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webrtc / src / 0242939296c0fd12e745d2f09d6256e390de8a2e / . / p2p / base / turn_port.cc
blob: 965a68b3a39f100153219683c9e472341add3132 [file] [log] [blame]
/*
* 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 "p2p/base/turn_port.h"
#include <cstdint>
#include <functional>
#include <memory>
#include <utility>
#include <vector>
#include "absl/algorithm/container.h"
#include "absl/strings/match.h"
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "api/task_queue/pending_task_safety_flag.h"
#include "api/transport/stun.h"
#include "api/turn_customizer.h"
#include "p2p/base/connection.h"
#include "p2p/base/p2p_constants.h"
#include "rtc_base/async_packet_socket.h"
#include "rtc_base/byte_order.h"
#include "rtc_base/checks.h"
#include "rtc_base/experiments/field_trial_parser.h"
#include "rtc_base/logging.h"
#include "rtc_base/net_helpers.h"
#include "rtc_base/network/received_packet.h"
#include "rtc_base/socket_address.h"
#include "rtc_base/strings/string_builder.h"
namespace cricket {
using ::webrtc::IceCandidateType;
using ::webrtc::SafeTask;
using ::webrtc::TaskQueueBase;
using ::webrtc::TimeDelta;
// TODO(juberti): Move to stun.h when relay messages have been renamed.
static const int TURN_ALLOCATE_REQUEST = STUN_ALLOCATE_REQUEST;
// Attributes in comprehension-optional range,
// ignored by TURN server that doesn't know about them.
// https://tools.ietf.org/html/rfc5389#section-18.2
const int STUN_ATTR_TURN_LOGGING_ID = 0xff05;
// TODO(juberti): Extract to turnmessage.h
static const int TURN_DEFAULT_PORT = 3478;
static const int TURN_CHANNEL_NUMBER_START = 0x4000;
static constexpr TimeDelta kTurnPermissionTimeout = TimeDelta::Minutes(5);
static const size_t TURN_CHANNEL_HEADER_SIZE = 4U;
// Retry at most twice (i.e. three different ALLOCATE requests) on
// STUN_ERROR_ALLOCATION_MISMATCH error per rfc5766.
static const size_t MAX_ALLOCATE_MISMATCH_RETRIES = 2;
static const int TURN_SUCCESS_RESULT_CODE = 0;
inline bool IsTurnChannelData(uint16_t msg_type) {
return ((msg_type & 0xC000) == 0x4000); // MSB are 0b01
}
static int GetRelayPreference(cricket::ProtocolType proto) {
switch (proto) {
case cricket::PROTO_TCP:
return ICE_TYPE_PREFERENCE_RELAY_TCP;
case cricket::PROTO_TLS:
return ICE_TYPE_PREFERENCE_RELAY_TLS;
default:
RTC_DCHECK(proto == PROTO_UDP);
return ICE_TYPE_PREFERENCE_RELAY_UDP;
}
}
class TurnAllocateRequest : public StunRequest {
public:
explicit TurnAllocateRequest(TurnPort* port);
void OnSent() override;
void OnResponse(StunMessage* response) override;
void OnErrorResponse(StunMessage* response) override;
void OnTimeout() override;
private:
// Handles authentication challenge from the server.
void OnAuthChallenge(StunMessage* response, int code);
void OnTryAlternate(StunMessage* response, int code);
void OnUnknownAttribute(StunMessage* response);
TurnPort* port_;
};
class TurnRefreshRequest : public StunRequest {
public:
explicit TurnRefreshRequest(TurnPort* port, int lifetime = -1);
void OnSent() override;
void OnResponse(StunMessage* response) override;
void OnErrorResponse(StunMessage* response) override;
void OnTimeout() override;
private:
TurnPort* port_;
};
class TurnCreatePermissionRequest : public StunRequest {
public:
TurnCreatePermissionRequest(TurnPort* port,
TurnEntry* entry,
const rtc::SocketAddress& ext_addr);
~TurnCreatePermissionRequest() override;
void OnSent() override;
void OnResponse(StunMessage* response) override;
void OnErrorResponse(StunMessage* response) override;
void OnTimeout() override;
private:
TurnPort* port_;
TurnEntry* entry_;
rtc::SocketAddress ext_addr_;
};
class TurnChannelBindRequest : public StunRequest {
public:
TurnChannelBindRequest(TurnPort* port,
TurnEntry* entry,
int channel_id,
const rtc::SocketAddress& ext_addr);
~TurnChannelBindRequest() override;
void OnSent() override;
void OnResponse(StunMessage* response) override;
void OnErrorResponse(StunMessage* response) override;
void OnTimeout() override;
private:
TurnPort* port_;
TurnEntry* entry_;
int channel_id_;
rtc::SocketAddress ext_addr_;
};
// Manages a "connection" to a remote destination. We will attempt to bring up
// a channel for this remote destination to reduce the overhead of sending data.
class TurnEntry : public sigslot::has_slots<> {
public:
enum BindState { STATE_UNBOUND, STATE_BINDING, STATE_BOUND };
TurnEntry(TurnPort* port, Connection* conn, int channel_id);
~TurnEntry();
TurnPort* port() { return port_; }
int channel_id() const { return channel_id_; }
// For testing only.
void set_channel_id(int channel_id) { channel_id_ = channel_id; }
const rtc::SocketAddress& address() const { return ext_addr_; }
BindState state() const { return state_; }
// Adds a new connection object to the list of connections that are associated
// with this entry. If prior to this call there were no connections being
// tracked (i.e. count goes from 0 -> 1), the internal safety flag is reset
// which cancels any potential pending deletion tasks.
void TrackConnection(Connection* conn);
// Removes a connection from the list of tracked connections.
// * If `conn` was the last connection removed, the function returns a
// safety flag that's used to schedule the deletion of the entry after a
// timeout expires. If during this timeout `TrackConnection` is called, the
// flag will be reset and pending tasks associated with it, cancelled.
// * If `conn` was not the last connection, the return value will be nullptr.
rtc::scoped_refptr<webrtc::PendingTaskSafetyFlag> UntrackConnection(
Connection* conn);
// Helper methods to send permission and channel bind requests.
void SendCreatePermissionRequest(int delay);
void SendChannelBindRequest(int delay);
// Sends a packet to the given destination address.
// This will wrap the packet in STUN if necessary.
int Send(const void* data,
size_t size,
bool payload,
const rtc::PacketOptions& options);
void OnCreatePermissionSuccess();
void OnCreatePermissionError(StunMessage* response, int code);
void OnCreatePermissionTimeout();
void OnChannelBindSuccess();
void OnChannelBindError(StunMessage* response, int code);
void OnChannelBindTimeout();
// Signal sent when TurnEntry is destroyed.
webrtc::CallbackList<TurnEntry*> destroyed_callback_list_;
private:
TurnPort* port_;
int channel_id_;
rtc::SocketAddress ext_addr_;
BindState state_;
// List of associated connection instances to keep track of how many and
// which connections are associated with this entry. Once this is empty,
// the entry can be deleted.
