First step in providing a UdpTransportChannel.

webrtc/p2p/base/udptransportchannel.cc

+/*
+ *  Copyright 2016 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.
+ */
+
+#include "webrtc/p2p/base/udptransportchannel.h"
+
+#include <string>
+
+#include "webrtc/base/asyncudpsocket.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/thread_checker.h"
+
+namespace cricket {
+
+UdpTransportChannel::UdpTransportChannel(const std::string& transport_name,
+                                         int component)
+    : UdpTransportChannel(transport_name,
+                          component,
+                          rtc::Thread::Current()->socketserver()) {}
+
+UdpTransportChannel::UdpTransportChannel(const std::string& transport_name,
+                                         int component,
+                                         rtc::SocketServer* socket_server)
+    : TransportChannelImpl(transport_name, component),
+      socket_server_(socket_server) {
+  RTC_DCHECK_RUN_ON(&network_thread_checker_);
+}
+
+UdpTransportChannel::~UdpTransportChannel() {
+  RTC_DCHECK_RUN_ON(&network_thread_checker_);
+}
+
+void UdpTransportChannel::OnSocketReadPacket(
+    rtc::AsyncPacketSocket* socket,
+    const char* data,
+    size_t len,
+    const rtc::SocketAddress& remote_addr,
+    const rtc::PacketTime& packet_time) {
+  // No thread_checker in high frequency network function.
+  SignalReadPacket(this, data, len, packet_time, 0);
+}
+
+int UdpTransportChannel::SendPacket(const char* data,
+                                    size_t len,
+                                    const rtc::PacketOptions& options,
+                                    int flags) {
+  // No thread_checker in high frequency network function.
+  if (!remote_parameters_) {
+    LOG(LS_WARNING) << "Remote parameters not set.";
+    send_error_ = ENOTCONN;
+    return -1;
+  }
+  const rtc::SocketAddress& remote_addr_ = remote_parameters_->address();
+  int result = socket_->SendTo((const void*)data, len, remote_addr_, options);
+  LOG(LS_VERBOSE) << "SendPacket() " << result;
+  return result;
+}
+
+bool UdpTransportChannel::TryAllocateSockets() {
+  RTC_DCHECK_RUN_ON(&network_thread_checker_);
+  static constexpr uint16_t kMaxTries = 100;
+  static constexpr uint16_t kMinPortNumber = 2000;
+  // TODO(johan) provide configuration option for kMinPortNumber.
+  rtc::SocketAddress socket_addr("0.0.0.0", 0);
+  // TODO(johan): use rtc::PacketSocketFactory.
+  for (uint16_t count = 0; count < kMaxTries; ++count) {
+    uint16_t rtpport = kMinPortNumber + (2 * count);
+    socket_addr.SetPort(rtpport);
+    socket_.reset(rtc::AsyncUDPSocket::Create(socket_server_, socket_addr));
+    if (!socket_) {
+      continue;
+    }
+    if (socket_) {
+      LOG(INFO) << "Allocated Rtp socket with local port " << rtpport;
+      socket_->SignalReadPacket.connect(
+          this, &UdpTransportChannel::OnSocketReadPacket);
+      local_parameters_ = rtc::Optional<Candidate>(Candidate());
+      local_parameters_->set_address(socket_addr);
+      return true;
+    }
+  }
+  socket_.reset();
+  LOG(INFO) << "Local socket allocation failure";
+  return false;
+}
+
+void UdpTransportChannel::MaybeStartGathering() {
+  RTC_DCHECK_RUN_ON(&network_thread_checker_);
+  if (gathering_state_ != kIceGatheringNew) {
+    LOG(INFO) << "candidates gathering already done, early return";
+    return;
+  }
+  SetGatheringState(kIceGatheringGathering);
+  bool gathering_success = TryAllocateSockets();
+  if (gathering_success) {
+    SignalCandidateGathered(this, *local_parameters_);
+    SetGatheringState(kIceGatheringComplete);
+  } else {
+    SetGatheringState(kIceGatheringNew);
+  }
+  UpdateState();
+}
+
+bool UdpTransportChannel::IsLocalConsistent() {
+  if (!local_parameters_) {
+    return true;
+  }
+  if (!socket_) {
+    LOG(INFO) << "socket_ is false";
+    return false;
+  }
+  return true;
+}
+
+bool UdpTransportChannel::IsRemoteConsistent() {
+  if (!remote_parameters_) {
+    return true;
+  }
+  if (!remote_parameters_->address().IsComplete()) {
+    LOG(INFO) << "remote_addr_ not complete";
+    return false;
+  }
+  return true;
+}
+
+void UdpTransportChannel::UpdateState() {
+  RTC_DCHECK_RUN_ON(&network_thread_checker_);
+  TransportChannelState state;
+  if (!IsLocalConsistent()) {
+    state = STATE_FAILED;
+  } else if (!IsRemoteConsistent()) {
+    state = STATE_FAILED;
+  } else if (!local_parameters_ && !remote_parameters_) {
+    state = STATE_INIT;
+  } else if (local_parameters_ && !remote_parameters_) {
+    state = STATE_CONNECTING;
+  } else if (local_parameters_ && remote_parameters_) {
+    state = STATE_COMPLETED;
+  } else {
+    state = STATE_FAILED;
+  }
+  set_writable(state == STATE_COMPLETED);
+  SetTransportChannelState(state);
+}
+
+void UdpTransportChannel::AddRemoteCandidate(const Candidate& candidate) {
+  RTC_DCHECK_RUN_ON(&network_thread_checker_);
+  // TODO(johan) check for ipv4, other settings.
+  remote_parameters_ = rtc::Optional<Candidate>(candidate);
+  UpdateState();
+}
+
+void UdpTransportChannel::SetGatheringState(IceGatheringState gathering_state) {
+  RTC_DCHECK_RUN_ON(&network_thread_checker_);
+  if (gathering_state_ != gathering_state) {
+    gathering_state_ = gathering_state;
+    SignalGatheringState(this);
+  }
+}
+
+void UdpTransportChannel::SetTransportChannelState(
+    TransportChannelState state) {
+  RTC_DCHECK_RUN_ON(&network_thread_checker_);
+  if (state_ != state) {
+    state_ = state;
+    SignalStateChanged(this);
+  }
+}
+}  // namespace cricket