Google Git
Sign in
webrtc / src / f4f5cb09277d5ef6aeac8341e5f54a055867803a / . / webrtc / p2p / base / port.cc
blob: ddf38dcb189cfe90e1a1ecfa0278a8837d109271 [file] [log] [blame]
/*
* Copyright 2004 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 "webrtc/p2p/base/port.h"
#include <algorithm>
#include <vector>
#include "webrtc/p2p/base/common.h"
#include "webrtc/p2p/base/portallocator.h"
#include "webrtc/base/base64.h"
#include "webrtc/base/crc32.h"
#include "webrtc/base/helpers.h"
#include "webrtc/base/logging.h"
#include "webrtc/base/messagedigest.h"
#include "webrtc/base/scoped_ptr.h"
#include "webrtc/base/stringencode.h"
#include "webrtc/base/stringutils.h"
namespace {
// Determines whether we have seen at least the given maximum number of
// pings fail to have a response.
inline bool TooManyFailures(
const std::vector<cricket::Connection::SentPing>& pings_since_last_response,
uint32_t maximum_failures,
uint32_t rtt_estimate,
uint32_t now) {
// If we haven't sent that many pings, then we can't have failed that many.
if (pings_since_last_response.size() < maximum_failures)
return false;
// Check if the window in which we would expect a response to the ping has
// already elapsed.
uint32_t expected_response_time =
pings_since_last_response[maximum_failures - 1].sent_time + rtt_estimate;
return now > expected_response_time;
}
// Determines whether we have gone too long without seeing any response.
inline bool TooLongWithoutResponse(
const std::vector<cricket::Connection::SentPing>& pings_since_last_response,
uint32_t maximum_time,
uint32_t now) {
if (pings_since_last_response.size() == 0)
return false;
auto first = pings_since_last_response[0];
return now > (first.sent_time + maximum_time);
}
// We will restrict RTT estimates (when used for determining state) to be
// within a reasonable range.
const uint32_t MINIMUM_RTT = 100; // 0.1 seconds
const uint32_t MAXIMUM_RTT = 3000; // 3 seconds
// When we don't have any RTT data, we have to pick something reasonable. We
// use a large value just in case the connection is really slow.
const uint32_t DEFAULT_RTT = MAXIMUM_RTT;
// Computes our estimate of the RTT given the current estimate.
inline uint32_t ConservativeRTTEstimate(uint32_t rtt) {
return std::max(MINIMUM_RTT, std::min(MAXIMUM_RTT, 2 * rtt));
}
// Weighting of the old rtt value to new data.
const int RTT_RATIO = 3; // 3 : 1
// The delay before we begin checking if this port is useless.
const int kPortTimeoutDelay = 30 * 1000; // 30 seconds
}
namespace cricket {
// TODO(ronghuawu): Use "host", "srflx", "prflx" and "relay". But this requires
// the signaling part be updated correspondingly as well.
const char LOCAL_PORT_TYPE[] = "local";
const char STUN_PORT_TYPE[] = "stun";
const char PRFLX_PORT_TYPE[] = "prflx";
const char RELAY_PORT_TYPE[] = "relay";
const char UDP_PROTOCOL_NAME[] = "udp";
const char TCP_PROTOCOL_NAME[] = "tcp";
const char SSLTCP_PROTOCOL_NAME[] = "ssltcp";
static const char* const PROTO_NAMES[] = { UDP_PROTOCOL_NAME,
TCP_PROTOCOL_NAME,
SSLTCP_PROTOCOL_NAME };
const char* ProtoToString(ProtocolType proto) {
return PROTO_NAMES[proto];
}
bool StringToProto(const char* value, ProtocolType* proto) {
for (size_t i = 0; i <= PROTO_LAST; ++i) {
if (_stricmp(PROTO_NAMES[i], value) == 0) {
*proto = static_cast<ProtocolType>(i);
return true;
}
}
return false;
}
// RFC 6544, TCP candidate encoding rules.
const int DISCARD_PORT = 9;
const char TCPTYPE_ACTIVE_STR[] = "active";
const char TCPTYPE_PASSIVE_STR[] = "passive";
const char TCPTYPE_SIMOPEN_STR[] = "so";
// Foundation: An arbitrary string that is the same for two candidates
// that have the same type, base IP address, protocol (UDP, TCP,
// etc.), and STUN or TURN server. If any of these are different,
// then the foundation will be different. Two candidate pairs with
// the same foundation pairs are likely to have similar network
// characteristics. Foundations are used in the frozen algorithm.
static std::string ComputeFoundation(
const std::string& type,
const std::string& protocol,
const rtc::SocketAddress& base_address) {
std::ostringstream ost;
ost << type << base_address.ipaddr().ToString() << protocol;
return rtc::ToString<uint32_t>(rtc::ComputeCrc32(ost.str()));
}
Port::Port(rtc::Thread* thread,
rtc::PacketSocketFactory* factory,
rtc::Network* network,
const rtc::IPAddress& ip,
const std::string& username_fragment,
const std::string& password)
: thread_(thread),
factory_(factory),
send_retransmit_count_attribute_(false),
network_(network),
ip_(ip),
min_port_(0),
max_port_(0),
component_(ICE_CANDIDATE_COMPONENT_DEFAULT),
generation_(0),
ice_username_fragment_(username_fragment),
password_(password),
timeout_delay_(kPortTimeoutDelay),
enable_port_packets_(false),
ice_role_(ICEROLE_UNKNOWN),
tiebreaker_(0),
shared_socket_(true),
candidate_filter_(CF_ALL) {
Construct();
}
Port::Port(rtc::Thread* thread,
const std::string& type,
rtc::PacketSocketFactory* factory,
rtc::Network* network,
const rtc::IPAddress& ip,
uint16_t min_port,
uint16_t max_port,
const std::string& username_fragment,
const std::string& password)
: thread_(thread),
factory_(factory),
type_(type),
send_retransmit_count_attribute_(false),
network_(network),
ip_(ip),
min_port_(min_port),
max_port_(max_port),
component_(ICE_CANDIDATE_COMPONENT_DEFAULT),
generation_(0),
ice_username_fragment_(username_fragment),
password_(password),
timeout_delay_(kPortTimeoutDelay),
enable_port_packets_(false),
ice_role_(ICEROLE_UNKNOWN),
tiebreaker_(0),
shared_socket_(false),
candidate_filter_(CF_ALL) {
ASSERT(factory_ != NULL);
Construct();
}
void Port::Construct() {
// TODO(pthatcher): Remove this old behavior once we're sure no one
// relies on it. If the username_fragment and password are empty,
// we should just create one.
