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-rw-r--r--src/resolve/resolved-dns-scope.c636
1 files changed, 440 insertions, 196 deletions
diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 7b72c090c2..03811ac8e7 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -1,5 +1,3 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
/***
This file is part of systemd.
@@ -21,19 +19,26 @@
#include <netinet/tcp.h>
-#include "missing.h"
-#include "strv.h"
-#include "socket-util.h"
#include "af-list.h"
-#include "random-util.h"
-#include "hostname-util.h"
+#include "alloc-util.h"
#include "dns-domain.h"
-#include "resolved-llmnr.h"
+#include "fd-util.h"
+#include "hostname-util.h"
+#include "missing.h"
+#include "random-util.h"
#include "resolved-dns-scope.h"
+#include "resolved-llmnr.h"
+#include "resolved-mdns.h"
+#include "socket-util.h"
+#include "strv.h"
#define MULTICAST_RATELIMIT_INTERVAL_USEC (1*USEC_PER_SEC)
#define MULTICAST_RATELIMIT_BURST 1000
+/* After how much time to repeat LLMNR requests, see RFC 4795 Section 7 */
+#define MULTICAST_RESEND_TIMEOUT_MIN_USEC (100 * USEC_PER_MSEC)
+#define MULTICAST_RESEND_TIMEOUT_MAX_USEC (1 * USEC_PER_SEC)
+
int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int family) {
DnsScope *s;
@@ -48,10 +53,26 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int
s->link = l;
s->protocol = protocol;
s->family = family;
+ s->resend_timeout = MULTICAST_RESEND_TIMEOUT_MIN_USEC;
+
+ if (protocol == DNS_PROTOCOL_DNS) {
+ /* Copy DNSSEC mode from the link if it is set there,
+ * otherwise take the manager's DNSSEC mode. Note that
+ * we copy this only at scope creation time, and do
+ * not update it from the on, even if the setting
+ * changes. */
+
+ if (l)
+ s->dnssec_mode = link_get_dnssec_mode(l);
+ else
+ s->dnssec_mode = manager_get_dnssec_mode(m);
+ } else
+ s->dnssec_mode = DNSSEC_NO;
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));
@@ -62,8 +83,25 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int
return 0;
}
+static void dns_scope_abort_transactions(DnsScope *s) {
+ assert(s);
+
+ while (s->transactions) {
+ DnsTransaction *t = s->transactions;
+
+ /* Abort the transaction, but make sure it is not
+ * freed while we still look at it */
+
+ t->block_gc++;
+ if (DNS_TRANSACTION_IS_LIVE(t->state))
+ dns_transaction_complete(t, DNS_TRANSACTION_ABORTED);
+ t->block_gc--;
+
+ dns_transaction_free(t);
+ }
+}
+
DnsScope* dns_scope_free(DnsScope *s) {
- DnsTransaction *t;
DnsResourceRecord *rr;
if (!s)
@@ -72,18 +110,13 @@ DnsScope* dns_scope_free(DnsScope *s) {
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 ((t = s->transactions)) {
+ while (s->query_candidates)
+ dns_query_candidate_free(s->query_candidates);
- /* Abort the transaction, but make sure it is not
- * freed while we still look at it */
-
- t->block_gc++;
- dns_transaction_complete(t, DNS_TRANSACTION_ABORTED);
- t->block_gc--;
-
- dns_transaction_free(t);
- }
+ hashmap_free(s->transactions_by_key);
while ((rr = ordered_hashmap_steal_first(s->conflict_queue)))
dns_resource_record_unref(rr);
@@ -95,7 +128,6 @@ DnsScope* dns_scope_free(DnsScope *s) {
dns_zone_flush(&s->zone);
LIST_REMOVE(scopes, s->manager->dns_scopes, s);
- strv_free(s->domains);
free(s);
return NULL;
@@ -125,14 +157,28 @@ void dns_scope_next_dns_server(DnsScope *s) {
