pc/jsep_session_description.cc - src - Git at Google

 /*
  *  Copyright 2012 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 "api/jsep_session_description.h"

 #include <memory>

 #include "p2p/base/port.h"
 #include "pc/media_session.h"
 #include "pc/webrtc_sdp.h"
 #include "rtc_base/arraysize.h"

 using cricket::SessionDescription;

 namespace webrtc {
 namespace {

 // 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.
 constexpr int kPreferenceUnknown = 0;
 constexpr int kPreferenceHost = 1;
 constexpr int kPreferenceReflexive = 2;
 constexpr int kPreferenceRelayed = 3;

 constexpr char kDummyAddress[] = "0.0.0.0";
 constexpr int kDummyPort = 9;

 int GetCandidatePreferenceFromType(const std::string& 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 {
     preference = kPreferenceUnknown;
   }
   return preference;
 }

 // Update the connection address for the MediaContentDescription based on the
 // candidates.
 void UpdateConnectionAddress(
     const JsepCandidateCollection& candidate_collection,
     cricket::MediaContentDescription* media_desc) {
   int port = kDummyPort;
   std::string ip = kDummyAddress;
   std::string hostname;
   int current_preference = kPreferenceUnknown;
   int current_family = AF_UNSPEC;
   for (size_t i = 0; i < candidate_collection.count(); ++i) {
     const IceCandidateInterface* jsep_candidate = candidate_collection.at(i);
     if (jsep_candidate->candidate().component() !=
         cricket::ICE_CANDIDATE_COMPONENT_RTP) {
       continue;
     }
     // Default destination should be UDP only.
     if (jsep_candidate->candidate().protocol() != cricket::UDP_PROTOCOL_NAME) {
       continue;
     }
     const int preference =
         GetCandidatePreferenceFromType(jsep_candidate->candidate().type());
     const int family = jsep_candidate->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;
     }
     current_preference = preference;
     current_family = family;
     const rtc::SocketAddress& candidate_addr =
         jsep_candidate->candidate().address();
     port = candidate_addr.port();
     ip = candidate_addr.ipaddr().ToString();
     hostname = candidate_addr.hostname();
   }
   rtc::SocketAddress connection_addr(ip, port);
   if (rtc::IPIsUnspec(connection_addr.ipaddr()) && !hostname.empty()) {
     // When a hostname candidate becomes the (default) connection address,
     // we use the dummy address 0.0.0.0 and port 9 in the c= and the m= lines.
     //
     // We have observed in deployment that with a FQDN in a c= line, SDP parsing
     // could fail in other JSEP implementations. We note that the wildcard
     // addresses (0.0.0.0 or ::) with port 9 are given the exception as the
     // connection address that will not result in an ICE mismatch
     // (draft-ietf-mmusic-ice-sip-sdp). Also, 0.0.0.0 or :: can be used as the
     // connection address in the initial offer or answer with trickle ICE
     // if the offerer or answerer does not want to include the host IP address
     // (draft-ietf-mmusic-trickle-ice-sip), and in particular 0.0.0.0 has been
     // widely deployed for this use without outstanding compatibility issues.
     // Combining the above considerations, we use 0.0.0.0 with port 9 to
     // populate the c= and the m= lines. See |BuildMediaDescription| in
     // webrtc_sdp.cc for the SDP generation with
     // |media_desc->connection_address()|.
     connection_addr = rtc::SocketAddress(kDummyAddress, kDummyPort);
   }
   media_desc->set_connection_address(connection_addr);
 }

 }  // namespace

 const int JsepSessionDescription::kDefaultVideoCodecId = 100;
 const char JsepSessionDescription::kDefaultVideoCodecName[] = "VP8";

 // TODO(steveanton): Remove this default implementation once Chromium has been
 // updated.
 SdpType SessionDescriptionInterface::GetType() const {
   absl::optional<SdpType> maybe_type = SdpTypeFromString(type());
   if (maybe_type) {
     return *maybe_type;
   } else {
     RTC_LOG(LS_WARNING) << "Default implementation of "
                            "SessionDescriptionInterface::GetType does not "
                            "recognize the result from type(), returning "
                            "kOffer.";
     return SdpType::kOffer;
   }
 }

