| /* |
| * Copyright 2011 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #include "pc/webrtc_sdp.h" |
| |
| #include <ctype.h> |
| #include <limits.h> |
| |
| #include <algorithm> |
| #include <cstddef> |
| #include <cstdint> |
| #include <map> |
| #include <memory> |
| #include <set> |
| #include <string> |
| #include <type_traits> |
| #include <unordered_map> |
| #include <utility> |
| #include <vector> |
| |
| #include "absl/algorithm/container.h" |
| #include "absl/strings/ascii.h" |
| #include "absl/strings/match.h" |
| #include "api/candidate.h" |
| #include "api/crypto_params.h" |
| #include "api/jsep_ice_candidate.h" |
| #include "api/jsep_session_description.h" |
| #include "api/media_types.h" |
| // for RtpExtension |
| #include "absl/strings/string_view.h" |
| #include "absl/types/optional.h" |
| #include "api/rtc_error.h" |
| #include "api/rtp_parameters.h" |
| #include "api/rtp_transceiver_direction.h" |
| #include "media/base/codec.h" |
| #include "media/base/media_constants.h" |
| #include "media/base/rid_description.h" |
| #include "media/base/rtp_utils.h" |
| #include "media/base/stream_params.h" |
| #include "media/sctp/sctp_transport_internal.h" |
| #include "p2p/base/candidate_pair_interface.h" |
| #include "p2p/base/ice_transport_internal.h" |
| #include "p2p/base/p2p_constants.h" |
| #include "p2p/base/port.h" |
| #include "p2p/base/port_interface.h" |
| #include "p2p/base/transport_description.h" |
| #include "p2p/base/transport_info.h" |
| #include "pc/media_protocol_names.h" |
| #include "pc/media_session.h" |
| #include "pc/session_description.h" |
| #include "pc/simulcast_description.h" |
| #include "pc/simulcast_sdp_serializer.h" |
| #include "rtc_base/arraysize.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/helpers.h" |
| #include "rtc_base/ip_address.h" |
| #include "rtc_base/logging.h" |
| #include "rtc_base/net_helper.h" |
| #include "rtc_base/network_constants.h" |
| #include "rtc_base/socket_address.h" |
| #include "rtc_base/ssl_fingerprint.h" |
| #include "rtc_base/string_encode.h" |
| #include "rtc_base/string_utils.h" |
| #include "rtc_base/strings/string_builder.h" |
| |
| using cricket::AudioContentDescription; |
| using cricket::Candidate; |
| using cricket::Candidates; |
| using cricket::ContentInfo; |
| using cricket::CryptoParams; |
| using cricket::ICE_CANDIDATE_COMPONENT_RTCP; |
| using cricket::ICE_CANDIDATE_COMPONENT_RTP; |
| using cricket::kApplicationSpecificBandwidth; |
| using cricket::kCodecParamMaxPTime; |
| using cricket::kCodecParamMinPTime; |
| using cricket::kCodecParamPTime; |
| using cricket::kTransportSpecificBandwidth; |
| using cricket::MediaContentDescription; |
| using cricket::MediaProtocolType; |
| using cricket::MediaType; |
| using cricket::RidDescription; |
| using cricket::RtpHeaderExtensions; |
| using cricket::SctpDataContentDescription; |
| using cricket::SimulcastDescription; |
| using cricket::SimulcastLayer; |
| using cricket::SimulcastLayerList; |
| using cricket::SsrcGroup; |
| using cricket::StreamParams; |
| using cricket::StreamParamsVec; |
| using cricket::TransportDescription; |
| using cricket::TransportInfo; |
| using cricket::UnsupportedContentDescription; |
| using cricket::VideoContentDescription; |
| using rtc::SocketAddress; |
| |
| // TODO(deadbeef): Switch to using anonymous namespace rather than declaring |
| // everything "static". |
| namespace webrtc { |
| |
| // Line type |
| // RFC 4566 |
| // An SDP session description consists of a number of lines of text of |
| // the form: |
| // <type>=<value> |
| // where <type> MUST be exactly one case-significant character. |
| |
| // Check if passed character is a "token-char" from RFC 4566. |
| // https://datatracker.ietf.org/doc/html/rfc4566#section-9 |
| // token-char = %x21 / %x23-27 / %x2A-2B / %x2D-2E / %x30-39 |
| // / %x41-5A / %x5E-7E |
| bool IsTokenChar(char ch) { |
| return ch == 0x21 || (ch >= 0x23 && ch <= 0x27) || ch == 0x2a || ch == 0x2b || |
| ch == 0x2d || ch == 0x2e || (ch >= 0x30 && ch <= 0x39) || |
| (ch >= 0x41 && ch <= 0x5a) || (ch >= 0x5e && ch <= 0x7e); |
| } |
| static const int kLinePrefixLength = 2; // Length of <type>= |
| static const char kLineTypeVersion = 'v'; |
| static const char kLineTypeOrigin = 'o'; |
| static const char kLineTypeSessionName = 's'; |
| static const char kLineTypeSessionInfo = 'i'; |
| static const char kLineTypeSessionUri = 'u'; |
| static const char kLineTypeSessionEmail = 'e'; |
| static const char kLineTypeSessionPhone = 'p'; |
| static const char kLineTypeSessionBandwidth = 'b'; |
| static const char kLineTypeTiming = 't'; |
| static const char kLineTypeRepeatTimes = 'r'; |
| static const char kLineTypeTimeZone = 'z'; |
| static const char kLineTypeEncryptionKey = 'k'; |
| static const char kLineTypeMedia = 'm'; |
| static const char kLineTypeConnection = 'c'; |
| static const char kLineTypeAttributes = 'a'; |
| |
| // Attributes |
| static const char kAttributeGroup[] = "group"; |
| static const char kAttributeMid[] = "mid"; |
| static const char kAttributeMsid[] = "msid"; |
| static const char kAttributeBundleOnly[] = "bundle-only"; |
| static const char kAttributeRtcpMux[] = "rtcp-mux"; |
| static const char kAttributeRtcpReducedSize[] = "rtcp-rsize"; |
| static const char kAttributeSsrc[] = "ssrc"; |
| static const char kSsrcAttributeCname[] = "cname"; |
| static const char kAttributeExtmapAllowMixed[] = "extmap-allow-mixed"; |
| static const char kAttributeExtmap[] = "extmap"; |
| // draft-alvestrand-mmusic-msid-01 |
| // a=msid-semantic: WMS |
| // This is a legacy field supported only for Plan B semantics. |
| static const char kAttributeMsidSemantics[] = "msid-semantic"; |
| static const char kMediaStreamSemantic[] = "WMS"; |
| static const char kSsrcAttributeMsid[] = "msid"; |
| static const char kDefaultMsid[] = "default"; |
| static const char kNoStreamMsid[] = "-"; |
| static const char kAttributeSsrcGroup[] = "ssrc-group"; |
| static const char kAttributeCrypto[] = "crypto"; |
| static const char kAttributeCandidate[] = "candidate"; |
| static const char kAttributeCandidateTyp[] = "typ"; |
| static const char kAttributeCandidateRaddr[] = "raddr"; |
| static const char kAttributeCandidateRport[] = "rport"; |
| static const char kAttributeCandidateUfrag[] = "ufrag"; |
| static const char kAttributeCandidatePwd[] = "pwd"; |
| static const char kAttributeCandidateGeneration[] = "generation"; |
| static const char kAttributeCandidateNetworkId[] = "network-id"; |
| static const char kAttributeCandidateNetworkCost[] = "network-cost"; |
| static const char kAttributeFingerprint[] = "fingerprint"; |
| static const char kAttributeSetup[] = "setup"; |
| static const char kAttributeFmtp[] = "fmtp"; |
| static const char kAttributeRtpmap[] = "rtpmap"; |
| static const char kAttributeSctpmap[] = "sctpmap"; |
| static const char kAttributeRtcp[] = "rtcp"; |
| static const char kAttributeIceUfrag[] = "ice-ufrag"; |
| static const char kAttributeIcePwd[] = "ice-pwd"; |
| static const char kAttributeIceLite[] = "ice-lite"; |
| static const char kAttributeIceOption[] = "ice-options"; |
| static const char kAttributeSendOnly[] = "sendonly"; |
| static const char kAttributeRecvOnly[] = "recvonly"; |
| static const char kAttributeRtcpFb[] = "rtcp-fb"; |
| static const char kAttributeSendRecv[] = "sendrecv"; |
| static const char kAttributeInactive[] = "inactive"; |
| // draft-ietf-mmusic-sctp-sdp-26 |
| // a=sctp-port, a=max-message-size |
| static const char kAttributeSctpPort[] = "sctp-port"; |
| static const char kAttributeMaxMessageSize[] = "max-message-size"; |
| static const int kDefaultSctpMaxMessageSize = 65536; |
| // draft-ietf-mmusic-sdp-simulcast-13 |
| // a=simulcast |
| static const char kAttributeSimulcast[] = "simulcast"; |
| // draft-ietf-mmusic-rid-15 |
| // a=rid |
| static const char kAttributeRid[] = "rid"; |
| static const char kAttributePacketization[] = "packetization"; |
| |
| // Experimental flags |
| static const char kAttributeXGoogleFlag[] = "x-google-flag"; |
| static const char kValueConference[] = "conference"; |
| |
| static const char kAttributeRtcpRemoteEstimate[] = "remote-net-estimate"; |
| |
| // Candidate |
| static const char kCandidateHost[] = "host"; |
| static const char kCandidateSrflx[] = "srflx"; |
| static const char kCandidatePrflx[] = "prflx"; |
| static const char kCandidateRelay[] = "relay"; |
| static const char kTcpCandidateType[] = "tcptype"; |
| |
| // rtc::StringBuilder doesn't have a << overload for chars, while rtc::split and |
| // rtc::tokenize_first both take a char delimiter. To handle both cases these |
| // constants come in pairs of a chars and length-one strings. |
| static const char kSdpDelimiterEqual[] = "="; |
| static const char kSdpDelimiterEqualChar = '='; |
| static const char kSdpDelimiterSpace[] = " "; |
| static const char kSdpDelimiterSpaceChar = ' '; |
| static const char kSdpDelimiterColon[] = ":"; |
| static const char kSdpDelimiterColonChar = ':'; |
| static const char kSdpDelimiterSemicolon[] = ";"; |
| static const char kSdpDelimiterSemicolonChar = ';'; |
| static const char kSdpDelimiterSlashChar = '/'; |
| static const char kNewLineChar = '\n'; |
| static const char kReturnChar = '\r'; |
| static const char kLineBreak[] = "\r\n"; |
| |
| // TODO(deadbeef): Generate the Session and Time description |
| // instead of hardcoding. |
| static const char kSessionVersion[] = "v=0"; |
| // RFC 4566 |
| static const char kSessionOriginUsername[] = "-"; |
| static const char kSessionOriginSessionId[] = "0"; |
| static const char kSessionOriginSessionVersion[] = "0"; |
| static const char kSessionOriginNettype[] = "IN"; |
| static const char kSessionOriginAddrtype[] = "IP4"; |
| static const char kSessionOriginAddress[] = "127.0.0.1"; |
| static const char kSessionName[] = "s=-"; |
| static const char kTimeDescription[] = "t=0 0"; |
| static const char kAttrGroup[] = "a=group:BUNDLE"; |
| static const char kConnectionNettype[] = "IN"; |
| static const char kConnectionIpv4Addrtype[] = "IP4"; |
| static const char kConnectionIpv6Addrtype[] = "IP6"; |
| static const char kMediaTypeVideo[] = "video"; |
| static const char kMediaTypeAudio[] = "audio"; |
| static const char kMediaTypeData[] = "application"; |
| static const char kMediaPortRejected[] = "0"; |
| // draft-ietf-mmusic-trickle-ice-01 |
| // When no candidates have been gathered, set the connection |
| // address to IP6 ::. |
| // TODO(perkj): FF can not parse IP6 ::. See http://crbug/430333 |
| // Use IPV4 per default. |
| static const char kDummyAddress[] = "0.0.0.0"; |
| static const char kDummyPort[] = "9"; |
| |
| static const char kDefaultSctpmapProtocol[] = "webrtc-datachannel"; |
| |
| // RTP payload type is in the 0-127 range. Use -1 to indicate "all" payload |
| // types. |
| const int kWildcardPayloadType = -1; |
| |
| // Maximum number of channels allowed. |
| static const size_t kMaxNumberOfChannels = 24; |
| |
| struct SsrcInfo { |
| uint32_t ssrc_id; |
| std::string cname; |
| std::string stream_id; |
| std::string track_id; |
| }; |
| typedef std::vector<SsrcInfo> SsrcInfoVec; |
| typedef std::vector<SsrcGroup> SsrcGroupVec; |
| |
| template <class T> |
| static void AddFmtpLine(const T& codec, std::string* message); |
| static void BuildMediaDescription(const ContentInfo* content_info, |
| const TransportInfo* transport_info, |
| const cricket::MediaType media_type, |
| const std::vector<Candidate>& candidates, |
| int msid_signaling, |
| std::string* message); |
| static void BuildMediaLine(const cricket::MediaType media_type, |
| const ContentInfo* content_info, |
| const MediaContentDescription* media_desc, |
| std::string* message); |
| static void BuildRtpContentAttributes(const MediaContentDescription* media_desc, |
| const cricket::MediaType media_type, |
| int msid_signaling, |
| std::string* message); |
| static void BuildRtpHeaderExtensions(const RtpHeaderExtensions& extensions, |
| std::string* message); |
| static void BuildRtpmap(const MediaContentDescription* media_desc, |
| const cricket::MediaType media_type, |
| std::string* message); |
| static void BuildCandidate(const std::vector<Candidate>& candidates, |
| bool include_ufrag, |
| std::string* message); |
| static void BuildIceUfragPwd(const TransportInfo* transport_info, |
| std::string* message); |
| static void BuildDtlsFingerprintSetup(const TransportInfo* transport_info, |
| std::string* message); |
| static void BuildIceOptions(const std::vector<std::string>& transport_options, |
