ZLMediaKit/webrtc/WebRtcTransport.cpp

/*
 * Copyright (c) 2016-present The ZLMediaKit project authors. All Rights Reserved.
 *
 * This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
 *
 * Use of this source code is governed by MIT-like 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.
 */

#include <iostream>
#include <srtp2/srtp.h>
#include "Util/base64.h"
#include "Network/sockutil.h"
#include "Common/config.h"
#include "Nack.h"
#include "RtpExt.h"
#include "Rtcp/Rtcp.h"
#include "Rtcp/RtcpFCI.h"
#include "Rtcp/RtcpContext.h"
#include "Rtsp/Rtsp.h"
#include "Rtsp/RtpReceiver.h"
#include "WebRtcTransport.h"

#include "WebRtcEchoTest.h"
#include "WebRtcPlayer.h"
#include "WebRtcPusher.h"
#include "Rtsp/RtspMediaSourceImp.h"

#define RTP_SSRC_OFFSET 1
#define RTX_SSRC_OFFSET 2
#define RTP_CNAME "zlmediakit-rtp"
#define RTP_LABEL "zlmediakit-label"
#define RTP_MSLABEL "zlmediakit-mslabel"

using namespace std;

namespace mediakit {

// RTC配置项目
namespace Rtc {
#define RTC_FIELD "rtc."
// rtp和rtcp接受超时时间
const string kTimeOutSec = RTC_FIELD "timeoutSec";
// 服务器外网ip
const string kExternIP = RTC_FIELD "externIP";
// 设置remb比特率，非0时关闭twcc并开启remb。该设置在rtc推流时有效，可以控制推流画质
const string kRembBitRate = RTC_FIELD "rembBitRate";
// webrtc单端口udp服务器
const string kPort = RTC_FIELD "port";
const string kTcpPort = RTC_FIELD "tcpPort";

// 比特率设置
const string kStartBitrate = RTC_FIELD "start_bitrate";
const string kMaxBitrate = RTC_FIELD "max_bitrate";
const string kMinBitrate = RTC_FIELD "min_bitrate";

// 数据通道设置
const string kDataChannelEcho = RTC_FIELD "datachannel_echo";

static onceToken token([]() {
    mINI::Instance()[kTimeOutSec] = 15;
    mINI::Instance()[kExternIP] = "";
    mINI::Instance()[kRembBitRate] = 0;
    mINI::Instance()[kPort] = 8000;
    mINI::Instance()[kTcpPort] = 8000;

    mINI::Instance()[kStartBitrate] = 0;
    mINI::Instance()[kMaxBitrate] = 0;
    mINI::Instance()[kMinBitrate] = 0;

    mINI::Instance()[kDataChannelEcho] = true;
});

} // namespace RTC

static atomic<uint64_t> s_key { 0 };

static void translateIPFromEnv(std::vector<std::string> &v) {
    for (auto iter = v.begin(); iter != v.end();) {
        if (start_with(*iter, "$")) {
            auto ip = toolkit::getEnv(*iter);
            if (ip.empty()) {
                iter = v.erase(iter);
            } else {
                *iter++ = ip;
            }
        } else {
            ++iter;
        }
    }
}

static std::string getServerPrefix() {
    //stun_user_name格式: base64(ip+udp_port+tcp_port) + _ + number
    //其中ip为二进制char[4], udp_port/tcp_port为大端 uint16.
    //number为自增长数，确保短时间内唯一
    GET_CONFIG(uint16_t, udp_port, Rtc::kPort);
    GET_CONFIG(uint16_t, tcp_port, Rtc::kTcpPort);
    char buf[8];
    auto host = SockUtil::get_local_ip();
    auto addr = SockUtil::make_sockaddr(host.data(), udp_port);
    //拷贝ipv4地址
    memcpy(buf, &(reinterpret_cast<sockaddr_in *>(&addr)->sin_addr), 4);
    //拷贝udp端口
    memcpy(buf + 4, &(reinterpret_cast<sockaddr_in *>(&addr)->sin_port), 2);
    //tcp端口转大端模式
    addr = SockUtil::make_sockaddr(host.data(), tcp_port);
    //拷贝tcp端口
    memcpy(buf + 6, &(reinterpret_cast<sockaddr_in *>(&addr)->sin_port), 2);
    auto ret = encodeBase64(string(buf, 8)) + '_';
    InfoL << "MediaServer(" << host << ":" << udp_port << ":" << tcp_port << ") prefix: " << ret;
    return ret;
}

const char* sockTypeStr(Session* session) {
    if (session) {
        switch (session->getSock()->sockType()) {
            case SockNum::Sock_TCP: return "tcp";
            case SockNum::Sock_UDP: return "udp";
            default: break;
        }
    }
    return "unknown";
}

WebRtcTransport::WebRtcTransport(const EventPoller::Ptr &poller) {
    _poller = poller;
    static auto prefix = getServerPrefix();
    _identifier = prefix + to_string(++s_key);
    _packet_pool.setSize(64);
}

void WebRtcTransport::onCreate() {
    _dtls_transport = std::make_shared<RTC::DtlsTransport>(_poller, this);
    _ice_server = std::make_shared<RTC::IceServer>(this, _identifier, makeRandStr(24));
}

void WebRtcTransport::onDestory() {
#ifdef ENABLE_SCTP
    _sctp = nullptr;
#endif
    _dtls_transport = nullptr;
    _ice_server = nullptr;
}

const EventPoller::Ptr &WebRtcTransport::getPoller() const {
    return _poller;
}

const string &WebRtcTransport::getIdentifier() const {
    return _identifier;
}

const std::string& WebRtcTransport::deleteRandStr() const {
    if (_delete_rand_str.empty()) {
        _delete_rand_str = makeRandStr(32);
    }
    return _delete_rand_str;
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

void WebRtcTransport::OnIceServerSendStunPacket(
    const RTC::IceServer *iceServer, const RTC::StunPacket *packet, RTC::TransportTuple *tuple) {
    sendSockData((char *)packet->GetData(), packet->GetSize(), tuple);
}

void WebRtcTransportImp::OnIceServerSelectedTuple(const RTC::IceServer *iceServer, RTC::TransportTuple *tuple) {
    InfoL << getIdentifier() << " select tuple " << sockTypeStr(tuple) << " " << tuple->get_peer_ip() << ":" << tuple->get_peer_port();
    tuple->setSendFlushFlag(false);
    unrefSelf();
}

void WebRtcTransport::OnIceServerConnected(const RTC::IceServer *iceServer) {
    InfoL << getIdentifier();
}

void WebRtcTransport::OnIceServerCompleted(const RTC::IceServer *iceServer) {
    InfoL << getIdentifier();
    if (_answer_sdp->media[0].role == DtlsRole::passive) {
        _dtls_transport->Run(RTC::DtlsTransport::Role::SERVER);
    } else {
        _dtls_transport->Run(RTC::DtlsTransport::Role::CLIENT);
    }
}

void WebRtcTransport::OnIceServerDisconnected(const RTC::IceServer *iceServer) {
    InfoL << getIdentifier();
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

void WebRtcTransport::OnDtlsTransportConnected(
    const RTC::DtlsTransport *dtlsTransport, RTC::SrtpSession::CryptoSuite srtpCryptoSuite, uint8_t *srtpLocalKey,
    size_t srtpLocalKeyLen, uint8_t *srtpRemoteKey, size_t srtpRemoteKeyLen, std::string &remoteCert) {
    InfoL << getIdentifier();
    _srtp_session_send = std::make_shared<RTC::SrtpSession>(
        RTC::SrtpSession::Type::OUTBOUND, srtpCryptoSuite, srtpLocalKey, srtpLocalKeyLen);
    _srtp_session_recv = std::make_shared<RTC::SrtpSession>(
        RTC::SrtpSession::Type::INBOUND, srtpCryptoSuite, srtpRemoteKey, srtpRemoteKeyLen);
#ifdef ENABLE_SCTP
    _sctp = std::make_shared<RTC::SctpAssociationImp>(getPoller(), this, 128, 128, 262144, true);
    _sctp->TransportConnected();
#endif
    onStartWebRTC();
}

