#define CNAME_MAX 8
#define QUERIES_MAX 2048
-static int dns_query_transaction_start(DnsQueryTransaction *t);
+static int dns_query_transaction_go(DnsQueryTransaction *t);
DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t) {
+ DnsQuery *q;
+
if (!t)
return NULL;
sd_event_source_unref(t->timeout_event_source);
+ dns_question_unref(t->question);
dns_packet_unref(t->sent);
dns_packet_unref(t->received);
+ dns_answer_unref(t->cached);
sd_event_source_unref(t->tcp_event_source);
safe_close(t->tcp_fd);
- 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 (t->scope) {
+ LIST_REMOVE(transactions_by_scope, t->scope->transactions, t);
+
+ if (t->id != 0)
+ hashmap_remove(t->scope->manager->dns_query_transactions, UINT_TO_PTR(t->id));
}
- if (t->scope)
- LIST_REMOVE(transactions_by_scope, t->scope->transactions, t);
+ while ((q = set_steal_first(t->queries)))
+ set_remove(q->transactions, t);
+
+ set_free(t->queries);
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) {
+static void dns_query_transaction_gc(DnsQueryTransaction *t) {
+ assert(t);
+
+ if (t->block_gc > 0)
+ return;
+
+ if (set_isempty(t->queries))
+ dns_query_transaction_free(t);
+}
+
+static int dns_query_transaction_new(DnsQueryTransaction **ret, DnsScope *s, DnsQuestion *q) {
_cleanup_(dns_query_transaction_freep) DnsQueryTransaction *t = NULL;
int r;
- assert(q);
+ assert(ret);
assert(s);
+ assert(q);
- r = hashmap_ensure_allocated(&q->manager->dns_query_transactions, NULL, NULL);
+ r = hashmap_ensure_allocated(&s->manager->dns_query_transactions, NULL, NULL);
if (r < 0)
return r;
return -ENOMEM;
t->tcp_fd = -1;
+ t->question = dns_question_ref(q);
do
random_bytes(&t->id, sizeof(t->id));
while (t->id == 0 ||
- hashmap_get(q->manager->dns_query_transactions, UINT_TO_PTR(t->id)));
+ hashmap_get(s->manager->dns_query_transactions, UINT_TO_PTR(t->id)));
- r = hashmap_put(q->manager->dns_query_transactions, UINT_TO_PTR(t->id), t);
+ r = hashmap_put(s->manager->dns_query_transactions, UINT_TO_PTR(t->id), t);
if (r < 0) {
t->id = 0;
return r;
}
- LIST_PREPEND(transactions_by_query, q->transactions, t);
- t->query = q;
-
LIST_PREPEND(transactions_by_scope, s->transactions, t);
t->scope = s;
t->tcp_fd = safe_close(t->tcp_fd);
}
-static void dns_query_transaction_set_state(DnsQueryTransaction *t, DnsQueryState state) {
+void dns_query_transaction_complete(DnsQueryTransaction *t, DnsQueryState state) {
+ DnsQuery *q;
+ Iterator i;
+
assert(t);
+ assert(!IN_SET(state, DNS_QUERY_NULL, DNS_QUERY_PENDING));
+ assert(IN_SET(t->state, DNS_QUERY_NULL, DNS_QUERY_PENDING));
- if (t->state == state)
- return;
+ /* 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;
- if (state != DNS_QUERY_PENDING) {
- dns_query_transaction_stop(t);
- dns_query_finish(t->query);
- }
+ dns_query_transaction_stop(t);
+
+ /* Notify all queries that are interested, but make sure the
+ * transaction isn't freed while we are still looking at it */
+ t->block_gc++;
+ SET_FOREACH(q, t->queries, i)
+ dns_query_ready(q);
+ t->block_gc--;
+
+ dns_query_transaction_gc(t);
}
static int on_tcp_ready(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
ss = writev(fd, iov, 2);
if (ss < 0) {
if (errno != EINTR && errno != EAGAIN) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
return -errno;
}
} else
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);
+ dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