| std::string* message); |
| static bool ParseSessionDescription(absl::string_view message, |
| size_t* pos, |
| std::string* session_id, |
| std::string* session_version, |
| TransportDescription* session_td, |
| RtpHeaderExtensions* session_extmaps, |
| rtc::SocketAddress* connection_addr, |
| cricket::SessionDescription* desc, |
| SdpParseError* error); |
| static bool ParseMediaDescription( |
| absl::string_view message, |
| const TransportDescription& session_td, |
| const RtpHeaderExtensions& session_extmaps, |
| size_t* pos, |
| const rtc::SocketAddress& session_connection_addr, |
| cricket::SessionDescription* desc, |
| std::vector<std::unique_ptr<JsepIceCandidate>>* candidates, |
| SdpParseError* error); |
| static bool ParseContent( |
| absl::string_view message, |
| const cricket::MediaType media_type, |
| int mline_index, |
| absl::string_view protocol, |
| const std::vector<int>& payload_types, |
| size_t* pos, |
| std::string* content_name, |
| bool* bundle_only, |
| int* msid_signaling, |
| MediaContentDescription* media_desc, |
| TransportDescription* transport, |
| std::vector<std::unique_ptr<JsepIceCandidate>>* candidates, |
| SdpParseError* error); |
| static bool ParseGroupAttribute(absl::string_view line, |
| cricket::SessionDescription* desc, |
| SdpParseError* error); |
| static bool ParseSsrcAttribute(absl::string_view line, |
| SsrcInfoVec* ssrc_infos, |
| int* msid_signaling, |
| SdpParseError* error); |
| static bool ParseSsrcGroupAttribute(absl::string_view line, |
| SsrcGroupVec* ssrc_groups, |
| SdpParseError* error); |
| static bool ParseCryptoAttribute(absl::string_view line, |
| MediaContentDescription* media_desc, |
| SdpParseError* error); |
| static bool ParseRtpmapAttribute(absl::string_view line, |
| const cricket::MediaType media_type, |
| const std::vector<int>& payload_types, |
| MediaContentDescription* media_desc, |
| SdpParseError* error); |
| static bool ParseFmtpAttributes(absl::string_view line, |
| const cricket::MediaType media_type, |
| MediaContentDescription* media_desc, |
| SdpParseError* error); |
| static bool ParseFmtpParam(absl::string_view line, |
| std::string* parameter, |
| std::string* value, |
| SdpParseError* error); |
| static bool ParsePacketizationAttribute(absl::string_view line, |
| const cricket::MediaType media_type, |
| MediaContentDescription* media_desc, |
| SdpParseError* error); |
| static bool ParseRtcpFbAttribute(absl::string_view line, |
| const cricket::MediaType media_type, |
| MediaContentDescription* media_desc, |
| SdpParseError* error); |
| static bool ParseIceOptions(absl::string_view line, |
| std::vector<std::string>* transport_options, |
| SdpParseError* error); |
| static bool ParseExtmap(absl::string_view line, |
| RtpExtension* extmap, |
| SdpParseError* error); |
| static bool ParseFingerprintAttribute( |
| absl::string_view line, |
| std::unique_ptr<rtc::SSLFingerprint>* fingerprint, |
| SdpParseError* error); |
| static bool ParseDtlsSetup(absl::string_view line, |
| cricket::ConnectionRole* role, |
| SdpParseError* error); |
| static bool ParseMsidAttribute(absl::string_view line, |
| std::vector<std::string>* stream_ids, |
| std::string* track_id, |
| SdpParseError* error); |
| |
| static void RemoveInvalidRidDescriptions(const std::vector<int>& payload_types, |
| std::vector<RidDescription>* rids); |
| |
| static SimulcastLayerList RemoveRidsFromSimulcastLayerList( |
| const std::set<std::string>& to_remove, |
| const SimulcastLayerList& layers); |
| |
| static void RemoveInvalidRidsFromSimulcast( |
| const std::vector<RidDescription>& rids, |
| SimulcastDescription* simulcast); |
| |
| // Helper functions |
| |
| // Below ParseFailed*** functions output the line that caused the parsing |
| // failure and the detailed reason (`description`) of the failure to `error`. |
| // The functions always return false so that they can be used directly in the |
| // following way when error happens: |
| // "return ParseFailed***(...);" |
| |
| // The line starting at `line_start` of `message` is the failing line. |
| // The reason for the failure should be provided in the `description`. |
| // An example of a description could be "unknown character". |
| static bool ParseFailed(absl::string_view message, |
| size_t line_start, |
| std::string description, |
| SdpParseError* error) { |
| // Get the first line of `message` from `line_start`. |
| absl::string_view first_line; |
| size_t line_end = message.find(kNewLineChar, line_start); |
| if (line_end != std::string::npos) { |
| if (line_end > 0 && (message.at(line_end - 1) == kReturnChar)) { |
| --line_end; |
| } |
| first_line = message.substr(line_start, (line_end - line_start)); |
| } else { |
| first_line = message.substr(line_start); |
| } |
| |
| RTC_LOG(LS_ERROR) << "Failed to parse: \"" << first_line |
| << "\". Reason: " << description; |
| if (error) { |
| // TODO(bugs.webrtc.org/13220): In C++17, we can use plain assignment, with |
| // a string_view on the right hand side. |
| error->line.assign(first_line.data(), first_line.size()); |
| error->description = std::move(description); |
| } |
| return false; |
| } |
| |
| // `line` is the failing line. The reason for the failure should be |
| // provided in the `description`. |
| static bool ParseFailed(absl::string_view line, |
| std::string description, |
| SdpParseError* error) { |
| return ParseFailed(line, 0, std::move(description), error); |
| } |
| |
| // Parses failure where the failing SDP line isn't know or there are multiple |
| // failing lines. |
| static bool ParseFailed(std::string description, SdpParseError* error) { |
| return ParseFailed("", std::move(description), error); |
| } |
| |
| // `line` is the failing line. The failure is due to the fact that `line` |
| // doesn't have `expected_fields` fields. |
| static bool ParseFailedExpectFieldNum(absl::string_view line, |
| int expected_fields, |
| SdpParseError* error) { |
| rtc::StringBuilder description; |
| description << "Expects " << expected_fields << " fields."; |
| return ParseFailed(line, description.Release(), error); |
| } |
| |
| // `line` is the failing line. The failure is due to the fact that `line` has |
| // less than `expected_min_fields` fields. |
| static bool ParseFailedExpectMinFieldNum(absl::string_view line, |
| int expected_min_fields, |
| SdpParseError* error) { |
| rtc::StringBuilder description; |
| description << "Expects at least " << expected_min_fields << " fields."; |
| return ParseFailed(line, description.Release(), error); |
| } |
| |
| // `line` is the failing line. The failure is due to the fact that it failed to |
| // get the value of `attribute`. |
| static bool ParseFailedGetValue(absl::string_view line, |
| absl::string_view attribute, |
| SdpParseError* error) { |
| rtc::StringBuilder description; |
| description << "Failed to get the value of attribute: " << attribute; |
| return ParseFailed(line, description.Release(), error); |
| } |
| |
| // The line starting at `line_start` of `message` is the failing line. The |
| // failure is due to the line type (e.g. the "m" part of the "m-line") |
| // not matching what is expected. The expected line type should be |
| // provided as `line_type`. |
| static bool ParseFailedExpectLine(absl::string_view message, |
| size_t line_start, |
| const char line_type, |
| absl::string_view line_value, |
| SdpParseError* error) { |
| rtc::StringBuilder description; |
| description << "Expect line: " << std::string(1, line_type) << "=" |
| << line_value; |
| return ParseFailed(message, line_start, description.Release(), error); |
| } |
| |
| static bool AddLine(absl::string_view line, std::string* message) { |
| if (!message) |
| return false; |
| |
| message->append(line.data(), line.size()); |
| message->append(kLineBreak); |
| return true; |
| } |
| |
| // Trim return character, if any. |
| static absl::string_view TrimReturnChar(absl::string_view line) { |
| if (!line.empty() && line.back() == kReturnChar) { |
| line.remove_suffix(1); |
| } |
| return line; |
| } |
| |
| // Gets line of `message` starting at `pos`, and checks overall SDP syntax. On |
| // success, advances `pos` to the next line. |
| static absl::optional<absl::string_view> GetLine(absl::string_view message, |
| size_t* pos) { |
| size_t line_end = message.find(kNewLineChar, *pos); |
| if (line_end == absl::string_view::npos) { |
| return absl::nullopt; |
| } |
| absl::string_view line = |
| TrimReturnChar(message.substr(*pos, line_end - *pos)); |
| |
| // RFC 4566 |
| // An SDP session description consists of a number of lines of text of |
| // the form: |
| // <type>=<value> |
| // where <type> MUST be exactly one case-significant character and |
| // <value> is structured text whose format depends on <type>. |
| // Whitespace MUST NOT be used on either side of the "=" sign. |
| // |
| // However, an exception to the whitespace rule is made for "s=", since |
| // RFC4566 also says: |
| // |
| // If a session has no meaningful name, the value "s= " SHOULD be used |
| // (i.e., a single space as the session name). |
| if (line.length() < 3 || !islower(static_cast<unsigned char>(line[0])) || |
| line[1] != kSdpDelimiterEqualChar || |
| (line[0] != kLineTypeSessionName && line[2] == kSdpDelimiterSpaceChar)) { |
| return absl::nullopt; |
| } |
| *pos = line_end + 1; |
| return line; |
| } |
| |
| // Init `os` to "`type`=`value`". |
| static void InitLine(const char type, |
| absl::string_view value, |
| rtc::StringBuilder* os) { |
| os->Clear(); |
| *os << std::string(1, type) << kSdpDelimiterEqual << value; |
| } |
| |
| // Init `os` to "a=`attribute`". |
| static void InitAttrLine(absl::string_view attribute, rtc::StringBuilder* os) { |
| InitLine(kLineTypeAttributes, attribute, os); |
| } |
| |
| // Writes a SDP attribute line based on `attribute` and `value` to `message`. |
| static void AddAttributeLine(absl::string_view attribute, |
| int value, |
| std::string* message) { |
| rtc::StringBuilder os; |
| InitAttrLine(attribute, &os); |
| os << kSdpDelimiterColon << value; |
| AddLine(os.str(), message); |
| } |
| |
| static bool IsLineType(absl::string_view message, |
| const char type, |
| size_t line_start) { |
| if (message.size() < line_start + kLinePrefixLength) { |
| return false; |
| } |
| return (message[line_start] == type && |
| message[line_start + 1] == kSdpDelimiterEqualChar); |
| } |
| |
| static bool IsLineType(absl::string_view line, const char type) { |
| return IsLineType(line, type, 0); |
| } |
| |
| static absl::optional<absl::string_view> |
| GetLineWithType(absl::string_view message, size_t* pos, const char type) { |
| if (IsLineType(message, type, *pos)) { |
| return GetLine(message, pos); |
| } |
| return absl::nullopt; |
| } |
| |
| static bool HasAttribute(absl::string_view line, absl::string_view attribute) { |
| if (line.compare(kLinePrefixLength, attribute.size(), attribute) == 0) { |
| // Make sure that the match is not only a partial match. If length of |
| // strings doesn't match, the next character of the line must be ':' or ' '. |
| // This function is also used for media descriptions (e.g., "m=audio 9..."), |
| // hence the need to also allow space in the end. |
| RTC_CHECK_LE(kLinePrefixLength + attribute.size(), line.size()); |
| if ((kLinePrefixLength + attribute.size()) == line.size() || |
| line[kLinePrefixLength + attribute.size()] == kSdpDelimiterColonChar || |
| line[kLinePrefixLength + attribute.size()] == kSdpDelimiterSpaceChar) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| static bool AddSsrcLine(uint32_t ssrc_id, |
| absl::string_view attribute, |
| absl::string_view value, |
| std::string* message) { |
| // RFC 5576 |
| // a=ssrc:<ssrc-id> <attribute>:<value> |
| rtc::StringBuilder os; |
| InitAttrLine(kAttributeSsrc, &os); |
| os << kSdpDelimiterColon << ssrc_id << kSdpDelimiterSpace << attribute |
| << kSdpDelimiterColon << value; |
| return AddLine(os.str(), message); |
| } |
| |
| // Get value only from <attribute>:<value>. |
| static bool GetValue(absl::string_view message, |
| absl::string_view attribute, |
| std::string* value, |
| SdpParseError* error) { |
| std::string leftpart; |
| if (!rtc::tokenize_first(message, kSdpDelimiterColonChar, &leftpart, value)) { |
| return ParseFailedGetValue(message, attribute, error); |
| } |
| // The left part should end with the expected attribute. |
| if (leftpart.length() < attribute.length() || |
