确保rtp/rtcp端口号为偶奇数

src/Rtsp/Rtsp.cpp

@@ -365,5 +365,43 @@ bool RtspUrl::setup(bool isSSL, const string &strUrl, const string &strUser, con
     return true;
 }
 
-}//namespace mediakit
+std::pair<Socket::Ptr, Socket::Ptr> makeSockPair_l(const EventPoller::Ptr &poller, const string &local_ip){
+    auto pSockRtp = std::make_shared<Socket>(poller);
+    if (!pSockRtp->bindUdpSock(0, local_ip.data())) {
+        //分配端口失败
+        throw runtime_error("open udp socket failed");
+    }
+
+    //是否是偶数
+    bool even_numbers = pSockRtp->get_local_port() % 2 != 0;
+    auto pSockRtcp = std::make_shared<Socket>(poller);
+    if (!pSockRtcp->bindUdpSock(pSockRtp->get_local_port() + (even_numbers ? 1 : -1), local_ip.data())) {
+        //分配端口失败
+        throw runtime_error("open udp socket failed");
+    }
+
+    if (!even_numbers) {
+        //如果rtp端口不是偶数，那么与rtcp端口互换，目的是兼容一些要求严格的播放器或服务器
+        Socket::Ptr tmp = pSockRtp;
+        pSockRtp = pSockRtcp;
+        pSockRtcp = tmp;
+    }
+
+    return std::make_pair(pSockRtp, pSockRtcp);
+}
+
+std::pair<Socket::Ptr, Socket::Ptr> makeSockPair(const EventPoller::Ptr &poller, const string &local_ip){
+    int try_count = 0;
+    while (true) {
+        try {
+            return makeSockPair_l(poller, local_ip);
+        } catch (...) {
+            if (++try_count == 3) {
+                throw;
+            }
+            WarnL << "open udp socket failed, retry: " << try_count;
+        }
+    }
+}
 
+}//namespace mediakit
\ No newline at end of file

src/Rtsp/Rtsp.h

@@ -271,5 +271,7 @@ private:
     _StrPrinter _printer;
 };
 
+std::pair<Socket::Ptr, Socket::Ptr> makeSockPair(const EventPoller::Ptr &poller, const string &local_ip);
+
 } //namespace mediakit
 #endif //RTSP_RTSP_H_

src/Rtsp/RtspPlayer.cpp

@@ -214,29 +214,10 @@ void RtspPlayer::handleResDESCRIBE(const Parser& parser) {
 void RtspPlayer::createUdpSockIfNecessary(int track_idx){
     auto &rtpSockRef = _apRtpSock[track_idx];
     auto &rtcpSockRef = _apRtcpSock[track_idx];
-    if(!rtpSockRef){
-        rtpSockRef.reset(new Socket(getPoller()));
-        //rtp随机端口
-        if (!rtpSockRef->bindUdpSock(0, get_local_ip().data())) {
-            rtpSockRef.reset();
-            throw std::runtime_error("open rtp sock failed");
-        }
-    }
-
-    if(!rtcpSockRef){
-        rtcpSockRef.reset(new Socket(getPoller()));
-        //rtcp端口为rtp端口+1，目的是为了兼容某些服务器，其实更推荐随机端口
-        if (!rtcpSockRef->bindUdpSock(rtpSockRef->get_local_port() + 1, get_local_ip().data())) {
-            rtcpSockRef.reset();
-            throw std::runtime_error("open rtcp sock failed");
-        }
-    }
-
-    if(rtpSockRef->get_local_port() % 2 != 0){
-        //如果rtp端口不是偶数，那么与rtcp端口互换，目的是兼容一些要求严格的服务器
-        Socket::Ptr tmp = rtpSockRef;
-        rtpSockRef = rtcpSockRef;
-        rtcpSockRef = tmp;
+    if (!rtpSockRef || !rtcpSockRef) {
+        auto pr = makeSockPair(getPoller(), get_local_ip());
+        rtpSockRef = pr.first;
+        rtcpSockRef = pr.second;
     }
 }
 

