src/network/getaddrinfo.c

   1 /*****************************************************************************
   2  * getaddrinfo.c: getaddrinfo/getnameinfo replacement functions
   3  *****************************************************************************
   4  * Copyright (C) 2005 the VideoLAN team
   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
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 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 General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, 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     if( hints.ai_family == AF_UNSPEC )
 138     {
 139 #ifdef AF_INET6
 140         if (var_CreateGetBool (p_this, "ipv6"))
 141             hints.ai_family = AF_INET6;
 142         else
 143 #endif
 144         if (var_CreateGetBool (p_this, "ipv4"))
 145             hints.ai_family = AF_INET;
 146     }
 147
 148     /*
 149      * VLC extensions :
 150      * - accept "" as NULL
 151      * - ignore square brackets
 152      */
 153     if (node != NULL)
 154     {
 155         if (node[0] == '[')
 156         {
 157             size_t len = strlen (node + 1);
 158             if ((len <= sizeof (psz_buf)) && (node[len] == ']'))
 159             {
 160                 assert (len > 0);
 161                 memcpy (psz_buf, node + 1, len - 1);
 162                 psz_buf[len - 1] = '\0';
 163                 node = psz_buf;
 164             }
 165         }
 166         if (node[0] == '\0')
 167             node = NULL;
 168     }
 169
 170     int ret;
 171     node = ToLocale (node);
 172 #ifdef WIN32
 173     /*
 174      * Winsock tries to resolve numerical IPv4 addresses as AAAA
 175      * and IPv6 addresses as A... There comes the bug-to-bug fix.
 176      */
 177     if ((hints.ai_flags & AI_NUMERICHOST) == 0)
 178     {
 179         hints.ai_flags |= AI_NUMERICHOST;
 180         ret = getaddrinfo (node, psz_service, &hints, res);
 181         if (ret == 0)
 182             goto out;
 183         hints.ai_flags &= ~AI_NUMERICHOST;
 184     }
 185 #endif
 186 #ifdef AI_IDN
 187     /* Run-time I18n Domain Names support */
 188     hints.ai_flags |= AI_IDN;
 189     ret = getaddrinfo (node, psz_service, &hints, res);
 190     if (ret != EAI_BADFLAGS)
 191         goto out;
 192     /* IDN not available: disable and retry without it */
 193     hints.ai_flags &= ~AI_IDN;
 194 #endif
 195     ret = getaddrinfo (node, psz_service, &hints, res);
 196
 197 #if defined(AI_IDN) || defined(WIN32)
 198 out:
 199 #endif
 200     LocaleFree (node);
 201     return ret;
 202 }
 203
 204
 205 /**
 206  * inet_pton() replacement
 207  */
 208 int vlc_inet_pton (int af, const char *src, void *dst)
 209 {
 210 #ifndef HAVE_INET_PTON
 211     /* Windows Vista has inet_pton(), but not XP. */
 212     /* We have a pretty good example of abstraction inversion here... */
 213     struct addrinfo hints = {
 214         .ai_family = af,
 215         .ai_socktype = SOCK_DGRAM, /* make sure we have... */
 216         .ai_protocol = IPPROTO_UDP, /* ...only one response */
 217         .ai_flags = AI_NUMERICHOST,
 218     }, *res;
 219
 220     if (getaddrinfo (src, NULL, &hints, &res))
 221         return 0;
 222
 223     const void *data;
 224     size_t len;
 225
 226     switch (af)
 227     {
 228         case AF_INET:
 229             data = &((const struct sockaddr_in *)res->ai_addr)->sin_addr;
 230             len = sizeof (struct in_addr);
 231             break;
 232 #ifdef AF_INET6
 233         case AF_INET6:
 234             data = &((const struct sockaddr_in6 *)res->ai_addr)->sin6_addr;
 235             len = sizeof (struct in6_addr);
 236             break;
 237 #endif
 238         default:
 239             freeaddrinfo (res);
 240             return -1;
 241     }
 242     memcpy (dst, data, len);
 243     freeaddrinfo (res);
 244     return 1;
 245 #else /* HAVE_INET_PTON */
 246     return inet_pton( af, src, dst );
 247 #endif /* HAVE_INET_PTON */
 248 }
 249
 250 /**
 251  * inet_ntop() replacement
 252  */
 253 const char *vlc_inet_ntop (int af, const void *src, char *dst, socklen_t cnt)
 254 {
 255 #ifndef HAVE_INET_NTOP
 256     int ret = EAI_FAMILY;
 257
 258     switch (af)
 259     {
 260 #ifdef AF_INET6
 261         case AF_INET6:
 262             {
 263                 struct sockaddr_in6 addr;
 264                 memset (&addr, 0, sizeof(addr));
 265                 addr.sin6_family = AF_INET6;
 266                 addr.sin6_addr = *(struct in6_addr *)src;
 267                 ret = getnameinfo ((struct sockaddr *)&addr, sizeof (addr),
 268                                    dst, cnt, NULL, 0, NI_NUMERICHOST);
 269             }
 270
 271 #endif
 272         case AF_INET:
 273             {
 274                 struct sockaddr_in addr;
 275                 memset(&addr, 0, sizeof(addr));
 276                 addr.sin_family = AF_INET;
 277                 addr.sin_addr = *(struct in_addr *)src;
 278                 ret = getnameinfo ((struct sockaddr *)&addr, sizeof (addr),
 279                                    dst, cnt, NULL, 0, NI_NUMERICHOST);
 280             }
 281     }
 282     return (ret == 0) ? dst : NULL;
 283 #else /* HAVE_INET_NTOP */
 284     return inet_ntop( af, src, dst, cnt );
 285 #endif /* HAVE_INET_NTOP */
 286 }
 287