1// Copyright 2014 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 5#include "media/cast/net/udp_transport.h" 6 7#include <algorithm> 8#include <string> 9 10#include "base/bind.h" 11#include "base/logging.h" 12#include "base/memory/ref_counted.h" 13#include "base/memory/scoped_ptr.h" 14#include "base/message_loop/message_loop.h" 15#include "base/rand_util.h" 16#include "net/base/io_buffer.h" 17#include "net/base/net_errors.h" 18#include "net/base/rand_callback.h" 19 20namespace media { 21namespace cast { 22 23namespace { 24const int kMaxPacketSize = 1500; 25 26bool IsEmpty(const net::IPEndPoint& addr) { 27 net::IPAddressNumber empty_addr(addr.address().size()); 28 return std::equal( 29 empty_addr.begin(), empty_addr.end(), addr.address().begin()) && 30 !addr.port(); 31} 32 33bool IsEqual(const net::IPEndPoint& addr1, const net::IPEndPoint& addr2) { 34 return addr1.port() == addr2.port() && std::equal(addr1.address().begin(), 35 addr1.address().end(), 36 addr2.address().begin()); 37} 38} // namespace 39 40UdpTransport::UdpTransport( 41 net::NetLog* net_log, 42 const scoped_refptr<base::SingleThreadTaskRunner>& io_thread_proxy, 43 const net::IPEndPoint& local_end_point, 44 const net::IPEndPoint& remote_end_point, 45 const CastTransportStatusCallback& status_callback) 46 : io_thread_proxy_(io_thread_proxy), 47 local_addr_(local_end_point), 48 remote_addr_(remote_end_point), 49 udp_socket_(new net::UDPSocket(net::DatagramSocket::DEFAULT_BIND, 50 net::RandIntCallback(), 51 net_log, 52 net::NetLog::Source())), 53 send_pending_(false), 54 receive_pending_(false), 55 client_connected_(false), 56 next_dscp_value_(net::DSCP_NO_CHANGE), 57 status_callback_(status_callback), 58 bytes_sent_(0), 59 weak_factory_(this) { 60 DCHECK(!IsEmpty(local_end_point) || !IsEmpty(remote_end_point)); 61} 62 63UdpTransport::~UdpTransport() {} 64 65void UdpTransport::StartReceiving( 66 const PacketReceiverCallback& packet_receiver) { 67 DCHECK(io_thread_proxy_->RunsTasksOnCurrentThread()); 68 69 packet_receiver_ = packet_receiver; 70 udp_socket_->AllowAddressReuse(); 71 udp_socket_->SetMulticastLoopbackMode(true); 72 if (!IsEmpty(local_addr_)) { 73 if (udp_socket_->Bind(local_addr_) < 0) { 74 status_callback_.Run(TRANSPORT_SOCKET_ERROR); 75 LOG(ERROR) << "Failed to bind local address."; 76 return; 77 } 78 } else if (!IsEmpty(remote_addr_)) { 79 if (udp_socket_->Connect(remote_addr_) < 0) { 80 status_callback_.Run(TRANSPORT_SOCKET_ERROR); 81 LOG(ERROR) << "Failed to connect to remote address."; 82 return; 83 } 84 client_connected_ = true; 85 } else { 86 NOTREACHED() << "Either local or remote address has to be defined."; 87 } 88 89 ScheduleReceiveNextPacket(); 90} 91 92void UdpTransport::SetDscp(net::DiffServCodePoint dscp) { 93 DCHECK(io_thread_proxy_->RunsTasksOnCurrentThread()); 94 next_dscp_value_ = dscp; 95} 96 97void UdpTransport::ScheduleReceiveNextPacket() { 98 DCHECK(io_thread_proxy_->RunsTasksOnCurrentThread()); 99 if (!packet_receiver_.is_null() && !receive_pending_) { 100 receive_pending_ = true; 101 io_thread_proxy_->PostTask(FROM_HERE, 102 base::Bind(&UdpTransport::ReceiveNextPacket, 103 weak_factory_.GetWeakPtr(), 104 net::ERR_IO_PENDING)); 105 } 106} 107 108void UdpTransport::ReceiveNextPacket(int length_or_status) { 109 DCHECK(io_thread_proxy_->RunsTasksOnCurrentThread()); 110 111 // Loop while UdpSocket is delivering data synchronously. When it responds 112 // with a "pending" status, break and expect this method to be called back in 113 // the future when a packet is ready. 