diff options
Diffstat (limited to 'src/resolve/resolved-dns-question.c')
| -rw-r--r-- | src/resolve/resolved-dns-question.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/src/resolve/resolved-dns-question.c b/src/resolve/resolved-dns-question.c new file mode 100644 index 0000000000..026a67d7b3 --- /dev/null +++ b/src/resolve/resolved-dns-question.c @@ -0,0 +1,226 @@ +/*-*- 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 "resolved-dns-question.h" +#include "resolved-dns-domain.h" + +DnsQuestion *dns_question_new(unsigned n) { + DnsQuestion *q; + + assert(n > 0); + + q = malloc0(offsetof(DnsQuestion, keys) + sizeof(DnsResourceKey*) * n); + if (!q) + return NULL; + + q->n_ref = 1; + q->n_allocated = n; + + return q; +} + +DnsQuestion *dns_question_ref(DnsQuestion *q) { + if (!q) + return NULL; + + assert(q->n_ref > 0); + q->n_ref++; + return q; +} + +DnsQuestion *dns_question_unref(DnsQuestion *q) { + if (!q) + return NULL; + + assert(q->n_ref > 0); + + if (q->n_ref == 1) { + unsigned i; + + for (i = 0; i < q->n_keys; i++) + dns_resource_key_unref(q->keys[i]); + free(q); + } else + q->n_ref--; + + return NULL; +} + +int dns_question_add(DnsQuestion *q, DnsResourceKey *key) { + assert(q); + assert(key); + + if (q->n_keys >= q->n_allocated) + return -ENOSPC; + + q->keys[q->n_keys++] = dns_resource_key_ref(key); + return 0; +} + +int dns_question_matches_rr(DnsQuestion *q, DnsResourceRecord *rr) { + unsigned i; + int r; + + assert(q); + assert(rr); + + for (i = 0; i < q->n_keys; i++) { + r = dns_resource_key_match_rr(q->keys[i], rr); + if (r != 0) + return r; + } + + return 0; +} + +int dns_question_matches_cname(DnsQuestion *q, DnsResourceRecord *rr) { + unsigned i; + int r; + + assert(q); + assert(rr); + + for (i = 0; i < q->n_keys; i++) { + r = dns_resource_key_match_cname(q->keys[i], rr); + if (r != 0) + return r; + } + + return 1; +} + +int dns_question_is_valid(DnsQuestion *q) { + const char *name; + unsigned i; + int r; + + assert(q); + + if (q->n_keys <= 0) + return 0; + + if (q->n_keys > 65535) + return 0; + + name = DNS_RESOURCE_KEY_NAME(q->keys[0]); + if (!name) + return 0; + + /* Check that all keys in this question bear the same name */ + for (i = 1; i < q->n_keys; i++) { + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(q->keys[i]), name); + if (r <= 0) + return r; + } + + return 1; +} + +int dns_question_is_superset(DnsQuestion *q, DnsQuestion *other) { + unsigned j; + int r; + + assert(q); + assert(other); + + /* Checks if all keys in "other" are also contained in "q" */ + + for (j = 0; j < other->n_keys; j++) { + DnsResourceKey *b = other->keys[j]; + bool found = false; + unsigned i; + + for (i = 0; i < q->n_keys; i++) { + DnsResourceKey *a = q->keys[i]; + + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(a), DNS_RESOURCE_KEY_NAME(b)); + if (r < 0) + return r; + + if (r == 0) + continue; + + if (a->class != b->class && a->class != DNS_CLASS_ANY) + continue; + + if (a->type != b->type && a->type != DNS_TYPE_ANY) + continue; + + found = true; + break; + } + + if (!found) + return 0; + } + + return 1; +} + +int dns_question_cname_redirect(DnsQuestion *q, const char *name, DnsQuestion **ret) { + _cleanup_(dns_question_unrefp) DnsQuestion *n = NULL; + bool same = true; + unsigned i; + int r; + + assert(q); + assert(name); + assert(ret); + + for (i = 0; i < q->n_keys; i++) { + r = dns_name_equal(DNS_RESOURCE_KEY_NAME(q->keys[i]), name); + if (r < 0) + return r; + + if (r == 0) { + same = false; + break; + } + } + + if (same) { + /* Shortcut, the names are already right */ + *ret = dns_question_ref(q); + return 0; + } + + n = dns_question_new(q->n_keys); + if (!n) + return -ENOMEM; + + /* Create a new question, and patch in the new name */ + for (n->n_keys = 0; n->n_keys < q->n_keys; n->n_keys++) { + _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; + + k = dns_resource_key_new(q->keys[i]->class, q->keys[i]->type, name); + if (!k) + return -ENOMEM; + + r = dns_question_add(n, k); + if (r < 0) + return r; + } + + *ret = n; + n = NULL; + + return 1; +} |