ap: Don't defer ap_reset when ap_free called in event

Previously we added logic to defer doing anything in ap_free() to after
the AP event handler has returned so that ap_event() has a chance to
inform whoever called it that the ap_state has been freed.  But there's
also a chance that the event handler is destroying both the AP and the
netdev it runs on, so after the handler has returned we can't even use
netdev_get_wdev_id or netdev_get_ifindex.  The easiest solution seems to
be to call ap_reset() in ap_free() even if we're within an event handler
to ensure we no longer need any external objects.  Also make sure
ap_reset() can be called multiple times.

Another option would be to watch for NETDEV_WATCH_EVENT_DEL and remove
our reference to the netdev (because there's no need actually call
l_rtnl_ifaddr_delete or frame_watch_wdev_remove if the netdev was
destroyed -- frame_watch already tracks netdev removals), or to save
just the ifindex and the wdev id...
This commit is contained in:
Andrew Zaborowski 2022-01-21 11:24:37 +01:00 committed by Denis Kenzior
parent 4a3792da7e
commit 079489bd66
1 changed files with 16 additions and 8 deletions

View File

@ -207,16 +207,22 @@ static void ap_reset(struct ap_state *ap)
ap->authorized_macs_num = 0;
}
if (ap->mlme_watch)
if (ap->mlme_watch) {
l_genl_family_unregister(ap->nl80211, ap->mlme_watch);
ap->mlme_watch = 0;
}
frame_watch_wdev_remove(netdev_get_wdev_id(netdev));
if (ap->start_stop_cmd_id)
if (ap->start_stop_cmd_id) {
l_genl_family_cancel(ap->nl80211, ap->start_stop_cmd_id);
ap->start_stop_cmd_id = 0;
}
if (ap->rtnl_add_cmd)
if (ap->rtnl_add_cmd) {
l_netlink_cancel(rtnl, ap->rtnl_add_cmd);
ap->rtnl_add_cmd = 0;
}
if (ap->rtnl_get_gateway4_mac_cmd) {
l_netlink_cancel(rtnl, ap->rtnl_get_gateway4_mac_cmd);
@ -228,12 +234,12 @@ static void ap_reset(struct ap_state *ap)
ap->rtnl_get_dns4_mac_cmd = 0;
}
l_queue_destroy(ap->sta_states, ap_sta_free);
l_queue_destroy(l_steal_ptr(ap->sta_states), ap_sta_free);
if (ap->rates)
l_uintset_free(ap->rates);
l_uintset_free(l_steal_ptr(ap->rates));
l_queue_destroy(ap->wsc_pbc_probes, l_free);
l_queue_destroy(l_steal_ptr(ap->wsc_pbc_probes), l_free);
l_timeout_remove(ap->wsc_pbc_timeout);
ap->started = false;
@ -258,7 +264,8 @@ static bool ap_event_done(struct ap_state *ap, bool prev_in_event)
ap->in_event = prev_in_event;
if (!prev_in_event && ap->free_pending) {
ap_free(ap);
l_genl_family_free(ap->nl80211);
l_free(ap);
return true;
}
@ -3386,12 +3393,13 @@ free_ap:
/* Free @ap without a graceful shutdown */
void ap_free(struct ap_state *ap)
{
ap_reset(ap);
if (ap->in_event) {
ap->free_pending = true;
return;
}
ap_reset(ap);
l_genl_family_free(ap->nl80211);
l_free(ap);
}