std::vector<Connection*> connections_;
webrtc::ScopedTaskSafety task_safety_;
};
TurnPort::TurnPort(TaskQueueBase* thread,
rtc::PacketSocketFactory* factory,
const rtc::Network* network,
rtc::AsyncPacketSocket* socket,
absl::string_view username,
absl::string_view password,
const ProtocolAddress& server_address,
const RelayCredentials& credentials,
int server_priority,
const std::vector<std::string>& tls_alpn_protocols,
const std::vector<std::string>& tls_elliptic_curves,
webrtc::TurnCustomizer* customizer,
rtc::SSLCertificateVerifier* tls_cert_verifier,
const webrtc::FieldTrialsView* field_trials)
: Port(thread,
IceCandidateType::kRelay,
factory,
network,
username,
password,
field_trials),
server_address_(server_address),
server_url_(ReconstructServerUrl()),
tls_alpn_protocols_(tls_alpn_protocols),
tls_elliptic_curves_(tls_elliptic_curves),
tls_cert_verifier_(tls_cert_verifier),
credentials_(credentials),
socket_(socket),
error_(0),
stun_dscp_value_(rtc::DSCP_NO_CHANGE),
request_manager_(
thread,
[this](const void* data, size_t size, StunRequest* request) {
OnSendStunPacket(data, size, request);
}),
next_channel_number_(TURN_CHANNEL_NUMBER_START),
state_(STATE_CONNECTING),
server_priority_(server_priority),
allocate_mismatch_retries_(0),
turn_customizer_(customizer) {}
TurnPort::TurnPort(TaskQueueBase* thread,
rtc::PacketSocketFactory* factory,
const rtc::Network* network,
uint16_t min_port,
uint16_t max_port,
absl::string_view username,
absl::string_view password,
const ProtocolAddress& server_address,
const RelayCredentials& credentials,
int server_priority,
const std::vector<std::string>& tls_alpn_protocols,
const std::vector<std::string>& tls_elliptic_curves,
webrtc::TurnCustomizer* customizer,
rtc::SSLCertificateVerifier* tls_cert_verifier,
const webrtc::FieldTrialsView* field_trials)
: Port(thread,
IceCandidateType::kRelay,
factory,
network,
min_port,
max_port,
username,
password,
field_trials),
server_address_(server_address),
server_url_(ReconstructServerUrl()),
tls_alpn_protocols_(tls_alpn_protocols),
tls_elliptic_curves_(tls_elliptic_curves),
tls_cert_verifier_(tls_cert_verifier),
credentials_(credentials),
socket_(nullptr),
error_(0),
stun_dscp_value_(rtc::DSCP_NO_CHANGE),
request_manager_(
thread,
[this](const void* data, size_t size, StunRequest* request) {
OnSendStunPacket(data, size, request);
}),
next_channel_number_(TURN_CHANNEL_NUMBER_START),
state_(STATE_CONNECTING),
server_priority_(server_priority),
allocate_mismatch_retries_(0),
turn_customizer_(customizer) {}
TurnPort::~TurnPort() {
// TODO(juberti): Should this even be necessary?
// release the allocation by sending a refresh with
// lifetime 0.
if (ready()) {
Release();
}
entries_.clear();
if (socket_)
socket_->UnsubscribeCloseEvent(this);
if (!SharedSocket()) {
delete socket_;
}
}
rtc::SocketAddress TurnPort::GetLocalAddress() const {
return socket_ ? socket_->GetLocalAddress() : rtc::SocketAddress();
}
ProtocolType TurnPort::GetProtocol() const {
return server_address_.proto;
}
TlsCertPolicy TurnPort::GetTlsCertPolicy() const {
return tls_cert_policy_;
}
void TurnPort::SetTlsCertPolicy(TlsCertPolicy tls_cert_policy) {
tls_cert_policy_ = tls_cert_policy;
}
void TurnPort::SetTurnLoggingId(absl::string_view turn_logging_id) {
turn_logging_id_ = std::string(turn_logging_id);
}
std::vector<std::string> TurnPort::GetTlsAlpnProtocols() const {
return tls_alpn_protocols_;
}
std::vector<std::string> TurnPort::GetTlsEllipticCurves() const {
return tls_elliptic_curves_;
}
void TurnPort::PrepareAddress() {
if (credentials_.username.empty() || credentials_.password.empty()) {
RTC_LOG(LS_ERROR) << "Allocation can't be started without setting the"
" TURN server credentials for the user.";
OnAllocateError(STUN_ERROR_UNAUTHORIZED,
"Missing TURN server credentials.");
return;
}
if (!server_address_.address.port()) {
// We will set default TURN port, if no port is set in the address.
server_address_.address.SetPort(TURN_DEFAULT_PORT);
}
if (!AllowedTurnPort(server_address_.address.port(), &field_trials())) {
// This can only happen after a 300 ALTERNATE SERVER, since the port can't
// be created with a disallowed port number.
RTC_LOG(LS_ERROR) << "Attempt to start allocation with disallowed port# "
<< server_address_.address.port();
OnAllocateError(STUN_ERROR_SERVER_ERROR,
"Attempt to start allocation to a disallowed port");
return;
}
if (server_address_.address.IsUnresolvedIP()) {
ResolveTurnAddress(server_address_.address);
} else {
// If protocol family of server address doesn't match with local, return.
if (!IsCompatibleAddress(server_address_.address)) {
RTC_LOG(LS_ERROR) << "IP address family does not match. server: "
<< server_address_.address.family()
<< " local: " << Network()->GetBestIP().family();
OnAllocateError(STUN_ERROR_GLOBAL_FAILURE,
"IP address family does not match.");
return;
}
// Insert the current address to prevent redirection pingpong.
attempted_server_addresses_.insert(server_address_.address);
RTC_LOG(LS_INFO)
<< ToString() << ": Trying to connect to TURN server via "
<< ProtoToString(server_address_.proto) << " @ "
<< server_address_.address.ToSensitiveNameAndAddressString();
if (!CreateTurnClientSocket()) {
RTC_LOG(LS_ERROR) << "Failed to create TURN client socket";
OnAllocateError(SERVER_NOT_REACHABLE_ERROR,
"Failed to create TURN client socket.");
return;
}
if (server_address_.proto == PROTO_UDP) {
// If its UDP, send AllocateRequest now.
// For TCP and TLS AllcateRequest will be sent by OnSocketConnect.
SendRequest(new TurnAllocateRequest(this), 0);
}
}
}
bool TurnPort::CreateTurnClientSocket() {
RTC_DCHECK(!socket_ || SharedSocket());
if (server_address_.proto == PROTO_UDP && !SharedSocket()) {
socket_ = socket_factory()->CreateUdpSocket(
rtc::SocketAddress(Network()->GetBestIP(), 0), min_port(), max_port());
} else if (server_address_.proto == PROTO_TCP ||
server_address_.proto == PROTO_TLS) {
RTC_DCHECK(!SharedSocket());
int opts = rtc::PacketSocketFactory::OPT_STUN;
// Apply server address TLS and insecure bits to options.
if (server_address_.proto == PROTO_TLS) {
if (tls_cert_policy_ ==
TlsCertPolicy::TLS_CERT_POLICY_INSECURE_NO_CHECK) {
opts |= rtc::PacketSocketFactory::OPT_TLS_INSECURE;
} else {
opts |= rtc::PacketSocketFactory::OPT_TLS;
}
}
rtc::PacketSocketTcpOptions tcp_options;
tcp_options.opts = opts;
tcp_options.tls_alpn_protocols = tls_alpn_protocols_;
tcp_options.tls_elliptic_curves = tls_elliptic_curves_;
tcp_options.tls_cert_verifier = tls_cert_verifier_;
socket_ = socket_factory()->CreateClientTcpSocket(
rtc::SocketAddress(Network()->GetBestIP(), 0), server_address_.address,
proxy(), user_agent(), tcp_options);
}
if (!socket_) {
error_ = SOCKET_ERROR;
return false;
}
// Apply options if any.
for (SocketOptionsMap::iterator iter = socket_options_.begin();
iter != socket_options_.end(); ++iter) {
socket_->SetOption(iter->first, iter->second);
}
if (!SharedSocket()) {
// If socket is shared, AllocationSequence will receive the packet.
socket_->RegisterReceivedPacketCallback(
[&](rtc::AsyncPacketSocket* socket, const rtc::ReceivedPacket& packet) {
OnReadPacket(socket, packet);
});
}
socket_->SignalReadyToSend.connect(this, &TurnPort::OnReadyToSend);
socket_->SignalSentPacket.connect(this, &TurnPort::OnSentPacket);
// TCP port is ready to send stun requests after the socket is connected,
// while UDP port is ready to do so once the socket is created.
if (server_address_.proto == PROTO_TCP ||
server_address_.proto == PROTO_TLS) {
socket_->SignalConnect.connect(this, &TurnPort::OnSocketConnect);
socket_->SubscribeCloseEvent(
this,
[this](rtc::AsyncPacketSocket* s, int err) { OnSocketClose(s, err); });
} else {
state_ = STATE_CONNECTED;
}
return true;
}
void TurnPort::OnSocketConnect(rtc::AsyncPacketSocket* socket) {
// This slot should only be invoked if we're using a connection-oriented
// protocol.
RTC_DCHECK(server_address_.proto == PROTO_TCP ||
server_address_.proto == PROTO_TLS);
// Do not use this port if the socket bound to an address not associated with
// the desired network interface. This is seen in Chrome, where TCP sockets
// cannot be given a binding address, and the platform is expected to pick
// the correct local address.
