along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
+#include "hostname-util.h"
+#include "dns-domain.h"
+#include "local-addresses.h"
+
#include "resolved-dns-query.h"
-#include "resolved-dns-domain.h"
-#define TRANSACTION_TIMEOUT_USEC (5 * USEC_PER_SEC)
+/* How long to wait for the query in total */
#define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC)
-#define ATTEMPTS_MAX 8
+
#define CNAME_MAX 8
+#define QUERIES_MAX 2048
+
+static void dns_query_stop(DnsQuery *q) {
+ DnsTransaction *t;
-static int dns_query_transaction_start(DnsQueryTransaction *t);
+ assert(q);
-DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t) {
- if (!t)
+ q->timeout_event_source = sd_event_source_unref(q->timeout_event_source);
+
+ while ((t = set_steal_first(q->transactions))) {
+ set_remove(t->queries, q);
+ dns_transaction_gc(t);
+ }
+}
+
+DnsQuery *dns_query_free(DnsQuery *q) {
+ if (!q)
return NULL;
- sd_event_source_unref(t->timeout_event_source);
+ dns_query_stop(q);
+ set_free(q->transactions);
- dns_packet_unref(t->sent);
- dns_packet_unref(t->received);
+ dns_question_unref(q->question);
+ dns_answer_unref(q->answer);
- sd_event_source_unref(t->tcp_event_source);
- safe_close(t->tcp_fd);
+ sd_bus_message_unref(q->request);
+ sd_bus_track_unref(q->bus_track);
- if (t->query) {
- LIST_REMOVE(transactions_by_query, t->query->transactions, t);
- hashmap_remove(t->query->manager->dns_query_transactions, UINT_TO_PTR(t->id));
+ if (q->manager) {
+ LIST_REMOVE(queries, q->manager->dns_queries, q);
+ q->manager->n_dns_queries--;
}
- if (t->scope)
- LIST_REMOVE(transactions_by_scope, t->scope->transactions, t);
+ free(q);
- free(t);
return NULL;
}
-DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQueryTransaction*, dns_query_transaction_free);
-
-static int dns_query_transaction_new(DnsQuery *q, DnsQueryTransaction **ret, DnsScope *s) {
- _cleanup_(dns_query_transaction_freep) DnsQueryTransaction *t = NULL;
+int dns_query_new(Manager *m, DnsQuery **ret, DnsQuestion *question, int ifindex, uint64_t flags) {
+ _cleanup_(dns_query_freep) DnsQuery *q = NULL;
+ unsigned i;
int r;
- assert(q);
- assert(s);
+ assert(m);
+ assert(question);
- r = hashmap_ensure_allocated(&q->manager->dns_query_transactions, NULL, NULL);
+ r = dns_question_is_valid(question);
if (r < 0)
return r;
- t = new0(DnsQueryTransaction, 1);
- if (!t)
+ if (m->n_dns_queries >= QUERIES_MAX)
+ return -EBUSY;
+
+ q = new0(DnsQuery, 1);
+ if (!q)
return -ENOMEM;
- t->tcp_fd = -1;
+ q->question = dns_question_ref(question);
+ q->ifindex = ifindex;
+ q->flags = flags;
- do
- random_bytes(&t->id, sizeof(t->id));
- while (t->id == 0 ||
- hashmap_get(q->manager->dns_query_transactions, UINT_TO_PTR(t->id)));
+ for (i = 0; i < question->n_keys; i++) {
+ _cleanup_free_ char *p;
- r = hashmap_put(q->manager->dns_query_transactions, UINT_TO_PTR(t->id), t);
- if (r < 0) {
- t->id = 0;
- return r;
- }
+ r = dns_resource_key_to_string(question->keys[i], &p);
+ if (r < 0)
+ return r;
- LIST_PREPEND(transactions_by_query, q->transactions, t);
- t->query = q;
+ log_debug("Looking up RR for %s", p);
+ }
- LIST_PREPEND(transactions_by_scope, s->transactions, t);
- t->scope = s;
+ LIST_PREPEND(queries, m->dns_queries, q);
+ m->n_dns_queries++;
+ q->manager = m;
if (ret)
- *ret = t;
-
- t = NULL;
+ *ret = q;
+ q = NULL;
return 0;
}
-static void dns_query_transaction_stop(DnsQueryTransaction *t) {
- assert(t);
+static void dns_query_complete(DnsQuery *q, DnsTransactionState state) {
+ assert(q);
+ assert(!IN_SET(state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING));
+ assert(IN_SET(q->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING));
- t->timeout_event_source = sd_event_source_unref(t->timeout_event_source);
- t->tcp_event_source = sd_event_source_unref(t->tcp_event_source);
- t->tcp_fd = safe_close(t->tcp_fd);
-}
+ /* Note that this call might invalidate the query. Callers
+ * should hence not attempt to access the query or transaction
+ * after calling this function. */
