BUG/MEDIUM: resolvers: Fix the loop looking for an existing ADD item

For each ADD item found in a SRV response, we try to find a corresponding
ADD item already attached to an existing SRV item. If found, the ADD
last_seen time is updated, otherwise we try to find a SRV item with no ADD
to attached the new one.

However, the loop is buggy. Instead of comparing 2 ADD items, it compares
the new ADD item with the SRV item. Because of this bug, we are unable to
renew last_seen time of existing ADD.

This patch must be backported as far as 2.2.

diff --git a/src/resolvers.c b/src/resolvers.c
index 859189d1a8081f7424cf3bc0865c0a6c706ca423..4d960b7be613828bd25de840f73c2c51b992f32d 100644 (file)
--- a/src/resolvers.c
+++ b/src/resolvers.c
@@ -1187,27 +1187,33 @@ static int resolv_validate_dns_response(unsigned char *resp, unsigned char *bufe
 
                /* Move forward answer_record->data_len for analyzing next
                 * record in the response */
-               reader += ((answer_record->type == DNS_RTYPE_SRV)
-                          ? offset
-                          : answer_record->data_len);
+               reader += answer_record->data_len;
 
                /* Lookup to see if we already had this entry */
                found = 0;
                list_for_each_entry(tmp_record, &r_res->answer_list, list) {
-                       if (tmp_record->type != answer_record->type)
+                       struct resolv_answer_item *ar_item;
+
+                       if (tmp_record->type != DNS_RTYPE_SRV || !tmp_record->ar_item)
                                continue;
 
-                       switch(tmp_record->type) {
+                       ar_item = tmp_record->ar_item;
+                       if (ar_item->type != answer_record->type ||
+                           len != tmp_record->data_len ||
+                           resolv_hostname_cmp(answer_record->name, tmp_record->target, tmp_record->data_len))
+                               continue;
+
+                       switch(ar_item->type) {
                                case DNS_RTYPE_A:
                                        if (!memcmp(&((struct sockaddr_in *)&answer_record->address)->sin_addr,
-                                                   &((struct sockaddr_in *)&tmp_record->address)->sin_addr,
+                                                   &((struct sockaddr_in *)&ar_item->address)->sin_addr,
                                                    sizeof(in_addr_t)))
                                                found = 1;
                                        break;
 
                                case DNS_RTYPE_AAAA:
                                        if (!memcmp(&((struct sockaddr_in6 *)&answer_record->address)->sin6_addr,
-                                                   &((struct sockaddr_in6 *)&tmp_record->address)->sin6_addr,
+                                                   &((struct sockaddr_in6 *)&ar_item->address)->sin6_addr,
                                                    sizeof(struct in6_addr)))
                                                found = 1;
                                        break;
@@ -1221,7 +1227,7 @@ static int resolv_validate_dns_response(unsigned char *resp, unsigned char *bufe
                }
 
                if (found == 1) {
-                       tmp_record->last_seen = now.tv_sec;
+                       tmp_record->ar_item->last_seen = now.tv_sec;
                        pool_free(resolv_answer_item_pool, answer_record);
                        answer_record = NULL;
                }