#include "random-util.h"
#include "resolved-dns-scope.h"
#include "resolved-llmnr.h"
+#include "resolved-mdns.h"
#include "socket-util.h"
#include "strv.h"
LIST_PREPEND(scopes, m->dns_scopes, s);
dns_scope_llmnr_membership(s, true);
+ dns_scope_mdns_membership(s, true);
log_debug("New scope on link %s, protocol %s, family %s", l ? l->name : "*", dns_protocol_to_string(protocol), family == AF_UNSPEC ? "*" : af_to_name(family));
* freed while we still look at it */
t->block_gc++;
- dns_transaction_complete(t, DNS_TRANSACTION_ABORTED);
+ if (DNS_TRANSACTION_IS_LIVE(t->state))
+ dns_transaction_complete(t, DNS_TRANSACTION_ABORTED);
t->block_gc--;
dns_transaction_free(t);
log_debug("Removing scope on link %s, protocol %s, family %s", s->link ? s->link->name : "*", dns_protocol_to_string(s->protocol), s->family == AF_UNSPEC ? "*" : af_to_name(s->family));
dns_scope_llmnr_membership(s, false);
+ dns_scope_mdns_membership(s, false);
dns_scope_abort_transactions(s);
while (s->query_candidates)
s->resend_timeout = MIN(s->resend_timeout * 2, MULTICAST_RESEND_TIMEOUT_MAX_USEC);
}
-int dns_scope_emit(DnsScope *s, int fd, DnsServer *server, DnsPacket *p) {
+static int dns_scope_emit_one(DnsScope *s, int fd, DnsPacket *p) {
union in_addr_union addr;
int ifindex = 0, r;
int family;
- uint16_t port;
uint32_t mtu;
- size_t saved_size = 0;
assert(s);
assert(p);
assert(p->protocol == s->protocol);
- assert((s->protocol == DNS_PROTOCOL_DNS) != (fd < 0));
if (s->link) {
mtu = s->link->mtu;
mtu = manager_find_mtu(s->manager);
switch (s->protocol) {
+
case DNS_PROTOCOL_DNS:
- assert(server);
+ assert(fd >= 0);
if (DNS_PACKET_QDCOUNT(p) > 1)
return -EOPNOTSUPP;
- if (server->possible_features >= DNS_SERVER_FEATURE_LEVEL_EDNS0) {
- bool edns_do;
- size_t packet_size;
-
- edns_do = server->possible_features >= DNS_SERVER_FEATURE_LEVEL_DO;
-
- if (server->possible_features >= DNS_SERVER_FEATURE_LEVEL_LARGE)
- packet_size = DNS_PACKET_UNICAST_SIZE_LARGE_MAX;
- else
- packet_size = server->received_udp_packet_max;
-
- r = dns_packet_append_opt_rr(p, packet_size, edns_do, &saved_size);
- if (r < 0)
- return r;
-
- DNS_PACKET_HEADER(p)->arcount = htobe16(be16toh(DNS_PACKET_HEADER(p)->arcount) + 1);
- }
-
if (p->size > DNS_PACKET_UNICAST_SIZE_MAX)
return -EMSGSIZE;
if (r < 0)
return r;
- if (saved_size > 0) {
- dns_packet_truncate(p, saved_size);
-
- DNS_PACKET_HEADER(p)->arcount = htobe16(be16toh(DNS_PACKET_HEADER(p)->arcount) - 1);
- }
-
break;
case DNS_PROTOCOL_LLMNR:
+ assert(fd < 0);
+
if (DNS_PACKET_QDCOUNT(p) > 1)
return -EOPNOTSUPP;
return -EBUSY;
family = s->family;
- port = LLMNR_PORT;
if (family == AF_INET) {
addr.in = LLMNR_MULTICAST_IPV4_ADDRESS;
if (fd < 0)
return fd;
- r = manager_send(s->manager, fd, ifindex, family, &addr, port, p);
+ r = manager_send(s->manager, fd, ifindex, family, &addr, LLMNR_PORT, p);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case DNS_PROTOCOL_MDNS:
+ assert(fd < 0);
+
+ if (!ratelimit_test(&s->ratelimit))
+ return -EBUSY;
+
+ family = s->family;
+
+ if (family == AF_INET) {
+ addr.in = MDNS_MULTICAST_IPV4_ADDRESS;
+ fd = manager_mdns_ipv4_fd(s->manager);
+ } else if (family == AF_INET6) {
