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-rw-r--r--src/resolve/resolved-dns-scope.c1028
1 files changed, 0 insertions, 1028 deletions
diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
deleted file mode 100644
index 66e4585c18..0000000000
--- a/src/resolve/resolved-dns-scope.c
+++ /dev/null
@@ -1,1028 +0,0 @@
-/***
- 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 <netinet/tcp.h>
-
-#include "af-list.h"
-#include "alloc-util.h"
-#include "dns-domain.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;
-
- assert(m);
- assert(ret);
-
- s = new0(DnsScope, 1);
- if (!s)
- return -ENOMEM;
-
- s->manager = m;
- 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));
-
- /* Enforce ratelimiting for the multicast protocols */
- RATELIMIT_INIT(s->ratelimit, MULTICAST_RATELIMIT_INTERVAL_USEC, MULTICAST_RATELIMIT_BURST);
-
- *ret = s;
- 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) {
- DnsResourceRecord *rr;
-
- if (!s)
- return NULL;
-
- 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)
- dns_query_candidate_free(s->query_candidates);
-
- hashmap_free(s->transactions_by_key);
-
- while ((rr = ordered_hashmap_steal_first(s->conflict_queue)))
- dns_resource_record_unref(rr);
-
- ordered_hashmap_free(s->conflict_queue);
- sd_event_source_unref(s->conflict_event_source);
-
- dns_cache_flush(&s->cache);
- dns_zone_flush(&s->zone);
-
- LIST_REMOVE(scopes, s->manager->dns_scopes, s);
- free(s);
-
- return NULL;
-}
-
-DnsServer *dns_scope_get_dns_server(DnsScope *s) {
- assert(s);
-
- if (s->protocol != DNS_PROTOCOL_DNS)
- return NULL;
-
- if (s->link)
- return link_get_dns_server(s->link);
- else
- return manager_get_dns_server(s->manager);
-}
-
-void dns_scope_next_dns_server(DnsScope *s) {
- assert(s);
-
- if (s->protocol != DNS_PROTOCOL_DNS)
- return;
-
- if (s->link)
- link_next_dns_server(s->link);
- else
- manager_next_dns_server(s->manager);
-}
-
-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;
- uint32_t mtu;
-
- assert(s);
- assert(p);
- assert(p->protocol == s->protocol);
-
- if (s->link) {
- mtu = s->link->mtu;
- ifindex = s->link->ifindex;
- } else
- mtu = manager_find_mtu(s->manager);
-
- switch (s->protocol) {
-
- case DNS_PROTOCOL_DNS:
- assert(fd >= 0);
-
- if (DNS_PACKET_QDCOUNT(p) > 1)
- return -EOPNOTSUPP;
-
- if (p->size > DNS_PACKET_UNICAST_SIZE_MAX)
- return -EMSGSIZE;
-
- if (p->size + UDP_PACKET_HEADER_SIZE > mtu)
- return -EMSGSIZE;
-
- r = manager_write(s->manager, fd, p);
- if (r < 0)
- return r;
-
- break;
-
- case DNS_PROTOCOL_LLMNR:
- assert(fd < 0);
-
- if (DNS_PACKET_QDCOUNT(p) > 1)
- return -EOPNOTSUPP;
-
- if (!ratelimit_test(&s->ratelimit))
- return -EBUSY;
-
- family = s->family;
-
- if (family == AF_INET) {
- addr.in = LLMNR_MULTICAST_IPV4_ADDRESS;
- fd = manager_llmnr_ipv4_udp_fd(s->manager);
- } else if (family == AF_INET6) {
- addr.in6 = LLMNR_MULTICAST_IPV6_ADDRESS;
- fd = manager_llmnr_ipv6_udp_fd(s->manager);
- } else
- return -EAFNOSUPPORT;
- if (fd < 0)
- return fd;
-
- 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;
-
- break;
-
- default:
- return -EAFNOSUPPORT;
- }
-
- return 1;
-}
-
-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;
-
- assert(s);
-
- if (server) {
- assert(family == AF_UNSPEC);
- assert(!address);
-
- sa.sa.sa_family = server->family;
- if (server->family == AF_INET) {
- sa.in.sin_port = htobe16(port);
- sa.in.sin_addr = server->address.in;
- salen = sizeof(sa.in);
- } else if (server->family == AF_INET6) {
- sa.in6.sin6_port = htobe16(port);
- 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) {
- sa.in.sin_port = htobe16(port);
- sa.in.sin_addr = address->in;
- salen = sizeof(sa.in);
- } 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;
- salen = sizeof(sa.in6);
- } else
- return -EAFNOSUPPORT;
- }
-
- fd = socket(sa.sa.sa_family, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
- if (fd < 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);
-
- if (sa.sa.sa_family == AF_INET) {
- r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex, sizeof(ifindex));
- if (r < 0)
- return -errno;
- } else if (sa.sa.sa_family == AF_INET6) {
- r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex, sizeof(ifindex));
- if (r < 0)
- return -errno;
- }
- }
-
- if (s->protocol == DNS_PROTOCOL_LLMNR) {
- /* RFC 4795, section 2.5 requires the TTL to be set to 1 */
-
- if (sa.sa.sa_family == AF_INET) {
- r = setsockopt(fd, IPPROTO_IP, IP_TTL, &one, sizeof(one));
- if (r < 0)
- return -errno;
- } else if (sa.sa.sa_family == AF_INET6) {
- r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one));
- if (r < 0)
