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/*
* 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 <utility>
#include "absl/types/optional.h"
#include "p2p/base/p2p_constants.h"
#include "p2p/base/port.h"
#include "p2p/base/transport_description.h"
#include "p2p/base/transport_info.h"
#include "pc/media_session.h" // IWYU pragma: keep
#include "pc/webrtc_sdp.h"
#include "rtc_base/checks.h"
#include "rtc_base/ip_address.h"
#include "rtc_base/logging.h"
#include "rtc_base/net_helper.h"
#include "rtc_base/socket_address.h"
using cricket::Candidate;
using cricket::SessionDescription;
namespace webrtc {
namespace {
constexpr char kDummyAddress[] = "0.0.0.0";
constexpr int kDummyPort = 9;
// 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 = 0; // Start with lowest preference.
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 = jsep_candidate->candidate().type_preference();
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
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
// 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;
}
std::unique_ptr<SessionDescriptionInterface> JsepSessionDescription::Clone()
const {
auto new_description = std::make_unique<JsepSessionDescription>(type_);
new_description->session_id_ = session_id_;
new_description->session_version_ = session_version_;
if (description_) {
new_description->description_ = description_->Clone();
}
for (const auto& collection : candidate_collection_) {
new_description->candidate_collection_.push_back(collection.Clone());
}
return new_description;
}
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;
}
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<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 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