Commit 761ab470 authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville

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: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 6a8579d0
......@@ -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:
......
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