packet_transport_internal.h

/*

 *  Copyright 2017 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.

*/

#ifndef P2P_BASE_PACKET_TRANSPORT_INTERNAL_H_

#define P2P_BASE_PACKET_TRANSPORT_INTERNAL_H_

#include <optional>

#include <string>

#include <utility>

#include <vector>

#include "absl/functional/any_invocable.h"

#include "p2p/base/port.h"

#include "rtc_base/async_packet_socket.h"

#include "rtc_base/callback_list.h"

#include "rtc_base/network/received_packet.h"

#include "rtc_base/network_route.h"

#include "rtc_base/socket.h"

#include "rtc_base/system/rtc_export.h"

#include "rtc_base/third_party/sigslot/sigslot.h"

namespace rtc {

struct PacketOptions;

struct SentPacket;

class RTC_EXPORT PacketTransportInternal : public sigslot::has_slots<> {

 public:

  virtual const std::string& transport_name() const = 0;

  // The transport has been established.

  virtual bool writable() const = 0;

  // The transport has received a packet in the last X milliseconds, here X is

  // configured by each implementation.

  virtual bool receiving() const = 0;

  // Attempts to send the given packet.

  // The return value is < 0 on failure. The return value in failure case is not

  // descriptive. Depending on failure cause and implementation details

  // GetError() returns an descriptive errno.h error value.

  // This mimics posix socket send() or sendto() behavior.

  // TODO(johan): Reliable, meaningful, consistent error codes for all

  // implementations would be nice.

  // TODO(johan): Remove the default argument once channel code is updated.

  virtual int SendPacket(const char* data,

                         size_t len,

                         const rtc::PacketOptions& options,

                         int flags = 0) = 0;

  // Sets a socket option. Note that not all options are

  // supported by all transport types.

  virtual int SetOption(rtc::Socket::Option opt, int value) = 0;

  // TODO(pthatcher): Once Chrome's MockPacketTransportInterface implements

  // this, remove the default implementation.

  virtual bool GetOption(rtc::Socket::Option opt, int* value);

  // Returns the most recent error that occurred on this channel.

  virtual int GetError() = 0;

  // Returns the current network route with transport overhead.

  // TODO(zhihuang): Make it pure virtual once the Chrome/remoting is updated.

  virtual std::optional<NetworkRoute> network_route() const;

  // Emitted when the writable state, represented by `writable()`, changes.

  sigslot::signal1<PacketTransportInternal*> SignalWritableState;

  //  Emitted when the PacketTransportInternal is ready to send packets. "Ready

  //  to send" is more sensitive than the writable state; a transport may be

  //  writable, but temporarily not able to send packets. For example, the

  //  underlying transport's socket buffer may be full, as indicated by

  //  SendPacket's return code and/or GetError.

  sigslot::signal1<PacketTransportInternal*> SignalReadyToSend;

  // Emitted when receiving state changes to true.

  sigslot::signal1<PacketTransportInternal*> SignalReceivingState;

  // Callback is invoked each time a packet is received on this channel.

  void RegisterReceivedPacketCallback(

      void* id,

      absl::AnyInvocable<void(PacketTransportInternal*,

                              const rtc::ReceivedPacket&)> callback);

  void DeregisterReceivedPacketCallback(void* id);

  // Signalled each time a packet is sent on this channel.

  sigslot::signal2<PacketTransportInternal*, const rtc::SentPacket&>

      SignalSentPacket;

  // Signalled when the current network route has changed.

  sigslot::signal1<std::optional<rtc::NetworkRoute>> SignalNetworkRouteChanged;

  // Signalled when the transport is closed.

  void SetOnCloseCallback(absl::AnyInvocable<void() &&> callback);

 protected:

  PacketTransportInternal();

  ~PacketTransportInternal() override;

  void NotifyPacketReceived(const rtc::ReceivedPacket& packet);

  void NotifyOnClose();

  webrtc::SequenceChecker network_checker_{webrtc::SequenceChecker::kDetached};

 private:

  webrtc::CallbackList<PacketTransportInternal*, const rtc::ReceivedPacket&>

      received_packet_callback_list_ RTC_GUARDED_BY(&network_checker_);

  absl::AnyInvocable<void() &&> on_close_;

};

}  // namespace rtc

#endif  // P2P_BASE_PACKET_TRANSPORT_INTERNAL_H_