-static void dns_query_transaction_set_state(DnsQueryTransaction *t, DnsQueryState state) {
- assert(t);
+ q->state = state;
- if (t->state == state)
- return;
+ dns_query_stop(q);
+ if (q->complete)
+ q->complete(q);
+}
+
+static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
+ DnsQuery *q = userdata;
- t->state = state;
+ assert(s);
+ assert(q);
- if (state != DNS_QUERY_PENDING) {
- dns_query_transaction_stop(t);
- dns_query_finish(t->query);
- }
+ dns_query_complete(q, DNS_TRANSACTION_TIMEOUT);
+ return 0;
}
-static int on_tcp_ready(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
- DnsQueryTransaction *t = userdata;
+static int dns_query_add_transaction(DnsQuery *q, DnsScope *s, DnsResourceKey *key) {
+ DnsTransaction *t;
int r;
- assert(t);
+ assert(q);
+ assert(s);
+ assert(key);
- if (revents & EPOLLOUT) {
- struct iovec iov[2];
- be16_t sz;
- ssize_t ss;
+ r = set_ensure_allocated(&q->transactions, NULL);
+ if (r < 0)
+ return r;
- sz = htobe16(t->sent->size);
+ t = dns_scope_find_transaction(s, key, true);
+ if (!t) {
+ r = dns_transaction_new(&t, s, key);
+ if (r < 0)
+ return r;
+ }
- iov[0].iov_base = &sz;
- iov[0].iov_len = sizeof(sz);
- iov[1].iov_base = DNS_PACKET_DATA(t->sent);
- iov[1].iov_len = t->sent->size;
+ r = set_ensure_allocated(&t->queries, NULL);
+ if (r < 0)
+ goto gc;
- IOVEC_INCREMENT(iov, 2, t->tcp_written);
+ r = set_put(t->queries, q);
+ if (r < 0)
+ goto gc;
- ss = writev(fd, iov, 2);
- if (ss < 0) {
- if (errno != EINTR && errno != EAGAIN) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
- return -errno;
- }
- } else
- t->tcp_written += ss;
-
- /* Are we done? If so, disable the event source for EPOLLOUT */
- if (t->tcp_written >= sizeof(sz) + t->sent->size) {
- r = sd_event_source_set_io_events(s, EPOLLIN);
- if (r < 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
- return r;
- }
- }
+ r = set_put(q->transactions, t);
+ if (r < 0) {
+ set_remove(t->queries, q);
+ goto gc;
}
- if (revents & (EPOLLIN|EPOLLHUP|EPOLLRDHUP)) {
+ return 0;
- if (t->tcp_read < sizeof(t->tcp_read_size)) {
- ssize_t ss;
+gc:
+ dns_transaction_gc(t);
+ return r;
+}
- ss = read(fd, (uint8_t*) &t->tcp_read_size + t->tcp_read, sizeof(t->tcp_read_size) - t->tcp_read);
- if (ss < 0) {
- if (errno != EINTR && errno != EAGAIN) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
- return -errno;
- }
- } else if (ss == 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
- return -EIO;
- } else
- t->tcp_read += ss;
- }
+static int dns_query_add_transaction_split(DnsQuery *q, DnsScope *s) {
+ unsigned i;
+ int r;
- if (t->tcp_read >= sizeof(t->tcp_read_size)) {
+ assert(q);
+ assert(s);
- if (be16toh(t->tcp_read_size) < DNS_PACKET_HEADER_SIZE) {
- dns_query_transaction_set_state(t, DNS_QUERY_INVALID_REPLY);
- return -EBADMSG;
- }
+ /* Create one transaction per question key */
- if (t->tcp_read < sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size)) {
- ssize_t ss;
+ for (i = 0; i < q->question->n_keys; i++) {
+ r = dns_query_add_transaction(q, s, q->question->keys[i]);
+ if (r < 0)
+ return r;
+ }
- if (!t->received) {
- r = dns_packet_new(&t->received, be16toh(t->tcp_read_size));
- if (r < 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
- return r;
- }
- }
+ return 0;
+}
- ss = read(fd,
- (uint8_t*) DNS_PACKET_DATA(t->received) + t->tcp_read - sizeof(t->tcp_read_size),
- sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size) - t->tcp_read);
- if (ss < 0) {
- if (errno != EINTR && errno != EAGAIN) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
- return -errno;
- }
- } else if (ss == 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
- return -EIO;
- } else
- t->tcp_read += ss;
- }
+static int SYNTHESIZE_IFINDEX(int ifindex) {
- if (t->tcp_read >= sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size)) {
- t->received->size = be16toh(t->tcp_read_size);
- dns_query_transaction_reply(t, t->received);
- return 0;
- }
- }
+ /* When the caller asked for resolving on a specific
+ * interface, we synthesize the answer for that
