1 /*
2 * Copyright (c) 1999 - 2002 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <config.h>
35
36 #include "roken.h"
37
38 /*
39 * Try to obtain a verified name for the address in `sa, salen' (much
40 * similar to getnameinfo).
41 * Verified in this context means that forwards and backwards lookups
42 * in DNS are consistent. If that fails, return an error if the
43 * NI_NAMEREQD flag is set or return the numeric address as a string.
44 */
45
46 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
getnameinfo_verified(const struct sockaddr * sa,socklen_t salen,char * host,size_t hostlen,char * serv,size_t servlen,int flags)47 getnameinfo_verified(const struct sockaddr *sa, socklen_t salen,
48 char *host, size_t hostlen,
49 char *serv, size_t servlen,
50 int flags)
51 {
52 int ret;
53 struct addrinfo *ai, *a;
54 char servbuf[NI_MAXSERV];
55 struct addrinfo hints;
56 void *saaddr;
57 size_t sasize;
58
59 if (host == NULL)
60 return EAI_NONAME;
61
62 if (serv == NULL) {
63 serv = servbuf;
64 servlen = sizeof(servbuf);
65 }
66
67 ret = getnameinfo (sa, salen, host, hostlen, serv, servlen,
68 flags | NI_NUMERICSERV);
69 if (ret)
70 goto fail;
71
72 memset (&hints, 0, sizeof(hints));
73 hints.ai_socktype = SOCK_STREAM;
74 ret = getaddrinfo (host, serv, &hints, &ai);
75 if (ret)
76 goto fail;
77
78 saaddr = socket_get_address(sa);
79 sasize = socket_addr_size(sa);
80 for (a = ai; a != NULL; a = a->ai_next) {
81 if (sasize == socket_addr_size(a->ai_addr) &&
82 memcmp(saaddr, socket_get_address(a->ai_addr), sasize) == 0) {
83 freeaddrinfo (ai);
84 return 0;
85 }
86 }
87 freeaddrinfo (ai);
88 fail:
89 if (flags & NI_NAMEREQD)
90 return EAI_NONAME;
91 ret = getnameinfo (sa, salen, host, hostlen, serv, servlen,
92 flags | NI_NUMERICSERV | NI_NUMERICHOST);
93 return ret;
94 }
95