1 /*
2  *  Copyright 2004 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 
11 #include "webrtc/base/asynctcpsocket.h"
12 
13 #include <string.h>
14 
15 #include "webrtc/base/byteorder.h"
16 #include "webrtc/base/common.h"
17 #include "webrtc/base/logging.h"
18 
19 #if defined(WEBRTC_POSIX)
20 #include <errno.h>
21 #endif  // WEBRTC_POSIX
22 
23 namespace rtc {
24 
25 static const size_t kMaxPacketSize = 64 * 1024;
26 
27 typedef uint16_t PacketLength;
28 static const size_t kPacketLenSize = sizeof(PacketLength);
29 
30 static const size_t kBufSize = kMaxPacketSize + kPacketLenSize;
31 
32 static const int kListenBacklog = 5;
33 
34 // Binds and connects |socket|
ConnectSocket(rtc::AsyncSocket * socket,const rtc::SocketAddress & bind_address,const rtc::SocketAddress & remote_address)35 AsyncSocket* AsyncTCPSocketBase::ConnectSocket(
36     rtc::AsyncSocket* socket,
37     const rtc::SocketAddress& bind_address,
38     const rtc::SocketAddress& remote_address) {
39   rtc::scoped_ptr<rtc::AsyncSocket> owned_socket(socket);
40   if (socket->Bind(bind_address) < 0) {
41     LOG(LS_ERROR) << "Bind() failed with error " << socket->GetError();
42     return NULL;
43   }
44   if (socket->Connect(remote_address) < 0) {
45     LOG(LS_ERROR) << "Connect() failed with error " << socket->GetError();
46     return NULL;
47   }
48   return owned_socket.release();
49 }
50 
AsyncTCPSocketBase(AsyncSocket * socket,bool listen,size_t max_packet_size)51 AsyncTCPSocketBase::AsyncTCPSocketBase(AsyncSocket* socket, bool listen,
52                                        size_t max_packet_size)
53     : socket_(socket),
54       listen_(listen),
55       insize_(max_packet_size),
56       inpos_(0),
57       outsize_(max_packet_size),
58       outpos_(0) {
59   inbuf_ = new char[insize_];
60   outbuf_ = new char[outsize_];
61 
62   ASSERT(socket_.get() != NULL);
63   socket_->SignalConnectEvent.connect(
64       this, &AsyncTCPSocketBase::OnConnectEvent);
65   socket_->SignalReadEvent.connect(this, &AsyncTCPSocketBase::OnReadEvent);
66   socket_->SignalWriteEvent.connect(this, &AsyncTCPSocketBase::OnWriteEvent);
67   socket_->SignalCloseEvent.connect(this, &AsyncTCPSocketBase::OnCloseEvent);
68 
69   if (listen_) {
70     if (socket_->Listen(kListenBacklog) < 0) {
71       LOG(LS_ERROR) << "Listen() failed with error " << socket_->GetError();
72     }
73   }
74 }
75 
~AsyncTCPSocketBase()76 AsyncTCPSocketBase::~AsyncTCPSocketBase() {
77   delete [] inbuf_;
78   delete [] outbuf_;
79 }
80 
GetLocalAddress() const81 SocketAddress AsyncTCPSocketBase::GetLocalAddress() const {
82   return socket_->GetLocalAddress();
83 }
84 
GetRemoteAddress() const85 SocketAddress AsyncTCPSocketBase::GetRemoteAddress() const {
86   return socket_->GetRemoteAddress();
87 }
88 
Close()89 int AsyncTCPSocketBase::Close() {
90   return socket_->Close();
91 }
92 
GetState() const93 AsyncTCPSocket::State AsyncTCPSocketBase::GetState() const {
94   switch (socket_->GetState()) {
95     case Socket::CS_CLOSED:
96       return STATE_CLOSED;
97     case Socket::CS_CONNECTING:
98       if (listen_) {
99         return STATE_BOUND;
100       } else {
101         return STATE_CONNECTING;
102       }
103     case Socket::CS_CONNECTED:
