resolved-link.c revision dfc1091b2f5f21f69e0aa6d3c4536b8990d4b100
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2014 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
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 <net/if.h>
#include "sd-network.h"
#include "alloc-util.h"
#include "missing.h"
#include "parse-util.h"
#include "resolved-link.h"
#include "string-util.h"
#include "strv.h"
int link_new(Manager *m, Link **ret, int ifindex) {
_cleanup_(link_freep) Link *l = NULL;
int r;
assert(m);
assert(ifindex > 0);
r = hashmap_ensure_allocated(&m->links, NULL);
if (r < 0)
return r;
l = new0(Link, 1);
if (!l)
return -ENOMEM;
l->ifindex = ifindex;
l->llmnr_support = RESOLVE_SUPPORT_YES;
l->mdns_support = RESOLVE_SUPPORT_NO;
l->dnssec_mode = _DNSSEC_MODE_INVALID;
r = hashmap_put(m->links, INT_TO_PTR(ifindex), l);
if (r < 0)
return r;
l->manager = m;
if (ret)
*ret = l;
l = NULL;
return 0;
}
Link *link_free(Link *l) {
if (!l)
return NULL;
dns_server_unlink_all(l->dns_servers);
dns_search_domain_unlink_all(l->search_domains);
while (l->addresses)
link_address_free(l->addresses);
if (l->manager)
hashmap_remove(l->manager->links, INT_TO_PTR(l->ifindex));
dns_scope_free(l->unicast_scope);
dns_scope_free(l->llmnr_ipv4_scope);
dns_scope_free(l->llmnr_ipv6_scope);
dns_scope_free(l->mdns_ipv4_scope);
dns_scope_free(l->mdns_ipv6_scope);
set_free_free(l->dnssec_negative_trust_anchors);
free(l);
return NULL;
}
static void link_allocate_scopes(Link *l) {
int r;
assert(l);
if (link_relevant(l, AF_UNSPEC, false) &&
l->dns_servers) {
if (!l->unicast_scope) {
r = dns_scope_new(l->manager, &l->unicast_scope, l, DNS_PROTOCOL_DNS, AF_UNSPEC);
if (r < 0)
log_warning_errno(r, "Failed to allocate DNS scope: %m");
}
} else
l->unicast_scope = dns_scope_free(l->unicast_scope);
if (link_relevant(l, AF_INET, true) &&
l->llmnr_support != RESOLVE_SUPPORT_NO &&
l->manager->llmnr_support != RESOLVE_SUPPORT_NO) {
if (!l->llmnr_ipv4_scope) {
r = dns_scope_new(l->manager, &l->llmnr_ipv4_scope, l, DNS_PROTOCOL_LLMNR, AF_INET);
if (r < 0)
log_warning_errno(r, "Failed to allocate LLMNR IPv4 scope: %m");
}
} else
l->llmnr_ipv4_scope = dns_scope_free(l->llmnr_ipv4_scope);
if (link_relevant(l, AF_INET6, true) &&
l->llmnr_support != RESOLVE_SUPPORT_NO &&
l->manager->llmnr_support != RESOLVE_SUPPORT_NO &&
socket_ipv6_is_supported()) {
if (!l->llmnr_ipv6_scope) {
r = dns_scope_new(l->manager, &l->llmnr_ipv6_scope, l, DNS_PROTOCOL_LLMNR, AF_INET6);
if (r < 0)
log_warning_errno(r, "Failed to allocate LLMNR IPv6 scope: %m");
}
} else
l->llmnr_ipv6_scope = dns_scope_free(l->llmnr_ipv6_scope);
if (link_relevant(l, AF_INET, true) &&
l->mdns_support != RESOLVE_SUPPORT_NO &&
l->manager->mdns_support != RESOLVE_SUPPORT_NO) {
if (!l->mdns_ipv4_scope) {
r = dns_scope_new(l->manager, &l->mdns_ipv4_scope, l, DNS_PROTOCOL_MDNS, AF_INET);
if (r < 0)
log_warning_errno(r, "Failed to allocate mDNS IPv4 scope: %m");
}
} else
l->mdns_ipv4_scope = dns_scope_free(l->mdns_ipv4_scope);
if (link_relevant(l, AF_INET6, true) &&
l->mdns_support != RESOLVE_SUPPORT_NO &&
l->manager->mdns_support != RESOLVE_SUPPORT_NO) {
