重写webrtc sdp校验逻辑,确保无有效track时抛异常:#1157

9433a0c3 · ziyue · b10fc523 · 9433a0c3 · 9433a0c3 · 9433a0c3
Commit 9433a0c3 authored Oct 16, 2021 by ziyue
--- a/webrtc/Sdp.cpp
+++ b/webrtc/Sdp.cpp
@@ -291,12 +291,10 @@ string RtcSessionSdp::toString() const {
 //////////////////////////////////////////////////////////////////////////////////////////
-#define SDP_THROW() throw std::invalid_argument(StrPrinter << "解析sdp " << getKey() << " 字段失败:" << str)
+#define CHECK_SDP(exp) CHECK(exp, "解析sdp ", getKey(), " 字段失败:", str)
 void SdpTime::parse(const string &str) {
-    if (sscanf(str.data(), "%" SCNu64 " %" SCNu64, &start, &stop) != 2) {
+    CHECK_SDP(sscanf(str.data(), "%" SCNu64 " %" SCNu64, &start, &stop) == 2);
-        SDP_THROW();
-    }
 }
 string SdpTime::toString() const {
@@ -308,9 +306,7 @@ string SdpTime::toString() const {
 void SdpOrigin::parse(const string &str) {
    auto vec = split(str, " ");
-    if (vec.size() != 6) {
+    CHECK_SDP(vec.size() == 6);
-        SDP_THROW();
-    }
    username = vec[0];
    session_id = vec[1];
    session_version = vec[2];
@@ -328,9 +324,7 @@ string SdpOrigin::toString() const {
 void SdpConnection::parse(const string &str) {
    auto vec = split(str, " ");
-    if (vec.size() != 3) {
+    CHECK_SDP(vec.size() == 3);
-        SDP_THROW();
-    }
    nettype = vec[0];
    addrtype = vec[1];
    address = vec[2];
@@ -345,9 +339,7 @@ string SdpConnection::toString() const {
 void SdpBandwidth::parse(const string &str) {
    auto vec = split(str, ":");
-    if (vec.size() != 2) {
+    CHECK_SDP(vec.size() == 2);
-        SDP_THROW();
-    }
    bwtype = vec[0];
    bandwidth = atoi(vec[1].data());
 }
@@ -361,20 +353,14 @@ string SdpBandwidth::toString() const {
 void SdpMedia::parse(const string &str) {
    auto vec = split(str, " ");
-    if (vec.size() < 4) {
+    CHECK_SDP(vec.size() >= 4);
-        SDP_THROW();
-    }
    type = getTrackType(vec[0]);
-    if (type == TrackInvalid) {
+    CHECK_SDP(type != TrackInvalid);
-        SDP_THROW();
-    }
    port = atoi(vec[1].data());
    proto = vec[2];
    for (size_t i = 3; i < vec.size(); ++i) {
        auto pt = atoi(vec[i].data());
-        if (type != TrackApplication && pt > 0xFF) {
+        CHECK_SDP(type == TrackApplication || pt <= 0xFF);
-            SDP_THROW();
-        }
        fmts.emplace_back(pt);
    }
 }
@@ -417,9 +403,7 @@ string SdpAttr::toString() const {
 void SdpAttrGroup::parse(const string &str)  {
    auto vec = split(str, " ");
-    if (vec.size() < 2) {
+    CHECK_SDP(vec.size() >= 2);
-        SDP_THROW();
-    }
    type = vec[0];
    vec.erase(vec.begin());
    mids = std::move(vec);
@@ -438,9 +422,7 @@ string SdpAttrGroup::toString() const  {
 void SdpAttrMsidSemantic::parse(const string &str)  {
    auto vec = split(str, " ");
-    if (vec.size() < 1) {
+    CHECK_SDP(vec.size() >= 1);
-        SDP_THROW();
-    }
    msid = vec[0];
    token = vec.size() > 1 ? vec[1] : "";
 }
@@ -458,9 +440,7 @@ string SdpAttrMsidSemantic::toString() const  {
 void SdpAttrRtcp::parse(const string &str)  {
    auto vec = split(str, " ");
-    if (vec.size() != 4) {
+    CHECK_SDP(vec.size() == 4);
-        SDP_THROW();
-    }
    port = atoi(vec[0].data());
    nettype = vec[1];
    addrtype = vec[2];
@@ -503,9 +483,7 @@ string SdpAttrIceOption::toString() const{
 void SdpAttrFingerprint::parse(const string &str)  {
    auto vec = split(str, " ");
-    if (vec.size() != 2) {
