Home | History | Annotate | Download | only in base
      1 /*
      2  * libjingle
      3  * Copyright 2004--2010, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include "talk/base/asynctcpsocket.h"
     29 
     30 #include <cstring>
     31 
     32 #include "talk/base/byteorder.h"
     33 #include "talk/base/common.h"
     34 #include "talk/base/logging.h"
     35 
     36 #ifdef POSIX
     37 #include <errno.h>
     38 #endif  // POSIX
     39 
     40 namespace talk_base {
     41 
     42 static const size_t MAX_PACKET_SIZE = 64 * 1024;
     43 
     44 typedef uint16 PacketLength;
     45 static const size_t PKT_LEN_SIZE = sizeof(PacketLength);
     46 
     47 static const size_t BUF_SIZE = MAX_PACKET_SIZE + PKT_LEN_SIZE;
     48 
     49 static const int LISTEN_BACKLOG = 5;
     50 
     51 AsyncTCPSocket* AsyncTCPSocket::Create(SocketFactory* factory, bool listen) {
     52   AsyncSocket* sock = factory->CreateAsyncSocket(SOCK_STREAM);
     53   // This will still return a socket even if we failed to listen on
     54   // it. It is neccessary because even if we can't accept new
     55   // connections on this socket, the corresponding port is still
     56   // useful for outgoing connections.
     57   //
     58   // TODO: It might be better to pass listen() error to the
     59   // upper layer and let it handle the problem.
     60   return (sock) ? new AsyncTCPSocket(sock, listen) : NULL;
     61 }
     62 
     63 AsyncTCPSocket::AsyncTCPSocket(AsyncSocket* socket, bool listen)
     64     : socket_(socket),
     65       listen_(listen),
     66       insize_(BUF_SIZE),
     67       inpos_(0),
     68       outsize_(BUF_SIZE),
     69       outpos_(0) {
     70   inbuf_ = new char[insize_];
     71   outbuf_ = new char[outsize_];
     72 
     73   ASSERT(socket_.get() != NULL);
     74   socket_->SignalConnectEvent.connect(this, &AsyncTCPSocket::OnConnectEvent);
     75   socket_->SignalReadEvent.connect(this, &AsyncTCPSocket::OnReadEvent);
     76   socket_->SignalWriteEvent.connect(this, &AsyncTCPSocket::OnWriteEvent);
     77   socket_->SignalCloseEvent.connect(this, &AsyncTCPSocket::OnCloseEvent);
     78 
     79   if (listen_) {
     80     if (socket_->Listen(LISTEN_BACKLOG) < 0) {
     81       LOG(LS_ERROR) << "Listen() failed with error " << socket_->GetError();
     82     }
     83   }
     84 }
     85 
     86 AsyncTCPSocket::~AsyncTCPSocket() {
     87   delete [] inbuf_;
     88   delete [] outbuf_;
     89 }
     90 
     91 SocketAddress AsyncTCPSocket::GetLocalAddress(bool* allocated) const {
     92   if (allocated)
     93     *allocated = true;
     94   return socket_->GetLocalAddress();
     95 }
     96 
     97 SocketAddress AsyncTCPSocket::GetRemoteAddress() const {
     98   return socket_->GetRemoteAddress();
     99 }
    100 
    101 int AsyncTCPSocket::Send(const void *pv, size_t cb) {
    102   if (cb > MAX_PACKET_SIZE) {
    103     socket_->SetError(EMSGSIZE);
    104     return -1;
    105   }
    106 
    107   // If we are blocking on send, then silently drop this packet
    108   if (outpos_)
    109     return static_cast<int>(cb);
    110 
    111   PacketLength pkt_len = HostToNetwork16(static_cast<PacketLength>(cb));
    112   memcpy(outbuf_, &pkt_len, PKT_LEN_SIZE);
    113   memcpy(outbuf_ + PKT_LEN_SIZE, pv, cb);
    114   outpos_ = PKT_LEN_SIZE + cb;
    115 
    116   int res = Flush();
    117   if (res <= 0) {
    118     // drop packet if we made no progress
    119     outpos_ = 0;
    120     return res;
    121   }
    122 
    123   // We claim to have sent the whole thing, even if we only sent partial
    124   return static_cast<int>(cb);
    125 }
    126 
    127 int AsyncTCPSocket::SendTo(const void *pv, size_t cb,
    128                            const SocketAddress& addr) {
    129   if (addr == GetRemoteAddress())
    130     return Send(pv, cb);
    131 
    132   ASSERT(false);
    133   socket_->SetError(ENOTCONN);
    134   return -1;
    135 }
    136 
    137 int AsyncTCPSocket::Close() {