if (!l->mdns_ipv6_scope) {
r = dns_scope_new(l->manager, &l->mdns_ipv6_scope, l, DNS_PROTOCOL_MDNS, AF_INET6);
if (r < 0)
log_warning_errno(r, "Failed to allocate mDNS IPv6 scope: %m");
}
} else
l->mdns_ipv6_scope = dns_scope_free(l->mdns_ipv6_scope);
}
void link_add_rrs(Link *l, bool force_remove) {
LinkAddress *a;
LIST_FOREACH(addresses, a, l->addresses)
link_address_add_rrs(a, force_remove);
}
int link_update_rtnl(Link *l, sd_netlink_message *m) {
const char *n = NULL;
int r;
assert(l);
assert(m);
r = sd_rtnl_message_link_get_flags(m, &l->flags);
if (r < 0)
return r;
sd_netlink_message_read_u32(m, IFLA_MTU, &l->mtu);
if (sd_netlink_message_read_string(m, IFLA_IFNAME, &n) >= 0) {
strncpy(l->name, n, sizeof(l->name)-1);
char_array_0(l->name);
}
link_allocate_scopes(l);
link_add_rrs(l, false);
return 0;
}
static int link_update_dns_servers(Link *l) {
_cleanup_strv_free_ char **nameservers = NULL;
char **nameserver;
int r;
assert(l);
r = sd_network_link_get_dns(l->ifindex, &nameservers);
if (r == -ENODATA) {
r = 0;
goto clear;
}
if (r < 0)
goto clear;
dns_server_mark_all(l->dns_servers);
STRV_FOREACH(nameserver, nameservers) {
union in_addr_union a;
DnsServer *s;
int family;
r = in_addr_from_string_auto(*nameserver, &family, &a);
if (r < 0)
goto clear;
s = dns_server_find(l->dns_servers, family, &a);
if (s)
dns_server_move_back_and_unmark(s);
else {
r = dns_server_new(l->manager, NULL, DNS_SERVER_LINK, l, family, &a);
if (r < 0)
goto clear;
}
}
dns_server_unlink_marked(l->dns_servers);
return 0;
clear:
dns_server_unlink_all(l->dns_servers);
return r;
}
static int link_update_llmnr_support(Link *l) {
_cleanup_free_ char *b = NULL;
int r;
assert(l);
r = sd_network_link_get_llmnr(l->ifindex, &b);
if (r == -ENODATA) {
r = 0;
goto clear;
}
if (r < 0)
goto clear;
l->llmnr_support = resolve_support_from_string(b);
if (l->llmnr_support < 0) {
r = -EINVAL;
goto clear;
}
return 0;
clear:
l->llmnr_support = RESOLVE_SUPPORT_YES;
return r;
}
static int link_update_mdns_support(Link *l) {
_cleanup_free_ char *b = NULL;
int r;
assert(l);
r = sd_network_link_get_mdns(l->ifindex, &b);
if (r == -ENODATA) {
r = 0;
goto clear;
}
if (r < 0)
goto clear;
l->mdns_support = resolve_support_from_string(b);
if (l->mdns_support < 0) {
r = -EINVAL;
goto clear;
}
return 0;
clear:
l->mdns_support = RESOLVE_SUPPORT_NO;
return r;
}
static int link_update_dnssec_mode(Link *l) {
_cleanup_free_ char *m = NULL;
DnssecMode mode;
int r;
assert(l);
r = sd_network_link_get_dnssec(l->ifindex, &m);
if (r == -ENODATA) {
r = 0;
goto clear;
}
if (r < 0)
goto clear;
mode = dnssec_mode_from_string(m);
if (mode < 0) {
r = -EINVAL;
goto clear;
}
if ((l->dnssec_mode == DNSSEC_NO && mode != DNSSEC_NO) ||
(l->dnssec_mode == DNSSEC_ALLOW_DOWNGRADE && mode == DNSSEC_YES)) {
/* When switching from non-DNSSEC mode to DNSSEC mode, flush the cache. Also when switching from the
* allow-downgrade mode to full DNSSEC mode, flush it too. */
if (l->unicast_scope)
dns_cache_flush(&l->unicast_scope->cache);
}
l->dnssec_mode = mode;
return 0;
clear:
l->dnssec_mode = _DNSSEC_MODE_INVALID;
return r;
}