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);
+ dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
return -errno;
}
} else if (ss == 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
return -EIO;
} else
t->tcp_read += ss;
if (t->tcp_read >= sizeof(t->tcp_read_size)) {
if (be16toh(t->tcp_read_size) < DNS_PACKET_HEADER_SIZE) {
- dns_query_transaction_set_state(t, DNS_QUERY_INVALID_REPLY);
+ dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY);
return -EBADMSG;
}
ssize_t ss;
if (!t->received) {
- r = dns_packet_new(&t->received, be16toh(t->tcp_read_size));
+ r = dns_packet_new(&t->received, t->scope->protocol, be16toh(t->tcp_read_size));
if (r < 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
return r;
}
}
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);
+ dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
return -errno;
}
} else if (ss == 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
return -EIO;
} else
t->tcp_read += ss;
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);
+ dns_query_transaction_process_reply(t, t->received);
return 0;
}
}
return 0;
}
-static int dns_query_transaction_start_tcp(DnsQueryTransaction *t) {
+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;
if (t->tcp_fd < 0)
return t->tcp_fd;
- r = sd_event_add_io(t->query->manager->event, &t->tcp_event_source, t->tcp_fd, EPOLLIN|EPOLLOUT, on_tcp_ready, t);
+ r = sd_event_add_io(t->scope->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;
return 0;
}
-void dns_query_transaction_reply(DnsQueryTransaction *t, DnsPacket *p) {
+void dns_query_transaction_process_reply(DnsQueryTransaction *t, DnsPacket *p) {
int r;
assert(t);
assert(p);
+ assert(t->state == DNS_QUERY_PENDING);
- if (t->state != DNS_QUERY_PENDING)
- return;
+ /* 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);
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);
+ 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_set_state(t, DNS_QUERY_INVALID_REPLY);
+ 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_start_tcp(t);
+ r = dns_query_transaction_open_tcp(t);
if (r == -ESRCH) {
/* No servers found? Damn! */
- dns_query_transaction_set_state(t, DNS_QUERY_NO_SERVERS);
+ 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_start(t);
+ r = dns_query_transaction_go(t);
if (r < 0) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
return;
}
}
}
+ /* Parse and update the cache */
+ r = dns_packet_extract(p);
+ if (r < 0) {
+ dns_query_transaction_complete(t, DNS_QUERY_INVALID_REPLY);
+ return;
+ }
+
+ dns_cache_put(&t->scope->cache, p->question, DNS_PACKET_RCODE(p), p->answer, 0);
+
if (DNS_PACKET_RCODE(p) == DNS_RCODE_SUCCESS)
- dns_query_transaction_set_state(t, DNS_QUERY_SUCCESS);
+ dns_query_transaction_complete(t, DNS_QUERY_SUCCESS);
else
- dns_query_transaction_set_state(t, DNS_QUERY_FAILURE);
+ dns_query_transaction_complete(t, DNS_QUERY_FAILURE);
}
static int on_transaction_timeout(sd_event_source *s, usec_t usec, void *userdata) {
/* Timeout reached? Try again, with a new server */
dns_scope_next_dns_server(t->scope);
- r = dns_query_transaction_start(t);
+ r = dns_query_transaction_go(t);
if (r < 0)
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ dns_query_transaction_complete(t, DNS_QUERY_RESOURCES);
return 0;
}
static int dns_query_make_packet(DnsQueryTransaction *t) {
_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
- unsigned n;
+ unsigned n, added = 0;
int r;
