QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 1 | // Copyright 2013 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
QUICHE team | 5be974e | 2020-12-29 18:35:24 -0500 | [diff] [blame] | 5 | #include "quic/test_tools/packet_dropping_test_writer.h" |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 6 | |
QUICHE team | 5be974e | 2020-12-29 18:35:24 -0500 | [diff] [blame] | 7 | #include "quic/core/quic_epoll_connection_helper.h" |
| 8 | #include "quic/platform/api/quic_logging.h" |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 9 | |
| 10 | namespace quic { |
| 11 | namespace test { |
| 12 | |
bnc | ed1fe4f | 2020-07-01 04:48:53 -0700 | [diff] [blame] | 13 | // Every dropped packet must be followed by this number of succesfully written |
| 14 | // packets. This is to avoid flaky test failures and timeouts, for example, in |
| 15 | // case both the client and the server drop every other packet (which is |
| 16 | // statistically possible even if drop percentage is less than 50%). |
| 17 | const int32_t kMinSuccesfulWritesAfterPacketLoss = 2; |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 18 | |
| 19 | // An alarm that is scheduled if a blocked socket is simulated to indicate |
| 20 | // it's writable again. |
wub | f9e025b | 2021-09-01 07:53:35 -0700 | [diff] [blame] | 21 | class WriteUnblockedAlarm : public QuicAlarm::DelegateWithoutContext { |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 22 | public: |
| 23 | explicit WriteUnblockedAlarm(PacketDroppingTestWriter* writer) |
| 24 | : writer_(writer) {} |
| 25 | |
| 26 | void OnAlarm() override { |
| 27 | QUIC_DLOG(INFO) << "Unblocking socket."; |
| 28 | writer_->OnCanWrite(); |
| 29 | } |
| 30 | |
| 31 | private: |
| 32 | PacketDroppingTestWriter* writer_; |
| 33 | }; |
| 34 | |
| 35 | // An alarm that is scheduled every time a new packet is to be written at a |
| 36 | // later point. |
wub | f9e025b | 2021-09-01 07:53:35 -0700 | [diff] [blame] | 37 | class DelayAlarm : public QuicAlarm::DelegateWithoutContext { |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 38 | public: |
| 39 | explicit DelayAlarm(PacketDroppingTestWriter* writer) : writer_(writer) {} |
| 40 | |
| 41 | void OnAlarm() override { |
| 42 | QuicTime new_deadline = writer_->ReleaseOldPackets(); |
| 43 | if (new_deadline.IsInitialized()) { |
| 44 | writer_->SetDelayAlarm(new_deadline); |
| 45 | } |
| 46 | } |
| 47 | |
| 48 | private: |
| 49 | PacketDroppingTestWriter* writer_; |
| 50 | }; |
| 51 | |
| 52 | PacketDroppingTestWriter::PacketDroppingTestWriter() |
| 53 | : clock_(nullptr), |
| 54 | cur_buffer_size_(0), |
| 55 | num_calls_to_write_(0), |
bnc | ed1fe4f | 2020-07-01 04:48:53 -0700 | [diff] [blame] | 56 | // Do not require any number of successful writes before the first dropped |
| 57 | // packet. |
| 58 | num_consecutive_succesful_writes_(kMinSuccesfulWritesAfterPacketLoss), |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 59 | fake_packet_loss_percentage_(0), |
| 60 | fake_drop_first_n_packets_(0), |
| 61 | fake_blocked_socket_percentage_(0), |
| 62 | fake_packet_reorder_percentage_(0), |
