add forward_peer,to support forward between origins.the streams pushed from peer

origins will not be forward any more.
remove forward_server_srs,which used to indicate the forward target server is or is not srs,
add forward_server_other, to list the target rtmp server other than srs in.

@@ -11,6 +11,9 @@ vhost __defaultVhost__ {
     forward         127.0.0.1:19350;
 #select on of the listed servers in turn to forward,not all of them
     forward_in_turn 127.0.0.1:19351 127.0.0.1:19352;
-#the forward destination server type,default true. if the server is not srs server,connect app maybe fail,try config as false 
-    forward_server_srs  true;
+#if the forward destination server is not srs,such as some rtmp server in cdn,write the address of them below 
+    forward_server_other 127.0.0.1:19350;
+#if the forward server is same as this server , a origin,try use forward_peer,
+#the stream pushed from other forward peer will not forward any more in this server
+    forward_peer 127.0.0.1:1936;
 }

@@ -1823,7 +1823,7 @@ int SrsConfig::check_config()
                 && n != "dvr" && n != "ingest" && n != "hls" && n != "http_hooks"
                 && n != "gop_cache" && n != "queue_length"
                 && n != "refer" && n != "refer_publish" && n != "refer_play"
-                && n != "forward" && n != "forward_server_srs" && n != "forward_in_turn" && n != "transcode" && n != "bandcheck"
+                && n != "forward" && n != "forward_server_other" && n != "forward_in_turn" && n != "forward_peer" && n != "transcode" && n != "bandcheck"
                 && n != "time_jitter" && n != "mix_correct"
                 && n != "atc" && n != "atc_auto"
                 && n != "debug_srs_upnode"
@@ -1939,15 +1939,6 @@ int SrsConfig::check_config()
                         return ret;
                     }
                 }*/
-            } else if (n == "forward_server_srs") {
-               for (int j = 0; j < (int)conf->directives.size(); j++) {
-                    string m = conf->at(j)->name.c_str();
-                    if (m != "true" && m != "false") {
-                        ret = ERROR_SYSTEM_CONFIG_INVALID;
-                        srs_error("unsupported vhost forward_server_srs directive %s(only support true or flase), ret=%d", m.c_str(), ret);
-                        return ret;
-                    }
-                }
             }
             else if (n == "security") {
                 for (int j = 0; j < (int)conf->directives.size(); j++) {
@@ -2756,20 +2747,15 @@ SrsConfDirective* SrsConfig::get_forward(string vhost)
     return conf->get("forward");
 }
 
-bool SrsConfig::get_forward_server_srs(string vhost)
+SrsConfDirective* SrsConfig::get_forward_server_other(string vhost)
 {
     SrsConfDirective* conf = get_vhost(vhost);
 
     if (!conf) {
-        return true;
-    }
-
-    conf = conf->get("forward_server_srs");
-    if (!conf || conf->arg0().empty()) {
-        return true;
+        return NULL;
     }
 
-    return conf->arg0()=="true";
+    return conf->get("forward_server_other");
 }
 
 SrsConfDirective* SrsConfig::get_forward_in_turn(string vhost)
@@ -2783,6 +2769,17 @@ SrsConfDirective* SrsConfig::get_forward_in_turn(string vhost)
     return conf->get("forward_in_turn");
 }
 
+SrsConfDirective* SrsConfig::get_forward_peer(string vhost)
+{
+    SrsConfDirective* conf = get_vhost(vhost);
+
+    if (!conf) {
+        return NULL;
+    }
+
+    return conf->get("forward_peer");
+}
+
 SrsConfDirective* SrsConfig::get_vhost_http_hooks(string vhost)
 {
     SrsConfDirective* conf = get_vhost(vhost);

@@ -570,13 +570,17 @@ public:
     */
     virtual SrsConfDirective*   get_forward(std::string vhost);
     /**
-    * get the forward server type  of vhost,if srs return true,else false.
+    * get the forward_server_other directive of vhost
     */
-    virtual bool                get_forward_server_srs(std::string vhost);
+    virtual SrsConfDirective*   get_forward_server_other(std::string vhost);
     /**
     * get the forward_in_turn directive of vhost.
     */
     virtual SrsConfDirective*   get_forward_in_turn(std::string vhost);
+    /**
+    * get the forward_peer directive of vhost.
+    */
+    virtual SrsConfDirective*   get_forward_peer(std::string vhost);
 // http_hooks section
 private:
     /**

@@ -52,6 +52,8 @@ SrsForwarder::SrsForwarder(SrsSource* _source)
 {
     source = _source;
     
+    server_type = 0;
+
     _req = NULL;
     io = NULL;
     client = NULL;
@@ -117,13 +119,7 @@ int SrsForwarder::check_dead_loop(SrsRequest* req, std::string ep_forward)
 
 	if (source_ep == dest_ep) {
 		ret = ERROR_SYSTEM_FORWARD_LOOP;
-		srs_warn("forward loop detected. src=%s, dest=%s, ret=%d",
-			source_ep.c_str(), dest_ep.c_str(), ret);
-		return ret;
 	}
-	srs_trace("start forward %s to %s, tcUrl=%s, stream=%s",
-		source_ep.c_str(), dest_ep.c_str(), tc_url.c_str(),
-		req->stream.c_str());
 
 	return ret;
 }
@@ -139,6 +135,15 @@ int SrsForwarder::initialize(SrsRequest* req, string ep_forward)
     // the ep(endpoint) to forward to
     _ep_forward = ep_forward;
     
