ZLMediaKit/src/Rtp/RtpSender.cpp

/*
 * Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved.
 *
 * This file is part of ZLMediaKit(https://github.com/xia-chu/ZLMediaKit).
 *
 * Use of this source code is governed by MIT license that can be found in the
 * LICENSE file in the root of the source tree. All contributing project authors
 * may be found in the AUTHORS file in the root of the source tree.
 */

#if defined(ENABLE_RTPPROXY)
#include "RtpSender.h"
#include "Rtsp/RtspSession.h"
#include "Thread/WorkThreadPool.h"
#include "Util/uv_errno.h"
#include "RtpCache.h"
#include "Rtcp/RtcpContext.h"

using namespace std;
using namespace toolkit;

namespace mediakit{

RtpSender::RtpSender(EventPoller::Ptr poller) {
    _poller = poller ? std::move(poller) : EventPollerPool::Instance().getPoller();
    _socket_rtp = Socket::createSocket(_poller, false);
}

RtpSender::~RtpSender() {
    flush();
}

void RtpSender::startSend(const MediaSourceEvent::SendRtpArgs &args, const function<void(uint16_t local_port, const SockException &ex)> &cb){
    _args = args;
    if (!_interface) {
        //重连时不重新创建对象
        auto lam = [this](std::shared_ptr<List<Buffer::Ptr>> list) { onFlushRtpList(std::move(list)); };
        if (args.use_ps) {
            _interface = std::make_shared<RtpCachePS>(lam, atoi(args.ssrc.data()), args.pt);
        } else {
            _interface = std::make_shared<RtpCacheRaw>(lam, atoi(args.ssrc.data()), args.pt, args.only_audio);
        }
    }

    weak_ptr<RtpSender> weak_self = shared_from_this();
    if (args.passive) {
        // tcp被动发流模式
        _args.is_udp = false;
        // 默认等待链接
        bool is_wait = true;
        try {
            auto tcp_listener = Socket::createSocket(_poller, false);
            if (args.src_port) {
                //指定端口
                if (!tcp_listener->listen(args.src_port)) {
                    throw std::invalid_argument(StrPrinter << "open tcp passive server failed on port:" << args.src_port
                                                           << ", err:" << get_uv_errmsg(true));
                }
                is_wait = true;
            } else {
                auto pr = std::make_pair(tcp_listener, Socket::createSocket(_poller, false));
                //从端口池获取随机端口
                makeSockPair(pr, "::", false, false);
                // 随机端口不等待，保证调用者可以知道端口
                is_wait = false;
            }
            // tcp服务器默认开启5秒
            auto delay_task = _poller->doDelayTask(_args.tcp_passive_close_delay_ms, [tcp_listener, cb,is_wait]() mutable {
                if (is_wait) {
                    cb(0, SockException(Err_timeout, "wait tcp connection timeout"));
                }
                tcp_listener = nullptr;
                return 0;
            });
            tcp_listener->setOnAccept([weak_self, cb, delay_task,is_wait](Socket::Ptr &sock, std::shared_ptr<void> &complete) {
                auto strong_self = weak_self.lock();
                if (!strong_self) {
                    return;
                }
                //立即关闭tcp服务器
                delay_task->cancel();
                strong_self->_socket_rtp = sock;
                strong_self->onConnect();
                if (is_wait) {
                    cb(sock->get_local_port(), SockException());
                }
                InfoL << "accept connection from:" << sock->get_peer_ip() << ":" << sock->get_peer_port();
            });
            InfoL << "start tcp passive server on:" << tcp_listener->get_local_port();
            if (!is_wait) {
                // 随机端口马上返回端口，保证调用者知道端口
                cb(tcp_listener->get_local_port(), SockException());
            }
        } catch (std::exception &ex) {
            cb(0, SockException(Err_other, ex.what()));
            return;
        }
        return;
    }
    if (args.is_udp) {
        auto poller = _poller;
        WorkThreadPool::Instance().getPoller()->async([cb, args, weak_self, poller]() {
            struct sockaddr_storage addr;
            //切换线程目的是为了dns解析放在后台线程执行
            if (!SockUtil::getDomainIP(args.dst_url.data(), args.dst_port, addr, AF_INET, SOCK_DGRAM, IPPROTO_UDP)) {
                poller->async([args, cb]() {
                    //切回自己的线程
                    cb(0, SockException(Err_dns, StrPrinter << "dns解析域名失败:" << args.dst_url));
                });
                return;
            }