+ addr.in6 = MDNS_MULTICAST_IPV6_ADDRESS;
+ fd = manager_mdns_ipv6_fd(s->manager);
+ } else
+ return -EAFNOSUPPORT;
+ if (fd < 0)
+ return fd;
+
+ r = manager_send(s->manager, fd, ifindex, family, &addr, MDNS_PORT, p);
if (r < 0)
return r;
return 1;
}
-static int dns_scope_socket(DnsScope *s, int type, int family, const union in_addr_union *address, uint16_t port, DnsServer **server) {
- DnsServer *srv = NULL;
+int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p) {
+ int r;
+
+ assert(s);
+ assert(p);
+ assert(p->protocol == s->protocol);
+ assert((s->protocol == DNS_PROTOCOL_DNS) == (fd >= 0));
+
+ do {
+ /* If there are multiple linked packets, set the TC bit in all but the last of them */
+ if (p->more) {
+ assert(p->protocol == DNS_PROTOCOL_MDNS);
+ dns_packet_set_flags(p, true, true);
+ }
+
+ r = dns_scope_emit_one(s, fd, p);
+ if (r < 0)
+ return r;
+
+ p = p->more;
+ } while (p);
+
+ return 0;
+}
+
+static int dns_scope_socket(
+ DnsScope *s,
+ int type,
+ int family,
+ const union in_addr_union *address,
+ DnsServer *server,
+ uint16_t port) {
+
_cleanup_close_ int fd = -1;
union sockaddr_union sa = {};
socklen_t salen;
int ret, r;
assert(s);
- assert((family == AF_UNSPEC) == !address);
-
- if (family == AF_UNSPEC) {
- srv = dns_scope_get_dns_server(s);
- if (!srv)
- return -ESRCH;
- srv->possible_features = dns_server_possible_features(srv);
+ if (server) {
+ assert(family == AF_UNSPEC);
+ assert(!address);
- if (type == SOCK_DGRAM && srv->possible_features < DNS_SERVER_FEATURE_LEVEL_UDP)
- return -EAGAIN;
-
- sa.sa.sa_family = srv->family;
- if (srv->family == AF_INET) {
+ sa.sa.sa_family = server->family;
+ if (server->family == AF_INET) {
sa.in.sin_port = htobe16(port);
- sa.in.sin_addr = srv->address.in;
+ sa.in.sin_addr = server->address.in;
salen = sizeof(sa.in);
- } else if (srv->family == AF_INET6) {
+ } else if (server->family == AF_INET6) {
sa.in6.sin6_port = htobe16(port);
- sa.in6.sin6_addr = srv->address.in6;
+ sa.in6.sin6_addr = server->address.in6;
sa.in6.sin6_scope_id = s->link ? s->link->ifindex : 0;
salen = sizeof(sa.in6);
} else
return -EAFNOSUPPORT;
} else {
+ assert(family != AF_UNSPEC);
+ assert(address);
+
sa.sa.sa_family = family;
if (family == AF_INET) {
if (r < 0 && errno != EINPROGRESS)
return -errno;
- if (server)
- *server = srv;
-
ret = fd;
fd = -1;
return ret;
}
-int dns_scope_udp_dns_socket(DnsScope *s, DnsServer **server) {
- return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, 53, server);
+int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port) {
+ return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, port);
}
-int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *address, uint16_t port, DnsServer **server) {
- return dns_scope_socket(s, SOCK_STREAM, family, address, port, server);
+int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port) {
+ return dns_scope_socket(s, SOCK_STREAM, family, address, server, port);
}
DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain) {
dns_name_equal(domain, "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0)
return DNS_SCOPE_NO;