#pragma pack(push, 1)
struct DtlsHeader {
    uint8_t content_type;
    uint16_t dtls_version;
    uint16_t epoch;
    uint8_t seq[6];
    uint16_t length;
    uint8_t payload[1];
};
#pragma pack(pop)

void WebRtcTransport::OnDtlsTransportSendData(
    const RTC::DtlsTransport *dtlsTransport, const uint8_t *data, size_t len) {
    size_t offset = 0;
    while(offset < len) {
        auto *header = reinterpret_cast<const DtlsHeader *>(data + offset);
        auto length = ntohs(header->length) + offsetof(DtlsHeader, payload);
        sendSockData((char *)data + offset, length, nullptr);
        offset += length;
    }
}

void WebRtcTransport::OnDtlsTransportConnecting(const RTC::DtlsTransport *dtlsTransport) {
    InfoL << getIdentifier();
}

void WebRtcTransport::OnDtlsTransportFailed(const RTC::DtlsTransport *dtlsTransport) {
    InfoL << getIdentifier();
    onShutdown(SockException(Err_shutdown, "dtls transport failed"));
}

void WebRtcTransport::OnDtlsTransportClosed(const RTC::DtlsTransport *dtlsTransport) {
    InfoL << getIdentifier();
    onShutdown(SockException(Err_shutdown, "dtls close notify received"));
}

void WebRtcTransport::OnDtlsTransportApplicationDataReceived(
    const RTC::DtlsTransport *dtlsTransport, const uint8_t *data, size_t len) {
#ifdef ENABLE_SCTP
    _sctp->ProcessSctpData(data, len);
#else
    InfoL << hexdump(data, len);
#endif
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#ifdef ENABLE_SCTP
void WebRtcTransport::OnSctpAssociationConnecting(RTC::SctpAssociation *sctpAssociation) {
    TraceL << getIdentifier();
    try {
        NOTICE_EMIT(BroadcastRtcSctpConnectArgs, Broadcast::kBroadcastRtcSctpConnecting, *this);
    } catch (std::exception &ex) {
        WarnL << "Exception occurred: " << ex.what();
    }
}

void WebRtcTransport::OnSctpAssociationConnected(RTC::SctpAssociation *sctpAssociation) {
    InfoL << getIdentifier();
    try {
        NOTICE_EMIT(BroadcastRtcSctpConnectArgs, Broadcast::kBroadcastRtcSctpConnected, *this);
    } catch (std::exception &ex) {
        WarnL << "Exception occurred: " << ex.what();
    }
}

void WebRtcTransport::OnSctpAssociationFailed(RTC::SctpAssociation *sctpAssociation) {
    WarnL << getIdentifier();
    try {
        NOTICE_EMIT(BroadcastRtcSctpConnectArgs, Broadcast::kBroadcastRtcSctpFailed, *this);
    } catch (std::exception &ex) {
        WarnL << "Exception occurred: " << ex.what();
    }
}

void WebRtcTransport::OnSctpAssociationClosed(RTC::SctpAssociation *sctpAssociation) {
    InfoL << getIdentifier();
    try {
        NOTICE_EMIT(BroadcastRtcSctpConnectArgs, Broadcast::kBroadcastRtcSctpClosed, *this);
    } catch (std::exception &ex) {
        WarnL << "Exception occurred: " << ex.what();
    }
}

void WebRtcTransport::OnSctpAssociationSendData(
    RTC::SctpAssociation *sctpAssociation, const uint8_t *data, size_t len) {
    try {
        NOTICE_EMIT(BroadcastRtcSctpSendArgs, Broadcast::kBroadcastRtcSctpSend, *this, data, len);
    } catch (std::exception &ex) {
        WarnL << "Exception occurred: " << ex.what();
    }
    _dtls_transport->SendApplicationData(data, len);
}

void WebRtcTransport::OnSctpAssociationMessageReceived(
    RTC::SctpAssociation *sctpAssociation, uint16_t streamId, uint32_t ppid, const uint8_t *msg, size_t len) {
    InfoL << getIdentifier() << " " << streamId << " " << ppid << " " << len << " " << string((char *)msg, len);
    RTC::SctpStreamParameters params;
    params.streamId = streamId;

    GET_CONFIG(bool, datachannel_echo, Rtc::kDataChannelEcho);
    if (datachannel_echo) {
        // 回显数据
        _sctp->SendSctpMessage(params, ppid, msg, len);
    }

    try {
        NOTICE_EMIT(BroadcastRtcSctpReceivedArgs, Broadcast::kBroadcastRtcSctpReceived, *this, streamId, ppid, msg, len);
    } catch (std::exception &ex) {
        WarnL << "Exception occurred: " << ex.what();
    }
}
#endif

void WebRtcTransport::sendDatachannel(uint16_t streamId, uint32_t ppid, const char *msg, size_t len) {
#ifdef ENABLE_SCTP
    if (_sctp) {
        RTC::SctpStreamParameters params;
        params.streamId = streamId;
        _sctp->SendSctpMessage(params, ppid, (uint8_t *)msg, len);
    }
#else
    WarnL << "WebRTC datachannel disabled!";
#endif
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

void WebRtcTransport::sendSockData(const char *buf, size_t len, RTC::TransportTuple *tuple) {
    auto pkt = _packet_pool.obtain2();
    pkt->assign(buf, len);
    onSendSockData(std::move(pkt), true, tuple ? tuple : _ice_server->GetSelectedTuple());
}

Session::Ptr WebRtcTransport::getSession() const {
    auto tuple = _ice_server ? _ice_server->GetSelectedTuple(true) : nullptr;
    return tuple ? static_pointer_cast<Session>(tuple->shared_from_this()) : nullptr;
}

void WebRtcTransport::sendRtcpRemb(uint32_t ssrc, size_t bit_rate) {
    auto remb = FCI_REMB::create({ ssrc }, (uint32_t)bit_rate);
    auto fb = RtcpFB::create(PSFBType::RTCP_PSFB_REMB, remb.data(), remb.size());
    fb->ssrc = htonl(0);
    fb->ssrc_media = htonl(ssrc);
    sendRtcpPacket((char *)fb.get(), fb->getSize(), true);
}

void WebRtcTransport::sendRtcpPli(uint32_t ssrc) {
    auto pli = RtcpFB::create(PSFBType::RTCP_PSFB_PLI);
    pli->ssrc = htonl(0);
    pli->ssrc_media = htonl(ssrc);
    sendRtcpPacket((char *)pli.get(), pli->getSize(), true);
}

