along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
+#include "af-list.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 int dns_query_transaction_go(DnsQueryTransaction *t);
-
-DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t) {
- if (!t)
- return NULL;
-
- sd_event_source_unref(t->timeout_event_source);
-
- dns_packet_unref(t->sent);
- dns_packet_unref(t->received);
+static void dns_query_stop(DnsQuery *q) {
+ DnsTransaction *t;
- dns_resource_record_freev(t->cached_rrs, t->n_cached_rrs);
+ assert(q);
- sd_event_source_unref(t->tcp_event_source);
- safe_close(t->tcp_fd);
+ q->timeout_event_source = sd_event_source_unref(q->timeout_event_source);
- 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));
+ while ((t = set_steal_first(q->transactions))) {
+ set_remove(t->queries, q);
+ dns_transaction_gc(t);
}
-
- if (t->scope)
- LIST_REMOVE(transactions_by_scope, t->scope->transactions, t);
-
- 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 r;
-
- assert(q);
- assert(s);
-
- r = hashmap_ensure_allocated(&q->manager->dns_query_transactions, NULL, NULL);
- if (r < 0)
- return r;
+DnsQuery *dns_query_free(DnsQuery *q) {
+ if (!q)
+ return NULL;
- t = new0(DnsQueryTransaction, 1);
- if (!t)
- return -ENOMEM;
+ dns_query_stop(q);
+ set_free(q->transactions);
- t->tcp_fd = -1;
+ dns_question_unref(q->question);
+ dns_answer_unref(q->answer);
- do
- random_bytes(&t->id, sizeof(t->id));
- while (t->id == 0 ||
- hashmap_get(q->manager->dns_query_transactions, UINT_TO_PTR(t->id)));
+ sd_bus_message_unref(q->request);
+ sd_bus_track_unref(q->bus_track);
- r = hashmap_put(q->manager->dns_query_transactions, UINT_TO_PTR(t->id), t);
- if (r < 0) {
- t->id = 0;
- return r;
+ if (q->manager) {
+ LIST_REMOVE(queries, q->manager->dns_queries, q);
+ q->manager->n_dns_queries--;
}
- LIST_PREPEND(transactions_by_query, q->transactions, t);
- t->query = q;
-
- LIST_PREPEND(transactions_by_scope, s->transactions, t);
- t->scope = s;
-
- if (ret)
- *ret = t;
-
- t = NULL;
-
- return 0;
-}
-
-static void dns_query_transaction_stop(DnsQueryTransaction *t) {
- assert(t);
-
- 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);
-}
-
-static void dns_query_transaction_complete(DnsQueryTransaction *t, DnsQueryState state) {
- assert(t);
- assert(!IN_SET(state, DNS_QUERY_NULL, DNS_QUERY_PENDING));
- assert(IN_SET(t->state, DNS_QUERY_NULL, DNS_QUERY_PENDING));
-
- /* Note that this call might invalidate the query. Callers
- * should hence not attempt to access the query or transaction
- * after calling this function. */
-
- t->state = state;
+ free(q);
- dns_query_transaction_stop(t);
- dns_query_finish(t->query);
+ return NULL;
}
-static int on_tcp_ready(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
- DnsQueryTransaction *t = userdata;
+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(t);
-
- if (revents & EPOLLOUT) {
- struct iovec iov[2];
- be16_t sz;
- ssize_t ss;
-
- sz = htobe16(t->sent->size);
-
- 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;
-
- IOVEC_INCREMENT(iov, 2, t->tcp_written);
-
- ss = writev(fd, iov, 2);
- if (ss < 0) {
- if (errno != EINTR && errno != EAGAIN) {
- dns_query_transaction_complete(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_complete(t, DNS_QUERY_RESOURCES);
- return r;