+    CHECK_SDP(vec.size() == 2);
-        SDP_THROW();
-    }
    algorithm = vec[0];
    hash = vec[1];
 }
@@ -519,9 +497,7 @@ string SdpAttrFingerprint::toString() const  {
 void SdpAttrSetup::parse(const string &str)  {
    role = getDtlsRole(str);
-    if (role == DtlsRole::invalid) {
+    CHECK_SDP(role != DtlsRole::invalid);
-        SDP_THROW();
-    }
 }
 string SdpAttrSetup::toString() const  {
@@ -535,9 +511,7 @@ void SdpAttrExtmap::parse(const string &str)  {
    char buf[128] = {0};
    char direction_buf[32] = {0};
    if (sscanf(str.data(), "%" SCNd8 "/%31[^ ] %127s", &id, direction_buf, buf) != 3) {
-        if (sscanf(str.data(), "%" SCNd8 " %127s", &id, buf) != 2) {
+        CHECK_SDP(sscanf(str.data(), "%" SCNd8 " %127s", &id, buf) == 2);
-            SDP_THROW();
-        }
        direction = RtpDirection::sendrecv;
    } else {
        direction = getRtpDirection(direction_buf);
@@ -559,9 +533,7 @@ string SdpAttrExtmap::toString() const  {
 void SdpAttrRtpMap::parse(const string &str)  {
    char buf[32] = {0};
    if (sscanf(str.data(), "%" SCNu8 " %31[^/]/%" SCNd32 "/%" SCNd32, &pt, buf, &sample_rate, &channel) != 4) {
-        if (sscanf(str.data(), "%" SCNu8 " %31[^/]/%" SCNd32, &pt, buf, &sample_rate) != 3) {
+        CHECK_SDP(sscanf(str.data(), "%" SCNu8 " %31[^/]/%" SCNd32, &pt, buf, &sample_rate) == 3);
-            SDP_THROW();
-        }
        if (getTrackType(getCodecId(buf)) == TrackAudio) {
            //未指定通道数时，且为音频时，那么通道数默认为1
            channel = 1;
@@ -584,9 +556,7 @@ string SdpAttrRtpMap::toString() const  {
 void SdpAttrRtcpFb::parse(const string &str_in)  {
    auto str = str_in + "\n";
    char rtcp_type_buf[32] = {0};
-    if (2 != sscanf(str.data(), "%" SCNu8 " %31[^\n]", &pt, rtcp_type_buf)) {
+    CHECK_SDP(sscanf(str.data(), "%" SCNu8 " %31[^\n]", &pt, rtcp_type_buf) == 2);
-        SDP_THROW();
-    }
    rtcp_type = rtcp_type_buf;
 }
@@ -599,9 +569,7 @@ string SdpAttrRtcpFb::toString() const  {
 void SdpAttrFmtp::parse(const string &str)  {
    auto pos = str.find(' ');
-    if (pos == string::npos) {
+    CHECK_SDP(pos != string::npos);
-        SDP_THROW();
-    }
    pt = atoi(str.substr(0, pos).data());
    auto vec = split(str.substr(pos + 1), ";");
    for (auto &item : vec) {
@@ -613,9 +581,7 @@ void SdpAttrFmtp::parse(const string &str)  {
            fmtp.emplace(std::make_pair(item.substr(0, pos), item.substr(pos + 1)));
        }
    }
-    if (fmtp.empty()) {
+    CHECK_SDP(!fmtp.empty());
-        SDP_THROW();
-    }
 }
 string SdpAttrFmtp::toString() const  {
@@ -640,7 +606,7 @@ void SdpAttrSSRC::parse(const string &str_in)  {
    } else if (2 == sscanf(str.data(), "%" SCNu32 " %31s[^\n]", &ssrc, attr_buf)) {
        attribute = attr_buf;
    } else {
-        SDP_THROW();
+        CHECK_SDP(0);
    }
 }
@@ -658,15 +624,12 @@ string SdpAttrSSRC::toString() const  {
 void SdpAttrSSRCGroup::parse(const string &str) {
    auto vec = split(str, " ");
-    if (vec.size() >= 3) {
+    CHECK_SDP(vec.size() >= 3);
-        type = std::move(vec[0]);
+    type = std::move(vec[0]);
-        CHECK(isFID() || isSIM());
+    CHECK(isFID() || isSIM());
-        vec.erase(vec.begin());
+    vec.erase(vec.begin());
-        for (auto ssrc : vec) {
+    for (auto ssrc : vec) {
-            ssrcs.emplace_back((uint32_t)atoll(ssrc.data()));
+        ssrcs.emplace_back((uint32_t) atoll(ssrc.data()));
-        }
-    } else {
-        SDP_THROW();
    }
 }