static int link_update_dnssec_negative_trust_anchors(Link *l) {
_cleanup_strv_free_ char **ntas = NULL;
_cleanup_set_free_free_ Set *ns = NULL;
char **i;
int r;
assert(l);
r = sd_network_link_get_dnssec_negative_trust_anchors(l->ifindex, &ntas);
if (r == -ENODATA) {
r = 0;
goto clear;
}
if (r < 0)
goto clear;
ns = set_new(&dns_name_hash_ops);
if (!ns)
return -ENOMEM;
STRV_FOREACH(i, ntas) {
r = set_put_strdup(ns, *i);
if (r < 0)
return r;
}
set_free_free(l->dnssec_negative_trust_anchors);
l->dnssec_negative_trust_anchors = ns;
ns = NULL;
return 0;
clear:
l->dnssec_negative_trust_anchors = set_free_free(l->dnssec_negative_trust_anchors);
return r;
}
static int link_update_search_domains(Link *l) {
_cleanup_strv_free_ char **domains = NULL;
char **i;
int r;
assert(l);
r = sd_network_link_get_domains(l->ifindex, &domains);
if (r == -ENODATA) {
/* networkd knows nothing about this interface, and that's fine. */
r = 0;
goto clear;
}
if (r < 0)
goto clear;
dns_search_domain_mark_all(l->search_domains);
STRV_FOREACH(i, domains) {
DnsSearchDomain *d;
r = dns_search_domain_find(l->search_domains, *i, &d);
if (r < 0)
goto clear;
if (r > 0)
dns_search_domain_move_back_and_unmark(d);
else {
r = dns_search_domain_new(l->manager, NULL, DNS_SEARCH_DOMAIN_LINK, l, *i);
if (r < 0)
goto clear;
}
}
dns_search_domain_unlink_marked(l->search_domains);
return 0;
clear:
dns_search_domain_unlink_all(l->search_domains);
return r;
}
int link_update_monitor(Link *l) {
int r;
assert(l);
r = link_update_dns_servers(l);
if (r < 0)
log_warning_errno(r, "Failed to read DNS servers for interface %s, ignoring: %m", l->name);
r = link_update_llmnr_support(l);
if (r < 0)
log_warning_errno(r, "Failed to read LLMNR support for interface %s, ignoring: %m", l->name);
r = link_update_mdns_support(l);
if (r < 0)
log_warning_errno(r, "Failed to read mDNS support for interface %s, ignoring: %m", l->name);
r = link_update_dnssec_mode(l);
if (r < 0)
log_warning_errno(r, "Failed to read DNSSEC mode for interface %s, ignoring: %m", l->name);
r = link_update_dnssec_negative_trust_anchors(l);
if (r < 0)
log_warning_errno(r, "Failed to read DNSSEC negative trust anchors for interface %s, ignoring: %m", l->name);
r = link_update_search_domains(l);
if (r < 0)
log_warning_errno(r, "Failed to read search domains for interface %s, ignoring: %m", l->name);
link_allocate_scopes(l);
link_add_rrs(l, false);
return 0;
}
bool link_relevant(Link *l, int family, bool multicast) {
_cleanup_free_ char *state = NULL;
LinkAddress *a;
assert(l);
/* A link is relevant for multicast traffic if it isn't a loopback or pointopoint device, has a link beat, can
* do multicast and has at least one relevant IP address */
if (l->flags & (IFF_LOOPBACK|IFF_DORMANT))
return false;
if ((l->flags & (IFF_UP|IFF_LOWER_UP)) != (IFF_UP|IFF_LOWER_UP))
return false;
if (multicast) {
if (l->flags & IFF_POINTOPOINT)
return false;
if ((l->flags & IFF_MULTICAST) != IFF_MULTICAST)
return false;
}
sd_network_link_get_operational_state(l->ifindex, &state);
if (state && !STR_IN_SET(state, "unknown", "degraded", "routable"))
return false;
