blob: 09a7a8345ea4f640990961891da37757dbff9ccd [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 "p2p/base/stun_request.h"
#include <algorithm>
#include <memory>
#include <vector>
#include "rtc_base/checks.h"
#include "rtc_base/helpers.h"
#include "rtc_base/logging.h"
#include "rtc_base/string_encode.h"
#include "rtc_base/time_utils.h" // For TimeMillis
#include "system_wrappers/include/field_trial.h"
namespace cricket {
const uint32_t MSG_STUN_SEND = 1;
// RFC 5389 says SHOULD be 500ms.
// For years, this was 100ms, but for networks that
// experience moments of high RTT (such as 2G networks), this doesn't
// work well.
const int STUN_INITIAL_RTO = 250; // milliseconds
// The timeout doubles each retransmission, up to this many times
// RFC 5389 says SHOULD retransmit 7 times.
// This has been 8 for years (not sure why).
const int STUN_MAX_RETRANSMISSIONS = 8; // Total sends: 9
// We also cap the doubling, even though the standard doesn't say to.
// This has been 1.6 seconds for years, but for networks that
// experience moments of high RTT (such as 2G networks), this doesn't
// work well.
const int STUN_MAX_RTO = 8000; // milliseconds, or 5 doublings
StunRequestManager::StunRequestManager(rtc::Thread* thread) : thread_(thread) {}
StunRequestManager::~StunRequestManager() {
while (requests_.begin() != requests_.end()) {
StunRequest* request = requests_.begin()->second;
requests_.erase(requests_.begin());
delete request;
}
}
void StunRequestManager::Send(StunRequest* request) {
SendDelayed(request, 0);
}
void StunRequestManager::SendDelayed(StunRequest* request, int delay) {
request->set_manager(this);
RTC_DCHECK(requests_.find(request->id()) == requests_.end());
request->Construct();
requests_[request->id()] = request;
if (delay > 0) {
thread_->PostDelayed(RTC_FROM_HERE, delay, request, MSG_STUN_SEND, NULL);
} else {
thread_->Send(RTC_FROM_HERE, request, MSG_STUN_SEND, NULL);
}
}
void StunRequestManager::Flush(int msg_type) {
for (const auto& kv : requests_) {
StunRequest* request = kv.second;
if (msg_type == kAllRequests || msg_type == request->type()) {
thread_->Clear(request, MSG_STUN_SEND);
thread_->Send(RTC_FROM_HERE, request, MSG_STUN_SEND, NULL);
}
}
}
bool StunRequestManager::HasRequest(int msg_type) {
for (const auto& kv : requests_) {
StunRequest* request = kv.second;
if (msg_type == kAllRequests || msg_type == request->type()) {
return true;
}
}
return false;
}
void StunRequestManager::Remove(StunRequest* request) {
RTC_DCHECK(request->manager() == this);
RequestMap::iterator iter = requests_.find(request->id());
if (iter != requests_.end()) {
RTC_DCHECK(iter->second == request);
requests_.erase(iter);
thread_->Clear(request);
}
}
void StunRequestManager::Clear() {
std::vector<StunRequest*> requests;
for (RequestMap::iterator i = requests_.begin(); i != requests_.end(); ++i)
requests.push_back(i->second);
for (uint32_t i = 0; i < requests.size(); ++i) {
// StunRequest destructor calls Remove() which deletes requests
// from `requests_`.
delete requests[i];
}
}
bool StunRequestManager::CheckResponse(StunMessage* msg) {
RequestMap::iterator iter = requests_.find(msg->transaction_id());
if (iter == requests_.end()) {
// TODO(pthatcher): Log unknown responses without being too spammy
// in the logs.
return false;
}
StunRequest* request = iter->second;
// Now that we know the request, we can see if the response is
// integrity-protected or not.
// For some tests, the message integrity is not set in the request.
// Complain, and then don't check.
bool skip_integrity_checking = false;
if (request->msg()->integrity() == StunMessage::IntegrityStatus::kNotSet) {
skip_integrity_checking = true;
} else {
msg->ValidateMessageIntegrity(request->msg()->password());
}
if (!msg->GetNonComprehendedAttributes().empty()) {
// If a response contains unknown comprehension-required attributes, it's
// simply discarded and the transaction is considered failed. See RFC5389
// sections 7.3.3 and 7.3.4.