src/Rtsp/RtspSession.cpp

@@ -627,29 +627,18 @@ void RtspSession::handleReq_Setup(const Parser &parser) {
     }
         break;
     case Rtsp::RTP_UDP: {
-        //我们用trackIdx区分rtp和rtcp包
-        auto pSockRtp = std::make_shared<Socket>(_sock->getPoller());
-        if (!pSockRtp->bindUdpSock(0,get_local_ip().data())) {
-            //分配端口失败
-            send_NotAcceptable();
-            throw SockException(Err_shutdown, "open rtp socket failed");
-        }
-        auto pSockRtcp = std::make_shared<Socket>(_sock->getPoller());
-        if (!pSockRtcp->bindUdpSock(pSockRtp->get_local_port() + 1,get_local_ip().data())) {
+        std::pair<Socket::Ptr, Socket::Ptr> pr;
+        try{
+            pr = makeSockPair(_sock->getPoller(), get_local_ip());
+        }catch(std::exception &ex) {
             //分配端口失败
             send_NotAcceptable();
-            throw SockException(Err_shutdown, "open rtcp socket failed");
+            throw SockException(Err_shutdown, ex.what());
         }
 
-        if(pSockRtp->get_local_port() % 2 != 0){
-            //如果rtp端口不是偶数，那么与rtcp端口互换，目的是兼容一些要求严格的播放器
-            Socket::Ptr tmp = pSockRtp;
-            pSockRtp = pSockRtcp;
-            pSockRtcp = tmp;
-        }
+        _apRtpSock[trackIdx] = pr.first;
+        _apRtcpSock[trackIdx] = pr.second;
 
-        _apRtpSock[trackIdx] = pSockRtp;
-        _apRtcpSock[trackIdx] = pSockRtcp;
         //设置客户端内网端口信息
         string strClientPort = FindField(parser["Transport"].data(), "client_port=", NULL);
         uint16_t ui16RtpPort = atoi( FindField(strClientPort.data(), NULL, "-").data());
@@ -661,24 +650,24 @@ void RtspSession::handleReq_Setup(const Parser &parser) {
         peerAddr.sin_port = htons(ui16RtpPort);
         peerAddr.sin_addr.s_addr = inet_addr(get_peer_ip().data());
         bzero(&(peerAddr.sin_zero), sizeof peerAddr.sin_zero);
-        pSockRtp->setSendPeerAddr((struct sockaddr *)(&peerAddr));
+        pr.first->setSendPeerAddr((struct sockaddr *)(&peerAddr));
 
         //设置rtcp发送目标地址
         peerAddr.sin_family = AF_INET;
         peerAddr.sin_port = htons(ui16RtcpPort);
         peerAddr.sin_addr.s_addr = inet_addr(get_peer_ip().data());
         bzero(&(peerAddr.sin_zero), sizeof peerAddr.sin_zero);
-        pSockRtcp->setSendPeerAddr((struct sockaddr *)(&peerAddr));
+        pr.second->setSendPeerAddr((struct sockaddr *)(&peerAddr));
 
         //尝试获取客户端nat映射地址
         startListenPeerUdpData(trackIdx);
         //InfoP(this) << "分配端口:" << srv_port;
 
         sendRtspResponse("200 OK",
-                         {"Transport",StrPrinter << "RTP/AVP/UDP;unicast;"
-                                                 << "client_port=" << strClientPort << ";"
-                                                 << "server_port=" << pSockRtp->get_local_port() << "-" << pSockRtcp->get_local_port() << ";"
-                                                 << "ssrc=" << printSSRC(trackRef->_ssrc)
+                         {"Transport", StrPrinter << "RTP/AVP/UDP;unicast;"
+                                                  << "client_port=" << strClientPort << ";"
+                                                  << "server_port=" << pr.first->get_local_port() << "-" << pr.second->get_local_port() << ";"
+                                                  << "ssrc=" << printSSRC(trackRef->_ssrc)
                          });
     }
         break;