && ip[1] == 0x01 &&
+					ip[2] == 0x00 && ip[3] == 0x00 {
+					addr = net.IPv4(ip[12], ip[13], ip[14], ip[15]).String()
+					port = int(ip[10])<<8 | int(ip[11])
+					break
+				}
+			}
+		}
+	}
+	return addr, port
+}

client/service.go

@@ -378,9 +378,10 @@ func (cm *ConnectionManager) OpenConnection() error {
 		}
 		tlsConfig.NextProtos = []string{"frp"}
 
+		addr, port := lookupIP4P(cm.cfg.ServerAddr, cm.cfg.ServerPort)
 		conn, err := quic.DialAddrContext(
 			cm.ctx,
-			net.JoinHostPort(cm.cfg.ServerAddr, strconv.Itoa(cm.cfg.ServerPort)),
+			net.JoinHostPort(addr, strconv.Itoa(port)),
 			tlsConfig, &quic.Config{
 				MaxIdleTimeout:     time.Duration(cm.cfg.QUICMaxIdleTimeout) * time.Second,
 				MaxIncomingStreams: int64(cm.cfg.QUICMaxIncomingStreams),
@@ -491,9 +492,10 @@ func (cm *ConnectionManager) realConnect() (net.Conn, error) {
 		libdial.WithProxy(proxyType, addr),
 		libdial.WithProxyAuth(auth),
 	)
+	addr, port := lookupIP4P(cm.cfg.ServerAddr, cm.cfg.ServerPort)
 	conn, err := libdial.DialContext(
 		cm.ctx,
-		net.JoinHostPort(cm.cfg.ServerAddr, strconv.Itoa(cm.cfg.ServerPort)),
+		net.JoinHostPort(addr, strconv.Itoa(port)),
 		dialOptions...,
 	)
 	return conn, err