if (ice_username_fragment_.empty()) {
ASSERT(password_.empty());
ice_username_fragment_ = rtc::CreateRandomString(ICE_UFRAG_LENGTH);
password_ = rtc::CreateRandomString(ICE_PWD_LENGTH);
}
LOG_J(LS_INFO, this) << "Port created";
}
Port::~Port() {
// Delete all of the remaining connections. We copy the list up front
// because each deletion will cause it to be modified.
std::vector<Connection*> list;
AddressMap::iterator iter = connections_.begin();
while (iter != connections_.end()) {
list.push_back(iter->second);
++iter;
}
for (uint32_t i = 0; i < list.size(); i++)
delete list[i];
}
Connection* Port::GetConnection(const rtc::SocketAddress& remote_addr) {
AddressMap::const_iterator iter = connections_.find(remote_addr);
if (iter != connections_.end())
return iter->second;
else
return NULL;
}
void Port::AddAddress(const rtc::SocketAddress& address,
const rtc::SocketAddress& base_address,
const rtc::SocketAddress& related_address,
const std::string& protocol,
const std::string& relay_protocol,
const std::string& tcptype,
const std::string& type,
uint32_t type_preference,
uint32_t relay_preference,
bool final) {
if (protocol == TCP_PROTOCOL_NAME && type == LOCAL_PORT_TYPE) {
ASSERT(!tcptype.empty());
}
Candidate c;
c.set_id(rtc::CreateRandomString(8));
c.set_component(component_);
c.set_type(type);
c.set_protocol(protocol);
c.set_relay_protocol(relay_protocol);
c.set_tcptype(tcptype);
c.set_address(address);
c.set_priority(c.GetPriority(type_preference, network_->preference(),
relay_preference));
c.set_username(username_fragment());
c.set_password(password_);
c.set_network_name(network_->name());
c.set_network_type(network_->type());
c.set_generation(generation_);
c.set_related_address(related_address);
c.set_foundation(ComputeFoundation(type, protocol, base_address));
candidates_.push_back(c);
SignalCandidateReady(this, c);
if (final) {
SignalPortComplete(this);
}
}
void Port::AddConnection(Connection* conn) {
connections_[conn->remote_candidate().address()] = conn;
conn->SignalDestroyed.connect(this, &Port::OnConnectionDestroyed);
SignalConnectionCreated(this, conn);
}
void Port::OnReadPacket(
const char* data, size_t size, const rtc::SocketAddress& addr,
ProtocolType proto) {
// If the user has enabled port packets, just hand this over.
if (enable_port_packets_) {
SignalReadPacket(this, data, size, addr);
return;
}
// If this is an authenticated STUN request, then signal unknown address and
// send back a proper binding response.
rtc::scoped_ptr<IceMessage> msg;
std::string remote_username;
if (!GetStunMessage(data, size, addr, msg.accept(), &remote_username)) {
LOG_J(LS_ERROR, this) << "Received non-STUN packet from unknown address ("
<< addr.ToSensitiveString() << ")";
} else if (!msg) {
// STUN message handled already
} else if (msg->type() == STUN_BINDING_REQUEST) {
LOG(LS_INFO) << "Received STUN ping "
<< " id=" << rtc::hex_encode(msg->transaction_id())
<< " from unknown address " << addr.ToSensitiveString();
// Check for role conflicts.
if (!MaybeIceRoleConflict(addr, msg.get(), remote_username)) {
LOG(LS_INFO) << "Received conflicting role from the peer.";
return;
}
SignalUnknownAddress(this, addr, proto, msg.get(), remote_username, false);
} else {
// NOTE(tschmelcher): STUN_BINDING_RESPONSE is benign. It occurs if we
// pruned a connection for this port while it had STUN requests in flight,
// because we then get back responses for them, which this code correctly
// does not handle.
if (msg->type() != STUN_BINDING_RESPONSE) {
LOG_J(LS_ERROR, this) << "Received unexpected STUN message type ("
<< msg->type() << ") from unknown address ("
<< addr.ToSensitiveString() << ")";
}
}
}
void Port::OnSentPacket(const rtc::SentPacket& sent_packet) {
PortInterface::SignalSentPacket(this, sent_packet);
}
void Port::OnReadyToSend() {
AddressMap::iterator iter = connections_.begin();
for (; iter != connections_.end(); ++iter) {
iter->second->OnReadyToSend();
}
}
size_t Port::AddPrflxCandidate(const Candidate& local) {
candidates_.push_back(local);
return (candidates_.size() - 1);
}
bool Port::GetStunMessage(const char* data, size_t size,
const rtc::SocketAddress& addr,
IceMessage** out_msg, std::string* out_username) {
// NOTE: This could clearly be optimized to avoid allocating any memory.
// However, at the data rates we'll be looking at on the client side,
// this probably isn't worth worrying about.
ASSERT(out_msg != NULL);
ASSERT(out_username != NULL);
*out_msg = NULL;
out_username->clear();
// Don't bother parsing the packet if we can tell it's not STUN.
// In ICE mode, all STUN packets will have a valid fingerprint.
if (!StunMessage::ValidateFingerprint(data, size)) {
return false;
}
// Parse the request message. If the packet is not a complete and correct
// STUN message, then ignore it.
rtc::scoped_ptr<IceMessage> stun_msg(new IceMessage());
rtc::ByteBuffer buf(data, size);
if (!stun_msg->Read(&buf) || (buf.Length() > 0)) {
return false;
}
if (stun_msg->type() == STUN_BINDING_REQUEST) {
// Check for the presence of USERNAME and MESSAGE-INTEGRITY (if ICE) first.
