diff options
| author | Zhu Yi <yi.zhu@intel.com> | 2010-04-08 15:35:10 +0800 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2010-04-09 13:43:09 -0400 |
| commit | 39184b151cbe5ce9f1487190ac4244f69bf6a04b (patch) | |
| tree | c3dc45e8053ff3066c7a94a3d5a6dfb736be7b5f /net/mac80211/rx.c | |
| parent | 1805a34fa33b6284ab8139dd43779b94de58669a (diff) | |
| download | lwn-39184b151cbe5ce9f1487190ac4244f69bf6a04b.tar.gz lwn-39184b151cbe5ce9f1487190ac4244f69bf6a04b.zip | |
mac80211: delay skb linearising in rx decryption
We delay the skb linearising in ieee80211_rx_h_decrypt so that
frames do not require software decryption are not linearized. We
are safe to do this because ieee80211_get_mmie_keyidx() only
requires to touch nonlinear data for management frames, which are
already linearized before getting here.
Cc: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/rx.c')
| -rw-r--r-- | net/mac80211/rx.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index d08ede44ac7e..8ee7db193269 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -820,7 +820,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) { struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); - struct ieee80211_hdr *hdr; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; int keyidx; int hdrlen; ieee80211_rx_result result = RX_DROP_UNUSABLE; @@ -861,11 +861,6 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) if (!(rx->flags & IEEE80211_RX_RA_MATCH)) return RX_CONTINUE; - if (skb_linearize(rx->skb)) - return RX_DROP_UNUSABLE; - - hdr = (struct ieee80211_hdr *)skb->data; - /* start without a key */ rx->key = NULL; @@ -906,6 +901,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) rx->key = key; return RX_CONTINUE; } else { + u8 keyid; /* * The device doesn't give us the IV so we won't be * able to look up the key. That's ok though, we @@ -928,7 +924,8 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) * no need to call ieee80211_wep_get_keyidx, * it verifies a bunch of things we've done already */ - keyidx = rx->skb->data[hdrlen + 3] >> 6; + skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1); + keyidx = keyid >> 6; rx->key = rcu_dereference(rx->sdata->keys[keyidx]); @@ -949,6 +946,11 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) return RX_DROP_MONITOR; } + if (skb_linearize(rx->skb)) + return RX_DROP_UNUSABLE; + + hdr = (struct ieee80211_hdr *)rx->skb->data; + /* Check for weak IVs if possible */ if (rx->sta && rx->key->conf.alg == ALG_WEP && ieee80211_is_data(hdr->frame_control) && |