+ * interface. However, if nothing specific was claimed and we
+ * only return localhost RRs, we synthesize the answer for
+ * localhost. */
+
+ if (ifindex > 0)
+ return ifindex;
+
+ return LOOPBACK_IFINDEX;
+}
+
+static int SYNTHESIZE_FAMILY(uint64_t flags) {
+
+ /* Picks an address family depending on set flags. This is
+ * purely for synthesized answers, where the family we return
+ * for the reply should match what was requested in the
+ * question, even though we are synthesizing the answer
+ * here. */
+
+ if (!(flags & SD_RESOLVED_DNS)) {
+ if (flags & SD_RESOLVED_LLMNR_IPV4)
+ return AF_INET;
+ if (flags & SD_RESOLVED_LLMNR_IPV6)
+ return AF_INET6;
}
- return 0;
+ return AF_UNSPEC;
}
-static int dns_query_transaction_start_tcp(DnsQueryTransaction *t) {
- int r;
+static DnsProtocol SYNTHESIZE_PROTOCOL(uint64_t flags) {
- assert(t);
+ /* Similar as SYNTHESIZE_FAMILY() but does this for the
+ * protocol. If resolving via DNS was requested, we claim it
+ * was DNS. Similar, if nothing specific was
+ * requested. However, if only resolving via LLMNR was
+ * requested we return that. */
- if (t->tcp_fd >= 0)
- return 0;
+ if (flags & SD_RESOLVED_DNS)
+ return DNS_PROTOCOL_DNS;
+ if (flags & SD_RESOLVED_LLMNR)
+ return DNS_PROTOCOL_LLMNR;
- t->tcp_written = 0;
- t->tcp_read = 0;
- t->received = dns_packet_unref(t->received);
+ return DNS_PROTOCOL_DNS;
+}
- t->tcp_fd = dns_scope_tcp_socket(t->scope);
- if (t->tcp_fd < 0)
- return t->tcp_fd;
+static int dns_type_to_af(uint16_t t) {
+ switch (t) {
- r = sd_event_add_io(t->query->manager->event, &t->tcp_event_source, t->tcp_fd, EPOLLIN|EPOLLOUT, on_tcp_ready, t);
- if (r < 0) {
- t->tcp_fd = safe_close(t->tcp_fd);
- return r;
- }
+ case DNS_TYPE_A:
+ return AF_INET;
- return 0;
+ case DNS_TYPE_AAAA:
+ return AF_INET6;
+
+ case DNS_TYPE_ANY:
+ return AF_UNSPEC;
+
+ default:
+ return -EINVAL;
+ }
}
-void dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p) {
+static int synthesize_localhost_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) {
int r;
- assert(t);
- assert(p);
+ assert(q);
+ assert(key);
+ assert(answer);
- if (t->state != DNS_QUERY_PENDING)
- return;
+ r = dns_answer_reserve(answer, 2);
+ if (r < 0)
+ return r;
- if (t->received != p) {
- dns_packet_unref(t->received);
- t->received = dns_packet_ref(p);
- }
+ if (IN_SET(key->type, DNS_TYPE_A, DNS_TYPE_ANY)) {
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
- if (t->tcp_fd >= 0) {
- if (DNS_PACKET_TC(p)) {
- /* Truncated via TCP? Somebody must be fucking with us */
- dns_query_transaction_set_state(t, DNS_QUERY_INVALID_REPLY);
- return;
- }
+ rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_A, DNS_RESOURCE_KEY_NAME(key));
+ if (!rr)
+ return -ENOMEM;
- if (DNS_PACKET_ID(p) != t->id) {
- /* Not the reply to our query? Somebody must be fucking with us */
- dns_query_transaction_set_state(t, DNS_QUERY_INVALID_REPLY);
- return;
- }
+ rr->a.in_addr.s_addr = htobe32(INADDR_LOOPBACK);
+
+ r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex));
+ if (r < 0)
+ return r;
}
- if (DNS_PACKET_TC(p)) {
- /* Response was truncated, let's try again with good old TCP */
- r = dns_query_transaction_start_tcp(t);
- if (r == -ESRCH) {
- /* No servers found? Damn! */
- dns_query_transaction_set_state(t, DNS_QUERY_NO_SERVERS);
- return;
- }
- if (r < 0) {
- /* Couldn't send? Try immediately again, with a new server */
- dns_scope_next_dns_server(t->scope);
+ if (IN_SET(key->type, DNS_TYPE_AAAA, DNS_TYPE_ANY)) {
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
- r = dns_query_transaction_start(t);
- if (r < 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
- return;
- }
+ rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_AAAA, DNS_RESOURCE_KEY_NAME(key));
+ if (!rr)
+ return -ENOMEM;
- return;
- }
+ rr->aaaa.in6_addr = in6addr_loopback;
+
+ r = dns_answer_add(*answer, rr, SYNTHESIZE_IFINDEX(q->ifindex));
+ if (r < 0)
+ return r;
}
- if (DNS_PACKET_RCODE(p) == DNS_RCODE_SUCCESS)
- dns_query_transaction_set_state(t, DNS_QUERY_SUCCESS);
- else
