From 9dc574d49a8bd444271e43ad90f63fa9896f43e9 Mon Sep 17 00:00:00 2001
From: chenall <chenall.cn@gmail.com>
Date: Wed, 1 Nov 2017 20:51:57 +0800
Subject: [PATCH] frpc: new parameter 'server_dynamic',support
 --user,--server-dynamic command.

---
 client/control.go              | 44 ++++++++++++++++++++++++++++++++++
 cmd/frpc/main.go               | 11 ++++++++-
 models/config/client_common.go |  6 +++--
 3 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/client/control.go b/client/control.go
index b6c4d481..d5a61d55 100644
--- a/client/control.go
+++ b/client/control.go
@@ -17,7 +17,11 @@ package client
 import (
 	"fmt"
 	"io"
+	"io/ioutil"
+	"net/http"
 	"runtime"
+	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -211,6 +215,41 @@ func (ctl *Control) init() {
 	ctl.closedCh = make(chan int)
 }
 
+func (ctl *Control) getDynamicServer() (err error) {
+	if config.ClientCommonCfg.ServerDynamic == "" {
+		return
+	}
+
+	serv := config.ClientCommonCfg.ServerDynamic
+	if strings.ToLower(serv[:4]) != "http" {
+		return
+	}
+
+	res, err := http.Get(serv + "?user=" + config.ClientCommonCfg.User)
+	if err != nil {
+		return err
+	}
+
+	data, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return err
+	}
+
+	serv = string(data)
+	addr := strings.Split(serv, ":")
+	if len(addr) != 2 {
+		ctl.Error("dynamic server info error: %v", serv)
+		return
+	}
+	serverPort, err := strconv.ParseInt(addr[1], 10, 64)
+	if err != nil {
+		return err
+	}
+	config.ClientCommonCfg.ServerAddr = addr[0]
+	config.ClientCommonCfg.ServerPort = serverPort
+	return
+}
+
 // login send a login message to server and wait for a loginResp message.
 func (ctl *Control) login() (err error) {
 	if ctl.conn != nil {
@@ -220,6 +259,11 @@ func (ctl *Control) login() (err error) {
 		ctl.session.Close()
 	}
 
+	errDynamic := ctl.getDynamicServer()
+	if errDynamic != nil {
+		ctl.Error("Get dynamic server error: %s", errDynamic.Error())
+	}
+
 	conn, err := frpNet.ConnectServerByHttpProxy(config.ClientCommonCfg.HttpProxy, config.ClientCommonCfg.Protocol,
 		fmt.Sprintf("%s:%d", config.ClientCommonCfg.ServerAddr, config.ClientCommonCfg.ServerPort))
 	if err != nil {
diff --git a/cmd/frpc/main.go b/cmd/frpc/main.go
index 93642c82..7ead97b1 100644
--- a/cmd/frpc/main.go
+++ b/cmd/frpc/main.go
@@ -43,7 +43,7 @@ var (
 var usage string = `frpc is the client of frp
 
 Usage: 
-    frpc [-c config_file] [-L log_file] [--log-level=<log_level>] [--server-addr=<server_addr>]
+    frpc [-c config_file] [-L log_file] [--log-level=<log_level>] [--user=<user_name>] [--server-addr=<server_addr>] [--server-dynamic=<http_url>]
     frpc [-c config_file] --reload
     frpc -h | --help
     frpc -v | --version
@@ -53,6 +53,7 @@ Options:
     -L log_file                 set output log file, including console
     --log-level=<log_level>     set log level: debug, info, warn, error
     --server-addr=<server_addr> addr which frps is listening for, example: 0.0.0.0:7000
+    --server-dynamic=<http_url> get frps addr from http_url, example: http://server.com/frp/
     --reload                    reload configure file without program exit
     -h --help                   show this screen
     -v --version                show version
@@ -134,6 +135,14 @@ func main() {
 		config.ClientCommonCfg.LogLevel = args["--log-level"].(string)
 	}
 
+	if args["--user"] != nil {
+		config.ClientCommonCfg.User = args["--user"].(string)
+	}
+
+	if args["--server-dynamic"] != nil {
+		config.ClientCommonCfg.ServerDynamic = args["--server-dynamic"].(string)
+	}
+
 	if args["--server-addr"] != nil {
 		addr := strings.Split(args["--server-addr"].(string), ":")
 		if len(addr) != 2 {
diff --git a/models/config/client_common.go b/models/config/client_common.go
index f98169e7..912989e4 100644
--- a/models/config/client_common.go
+++ b/models/config/client_common.go
@@ -28,6 +28,7 @@ var ClientCommonCfg *ClientCommonConf
 // client common config
 type ClientCommonConf struct {
 	ConfigFile        string
+	ServerDynamic     string
 	ServerAddr        string
 	ServerPort        int64
 	ServerUdpPort     int64 // this is specified by login response message from frps
@@ -54,6 +55,7 @@ type ClientCommonConf struct {
 func GetDeaultClientCommonConf() *ClientCommonConf {
 	return &ClientCommonConf{
 		ConfigFile:        "./frpc.ini",
+		ServerDynamic:     "",
 		ServerAddr:        "0.0.0.0",
 		ServerPort:        7000,
 		ServerUdpPort:     0,
@@ -86,9 +88,9 @@ func LoadClientCommonConf(conf ini.File) (cfg *ClientCommonConf, err error) {
 	)
 	cfg = GetDeaultClientCommonConf()
 
-	tmpStr, ok = conf.Get("common", "server_addr")
+	tmpStr, ok = conf.Get("common", "server_dynamic")
 	if ok {
-		cfg.ServerAddr = tmpStr
+		cfg.ServerDynamic = tmpStr
 	}
 
 	tmpStr, ok = conf.Get("common", "server_port")