freebsd-dev/contrib/ldns/update.c
2013-02-15 13:44:18 +00:00

319 lines
7.3 KiB
C

/* update.c
*
* Functions for RFC 2136 Dynamic Update
*
* Copyright (c) 2005-2008, NLnet Labs. All rights reserved.
*
* See LICENSE for the license.
*/
#include <ldns/config.h>
#include <ldns/ldns.h>
#include <strings.h>
#include <stdlib.h>
#include <limits.h>
/*
* RFC 2136 sections mapped to RFC 1035:
* zone/ZO -- QD/question
* prerequisites/PR -- AN/answers
* updates/UP -- NS/authority records
* additional data/AD -- AR/additional records
*/
ldns_pkt *
ldns_update_pkt_new(ldns_rdf *zone_rdf, ldns_rr_class c,
ldns_rr_list *pr_rrlist, ldns_rr_list *up_rrlist, ldns_rr_list *ad_rrlist)
{
ldns_pkt *p;
if (!zone_rdf || !up_rrlist) {
return NULL;
}
if (c == 0) {
c = LDNS_RR_CLASS_IN;
}
/* Create packet, fill in Zone Section. */
p = ldns_pkt_query_new(zone_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD);
if (!p) {
return NULL;
}
zone_rdf = NULL; /* No longer safe to use. */
ldns_pkt_set_opcode(p, LDNS_PACKET_UPDATE);
ldns_rr_list_deep_free(p->_authority);
ldns_pkt_set_authority(p, ldns_rr_list_clone(up_rrlist));
ldns_update_set_upcount(p, ldns_rr_list_rr_count(up_rrlist));
if (pr_rrlist) {
ldns_rr_list_deep_free(p->_answer); /*XXX access function */
ldns_pkt_set_answer(p, ldns_rr_list_clone(pr_rrlist));
ldns_update_set_prcount(p, ldns_rr_list_rr_count(pr_rrlist));
}
if (ad_rrlist) {
ldns_rr_list_deep_free(p->_additional);
ldns_pkt_set_additional(p, ldns_rr_list_clone(ad_rrlist));
ldns_update_set_adcount(p, ldns_rr_list_rr_count(ad_rrlist));
}
return p;
}
ldns_status
ldns_update_pkt_tsig_add(ldns_pkt *p, ldns_resolver *r)
{
#ifdef HAVE_SSL
uint16_t fudge = 300; /* Recommended fudge. [RFC2845 6.4] */
if (ldns_resolver_tsig_keyname(r) && ldns_resolver_tsig_keydata(r))
return ldns_pkt_tsig_sign(p, ldns_resolver_tsig_keyname(r),
ldns_resolver_tsig_keydata(r), fudge,
ldns_resolver_tsig_algorithm(r), NULL);
#else
/* do nothing */
(void)p;
(void)r;
#endif /* HAVE_SSL */
/* No TSIG to do. */
return LDNS_STATUS_OK;
}
/* Move to higher.c or similar? */
/* XXX doc */
ldns_status
ldns_update_soa_mname(ldns_rdf *zone, ldns_resolver *r,
ldns_rr_class c, ldns_rdf **mname)
{
ldns_rr *soa_rr;
ldns_pkt *query, *resp;
/* Nondestructive, so clone 'zone' here */
query = ldns_pkt_query_new(ldns_rdf_clone(zone), LDNS_RR_TYPE_SOA,
c, LDNS_RD);
if (!query) {
return LDNS_STATUS_ERR;
}
ldns_pkt_set_random_id(query);
if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
ldns_pkt_free(query);
return LDNS_STATUS_ERR;
}
ldns_pkt_free(query);
if (!resp) {
return LDNS_STATUS_ERR;
}
/* Expect a SOA answer. */
*mname = NULL;
while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_answer(resp)))) {
if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA
|| ldns_rr_rdf(soa_rr, 0) == NULL)
continue;
/* [RFC1035 3.3.13] */
*mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0));
break;
}
ldns_pkt_free(resp);
return *mname ? LDNS_STATUS_OK : LDNS_STATUS_ERR;
}
/* Try to get zone and MNAME from SOA queries. */
ldns_status
ldns_update_soa_zone_mname(const char *fqdn, ldns_resolver *r,
ldns_rr_class c, ldns_rdf **zone_rdf, ldns_rdf **mname_rdf)
{
ldns_rr *soa_rr, *rr;
ldns_rdf *soa_zone = NULL, *soa_mname = NULL;
ldns_rdf *ipaddr, *fqdn_rdf, *tmp;
ldns_rdf **nslist;
ldns_pkt *query, *resp;
size_t i;
/*
* XXX Ok, this cannot be the best way to find this...?