104       return STATE_CONNECTED;
105     default:
106       ASSERT(false);
107       return STATE_CLOSED;
108   }
109 }
110 
GetOption(Socket::Option opt,int * value)111 int AsyncTCPSocketBase::GetOption(Socket::Option opt, int* value) {
112   return socket_->GetOption(opt, value);
113 }
114 
SetOption(Socket::Option opt,int value)115 int AsyncTCPSocketBase::SetOption(Socket::Option opt, int value) {
116   return socket_->SetOption(opt, value);
117 }
118 
GetError() const119 int AsyncTCPSocketBase::GetError() const {
120   return socket_->GetError();
121 }
122 
SetError(int error)123 void AsyncTCPSocketBase::SetError(int error) {
124   return socket_->SetError(error);
125 }
126 
SendTo(const void * pv,size_t cb,const SocketAddress & addr,const rtc::PacketOptions & options)127 int AsyncTCPSocketBase::SendTo(const void *pv, size_t cb,
128                                const SocketAddress& addr,
129                                const rtc::PacketOptions& options) {
130   const SocketAddress& remote_address = GetRemoteAddress();
131   if (addr == remote_address)
132     return Send(pv, cb, options);
133   // Remote address may be empty if there is a sudden network change.
134   ASSERT(remote_address.IsNil());
135   socket_->SetError(ENOTCONN);
136   return -1;
137 }
138 
SendRaw(const void * pv,size_t cb)139 int AsyncTCPSocketBase::SendRaw(const void * pv, size_t cb) {
140   if (outpos_ + cb > outsize_) {
141     socket_->SetError(EMSGSIZE);
142     return -1;
143   }
144 
145   memcpy(outbuf_ + outpos_, pv, cb);
146   outpos_ += cb;
147 
148   return FlushOutBuffer();
149 }
150 
FlushOutBuffer()151 int AsyncTCPSocketBase::FlushOutBuffer() {
152   int res = socket_->Send(outbuf_, outpos_);
153   if (res <= 0) {
154     return res;
155   }
156   if (static_cast<size_t>(res) <= outpos_) {
157     outpos_ -= res;
158   } else {
159     ASSERT(false);
160     return -1;
161   }
162   if (outpos_ > 0) {
163     memmove(outbuf_, outbuf_ + res, outpos_);
164   }
165   return res;
166 }
167 
AppendToOutBuffer(const void * pv,size_t cb)168 void AsyncTCPSocketBase::AppendToOutBuffer(const void* pv, size_t cb) {
169   ASSERT(outpos_ + cb < outsize_);
170   memcpy(outbuf_ + outpos_, pv, cb);
171   outpos_ += cb;
172 }
173 
OnConnectEvent(AsyncSocket * socket)174 void AsyncTCPSocketBase::OnConnectEvent(AsyncSocket* socket) {
175   SignalConnect(this);
176 }
177 
OnReadEvent(AsyncSocket * socket)178 void AsyncTCPSocketBase::OnReadEvent(AsyncSocket* socket) {
179   ASSERT(socket_.get() == socket);
180 
181   if (listen_) {
182     rtc::SocketAddress address;
183     rtc::AsyncSocket* new_socket = socket->Accept(&address);
184     if (!new_socket) {
185       // TODO: Do something better like forwarding the error
186       // to the user.
187       LOG(LS_ERROR) << "TCP accept failed with error " << socket_->GetError();
188       return;
189     }
190 
191     HandleIncomingConnection(new_socket);
192 
193     // Prime a read event in case data is waiting.
194     new_socket->SignalReadEvent(new_socket);
195   } else {
196     int len = socket_->Recv(inbuf_ + inpos_, insize_ - inpos_);
197     if (len < 0) {
198       // TODO: Do something better like forwarding the error to the user.
