src/nxcproxy/listener.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: listener.cpp
  20 **
  21 **/
  22
  23 #include "nxcproxy.h"
  24
  25 /**
  26  * Listener thread
  27  */
  28 THREAD_RESULT THREAD_CALL ListenerThread(void *)
  29 {
  30    SOCKET hSocket, hClientSocket;
  31    struct sockaddr_in servAddr;
  32    int iNumErrors = 0, nRet;
  33    socklen_t iSize;
  34    TCHAR szBuffer[256];
  35    struct timeval tv;
  36    fd_set rdfs;
  37
  38    // Create socket
  39    if ((hSocket = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
  40    {
  41       nxlog_write(MSG_SOCKET_ERROR, EVENTLOG_ERROR_TYPE, "e", WSAGetLastError());
  42       exit(1);
  43    }
  44
  45         SetSocketExclusiveAddrUse(hSocket);
  46         SetSocketReuseFlag(hSocket);
  47
  48    // Fill in local address structure
  49    memset(&servAddr, 0, sizeof(struct sockaddr_in));
  50    servAddr.sin_family = AF_INET;
  51         if (!_tcscmp(g_listenAddress, _T("*")))
  52         {
  53                 servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  54         }
  55         else
  56         {
  57       servAddr.sin_addr.s_addr = InetAddress::resolveHostName(g_listenAddress, AF_INET).getAddressV4();
  58                 if (servAddr.sin_addr.s_addr == htonl(INADDR_NONE))
  59                         servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  60         }
  61    servAddr.sin_port = htons(g_listenPort);
  62
  63    // Bind socket
  64         DebugPrintf(1, _T("Trying to bind on %s:%d"), IpToStr(ntohl(servAddr.sin_addr.s_addr), szBuffer), ntohs(servAddr.sin_port));
  65    if (bind(hSocket, (struct sockaddr *)&servAddr, sizeof(struct sockaddr_in)) != 0)
  66    {
  67       nxlog_write(MSG_BIND_ERROR, EVENTLOG_ERROR_TYPE, "e", WSAGetLastError());
  68       exit(1);
  69    }
  70
  71    // Set up queue
  72    listen(hSocket, SOMAXCONN);
  73         nxlog_write(MSG_LISTENING, EVENTLOG_INFORMATION_TYPE, "ad", ntohl(servAddr.sin_addr.s_addr), g_listenPort);
  74
  75    // Wait for connection requests
  76    while(!(g_flags & AF_SHUTDOWN))
  77    {
  78       tv.tv_sec = 1;
  79       tv.tv_usec = 0;
  80       FD_ZERO(&rdfs);
  81       FD_SET(hSocket, &rdfs);
  82       nRet = select(SELECT_NFDS(hSocket + 1), &rdfs, NULL, NULL, &tv);
  83       if ((nRet > 0) && (!(g_flags & AF_SHUTDOWN)))
  84       {
  85          iSize = sizeof(struct sockaddr_in);
  86          if ((hClientSocket = accept(hSocket, (struct sockaddr *)&servAddr, &iSize)) == -1)
  87          {
  88             int error = WSAGetLastError();
  89
  90             if (error != WSAEINTR)
  91                nxlog_write(MSG_ACCEPT_ERROR, EVENTLOG_ERROR_TYPE, "e", error);
  92             iNumErrors++;
  93             if (iNumErrors > 1000)
  94             {
  95                nxlog_write(MSG_TOO_MANY_ERRORS, EVENTLOG_WARNING_TYPE, NULL);
  96                iNumErrors = 0;
  97             }
  98             ThreadSleepMs(500);
  99             continue;
 100          }
 101
 102          iNumErrors = 0;     // Reset consecutive errors counter
 103          DebugPrintf(5, _T("Incoming connection from %s"), IpToStr(ntohl(servAddr.sin_addr.s_addr), szBuffer));
 104
 105          SetSocketNonBlocking(hClientSocket);
 106
 107          ProxySession *session = new ProxySession(hClientSocket);
 108          session->run();
 109       }
 110       else if (nRet == -1)
 111       {
 112          int error = WSAGetLastError();
 113
 114          // On AIX, select() returns ENOENT after SIGINT for unknown reason
 115 #ifdef _WIN32
 116          if (error != WSAEINTR)
 117 #else
 118          if ((error != EINTR) && (error != ENOENT))
 119 #endif
 120          {
 121             nxlog_write(MSG_SELECT_ERROR, EVENTLOG_ERROR_TYPE, "e", error);
 122             ThreadSleepMs(100);
 123          }
 124       }
 125    }
 126
 127    closesocket(hSocket);
 128    DebugPrintf(1, _T("Listener thread terminated"));
 129    return THREAD_OK;
 130 }