* XXX (I run into weird cache-related stuff here)
*/
/* Step 1 - first find a nameserver that should know *something* */
fqdn_rdf = ldns_dname_new_frm_str(fqdn);
query = ldns_pkt_query_new(fqdn_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD);
if (!query) {
return LDNS_STATUS_ERR;
}
fqdn_rdf = NULL;
ldns_pkt_set_random_id(query);
if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
ldns_pkt_free(query);
return LDNS_STATUS_ERR;
}
ldns_pkt_free(query);
if (!resp) {
return LDNS_STATUS_ERR;
}
/* XXX Is it safe to only look in authority section here? */
while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_authority(resp)))) {
if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA
|| ldns_rr_rdf(soa_rr, 0) == NULL)
continue;
/* [RFC1035 3.3.13] */
soa_mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0));
break;
}
ldns_pkt_free(resp);
if (!soa_rr) {
return LDNS_STATUS_ERR;
}
/* Step 2 - find SOA MNAME IP address, add to resolver */
query = ldns_pkt_query_new(soa_mname, LDNS_RR_TYPE_A, c, LDNS_RD);
if (!query) {
return LDNS_STATUS_ERR;
}
soa_mname = NULL;
ldns_pkt_set_random_id(query);
if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
ldns_pkt_free(query);
return LDNS_STATUS_ERR;
}
ldns_pkt_free(query);
if (!resp) {
return LDNS_STATUS_ERR;
}
if (ldns_pkt_ancount(resp) == 0) {
ldns_pkt_free(resp);
return LDNS_STATUS_ERR;
}
/* XXX There may be more than one answer RR here. */
rr = ldns_rr_list_pop_rr(ldns_pkt_answer(resp));
ipaddr = ldns_rr_rdf(rr, 0);
/* Put the SOA mname IP first in the nameserver list. */
nslist = ldns_resolver_nameservers(r);
for (i = 0; i < ldns_resolver_nameserver_count(r); i++) {
if (ldns_rdf_compare(ipaddr, nslist[i]) == 0) {
if (i) {
tmp = nslist[0];
nslist[0] = nslist[i];
nslist[i] = tmp;
}
break;
}
}
if (i >= ldns_resolver_nameserver_count(r)) {
/* SOA mname was not part of the resolver so add it first. */
(void) ldns_resolver_push_nameserver(r, ipaddr);
nslist = ldns_resolver_nameservers(r);
i = ldns_resolver_nameserver_count(r) - 1;
tmp = nslist[0];
nslist[0] = nslist[i];
nslist[i] = tmp;
}
ldns_pkt_free(resp);
/* Make sure to ask the first in the list, i.e SOA mname */
ldns_resolver_set_random(r, false);
/* Step 3 - Redo SOA query, sending to SOA MNAME directly. */
fqdn_rdf = ldns_dname_new_frm_str(fqdn);
query = ldns_pkt_query_new(fqdn_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD);
if (!query) {
return LDNS_STATUS_ERR;
}
fqdn_rdf = NULL;
ldns_pkt_set_random_id(query);
if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
ldns_pkt_free(query);
return LDNS_STATUS_ERR;
}
ldns_pkt_free(query);
if (!resp) {
return LDNS_STATUS_ERR;
}
/* XXX Is it safe to only look in authority section here, too? */
while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_authority(resp)))) {
if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA
|| ldns_rr_rdf(soa_rr, 0) == NULL)
continue;
/* [RFC1035 3.3.13] */
soa_mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0));
soa_zone = ldns_rdf_clone(ldns_rr_owner(soa_rr));
break;
}
ldns_pkt_free(resp);
if (!soa_rr) {
return LDNS_STATUS_ERR;
}
/* That seems to have worked, pass results to caller. */
*zone_rdf = soa_zone;
*mname_rdf = soa_mname;
return LDNS_STATUS_OK;
}
/*
* ldns_update_{get,set}_{zo,pr,up,ad}count
*/
uint16_t
ldns_update_zocount(const ldns_pkt *p)
{
return ldns_pkt_qdcount(p);
}
uint16_t
ldns_update_prcount(const ldns_pkt *p)
{
return ldns_pkt_ancount(p);
}
uint16_t
ldns_update_upcount(const ldns_pkt *p)
{
return ldns_pkt_nscount(p);
}
uint16_t
ldns_update_ad(const ldns_pkt *p)
{
return ldns_pkt_arcount(p);
}
void
ldns_update_set_zo(ldns_pkt *p, uint16_t v)
{
ldns_pkt_set_qdcount(p, v);
}
void
ldns_update_set_prcount(ldns_pkt *p, uint16_t v)
{
ldns_pkt_set_ancount(p, v);
}
void
ldns_update_set_upcount(ldns_pkt *p, uint16_t v)
{
ldns_pkt_set_nscount(p, v);
}
void
ldns_update_set_adcount(ldns_pkt *p, uint16_t v)
{
ldns_pkt_set_arcount(p, v);
}