            //dns解析成功
            poller->async([args, addr, weak_self, cb]() {
                //切回自己的线程
                auto strong_self = weak_self.lock();
                if (!strong_self) {
                    return;
                }
                string ifr_ip = addr.ss_family == AF_INET ? "0.0.0.0" : "::";
                try {
                    if (args.src_port) {
                        //指定端口
                        if (!strong_self->_socket_rtp->bindUdpSock(args.src_port, ifr_ip)) {
                            throw std::invalid_argument(StrPrinter << "bindUdpSock failed on port:" << args.src_port
                                                                   << ", err:" << get_uv_errmsg(true));
                        }
                    } else {
                        auto pr = std::make_pair(strong_self->_socket_rtp, Socket::createSocket(strong_self->_poller, false));
                        //从端口池获取随机端口
                        makeSockPair(pr, ifr_ip, true);
                    }
                } catch (std::exception &ex) {
                    cb(0, SockException(Err_other, ex.what()));
                    return;
                }
                strong_self->_socket_rtp->bindPeerAddr((struct sockaddr *)&addr);
                strong_self->onConnect();
                cb(strong_self->_socket_rtp->get_local_port(), SockException());
            });
        });
    } else {
        _socket_rtp->connect(args.dst_url, args.dst_port, [cb, weak_self](const SockException &err) {
            auto strong_self = weak_self.lock();
            if (strong_self) {
                if (!err) {
                    //tcp连接成功
                    strong_self->onConnect();
                }
                cb(strong_self->_socket_rtp->get_local_port(), err);
            } else {
                cb(0, err);
            }
        }, 5.0F, "::", args.src_port);
    }
}

void RtpSender::createRtcpSocket() {
    if (_socket_rtcp) {
        return;
    }
    _socket_rtcp = Socket::createSocket(_socket_rtp->getPoller(), false);
    //rtcp端口使用户rtp端口+1
    if(!_socket_rtcp->bindUdpSock(_socket_rtp->get_local_port() + 1, _socket_rtp->get_local_ip(), false)){
        WarnL << "bind rtcp udp socket failed:" << get_uv_errmsg(true);
        _socket_rtcp = nullptr;
        return;
    }

    struct sockaddr_storage addr;
    //目标rtp端口
    SockUtil::get_sock_peer_addr(_socket_rtp->rawFD(), addr);
    //绑定目标rtcp端口(目标rtp端口 + 1)
    switch (addr.ss_family) {
        case AF_INET: ((sockaddr_in *)&addr)->sin_port = htons(ntohs(((sockaddr_in *)&addr)->sin_port) + 1); break;
        case AF_INET6: ((sockaddr_in6 *)&addr)->sin6_port = htons(ntohs(((sockaddr_in6 *)&addr)->sin6_port) + 1); break;
        default: assert(0); break;
    }
    _socket_rtcp->bindPeerAddr((struct sockaddr *)&addr);

    _rtcp_context = std::make_shared<RtcpContextForSend>();
    weak_ptr<RtpSender> weak_self = shared_from_this();
    _socket_rtcp->setOnRead([weak_self](const Buffer::Ptr &buf, struct sockaddr *, int) {
        //接收receive report rtcp
        auto strong_self = weak_self.lock();
        if (!strong_self) {
            return;
        }
        auto rtcp_arr = RtcpHeader::loadFromBytes(buf->data(), buf->size());
        for (auto &rtcp : rtcp_arr) {
            strong_self->onRecvRtcp(rtcp);
        }
    });
    InfoL << "open rtcp port success, start check rr rtcp timeout";
}

void RtpSender::onRecvRtcp(RtcpHeader *rtcp) {
    _rtcp_context->onRtcp(rtcp);
    _rtcp_recv_ticker.resetTime();
}