LIST_FOREACH(addresses, a, l->addresses)
if ((family == AF_UNSPEC || a->family == family) && link_address_relevant(a))
return true;
return false;
}
LinkAddress *link_find_address(Link *l, int family, const union in_addr_union *in_addr) {
LinkAddress *a;
assert(l);
LIST_FOREACH(addresses, a, l->addresses)
if (a->family == family && in_addr_equal(family, &a->in_addr, in_addr))
return a;
return NULL;
}
DnsServer* link_set_dns_server(Link *l, DnsServer *s) {
assert(l);
if (l->current_dns_server == s)
return s;
if (s)
log_info("Switching to DNS server %s for interface %s.", dns_server_string(s), l->name);
dns_server_unref(l->current_dns_server);
l->current_dns_server = dns_server_ref(s);
if (l->unicast_scope)
dns_cache_flush(&l->unicast_scope->cache);
return s;
}
DnsServer *link_get_dns_server(Link *l) {
assert(l);
if (!l->current_dns_server)
link_set_dns_server(l, l->dns_servers);
return l->current_dns_server;
}
void link_next_dns_server(Link *l) {
assert(l);
if (!l->current_dns_server)
return;
/* Change to the next one, but make sure to follow the linked
* list only if this server is actually still linked. */
if (l->current_dns_server->linked && l->current_dns_server->servers_next) {
link_set_dns_server(l, l->current_dns_server->servers_next);
return;
}
link_set_dns_server(l, l->dns_servers);
}
int link_address_new(Link *l, LinkAddress **ret, int family, const union in_addr_union *in_addr) {
LinkAddress *a;
assert(l);
assert(in_addr);
a = new0(LinkAddress, 1);
if (!a)
return -ENOMEM;
a->family = family;
a->in_addr = *in_addr;
a->link = l;
LIST_PREPEND(addresses, l->addresses, a);
if (ret)
*ret = a;
return 0;
}
LinkAddress *link_address_free(LinkAddress *a) {
if (!a)
return NULL;
if (a->link) {
LIST_REMOVE(addresses, a->link->addresses, a);
if (a->llmnr_address_rr) {
if (a->family == AF_INET && a->link->llmnr_ipv4_scope)
dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
}
if (a->llmnr_ptr_rr) {
if (a->family == AF_INET && a->link->llmnr_ipv4_scope)
dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
else if (a->family == AF_INET6 && a->link->llmnr_ipv6_scope)
dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
}
}
dns_resource_record_unref(a->llmnr_address_rr);
dns_resource_record_unref(a->llmnr_ptr_rr);
free(a);
return NULL;
}
void link_address_add_rrs(LinkAddress *a, bool force_remove) {
int r;
assert(a);
if (a->family == AF_INET) {
if (!force_remove &&
link_address_relevant(a) &&
a->link->llmnr_ipv4_scope &&
a->link->llmnr_support == RESOLVE_SUPPORT_YES &&
a->link->manager->llmnr_support == RESOLVE_SUPPORT_YES) {
if (!a->link->manager->llmnr_host_ipv4_key) {
a->link->manager->llmnr_host_ipv4_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, a->link->manager->llmnr_hostname);
if (!a->link->manager->llmnr_host_ipv4_key) {
r = -ENOMEM;
goto fail;
}
}
if (!a->llmnr_address_rr) {
a->llmnr_address_rr = dns_resource_record_new(a->link->manager->llmnr_host_ipv4_key);
if (!a->llmnr_address_rr) {
r = -ENOMEM;
goto fail;
}
a->llmnr_address_rr->a.in_addr = a->in_addr.in;
a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
}
if (!a->llmnr_ptr_rr) {