@@ -685,11 +648,8 @@ string SdpAttrSSRCGroup::toString() const  {
 void SdpAttrSctpMap::parse(const string &str)  {
    char subtypes_buf[64] = {0};
-    if (3 == sscanf(str.data(), "%" SCNu16 " %63[^ ] %" SCNd32, &port, subtypes_buf, &streams)) {
+    CHECK_SDP(3 == sscanf(str.data(), "%" SCNu16 " %63[^ ] %" SCNd32, &port, subtypes_buf, &streams));
-        subtypes = subtypes_buf;
+    subtypes = subtypes_buf;
-    } else {
-        SDP_THROW();
-    }
 }
 string SdpAttrSctpMap::toString() const  {
@@ -710,10 +670,8 @@ void SdpAttrCandidate::parse(const string &str)  {
    char type_buf[16] = {0};
    // https://datatracker.ietf.org/doc/html/rfc5245#section-15.1
-    if (7 != sscanf(str.data(), "%32[^ ] %" SCNu32 " %15[^ ] %" SCNu32 " %31[^ ] %" SCNu16 " typ %15[^ ]",
+    CHECK_SDP(sscanf(str.data(), "%32[^ ] %" SCNu32 " %15[^ ] %" SCNu32 " %31[^ ] %" SCNu16 " typ %15[^ ]",
-                    foundation_buf, &component, transport_buf, &priority, address_buf, &port, type_buf)) {
+            foundation_buf, &component, transport_buf, &priority, address_buf, &port, type_buf) == 7);
-        SDP_THROW();
-    }
    foundation = foundation_buf;
    transport = transport_buf;
    address = address_buf;
@@ -757,9 +715,7 @@ void SdpAttrSimulcast::parse(const string &str) {
    //a=simulcast: recv h;m;l
    //
    auto vec = split(str, " ");
-    if (vec.size() != 2) {
+    CHECK_SDP(vec.size() == 2);
-        SDP_THROW();
-    }
    direction = vec[0];
    rids = split(vec[1], ";");
 }
@@ -794,7 +750,7 @@ string SdpAttrRid::toString() const {
    return SdpItem::toString();
 }
-void RtcSession::loadFrom(const string &str, bool check) {
+void RtcSession::loadFrom(const string &str) {
    RtcSessionSdp sdp;
    sdp.parse(str);
@@ -808,12 +764,6 @@ void RtcSession::loadFrom(const string &str, bool check) {
    msid_semantic = sdp.getItemClass<SdpAttrMsidSemantic>('a', "msid-semantic");
    for (auto &media : sdp.medias) {
        auto mline = media.getItemClass<SdpMedia>('m');
-        switch (mline.type) {
-            case TrackVideo:
-            case TrackAudio:
-            case TrackApplication: break;
-            default: throw std::invalid_argument(StrPrinter << "不识别的media类型:" << mline.toString());
-        }
        this->media.emplace_back();
        auto &rtc_media = this->media.back();
        rtc_media.type = mline.type;
@@ -949,19 +899,15 @@ void RtcSession::loadFrom(const string &str, bool check) {
        map<uint8_t, SdpAttrFmtp &> fmtp_map;
        for (auto &rtpmap : rtpmap_arr) {
-            if (!rtpmap_map.emplace(rtpmap.pt, rtpmap).second) {
+            //添加失败，有多条
-                //添加失败，有多条
+            CHECK(rtpmap_map.emplace(rtpmap.pt, rtpmap).second, "该pt存在多条a=rtpmap:", (int)rtpmap.pt);
-                throw std::invalid_argument(StrPrinter << "该pt存在多条a=rtpmap:" << rtpmap.pt);
-            }
        }
        for (auto &rtpfb : rtcpfb_arr) {
            rtcpfb_map.emplace(rtpfb.pt, rtpfb);
        }
        for (auto &fmtp : fmtp_aar) {
-            if (!fmtp_map.emplace(fmtp.pt, fmtp).second) {
+            //添加失败，有多条
-                //添加失败，有多条
+            CHECK(fmtp_map.emplace(fmtp.pt, fmtp).second, "该pt存在多条a=fmtp:", (int)fmtp.pt);
-                throw std::invalid_argument(StrPrinter << "该pt存在多条a=fmtp:" << fmtp.pt);
-            }
        }
        for (auto &pt : mline.fmts) {
            //遍历所有编码方案的pt
@@ -992,9 +938,6 @@ void RtcSession::loadFrom(const string &str, bool check) {