//连接建立成功事件
void RtpSender::onConnect(){
    _is_connect = true;
    //加大发送缓存,防止udp丢包之类的问题
    SockUtil::setSendBuf(_socket_rtp->rawFD(), 4 * 1024 * 1024);
    if (!_args.is_udp) {
        //关闭tcp no_delay并开启MSG_MORE, 提高发送性能
        SockUtil::setNoDelay(_socket_rtp->rawFD(), false);
        _socket_rtp->setSendFlags(SOCKET_DEFAULE_FLAGS | FLAG_MORE);
    } else if (_args.udp_rtcp_timeout) {
        createRtcpSocket();
    }
    //连接建立成功事件
    weak_ptr<RtpSender> weak_self = shared_from_this();
    _socket_rtp->setOnErr([weak_self](const SockException &err) {
        auto strong_self = weak_self.lock();
        if (strong_self) {
            strong_self->onErr(err);
        }
    });
    //获取本地端口，断开重连后确保端口不变
    _args.src_port = _socket_rtp->get_local_port();
    InfoL << "开始发送 rtp:" << _socket_rtp->get_peer_ip() << ":" << _socket_rtp->get_peer_port() << ", 是否为udp方式:" << _args.is_udp;
}

bool RtpSender::addTrack(const Track::Ptr &track){
    return _interface->addTrack(track);
}

void RtpSender::addTrackCompleted(){
    _interface->addTrackCompleted();
}

void RtpSender::resetTracks(){
    _interface->resetTracks();
}

void RtpSender::flush() {
    if (_interface) {
        _interface->flush();
    }
}

//此函数在其他线程执行
bool RtpSender::inputFrame(const Frame::Ptr &frame) {
    //连接成功后才做实质操作(节省cpu资源)
    return _is_connect ? _interface->inputFrame(frame) : false;
}

void RtpSender::onSendRtpUdp(const toolkit::Buffer::Ptr &buf, bool check) {
    if (!_socket_rtcp) {
        return;
    }
    auto rtp = static_pointer_cast<RtpPacket>(buf);
    _rtcp_context->onRtp(rtp->getSeq(), rtp->getStamp(), rtp->getStampMS(), 90000 /*not used*/, rtp->size());

    if (!check) {
        //减少判断次数
        return;
    }
    //每5秒发送一次rtcp
    if (_rtcp_send_ticker.elapsedTime() > _args.rtcp_send_interval_ms) {
        _rtcp_send_ticker.resetTime();
        //rtcp ssrc为rtp ssrc + 1
       auto sr = _rtcp_context->createRtcpSR(atoi(_args.ssrc.data()) + 1);
       //send sender report rtcp
       _socket_rtcp->send(sr);
    }

    if (_rtcp_recv_ticker.elapsedTime() > _args.rtcp_timeout_ms) {
        //接收rr rtcp超时
        WarnL << "recv rr rtcp timeout";
        _rtcp_recv_ticker.resetTime();
        onClose(SockException(Err_timeout, "recv rr rtcp timeout"));
    }
}

void RtpSender::onClose(const SockException &ex) {
    auto cb = _on_close;
    if (cb) {
        //在下次循环时触发onClose，原因是防止遍历map时删除元素
        _poller->async([cb, ex]() { cb(ex); }, false);
    }
}

//此函数在其他线程执行
void RtpSender::onFlushRtpList(shared_ptr<List<Buffer::Ptr> > rtp_list) {
    if(!_is_connect){
        //连接成功后才能发送数据
        return;
    }

    size_t i = 0;
    auto size = rtp_list->size();
    rtp_list->for_each([&](Buffer::Ptr &packet) {
        if (_args.is_udp) {
            onSendRtpUdp(packet, i == 0);
            // udp模式，rtp over tcp前4个字节可以忽略
            _socket_rtp->send(std::make_shared<BufferRtp>(std::move(packet), RtpPacket::kRtpTcpHeaderSize), nullptr, 0, ++i == size);
        } else {
            // tcp模式, rtp over tcp前2个字节可以忽略,只保留后续rtp长度的2个字节
            _socket_rtp->send(std::make_shared<BufferRtp>(std::move(packet), 2), nullptr, 0, ++i == size);
        }
    });
}

void RtpSender::onErr(const SockException &ex) {
    _is_connect = false;
    WarnL << "send rtp connection lost: " << ex.what();
    onClose(ex);
}

void RtpSender::setOnClose(std::function<void(const toolkit::SockException &ex)> on_close){
    _on_close = std::move(on_close);
}

}//namespace mediakit
#endif// defined(ENABLE_RTPPROXY)