manager_next_dns_server(s->manager);
}
-int dns_scope_emit(DnsScope *s, DnsTransaction *t, DnsPacket *p, DnsServer **server) {
- DnsServer *srv = NULL;
+void dns_scope_packet_received(DnsScope *s, usec_t rtt) {
+ assert(s);
+
+ if (rtt <= s->max_rtt)
+ return;
+
+ s->max_rtt = rtt;
+ s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2), MULTICAST_RESEND_TIMEOUT_MAX_USEC);
+}
+
+void dns_scope_packet_lost(DnsScope *s, usec_t usec) {
+ assert(s);
+
+ if (s->resend_timeout <= usec)
+ s->resend_timeout = MIN(s->resend_timeout * 2, MULTICAST_RESEND_TIMEOUT_MAX_USEC);
+}
+
+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;
- int fd;
assert(s);
assert(p);
@@ -144,17 +190,13 @@ int dns_scope_emit(DnsScope *s, DnsTransaction *t, DnsPacket *p, DnsServer **ser
} else
mtu = manager_find_mtu(s->manager);
- if (s->protocol == DNS_PROTOCOL_DNS) {
- if (DNS_PACKET_QDCOUNT(p) > 1)
- return -EOPNOTSUPP;
+ switch (s->protocol) {
- srv = dns_scope_get_dns_server(s);
- if (!srv)
- return -ESRCH;
+ case DNS_PROTOCOL_DNS:
+ assert(fd >= 0);
- family = srv->family;
- addr = srv->address;
- port = 53;
+ if (DNS_PACKET_QDCOUNT(p) > 1)
+ return -EOPNOTSUPP;
if (p->size > DNS_PACKET_UNICAST_SIZE_MAX)
return -EMSGSIZE;
@@ -162,16 +204,14 @@ int dns_scope_emit(DnsScope *s, DnsTransaction *t, DnsPacket *p, DnsServer **ser
if (p->size + UDP_PACKET_HEADER_SIZE > mtu)
return -EMSGSIZE;
- if (family == AF_INET)
- fd = transaction_dns_ipv4_fd(t);
- else if (family == AF_INET6)
- fd = transaction_dns_ipv6_fd(t);
- else
- return -EAFNOSUPPORT;
- if (fd < 0)
- return fd;
+ r = manager_write(s->manager, fd, p);
+ if (r < 0)
+ return r;
+
+ break;
- } else if (s->protocol == DNS_PROTOCOL_LLMNR) {
+ case DNS_PROTOCOL_LLMNR:
+ assert(fd < 0);
if (DNS_PACKET_QDCOUNT(p) > 1)
return -EOPNOTSUPP;
@@ -180,7 +220,6 @@ int dns_scope_emit(DnsScope *s, DnsTransaction *t, DnsPacket *p, DnsServer **ser
return -EBUSY;
family = s->family;
- port = LLMNR_PORT;
if (family == AF_INET) {
addr.in = LLMNR_MULTICAST_IPV4_ADDRESS;
@@ -192,49 +231,110 @@ int dns_scope_emit(DnsScope *s, DnsTransaction *t, DnsPacket *p, DnsServer **ser
return -EAFNOSUPPORT;
if (fd < 0)
return fd;
- } else
- return -EAFNOSUPPORT;
- r = manager_send(s->manager, fd, ifindex, family, &addr, port, p);
- if (r < 0)
- return r;
+ r = manager_send(s->manager, fd, ifindex, family, &addr, LLMNR_PORT, NULL, 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, NULL, p);
+ if (r < 0)
+ return r;
- if (server)
- *server = srv;
+ break;
+
+ default:
+ return -EAFNOSUPPORT;
+ }
return 1;
}
-int dns_scope_tcp_socket(DnsScope *s, 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;
static const int one = 1;
- int ret, r;
+ int ret, r, ifindex;
assert(s);
- assert((family == AF_UNSPEC) == !address);
- if (family == AF_UNSPEC) {
- srv = dns_scope_get_dns_server(s);
- if (!srv)
- return -ESRCH;
+ if (server) {
+ assert(family == AF_UNSPEC);
+ assert(!address);
+
+ ifindex = dns_server_ifindex(server);
- 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_scope_id = s->link ? s->link->ifindex : 0;
+ sa.in6.sin6_addr = server->address.in6;
+ sa.in6.sin6_scope_id = ifindex;
salen = sizeof(sa.in6);
} else
return -EAFNOSUPPORT;
} else {
+ assert(family != AF_UNSPEC);
+ assert(address);
+
sa.sa.sa_family = family;
