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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2014 Lennart Poettering
systemd 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.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include "list.h"
#include "resolved-dns-zone.h"
#include "resolved-dns-domain.h"
#include "resolved-dns-packet.h"
/* Never allow more than 1K entries */
#define ZONE_MAX 1024
typedef struct DnsZoneItem DnsZoneItem;
struct DnsZoneItem {
DnsResourceRecord *rr;
bool verified;
LIST_FIELDS(DnsZoneItem, by_key);
LIST_FIELDS(DnsZoneItem, by_name);
};
static void dns_zone_item_free(DnsZoneItem *i) {
if (!i)
return;
dns_resource_record_unref(i->rr);
free(i);
}
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsZoneItem*, dns_zone_item_free);
static void dns_zone_item_remove_and_free(DnsZone *z, DnsZoneItem *i) {
DnsZoneItem *first;
assert(z);
if (!i)
return;
first = hashmap_get(z->by_key, i->rr->key);
LIST_REMOVE(by_key, first, i);
if (first)
assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0);
else
hashmap_remove(z->by_key, i->rr->key);
first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key));
LIST_REMOVE(by_name, first, i);
if (first)
assert_se(hashmap_replace(z->by_name, DNS_RESOURCE_KEY_NAME(first->rr->key), first) >= 0);
else
hashmap_remove(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key));
dns_zone_item_free(i);
}
void dns_zone_flush(DnsZone *z) {
DnsZoneItem *i;
assert(z);
while ((i = hashmap_first(z->by_key)))
dns_zone_item_remove_and_free(z, i);
assert(hashmap_size(z->by_key) == 0);
assert(hashmap_size(z->by_name) == 0);
hashmap_free(z->by_key);
z->by_key = NULL;
hashmap_free(z->by_name);
z->by_name = NULL;
}
static DnsZoneItem* dns_zone_get(DnsZone *z, DnsResourceRecord *rr) {
DnsZoneItem *i;
assert(z);
assert(rr);
LIST_FOREACH(by_key, i, hashmap_get(z->by_key, rr->key))
if (dns_resource_record_equal(i->rr, rr))
return i;
return NULL;
}
void dns_zone_remove_rr(DnsZone *z, DnsResourceRecord *rr) {
DnsZoneItem *i;
assert(z);
assert(rr);
i = dns_zone_get(z, rr);
if (i)
dns_zone_item_remove_and_free(z, i);
}
static int dns_zone_init(DnsZone *z) {
int r;
assert(z);
r = hashmap_ensure_allocated(&z->by_key, dns_resource_key_hash_func, dns_resource_key_compare_func);
if (r < 0)
return r;
r = hashmap_ensure_allocated(&z->by_name, dns_name_hash_func, dns_name_compare_func);
if (r < 0)
return r;
return 0;
}
static int dns_zone_link_item(DnsZone *z, DnsZoneItem *i) {
DnsZoneItem *first;
int r;
first = hashmap_get(z->by_key, i->rr->key);
if (first) {
LIST_PREPEND(by_key, first, i);
assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0);
} else {
r = hashmap_put(z->by_key, i->rr->key, i);
if (r < 0)
return r;
}
first = hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key));
if (first) {
LIST_PREPEND(by_name, first, i);
assert_se(hashmap_replace(z->by_name, DNS_RESOURCE_KEY_NAME(first->rr->key), first) >= 0);
} else {
r = hashmap_put(z->by_name, DNS_RESOURCE_KEY_NAME(i->rr->key), i);
if (r < 0)
return r;
}
return 0;
}
int dns_zone_put(DnsZone *z, DnsResourceRecord *rr) {
_cleanup_(dns_zone_item_freep) DnsZoneItem *i = NULL;
DnsZoneItem *existing;
int r;
assert(z);
assert(rr);
if (rr->key->class == DNS_CLASS_ANY)
return -EINVAL;
if (rr->key->type == DNS_TYPE_ANY)
return -EINVAL;
existing = dns_zone_get(z, rr);
if (existing)
return 0;
r = dns_zone_init(z);
if (r < 0)
return r;
i = new0(DnsZoneItem, 1);
if (!i)
return -ENOMEM;
i->rr = dns_resource_record_ref(rr);
r = dns_zone_link_item(z, i);
if (r < 0)
return r;
i = NULL;
return 0;
}
int dns_zone_lookup(DnsZone *z, DnsQuestion *q, DnsAnswer **ret) {
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
int r;
unsigned i, n = 0;
bool has_other_rrs = false;
assert(z);
assert(q);
assert(ret);
if (q->n_keys <= 0) {
*ret = NULL;
return 0;
}
for (i = 0; i < q->n_keys; i++) {
DnsZoneItem *j;
j = hashmap_get(z->by_key, q->keys[i]);
if (!j) {
if (hashmap_get(z->by_name, DNS_RESOURCE_KEY_NAME(q->keys[i])))
has_other_rrs = true;
continue;
}
LIST_FOREACH(by_name, j, j)
n++;
}
if (n <= 0) {
*ret = NULL;
return has_other_rrs;
}
answer = dns_answer_new(n);
if (!answer)
return -ENOMEM;
for (i = 0; i < q->n_keys; i++) {
DnsZoneItem *j;
j = hashmap_get(z->by_key, q->keys[i]);
LIST_FOREACH(by_key, j, j) {
r = dns_answer_add(answer, j->rr);
if (r < 0)
return r;
}
}
*ret = answer;
answer = NULL;
return 1;
}
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