// If not present, fail with a 400 Bad Request.
if (!stun_msg->GetByteString(STUN_ATTR_USERNAME) ||
!stun_msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY)) {
LOG_J(LS_ERROR, this) << "Received STUN request without username/M-I "
<< "from " << addr.ToSensitiveString();
SendBindingErrorResponse(stun_msg.get(), addr, STUN_ERROR_BAD_REQUEST,
STUN_ERROR_REASON_BAD_REQUEST);
return true;
}
// If the username is bad or unknown, fail with a 401 Unauthorized.
std::string local_ufrag;
std::string remote_ufrag;
if (!ParseStunUsername(stun_msg.get(), &local_ufrag, &remote_ufrag) ||
local_ufrag != username_fragment()) {
LOG_J(LS_ERROR, this) << "Received STUN request with bad local username "
<< local_ufrag << " from "
<< addr.ToSensitiveString();
SendBindingErrorResponse(stun_msg.get(), addr, STUN_ERROR_UNAUTHORIZED,
STUN_ERROR_REASON_UNAUTHORIZED);
return true;
}
// If ICE, and the MESSAGE-INTEGRITY is bad, fail with a 401 Unauthorized
if (!stun_msg->ValidateMessageIntegrity(data, size, password_)) {
LOG_J(LS_ERROR, this) << "Received STUN request with bad M-I "
<< "from " << addr.ToSensitiveString()
<< ", password_=" << password_;
SendBindingErrorResponse(stun_msg.get(), addr, STUN_ERROR_UNAUTHORIZED,
STUN_ERROR_REASON_UNAUTHORIZED);
return true;
}
out_username->assign(remote_ufrag);
} else if ((stun_msg->type() == STUN_BINDING_RESPONSE) ||
(stun_msg->type() == STUN_BINDING_ERROR_RESPONSE)) {
if (stun_msg->type() == STUN_BINDING_ERROR_RESPONSE) {
if (const StunErrorCodeAttribute* error_code = stun_msg->GetErrorCode()) {
LOG_J(LS_ERROR, this) << "Received STUN binding error:"
<< " class=" << error_code->eclass()
<< " number=" << error_code->number()
<< " reason='" << error_code->reason() << "'"
<< " from " << addr.ToSensitiveString();
// Return message to allow error-specific processing
} else {
LOG_J(LS_ERROR, this) << "Received STUN binding error without a error "
<< "code from " << addr.ToSensitiveString();
return true;
}
}
// NOTE: Username should not be used in verifying response messages.
out_username->clear();
} else if (stun_msg->type() == STUN_BINDING_INDICATION) {
LOG_J(LS_VERBOSE, this) << "Received STUN binding indication:"
<< " from " << addr.ToSensitiveString();
out_username->clear();
// No stun attributes will be verified, if it's stun indication message.
// Returning from end of the this method.
} else {
LOG_J(LS_ERROR, this) << "Received STUN packet with invalid type ("
<< stun_msg->type() << ") from "
<< addr.ToSensitiveString();
return true;
}
// Return the STUN message found.
*out_msg = stun_msg.release();
return true;
}
bool Port::IsCompatibleAddress(const rtc::SocketAddress& addr) {
int family = ip().family();
// We use single-stack sockets, so families must match.
if (addr.family() != family) {
return false;
}
// Link-local IPv6 ports can only connect to other link-local IPv6 ports.
if (family == AF_INET6 &&
(IPIsLinkLocal(ip()) != IPIsLinkLocal(addr.ipaddr()))) {
return false;
}
return true;
}
bool Port::ParseStunUsername(const StunMessage* stun_msg,
std::string* local_ufrag,
std::string* remote_ufrag) const {
// The packet must include a username that either begins or ends with our
// fragment. It should begin with our fragment if it is a request and it
// should end with our fragment if it is a response.
local_ufrag->clear();
remote_ufrag->clear();
const StunByteStringAttribute* username_attr =
stun_msg->GetByteString(STUN_ATTR_USERNAME);
if (username_attr == NULL)
return false;
// RFRAG:LFRAG
const std::string username = username_attr->GetString();
size_t colon_pos = username.find(":");
if (colon_pos == std::string::npos) {
return false;
}
*local_ufrag = username.substr(0, colon_pos);
*remote_ufrag = username.substr(colon_pos + 1, username.size());
return true;
}
bool Port::MaybeIceRoleConflict(
const rtc::SocketAddress& addr, IceMessage* stun_msg,
const std::string& remote_ufrag) {
// Validate ICE_CONTROLLING or ICE_CONTROLLED attributes.
bool ret = true;
IceRole remote_ice_role = ICEROLE_UNKNOWN;
uint64_t remote_tiebreaker = 0;
const StunUInt64Attribute* stun_attr =
stun_msg->GetUInt64(STUN_ATTR_ICE_CONTROLLING);
if (stun_attr) {
remote_ice_role = ICEROLE_CONTROLLING;
remote_tiebreaker = stun_attr->value();
}
// If |remote_ufrag| is same as port local username fragment and
// tie breaker value received in the ping message matches port
// tiebreaker value this must be a loopback call.
// We will treat this as valid scenario.
if (remote_ice_role == ICEROLE_CONTROLLING &&
username_fragment() == remote_ufrag &&
remote_tiebreaker == IceTiebreaker()) {
return true;
}
stun_attr = stun_msg->GetUInt64(STUN_ATTR_ICE_CONTROLLED);
if (stun_attr) {
remote_ice_role = ICEROLE_CONTROLLED;
remote_tiebreaker = stun_attr->value();
}
switch (ice_role_) {
case ICEROLE_CONTROLLING:
if (ICEROLE_CONTROLLING == remote_ice_role) {
if (remote_tiebreaker >= tiebreaker_) {
SignalRoleConflict(this);
} else {
// Send Role Conflict (487) error response.
SendBindingErrorResponse(stun_msg, addr,
STUN_ERROR_ROLE_CONFLICT, STUN_ERROR_REASON_ROLE_CONFLICT);
ret = false;
}
}
break;
case ICEROLE_CONTROLLED:
if (ICEROLE_CONTROLLED == remote_ice_role) {
if (remote_tiebreaker < tiebreaker_) {
SignalRoleConflict(this);
} else {
// Send Role Conflict (487) error response.