- }
- }
- }
-
- if (revents & (EPOLLIN|EPOLLHUP|EPOLLRDHUP)) {
-
- if (t->tcp_read < sizeof(t->tcp_read_size)) {
- ssize_t ss;
+ assert(m);
+ assert(question);
- 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_complete(t, DNS_QUERY_RESOURCES);
- return -errno;
- }
- } else if (ss == 0) {
- dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
- return -EIO;
- } else
- t->tcp_read += ss;
- }
+ r = dns_question_is_valid(question);
+ if (r < 0)
+ return r;
- if (t->tcp_read >= sizeof(t->tcp_read_size)) {
+ if (m->n_dns_queries >= QUERIES_MAX)
+ return -EBUSY;
- if (be16toh(t->tcp_read_size) < DNS_PACKET_HEADER_SIZE) {
- dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY);
- return -EBADMSG;
- }
+ q = new0(DnsQuery, 1);
+ if (!q)
+ return -ENOMEM;
- if (t->tcp_read < sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size)) {
- ssize_t ss;
+ q->question = dns_question_ref(question);
+ q->ifindex = ifindex;
+ q->flags = flags;
- if (!t->received) {
- r = dns_packet_new(&t->received, t->scope->protocol, be16toh(t->tcp_read_size));
- if (r < 0) {
- dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
- return r;
- }
- }
+ for (i = 0; i < question->n_keys; i++) {
+ _cleanup_free_ char *p;
- 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_complete(t, DNS_QUERY_RESOURCES);
- return -errno;
- }
- } else if (ss == 0) {
- dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
- return -EIO;
- } else
- t->tcp_read += ss;
- }
+ r = dns_resource_key_to_string(question->keys[i], &p);
+ if (r < 0)
+ return r;
- 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;
- }
- }
+ log_debug("Looking up RR for %s", p);
}
- return 0;
-}
-
-static int dns_query_transaction_open_tcp(DnsQueryTransaction *t) {
- int r;
-
- assert(t);
-
- if (t->scope->protocol == DNS_PROTOCOL_DNS)
- return -ENOTSUP;
-
- if (t->tcp_fd >= 0)
- return 0;
-
- t->tcp_written = 0;
- t->tcp_read = 0;
- t->received = dns_packet_unref(t->received);
-
- t->tcp_fd = dns_scope_tcp_socket(t->scope);
- if (t->tcp_fd < 0)
- return t->tcp_fd;
+ LIST_PREPEND(queries, m->dns_queries, q);
+ m->n_dns_queries++;
+ q->manager = m;
- 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;
- }
+ if (ret)
+ *ret = q;
+ q = NULL;
return 0;
}
-void dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p) {
- int r;
-
- assert(t);
- assert(p);
- assert(t->state == DNS_QUERY_PENDING);
+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));
/* Note that this call might invalidate the query. Callers
* should hence not attempt to access the query or transaction
* after calling this function. */
- if (t->received != p) {
- dns_packet_unref(t->received);
- t->received = dns_packet_ref(p);
- }
-
- if (t->tcp_fd >= 0) {
- if (DNS_PACKET_TC(p)) {
- /* Truncated via TCP? Somebody must be fucking with us */
- dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY);
- return;
- }
-
- if (DNS_PACKET_ID(p) != t->id) {
- /* Not the reply to our query? Somebody must be fucking with us */
- dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY);
- return;
- }
- }
-
- if (DNS_PACKET_TC(p)) {
- /* Response was truncated, let's try again with good old TCP */
- r = dns_query_transaction_open_tcp(t);
- if (r == -ESRCH) {
- /* No servers found? Damn! */
