From 39dd0ecdce0adf40c31d52492a61df4ebb2082a8 Mon Sep 17 00:00:00 2001
From: gdmmx <gdmmx@163.com>
Date: Tue, 5 Mar 2019 18:36:20 +0800
Subject: [PATCH] Add getmyextip RPC

Signed-off-by: gdmmx <gdmmx@163.com>
---
 api/common/interfaces.go  | 29 +++++++++++++++++++++++++++++
 api/httpjson/RPCserver.go | 13 +++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/api/common/interfaces.go b/api/common/interfaces.go
index 543f87fc6..7fa655e7b 100644
--- a/api/common/interfaces.go
+++ b/api/common/interfaces.go
@@ -5,6 +5,8 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"math"
+	"net"
+	"strings"
 
 	"github.com/gogo/protobuf/proto"
 	"github.com/nknorg/nkn/common"
@@ -1154,6 +1156,32 @@ func getTopicBucketsCount(s Serverer, params map[string]interface{}) map[string]
 	return respPacking(count, SUCCESS)
 }
 
+// getMyExtIP get RPC client's external IP
+// params: ["address":<address>]
+// return: {"result":<result>, "error":<errcode>}
+func getMyExtIP(s Serverer, params map[string]interface{}) map[string]interface{} {
+	if len(params) < 1 {
+		return respPacking(nil, INVALID_PARAMS)
+	}
+
+	addr, ok := params["RemoteAddr"].(string)
+	if !ok || len(addr) == 0 {
+		log.Errorf("Invalid params: [%v, %v]", ok, addr)
+		return respPacking(nil, INVALID_PARAMS)
+	}
+
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		if strings.LastIndexByte(addr, ':') >= 0 {
+			log.Errorf("getMyExtIP met invalid params %v: %v", addr, err)
+			return respPacking(nil, INVALID_PARAMS)
+		}
+		host = addr // addr just only host, without port
+	}
+	ret := map[string]interface{}{"RemoteAddr": host}
+	return respPacking(ret, SUCCESS)
+}
+
 // findSuccessorAddrs find the successors of a key
 // params: ["address":<address>]
 // return: {"result":<result>, "error":<errcode>}
@@ -1254,6 +1282,7 @@ var InitialAPIHandlers = map[string]APIHandler{
 	"getsubscribers":               {Handler: getSubscribers, AccessCtrl: BIT_JSONRPC},
 	"getfirstavailabletopicbucket": {Handler: getFirstAvailableTopicBucket, AccessCtrl: BIT_JSONRPC},
 	"gettopicbucketscount":         {Handler: getTopicBucketsCount, AccessCtrl: BIT_JSONRPC},
+	"getmyextip":                   {Handler: getMyExtIP, AccessCtrl: BIT_JSONRPC},
 	"findsuccessoraddr":            {Handler: findSuccessorAddr, AccessCtrl: BIT_JSONRPC},
 	"findsuccessoraddrs":           {Handler: findSuccessorAddrs, AccessCtrl: BIT_JSONRPC},
 }
diff --git a/api/httpjson/RPCserver.go b/api/httpjson/RPCserver.go
index 0ed425110..a8b08a0f8 100644
--- a/api/httpjson/RPCserver.go
+++ b/api/httpjson/RPCserver.go
@@ -109,6 +109,19 @@ func (s *RPCServer) Handle(w http.ResponseWriter, r *http.Request) {
 			w.Write(data)
 			return
 		}
+		// if params["RemoteAddr"] set but empty, used request.RemoteAddr
+		if addr, ok := params["RemoteAddr"]; ok {
+			switch addr.(type) {
+			case []byte, string:
+				if len(addr.(string)) == 0 { // empty string
+					params["RemoteAddr"] = r.RemoteAddr
+				}
+			case bool: // save remoteAddr whatever true or false
+				params["RemoteAddr"] = r.RemoteAddr
+			default:
+				log.Warningf("RemoteAddr unsupport type for %v", addr)
+			}
+		}
 
 		//get the corresponding function
 		function, ok := s.mainMux.m[method]