+ ifindex = s->link ? s->link->ifindex : 0;
if (family == AF_INET) {
sa.in.sin_port = htobe16(port);
@@ -243,29 +343,31 @@ int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *add
} else if (family == AF_INET6) {
sa.in6.sin6_port = htobe16(port);
sa.in6.sin6_addr = address->in6;
- sa.in6.sin6_scope_id = s->link ? s->link->ifindex : 0;
+ sa.in6.sin6_scope_id = ifindex;
salen = sizeof(sa.in6);
} else
return -EAFNOSUPPORT;
}
- fd = socket(sa.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ fd = socket(sa.sa.sa_family, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (fd < 0)
return -errno;
- r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
- if (r < 0)
- return -errno;
+ if (type == SOCK_STREAM) {
+ r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one));
+ if (r < 0)
+ return -errno;
+ }
if (s->link) {
- uint32_t ifindex = htobe32(s->link->ifindex);
+ be32_t ifindex_be = htobe32(ifindex);
if (sa.sa.sa_family == AF_INET) {
- r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex, sizeof(ifindex));
+ r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex_be, sizeof(ifindex_be));
if (r < 0)
return -errno;
} else if (sa.sa.sa_family == AF_INET6) {
- r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex, sizeof(ifindex));
+ r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex_be, sizeof(ifindex_be));
if (r < 0)
return -errno;
}
@@ -289,100 +391,163 @@ int dns_scope_tcp_socket(DnsScope *s, int family, const union in_addr_union *add
if (r < 0 && errno != EINPROGRESS)
return -errno;
- if (server)
- *server = srv;
-
ret = fd;
fd = -1;
return ret;
}
+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_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) {
- char **i;
+ DnsSearchDomain *d;
+ DnsServer *dns_server;
assert(s);
assert(domain);
+ /* Checks if the specified domain is something to look up on
+ * this scope. Note that this accepts non-qualified hostnames,
+ * i.e. those without any search path prefixed yet. */
+
if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex))
return DNS_SCOPE_NO;
- if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family) & flags) == 0)
+ if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, 0) & flags) == 0)
return DNS_SCOPE_NO;
- STRV_FOREACH(i, s->domains)
- if (dns_name_endswith(domain, *i) > 0)
- return DNS_SCOPE_YES;
+ /* Never resolve any loopback hostname or IP address via DNS,
+ * LLMNR or mDNS. Instead, always rely on synthesized RRs for
+ * these. */
+ if (is_localhost(domain) ||
+ dns_name_endswith(domain, "127.in-addr.arpa") > 0 ||
+ dns_name_equal(domain, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0)
+ return DNS_SCOPE_NO;
- if (dns_name_root(domain) != 0)
+ /* Never respond to some of the domains listed in RFC6303 */
+ if (dns_name_endswith(domain, "0.in-addr.arpa") > 0 ||
+ dns_name_equal(domain, "255.255.255.255.in-addr.arpa") > 0 ||
+ 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;
- if (is_localhost(domain))
+ /* Never respond to some of the domains listed in RFC6761 */
+ if (dns_name_endswith(domain, "invalid") > 0)
return DNS_SCOPE_NO;
- if (s->protocol == DNS_PROTOCOL_DNS) {
+ /* 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
+ * considered anymore. */
+ LIST_FOREACH(domains, d, dns_scope_get_search_domains(s))