| absl::string_view(leftpart).compare( |
| leftpart.length() - attribute.length(), attribute.length(), |
| attribute) != 0) { |
| return ParseFailedGetValue(message, attribute, error); |
| } |
| return true; |
| } |
| |
| // Get a single [token] from <attribute>:<token> |
| static bool GetSingleTokenValue(absl::string_view message, |
| absl::string_view attribute, |
| std::string* value, |
| SdpParseError* error) { |
| if (!GetValue(message, attribute, value, error)) { |
| return false; |
| } |
| if (!absl::c_all_of(absl::string_view(*value), IsTokenChar)) { |
| rtc::StringBuilder description; |
| description << "Illegal character found in the value of " << attribute; |
| return ParseFailed(message, description.Release(), error); |
| } |
| return true; |
| } |
| |
| static bool CaseInsensitiveFind(std::string str1, std::string str2) { |
| absl::c_transform(str1, str1.begin(), ::tolower); |
| absl::c_transform(str2, str2.begin(), ::tolower); |
| return str1.find(str2) != std::string::npos; |
| } |
| |
| template <class T> |
| static bool GetValueFromString(absl::string_view line, |
| absl::string_view s, |
| T* t, |
| SdpParseError* error) { |
| if (!rtc::FromString(s, t)) { |
| rtc::StringBuilder description; |
| description << "Invalid value: " << s << "."; |
| return ParseFailed(line, description.Release(), error); |
| } |
| return true; |
| } |
| |
| static bool GetPayloadTypeFromString(absl::string_view line, |
| absl::string_view s, |
| int* payload_type, |
| SdpParseError* error) { |
| return GetValueFromString(line, s, payload_type, error) && |
| cricket::IsValidRtpPayloadType(*payload_type); |
| } |
| |
| // Creates a StreamParams track in the case when no SSRC lines are signaled. |
| // This is a track that does not contain SSRCs and only contains |
| // stream_ids/track_id if it's signaled with a=msid lines. |
| void CreateTrackWithNoSsrcs(const std::vector<std::string>& msid_stream_ids, |
| absl::string_view msid_track_id, |
| const std::vector<RidDescription>& rids, |
| StreamParamsVec* tracks) { |
| StreamParams track; |
| if (msid_track_id.empty() && rids.empty()) { |
| // We only create an unsignaled track if a=msid lines were signaled. |
| RTC_LOG(LS_INFO) << "MSID not signaled, skipping creation of StreamParams"; |
| return; |
| } |
| track.set_stream_ids(msid_stream_ids); |
| track.id = std::string(msid_track_id); |
| track.set_rids(rids); |
| tracks->push_back(track); |
| } |
| |
| // Creates the StreamParams tracks, for the case when SSRC lines are signaled. |
| // `msid_stream_ids` and `msid_track_id` represent the stream/track ID from the |
| // "a=msid" attribute, if it exists. They are empty if the attribute does not |
| // exist. We prioritize getting stream_ids/track_ids signaled in a=msid lines. |
| void CreateTracksFromSsrcInfos(const SsrcInfoVec& ssrc_infos, |
| const std::vector<std::string>& msid_stream_ids, |
| absl::string_view msid_track_id, |
| StreamParamsVec* tracks, |
| int msid_signaling) { |
| RTC_DCHECK(tracks); |
| for (const SsrcInfo& ssrc_info : ssrc_infos) { |
| // According to https://tools.ietf.org/html/rfc5576#section-6.1, the CNAME |
| // attribute is mandatory, but we relax that restriction. |
| if (ssrc_info.cname.empty()) { |
| RTC_LOG(LS_WARNING) << "CNAME attribute missing for SSRC " |
| << ssrc_info.ssrc_id; |
| } |
| std::vector<std::string> stream_ids; |
| std::string track_id; |
| if (msid_signaling & cricket::kMsidSignalingMediaSection) { |
| // This is the case with Unified Plan SDP msid signaling. |
| stream_ids = msid_stream_ids; |
| track_id = std::string(msid_track_id); |
| } else if (msid_signaling & cricket::kMsidSignalingSsrcAttribute) { |
| // This is the case with Plan B SDP msid signaling. |
| stream_ids.push_back(ssrc_info.stream_id); |
| track_id = ssrc_info.track_id; |
| } else { |
| // Since no media streams isn't supported with older SDP signaling, we |
| // use a default stream id. |
| stream_ids.push_back(kDefaultMsid); |
| } |
| |
| auto track_it = absl::c_find_if( |
| *tracks, |
| [track_id](const StreamParams& track) { return track.id == track_id; }); |
| if (track_it == tracks->end()) { |
| // If we don't find an existing track, create a new one. |
| tracks->push_back(StreamParams()); |
| track_it = tracks->end() - 1; |
| } |
| StreamParams& track = *track_it; |
| track.add_ssrc(ssrc_info.ssrc_id); |
| track.cname = ssrc_info.cname; |
| track.set_stream_ids(stream_ids); |
| track.id = track_id; |
| } |
| for (StreamParams& stream : *tracks) { |
| // If a track ID wasn't populated from the SSRC attributes OR the |
| // msid attribute, use default/random values. This happens after |
| // deduplication. |
| if (stream.id.empty()) { |
| stream.id = rtc::CreateRandomString(8); |
| } |
| } |
| } |
| |
| void GetMediaStreamIds(const ContentInfo* content, |
| std::set<std::string>* labels) { |
| for (const StreamParams& stream_params : |
| content->media_description()->streams()) { |
| for (const std::string& stream_id : stream_params.stream_ids()) { |
| labels->insert(stream_id); |
| } |
| } |
| } |
| |
| // RFC 5245 |
| // It is RECOMMENDED that default candidates be chosen based on the |
| // likelihood of those candidates to work with the peer that is being |
| // contacted. It is RECOMMENDED that relayed > reflexive > host. |
| static const int kPreferenceUnknown = 0; |
| static const int kPreferenceHost = 1; |
| static const int kPreferenceReflexive = 2; |
| static const int kPreferenceRelayed = 3; |
| |
| static int GetCandidatePreferenceFromType(absl::string_view type) { |
| int preference = kPreferenceUnknown; |
| if (type == cricket::LOCAL_PORT_TYPE) { |
| preference = kPreferenceHost; |
| } else if (type == cricket::STUN_PORT_TYPE) { |
| preference = kPreferenceReflexive; |
| } else if (type == cricket::RELAY_PORT_TYPE) { |
| preference = kPreferenceRelayed; |
| } else { |
| RTC_DCHECK_NOTREACHED(); |
| } |
| return preference; |
| } |
| |
| // Get ip and port of the default destination from the `candidates` with the |
| // given value of `component_id`. The default candidate should be the one most |
| // likely to work, typically IPv4 relay. |
| // RFC 5245 |
| // The value of `component_id` currently supported are 1 (RTP) and 2 (RTCP). |
| // TODO(deadbeef): Decide the default destination in webrtcsession and |
| // pass it down via SessionDescription. |
| static void GetDefaultDestination(const std::vector<Candidate>& candidates, |
| int component_id, |
| std::string* port, |
| std::string* ip, |
| std::string* addr_type) { |
| *addr_type = kConnectionIpv4Addrtype; |
| *port = kDummyPort; |
| *ip = kDummyAddress; |
| int current_preference = kPreferenceUnknown; |
| int current_family = AF_UNSPEC; |
| for (const Candidate& candidate : candidates) { |
| if (candidate.component() != component_id) { |
| continue; |
| } |
| // Default destination should be UDP only. |
| if (candidate.protocol() != cricket::UDP_PROTOCOL_NAME) { |
| continue; |
| } |
| const int preference = GetCandidatePreferenceFromType(candidate.type()); |
| const int family = candidate.address().ipaddr().family(); |
| // See if this candidate is more preferable then the current one if it's the |
| // same family. Or if the current family is IPv4 already so we could safely |
| // ignore all IPv6 ones. WebRTC bug 4269. |
| // http://code.google.com/p/webrtc/issues/detail?id=4269 |
| if ((preference <= current_preference && current_family == family) || |
| (current_family == AF_INET && family == AF_INET6)) { |
| continue; |
| } |
| if (family == AF_INET) { |
| addr_type->assign(kConnectionIpv4Addrtype); |
| } else if (family == AF_INET6) { |
| addr_type->assign(kConnectionIpv6Addrtype); |
| } |
| current_preference = preference; |
| current_family = family; |
| *port = candidate.address().PortAsString(); |
| *ip = candidate.address().ipaddr().ToString(); |
| } |
| } |
| |
| // Gets "a=rtcp" line if found default RTCP candidate from `candidates`. |
| static std::string GetRtcpLine(const std::vector<Candidate>& candidates) { |
| std::string rtcp_line, rtcp_port, rtcp_ip, addr_type; |
| GetDefaultDestination(candidates, ICE_CANDIDATE_COMPONENT_RTCP, &rtcp_port, |
| &rtcp_ip, &addr_type); |
| // Found default RTCP candidate. |
| // RFC 5245 |
| // If the agent is utilizing RTCP, it MUST encode the RTCP candidate |
| // using the a=rtcp attribute as defined in RFC 3605. |
| |
| // RFC 3605 |
| // rtcp-attribute = "a=rtcp:" port [nettype space addrtype space |
| // connection-address] CRLF |
| rtc::StringBuilder os; |
| InitAttrLine(kAttributeRtcp, &os); |
| os << kSdpDelimiterColon << rtcp_port << " " << kConnectionNettype << " " |
| << addr_type << " " << rtcp_ip; |
| rtcp_line = os.str(); |
| return rtcp_line; |
| } |
| |
| // Get candidates according to the mline index from SessionDescriptionInterface. |
| static void GetCandidatesByMindex(const SessionDescriptionInterface& desci, |
| int mline_index, |
| std::vector<Candidate>* candidates) { |
| if (!candidates) { |
| return; |
| } |
| const IceCandidateCollection* cc = desci.candidates(mline_index); |
| for (size_t i = 0; i < cc->count(); ++i) { |
| const IceCandidateInterface* candidate = cc->at(i); |
| candidates->push_back(candidate->candidate()); |
| } |
| } |
| |
| static bool IsValidPort(int port) { |
| return port >= 0 && port <= 65535; |
| } |
| |
| std::string SdpSerialize(const JsepSessionDescription& jdesc) { |
| const cricket::SessionDescription* desc = jdesc.description(); |
| if (!desc) { |
| return ""; |
| } |
| |
| std::string message; |
| |
| // Session Description. |
| AddLine(kSessionVersion, &message); |
| // Session Origin |
| // RFC 4566 |
| // o=<username> <sess-id> <sess-version> <nettype> <addrtype> |
| // <unicast-address> |
| rtc::StringBuilder os; |
| InitLine(kLineTypeOrigin, kSessionOriginUsername, &os); |
| const std::string& session_id = |
| jdesc.session_id().empty() ? kSessionOriginSessionId : jdesc.session_id(); |
| const std::string& session_version = jdesc.session_version().empty() |
| ? kSessionOriginSessionVersion |
| : jdesc.session_version(); |
| os << " " << session_id << " " << session_version << " " |
| << kSessionOriginNettype << " " << kSessionOriginAddrtype << " " |
| << kSessionOriginAddress; |
| AddLine(os.str(), &message); |
| AddLine(kSessionName, &message); |
| |
| // Time Description. |
| AddLine(kTimeDescription, &message); |
| |
| // BUNDLE Groups |
| std::vector<const cricket::ContentGroup*> groups = |
| desc->GetGroupsByName(cricket::GROUP_TYPE_BUNDLE); |
| for (const cricket::ContentGroup* group : groups) { |
| std::string group_line = kAttrGroup; |
| RTC_DCHECK(group != NULL); |
| for (const std::string& content_name : group->content_names()) { |
| group_line.append(" "); |
| group_line.append(content_name); |
| } |
| AddLine(group_line, &message); |
| } |
| |
| // Mixed one- and two-byte header extension. |
| if (desc->extmap_allow_mixed()) { |
| InitAttrLine(kAttributeExtmapAllowMixed, &os); |
| AddLine(os.str(), &message); |
| } |
| |
| // MediaStream semantics |
| InitAttrLine(kAttributeMsidSemantics, &os); |
| os << kSdpDelimiterColon << " " << kMediaStreamSemantic; |
| |
| std::set<std::string> media_stream_ids; |
| const ContentInfo* audio_content = GetFirstAudioContent(desc); |
| if (audio_content) |
| GetMediaStreamIds(audio_content, &media_stream_ids); |
| |
| const ContentInfo* video_content = GetFirstVideoContent(desc); |
| if (video_content) |
| GetMediaStreamIds(video_content, &media_stream_ids); |
| |
| for (const std::string& id : media_stream_ids) { |
| os << " " << id; |
| } |
| AddLine(os.str(), &message); |
| |
| // a=ice-lite |
| // |
| // TODO(deadbeef): It's weird that we need to iterate TransportInfos for |
| // this, when it's a session-level attribute. It really should be moved to a |
| // session-level structure like SessionDescription. |
| for (const cricket::TransportInfo& transport : desc->transport_infos()) { |
| if (transport.description.ice_mode == cricket::ICEMODE_LITE) { |
| InitAttrLine(kAttributeIceLite, &os); |
| AddLine(os.str(), &message); |
| break; |
| } |
| } |
| |
| // Preserve the order of the media contents. |
| int mline_index = -1; |
| for (const ContentInfo& content : desc->contents()) { |
| std::vector<Candidate> candidates; |
| GetCandidatesByMindex(jdesc, ++mline_index, &candidates); |
| BuildMediaDescription(&content, desc->GetTransportInfoByName(content.name), |
| content.media_description()->type(), candidates, |
| desc->msid_signaling(), &message); |
| } |
