#define TRANSACTION_TIMEOUT_USEC (5 * USEC_PER_SEC)
#define QUERY_TIMEOUT_USEC (30 * USEC_PER_SEC)
#define ATTEMPTS_MAX 8
+#define CNAME_MAX 8
+
+static int dns_query_transaction_start(DnsQueryTransaction *t);
DnsQueryTransaction* dns_query_transaction_free(DnsQueryTransaction *t) {
if (!t)
t->state = state;
- if (state != DNS_QUERY_SENT) {
+ if (state != DNS_QUERY_PENDING) {
dns_query_transaction_stop(t);
dns_query_finish(t->query);
}
assert(t);
assert(p);
- if (t->state != DNS_QUERY_SENT)
+ if (t->state != DNS_QUERY_PENDING)
return;
if (t->received != p) {
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) {
- dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ /* Couldn't send? Try immediately again, with a new server */
+ dns_scope_next_dns_server(t->scope);
+
+ r = dns_query_transaction_start(t);
+ if (r < 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return;
+ }
+
return;
}
}
return 0;
}
-int dns_query_transaction_start(DnsQueryTransaction *t) {
+static int dns_query_transaction_start(DnsQueryTransaction *t) {
int r;
assert(t);
dns_query_transaction_set_state(t, DNS_QUERY_ATTEMPTS_MAX);
return 0;
}
- t->n_attempts++;
r = dns_query_make_packet(t);
if (r < 0)
return r;
+ t->n_attempts++;
+ t->received = dns_packet_unref(t->received);
+
/* 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)
if (r < 0)
return r;
- dns_query_transaction_set_state(t, DNS_QUERY_SENT);
+ dns_query_transaction_set_state(t, DNS_QUERY_PENDING);
return 1;
}
int dns_query_new(Manager *m, DnsQuery **ret, DnsResourceKey *keys, unsigned n_keys) {
_cleanup_(dns_query_freep) DnsQuery *q = NULL;
- DnsScope *s, *first = NULL;
- DnsScopeMatch found = DNS_SCOPE_NO;
const char *name = NULL;
- int n, r;
assert(m);
LIST_PREPEND(queries, m->dns_queries, q);
q->manager = m;
- LIST_FOREACH(scopes, s, m->dns_scopes) {
+ 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);
+}
+
+static void dns_query_set_state(DnsQuery *q, DnsQueryState state) {
+ DnsQueryState old_state;
+ assert(q);
+
+ if (q->state == state)
+ return;
+
+ 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);
+ }
+}
+
+static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
+ DnsQuery *q = userdata;
+
+ assert(s);
+ assert(q);
+
+ dns_query_set_state(q, DNS_QUERY_TIMEOUT);
+ return 0;
+}
+
+int dns_query_start(DnsQuery *q) {
+ DnsScopeMatch found = DNS_SCOPE_NO;
+ DnsScope *s, *first = NULL;
+ DnsQueryTransaction *t;
+ int r;
+
+ assert(q);
+
+ if (q->state != DNS_QUERY_NULL)
+ return 0;
+
+ assert(q->n_keys > 0);
+
+ LIST_FOREACH(scopes, s, q->manager->dns_scopes) {
DnsScopeMatch match;
- match = dns_scope_test(s, name);
+ match = dns_scope_test(s, q->keys[0].name);
if (match < 0)
return match;
}
if (found == DNS_SCOPE_NO)
- return -ENETDOWN;
+ return -ESRCH;
r = dns_query_transaction_new(q, NULL, first);
if (r < 0)
return r;
- n = 1;
LIST_FOREACH(scopes, s, first->scopes_next) {
DnsScopeMatch match;
- match = dns_scope_test(s, name);
+ match = dns_scope_test(s, q->keys[0].name);
if (match < 0)
return match;
r = dns_query_transaction_new(q, NULL, s);
if (r < 0)
return r;
-
- n++;
}
- if (ret)
- *ret = q;
- q = NULL;
-
- return n;
-}
-
-static void dns_query_set_state(DnsQuery *q, DnsQueryState state) {
- assert(q);
-
- if (q->state == state)
- return;
-
- q->state = state;
-
- if (state == DNS_QUERY_SENT)
- return;
-
- q->timeout_event_source = sd_event_source_unref(q->timeout_event_source);
-
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
-
- if (q->complete)
- q->complete(q);
-}
-
-static int on_query_timeout(sd_event_source *s, usec_t usec, void *userdata) {
- DnsQuery *q = userdata;
-
- assert(s);
- assert(q);
-
- dns_query_set_state(q, DNS_QUERY_TIMEOUT);
- return 0;
-}
-
-int dns_query_start(DnsQuery *q) {
- DnsQueryTransaction *t;
- int r;
-
- assert(q);
- assert(q->state == DNS_QUERY_NULL);
-
- if (!q->transactions)
- return -ENETDOWN;
+ 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);
if (r < 0)
goto fail;
- dns_query_set_state(q, DNS_QUERY_SENT);
+ dns_query_set_state(q, DNS_QUERY_PENDING);
LIST_FOREACH(transactions_by_query, t, q->transactions) {
if (r < 0)
goto fail;
- if (q->state != DNS_QUERY_SENT)
+ if (q->state != DNS_QUERY_PENDING)
break;
}
- return 0;
+ return 1;
fail:
- while (q->transactions)
- dns_query_transaction_free(q->transactions);
-
+ dns_query_stop(q);
return r;
}
assert(q);
- if (q->state != DNS_QUERY_SENT)
+ if (q->state != DNS_QUERY_PENDING)
return;
LIST_FOREACH(transactions_by_query, t, q->transactions) {
/* One of the transactions is still going on, let's wait for it */
- if (t->state == DNS_QUERY_SENT || t->state == DNS_QUERY_NULL)
+ if (t->state == DNS_QUERY_PENDING || t->state == DNS_QUERY_NULL)
return;
/* One of the transactions is successful, let's use it */
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;
+ }
+ }
+
+ 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;
+}
+
+int dns_query_matches_rr(DnsQuery *q, DnsResourceRecord *rr) {
+ unsigned i;
+ 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;
+
+ 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;
+ }
+
+ return 0;
+}
~ianmdlvl / elogind.git / blobdiff