- dns_query_transaction_set_state(t, DNS_QUERY_FAILURE);
+ return 0;
}
-static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) {
- DnsQueryTransaction *t = userdata;
- int r;
+static int answer_add_ptr(DnsAnswer **answer, const char *from, const char *to, int ifindex) {
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
- assert(s);
- assert(t);
+ rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, from);
+ if (!rr)
+ return -ENOMEM;
+
+ rr->ptr.name = strdup(to);
+ if (!rr->ptr.name)
+ return -ENOMEM;
+
+ return dns_answer_add(*answer, rr, ifindex);
+}
- /* Timeout reached? Try again, with a new server */
- dns_scope_next_dns_server(t->scope);
+static int synthesize_localhost_ptr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) {
+ int r;
+
+ assert(q);
+ assert(key);
+ assert(answer);
- r = dns_query_transaction_start(t);
+ r = dns_answer_reserve(answer, 1);
if (r < 0)
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return r;
+
+ if (IN_SET(key->type, DNS_TYPE_PTR, DNS_TYPE_ANY)) {
+ r = answer_add_ptr(answer, DNS_RESOURCE_KEY_NAME(key), "localhost", SYNTHESIZE_IFINDEX(q->ifindex));
+ if (r < 0)
+ return r;
+ }
return 0;
}
-static int dns_query_make_packet(DnsQueryTransaction *t) {
- _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
- unsigned n;
- int r;
+static int answer_add_addresses_rr(
+ DnsAnswer **answer,
+ const char *name,
+ struct local_address *addresses,
+ unsigned n_addresses) {
- assert(t);
+ unsigned j;
+ int r;
- if (t->sent)
- return 0;
+ assert(answer);
+ assert(name);
- r = dns_packet_new_query(&p, 0);
+ r = dns_answer_reserve(answer, n_addresses);
if (r < 0)
return r;
- for (n = 0; n < t->query->n_keys; n++) {
- r = dns_packet_append_key(p, &t->query->keys[n], NULL);
+ for (j = 0; j < n_addresses; j++) {
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
+
+ r = dns_resource_record_new_address(&rr, addresses[j].family, &addresses[j].address, name);
if (r < 0)
return r;
- }
-
- DNS_PACKET_HEADER(p)->qdcount = htobe16(t->query->n_keys);
- DNS_PACKET_HEADER(p)->id = t->id;
- t->sent = p;
- p = NULL;
+ r = dns_answer_add(*answer, rr, addresses[j].ifindex);
+ if (r < 0)
+ return r;
+ }
return 0;
}
-static int dns_query_transaction_start(DnsQueryTransaction *t) {
+static int answer_add_addresses_ptr(
+ DnsAnswer **answer,
+ const char *name,
+ struct local_address *addresses,
+ unsigned n_addresses,
+ int af, const union in_addr_union *match) {
+
+ unsigned j;
int r;
- assert(t);
+ assert(answer);
+ assert(name);
- dns_query_transaction_stop(t);
+ for (j = 0; j < n_addresses; j++) {
+ _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
- if (t->n_attempts >= ATTEMPTS_MAX) {
- dns_query_transaction_set_state(t, DNS_QUERY_ATTEMPTS_MAX);
- return 0;
+ if (af != AF_UNSPEC) {
+
+ if (addresses[j].family != af)
+ continue;
+
+ if (match && !in_addr_equal(af, match, &addresses[j].address))
+ continue;
+ }
+
+ r = dns_answer_reserve(answer, 1);
+ if (r < 0)
+ return r;
+
+ r = dns_resource_record_new_reverse(&rr, addresses[j].family, &addresses[j].address, name);
+ if (r < 0)
+ return r;
+
+ r = dns_answer_add(*answer, rr, addresses[j].ifindex);
+ if (r < 0)
+ return r;
}
- r = dns_query_make_packet(t);
- if (r < 0)
- return r;
+ return 0;
+}
+
+static int synthesize_system_hostname_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) {
+ _cleanup_free_ struct local_address *addresses = NULL;
+ int n = 0, af;
+
+ assert(q);
+ assert(key);
+ assert(answer);
+
+ af = dns_type_to_af(key->type);
+ if (af >= 0) {
+ n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses);
+ if (n < 0)
+ return n;
+
+ if (n == 0) {
+ struct local_address buffer[2];
+
+ /* If we have no local addresses then use ::1
+ * and 127.0.0.2 as local ones. */
+
+ if (af == AF_INET || af == AF_UNSPEC)
+ buffer[n++] = (struct local_address) {
+ .family = AF_INET,
+ .ifindex = SYNTHESIZE_IFINDEX(q->ifindex),
+ .address.in.s_addr = htobe32(0x7F000002),
+ };
+
+ if (af == AF_INET6 || af == AF_UNSPEC)
+ buffer[n++] = (struct local_address) {
+ .family = AF_INET6,