RTC_LOG(LS_ERROR) << ": Discarding response due to unknown "
"comprehension-required attribute.";
delete request;
return false;
} else if (msg->type() == GetStunSuccessResponseType(request->type())) {
if (!msg->IntegrityOk() && !skip_integrity_checking) {
return false;
}
request->OnResponse(msg);
} else if (msg->type() == GetStunErrorResponseType(request->type())) {
request->OnErrorResponse(msg);
} else {
RTC_LOG(LS_ERROR) << "Received response with wrong type: " << msg->type()
<< " (expecting "
<< GetStunSuccessResponseType(request->type()) << ")";
return false;
}
delete request;
return true;
}
bool StunRequestManager::CheckResponse(const char* data, size_t size) {
// Check the appropriate bytes of the stream to see if they match the
// transaction ID of a response we are expecting.
if (size < 20)
return false;
std::string id;
id.append(data + kStunTransactionIdOffset, kStunTransactionIdLength);
RequestMap::iterator iter = requests_.find(id);
if (iter == requests_.end()) {
// TODO(pthatcher): Log unknown responses without being too spammy
// in the logs.
return false;
}
// Parse the STUN message and continue processing as usual.
rtc::ByteBufferReader buf(data, size);
std::unique_ptr<StunMessage> response(iter->second->msg_->CreateNew());
if (!response->Read(&buf)) {
RTC_LOG(LS_WARNING) << "Failed to read STUN response "
<< rtc::hex_encode(id);
return false;
}
return CheckResponse(response.get());
}
StunRequest::StunRequest()
: count_(0),
timeout_(false),
manager_(0),
msg_(new StunMessage()),
tstamp_(0) {
msg_->SetTransactionID(rtc::CreateRandomString(kStunTransactionIdLength));
}
StunRequest::StunRequest(StunMessage* request)
: count_(0), timeout_(false), manager_(0), msg_(request), tstamp_(0) {
msg_->SetTransactionID(rtc::CreateRandomString(kStunTransactionIdLength));
}
StunRequest::~StunRequest() {
RTC_DCHECK(manager_ != NULL);
if (manager_) {
manager_->Remove(this);
manager_->thread_->Clear(this);
}
delete msg_;
}
void StunRequest::Construct() {
if (msg_->type() == 0) {
Prepare(msg_);
RTC_DCHECK(msg_->type() != 0);
}
}
int StunRequest::type() {
RTC_DCHECK(msg_ != NULL);
return msg_->type();
}
const StunMessage* StunRequest::msg() const {
return msg_;
}
StunMessage* StunRequest::mutable_msg() {
return msg_;
}
int StunRequest::Elapsed() const {
return static_cast<int>(rtc::TimeMillis() - tstamp_);
}
void StunRequest::set_manager(StunRequestManager* manager) {
RTC_DCHECK(!manager_);
manager_ = manager;
}
void StunRequest::OnMessage(rtc::Message* pmsg) {
RTC_DCHECK(manager_ != NULL);
RTC_DCHECK(pmsg->message_id == MSG_STUN_SEND);
if (timeout_) {
OnTimeout();
delete this;
return;
}
tstamp_ = rtc::TimeMillis();
rtc::ByteBufferWriter buf;
msg_->Write(&buf);
manager_->SignalSendPacket(buf.Data(), buf.Length(), this);
OnSent();
manager_->thread_->PostDelayed(RTC_FROM_HERE, resend_delay(), this,
MSG_STUN_SEND, NULL);
}
void StunRequest::OnSent() {
count_ += 1;
int retransmissions = (count_ - 1);
if (retransmissions >= STUN_MAX_RETRANSMISSIONS) {
timeout_ = true;
}
RTC_LOG(LS_VERBOSE) << "Sent STUN request " << count_
<< "; resend delay = " << resend_delay();
}
int StunRequest::resend_delay() {
if (count_ == 0) {
return 0;
}
int retransmissions = (count_ - 1);
int rto = STUN_INITIAL_RTO << retransmissions;
return std::min(rto, STUN_MAX_RTO);
}
} // namespace cricket