    138   return socket_->Close();
    139 }
    140 
    141 Socket::ConnState AsyncTCPSocket::GetState() const {
    142   return socket_->GetState();
    143 }
    144 
    145 int AsyncTCPSocket::GetOption(Socket::Option opt, int* value) {
    146   return socket_->GetOption(opt, value);
    147 }
    148 
    149 int AsyncTCPSocket::SetOption(Socket::Option opt, int value) {
    150   return socket_->SetOption(opt, value);
    151 }
    152 
    153 int AsyncTCPSocket::GetError() const {
    154   return socket_->GetError();
    155 }
    156 
    157 void AsyncTCPSocket::SetError(int error) {
    158   return socket_->SetError(error);
    159 }
    160 
    161 int AsyncTCPSocket::SendRaw(const void * pv, size_t cb) {
    162   if (outpos_ + cb > outsize_) {
    163     socket_->SetError(EMSGSIZE);
    164     return -1;
    165   }
    166 
    167   memcpy(outbuf_ + outpos_, pv, cb);
    168   outpos_ += cb;
    169 
    170   return Flush();
    171 }
    172 
    173 void AsyncTCPSocket::ProcessInput(char * data, size_t& len) {
    174   SocketAddress remote_addr(GetRemoteAddress());
    175 
    176   while (true) {
    177     if (len < PKT_LEN_SIZE)
    178       return;
    179 
    180     PacketLength pkt_len;
    181     memcpy(&pkt_len, data, PKT_LEN_SIZE);
    182     pkt_len = NetworkToHost16(pkt_len);
    183 
    184     if (len < PKT_LEN_SIZE + pkt_len)
    185       return;
    186 
    187     SignalReadPacket(this, data + PKT_LEN_SIZE, pkt_len, remote_addr);
    188 
    189     len -= PKT_LEN_SIZE + pkt_len;
    190     if (len > 0) {
    191       memmove(data, data + PKT_LEN_SIZE + pkt_len, len);
    192     }
    193   }
    194 }
    195 
    196 int AsyncTCPSocket::Flush() {
    197   int res = socket_->Send(outbuf_, outpos_);
    198   if (res <= 0) {
    199     return res;
    200   }
    201   if (static_cast<size_t>(res) <= outpos_) {
    202     outpos_ -= res;
    203   } else {
    204     ASSERT(false);
    205     return -1;
    206   }
    207   if (outpos_ > 0) {
    208     memmove(outbuf_, outbuf_ + res, outpos_);
    209   }
    210   return res;
    211 }
    212 
    213 void AsyncTCPSocket::OnConnectEvent(AsyncSocket* socket) {
    214   SignalConnect(this);
    215 }
    216 
    217 void AsyncTCPSocket::OnReadEvent(AsyncSocket* socket) {
    218   ASSERT(socket_.get() == socket);
    219 
    220   if (listen_) {
    221     talk_base::SocketAddress address;
    222     talk_base::AsyncSocket* new_socket = socket->Accept(&address);
    223     if (!new_socket) {
    224       // TODO: Do something better like forwarding the error
    225       // to the user.
    226       LOG(LS_ERROR) << "TCP accept failed with error " << socket_->GetError();
    227       return;
    228     }
    229 
    230     SignalNewConnection(this, new AsyncTCPSocket(new_socket, false));
    231 
    232     // Prime a read event in case data is waiting.
    233     new_socket->SignalReadEvent(new_socket);
    234   } else {
    235     int len = socket_->Recv(inbuf_ + inpos_, insize_ - inpos_);
    236     if (len < 0) {
    237       // TODO: Do something better like forwarding the error to the user.
    238       if (!socket_->IsBlocking()) {
    239         LOG(LS_ERROR) << "Recv() returned error: " << socket_->GetError();
    240       }
    241       return;
    242     }
    243 
    244     inpos_ += len;
    245 
    246     ProcessInput(inbuf_, inpos_);
    247 
    248     if (inpos_ >= insize_) {
    249       LOG(LS_ERROR) << "input buffer overflow";
    250       ASSERT(false);
    251       inpos_ = 0;
    252     }
    253   }
    254 }
    255 
    256 void AsyncTCPSocket::OnWriteEvent(AsyncSocket* socket) {
    257   ASSERT(socket_.get() == socket);
    258 
    259   if (outpos_ > 0) {
    260     Flush();
    261   }
    262 }
    263 
    264 void AsyncTCPSocket::OnCloseEvent(AsyncSocket* socket, int error) {
    265   SignalClose(this, error);
    266 }
    267 
    268 }  // namespace talk_base
    269