+ .ifindex = SYNTHESIZE_IFINDEX(q->ifindex),
+ .address.in6 = in6addr_loopback,
+ };
+
+ return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), buffer, n);
+ }
+ }
+
+ return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n);
+}
- t->n_attempts++;
- t->received = dns_packet_unref(t->received);
+static int synthesize_system_hostname_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) {
+ _cleanup_free_ struct local_address *addresses = NULL;
+ int n, r;
+
+ assert(q);
+ assert(address);
+ assert(answer);
- /* Try via UDP, and if that fails due to large size try via TCP */
- r = dns_scope_send(t->scope, t->sent);
- if (r == -EMSGSIZE)
- r = dns_query_transaction_start_tcp(t);
+ if (af == AF_INET && address->in.s_addr == htobe32(0x7F000002)) {
+
+ /* Always map the IPv4 address 127.0.0.2 to the local
+ * hostname, in addition to "localhost": */
+
+ r = dns_answer_reserve(answer, 3);
+ if (r < 0)
+ return r;
+
+ r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->llmnr_hostname, SYNTHESIZE_IFINDEX(q->ifindex));
+ if (r < 0)
+ return r;
+
+ r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", q->manager->mdns_hostname, SYNTHESIZE_IFINDEX(q->ifindex));
+ if (r < 0)
+ return r;
+
+ r = answer_add_ptr(answer, "2.0.0.127.in-addr.arpa", "localhost", SYNTHESIZE_IFINDEX(q->ifindex));
+ if (r < 0)
+ return r;
- if (r == -ESRCH) {
- dns_query_transaction_set_state(t, DNS_QUERY_NO_SERVERS);
return 0;
}
- if (r < 0) {
- /* Couldn't send? Try immediately again, with a new server */
- dns_scope_next_dns_server(t->scope);
- return dns_query_transaction_start(t);
- }
+ n = local_addresses(q->manager->rtnl, q->ifindex, af, &addresses);
+ if (n < 0)
+ return n;
- r = sd_event_add_time(t->query->manager->event, &t->timeout_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + TRANSACTION_TIMEOUT_USEC, 0, on_transaction_timeout, t);
+ r = answer_add_addresses_ptr(answer, q->manager->llmnr_hostname, addresses, n, af, address);
if (r < 0)
return r;
- dns_query_transaction_set_state(t, DNS_QUERY_PENDING);
- return 1;
+ return answer_add_addresses_ptr(answer, q->manager->mdns_hostname, addresses, n, af, address);
}
-DnsQuery *dns_query_free(DnsQuery *q) {
- unsigned n;
+static int synthesize_gateway_rr(DnsQuery *q, DnsResourceKey *key, DnsAnswer **answer) {
+ _cleanup_free_ struct local_address *addresses = NULL;
+ int n = 0, af;
- if (!q)
- return NULL;
+ assert(q);
+ assert(key);
+ assert(answer);
+
+ af = dns_type_to_af(key->type);
+ if (af >= 0) {
+ n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses);
+ if (n < 0)
+ return n;
+ }
- sd_bus_message_unref(q->request);
- dns_packet_unref(q->received);
- sd_event_source_unref(q->timeout_event_source);
+ return answer_add_addresses_rr(answer, DNS_RESOURCE_KEY_NAME(key), addresses, n);
+}
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
+static int synthesize_gateway_ptr(DnsQuery *q, int af, const union in_addr_union *address, DnsAnswer **answer) {
+ _cleanup_free_ struct local_address *addresses = NULL;
+ int n;
- if (q->manager)
- LIST_REMOVE(queries, q->manager->dns_queries, q);
+ assert(q);
+ assert(address);
+ assert(answer);
- for (n = 0; n < q->n_keys; n++)
- free(q->keys[n].name);
- free(q->keys);
- free(q);
+ n = local_gateways(q->manager->rtnl, q->ifindex, af, &addresses);
+ if (n < 0)
+ return n;
- return NULL;
+ return answer_add_addresses_ptr(answer, "gateway", addresses, n, af, address);
}
-int dns_query_new(Manager *m, DnsQuery **ret, DnsResourceKey *keys, unsigned n_keys) {
- _cleanup_(dns_query_freep) DnsQuery *q = NULL;
- const char *name = NULL;
-
- assert(m);
+static int dns_query_synthesize_reply(DnsQuery *q, DnsTransactionState *state) {
+ _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
+ unsigned i;
+ int r;
- if (n_keys <= 0 || n_keys >= 65535)
- return -EINVAL;
+ assert(q);
+ assert(state);
- assert(keys);
+ /* Tries to synthesize localhost RR replies where appropriate */
- q = new0(DnsQuery, 1);
- if (!q)
- return -ENOMEM;
+ if (!IN_SET(*state,
+ DNS_TRANSACTION_FAILURE,
+ DNS_TRANSACTION_NO_SERVERS,
