| // Copyright 2016 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "net/nqe/socket_watcher.h" |
| |
| #include "base/functional/bind.h" |
| #include "base/location.h" |
| #include "base/task/single_thread_task_runner.h" |
| #include "base/time/tick_clock.h" |
| #include "base/time/time.h" |
| #include "net/base/ip_address.h" |
| |
| namespace net::nqe::internal { |
| |
| namespace { |
| |
| // Generate a compact representation for |ip_addr|. For IPv4, all 32 bits |
| // are used and for IPv6, the first 64 bits are used as the remote host |
| // identifier. |
| std::optional<IPHash> CalculateIPHash(const IPAddress& ip_addr) { |
| IPAddressBytes bytes = ip_addr.bytes(); |
| |
| // For IPv4, the first four bytes are taken. For IPv6, the first 8 bytes are |
| // taken. For IPv4MappedIPv6, the last 4 bytes are taken. |
| int index_min = ip_addr.IsIPv4MappedIPv6() ? 12 : 0; |
| int index_max; |
| if (ip_addr.IsIPv4MappedIPv6()) |
| index_max = 16; |
| else |
| index_max = ip_addr.IsIPv4() ? 4 : 8; |
| |
| DCHECK_LE(index_min, index_max); |
| DCHECK_GE(8, index_max - index_min); |
| |
| uint64_t result = 0ULL; |
| for (int i = index_min; i < index_max; ++i) { |
| result = result << 8; |
| result |= bytes[i]; |
| } |
| return result; |
| } |
| |
| } // namespace |
| |
| SocketWatcher::SocketWatcher( |
| SocketPerformanceWatcherFactory::Protocol protocol, |
| const IPAddress& address, |
| base::TimeDelta min_notification_interval, |
| bool allow_rtt_private_address, |
| scoped_refptr<base::SingleThreadTaskRunner> task_runner, |
| OnUpdatedRTTAvailableCallback updated_rtt_observation_callback, |
| ShouldNotifyRTTCallback should_notify_rtt_callback, |
| const base::TickClock* tick_clock) |
| : protocol_(protocol), |
| task_runner_(std::move(task_runner)), |
| updated_rtt_observation_callback_(updated_rtt_observation_callback), |
| should_notify_rtt_callback_(should_notify_rtt_callback), |
| rtt_notifications_minimum_interval_(min_notification_interval), |
| allow_rtt_private_address_(allow_rtt_private_address), |
| run_rtt_callback_(allow_rtt_private_address || |
| address.IsPubliclyRoutable()), |
| tick_clock_(tick_clock), |
| host_(CalculateIPHash(address)) { |
| DCHECK(tick_clock_); |
| DCHECK(last_rtt_notification_.is_null()); |
| } |
| |
| SocketWatcher::~SocketWatcher() = default; |
| |
| bool SocketWatcher::ShouldNotifyUpdatedRTT() const { |
| DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); |
| |
| if (!run_rtt_callback_) |
| return false; |
| |
| const base::TimeTicks now = tick_clock_->NowTicks(); |
| |
| if (task_runner_->RunsTasksInCurrentSequence()) { |
| // Enables socket watcher to send more frequent RTT observations when very |
| // few sockets are receiving data. |
| if (should_notify_rtt_callback_.Run(now)) |
| return true; |
| } |
| |
| // Do not allow incoming notifications if the last notification was more |
| // recent than |rtt_notifications_minimum_interval_| ago. This helps in |
| // reducing the overhead of obtaining the RTT values. |
| // Enables a socket watcher to send RTT observation, helps in reducing |
| // starvation by allowing every socket watcher to notify at least one RTT |
| // notification every |rtt_notifications_minimum_interval_| duration. |
| return now - last_rtt_notification_ >= rtt_notifications_minimum_interval_; |
| } |
| |
| void SocketWatcher::OnUpdatedRTTAvailable(const base::TimeDelta& rtt) { |
| DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); |
| |
| // tcp_socket_posix may sometimes report RTT as 1 microsecond when the RTT was |
| // actually invalid. See: |
| // https://cs.chromium.org/chromium/src/net/socket/tcp_socket_posix.cc?rcl=7ad660e34f2a996e381a85b2a515263003b0c171&l=106. |
| // Connections to private address eg localhost because they typically have |
| // small rtt. |
| if (!allow_rtt_private_address_ && rtt <= base::Microseconds(1)) { |
| return; |
| } |
| |
| if (!first_quic_rtt_notification_received_ && |
| protocol_ == SocketPerformanceWatcherFactory::PROTOCOL_QUIC) { |
| // First RTT sample from QUIC connections may be synthetically generated, |
| // and may not reflect the actual network quality. |
| first_quic_rtt_notification_received_ = true; |
| return; |
| } |
| |
| last_rtt_notification_ = tick_clock_->NowTicks(); |
| task_runner_->PostTask( |
| FROM_HERE, |
| base::BindOnce(updated_rtt_observation_callback_, protocol_, rtt, host_)); |
| } |
| |
| void SocketWatcher::OnConnectionChanged() { |
| DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); |
| } |
| |
| } // namespace net::nqe::internal |