r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->llmnr_hostname);
if (r < 0)
goto fail;
a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
}
r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_address_rr, true);
if (r < 0)
log_warning_errno(r, "Failed to add A record to LLMNR zone: %m");
r = dns_zone_put(&a->link->llmnr_ipv4_scope->zone, a->link->llmnr_ipv4_scope, a->llmnr_ptr_rr, false);
if (r < 0)
log_warning_errno(r, "Failed to add IPv6 PTR record to LLMNR zone: %m");
} else {
if (a->llmnr_address_rr) {
if (a->link->llmnr_ipv4_scope)
dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_address_rr);
a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr);
}
if (a->llmnr_ptr_rr) {
if (a->link->llmnr_ipv4_scope)
dns_zone_remove_rr(&a->link->llmnr_ipv4_scope->zone, a->llmnr_ptr_rr);
a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
}
}
}
if (a->family == AF_INET6) {
if (!force_remove &&
link_address_relevant(a) &&
a->link->llmnr_ipv6_scope &&
a->link->llmnr_support == RESOLVE_SUPPORT_YES &&
a->link->manager->llmnr_support == RESOLVE_SUPPORT_YES) {
if (!a->link->manager->llmnr_host_ipv6_key) {
a->link->manager->llmnr_host_ipv6_key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, a->link->manager->llmnr_hostname);
if (!a->link->manager->llmnr_host_ipv6_key) {
r = -ENOMEM;
goto fail;
}
}
if (!a->llmnr_address_rr) {
a->llmnr_address_rr = dns_resource_record_new(a->link->manager->llmnr_host_ipv6_key);
if (!a->llmnr_address_rr) {
r = -ENOMEM;
goto fail;
}
a->llmnr_address_rr->aaaa.in6_addr = a->in_addr.in6;
a->llmnr_address_rr->ttl = LLMNR_DEFAULT_TTL;
}
if (!a->llmnr_ptr_rr) {
r = dns_resource_record_new_reverse(&a->llmnr_ptr_rr, a->family, &a->in_addr, a->link->manager->llmnr_hostname);
if (r < 0)
goto fail;
a->llmnr_ptr_rr->ttl = LLMNR_DEFAULT_TTL;
}
r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_address_rr, true);
if (r < 0)
log_warning_errno(r, "Failed to add AAAA record to LLMNR zone: %m");
r = dns_zone_put(&a->link->llmnr_ipv6_scope->zone, a->link->llmnr_ipv6_scope, a->llmnr_ptr_rr, false);
if (r < 0)
log_warning_errno(r, "Failed to add IPv6 PTR record to LLMNR zone: %m");
} else {
if (a->llmnr_address_rr) {
if (a->link->llmnr_ipv6_scope)
dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_address_rr);
a->llmnr_address_rr = dns_resource_record_unref(a->llmnr_address_rr);
}
if (a->llmnr_ptr_rr) {
if (a->link->llmnr_ipv6_scope)
dns_zone_remove_rr(&a->link->llmnr_ipv6_scope->zone, a->llmnr_ptr_rr);
a->llmnr_ptr_rr = dns_resource_record_unref(a->llmnr_ptr_rr);
}
}
}
return;
fail:
log_debug_errno(r, "Failed to update address RRs: %m");
}
int link_address_update_rtnl(LinkAddress *a, sd_netlink_message *m) {
int r;
assert(a);
assert(m);
r = sd_rtnl_message_addr_get_flags(m, &a->flags);
if (r < 0)
return r;
sd_rtnl_message_addr_get_scope(m, &a->scope);
link_allocate_scopes(a->link);
link_add_rrs(a->link, false);
return 0;
}
bool link_address_relevant(LinkAddress *a) {
assert(a);
if (a->flags & (IFA_F_DEPRECATED|IFA_F_TENTATIVE))
return false;
if (IN_SET(a->scope, RT_SCOPE_HOST, RT_SCOPE_NOWHERE))
return false;
return true;
}