src/resolve/resolved-dns-server.c

	resolved-dns-server.c revision f2f1dbe50fea13abadc9c1e845a29031b90b40f3
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering/***
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  This file is part of systemd.
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  Copyright 2014 Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  systemd is free software; you can redistribute it and/or modify it
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  under the terms of the GNU Lesser General Public License as published by
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  the Free Software Foundation; either version 2.1 of the License, or
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  (at your option) any later version.
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  systemd is distributed in the hope that it will be useful, but
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  WITHOUT ANY WARRANTY; without even the implied warranty of
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  Lesser General Public License for more details.
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  You should have received a copy of the GNU Lesser General Public License
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering  along with systemd; If not, see <http://www.gnu.org/licenses/>.
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering***/
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
8bdbb8d9cbe1d35708385573d70984ab4533812dLennart Poettering#include "alloc-util.h"
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering#include "resolved-dns-server.h"
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering#include "resolved-resolv-conf.h"
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering#include "siphash24.h"
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering#include "string-util.h"
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering/* After how much time to repeat classic DNS requests */
04d39279245834494baccfdb9349db8bf80abd13Lennart Poettering#define DNS_TIMEOUT_MIN_USEC (500 * USEC_PER_MSEC)
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering#define DNS_TIMEOUT_MAX_USEC (5 * USEC_PER_SEC)
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poetteringint dns_server_new(
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                Manager *m,
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen                DnsServer **ret,
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                DnsServerType type,
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                Link *l,
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                int family,
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                const union in_addr_union *in_addr) {
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        DnsServer *s, *tail;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        assert(m);
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        assert((type == DNS_SERVER_LINK) == !!l);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        assert(in_addr);
9d12709626bccc0cae677a7035f62efe6aabb4abLennart Poettering
04d39279245834494baccfdb9349db8bf80abd13Lennart Poettering        s = new0(DnsServer, 1);
023fb90b83871a15ef7f57e8cd126e3426f99b9eLennart Poettering        if (!s)
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                return -ENOMEM;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        s->n_ref = 1;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        s->type = type;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        s->family = family;
e56056e93d33619a3acf13e483900b4f8938228fThomas Hindoe Paaboel Andersen        s->address = *in_addr;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        s->resend_timeout = DNS_TIMEOUT_MIN_USEC;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
d21ed1ead18d16d35c30299a69d3366847f8a039Lennart Poettering        if (type == DNS_SERVER_LINK) {
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                LIST_FIND_TAIL(servers, l->dns_servers, tail);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                LIST_INSERT_AFTER(servers, l->dns_servers, tail, s);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                s->link = l;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        } else if (type == DNS_SERVER_SYSTEM) {
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                LIST_FIND_TAIL(servers, m->dns_servers, tail);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                LIST_INSERT_AFTER(servers, m->dns_servers, tail, s);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        } else if (type == DNS_SERVER_FALLBACK) {
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                LIST_FIND_TAIL(servers, m->fallback_dns_servers, tail);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                LIST_INSERT_AFTER(servers, m->fallback_dns_servers, tail, s);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        } else
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                assert_not_reached("Unknown server type");
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        s->manager = m;
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        /* A new DNS server that isn't fallback is added and the one
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering         * we used so far was a fallback one? Then let's try to pick
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering         * the new one */
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        if (type != DNS_SERVER_FALLBACK &&
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering            m->current_dns_server &&
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering            m->current_dns_server->type == DNS_SERVER_FALLBACK)
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen                manager_set_dns_server(m, NULL);
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        if (ret)
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen                *ret = s;
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        return 0;
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen}
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom GundersenDnsServer* dns_server_ref(DnsServer *s)  {
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        if (!s)
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen                return NULL;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        assert(s->n_ref > 0);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
e56056e93d33619a3acf13e483900b4f8938228fThomas Hindoe Paaboel Andersen        s->n_ref ++;
e56056e93d33619a3acf13e483900b4f8938228fThomas Hindoe Paaboel Andersen
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        return s;
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen}
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
5b30bef856e89a571df57b7b953e9a1409d9acedLennart Poetteringstatic DnsServer* dns_server_free(DnsServer *s)  {