assert(t);
if (t->sent)
return 0;
- r = dns_packet_new_query(&p, 0);
+ r = dns_packet_new_query(&p, t->scope->protocol, 0);
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 (n = 0; n < t->question->n_keys; n++) {
+ r = dns_scope_good_key(t->scope, t->question->keys[n]);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ continue;
+
+ r = dns_packet_append_key(p, t->question->keys[n], NULL);
if (r < 0)
return r;
+
+ added++;
}
- DNS_PACKET_HEADER(p)->qdcount = htobe16(t->query->n_keys);
+ if (added <= 0)
+ return -EDOM;
+
+ DNS_PACKET_HEADER(p)->qdcount = htobe16(added);
DNS_PACKET_HEADER(p)->id = t->id;
t->sent = p;
return 0;
}
-static int dns_query_transaction_start(DnsQueryTransaction *t) {
+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_set_state(t, DNS_QUERY_ATTEMPTS_MAX);
+ dns_query_transaction_complete(t, DNS_QUERY_ATTEMPTS_MAX);
return 0;
}
- r = dns_query_make_packet(t);
+ t->n_attempts++;
+ t->received = dns_packet_unref(t->received);
+ t->cached = dns_answer_unref(t->cached);
+ t->cached_rcode = 0;
+
+ /* First, let's try the cache */
+ dns_cache_prune(&t->scope->cache);
+ r = dns_cache_lookup(&t->scope->cache, t->question, &t->cached_rcode, &t->cached);
if (r < 0)
return r;
+ if (r > 0) {
+ if (t->cached_rcode == DNS_RCODE_SUCCESS)
+ dns_query_transaction_complete(t, DNS_QUERY_SUCCESS);
+ else
+ dns_query_transaction_complete(t, DNS_QUERY_FAILURE);
+ return 0;
+ }
- t->n_attempts++;
- t->received = dns_packet_unref(t->received);
+ /* 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;
+ }
+ if (r < 0)
+ return r;
/* 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);
-
+ r = dns_query_transaction_open_tcp(t);
if (r == -ESRCH) {
- dns_query_transaction_set_state(t, DNS_QUERY_NO_SERVERS);
+ /* No servers to send this to? */
+ dns_query_transaction_complete(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);
+ return dns_query_transaction_go(t);
}
- 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 = sd_event_add_time(t->scope->manager->event, &t->timeout_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + TRANSACTION_TIMEOUT_USEC, 0, on_transaction_timeout, t);
if (r < 0)
return r;
- dns_query_transaction_set_state(t, DNS_QUERY_PENDING);
+ t->state = DNS_QUERY_PENDING;
return 1;
}
DnsQuery *dns_query_free(DnsQuery *q) {
- unsigned n;
+ DnsQueryTransaction *t;
if (!q)
return NULL;
sd_bus_message_unref(q->request);
- dns_packet_unref(q->received);
+
+ dns_question_unref(q->question);
+ dns_answer_unref(q->answer);
+
sd_event_source_unref(q->timeout_event_source);
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
+ while ((t = set_steal_first(q->transactions))) {
+ set_remove(t->queries, q);
+ dns_query_transaction_gc(t);
+ }
+
+ set_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) {
+int dns_query_new(Manager *m, DnsQuery **ret, DnsQuestion *question) {
_cleanup_(dns_query_freep) DnsQuery *q = NULL;
- const char *name = NULL;
+ unsigned i;
+ int r;
assert(m);
+ assert(question);
- if (n_keys <= 0 || n_keys >= 65535)
- return -EINVAL;
+ r = dns_question_is_valid(question);
+ if (r < 0)
+ return r;
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;
+ q->question = dns_question_ref(question);
- 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;
+ for (i = 0; i < question->n_keys; i++) {
+ log_debug("Looking up RR for %s %s %s",
+ strna(dns_class_to_string(question->keys[i]->class)),