- return -errno;
- }
- }
-
- r = connect(fd, &sa.sa, salen);
- if (r < 0 && errno != EINPROGRESS)
- return -errno;
-
- 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) {
- DnsSearchDomain *d;
-
- 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, 0) & flags) == 0)
- return DNS_SCOPE_NO;
-
- /* 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;
-
- /* 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;
-
- /* 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
- * considered anymore. */
- LIST_FOREACH(domains, d, dns_scope_get_search_domains(s))
- if (dns_name_endswith(domain, d->name) > 0)
- return DNS_SCOPE_YES;
-
- 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, "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;
-
- 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;
-
- 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;
-
- default:
- assert_not_reached("Unknown scope protocol");
- }
-}
-
-bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key) {
- int key_family;
-
- assert(s);
- assert(key);
-
- /* 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 */
-
- key_family = dns_type_to_af(key->type);
- if (key_family < 0)
- return true;
-
- return key_family == s->family;
-}
-
-static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) {
- int fd;
-
- assert(s);
- assert(s->link);
-
- if (s->family == AF_INET) {
- struct ip_mreqn mreqn = {
- .imr_multiaddr = in,
- .imr_ifindex = s->link->ifindex,
- };
-
- fd = manager_llmnr_ipv4_udp_fd(s->manager);
- if (fd < 0)
- return fd;
-
- /* Always first try to drop membership before we add
- * one. This is necessary on some devices, such as
- * veth. */
- if (b)
- (void) setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn));
-
- if (setsockopt(fd, IPPROTO_IP, b ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)) < 0)
- return -errno;
-
- } else if (s->family == AF_INET6) {
- struct ipv6_mreq mreq = {
- .ipv6mr_multiaddr = in6,
- .ipv6mr_interface = s->link->ifindex,
- };
-
- fd = manager_llmnr_ipv6_udp_fd(s->manager);
- if (fd < 0)
- return fd;
-
- if (b)
- (void) setsockopt(fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
-
- if (setsockopt(fd, IPPROTO_IPV6, b ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
- return -errno;
- } else
- return -EAFNOSUPPORT;
-
- 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,
- int rcode,
- DnsQuestion *q,
- DnsAnswer *answer,
- DnsAnswer *soa,
- bool tentative,
- 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))
- return -EINVAL;
-
- r = dns_packet_new(&p, s->protocol, 0);
- if (r < 0)
- return r;
-
- DNS_PACKET_HEADER(p)->id = id;
- DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS(
- 1 /* qr */,
- 0 /* opcode */,
- 0 /* c */,
- 0 /* tc */,
- tentative,
- 0 /* (ra) */,
- 0 /* (ad) */,
- 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->items[i].rr, NULL, NULL);
- if (r < 0)
- return r;
- }
-
- DNS_PACKET_HEADER(p)->ancount = htobe16(answer->n_rrs);
- }
-
- if (soa) {
- for (i = 0; i < soa->n_rrs; i++) {
- r = dns_packet_append_rr(p, soa->items[i].rr, NULL, NULL);
- if (r < 0)
- return r;
- }
-
- DNS_PACKET_HEADER(p)->arcount = htobe16(soa->n_rrs);
- }
-
- *ret = p;
- p = NULL;
-
- return 0;
-}
-
-static void dns_scope_verify_conflicts(DnsScope *s, DnsPacket *p) {
- unsigned n;
-
- 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->items[n].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;
- DnsResourceKey *key = NULL;
- bool tentative = false;
- int r, fd;
-
- assert(s);
- assert(p);
-
- if (p->protocol != DNS_PROTOCOL_LLMNR)
- return;
-
- if (p->ipproto == IPPROTO_UDP) {
- /* Don't accept UDP queries directed to anything but
- * the LLMNR multicast addresses. See RFC 4795,
- * section 2.5. */
-
- if (p->family == AF_INET && !in_addr_equal(AF_INET, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV4_ADDRESS))
- return;
-
- if (p->family == AF_INET6 && !in_addr_equal(AF_INET6, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV6_ADDRESS))
- return;
- }
-
- r = dns_packet_extract(p);
- if (r < 0) {
- log_debug_errno(r, "Failed to extract resources from incoming packet: %m");
- return;
- }
-
- if (DNS_PACKET_LLMNR_C(p)) {
- /* Somebody notified us about a possible conflict */
- dns_scope_verify_conflicts(s, p);
- return;
- }
-
- assert(p->question->n_keys == 1);
- key = p->question->keys[0];
-
- r = dns_zone_lookup(&s->zone, key, &answer, &soa, &tentative);
- if (r < 0) {
- log_debug_errno(r, "Failed to lookup key: %m");
- return;
- }
- if (r == 0)
- return;
-
- if (answer)
- dns_answer_order_by_scope(answer, in_addr_is_link_local(p->family, &p->sender) > 0);