//
// However, there are two situations in which we allow the bound address to
// not be one of the addresses of the requested interface:
// 1. The bound address is the loopback address. This happens when a proxy
// forces TCP to bind to only the localhost address (see issue 3927).
// 2. The bound address is the "any address". This happens when
// multiple_routes is disabled (see issue 4780).
//
// Note that, aside from minor differences in log statements, this logic is
// identical to that in TcpPort.
const rtc::SocketAddress& socket_address = socket->GetLocalAddress();
if (absl::c_none_of(Network()->GetIPs(),
[socket_address](const rtc::InterfaceAddress& addr) {
return socket_address.ipaddr() == addr;
})) {
if (socket->GetLocalAddress().IsLoopbackIP()) {
RTC_LOG(LS_WARNING) << "Socket is bound to the address:"
<< socket_address.ToSensitiveNameAndAddressString()
<< ", rather than an address associated with network:"
<< Network()->ToString()
<< ". Still allowing it since it's localhost.";
} else if (IPIsAny(Network()->GetBestIP())) {
RTC_LOG(LS_WARNING)
<< "Socket is bound to the address:"
<< socket_address.ToSensitiveNameAndAddressString()
<< ", rather than an address associated with network:"
<< Network()->ToString()
<< ". Still allowing it since it's the 'any' address"
", possibly caused by multiple_routes being disabled.";
} else {
RTC_LOG(LS_WARNING) << "Socket is bound to the address:"
<< socket_address.ToSensitiveNameAndAddressString()
<< ", rather than an address associated with network:"
<< Network()->ToString() << ". Discarding TURN port.";
OnAllocateError(
STUN_ERROR_GLOBAL_FAILURE,
"Address not associated with the desired network interface.");
return;
}
}
state_ = STATE_CONNECTED; // It is ready to send stun requests.
if (server_address_.address.IsUnresolvedIP()) {
server_address_.address = socket_->GetRemoteAddress();
}
RTC_LOG(LS_INFO) << "TurnPort connected to "
<< socket->GetRemoteAddress().ToSensitiveString()
<< " using tcp.";
SendRequest(new TurnAllocateRequest(this), 0);
}
void TurnPort::OnSocketClose(rtc::AsyncPacketSocket* socket, int error) {
RTC_LOG(LS_WARNING) << ToString()
<< ": Connection with server failed with error: "
<< error;
RTC_DCHECK(socket == socket_);
Close();
}
void TurnPort::OnAllocateMismatch() {
if (allocate_mismatch_retries_ >= MAX_ALLOCATE_MISMATCH_RETRIES) {
RTC_LOG(LS_WARNING) << ToString() << ": Giving up on the port after "
<< allocate_mismatch_retries_
<< " retries for STUN_ERROR_ALLOCATION_MISMATCH";
OnAllocateError(STUN_ERROR_ALLOCATION_MISMATCH,
"Maximum retries reached for allocation mismatch.");
return;
}
RTC_LOG(LS_INFO) << ToString()
<< ": Allocating a new socket after "
"STUN_ERROR_ALLOCATION_MISMATCH, retry: "
<< allocate_mismatch_retries_ + 1;
socket_->UnsubscribeCloseEvent(this);
if (SharedSocket()) {
ResetSharedSocket();
} else {
delete socket_;
}
socket_ = nullptr;
ResetNonce();
PrepareAddress();
++allocate_mismatch_retries_;
}
Connection* TurnPort::CreateConnection(const Candidate& remote_candidate,
CandidateOrigin origin) {
// TURN-UDP can only connect to UDP candidates.
if (!SupportsProtocol(remote_candidate.protocol())) {
return nullptr;
}
if (state_ == STATE_DISCONNECTED || state_ == STATE_RECEIVEONLY) {
return nullptr;
}
// If the remote endpoint signaled us an mDNS candidate, we do not form a pair
// with the relay candidate to avoid IP leakage in the CreatePermission
// request.
if (absl::EndsWith(remote_candidate.address().hostname(), LOCAL_TLD)) {
return nullptr;
}
// A TURN port will have two candidates, STUN and TURN. STUN may not
// present in all cases. If present stun candidate will be added first
// and TURN candidate later.
for (size_t index = 0; index < Candidates().size(); ++index) {
const Candidate& local_candidate = Candidates()[index];
if (local_candidate.is_relay() && local_candidate.address().family() ==
remote_candidate.address().family()) {
ProxyConnection* conn =
new ProxyConnection(NewWeakPtr(), index, remote_candidate);
// Create an entry, if needed, so we can get our permissions set up
// correctly.
if (CreateOrRefreshEntry(conn, next_channel_number_)) {
next_channel_number_++;
}
AddOrReplaceConnection(conn);
return conn;
}
}
return nullptr;
}
bool TurnPort::FailAndPruneConnection(const rtc::SocketAddress& address) {
Connection* conn = GetConnection(address);
if (conn != nullptr) {
conn->FailAndPrune();
return true;
}
return false;
}
int TurnPort::SetOption(rtc::Socket::Option opt, int value) {
// Remember the last requested DSCP value, for STUN traffic.
if (opt == rtc::Socket::OPT_DSCP)
stun_dscp_value_ = static_cast<rtc::DiffServCodePoint>(value);
if (!socket_) {
// If socket is not created yet, these options will be applied during socket
// creation.
socket_options_[opt] = value;
return 0;
}
return socket_->SetOption(opt, value);
}
int TurnPort::GetOption(rtc::Socket::Option opt, int* value) {
if (!socket_) {
SocketOptionsMap::const_iterator it = socket_options_.find(opt);
if (it == socket_options_.end()) {
return -1;
}
*value = it->second;
return 0;
}
return socket_->GetOption(opt, value);
}
int TurnPort::GetError() {
return error_;
}
int TurnPort::SendTo(const void* data,
size_t size,
const rtc::SocketAddress& addr,
const rtc::PacketOptions& options,
bool payload) {
// Try to find an entry for this specific address; we should have one.
TurnEntry* entry = FindEntry(addr);
RTC_DCHECK(entry);
if (!ready()) {
error_ = ENOTCONN;
return SOCKET_ERROR;
}
// Send the actual contents to the server using the usual mechanism.
rtc::PacketOptions modified_options(options);
CopyPortInformationToPacketInfo(&modified_options.info_signaled_after_sent);
int sent = entry->Send(data, size, payload, modified_options);
if (sent <= 0) {
error_ = socket_->GetError();
return SOCKET_ERROR;
}
// The caller of the function is expecting the number of user data bytes,
// rather than the size of the packet.
return static_cast<int>(size);
}
bool TurnPort::CanHandleIncomingPacketsFrom(
const rtc::SocketAddress& addr) const {
return server_address_.address == addr;
}
void TurnPort::SendBindingErrorResponse(StunMessage* message,
const rtc::SocketAddress& addr,
int error_code,
absl::string_view reason) {
if (!GetConnection(addr))
return;
Port::SendBindingErrorResponse(message, addr, error_code, reason);
}
bool TurnPort::HandleIncomingPacket(rtc::AsyncPacketSocket* socket,
const rtc::ReceivedPacket& packet) {
if (socket != socket_) {
// The packet was received on a shared socket after we've allocated a new
// socket for this TURN port.
return false;
}
// This is to guard against a STUN response from previous server after
// alternative server redirection. TODO(guoweis): add a unit test for this
// race condition.
if (packet.source_address() != server_address_.address) {
RTC_LOG(LS_WARNING)
<< ToString() << ": Discarding TURN message from unknown address: "
<< packet.source_address().ToSensitiveNameAndAddressString()
<< " server_address_: "
<< server_address_.address.ToSensitiveNameAndAddressString();
return false;
}
// The message must be at least the size of a channel header.
if (packet.payload().size() < TURN_CHANNEL_HEADER_SIZE) {
RTC_LOG(LS_WARNING) << ToString()
<< ": Received TURN message that was too short";
return false;
}
if (state_ == STATE_DISCONNECTED) {
RTC_LOG(LS_WARNING)
<< ToString()
<< ": Received TURN message while the TURN port is disconnected";
return false;
}
const char* data = reinterpret_cast<const char*>(packet.payload().data());
int size = packet.payload().size();
int64_t packet_time_us =
packet.arrival_time() ? packet.arrival_time()->us() : -1;
// Check the message type, to see if is a Channel Data message.