- dns_query_transaction_complete(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);
-
- r = dns_query_transaction_go(t);
- if (r < 0) {
- dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
- return;
- }
-
- return;
- }
- }
-
- /* Parse and update the cache */
- r = dns_packet_extract_rrs(p);
- if (r < 0) {
- dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY);
- return;
- } else if (r > 0)
- dns_cache_put_rrs(&t->scope->cache, p->rrs, r, 0);
+ q->state = state;
- if (DNS_PACKET_RCODE(p) == DNS_RCODE_SUCCESS)
- dns_query_transaction_complete(t, DNS_QUERY_SUCCESS);
- else
- dns_query_transaction_complete(t, DNS_QUERY_FAILURE);
+ dns_query_stop(q);
+ if (q->complete)
+ q->complete(q);
}
-static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) {
- DnsQueryTransaction *t = userdata;
- int r;
+static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
+ DnsQuery *q = userdata;
assert(s);
- assert(t);
-
- /* Timeout reached? Try again, with a new server */
- dns_scope_next_dns_server(t->scope);
-
- r = dns_query_transaction_go(t);
- if (r < 0)
- dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
+ assert(q);
+ dns_query_complete(q, DNS_TRANSACTION_TIMEOUT);
return 0;
}
-static int dns_query_make_packet(DnsQueryTransaction *t) {
- _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
- unsigned n, added = 0;
+static int dns_query_add_transaction(DnsQuery *q, DnsScope *s, DnsResourceKey *key) {
+ _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
+ DnsTransaction *t;
int r;
- assert(t);
-
- if (t->sent)
- return 0;
+ assert(q);
+ assert(s);
- r = dns_packet_new_query(&p, t->scope->protocol, 0);
+ r = set_ensure_allocated(&q->transactions, NULL);
if (r < 0)
return r;
- for (n = 0; n < t->query->n_keys; n++) {
- r = dns_scope_good_key(t->scope, &t->query->keys[n]);
+ if (key) {
+ question = dns_question_new(1);
+ if (!question)
+ return -ENOMEM;
+
+ r = dns_question_add(question, key);
if (r < 0)
return r;
- if (r == 0)
- continue;
+ } else
+ question = dns_question_ref(q->question);
- r = dns_packet_append_key(p, &t->query->keys[n], NULL);
+ t = dns_scope_find_transaction(s, question, true);
+ if (!t) {
+ r = dns_transaction_new(&t, s, question);
if (r < 0)
return r;
-
- added++;
- }
-
- if (added <= 0)
- return -EDOM;
-
- DNS_PACKET_HEADER(p)->qdcount = htobe16(added);
- DNS_PACKET_HEADER(p)->id = t->id;
-
- t->sent = p;
- p = NULL;
-
- return 0;
-}
-
-static int dns_query_transaction_go(DnsQueryTransaction *t) {
- int r;
-
- assert(t);
-
- dns_query_transaction_stop(t);
-
- if (t->n_attempts >= ATTEMPTS_MAX) {
- dns_query_transaction_complete(t, DNS_QUERY_ATTEMPTS_MAX);
- return 0;
}
- t->n_attempts++;
- t->received = dns_packet_unref(t->received);
- t->cached_rrs = dns_resource_record_freev(t->cached_rrs, t->n_cached_rrs);
- t->n_cached_rrs = 0;
-
- /* First, let's try the cache */
- dns_cache_prune(&t->scope->cache);
- r = dns_cache_lookup_many(&t->scope->cache, t->query->keys, t->query->n_keys, &t->cached_rrs);
+ r = set_ensure_allocated(&t->queries, NULL);
if (r < 0)
- return r;
- if (r > 0) {
- t->n_cached_rrs = r;
- dns_query_transaction_complete(t, DNS_QUERY_SUCCESS);
- return 0;
- }
+ goto gc;
- /* Otherwise, we need to ask the network */
- r = dns_query_make_packet(t);
- if (r == -EDOM) {
- /* Not the right request to make on this network?
