#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_start(DnsQueryTransaction *t);
+static int dns_query_transaction_go(DnsQueryTransaction *t);
DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t) {
if (!t)
dns_packet_unref(t->sent);
dns_packet_unref(t->received);
+ dns_resource_record_freev(t->cached_rrs, t->n_cached_rrs);
+
sd_event_source_unref(t->tcp_event_source);
safe_close(t->tcp_fd);
t->tcp_fd = safe_close(t->tcp_fd);
}
-static void dns_query_transaction_set_state(DnsQueryTransaction *t, DnsQueryState state) {
+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));
- 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);
+ dns_query_finish(t->query);
}
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;
}
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);
+ 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;
return 0;
}
-static int dns_query_transaction_start_tcp(DnsQueryTransaction *t) {
+static int dns_query_transaction_open_tcp(DnsQueryTransaction *t) {
int r;
assert(t);
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_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);
+
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;
}
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_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);
if (r < 0)
return r;
+ if (r > 0) {
+ t->n_cached_rrs = r;
+ dns_query_transaction_complete(t, DNS_QUERY_SUCCESS);
+ 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 < 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);
+ 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);
if (r < 0)
return r;
- dns_query_transaction_set_state(t, DNS_QUERY_PENDING);
+ t->state = DNS_QUERY_PENDING;
return 1;
}
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)
+ 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);
if (n_keys <= 0 || n_keys >= 65535)
return -EINVAL;
+ if (m->n_dns_queries >= QUERIES_MAX)
+ return -EBUSY;
+
assert(keys);
q = new0(DnsQuery, 1);
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)
dns_query_transaction_free(q->transactions);
}
-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;
}
-int dns_query_start(DnsQuery *q) {
+int dns_query_go(DnsQuery *q) {
DnsScopeMatch found = DNS_SCOPE_NO;
DnsScope *s, *first = NULL;
DnsQueryTransaction *t;
if (r < 0)
goto fail;
- dns_query_set_state(q, DNS_QUERY_PENDING);
+ q->state = DNS_QUERY_PENDING;
+ q->block_finish++;
LIST_FOREACH(transactions_by_query, t, q->transactions) {
-
- r = dns_query_transaction_start(t);
+ r = dns_query_transaction_go(t);
if (r < 0)
goto fail;
-
- if (q->state != DNS_QUERY_PENDING)
- break;
}
+ q->block_finish--;
+ dns_query_finish(q);
+
return 1;
fail:
DnsPacket *received = NULL;
assert(q);
+ assert(IN_SET(q->state, DNS_QUERY_NULL, DNS_QUERY_PENDING));
- if (q->state != 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_finish
+ * counter was explicitly bumped before doing so. */
+
+ if (q->block_finish > 0)
return;
LIST_FOREACH(transactions_by_query, t, q->transactions) {
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);
+
+ /* 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;
+
+ dns_query_complete(q, DNS_QUERY_SUCCESS);
return;
}
if (state == DNS_QUERY_FAILURE)
q->received = dns_packet_ref(received);
- dns_query_set_state(q, state);
+ dns_query_complete(q, state);
}
-int dns_query_follow_cname(DnsQuery *q, const char *name) {
+int dns_query_cname_redirect(DnsQuery *q, const char *name) {
DnsResourceKey *keys;
unsigned i;
q->n_cname++;
- dns_query_set_state(q, DNS_QUERY_NULL);
+ dns_query_stop(q);
+ q->state = DNS_QUERY_NULL;
+
return 0;
}
return 0;
}
+
+int dns_query_get_rrs(DnsQuery *q, DnsResourceRecord ***rrs) {
+ int r;
+
+ assert(q);
+ assert(rrs);
+
+ if (IN_SET(q->state, DNS_QUERY_NULL, DNS_QUERY_PENDING))
+ return -EBUSY;
+
+ if (q->received) {
+ r = dns_packet_extract_rrs(q->received);
+ 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;
+
+ return q->received->ifindex;
+}
~ianmdlvl / elogind.git / blobdiff