| return message; |
| } |
| |
| // Serializes the passed in IceCandidateInterface to a SDP string. |
| // candidate - The candidate to be serialized. |
| std::string SdpSerializeCandidate(const IceCandidateInterface& candidate) { |
| return SdpSerializeCandidate(candidate.candidate()); |
| } |
| |
| // Serializes a cricket Candidate. |
| std::string SdpSerializeCandidate(const cricket::Candidate& candidate) { |
| std::string message; |
| std::vector<cricket::Candidate> candidates(1, candidate); |
| BuildCandidate(candidates, true, &message); |
| // From WebRTC draft section 4.8.1.1 candidate-attribute will be |
| // just candidate:<candidate> not a=candidate:<blah>CRLF |
| RTC_DCHECK(message.find("a=") == 0); |
| message.erase(0, 2); |
| RTC_DCHECK(message.find(kLineBreak) == message.size() - 2); |
| message.resize(message.size() - 2); |
| return message; |
| } |
| |
| bool SdpDeserialize(absl::string_view message, |
| JsepSessionDescription* jdesc, |
| SdpParseError* error) { |
| std::string session_id; |
| std::string session_version; |
| TransportDescription session_td("", ""); |
| RtpHeaderExtensions session_extmaps; |
| rtc::SocketAddress session_connection_addr; |
| auto desc = std::make_unique<cricket::SessionDescription>(); |
| size_t current_pos = 0; |
| |
| // Session Description |
| if (!ParseSessionDescription(message, ¤t_pos, &session_id, |
| &session_version, &session_td, &session_extmaps, |
| &session_connection_addr, desc.get(), error)) { |
| return false; |
| } |
| |
| // Media Description |
| std::vector<std::unique_ptr<JsepIceCandidate>> candidates; |
| if (!ParseMediaDescription(message, session_td, session_extmaps, ¤t_pos, |
| session_connection_addr, desc.get(), &candidates, |
| error)) { |
| return false; |
| } |
| |
| jdesc->Initialize(std::move(desc), session_id, session_version); |
| |
| for (const auto& candidate : candidates) { |
| jdesc->AddCandidate(candidate.get()); |
| } |
| return true; |
| } |
| |
| bool SdpDeserializeCandidate(absl::string_view message, |
| JsepIceCandidate* jcandidate, |
| SdpParseError* error) { |
| RTC_DCHECK(jcandidate != NULL); |
| Candidate candidate; |
| if (!ParseCandidate(message, &candidate, error, true)) { |
| return false; |
| } |
| jcandidate->SetCandidate(candidate); |
| return true; |
| } |
| |
| bool SdpDeserializeCandidate(absl::string_view transport_name, |
| absl::string_view message, |
| cricket::Candidate* candidate, |
| SdpParseError* error) { |
| RTC_DCHECK(candidate != nullptr); |
| if (!ParseCandidate(message, candidate, error, true)) { |
| return false; |
| } |
| candidate->set_transport_name(transport_name); |
| return true; |
| } |
| |
| bool ParseCandidate(absl::string_view message, |
| Candidate* candidate, |
| SdpParseError* error, |
| bool is_raw) { |
| RTC_DCHECK(candidate != NULL); |
| |
| // Makes sure `message` contains only one line. |
| absl::string_view first_line; |
| |
| size_t line_end = message.find(kNewLineChar); |
| if (line_end == absl::string_view::npos) { |
| first_line = message; |
| } else if (line_end + 1 == message.size()) { |
| first_line = message.substr(0, line_end); |
| } else { |
| return ParseFailed(message, 0, "Expect one line only", error); |
| } |
| |
| // Trim return char, if any. |
| first_line = TrimReturnChar(first_line); |
| |
| // From WebRTC draft section 4.8.1.1 candidate-attribute should be |
| // candidate:<candidate> when trickled, but we still support |
| // a=candidate:<blah>CRLF for backward compatibility and for parsing a line |
| // from the SDP. |
| if (IsLineType(first_line, kLineTypeAttributes)) { |
| first_line = first_line.substr(kLinePrefixLength); |
| } |
| |
| std::string attribute_candidate; |
| std::string candidate_value; |
| |
| // `first_line` must be in the form of "candidate:<value>". |
| if (!rtc::tokenize_first(first_line, kSdpDelimiterColonChar, |
| &attribute_candidate, &candidate_value) || |
| attribute_candidate != kAttributeCandidate) { |
| if (is_raw) { |
| rtc::StringBuilder description; |
| description << "Expect line: " << kAttributeCandidate |
| << ":" |
| "<candidate-str>"; |
| return ParseFailed(first_line, 0, description.Release(), error); |
| } else { |
| return ParseFailedExpectLine(first_line, 0, kLineTypeAttributes, |
| kAttributeCandidate, error); |
| } |
| } |
| |
| std::vector<absl::string_view> fields = |
| rtc::split(candidate_value, kSdpDelimiterSpaceChar); |
| |
| // RFC 5245 |
| // a=candidate:<foundation> <component-id> <transport> <priority> |
| // <connection-address> <port> typ <candidate-types> |
| // [raddr <connection-address>] [rport <port>] |
| // *(SP extension-att-name SP extension-att-value) |
| const size_t expected_min_fields = 8; |
| if (fields.size() < expected_min_fields || |
| (fields[6] != kAttributeCandidateTyp)) { |
| return ParseFailedExpectMinFieldNum(first_line, expected_min_fields, error); |
| } |
| const absl::string_view foundation = fields[0]; |
| |
| int component_id = 0; |
| if (!GetValueFromString(first_line, fields[1], &component_id, error)) { |
| return false; |
| } |
| const absl::string_view transport = fields[2]; |
| uint32_t priority = 0; |
| if (!GetValueFromString(first_line, fields[3], &priority, error)) { |
| return false; |
| } |
| const absl::string_view connection_address = fields[4]; |
| int port = 0; |
| if (!GetValueFromString(first_line, fields[5], &port, error)) { |
| return false; |
| } |
| if (!IsValidPort(port)) { |
| return ParseFailed(first_line, "Invalid port number.", error); |
| } |
| SocketAddress address(connection_address, port); |
| |
| absl::optional<cricket::ProtocolType> protocol = |
| cricket::StringToProto(transport); |
| if (!protocol) { |
| return ParseFailed(first_line, "Unsupported transport type.", error); |
| } |
| bool tcp_protocol = false; |
| switch (*protocol) { |
| // Supported protocols. |
| case cricket::PROTO_UDP: |
| break; |
| case cricket::PROTO_TCP: |
| case cricket::PROTO_SSLTCP: |
| tcp_protocol = true; |
| break; |
| default: |
| return ParseFailed(first_line, "Unsupported transport type.", error); |
| } |
| |
| std::string candidate_type; |
| const absl::string_view type = fields[7]; |
| if (type == kCandidateHost) { |
| candidate_type = cricket::LOCAL_PORT_TYPE; |
| } else if (type == kCandidateSrflx) { |
| candidate_type = cricket::STUN_PORT_TYPE; |
| } else if (type == kCandidateRelay) { |
| candidate_type = cricket::RELAY_PORT_TYPE; |
| } else if (type == kCandidatePrflx) { |
| candidate_type = cricket::PRFLX_PORT_TYPE; |
| } else { |
| return ParseFailed(first_line, "Unsupported candidate type.", error); |
| } |
| |
| size_t current_position = expected_min_fields; |
| SocketAddress related_address; |
| // The 2 optional fields for related address |
| // [raddr <connection-address>] [rport <port>] |
| if (fields.size() >= (current_position + 2) && |
| fields[current_position] == kAttributeCandidateRaddr) { |
| related_address.SetIP(fields[++current_position]); |
| ++current_position; |
| } |
| if (fields.size() >= (current_position + 2) && |
| fields[current_position] == kAttributeCandidateRport) { |
| int port = 0; |
| if (!GetValueFromString(first_line, fields[++current_position], &port, |
| error)) { |
| return false; |
| } |
| if (!IsValidPort(port)) { |
| return ParseFailed(first_line, "Invalid port number.", error); |
| } |
| related_address.SetPort(port); |
| ++current_position; |
| } |
| |
| // If this is a TCP candidate, it has additional extension as defined in |
| // RFC 6544. |
| absl::string_view tcptype; |
| if (fields.size() >= (current_position + 2) && |
| fields[current_position] == kTcpCandidateType) { |
| tcptype = fields[++current_position]; |
| ++current_position; |
| |
| if (tcptype != cricket::TCPTYPE_ACTIVE_STR && |
| tcptype != cricket::TCPTYPE_PASSIVE_STR && |
| tcptype != cricket::TCPTYPE_SIMOPEN_STR) { |
| return ParseFailed(first_line, "Invalid TCP candidate type.", error); |
| } |
| |
| if (!tcp_protocol) { |
| return ParseFailed(first_line, "Invalid non-TCP candidate", error); |
| } |
| } else if (tcp_protocol) { |
| // We allow the tcptype to be missing, for backwards compatibility, |
| // treating it as a passive candidate. |
| // TODO(bugs.webrtc.org/11466): Treat a missing tcptype as an error? |
| tcptype = cricket::TCPTYPE_PASSIVE_STR; |
| } |
| |
| // Extension |
| // Though non-standard, we support the ICE ufrag and pwd being signaled on |
| // the candidate to avoid issues with confusing which generation a candidate |
| // belongs to when trickling multiple generations at the same time. |
| absl::string_view username; |
| absl::string_view password; |
| uint32_t generation = 0; |
| uint16_t network_id = 0; |
| uint16_t network_cost = 0; |
| for (size_t i = current_position; i + 1 < fields.size(); ++i) { |
| // RFC 5245 |
| // *(SP extension-att-name SP extension-att-value) |
| if (fields[i] == kAttributeCandidateGeneration) { |
| if (!GetValueFromString(first_line, fields[++i], &generation, error)) { |
| return false; |
| } |
| } else if (fields[i] == kAttributeCandidateUfrag) { |
| username = fields[++i]; |
| } else if (fields[i] == kAttributeCandidatePwd) { |
| password = fields[++i]; |
| } else if (fields[i] == kAttributeCandidateNetworkId) { |
| if (!GetValueFromString(first_line, fields[++i], &network_id, error)) { |
| return false; |
| } |
| } else if (fields[i] == kAttributeCandidateNetworkCost) { |
| if (!GetValueFromString(first_line, fields[++i], &network_cost, error)) { |
| return false; |
| } |
| network_cost = std::min(network_cost, rtc::kNetworkCostMax); |
| } else { |
| // Skip the unknown extension. |
| ++i; |
| } |
| } |
| |
| *candidate = Candidate(component_id, cricket::ProtoToString(*protocol), |
| address, priority, username, password, candidate_type, |
| generation, foundation, network_id, network_cost); |
| candidate->set_related_address(related_address); |
| candidate->set_tcptype(tcptype); |
| return true; |
| } |
| |
| bool ParseIceOptions(absl::string_view line, |
| std::vector<std::string>* transport_options, |
| SdpParseError* error) { |
| std::string ice_options; |
| if (!GetValue(line, kAttributeIceOption, &ice_options, error)) { |
| return false; |
| } |
| std::vector<absl::string_view> fields = |
| rtc::split(ice_options, kSdpDelimiterSpaceChar); |
| for (size_t i = 0; i < fields.size(); ++i) { |
| transport_options->emplace_back(fields[i]); |
| } |
| return true; |
| } |
| |
| bool ParseSctpPort(absl::string_view line, |
| int* sctp_port, |
| SdpParseError* error) { |
| // draft-ietf-mmusic-sctp-sdp-26 |
| // a=sctp-port |
| const size_t expected_min_fields = 2; |
| std::vector<absl::string_view> fields = |
| rtc::split(line.substr(kLinePrefixLength), kSdpDelimiterColonChar); |
| if (fields.size() < expected_min_fields) { |
| fields = rtc::split(line.substr(kLinePrefixLength), kSdpDelimiterSpaceChar); |
| } |
| if (fields.size() < expected_min_fields) { |
| return ParseFailedExpectMinFieldNum(line, expected_min_fields, error); |
| } |
| if (!rtc::FromString(fields[1], sctp_port)) { |
| return ParseFailed(line, "Invalid sctp port value.", error); |
| } |
| return true; |
| } |
| |
| bool ParseSctpMaxMessageSize(absl::string_view line, |
| int* max_message_size, |
| SdpParseError* error) { |
| // draft-ietf-mmusic-sctp-sdp-26 |
| // a=max-message-size:199999 |
| const size_t expected_min_fields = 2; |
| std::vector<absl::string_view> fields = |
| rtc::split(line.substr(kLinePrefixLength), kSdpDelimiterColonChar); |
| if (fields.size() < expected_min_fields) { |
| return ParseFailedExpectMinFieldNum(line, expected_min_fields, error); |
| } |
| if (!rtc::FromString(fields[1], max_message_size)) { |
| return ParseFailed(line, "Invalid SCTP max message size.", error); |
| } |
| return true; |
| } |
| |
| bool ParseExtmap(absl::string_view line, |
| RtpExtension* extmap, |
| SdpParseError* error) { |
| // RFC 5285 |
| // a=extmap:<value>["/"<direction>] <URI> <extensionattributes> |
| std::vector<absl::string_view> fields = |
| rtc::split(line.substr(kLinePrefixLength), kSdpDelimiterSpaceChar); |
| const size_t expected_min_fields = 2; |
| if (fields.size() < expected_min_fields) { |
| return ParseFailedExpectMinFieldNum(line, expected_min_fields, error); |
| } |
| absl::string_view uri = fields[1]; |
| |
| std::string value_direction; |
| if (!GetValue(fields[0], kAttributeExtmap, &value_direction, error)) { |
| return false; |
| } |
| std::vector<absl::string_view> sub_fields = |
| rtc::split(value_direction, kSdpDelimiterSlashChar); |
| int value = 0; |
