src/network/getaddrinfo.c

   1 /*****************************************************************************
   2  * getaddrinfo.c: getaddrinfo/getnameinfo replacement functions
   3  *****************************************************************************
   4  * Copyright (C) 2005 VLC authors and VideoLAN
   5  * Copyright (C) 2002-2007 Rémi Denis-Courmont
   6  * $Id$
   7  *
   8  * Author: Rémi Denis-Courmont <rem # videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 #ifdef HAVE_CONFIG_H
  26 # include "config.h"
  27 #endif
  28
  29 #include <vlc_common.h>
  30 #include <vlc_charset.h>
  31
  32 #include <stddef.h> /* size_t */
  33 #include <string.h> /* strlen(), memcpy(), memset(), strchr() */
  34 #include <stdlib.h> /* malloc(), free(), strtoul() */
  35 #include <errno.h>
  36 #include <assert.h>
  37
  38 #include <sys/types.h>
  39 #include <vlc_network.h>
  40
  41 #ifndef AF_UNSPEC
  42 #   define AF_UNSPEC   0
  43 #endif
  44
  45 int vlc_getnameinfo( const struct sockaddr *sa, int salen,
  46                      char *host, int hostlen, int *portnum, int flags )
  47 {
  48     char psz_servbuf[6], *psz_serv;
  49     int i_servlen, i_val;
  50
  51     flags |= NI_NUMERICSERV;
  52     if( portnum != NULL )
  53     {
  54         psz_serv = psz_servbuf;
  55         i_servlen = sizeof( psz_servbuf );
  56     }
  57     else
  58     {
  59         psz_serv = NULL;
  60         i_servlen = 0;
  61     }
  62
  63     i_val = getnameinfo(sa, salen, host, hostlen, psz_serv, i_servlen, flags);
  64
  65     if( portnum != NULL )
  66         *portnum = atoi( psz_serv );
  67
  68     return i_val;
  69 }
  70
  71
  72 /**
  73  * Resolves a host name to a list of socket addresses (like getaddrinfo()).
  74  *
  75  * @param p_this a VLC object
  76  * @param node host name to resolve (encoded as UTF-8), or NULL
  77  * @param i_port port number for the socket addresses
  78  * @param p_hints parameters (see getaddrinfo() manual page)
  79  * @param res pointer set to the resulting chained list.
  80  * @return 0 on success, a getaddrinfo() error otherwise.
  81  * On failure, *res is undefined. On success, it must be freed with
  82  * freeaddrinfo().
  83  */
  84 int vlc_getaddrinfo( vlc_object_t *p_this, const char *node,
  85                      int i_port, const struct addrinfo *p_hints,
  86                      struct addrinfo **res )
  87 {
  88     struct addrinfo hints;
  89     char psz_buf[NI_MAXHOST], psz_service[6];
  90
  91     /*
  92      * In VLC, we always use port number as integer rather than strings
  93      * for historical reasons (and portability).
  94      */
  95     if( ( i_port > 65535 ) || ( i_port < 0 ) )
  96     {
  97         msg_Err( p_this, "invalid port number %d specified", i_port );
  98         return EAI_SERVICE;
  99     }
 100
 101     /* cannot overflow */
 102     snprintf( psz_service, 6, "%d", i_port );
 103
 104     /* Check if we have to force ipv4 or ipv6 */
 105     memset (&hints, 0, sizeof (hints));
 106     if (p_hints != NULL)
 107     {
 108         const int safe_flags =
 109             AI_PASSIVE |
 110             AI_CANONNAME |
 111             AI_NUMERICHOST |
 112             AI_NUMERICSERV |
 113 #ifdef AI_ALL
 114             AI_ALL |
 115 #endif
 116 #ifdef AI_ADDRCONFIG
 117             AI_ADDRCONFIG |
 118 #endif
 119 #ifdef AI_V4MAPPED
 120             AI_V4MAPPED |
 121 #endif
 122             0;
 123
 124         hints.ai_family = p_hints->ai_family;
 125         hints.ai_socktype = p_hints->ai_socktype;
 126         hints.ai_protocol = p_hints->ai_protocol;
 127         /* Unfortunately, some flags chang the layout of struct addrinfo, so
 128          * they cannot be copied blindly from p_hints to &hints. Therefore, we
 129          * only copy flags that we know for sure are "safe".
 130          */
 131         hints.ai_flags = p_hints->ai_flags & safe_flags;
 132     }
 133
 134     /* We only ever use port *numbers* */
 135     hints.ai_flags |= AI_NUMERICSERV;
 136
 137     /*
 138      * VLC extensions :
 139      * - accept "" as NULL
 140      * - ignore square brackets
 141      */
 142     if (node != NULL)
 143     {
 144         if (node[0] == '[')
 145         {
 146             size_t len = strlen (node + 1);
 147             if ((len <= sizeof (psz_buf)) && (node[len] == ']'))
 148             {
 149                 assert (len > 0);
 150                 memcpy (psz_buf, node + 1, len - 1);
 151                 psz_buf[len - 1] = '\0';
 152                 node = psz_buf;
 153             }
 154         }
 155         if (node[0] == '\0')
 156             node = NULL;
 157     }
 158
 159     int ret;
 160     node = ToLocale (node);
 161 #ifdef WIN32
 162     /*
 163      * Winsock tries to resolve numerical IPv4 addresses as AAAA
 164      * and IPv6 addresses as A... There comes the bug-to-bug fix.
 165      */
 166     if ((hints.ai_flags & AI_NUMERICHOST) == 0)
 167     {
 168         hints.ai_flags |= AI_NUMERICHOST;
 169         ret = getaddrinfo (node, psz_service, &hints, res);
 170         if (ret == 0)
 171             goto out;
 172         hints.ai_flags &= ~AI_NUMERICHOST;
 173     }
 174 #endif
 175 #ifdef AI_IDN
 176     /* Run-time I18n Domain Names support */
 177     hints.ai_flags |= AI_IDN;
 178     ret = getaddrinfo (node, psz_service, &hints, res);
 179     if (ret != EAI_BADFLAGS)
 180         goto out;
 181     /* IDN not available: disable and retry without it */
 182     hints.ai_flags &= ~AI_IDN;
 183 #endif
 184     ret = getaddrinfo (node, psz_service, &hints, res);
 185
 186 #if defined(AI_IDN) || defined(WIN32)
 187 out:
 188 #endif
 189     LocaleFree (node);
 190     return ret;
 191 }