SendBindingErrorResponse(stun_msg, addr,
STUN_ERROR_ROLE_CONFLICT, STUN_ERROR_REASON_ROLE_CONFLICT);
ret = false;
}
}
break;
default:
ASSERT(false);
}
return ret;
}
void Port::CreateStunUsername(const std::string& remote_username,
std::string* stun_username_attr_str) const {
stun_username_attr_str->clear();
*stun_username_attr_str = remote_username;
stun_username_attr_str->append(":");
stun_username_attr_str->append(username_fragment());
}
void Port::SendBindingResponse(StunMessage* request,
const rtc::SocketAddress& addr) {
ASSERT(request->type() == STUN_BINDING_REQUEST);
// Retrieve the username from the request.
const StunByteStringAttribute* username_attr =
request->GetByteString(STUN_ATTR_USERNAME);
ASSERT(username_attr != NULL);
if (username_attr == NULL) {
// No valid username, skip the response.
return;
}
// Fill in the response message.
StunMessage response;
response.SetType(STUN_BINDING_RESPONSE);
response.SetTransactionID(request->transaction_id());
const StunUInt32Attribute* retransmit_attr =
request->GetUInt32(STUN_ATTR_RETRANSMIT_COUNT);
if (retransmit_attr) {
// Inherit the incoming retransmit value in the response so the other side
// can see our view of lost pings.
response.AddAttribute(new StunUInt32Attribute(
STUN_ATTR_RETRANSMIT_COUNT, retransmit_attr->value()));
if (retransmit_attr->value() > CONNECTION_WRITE_CONNECT_FAILURES) {
LOG_J(LS_INFO, this)
<< "Received a remote ping with high retransmit count: "
<< retransmit_attr->value();
}
}
response.AddAttribute(
new StunXorAddressAttribute(STUN_ATTR_XOR_MAPPED_ADDRESS, addr));
response.AddMessageIntegrity(password_);
response.AddFingerprint();
// Send the response message.
rtc::ByteBuffer buf;
response.Write(&buf);
rtc::PacketOptions options(DefaultDscpValue());
auto err = SendTo(buf.Data(), buf.Length(), addr, options, false);
if (err < 0) {
LOG_J(LS_ERROR, this)
<< "Failed to send STUN ping response"
<< ", to=" << addr.ToSensitiveString()
<< ", err=" << err
<< ", id=" << rtc::hex_encode(response.transaction_id());
} else {
// Log at LS_INFO if we send a stun ping response on an unwritable
// connection.
Connection* conn = GetConnection(addr);
rtc::LoggingSeverity sev = (conn && !conn->writable()) ?
rtc::LS_INFO : rtc::LS_VERBOSE;
LOG_JV(sev, this)
<< "Sent STUN ping response"
<< ", to=" << addr.ToSensitiveString()
<< ", id=" << rtc::hex_encode(response.transaction_id());
}
}
void Port::SendBindingErrorResponse(StunMessage* request,
const rtc::SocketAddress& addr,
int error_code, const std::string& reason) {
ASSERT(request->type() == STUN_BINDING_REQUEST);
// Fill in the response message.
StunMessage response;
response.SetType(STUN_BINDING_ERROR_RESPONSE);
response.SetTransactionID(request->transaction_id());
// When doing GICE, we need to write out the error code incorrectly to
// maintain backwards compatiblility.
StunErrorCodeAttribute* error_attr = StunAttribute::CreateErrorCode();
error_attr->SetCode(error_code);
error_attr->SetReason(reason);
response.AddAttribute(error_attr);
// Per Section 10.1.2, certain error cases don't get a MESSAGE-INTEGRITY,
// because we don't have enough information to determine the shared secret.
if (error_code != STUN_ERROR_BAD_REQUEST &&
error_code != STUN_ERROR_UNAUTHORIZED)
response.AddMessageIntegrity(password_);
response.AddFingerprint();
// Send the response message.
rtc::ByteBuffer buf;
response.Write(&buf);
rtc::PacketOptions options(DefaultDscpValue());
SendTo(buf.Data(), buf.Length(), addr, options, false);
LOG_J(LS_INFO, this) << "Sending STUN binding error: reason=" << reason
<< " to " << addr.ToSensitiveString();
}
void Port::OnMessage(rtc::Message *pmsg) {
ASSERT(pmsg->message_id == MSG_DEAD);
if (dead()) {
Destroy();
}
}
std::string Port::ToString() const {
std::stringstream ss;
ss << "Port[" << content_name_ << ":" << component_
<< ":" << generation_ << ":" << type_
<< ":" << network_->ToString() << "]";
return ss.str();
}
void Port::EnablePortPackets() {
enable_port_packets_ = true;
}
void Port::OnConnectionDestroyed(Connection* conn) {
AddressMap::iterator iter =
connections_.find(conn->remote_candidate().address());
ASSERT(iter != connections_.end());
connections_.erase(iter);
// On the controlled side, ports time out after all connections fail.
// Note: If a new connection is added after this message is posted, but it
// fails and is removed before kPortTimeoutDelay, then this message will
// still cause the Port to be destroyed.
if (dead()) {
thread_->PostDelayed(timeout_delay_, this, MSG_DEAD);
}
}
void Port::Destroy() {
ASSERT(connections_.empty());
LOG_J(LS_INFO, this) << "Port deleted";
SignalDestroyed(this);
delete this;
}
const std::string Port::username_fragment() const {
return ice_username_fragment_;
}
// A ConnectionRequest is a simple STUN ping used to determine writability.
class ConnectionRequest : public StunRequest {
public:
explicit ConnectionRequest(Connection* connection)
: StunRequest(new IceMessage()),
connection_(connection) {
}
virtual ~ConnectionRequest() {
}
void Prepare(StunMessage* request) override {
request->SetType(STUN_BINDING_REQUEST);
std::string username;
connection_->port()->CreateStunUsername(
connection_->remote_candidate().username(), &username);
request->AddAttribute(
new StunByteStringAttribute(STUN_ATTR_USERNAME, username));
// connection_ already holds this ping, so subtract one from count.
if (connection_->port()->send_retransmit_count_attribute()) {
request->AddAttribute(new StunUInt32Attribute(
STUN_ATTR_RETRANSMIT_COUNT,
static_cast<uint32_t>(connection_->pings_since_last_response_.size() -
1)));
}
// Adding ICE_CONTROLLED or ICE_CONTROLLING attribute based on the role.
if (connection_->port()->GetIceRole() == ICEROLE_CONTROLLING) {
request->AddAttribute(new StunUInt64Attribute(
STUN_ATTR_ICE_CONTROLLING, connection_->port()->IceTiebreaker()));
// Since we are trying aggressive nomination, sending USE-CANDIDATE
// attribute in every ping.
