BUG/MINOR: resolvers: new callback to properly handle SRV record errors
When a SRV record was created, it used to register the regular server name
resolution callbacks. That said, SRV records and regular server name
resolution don't work the same way, furthermore on error management.
This patch introduces a new call back to manage DNS errors related to
the SRV queries.
this fixes github issue #50.
Backport status: 2.3, 2.2, 2.1, 2.0
(cherry picked from commit b4badf720ce484001f606011aee7cd216e5ce4e3)
[cf: Changes applied in src/dns.c and structures renamed]
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/server.c b/src/server.c
index 035494b..daa9d4a 100644
--- a/src/server.c
+++ b/src/server.c
@@ -3901,6 +3901,78 @@
}
/*
+ * SRV record error management callback
+ * returns:
+ * 0 on error
+ * 1 when no error or safe ignore
+ *
+ * Grabs the server's lock.
+ */
+int srvrq_resolution_error_cb(struct dns_requester *requester, int error_code)
+{
+ struct server *s;
+ struct dns_srvrq *srvrq;
+ struct dns_resolution *res;
+ struct dns_resolvers *resolvers;
+ int exp;
+
+ /* SRV records */
+ srvrq = objt_dns_srvrq(requester->owner);
+ if (!srvrq)
+ return 1;
+
+ resolvers = srvrq->resolvers;
+ res = requester->resolution;
+
+ switch (res->status) {
+
+ case RSLV_STATUS_NX:
+ /* stop server if resolution is NX for a long enough period */
+ exp = tick_add(res->last_valid, resolvers->hold.nx);
+ if (!tick_is_expired(exp, now_ms))
+ return 1;
+ break;
+
+ case RSLV_STATUS_TIMEOUT:
+ /* stop server if resolution is TIMEOUT for a long enough period */
+ exp = tick_add(res->last_valid, resolvers->hold.timeout);
+ if (!tick_is_expired(exp, now_ms))
+ return 1;
+ break;
+
+ case RSLV_STATUS_REFUSED:
+ /* stop server if resolution is REFUSED for a long enough period */
+ exp = tick_add(res->last_valid, resolvers->hold.refused);
+ if (!tick_is_expired(exp, now_ms))
+ return 1;
+ break;
+
+ default:
+ /* stop server if resolution failed for a long enough period */
+ exp = tick_add(res->last_valid, resolvers->hold.other);
+ if (!tick_is_expired(exp, now_ms))
+ return 1;
+ }
+
+ /* Remove any associated server */
+ for (s = srvrq->proxy->srv; s != NULL; s = s->next) {
+ HA_SPIN_LOCK(SERVER_LOCK, &s->lock);
+ if (s->srvrq == srvrq) {
+ snr_update_srv_status(s, 1);
+ free(s->hostname);
+ free(s->hostname_dn);
+ s->hostname = NULL;
+ s->hostname_dn = NULL;
+ s->hostname_dn_len = 0;
+ dns_unlink_resolution(s->dns_requester);
+ }
+ HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
+ }
+
+ return 1;
+}
+
+/*
* Server Name Resolution error management callback
* returns:
* 0 on error