map_v4v6.c revision 292550 
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 * 4. 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
52#if defined(LIBC_SCCS) && !defined(lint)
53static char sccsid[] = "@(#)gethostnamadr.c	8.1 (Berkeley) 6/4/93";
54#endif /* LIBC_SCCS and not lint */
55#include <sys/cdefs.h>
56__FBSDID("$FreeBSD: head/lib/libc/net/map_v4v6.c 292550 2015-12-21 16:55:36Z ume $");
57
58#include <sys/types.h>
59#include <sys/param.h>
60#include <sys/socket.h>
61#include <netinet/in.h>
62#include <arpa/inet.h>
63#include <arpa/nameser.h>
64
65#include <stdio.h>
66#include <string.h>
67#include <netdb.h>
68#include <resolv.h>
69#include <ctype.h>
70#include <syslog.h>
71#include "netdb_private.h"
72
73typedef union {
74	int32_t al;
75	char ac;
76} align;
77
78void
79_map_v4v6_address(const char *src, char *dst)
80{
81	char tmp[NS_INADDRSZ];
82
83	/* Stash a temporary copy so our caller can update in place. */
84	memcpy(tmp, src, NS_INADDRSZ);
85	/* Mark this ipv6 addr as a mapped ipv4. */
86	memset(&dst[0], 0, 10);
87	memset(&dst[10], 0xff, 2);
88	/* Retrieve the saved copy and we're done. */
89	memcpy(&dst[12], tmp, NS_INADDRSZ);
90}
91
92void
93_map_v4v6_hostent(struct hostent *hp, char **bpp, char *ep) {
94	char **ap;
95
96	if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ)
97		return;
98	hp->h_addrtype = AF_INET6;
99	hp->h_length = IN6ADDRSZ;
100	for (ap = hp->h_addr_list; *ap; ap++) {
101		int i = (u_long)*bpp % sizeof(align);
102
103		if (i != 0)
104			i = sizeof(align) - i;
105
106		if ((ep - *bpp) < (i + IN6ADDRSZ)) {
107			/* Out of memory.  Truncate address list here. */
108			*ap = NULL;
109			return;
110		}
111		*bpp += i;
112		_map_v4v6_address(*ap, *bpp);
113		*ap = *bpp;
114		*bpp += IN6ADDRSZ;
115	}
116}
117