// If we are dealing with a ice-lite end point, nomination flag
// in Connection will be set to false by default. Once the connection
// becomes "best connection", nomination flag will be turned on.
if (connection_->use_candidate_attr()) {
request->AddAttribute(new StunByteStringAttribute(
STUN_ATTR_USE_CANDIDATE));
}
} else if (connection_->port()->GetIceRole() == ICEROLE_CONTROLLED) {
request->AddAttribute(new StunUInt64Attribute(
STUN_ATTR_ICE_CONTROLLED, connection_->port()->IceTiebreaker()));
} else {
ASSERT(false);
}
// Adding PRIORITY Attribute.
// Changing the type preference to Peer Reflexive and local preference
// and component id information is unchanged from the original priority.
// priority = (2^24)*(type preference) +
// (2^8)*(local preference) +
// (2^0)*(256 - component ID)
uint32_t prflx_priority =
ICE_TYPE_PREFERENCE_PRFLX << 24 |
(connection_->local_candidate().priority() & 0x00FFFFFF);
request->AddAttribute(
new StunUInt32Attribute(STUN_ATTR_PRIORITY, prflx_priority));
// Adding Message Integrity attribute.
request->AddMessageIntegrity(connection_->remote_candidate().password());
// Adding Fingerprint.
request->AddFingerprint();
}
void OnResponse(StunMessage* response) override {
connection_->OnConnectionRequestResponse(this, response);
}
void OnErrorResponse(StunMessage* response) override {
connection_->OnConnectionRequestErrorResponse(this, response);
}
void OnTimeout() override {
connection_->OnConnectionRequestTimeout(this);
}
void OnSent() override {
connection_->OnConnectionRequestSent(this);
// Each request is sent only once. After a single delay , the request will
// time out.
timeout_ = true;
}
int resend_delay() override {
return CONNECTION_RESPONSE_TIMEOUT;
}
private:
Connection* connection_;
};
//
// Connection
//
Connection::Connection(Port* port,
size_t index,
const Candidate& remote_candidate)
: port_(port),
local_candidate_index_(index),
remote_candidate_(remote_candidate),
write_state_(STATE_WRITE_INIT),
receiving_(false),
connected_(true),
pruned_(false),
use_candidate_attr_(false),
nominated_(false),
remote_ice_mode_(ICEMODE_FULL),
requests_(port->thread()),
rtt_(DEFAULT_RTT),
last_ping_sent_(0),
last_ping_received_(0),
last_data_received_(0),
last_ping_response_received_(0),
recv_rate_tracker_(100u, 10u),
send_rate_tracker_(100u, 10u),
sent_packets_discarded_(0),
sent_packets_total_(0),
reported_(false),
state_(STATE_WAITING),
receiving_timeout_(WEAK_CONNECTION_RECEIVE_TIMEOUT),
time_created_ms_(rtc::Time()) {
// All of our connections start in WAITING state.
// TODO(mallinath) - Start connections from STATE_FROZEN.
// Wire up to send stun packets
requests_.SignalSendPacket.connect(this, &Connection::OnSendStunPacket);
LOG_J(LS_INFO, this) << "Connection created";
}
Connection::~Connection() {
}
const Candidate& Connection::local_candidate() const {
ASSERT(local_candidate_index_ < port_->Candidates().size());
return port_->Candidates()[local_candidate_index_];
}
uint64_t Connection::priority() const {
uint64_t priority = 0;
// RFC 5245 - 5.7.2. Computing Pair Priority and Ordering Pairs
// Let G be the priority for the candidate provided by the controlling
// agent. Let D be the priority for the candidate provided by the
// controlled agent.
// pair priority = 2^32*MIN(G,D) + 2*MAX(G,D) + (G>D?1:0)
IceRole role = port_->GetIceRole();
if (role != ICEROLE_UNKNOWN) {
uint32_t g = 0;
uint32_t d = 0;
if (role == ICEROLE_CONTROLLING) {
g = local_candidate().priority();
d = remote_candidate_.priority();
} else {
g = remote_candidate_.priority();
d = local_candidate().priority();
}
priority = std::min(g, d);
priority = priority << 32;
priority += 2 * std::max(g, d) + (g > d ? 1 : 0);
}
return priority;
}
void Connection::set_write_state(WriteState value) {
WriteState old_value = write_state_;
write_state_ = value;
if (value != old_value) {
LOG_J(LS_VERBOSE, this) << "set_write_state from: " << old_value << " to "
<< value;
SignalStateChange(this);
}
}
void Connection::set_receiving(bool value) {
if (value != receiving_) {
LOG_J(LS_VERBOSE, this) << "set_receiving to " << value;
receiving_ = value;
SignalStateChange(this);
}
}
void Connection::set_state(State state) {
State old_state = state_;
state_ = state;
if (state != old_state) {
LOG_J(LS_VERBOSE, this) << "set_state";
}
}
void Connection::set_connected(bool value) {
bool old_value = connected_;
connected_ = value;
if (value != old_value) {
LOG_J(LS_VERBOSE, this) << "set_connected from: " << old_value << " to "
<< value;
}
}
void Connection::set_use_candidate_attr(bool enable) {
use_candidate_attr_ = enable;
}
void Connection::OnSendStunPacket(const void* data, size_t size,
StunRequest* req) {
rtc::PacketOptions options(port_->DefaultDscpValue());
auto err = port_->SendTo(
data, size, remote_candidate_.address(), options, false);
if (err < 0) {
LOG_J(LS_WARNING, this) << "Failed to send STUN ping "
<< " err=" << err
<< " id=" << rtc::hex_encode(req->id());
}
}
void Connection::OnReadPacket(
const char* data, size_t size, const rtc::PacketTime& packet_time) {
rtc::scoped_ptr<IceMessage> msg;
std::string remote_ufrag;
const rtc::SocketAddress& addr(remote_candidate_.address());
if (!port_->GetStunMessage(data, size, addr, msg.accept(), &remote_ufrag)) {
// The packet did not parse as a valid STUN message
// This is a data packet, pass it along.
set_receiving(true);
last_data_received_ = rtc::Time();
recv_rate_tracker_.AddSamples(size);
SignalReadPacket(this, data, size, packet_time);
// If timed out sending writability checks, start up again
if (!pruned_ && (write_state_ == STATE_WRITE_TIMEOUT)) {
LOG(LS_WARNING) << "Received a data packet on a timed-out Connection. "
<< "Resetting state to STATE_WRITE_INIT.";
set_write_state(STATE_WRITE_INIT);
}
} else if (!msg) {
// The packet was STUN, but failed a check and was handled internally.
