frpc: support nathole discover (#3381)

cmd/frpc/sub/nathole.go

@@ -0,0 +1,86 @@
+// Copyright 2023 The frp Authors
+//
+// 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 sub
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"strconv"
+
+	"github.com/spf13/cobra"
+
+	"github.com/fatedier/frp/pkg/config"
+	"github.com/fatedier/frp/pkg/nathole"
+)
+
+func init() {
+	RegisterCommonFlags(natholeCmd)
+
+	rootCmd.AddCommand(natholeCmd)
+	natholeCmd.AddCommand(natholeDiscoveryCmd)
+}
+
+var natholeCmd = &cobra.Command{
+	Use:   "nathole",
+	Short: "Actions about nathole",
+}
+
+var natholeDiscoveryCmd = &cobra.Command{
+	Use:   "discover",
+	Short: "Discover nathole information by frps and stun server",
+	RunE: func(cmd *cobra.Command, args []string) error {
+		cfg, _, _, err := config.ParseClientConfig(cfgFile)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		if err := validateForNatHoleDiscovery(cfg); err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		addresses, err := nathole.Discover(
+			net.JoinHostPort(cfg.ServerAddr, strconv.Itoa(cfg.ServerUDPPort)),
+			[]string{cfg.NatHoleSTUNServer},
+			[]byte(cfg.Token),
+		)
+		if err != nil {
+			fmt.Println("discover error:", err)
+			os.Exit(1)
+		}
+
+		natType, behavior, err := nathole.ClassifyNATType(addresses)
+		if err != nil {
+			fmt.Println("classify nat type error:", err)
+			os.Exit(1)
+		}
+		fmt.Println("Your NAT type is:", natType)
+		fmt.Println("Behavior is:", behavior)
+		fmt.Println("External address is:", addresses)
+		return nil
+	},
+}
+
+func validateForNatHoleDiscovery(cfg config.ClientCommonConf) error {
+	if cfg.NatHoleSTUNServer == "" {
+		return fmt.Errorf("nat_hole_stun_server can not be empty")
+	}
+	if cfg.ServerUDPPort == 0 {
+		return fmt.Errorf("server udp port can not be empty")
+	}
+	return nil
+}