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-rw-r--r--src/resolve/resolved-dns-question.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/src/resolve/resolved-dns-question.c b/src/resolve/resolved-dns-question.c
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index 0000000000..026a67d7b3
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+++ b/src/resolve/resolved-dns-question.c
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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 "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;
+}