// The message will either be channel data, a TURN data indication, or
// a response to a previous request.
uint16_t msg_type = rtc::GetBE16(packet.payload().data());
if (IsTurnChannelData(msg_type)) {
HandleChannelData(msg_type, data, size, packet_time_us);
return true;
}
if (msg_type == TURN_DATA_INDICATION) {
HandleDataIndication(data, size, packet_time_us);
return true;
}
if (SharedSocket() && (msg_type == STUN_BINDING_RESPONSE ||
msg_type == STUN_BINDING_ERROR_RESPONSE)) {
RTC_LOG(LS_VERBOSE)
<< ToString()
<< ": Ignoring STUN binding response message on shared socket.";
return false;
}
request_manager_.CheckResponse(data, size);
return true;
}
void TurnPort::OnReadPacket(rtc::AsyncPacketSocket* socket,
const rtc::ReceivedPacket& packet) {
HandleIncomingPacket(socket, packet);
}
void TurnPort::OnSentPacket(rtc::AsyncPacketSocket* socket,
const rtc::SentPacket& sent_packet) {
PortInterface::SignalSentPacket(sent_packet);
}
void TurnPort::OnReadyToSend(rtc::AsyncPacketSocket* socket) {
if (ready()) {
Port::OnReadyToSend();
}
}
bool TurnPort::SupportsProtocol(absl::string_view protocol) const {
// Turn port only connects to UDP candidates.
return protocol == UDP_PROTOCOL_NAME;
}
// Update current server address port with the alternate server address port.
bool TurnPort::SetAlternateServer(const rtc::SocketAddress& address) {
// Check if we have seen this address before and reject if we did.
AttemptedServerSet::iterator iter = attempted_server_addresses_.find(address);
if (iter != attempted_server_addresses_.end()) {
RTC_LOG(LS_WARNING) << ToString() << ": Redirection to ["
<< address.ToSensitiveNameAndAddressString()
<< "] ignored, allocation failed.";
return false;
}
// If protocol family of server address doesn't match with local, return.
if (!IsCompatibleAddress(address)) {
RTC_LOG(LS_WARNING) << "Server IP address family does not match with "
"local host address family type";
return false;
}
// Block redirects to a loopback address.
// See: https://bugs.chromium.org/p/chromium/issues/detail?id=649118
if (address.IsLoopbackIP()) {
RTC_LOG(LS_WARNING) << ToString()
<< ": Blocking attempted redirect to loopback address.";
return false;
}
RTC_LOG(LS_INFO) << ToString() << ": Redirecting from TURN server ["
<< server_address_.address.ToSensitiveNameAndAddressString()
<< "] to TURN server ["
<< address.ToSensitiveNameAndAddressString() << "]";
server_address_ = ProtocolAddress(address, server_address_.proto);
// Insert the current address to prevent redirection pingpong.
attempted_server_addresses_.insert(server_address_.address);
return true;
}
void TurnPort::ResolveTurnAddress(const rtc::SocketAddress& address) {
if (resolver_)
return;
RTC_LOG(LS_INFO) << ToString() << ": Starting TURN host lookup for "
<< address.ToSensitiveString();
resolver_ = socket_factory()->CreateAsyncDnsResolver();
auto callback = [this] {
// If DNS resolve is failed when trying to connect to the server using TCP,
// one of the reason could be due to DNS queries blocked by firewall.
// In such cases we will try to connect to the server with hostname,
// assuming socket layer will resolve the hostname through a HTTP proxy (if
// any).
auto& result = resolver_->result();
if (result.GetError() != 0 && (server_address_.proto == PROTO_TCP ||
server_address_.proto == PROTO_TLS)) {
if (!CreateTurnClientSocket()) {
OnAllocateError(SERVER_NOT_REACHABLE_ERROR,
"TURN host lookup received error.");
}
return;
}
// Copy the original server address in `resolved_address`. For TLS based
// sockets we need hostname along with resolved address.
rtc::SocketAddress resolved_address = server_address_.address;
if (result.GetError() != 0 ||
!result.GetResolvedAddress(Network()->GetBestIP().family(),
&resolved_address)) {
RTC_LOG(LS_WARNING) << ToString() << ": TURN host lookup received error "
<< result.GetError();
error_ = result.GetError();
OnAllocateError(SERVER_NOT_REACHABLE_ERROR,
"TURN host lookup received error.");
return;
}
server_address_.address = resolved_address;
PrepareAddress();
};
resolver_->Start(address, Network()->family(), std::move(callback));
}
void TurnPort::OnSendStunPacket(const void* data,
size_t size,
StunRequest* request) {
RTC_DCHECK(connected());
rtc::PacketOptions options(StunDscpValue());
options.info_signaled_after_sent.packet_type = rtc::PacketType::kTurnMessage;
CopyPortInformationToPacketInfo(&options.info_signaled_after_sent);
if (Send(data, size, options) < 0) {
RTC_LOG(LS_ERROR) << ToString() << ": Failed to send TURN message, error: "
<< socket_->GetError();
}
}
void TurnPort::OnStunAddress(const rtc::SocketAddress& address) {
// STUN Port will discover STUN candidate, as it's supplied with first TURN
// server address.
// Why not using this address? - P2PTransportChannel will start creating
// connections after first candidate, which means it could start creating the
// connections before TURN candidate added. For that to handle, we need to
// supply STUN candidate from this port to UDPPort, and TurnPort should have
// handle to UDPPort to pass back the address.
}
void TurnPort::OnAllocateSuccess(const rtc::SocketAddress& address,
const rtc::SocketAddress& stun_address) {
state_ = STATE_READY;
rtc::SocketAddress related_address = stun_address;
// For relayed candidate, Base is the candidate itself.
AddAddress(address, // Candidate address.
address, // Base address.
related_address, // Related address.
UDP_PROTOCOL_NAME,
ProtoToString(server_address_.proto), // The first hop protocol.
"", // TCP candidate type, empty for turn candidates.
IceCandidateType::kRelay,
GetRelayPreference(server_address_.proto), server_priority_,
server_url_, true);
}
void TurnPort::OnAllocateError(int error_code, absl::string_view reason) {
// We will send SignalPortError asynchronously as this can be sent during
// port initialization. This way it will not be blocking other port
// creation.
thread()->PostTask(
SafeTask(task_safety_.flag(), [this] { SignalPortError(this); }));
std::string address = GetLocalAddress().HostAsSensitiveURIString();
int port = GetLocalAddress().port();
if (server_address_.proto == PROTO_TCP &&
server_address_.address.IsPrivateIP()) {
address.clear();
port = 0;
}
SignalCandidateError(this, IceCandidateErrorEvent(address, port, server_url_,
error_code, reason));
}
void TurnPort::OnRefreshError() {
// Need to clear the requests asynchronously because otherwise, the refresh
// request may be deleted twice: once at the end of the message processing
// and the other in HandleRefreshError().
thread()->PostTask(
SafeTask(task_safety_.flag(), [this] { HandleRefreshError(); }));
}
void TurnPort::HandleRefreshError() {
request_manager_.Clear();
state_ = STATE_RECEIVEONLY;
// Fail and prune all connections; stop sending data.
for (auto kv : connections()) {
kv.second->FailAndPrune();
}
}
void TurnPort::Release() {
// Remove any pending refresh requests.
request_manager_.Clear();
// Send refresh with lifetime 0.
TurnRefreshRequest* req = new TurnRefreshRequest(this, 0);
SendRequest(req, 0);
state_ = STATE_RECEIVEONLY;
}
void TurnPort::Close() {
if (!ready()) {
OnAllocateError(SERVER_NOT_REACHABLE_ERROR, "");
}
request_manager_.Clear();
// Stop the port from creating new connections.
state_ = STATE_DISCONNECTED;
// Delete all existing connections; stop sending data.
DestroyAllConnections();
if (callbacks_for_test_) {
callbacks_for_test_->OnTurnPortClosed();
}
}
rtc::DiffServCodePoint TurnPort::StunDscpValue() const {
return stun_dscp_value_;
}
// static
bool TurnPort::AllowedTurnPort(int port,
const webrtc::FieldTrialsView* field_trials) {
// Port 53, 80 and 443 are used for existing deployments.
