gio/gnetworking.c

   1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
   2
   3 /* GIO - GLib Input, Output and Streaming Library
   4  *
   5  * Copyright (C) 2011 Red Hat, Inc.
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General
  18  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "config.h"
  22
  23 #include "gnetworking.h"
  24
  25 #ifdef G_OS_WIN32
  26 /* For Windows XP run-time compatibility */
  27 #include "gwin32networking.h"
  28
  29 GWin32WinsockFuncs ws2funcs = {0};
  30 #endif
  31
  32 /**
  33  * SECTION:gnetworking
  34  * @title: gnetworking.h
  35  * @short_description: System networking includes
  36  * @include: gio/gnetworking.h
  37  *
  38  * The `<gio/gnetworking.h>` header can be included to get
  39  * various low-level networking-related system headers, automatically
  40  * taking care of certain portability issues for you.
  41  *
  42  * This can be used, for example, if you want to call setsockopt()
  43  * on a #GSocket.
  44  *
  45  * Note that while WinSock has many of the same APIs as the
  46  * traditional UNIX socket API, most of them behave at least slightly
  47  * differently (particularly with respect to error handling). If you
  48  * want your code to work under both UNIX and Windows, you will need
  49  * to take these differences into account.
  50  *
  51  * Also, under GNU libc, certain non-portable functions are only visible
  52  * in the headers if you define %_GNU_SOURCE before including them. Note
  53  * that this symbol must be defined before including any headers, or it
  54  * may not take effect.
  55  */
  56
  57 /**
  58  * g_networking_init:
  59  *
  60  * Initializes the platform networking libraries (eg, on Windows, this
  61  * calls WSAStartup()). GLib will call this itself if it is needed, so
  62  * you only need to call it if you directly call system networking
  63  * functions (without calling any GLib networking functions first).
  64  *
  65  * Since: 2.36
  66  */
  67 void
  68 g_networking_init (void)
  69 {
  70 #ifdef G_OS_WIN32
  71   static volatile gsize inited = 0;
  72
  73   if (g_once_init_enter (&inited))
  74     {
  75       WSADATA wsadata;
  76       HMODULE ws2dll, iphlpapidll;
  77
  78       if (WSAStartup (MAKEWORD (2, 0), &wsadata) != 0)
  79         g_error ("Windows Sockets could not be initialized");
  80
  81       /* We want to use these functions if they are available, but
  82        * still need to make sure the code still runs on Windows XP
  83        */
  84       ws2dll = LoadLibraryW (L"ws2_32.dll");
  85       iphlpapidll = LoadLibraryW (L"iphlpapi.dll");
  86
  87       if (ws2dll != NULL)
  88         {
  89           ws2funcs.pInetNtop =
  90             (PFN_InetNtop) GetProcAddress (ws2dll, "inet_ntop");
  91           ws2funcs.pInetPton =
  92             (PFN_InetPton) GetProcAddress (ws2dll, "inet_pton");
  93           FreeLibrary (ws2dll);
  94         }
  95       else
  96         {
  97           ws2funcs.pInetNtop = NULL;
  98           ws2funcs.pInetPton = NULL;
  99         }
 100
 101       if (iphlpapidll != NULL)
 102         {
 103           ws2funcs.pIfNameToIndex =
 104             (PFN_IfNameToIndex) GetProcAddress (iphlpapidll, "if_nametoindex");
 105           FreeLibrary (iphlpapidll);
 106         }
 107       else
 108         ws2funcs.pIfNameToIndex = NULL;
 109
 110       g_once_init_leave (&inited, 1);
 111     }
 112 #endif
 113 }