+    SrsConfDirective* conf = _srs_config->get_forward_server_other(_req->vhost);
+    for (int i = 0; conf && i < (int)conf->args.size(); i++) {
+        std::string forward_server = conf->args.at(i);
+        if(ep_forward == forward_server){
+        	server_type = 1;
+        	break;
+        }
+    }
+
     return ret;
 }
 
@@ -428,13 +433,12 @@ int SrsForwarder::connect_app(string ep_server, string ep_port)
     bool debug_srs_upnode = _srs_config->get_debug_srs_upnode(req->vhost);
 
     //if forward_server is not srs,or srs compatible,don't send req when connect app,in case of be rejected
-    bool forward_server_srs = _srs_config->get_forward_server_srs(req->vhost);
-	if (!forward_server_srs) {
+	if (server_type) {
 		srs_trace("forward to srs incompatible server, tcUrl=%s,vhost:%s",
 				tc_url.c_str(), req->vhost.c_str());
 	}
 
-    if ((ret = client->connect_app(req->app, tc_url, forward_server_srs ? req : NULL, debug_srs_upnode)) != ERROR_SUCCESS) {
+    if ((ret = client->connect_app(req->app, tc_url, server_type ?  NULL : req, debug_srs_upnode)) != ERROR_SUCCESS) {
         srs_error("connect with server failed, tcUrl=%s, dsu=%d. ret=%d", 
             tc_url.c_str(), debug_srs_upnode, ret);
         return ret;

@@ -71,6 +71,8 @@ private:
     */
     SrsSharedPtrMessage* sh_audio;
     SrsSharedPtrMessage* sh_video;
+
+    int server_type; //server_type 0, srs, 1,other
 public:
     SrsForwarder(SrsSource* _source);
     virtual ~SrsForwarder();

@@ -2424,11 +2424,57 @@ int SrsSource::create_forwarders()
 {
     int ret = ERROR_SUCCESS;
     
-    SrsConfDirective* conf = _srs_config->get_forward(_req->vhost);
+    //forward_peer    
+    SrsConfDirective* conf = _srs_config->get_forward_peer(_req->vhost);
+    for (int i = 0; conf && i < (int)conf->args.size(); i++) {
+        std::string forward_server = conf->args.at(i);
+
+		if (SrsForwarder::check_dead_loop(_req, forward_server)) {//if the source is from any of the peer list,don't forward it 
+		   srs_trace("the source is come from forward_peer,don't forward it any more: "
+                "vhost=%s, app=%s, stream=%s, forward-to=%s",
+                _req->vhost.c_str(), _req->app.c_str(), _req->stream.c_str(),
+                forward_server.c_str());
+			return ret;
+		}
+	}
+    
+    for (int i = 0; conf && i < (int)conf->args.size(); i++) {
+        std::string forward_server = conf->args.at(i);
+        
+        SrsForwarder* forwarder = new SrsForwarder(this);
+        forwarders.push_back(forwarder);
+        
+        // initialize the forwarder with request.
+        if ((ret = forwarder->initialize(_req, forward_server)) != ERROR_SUCCESS) {
+            return ret;
+        }
+    
+        double queue_size = _srs_config->get_queue_length(_req->vhost);
+        forwarder->set_queue_size(queue_size);
+        
+        srs_trace("start forward_peer: "
+                "vhost=%s, app=%s, stream=%s, forward-to=%s",
+                _req->vhost.c_str(), _req->app.c_str(), _req->stream.c_str(),
+                forward_server.c_str());
+        if ((ret = forwarder->on_publish()) != ERROR_SUCCESS) {
+            srs_error("start forwarder failed. "
+                "vhost=%s, app=%s, stream=%s, forward-to=%s",
+                _req->vhost.c_str(), _req->app.c_str(), _req->stream.c_str(),
+                forward_server.c_str());
+            return ret;
+        }
+    }
+    
+    //forward
+    conf = _srs_config->get_forward(_req->vhost);
     for (int i = 0; conf && i < (int)conf->args.size(); i++) {
         std::string forward_server = conf->args.at(i);
 
 		if (SrsForwarder::check_dead_loop(_req, forward_server)) {
+		        srs_trace("start forward,dead loop checked,don't forward it: "
+                "vhost=%s, app=%s, stream=%s, forward-to=%s",
+                _req->vhost.c_str(), _req->app.c_str(), _req->stream.c_str(),
+                forward_server.c_str());
 			continue;
 		}
         
@@ -2474,6 +2520,10 @@ int SrsSource::create_forwarders()
     	server_index ++;
 
     	if (SrsForwarder::check_dead_loop(_req, forward_server)) {
+    		srs_trace("start forward_in_turn,dead loop checked,don't forward it: "
+                "vhost=%s, app=%s, stream=%s, forward-to=%s",
+                _req->vhost.c_str(), _req->app.c_str(), _req->stream.c_str(),
+                forward_server.c_str());
 			continue;
     	}
 
@@ -2488,6 +2538,11 @@ int SrsSource::create_forwarders()
     	double queue_size = _srs_config->get_queue_length(_req->vhost);
     	forwarder->set_queue_size(queue_size);
 
+
+    	srs_trace("start forward_in_turn: "
+                "vhost=%s, app=%s, stream=%s, forward-to=%s",
+                _req->vhost.c_str(), _req->app.c_str(), _req->stream.c_str(),
+                forward_server.c_str());
     	if ((ret = forwarder->on_publish()) != ERROR_SUCCESS) {
         	    srs_error("start forwarder failed. "
                 	"vhost=%s, app=%s, stream=%s, forward-to=%s",