+ strna(dns_type_to_string(question->keys[i]->type)),
+ DNS_RESOURCE_KEY_NAME(question->keys[i]));
}
LIST_PREPEND(queries, m->dns_queries, q);
}
static void dns_query_stop(DnsQuery *q) {
+ DnsQueryTransaction *t;
+
assert(q);
q->timeout_event_source = sd_event_source_unref(q->timeout_event_source);
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
+ while ((t = set_steal_first(q->transactions))) {
+ set_remove(t->queries, q);
+ dns_query_transaction_gc(t);
+ }
}
-static void dns_query_set_state(DnsQuery *q, DnsQueryState state) {
- DnsQueryState old_state;
+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));
- if (q->state == state)
- return;
+ /* Note that this call might invalidate the query. Callers
+ * should hence not attempt to access the query or transaction
+ * after calling this function. */
- old_state = q->state;
q->state = state;
- if (!IN_SET(state, DNS_QUERY_NULL, DNS_QUERY_PENDING)) {
- dns_query_stop(q);
-
- if (old_state == DNS_QUERY_PENDING && q->complete)
- q->complete(q);
- }
+ dns_query_stop(q);
+ if (q->complete)
+ q->complete(q);
}
static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
assert(s);
assert(q);
- dns_query_set_state(q, DNS_QUERY_TIMEOUT);
+ dns_query_complete(q, DNS_QUERY_TIMEOUT);
+ return 0;
+}
+
+static int dns_query_add_transaction(DnsQuery *q, DnsScope *s, DnsResourceKey *key) {
+ _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
+ DnsQueryTransaction *t;
+ int r;
+
+ assert(q);
+
+ r = set_ensure_allocated(&q->transactions, NULL, NULL);
+ if (r < 0)
+ return r;
+
+ if (key) {
+ question = dns_question_new(1);
+ if (!question)
+ return -ENOMEM;
+
+ r = dns_question_add(question, key);
+ if (r < 0)
+ return r;
+ } else
+ question = dns_question_ref(q->question);
+
+ LIST_FOREACH(transactions_by_scope, t, s->transactions)
+ if (dns_question_is_superset(t->question, question))
+ break;
+
+ if (!t) {
+ r = dns_query_transaction_new(&t, s, question);
+ if (r < 0)
+ return r;
+ }
+
+ r = set_ensure_allocated(&t->queries, NULL, NULL);
+ if (r < 0)
+ goto fail;
+
+ r = set_put(t->queries, q);
+ if (r < 0)
+ goto fail;
+
+ r = set_put(q->transactions, t);
+ if (r < 0) {
+ set_remove(t->queries, q);
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ dns_query_transaction_gc(t);
+ return r;
+}
+
+static int dns_query_add_transaction_split(DnsQuery *q, DnsScope *s) {
+ int r;
+
+ assert(q);
+ assert(s);
+
+ if (s->protocol == DNS_PROTOCOL_MDNS) {
+ r = dns_query_add_transaction(q, s, NULL);
+ if (r < 0)
+ return r;
+ } else {
+ unsigned i;
+
+ /* On DNS and LLMNR we can only send a single
+ * question per datagram, hence issue multiple
+ * transactions. */
+
+ 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;
+ }
+ }
+
return 0;
}
-int dns_query_start(DnsQuery *q) {
+int dns_query_go(DnsQuery *q) {
DnsScopeMatch found = DNS_SCOPE_NO;
DnsScope *s, *first = NULL;
DnsQueryTransaction *t;
+ const char *name;
+ Iterator i;
int r;
assert(q);
if (q->state != DNS_QUERY_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, 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;
LIST_FOREACH(scopes, s, first->scopes_next) {
DnsScopeMatch match;
- match = dns_scope_test(s, q->keys[0].name);
+ match = dns_scope_good_domain(s, name);
if (match < 0)
return match;
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;
}
- q->received = dns_packet_unref(q->received);
+ q->answer = dns_answer_unref(q->answer);
+ q->answer_ifindex = 0;
