diff options
Diffstat (limited to 'src/resolve/resolved-dns-zone.c')
| -rw-r--r-- | src/resolve/resolved-dns-zone.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/src/resolve/resolved-dns-zone.c b/src/resolve/resolved-dns-zone.c new file mode 100644 index 0000000000..2325ddfe7f --- /dev/null +++ b/src/resolve/resolved-dns-zone.c @@ -0,0 +1,244 @@ +/*-*- 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); + + 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; +} |