+ /* Never respond to some of the domains listed in RFC6761 */
+ if (dns_name_endswith(domain, "invalid") > 0)
+ return DNS_SCOPE_NO;
+
/* Always honour search domains for routing queries. Note that
* we return DNS_SCOPE_YES here, rather than just
* DNS_SCOPE_MAYBE, which means wildcard scopes won't be
dns_name_endswith(domain, "8.e.f.ip6.arpa") == 0 &&
dns_name_endswith(domain, "9.e.f.ip6.arpa") == 0 &&
dns_name_endswith(domain, "a.e.f.ip6.arpa") == 0 &&
- dns_name_endswith(domain, "b.e.f.ip6.arpa") == 0)
+ dns_name_endswith(domain, "b.e.f.ip6.arpa") == 0 &&
+ /* If networks use .local in their private setups, they are supposed to also add .local to their search
+ * domains, which we already checked above. Otherwise, we consider .local specific to mDNS and won't
+ * send such queries ordinary DNS servers. */
+ dns_name_endswith(domain, "local") == 0)
return DNS_SCOPE_MAYBE;
return DNS_SCOPE_NO;
if (s->protocol == DNS_PROTOCOL_DNS) {
- /* On classic DNS, lookin up non-address RRs is always
+ /* On classic DNS, looking up non-address RRs is always
* fine. (Specifically, we want to permit looking up
* DNSKEY and DS records on the root and top-level
* domains.) */
return true;
}
-int dns_scope_llmnr_membership(DnsScope *s, bool b) {
+static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) {
int fd;
assert(s);
-
- if (s->protocol != DNS_PROTOCOL_LLMNR)
- return 0;
-
assert(s->link);
if (s->family == AF_INET) {
struct ip_mreqn mreqn = {
- .imr_multiaddr = LLMNR_MULTICAST_IPV4_ADDRESS,
+ .imr_multiaddr = in,
.imr_ifindex = s->link->ifindex,
};
} else if (s->family == AF_INET6) {
struct ipv6_mreq mreq = {
- .ipv6mr_multiaddr = LLMNR_MULTICAST_IPV6_ADDRESS,
+ .ipv6mr_multiaddr = in6,
.ipv6mr_interface = s->link->ifindex,
};
return 0;
}
+int dns_scope_llmnr_membership(DnsScope *s, bool b) {
+
+ if (s->protocol != DNS_PROTOCOL_LLMNR)
+ return 0;
+
+ return dns_scope_multicast_membership(s, b, LLMNR_MULTICAST_IPV4_ADDRESS, LLMNR_MULTICAST_IPV6_ADDRESS);
+}
+
+int dns_scope_mdns_membership(DnsScope *s, bool b) {
+
+ if (s->protocol != DNS_PROTOCOL_MDNS)
+ return 0;
+
+ return dns_scope_multicast_membership(s, b, MDNS_MULTICAST_IPV4_ADDRESS, MDNS_MULTICAST_IPV6_ADDRESS);
+}
+
static int dns_scope_make_reply_packet(
DnsScope *s,
uint16_t id,
/* Refuse reusing transactions that completed based on cached
* data instead of a real packet, if that's requested. */
if (!cache_ok &&
- IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_FAILURE) &&
+ IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_RCODE_FAILURE) &&
t->answer_source != DNS_TRANSACTION_NETWORK)
return NULL;
0 /* (ad) */,
0 /* (cd) */,
0));
- random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t));
+
+ /* For mDNS, the transaction ID should always be 0 */
+ if (s->protocol != DNS_PROTOCOL_MDNS)
+ random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t));
+
DNS_PACKET_HEADER(p)->qdcount = htobe16(1);
DNS_PACKET_HEADER(p)->arcount = htobe16(1);
return 0;
}
- r = dns_scope_emit(scope, -1, NULL, p);
+ r = dns_scope_emit_udp(scope, -1, p);
if (r < 0)
log_debug_errno(r, "Failed to send conflict packet: %m");
}
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