+ DNS_TRANSACTION_TIMEOUT,
+ DNS_TRANSACTION_ATTEMPTS_MAX_REACHED))
+ return 0;
- q->keys = new(DnsResourceKey, n_keys);
- if (!q->keys)
- return -ENOMEM;
+ for (i = 0; i < q->question->n_keys; i++) {
+ union in_addr_union address;
+ const char *name;
+ int af;
- for (q->n_keys = 0; q->n_keys < n_keys; q->n_keys++) {
- q->keys[q->n_keys].class = keys[q->n_keys].class;
- q->keys[q->n_keys].type = keys[q->n_keys].type;
- q->keys[q->n_keys].name = strdup(keys[q->n_keys].name);
- if (!q->keys[q->n_keys].name)
- return -ENOMEM;
+ if (q->question->keys[i]->class != DNS_CLASS_IN &&
+ q->question->keys[i]->class != DNS_CLASS_ANY)
+ continue;
- if (!name)
- name = q->keys[q->n_keys].name;
- else if (!dns_name_equal(name, q->keys[q->n_keys].name))
- return -EINVAL;
- }
+ name = DNS_RESOURCE_KEY_NAME(q->question->keys[i]);
- LIST_PREPEND(queries, m->dns_queries, q);
- q->manager = m;
+ if (is_localhost(name)) {
- if (ret)
- *ret = q;
- q = NULL;
+ r = synthesize_localhost_rr(q, q->question->keys[i], &answer);
+ if (r < 0)
+ return log_error_errno(r, "Failed to synthesize localhost RRs: %m");
- return 0;
-}
+ } else if (manager_is_own_hostname(q->manager, name)) {
-static void dns_query_stop(DnsQuery *q) {
- assert(q);
+ r = synthesize_system_hostname_rr(q, q->question->keys[i], &answer);
+ if (r < 0)
+ return log_error_errno(r, "Failed to synthesize system hostname RRs: %m");
- q->timeout_event_source = sd_event_source_unref(q->timeout_event_source);
+ } else if (is_gateway_hostname(name)) {
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
-}
+ r = synthesize_gateway_rr(q, q->question->keys[i], &answer);
+ if (r < 0)
+ return log_error_errno(r, "Failed to synthesize gateway RRs: %m");
-static void dns_query_set_state(DnsQuery *q, DnsQueryState state) {
- DnsQueryState old_state;
- assert(q);
+ } else if ((dns_name_endswith(name, "127.in-addr.arpa") > 0 && dns_name_equal(name, "2.0.0.127.in-addr.arpa") == 0) ||
+ dns_name_equal(name, "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) {
- if (q->state == state)
- return;
+ r = synthesize_localhost_ptr(q, q->question->keys[i], &answer);
+ if (r < 0)
+ return log_error_errno(r, "Failed to synthesize localhost PTR RRs: %m");
- old_state = q->state;
- q->state = state;
+ } else if (dns_name_address(name, &af, &address) > 0) {
- if (!IN_SET(state, DNS_QUERY_NULL, DNS_QUERY_PENDING)) {
- dns_query_stop(q);
+ r = synthesize_system_hostname_ptr(q, af, &address, &answer);
+ if (r < 0)
+ return log_error_errno(r, "Failed to synthesize system hostname PTR RR: %m");
- if (old_state == DNS_QUERY_PENDING && q->complete)
- q->complete(q);
+ r = synthesize_gateway_ptr(q, af, &address, &answer);
+ if (r < 0)
+ return log_error_errno(r, "Failed to synthesize gateway hostname PTR RR: %m");
+ }
}
-}
-static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
- DnsQuery *q = userdata;
+ if (!answer)
+ return 0;
- assert(s);
- assert(q);
+ dns_answer_unref(q->answer);
+ q->answer = answer;
+ answer = NULL;
- dns_query_set_state(q, DNS_QUERY_TIMEOUT);
- return 0;
+ q->answer_family = SYNTHESIZE_FAMILY(q->flags);
+ q->answer_protocol = SYNTHESIZE_PROTOCOL(q->flags);
+ q->answer_rcode = DNS_RCODE_SUCCESS;
+
+ *state = DNS_TRANSACTION_SUCCESS;
+
+ return 1;
}
-int dns_query_start(DnsQuery *q) {
+int dns_query_go(DnsQuery *q) {
DnsScopeMatch found = DNS_SCOPE_NO;
DnsScope *s, *first = NULL;
- DnsQueryTransaction *t;
+ DnsTransaction *t;
+ const char *name;
+ Iterator i;
int r;
assert(q);
- if (q->state != DNS_QUERY_NULL)
+ if (q->state != DNS_TRANSACTION_NULL)
return 0;
- assert(q->n_keys > 0);
+ assert(q->question);
+ assert(q->question->n_keys > 0);
+
+ name = DNS_RESOURCE_KEY_NAME(q->question->keys[0]);
LIST_FOREACH(scopes, s, q->manager->dns_scopes) {
DnsScopeMatch match;
- match = dns_scope_test(s, q->keys[0].name);
+ match = dns_scope_good_domain(s, q->ifindex, q->flags, name);
if (match < 0)
return match;
}
}
- if (found == DNS_SCOPE_NO)
- return -ESRCH;
+ if (found == DNS_SCOPE_NO) {
+ DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS;
