From 1f08e84ff642294e42d138442a388989ffb20865 Mon Sep 17 00:00:00 2001 From: Igor Perminov Date: Tue, 22 Sep 2009 00:25:44 +0400 Subject: [PATCH] mac80211: Fix [re]association power saving issue on AP side Consider the following step-by step: 1. A STA authenticates and associates with the AP and exchanges traffic. 2. The STA reports to the AP that it is going to PS state. 3. Some time later the STA device goes to the stand-by mode (not only its wi-fi card, but the device itself) and drops the association state without sending a disassociation frame. 4. The STA device wakes up and begins authentication with an Auth frame as it hasn't been authenticated/associated previously. At the step 4 the AP "remembers" the STA and considers it is still in the PS state, so the AP buffers frames, which it has to send to the STA. But the STA isn't actually in the PS state and so it neither checks TIM bits nor reports to the AP that it isn't power saving. Because of that authentication/[re]association fails. To fix authentication/[re]association stage of this issue, Auth, Assoc Resp and Reassoc Resp frames are transmitted disregarding of STA's power saving state. N.B. This patch doesn't fix further data frame exchange after authentication/[re]association. A patch in hostapd is required to fix that. Signed-off-by: Igor Perminov Signed-off-by: John W. Linville --- net/mac80211/tx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 5143d20..fd40282 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -367,7 +367,10 @@ ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx) struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; u32 staflags; - if (unlikely(!sta || ieee80211_is_probe_resp(hdr->frame_control))) + if (unlikely(!sta || ieee80211_is_probe_resp(hdr->frame_control) + || ieee80211_is_auth(hdr->frame_control) + || ieee80211_is_assoc_resp(hdr->frame_control) + || ieee80211_is_reassoc_resp(hdr->frame_control))) return TX_CONTINUE; staflags = get_sta_flags(sta); -- 2.7.4