+ if (dns_name_endswith(domain, d->name) > 0)
+ return DNS_SCOPE_YES;
+
+ /* If the DNS server has route-only domains, don't send other requests
+ * to it. This would be a privacy violation, will most probably fail
+ * anyway, and adds unnecessary load. */
+ dns_server = dns_scope_get_dns_server(s);
+ if (dns_server && dns_server_limited_domains(dns_server))
+ return DNS_SCOPE_NO;
+
+ switch (s->protocol) {
+
+ case DNS_PROTOCOL_DNS:
+
+ /* Exclude link-local IP ranges */
if (dns_name_endswith(domain, "254.169.in-addr.arpa") == 0 &&
- dns_name_endswith(domain, "0.8.e.f.ip6.arpa") == 0 &&
- dns_name_single_label(domain) == 0)
+ 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 &&
+ /* 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_MDNS) {
- if (dns_name_endswith(domain, "254.169.in-addr.arpa") > 0 ||
- dns_name_endswith(domain, "0.8.e.f.ip6.arpa") > 0 ||
- (dns_name_endswith(domain, "local") > 0 && dns_name_equal(domain, "local") == 0))
+ case DNS_PROTOCOL_MDNS:
+ if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) ||
+ (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) ||
+ (dns_name_endswith(domain, "local") > 0 && /* only resolve names ending in .local via mDNS */
+ dns_name_equal(domain, "local") == 0 && /* but not the single-label "local" name itself */
+ manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via mDNS */
return DNS_SCOPE_MAYBE;
return DNS_SCOPE_NO;
- }
- if (s->protocol == DNS_PROTOCOL_LLMNR) {
- if (dns_name_endswith(domain, "in-addr.arpa") > 0 ||
- dns_name_endswith(domain, "ip6.arpa") > 0 ||
- (dns_name_single_label(domain) > 0 &&
- dns_name_equal(domain, "gateway") <= 0)) /* don't resolve "gateway" with LLMNR, let nss-myhostname handle this */
+ case DNS_PROTOCOL_LLMNR:
+ if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) ||
+ (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) ||
+ (dns_name_is_single_label(domain) && /* only resolve single label names via LLMNR */
+ !is_gateway_hostname(domain) && /* don't resolve "gateway" with LLMNR, let nss-myhostname handle this */
+ manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via LLMNR */
return DNS_SCOPE_MAYBE;
return DNS_SCOPE_NO;
- }
- assert_not_reached("Unknown scope protocol");
+ default:
+ assert_not_reached("Unknown scope protocol");
+ }
}
-int dns_scope_good_key(DnsScope *s, DnsResourceKey *key) {
+bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key) {
+ int key_family;
+
assert(s);
assert(key);
- if (s->protocol == DNS_PROTOCOL_DNS)
- return true;
+ /* Check if it makes sense to resolve the specified key on
+ * this scope. Note that this call assumes as fully qualified
+ * name, i.e. the search suffixes already appended. */
+
+ if (key->class != DNS_CLASS_IN)
+ return false;
+
+ if (s->protocol == DNS_PROTOCOL_DNS) {
+
+ /* 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.) */
+ if (!dns_resource_key_is_address(key))
+ return true;
+
+ /* However, we refuse to look up A and AAAA RRs on the
+ * root and single-label domains, under the assumption
+ * that those should be resolved via LLMNR or search
+ * path only, and should not be leaked onto the
+ * internet. */
+ return !(dns_name_is_single_label(dns_resource_key_name(key)) ||
+ dns_name_is_root(dns_resource_key_name(key)));
+ }
/* On mDNS and LLMNR, send A and AAAA queries only on the
