1 /* $OpenBSD: res_mkquery.c,v 1.14 2021/11/22 20:18:27 jca 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 <sys/socket.h>
20 #include <netinet/in.h>
21 #include <arpa/nameser.h> /* for MAXDNAME */
22 #include <netdb.h>
23
24 #include <asr.h>
25 #include <errno.h>
26 #include <resolv.h>
27 #include <string.h>
28
29 #include "asr_private.h"
30
31 /* This function is apparently needed by some ports. */
32 int
res_mkquery(int op,const char * dname,int class,int type,const unsigned char * data,int datalen,const unsigned char * newrr,unsigned char * buf,int buflen)33 res_mkquery(int op, const char *dname, int class, int type,
34 const unsigned char *data, int datalen, const unsigned char *newrr,
35 unsigned char *buf, int buflen)
36 {
37 struct asr_ctx *ac;
38 struct asr_pack p;
39 struct asr_dns_header h;
40 char fqdn[MAXDNAME];
41 char dn[MAXDNAME];
42
43 /* we currently only support QUERY */
44 if (op != QUERY || data)
45 return (-1);
46
47 if (dname[0] == '\0' || dname[strlen(dname) - 1] != '.') {
48 if (strlcpy(fqdn, dname, sizeof(fqdn)) >= sizeof(fqdn) ||
49 strlcat(fqdn, ".", sizeof(fqdn)) >= sizeof(fqdn))
50 return (-1);
51 dname = fqdn;
52 }
53
54 if (_asr_dname_from_fqdn(dname, dn, sizeof(dn)) == -1)
55 return (-1);
56
57 ac = _asr_use_resolver(NULL);
58
59 memset(&h, 0, sizeof h);
60 h.id = res_randomid();
61 if (ac->ac_options & RES_RECURSE)
62 h.flags |= RD_MASK;
63 if (ac->ac_options & RES_USE_CD)
64 h.flags |= CD_MASK;
65 if (ac->ac_options & RES_TRUSTAD)
66 h.flags |= AD_MASK;
67 h.qdcount = 1;
68 if (ac->ac_options & (RES_USE_EDNS0 | RES_USE_DNSSEC))
69 h.arcount = 1;
70
71 _asr_pack_init(&p, buf, buflen);
72 _asr_pack_header(&p, &h);
73 _asr_pack_query(&p, type, class, dn);
74 if (ac->ac_options & (RES_USE_EDNS0 | RES_USE_DNSSEC))
75 _asr_pack_edns0(&p, MAXPACKETSZ,
76 ac->ac_options & RES_USE_DNSSEC);
77
78 _asr_ctx_unref(ac);
79
80 if (p.err)
81 return (-1);
82
83 return (p.offset);
84 }
85
86 /*
87 * This function is not documented, but used by sendmail.
88 * Put here because it uses asr_private.h too.
89 */
90 int
res_querydomain(const char * name,const char * domain,int class,int type,u_char * answer,int anslen)91 res_querydomain(const char *name,
92 const char *domain,
93 int class,
94 int type,
95 u_char *answer,
96 int anslen)
97 {
98 char fqdn[MAXDNAME], ndom[MAXDNAME];
99 size_t n;
100
101 /* we really want domain to end with a dot for now */
102 if (domain && ((n = strlen(domain)) == 0 || domain[n - 1 ] != '.')) {
103 if (strlcpy(ndom, domain, sizeof(ndom)) >= sizeof(ndom) ||
104 strlcat(ndom, ".", sizeof(ndom)) >= sizeof(ndom)) {
105 h_errno = NETDB_INTERNAL;
106 errno = EINVAL;
107 return (-1);
108 }
109 domain = ndom;
110 }
111
112 if (_asr_make_fqdn(name, domain, fqdn, sizeof fqdn) == 0) {
113 h_errno = NETDB_INTERNAL;
114 errno = EINVAL;
115 return (-1);
116 }
117
118 return (res_query(fqdn, class, type, answer, anslen));
119 }
120