| 63 | fake_packet_delay_(QuicTime::Delta::Zero()), |
| 64 | fake_bandwidth_(QuicBandwidth::Zero()), |
bnc | ed1fe4f | 2020-07-01 04:48:53 -0700 | [diff] [blame] | 65 | buffer_size_(0) { |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 66 | uint64_t seed = QuicRandom::GetInstance()->RandUint64(); |
| 67 | QUIC_LOG(INFO) << "Seeding packet loss with " << seed; |
| 68 | simple_random_.set_seed(seed); |
| 69 | } |
| 70 | |
wub | d44ad7c | 2021-08-02 15:16:59 -0700 | [diff] [blame] | 71 | PacketDroppingTestWriter::~PacketDroppingTestWriter() { |
| 72 | if (write_unblocked_alarm_ != nullptr) { |
| 73 | write_unblocked_alarm_->PermanentCancel(); |
| 74 | } |
| 75 | if (delay_alarm_ != nullptr) { |
| 76 | delay_alarm_->PermanentCancel(); |
| 77 | } |
| 78 | } |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 79 | |
| 80 | void PacketDroppingTestWriter::Initialize( |
| 81 | QuicConnectionHelperInterface* helper, |
| 82 | QuicAlarmFactory* alarm_factory, |
| 83 | std::unique_ptr<Delegate> on_can_write) { |
| 84 | clock_ = helper->GetClock(); |
| 85 | write_unblocked_alarm_.reset( |
| 86 | alarm_factory->CreateAlarm(new WriteUnblockedAlarm(this))); |
| 87 | delay_alarm_.reset(alarm_factory->CreateAlarm(new DelayAlarm(this))); |
| 88 | on_can_write_ = std::move(on_can_write); |
| 89 | } |
| 90 | |
| 91 | WriteResult PacketDroppingTestWriter::WritePacket( |
| 92 | const char* buffer, |
| 93 | size_t buf_len, |
| 94 | const QuicIpAddress& self_address, |
| 95 | const QuicSocketAddress& peer_address, |
| 96 | PerPacketOptions* options) { |
| 97 | ++num_calls_to_write_; |
| 98 | ReleaseOldPackets(); |
| 99 | |
| 100 | QuicWriterMutexLock lock(&config_mutex_); |
| 101 | if (fake_drop_first_n_packets_ > 0 && |
| 102 | num_calls_to_write_ <= |
| 103 | static_cast<uint64_t>(fake_drop_first_n_packets_)) { |
| 104 | QUIC_DVLOG(1) << "Dropping first " << fake_drop_first_n_packets_ |
| 105 | << " packets (packet number " << num_calls_to_write_ << ")"; |
bnc | ed1fe4f | 2020-07-01 04:48:53 -0700 | [diff] [blame] | 106 | num_consecutive_succesful_writes_ = 0; |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 107 | return WriteResult(WRITE_STATUS_OK, buf_len); |
| 108 | } |
bnc | ed1fe4f | 2020-07-01 04:48:53 -0700 | [diff] [blame] | 109 | |
| 110 | // Drop every packet at 100%, otherwise always succeed for at least |
| 111 | // kMinSuccesfulWritesAfterPacketLoss packets between two dropped ones. |
| 112 | if (fake_packet_loss_percentage_ == 100 || |
| 113 | (fake_packet_loss_percentage_ > 0 && |
| 114 | num_consecutive_succesful_writes_ >= |
| 115 | kMinSuccesfulWritesAfterPacketLoss && |
| 116 | (simple_random_.RandUint64() % 100 < |
| 117 | static_cast<uint64_t>(fake_packet_loss_percentage_)))) { |
| 118 | QUIC_DVLOG(1) << "Dropping packet " << num_calls_to_write_; |
| 119 | num_consecutive_succesful_writes_ = 0; |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 120 | return WriteResult(WRITE_STATUS_OK, buf_len); |
| 121 | } else { |
bnc | ed1fe4f | 2020-07-01 04:48:53 -0700 | [diff] [blame] | 122 | ++num_consecutive_succesful_writes_; |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 123 | } |