199       if (!socket_->IsBlocking()) {
200         LOG(LS_ERROR) << "Recv() returned error: " << socket_->GetError();
201       }
202       return;
203     }
204 
205     inpos_ += len;
206 
207     ProcessInput(inbuf_, &inpos_);
208 
209     if (inpos_ >= insize_) {
210       LOG(LS_ERROR) << "input buffer overflow";
211       ASSERT(false);
212       inpos_ = 0;
213     }
214   }
215 }
216 
OnWriteEvent(AsyncSocket * socket)217 void AsyncTCPSocketBase::OnWriteEvent(AsyncSocket* socket) {
218   ASSERT(socket_.get() == socket);
219 
220   if (outpos_ > 0) {
221     FlushOutBuffer();
222   }
223 
224   if (outpos_ == 0) {
225     SignalReadyToSend(this);
226   }
227 }
228 
OnCloseEvent(AsyncSocket * socket,int error)229 void AsyncTCPSocketBase::OnCloseEvent(AsyncSocket* socket, int error) {
230   SignalClose(this, error);
231 }
232 
233 // AsyncTCPSocket
234 // Binds and connects |socket| and creates AsyncTCPSocket for
235 // it. Takes ownership of |socket|. Returns NULL if bind() or
236 // connect() fail (|socket| is destroyed in that case).
Create(AsyncSocket * socket,const SocketAddress & bind_address,const SocketAddress & remote_address)237 AsyncTCPSocket* AsyncTCPSocket::Create(
238     AsyncSocket* socket,
239     const SocketAddress& bind_address,
240     const SocketAddress& remote_address) {
241   return new AsyncTCPSocket(AsyncTCPSocketBase::ConnectSocket(
242       socket, bind_address, remote_address), false);
243 }
244 
AsyncTCPSocket(AsyncSocket * socket,bool listen)245 AsyncTCPSocket::AsyncTCPSocket(AsyncSocket* socket, bool listen)
246     : AsyncTCPSocketBase(socket, listen, kBufSize) {
247 }
248 
Send(const void * pv,size_t cb,const rtc::PacketOptions & options)249 int AsyncTCPSocket::Send(const void *pv, size_t cb,
250                          const rtc::PacketOptions& options) {
251   if (cb > kBufSize) {
252     SetError(EMSGSIZE);
253     return -1;
254   }
255 
256   // If we are blocking on send, then silently drop this packet
257   if (!IsOutBufferEmpty())
258     return static_cast<int>(cb);
259 
260   PacketLength pkt_len = HostToNetwork16(static_cast<PacketLength>(cb));
261   AppendToOutBuffer(&pkt_len, kPacketLenSize);
262   AppendToOutBuffer(pv, cb);
263 
264   int res = FlushOutBuffer();
265   if (res <= 0) {
266     // drop packet if we made no progress
267     ClearOutBuffer();
268     return res;
269   }
270 
271   rtc::SentPacket sent_packet(options.packet_id, rtc::Time());
272   SignalSentPacket(this, sent_packet);
273 
274   // We claim to have sent the whole thing, even if we only sent partial
275   return static_cast<int>(cb);
276 }
277 
ProcessInput(char * data,size_t * len)278 void AsyncTCPSocket::ProcessInput(char * data, size_t* len) {
279   SocketAddress remote_addr(GetRemoteAddress());
280 
281   while (true) {
282     if (*len < kPacketLenSize)
283       return;
284 
285     PacketLength pkt_len = rtc::GetBE16(data);
286     if (*len < kPacketLenSize + pkt_len)
287       return;
288 
289     SignalReadPacket(this, data + kPacketLenSize, pkt_len, remote_addr,
290                      CreatePacketTime(0));
291 
292     *len -= kPacketLenSize + pkt_len;
293     if (*len > 0) {
294       memmove(data, data + kPacketLenSize + pkt_len, *len);
295     }
296   }
297 }
298 
HandleIncomingConnection(AsyncSocket * socket)299 void AsyncTCPSocket::HandleIncomingConnection(AsyncSocket* socket) {
300   SignalNewConnection(this, new AsyncTCPSocket(socket, false));
301 }
302 
303 }  // namespace rtc
304