| if (!GetValueFromString(line, sub_fields[0], &value, error)) { |
| return false; |
| } |
| |
| bool encrypted = false; |
| if (uri == RtpExtension::kEncryptHeaderExtensionsUri) { |
| // RFC 6904 |
| // a=extmap:<value["/"<direction>] urn:ietf:params:rtp-hdrext:encrypt <URI> |
| // <extensionattributes> |
| const size_t expected_min_fields_encrypted = expected_min_fields + 1; |
| if (fields.size() < expected_min_fields_encrypted) { |
| return ParseFailedExpectMinFieldNum(line, expected_min_fields_encrypted, |
| error); |
| } |
| |
| encrypted = true; |
| uri = fields[2]; |
| if (uri == RtpExtension::kEncryptHeaderExtensionsUri) { |
| return ParseFailed(line, "Recursive encrypted header.", error); |
| } |
| } |
| |
| *extmap = RtpExtension(uri, value, encrypted); |
| return true; |
| } |
| |
| static void BuildSctpContentAttributes( |
| std::string* message, |
| const cricket::SctpDataContentDescription* data_desc) { |
| rtc::StringBuilder os; |
| if (data_desc->use_sctpmap()) { |
| // draft-ietf-mmusic-sctp-sdp-04 |
| // a=sctpmap:sctpmap-number protocol [streams] |
| rtc::StringBuilder os; |
| InitAttrLine(kAttributeSctpmap, &os); |
| os << kSdpDelimiterColon << data_desc->port() << kSdpDelimiterSpace |
| << kDefaultSctpmapProtocol << kSdpDelimiterSpace |
| << cricket::kMaxSctpStreams; |
| AddLine(os.str(), message); |
| } else { |
| // draft-ietf-mmusic-sctp-sdp-23 |
| // a=sctp-port:<port> |
| InitAttrLine(kAttributeSctpPort, &os); |
| os << kSdpDelimiterColon << data_desc->port(); |
| AddLine(os.str(), message); |
| if (data_desc->max_message_size() != kDefaultSctpMaxMessageSize) { |
| InitAttrLine(kAttributeMaxMessageSize, &os); |
| os << kSdpDelimiterColon << data_desc->max_message_size(); |
| AddLine(os.str(), message); |
| } |
| } |
| } |
| |
| void BuildIceUfragPwd(const TransportInfo* transport_info, |
| std::string* message) { |
| RTC_DCHECK(transport_info); |
| |
| rtc::StringBuilder os; |
| // RFC 5245 |
| // ice-pwd-att = "ice-pwd" ":" password |
| // ice-ufrag-att = "ice-ufrag" ":" ufrag |
| // ice-ufrag |
| if (!transport_info->description.ice_ufrag.empty()) { |
| InitAttrLine(kAttributeIceUfrag, &os); |
| os << kSdpDelimiterColon << transport_info->description.ice_ufrag; |
| AddLine(os.str(), message); |
| } |
| // ice-pwd |
| if (!transport_info->description.ice_pwd.empty()) { |
| InitAttrLine(kAttributeIcePwd, &os); |
| os << kSdpDelimiterColon << transport_info->description.ice_pwd; |
| AddLine(os.str(), message); |
| } |
| } |
| |
| void BuildDtlsFingerprintSetup(const TransportInfo* transport_info, |
| std::string* message) { |
| RTC_DCHECK(transport_info); |
| |
| rtc::StringBuilder os; |
| // RFC 4572 |
| // fingerprint-attribute = |
| // "fingerprint" ":" hash-func SP fingerprint |
| // When using max-bundle this is already included at session level. |
| // Insert the fingerprint attribute. |
| auto fingerprint = transport_info->description.identity_fingerprint.get(); |
| if (!fingerprint) { |
| return; |
| } |
| InitAttrLine(kAttributeFingerprint, &os); |
| os << kSdpDelimiterColon << fingerprint->algorithm << kSdpDelimiterSpace |
| << fingerprint->GetRfc4572Fingerprint(); |
| AddLine(os.str(), message); |
| |
| // Inserting setup attribute. |
| if (transport_info->description.connection_role != |
| cricket::CONNECTIONROLE_NONE) { |
| // Making sure we are not using "passive" mode. |
| cricket::ConnectionRole role = transport_info->description.connection_role; |
| std::string dtls_role_str; |
| const bool success = cricket::ConnectionRoleToString(role, &dtls_role_str); |
| RTC_DCHECK(success); |
| InitAttrLine(kAttributeSetup, &os); |
| os << kSdpDelimiterColon << dtls_role_str; |
| AddLine(os.str(), message); |
| } |
| } |
| |
| void BuildMediaLine(const cricket::MediaType media_type, |
| const ContentInfo* content_info, |
| const MediaContentDescription* media_desc, |
| std::string* message) { |
| rtc::StringBuilder os; |
| |
| // RFC 4566 |
| // m=<media> <port> <proto> <fmt> |
| // fmt is a list of payload type numbers that MAY be used in the session. |
| std::string type; |
| std::string fmt; |
| if (media_type == cricket::MEDIA_TYPE_AUDIO || |
| media_type == cricket::MEDIA_TYPE_VIDEO) { |
| type = media_type == cricket::MEDIA_TYPE_AUDIO ? kMediaTypeAudio |
| : kMediaTypeVideo; |
| for (const cricket::VideoCodec& codec : media_desc->codecs()) { |
| fmt.append(" "); |
| fmt.append(rtc::ToString(codec.id)); |
| } |
| } else if (media_type == cricket::MEDIA_TYPE_DATA) { |
| type = kMediaTypeData; |
| const cricket::SctpDataContentDescription* sctp_data_desc = |
| media_desc->as_sctp(); |
| if (sctp_data_desc) { |
| fmt.append(" "); |
| |
| if (sctp_data_desc->use_sctpmap()) { |
| fmt.append(rtc::ToString(sctp_data_desc->port())); |
| } else { |
| fmt.append(kDefaultSctpmapProtocol); |
| } |
| } else { |
| RTC_DCHECK_NOTREACHED() << "Data description without SCTP"; |
| } |
| } else if (media_type == cricket::MEDIA_TYPE_UNSUPPORTED) { |
| const UnsupportedContentDescription* unsupported_desc = |
| media_desc->as_unsupported(); |
| type = unsupported_desc->media_type(); |
| } else { |
| RTC_DCHECK_NOTREACHED(); |
| } |
| // The fmt must never be empty. If no codecs are found, set the fmt attribute |
| // to 0. |
| if (fmt.empty()) { |
| fmt = " 0"; |
| } |
| |
| // The port number in the m line will be updated later when associated with |
| // the candidates. |
| // |
| // A port value of 0 indicates that the m= section is rejected. |
| // RFC 3264 |
| // To reject an offered stream, the port number in the corresponding stream in |
| // the answer MUST be set to zero. |
| // |
| // However, the BUNDLE draft adds a new meaning to port zero, when used along |
| // with a=bundle-only. |
| std::string port = kDummyPort; |
| if (content_info->rejected || content_info->bundle_only) { |
| port = kMediaPortRejected; |
| } else if (!media_desc->connection_address().IsNil()) { |
| port = rtc::ToString(media_desc->connection_address().port()); |
| } |
| |
| // Add the m and c lines. |
| InitLine(kLineTypeMedia, type, &os); |
| os << " " << port << " " << media_desc->protocol() << fmt; |
| AddLine(os.str(), message); |
| } |
| |
| void BuildMediaDescription(const ContentInfo* content_info, |
| const TransportInfo* transport_info, |
| const cricket::MediaType media_type, |
| const std::vector<Candidate>& candidates, |
| int msid_signaling, |
| std::string* message) { |
| RTC_DCHECK(message); |
| if (!content_info) { |
| return; |
| } |
| rtc::StringBuilder os; |
| const MediaContentDescription* media_desc = content_info->media_description(); |
| RTC_DCHECK(media_desc); |
| |
| // Add the m line. |
| BuildMediaLine(media_type, content_info, media_desc, message); |
| // Add the c line. |
| InitLine(kLineTypeConnection, kConnectionNettype, &os); |
| if (media_desc->connection_address().IsNil()) { |
| os << " " << kConnectionIpv4Addrtype << " " << kDummyAddress; |
| } else if (media_desc->connection_address().family() == AF_INET) { |
| os << " " << kConnectionIpv4Addrtype << " " |
| << media_desc->connection_address().ipaddr().ToString(); |
| } else if (media_desc->connection_address().family() == AF_INET6) { |
| os << " " << kConnectionIpv6Addrtype << " " |
| << media_desc->connection_address().ipaddr().ToString(); |
| } else { |
| os << " " << kConnectionIpv4Addrtype << " " << kDummyAddress; |
| } |
| AddLine(os.str(), message); |
| |
| // RFC 4566 |
| // b=AS:<bandwidth> or |
| // b=TIAS:<bandwidth> |
| int bandwidth = media_desc->bandwidth(); |
| std::string bandwidth_type = media_desc->bandwidth_type(); |
| if (bandwidth_type == kApplicationSpecificBandwidth && bandwidth >= 1000) { |
| InitLine(kLineTypeSessionBandwidth, bandwidth_type, &os); |
| bandwidth /= 1000; |
| os << kSdpDelimiterColon << bandwidth; |
| AddLine(os.str(), message); |
| } else if (bandwidth_type == kTransportSpecificBandwidth && bandwidth > 0) { |
| InitLine(kLineTypeSessionBandwidth, bandwidth_type, &os); |
| os << kSdpDelimiterColon << bandwidth; |
| AddLine(os.str(), message); |
| } |
| |
| // Add the a=bundle-only line. |
| if (content_info->bundle_only) { |
| InitAttrLine(kAttributeBundleOnly, &os); |
| AddLine(os.str(), message); |
| } |
| |
| // Add the a=rtcp line. |
| if (cricket::IsRtpProtocol(media_desc->protocol())) { |
| std::string rtcp_line = GetRtcpLine(candidates); |
| if (!rtcp_line.empty()) { |
| AddLine(rtcp_line, message); |
| } |
| } |
| |
| // Build the a=candidate lines. We don't include ufrag and pwd in the |
| // candidates in the SDP to avoid redundancy. |
| BuildCandidate(candidates, false, message); |
| |
| // Use the transport_info to build the media level ice-ufrag, ice-pwd |
| // and DTLS fingerprint and setup attributes. |
| if (transport_info) { |
| BuildIceUfragPwd(transport_info, message); |
| |
| // draft-petithuguenin-mmusic-ice-attributes-level-03 |
| BuildIceOptions(transport_info->description.transport_options, message); |
| |
| // Also include the DTLS fingerprint and setup attribute if available. |
| BuildDtlsFingerprintSetup(transport_info, message); |
| } |
| |
| // RFC 3388 |
| // mid-attribute = "a=mid:" identification-tag |
| // identification-tag = token |
| // Use the content name as the mid identification-tag. |
| InitAttrLine(kAttributeMid, &os); |
| os << kSdpDelimiterColon << content_info->name; |
| AddLine(os.str(), message); |
| |
| if (cricket::IsDtlsSctp(media_desc->protocol())) { |
| const cricket::SctpDataContentDescription* data_desc = |
| media_desc->as_sctp(); |
| BuildSctpContentAttributes(message, data_desc); |
| } else if (cricket::IsRtpProtocol(media_desc->protocol())) { |
| BuildRtpContentAttributes(media_desc, media_type, msid_signaling, message); |
| } |
| } |
| |
| void BuildRtpContentAttributes(const MediaContentDescription* media_desc, |
| const cricket::MediaType media_type, |
| int msid_signaling, |
| std::string* message) { |
| SimulcastSdpSerializer serializer; |
| rtc::StringBuilder os; |
| // RFC 8285 |
| // a=extmap-allow-mixed |
| // The attribute MUST be either on session level or media level. We support |
| // responding on both levels, however, we don't respond on media level if it's |
| // set on session level. |
| if (media_desc->extmap_allow_mixed_enum() == |
| MediaContentDescription::kMedia) { |
| InitAttrLine(kAttributeExtmapAllowMixed, &os); |
| AddLine(os.str(), message); |
| } |
| BuildRtpHeaderExtensions(media_desc->rtp_header_extensions(), message); |
| |
| // RFC 3264 |
| // a=sendrecv || a=sendonly || a=sendrecv || a=inactive |
| switch (media_desc->direction()) { |
| // Special case that for sdp purposes should be treated same as inactive. |
| case RtpTransceiverDirection::kStopped: |
| case RtpTransceiverDirection::kInactive: |
| InitAttrLine(kAttributeInactive, &os); |
| break; |
| case RtpTransceiverDirection::kSendOnly: |
| InitAttrLine(kAttributeSendOnly, &os); |
| break; |
| case RtpTransceiverDirection::kRecvOnly: |
| InitAttrLine(kAttributeRecvOnly, &os); |
| break; |
| case RtpTransceiverDirection::kSendRecv: |
| InitAttrLine(kAttributeSendRecv, &os); |
| break; |
| default: |
| RTC_DCHECK_NOTREACHED(); |
| InitAttrLine(kAttributeSendRecv, &os); |
| break; |
| } |
| AddLine(os.str(), message); |
| |
| // Specified in https://datatracker.ietf.org/doc/draft-ietf-mmusic-msid/16/ |
| // a=msid:<msid-id> <msid-appdata> |
| // The msid-id is a 1*64 token char representing the media stream id, and the |
| // msid-appdata is a 1*64 token char representing the track id. There is a |
| // line for every media stream, with a special msid-id value of "-" |
| // representing no streams. The value of "msid-appdata" MUST be identical for |
| // all lines. |
| if (msid_signaling & cricket::kMsidSignalingMediaSection) { |
| const StreamParamsVec& streams = media_desc->streams(); |
| if (streams.size() == 1u) { |
| const StreamParams& track = streams[0]; |
| std::vector<std::string> stream_ids = track.stream_ids(); |
| if (stream_ids.empty()) { |
| stream_ids.push_back(kNoStreamMsid); |
| } |
| for (const std::string& stream_id : stream_ids) { |
| InitAttrLine(kAttributeMsid, &os); |
| os << kSdpDelimiterColon << stream_id << kSdpDelimiterSpace << track.id; |
| AddLine(os.str(), message); |
| } |
| } else if (streams.size() > 1u) { |
| RTC_LOG(LS_WARNING) |
| << "Trying to serialize Unified Plan SDP with more than " |
| "one track in a media section. Omitting 'a=msid'."; |
| } |
| } |
| |
| // RFC 5761 |
| // a=rtcp-mux |
| if (media_desc->rtcp_mux()) { |
| InitAttrLine(kAttributeRtcpMux, &os); |
