From 761ab470364b550c9b1a5e1e31be51d415aaf42b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 28 May 2010 14:24:19 +0200 Subject: [PATCH] mac80211: move WEP weak IV check I suspect the compiler will do this optimisation anyway, but it seems cleaner to move this into the WEP switch case. Also make rx_h_decrypt use a local variable for the frame_control so that we don't need to reload the hdr variable for this after linearizing. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/rx.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 6e2a7bcd8cb8..0ade26793918 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -825,6 +825,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) ieee80211_rx_result result = RX_DROP_UNUSABLE; struct ieee80211_key *stakey = NULL; int mmie_keyidx = -1; + __le16 fc; /* * Key selection 101 @@ -866,13 +867,15 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) if (rx->sta) stakey = rcu_dereference(rx->sta->key); - if (!ieee80211_has_protected(hdr->frame_control)) + fc = hdr->frame_control; + + if (!ieee80211_has_protected(fc)) mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb); if (!is_multicast_ether_addr(hdr->addr1) && stakey) { rx->key = stakey; /* Skip decryption if the frame is not protected. */ - if (!ieee80211_has_protected(hdr->frame_control)) + if (!ieee80211_has_protected(fc)) return RX_CONTINUE; } else if (mmie_keyidx >= 0) { /* Broadcast/multicast robust management frame / BIP */ @@ -884,7 +887,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS) return RX_DROP_MONITOR; /* unexpected BIP keyidx */ rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]); - } else if (!ieee80211_has_protected(hdr->frame_control)) { + } else if (!ieee80211_has_protected(fc)) { /* * The frame was not protected, so skip decryption. However, we * need to set rx->key if there is a key that could have been @@ -892,7 +895,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) * have been expected. */ struct ieee80211_key *key = NULL; - if (ieee80211_is_mgmt(hdr->frame_control) && + if (ieee80211_is_mgmt(fc) && is_multicast_ether_addr(hdr->addr1) && (key = rcu_dereference(rx->sdata->default_mgmt_key))) rx->key = key; @@ -914,7 +917,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) (status->flag & RX_FLAG_IV_STRIPPED)) return RX_CONTINUE; - hdrlen = ieee80211_hdrlen(hdr->frame_control); + hdrlen = ieee80211_hdrlen(fc); if (rx->skb->len < 8 + hdrlen) return RX_DROP_UNUSABLE; /* TODO: count this? */ @@ -947,19 +950,17 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx) 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) && - (!(status->flag & RX_FLAG_IV_STRIPPED) || - !(status->flag & RX_FLAG_DECRYPTED)) && - ieee80211_wep_is_weak_iv(rx->skb, rx->key)) - rx->sta->wep_weak_iv_count++; + /* the hdr variable is invalid now! */ switch (rx->key->conf.alg) { case ALG_WEP: + /* Check for weak IVs if possible */ + if (rx->sta && ieee80211_is_data(fc) && + (!(status->flag & RX_FLAG_IV_STRIPPED) || + !(status->flag & RX_FLAG_DECRYPTED)) && + ieee80211_wep_is_weak_iv(rx->skb, rx->key)) + rx->sta->wep_weak_iv_count++; + result = ieee80211_crypto_wep_decrypt(rx); break; case ALG_TKIP: -- 2.20.1