/*-*- 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 "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) { unsigned i; int r; assert(key); if (!q) return -ENOSPC; for (i = 0; i < q->n_keys; i++) { r = dns_resource_key_equal(q->keys[i], key); if (r < 0) return r; if (r > 0) return 0; } 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(rr); if (!q) return 0; 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(rr); if (!q) return 0; for (i = 0; i < q->n_keys; i++) { r = dns_resource_key_match_cname(q->keys[i], rr); if (r != 0) return r; } return 0; } int dns_question_is_valid(DnsQuestion *q) { const char *name; unsigned i; int r; if (!q) return 0; 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++) { assert(q->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; /* Checks if all keys in "other" are also contained in "q" */ if (!other) return 1; for (j = 0; j < other->n_keys; j++) { DnsResourceKey *b = other->keys[j]; bool found = false; unsigned i; if (!q) return 0; 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_contains(DnsQuestion *a, DnsResourceKey *k) { unsigned j; int r; assert(k); if (!a) return 0; for (j = 0; j < a->n_keys; j++) { r = dns_resource_key_equal(a->keys[j], k); if (r != 0) return r; } return 0; } int dns_question_is_equal(DnsQuestion *a, DnsQuestion *b) { unsigned j; int r; if (!a) return !b || b->n_keys == 0; if (!b) return a->n_keys == 0; /* Checks if all keys in a are also contained b, and vice versa */ for (j = 0; j < a->n_keys; j++) { r = dns_question_contains(b, a->keys[j]); if (r <= 0) return r; } for (j = 0; j < b->n_keys; j++) { r = dns_question_contains(a, b->keys[j]); if (r <= 0) return r; } return 1; } int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname, DnsQuestion **ret) { _cleanup_(dns_question_unrefp) DnsQuestion *n = NULL; bool same = true; unsigned i; int r; assert(cname); assert(ret); if (!q) { n = dns_question_new(0); if (!n) return -ENOMEM; *ret = n; n = 0; return 0; } for (i = 0; i < q->n_keys; i++) { r = dns_name_equal(DNS_RESOURCE_KEY_NAME(q->keys[i]), cname->cname.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 (i = 0; i < q->n_keys; i++) { _cleanup_(dns_resource_key_unrefp) DnsResourceKey *k = NULL; k = dns_resource_key_new_redirect(q->keys[i], cname); if (!k) return -ENOMEM; r = dns_question_add(n, k); if (r < 0) return r; } *ret = n; n = NULL; return 1; }