[Minor] Improve monitored errors

diff --git a/src/libserver/monitored.c b/src/libserver/monitored.c
index b94229a24d15498eed6957e1f9e5441dac14cc69..ff4e4edab06a66423ab8d7025e6e276fc0bc66d0 100644 (file)
--- a/src/libserver/monitored.c
+++ b/src/libserver/monitored.c
@@ -14,11 +14,13 @@
  * limitations under the License.
  */
 
+#include <contrib/librdns/rdns.h>
 #include "rdns.h"
 #include "mem_pool.h"
 #include "cfg_file.h"
 #include "cryptobox.h"
 #include "logger.h"
+#include "contrib/uthash/utlist.h"
 
 static const gdouble default_monitoring_interval = 60.0;
 static const guint default_max_errors = 3;
@@ -272,6 +274,8 @@ rspamd_monitored_dns_cb (struct rdns_reply *reply, void *arg)
 {
        struct rspamd_dns_monitored_conf *conf = arg;
        struct rspamd_monitored *m;
+       struct rdns_reply_entry *cur;
+       gboolean is_special_reply = FALSE;
        gdouble lat;
 
        m = conf->m;
@@ -297,11 +301,30 @@ rspamd_monitored_dns_cb (struct rdns_reply *reply, void *arg)
                                        rspamd_monitored_propagate_success (m, lat);
                                }
                                else {
-                                       msg_info_mon ("DNS reply returned '%s' for %s while '%s' "
-                                                       "was expected",
-                                                       rdns_strerror (reply->code),
-                                                       m->url,
-                                                       rdns_strerror (conf->expected_code));
+                                       LL_FOREACH (reply->entries, cur) {
+                                               if (cur->type == RDNS_REQUEST_A) {
+                                                       if ((guint32)cur->content.a.addr.s_addr ==
+                                                               INADDR_LOOPBACK) {
+                                                               is_special_reply = TRUE;
+                                                       }
+                                               }
+                                       }
+
+                                       if (is_special_reply) {
+                                               msg_info_mon ("DNS query blocked on %s "
+                                                                         "(127.0.0.1 returned), "
+                                                                         "possibly due to high volume",
+                                                               m->url);
+                                       }
+                                       else {
+                                               msg_info_mon ("DNS reply returned '%s' for %s while '%s' "
+                                                                         "was expected "
+                                                                         "(likely DNS spoofing or BL internal issues)",
+                                                               rdns_strerror (reply->code),
+                                                               m->url,
+                                                               rdns_strerror (conf->expected_code));
+                                       }
+
                                        rspamd_monitored_propagate_error (m, "invalid return");
                                }
                        }