native_client_sdk/src/examples/api/socket/echo_server.cc

   1 // Copyright (c) 2013 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 "echo_server.h"
   6
   7 #include <string.h>
   8 #include <sstream>
   9
  10 #include "ppapi/c/pp_errors.h"
  11 #include "ppapi/cpp/var.h"
  12 #include "ppapi/utility/completion_callback_factory.h"
  13
  14 #ifdef WIN32
  15 #undef PostMessage
  16 #endif
  17
  18 // Number of connections to queue up on the listening
  19 // socket before new ones get "Connection Refused"
  20 static const int kBacklog = 10;
  21
  22 // Implement htons locally.  Even though this is provided by
  23 // nacl_io we don't want to include nacl_io in this simple
  24 // example.
  25 static uint16_t Htons(uint16_t hostshort) {
  26   uint8_t result_bytes[2];
  27   result_bytes[0] = (uint8_t) ((hostshort >> 8) & 0xFF);
  28   result_bytes[1] = (uint8_t) (hostshort & 0xFF);
  29
  30   uint16_t result;
  31   memcpy(&result, result_bytes, 2);
  32   return result;
  33 }
  34
  35 void EchoServer::Start(uint16_t port) {
  36   if (!pp::TCPSocket::IsAvailable()) {
  37     instance_->PostMessage("TCPSocket not available");
  38     return;
  39   }
  40
  41   listening_socket_ = pp::TCPSocket(instance_);
  42   if (listening_socket_.is_null()) {
  43     instance_->PostMessage("Error creating TCPSocket.");
  44     return;
  45   }
  46
  47   std::ostringstream status;
  48   status << "Starting server on port: " << port;
  49   instance_->PostMessage(status.str());
  50
  51   // Attempt to listen on all interfaces (0.0.0.0)
  52   // on the given port number.
  53   PP_NetAddress_IPv4 ipv4_addr = { Htons(port), { 0 } };
  54   pp::NetAddress addr(instance_, ipv4_addr);
  55   pp::CompletionCallback callback =
  56       callback_factory_.NewCallback(&EchoServer::OnBindCompletion);
  57   int32_t rtn = listening_socket_.Bind(addr, callback);
  58   if (rtn != PP_OK_COMPLETIONPENDING) {
  59     instance_->PostMessage("Error binding listening socket.");
  60     return;
  61   }
  62 }
  63
  64 void EchoServer::OnBindCompletion(int32_t result) {
  65   if (result != PP_OK) {
  66     std::ostringstream status;
  67     status << "server: Bind failed with: " << result;
  68     instance_->PostMessage(status.str());
  69     return;
  70   }
  71
  72   pp::CompletionCallback callback =
  73       callback_factory_.NewCallback(&EchoServer::OnListenCompletion);
  74
  75   int32_t rtn = listening_socket_.Listen(kBacklog, callback);
  76   if (rtn != PP_OK_COMPLETIONPENDING) {
  77     instance_->PostMessage("server: Error listening on server socket.");
  78     return;
  79   }
  80 }
  81
  82 void EchoServer::OnListenCompletion(int32_t result) {
  83   std::ostringstream status;
  84   if (result != PP_OK) {
  85     status << "server: Listen failed with: " << result;
  86     instance_->PostMessage(status.str());
  87     return;
  88   }
  89
  90   pp::NetAddress addr = listening_socket_.GetLocalAddress();
  91   status << "server: Listening on: " << addr.DescribeAsString(true).AsString();
  92   instance_->PostMessage(status.str());
  93
  94   TryAccept();
  95 }
  96
  97 void EchoServer::OnAcceptCompletion(int32_t result, pp::TCPSocket socket) {
  98   std::ostringstream status;
  99
 100   if (result != PP_OK) {
 101     status << "server: Accept failed: " << result;
 102     instance_->PostMessage(status.str());
 103     return;
 104   }
 105
 106   pp::NetAddress addr = socket.GetLocalAddress();
 107   status << "server: New connection from: ";
 108   status << addr.DescribeAsString(true).AsString();
 109   instance_->PostMessage(status.str());
 110   incoming_socket_ = socket;
 111
 112   TryRead();
 113 }
 114
 115 void EchoServer::OnReadCompletion(int32_t result) {
 116   std::ostringstream status;
 117   if (result <= 0) {
 118     if (result == 0)
 119       status << "server: client disconnected";
 120     else
 121       status << "server: Read failed: " << result;
 122     instance_->PostMessage(status.str());
 123
 124     // Remove the current incoming socket and try
 125     // to accept the next one.
 126     incoming_socket_.Close();
 127     incoming_socket_ = pp::TCPSocket();
 128     TryAccept();
 129     return;
 130   }
 131
 132   status << "server: Read " << result << " bytes";
 133   instance_->PostMessage(status.str());
 134
 135   // Echo the bytes back to the client
 136   pp::CompletionCallback callback =
 137       callback_factory_.NewCallback(&EchoServer::OnWriteCompletion);
 138   result = incoming_socket_.Write(receive_buffer_, result, callback);
 139   if (result != PP_OK_COMPLETIONPENDING) {
 140     status << "server: Write failed: " << result;
 141     instance_->PostMessage(status.str());
 142   }
 143 }
 144
 145 void EchoServer::OnWriteCompletion(int32_t result) {
 146   std::ostringstream status;
 147   if (result < 0) {
 148     status << "server: Write failed: " << result;
 149     instance_->PostMessage(status.str());
 150     return;
 151   }
 152
 153   status << "server: Wrote " << result << " bytes";
 154   instance_->PostMessage(status.str());
 155
 156   // Try and read more bytes from the client
 157   TryRead();
 158 }
 159
 160 void EchoServer::TryRead() {
 161   pp::CompletionCallback callback =
 162       callback_factory_.NewCallback(&EchoServer::OnReadCompletion);
 163   incoming_socket_.Read(receive_buffer_, kBufferSize, callback);
 164 }
 165
 166 void EchoServer::TryAccept() {
 167   pp::CompletionCallbackWithOutput<pp::TCPSocket> callback =
 168       callback_factory_.NewCallbackWithOutput(
 169           &EchoServer::OnAcceptCompletion);
 170   listening_socket_.Accept(callback);
 171 }