Currently, filter-redirector does not implement the status_changed
callback, which means the 'status' property cannot be used to
dynamically enable/disable the filter at runtime. When status is
set to 'off' via QMP/HMP, the filter still receives data from the
indev chardev because the chardev handlers remain registered.
This patch adds proper support for the 'status' property:
1. Implement filter_redirector_status_changed() callback:
- When status changes to 'off': remove chardev read handlers
- When status changes to 'on': re-register chardev handlers
(only if chardev is already open)
2. Update filter_redirector_setup() to respect initial status:
- If filter is created with status=off, do not register handlers
- This allows creating disabled filters via command line or QMP
3. Handle chardev OPENED/CLOSED events to re-arm handlers on reconnect:
- Keep the chr_event callback installed on CLOSE so a later OPENED
can re-register the read handlers when nf->on
- Use qemu_chr_fe_set_handlers_full(..., set_open=false, sync_state=false)
instead of qemu_chr_fe_set_handlers() because the latter forces
sync_state=true and may emit CHR_EVENT_OPENED for an already-open
backend. Doing that from inside the chr_event callback would cause
recursive/re-entrant OPENED handling.
Signed-off-by: Jason Wang <[email protected]>
---
net/filter-mirror.c | 38 +++++++++++++++++++++++++++++++++-----
1 file changed, 33 insertions(+), 5 deletions(-)
diff --git a/net/filter-mirror.c b/net/filter-mirror.c
index 8e01e98f40..aa2ab452fd 100644
--- a/net/filter-mirror.c
+++ b/net/filter-mirror.c
@@ -179,9 +179,16 @@ static void redirector_chr_event(void *opaque,
QEMUChrEvent event)
MirrorState *s = FILTER_REDIRECTOR(nf);
switch (event) {
+ case CHR_EVENT_OPENED:
+ if (nf->on) {
+ qemu_chr_fe_set_handlers_full(&s->chr_in, redirector_chr_can_read,
+ redirector_chr_read,
redirector_chr_event,
+ NULL, nf, NULL, false, false);
+ }
+ break;
case CHR_EVENT_CLOSED:
- qemu_chr_fe_set_handlers(&s->chr_in, NULL, NULL, NULL,
- NULL, NULL, NULL, true);
+ qemu_chr_fe_set_handlers_full(&s->chr_in, NULL, NULL,
redirector_chr_event,
+ NULL, nf, NULL, false, false);
break;
default:
break;
@@ -306,9 +313,11 @@ static void filter_redirector_setup(NetFilterState *nf,
Error **errp)
return;
}
- qemu_chr_fe_set_handlers(&s->chr_in, redirector_chr_can_read,
- redirector_chr_read, redirector_chr_event,
- NULL, nf, NULL, true);
+ if (nf->on) {
+ qemu_chr_fe_set_handlers(&s->chr_in, redirector_chr_can_read,
+ redirector_chr_read, redirector_chr_event,
+ NULL, nf, NULL, true);
+ }
}
if (s->outdev) {
@@ -324,6 +333,24 @@ static void filter_redirector_setup(NetFilterState *nf,
Error **errp)
}
}
+static void filter_redirector_status_changed(NetFilterState *nf, Error **errp)
+{
+ MirrorState *s = FILTER_REDIRECTOR(nf);
+
+ if (!s->indev) {
+ return;
+ }
+
+ if (nf->on) {
+ qemu_chr_fe_set_handlers(&s->chr_in, redirector_chr_can_read,
+ redirector_chr_read, redirector_chr_event,
+ NULL, nf, NULL, true);
+ } else {
+ qemu_chr_fe_set_handlers(&s->chr_in, NULL, NULL, NULL,
+ NULL, NULL, NULL, true);
+ }
+}
+
static char *filter_redirector_get_indev(Object *obj, Error **errp)
{
MirrorState *s = FILTER_REDIRECTOR(obj);
@@ -440,6 +467,7 @@ static void filter_redirector_class_init(ObjectClass *oc,
const void *data)
nfc->setup = filter_redirector_setup;
nfc->cleanup = filter_redirector_cleanup;
nfc->receive_iov = filter_redirector_receive_iov;
+ nfc->status_changed = filter_redirector_status_changed;
}
static void filter_mirror_init(Object *obj)
--
2.34.1
