lib/libc/net/map_v4v6.c

   1 /*
   2  * ++Copyright++ 1985, 1988, 1993
   3  * -
   4  * Copyright (c) 1985, 1988, 1993
   5  *    The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  * -
  31  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  32  *
  33  * Permission to use, copy, modify, and distribute this software for any
  34  * purpose with or without fee is hereby granted, provided that the above
  35  * copyright notice and this permission notice appear in all copies, and that
  36  * the name of Digital Equipment Corporation not be used in advertising or
  37  * publicity pertaining to distribution of the document or software without
  38  * specific, written prior permission.
  39  *
  40  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  41  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  42  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  43  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  44  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  45  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  46  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  47  * SOFTWARE.
  48  * -
  49  * --Copyright--
  50  *
  51  * @(#)gethostnamadr.c  8.1 (Berkeley) 6/4/93
  52  * $FreeBSD: src/lib/libc/net/map_v4v6.c,v 1.10 2007/01/09 00:28:02 imp Exp $
  53  * $DragonFly: src/lib/libc/net/map_v4v6.c,v 1.4 2005/11/13 02:04:47 swildner Exp $
  54  */
  55
  56 #include <sys/types.h>
  57 #include <sys/param.h>
  58 #include <sys/socket.h>
  59 #include <netinet/in.h>
  60 #include <arpa/inet.h>
  61 #include <arpa/nameser.h>
  62
  63 #include <stdio.h>
  64 #include <string.h>
  65 #include <netdb.h>
  66 #include <resolv.h>
  67 #include <ctype.h>
  68 #include <syslog.h>
  69
  70 typedef union {
  71         int32_t al;
  72         char ac;
  73 } align;
  74
  75 void
  76 _map_v4v6_address(const char *src, char *dst)
  77 {
  78         u_char *p = (u_char *)dst;
  79         char tmp[NS_INADDRSZ];
  80         int i;
  81
  82         /* Stash a temporary copy so our caller can update in place. */
  83         memcpy(tmp, src, NS_INADDRSZ);
  84         /* Mark this ipv6 addr as a mapped ipv4. */
  85         for (i = 0; i < 10; i++)
  86                 *p++ = 0x00;
  87         *p++ = 0xff;
  88         *p++ = 0xff;
  89         /* Retrieve the saved copy and we're done. */
  90         memcpy((void*)p, tmp, NS_INADDRSZ);
  91 }
  92
  93 void
  94 _map_v4v6_hostent(struct hostent *hp, char **bpp, char *ep) {
  95         char **ap;
  96
  97         if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ)
  98                 return;
  99         hp->h_addrtype = AF_INET6;
 100         hp->h_length = IN6ADDRSZ;
 101         for (ap = hp->h_addr_list; *ap; ap++) {
 102                 int i = (u_long)*bpp % sizeof(align);
 103
 104                 if (i != 0)
 105                         i = sizeof(align) - i;
 106
 107                 if ((ep - *bpp) < (i + IN6ADDRSZ)) {
 108                         /* Out of memory.  Truncate address list here. */
 109                         *ap = NULL;
 110                         return;
 111                 }
 112                 *bpp += i;
 113                 _map_v4v6_address(*ap, *bpp);
 114                 *ap = *bpp;
 115                 *bpp += IN6ADDRSZ;
 116         }
 117 }