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        if (!s)
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen                return NULL;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        if (s->link && s->link->current_dns_server == s)
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                link_set_dns_server(s->link, NULL);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        if (s->manager && s->manager->current_dns_server == s)
5b30bef856e89a571df57b7b953e9a1409d9acedLennart Poettering                manager_set_dns_server(s->manager, NULL);
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        free(s);
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
5b30bef856e89a571df57b7b953e9a1409d9acedLennart Poettering        return NULL;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering}
e56056e93d33619a3acf13e483900b4f8938228fThomas Hindoe Paaboel Andersen
e56056e93d33619a3acf13e483900b4f8938228fThomas Hindoe Paaboel AndersenDnsServer* dns_server_unref(DnsServer *s)  {
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        if (!s)
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                return NULL;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        assert(s->n_ref > 0);
89f7c8465cd1ab37347dd0c15920bce31e8225dfLennart Poettering
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        if (s->n_ref == 1)
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen                dns_server_free(s);
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        else
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering                s->n_ref --;
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        return NULL;
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering}
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poetteringvoid dns_server_packet_received(DnsServer *s, usec_t rtt) {
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        assert(s);
d21ed1ead18d16d35c30299a69d3366847f8a039Lennart Poettering
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        if (rtt <= s->max_rtt)
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering                return;
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        s->max_rtt = rtt;
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        s->resend_timeout = MIN(MAX(DNS_TIMEOUT_MIN_USEC, s->max_rtt * 2), DNS_TIMEOUT_MAX_USEC);
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering}
a7893c6b28772edbc7e1fea3c209caa54d465648Lennart Poettering
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poetteringvoid dns_server_packet_lost(DnsServer *s, usec_t usec) {
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        assert(s);
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
89f7c8465cd1ab37347dd0c15920bce31e8225dfLennart Poettering        if (s->resend_timeout > usec)
a7893c6b28772edbc7e1fea3c209caa54d465648Lennart Poettering                return;
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen        s->resend_timeout = MIN(s->resend_timeout * 2, DNS_TIMEOUT_MAX_USEC);
a7893c6b28772edbc7e1fea3c209caa54d465648Lennart Poettering}
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersenstatic void dns_server_hash_func(const void *p, struct siphash *state) {
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        const DnsServer *s = p;
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        assert(s);
a7893c6b28772edbc7e1fea3c209caa54d465648Lennart Poettering
5b30bef856e89a571df57b7b953e9a1409d9acedLennart Poettering        siphash24_compress(&s->family, sizeof(s->family), state);
5b30bef856e89a571df57b7b953e9a1409d9acedLennart Poettering        siphash24_compress(&s->address, FAMILY_ADDRESS_SIZE(s->family), state);
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering}
9d12709626bccc0cae677a7035f62efe6aabb4abLennart Poettering
9d12709626bccc0cae677a7035f62efe6aabb4abLennart Poetteringstatic int dns_server_compare_func(const void *a, const void *b) {
9d12709626bccc0cae677a7035f62efe6aabb4abLennart Poettering        const DnsServer *x = a, *y = b;
9d12709626bccc0cae677a7035f62efe6aabb4abLennart Poettering
9d12709626bccc0cae677a7035f62efe6aabb4abLennart Poettering        if (x->family < y->family)
9d12709626bccc0cae677a7035f62efe6aabb4abLennart Poettering                return -1;
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        if (x->family > y->family)
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering                return 1;
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        return memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering}
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poetteringconst struct hash_ops dns_server_hash_ops = {
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        .hash = dns_server_hash_func,
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        .compare = dns_server_compare_func
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering};
9d12709626bccc0cae677a7035f62efe6aabb4abLennart Poettering
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poetteringvoid manager_flush_dns_servers(Manager *m, DnsServerType type) {
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering        DnsServer **first, *s;
aa1936ea1a89c2bb968ba33e3274898a4eeae771Lennart Poettering
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poettering        assert(m);
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        first = type == DNS_SERVER_FALLBACK ? &m->fallback_dns_servers : &m->dns_servers;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        while (*first) {
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                s = *first;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                LIST_REMOVE(servers, *first, s);
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                dns_server_unref(s);
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        }
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering}
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poetteringvoid manager_flush_marked_dns_servers(Manager *m, DnsServerType type) {
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        DnsServer **first, *s, *next;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        assert(m);
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        first = type == DNS_SERVER_FALLBACK ? &m->fallback_dns_servers : &m->dns_servers;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        LIST_FOREACH_SAFE(servers, s, next, *first) {
0dd25fb9f005d8ab7ac4bc10a609d00569f8c56aLennart Poettering                if (!s->marked)
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                        continue;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                LIST_REMOVE(servers, *first, s);
0dd25fb9f005d8ab7ac4bc10a609d00569f8c56aLennart Poettering                dns_server_unref(s);
0dd25fb9f005d8ab7ac4bc10a609d00569f8c56aLennart Poettering        }
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering}
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poetteringvoid manager_mark_dns_servers(Manager *m, DnsServerType type) {