string getFingerprint(const string &algorithm_str, const std::shared_ptr<RTC::DtlsTransport> &transport) {
    auto algorithm = RTC::DtlsTransport::GetFingerprintAlgorithm(algorithm_str);
    for (auto &finger_prints : transport->GetLocalFingerprints()) {
        if (finger_prints.algorithm == algorithm) {
            return finger_prints.value;
        }
    }
    throw std::invalid_argument(StrPrinter << "不支持的加密算法:" << algorithm_str);
}

void WebRtcTransport::setRemoteDtlsFingerprint(const RtcSession &remote) {
    // 设置远端dtls签名
    RTC::DtlsTransport::Fingerprint remote_fingerprint;
    remote_fingerprint.algorithm
        = RTC::DtlsTransport::GetFingerprintAlgorithm(_offer_sdp->media[0].fingerprint.algorithm);
    remote_fingerprint.value = _offer_sdp->media[0].fingerprint.hash;
    _dtls_transport->SetRemoteFingerprint(remote_fingerprint);
}

void WebRtcTransport::onRtcConfigure(RtcConfigure &configure) const {
    SdpAttrFingerprint fingerprint;
    fingerprint.algorithm = _offer_sdp->media[0].fingerprint.algorithm;
    fingerprint.hash = getFingerprint(fingerprint.algorithm, _dtls_transport);
    configure.setDefaultSetting(
            _ice_server->GetUsernameFragment(), _ice_server->GetPassword(), RtpDirection::sendrecv, fingerprint);

    // 开启remb后关闭twcc，因为开启twcc后remb无效
    GET_CONFIG(size_t, remb_bit_rate, Rtc::kRembBitRate);
    configure.enableTWCC(!remb_bit_rate);
}

static void setSdpBitrate(RtcSession &sdp) {
    GET_CONFIG(size_t, max_bitrate, Rtc::kMaxBitrate);
    GET_CONFIG(size_t, min_bitrate, Rtc::kMinBitrate);
    GET_CONFIG(size_t, start_bitrate, Rtc::kStartBitrate);

    auto m = (RtcMedia *)(sdp.getMedia(TrackType::TrackVideo));
    if (m) {
        auto &plan = m->plan[0];
        if (max_bitrate) plan.fmtp["x-google-max-bitrate"] = std::to_string(max_bitrate);
        if (min_bitrate) plan.fmtp["x-google-min-bitrate"] = std::to_string(min_bitrate);
        if (start_bitrate) plan.fmtp["x-google-start-bitrate"] = std::to_string(start_bitrate);
    }
}

std::string WebRtcTransport::getAnswerSdp(const string &offer) {
    try {
        //// 解析offer sdp ////
        _offer_sdp = std::make_shared<RtcSession>();
        _offer_sdp->loadFrom(offer);
        onCheckSdp(SdpType::offer, *_offer_sdp);
        _offer_sdp->checkValid();
        setRemoteDtlsFingerprint(*_offer_sdp);

        //// sdp 配置 ////
        RtcConfigure configure;
        onRtcConfigure(configure);

        //// 生成answer sdp ////
        _answer_sdp = configure.createAnswer(*_offer_sdp);
        onCheckSdp(SdpType::answer, *_answer_sdp);
        setSdpBitrate(*_answer_sdp);
        _answer_sdp->checkValid();
        return _answer_sdp->toString();
    } catch (exception &ex) {
        onShutdown(SockException(Err_shutdown, ex.what()));
        throw;
    }
}

static bool isDtls(char *buf) {
    return ((*buf > 19) && (*buf < 64));
}

void WebRtcTransport::inputSockData(char *buf, int len, RTC::TransportTuple *tuple) {
    if (RTC::StunPacket::IsStun((const uint8_t *)buf, len)) {
        std::unique_ptr<RTC::StunPacket> packet(RTC::StunPacket::Parse((const uint8_t *)buf, len));
        if (!packet) {
            WarnL << "parse stun error";
            return;
        }
        _ice_server->ProcessStunPacket(packet.get(), tuple);
        return;
    }
    if (isDtls(buf)) {
        _dtls_transport->ProcessDtlsData((uint8_t *)buf, len);
        return;
    }
    if (isRtp(buf, len)) {
        if (!_srtp_session_recv) {
            WarnL << "received rtp packet when dtls not completed from:" << tuple->get_peer_ip();
            return;
        }
        if (_srtp_session_recv->DecryptSrtp((uint8_t *)buf, &len)) {
            onRtp(buf, len, _ticker.createdTime());
        }
        return;
    }
    if (isRtcp(buf, len)) {
        if (!_srtp_session_recv) {
            WarnL << "received rtcp packet when dtls not completed from:" << tuple->get_peer_ip();
            return;
        }
        if (_srtp_session_recv->DecryptSrtcp((uint8_t *)buf, &len)) {
            onRtcp(buf, len);
        }
        return;
    }
}

void WebRtcTransport::sendRtpPacket(const char *buf, int len, bool flush, void *ctx) {
    if (_srtp_session_send) {
        auto pkt = _packet_pool.obtain2();
        // 预留rtx加入的两个字节
        pkt->setCapacity((size_t)len + SRTP_MAX_TRAILER_LEN + 2);
        memcpy(pkt->data(), buf, len);
        onBeforeEncryptRtp(pkt->data(), len, ctx);
        if (_srtp_session_send->EncryptRtp(reinterpret_cast<uint8_t *>(pkt->data()), &len)) {
            pkt->setSize(len);
            onSendSockData(std::move(pkt), flush);
        }
    }
}

void WebRtcTransport::sendRtcpPacket(const char *buf, int len, bool flush, void *ctx) {
    if (_srtp_session_send) {
        auto pkt = _packet_pool.obtain2();
        // 预留rtx加入的两个字节
        pkt->setCapacity((size_t)len + SRTP_MAX_TRAILER_LEN + 2);
        memcpy(pkt->data(), buf, len);
        onBeforeEncryptRtcp(pkt->data(), len, ctx);
        if (_srtp_session_send->EncryptRtcp(reinterpret_cast<uint8_t *>(pkt->data()), &len)) {
            pkt->setSize(len);
            onSendSockData(std::move(pkt), flush);
        }
    }
}

///////////////////////////////////////////////////////////////////////////////////

void WebRtcTransportImp::onCreate() {
    WebRtcTransport::onCreate();
    registerSelf();

    weak_ptr<WebRtcTransportImp> weak_self = static_pointer_cast<WebRtcTransportImp>(shared_from_this());
    GET_CONFIG(float, timeoutSec, Rtc::kTimeOutSec);
    _timer = std::make_shared<Timer>(
        timeoutSec / 2,
        [weak_self]() {
            auto strong_self = weak_self.lock();
            if (!strong_self) {
                return false;
            }
            if (strong_self->_alive_ticker.elapsedTime() > timeoutSec * 1000) {
                strong_self->onShutdown(SockException(Err_timeout, "接受rtp/rtcp/datachannel超时"));
            }
            return true;
        },
        getPoller());

    _twcc_ctx.setOnSendTwccCB([this](uint32_t ssrc, string fci) { onSendTwcc(ssrc, fci); });
}

void WebRtcTransportImp::OnDtlsTransportApplicationDataReceived(const RTC::DtlsTransport *dtlsTransport, const uint8_t *data, size_t len) {
    WebRtcTransport::OnDtlsTransportApplicationDataReceived(dtlsTransport, data, len);
#ifdef ENABLE_SCTP
    if (_answer_sdp->isOnlyDatachannel()) {
        _alive_ticker.resetTime();
    }
#endif
}

WebRtcTransportImp::WebRtcTransportImp(const EventPoller::Ptr &poller) : WebRtcTransport(poller) {
    InfoL << getIdentifier();
}

