blob: da29facf4682b7d703d3bfa708fd52ac8de912a7 [file] [log] [blame]
// Copyright (c) 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "quiche/quic/core/quic_path_validator.h"
#include "quiche/quic/core/quic_constants.h"
#include "quiche/quic/core/quic_types.h"
#include "quiche/quic/platform/api/quic_socket_address.h"
namespace quic {
class RetryAlarmDelegate : public QuicAlarm::DelegateWithContext {
public:
explicit RetryAlarmDelegate(QuicPathValidator* path_validator,
QuicConnectionContext* context)
: QuicAlarm::DelegateWithContext(context),
path_validator_(path_validator) {}
RetryAlarmDelegate(const RetryAlarmDelegate&) = delete;
RetryAlarmDelegate& operator=(const RetryAlarmDelegate&) = delete;
void OnAlarm() override { path_validator_->OnRetryTimeout(); }
private:
QuicPathValidator* path_validator_;
};
std::ostream& operator<<(std::ostream& os,
const QuicPathValidationContext& context) {
return os << " from " << context.self_address_ << " to "
<< context.peer_address_;
}
QuicPathValidator::QuicPathValidator(QuicAlarmFactory* alarm_factory,
QuicConnectionArena* arena,
SendDelegate* send_delegate,
QuicRandom* random, const QuicClock* clock,
QuicConnectionContext* context)
: send_delegate_(send_delegate),
random_(random),
clock_(clock),
retry_timer_(alarm_factory->CreateAlarm(
arena->New<RetryAlarmDelegate>(this, context), arena)),
retry_count_(0u) {}
void QuicPathValidator::OnPathResponse(const QuicPathFrameBuffer& probing_data,
QuicSocketAddress self_address) {
if (!HasPendingPathValidation()) {
return;
}
QUIC_DVLOG(1) << "Match PATH_RESPONSE received on " << self_address;
QUIC_BUG_IF(quic_bug_12402_1, !path_context_->self_address().IsInitialized())
<< "Self address should have been known by now";
if (self_address != path_context_->self_address()) {
QUIC_DVLOG(1) << "Expect the response to be received on "
<< path_context_->self_address();
return;
}
// This iterates at most 3 times.
for (auto it = probing_data_.begin(); it != probing_data_.end(); ++it) {
if (it->frame_buffer == probing_data) {
result_delegate_->OnPathValidationSuccess(std::move(path_context_),
it->send_time);
ResetPathValidation();
return;
}
}
QUIC_DVLOG(1) << "PATH_RESPONSE with payload " << probing_data.data()
<< " doesn't match the probing data.";
}
void QuicPathValidator::StartPathValidation(
std::unique_ptr<QuicPathValidationContext> context,
std::unique_ptr<ResultDelegate> result_delegate,
PathValidationReason reason) {
QUICHE_DCHECK(context);
QUIC_DLOG(INFO) << "Start validating path " << *context
<< " via writer: " << context->WriterToUse();
if (path_context_ != nullptr) {
QUIC_BUG(quic_bug_10876_1)
<< "There is an on-going validation on path " << *path_context_;
ResetPathValidation();
}
reason_ = reason;
path_context_ = std::move(context);
result_delegate_ = std::move(result_delegate);
SendPathChallengeAndSetAlarm();
}
void QuicPathValidator::ResetPathValidation() {
path_context_ = nullptr;
result_delegate_ = nullptr;
retry_timer_->Cancel();
retry_count_ = 0;
reason_ = PathValidationReason::kReasonUnknown;
}
void QuicPathValidator::CancelPathValidation() {
if (path_context_ == nullptr) {
return;
}
QUIC_DVLOG(1) << "Cancel validation on path" << *path_context_;
result_delegate_->OnPathValidationFailure(std::move(path_context_));
ResetPathValidation();
}
bool QuicPathValidator::HasPendingPathValidation() const {
return path_context_ != nullptr;
}
QuicPathValidationContext* QuicPathValidator::GetContext() const {
return path_context_.get();
}
const QuicPathFrameBuffer& QuicPathValidator::GeneratePathChallengePayload() {
probing_data_.emplace_back(clock_->Now());
random_->RandBytes(probing_data_.back().frame_buffer.data(),
sizeof(QuicPathFrameBuffer));
return probing_data_.back().frame_buffer;
}
void QuicPathValidator::OnRetryTimeout() {
++retry_count_;
if (retry_count_ > kMaxRetryTimes) {
CancelPathValidation();
return;
}
QUIC_DVLOG(1) << "Send another PATH_CHALLENGE on path " << *path_context_;
SendPathChallengeAndSetAlarm();
}
void QuicPathValidator::SendPathChallengeAndSetAlarm() {
bool should_continue = send_delegate_->SendPathChallenge(
GeneratePathChallengePayload(), path_context_->self_address(),
path_context_->peer_address(), path_context_->effective_peer_address(),
path_context_->WriterToUse());
if (!should_continue) {
// The delegate doesn't want to continue the path validation.
CancelPathValidation();
return;
}
retry_timer_->Set(send_delegate_->GetRetryTimeout(
path_context_->peer_address(), path_context_->WriterToUse()));
}
bool QuicPathValidator::IsValidatingPeerAddress(
const QuicSocketAddress& effective_peer_address) {
return path_context_ != nullptr &&
path_context_->effective_peer_address() == effective_peer_address;
}
void QuicPathValidator::MaybeWritePacketToAddress(
const char* buffer, size_t buf_len, const QuicSocketAddress& peer_address) {
if (!HasPendingPathValidation() ||
path_context_->peer_address() != peer_address) {
return;
}
QUIC_DVLOG(1) << "Path validator is sending packet of size " << buf_len
<< " from " << path_context_->self_address() << " to "
<< path_context_->peer_address();
path_context_->WriterToUse()->WritePacket(
buffer, buf_len, path_context_->self_address().host(),
path_context_->peer_address(), nullptr);
}
} // namespace quic