res_mkquery.c revision 1.3 
1/*	$OpenBSD: res_mkquery.c,v 1.3 2012/11/24 15:12:48 eric Exp $	*/
2/*
3 * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include <sys/types.h>
19#include <netinet/in.h>
20#include <arpa/nameser.h> /* for MAXDNAME */
21
22#include <errno.h>
23#include <resolv.h>
24#include <string.h>
25
26#include "asr.h"
27#include "asr_private.h"
28
29/* This function is apparently needed by some ports. */
30int
31res_mkquery(int op, const char *dname, int class, int type,
32    const unsigned char *data, int datalen, const unsigned char *newrr,
33    unsigned char *buf, int buflen)
34{
35	struct asr_ctx	*ac;
36	struct pack	 p;
37	struct header	 h;
38	char		 fqdn[MAXDNAME];
39	char		 dn[MAXDNAME];
40
41	/* we currently only support QUERY */
42	if (op != QUERY || data)
43		return (-1);
44
45	if (dname[0] == '\0' || dname[strlen(dname) - 1] != '.') {
46		strlcpy(fqdn, dname, sizeof fqdn);
47		if (strlcat(fqdn, ".", sizeof fqdn) >= sizeof fqdn)
48			return (-1);
49		dname = fqdn;
50	}
51
52	if (dname_from_fqdn(dname, dn, sizeof(dn)) == -1)
53		return (-1);
54
55	ac = asr_use_resolver(NULL);
56
57	memset(&h, 0, sizeof h);
58	h.id = res_randomid();
59	if (ac->ac_options & RES_RECURSE)
60		h.flags |= RD_MASK;
61	h.qdcount = 1;
62
63	pack_init(&p, buf, buflen);
64	pack_header(&p, &h);
65	pack_query(&p, type, class, dn);
66
67	asr_ctx_unref(ac);
68
69	if (p.err)
70		return (-1);
71
72	return (p.offset);
73}
74
75/*
76 * This function is not documented, but used by sendmail.
77 * Put here because it uses asr_private.h too.
78 */
79int
80res_querydomain(const char *name,
81    const char *domain,
82    int class,
83    int type,
84    u_char *answer,
85    int anslen)
86{
87	char	fqdn[MAXDNAME], ndom[MAXDNAME];
88	size_t	n;
89
90	/* we really want domain to end with a dot for now */
91	if (domain && ((n = strlen(domain)) == 0 || domain[n - 1 ] != '.')) {
92		domain = ndom;
93		strlcpy(ndom, domain, sizeof ndom);
94		strlcat(ndom, ".", sizeof ndom);
95	}
96
97	if (asr_make_fqdn(name, domain, fqdn, sizeof fqdn) == 0) {
98		h_errno = NO_RECOVERY;
99		errno = EINVAL;
100		return (-1);
101	}
102
103	return (res_query(fqdn, class, type, answer, anslen));
104}
105