WebRtcTransportImp::~WebRtcTransportImp() {
    InfoL << getIdentifier();
}

void WebRtcTransportImp::onDestory() {
    WebRtcTransport::onDestory();
    unregisterSelf();
}

void WebRtcTransportImp::onSendSockData(Buffer::Ptr buf, bool flush, RTC::TransportTuple *tuple) {
    if (tuple == nullptr) {
        tuple = _ice_server->GetSelectedTuple();
        if (!tuple) {
            WarnL << "send data failed:" << buf->size();
            return;
        }
    }

    // 一次性发送一帧的rtp数据，提高网络io性能
    if (tuple->getSock()->sockType() == SockNum::Sock_TCP) {
        // 增加tcp两字节头
        auto len = buf->size();
        char tcp_len[2] = { 0 };
        tcp_len[0] = (len >> 8) & 0xff;
        tcp_len[1] = len & 0xff;
        tuple->SockSender::send(tcp_len, 2);
    }
    tuple->send(std::move(buf));

    if (flush) {
        tuple->flushAll();
    }
}

///////////////////////////////////////////////////////////////////

bool WebRtcTransportImp::canSendRtp() const {
    for (auto &m : _answer_sdp->media) {
        if (m.direction == RtpDirection::sendrecv || m.direction == RtpDirection::sendonly) {
            return true;
        }
    }
    return false;
}

bool WebRtcTransportImp::canRecvRtp() const {
    for (auto &m : _answer_sdp->media) {
        if (m.direction == RtpDirection::sendrecv || m.direction == RtpDirection::recvonly) {
            return true;
        }
    }
    return false;
}

void WebRtcTransportImp::onStartWebRTC() {
    // 获取ssrc和pt相关信息,届时收到rtp和rtcp时分别可以根据pt和ssrc找到相关的信息
    for (auto &m_answer : _answer_sdp->media) {
        if (m_answer.type == TrackApplication) {
            continue;
        }
        auto m_offer = _offer_sdp->getMedia(m_answer.type);
        auto track = std::make_shared<MediaTrack>();

        track->media = &m_answer;
        track->answer_ssrc_rtp = m_answer.getRtpSSRC();
        track->answer_ssrc_rtx = m_answer.getRtxSSRC();
        track->offer_ssrc_rtp = m_offer->getRtpSSRC();
        track->offer_ssrc_rtx = m_offer->getRtxSSRC();
        track->plan_rtp = &m_answer.plan[0];
        track->plan_rtx = m_answer.getRelatedRtxPlan(track->plan_rtp->pt);
        track->rtcp_context_send = std::make_shared<RtcpContextForSend>();

        // rtp track type --> MediaTrack
        if (m_answer.direction == RtpDirection::sendonly || m_answer.direction == RtpDirection::sendrecv) {
            // 该类型的track 才支持发送
            _type_to_track[m_answer.type] = track;
        }
        // send ssrc --> MediaTrack
        _ssrc_to_track[track->answer_ssrc_rtp] = track;
        _ssrc_to_track[track->answer_ssrc_rtx] = track;

        // recv ssrc --> MediaTrack
        _ssrc_to_track[track->offer_ssrc_rtp] = track;
        _ssrc_to_track[track->offer_ssrc_rtx] = track;

        // rtp pt --> MediaTrack
        _pt_to_track.emplace(
            track->plan_rtp->pt, std::unique_ptr<WrappedMediaTrack>(new WrappedRtpTrack(track, _twcc_ctx, *this)));
        if (track->plan_rtx) {
            // rtx pt --> MediaTrack
            _pt_to_track.emplace(track->plan_rtx->pt, std::unique_ptr<WrappedMediaTrack>(new WrappedRtxTrack(track)));
        }
        // 记录rtp ext类型与id的关系，方便接收或发送rtp时修改rtp ext id
        track->rtp_ext_ctx = std::make_shared<RtpExtContext>(m_answer);
        weak_ptr<MediaTrack> weak_track = track;
        track->rtp_ext_ctx->setOnGetRtp([this, weak_track](uint8_t pt, uint32_t ssrc, const string &rid) {
            // ssrc --> MediaTrack
            auto track = weak_track.lock();
            assert(track);
            _ssrc_to_track[ssrc] = std::move(track);
            InfoL << "get rtp, pt:" << (int)pt << ", ssrc:" << ssrc << ", rid:" << rid;
        });

        size_t index = 0;
        for (auto &ssrc : m_offer->rtp_ssrc_sim) {
            // 记录ssrc对应的MediaTrack
            _ssrc_to_track[ssrc.ssrc] = track;
            if (m_offer->rtp_rids.size() > index) {
                // 支持firefox的simulcast, 提前映射好ssrc和rid的关系
                track->rtp_ext_ctx->setRid(ssrc.ssrc, m_offer->rtp_rids[index]);
            } else {
                // SDP munging没有rid, 它通过group-ssrc:SIM给出ssrc列表;
                // 系统又要有rid，这里手工生成rid，并为其绑定ssrc
                std::string rid = "r" + std::to_string(index);
                track->rtp_ext_ctx->setRid(ssrc.ssrc, rid);
                if (ssrc.rtx_ssrc) {
                    track->rtp_ext_ctx->setRid(ssrc.rtx_ssrc, rid);
                }
            }
            ++index;
        }
    }
}

void WebRtcTransportImp::onCheckAnswer(RtcSession &sdp) {
    // 修改answer sdp的ip、端口信息
    GET_CONFIG_FUNC(std::vector<std::string>, extern_ips, Rtc::kExternIP, [](string str) {
        std::vector<std::string> ret;
        if (str.length()) {
            ret = split(str, ",");
        }
        translateIPFromEnv(ret);
        return ret;
    });
    for (auto &m : sdp.media) {
        m.addr.reset();
        m.addr.address = extern_ips.empty() ? _local_ip.empty() ? SockUtil::get_local_ip() : _local_ip : extern_ips[0];
        m.rtcp_addr.reset();
        m.rtcp_addr.address = m.addr.address;

        GET_CONFIG(uint16_t, udp_port, Rtc::kPort);
        GET_CONFIG(uint16_t, tcp_port, Rtc::kTcpPort);
        m.port = m.port ? (udp_port ? udp_port : tcp_port) : 0;
        if (m.type != TrackApplication) {
            m.rtcp_addr.port = m.port;
        }
        sdp.origin.address = m.addr.address;
    }

    if (!canSendRtp()) {
        // 设置我们发送的rtp的ssrc
        return;
    }

    for (auto &m : sdp.media) {
        if (m.type == TrackApplication) {
            continue;
        }
        if (!m.rtp_rtx_ssrc.empty()) {
            // 已经生成了ssrc
            continue;
        }
        // 添加answer sdp的ssrc信息
        m.rtp_rtx_ssrc.emplace_back();
        auto &ssrc = m.rtp_rtx_ssrc.back();
        // 发送的ssrc我们随便定义，因为在发送rtp时会修改为此值
        ssrc.ssrc = m.type + RTP_SSRC_OFFSET;
        ssrc.cname = RTP_CNAME;
        ssrc.label = std::string(RTP_LABEL) + '-' + m.mid;
        ssrc.mslabel = RTP_MSLABEL;
        ssrc.msid = ssrc.mslabel + ' ' + ssrc.label;

        if (m.getRelatedRtxPlan(m.plan[0].pt)) {
            // rtx ssrc
            ssrc.rtx_ssrc = ssrc.ssrc + RTX_SSRC_OFFSET;
        }
    }
}

void WebRtcTransportImp::onCheckSdp(SdpType type, RtcSession &sdp) {
    switch (type) {
    case SdpType::answer:
        onCheckAnswer(sdp);
        break;
    case SdpType::offer:
        break;
    default: /*不可达*/
        assert(0);
        break;
    }
}

