src/resolve/resolved-dns-server.h

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 #pragma once
   4
   5 /***
   6   This file is part of systemd.
   7
   8   Copyright 2014 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU Lesser General Public License as published by
  12   the Free Software Foundation; either version 2.1 of the License, or
  13   (at your option) any later version.
  14
  15   systemd is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 ***/
  23
  24 #include "in-addr-util.h"
  25
  26 typedef struct DnsServer DnsServer;
  27
  28 typedef enum DnsServerType {
  29         DNS_SERVER_SYSTEM,
  30         DNS_SERVER_FALLBACK,
  31         DNS_SERVER_LINK,
  32 } DnsServerType;
  33
  34 typedef enum DnsServerFeatureLevel {
  35         DNS_SERVER_FEATURE_LEVEL_TCP,
  36         DNS_SERVER_FEATURE_LEVEL_UDP,
  37         DNS_SERVER_FEATURE_LEVEL_EDNS0,
  38         DNS_SERVER_FEATURE_LEVEL_DO,
  39         DNS_SERVER_FEATURE_LEVEL_LARGE,
  40         _DNS_SERVER_FEATURE_LEVEL_MAX,
  41         _DNS_SERVER_FEATURE_LEVEL_INVALID = -1
  42 } DnsServerFeatureLevel;
  43
  44 #define DNS_SERVER_FEATURE_LEVEL_WORST 0
  45 #define DNS_SERVER_FEATURE_LEVEL_BEST (_DNS_SERVER_FEATURE_LEVEL_MAX - 1)
  46
  47 const char* dns_server_feature_level_to_string(int i) _const_;
  48 int dns_server_feature_level_from_string(const char *s) _pure_;
  49
  50 #include "resolved-link.h"
  51 #include "resolved-manager.h"
  52
  53 struct DnsServer {
  54         Manager *manager;
  55
  56         unsigned n_ref;
  57
  58         DnsServerType type;
  59         Link *link;
  60
  61         int family;
  62         union in_addr_union address;
  63
  64         usec_t resend_timeout;
  65         usec_t max_rtt;
  66
  67         DnsServerFeatureLevel verified_features;
  68         DnsServerFeatureLevel possible_features;
  69         size_t received_udp_packet_max;
  70         unsigned n_failed_attempts;
  71         usec_t verified_usec;
  72         usec_t features_grace_period_usec;
  73
  74         /* Indicates whether responses are augmented with RRSIG by
  75          * server or not. Note that this is orthogonal to the feature
  76          * level stuff, as it's only information describing responses,
  77          * and has no effect on how the questions are asked. */
  78         bool rrsig_missing:1;
  79
  80         /* Used when GC'ing old DNS servers when configuration changes. */
  81         bool marked:1;
  82
  83         /* If linked is set, then this server appears in the servers linked list */
  84         bool linked:1;
  85         LIST_FIELDS(DnsServer, servers);
  86 };
  87
  88 int dns_server_new(
  89                 Manager *m,
  90                 DnsServer **ret,
  91                 DnsServerType type,
  92                 Link *link,
  93                 int family,
  94                 const union in_addr_union *address);
  95
  96 DnsServer* dns_server_ref(DnsServer *s);
  97 DnsServer* dns_server_unref(DnsServer *s);
  98
  99 void dns_server_unlink(DnsServer *s);
 100 void dns_server_move_back_and_unmark(DnsServer *s);
 101
 102 void dns_server_packet_received(DnsServer *s, DnsServerFeatureLevel features, usec_t rtt, size_t size);
 103 void dns_server_packet_lost(DnsServer *s, DnsServerFeatureLevel features, usec_t usec);
 104 void dns_server_packet_failed(DnsServer *s, DnsServerFeatureLevel features);
 105 void dns_server_packet_rrsig_missing(DnsServer *s);
 106
 107 int dns_server_adjust_opt(DnsServer *server, DnsPacket *packet, DnsServerFeatureLevel level);
 108
 109 DnsServer *dns_server_find(DnsServer *first, int family, const union in_addr_union *in_addr);
 110
 111 void dns_server_unlink_all(DnsServer *first);
 112 void dns_server_unlink_marked(DnsServer *first);
 113 void dns_server_mark_all(DnsServer *first);
 114
 115 DnsServer *manager_get_first_dns_server(Manager *m, DnsServerType t);
 116
 117 DnsServer *manager_set_dns_server(Manager *m, DnsServer *s);
 118 DnsServer *manager_get_dns_server(Manager *m);
 119 void manager_next_dns_server(Manager *m);
 120
 121 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsServer*, dns_server_unref);
 122
 123 DnsServerFeatureLevel dns_server_possible_features(DnsServer *s);
 124
 125 extern const struct hash_ops dns_server_hash_ops;