From 837925df022a667c302b24aad9d6a58f94efd959 Mon Sep 17 00:00:00 2001 From: Larry Finger Date: Tue, 3 Oct 2006 18:49:32 -0500 Subject: [PATCH] [PATCH] ieee80211: Drop and count duplicate data frames to remove 'replay detected' log messages In the SoftMAC version of the IEEE 802.11 stack, not all duplicate messages are detected. For the most part, there is no difficulty; however for TKIP and CCMP encryption, the duplicates result in a "replay detected" log message where the received and previous values of the TSC are identical. This change adds a new variable to the ieee80211_device structure that holds the 'seq_ctl' value for the previous frame. When a new frame repeats the value, the frame is dropped and the appropriate counter is incremented. Signed-off-by: Larry Finger Signed-off-by: John W. Linville --- include/net/ieee80211.h | 2 ++ net/ieee80211/ieee80211_rx.c | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/include/net/ieee80211.h b/include/net/ieee80211.h index cb255432e4e..e6af381e206 100644 --- a/include/net/ieee80211.h +++ b/include/net/ieee80211.h @@ -1080,6 +1080,8 @@ struct ieee80211_device { int perfect_rssi; int worst_rssi; + u16 prev_seq_ctl; /* used to drop duplicate frames */ + /* Callback functions */ void (*set_security) (struct net_device * dev, struct ieee80211_security * sec); diff --git a/net/ieee80211/ieee80211_rx.c b/net/ieee80211/ieee80211_rx.c index d9265195656..ce28d571afa 100644 --- a/net/ieee80211/ieee80211_rx.c +++ b/net/ieee80211/ieee80211_rx.c @@ -478,6 +478,11 @@ int ieee80211_rx(struct ieee80211_device *ieee, struct sk_buff *skb, goto rx_exit; } #endif + /* drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.29) */ + if (sc == ieee->prev_seq_ctl) + goto rx_dropped; + else + ieee->prev_seq_ctl = sc; /* Data frame - extract src/dst addresses */ if (skb->len < IEEE80211_3ADDR_LEN) -- 2.41.1