nl80211: add generation number to all dumps

In order for userspace to be able to figure out whether
it obtained a consistent snapshot of data or not when
using netlink dumps, we need to have a generation number
in each dump message that indicates whether the list has
changed or not -- its value is arbitrary.

This patch adds such a number to all dumps, this needs
some mac80211 involvement to keep track of a generation
number to start with when adding/removing mesh paths or
stations.

The wiphy and netdev lists can be fully handled within
cfg80211, of course, but generation numbers need to be
stored there as well.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 4bbf5007799b..5608f6c68413 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -323,6 +323,8 @@ static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 {
         struct ieee80211_sub_if_data *sdata = sta->sdata;
 
+        sinfo->generation = sdata->local->sta_generation;
+
         sinfo->filled = STATION_INFO_INACTIVE_TIME |
                         STATION_INFO_RX_BYTES |
                         STATION_INFO_TX_BYTES |
@@ -909,6 +911,8 @@ static void mpath_set_pinfo(struct mesh_path *mpath, u8 *next_hop,
         else
                 memset(next_hop, 0, ETH_ALEN);
 
+        pinfo->generation = mesh_paths_generation;
+
         pinfo->filled = MPATH_INFO_FRAME_QLEN |
                         MPATH_INFO_DSN |
                         MPATH_INFO_METRIC |