SdpAttrCandidate::Ptr
makeIceCandidate(std::string ip, uint16_t port, uint32_t priority = 100, std::string proto = "udp") {
    auto candidate = std::make_shared<SdpAttrCandidate>();
    // rtp端口
    candidate->component = 1;
    candidate->transport = proto;
    candidate->foundation = proto + "candidate";
    // 优先级，单candidate时随便
    candidate->priority = priority;
    candidate->address = std::move(ip);
    candidate->port = port;
    candidate->type = "host";
    if (proto == "tcp") {
        candidate->type += " tcptype passive";
    }
    return candidate;
}

void WebRtcTransportImp::onRtcConfigure(RtcConfigure &configure) const {
    WebRtcTransport::onRtcConfigure(configure);
    if (!_cands.empty()) {
        for (auto &cand : _cands) {
            configure.addCandidate(cand);
        }
        return;
    }

    GET_CONFIG(uint16_t, local_udp_port, Rtc::kPort);
    GET_CONFIG(uint16_t, local_tcp_port, Rtc::kTcpPort);
    // 添加接收端口candidate信息
    GET_CONFIG_FUNC(std::vector<std::string>, extern_ips, Rtc::kExternIP, [](string str) {
        std::vector<std::string> ret;
        if (str.length()) {
            ret = split(str, ",");
        }
        translateIPFromEnv(ret);
        return ret;
    });
    if (extern_ips.empty()) {
        std::string local_ip = _local_ip.empty() ? SockUtil::get_local_ip() : _local_ip;
        if (local_udp_port) { configure.addCandidate(*makeIceCandidate(local_ip, local_udp_port, 120, "udp")); }
        if (local_tcp_port) { configure.addCandidate(*makeIceCandidate(local_ip, local_tcp_port, _preferred_tcp ? 125 : 115, "tcp")); }
    } else {
        const uint32_t delta = 10;
        uint32_t priority = 100 + delta * extern_ips.size();
        for (auto ip : extern_ips) {
            if (local_udp_port) { configure.addCandidate(*makeIceCandidate(ip, local_udp_port, priority, "udp")); }
            if (local_tcp_port) { configure.addCandidate(*makeIceCandidate(ip, local_tcp_port, priority - (_preferred_tcp ? -5 : 5), "tcp")); }
            priority -= delta;
        }
    }
}

void WebRtcTransportImp::setPreferredTcp(bool flag) {
    _preferred_tcp = flag;
}

void WebRtcTransportImp::setLocalIp(std::string local_ip) {
    _local_ip = std::move(local_ip);
}

void WebRtcTransportImp::setIceCandidate(vector<SdpAttrCandidate> cands) {
    _cands = std::move(cands);
}

///////////////////////////////////////////////////////////////////

class RtpChannel : public RtpTrackImp, public std::enable_shared_from_this<RtpChannel> {
public:
    RtpChannel(EventPoller::Ptr poller, RtpTrackImp::OnSorted cb, function<void(const FCI_NACK &nack)> on_nack) {
        _poller = std::move(poller);
        _on_nack = std::move(on_nack);
        setOnSorted(std::move(cb));
        //设置jitter buffer参数
        GET_CONFIG(uint32_t, nack_maxms, Rtc::kNackMaxMS);
        GET_CONFIG(uint32_t, nack_max_rtp, Rtc::kNackMaxSize);
        RtpTrackImp::setParams(nack_max_rtp, nack_maxms, nack_max_rtp / 2);
        _nack_ctx.setOnNack([this](const FCI_NACK &nack) { onNack(nack); });
    }

    RtpPacket::Ptr inputRtp(TrackType type, int sample_rate, uint8_t *ptr, size_t len, bool is_rtx) {
        auto rtp = RtpTrack::inputRtp(type, sample_rate, ptr, len);
        if (!rtp) {
            return rtp;
        }
        auto seq = rtp->getSeq();
        _nack_ctx.received(seq, is_rtx);
        if (!is_rtx) {
            // 统计rtp接受情况，便于生成nack rtcp包
            _rtcp_context.onRtp(seq, rtp->getStamp(), rtp->ntp_stamp, sample_rate, len);
        }
        return rtp;
    }

    Buffer::Ptr createRtcpRR(RtcpHeader *sr, uint32_t ssrc) {
        _rtcp_context.onRtcp(sr);
        return _rtcp_context.createRtcpRR(ssrc, getSSRC());
    }

    float getLossRate() {
        auto expected = _rtcp_context.getExpectedPacketsInterval();
        if (!expected) {
            return -1;
        }
        return _rtcp_context.getLostInterval() * 100 / expected;
    }

private:
    void starNackTimer() {
        if (_delay_task) {
            return;
        }
        weak_ptr<RtpChannel> weak_self = shared_from_this();
        _delay_task = _poller->doDelayTask(10, [weak_self]() -> uint64_t {
            auto strong_self = weak_self.lock();
            if (!strong_self) {
                return 0;
            }
            auto ret = strong_self->_nack_ctx.reSendNack();
            if (!ret) {
                strong_self->_delay_task = nullptr;
            }
            return ret;
        });
    }

    void onNack(const FCI_NACK &nack) {
        _on_nack(nack);
        starNackTimer();
    }

private:
    NackContext _nack_ctx;
    RtcpContextForRecv _rtcp_context;
    EventPoller::Ptr _poller;
    EventPoller::DelayTask::Ptr _delay_task;
    function<void(const FCI_NACK &nack)> _on_nack;
};

std::shared_ptr<RtpChannel> MediaTrack::getRtpChannel(uint32_t ssrc) const {
    auto it_chn = rtp_channel.find(rtp_ext_ctx->getRid(ssrc));
    if (it_chn == rtp_channel.end()) {
        return nullptr;
    }
    return it_chn->second;
}

float WebRtcTransportImp::getLossRate(TrackType type) {
    for (auto &pr : _ssrc_to_track) {
        auto ssrc = pr.first;
        auto &track = pr.second;
        auto rtp_chn = track->getRtpChannel(ssrc);
        if (rtp_chn) {
            if (track->media && type == track->media->type) {
                return rtp_chn->getLossRate();
            }
        }
    }
    return -1;
}