- * (i.e. an A request made on IPv6 or an AAAA request
- * made on IPv4, on LLMNR or mDNS.) */
- dns_query_transaction_complete(t, DNS_QUERY_NO_SERVERS);
- return 0;
- }
+ r = set_put(t->queries, q);
if (r < 0)
- return r;
+ goto gc;
- /* 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_open_tcp(t);
- if (r == -ESRCH) {
- /* No servers to send this to? */
- dns_query_transaction_complete(t, DNS_QUERY_NO_SERVERS);
- return 0;
- }
+ r = set_put(q->transactions, t);
if (r < 0) {
- /* Couldn't send? Try immediately again, with a new server */
- dns_scope_next_dns_server(t->scope);
-
- return dns_query_transaction_go(t);
+ set_remove(t->queries, q);
+ goto gc;
}
- 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);
- if (r < 0)
- return r;
-
- t->state = DNS_QUERY_PENDING;
- return 1;
-}
-
-DnsQuery *dns_query_free(DnsQuery *q) {
- unsigned n;
-
- if (!q)
- return NULL;
-
- sd_bus_message_unref(q->request);
- dns_packet_unref(q->received);
-
- dns_resource_record_freev(q->cached_rrs, q->n_cached_rrs);
-
- sd_event_source_unref(q->timeout_event_source);
-
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
-
- if (q->manager) {
- LIST_REMOVE(queries, q->manager->dns_queries, q);
- q->manager->n_dns_queries--;
- }
-
- for (n = 0; n < q->n_keys; n++)
- free(q->keys[n].name);
- free(q->keys);
- free(q);
-
- return NULL;
-}
-
-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);
-
- if (n_keys <= 0 || n_keys >= 65535)
- return -EINVAL;
-
- if (m->n_dns_queries >= QUERIES_MAX)
- return -EBUSY;
-
- assert(keys);
-
- q = new0(DnsQuery, 1);
- if (!q)
- return -ENOMEM;
-
- q->keys = new(DnsResourceKey, n_keys);
- if (!q->keys)
- return -ENOMEM;
-
- 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 (!name)
- name = q->keys[q->n_keys].name;
- else if (!dns_name_equal(name, q->keys[q->n_keys].name))
- return -EINVAL;
-
- log_debug("Looking up RR for %s %s %s",
- strna(dns_class_to_string(keys[q->n_keys].class)),
- strna(dns_type_to_string(keys[q->n_keys].type)),
- keys[q->n_keys].name);
- }
-
- LIST_PREPEND(queries, m->dns_queries, q);
- m->n_dns_queries++;
- q->manager = m;
-
- if (ret)
- *ret = q;
- q = NULL;
-
return 0;
-}
-
-static void dns_query_stop(DnsQuery *q) {
- assert(q);
-
- q->timeout_event_source = sd_event_source_unref(q->timeout_event_source);
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
+gc:
+ dns_transaction_gc(t);
+ return r;
}
-static void dns_query_complete(DnsQuery *q, DnsQueryState state) {
- assert(q);
- assert(!IN_SET(state, DNS_QUERY_NULL, DNS_QUERY_PENDING));
- assert(IN_SET(q->state, DNS_QUERY_NULL, DNS_QUERY_PENDING));
-
- /* Note that this call might invalidate the query. Callers
- * should hence not attempt to access the query or transaction
- * after calling this function. */
+static int dns_query_add_transaction_split(DnsQuery *q, DnsScope *s) {
+ int r;
- q->state = state;
+ assert(q);
+ assert(s);
- dns_query_stop(q);
- if (q->complete)
- q->complete(q);
-}
+ if (s->protocol == DNS_PROTOCOL_MDNS) {
+ r = dns_query_add_transaction(q, s, NULL);
+ if (r < 0)
+ return r;
+ } else {
+ unsigned i;
-static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
- DnsQuery *q = userdata;
+ /* On DNS and LLMNR we can only send a single
+ * question per datagram, hence issue multiple
+ * transactions. */
- assert(s);
- assert(q);
+ 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;
+ }
+ }
- dns_query_complete(q, DNS_QUERY_TIMEOUT);
return 0;
}
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_good_domain(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;
- 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_good_domain(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_ifindex = 0;
