From 4d050f1daed3babf6fcc337f862a245d31af4452 Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Tue, 5 May 2009 20:35:14 +0300 Subject: mac80211: Add a timeout for frames in the RX reorder buffer This patch allows skbs to be released from the RX reorder buffer in case they have been there for an unexpectedly long time without us having received the missing frames before them. Previously, these frames were only released when the reorder window moved and that could take very long time unless new frames were received constantly (e.g., TCP connections could be killed more or less indefinitely). This situation should not happen very frequently, but it looks like there are some scenarious that trigger it for some reason. As such, this should be considered mostly a workaround to speed up recovery from unexpected siutation that could result in connections hanging for long periods of time. The changes here will only check for timeout situation when adding new RX frames to the reorder buffer. It does not handle all possible cases, but seems to help for most cases that could result from common network usage (e.g., TCP retrying at least couple of times). For more completely coverage, a timer could be used to periodically check whether there are any frames remaining in the reorder buffer if no new frames are received. Signed-off-by: Jouni Malinen Signed-off-by: John W. Linville --- net/mac80211/agg-rx.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'net/mac80211/agg-rx.c') diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c index fff24c3d6460..bc064d7933ff 100644 --- a/net/mac80211/agg-rx.c +++ b/net/mac80211/agg-rx.c @@ -68,6 +68,7 @@ void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid, spin_lock_bh(&sta->lock); /* free resources */ kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf); + kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_time); if (!sta->ampdu_mlme.tid_rx[tid]->shutdown) { kfree(sta->ampdu_mlme.tid_rx[tid]); @@ -268,13 +269,18 @@ void ieee80211_process_addba_request(struct ieee80211_local *local, /* prepare reordering buffer */ tid_agg_rx->reorder_buf = kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC); - if (!tid_agg_rx->reorder_buf) { + tid_agg_rx->reorder_time = + kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC); + if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) { #ifdef CONFIG_MAC80211_HT_DEBUG if (net_ratelimit()) printk(KERN_ERR "can not allocate reordering buffer " "to tid %d\n", tid); #endif + kfree(tid_agg_rx->reorder_buf); + kfree(tid_agg_rx->reorder_time); kfree(sta->ampdu_mlme.tid_rx[tid]); + sta->ampdu_mlme.tid_rx[tid] = NULL; goto end; } -- cgit v1.2.1