void WebRtcTransportImp::onRtcp(const char *buf, size_t len) {
    _bytes_usage += len;
    auto rtcps = RtcpHeader::loadFromBytes((char *)buf, len);
    for (auto rtcp : rtcps) {
        switch ((RtcpType)rtcp->pt) {
        case RtcpType::RTCP_SR: {
            _alive_ticker.resetTime();
            // 对方汇报rtp发送情况
            RtcpSR *sr = (RtcpSR *)rtcp;
            auto it = _ssrc_to_track.find(sr->ssrc);
            if (it != _ssrc_to_track.end()) {
                auto &track = it->second;
                auto rtp_chn = track->getRtpChannel(sr->ssrc);
                if (!rtp_chn) {
                    WarnL << "未识别的sr rtcp包:" << rtcp->dumpString();
                } else {
                    // 设置rtp时间戳与ntp时间戳的对应关系
                    rtp_chn->setNtpStamp(sr->rtpts, sr->getNtpUnixStampMS());
                    auto rr = rtp_chn->createRtcpRR(sr, track->answer_ssrc_rtp);
                    sendRtcpPacket(rr->data(), rr->size(), true);
                }
            } else {
                WarnL << "未识别的sr rtcp包:" << rtcp->dumpString();
            }
            break;
        }
        case RtcpType::RTCP_RR: {
            _alive_ticker.resetTime();
            // 对方汇报rtp接收情况
            RtcpRR *rr = (RtcpRR *)rtcp;
            for (auto item : rr->getItemList()) {
                auto it = _ssrc_to_track.find(item->ssrc);
                if (it != _ssrc_to_track.end()) {
                    auto &track = it->second;
                    track->rtcp_context_send->onRtcp(rtcp);
                    auto sr = track->rtcp_context_send->createRtcpSR(track->answer_ssrc_rtp);
                    sendRtcpPacket(sr->data(), sr->size(), true);
                } else {
                    WarnL << "未识别的rr rtcp包:" << rtcp->dumpString();
                }
            }
            break;
        }
        case RtcpType::RTCP_BYE: {
            // 对方汇报停止发送rtp
            RtcpBye *bye = (RtcpBye *)rtcp;
            for (auto ssrc : bye->getSSRC()) {
                auto it = _ssrc_to_track.find(*ssrc);
                if (it == _ssrc_to_track.end()) {
                    WarnL << "未识别的bye rtcp包:" << rtcp->dumpString();
                    continue;
                }
                _ssrc_to_track.erase(it);
            }
            onRtcpBye();
            // bye 会在 sender audio track mute 时出现, 因此不能作为 shutdown 的依据
            break;
        }
        case RtcpType::RTCP_PSFB:
        case RtcpType::RTCP_RTPFB: {
            if ((RtcpType)rtcp->pt == RtcpType::RTCP_PSFB) {
                break;
            }
            // RTPFB
            switch ((RTPFBType)rtcp->report_count) {
            case RTPFBType::RTCP_RTPFB_NACK: {
                RtcpFB *fb = (RtcpFB *)rtcp;
                auto it = _ssrc_to_track.find(fb->ssrc_media);
                if (it == _ssrc_to_track.end()) {
                    WarnL << "未识别的 rtcp包:" << rtcp->dumpString();
                    return;
                }
                auto &track = it->second;
                auto &fci = fb->getFci<FCI_NACK>();
                track->nack_list.forEach(fci, [&](const RtpPacket::Ptr &rtp) {
                    // rtp重传
                    onSendRtp(rtp, true, true);
                });
                break;
            }
            default:
                break;
            }
            break;
        }
        case RtcpType::RTCP_XR: {
            RtcpXRRRTR *xr = (RtcpXRRRTR *)rtcp;
            if (xr->bt != 4) {
                break;
            }
            auto it = _ssrc_to_track.find(xr->ssrc);
            if (it == _ssrc_to_track.end()) {
                WarnL << "未识别的 rtcp包:" << rtcp->dumpString();
                return;
            }
            auto &track = it->second;
            track->rtcp_context_send->onRtcp(rtcp);
            auto xrdlrr = track->rtcp_context_send->createRtcpXRDLRR(track->answer_ssrc_rtp, track->answer_ssrc_rtp);
            sendRtcpPacket(xrdlrr->data(), xrdlrr->size(), true);

            break;
        }
        default:
            break;
        }
    }
}

///////////////////////////////////////////////////////////////////

void WebRtcTransportImp::createRtpChannel(const string &rid, uint32_t ssrc, MediaTrack &track) {
    // rid --> RtpReceiverImp
    auto &ref = track.rtp_channel[rid];
    weak_ptr<WebRtcTransportImp> weak_self = static_pointer_cast<WebRtcTransportImp>(shared_from_this());
    ref = std::make_shared<RtpChannel>(
        getPoller(), [&track, this, rid](RtpPacket::Ptr rtp) mutable { onSortedRtp(track, rid, std::move(rtp)); },
        [&track, weak_self, ssrc](const FCI_NACK &nack) mutable {
            // nack发送可能由定时器异步触发
            auto strong_self = weak_self.lock();
            if (strong_self) {
                strong_self->onSendNack(track, nack, ssrc);
            }
        });
    InfoL << "create rtp receiver of ssrc:" << ssrc << ", rid:" << rid << ", codec:" << track.plan_rtp->codec;
}

void WebRtcTransportImp::updateTicker() {
    _alive_ticker.resetTime();
}

void WebRtcTransportImp::onRtp(const char *buf, size_t len, uint64_t stamp_ms) {
    _bytes_usage += len;
    _alive_ticker.resetTime();

    RtpHeader *rtp = (RtpHeader *)buf;
    // 根据接收到的rtp的pt信息，找到该流的信息
    auto it = _pt_to_track.find(rtp->pt);
    if (it == _pt_to_track.end()) {
        WarnL << "unknown rtp pt:" << (int)rtp->pt;
        return;
    }
    it->second->inputRtp(buf, len, stamp_ms, rtp);
}

void WrappedRtpTrack::inputRtp(const char *buf, size_t len, uint64_t stamp_ms, RtpHeader *rtp) {
#if 0
    auto seq = ntohs(rtp->seq);
    if (track->media->type == TrackVideo && seq % 100 == 0) {
        //此处模拟接受丢包
        return;
    }
#endif

    auto ssrc = ntohl(rtp->ssrc);

    // 修改ext id至统一
    string rid;
    auto twcc_ext = track->rtp_ext_ctx->changeRtpExtId(rtp, true, &rid, RtpExtType::transport_cc);

    if (twcc_ext) {
        _twcc_ctx.onRtp(ssrc, twcc_ext.getTransportCCSeq(), stamp_ms);
    }

    auto &ref = track->rtp_channel[rid];
    if (!ref) {
        _transport.createRtpChannel(rid, ssrc, *track);
    }

    // 解析并排序rtp
    ref->inputRtp(track->media->type, track->plan_rtp->sample_rate, (uint8_t *)buf, len, false);
}

void WrappedRtxTrack::inputRtp(const char *buf, size_t len, uint64_t stamp_ms, RtpHeader *rtp) {
    // 修改ext id至统一
    string rid;
    track->rtp_ext_ctx->changeRtpExtId(rtp, true, &rid, RtpExtType::transport_cc);

    auto &ref = track->rtp_channel[rid];
    if (!ref) {
        // 再接收到对应的rtp前，丢弃rtx包
        WarnL << "unknown rtx rtp, rid:" << rid << ", ssrc:" << ntohl(rtp->ssrc) << ", codec:" << track->plan_rtp->codec
              << ", seq:" << ntohs(rtp->seq);
        return;
    }

    // 这里是rtx重传包
    //  https://datatracker.ietf.org/doc/html/rfc4588#section-4
    auto payload = rtp->getPayloadData();
    auto size = rtp->getPayloadSize(len);
    if (size < 2) {
        return;
    }