* respective scopes */
- if (s->family == AF_INET && key->class == DNS_CLASS_IN && key->type == DNS_TYPE_AAAA)
- return false;
-
- if (s->family == AF_INET6 && key->class == DNS_CLASS_IN && key->type == DNS_TYPE_A)
- return false;
+ key_family = dns_type_to_af(key->type);
+ if (key_family < 0)
+ return true;
- return true;
+ return key_family == s->family;
}
-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,
};
@@ -401,7 +566,7 @@ int dns_scope_llmnr_membership(DnsScope *s, bool b) {
} else if (s->family == AF_INET6) {
struct ipv6_mreq mreq = {
- .ipv6mr_multiaddr = LLMNR_MULTICAST_IPV6_ADDRESS,
+ .ipv6mr_multiaddr = in6,
.ipv6mr_interface = s->link->ifindex,
};
@@ -420,17 +585,22 @@ int dns_scope_llmnr_membership(DnsScope *s, bool b) {
return 0;
}
-int dns_scope_good_dns_server(DnsScope *s, int family, const union in_addr_union *address) {
+int dns_scope_llmnr_membership(DnsScope *s, bool b) {
assert(s);
- assert(address);
- if (s->protocol != DNS_PROTOCOL_DNS)
- return 1;
+ if (s->protocol != DNS_PROTOCOL_LLMNR)
+ return 0;
- if (s->link)
- return !!link_find_dns_server(s->link, family, address);
- else
- return !!manager_find_dns_server(s->manager, family, address);
+ return dns_scope_multicast_membership(s, b, LLMNR_MULTICAST_IPV4_ADDRESS, LLMNR_MULTICAST_IPV6_ADDRESS);
+}
+
+int dns_scope_mdns_membership(DnsScope *s, bool b) {
+ assert(s);
+
+ 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(
@@ -444,15 +614,14 @@ static int dns_scope_make_reply_packet(
DnsPacket **ret) {
_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
- unsigned i;
int r;
assert(s);
assert(ret);
- if ((!q || q->n_keys <= 0)
- && (!answer || answer->n_rrs <= 0)
- && (!soa || soa->n_rrs <= 0))
+ if (dns_question_isempty(q) &&
+ dns_answer_isempty(answer) &&
+ dns_answer_isempty(soa))
return -EINVAL;
r = dns_packet_new(&p, s->protocol, 0);
@@ -471,35 +640,20 @@ static int dns_scope_make_reply_packet(
0 /* (cd) */,
rcode));
- if (q) {
- for (i = 0; i < q->n_keys; i++) {
- r = dns_packet_append_key(p, q->keys[i], NULL);
- if (r < 0)
- return r;
- }
-
- DNS_PACKET_HEADER(p)->qdcount = htobe16(q->n_keys);
- }
-
- if (answer) {
- for (i = 0; i < answer->n_rrs; i++) {
- r = dns_packet_append_rr(p, answer->rrs[i], NULL);
- if (r < 0)
- return r;
- }
-
- DNS_PACKET_HEADER(p)->ancount = htobe16(answer->n_rrs);
- }
+ r = dns_packet_append_question(p, q);
+ if (r < 0)
+ return r;
+ DNS_PACKET_HEADER(p)->qdcount = htobe16(dns_question_size(q));
- if (soa) {
- for (i = 0; i < soa->n_rrs; i++) {
- r = dns_packet_append_rr(p, soa->rrs[i], NULL);
- if (r < 0)
- return r;
- }
+ r = dns_packet_append_answer(p, answer);
+ if (r < 0)
+ return r;
+ DNS_PACKET_HEADER(p)->ancount = htobe16(dns_answer_size(answer));
- DNS_PACKET_HEADER(p)->arcount = htobe16(soa->n_rrs);
- }
+ r = dns_packet_append_answer(p, soa);
+ if (r < 0)
+ return r;
+ DNS_PACKET_HEADER(p)->arcount = htobe16(dns_answer_size(soa));
*ret = p;
p = NULL;
@@ -508,24 +662,25 @@ static int dns_scope_make_reply_packet(
}
static void dns_scope_verify_conflicts(DnsScope *s, DnsPacket *p) {
- unsigned n;
+ DnsResourceRecord *rr;
+ DnsResourceKey *key;
assert(s);
assert(p);
- if (p->question)
- for (n = 0; n < p->question->n_keys; n++)
- dns_zone_verify_conflicts(&s->zone, p->question->keys[n]);