    }
    group = sdp.getItemClass<SdpAttrGroup>('a', "group");
-    if (check) {
-        checkValid();
-    }
 }
 std::shared_ptr<SdpItem> wrapSdpAttr(SdpItem::Ptr item){
@@ -1042,7 +985,6 @@ static void toRtsp(vector <SdpItem::Ptr> &items) {
 }
 string RtcSession::toRtspSdp() const{
-    checkValid();
    RtcSession copy = *this;
    copy.media.clear();
    for (auto &m : media) {
@@ -1269,7 +1211,6 @@ RtcSessionSdp::Ptr RtcSession::toRtcSessionSdp() const{
 }
 string RtcSession::toString() const{
-    checkValid();
    return toRtcSessionSdp()->toString();
 }
@@ -1341,10 +1282,9 @@ void RtcMedia::checkValid() const{
    CHECK(!mid.empty());
    CHECK(!proto.empty());
    CHECK(direction != RtpDirection::invalid || type == TrackApplication);
-    CHECK(!plan.empty() || type == TrackApplication );
+    CHECK(!plan.empty() || type == TrackApplication);
-}
+    CHECK(type == TrackApplication || rtcp_mux, "只支持rtcp-mux模式");
-void RtcMedia::checkValidSSRC() const {
    bool send_rtp = (direction == RtpDirection::sendonly || direction == RtpDirection::sendrecv);
    if (rtp_rids.empty() && rtp_ssrc_sim.empty()) {
        //非simulcast时，检查有没有指定rtp ssrc
@@ -1367,16 +1307,19 @@ void RtcSession::checkValid() const{
    CHECK(!session_name.empty());
    CHECK(!msid_semantic.empty());
    CHECK(!media.empty());
-    CHECK(group.mids.size() <= media.size());
+    CHECK(!group.mids.empty() && group.mids.size() <= media.size(), "只支持group BUNDLE模式");
-    for (auto &item : media) {
-        item.checkValid();
-    }
-}
-void RtcSession::checkValidSSRC() const{
+    bool have_active_media = false;
    for (auto &item : media) {
-        item.checkValidSSRC();
+        item.checkValid();
+        switch (item.direction) {
+            case RtpDirection::sendrecv:
+            case RtpDirection::sendonly:
+            case RtpDirection::recvonly: have_active_media = true; break;
+            default : break;
+        }
    }
+    CHECK(have_active_media, "必须确保最少有一个活跃的track");
 }
 const RtcMedia *RtcSession::getMedia(TrackType type) const{
@@ -1388,15 +1331,6 @@ const RtcMedia *RtcSession::getMedia(TrackType type) const{
    return nullptr;
 }
-bool RtcSession::haveSSRC() const {
-    for (auto &m : media) {
-        if (!m.rtp_rtx_ssrc.empty()) {
-            return true;
-        }
-    }
-    return false;
-}
 bool RtcSession::supportRtcpFb(const string &name, TrackType type) const {
    auto media = getMedia(type);
    if (!media) {
@@ -1415,17 +1349,6 @@ bool RtcSession::supportSimulcast() const {
    return false;
 }
-void RtcSession::checkSdp() const {
-    for (auto &m : media) {
-        if (m.type != TrackApplication && !m.rtcp_mux) {
-            throw std::invalid_argument("只支持rtcp-mux模式");
-        }
-    }
-    if (group.mids.empty()) {
-        throw std::invalid_argument("只支持group BUNDLE模式");
-    }
-}
 string const SdpConst::kTWCCRtcpFb = "transport-cc";
 string const SdpConst::kRembRtcpFb = "goog-remb";
@@ -1596,17 +1519,12 @@ void RtcConfigure::enableREMB(bool enable, TrackType type){
 shared_ptr<RtcSession> RtcConfigure::createAnswer(const RtcSession &offer){
    shared_ptr<RtcSession> ret = std::make_shared<RtcSession>();
    ret->version = offer.version;
-    //todo 此处设置会话id与会话地址，貌似没什么作用
    ret->origin = offer.origin;
    ret->session_name = offer.session_name;
    ret->msid_semantic = offer.msid_semantic;
    matchMedia(ret, TrackAudio, offer.media, audio);
    matchMedia(ret, TrackVideo, offer.media, video);