bnc | ed1fe4f | 2020-07-01 04:48:53 -0700 | [diff] [blame] | 124 | |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 125 | if (fake_blocked_socket_percentage_ > 0 && |
| 126 | simple_random_.RandUint64() % 100 < |
| 127 | static_cast<uint64_t>(fake_blocked_socket_percentage_)) { |
vasilvv | f803516 | 2021-02-01 14:49:14 -0800 | [diff] [blame] | 128 | QUICHE_CHECK(on_can_write_ != nullptr); |
bnc | ed1fe4f | 2020-07-01 04:48:53 -0700 | [diff] [blame] | 129 | QUIC_DVLOG(1) << "Blocking socket for packet " << num_calls_to_write_; |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 130 | if (!write_unblocked_alarm_->IsSet()) { |
| 131 | // Set the alarm to fire immediately. |
| 132 | write_unblocked_alarm_->Set(clock_->ApproximateNow()); |
| 133 | } |
bnc | ed1fe4f | 2020-07-01 04:48:53 -0700 | [diff] [blame] | 134 | |
| 135 | // Dropping this packet on retry could result in PTO timeout, |
| 136 | // make sure to avoid this. |
| 137 | num_consecutive_succesful_writes_ = 0; |
| 138 | |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 139 | return WriteResult(WRITE_STATUS_BLOCKED, EAGAIN); |
| 140 | } |
| 141 | |
| 142 | if (!fake_packet_delay_.IsZero() || !fake_bandwidth_.IsZero()) { |
| 143 | if (buffer_size_ > 0 && buf_len + cur_buffer_size_ > buffer_size_) { |
| 144 | // Drop packets which do not fit into the buffer. |
| 145 | QUIC_DVLOG(1) << "Dropping packet because the buffer is full."; |
| 146 | return WriteResult(WRITE_STATUS_OK, buf_len); |
| 147 | } |
| 148 | |
| 149 | // Queue it to be sent. |
| 150 | QuicTime send_time = clock_->ApproximateNow() + fake_packet_delay_; |
| 151 | if (!fake_bandwidth_.IsZero()) { |
| 152 | // Calculate a time the bandwidth limit would impose. |
| 153 | QuicTime::Delta bandwidth_delay = QuicTime::Delta::FromMicroseconds( |
| 154 | (buf_len * kNumMicrosPerSecond) / fake_bandwidth_.ToBytesPerSecond()); |
| 155 | send_time = delayed_packets_.empty() |
| 156 | ? send_time + bandwidth_delay |
| 157 | : delayed_packets_.back().send_time + bandwidth_delay; |
| 158 | } |
| 159 | std::unique_ptr<PerPacketOptions> delayed_options; |
| 160 | if (options != nullptr) { |
| 161 | delayed_options = options->Clone(); |
| 162 | } |
| 163 | delayed_packets_.push_back( |
| 164 | DelayedWrite(buffer, buf_len, self_address, peer_address, |
| 165 | std::move(delayed_options), send_time)); |
| 166 | cur_buffer_size_ += buf_len; |
| 167 | |
| 168 | // Set the alarm if it's not yet set. |
| 169 | if (!delay_alarm_->IsSet()) { |
| 170 | delay_alarm_->Set(send_time); |
| 171 | } |
| 172 | |
| 173 | return WriteResult(WRITE_STATUS_OK, buf_len); |
| 174 | } |
| 175 | |
| 176 | return QuicPacketWriterWrapper::WritePacket(buffer, buf_len, self_address, |
| 177 | peer_address, options); |
| 178 | } |
| 179 | |
| 180 | bool PacketDroppingTestWriter::IsWriteBlocked() const { |
| 181 | if (write_unblocked_alarm_ != nullptr && write_unblocked_alarm_->IsSet()) { |
| 182 | return true; |
| 183 | } |
| 184 | return QuicPacketWriterWrapper::IsWriteBlocked(); |
| 185 | } |
| 186 | |
| 187 | void PacketDroppingTestWriter::SetWritable() { |