    // 前两个字节是原始的rtp的seq
    auto origin_seq = payload[0] << 8 | payload[1];
    // rtx 转换为 rtp
    rtp->pt = track->plan_rtp->pt;
    rtp->seq = htons(origin_seq);
    rtp->ssrc = htonl(ref->getSSRC());

    memmove((uint8_t *)buf + 2, buf, payload - (uint8_t *)buf);
    buf += 2;
    len -= 2;
    ref->inputRtp(track->media->type, track->plan_rtp->sample_rate, (uint8_t *)buf, len, true);
}

void WebRtcTransportImp::onSendNack(MediaTrack &track, const FCI_NACK &nack, uint32_t ssrc) {
    auto rtcp = RtcpFB::create(RTPFBType::RTCP_RTPFB_NACK, &nack, FCI_NACK::kSize);
    rtcp->ssrc = htonl(track.answer_ssrc_rtp);
    rtcp->ssrc_media = htonl(ssrc);
    sendRtcpPacket((char *)rtcp.get(), rtcp->getSize(), true);
}

void WebRtcTransportImp::onSendTwcc(uint32_t ssrc, const string &twcc_fci) {
    auto rtcp = RtcpFB::create(RTPFBType::RTCP_RTPFB_TWCC, twcc_fci.data(), twcc_fci.size());
    rtcp->ssrc = htonl(0);
    rtcp->ssrc_media = htonl(ssrc);
    sendRtcpPacket((char *)rtcp.get(), rtcp->getSize(), true);
}

///////////////////////////////////////////////////////////////////

void WebRtcTransportImp::onSortedRtp(MediaTrack &track, const string &rid, RtpPacket::Ptr rtp) {
    if (track.media->type == TrackVideo && _pli_ticker.elapsedTime() > 2000) {
        // 定期发送pli请求关键帧，方便非rtc等协议
        _pli_ticker.resetTime();
        sendRtcpPli(rtp->getSSRC());

        // 开启remb，则发送remb包调节比特率
        GET_CONFIG(size_t, remb_bit_rate, Rtc::kRembBitRate);
        if (remb_bit_rate && _answer_sdp->supportRtcpFb(SdpConst::kRembRtcpFb)) {
            sendRtcpRemb(rtp->getSSRC(), remb_bit_rate);
        }
    }

    onRecvRtp(track, rid, std::move(rtp));
}

///////////////////////////////////////////////////////////////////

void WebRtcTransportImp::onSendRtp(const RtpPacket::Ptr &rtp, bool flush, bool rtx) {
    auto &track = _type_to_track[rtp->type];
    if (!track) {
        // 忽略，对方不支持该编码类型
        return;
    }
    if (!rtx) {
        // 统计rtp发送情况，好做sr汇报
        track->rtcp_context_send->onRtp(
            rtp->getSeq(), rtp->getStamp(), rtp->ntp_stamp, rtp->sample_rate,
            rtp->size() - RtpPacket::kRtpTcpHeaderSize);
        track->nack_list.pushBack(rtp);
#if 0
        //此处模拟发送丢包
        if (rtp->type == TrackVideo && rtp->getSeq() % 100 == 0) {
            return;
        }
#endif
    } else {
        // 发送rtx重传包
        // TraceL << "send rtx rtp:" << rtp->getSeq();
    }
    pair<bool /*rtx*/, MediaTrack *> ctx { rtx, track.get() };
    sendRtpPacket(rtp->data() + RtpPacket::kRtpTcpHeaderSize, rtp->size() - RtpPacket::kRtpTcpHeaderSize, flush, &ctx);
    _bytes_usage += rtp->size() - RtpPacket::kRtpTcpHeaderSize;
}

void WebRtcTransportImp::onBeforeEncryptRtp(const char *buf, int &len, void *ctx) {
    auto pr = (pair<bool /*rtx*/, MediaTrack *> *)ctx;
    auto header = (RtpHeader *)buf;

    if (!pr->first || !pr->second->plan_rtx) {
        // 普通的rtp,或者不支持rtx, 修改目标pt和ssrc
        pr->second->rtp_ext_ctx->changeRtpExtId(header, false);
        header->pt = pr->second->plan_rtp->pt;
        header->ssrc = htonl(pr->second->answer_ssrc_rtp);
    } else {
        // 重传的rtp, rtx
        pr->second->rtp_ext_ctx->changeRtpExtId(header, false);
        header->pt = pr->second->plan_rtx->pt;
        if (pr->second->answer_ssrc_rtx) {
            // 有rtx单独的ssrc,有些情况下，浏览器支持rtx，但是未指定rtx单独的ssrc
            header->ssrc = htonl(pr->second->answer_ssrc_rtx);
        } else {
            // 未单独指定rtx的ssrc，那么使用rtp的ssrc
            header->ssrc = htonl(pr->second->answer_ssrc_rtp);
        }

        auto origin_seq = ntohs(header->seq);
        // seq跟原来的不一样
        header->seq = htons(_rtx_seq[pr->second->media->type]);
        ++_rtx_seq[pr->second->media->type];

        auto payload = header->getPayloadData();
        auto payload_size = header->getPayloadSize(len);
        if (payload_size) {
            // rtp负载后移两个字节，这两个字节用于存放osn
            // https://datatracker.ietf.org/doc/html/rfc4588#section-4
            memmove(payload + 2, payload, payload_size);
        }
        payload[0] = origin_seq >> 8;
        payload[1] = origin_seq & 0xFF;
        len += 2;
    }
}

void WebRtcTransportImp::safeShutdown(const SockException &ex) {
    std::weak_ptr<WebRtcTransportImp> weak_self = static_pointer_cast<WebRtcTransportImp>(shared_from_this());
    getPoller()->async([ex, weak_self]() {
        if (auto strong_self = weak_self.lock()) {
            strong_self->onShutdown(ex);
        }
    });
}

void WebRtcTransportImp::onShutdown(const SockException &ex) {
    WarnL << ex;
    unrefSelf();
    for (auto &tuple : _ice_server->GetTuples()) {
        tuple->shutdown(ex);
    }
}

void WebRtcTransportImp::removeTuple(RTC::TransportTuple *tuple) {
    InfoL << getIdentifier() << " remove tuple " << tuple->get_peer_ip() << ":" << tuple->get_peer_port();
    this->_ice_server->RemoveTuple(tuple);
}

uint64_t WebRtcTransportImp::getBytesUsage() const {
    return _bytes_usage;
}

uint64_t WebRtcTransportImp::getDuration() const {
    return _alive_ticker.createdTime() / 1000;
}

void WebRtcTransportImp::onRtcpBye(){}

/////////////////////////////////////////////////////////////////////////////////////////////

void WebRtcTransportImp::registerSelf() {
    _self = static_pointer_cast<WebRtcTransportImp>(shared_from_this());
    WebRtcTransportManager::Instance().addItem(getIdentifier(), _self);
}

void WebRtcTransportImp::unrefSelf() {
    _self = nullptr;
}

void WebRtcTransportImp::unregisterSelf() {
    unrefSelf();
    WebRtcTransportManager::Instance().removeItem(getIdentifier());
}

WebRtcTransportManager &WebRtcTransportManager::Instance() {
    static WebRtcTransportManager s_instance;
    return s_instance;
}

void WebRtcTransportManager::addItem(const string &key, const WebRtcTransportImp::Ptr &ptr) {
    lock_guard<mutex> lck(_mtx);
    _map[key] = ptr;
}

WebRtcTransportImp::Ptr WebRtcTransportManager::getItem(const string &key) {
    if (key.empty()) {
        return nullptr;
    }
    lock_guard<mutex> lck(_mtx);
    auto it = _map.find(key);
    if (it == _map.end()) {
        return nullptr;
    }
    return it->second.lock();
}

void WebRtcTransportManager::removeItem(const string &key) {
    lock_guard<mutex> lck(_mtx);
    _map.erase(key);
}