// Ports above 1024 are assumed to be OK to use.
if (port == 53 || port == 80 || port == 443 || port >= 1024) {
return true;
}
return false;
}
void TurnPort::TryAlternateServer() {
if (server_address().proto == PROTO_UDP) {
// Send another allocate request to alternate server, with the received
// realm and nonce values.
SendRequest(new TurnAllocateRequest(this), 0);
} else {
// Since it's TCP, we have to delete the connected socket and reconnect
// with the alternate server. PrepareAddress will send stun binding once
// the new socket is connected.
RTC_DCHECK(server_address().proto == PROTO_TCP ||
server_address().proto == PROTO_TLS);
RTC_DCHECK(!SharedSocket());
delete socket_;
socket_ = nullptr;
PrepareAddress();
}
}
void TurnPort::OnAllocateRequestTimeout() {
OnAllocateError(SERVER_NOT_REACHABLE_ERROR,
"TURN allocate request timed out.");
}
void TurnPort::HandleDataIndication(const char* data,
size_t size,
int64_t packet_time_us) {
// Read in the message, and process according to RFC5766, Section 10.4.
rtc::ByteBufferReader buf(
rtc::MakeArrayView(reinterpret_cast<const uint8_t*>(data), size));
TurnMessage msg;
if (!msg.Read(&buf)) {
RTC_LOG(LS_WARNING) << ToString()
<< ": Received invalid TURN data indication";
return;
}
// Check mandatory attributes.
const StunAddressAttribute* addr_attr =
msg.GetAddress(STUN_ATTR_XOR_PEER_ADDRESS);
if (!addr_attr) {
RTC_LOG(LS_WARNING) << ToString()
<< ": Missing STUN_ATTR_XOR_PEER_ADDRESS attribute "
"in data indication.";
return;
}
const StunByteStringAttribute* data_attr = msg.GetByteString(STUN_ATTR_DATA);
if (!data_attr) {
RTC_LOG(LS_WARNING) << ToString()
<< ": Missing STUN_ATTR_DATA attribute in "
"data indication.";
return;
}
// Log a warning if the data didn't come from an address that we think we have
// a permission for.
rtc::SocketAddress ext_addr(addr_attr->GetAddress());
if (!HasPermission(ext_addr.ipaddr())) {
RTC_LOG(LS_WARNING) << ToString()
<< ": Received TURN data indication with unknown "
"peer address, addr: "
<< ext_addr.ToSensitiveString();
}
// TODO(bugs.webrtc.org/14870): rebuild DispatchPacket to take an
// ArrayView<uint8_t>
DispatchPacket(reinterpret_cast<const char*>(data_attr->array_view().data()),
data_attr->length(), ext_addr, PROTO_UDP, packet_time_us);
}
void TurnPort::HandleChannelData(int channel_id,
const char* data,
size_t size,
int64_t packet_time_us) {
// Read the message, and process according to RFC5766, Section 11.6.
// 0 1 2 3
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Channel Number | Length |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | |
// / Application Data /
// / /
// | |
// | +-------------------------------+
// | |
// +-------------------------------+
// Extract header fields from the message.
uint16_t len = rtc::GetBE16(data + 2);
if (len > size - TURN_CHANNEL_HEADER_SIZE) {
RTC_LOG(LS_WARNING) << ToString()
<< ": Received TURN channel data message with "
"incorrect length, len: "
<< len;
return;
}
// Allowing messages larger than `len`, as ChannelData can be padded.
TurnEntry* entry = FindEntry(channel_id);
if (!entry) {
RTC_LOG(LS_WARNING) << ToString()
<< ": Received TURN channel data message for invalid "
"channel, channel_id: "
<< channel_id;
return;
}
DispatchPacket(data + TURN_CHANNEL_HEADER_SIZE, len, entry->address(),
PROTO_UDP, packet_time_us);
}
void TurnPort::DispatchPacket(const char* data,
size_t size,
const rtc::SocketAddress& remote_addr,
ProtocolType proto,
int64_t packet_time_us) {
rtc::ReceivedPacket packet = rtc::ReceivedPacket::CreateFromLegacy(
data, size, packet_time_us, remote_addr);
if (Connection* conn = GetConnection(remote_addr)) {
conn->OnReadPacket(packet);
} else {
Port::OnReadPacket(packet, proto);
}
}
bool TurnPort::ScheduleRefresh(uint32_t lifetime) {
// Lifetime is in seconds, delay is in milliseconds.
int delay = 1 * 60 * 1000;
// Cutoff lifetime bigger than 1h.
constexpr uint32_t max_lifetime = 60 * 60;
if (lifetime < 2 * 60) {
// The RFC does not mention a lower limit on lifetime.
// So if server sends a value less than 2 minutes, we schedule a refresh
// for half lifetime.
RTC_LOG(LS_WARNING) << ToString()
<< ": Received response with short lifetime: "
<< lifetime << " seconds.";
delay = (lifetime * 1000) / 2;
} else if (lifetime > max_lifetime) {
// Make 1 hour largest delay, and then we schedule a refresh for one minute
// less than max lifetime.
RTC_LOG(LS_WARNING) << ToString()
<< ": Received response with long lifetime: "
<< lifetime << " seconds.";
delay = (max_lifetime - 60) * 1000;
} else {
// Normal case,
// we schedule a refresh for one minute less than requested lifetime.
delay = (lifetime - 60) * 1000;
}
SendRequest(new TurnRefreshRequest(this), delay);
RTC_LOG(LS_INFO) << ToString() << ": Scheduled refresh in " << delay << "ms.";
return true;
}
void TurnPort::SendRequest(StunRequest* req, int delay) {
request_manager_.SendDelayed(req, delay);
}
void TurnPort::AddRequestAuthInfo(StunMessage* msg) {
// If we've gotten the necessary data from the server, add it to our request.
RTC_DCHECK(!hash_.empty());
msg->AddAttribute(std::make_unique<StunByteStringAttribute>(
STUN_ATTR_USERNAME, credentials_.username));
msg->AddAttribute(
std::make_unique<StunByteStringAttribute>(STUN_ATTR_REALM, realm_));
msg->AddAttribute(
std::make_unique<StunByteStringAttribute>(STUN_ATTR_NONCE, nonce_));
const bool success = msg->AddMessageIntegrity(hash());
RTC_DCHECK(success);
}
int TurnPort::Send(const void* data,
size_t len,
const rtc::PacketOptions& options) {
return socket_->SendTo(data, len, server_address_.address, options);
}
void TurnPort::UpdateHash() {
const bool success = ComputeStunCredentialHash(credentials_.username, realm_,
credentials_.password, &hash_);
RTC_DCHECK(success);
}
bool TurnPort::UpdateNonce(StunMessage* response) {
// When stale nonce error received, we should update
// hash and store realm and nonce.
// Check the mandatory attributes.
const StunByteStringAttribute* realm_attr =
response->GetByteString(STUN_ATTR_REALM);
if (!realm_attr) {
RTC_LOG(LS_ERROR) << "Missing STUN_ATTR_REALM attribute in "
"stale nonce error response.";
return false;
}
set_realm(realm_attr->string_view());
const StunByteStringAttribute* nonce_attr =
response->GetByteString(STUN_ATTR_NONCE);
if (!nonce_attr) {
RTC_LOG(LS_ERROR) << "Missing STUN_ATTR_NONCE attribute in "
"stale nonce error response.";
return false;
}
set_nonce(nonce_attr->string_view());
return true;
}
void TurnPort::ResetNonce() {
hash_.clear();
nonce_.clear();
realm_.clear();
}
bool TurnPort::HasPermission(const rtc::IPAddress& ipaddr) const {
return absl::c_any_of(entries_, [&ipaddr](const auto& e) {
return e->address().ipaddr() == ipaddr;
});
}
TurnEntry* TurnPort::FindEntry(const rtc::SocketAddress& addr) const {
auto it = absl::c_find_if(
entries_, [&addr](const auto& e) { return e->address() == addr; });
return (it != entries_.end()) ? it->get() : nullptr;
}
TurnEntry* TurnPort::FindEntry(int channel_id) const {
auto it = absl::c_find_if(entries_, [&channel_id](const auto& e) {
return e->channel_id() == channel_id;
});
return (it != entries_.end()) ? it->get() : nullptr;
}
bool TurnPort::CreateOrRefreshEntry(Connection* conn, int channel_number) {
const Candidate& remote_candidate = conn->remote_candidate();
TurnEntry* entry = FindEntry(remote_candidate.address());
if (entry == nullptr) {
entries_.push_back(std::make_unique<TurnEntry>(this, conn, channel_number));
return true;
}
// Associate this connection object with an existing entry. If the entry
// has been scheduled for deletion, this will cancel that task.
entry->TrackConnection(conn);
return false;
}
void TurnPort::HandleConnectionDestroyed(Connection* conn) {
// Schedule an event to destroy TurnEntry for the connection, which is
// being destroyed.
const rtc::SocketAddress& remote_address = conn->remote_candidate().address();
// We should always have an entry for this connection.
