127 lines
3.7 KiB
C
127 lines
3.7 KiB
C
/* udns_rr_a.c
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parse/query A/AAAA IN records
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Copyright (C) 2005 Michael Tokarev <mjt@corpit.ru>
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This file is part of UDNS library, an async DNS stub resolver.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library, in file named COPYING.LGPL; if not,
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write to the Free Software Foundation, Inc., 59 Temple Place,
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Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <string.h>
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#include <stdlib.h>
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#include <assert.h>
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#if !defined(_WINDOWS) && !defined(WINDOWS)
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# include <sys/types.h>
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# include <netinet/in.h>
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#endif
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#include "udns.h"
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/* here, we use common routine to parse both IPv4 and IPv6 addresses.
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*/
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/* this structure should match dns_rr_a[46] */
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struct dns_rr_a {
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dns_rr_common(dnsa);
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unsigned char *dnsa_addr;
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};
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static int
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dns_parse_a(dnscc_t *qdn, dnscc_t *pkt, dnscc_t *cur, dnscc_t *end,
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void **result, unsigned dsize) {
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struct dns_rr_a *ret;
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struct dns_parse p;
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struct dns_rr rr;
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int r;
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/* first, validate and count number of addresses */
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dns_initparse(&p, qdn, pkt, cur, end);
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while((r = dns_nextrr(&p, &rr)) > 0)
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if (rr.dnsrr_dsz != dsize)
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return DNS_E_PROTOCOL;
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if (r < 0)
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return DNS_E_PROTOCOL;
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else if (!p.dnsp_nrr)
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return DNS_E_NODATA;
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ret = malloc(sizeof(*ret) + dsize * p.dnsp_nrr + dns_stdrr_size(&p));
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if (!ret)
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return DNS_E_NOMEM;
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ret->dnsa_nrr = p.dnsp_nrr;
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ret->dnsa_addr = (unsigned char*)(ret+1);
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/* copy the RRs */
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for (dns_rewind(&p, qdn), r = 0; dns_nextrr(&p, &rr); ++r)
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memcpy(ret->dnsa_addr + dsize * r, rr.dnsrr_dptr, dsize);
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dns_stdrr_finish((struct dns_rr_null *)ret,
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(char *)(ret->dnsa_addr + dsize * p.dnsp_nrr), &p);
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*result = ret;
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return 0;
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}
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int
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dns_parse_a4(dnscc_t *qdn, dnscc_t *pkt, dnscc_t *cur, dnscc_t *end,
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void **result) {
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#ifdef AF_INET
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assert(sizeof(struct in_addr) == 4);
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#endif
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assert(dns_get16(cur+2) == DNS_C_IN && dns_get16(cur+0) == DNS_T_A);
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return dns_parse_a(qdn, pkt, cur, end, result, 4);
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}
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struct dns_query *
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dns_submit_a4(struct dns_ctx *ctx, const char *name, int flags,
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dns_query_a4_fn *cbck, void *data) {
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return
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dns_submit_p(ctx, name, DNS_C_IN, DNS_T_A, flags,
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dns_parse_a4, (dns_query_fn*)cbck, data);
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}
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struct dns_rr_a4 *
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dns_resolve_a4(struct dns_ctx *ctx, const char *name, int flags) {
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return (struct dns_rr_a4 *)
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dns_resolve_p(ctx, name, DNS_C_IN, DNS_T_A, flags, dns_parse_a4);
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}
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int
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dns_parse_a6(dnscc_t *qdn, dnscc_t *pkt, dnscc_t *cur, dnscc_t *end,
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void **result) {
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#ifdef AF_INET6
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assert(sizeof(struct in6_addr) == 16);
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#endif
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assert(dns_get16(cur+2) == DNS_C_IN && dns_get16(cur+0) == DNS_T_AAAA);
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return dns_parse_a(qdn, pkt, cur, end, result, 16);
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}
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struct dns_query *
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dns_submit_a6(struct dns_ctx *ctx, const char *name, int flags,
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dns_query_a6_fn *cbck, void *data) {
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return
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dns_submit_p(ctx, name, DNS_C_IN, DNS_T_AAAA, flags,
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dns_parse_a6, (dns_query_fn*)cbck, data);
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}
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struct dns_rr_a6 *
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dns_resolve_a6(struct dns_ctx *ctx, const char *name, int flags) {
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return (struct dns_rr_a6 *)
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dns_resolve_p(ctx, name, DNS_C_IN, DNS_T_AAAA, flags, dns_parse_a6);
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}
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