Systemd/src/resolve/resolved-dns-server.h
Lennart Poettering ce7c8b20df resolved: when the dns server feature level grace period elapses, flush caches
The cache might contain all kinds of unauthenticated data that we really
shouldn't be using if we upgrade our feature level and suddenly are able
to get authenticated data again.

Might fix: #4866
2017-02-17 10:25:15 +01:00

154 lines
4.9 KiB
C

#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/>.
***/
#include "in-addr-util.h"
typedef struct DnsServer DnsServer;
typedef enum DnsServerType {
DNS_SERVER_SYSTEM,
DNS_SERVER_FALLBACK,
DNS_SERVER_LINK,
} DnsServerType;
#define _DNS_SERVER_TYPE_MAX (DNS_SERVER_LINK + 1)
const char* dns_server_type_to_string(DnsServerType i) _const_;
DnsServerType dns_server_type_from_string(const char *s) _pure_;
typedef enum DnsServerFeatureLevel {
DNS_SERVER_FEATURE_LEVEL_TCP,
DNS_SERVER_FEATURE_LEVEL_UDP,
DNS_SERVER_FEATURE_LEVEL_EDNS0,
DNS_SERVER_FEATURE_LEVEL_DO,
DNS_SERVER_FEATURE_LEVEL_LARGE,
_DNS_SERVER_FEATURE_LEVEL_MAX,
_DNS_SERVER_FEATURE_LEVEL_INVALID = -1
} DnsServerFeatureLevel;
#define DNS_SERVER_FEATURE_LEVEL_WORST 0
#define DNS_SERVER_FEATURE_LEVEL_BEST (_DNS_SERVER_FEATURE_LEVEL_MAX - 1)
const char* dns_server_feature_level_to_string(int i) _const_;
int dns_server_feature_level_from_string(const char *s) _pure_;
#include "resolved-link.h"
#include "resolved-manager.h"
struct DnsServer {
Manager *manager;
unsigned n_ref;
DnsServerType type;
Link *link;
int family;
union in_addr_union address;
int ifindex; /* for IPv6 link-local DNS servers */
char *server_string;
usec_t resend_timeout;
usec_t max_rtt;
DnsServerFeatureLevel verified_feature_level;
DnsServerFeatureLevel possible_feature_level;
size_t received_udp_packet_max;
unsigned n_failed_udp;
unsigned n_failed_tcp;
bool packet_truncated:1;
bool packet_bad_opt:1;
bool packet_rrsig_missing:1;
usec_t verified_usec;
usec_t features_grace_period_usec;
/* Whether we already warned about downgrading to non-DNSSEC mode for this server */
bool warned_downgrade:1;
/* Used when GC'ing old DNS servers when configuration changes. */
bool marked:1;
/* If linked is set, then this server appears in the servers linked list */
bool linked:1;
LIST_FIELDS(DnsServer, servers);
};
int dns_server_new(
Manager *m,
DnsServer **ret,
DnsServerType type,
Link *link,
int family,
const union in_addr_union *address,
int ifindex);
DnsServer* dns_server_ref(DnsServer *s);
DnsServer* dns_server_unref(DnsServer *s);
void dns_server_unlink(DnsServer *s);
void dns_server_move_back_and_unmark(DnsServer *s);
void dns_server_packet_received(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t rtt, size_t size);
void dns_server_packet_lost(DnsServer *s, int protocol, DnsServerFeatureLevel level, usec_t usec);
void dns_server_packet_truncated(DnsServer *s, DnsServerFeatureLevel level);
void dns_server_packet_rrsig_missing(DnsServer *s, DnsServerFeatureLevel level);
void dns_server_packet_bad_opt(DnsServer *s, DnsServerFeatureLevel level);
void dns_server_packet_rcode_downgrade(DnsServer *s, DnsServerFeatureLevel level);
DnsServerFeatureLevel dns_server_possible_feature_level(DnsServer *s);
int dns_server_adjust_opt(DnsServer *server, DnsPacket *packet, DnsServerFeatureLevel level);
const char *dns_server_string(DnsServer *server);
int dns_server_ifindex(const DnsServer *s);
bool dns_server_dnssec_supported(DnsServer *server);
void dns_server_warn_downgrade(DnsServer *server);
bool dns_server_limited_domains(DnsServer *server);
DnsServer *dns_server_find(DnsServer *first, int family, const union in_addr_union *in_addr, int ifindex);
void dns_server_unlink_all(DnsServer *first);
void dns_server_unlink_marked(DnsServer *first);
void dns_server_mark_all(DnsServer *first);
DnsServer *manager_get_first_dns_server(Manager *m, DnsServerType t);
DnsServer *manager_set_dns_server(Manager *m, DnsServer *s);
DnsServer *manager_get_dns_server(Manager *m);
void manager_next_dns_server(Manager *m);
bool dns_server_address_valid(int family, const union in_addr_union *sa);
DnssecMode dns_server_get_dnssec_mode(DnsServer *s);
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsServer*, dns_server_unref);
extern const struct hash_ops dns_server_hash_ops;
void dns_server_flush_cache(DnsServer *s);