    matchMedia(ret, TrackApplication, offer.media, application);
-    if (ret->media.empty()) {
-        throw std::invalid_argument("生成的answer sdp中媒体个数为0");
-    }
    //设置音视频端口复用
    if (!offer.group.mids.empty()) {
        for (auto &m : ret->media) {
@@ -1678,11 +1596,8 @@ RETRY:
            answer_media.type = offer_media.type;
            answer_media.mid = offer_media.mid;
            answer_media.proto = offer_media.proto;
-            //todo(此处设置rtp端口，貌似没什么作用)
            answer_media.port = offer_media.port;
-            //todo(此处设置rtp的ip地址，貌似没什么作用)
            answer_media.addr = offer_media.addr;
-            //todo(此处设置rtcp地址，貌似没什么作用)
            answer_media.rtcp_addr = offer_media.rtcp_addr;
            answer_media.rtcp_mux = offer_media.rtcp_mux && configure.rtcp_mux;
            answer_media.rtcp_rsize = offer_media.rtcp_rsize && configure.rtcp_rsize;
@@ -1804,7 +1719,7 @@ RETRY:
 void RtcConfigure::setPlayRtspInfo(const string &sdp){
    RtcSession session;
-    session.loadFrom(sdp, false);
+    session.loadFrom(sdp);
    for (auto &m : session.media) {
        switch (m.type) {
            case TrackVideo : {

--- a/webrtc/Sdp.h
+++ b/webrtc/Sdp.h
@@ -641,8 +641,6 @@ public:
    uint32_t sctp_port{0};
    void checkValid() const;
-    //offer sdp,如果指定了发送rtp,那么应该指定ssrc
-    void checkValidSSRC() const;
    const RtcCodecPlan *getPlan(uint8_t pt) const;
    const RtcCodecPlan *getPlan(const char *codec) const;
    const RtcCodecPlan *getRelatedRtxPlan(uint8_t pt) const;
@@ -651,7 +649,7 @@ public:
    bool supportSimulcast() const;
 };
-class RtcSession{
+class RtcSession {
 public:
    using Ptr = std::shared_ptr<RtcSession>;
@@ -666,15 +664,11 @@ public:
    vector<RtcMedia> media;
    SdpAttrGroup group;
-    void loadFrom(const string &sdp, bool check = true);
+    void loadFrom(const string &sdp);
    void checkValid() const;
-    void checkSdp() const;
-    //offer sdp,如果指定了发送rtp,那么应该指定ssrc
-    void checkValidSSRC() const;
    string toString() const;
    string toRtspSdp() const;
    const  RtcMedia *getMedia(TrackType type) const;
-    bool haveSSRC() const;
    bool supportRtcpFb(const string &name, TrackType type = TrackType::TrackVideo) const;
    bool supportSimulcast() const;

--- a/webrtc/WebRtcTransport.cpp
+++ b/webrtc/WebRtcTransport.cpp
@@ -187,6 +187,7 @@ std::string WebRtcTransport::getAnswerSdp(const string &offer){
        _offer_sdp = std::make_shared<RtcSession>();
        _offer_sdp->loadFrom(offer);
        onCheckSdp(SdpType::offer, *_offer_sdp);
+        _offer_sdp->checkValid();
        setRemoteDtlsFingerprint(*_offer_sdp);
        //// sdp 配置 ////
@@ -201,6 +202,7 @@ std::string WebRtcTransport::getAnswerSdp(const string &offer){
        //// 生成answer sdp ////
        _answer_sdp = configure.createAnswer(*_offer_sdp);
        onCheckSdp(SdpType::answer, *_answer_sdp);
+        _answer_sdp->checkValid();
        return _answer_sdp->toString();
    } catch (exception &ex) {
        onShutdown(SockException(Err_shutdown, ex.what()));
@@ -457,10 +459,9 @@ void WebRtcTransportImp::onCheckAnswer(RtcSession &sdp) {
 }
 void WebRtcTransportImp::onCheckSdp(SdpType type, RtcSession &sdp) {
-    sdp.checkSdp();
    switch (type) {
        case SdpType::answer: onCheckAnswer(sdp); break;
-        case SdpType::offer: sdp.checkValidSSRC(); break;
+        case SdpType::offer: break;
        default: /*不可达*/ assert(0); break;
    }
 }