xapian-core/common/socket_utils.cc

   1 /** @file
   2  *  @brief Socket handling utilities.
   3  */
   4 /* Copyright (C) 2006,2007,2008,2015 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #include <config.h>
  22 #include "socket_utils.h"
  23
  24 #include <limits>
  25
  26 #include "realtime.h"
  27 #include "safesyssocket.h"
  28
  29 using namespace std;
  30
  31 #ifdef __WIN32__
  32 # include <io.h>
  33 # include "msvcignoreinvalidparam.h"
  34 # include <cerrno>
  35
  36 /// Convert an fd (which might be a socket) to a WIN32 HANDLE.
  37 extern HANDLE fd_to_handle(int fd) {
  38     MSVCIgnoreInvalidParameter invalid_handle_value_is_ok;
  39     HANDLE handle = (HANDLE)_get_osfhandle(fd);
  40     if (handle != INVALID_HANDLE_VALUE) return handle;
  41     // On WIN32, a socket fd isn't the same as a non-socket fd - in fact it's
  42     // already a HANDLE!
  43     return reinterpret_cast<HANDLE>(fd);
  44 }
  45
  46 /// Close an fd, which might be a socket.
  47 extern void close_fd_or_socket(int fd) {
  48     MSVCIgnoreInvalidParameter invalid_fd_value_is_ok;
  49     if (close(fd) == -1 && errno == EBADF) {
  50         // Bad file descriptor - probably because the fd is actually
  51         // a socket.
  52         closesocket(fd);
  53     }
  54 }
  55
  56 #endif
  57
  58 void
  59 set_socket_timeouts(int fd, double timeout)
  60 {
  61     (void)fd;
  62     (void)timeout;
  63 #if defined SO_SNDTIMEO || defined SO_RCVTIMEO
  64     {
  65 # ifndef __WIN32__
  66         struct timeval t;
  67         RealTime::to_timeval(timeout, &t);
  68 # else
  69         // Just to be different, it's a DWORD counting in milliseconds.
  70         DWORD t;
  71         if (usual(timeout < numeric_limits<DWORD>::max() / 1000))
  72             t = timeout * 1000;
  73         else
  74             t = numeric_limits<DWORD>::max();
  75 # endif
  76 # ifdef SO_SNDTIMEO
  77         (void)setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO,
  78                          reinterpret_cast<char*>(&t), sizeof(t));
  79 # endif
  80 # ifdef SO_RCVTIMEO
  81         (void)setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO,
  82                          reinterpret_cast<char*>(&t), sizeof(t));
  83 # endif
  84     }
  85 #endif
  86 #ifdef SO_KEEPALIVE
  87     // SO_SNDTIMEO and SO_RCVTIMEO may be ignored even if they exist, so set
  88     // SO_KEEPALIVE anyway if it exists, as it will cause stuck connections to
  89     // time out eventually (though it may take ~2 hours).
  90     {
  91 # ifndef __WIN32__
  92         int flag = 1;
  93 # else
  94         DWORD flag = 1;
  95 # endif
  96         (void)setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE,
  97                          reinterpret_cast<char*>(&flag), sizeof(flag));
  98     }
  99 #endif
 100 }