} else {
// The packet is STUN and passed the Port checks.
// Perform our own checks to ensure this packet is valid.
// If this is a STUN request, then update the receiving bit and respond.
// If this is a STUN response, then update the writable bit.
// Log at LS_INFO if we receive a ping on an unwritable connection.
rtc::LoggingSeverity sev = (!writable() ? rtc::LS_INFO : rtc::LS_VERBOSE);
switch (msg->type()) {
case STUN_BINDING_REQUEST:
LOG_JV(sev, this) << "Received STUN ping"
<< ", id=" << rtc::hex_encode(msg->transaction_id());
if (remote_ufrag == remote_candidate_.username()) {
HandleBindingRequest(msg.get());
} else {
// The packet had the right local username, but the remote username
// was not the right one for the remote address.
LOG_J(LS_ERROR, this)
<< "Received STUN request with bad remote username "
<< remote_ufrag;
port_->SendBindingErrorResponse(msg.get(), addr,
STUN_ERROR_UNAUTHORIZED,
STUN_ERROR_REASON_UNAUTHORIZED);
}
break;
// Response from remote peer. Does it match request sent?
// This doesn't just check, it makes callbacks if transaction
// id's match.
case STUN_BINDING_RESPONSE:
case STUN_BINDING_ERROR_RESPONSE:
if (msg->ValidateMessageIntegrity(
data, size, remote_candidate().password())) {
requests_.CheckResponse(msg.get());
}
// Otherwise silently discard the response message.
break;
// Remote end point sent an STUN indication instead of regular binding
// request. In this case |last_ping_received_| will be updated but no
// response will be sent.
case STUN_BINDING_INDICATION:
ReceivedPing();
break;
default:
ASSERT(false);
break;
}
}
}
void Connection::HandleBindingRequest(IceMessage* msg) {
// This connection should now be receiving.
ReceivedPing();
const rtc::SocketAddress& remote_addr = remote_candidate_.address();
const std::string& remote_ufrag = remote_candidate_.username();
// Check for role conflicts.
if (!port_->MaybeIceRoleConflict(remote_addr, msg, remote_ufrag)) {
// Received conflicting role from the peer.
LOG(LS_INFO) << "Received conflicting role from the peer.";
return;
}
// This is a validated stun request from remote peer.
port_->SendBindingResponse(msg, remote_addr);
// If it timed out on writing check, start up again
if (!pruned_ && write_state_ == STATE_WRITE_TIMEOUT) {
set_write_state(STATE_WRITE_INIT);
}
if (port_->GetIceRole() == ICEROLE_CONTROLLED) {
const StunByteStringAttribute* use_candidate_attr =
msg->GetByteString(STUN_ATTR_USE_CANDIDATE);
if (use_candidate_attr) {
set_nominated(true);
SignalNominated(this);
}
}
}
void Connection::OnReadyToSend() {
if (write_state_ == STATE_WRITABLE) {
SignalReadyToSend(this);
}
}
void Connection::Prune() {
if (!pruned_ || active()) {
LOG_J(LS_VERBOSE, this) << "Connection pruned";
pruned_ = true;
requests_.Clear();
set_write_state(STATE_WRITE_TIMEOUT);
}
}
void Connection::Destroy() {
LOG_J(LS_VERBOSE, this) << "Connection destroyed";
port_->thread()->Post(this, MSG_DELETE);
}
void Connection::FailAndDestroy() {
set_state(Connection::STATE_FAILED);
Destroy();
}
void Connection::PrintPingsSinceLastResponse(std::string* s, size_t max) {
std::ostringstream oss;
oss << std::boolalpha;
if (pings_since_last_response_.size() > max) {
for (size_t i = 0; i < max; i++) {
const SentPing& ping = pings_since_last_response_[i];
oss << rtc::hex_encode(ping.id) << " ";
}
oss << "... " << (pings_since_last_response_.size() - max) << " more";
} else {
for (const SentPing& ping : pings_since_last_response_) {
oss << rtc::hex_encode(ping.id) << " ";
}
}
*s = oss.str();
}
void Connection::UpdateState(uint32_t now) {
uint32_t rtt = ConservativeRTTEstimate(rtt_);
if (LOG_CHECK_LEVEL(LS_VERBOSE)) {
std::string pings;
PrintPingsSinceLastResponse(&pings, 5);
LOG_J(LS_VERBOSE, this) << "UpdateState()"
<< ", ms since last received response="
<< now - last_ping_response_received_
<< ", ms since last received data="
<< now - last_data_received_
<< ", rtt=" << rtt
<< ", pings_since_last_response=" << pings;
}
// Check the writable state. (The order of these checks is important.)
//
// Before becoming unwritable, we allow for a fixed number of pings to fail
// (i.e., receive no response). We also have to give the response time to
// get back, so we include a conservative estimate of this.
