src/nxcproxy/session.cpp

   1 /*
   2 ** NetXMS client proxy
   3 ** Copyright (C) 2003-2013 Victor Kirhenshtein
   4 **
   5 ** This program is free software; you can redistribute it and/or modify
   6 ** it under the terms of the GNU General Public License as published by
   7 ** the Free Software Foundation; either version 2 of the License, or
   8 ** (at your option) any later version.
   9 **
  10 ** This program is distributed in the hope that it will be useful,
  11 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 ** GNU General Public License for more details.
  14 **
  15 ** You should have received a copy of the GNU General Public License
  16 ** along with this program; if not, write to the Free Software
  17 ** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18 **
  19 ** File: session.cpp
  20 **
  21 **/
  22
  23 #include "nxcproxy.h"
  24
  25 /**
  26  * Constructor
  27  */
  28 ProxySession::ProxySession(SOCKET s)
  29 {
  30    m_client = s;
  31    m_server = INVALID_SOCKET;
  32 }
  33
  34 /**
  35  * Destructor
  36  */
  37 ProxySession::~ProxySession()
  38 {
  39 }
  40
  41 /**
  42  * Run session
  43  */
  44 void ProxySession::run()
  45 {
  46    ThreadCreate(ProxySession::clientThreadStarter, 0, this);
  47 }
  48
  49 /**
  50  * Client thread starter
  51  */
  52 THREAD_RESULT THREAD_CALL ProxySession::clientThreadStarter(void *arg)
  53 {
  54    ((ProxySession *)arg)->clientThread();
  55    // server thread is not running at this point, so it's safe to delete self
  56    delete (ProxySession *)arg;
  57    return THREAD_OK;
  58 }
  59
  60 /**
  61  * Server thread starter
  62  */
  63 THREAD_RESULT THREAD_CALL ProxySession::serverThreadStarter(void *arg)
  64 {
  65    ((ProxySession *)arg)->serverThread();
  66    return THREAD_OK;
  67 }
  68
  69 /**
  70  * Client thread
  71  */
  72 void ProxySession::clientThread()
  73 {
  74    DebugPrintf(7, _T("Client thread started, connecting to server"));
  75    InetAddress addr = InetAddress::resolveHostName(g_serverAddress);
  76    if (addr.isValidUnicast())
  77    {
  78       m_server = socket(addr.getFamily(), SOCK_STREAM, 0);
  79       if (m_server != INVALID_SOCKET)
  80       {
  81          SockAddrBuffer sa;
  82          addr.fillSockAddr(&sa, g_serverPort);
  83          if (ConnectEx(m_server, (struct sockaddr *)&sa, SA_LEN((struct sockaddr *)&sa), 5000) != -1)
  84          {
  85             DebugPrintf(7, _T("Connected to server %s:%d"), g_serverAddress, (int)g_serverPort);
  86             THREAD serverThread = ThreadCreateEx(ProxySession::serverThreadStarter, 0, this);
  87             forward(m_client, m_server);
  88             ThreadJoin(serverThread);
  89          }
  90          closesocket(m_server);
  91       }
  92       else
  93       {
  94          DebugPrintf(5, _T("Cannot create socket for server connection"));
  95       }
  96    }
  97    else
  98    {
  99       DebugPrintf(4, _T("Cannot resolve server address %s"), g_serverAddress);
 100    }
 101
 102    shutdown(m_client, SHUT_RDWR);
 103    closesocket(m_client);
 104    DebugPrintf(7, _T("Client thread stopped"));
 105 }
 106
 107 /**
 108  * Server thread
 109  */
 110 void ProxySession::serverThread()
 111 {
 112    DebugPrintf(7, _T("Server thread started"));
 113    SetSocketNonBlocking(m_server);
 114    forward(m_server, m_client);
 115    DebugPrintf(7, _T("Server thread stopped"));
 116 }
 117
 118 /**
 119  * Forward messages between two sockets
 120  */
 121 void ProxySession::forward(SOCKET rs, SOCKET ws)
 122 {
 123    fd_set rdfs;
 124    struct timeval tv;
 125    char buffer[8192];
 126
 127    while(true)
 128    {
 129       FD_ZERO(&rdfs);
 130       FD_SET(rs, &rdfs);
 131       tv.tv_sec = 0;
 132       tv.tv_usec = 5000000;   // Half-second timeout
 133       int ret = select(SELECT_NFDS(rs + 1), &rdfs, NULL, NULL, &tv);
 134       if (ret < 0)
 135          break;
 136       if (ret > 0)
 137       {
 138          ret = recv(rs, buffer, 8192, 0);
 139          if (ret <= 0)
 140             break;
 141          SendEx(ws, buffer, ret, 0, NULL);
 142       }
 143    }
 144
 145    // shutdown other end
 146    shutdown(ws, SHUT_RDWR);
 147 }