Re: [PATCH] mac80211: Defer setting of RX_FLAG_DECRYPTED.

[Mattias Nissler <mattias.nissler@gmx.de>]

On Sun, 2007-10-07 at 16:53 +0200, Michael Buesch wrote:
> On Sunday 07 October 2007 16:35:31 Mattias Nissler wrote:
> > +	/* either the frame will be decrypted or dropped */
> 
> I think this comment doesn't apply then anymore, eh?

Well, I changed the wording to "has been decrypted or will be dropped".

Mattias


The decryption handlers will skip the frame if the RX_FLAG_DECRYPTED
flag is set, so the early flag setting introduced by Johannes breaks
decryption. To work around this, call the handlers first and then set
the flag.

Signed-off-by: Mattias Nissler <mattias.nissler@gmx.de>
---
 net/mac80211/rx.c |   20 +++++++++++---------
 1 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index de3f7ae..34699a1 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -424,6 +424,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data
*rx)
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)
rx->skb->data;
        int keyidx;
        int hdrlen;
+       ieee80211_txrx_result result = TXRX_DROP;
        struct ieee80211_key *stakey = NULL;
 
        /*
@@ -522,21 +523,22 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data
*rx)
            ieee80211_wep_is_weak_iv(rx->skb, rx->key))
                rx->sta->wep_weak_iv_count++;
 
-       /* either the frame will be decrypted or dropped */
-       rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
-
        switch (rx->key->conf.alg) {
        case ALG_WEP:
-               return ieee80211_crypto_wep_decrypt(rx);
+               result = ieee80211_crypto_wep_decrypt(rx);
+               break;
        case ALG_TKIP:
-               return ieee80211_crypto_tkip_decrypt(rx);
+               result = ieee80211_crypto_tkip_decrypt(rx);
+               break;
        case ALG_CCMP:
-               return ieee80211_crypto_ccmp_decrypt(rx);
+               result = ieee80211_crypto_ccmp_decrypt(rx);
+               break;
        }
 
-       /* not reached */
-       WARN_ON(1);
-       return TXRX_DROP;
+       /* either the frame has been decrypted or will be dropped */
+       rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
+
+       return result;
 }
 
 static void ap_sta_ps_start(struct net_device *dev, struct sta_info
*sta)
-- 
1.5.3