//////////////////////////////////////////////////////////////////////////////////////////////

WebRtcPluginManager &WebRtcPluginManager::Instance() {
    static WebRtcPluginManager s_instance;
    return s_instance;
}

void WebRtcPluginManager::registerPlugin(const string &type, Plugin cb) {
    lock_guard<mutex> lck(_mtx_creator);
    _map_creator[type] = std::move(cb);
}


void WebRtcPluginManager::setListener(Listener cb) {
    lock_guard<mutex> lck(_mtx_creator);
    _listener = std::move(cb);
}

void WebRtcPluginManager::negotiateSdp(Session &sender, const string &type, const WebRtcArgs &args, const onCreateWebRtc &cb_in) {
    onCreateWebRtc cb;
    lock_guard<mutex> lck(_mtx_creator);
    if (_listener) {
        auto listener = _listener;
        auto args_ptr = args.shared_from_this();
        auto sender_ptr = static_pointer_cast<Session>(sender.shared_from_this());
        cb = [listener, sender_ptr, type, args_ptr, cb_in](const WebRtcInterface &rtc) {
            listener(*sender_ptr, type, *args_ptr, rtc);
            cb_in(rtc);
        };
    } else {
        cb = cb_in;
    }

    auto it = _map_creator.find(type);
    if (it == _map_creator.end()) {
        cb_in(WebRtcException(SockException(Err_other, "the type can not supported")));
        return;
    }
    it->second(sender, args, cb);
}

void echo_plugin(Session &sender, const WebRtcArgs &args, const onCreateWebRtc &cb) {
    cb(*WebRtcEchoTest::create(EventPollerPool::Instance().getPoller()));
}

void push_plugin(Session &sender, const WebRtcArgs &args, const onCreateWebRtc &cb) {
    MediaInfo info(args["url"]);
    Broadcast::PublishAuthInvoker invoker = [cb, info](const string &err, const ProtocolOption &option) mutable {
        if (!err.empty()) {
            cb(WebRtcException(SockException(Err_other, err)));
            return;
        }

        RtspMediaSourceImp::Ptr push_src;
        std::shared_ptr<void> push_src_ownership;
        auto src = MediaSource::find(RTSP_SCHEMA, info.vhost, info.app, info.stream);
        auto push_failed = (bool)src;

        while (src) {
            // 尝试断连后继续推流
            auto rtsp_src = dynamic_pointer_cast<RtspMediaSourceImp>(src);
            if (!rtsp_src) {
                // 源不是rtsp推流产生的
                break;
            }
            auto ownership = rtsp_src->getOwnership();
            if (!ownership) {
                // 获取推流源所有权失败
                break;
            }
            push_src = std::move(rtsp_src);
            push_src_ownership = std::move(ownership);
            push_failed = false;
            break;
        }

        if (push_failed) {
            cb(WebRtcException(SockException(Err_other, "already publishing")));
            return;
        }

        if (!push_src) {
            push_src = std::make_shared<RtspMediaSourceImp>(info);
            push_src_ownership = push_src->getOwnership();
            push_src->setProtocolOption(option);
        }
        auto rtc = WebRtcPusher::create(EventPollerPool::Instance().getPoller(), push_src, push_src_ownership, info, option);
        push_src->setListener(rtc);
        cb(*rtc);
    };

    // rtsp推流需要鉴权
    auto flag = NOTICE_EMIT(BroadcastMediaPublishArgs, Broadcast::kBroadcastMediaPublish, MediaOriginType::rtc_push, info, invoker, sender);
    if (!flag) {
        // 该事件无人监听,默认不鉴权
        invoker("", ProtocolOption());
    }
}

void play_plugin(Session &sender, const WebRtcArgs &args, const onCreateWebRtc &cb) {
    MediaInfo info(args["url"]);
    auto session_ptr = static_pointer_cast<Session>(sender.shared_from_this());
    Broadcast::AuthInvoker invoker = [cb, info, session_ptr](const string &err) mutable {
        if (!err.empty()) {
            cb(WebRtcException(SockException(Err_other, err)));
            return;
        }

        // webrtc播放的是rtsp的源
        info.schema = RTSP_SCHEMA;
        MediaSource::findAsync(info, session_ptr, [=](const MediaSource::Ptr &src_in) mutable {
            auto src = dynamic_pointer_cast<RtspMediaSource>(src_in);
            if (!src) {
                cb(WebRtcException(SockException(Err_other, "stream not found")));
                return;
            }
            // 还原成rtc，目的是为了hook时识别哪种播放协议
            info.schema = "rtc";
            auto rtc = WebRtcPlayer::create(EventPollerPool::Instance().getPoller(), src, info);
            cb(*rtc);
        });
    };

    // 广播通用播放url鉴权事件
    auto flag = NOTICE_EMIT(BroadcastMediaPlayedArgs, Broadcast::kBroadcastMediaPlayed, info, invoker, sender);
    if (!flag) {
        // 该事件无人监听,默认不鉴权
        invoker("");
    }
}

static void setWebRtcArgs(const WebRtcArgs &args, WebRtcInterface &rtc) {
    {
        static auto is_vaild_ip = [](const std::string &ip) -> bool {
            int a, b, c, d;
            return sscanf(ip.c_str(), "%d.%d.%d.%d", &a, &b, &c, &d) == 4;
        };
        std::string host = args["Host"];
        if (!host.empty()) {
            auto local_ip = host.substr(0, host.find(':'));
            if (!is_vaild_ip(local_ip) || local_ip == "127.0.0.1") {
                local_ip = "";
            }
            rtc.setLocalIp(std::move(local_ip));
        }
    }

    bool preferred_tcp = args["preferred_tcp"];
    {
        rtc.setPreferredTcp(preferred_tcp);
    }

    {
        vector<SdpAttrCandidate> cands;
        {
            auto cand_str = trim(args["cand_udp"]);
            auto ip_port = toolkit::split(cand_str, ":");
            if (ip_port.size() == 2) {
                // udp优先
                auto ice_cand = makeIceCandidate(ip_port[0], atoi(ip_port[1].data()), preferred_tcp ? 100 : 120, "udp");
                cands.emplace_back(std::move(*ice_cand));
            }
        }
        {
            auto cand_str = trim(args["cand_tcp"]);
            auto ip_port = toolkit::split(cand_str, ":");
            if (ip_port.size() == 2) {
                // tcp模式
                auto ice_cand = makeIceCandidate(ip_port[0], atoi(ip_port[1].data()), preferred_tcp ? 120 : 100, "tcp");
                cands.emplace_back(std::move(*ice_cand));
            }
        }
        if (!cands.empty()) {
            // udp优先
            rtc.setIceCandidate(std::move(cands));
        }
    }
}

static onceToken s_rtc_auto_register([]() {
#if !defined (NDEBUG)
    // debug模式才开启echo插件
    WebRtcPluginManager::Instance().registerPlugin("echo", echo_plugin);
#endif
    WebRtcPluginManager::Instance().registerPlugin("push", push_plugin);
    WebRtcPluginManager::Instance().registerPlugin("play", play_plugin);
    WebRtcPluginManager::Instance().setListener([](Session &sender, const std::string &type, const WebRtcArgs &args, const WebRtcInterface &rtc) {
        setWebRtcArgs(args, const_cast<WebRtcInterface&>(rtc));
    });
});

}// namespace mediakit