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        DnsServer *first, *s;
0dd25fb9f005d8ab7ac4bc10a609d00569f8c56aLennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        assert(m);
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        first = type == DNS_SERVER_FALLBACK ? m->fallback_dns_servers : m->dns_servers;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        LIST_FOREACH(servers, s, first)
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                s->marked = true;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering}
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poettering
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart PoetteringDnsServer* manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr) {
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poettering        DnsServer *s;
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poettering
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poettering        assert(m);
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        assert(in_addr);
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        LIST_FOREACH(servers, s, m->dns_servers)
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                        return s;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        LIST_FOREACH(servers, s, m->fallback_dns_servers)
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                        return s;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        return NULL;
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering}
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart PoetteringDnsServer *manager_set_dns_server(Manager *m, DnsServer *s) {
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        assert(m);
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering        if (m->current_dns_server == s)
878cd7e95ca303f9851d227a22d2022bd49944b0Lennart Poettering                return s;
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        if (s) {
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                _cleanup_free_ char *ip = NULL;
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                in_addr_to_string(s->family, &s->address, &ip);
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                log_info("Switching to system DNS server %s.", strna(ip));
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        }
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        m->current_dns_server = s;
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        if (m->unicast_scope)
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                dns_cache_flush(&m->unicast_scope->cache);
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        return s;
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering}
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart PoetteringDnsServer *manager_get_dns_server(Manager *m) {
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        Link *l;
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        assert(m);
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        /* Try to read updates resolv.conf */
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        manager_read_resolv_conf(m);
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        /* If no DNS server was chose so far, pick the first one */
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        if (!m->current_dns_server)
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                manager_set_dns_server(m, m->dns_servers);
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering        if (!m->current_dns_server) {
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                bool found = false;
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                Iterator i;
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                /* No DNS servers configured, let's see if there are
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                 * any on any links. If not, we use the fallback
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                 * servers */
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                HASHMAP_FOREACH(l, m->links, i)
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                        if (l->dns_servers) {
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                                found = true;
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                                break;
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                        }
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering
717603e391b52983ca1fd218e7333a1b9dfc5c05Lennart Poettering                if (!found)
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                        manager_set_dns_server(m, m->fallback_dns_servers);
9f6eb1cd58f2ddf2eb6ba0e4de056e13d938af75Kay Sievers        }
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
9f6eb1cd58f2ddf2eb6ba0e4de056e13d938af75Kay Sievers        return m->current_dns_server;
9f6eb1cd58f2ddf2eb6ba0e4de056e13d938af75Kay Sievers}
89f7c8465cd1ab37347dd0c15920bce31e8225dfLennart Poettering
9f6eb1cd58f2ddf2eb6ba0e4de056e13d938af75Kay Sieversvoid manager_next_dns_server(Manager *m) {
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        assert(m);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poettering        /* If there's currently no DNS server set, then the next
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poettering         * manager_get_dns_server() will find one */
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        if (!m->current_dns_server)
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                return;
a1da85830bfaa77b9eb9c54693e5573559c97e50Tom Gundersen
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        /* Change to the next one */
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        if (m->current_dns_server->servers_next) {
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poettering                manager_set_dns_server(m, m->current_dns_server->servers_next);
f48e75cb9a8112d35855c44a156934f2ee0edb2eLennart Poettering                return;
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        }
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        /* If there was no next one, then start from the beginning of
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering         * the list */
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        if (m->current_dns_server->type == DNS_SERVER_FALLBACK)
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                manager_set_dns_server(m, m->fallback_dns_servers);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering        else
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering                manager_set_dns_server(m, m->dns_servers);
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering}
1ee306e1248866617c96ed9f4263f375588ad838Lennart Poettering