| AddLine(os.str(), message); |
| } |
| |
| // RFC 5506 |
| // a=rtcp-rsize |
| if (media_desc->rtcp_reduced_size()) { |
| InitAttrLine(kAttributeRtcpReducedSize, &os); |
| AddLine(os.str(), message); |
| } |
| |
| if (media_desc->conference_mode()) { |
| InitAttrLine(kAttributeXGoogleFlag, &os); |
| os << kSdpDelimiterColon << kValueConference; |
| AddLine(os.str(), message); |
| } |
| |
| if (media_desc->remote_estimate()) { |
| InitAttrLine(kAttributeRtcpRemoteEstimate, &os); |
| AddLine(os.str(), message); |
| } |
| |
| // RFC 4568 |
| // a=crypto:<tag> <crypto-suite> <key-params> [<session-params>] |
| for (const CryptoParams& crypto_params : media_desc->cryptos()) { |
| InitAttrLine(kAttributeCrypto, &os); |
| os << kSdpDelimiterColon << crypto_params.tag << " " |
| << crypto_params.crypto_suite << " " << crypto_params.key_params; |
| if (!crypto_params.session_params.empty()) { |
| os << " " << crypto_params.session_params; |
| } |
| AddLine(os.str(), message); |
| } |
| |
| // RFC 4566 |
| // a=rtpmap:<payload type> <encoding name>/<clock rate> |
| // [/<encodingparameters>] |
| BuildRtpmap(media_desc, media_type, message); |
| |
| for (const StreamParams& track : media_desc->streams()) { |
| // Build the ssrc-group lines. |
| for (const SsrcGroup& ssrc_group : track.ssrc_groups) { |
| // RFC 5576 |
| // a=ssrc-group:<semantics> <ssrc-id> ... |
| if (ssrc_group.ssrcs.empty()) { |
| continue; |
| } |
| InitAttrLine(kAttributeSsrcGroup, &os); |
| os << kSdpDelimiterColon << ssrc_group.semantics; |
| for (uint32_t ssrc : ssrc_group.ssrcs) { |
| os << kSdpDelimiterSpace << rtc::ToString(ssrc); |
| } |
| AddLine(os.str(), message); |
| } |
| // Build the ssrc lines for each ssrc. |
| for (uint32_t ssrc : track.ssrcs) { |
| // RFC 5576 |
| // a=ssrc:<ssrc-id> cname:<value> |
| AddSsrcLine(ssrc, kSsrcAttributeCname, track.cname, message); |
| |
| if (msid_signaling & cricket::kMsidSignalingSsrcAttribute) { |
| // draft-alvestrand-mmusic-msid-00 |
| // a=ssrc:<ssrc-id> msid:identifier [appdata] |
| // The appdata consists of the "id" attribute of a MediaStreamTrack, |
| // which corresponds to the "id" attribute of StreamParams. |
| // Since a=ssrc msid signaling is used in Plan B SDP semantics, and |
| // multiple stream ids are not supported for Plan B, we are only adding |
| // a line for the first media stream id here. |
| const std::string& track_stream_id = track.first_stream_id(); |
| // We use a special msid-id value of "-" to represent no streams, |
| // for Unified Plan compatibility. Plan B will always have a |
| // track_stream_id. |
| const std::string& stream_id = |
| track_stream_id.empty() ? kNoStreamMsid : track_stream_id; |
| InitAttrLine(kAttributeSsrc, &os); |
| os << kSdpDelimiterColon << ssrc << kSdpDelimiterSpace |
| << kSsrcAttributeMsid << kSdpDelimiterColon << stream_id |
| << kSdpDelimiterSpace << track.id; |
| AddLine(os.str(), message); |
| } |
| } |
| |
| // Build the rid lines for each layer of the track |
| for (const RidDescription& rid_description : track.rids()) { |
| InitAttrLine(kAttributeRid, &os); |
| os << kSdpDelimiterColon |
| << serializer.SerializeRidDescription(rid_description); |
| AddLine(os.str(), message); |
| } |
| } |
| |
| for (const RidDescription& rid_description : media_desc->receive_rids()) { |
| InitAttrLine(kAttributeRid, &os); |
| os << kSdpDelimiterColon |
| << serializer.SerializeRidDescription(rid_description); |
| AddLine(os.str(), message); |
| } |
| |
| // Simulcast (a=simulcast) |
| // https://tools.ietf.org/html/draft-ietf-mmusic-sdp-simulcast-13#section-5.1 |
| if (media_desc->HasSimulcast()) { |
| const auto& simulcast = media_desc->simulcast_description(); |
| InitAttrLine(kAttributeSimulcast, &os); |
| os << kSdpDelimiterColon |
| << serializer.SerializeSimulcastDescription(simulcast); |
| AddLine(os.str(), message); |
| } |
| } |
| |
| void BuildRtpHeaderExtensions(const RtpHeaderExtensions& extensions, |
| std::string* message) { |
| rtc::StringBuilder os; |
| |
| // RFC 8285 |
| // a=extmap:<value>["/"<direction>] <URI> <extensionattributes> |
| // The definitions MUST be either all session level or all media level. This |
| // implementation uses all media level. |
| for (const RtpExtension& extension : extensions) { |
| InitAttrLine(kAttributeExtmap, &os); |
| os << kSdpDelimiterColon << extension.id; |
| if (extension.encrypt) { |
| os << kSdpDelimiterSpace << RtpExtension::kEncryptHeaderExtensionsUri; |
| } |
| os << kSdpDelimiterSpace << extension.uri; |
| AddLine(os.str(), message); |
| } |
| } |
| |
| void WriteFmtpHeader(int payload_type, rtc::StringBuilder* os) { |
| // fmtp header: a=fmtp:`payload_type` <parameters> |
| // Add a=fmtp |
| InitAttrLine(kAttributeFmtp, os); |
| // Add :`payload_type` |
| *os << kSdpDelimiterColon << payload_type; |
| } |
| |
| void WritePacketizationHeader(int payload_type, rtc::StringBuilder* os) { |
| // packetization header: a=packetization:`payload_type` <packetization_format> |
| // Add a=packetization |
| InitAttrLine(kAttributePacketization, os); |
| // Add :`payload_type` |
| *os << kSdpDelimiterColon << payload_type; |
| } |
| |
| void WriteRtcpFbHeader(int payload_type, rtc::StringBuilder* os) { |
| // rtcp-fb header: a=rtcp-fb:`payload_type` |
| // <parameters>/<ccm <ccm_parameters>> |
| // Add a=rtcp-fb |
| InitAttrLine(kAttributeRtcpFb, os); |
| // Add : |
| *os << kSdpDelimiterColon; |
| if (payload_type == kWildcardPayloadType) { |
| *os << "*"; |
| } else { |
| *os << payload_type; |
| } |
| } |
| |
| void WriteFmtpParameter(absl::string_view parameter_name, |
| absl::string_view parameter_value, |
| rtc::StringBuilder* os) { |
| if (parameter_name.empty()) { |
| // RFC 2198 and RFC 4733 don't use key-value pairs. |
| *os << parameter_value; |
| } else { |
| // fmtp parameters: `parameter_name`=`parameter_value` |
| *os << parameter_name << kSdpDelimiterEqual << parameter_value; |
| } |
| } |
| |
| bool IsFmtpParam(absl::string_view name) { |
| // RFC 4855, section 3 specifies the mapping of media format parameters to SDP |
| // parameters. Only ptime, maxptime, channels and rate are placed outside of |
| // the fmtp line. In WebRTC, channels and rate are already handled separately |
| // and thus not included in the CodecParameterMap. |
| return name != kCodecParamPTime && name != kCodecParamMaxPTime; |
| } |
| |
| bool WriteFmtpParameters(const cricket::CodecParameterMap& parameters, |
| rtc::StringBuilder* os) { |
| bool empty = true; |
| const char* delimiter = ""; // No delimiter before first parameter. |
| for (const auto& entry : parameters) { |
| const std::string& key = entry.first; |
| const std::string& value = entry.second; |
| |
| if (IsFmtpParam(key)) { |
| *os << delimiter; |
| // A semicolon before each subsequent parameter. |
| delimiter = kSdpDelimiterSemicolon; |
| WriteFmtpParameter(key, value, os); |
| empty = false; |
| } |
| } |
| |
| return !empty; |
| } |
| |
| void AddFmtpLine(const cricket::Codec& codec, std::string* message) { |
| rtc::StringBuilder os; |
| WriteFmtpHeader(codec.id, &os); |
| os << kSdpDelimiterSpace; |
| // Create FMTP line and check that it's nonempty. |
| if (WriteFmtpParameters(codec.params, &os)) { |
| AddLine(os.str(), message); |
| } |
| return; |
| } |
| |
| void AddPacketizationLine(const cricket::Codec& codec, std::string* message) { |
| if (!codec.packetization) { |
| return; |
| } |
| rtc::StringBuilder os; |
| WritePacketizationHeader(codec.id, &os); |
| os << " " << *codec.packetization; |
| AddLine(os.str(), message); |
| } |
| |
| void AddRtcpFbLines(const cricket::Codec& codec, std::string* message) { |
| for (const cricket::FeedbackParam& param : codec.feedback_params.params()) { |
| rtc::StringBuilder os; |
| WriteRtcpFbHeader(codec.id, &os); |
| os << " " << param.id(); |
| if (!param.param().empty()) { |
| os << " " << param.param(); |
| } |
| AddLine(os.str(), message); |
| } |
| } |
| |
| bool GetMinValue(const std::vector<int>& values, int* value) { |
| if (values.empty()) { |
| return false; |
| } |
| auto it = absl::c_min_element(values); |
| *value = *it; |
| return true; |
| } |
| |
| bool GetParameter(const std::string& name, |
| const cricket::CodecParameterMap& params, |
| int* value) { |
| std::map<std::string, std::string>::const_iterator found = params.find(name); |
| if (found == params.end()) { |
| return false; |
| } |
| if (!rtc::FromString(found->second, value)) { |
| return false; |
| } |
| return true; |
| } |
| |
| void BuildRtpmap(const MediaContentDescription* media_desc, |
| const cricket::MediaType media_type, |
| std::string* message) { |
| RTC_DCHECK(message != NULL); |
| RTC_DCHECK(media_desc != NULL); |
| rtc::StringBuilder os; |
| if (media_type == cricket::MEDIA_TYPE_VIDEO) { |
| for (const cricket::Codec& codec : media_desc->codecs()) { |
| // RFC 4566 |
| // a=rtpmap:<payload type> <encoding name>/<clock rate> |
| // [/<encodingparameters>] |
| if (codec.id != kWildcardPayloadType) { |
| InitAttrLine(kAttributeRtpmap, &os); |
| os << kSdpDelimiterColon << codec.id << " " << codec.name << "/" |
| << cricket::kVideoCodecClockrate; |
| AddLine(os.str(), message); |
| } |
| AddPacketizationLine(codec, message); |
| AddRtcpFbLines(codec, message); |
| AddFmtpLine(codec, message); |
| } |
| } else if (media_type == cricket::MEDIA_TYPE_AUDIO) { |
| std::vector<int> ptimes; |
| std::vector<int> maxptimes; |
| int max_minptime = 0; |
| for (const cricket::Codec& codec : media_desc->codecs()) { |
| RTC_DCHECK(!codec.name.empty()); |
| // RFC 4566 |
| // a=rtpmap:<payload type> <encoding name>/<clock rate> |
| // [/<encodingparameters>] |
| InitAttrLine(kAttributeRtpmap, &os); |
| os << kSdpDelimiterColon << codec.id << " "; |
| os << codec.name << "/" << codec.clockrate; |
| if (codec.channels != 1) { |
| os << "/" << codec.channels; |
| } |
| AddLine(os.str(), message); |
| AddRtcpFbLines(codec, message); |
| AddFmtpLine(codec, message); |
| int minptime = 0; |
| if (GetParameter(kCodecParamMinPTime, codec.params, &minptime)) { |
| max_minptime = std::max(minptime, max_minptime); |
| } |
| int ptime; |
| if (GetParameter(kCodecParamPTime, codec.params, &ptime)) { |
| ptimes.push_back(ptime); |
| } |
| int maxptime; |
| if (GetParameter(kCodecParamMaxPTime, codec.params, &maxptime)) { |
| maxptimes.push_back(maxptime); |
| } |
| } |
| // Populate the maxptime attribute with the smallest maxptime of all codecs |
| // under the same m-line. |
| int min_maxptime = INT_MAX; |
| if (GetMinValue(maxptimes, &min_maxptime)) { |
| AddAttributeLine(kCodecParamMaxPTime, min_maxptime, message); |
| } |
| RTC_DCHECK_GE(min_maxptime, max_minptime); |
| // Populate the ptime attribute with the smallest ptime or the largest |
| // minptime, whichever is the largest, for all codecs under the same m-line. |
| int ptime = INT_MAX; |
| if (GetMinValue(ptimes, &ptime)) { |
| ptime = std::min(ptime, min_maxptime); |
| ptime = std::max(ptime, max_minptime); |
| AddAttributeLine(kCodecParamPTime, ptime, message); |
| } |
| } |
| } |
| |
| void BuildCandidate(const std::vector<Candidate>& candidates, |
| bool include_ufrag, |
| std::string* message) { |
| rtc::StringBuilder os; |
| |
| for (const Candidate& candidate : candidates) { |
| // RFC 5245 |
| // a=candidate:<foundation> <component-id> <transport> <priority> |
| // <connection-address> <port> typ <candidate-types> |
| // [raddr <connection-address>] [rport <port>] |
| // *(SP extension-att-name SP extension-att-value) |
| std::string type; |
| // Map the cricket candidate type to "host" / "srflx" / "prflx" / "relay" |
| if (candidate.type() == cricket::LOCAL_PORT_TYPE) { |
| type = kCandidateHost; |
| } else if (candidate.type() == cricket::STUN_PORT_TYPE) { |
| type = kCandidateSrflx; |
| } else if (candidate.type() == cricket::RELAY_PORT_TYPE) { |
| type = kCandidateRelay; |
| } else if (candidate.type() == cricket::PRFLX_PORT_TYPE) { |
| type = kCandidatePrflx; |
| // Peer reflexive candidate may be signaled for being removed. |
| } else { |
| RTC_DCHECK_NOTREACHED(); |
| // Never write out candidates if we don't know the type. |
| continue; |
| } |
| |
| InitAttrLine(kAttributeCandidate, &os); |
| os << kSdpDelimiterColon << candidate.foundation() << " " |
| << candidate.component() << " " << candidate.protocol() << " " |
| << candidate.priority() << " " |
| << (candidate.address().ipaddr().IsNil() |
| ? candidate.address().hostname() |
| : candidate.address().ipaddr().ToString()) |
