src/resolve/resolved-dns-server.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2014 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include "resolved-dns-server.h"
  23
  24 int dns_server_new(
  25                 Manager *m,
  26                 DnsServer **ret,
  27                 DnsServerType type,
  28                 Link *l,
  29                 int family,
  30                 const union in_addr_union *in_addr) {
  31
  32         DnsServer *s, *tail;
  33
  34         assert(m);
  35         assert((type == DNS_SERVER_LINK) == !!l);
  36         assert(in_addr);
  37
  38         s = new0(DnsServer, 1);
  39         if (!s)
  40                 return -ENOMEM;
  41
  42         s->type = type;
  43         s->family = family;
  44         s->address = *in_addr;
  45
  46         if (type == DNS_SERVER_LINK) {
  47                 LIST_FIND_TAIL(servers, l->dns_servers, tail);
  48                 LIST_INSERT_AFTER(servers, l->dns_servers, tail, s);
  49                 s->link = l;
  50         } else if (type == DNS_SERVER_SYSTEM) {
  51                 LIST_FIND_TAIL(servers, m->dns_servers, tail);
  52                 LIST_INSERT_AFTER(servers, m->dns_servers, tail, s);
  53         } else if (type == DNS_SERVER_FALLBACK) {
  54                 LIST_FIND_TAIL(servers, m->fallback_dns_servers, tail);
  55                 LIST_INSERT_AFTER(servers, m->fallback_dns_servers, tail, s);
  56         } else
  57                 assert_not_reached("Unknown server type");
  58
  59         s->manager = m;
  60
  61         /* A new DNS server that isn't fallback is added and the one
  62          * we used so far was a fallback one? Then let's try to pick
  63          * the new one */
  64         if (type != DNS_SERVER_FALLBACK &&
  65             s->manager->current_dns_server &&
  66             s->manager->current_dns_server->type == DNS_SERVER_FALLBACK)
  67                 s->manager->current_dns_server = NULL;
  68
  69         if (ret)
  70                 *ret = s;
  71
  72         return 0;
  73 }
  74
  75 DnsServer* dns_server_free(DnsServer *s)  {
  76         if (!s)
  77                 return NULL;
  78
  79         if (s->manager) {
  80                 if (s->type == DNS_SERVER_LINK)
  81                         LIST_REMOVE(servers, s->link->dns_servers, s);
  82                 else if (s->type == DNS_SERVER_SYSTEM)
  83                         LIST_REMOVE(servers, s->manager->dns_servers, s);
  84                 else if (s->type == DNS_SERVER_FALLBACK)
  85                         LIST_REMOVE(servers, s->manager->fallback_dns_servers, s);
  86                 else
  87                         assert_not_reached("Unknown server type");
  88         }
  89
  90         if (s->link && s->link->current_dns_server == s)
  91                 s->link->current_dns_server = NULL;
  92
  93         if (s->manager && s->manager->current_dns_server == s)
  94                 s->manager->current_dns_server = NULL;
  95
  96         free(s);
  97
  98         return NULL;
  99 }