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