TurnEntry* entry = FindEntry(remote_address);
rtc::scoped_refptr<webrtc::PendingTaskSafetyFlag> flag =
entry->UntrackConnection(conn);
if (flag) {
// An assumption here is that the lifetime flag for the entry, is within
// the lifetime scope of `task_safety_` and therefore use of `this` is safe.
// If an entry gets reused (associated with a new connection) while this
// task is pending, the entry will reset the safety flag, thus cancel this
// task.
thread()->PostDelayedTask(SafeTask(flag,
[this, entry] {
entries_.erase(absl::c_find_if(
entries_, [entry](const auto& e) {
return e.get() == entry;
}));
}),
kTurnPermissionTimeout);
}
}
void TurnPort::SetCallbacksForTest(CallbacksForTest* callbacks) {
RTC_DCHECK(!callbacks_for_test_);
callbacks_for_test_ = callbacks;
}
bool TurnPort::SetEntryChannelId(const rtc::SocketAddress& address,
int channel_id) {
TurnEntry* entry = FindEntry(address);
if (!entry) {
return false;
}
entry->set_channel_id(channel_id);
return true;
}
std::string TurnPort::ReconstructServerUrl() {
// https://www.rfc-editor.org/rfc/rfc7065#section-3.1
// turnURI = scheme ":" host [ ":" port ]
// [ "?transport=" transport ]
// scheme = "turn" / "turns"
// transport = "udp" / "tcp" / transport-ext
// transport-ext = 1*unreserved
std::string scheme = "turn";
std::string transport = "tcp";
switch (server_address_.proto) {
case PROTO_SSLTCP:
case PROTO_TLS:
scheme = "turns";
break;
case PROTO_UDP:
transport = "udp";
break;
case PROTO_TCP:
break;
}
rtc::StringBuilder url;
url << scheme << ":" << server_address_.address.HostAsURIString() << ":"
<< server_address_.address.port() << "?transport=" << transport;
return url.Release();
}
void TurnPort::TurnCustomizerMaybeModifyOutgoingStunMessage(
StunMessage* message) {
if (turn_customizer_ == nullptr) {
return;
}
turn_customizer_->MaybeModifyOutgoingStunMessage(this, message);
}
bool TurnPort::TurnCustomizerAllowChannelData(const void* data,
size_t size,
bool payload) {
if (turn_customizer_ == nullptr) {
return true;
}
return turn_customizer_->AllowChannelData(this, data, size, payload);
}
void TurnPort::MaybeAddTurnLoggingId(StunMessage* msg) {
if (!turn_logging_id_.empty()) {
msg->AddAttribute(std::make_unique<StunByteStringAttribute>(
STUN_ATTR_TURN_LOGGING_ID, turn_logging_id_));
}
}
TurnAllocateRequest::TurnAllocateRequest(TurnPort* port)
: StunRequest(port->request_manager(),
std::make_unique<TurnMessage>(TURN_ALLOCATE_REQUEST)),
port_(port) {
StunMessage* message = mutable_msg();
// Create the request as indicated in RFC 5766, Section 6.1.
RTC_DCHECK_EQ(message->type(), TURN_ALLOCATE_REQUEST);
auto transport_attr =
StunAttribute::CreateUInt32(STUN_ATTR_REQUESTED_TRANSPORT);
transport_attr->SetValue(IPPROTO_UDP << 24);
message->AddAttribute(std::move(transport_attr));
if (!port_->hash().empty()) {
port_->AddRequestAuthInfo(message);
} else {
SetAuthenticationRequired(false);
}
port_->MaybeAddTurnLoggingId(message);
port_->TurnCustomizerMaybeModifyOutgoingStunMessage(message);
}
void TurnAllocateRequest::OnSent() {
RTC_LOG(LS_INFO) << port_->ToString() << ": TURN allocate request sent, id="
<< rtc::hex_encode(id());
StunRequest::OnSent();
}
void TurnAllocateRequest::OnResponse(StunMessage* response) {
RTC_LOG(LS_INFO) << port_->ToString()
<< ": TURN allocate requested successfully, id="
<< rtc::hex_encode(id())
<< ", code=0" // Makes logging easier to parse.
", rtt="
<< Elapsed();
// Check mandatory attributes as indicated in RFC5766, Section 6.3.
const StunAddressAttribute* mapped_attr =
response->GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
if (!mapped_attr) {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Missing STUN_ATTR_XOR_MAPPED_ADDRESS "
"attribute in allocate success response";
return;
}
// Using XOR-Mapped-Address for stun.
port_->OnStunAddress(mapped_attr->GetAddress());
const StunAddressAttribute* relayed_attr =
response->GetAddress(STUN_ATTR_XOR_RELAYED_ADDRESS);
if (!relayed_attr) {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Missing STUN_ATTR_XOR_RELAYED_ADDRESS "
"attribute in allocate success response";
return;
}
const StunUInt32Attribute* lifetime_attr =
response->GetUInt32(STUN_ATTR_TURN_LIFETIME);
if (!lifetime_attr) {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Missing STUN_ATTR_TURN_LIFETIME attribute in "
"allocate success response";
return;
}
// Notify the port the allocate succeeded, and schedule a refresh request.
port_->OnAllocateSuccess(relayed_attr->GetAddress(),
mapped_attr->GetAddress());
port_->ScheduleRefresh(lifetime_attr->value());
}
void TurnAllocateRequest::OnErrorResponse(StunMessage* response) {
// Process error response according to RFC5766, Section 6.4.
int error_code = response->GetErrorCodeValue();
RTC_LOG(LS_INFO) << port_->ToString()
<< ": Received TURN allocate error response, id="
<< rtc::hex_encode(id()) << ", code=" << error_code
<< ", rtt=" << Elapsed();
switch (error_code) {
case STUN_ERROR_UNAUTHORIZED: // Unauthrorized.
OnAuthChallenge(response, error_code);
break;
case STUN_ERROR_TRY_ALTERNATE:
OnTryAlternate(response, error_code);
break;
case STUN_ERROR_ALLOCATION_MISMATCH: {
// We must handle this error async because trying to delete the socket in
// OnErrorResponse will cause a deadlock on the socket.
TurnPort* port = port_;
port->thread()->PostTask(SafeTask(
port->task_safety_.flag(), [port] { port->OnAllocateMismatch(); }));
} break;
default:
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Received TURN allocate error response, id="
<< rtc::hex_encode(id()) << ", code=" << error_code
<< ", rtt=" << Elapsed();
const StunErrorCodeAttribute* attr = response->GetErrorCode();
port_->OnAllocateError(error_code, attr ? attr->reason() : "");
}
}
void TurnAllocateRequest::OnTimeout() {
RTC_LOG(LS_WARNING) << port_->ToString() << ": TURN allocate request "
<< rtc::hex_encode(id()) << " timeout";
port_->OnAllocateRequestTimeout();
}
void TurnAllocateRequest::OnAuthChallenge(StunMessage* response, int code) {
// If we failed to authenticate even after we sent our credentials, fail hard.
if (code == STUN_ERROR_UNAUTHORIZED && !port_->hash().empty()) {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Failed to authenticate with the server "
"after challenge.";
const StunErrorCodeAttribute* attr = response->GetErrorCode();
port_->OnAllocateError(STUN_ERROR_UNAUTHORIZED, attr ? attr->reason() : "");
return;
}
// Check the mandatory attributes.