+
+ dns_query_synthesize_reply(q, &state);
+ dns_query_complete(q, state);
+ return 1;
+ }
- r = dns_query_transaction_new(q, NULL, first);
+ r = dns_query_add_transaction_split(q, first);
if (r < 0)
- return r;
+ goto fail;
LIST_FOREACH(scopes, s, first->scopes_next) {
DnsScopeMatch match;
- match = dns_scope_test(s, q->keys[0].name);
+ match = dns_scope_good_domain(s, q->ifindex, q->flags, name);
if (match < 0)
- return match;
+ goto fail;
if (match != found)
continue;
- r = dns_query_transaction_new(q, NULL, s);
+ r = dns_query_add_transaction_split(q, s);
if (r < 0)
- return r;
+ goto fail;
}
- q->received = dns_packet_unref(q->received);
-
- r = sd_event_add_time(q->manager->event, &q->timeout_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + QUERY_TIMEOUT_USEC, 0, on_query_timeout, q);
+ q->answer = dns_answer_unref(q->answer);
+ q->answer_rcode = 0;
+ q->answer_family = AF_UNSPEC;
+ q->answer_protocol = _DNS_PROTOCOL_INVALID;
+
+ r = sd_event_add_time(
+ q->manager->event,
+ &q->timeout_event_source,
+ clock_boottime_or_monotonic(),
+ now(clock_boottime_or_monotonic()) + QUERY_TIMEOUT_USEC, 0,
+ on_query_timeout, q);
if (r < 0)
goto fail;
- dns_query_set_state(q, DNS_QUERY_PENDING);
+ q->state = DNS_TRANSACTION_PENDING;
+ q->block_ready++;
- LIST_FOREACH(transactions_by_query, t, q->transactions) {
+ /* Start the transactions that are not started yet */
+ SET_FOREACH(t, q->transactions, i) {
+ if (t->state != DNS_TRANSACTION_NULL)
+ continue;
- r = dns_query_transaction_start(t);
+ r = dns_transaction_go(t);
if (r < 0)
goto fail;
-
- if (q->state != DNS_QUERY_PENDING)
- break;
}
+ q->block_ready--;
+ dns_query_ready(q);
+
return 1;
fail:
return r;
}
-void dns_query_finish(DnsQuery *q) {
- DnsQueryTransaction *t;
- DnsQueryState state = DNS_QUERY_NO_SERVERS;
- DnsPacket *received = NULL;
+void dns_query_ready(DnsQuery *q) {
+ DnsTransaction *t;
+ DnsTransactionState state = DNS_TRANSACTION_NO_SERVERS;
+ _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
+ int rcode = 0;
+ DnsScope *scope = NULL;
+ bool pending = false;
+ Iterator i;
assert(q);
+ assert(IN_SET(q->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING));
+
+ /* Note that this call might invalidate the query. Callers
+ * should hence not attempt to access the query or transaction
+ * after calling this function, unless the block_ready
+ * counter was explicitly bumped before doing so. */
- if (q->state != DNS_QUERY_PENDING)
+ if (q->block_ready > 0)
return;
- LIST_FOREACH(transactions_by_query, t, q->transactions) {
+ SET_FOREACH(t, q->transactions, i) {
- /* One of the transactions is still going on, let's wait for it */
- if (t->state == DNS_QUERY_PENDING || t->state == DNS_QUERY_NULL)
- return;
+ /* If we found a successful answer, ignore all answers from other scopes */
+ if (state == DNS_TRANSACTION_SUCCESS && t->scope != scope)
+ continue;
- /* One of the transactions is successful, let's use it */
- if (t->state == DNS_QUERY_SUCCESS) {
- q->received = dns_packet_ref(t->received);
- dns_query_set_state(q, DNS_QUERY_SUCCESS);
- return;
+ /* One of the transactions is still going on, let's maybe wait for it */
+ if (IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_NULL)) {
+ pending = true;
+ continue;
+ }
+
+ /* One of the transactions is successful, let's use
+ * it, and copy its data out */
+ if (t->state == DNS_TRANSACTION_SUCCESS) {
+ DnsAnswer *a;
+
+ if (t->received) {
+ rcode = DNS_PACKET_RCODE(t->received);
+ a = t->received->answer;
+ } else {
+ rcode = t->cached_rcode;
+ a = t->cached;
+ }
+
+ if (state == DNS_TRANSACTION_SUCCESS) {
+ DnsAnswer *merged;
+
+ merged = dns_answer_merge(answer, a);
+ if (!merged) {
+ dns_query_complete(q, DNS_TRANSACTION_RESOURCES);
+ return;
+ }
+
+ dns_answer_unref(answer);
+ answer = merged;
+ } else {
+ dns_answer_unref(answer);
+ answer = dns_answer_ref(a);
+ }
+
+ scope = t->scope;
+ state = DNS_TRANSACTION_SUCCESS;
+ continue;
}
/* One of the transactions has failed, let's see
* whether we find anything better, but if not, return