-
- r = dns_scope_make_reply_packet(s, DNS_PACKET_ID(p), DNS_RCODE_SUCCESS, p->question, answer, soa, tentative, &reply);
- if (r < 0) {
- log_debug_errno(r, "Failed to build reply packet: %m");
- return;
- }
-
- if (stream)
- r = dns_stream_write_packet(stream, reply);
- else {
- if (!ratelimit_test(&s->ratelimit))
- return;
-
- if (p->family == AF_INET)
- fd = manager_llmnr_ipv4_udp_fd(s->manager);
- else if (p->family == AF_INET6)
- fd = manager_llmnr_ipv6_udp_fd(s->manager);
- else {
- log_debug("Unknown protocol");
- return;
- }
- if (fd < 0) {
- log_debug_errno(fd, "Failed to get reply socket: %m");
- return;
- }
-
- /* Note that we always immediately reply to all LLMNR
- * requests, and do not wait any time, since we
- * 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;
- }
-}
-
-DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key, bool cache_ok) {
- DnsTransaction *t;
-
- assert(scope);
- assert(key);
-
- /* 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;
-
- /* 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 t;
-}
-
-static int dns_scope_make_conflict_packet(
- DnsScope *s,
- DnsResourceRecord *rr,
- DnsPacket **ret) {
-
- _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
- int r;
-
- assert(s);
- assert(rr);
- assert(ret);
-
- r = dns_packet_new(&p, s->protocol, 0);
- if (r < 0)
- return r;
-
- DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS(
- 0 /* qr */,
- 0 /* opcode */,
- 1 /* conflict */,
- 0 /* tc */,
- 0 /* t */,
- 0 /* (ra) */,
- 0 /* (ad) */,
- 0 /* (cd) */,
- 0));
-
- /* 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);
-
- r = dns_packet_append_key(p, rr->key, NULL);
- if (r < 0)
- return r;
-
- r = dns_packet_append_rr(p, rr, NULL, NULL);
- if (r < 0)
- return r;
-
- *ret = p;
- p = NULL;
-
- return 0;
-}
-
-static int on_conflict_dispatch(sd_event_source *es, usec_t usec, void *userdata) {
- DnsScope *scope = userdata;
- int r;
-
- assert(es);
- assert(scope);
-
- scope->conflict_event_source = sd_event_source_unref(scope->conflict_event_source);
-
- for (;;) {
- _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
- _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
-
- rr = ordered_hashmap_steal_first(scope->conflict_queue);
- if (!rr)
- break;
-
- r = dns_scope_make_conflict_packet(scope, rr, &p);
- if (r < 0) {
- log_error_errno(r, "Failed to make conflict packet: %m");
- return 0;
- }
-
- r = dns_scope_emit_udp(scope, -1, p);
- if (r < 0)
- log_debug_errno(r, "Failed to send conflict packet: %m");
- }
-
- return 0;
-}
-
-int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr) {
- usec_t jitter;
- int r;
-
- assert(scope);
- assert(rr);
-
- /* We don't send these queries immediately. Instead, we queue
- * them, and send them after some jitter delay. */
- r = ordered_hashmap_ensure_allocated(&scope->conflict_queue, &dns_resource_key_hash_ops);
- if (r < 0) {
- log_oom();
- return r;
- }
-
- /* We only place one RR per key in the conflict
- * messages, not all of them. That should be enough to
- * indicate where there might be a conflict */
- r = ordered_hashmap_put(scope->conflict_queue, rr->key, rr);
- if (r == -EEXIST || r == 0)
- return 0;
- if (r < 0)
- return log_debug_errno(r, "Failed to queue conflicting RR: %m");
-
- dns_resource_record_ref(rr);
-
- if (scope->conflict_event_source)
- return 0;
-
- random_bytes(&jitter, sizeof(jitter));
- jitter %= LLMNR_JITTER_INTERVAL_USEC;
-
- r = sd_event_add_time(scope->manager->event,
- &scope->conflict_event_source,
- clock_boottime_or_monotonic(),
- now(clock_boottime_or_monotonic()) + jitter,
- LLMNR_JITTER_INTERVAL_USEC,
- on_conflict_dispatch, scope);
- 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;
-}
-
-void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p) {
- unsigned i;
- int r;
-
- assert(scope);
- assert(p);
-
- if (p->protocol != DNS_PROTOCOL_LLMNR)
- return;
-
- if (DNS_PACKET_RRCOUNT(p) <= 0)
- return;
-
- if (DNS_PACKET_LLMNR_C(p) != 0)
- return;
-
- if (DNS_PACKET_LLMNR_T(p) != 0)
- return;
-
- if (manager_our_packet(scope->manager, p))
- return;
-
- r = dns_packet_extract(p);
- if (r < 0) {
- log_debug_errno(r, "Failed to extract packet: %m");
- return;
- }
-
- log_debug("Checking for conflicts...");
-
- for (i = 0; i < p->answer->n_rrs; i++) {
-
- /* 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->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->items[i].rr, p->family, &p->sender);
- if (r <= 0)
- continue;
-
- 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);
-}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-06 20:21:54 +0000