//
// Before timing out writability, we give a fixed amount of time. This is to
// allow for changes in network conditions.
if ((write_state_ == STATE_WRITABLE) &&
TooManyFailures(pings_since_last_response_,
CONNECTION_WRITE_CONNECT_FAILURES,
rtt,
now) &&
TooLongWithoutResponse(pings_since_last_response_,
CONNECTION_WRITE_CONNECT_TIMEOUT,
now)) {
uint32_t max_pings = CONNECTION_WRITE_CONNECT_FAILURES;
LOG_J(LS_INFO, this) << "Unwritable after " << max_pings
<< " ping failures and "
<< now - pings_since_last_response_[0].sent_time
<< " ms without a response,"
<< " ms since last received ping="
<< now - last_ping_received_
<< " ms since last received data="
<< now - last_data_received_
<< " rtt=" << rtt;
set_write_state(STATE_WRITE_UNRELIABLE);
}
if ((write_state_ == STATE_WRITE_UNRELIABLE ||
write_state_ == STATE_WRITE_INIT) &&
TooLongWithoutResponse(pings_since_last_response_,
CONNECTION_WRITE_TIMEOUT,
now)) {
LOG_J(LS_INFO, this) << "Timed out after "
<< now - pings_since_last_response_[0].sent_time
<< " ms without a response"
<< ", rtt=" << rtt;
set_write_state(STATE_WRITE_TIMEOUT);
}
// Check the receiving state.
uint32_t last_recv_time = last_received();
bool receiving = now <= last_recv_time + receiving_timeout_;
set_receiving(receiving);
if (dead(now)) {
Destroy();
}
}
void Connection::Ping(uint32_t now) {
last_ping_sent_ = now;
ConnectionRequest *req = new ConnectionRequest(this);
pings_since_last_response_.push_back(SentPing(req->id(), now));
LOG_J(LS_VERBOSE, this) << "Sending STUN ping "
<< ", id=" << rtc::hex_encode(req->id());
requests_.Send(req);
state_ = STATE_INPROGRESS;
}
void Connection::ReceivedPing() {
set_receiving(true);
last_ping_received_ = rtc::Time();
}
void Connection::ReceivedPingResponse() {
// We've already validated that this is a STUN binding response with
// the correct local and remote username for this connection.
// So if we're not already, become writable. We may be bringing a pruned
// connection back to life, but if we don't really want it, we can always
// prune it again.
set_receiving(true);
set_write_state(STATE_WRITABLE);
set_state(STATE_SUCCEEDED);
pings_since_last_response_.clear();
last_ping_response_received_ = rtc::Time();
}
bool Connection::dead(uint32_t now) const {
if (now < (time_created_ms_ + MIN_CONNECTION_LIFETIME)) {
// A connection that hasn't passed its minimum lifetime is still alive.
// We do this to prevent connections from being pruned too quickly
// during a network change event when two networks would be up
// simultaneously but only for a brief period.
return false;
}
// It is dead if it has not received anything for
// DEAD_CONNECTION_RECEIVE_TIMEOUT milliseconds.
return (now > (last_received() + DEAD_CONNECTION_RECEIVE_TIMEOUT));
}
std::string Connection::ToDebugId() const {
std::stringstream ss;
ss << std::hex << this;
return ss.str();
}
std::string Connection::ToString() const {
const char CONNECT_STATE_ABBREV[2] = {
'-', // not connected (false)
'C', // connected (true)
};
const char RECEIVE_STATE_ABBREV[2] = {
'-', // not receiving (false)
'R', // receiving (true)
};
const char WRITE_STATE_ABBREV[4] = {
'W', // STATE_WRITABLE
'w', // STATE_WRITE_UNRELIABLE
'-', // STATE_WRITE_INIT
'x', // STATE_WRITE_TIMEOUT
};
const std::string ICESTATE[4] = {
"W", // STATE_WAITING
"I", // STATE_INPROGRESS
"S", // STATE_SUCCEEDED
"F" // STATE_FAILED
};
const Candidate& local = local_candidate();
const Candidate& remote = remote_candidate();
std::stringstream ss;
ss << "Conn[" << ToDebugId()
<< ":" << port_->content_name()
<< ":" << local.id() << ":" << local.component()
<< ":" << local.generation()
<< ":" << local.type() << ":" << local.protocol()
<< ":" << local.address().ToSensitiveString()
<< "->" << remote.id() << ":" << remote.component()
<< ":" << remote.priority()
<< ":" << remote.type() << ":"
<< remote.protocol() << ":" << remote.address().ToSensitiveString() << "|"
<< CONNECT_STATE_ABBREV[connected()]
<< RECEIVE_STATE_ABBREV[receiving()]
<< WRITE_STATE_ABBREV[write_state()]
<< ICESTATE[state()] << "|"
<< priority() << "|";
if (rtt_ < DEFAULT_RTT) {
ss << rtt_ << "]";
} else {
ss << "-]";
}
return ss.str();
}
std::string Connection::ToSensitiveString() const {
return ToString();
}
void Connection::OnConnectionRequestResponse(ConnectionRequest* request,
StunMessage* response) {
// Log at LS_INFO if we receive a ping response on an unwritable
// connection.
rtc::LoggingSeverity sev = !writable() ? rtc::LS_INFO : rtc::LS_VERBOSE;
uint32_t rtt = request->Elapsed();
ReceivedPingResponse();
if (LOG_CHECK_LEVEL_V(sev)) {
bool use_candidate = (
response->GetByteString(STUN_ATTR_USE_CANDIDATE) != nullptr);
std::string pings;
PrintPingsSinceLastResponse(&pings, 5);
LOG_JV(sev, this) << "Received STUN ping response"
<< ", id=" << rtc::hex_encode(request->id())
<< ", code=0" // Makes logging easier to parse.
<< ", rtt=" << rtt
<< ", use_candidate=" << use_candidate
<< ", pings_since_last_response=" << pings;
}
rtt_ = (RTT_RATIO * rtt_ + rtt) / (RTT_RATIO + 1);
MaybeAddPrflxCandidate(request, response);
}
void Connection::OnConnectionRequestErrorResponse(ConnectionRequest* request,
StunMessage* response) {
const StunErrorCodeAttribute* error_attr = response->GetErrorCode();
int error_code = STUN_ERROR_GLOBAL_FAILURE;
if (error_attr) {
error_code = error_attr->code();
}
LOG_J(LS_INFO, this) << "Received STUN error response"
<< " id=" << rtc::hex_encode(request->id())
<< " code=" << error_code
<< " rtt=" << request->Elapsed();
if (error_code == STUN_ERROR_UNKNOWN_ATTRIBUTE ||
error_code == STUN_ERROR_SERVER_ERROR ||
error_code == STUN_ERROR_UNAUTHORIZED) {
// Recoverable error, retry
} else if (error_code == STUN_ERROR_STALE_CREDENTIALS) {
// Race failure, retry
} else if (error_code == STUN_ERROR_ROLE_CONFLICT) {
HandleRoleConflictFromPeer();
} else {
// This is not a valid connection.
