-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
/***
This file is part of systemd.
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
+#include <sd-messages.h>
+
#include "alloc-util.h"
#include "resolved-dns-server.h"
+#include "resolved-dns-stub.h"
#include "resolved-resolv-conf.h"
#include "siphash24.h"
#include "string-table.h"
DnsServerType type,
Link *l,
int family,
- const union in_addr_union *in_addr) {
+ const union in_addr_union *in_addr,
+ int ifindex) {
DnsServer *s;
s->type = type;
s->family = family;
s->address = *in_addr;
+ s->ifindex = ifindex;
s->resend_timeout = DNS_TIMEOUT_MIN_USEC;
switch (type) {
return NULL;
assert(s->n_ref > 0);
- s->n_ref ++;
+ s->n_ref++;
return s;
}
return NULL;
assert(s->n_ref > 0);
- s->n_ref --;
+ s->n_ref--;
if (s->n_ref > 0)
return NULL;
assert(s->link);
assert(s->link->n_dns_servers > 0);
LIST_REMOVE(servers, s->link->dns_servers, s);
+ s->link->n_dns_servers--;
break;
case DNS_SERVER_SYSTEM:
if (s->possible_feature_level == level) {
if (protocol == IPPROTO_UDP)
- s->n_failed_udp ++;
+ s->n_failed_udp++;
else if (protocol == IPPROTO_TCP)
- s->n_failed_tcp ++;
+ s->n_failed_tcp++;
}
if (s->resend_timeout > usec)
s->n_failed_tcp = 0;
s->packet_failed = false;
s->packet_truncated = false;
- s->packet_bad_opt = false;
- s->packet_rrsig_missing = false;
s->verified_usec = 0;
+
+ /* Note that we do not reset s->packet_bad_opt and s->packet_rrsig_missing here. We reset them only when the
+ * grace period ends, but not when lowering the possible feature level, as a lower level feature level should
+ * not make RRSIGs appear or OPT appear, but rather make them disappear. If the reappear anyway, then that's
+ * indication for a differently broken OPT/RRSIG implementation, and we really don't want to support that
+ * either.
+ *
+ * This is particularly important to deal with certain Belkin routers which break OPT for certain lookups (A),
+ * but pass traffic through for others (AAAA). If we detect the broken behaviour on one lookup we should not
+ * reenable it for another, because we cannot validate things anyway, given that the RRSIG/OPT data will be
+ * incomplete. */
}
DnsServerFeatureLevel dns_server_possible_feature_level(DnsServer *s) {
dns_server_grace_period_expired(s)) {
s->possible_feature_level = DNS_SERVER_FEATURE_LEVEL_BEST;
+
dns_server_reset_counters(s);
+ s->packet_bad_opt = false;
+ s->packet_rrsig_missing = false;
+
log_info("Grace period over, resuming full feature set (%s) for DNS server %s.",
dns_server_feature_level_to_string(s->possible_feature_level),
dns_server_string(s));
else
packet_size = server->received_udp_packet_max;
- return dns_packet_append_opt(packet, packet_size, edns_do, NULL);
+ return dns_packet_append_opt(packet, packet_size, edns_do, 0, NULL);
+}
+
+int dns_server_ifindex(const DnsServer *s) {
+ assert(s);
+
+ /* The link ifindex always takes precedence */
+ if (s->link)
+ return s->link->ifindex;
+
+ if (s->ifindex > 0)
+ return s->ifindex;
+
+ return 0;
}
const char *dns_server_string(DnsServer *server) {
assert(server);
if (!server->server_string)
- (void) in_addr_to_string(server->family, &server->address, &server->server_string);
+ (void) in_addr_ifindex_to_string(server->family, &server->address, dns_server_ifindex(server), &server->server_string);
return strna(server->server_string);
}
return true;
}
+void dns_server_warn_downgrade(DnsServer *server) {
+ assert(server);
+
+ if (server->warned_downgrade)
+ return;
+
+ log_struct(LOG_NOTICE,
+ LOG_MESSAGE_ID(SD_MESSAGE_DNSSEC_DOWNGRADE),
+ LOG_MESSAGE("Server %s does not support DNSSEC, downgrading to non-DNSSEC mode.", dns_server_string(server)),
+ "DNS_SERVER=%s", dns_server_string(server),
+ "DNS_SERVER_FEATURE_LEVEL=%s", dns_server_feature_level_to_string(server->possible_feature_level),
+ NULL);
+
+ server->warned_downgrade = true;
+}
+
static void dns_server_hash_func(const void *p, struct siphash *state) {
const DnsServer *s = p;
siphash24_compress(&s->family, sizeof(s->family), state);
siphash24_compress(&s->address, FAMILY_ADDRESS_SIZE(s->family), state);
+ siphash24_compress(&s->ifindex, sizeof(s->ifindex), state);
}
static int dns_server_compare_func(const void *a, const void *b) {
const DnsServer *x = a, *y = b;
+ int r;
if (x->family < y->family)
return -1;
if (x->family > y->family)
return 1;
- return memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
+ r = memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
+ if (r != 0)
+ return r;
+
+ if (x->ifindex < y->ifindex)
+ return -1;
+ if (x->ifindex > y->ifindex)
+ return 1;
+
+ return 0;
}
const struct hash_ops dns_server_hash_ops = {
dns_server_mark_all(first->servers_next);
}
-DnsServer *dns_server_find(DnsServer *first, int family, const union in_addr_union *in_addr) {
+DnsServer *dns_server_find(DnsServer *first, int family, const union in_addr_union *in_addr, int ifindex) {
DnsServer *s;
LIST_FOREACH(servers, s, first)
- if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)
+ if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0 && s->ifindex == ifindex)
return s;
return NULL;
return s;
if (s)
- log_info("Switching to system DNS server %s.", dns_server_string(s));
+ log_info("Switching to %s DNS server %s.",
+ dns_server_type_to_string(s->type),
+ dns_server_string(s));
dns_server_unref(m->current_dns_server);
m->current_dns_server = dns_server_ref(s);
/* Try to read updates resolv.conf */
manager_read_resolv_conf(m);
- /* If no DNS server was chose so far, pick the first one */
+ /* If no DNS server was chosen so far, pick the first one */
if (!m->current_dns_server)
manager_set_dns_server(m, m->dns_servers);
manager_set_dns_server(m, m->dns_servers);
}
+bool dns_server_address_valid(int family, const union in_addr_union *sa) {
+
+ /* Refuses the 0 IP addresses as well as 127.0.0.53 (which is our own DNS stub) */
+
+ if (in_addr_is_null(family, sa))
+ return false;
+
+ if (family == AF_INET && sa->in.s_addr == htobe32(INADDR_DNS_STUB))
+ return false;
+
+ return true;
+}
+
+static const char* const dns_server_type_table[_DNS_SERVER_TYPE_MAX] = {
+ [DNS_SERVER_SYSTEM] = "system",
+ [DNS_SERVER_FALLBACK] = "fallback",
+ [DNS_SERVER_LINK] = "link",
+};
+DEFINE_STRING_TABLE_LOOKUP(dns_server_type, DnsServerType);
+
static const char* const dns_server_feature_level_table[_DNS_SERVER_FEATURE_LEVEL_MAX] = {
[DNS_SERVER_FEATURE_LEVEL_TCP] = "TCP",
[DNS_SERVER_FEATURE_LEVEL_UDP] = "UDP",
projects / thirdparty / systemd.git / blobdiff