cfg80211: allow userspace to take ownership of interfaces

When dynamically creating interfaces from userspace, e.g. for P2P usage,
such interfaces are usually owned by the process that created them, i.e.
wpa_supplicant. Should wpa_supplicant crash, such interfaces will often
cease operating properly and cause problems on restarting the process.

To avoid this problem, introduce an ownership concept for interfaces. If
an interface is owned by a netlink socket, then it will be destroyed if
the netlink socket is closed for any reason, including if the process it
belongs to crashed. This gives us a race-free way to get rid of any such
interfaces.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index f3539a15c411..6510ccf53a54 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3194,6 +3194,7 @@ struct cfg80211_cached_keys;
  * @ibss_dfs_possible: (private) IBSS may change to a DFS channel
  * @event_list: (private) list for internal event processing
  * @event_lock: (private) lock for event list
+ * @owner_nlportid: (private) owner socket port ID
  */
 struct wireless_dev {
         struct wiphy *wiphy;
@@ -3241,6 +3242,8 @@ struct wireless_dev {
         unsigned long cac_start_time;
         unsigned int cac_time_ms;
 
+        u32 owner_nlportid;
+
 #ifdef CONFIG_CFG80211_WEXT
         /* wext data */
         struct {