const StunByteStringAttribute* realm_attr =
response->GetByteString(STUN_ATTR_REALM);
if (!realm_attr) {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Missing STUN_ATTR_REALM attribute in "
"allocate unauthorized response.";
return;
}
port_->set_realm(realm_attr->string_view());
const StunByteStringAttribute* nonce_attr =
response->GetByteString(STUN_ATTR_NONCE);
if (!nonce_attr) {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Missing STUN_ATTR_NONCE attribute in "
"allocate unauthorized response.";
return;
}
port_->set_nonce(nonce_attr->string_view());
// Send another allocate request, with the received realm and nonce values.
port_->SendRequest(new TurnAllocateRequest(port_), 0);
}
void TurnAllocateRequest::OnTryAlternate(StunMessage* response, int code) {
// According to RFC 5389 section 11, there are use cases where
// authentication of response is not possible, we're not validating
// message integrity.
const StunErrorCodeAttribute* error_code_attr = response->GetErrorCode();
// Get the alternate server address attribute value.
const StunAddressAttribute* alternate_server_attr =
response->GetAddress(STUN_ATTR_ALTERNATE_SERVER);
if (!alternate_server_attr) {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Missing STUN_ATTR_ALTERNATE_SERVER "
"attribute in try alternate error response";
port_->OnAllocateError(STUN_ERROR_TRY_ALTERNATE,
error_code_attr ? error_code_attr->reason() : "");
return;
}
if (!port_->SetAlternateServer(alternate_server_attr->GetAddress())) {
port_->OnAllocateError(STUN_ERROR_TRY_ALTERNATE,
error_code_attr ? error_code_attr->reason() : "");
return;
}
// Check the attributes.
const StunByteStringAttribute* realm_attr =
response->GetByteString(STUN_ATTR_REALM);
if (realm_attr) {
RTC_LOG(LS_INFO) << port_->ToString()
<< ": Applying STUN_ATTR_REALM attribute in "
"try alternate error response.";
port_->set_realm(realm_attr->string_view());
}
const StunByteStringAttribute* nonce_attr =
response->GetByteString(STUN_ATTR_NONCE);
if (nonce_attr) {
RTC_LOG(LS_INFO) << port_->ToString()
<< ": Applying STUN_ATTR_NONCE attribute in "
"try alternate error response.";
port_->set_nonce(nonce_attr->string_view());
}
// For TCP, we can't close the original Tcp socket during handling a 300 as
// we're still inside that socket's event handler. Doing so will cause
// deadlock.
TurnPort* port = port_;
port->thread()->PostTask(SafeTask(port->task_safety_.flag(),
[port] { port->TryAlternateServer(); }));
}
TurnRefreshRequest::TurnRefreshRequest(TurnPort* port, int lifetime /*= -1*/)
: StunRequest(port->request_manager(),
std::make_unique<TurnMessage>(TURN_REFRESH_REQUEST)),
port_(port) {
StunMessage* message = mutable_msg();
// Create the request as indicated in RFC 5766, Section 7.1.
// No attributes need to be included.
RTC_DCHECK_EQ(message->type(), TURN_REFRESH_REQUEST);
if (lifetime > -1) {
message->AddAttribute(
std::make_unique<StunUInt32Attribute>(STUN_ATTR_LIFETIME, lifetime));
}
port_->AddRequestAuthInfo(message);
port_->TurnCustomizerMaybeModifyOutgoingStunMessage(message);
}
void TurnRefreshRequest::OnSent() {
RTC_LOG(LS_INFO) << port_->ToString() << ": TURN refresh request sent, id="
<< rtc::hex_encode(id());
StunRequest::OnSent();
}
void TurnRefreshRequest::OnResponse(StunMessage* response) {
RTC_LOG(LS_INFO) << port_->ToString()
<< ": TURN refresh requested successfully, id="
<< rtc::hex_encode(id())
<< ", code=0" // Makes logging easier to parse.
", rtt="
<< Elapsed();
// Check mandatory attributes as indicated in RFC5766, Section 7.3.
const StunUInt32Attribute* lifetime_attr =
response->GetUInt32(STUN_ATTR_TURN_LIFETIME);
if (!lifetime_attr) {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Missing STUN_ATTR_TURN_LIFETIME attribute in "
"refresh success response.";
return;
}
if (lifetime_attr->value() > 0) {
// Schedule a refresh based on the returned lifetime value.
port_->ScheduleRefresh(lifetime_attr->value());
} else {
// If we scheduled a refresh with lifetime 0, we're releasing this
// allocation; see TurnPort::Release.
TurnPort* port = port_;
port->thread()->PostTask(
SafeTask(port->task_safety_.flag(), [port] { port->Close(); }));
}
if (port_->callbacks_for_test_) {
port_->callbacks_for_test_->OnTurnRefreshResult(TURN_SUCCESS_RESULT_CODE);
}
}
void TurnRefreshRequest::OnErrorResponse(StunMessage* response) {
int error_code = response->GetErrorCodeValue();
if (error_code == STUN_ERROR_STALE_NONCE) {
if (port_->UpdateNonce(response)) {
// Send RefreshRequest immediately.
port_->SendRequest(new TurnRefreshRequest(port_), 0);
}
} else {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Received TURN refresh error response, id="
<< rtc::hex_encode(id()) << ", code=" << error_code
<< ", rtt=" << Elapsed();
port_->OnRefreshError();
if (port_->callbacks_for_test_) {
port_->callbacks_for_test_->OnTurnRefreshResult(error_code);
}
}
}
void TurnRefreshRequest::OnTimeout() {
RTC_LOG(LS_WARNING) << port_->ToString() << ": TURN refresh timeout "
<< rtc::hex_encode(id());
port_->OnRefreshError();
}
TurnCreatePermissionRequest::TurnCreatePermissionRequest(
TurnPort* port,
TurnEntry* entry,
const rtc::SocketAddress& ext_addr)
: StunRequest(
port->request_manager(),
std::make_unique<TurnMessage>(TURN_CREATE_PERMISSION_REQUEST)),
port_(port),
entry_(entry),
ext_addr_(ext_addr) {
RTC_DCHECK(entry_);
entry_->destroyed_callback_list_.AddReceiver(this, [this](TurnEntry* entry) {
RTC_DCHECK(entry_ == entry);
entry_ = nullptr;
});
StunMessage* message = mutable_msg();
// Create the request as indicated in RFC5766, Section 9.1.
RTC_DCHECK_EQ(message->type(), TURN_CREATE_PERMISSION_REQUEST);
message->AddAttribute(std::make_unique<StunXorAddressAttribute>(
STUN_ATTR_XOR_PEER_ADDRESS, ext_addr_));
port_->AddRequestAuthInfo(message);
port_->TurnCustomizerMaybeModifyOutgoingStunMessage(message);
}
TurnCreatePermissionRequest::~TurnCreatePermissionRequest() {
if (entry_) {
entry_->destroyed_callback_list_.RemoveReceivers(this);
}
}
void TurnCreatePermissionRequest::OnSent() {
RTC_LOG(LS_INFO) << port_->ToString()
<< ": TURN create permission request sent, id="
<< rtc::hex_encode(id());
StunRequest::OnSent();
}
void TurnCreatePermissionRequest::OnResponse(StunMessage* response) {
RTC_LOG(LS_INFO) << port_->ToString()
<< ": TURN permission requested successfully, id="
<< rtc::hex_encode(id())
<< ", code=0" // Makes logging easier to parse.
", rtt="
<< Elapsed();
if (entry_) {
entry_->OnCreatePermissionSuccess();
}
}
void TurnCreatePermissionRequest::OnErrorResponse(StunMessage* response) {
int error_code = response->GetErrorCodeValue();
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Received TURN create permission error response, id="
<< rtc::hex_encode(id()) << ", code=" << error_code
<< ", rtt=" << Elapsed();
if (entry_) {
entry_->OnCreatePermissionError(response, error_code);
}
}
void TurnCreatePermissionRequest::OnTimeout() {
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": TURN create permission timeout "
<< rtc::hex_encode(id());
if (entry_) {
entry_->OnCreatePermissionTimeout();
}
}
TurnChannelBindRequest::TurnChannelBindRequest(
TurnPort* port,
TurnEntry* entry,
int channel_id,
const rtc::SocketAddress& ext_addr)
: StunRequest(port->request_manager(),
std::make_unique<TurnMessage>(TURN_CHANNEL_BIND_REQUEST)),
port_(port),
entry_(entry),
channel_id_(channel_id),
ext_addr_(ext_addr) {
RTC_DCHECK(entry_);
entry_->destroyed_callback_list_.AddReceiver(this, [this](TurnEntry* entry) {
RTC_DCHECK(entry_ == entry);
entry_ = nullptr;
});
StunMessage* message = mutable_msg();
// Create the request as indicated in RFC5766, Section 11.1.