+ 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;
- q->state = DNS_QUERY_PENDING;
- q->block_finish++;
+ q->state = DNS_TRANSACTION_PENDING;
+ q->block_ready++;
+
+ /* Start the transactions that are not started yet */
+ SET_FOREACH(t, q->transactions, i) {
+ if (t->state != DNS_TRANSACTION_NULL)
+ continue;
- LIST_FOREACH(transactions_by_query, t, q->transactions) {
- r = dns_query_transaction_go(t);
+ r = dns_transaction_go(t);
if (r < 0)
goto fail;
}
- q->block_finish--;
- dns_query_finish(q);
+ q->block_ready--;
+ dns_query_ready(q);
return 1;
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_QUERY_NULL, DNS_QUERY_PENDING));
+ 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_finish
+ * after calling this function, unless the block_ready
* counter was explicitly bumped before doing so. */
- if (q->block_finish > 0)
+ 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 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_QUERY_SUCCESS) {
- q->received = dns_packet_ref(t->received);
+ 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;
+ }
- /* We simply steal the cached RRs array */
- q->cached_rrs = t->cached_rrs;
- q->n_cached_rrs = t->n_cached_rrs;
- t->cached_rrs = NULL;
- t->n_cached_rrs = 0;
+ if (state == DNS_TRANSACTION_SUCCESS) {
+ DnsAnswer *merged;
- dns_query_complete(q, DNS_QUERY_SUCCESS);
- return;
+ 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_complete(q, state);
-}
-
-int dns_query_cname_redirect(DnsQuery *q, const char *name) {
- DnsResourceKey *keys;
- unsigned i;
-
- assert(q);
-
- if (q->n_cname > CNAME_MAX)
- return -ELOOP;
-
- keys = new(DnsResourceKey, q->n_keys);
- if (!keys)
- return -ENOMEM;
+ if (pending) {
- 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;
-
- q->n_cname++;
-
- dns_query_stop(q);
- q->state = DNS_QUERY_NULL;
+ if (IN_SET(state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_FAILURE)) {
+ q->answer = dns_answer_ref(answer);
+ q->answer_rcode = rcode;
+ q->answer_ifindex = (scope && scope->link) ? scope->link->ifindex : 0;
+ q->answer_protocol = scope ? scope->protocol : _DNS_PROTOCOL_INVALID;
+ q->answer_family = scope ? scope->family : AF_UNSPEC;
+ }
- 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++) {
-
- if (rr->key.class != q->keys[i].class)
- continue;
-
- if (rr->key.type != DNS_TYPE_CNAME)
- continue;
-
- r = dns_name_equal(rr->key.name, q->keys[i].name);
- if (r != 0)
- return r;
- }
+ log_debug("Client of active query vanished, aborting query.");
+ dns_query_complete(q, DNS_TRANSACTION_ABORTED);
return 0;
}
-int dns_query_get_rrs(DnsQuery *q, DnsResourceRecord ***rrs) {
+int dns_query_bus_track(DnsQuery *q, sd_bus *bus, sd_bus_message *m) {
int r;
assert(q);
- assert(rrs);
-
- if (IN_SET(q->state, DNS_QUERY_NULL, DNS_QUERY_PENDING))
- return -EBUSY;
+ assert(m);
- if (q->received) {
- r = dns_packet_extract_rrs(q->received);
+ if (!q->bus_track) {
+ r = sd_bus_track_new(bus, &q->bus_track, on_bus_track, q);
if (r < 0)
return r;
- if (r == 0) {
- *rrs = NULL;
- return r;
- }
-
- *rrs = q->received->rrs;
- return r;
- }
-
- if (q->cached_rrs) {
- *rrs = q->cached_rrs;
- return q->n_cached_rrs;
}
- return -ESRCH;
-}
-
-int dns_query_get_rcode(DnsQuery *q) {
- assert(q);
-
- if (IN_SET(q->state, DNS_QUERY_NULL, DNS_QUERY_PENDING))
- return -EBUSY;
-
- if (!q->received)
- return -ESRCH;
-
- return DNS_PACKET_RCODE(q->received);
-}
-
-int dns_query_get_ifindex(DnsQuery *q) {
- assert(q);
-
- if (IN_SET(q->state, DNS_QUERY_NULL, DNS_QUERY_PENDING))
- return -EBUSY;
-
- if (!q->received)
- return -ESRCH;
+ r = sd_bus_track_add_sender(q->bus_track, m);
+ if (r < 0)
+ return r;
- return q->received->ifindex;
+ return 0;
}
~ianmdlvl / elogind.git / blobdiff