MEDIUM: proto_ux: properly suspend named UNIX listeners
When a listener is suspended, we expect that it may not process any data for
the time it is suspended.
Yet for named UNIX socket, as the suspend operation is a no-op at the proto
level, recv events on the socket may still be processed by the polling loop.
This is quite disturbing as someone may rely on a paused proxy being harmless,
which is true for all protos except for named UNIX sockets.
To fix this behavior, we explicitely disable io recv events when suspending a
named UNIX socket listener (we call disable() method on the listener).
The io recv events will automatically be restored when the listener is resumed
since the l->enable() method is called at the end of the resume() operation.
This could be backported up to 2.4 after a reasonable observation
period to make sure that this change doesn't cause unwanted side-effects.
(cherry picked from commit 2338dba18db3a895fd394a6c07544f03c7f39167)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 115b9fdc39d2408b38ac3331237a4deec4cd7346)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit 49da244638c88f4fa44c0c21fa7e90e9f394dee8)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 78af2135643de2456708672e71da03363999fe65)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/proto_uxdg.c b/src/proto_uxdg.c
index 3db94f1..36f4c59 100644
--- a/src/proto_uxdg.c
+++ b/src/proto_uxdg.c
@@ -126,17 +126,20 @@
}
/* Suspend a receiver. Returns < 0 in case of failure, 0 if the receiver
- * was totally stopped, or > 0 if correctly suspended. Nothing is done for
- * plain unix sockets since currently it's the new process which handles
- * the renaming. Abstract sockets are completely unbound and closed so
- * there's no need to stop the poller.
+ * was totally stopped, or > 0 if correctly suspended. For plain unix sockets
+ * we only disable the listener to prevent data from being handled but nothing
+ * more is done since currently it's the new process which handles the renaming.
+ * Abstract sockets are completely unbound and closed so there's no need to stop
+ * the poller.
*/
static int uxdg_suspend_receiver(struct receiver *rx)
{
struct listener *l = LIST_ELEM(rx, struct listener *, rx);
- if (((struct sockaddr_un *)&rx->addr)->sun_path[0])
+ if (((struct sockaddr_un *)&rx->addr)->sun_path[0]) {
+ uxdg_disable_listener(l);
return 1;
+ }
/* Listener's lock already held. Call lockless version of
* unbind_listener. */