 SessionDescriptionInterface* CreateSessionDescription(const std::string& type,
                                                       const std::string& sdp,
                                                       SdpParseError* error) {
   absl::optional<SdpType> maybe_type = SdpTypeFromString(type);
   if (!maybe_type) {
     return nullptr;
   }

   return CreateSessionDescription(*maybe_type, sdp, error).release();
 }

 std::unique_ptr<SessionDescriptionInterface> CreateSessionDescription(
     SdpType type,
     const std::string& sdp) {
   return CreateSessionDescription(type, sdp, nullptr);
 }

 std::unique_ptr<SessionDescriptionInterface> CreateSessionDescription(
     SdpType type,
     const std::string& sdp,
     SdpParseError* error_out) {
   auto jsep_desc = std::make_unique<JsepSessionDescription>(type);
   if (type != SdpType::kRollback) {
     if (!SdpDeserialize(sdp, jsep_desc.get(), error_out)) {
       return nullptr;
     }
   }
   return std::move(jsep_desc);
 }

 std::unique_ptr<SessionDescriptionInterface> CreateSessionDescription(
     SdpType type,
     const std::string& session_id,
     const std::string& session_version,
     std::unique_ptr<cricket::SessionDescription> description) {
   auto jsep_description = std::make_unique<JsepSessionDescription>(type);
   bool initialize_success = jsep_description->Initialize(
       std::move(description), session_id, session_version);
   RTC_DCHECK(initialize_success);
   return std::move(jsep_description);
 }

 JsepSessionDescription::JsepSessionDescription(SdpType type) : type_(type) {}

 JsepSessionDescription::JsepSessionDescription(const std::string& type) {
   absl::optional<SdpType> maybe_type = SdpTypeFromString(type);
   if (maybe_type) {
     type_ = *maybe_type;
   } else {
     RTC_LOG(LS_WARNING)
         << "JsepSessionDescription constructed with invalid type string: "
         << type << ". Assuming it is an offer.";
     type_ = SdpType::kOffer;
   }
 }

 JsepSessionDescription::JsepSessionDescription(
     SdpType type,
     std::unique_ptr<cricket::SessionDescription> description,
     absl::string_view session_id,
     absl::string_view session_version)
     : description_(std::move(description)),
       session_id_(session_id),
       session_version_(session_version),
       type_(type) {
   RTC_DCHECK(description_);
   candidate_collection_.resize(number_of_mediasections());
 }

 JsepSessionDescription::~JsepSessionDescription() {}

 bool JsepSessionDescription::Initialize(
     std::unique_ptr<cricket::SessionDescription> description,
     const std::string& session_id,
     const std::string& session_version) {
   if (!description)
     return false;

   session_id_ = session_id;
   session_version_ = session_version;
   description_ = std::move(description);
   candidate_collection_.resize(number_of_mediasections());
   return true;
 }

 bool JsepSessionDescription::AddCandidate(
     const IceCandidateInterface* candidate) {
   if (!candidate)
     return false;
   size_t mediasection_index = 0;
   if (!GetMediasectionIndex(candidate, &mediasection_index)) {
     return false;
   }
   if (mediasection_index >= number_of_mediasections())
     return false;
   const std::string& content_name =
       description_->contents()[mediasection_index].name;
   const cricket::TransportInfo* transport_info =
       description_->GetTransportInfoByName(content_name);
   if (!transport_info) {
     return false;
   }

   cricket::Candidate updated_candidate = candidate->candidate();
   if (updated_candidate.username().empty()) {
     updated_candidate.set_username(transport_info->description.ice_ufrag);
   }
   if (updated_candidate.password().empty()) {
     updated_candidate.set_password(transport_info->description.ice_pwd);
   }

   std::unique_ptr<JsepIceCandidate> updated_candidate_wrapper(
       new JsepIceCandidate(candidate->sdp_mid(),
                            static_cast<int>(mediasection_index),
                            updated_candidate));
   if (!candidate_collection_[mediasection_index].HasCandidate(
           updated_candidate_wrapper.get())) {
     candidate_collection_[mediasection_index].add(
         updated_candidate_wrapper.release());
     UpdateConnectionAddress(
         candidate_collection_[mediasection_index],
         description_->contents()[mediasection_index].media_description());
   }

   return true;
 }

 size_t JsepSessionDescription::RemoveCandidates(
     const std::vector<cricket::Candidate>& candidates) {
   size_t num_removed = 0;
   for (auto& candidate : candidates) {
     int mediasection_index = GetMediasectionIndex(candidate);
     if (mediasection_index < 0) {
       // Not found.
       continue;
     }
     num_removed += candidate_collection_[mediasection_index].remove(candidate);
     UpdateConnectionAddress(
         candidate_collection_[mediasection_index],
         description_->contents()[mediasection_index].media_description());
   }
   return num_removed;
 }