| << " " << candidate.address().PortAsString() << " " |
| << kAttributeCandidateTyp << " " << type << " "; |
| |
| // Related address |
| if (!candidate.related_address().IsNil()) { |
| os << kAttributeCandidateRaddr << " " |
| << candidate.related_address().ipaddr().ToString() << " " |
| << kAttributeCandidateRport << " " |
| << candidate.related_address().PortAsString() << " "; |
| } |
| |
| // Note that we allow the tcptype to be missing, for backwards |
| // compatibility; the implementation treats this as a passive candidate. |
| // TODO(bugs.webrtc.org/11466): Treat a missing tcptype as an error? |
| if (candidate.protocol() == cricket::TCP_PROTOCOL_NAME && |
| !candidate.tcptype().empty()) { |
| os << kTcpCandidateType << " " << candidate.tcptype() << " "; |
| } |
| |
| // Extensions |
| os << kAttributeCandidateGeneration << " " << candidate.generation(); |
| if (include_ufrag && !candidate.username().empty()) { |
| os << " " << kAttributeCandidateUfrag << " " << candidate.username(); |
| } |
| if (candidate.network_id() > 0) { |
| os << " " << kAttributeCandidateNetworkId << " " |
| << candidate.network_id(); |
| } |
| if (candidate.network_cost() > 0) { |
| os << " " << kAttributeCandidateNetworkCost << " " |
| << candidate.network_cost(); |
| } |
| |
| AddLine(os.str(), message); |
| } |
| } |
| |
| void BuildIceOptions(const std::vector<std::string>& transport_options, |
| std::string* message) { |
| if (!transport_options.empty()) { |
| rtc::StringBuilder os; |
| InitAttrLine(kAttributeIceOption, &os); |
| os << kSdpDelimiterColon << transport_options[0]; |
| for (size_t i = 1; i < transport_options.size(); ++i) { |
| os << kSdpDelimiterSpace << transport_options[i]; |
| } |
| AddLine(os.str(), message); |
| } |
| } |
| |
| bool ParseConnectionData(absl::string_view line, |
| rtc::SocketAddress* addr, |
| SdpParseError* error) { |
| // Parse the line from left to right. |
| std::string token; |
| std::string rightpart; |
| // RFC 4566 |
| // c=<nettype> <addrtype> <connection-address> |
| // Skip the "c=" |
| if (!rtc::tokenize_first(line, kSdpDelimiterEqualChar, &token, &rightpart)) { |
| return ParseFailed(line, "Failed to parse the network type.", error); |
| } |
| |
| // Extract and verify the <nettype> |
| if (!rtc::tokenize_first(rightpart, kSdpDelimiterSpaceChar, &token, |
| &rightpart) || |
| token != kConnectionNettype) { |
| return ParseFailed(line, |
| "Failed to parse the connection data. The network type " |
| "is not currently supported.", |
| error); |
| } |
| |
| // Extract the "<addrtype>" and "<connection-address>". |
| if (!rtc::tokenize_first(rightpart, kSdpDelimiterSpaceChar, &token, |
| &rightpart)) { |
| return ParseFailed(line, "Failed to parse the address type.", error); |
| } |
| |
| // The rightpart part should be the IP address without the slash which is used |
| // for multicast. |
| if (rightpart.find('/') != std::string::npos) { |
| return ParseFailed(line, |
| "Failed to parse the connection data. Multicast is not " |
| "currently supported.", |
| error); |
| } |
| addr->SetIP(rightpart); |
| |
| // Verify that the addrtype matches the type of the parsed address. |
| if ((addr->family() == AF_INET && token != "IP4") || |
| (addr->family() == AF_INET6 && token != "IP6")) { |
| addr->Clear(); |
| return ParseFailed( |
| line, |
| "Failed to parse the connection data. The address type is mismatching.", |
| error); |
| } |
| return true; |
| } |
| |
| bool ParseSessionDescription(absl::string_view message, |
| size_t* pos, |
| std::string* session_id, |
| std::string* session_version, |
| TransportDescription* session_td, |
| RtpHeaderExtensions* session_extmaps, |
| rtc::SocketAddress* connection_addr, |
| cricket::SessionDescription* desc, |
| SdpParseError* error) { |
| absl::optional<absl::string_view> line; |
| |
| desc->set_msid_supported(false); |
| desc->set_extmap_allow_mixed(false); |
| // RFC 4566 |
| // v= (protocol version) |
| line = GetLineWithType(message, pos, kLineTypeVersion); |
| if (!line) { |
| return ParseFailedExpectLine(message, *pos, kLineTypeVersion, std::string(), |
| error); |
| } |
| // RFC 4566 |
| // o=<username> <sess-id> <sess-version> <nettype> <addrtype> |
| // <unicast-address> |
| line = GetLineWithType(message, pos, kLineTypeOrigin); |
| if (!line) { |
| return ParseFailedExpectLine(message, *pos, kLineTypeOrigin, std::string(), |
| error); |
| } |
| std::vector<absl::string_view> fields = |
| rtc::split(line->substr(kLinePrefixLength), kSdpDelimiterSpaceChar); |
| const size_t expected_fields = 6; |
| if (fields.size() != expected_fields) { |
| return ParseFailedExpectFieldNum(*line, expected_fields, error); |
| } |
| *session_id = std::string(fields[1]); |
| *session_version = std::string(fields[2]); |
| |
| // RFC 4566 |
| // s= (session name) |
| line = GetLineWithType(message, pos, kLineTypeSessionName); |
| if (!line) { |
| return ParseFailedExpectLine(message, *pos, kLineTypeSessionName, |
| std::string(), error); |
| } |
| |
| // optional lines |
| // Those are the optional lines, so shouldn't return false if not present. |
| // RFC 4566 |
| // i=* (session information) |
| GetLineWithType(message, pos, kLineTypeSessionInfo); |
| |
| // RFC 4566 |
| // u=* (URI of description) |
| GetLineWithType(message, pos, kLineTypeSessionUri); |
| |
| // RFC 4566 |
| // e=* (email address) |
| GetLineWithType(message, pos, kLineTypeSessionEmail); |
| |
| // RFC 4566 |
| // p=* (phone number) |
| GetLineWithType(message, pos, kLineTypeSessionPhone); |
| |
| // RFC 4566 |
| // c=* (connection information -- not required if included in |
| // all media) |
| if (absl::optional<absl::string_view> cline = |
| GetLineWithType(message, pos, kLineTypeConnection); |
| cline.has_value()) { |
| if (!ParseConnectionData(*cline, connection_addr, error)) { |
| return false; |
| } |
| } |
| |
| // RFC 4566 |
| // b=* (zero or more bandwidth information lines) |
| while (GetLineWithType(message, pos, kLineTypeSessionBandwidth).has_value()) { |
| // By pass zero or more b lines. |
| } |
| |
| // RFC 4566 |
| // One or more time descriptions ("t=" and "r=" lines; see below) |
| // t= (time the session is active) |
| // r=* (zero or more repeat times) |
| // Ensure there's at least one time description |
| if (!GetLineWithType(message, pos, kLineTypeTiming).has_value()) { |
| return ParseFailedExpectLine(message, *pos, kLineTypeTiming, std::string(), |
| error); |
| } |
| |
| while (GetLineWithType(message, pos, kLineTypeRepeatTimes).has_value()) { |
| // By pass zero or more r lines. |
| } |
| |
| // Go through the rest of the time descriptions |
| while (GetLineWithType(message, pos, kLineTypeTiming).has_value()) { |
| while (GetLineWithType(message, pos, kLineTypeRepeatTimes).has_value()) { |
| // By pass zero or more r lines. |
| } |
| } |
| |
| // RFC 4566 |
| // z=* (time zone adjustments) |
| GetLineWithType(message, pos, kLineTypeTimeZone); |
| |
| // RFC 4566 |
| // k=* (encryption key) |
| GetLineWithType(message, pos, kLineTypeEncryptionKey); |
| |
| // RFC 4566 |
| // a=* (zero or more session attribute lines) |
| while (absl::optional<absl::string_view> aline = |
| GetLineWithType(message, pos, kLineTypeAttributes)) { |
| if (HasAttribute(*aline, kAttributeGroup)) { |
| if (!ParseGroupAttribute(*aline, desc, error)) { |
| return false; |
| } |
| } else if (HasAttribute(*aline, kAttributeIceUfrag)) { |
| if (!GetValue(*aline, kAttributeIceUfrag, &(session_td->ice_ufrag), |
| error)) { |
| return false; |
| } |
| } else if (HasAttribute(*aline, kAttributeIcePwd)) { |
| if (!GetValue(*aline, kAttributeIcePwd, &(session_td->ice_pwd), error)) { |
| return false; |
| } |
| } else if (HasAttribute(*aline, kAttributeIceLite)) { |
| session_td->ice_mode = cricket::ICEMODE_LITE; |
| } else if (HasAttribute(*aline, kAttributeIceOption)) { |
| if (!ParseIceOptions(*aline, &(session_td->transport_options), error)) { |
| return false; |
| } |
| } else if (HasAttribute(*aline, kAttributeFingerprint)) { |
| if (session_td->identity_fingerprint.get()) { |
| return ParseFailed( |
| *aline, |
| "Can't have multiple fingerprint attributes at the same level.", |
| error); |
| } |
| std::unique_ptr<rtc::SSLFingerprint> fingerprint; |
| if (!ParseFingerprintAttribute(*aline, &fingerprint, error)) { |
| return false; |
| } |
| session_td->identity_fingerprint = std::move(fingerprint); |
| } else if (HasAttribute(*aline, kAttributeSetup)) { |
| if (!ParseDtlsSetup(*aline, &(session_td->connection_role), error)) { |
| return false; |
| } |
| } else if (HasAttribute(*aline, kAttributeMsidSemantics)) { |
| std::string semantics; |
| if (!GetValue(*aline, kAttributeMsidSemantics, &semantics, error)) { |
| return false; |
| } |
| desc->set_msid_supported( |
| CaseInsensitiveFind(semantics, kMediaStreamSemantic)); |
| } else if (HasAttribute(*aline, kAttributeExtmapAllowMixed)) { |
| desc->set_extmap_allow_mixed(true); |
| } else if (HasAttribute(*aline, kAttributeExtmap)) { |
| RtpExtension extmap; |
| if (!ParseExtmap(*aline, &extmap, error)) { |
| return false; |
| } |
| session_extmaps->push_back(extmap); |
| } |
| } |
| return true; |
| } |
| |
| bool ParseGroupAttribute(absl::string_view line, |
| cricket::SessionDescription* desc, |
| SdpParseError* error) { |
| RTC_DCHECK(desc != NULL); |
| |
| // RFC 5888 and draft-holmberg-mmusic-sdp-bundle-negotiation-00 |
| // a=group:BUNDLE video voice |
| std::vector<absl::string_view> fields = |
| rtc::split(line.substr(kLinePrefixLength), kSdpDelimiterSpaceChar); |
| std::string semantics; |
| if (!GetValue(fields[0], kAttributeGroup, &semantics, error)) { |
| return false; |
| } |
| cricket::ContentGroup group(semantics); |
| for (size_t i = 1; i < fields.size(); ++i) { |
| group.AddContentName(fields[i]); |
| } |
| desc->AddGroup(group); |
| return true; |
| } |
| |
| static bool ParseFingerprintAttribute( |
| absl::string_view line, |
| std::unique_ptr<rtc::SSLFingerprint>* fingerprint, |
| SdpParseError* error) { |
| std::vector<absl::string_view> fields = |
| rtc::split(line.substr(kLinePrefixLength), kSdpDelimiterSpaceChar); |
| const size_t expected_fields = 2; |
| if (fields.size() != expected_fields) { |
| return ParseFailedExpectFieldNum(line, expected_fields, error); |
| } |
| |
| // The first field here is "fingerprint:<hash>. |
| std::string algorithm; |
| if (!GetValue(fields[0], kAttributeFingerprint, &algorithm, error)) { |
| return false; |
| } |
| |
| // Downcase the algorithm. Note that we don't need to downcase the |
| // fingerprint because hex_decode can handle upper-case. |
| absl::c_transform(algorithm, algorithm.begin(), ::tolower); |
| |
| // The second field is the digest value. De-hexify it. |
| *fingerprint = |
| rtc::SSLFingerprint::CreateUniqueFromRfc4572(algorithm, fields[1]); |
| if (!*fingerprint) { |
| return ParseFailed(line, "Failed to create fingerprint from the digest.", |
| error); |
| } |
| |
| return true; |
| } |
| |
| static bool ParseDtlsSetup(absl::string_view line, |
| cricket::ConnectionRole* role_ptr, |
| SdpParseError* error) { |
| // setup-attr = "a=setup:" role |
| // role = "active" / "passive" / "actpass" / "holdconn" |
| std::vector<absl::string_view> fields = |
| rtc::split(line.substr(kLinePrefixLength), kSdpDelimiterColonChar); |
| const size_t expected_fields = 2; |
| if (fields.size() != expected_fields) { |
| return ParseFailedExpectFieldNum(line, expected_fields, error); |
| } |
| if (absl::optional<cricket::ConnectionRole> role = |
| cricket::StringToConnectionRole(fields[1]); |
| role.has_value()) { |
| *role_ptr = *role; |
| return true; |
| } |
| return ParseFailed(line, "Invalid attribute value.", error); |
| } |
| |
| static bool ParseMsidAttribute(absl::string_view line, |
| std::vector<std::string>* stream_ids, |
| std::string* track_id, |
| SdpParseError* error) { |
| // https://datatracker.ietf.org/doc/rfc8830/ |
| // a=msid:<msid-value> |
| // msid-value = msid-id [ SP msid-appdata ] |
| // msid-id = 1*64token-char ; see RFC 4566 |
| // msid-appdata = 1*64token-char ; see RFC 4566 |
| // Note that JSEP stipulates not sending msid-appdata so |
| // a=msid:<stream id> <track id> |
| // is supported for backward compability reasons only. |
| std::vector<std::string> fields; |
| size_t num_fields = rtc::tokenize(line.substr(kLinePrefixLength), |
| kSdpDelimiterSpaceChar, &fields); |
| if (num_fields < 1 || num_fields > 2) { |
| return ParseFailed(line, "Expected a stream ID and optionally a track ID", |
| error); |