114 while (true) { 115 if (length_or_status == net::ERR_IO_PENDING) { 116 next_packet_.reset(new Packet(kMaxPacketSize)); 117 recv_buf_ = new net::WrappedIOBuffer( 118 reinterpret_cast<char*>(&next_packet_->front())); 119 length_or_status = 120 udp_socket_->RecvFrom(recv_buf_.get(), 121 kMaxPacketSize, 122 &recv_addr_, 123 base::Bind(&UdpTransport::ReceiveNextPacket, 124 weak_factory_.GetWeakPtr())); 125 if (length_or_status == net::ERR_IO_PENDING) { 126 receive_pending_ = true; 127 return; 128 } 129 } 130 131 // Note: At this point, either a packet is ready or an error has occurred. 132 if (length_or_status < 0) { 133 VLOG(1) << "Failed to receive packet: Status code is " 134 << length_or_status; 135 receive_pending_ = false; 136 return; 137 } 138 139 // Confirm the packet has come from the expected remote address; otherwise, 140 // ignore it. If this is the first packet being received and no remote 141 // address has been set, set the remote address and expect all future 142 // packets to come from the same one. 143 // TODO(hubbe): We should only do this if the caller used a valid ssrc. 144 if (IsEmpty(remote_addr_)) { 145 remote_addr_ = recv_addr_; 146 VLOG(1) << "Setting remote address from first received packet: " 147 << remote_addr_.ToString(); 148 } else if (!IsEqual(remote_addr_, recv_addr_)) { 149 VLOG(1) << "Ignoring packet received from an unrecognized address: " 150 << recv_addr_.ToString() << "."; 151 length_or_status = net::ERR_IO_PENDING; 152 continue; 153 } 154 155 next_packet_->resize(length_or_status); 156 packet_receiver_.Run(next_packet_.Pass()); 157 length_or_status = net::ERR_IO_PENDING; 158 } 159} 160 161bool UdpTransport::SendPacket(PacketRef packet, const base::Closure& cb) { 162 DCHECK(io_thread_proxy_->RunsTasksOnCurrentThread()); 163 164 // Increase byte count no matter the packet was sent or dropped. 165 bytes_sent_ += packet->data.size(); 166 167 DCHECK(!send_pending_); 168 if (send_pending_) { 169 VLOG(1) << "Cannot send because of pending IO."; 170 return true; 171 } 172 173 if (next_dscp_value_ != net::DSCP_NO_CHANGE) { 174 int result = udp_socket_->SetDiffServCodePoint(next_dscp_value_); 175 if (result != net::OK) { 176 VLOG(1) << "Unable to set DSCP: " << next_dscp_value_ 177 << " to socket; Error: " << result; 178 } 179 180 if (result != net::ERR_SOCKET_NOT_CONNECTED) { 181 // Don't change DSCP in next send. 182 next_dscp_value_ = net::DSCP_NO_CHANGE; 183 } 184 } 185 186 scoped_refptr<net::IOBuffer> buf = 187 new net::WrappedIOBuffer(reinterpret_cast<char*>(&packet->data.front())); 188 189 int result; 190 base::Callback<void(int)> callback = base::Bind(&UdpTransport::OnSent, 191 weak_factory_.GetWeakPtr(), 192 buf, 193 packet, 194 cb); 195 if (client_connected_) { 196 // If we called Connect() before we must call Write() instead of 197 // SendTo(). Otherwise on some platforms we might get 198 // ERR_SOCKET_IS_CONNECTED. 199 result = udp_socket_->Write( 200 buf.get(), static_cast<int>(packet->data.size()), callback); 201 } else if (!IsEmpty(remote_addr_)) { 202 result = udp_socket_->SendTo(buf.get(), 203 static_cast<int>(packet->data.size()), 204 remote_addr_, 205 callback); 206 } else { 207 VLOG(1) << "Failed to send packet; socket is neither bound nor " 208 << "connected."; 209 return true; 210 } 211 212 if (result == net::ERR_IO_PENDING) { 213 send_pending_ = true; 214 return false; 215 } 216 OnSent(buf, packet, base::Closure(), result); 217 return true; 218} 219 220int64 UdpTransport::GetBytesSent() { 221 return bytes_sent_; 222} 223 224void UdpTransport::OnSent(const scoped_refptr<net::IOBuffer>& buf, 225 PacketRef packet, 226 const base::Closure& cb, 227 int result) { 228 DCHECK(io_thread_proxy_->RunsTasksOnCurrentThread()); 229 230 send_pending_ = false; 231 if (result < 0) { 232 VLOG(1) << "Failed to send packet: " << result << "."; 233 } 234 ScheduleReceiveNextPacket(); 235 236 if (!cb.is_null()) { 237 cb.Run(); 238 } 239} 240 241} // namespace cast 242} // namespace media 243