- if (p->answer)
- for (n = 0; n < p->answer->n_rrs; n++)
- dns_zone_verify_conflicts(&s->zone, p->answer->rrs[n]->key);
+ DNS_QUESTION_FOREACH(key, p->question)
+ dns_zone_verify_conflicts(&s->zone, key);
+
+ DNS_ANSWER_FOREACH(rr, p->answer)
+ dns_zone_verify_conflicts(&s->zone, rr->key);
}
void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) {
- _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL;
_cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL;
+ _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL;
+ DnsResourceKey *key = NULL;
bool tentative = false;
- int r, fd;
+ int r;
assert(s);
assert(p);
@@ -547,7 +702,7 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) {
r = dns_packet_extract(p);
if (r < 0) {
- log_debug_errno(r, "Failed to extract resources from incoming packet: %m");
+ log_debug_errno(r, "Failed to extract resource records from incoming packet: %m");
return;
}
@@ -557,7 +712,10 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) {
return;
}
- r = dns_zone_lookup(&s->zone, p->question, &answer, &soa, &tentative);
+ assert(dns_question_size(p->question) == 1);
+ key = p->question->keys[0];
+
+ r = dns_zone_lookup(&s->zone, key, 0, &answer, &soa, &tentative);
if (r < 0) {
log_debug_errno(r, "Failed to lookup key: %m");
return;
@@ -574,9 +732,21 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) {
return;
}
- if (stream)
+ if (stream) {
r = dns_stream_write_packet(stream, reply);
- else {
+ if (r < 0) {
+ log_debug_errno(r, "Failed to enqueue reply packet: %m");
+ return;
+ }
+
+ /* Let's take an extra reference on this stream, so that it stays around after returning. The reference
+ * will be dangling until the stream is disconnected, and the default completion handler of the stream
+ * will then unref the stream and destroy it */
+ if (DNS_STREAM_QUEUED(stream))
+ dns_stream_ref(stream);
+ } else {
+ int fd;
+
if (!ratelimit_test(&s->ratelimit))
return;
@@ -598,39 +768,34 @@ void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) {
* verified uniqueness for all records. Also see RFC
* 4795, Section 2.7 */
- r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, reply);
- }
-
- if (r < 0) {
- log_debug_errno(r, "Failed to send reply packet: %m");
- return;
+ r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, NULL, reply);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to send reply packet: %m");
+ return;
+ }
}
}
-DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsQuestion *question, bool cache_ok) {
+DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key, bool cache_ok) {
DnsTransaction *t;
assert(scope);
- assert(question);
-
- /* Try to find an ongoing transaction that is a equal or a
- * superset of the specified question */
-
- LIST_FOREACH(transactions_by_scope, t, scope->transactions) {
+ assert(key);
- /* 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) &&
- !t->received)
- continue;
+ /* Try to find an ongoing transaction that is a equal to the
+ * specified question */
+ t = hashmap_get(scope->transactions_by_key, key);
+ if (!t)
+ return NULL;
- if (dns_question_is_superset(t->question, question) > 0)
- return t;
- }
+ /* 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_RCODE_FAILURE) &&
+ t->answer_source != DNS_TRANSACTION_NETWORK)
+ return NULL;
