diff mbox

mac80211: Fix mesh estab_plinks counting in STA removal case

Message ID 20160619205102.GA28350@w1.fi
State Accepted
Delegated to: Johannes Berg
Headers show

Commit Message

Jouni Malinen June 19, 2016, 8:51 p.m. UTC
If a user space program (e.g., wpa_supplicant) deletes a STA entry that
is currently in NL80211_PLINK_ESTAB state, the number of established
plinks counter was not decremented and this could result in rejecting
new plink establishment before really hitting the real maximum plink
limit. For !user_mpm case, this decrementation is handled by
mesh_plink_deactive().

Fix this by decrementing estab_plinks on STA deletion
(mesh_sta_cleanup() gets called from there) so that the counter has a
correct value and the Beacon frame advertisement in Mesh Configuration
element shows the proper value for capability to accept additional
peers.

Signed-off-by: Jouni Malinen <j@w1.fi>
---
 net/mac80211/mesh.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Comments

Johannes Berg June 21, 2016, 7:09 p.m. UTC | #1
>  	 */
> -	changed = mesh_accept_plinks_update(sdata);
> +	if (sdata->u.mesh.user_mpm &&
> +	    sta->mesh->plink_state == NL80211_PLINK_ESTAB)
> +		changed |= mesh_plink_dec_estab_count(sdata);
> +	changed |= mesh_accept_plinks_update(sdata);
>  	if (!sdata->u.mesh.user_mpm) {
>  		changed |= mesh_plink_deactivate(sta);
>  		del_timer_sync(&sta->mesh->plink_timer);
> 

Does it have to be done before the mesh_accept_plinks_update()?

If not, you should put it with the existing u.mesh.user_mpm check. If
yes, then the code is further buggy since only mesh_plink_deactivate()
will call it when the kernel MPM is used.

johannes
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Johannes Berg June 28, 2016, 10:40 a.m. UTC | #2
On Sun, 2016-06-19 at 23:51 +0300, Jouni Malinen wrote:
> If a user space program (e.g., wpa_supplicant) deletes a STA entry
> that
> is currently in NL80211_PLINK_ESTAB state, the number of established
> plinks counter was not decremented and this could result in rejecting
> new plink establishment before really hitting the real maximum plink
> limit. For !user_mpm case, this decrementation is handled by
> mesh_plink_deactive().
> 
> Fix this by decrementing estab_plinks on STA deletion
> (mesh_sta_cleanup() gets called from there) so that the counter has a
> correct value and the Beacon frame advertisement in Mesh
> Configuration
> element shows the proper value for capability to accept additional
> peers.
> 

Applied.

johannes
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diff mbox

Patch

diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 21b1fdf..6a1603b 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -148,14 +148,17 @@  u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
 void mesh_sta_cleanup(struct sta_info *sta)
 {
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
-	u32 changed;
+	u32 changed = 0;
 
 	/*
 	 * maybe userspace handles peer allocation and peering, but in either
 	 * case the beacon is still generated by the kernel and we might need
 	 * an update.
 	 */
-	changed = mesh_accept_plinks_update(sdata);
+	if (sdata->u.mesh.user_mpm &&
+	    sta->mesh->plink_state == NL80211_PLINK_ESTAB)
+		changed |= mesh_plink_dec_estab_count(sdata);
+	changed |= mesh_accept_plinks_update(sdata);
 	if (!sdata->u.mesh.user_mpm) {
 		changed |= mesh_plink_deactivate(sta);
 		del_timer_sync(&sta->mesh->plink_timer);