- * its response packet */
- if (t->state == DNS_QUERY_FAILURE) {
- received = t->received;
- state = DNS_QUERY_FAILURE;
+ * its response data */
+ if (state != DNS_TRANSACTION_SUCCESS && t->state == DNS_TRANSACTION_FAILURE) {
+ DnsAnswer *a;
+
+ if (t->received) {
+ rcode = DNS_PACKET_RCODE(t->received);
+ a = t->received->answer;
+ } else {
+ rcode = t->cached_rcode;
+ a = t->cached;
+ }
+
+ dns_answer_unref(answer);
+ answer = dns_answer_ref(a);
+
+ scope = t->scope;
+ state = DNS_TRANSACTION_FAILURE;
continue;
}
- if (state == DNS_QUERY_NO_SERVERS && t->state != DNS_QUERY_NO_SERVERS)
+ if (state == DNS_TRANSACTION_NO_SERVERS && t->state != DNS_TRANSACTION_NO_SERVERS)
state = t->state;
}
- if (state == DNS_QUERY_FAILURE)
- q->received = dns_packet_ref(received);
-
- dns_query_set_state(q, state);
-}
-
-int dns_query_follow_cname(DnsQuery *q, const char *name) {
- DnsResourceKey *keys;
- unsigned i;
-
- assert(q);
+ if (pending) {
- if (q->n_cname > CNAME_MAX)
- return -ELOOP;
-
- keys = new(DnsResourceKey, q->n_keys);
- if (!keys)
- return -ENOMEM;
-
- for (i = 0; i < q->n_keys; i++) {
- keys[i].class = q->keys[i].class;
- keys[i].type = q->keys[i].type;
- keys[i].name = strdup(name);
- if (!keys[i].name) {
+ /* If so far we weren't successful, and there's
+ * something still pending, then wait for it */
+ if (state != DNS_TRANSACTION_SUCCESS)
+ return;
- for (; i > 0; i--)
- free(keys[i-1].name);
- free(keys);
- return -ENOMEM;
+ /* If we already were successful, then only wait for
+ * other transactions on the same scope to finish. */
+ SET_FOREACH(t, q->transactions, i) {
+ if (t->scope == scope && IN_SET(t->state, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_NULL))
+ return;
}
}
- for (i = 0; i < q->n_keys; i++)
- free(q->keys[i].name);
- free(q->keys);
-
- q->keys = keys;
+ if (IN_SET(state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_FAILURE)) {
+ q->answer = dns_answer_ref(answer);
+ q->answer_rcode = rcode;
+ q->answer_protocol = scope ? scope->protocol : _DNS_PROTOCOL_INVALID;
+ q->answer_family = scope ? scope->family : AF_UNSPEC;
+ }
- q->n_cname++;
+ /* Try to synthesize a reply if we couldn't resolve something. */
+ dns_query_synthesize_reply(q, &state);
- dns_query_set_state(q, DNS_QUERY_NULL);
- return 0;
+ dns_query_complete(q, state);
}
-int dns_query_matches_rr(DnsQuery *q, DnsResourceRecord *rr) {
- unsigned i;
+int dns_query_cname_redirect(DnsQuery *q, const char *name) {
+ _cleanup_(dns_question_unrefp) DnsQuestion *nq = NULL;
int r;
assert(q);
- assert(rr);
- for (i = 0; i < q->n_keys; i++) {
+ if (q->n_cname_redirects > CNAME_MAX)
+ return -ELOOP;
- if (rr->key.class != q->keys[i].class)
- continue;
+ r = dns_question_cname_redirect(q->question, name, &nq);
+ if (r < 0)
+ return r;
- if (rr->key.type != q->keys[i].type &&
- q->keys[i].type != DNS_TYPE_ANY)
- continue;
+ dns_question_unref(q->question);
+ q->question = nq;
+ nq = NULL;
- r = dns_name_equal(rr->key.name, q->keys[i].name);
- if (r != 0)
- return r;
- }
+ q->n_cname_redirects++;
+
+ dns_query_stop(q);
+ q->state = DNS_TRANSACTION_NULL;
return 0;
}
-int dns_query_matches_cname(DnsQuery *q, DnsResourceRecord *rr) {
- unsigned i;
- int r;
+static int on_bus_track(sd_bus_track *t, void *userdata) {
+ DnsQuery *q = userdata;
+ assert(t);
assert(q);
- assert(rr);
- for (i = 0; i < q->n_keys; i++) {
+ log_debug("Client of active query vanished, aborting query.");
+ dns_query_complete(q, DNS_TRANSACTION_ABORTED);
+ return 0;
+}
- if (rr->key.class != q->keys[i].class)
- continue;
+int dns_query_bus_track(DnsQuery *q, sd_bus_message *m) {
+ int r;
- if (rr->key.type != DNS_TYPE_CNAME)
- continue;
+ assert(q);
+ assert(m);
- r = dns_name_equal(rr->key.name, q->keys[i].name);
- if (r != 0)
+ if (!q->bus_track) {
+ r = sd_bus_track_new(sd_bus_message_get_bus(m), &q->bus_track, on_bus_track, q);
+ if (r < 0)
return r;
}
+ r = sd_bus_track_add_sender(q->bus_track, m);
+ if (r < 0)
+ return r;
+
return 0;
}
projects / thirdparty / systemd.git / blobdiff