5eefe544ef
When a NXDATA or a NODATA response is received for an alias it may include CNAME records from the redirect chain. We should cache the response for each of these names to avoid needless roundtrips in the future. It is not sufficient to do the negative caching only for the canonical name, as the included redirection chain is not guaranteed to be complete. In fact, only the final CNAME record from the chain is guaranteed to be included. We take care not to cache entries that redirects outside the current zone, as the SOA will then not be valid.
61 lines
2 KiB
C
61 lines
2 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
|
|
|
|
#pragma once
|
|
|
|
/***
|
|
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/>.
|
|
***/
|
|
|
|
typedef struct DnsAnswer DnsAnswer;
|
|
typedef struct DnsAnswerItem DnsAnswerItem;
|
|
|
|
#include "resolved-dns-rr.h"
|
|
|
|
/* A simple array of resource records. We keep track of the
|
|
* originating ifindex for each RR where that makes sense, so that we
|
|
* can qualify A and AAAA RRs referring to a local link with the
|
|
* right ifindex. */
|
|
|
|
struct DnsAnswerItem {
|
|
DnsResourceRecord *rr;
|
|
int ifindex;
|
|
};
|
|
|
|
struct DnsAnswer {
|
|
unsigned n_ref;
|
|
unsigned n_rrs, n_allocated;
|
|
DnsAnswerItem items[0];
|
|
};
|
|
|
|
DnsAnswer *dns_answer_new(unsigned n);
|
|
DnsAnswer *dns_answer_ref(DnsAnswer *a);
|
|
DnsAnswer *dns_answer_unref(DnsAnswer *a);
|
|
|
|
int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex);
|
|
int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl);
|
|
int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key);
|
|
int dns_answer_match_soa(DnsResourceKey *key, DnsResourceKey *soa);
|
|
int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret);
|
|
|
|
DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b);
|
|
void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local);
|
|
|
|
int dns_answer_reserve(DnsAnswer **a, unsigned n_free);
|
|
|
|
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsAnswer*, dns_answer_unref);
|