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/mac80211/cfg.c b/net/mac80211/cfg.c
index 4bbf500..5608f6c 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -323,6 +323,8 @@
{
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 @@
else
memset(next_hop, 0, ETH_ALEN);
+ pinfo->generation = mesh_paths_generation;
+
pinfo->filled = MPATH_INFO_FRAME_QLEN |
MPATH_INFO_DSN |
MPATH_INFO_METRIC |
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 9895917..9943322 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -678,6 +678,7 @@
struct list_head sta_list;
struct sta_info *sta_hash[STA_HASH_SIZE];
struct timer_list sta_cleanup;
+ int sta_generation;
struct sk_buff_head pending[IEEE80211_MAX_QUEUES];
struct tasklet_struct tx_pending_tasklet;
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 2a2ed18..ce53881 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -265,6 +265,8 @@
void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
+extern int mesh_paths_generation;
+
#ifdef CONFIG_MAC80211_MESH
extern int mesh_allocated;
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 04b9e4d..431865a 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -38,6 +38,8 @@
static struct mesh_table *mesh_paths;
static struct mesh_table *mpp_paths; /* Store paths for MPP&MAP */
+int mesh_paths_generation;
+
/* This lock will have the grow table function as writer and add / delete nodes
* as readers. When reading the table (i.e. doing lookups) we are well protected
* by RCU
@@ -243,6 +245,8 @@
mesh_paths->mean_chain_len * (mesh_paths->hash_mask + 1))
grow = 1;
+ mesh_paths_generation++;
+
spin_unlock(&mesh_paths->hashwlock[hash_idx]);
read_unlock(&pathtbl_resize_lock);
if (grow) {
@@ -484,6 +488,7 @@
err = -ENXIO;
enddel:
+ mesh_paths_generation++;
spin_unlock(&mesh_paths->hashwlock[hash_idx]);
read_unlock(&pathtbl_resize_lock);
return err;
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index a360bce..eec0014 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -349,6 +349,7 @@
goto out_free;
}
list_add(&sta->list, &local->sta_list);
+ local->sta_generation++;
local->num_sta++;
sta_info_hash_add(local, sta);
@@ -485,6 +486,7 @@
}
local->num_sta--;
+ local->sta_generation++;
if (local->ops->sta_notify) {
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)