BUG/MINOR: resolvers: answser item list was randomly purged or errors
In case of SRV records, The answer item list was purged by the
error callback of the first requester which considers the error
could not be safely ignored. It makes this item list unavailable
for subsequent requesters even if they consider the error
could be ignored.
On A resolution or do_resolve action error, the answer items were
never trashed.
This patch re-work the error callbacks and the code to check the return code
If a callback return 1, we consider the error was ignored and
the answer item list must be kept. At the opposite, If all error callbacks
of all requesters of the same resolution returns 0 the list will be purged
This patch should be backported as far as 2.0.
diff --git a/src/action.c b/src/action.c
index e44ac53..1333fb3 100644
--- a/src/action.c
+++ b/src/action.c
@@ -157,6 +157,12 @@
return 0;
}
+/*
+ * Do resolve error management callback
+ * returns:
+ * 0 if we can trash answser items.
+ * 1 when safely ignored and we must kept answer items
+ */
int act_resolution_error_cb(struct resolv_requester *requester, int error_code)
{
struct stream *stream;
diff --git a/src/resolvers.c b/src/resolvers.c
index 9e08b64..85b10d6 100644
--- a/src/resolvers.c
+++ b/src/resolvers.c
@@ -1900,6 +1900,7 @@
unsigned short query_id;
struct eb32_node *eb;
struct resolv_requester *req;
+ int keep_answer_items;
resolvers = ns->parent;
HA_SPIN_LOCK(DNS_LOCK, &resolvers->lock);
@@ -2034,8 +2035,11 @@
goto report_res_success;
report_res_error:
+ keep_answer_items = 0;
list_for_each_entry(req, &res->requesters, list)
- req->requester_error_cb(req, dns_resp);
+ keep_answer_items |= req->requester_error_cb(req, dns_resp);
+ if (!keep_answer_items)
+ resolv_purge_resolution_answer_records(res);
resolv_reset_resolution(res);
LIST_DELETE(&res->list);
LIST_APPEND(&resolvers->resolutions.wait, &res->list);
@@ -2097,12 +2101,15 @@
* the list */
if (!res->try) {
struct resolv_requester *req;
+ int keep_answer_items = 0;
/* Notify the result to the requesters */
if (!res->nb_responses)
res->status = RSLV_STATUS_TIMEOUT;
list_for_each_entry(req, &res->requesters, list)
- req->requester_error_cb(req, res->status);
+ keep_answer_items |= req->requester_error_cb(req, res->status);
+ if (!keep_answer_items)
+ resolv_purge_resolution_answer_records(res);
/* Clean up resolution info and remove it from the
* current list */
diff --git a/src/server.c b/src/server.c
index 62f0bcb..c2c52e7 100644
--- a/src/server.c
+++ b/src/server.c
@@ -3436,8 +3436,8 @@
/*
* SRV record error management callback
* returns:
- * 0 on error
- * 1 when no error or safe ignore
+ * 0 if we can trash answser items.
+ * 1 when safely ignored and we must kept answer items
*
* Grabs the server's lock.
*/
@@ -3452,7 +3452,7 @@
/* SRV records */
srvrq = objt_resolv_srvrq(requester->owner);
if (!srvrq)
- return 1;
+ return 0;
resolvers = srvrq->resolvers;
res = requester->resolution;
@@ -3502,16 +3502,14 @@
HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
}
- resolv_purge_resolution_answer_records(res);
-
- return 1;
+ return 0;
}
/*
* Server Name Resolution error management callback
* returns:
- * 0 on error
- * 1 when no error or safe ignore
+ * 0 if we can trash answser items.
+ * 1 when safely ignored and we must kept answer items
*
* Grabs the server's lock.
*/
@@ -3521,11 +3519,16 @@
s = objt_server(requester->owner);
if (!s)
- return 1;
+ return 0;
+
HA_SPIN_LOCK(SERVER_LOCK, &s->lock);
- if (!snr_update_srv_status(s, 1))
+ if (!snr_update_srv_status(s, 1)) {
memset(&s->addr, 0, sizeof(s->addr));
+ HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
+ return 0;
+ }
HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
+
return 1;
}