Systemd/src/resolve/resolved-dns-server.h
Lennart Poettering 92ec902aad resolved: rework how and when we detect whether our chosen DNS server knows DNSSEC
Move detection into a set of new functions, that check whether one specific server can do DNSSEC, whether a server and
a specific transaction can do DNSSEC, or whether a transaction and all its auxiliary transactions could do so.

Also, do these checks both before we acquire additional RRs for the validation (so that we can skip them if the server
doesn't do DNSSEC anyway), and after we acquired them all (to see if any of the lookups changed our opinion about the
servers).

THis also tightens the checks a bit: a server that lacks TCP support is considered incompatible with DNSSEC too.
2016-01-11 19:40:00 +01:00

136 lines
4.4 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/>.
***/
#include "in-addr-util.h"
typedef struct DnsServer DnsServer;
typedef enum DnsServerType {
DNS_SERVER_SYSTEM,
DNS_SERVER_FALLBACK,
DNS_SERVER_LINK,
} DnsServerType;
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;
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_failed:1;
bool packet_truncated:1;
usec_t verified_usec;
usec_t features_grace_period_usec;
/* Indicates whether responses are augmented with RRSIG by
* server or not. Note that this is orthogonal to the feature
* level stuff, as it's only information describing responses,
* and has no effect on how the questions are asked. */
bool rrsig_missing: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);
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_failed(DnsServer *s, DnsServerFeatureLevel level);
void dns_server_packet_truncated(DnsServer *s, DnsServerFeatureLevel level);
void dns_server_packet_rrsig_missing(DnsServer *s);
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);
bool dns_server_dnssec_supported(DnsServer *server);
DnsServer *dns_server_find(DnsServer *first, int family, const union in_addr_union *in_addr);
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);
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsServer*, dns_server_unref);
extern const struct hash_ops dns_server_hash_ops;