src/resolve/resolved-dns-search-domain.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2015 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include "alloc-util.h"
  21 #include "dns-domain.h"
  22 #include "resolved-dns-search-domain.h"
  23
  24 int dns_search_domain_new(
  25                 Manager *m,
  26                 DnsSearchDomain **ret,
  27                 DnsSearchDomainType type,
  28                 Link *l,
  29                 const char *name) {
  30
  31         _cleanup_free_ char *normalized = NULL;
  32         DnsSearchDomain *d;
  33         int r;
  34
  35         assert(m);
  36         assert((type == DNS_SEARCH_DOMAIN_LINK) == !!l);
  37         assert(name);
  38
  39         r = dns_name_normalize(name, &normalized);
  40         if (r < 0)
  41                 return r;
  42
  43         if (l) {
  44                 if (l->n_search_domains >= LINK_SEARCH_DOMAINS_MAX)
  45                         return -E2BIG;
  46         } else {
  47                 if (m->n_search_domains >= MANAGER_SEARCH_DOMAINS_MAX)
  48                         return -E2BIG;
  49         }
  50
  51         d = new0(DnsSearchDomain, 1);
  52         if (!d)
  53                 return -ENOMEM;
  54
  55         d->n_ref = 1;
  56         d->manager = m;
  57         d->type = type;
  58         d->name = normalized;
  59         normalized = NULL;
  60
  61         switch (type) {
  62
  63         case DNS_SEARCH_DOMAIN_LINK:
  64                 d->link = l;
  65                 LIST_APPEND(domains, l->search_domains, d);
  66                 l->n_search_domains++;
  67                 break;
  68
  69         case DNS_SERVER_SYSTEM:
  70                 LIST_APPEND(domains, m->search_domains, d);
  71                 m->n_search_domains++;
  72                 break;
  73
  74         default:
  75                 assert_not_reached("Unknown search domain type");
  76         }
  77
  78         d->linked = true;
  79
  80         if (ret)
  81                 *ret = d;
  82
  83         return 0;
  84 }
  85
  86 DnsSearchDomain* dns_search_domain_ref(DnsSearchDomain *d) {
  87         if (!d)
  88                 return NULL;
  89
  90         assert(d->n_ref > 0);
  91         d->n_ref++;
  92
  93         return d;
  94 }
  95
  96 DnsSearchDomain* dns_search_domain_unref(DnsSearchDomain *d) {
  97         if (!d)
  98                 return NULL;
  99
 100         assert(d->n_ref > 0);
 101         d->n_ref--;
 102
 103         if (d->n_ref > 0)
 104                 return NULL;
 105
 106         free(d->name);
 107         return mfree(d);
 108 }
 109
 110 void dns_search_domain_unlink(DnsSearchDomain *d) {
 111         assert(d);
 112         assert(d->manager);
 113
 114         if (!d->linked)
 115                 return;
 116
 117         switch (d->type) {
 118
 119         case DNS_SEARCH_DOMAIN_LINK:
 120                 assert(d->link);
 121                 assert(d->link->n_search_domains > 0);
 122                 LIST_REMOVE(domains, d->link->search_domains, d);
 123                 d->link->n_search_domains--;
 124                 break;
 125
 126         case DNS_SEARCH_DOMAIN_SYSTEM:
 127                 assert(d->manager->n_search_domains > 0);
 128                 LIST_REMOVE(domains, d->manager->search_domains, d);
 129                 d->manager->n_search_domains--;
 130                 break;
 131         }
 132
 133         d->linked = false;
 134
 135         dns_search_domain_unref(d);
 136 }
 137
 138 void dns_search_domain_move_back_and_unmark(DnsSearchDomain *d) {
 139         DnsSearchDomain *tail;
 140
 141         assert(d);
 142
 143         if (!d->marked)
 144                 return;
 145
 146         d->marked = false;
 147
 148         if (!d->linked || !d->domains_next)
 149                 return;
 150
 151         switch (d->type) {
 152
 153         case DNS_SEARCH_DOMAIN_LINK:
 154                 assert(d->link);
 155                 LIST_FIND_TAIL(domains, d, tail);
 156                 LIST_REMOVE(domains, d->link->search_domains, d);
 157                 LIST_INSERT_AFTER(domains, d->link->search_domains, tail, d);
 158                 break;
 159
 160         case DNS_SEARCH_DOMAIN_SYSTEM:
 161                 LIST_FIND_TAIL(domains, d, tail);
 162                 LIST_REMOVE(domains, d->manager->search_domains, d);
 163                 LIST_INSERT_AFTER(domains, d->manager->search_domains, tail, d);
 164                 break;
 165
 166         default:
 167                 assert_not_reached("Unknown search domain type");
 168         }
 169 }
 170
 171 void dns_search_domain_unlink_all(DnsSearchDomain *first) {
 172         DnsSearchDomain *next;
 173
 174         if (!first)
 175                 return;
 176
 177         next = first->domains_next;
 178         dns_search_domain_unlink(first);
 179
 180         dns_search_domain_unlink_all(next);
 181 }
 182
 183 void dns_search_domain_unlink_marked(DnsSearchDomain *first) {
 184         DnsSearchDomain *next;
 185
 186         if (!first)
 187                 return;
 188
 189         next = first->domains_next;
 190
 191         if (first->marked)
 192                 dns_search_domain_unlink(first);
 193
 194         dns_search_domain_unlink_marked(next);
 195 }
 196
 197 void dns_search_domain_mark_all(DnsSearchDomain *first) {
 198         if (!first)
 199                 return;
 200
 201         first->marked = true;
 202         dns_search_domain_mark_all(first->domains_next);
 203 }
 204
 205 int dns_search_domain_find(DnsSearchDomain *first, const char *name, DnsSearchDomain **ret) {
 206         DnsSearchDomain *d;
 207         int r;
 208
 209         assert(name);
 210         assert(ret);
 211
 212         LIST_FOREACH(domains, d, first) {
 213
 214                 r = dns_name_equal(name, d->name);
 215                 if (r < 0)
 216                         return r;
 217                 if (r > 0) {
 218                         *ret = d;
 219                         return 1;
 220                 }
 221         }
 222
 223         *ret = NULL;
 224         return 0;
 225 }