| } |
| if (num_fields == 1) { |
| if (line.back() == kSdpDelimiterSpaceChar) { |
| return ParseFailed(line, "Missing track ID in msid attribute.", error); |
| } |
| if (!track_id->empty()) { |
| fields.push_back(*track_id); |
| } else { |
| // Ending with an empty string track will cause a random track id |
| // to be generated later in the process. |
| fields.push_back(""); |
| } |
| } |
| RTC_DCHECK_EQ(fields.size(), 2); |
| |
| // All track ids should be the same within an m section in a Unified Plan SDP. |
| if (!track_id->empty() && track_id->compare(fields[1]) != 0) { |
| return ParseFailed( |
| line, "Two different track IDs in msid attribute in one m= section", |
| error); |
| } |
| *track_id = fields[1]; |
| |
| // msid:<msid-id> |
| std::string new_stream_id; |
| if (!GetValue(fields[0], kAttributeMsid, &new_stream_id, error)) { |
| return false; |
| } |
| if (new_stream_id.empty()) { |
| return ParseFailed(line, "Missing stream ID in msid attribute.", error); |
| } |
| // The special value "-" indicates "no MediaStream". |
| if (new_stream_id.compare(kNoStreamMsid) != 0 && |
| !absl::c_any_of(*stream_ids, |
| [&new_stream_id](const std::string& existing_stream_id) { |
| return new_stream_id == existing_stream_id; |
| })) { |
| stream_ids->push_back(new_stream_id); |
| } |
| return true; |
| } |
| |
| static void RemoveInvalidRidDescriptions(const std::vector<int>& payload_types, |
| std::vector<RidDescription>* rids) { |
| RTC_DCHECK(rids); |
| std::set<std::string> to_remove; |
| std::set<std::string> unique_rids; |
| |
| // Check the rids to see which ones should be removed. |
| for (RidDescription& rid : *rids) { |
| // In the case of a duplicate, the entire "a=rid" line, and all "a=rid" |
| // lines with rid-ids that duplicate this line, are discarded and MUST NOT |
| // be included in the SDP Answer. |
| auto pair = unique_rids.insert(rid.rid); |
| // Insert will "fail" if element already exists. |
| if (!pair.second) { |
| to_remove.insert(rid.rid); |
| continue; |
| } |
| |
| // If the "a=rid" line contains a "pt=", the list of payload types |
| // is verified against the list of valid payload types for the media |
| // section (that is, those listed on the "m=" line). Any PT missing |
| // from the "m=" line is discarded from the set of values in the |
| // "pt=". If no values are left in the "pt=" parameter after this |
| // processing, then the "a=rid" line is discarded. |
| if (rid.payload_types.empty()) { |
| // If formats were not specified, rid should not be removed. |
| continue; |
| } |
| |
| // Note: Spec does not mention how to handle duplicate formats. |
| // Media section does not handle duplicates either. |
| std::set<int> removed_formats; |
| for (int payload_type : rid.payload_types) { |
| if (!absl::c_linear_search(payload_types, payload_type)) { |
| removed_formats.insert(payload_type); |
| } |
| } |
| |
| rid.payload_types.erase( |
| std::remove_if(rid.payload_types.begin(), rid.payload_types.end(), |
| [&removed_formats](int format) { |
| return removed_formats.count(format) > 0; |
| }), |
| rid.payload_types.end()); |
| |
| // If all formats were removed then remove the rid alogether. |
| if (rid.payload_types.empty()) { |
| to_remove.insert(rid.rid); |
| } |
| } |
| |
| // Remove every rid description that appears in the to_remove list. |
| if (!to_remove.empty()) { |
| rids->erase(std::remove_if(rids->begin(), rids->end(), |
| [&to_remove](const RidDescription& rid) { |
| return to_remove.count(rid.rid) > 0; |
| }), |
| rids->end()); |
| } |
| } |
| |
| // Create a new list (because SimulcastLayerList is immutable) without any |
| // layers that have a rid in the to_remove list. |
| // If a group of alternatives is empty after removing layers, the group should |
| // be removed altogether. |
| static SimulcastLayerList RemoveRidsFromSimulcastLayerList( |
| const std::set<std::string>& to_remove, |
| const SimulcastLayerList& layers) { |
| SimulcastLayerList result; |
| for (const std::vector<SimulcastLayer>& vector : layers) { |
| std::vector<SimulcastLayer> new_layers; |
| for (const SimulcastLayer& layer : vector) { |
| if (to_remove.find(layer.rid) == to_remove.end()) { |
| new_layers.push_back(layer); |
| } |
| } |
| // If all layers were removed, do not add an entry. |
| if (!new_layers.empty()) { |
| result.AddLayerWithAlternatives(new_layers); |
| } |
| } |
| |
| return result; |
| } |
| |
| // Will remove Simulcast Layers if: |
| // 1. They appear in both send and receive directions. |
| // 2. They do not appear in the list of `valid_rids`. |
| static void RemoveInvalidRidsFromSimulcast( |
| const std::vector<RidDescription>& valid_rids, |
| SimulcastDescription* simulcast) { |
| RTC_DCHECK(simulcast); |
| std::set<std::string> to_remove; |
| std::vector<SimulcastLayer> all_send_layers = |
| simulcast->send_layers().GetAllLayers(); |
| std::vector<SimulcastLayer> all_receive_layers = |
| simulcast->receive_layers().GetAllLayers(); |
| |
| // If a rid appears in both send and receive directions, remove it from both. |
| // This algorithm runs in O(n^2) time, but for small n (as is the case with |
| // simulcast layers) it should still perform well. |
| for (const SimulcastLayer& send_layer : all_send_layers) { |
| if (absl::c_any_of(all_receive_layers, |
| [&send_layer](const SimulcastLayer& layer) { |
| return layer.rid == send_layer.rid; |
| })) { |
| to_remove.insert(send_layer.rid); |
| } |
| } |
| |
| // Add any rid that is not in the valid list to the remove set. |
| for (const SimulcastLayer& send_layer : all_send_layers) { |
| if (absl::c_none_of(valid_rids, [&send_layer](const RidDescription& rid) { |
| return send_layer.rid == rid.rid && |
| rid.direction == cricket::RidDirection::kSend; |
| })) { |
| to_remove.insert(send_layer.rid); |
| } |
| } |
| |
| // Add any rid that is not in the valid list to the remove set. |
| for (const SimulcastLayer& receive_layer : all_receive_layers) { |
| if (absl::c_none_of( |
| valid_rids, [&receive_layer](const RidDescription& rid) { |
| return receive_layer.rid == rid.rid && |
| rid.direction == cricket::RidDirection::kReceive; |
| })) { |
| to_remove.insert(receive_layer.rid); |
| } |
| } |
| |
| simulcast->send_layers() = |
| RemoveRidsFromSimulcastLayerList(to_remove, simulcast->send_layers()); |
| simulcast->receive_layers() = |
| RemoveRidsFromSimulcastLayerList(to_remove, simulcast->receive_layers()); |
| } |
| |
| // RFC 3551 |
| // PT encoding media type clock rate channels |
| // name (Hz) |
| // 0 PCMU A 8,000 1 |
| // 1 reserved A |
| // 2 reserved A |
| // 3 GSM A 8,000 1 |
| // 4 G723 A 8,000 1 |
| // 5 DVI4 A 8,000 1 |
| // 6 DVI4 A 16,000 1 |
| // 7 LPC A 8,000 1 |
| // 8 PCMA A 8,000 1 |
| // 9 G722 A 8,000 1 |
| // 10 L16 A 44,100 2 |
| // 11 L16 A 44,100 1 |
| // 12 QCELP A 8,000 1 |
| // 13 CN A 8,000 1 |
| // 14 MPA A 90,000 (see text) |
| // 15 G728 A 8,000 1 |
| // 16 DVI4 A 11,025 1 |
| // 17 DVI4 A 22,050 1 |
| // 18 G729 A 8,000 1 |
| struct StaticPayloadAudioCodec { |
| const char* name; |
| int clockrate; |
| size_t channels; |
| }; |
| static const StaticPayloadAudioCodec kStaticPayloadAudioCodecs[] = { |
| {"PCMU", 8000, 1}, {"reserved", 0, 0}, {"reserved", 0, 0}, |
| {"GSM", 8000, 1}, {"G723", 8000, 1}, {"DVI4", 8000, 1}, |
| {"DVI4", 16000, 1}, {"LPC", 8000, 1}, {"PCMA", 8000, 1}, |
| {"G722", 8000, 1}, {"L16", 44100, 2}, {"L16", 44100, 1}, |
| {"QCELP", 8000, 1}, {"CN", 8000, 1}, {"MPA", 90000, 1}, |
| {"G728", 8000, 1}, {"DVI4", 11025, 1}, {"DVI4", 22050, 1}, |
| {"G729", 8000, 1}, |
| }; |
| |
| void MaybeCreateStaticPayloadAudioCodecs(const std::vector<int>& fmts, |
| AudioContentDescription* media_desc) { |
| if (!media_desc) { |
| return; |
| } |
| RTC_DCHECK(media_desc->codecs().empty()); |
| for (int payload_type : fmts) { |
| if (!media_desc->HasCodec(payload_type) && payload_type >= 0 && |
| static_cast<uint32_t>(payload_type) < |
| arraysize(kStaticPayloadAudioCodecs)) { |
| std::string encoding_name = kStaticPayloadAudioCodecs[payload_type].name; |
| int clock_rate = kStaticPayloadAudioCodecs[payload_type].clockrate; |
| size_t channels = kStaticPayloadAudioCodecs[payload_type].channels; |
| media_desc->AddCodec(cricket::CreateAudioCodec( |
| payload_type, encoding_name, clock_rate, channels)); |
| } |
| } |
| } |
| |
| template <class C> |
| static std::unique_ptr<C> ParseContentDescription( |
| absl::string_view message, |
| const cricket::MediaType media_type, |
| int mline_index, |
| absl::string_view protocol, |
| const std::vector<int>& payload_types, |
| size_t* pos, |
| std::string* content_name, |
| bool* bundle_only, |
| int* msid_signaling, |
| TransportDescription* transport, |
| std::vector<std::unique_ptr<JsepIceCandidate>>* candidates, |
| webrtc::SdpParseError* error) { |
| auto media_desc = std::make_unique<C>(); |
| media_desc->set_extmap_allow_mixed_enum(MediaContentDescription::kNo); |
| if (!ParseContent(message, media_type, mline_index, protocol, payload_types, |
| pos, content_name, bundle_only, msid_signaling, |
| media_desc.get(), transport, candidates, error)) { |
| return nullptr; |
| } |
| // Sort the codecs according to the m-line fmt list. |
| std::unordered_map<int, int> payload_type_preferences; |
| // "size + 1" so that the lowest preference payload type has a preference of |
| // 1, which is greater than the default (0) for payload types not in the fmt |
| // list. |
| int preference = static_cast<int>(payload_types.size() + 1); |
| for (int pt : payload_types) { |
| payload_type_preferences[pt] = preference--; |
| } |
| std::vector<cricket::Codec> codecs = media_desc->codecs(); |
| absl::c_sort(codecs, [&payload_type_preferences](const cricket::Codec& a, |
| const cricket::Codec& b) { |
| return payload_type_preferences[a.id] > payload_type_preferences[b.id]; |
| }); |
| media_desc->set_codecs(codecs); |
| return media_desc; |
| } |
| |
| bool ParseMediaDescription( |
| absl::string_view message, |
| const TransportDescription& session_td, |
| const RtpHeaderExtensions& session_extmaps, |
| size_t* pos, |
| const rtc::SocketAddress& session_connection_addr, |
| cricket::SessionDescription* desc, |
| std::vector<std::unique_ptr<JsepIceCandidate>>* candidates, |
| SdpParseError* error) { |
| RTC_DCHECK(desc != NULL); |
| int mline_index = -1; |
| int msid_signaling = 0; |
| |
| // Zero or more media descriptions |
| // RFC 4566 |
| // m=<media> <port> <proto> <fmt> |
| while (absl::optional<absl::string_view> mline = |
| GetLineWithType(message, pos, kLineTypeMedia)) { |
| ++mline_index; |
| |
| std::vector<absl::string_view> fields = |
| rtc::split(mline->substr(kLinePrefixLength), kSdpDelimiterSpaceChar); |
| |
| const size_t expected_min_fields = 4; |
| if (fields.size() < expected_min_fields) { |
| return ParseFailedExpectMinFieldNum(*mline, expected_min_fields, error); |
| } |
| bool port_rejected = false; |
| // RFC 3264 |
| // To reject an offered stream, the port number in the corresponding stream |
| // in the answer MUST be set to zero. |
| if (fields[1] == kMediaPortRejected) { |
| port_rejected = true; |
| } |
| |
| int port = 0; |
| if (!rtc::FromString<int>(fields[1], &port) || !IsValidPort(port)) { |
| return ParseFailed(*mline, "The port number is invalid", error); |
| } |
| absl::string_view protocol = fields[2]; |
| |
| // <fmt> |
| std::vector<int> payload_types; |
| if (cricket::IsRtpProtocol(protocol)) { |
| for (size_t j = 3; j < fields.size(); ++j) { |
| int pl = 0; |
| if (!GetPayloadTypeFromString(*mline, fields[j], &pl, error)) { |
| return false; |
| } |
| payload_types.push_back(pl); |
| } |
| } |
| |
| // Make a temporary TransportDescription based on `session_td`. |
| // Some of this gets overwritten by ParseContent. |
| TransportDescription transport( |
| session_td.transport_options, session_td.ice_ufrag, session_td.ice_pwd, |
| session_td.ice_mode, session_td.connection_role, |
| session_td.identity_fingerprint.get()); |
| |
| std::unique_ptr<MediaContentDescription> content; |
| std::string content_name; |
| bool bundle_only = false; |
| int section_msid_signaling = 0; |
| absl::string_view media_type = fields[0]; |
| if ((media_type == kMediaTypeVideo || media_type == kMediaTypeAudio) && |
| !cricket::IsRtpProtocol(protocol)) { |
| return ParseFailed(*mline, "Unsupported protocol for media type", error); |
| } |
| if (media_type == kMediaTypeVideo) { |
| content = ParseContentDescription<VideoContentDescription>( |
| message, cricket::MEDIA_TYPE_VIDEO<
|