root/src/udns/udns_rr_a.c

Revision 5a9b91bc0a14543e0995eba973fbeacc05aaee8b, 3.7 kB (checked in by Theo Schlossnagle <jesus@omniti.com>, 6 years ago)

svn merge -r 327:330 https://labs.omniti.com/reconnoiter/branches/dev/udns .

closes #38

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1 /* $Id: udns_rr_a.c,v 1.16 2007/01/09 04:44:51 mjt Exp $
2    parse/query A/AAAA IN records
3
4    Copyright (C) 2005  Michael Tokarev <mjt@corpit.ru>
5    This file is part of UDNS library, an async DNS stub resolver.
6
7    This library is free software; you can redistribute it and/or
8    modify it under the terms of the GNU Lesser General Public
9    License as published by the Free Software Foundation; either
10    version 2.1 of the License, or (at your option) any later version.
11
12    This library is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15    Lesser General Public License for more details.
16
17    You should have received a copy of the GNU Lesser General Public
18    License along with this library, in file named COPYING.LGPL; if not,
19    write to the Free Software Foundation, Inc., 59 Temple Place,
20    Suite 330, Boston, MA  02111-1307  USA
21
22  */
23
24 #include <string.h>
25 #include <stdlib.h>
26 #include <assert.h>
27 #ifndef WINDOWS
28 # include <sys/types.h>
29 # include <netinet/in.h>
30 #endif
31 #include "udns.h"
32
33 /* here, we use common routine to parse both IPv4 and IPv6 addresses.
34  */
35
36 /* this structure should match dns_rr_a[46] */
37 struct dns_rr_a {
38   dns_rr_common(dnsa);
39   unsigned char *dnsa_addr;
40 };
41
42 static int
43 dns_parse_a(dnscc_t *qdn, dnscc_t *pkt, dnscc_t *cur, dnscc_t *end,
44             void **result, unsigned dsize) {
45   struct dns_rr_a *ret;
46   struct dns_parse p;
47   struct dns_rr rr;
48   int r;
49
50   /* first, validate and count number of addresses */
51   dns_initparse(&p, qdn, pkt, cur, end);
52   while((r = dns_nextrr(&p, &rr)) > 0)
53     if (rr.dnsrr_dsz != dsize)
54       return DNS_E_PROTOCOL;
55   if (r < 0)
56     return DNS_E_PROTOCOL;
57   else if (!p.dnsp_nrr)
58     return DNS_E_NODATA;
59
60   ret = malloc(sizeof(*ret) + dsize * p.dnsp_nrr + dns_stdrr_size(&p));
61   if (!ret)
62     return DNS_E_NOMEM;
63
64   ret->dnsa_nrr = p.dnsp_nrr;
65   ret->dnsa_addr = (unsigned char*)(ret+1);
66
67   /* copy the RRs */
68   for (dns_rewind(&p, qdn), r = 0; dns_nextrr(&p, &rr); ++r)
69     memcpy(ret->dnsa_addr + dsize * r, rr.dnsrr_dptr, dsize);
70
71   dns_stdrr_finish((struct dns_rr_null *)ret,
72                    (char *)(ret->dnsa_addr + dsize * p.dnsp_nrr), &p);
73   *result = ret;
74   return 0;
75 }
76
77 int
78 dns_parse_a4(dnscc_t *qdn, dnscc_t *pkt, dnscc_t *cur, dnscc_t *end,
79              void **result) {
80 #ifdef AF_INET
81   assert(sizeof(struct in_addr) == 4);
82 #endif
83   assert(dns_get16(cur+2) == DNS_C_IN && dns_get16(cur+0) == DNS_T_A);
84   return dns_parse_a(qdn, pkt, cur, end, result, 4);
85 }
86
87 struct dns_query *
88 dns_submit_a4(struct dns_ctx *ctx, const char *name, int flags,
89               dns_query_a4_fn *cbck, void *data) {
90   return
91     dns_submit_p(ctx, name, DNS_C_IN, DNS_T_A, flags,
92                  dns_parse_a4, (dns_query_fn*)cbck, data);
93 }
94
95 struct dns_rr_a4 *
96 dns_resolve_a4(struct dns_ctx *ctx, const char *name, int flags) {
97   return (struct dns_rr_a4 *)
98     dns_resolve_p(ctx, name, DNS_C_IN, DNS_T_A, flags, dns_parse_a4);
99 }
100
101 int
102 dns_parse_a6(dnscc_t *qdn, dnscc_t *pkt, dnscc_t *cur, dnscc_t *end,
103              void **result) {
104 #ifdef AF_INET6
105   assert(sizeof(struct in6_addr) == 16);
106 #endif
107   assert(dns_get16(cur+2) == DNS_C_IN && dns_get16(cur+0) == DNS_T_AAAA);
108   return dns_parse_a(qdn, pkt, cur, end, result, 16);
109 }
110
111 struct dns_query *
112 dns_submit_a6(struct dns_ctx *ctx, const char *name, int flags,
113               dns_query_a6_fn *cbck, void *data) {
114   return
115     dns_submit_p(ctx, name, DNS_C_IN, DNS_T_AAAA, flags,
116                  dns_parse_a6, (dns_query_fn*)cbck, data);
117 }
118
119 struct dns_rr_a6 *
120 dns_resolve_a6(struct dns_ctx *ctx, const char *name, int flags) {
121   return (struct dns_rr_a6 *)
122     dns_resolve_p(ctx, name, DNS_C_IN, DNS_T_AAAA, flags, dns_parse_a6);
123 }
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