xref: /freebsd/lib/libc/net/map_v4v6.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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)
53 static char sccsid[] = "@(#)gethostnamadr.c	8.1 (Berkeley) 6/4/93";
54 #endif /* LIBC_SCCS and not lint */
55 #include <sys/cdefs.h>
56 __FBSDID("$FreeBSD$");
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 
72 typedef union {
73 	int32_t al;
74 	char ac;
75 } align;
76 
77 void
78 _map_v4v6_address(const char *src, char *dst)
79 {
80 	u_char *p = (u_char *)dst;
81 	char tmp[NS_INADDRSZ];
82 	int i;
83 
84 	/* Stash a temporary copy so our caller can update in place. */
85 	memcpy(tmp, src, NS_INADDRSZ);
86 	/* Mark this ipv6 addr as a mapped ipv4. */
87 	for (i = 0; i < 10; i++)
88 		*p++ = 0x00;
89 	*p++ = 0xff;
90 	*p++ = 0xff;
91 	/* Retrieve the saved copy and we're done. */
92 	memcpy((void*)p, tmp, NS_INADDRSZ);
93 }
94 
95 void
96 _map_v4v6_hostent(struct hostent *hp, char **bpp, char *ep) {
97 	char **ap;
98 
99 	if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ)
100 		return;
101 	hp->h_addrtype = AF_INET6;
102 	hp->h_length = IN6ADDRSZ;
103 	for (ap = hp->h_addr_list; *ap; ap++) {
104 		int i = (u_long)*bpp % sizeof(align);
105 
106 		if (i != 0)
107 			i = sizeof(align) - i;
108 
109 		if ((ep - *bpp) < (i + IN6ADDRSZ)) {
110 			/* Out of memory.  Truncate address list here. */
111 			*ap = NULL;
112 			return;
113 		}
114 		*bpp += i;
115 		_map_v4v6_address(*ap, *bpp);
116 		*ap = *bpp;
117 		*bpp += IN6ADDRSZ;
118 	}
119 }
120