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/* $Id: udns_rr_naptr.c,v 1.1 2006/11/28 22:58:04 mjt Exp $
parse/query NAPTR IN records
Copyright (C) 2005 Michael Tokarev <mjt@corpit.ru>
Copyright (C) 2006 Mikael Magnusson <mikma@users.sourceforge.net>
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
*/
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include "udns.h"
/* Get a single string for NAPTR record, pretty much like a DN label.
* String length is in first byte in *cur, so it can't be >255.
*/
static int dns_getstr(dnscc_t **cur, dnscc_t *ep, char *buf)
{
unsigned l;
dnscc_t *cp = *cur;
l = *cp++;
if (cp + l > ep)
return DNS_E_PROTOCOL;
if (buf) {
memcpy(buf, cp, l);
buf[l] = '\0';
}
cp += l;
*cur = cp;
return l + 1;
}
int
dns_parse_naptr(dnscc_t *qdn, dnscc_t *pkt, dnscc_t *cur, dnscc_t *end,
void **result) {
struct dns_rr_naptr *ret;
struct dns_parse p;
struct dns_rr rr;
int r, l;
char *sp;
dnsc_t dn[DNS_MAXDN];
assert(dns_get16(cur+2) == DNS_C_IN && dns_get16(cur+0) == DNS_T_NAPTR);
/* first, validate the answer and count size of the result */
l = 0;
dns_initparse(&p, qdn, pkt, cur, end);
while((r = dns_nextrr(&p, &rr)) > 0) {
int i;
dnscc_t *ep = rr.dnsrr_dend;
/* first 4 bytes: order & preference */
cur = rr.dnsrr_dptr + 4;
/* flags, services and regexp */
for (i = 0; i < 3; i++) {
r = dns_getstr(&cur, ep, NULL);
if (r < 0)
return r;
l += r;
}
/* replacement */
r = dns_getdn(pkt, &cur, end, dn, sizeof(dn));
if (r <= 0 || cur != rr.dnsrr_dend)
return DNS_E_PROTOCOL;
l += dns_dntop_size(dn);
}
if (r < 0)
return DNS_E_PROTOCOL;
if (!p.dnsp_nrr)
return DNS_E_NODATA;
/* next, allocate and set up result */
l += dns_stdrr_size(&p);
ret = malloc(sizeof(*ret) + sizeof(struct dns_naptr) * p.dnsp_nrr + l);
if (!ret)
return DNS_E_NOMEM;
ret->dnsnaptr_nrr = p.dnsp_nrr;
ret->dnsnaptr_naptr = (struct dns_naptr *)(ret+1);
/* and 3rd, fill in result, finally */
sp = (char*)(&ret->dnsnaptr_naptr[p.dnsp_nrr]);
for (dns_rewind(&p, qdn), r = 0; dns_nextrr(&p, &rr); ++r) {
cur = rr.dnsrr_dptr;
ret->dnsnaptr_naptr[r].order = dns_get16(cur); cur += 2;
ret->dnsnaptr_naptr[r].preference = dns_get16(cur); cur += 2;
sp += dns_getstr(&cur, end, (ret->dnsnaptr_naptr[r].flags = sp));
sp += dns_getstr(&cur, end, (ret->dnsnaptr_naptr[r].service = sp));
sp += dns_getstr(&cur, end, (ret->dnsnaptr_naptr[r].regexp = sp));
dns_getdn(pkt, &cur, end, dn, sizeof(dn));
sp += dns_dntop(dn, (ret->dnsnaptr_naptr[r].replacement = sp), DNS_MAXNAME);
}
dns_stdrr_finish((struct dns_rr_null *)ret, sp, &p);
*result = ret;
return 0;
}
struct dns_query *
dns_submit_naptr(struct dns_ctx *ctx, const char *name, int flags,
dns_query_naptr_fn *cbck, void *data) {
return
dns_submit_p(ctx, name, DNS_C_IN, DNS_T_NAPTR, flags,
dns_parse_naptr, (dns_query_fn *)cbck, data);
}
struct dns_rr_naptr *
dns_resolve_naptr(struct dns_ctx *ctx, const char *name, int flags) {
return (struct dns_rr_naptr *)
dns_resolve_p(ctx, name, DNS_C_IN, DNS_T_NAPTR, flags, dns_parse_naptr);
}
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