BUG/MAJOR: checks: break infinite loops when tcp-checks starts with comment
If a tcp-check sequence starts with "comment", then the action is not
matched in the while() loop and the pointer doesn't advance so we face
an endless loop. It is normally detected early except in the case where
very slow checks are performed causing it to trigger after the admin stops
watching.
This bug is 1.6-only and very recent so it didn't have the time to affect
anyone.
diff --git a/src/checks.c b/src/checks.c
index 9b09645..8d8c31c 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -2455,8 +2455,14 @@
* wait for a connection to complete unless we're before and existing
* step 1.
*/
+
+ /* find first rule and skip comments */
+ next = LIST_NEXT(head, struct tcpcheck_rule *, list);
+ while (&next->list != head && next->action == TCPCHK_ACT_COMMENT)
+ next = LIST_NEXT(&next->list, struct tcpcheck_rule *, list);
+
if ((!(conn->flags & CO_FL_CONNECTED) || (conn->flags & CO_FL_HANDSHAKE)) &&
- (check->current_step || LIST_ISEMPTY(head))) {
+ (check->current_step || &next->list == head)) {
/* we allow up to min(inter, timeout.connect) for a connection
* to establish but only when timeout.check is set
* as it may be to short for a full check otherwise
@@ -2474,7 +2480,7 @@
}
/* special case: option tcp-check with no rule, a connect is enough */
- if (LIST_ISEMPTY(head)) {
+ if (&next->list == head) {
set_server_check_status(check, HCHK_STATUS_L4OK, NULL);
goto out_end_tcpcheck;
}
@@ -2486,7 +2492,7 @@
check->bo->o = 0;
check->bi->p = check->bi->data;
check->bi->i = 0;
- check->current_step = LIST_ELEM(head->n, struct tcpcheck_rule *, list);
+ check->current_step = next;
t->expire = tick_add(now_ms, MS_TO_TICKS(check->inter));
if (s->proxy->timeout.check)
t->expire = tick_add_ifset(now_ms, s->proxy->timeout.check);