LOG_J(LS_ERROR, this) << "Received STUN error response, code="
<< error_code << "; killing connection";
FailAndDestroy();
}
}
void Connection::OnConnectionRequestTimeout(ConnectionRequest* request) {
// Log at LS_INFO if we miss a ping on a writable connection.
rtc::LoggingSeverity sev = writable() ? rtc::LS_INFO : rtc::LS_VERBOSE;
LOG_JV(sev, this) << "Timing-out STUN ping "
<< rtc::hex_encode(request->id())
<< " after " << request->Elapsed() << " ms";
}
void Connection::OnConnectionRequestSent(ConnectionRequest* request) {
// Log at LS_INFO if we send a ping on an unwritable connection.
rtc::LoggingSeverity sev = !writable() ? rtc::LS_INFO : rtc::LS_VERBOSE;
bool use_candidate = use_candidate_attr();
LOG_JV(sev, this) << "Sent STUN ping"
<< ", id=" << rtc::hex_encode(request->id())
<< ", use_candidate=" << use_candidate;
}
void Connection::HandleRoleConflictFromPeer() {
port_->SignalRoleConflict(port_);
}
void Connection::MaybeSetRemoteIceCredentials(const std::string& ice_ufrag,
const std::string& ice_pwd) {
if (remote_candidate_.username() == ice_ufrag &&
remote_candidate_.password().empty()) {
remote_candidate_.set_password(ice_pwd);
}
}
void Connection::MaybeUpdatePeerReflexiveCandidate(
const Candidate& new_candidate) {
if (remote_candidate_.type() == PRFLX_PORT_TYPE &&
new_candidate.type() != PRFLX_PORT_TYPE &&
remote_candidate_.protocol() == new_candidate.protocol() &&
remote_candidate_.address() == new_candidate.address() &&
remote_candidate_.username() == new_candidate.username() &&
remote_candidate_.password() == new_candidate.password() &&
remote_candidate_.generation() == new_candidate.generation()) {
remote_candidate_ = new_candidate;
}
}
void Connection::OnMessage(rtc::Message *pmsg) {
ASSERT(pmsg->message_id == MSG_DELETE);
LOG_J(LS_INFO, this) << "Connection deleted";
SignalDestroyed(this);
delete this;
}
uint32_t Connection::last_received() const {
return std::max(last_data_received_,
std::max(last_ping_received_, last_ping_response_received_));
}
size_t Connection::recv_bytes_second() {
return round(recv_rate_tracker_.ComputeRate());
}
size_t Connection::recv_total_bytes() {
return recv_rate_tracker_.TotalSampleCount();
}
size_t Connection::sent_bytes_second() {
return round(send_rate_tracker_.ComputeRate());
}
size_t Connection::sent_total_bytes() {
return send_rate_tracker_.TotalSampleCount();
}
size_t Connection::sent_discarded_packets() {
return sent_packets_discarded_;
}
size_t Connection::sent_total_packets() {
return sent_packets_total_;
}
void Connection::MaybeAddPrflxCandidate(ConnectionRequest* request,
StunMessage* response) {
// RFC 5245
// The agent checks the mapped address from the STUN response. If the
// transport address does not match any of the local candidates that the
// agent knows about, the mapped address represents a new candidate -- a
// peer reflexive candidate.
const StunAddressAttribute* addr =
response->GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
if (!addr) {
LOG(LS_WARNING) << "Connection::OnConnectionRequestResponse - "
<< "No MAPPED-ADDRESS or XOR-MAPPED-ADDRESS found in the "
<< "stun response message";
return;
}
bool known_addr = false;
for (size_t i = 0; i < port_->Candidates().size(); ++i) {
if (port_->Candidates()[i].address() == addr->GetAddress()) {
known_addr = true;
break;
}
}
if (known_addr) {
return;
}
// RFC 5245
// Its priority is set equal to the value of the PRIORITY attribute
// in the Binding request.
const StunUInt32Attribute* priority_attr =
request->msg()->GetUInt32(STUN_ATTR_PRIORITY);
if (!priority_attr) {
LOG(LS_WARNING) << "Connection::OnConnectionRequestResponse - "
<< "No STUN_ATTR_PRIORITY found in the "
<< "stun response message";
return;
}
const uint32_t priority = priority_attr->value();
std::string id = rtc::CreateRandomString(8);
Candidate new_local_candidate;
new_local_candidate.set_id(id);
new_local_candidate.set_component(local_candidate().component());
new_local_candidate.set_type(PRFLX_PORT_TYPE);
new_local_candidate.set_protocol(local_candidate().protocol());
new_local_candidate.set_address(addr->GetAddress());
new_local_candidate.set_priority(priority);
new_local_candidate.set_username(local_candidate().username());
new_local_candidate.set_password(local_candidate().password());
new_local_candidate.set_network_name(local_candidate().network_name());
new_local_candidate.set_network_type(local_candidate().network_type());
new_local_candidate.set_related_address(local_candidate().address());
new_local_candidate.set_foundation(
ComputeFoundation(PRFLX_PORT_TYPE, local_candidate().protocol(),
local_candidate().address()));
// Change the local candidate of this Connection to the new prflx candidate.
local_candidate_index_ = port_->AddPrflxCandidate(new_local_candidate);
// SignalStateChange to force a re-sort in P2PTransportChannel as this
// Connection's local candidate has changed.
SignalStateChange(this);
}
ProxyConnection::ProxyConnection(Port* port,
size_t index,
const Candidate& remote_candidate)
: Connection(port, index, remote_candidate) {}
int ProxyConnection::Send(const void* data, size_t size,
const rtc::PacketOptions& options) {
if (write_state_ == STATE_WRITE_INIT || write_state_ == STATE_WRITE_TIMEOUT) {
error_ = EWOULDBLOCK;
return SOCKET_ERROR;
}
sent_packets_total_++;
int sent = port_->SendTo(data, size, remote_candidate_.address(),
options, true);
if (sent <= 0) {
ASSERT(sent < 0);
error_ = port_->GetError();
sent_packets_discarded_++;
} else {
send_rate_tracker_.AddSamples(sent);
}
return sent;
}
} // namespace cricket