+ q->answer_rcode = 0;
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);
if (r < 0)
goto fail;
- dns_query_set_state(q, DNS_QUERY_PENDING);
-
- LIST_FOREACH(transactions_by_query, t, q->transactions) {
+ q->state = DNS_QUERY_PENDING;
+ q->block_ready++;
- r = dns_query_transaction_start(t);
- if (r < 0)
- goto fail;
-
- if (q->state != DNS_QUERY_PENDING)
- break;
+ SET_FOREACH(t, q->transactions, i) {
+ if (t->state == DNS_QUERY_NULL) {
+ r = dns_query_transaction_go(t);
+ if (r < 0)
+ goto fail;
+ }
}
+ q->block_ready--;
+ dns_query_ready(q);
+
return 1;
fail:
return r;
}
-void dns_query_finish(DnsQuery *q) {
+void dns_query_ready(DnsQuery *q) {
DnsQueryTransaction *t;
DnsQueryState state = DNS_QUERY_NO_SERVERS;
- DnsPacket *received = NULL;
+ _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
+ int rcode = 0;
+ DnsScope *scope = NULL;
+ Iterator i;
assert(q);
+ 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, 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) {
+
+ /* If we found a successful answer, ignore all answers from other scopes */
+ if (state == DNS_QUERY_SUCCESS && t->scope != scope)
+ continue;
/* 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;
- /* One of the transactions is successful, let's use it */
+ /* 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);
- dns_query_set_state(q, DNS_QUERY_SUCCESS);
- return;
+ 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_QUERY_SUCCESS) {
+ DnsAnswer *merged;
+
+ merged = dns_answer_merge(answer, a);
+ if (!merged) {
+ dns_query_complete(q, DNS_QUERY_RESOURCES);
+ return;
+ }
+
+ dns_answer_unref(answer);
+ answer = merged;
+ } else {
+ dns_answer_unref(answer);
+ answer = dns_answer_ref(a);
+ }
+
+ scope = t->scope;
+ state = DNS_QUERY_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;
+ * its response data */
+ if (state != DNS_QUERY_SUCCESS && t->state == DNS_QUERY_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_QUERY_FAILURE;
continue;
}
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 (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) {
-
- for (; i > 0; i--)
- free(keys[i-1].name);
- free(keys);
- return -ENOMEM;
- }
+ if (IN_SET(state, DNS_QUERY_SUCCESS, DNS_QUERY_FAILURE)) {
+ q->answer = dns_answer_ref(answer);
+ q->answer_rcode = rcode;
+ q->answer_ifindex = (scope && scope->link) ? scope->link->ifindex : 0;
}
- for (i = 0; i < q->n_keys; i++)
- free(q->keys[i].name);
- free(q->keys);
-
- q->keys = keys;
-
- q->n_cname++;
-
- 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 (rr->key.class != q->keys[i].class)
- continue;
-
- if (rr->key.type != q->keys[i].type &&
- q->keys[i].type != DNS_TYPE_ANY)
- continue;
-
- r = dns_name_equal(rr->key.name, q->keys[i].name);
- if (r != 0)
- return r;
- }
-
- return 0;
-}
-
-int dns_query_matches_cname(DnsQuery *q, DnsResourceRecord *rr) {
- unsigned i;
- int r;
+ if (q->n_cname_redirects > CNAME_MAX)
+ return -ELOOP;
- assert(q);
- assert(rr);
+ r = dns_question_cname_redirect(q->question, name, &nq);
+ if (r < 0)
+ return r;
- for (i = 0; i < q->n_keys; i++) {
+ dns_question_unref(q->question);
+ q->question = nq;
+ nq = NULL;
- if (rr->key.class != q->keys[i].class)
- continue;
+ q->n_cname_redirects++;
- if (rr->key.type != DNS_TYPE_CNAME)
- continue;
-
- r = dns_name_equal(rr->key.name, q->keys[i].name);
- if (r != 0)
- return r;
- }
+ dns_query_stop(q);
+ q->state = DNS_QUERY_NULL;
return 0;
}