 size_t JsepSessionDescription::number_of_mediasections() const {
   if (!description_)
     return 0;
   return description_->contents().size();
 }

 const IceCandidateCollection* JsepSessionDescription::candidates(
     size_t mediasection_index) const {
   if (mediasection_index >= candidate_collection_.size())
     return NULL;
   return &candidate_collection_[mediasection_index];
 }

 bool JsepSessionDescription::ToString(std::string* out) const {
   if (!description_ || !out) {
     return false;
   }
   *out = SdpSerialize(*this);
   return !out->empty();
 }

 bool JsepSessionDescription::GetMediasectionIndex(
     const IceCandidateInterface* candidate,
     size_t* index) {
   if (!candidate || !index) {
     return false;
   }

   // If the candidate has no valid mline index or sdp_mid, it is impossible
   // to find a match.
   if (candidate->sdp_mid().empty() &&
       (candidate->sdp_mline_index() < 0 ||
        static_cast<size_t>(candidate->sdp_mline_index()) >=
            description_->contents().size())) {
     return false;
   }

   if (candidate->sdp_mline_index() >= 0)
     *index = static_cast<size_t>(candidate->sdp_mline_index());
   if (description_ && !candidate->sdp_mid().empty()) {
     bool found = false;
     // Try to match the sdp_mid with content name.
     for (size_t i = 0; i < description_->contents().size(); ++i) {
       if (candidate->sdp_mid() == description_->contents().at(i).name) {
         *index = i;
         found = true;
         break;
       }
     }
     if (!found) {
       // If the sdp_mid is presented but we can't find a match, we consider
       // this as an error.
       return false;
     }
   }
   return true;
 }

 int JsepSessionDescription::GetMediasectionIndex(
     const cricket::Candidate& candidate) {
   // Find the description with a matching transport name of the candidate.
   const std::string& transport_name = candidate.transport_name();
   for (size_t i = 0; i < description_->contents().size(); ++i) {
     if (transport_name == description_->contents().at(i).name) {
       return static_cast<int>(i);
     }
   }
   return -1;
 }

 }  // namespace webrtc
	/*
	* Copyright 2012 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 "api/jsep_session_description.h"

	#include <memory>

	#include "p2p/base/port.h"
	#include "pc/media_session.h"
	#include "pc/webrtc_sdp.h"
	#include "rtc_base/arraysize.h"

	using cricket::SessionDescription;

	namespace webrtc {
	namespace {

	// 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.
	constexpr int kPreferenceUnknown = 0;
	constexpr int kPreferenceHost = 1;
	constexpr int kPreferenceReflexive = 2;
	constexpr int kPreferenceRelayed = 3;

	constexpr char kDummyAddress[] = "0.0.0.0";
	constexpr int kDummyPort = 9;

	int GetCandidatePreferenceFromType(const std::string& 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 {
	preference = kPreferenceUnknown;
	}
	return preference;
	}

	// Update the connection address for the MediaContentDescription based on the
	// candidates.
	void UpdateConnectionAddress(
	const JsepCandidateCollection& candidate_collection,
	cricket::MediaContentDescription* media_desc) {
	int port = kDummyPort;
	std::string ip = kDummyAddress;
	std::string hostname;
	int current_preference = kPreferenceUnknown;
	int current_family = AF_UNSPEC;
	for (size_t i = 0; i < candidate_collection.count(); ++i) {
	const IceCandidateInterface* jsep_candidate = candidate_collection.at(i);
	if (jsep_candidate->candidate().component() !=
	cricket::ICE_CANDIDATE_COMPONENT_RTP) {
	continue;
	}
	// Default destination should be UDP only.
	if (jsep_candidate->candidate().protocol() != cricket::UDP_PROTOCOL_NAME) {
	continue;
	}
	const int preference =
	GetCandidatePreferenceFromType(jsep_candidate->candidate().type());
	const int family = jsep_candidate->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;
	}
	current_preference = preference;
	current_family = family;
	const rtc::SocketAddress& candidate_addr =
	jsep_candidate->candidate().address();
	port = candidate_addr.port();
	ip = candidate_addr.ipaddr().ToString();
	hostname = candidate_addr.hostname();
	}
	rtc::SocketAddress connection_addr(ip, port);
	if (rtc::IPIsUnspec(connection_addr.ipaddr()) && !hostname.empty()) {
	// When a hostname candidate becomes the (default) connection address,
	// we use the dummy address 0.0.0.0 and port 9 in the c= and the m= lines.
	//
	// We have observed in deployment that with a FQDN in a c= line, SDP parsing
	// could fail in other JSEP implementations. We note that the wildcard
	// addresses (0.0.0.0 or ::) with port 9 are given the exception as the
	// connection address that will not result in an ICE mismatch
	// (draft-ietf-mmusic-ice-sip-sdp). Also, 0.0.0.0 or :: can be used as the
	// connection address in the initial offer or answer with trickle ICE
	// if the offerer or answerer does not want to include the host IP address
	// (draft-ietf-mmusic-trickle-ice-sip), and in particular 0.0.0.0 has been
	// widely deployed for this use without outstanding compatibility issues.
	// Combining the above considerations, we use 0.0.0.0 with port 9 to
	// populate the c= and the m= lines. See \|BuildMediaDescription\| in
	// webrtc_sdp.cc for the SDP generation with
	// \|media_desc->connection_address()\|.
	connection_addr = rtc::SocketAddress(kDummyAddress, kDummyPort);
	}
	media_desc->set_connection_address(connection_addr);
	}

