resolved-dns-server.c revision 4b95f1798f22c1bb75295f448188560cb6ec9ece
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2014 Lennart Poettering
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 "alloc-util.h"
#include "resolved-dns-server.h"
#include "resolved-resolv-conf.h"
#include "siphash24.h"
#include "string-util.h"
/* After how much time to repeat classic DNS requests */
int dns_server_new(
Manager *m,
Link *l,
int family,
const union in_addr_union *in_addr) {
assert(m);
if (!s)
return -ENOMEM;
s->n_ref = 1;
s->manager = m;
switch (type) {
case DNS_SERVER_LINK:
s->link = l;
break;
case DNS_SERVER_SYSTEM:
break;
case DNS_SERVER_FALLBACK:
break;
default:
assert_not_reached("Unknown server type");
}
s->linked = true;
/* A new DNS server that isn't fallback is added and the one
* we used so far was a fallback one? Then let's try to pick
* the new one */
if (type != DNS_SERVER_FALLBACK &&
m->current_dns_server &&
if (ret)
*ret = s;
return 0;
}
if (!s)
return NULL;
s->n_ref ++;
return s;
}
if (!s)
return NULL;
s->n_ref --;
if (s->n_ref > 0)
return NULL;
free(s);
return NULL;
}
void dns_server_unlink(DnsServer *s) {
assert(s);
/* This removes the specified server from the linked list of
* servers, but any server might still stay around if it has
* refs, for example from an ongoing transaction. */
if (!s->linked)
return;
switch (s->type) {
case DNS_SERVER_LINK:
break;
case DNS_SERVER_SYSTEM:
break;
case DNS_SERVER_FALLBACK:
break;
}
s->linked = false;
if (s->manager->current_dns_server == s)
dns_server_unref(s);
}
void dns_server_move_back_and_unmark(DnsServer *s) {
assert(s);
if (!s->marked)
return;
s->marked = false;
if (!s->linked || !s->servers_next)
return;
/* Move us to the end of the list, so that the order is
* strictly kept, if we are not at the end anyway. */
switch (s->type) {
case DNS_SERVER_LINK:
break;
case DNS_SERVER_SYSTEM:
break;
case DNS_SERVER_FALLBACK:
break;
default:
assert_not_reached("Unknown server type");
}
}
assert(s);
return;
}
assert(s);
if (s->resend_timeout > usec)
return;
}
const DnsServer *s = p;
assert(s);
}
static int dns_server_compare_func(const void *a, const void *b) {
const DnsServer *x = a, *y = b;
return -1;
return 1;
}
const struct hash_ops dns_server_hash_ops = {
};
if (!first)
return;
}
if (!first)
return;
}
if (!first)
return;
}
DnsServer *s;
return s;
return NULL;
}
assert(m);
switch (t) {
case DNS_SERVER_SYSTEM:
return m->dns_servers;
case DNS_SERVER_FALLBACK:
return m->fallback_dns_servers;
default:
return NULL;
}
}
assert(m);
if (m->current_dns_server == s)
return s;
if (s) {
}
m->current_dns_server = dns_server_ref(s);
if (m->unicast_scope)
return s;
}
Link *l;
assert(m);
/* Try to read updates resolv.conf */
/* If no DNS server was chose so far, pick the first one */
if (!m->current_dns_server)
manager_set_dns_server(m, m->dns_servers);
if (!m->current_dns_server) {
bool found = false;
Iterator i;
/* No DNS servers configured, let's see if there are
* any on any links. If not, we use the fallback
* servers */
HASHMAP_FOREACH(l, m->links, i)
if (l->dns_servers) {
found = true;
break;
}
if (!found)
}
return m->current_dns_server;
}
void manager_next_dns_server(Manager *m) {
assert(m);
/* If there's currently no DNS server set, then the next
* manager_get_dns_server() will find one */
if (!m->current_dns_server)
return;
/* Change to the next one, but make sure to follow the linked
* list only if the server is still linked. */
return;
}
/* If there was no next one, then start from the beginning of
* the list */
else
manager_set_dns_server(m, m->dns_servers);
}