RTC_DCHECK_EQ(message->type(), TURN_CHANNEL_BIND_REQUEST);
message->AddAttribute(std::make_unique<StunUInt32Attribute>(
STUN_ATTR_CHANNEL_NUMBER, channel_id_ << 16));
message->AddAttribute(std::make_unique<StunXorAddressAttribute>(
STUN_ATTR_XOR_PEER_ADDRESS, ext_addr_));
port_->AddRequestAuthInfo(message);
port_->TurnCustomizerMaybeModifyOutgoingStunMessage(message);
}
TurnChannelBindRequest::~TurnChannelBindRequest() {
if (entry_) {
entry_->destroyed_callback_list_.RemoveReceivers(this);
}
}
void TurnChannelBindRequest::OnSent() {
RTC_LOG(LS_INFO) << port_->ToString()
<< ": TURN channel bind request sent, id="
<< rtc::hex_encode(id());
StunRequest::OnSent();
}
void TurnChannelBindRequest::OnResponse(StunMessage* response) {
RTC_LOG(LS_INFO) << port_->ToString()
<< ": TURN channel bind requested successfully, id="
<< rtc::hex_encode(id())
<< ", code=0" // Makes logging easier to parse.
", rtt="
<< Elapsed();
if (entry_) {
entry_->OnChannelBindSuccess();
// Refresh the channel binding just under the permission timeout
// threshold. The channel binding has a longer lifetime, but
// this is the easiest way to keep both the channel and the
// permission from expiring.
TimeDelta delay = kTurnPermissionTimeout - TimeDelta::Minutes(1);
entry_->SendChannelBindRequest(delay.ms());
RTC_LOG(LS_INFO) << port_->ToString() << ": Scheduled channel bind in "
<< delay.ms() << "ms.";
}
}
void TurnChannelBindRequest::OnErrorResponse(StunMessage* response) {
int error_code = response->GetErrorCodeValue();
RTC_LOG(LS_WARNING) << port_->ToString()
<< ": Received TURN channel bind error response, id="
<< rtc::hex_encode(id()) << ", code=" << error_code
<< ", rtt=" << Elapsed();
if (entry_) {
entry_->OnChannelBindError(response, error_code);
}
}
void TurnChannelBindRequest::OnTimeout() {
RTC_LOG(LS_WARNING) << port_->ToString() << ": TURN channel bind timeout "
<< rtc::hex_encode(id());
if (entry_) {
entry_->OnChannelBindTimeout();
}
}
TurnEntry::TurnEntry(TurnPort* port, Connection* conn, int channel_id)
: port_(port),
channel_id_(channel_id),
ext_addr_(conn->remote_candidate().address()),
state_(STATE_UNBOUND),
connections_({conn}) {
// Creating permission for `ext_addr_`.
SendCreatePermissionRequest(0);
}
TurnEntry::~TurnEntry() {
destroyed_callback_list_.Send(this);
}
void TurnEntry::TrackConnection(Connection* conn) {
RTC_DCHECK(absl::c_find(connections_, conn) == connections_.end());
if (connections_.empty()) {
task_safety_.reset();
}
connections_.push_back(conn);
}
rtc::scoped_refptr<webrtc::PendingTaskSafetyFlag> TurnEntry::UntrackConnection(
Connection* conn) {
connections_.erase(absl::c_find(connections_, conn));
return connections_.empty() ? task_safety_.flag() : nullptr;
}
void TurnEntry::SendCreatePermissionRequest(int delay) {
port_->SendRequest(new TurnCreatePermissionRequest(port_, this, ext_addr_),
delay);
}
void TurnEntry::SendChannelBindRequest(int delay) {
port_->SendRequest(
new TurnChannelBindRequest(port_, this, channel_id_, ext_addr_), delay);
}
int TurnEntry::Send(const void* data,
size_t size,
bool payload,
const rtc::PacketOptions& options) {
rtc::ByteBufferWriter buf;
if (state_ != STATE_BOUND ||
!port_->TurnCustomizerAllowChannelData(data, size, payload)) {
// If we haven't bound the channel yet, we have to use a Send Indication.
// The turn_customizer_ can also make us use Send Indication.
TurnMessage msg(TURN_SEND_INDICATION);
msg.AddAttribute(std::make_unique<StunXorAddressAttribute>(
STUN_ATTR_XOR_PEER_ADDRESS, ext_addr_));
msg.AddAttribute(
std::make_unique<StunByteStringAttribute>(STUN_ATTR_DATA, data, size));
port_->TurnCustomizerMaybeModifyOutgoingStunMessage(&msg);
const bool success = msg.Write(&buf);
RTC_DCHECK(success);
// If we're sending real data, request a channel bind that we can use later.
if (state_ == STATE_UNBOUND && payload) {
SendChannelBindRequest(0);
state_ = STATE_BINDING;
}
} else {
// If the channel is bound, we can send the data as a Channel Message.
buf.WriteUInt16(channel_id_);
buf.WriteUInt16(static_cast<uint16_t>(size));
buf.WriteBytes(reinterpret_cast<const uint8_t*>(data), size);
}
rtc::PacketOptions modified_options(options);
modified_options.info_signaled_after_sent.turn_overhead_bytes =
buf.Length() - size;
return port_->Send(buf.Data(), buf.Length(), modified_options);
}
void TurnEntry::OnCreatePermissionSuccess() {
RTC_LOG(LS_INFO) << port_->ToString() << ": Create permission for "
<< ext_addr_.ToSensitiveString() << " succeeded";
if (port_->callbacks_for_test_) {
port_->callbacks_for_test_->OnTurnCreatePermissionResult(
TURN_SUCCESS_RESULT_CODE);
}
// If `state_` is STATE_BOUND, the permission will be refreshed
// by ChannelBindRequest.
if (state_ != STATE_BOUND) {
// Refresh the permission request about 1 minute before the permission
// times out.
TimeDelta delay = kTurnPermissionTimeout - TimeDelta::Minutes(1);
SendCreatePermissionRequest(delay.ms());
RTC_LOG(LS_INFO) << port_->ToString()
<< ": Scheduled create-permission-request in "
<< delay.ms() << "ms.";
}
}
void TurnEntry::OnCreatePermissionError(StunMessage* response, int code) {
if (code == STUN_ERROR_STALE_NONCE) {
if (port_->UpdateNonce(response)) {
SendCreatePermissionRequest(0);
}
} else {
bool found = port_->FailAndPruneConnection(ext_addr_);
if (found) {
RTC_LOG(LS_ERROR) << "Received TURN CreatePermission error response, "
"code="
<< code << "; pruned connection.";
}
}
if (port_->callbacks_for_test_) {
port_->callbacks_for_test_->OnTurnCreatePermissionResult(code);
}
}
void TurnEntry::OnCreatePermissionTimeout() {
port_->FailAndPruneConnection(ext_addr_);
}
void TurnEntry::OnChannelBindSuccess() {
RTC_LOG(LS_INFO) << port_->ToString() << ": Successful channel bind for "
<< ext_addr_.ToSensitiveString();
RTC_DCHECK(state_ == STATE_BINDING || state_ == STATE_BOUND);
state_ = STATE_BOUND;
}
void TurnEntry::OnChannelBindError(StunMessage* response, int code) {
// If the channel bind fails due to errors other than STATE_NONCE,
// we will fail and prune the connection and rely on ICE restart to
// re-establish a new connection if needed.
if (code == STUN_ERROR_STALE_NONCE) {
if (port_->UpdateNonce(response)) {
// Send channel bind request with fresh nonce.
SendChannelBindRequest(0);
}
} else {
state_ = STATE_UNBOUND;
port_->FailAndPruneConnection(ext_addr_);
}
}
void TurnEntry::OnChannelBindTimeout() {
state_ = STATE_UNBOUND;
port_->FailAndPruneConnection(ext_addr_);
}
} // namespace cricket