- return NULL;
+ return t;
}
static int dns_scope_make_conflict_packet(
@@ -659,7 +824,11 @@ static int dns_scope_make_conflict_packet(
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);
@@ -667,7 +836,7 @@ static int dns_scope_make_conflict_packet(
if (r < 0)
return r;
- r = dns_packet_append_rr(p, rr, NULL);
+ r = dns_packet_append_rr(p, rr, NULL, NULL);
if (r < 0)
return r;
@@ -700,7 +869,7 @@ static int on_conflict_dispatch(sd_event_source *es, usec_t usec, void *userdata
return 0;
}
- r = dns_scope_emit(scope, NULL, p, NULL);
+ r = dns_scope_emit_udp(scope, -1, p);
if (r < 0)
log_debug_errno(r, "Failed to send conflict packet: %m");
}
@@ -749,6 +918,8 @@ int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr) {
if (r < 0)
return log_debug_errno(r, "Failed to add conflict dispatch event: %m");
+ (void) sd_event_source_set_description(scope->conflict_event_source, "scope-conflict");
+
return 0;
}
@@ -786,16 +957,89 @@ void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p) {
/* Check for conflicts against the local zone. If we
* found one, we won't check any further */
- r = dns_zone_check_conflicts(&scope->zone, p->answer->rrs[i]);
+ r = dns_zone_check_conflicts(&scope->zone, p->answer->items[i].rr);
if (r != 0)
continue;
/* Check for conflicts against the local cache. If so,
* send out an advisory query, to inform everybody */
- r = dns_cache_check_conflicts(&scope->cache, p->answer->rrs[i], p->family, &p->sender);
+ r = dns_cache_check_conflicts(&scope->cache, p->answer->items[i].rr, p->family, &p->sender);
if (r <= 0)
continue;
- dns_scope_notify_conflict(scope, p->answer->rrs[i]);
+ dns_scope_notify_conflict(scope, p->answer->items[i].rr);
+ }
+}
+
+void dns_scope_dump(DnsScope *s, FILE *f) {
+ assert(s);
+
+ if (!f)
+ f = stdout;
+
+ fputs("[Scope protocol=", f);
+ fputs(dns_protocol_to_string(s->protocol), f);
+
+ if (s->link) {
+ fputs(" interface=", f);
+ fputs(s->link->name, f);
+ }
+
+ if (s->family != AF_UNSPEC) {
+ fputs(" family=", f);
+ fputs(af_to_name(s->family), f);
+ }
+
+ fputs("]\n", f);
+
+ if (!dns_zone_is_empty(&s->zone)) {
+ fputs("ZONE:\n", f);
+ dns_zone_dump(&s->zone, f);
}
+
+ if (!dns_cache_is_empty(&s->cache)) {
+ fputs("CACHE:\n", f);
+ dns_cache_dump(&s->cache, f);
+ }
+}
+
+DnsSearchDomain *dns_scope_get_search_domains(DnsScope *s) {
+ assert(s);
+
+ if (s->protocol != DNS_PROTOCOL_DNS)
+ return NULL;
+
+ if (s->link)
+ return s->link->search_domains;
+
+ return s->manager->search_domains;
+}
+
+bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name) {
+ assert(s);
+
+ if (s->protocol != DNS_PROTOCOL_DNS)
+ return false;
+
+ return dns_name_is_single_label(name);
+}
+
+bool dns_scope_network_good(DnsScope *s) {
+ /* Checks whether the network is in good state for lookups on this scope. For mDNS/LLMNR/Classic DNS scopes
+ * bound to links this is easy, as they don't even exist if the link isn't in a suitable state. For the global
+ * DNS scope we check whether there are any links that are up and have an address. */
+
+ if (s->link)
+ return true;
+
+ return manager_routable(s->manager, AF_UNSPEC);
+}
+
+int dns_scope_ifindex(DnsScope *s) {
+ assert(s);
+
+ if (s->link)
+ return s->link->ifindex;
+
+ return 0;
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-23 00:23:00 +0000