src/resolve/resolved-dns-server.c

	resolved-dns-server.c revision b5efdb8af40ea759a1ea584c1bc44ecc81dd00ce
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering/***
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  This file is part of systemd.
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  Copyright 2014 Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  systemd is free software; you can redistribute it and/or modify it
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  under the terms of the GNU Lesser General Public License as published by
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  the Free Software Foundation; either version 2.1 of the License, or
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  (at your option) any later version.
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  systemd is distributed in the hope that it will be useful, but
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  WITHOUT ANY WARRANTY; without even the implied warranty of
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  Lesser General Public License for more details.
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  You should have received a copy of the GNU Lesser General Public License
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  along with systemd; If not, see <http://www.gnu.org/licenses/>.
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering***/
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
b5efdb8af40ea759a1ea584c1bc44ecc81dd00ceLennart Poettering#include "alloc-util.h"
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering#include "resolved-dns-server.h"
b5efdb8af40ea759a1ea584c1bc44ecc81dd00ceLennart Poettering#include "siphash24.h"
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen/* After how much time to repeat classic DNS requests */
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen#define DNS_TIMEOUT_MIN_USEC (500 * USEC_PER_MSEC)
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen#define DNS_TIMEOUT_MAX_USEC (5 * USEC_PER_SEC)
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poetteringint dns_server_new(
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering                Manager *m,
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering                DnsServer **ret,
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering                DnsServerType type,
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering                Link *l,
0dd25fb9f005d8ab7ac4bc10a609d00569f8c56aLennart Poettering                int family,
3c0cf502796be355431d4a64d738e75f543aa51dLennart Poettering                const union in_addr_union *in_addr) {
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        DnsServer *s, *tail;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        assert(m);
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        assert((type == DNS_SERVER_LINK) == !!l);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        assert(in_addr);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        s = new0(DnsServer, 1);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        if (!s)
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering                return -ENOMEM;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        s->n_ref = 1;
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        s->type = type;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        s->family = family;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        s->address = *in_addr;
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen        s->resend_timeout = DNS_TIMEOUT_MIN_USEC;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        if (type == DNS_SERVER_LINK) {
6073b6f26ab9fc6bf335faa7073ec443eef093fdTom Gundersen                LIST_FIND_TAIL(servers, l->dns_servers, tail);
6073b6f26ab9fc6bf335faa7073ec443eef093fdTom Gundersen                LIST_INSERT_AFTER(servers, l->dns_servers, tail, s);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering                s->link = l;
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        } else if (type == DNS_SERVER_SYSTEM) {
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering                LIST_FIND_TAIL(servers, m->dns_servers, tail);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering                LIST_INSERT_AFTER(servers, m->dns_servers, tail, s);
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        } else if (type == DNS_SERVER_FALLBACK) {
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering                LIST_FIND_TAIL(servers, m->fallback_dns_servers, tail);
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering                LIST_INSERT_AFTER(servers, m->fallback_dns_servers, tail, s);
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        } else
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering                assert_not_reached("Unknown server type");
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        s->manager = m;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        /* A new DNS server that isn't fallback is added and the one
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering         * we used so far was a fallback one? Then let's try to pick
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering         * the new one */
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        if (type != DNS_SERVER_FALLBACK &&
3e684349c2cead2e6fd2f816c34eb17daba23a49Lennart Poettering            m->current_dns_server &&
3e684349c2cead2e6fd2f816c34eb17daba23a49Lennart Poettering            m->current_dns_server->type == DNS_SERVER_FALLBACK)
3e684349c2cead2e6fd2f816c34eb17daba23a49Lennart Poettering                manager_set_dns_server(m, NULL);
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        if (ret)
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering                *ret = s;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        return 0;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering}
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
91b14d6ff362b938a72db17b095ee9903d07381bTom GundersenDnsServer* dns_server_ref(DnsServer *s)  {
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        if (!s)
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering                return NULL;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        assert(s->n_ref > 0);
cab5b05903096e1c9cf5575ccc73f89d15c8db69Lennart Poettering
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        s->n_ref ++;
cab5b05903096e1c9cf5575ccc73f89d15c8db69Lennart Poettering
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        return s;
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen}
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersenstatic DnsServer* dns_server_free(DnsServer *s)  {
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        if (!s)
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen                return NULL;
3e684349c2cead2e6fd2f816c34eb17daba23a49Lennart Poettering
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        if (s->link && s->link->current_dns_server == s)
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen                link_set_dns_server(s->link, NULL);
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        if (s->manager && s->manager->current_dns_server == s)
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen                manager_set_dns_server(s->manager, NULL);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        free(s);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        return NULL;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering}
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering
91b14d6ff362b938a72db17b095ee9903d07381bTom GundersenDnsServer* dns_server_unref(DnsServer *s)  {
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        if (!s)
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen                return NULL;
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        assert(s->n_ref > 0);
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        if (s->n_ref == 1)
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen                dns_server_free(s);
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        else
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen                s->n_ref --;
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen        return NULL;
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen}
91b14d6ff362b938a72db17b095ee9903d07381bTom Gundersen
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersenvoid dns_server_packet_received(DnsServer *s, usec_t rtt) {
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen        assert(s);
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen        if (rtt > s->max_rtt) {
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen                s->max_rtt = rtt;
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen                s->resend_timeout = MIN(MAX(DNS_TIMEOUT_MIN_USEC, s->max_rtt * 2),
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen                                        DNS_TIMEOUT_MAX_USEC);
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen        }
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen}
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersenvoid dns_server_packet_lost(DnsServer *s, usec_t usec) {
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen        assert(s);
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen        if (s->resend_timeout <= usec)
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen                s->resend_timeout = MIN(s->resend_timeout * 2, DNS_TIMEOUT_MAX_USEC);
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen}
9df3ba6c6cb65eecec06f39dfe85a3596cedac4eTom Gundersen
b826ab586c9e0a9c0d438a75c28cf3a8ab485929Tom Gundersenstatic void dns_server_hash_func(const void *p, struct siphash *state) {
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering        const DnsServer *s = p;
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering
b826ab586c9e0a9c0d438a75c28cf3a8ab485929Tom Gundersen        assert(s);
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering
b826ab586c9e0a9c0d438a75c28cf3a8ab485929Tom Gundersen        siphash24_compress(&s->family, sizeof(s->family), state);
b826ab586c9e0a9c0d438a75c28cf3a8ab485929Tom Gundersen        siphash24_compress(&s->address, FAMILY_ADDRESS_SIZE(s->family), state);
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering}
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering
d5099efc47d4e6ac60816b5381a5f607ab03f06eMichal Schmidtstatic int dns_server_compare_func(const void *a, const void *b) {
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering        const DnsServer *x = a, *y = b;
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering        if (x->family < y->family)
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering                return -1;
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering        if (x->family > y->family)
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering                return 1;
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering        return memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
87f5a19343acf8ba697acc5a62bdb1a2b8c9eda3Lennart Poettering}
d5099efc47d4e6ac60816b5381a5f607ab03f06eMichal Schmidt
d5099efc47d4e6ac60816b5381a5f607ab03f06eMichal Schmidtconst struct hash_ops dns_server_hash_ops = {
d5099efc47d4e6ac60816b5381a5f607ab03f06eMichal Schmidt        .hash = dns_server_hash_func,
d5099efc47d4e6ac60816b5381a5f607ab03f06eMichal Schmidt        .compare = dns_server_compare_func
d5099efc47d4e6ac60816b5381a5f607ab03f06eMichal Schmidt};