1 /* 2 * Copyright (c) 2021 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 #ifndef NET_DCSCTP_SOCKET_HEARTBEAT_HANDLER_H_ 11 #define NET_DCSCTP_SOCKET_HEARTBEAT_HANDLER_H_ 12 13 #include <stdint.h> 14 15 #include <memory> 16 #include <string> 17 18 #include "absl/strings/string_view.h" 19 #include "net/dcsctp/packet/chunk/heartbeat_ack_chunk.h" 20 #include "net/dcsctp/packet/chunk/heartbeat_request_chunk.h" 21 #include "net/dcsctp/packet/sctp_packet.h" 22 #include "net/dcsctp/public/dcsctp_options.h" 23 #include "net/dcsctp/socket/context.h" 24 #include "net/dcsctp/timer/timer.h" 25 26 namespace dcsctp { 27 28 // HeartbeatHandler handles all logic around sending heartbeats and receiving 29 // the responses, as well as receiving incoming heartbeat requests. 30 // 31 // Heartbeats are sent on idle connections to ensure that the connection is 32 // still healthy and to measure the RTT. If a number of heartbeats time out, 33 // the connection will eventually be closed. 34 class HeartbeatHandler { 35 public: 36 HeartbeatHandler(absl::string_view log_prefix, 37 const DcSctpOptions& options, 38 Context* context, 39 TimerManager* timer_manager); 40 41 // Called when the heartbeat interval timer should be restarted. This is 42 // generally done every time data is sent, which makes the timer expire when 43 // the connection is idle. 44 void RestartTimer(); 45 46 // Called on received HeartbeatRequestChunk chunks. 47 void HandleHeartbeatRequest(HeartbeatRequestChunk chunk); 48 49 // Called on received HeartbeatRequestChunk chunks. 50 void HandleHeartbeatAck(HeartbeatAckChunk chunk); 51 52 private: 53 absl::optional<DurationMs> OnIntervalTimerExpiry(); 54 absl::optional<DurationMs> OnTimeoutTimerExpiry(); 55 56 const std::string log_prefix_; 57 Context* ctx_; 58 TimerManager* timer_manager_; 59 // The time for a connection to be idle before a heartbeat is sent. 60 const DurationMs interval_duration_; 61 // Adding RTT to the duration will add some jitter, which is good in 62 // production, but less good in unit tests, which is why it can be disabled. 63 const bool interval_duration_should_include_rtt_; 64 const std::unique_ptr<Timer> interval_timer_; 65 const std::unique_ptr<Timer> timeout_timer_; 66 }; 67 } // namespace dcsctp 68 69 #endif // NET_DCSCTP_SOCKET_HEARTBEAT_HANDLER_H_ 70