	} // namespace

	const int JsepSessionDescription::kDefaultVideoCodecId = 100;
	const char JsepSessionDescription::kDefaultVideoCodecName[] = "VP8";

	// TODO(steveanton): Remove this default implementation once Chromium has been
	// updated.
	SdpType SessionDescriptionInterface::GetType() const {
	absl::optional<SdpType> maybe_type = SdpTypeFromString(type());
	if (maybe_type) {
	return *maybe_type;
	} else {
	RTC_LOG(LS_WARNING) << "Default implementation of "
	"SessionDescriptionInterface::GetType does not "
	"recognize the result from type(), returning "
	"kOffer.";
	return SdpType::kOffer;
	}
	}

	SessionDescriptionInterface* CreateSessionDescription(const std::string& type,
	const std::string& sdp,
	SdpParseError* error) {
	absl::optional<SdpType> maybe_type = SdpTypeFromString(type);
	if (!maybe_type) {
	return nullptr;
	}

	return CreateSessionDescription(*maybe_type, sdp, error).release();
	}

	std::unique_ptr<SessionDescriptionInterface> CreateSessionDescription(
	SdpType type,
	const std::string& sdp) {
	return CreateSessionDescription(type, sdp, nullptr);
	}

	std::unique_ptr<SessionDescriptionInterface> CreateSessionDescription(
	SdpType type,
	const std::string& sdp,
	SdpParseError* error_out) {
	auto jsep_desc = std::make_unique<JsepSessionDescription>(type);
	if (type != SdpType::kRollback) {
	if (!SdpDeserialize(sdp, jsep_desc.get(), error_out)) {
	return nullptr;
	}
	}
	return std::move(jsep_desc);
	}

	std::unique_ptr<SessionDescriptionInterface> CreateSessionDescription(
	SdpType type,
	const std::string& session_id,
	const std::string& session_version,
	std::unique_ptr<cricket::SessionDescription> description) {
	auto jsep_description = std::make_unique<JsepSessionDescription>(type);
	bool initialize_success = jsep_description->Initialize(
	std::move(description), session_id, session_version);
	RTC_DCHECK(initialize_success);
	return std::move(jsep_description);
	}

	JsepSessionDescription::JsepSessionDescription(SdpType type) : type_(type) {}

	JsepSessionDescription::JsepSessionDescription(const std::string& type) {
	absl::optional<SdpType> maybe_type = SdpTypeFromString(type);
	if (maybe_type) {
	type_ = *maybe_type;
	} else {
	RTC_LOG(LS_WARNING)
	<< "JsepSessionDescription constructed with invalid type string: "
	<< type << ". Assuming it is an offer.";
	type_ = SdpType::kOffer;
	}
	}

	JsepSessionDescription::JsepSessionDescription(
	SdpType type,
	std::unique_ptr<cricket::SessionDescription> description,
	absl::string_view session_id,
	absl::string_view session_version)
	: description_(std::move(description)),
	session_id_(session_id),
	session_version_(session_version),
	type_(type) {
	RTC_DCHECK(description_);
	candidate_collection_.resize(number_of_mediasections());
	}