| 188 | if (write_unblocked_alarm_ != nullptr && write_unblocked_alarm_->IsSet()) { |
| 189 | write_unblocked_alarm_->Cancel(); |
| 190 | } |
| 191 | QuicPacketWriterWrapper::SetWritable(); |
| 192 | } |
| 193 | |
| 194 | QuicTime PacketDroppingTestWriter::ReleaseNextPacket() { |
| 195 | if (delayed_packets_.empty()) { |
| 196 | return QuicTime::Zero(); |
| 197 | } |
| 198 | QuicReaderMutexLock lock(&config_mutex_); |
| 199 | auto iter = delayed_packets_.begin(); |
| 200 | // Determine if we should re-order. |
| 201 | if (delayed_packets_.size() > 1 && fake_packet_reorder_percentage_ > 0 && |
| 202 | simple_random_.RandUint64() % 100 < |
| 203 | static_cast<uint64_t>(fake_packet_reorder_percentage_)) { |
| 204 | QUIC_DLOG(INFO) << "Reordering packets."; |
| 205 | ++iter; |
| 206 | // Swap the send times when re-ordering packets. |
| 207 | delayed_packets_.begin()->send_time = iter->send_time; |
| 208 | } |
| 209 | |
| 210 | QUIC_DVLOG(1) << "Releasing packet. " << (delayed_packets_.size() - 1) |
| 211 | << " remaining."; |
| 212 | // Grab the next one off the queue and send it. |
| 213 | QuicPacketWriterWrapper::WritePacket( |
| 214 | iter->buffer.data(), iter->buffer.length(), iter->self_address, |
| 215 | iter->peer_address, iter->options.get()); |
vasilvv | f803516 | 2021-02-01 14:49:14 -0800 | [diff] [blame] | 216 | QUICHE_DCHECK_GE(cur_buffer_size_, iter->buffer.length()); |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 217 | cur_buffer_size_ -= iter->buffer.length(); |
| 218 | delayed_packets_.erase(iter); |
| 219 | |
| 220 | // If there are others, find the time for the next to be sent. |
| 221 | if (delayed_packets_.empty()) { |
| 222 | return QuicTime::Zero(); |
| 223 | } |
| 224 | return delayed_packets_.begin()->send_time; |
| 225 | } |
| 226 | |
| 227 | QuicTime PacketDroppingTestWriter::ReleaseOldPackets() { |
| 228 | while (!delayed_packets_.empty()) { |
| 229 | QuicTime next_send_time = delayed_packets_.front().send_time; |
| 230 | if (next_send_time > clock_->Now()) { |
| 231 | return next_send_time; |
| 232 | } |
| 233 | ReleaseNextPacket(); |
| 234 | } |
| 235 | return QuicTime::Zero(); |
| 236 | } |
| 237 | |
| 238 | void PacketDroppingTestWriter::SetDelayAlarm(QuicTime new_deadline) { |
| 239 | delay_alarm_->Set(new_deadline); |
| 240 | } |
| 241 | |
| 242 | void PacketDroppingTestWriter::OnCanWrite() { |
| 243 | on_can_write_->OnCanWrite(); |
| 244 | } |
| 245 | |
QUICHE team | a6ef0a6 | 2019-03-07 20:34:33 -0500 | [diff] [blame] | 246 | PacketDroppingTestWriter::DelayedWrite::DelayedWrite( |
| 247 | const char* buffer, |
| 248 | size_t buf_len, |
| 249 | const QuicIpAddress& self_address, |
| 250 | const QuicSocketAddress& peer_address, |
| 251 | std::unique_ptr<PerPacketOptions> options, |
| 252 | QuicTime send_time) |
| 253 | : buffer(buffer, buf_len), |
| 254 | self_address(self_address), |
| 255 | peer_address(peer_address), |
| 256 | options(std::move(options)), |
| 257 | send_time(send_time) {} |
| 258 | |
| 259 | PacketDroppingTestWriter::DelayedWrite::~DelayedWrite() = default; |
| 260 | |
| 261 | } // namespace test |
| 262 | } // namespace quic |