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>
diff --git a/net/wireless/core.c b/net/wireless/core.c
index 1e18930..62e1ac0 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -32,6 +32,7 @@
* only read the list, and that can happen quite
* often because we need to do it for each command */
LIST_HEAD(cfg80211_rdev_list);
+int cfg80211_rdev_list_generation;
/*
* This is used to protect the cfg80211_rdev_list
@@ -511,6 +512,7 @@
wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
list_add(&rdev->list, &cfg80211_rdev_list);
+ cfg80211_rdev_list_generation++;
mutex_unlock(&cfg80211_mutex);
@@ -593,6 +595,7 @@
reg_device_remove(wiphy);
list_del(&rdev->list);
+ cfg80211_rdev_list_generation++;
device_del(&rdev->wiphy.dev);
debugfs_remove(rdev->wiphy.debugfsdir);
@@ -653,6 +656,7 @@
spin_lock_init(&wdev->event_lock);
mutex_lock(&rdev->devlist_mtx);
list_add(&wdev->list, &rdev->netdev_list);
+ rdev->devlist_generation++;
/* can only change netns with wiphy */
dev->features |= NETIF_F_NETNS_LOCAL;
@@ -733,6 +737,7 @@
if (!list_empty(&wdev->list)) {
sysfs_remove_link(&dev->dev.kobj, "phy80211");
list_del_init(&wdev->list);
+ rdev->devlist_generation++;
mutex_destroy(&wdev->mtx);
#ifdef CONFIG_WIRELESS_EXT
kfree(wdev->wext.keys);