	JsepSessionDescription::~JsepSessionDescription() {}

	bool JsepSessionDescription::Initialize(
	std::unique_ptr<cricket::SessionDescription> description,
	const std::string& session_id,
	const std::string& session_version) {
	if (!description)
	return false;

	session_id_ = session_id;
	session_version_ = session_version;
	description_ = std::move(description);
	candidate_collection_.resize(number_of_mediasections());
	return true;
	}

	bool JsepSessionDescription::AddCandidate(
	const IceCandidateInterface* candidate) {
	if (!candidate)
	return false;
	size_t mediasection_index = 0;
	if (!GetMediasectionIndex(candidate, &mediasection_index)) {
	return false;
	}
	if (mediasection_index >= number_of_mediasections())
	return false;
	const std::string& content_name =
	description_->contents()[mediasection_index].name;
	const cricket::TransportInfo* transport_info =
	description_->GetTransportInfoByName(content_name);
	if (!transport_info) {
	return false;
	}

	cricket::Candidate updated_candidate = candidate->candidate();
	if (updated_candidate.username().empty()) {
	updated_candidate.set_username(transport_info->description.ice_ufrag);
	}
	if (updated_candidate.password().empty()) {
	updated_candidate.set_password(transport_info->description.ice_pwd);
	}

	std::unique_ptr<JsepIceCandidate> updated_candidate_wrapper(
	new JsepIceCandidate(candidate->sdp_mid(),
	static_cast<int>(mediasection_index),
	updated_candidate));
	if (!candidate_collection_[mediasection_index].HasCandidate(
	updated_candidate_wrapper.get())) {
	candidate_collection_[mediasection_index].add(
	updated_candidate_wrapper.release());
	UpdateConnectionAddress(
	candidate_collection_[mediasection_index],
	description_->contents()[mediasection_index].media_description());
	}

	return true;
	}

	size_t JsepSessionDescription::RemoveCandidates(
	const std::vector<cricket::Candidate>& candidates) {
	size_t num_removed = 0;
	for (auto& candidate : candidates) {
	int mediasection_index = GetMediasectionIndex(candidate);
	if (mediasection_index < 0) {
	// Not found.
	continue;
	}
	num_removed += candidate_collection_[mediasection_index].remove(candidate);
	UpdateConnectionAddress(
	candidate_collection_[mediasection_index],
	description_->contents()[mediasection_index].media_description());
	}
	return num_removed;
	}

	size_t JsepSessionDescription::number_of_mediasections() const {
	if (!description_)
	return 0;
	return description_->contents().size();
	}

	const IceCandidateCollection* JsepSessionDescription::candidates(
	size_t mediasection_index) const {
	if (mediasection_index >= candidate_collection_.size())
	return NULL;
	return &candidate_collection_[mediasection_index];
	}

	bool JsepSessionDescription::ToString(std::string* out) const {
	if (!description_ \|\| !out) {
	return false;
	}
	out = SdpSerialize(this);
	return !out->empty();
	}

	bool JsepSessionDescription::GetMediasectionIndex(
	const IceCandidateInterface* candidate,
	size_t* index) {
	if (!candidate \|\| !index) {
	return false;
	}

	// If the candidate has no valid mline index or sdp_mid, it is impossible
	// to find a match.
	if (candidate->sdp_mid().empty() &&
	(candidate->sdp_mline_index() < 0 \|\|
	static_cast<size_t>(candidate->sdp_mline_index()) >=
	description_->contents().size())) {
	return false;
	}

	if (candidate->sdp_mline_index() >= 0)
	*index = static_cast<size_t>(candidate->sdp_mline_index());
	if (description_ && !candidate->sdp_mid().empty()) {
	bool found = false;
	// Try to match the sdp_mid with content name.
	for (size_t i = 0; i < description_->contents().size(); ++i) {
	if (candidate->sdp_mid() == description_->contents().at(i).name) {
	*index = i;
	found = true;
	break;
	}
	}
	if (!found) {
	// If the sdp_mid is presented but we can't find a match, we consider
	// this as an error.
	return false;
	}
	}
	return true;
	}

	int JsepSessionDescription::GetMediasectionIndex(
	const cricket::Candidate& candidate) {
	// Find the description with a matching transport name of the candidate.
	const std::string& transport_name = candidate.transport_name();
	for (size_t i = 0; i < description_->contents().size(); ++i) {
	if (transport_name == description_->contents().at(i).name) {
	return static_cast<int>(i);
	}
	}
	return -1;
	}

	} // namespace webrtc