2 files changed, 74 insertions, 46 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index b0959c249869..08ca066246b9 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -310,52 +310,77 @@ static ieee80211_txrx_result
 ieee80211_rx_h_load_key(struct ieee80211_txrx_data *rx)
 {
         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
-        int always_sta_key;
+        int keyidx;
+        int hdrlen;
 
-        if (rx->sdata->type == IEEE80211_IF_TYPE_STA)
-                always_sta_key = 0;
-        else
-                always_sta_key = 1;
+        /*
+         * Key selection 101
+         *
+         * There are three types of keys:
+         *  - GTK (group keys)
+         *  - PTK (pairwise keys)
+         *  - STK (station-to-station pairwise keys)
+         *
+         * When selecting a key, we have to distinguish between multicast
+         * (including broadcast) and unicast frames, the latter can only
+         * use PTKs and STKs while the former always use GTKs. Unless, of
+         * course, actual WEP keys ("pre-RSNA") are used, then unicast
+         * frames can also use key indizes like GTKs. Hence, if we don't
+         * have a PTK/STK we check the key index for a WEP key.
+         *
+         * There is also a slight problem in IBSS mode: GTKs are negotiated
+         * with each station, that is something we don't currently handle.
+         */
+
+        if (!(rx->fc & IEEE80211_FCTL_PROTECTED))
+                return TXRX_CONTINUE;
 
-        if (rx->sta && rx->sta->key && always_sta_key) {
+        /*
+         * No point in finding a key if the frame is neither
+         * addressed to us nor a multicast frame.
+         */
+        if (!rx->u.rx.ra_match)
+                return TXRX_CONTINUE;
+
+        if (!is_multicast_ether_addr(hdr->addr1) && rx->sta && rx->sta->key) {
                 rx->key = rx->sta->key;
         } else {
-                if (rx->sta && rx->sta->key)
-                        rx->key = rx->sta->key;
-                else
-                        rx->key = rx->sdata->default_key;
+                /*
+                 * The device doesn't give us the IV so we won't be
+                 * able to look up the key. That's ok though, we
+                 * don't need to decrypt the frame, we just won't
+                 * be able to keep statistics accurate.
+                 * Except for key threshold notifications, should
+                 * we somehow allow the driver to tell us which key
+                 * the hardware used if this flag is set?
+                 */
+                if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV))
+                        return TXRX_CONTINUE;
 
-                if ((rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
-                    rx->fc & IEEE80211_FCTL_PROTECTED) {
-                        int keyidx = ieee80211_wep_get_keyidx(rx->skb);
+                hdrlen = ieee80211_get_hdrlen(rx->fc);
 
-                        if (keyidx >= 0 && keyidx < NUM_DEFAULT_KEYS &&
-                            (!rx->sta || !rx->sta->key || keyidx > 0))
-                                rx->key = rx->sdata->keys[keyidx];
+                if (rx->skb->len < 8 + hdrlen)
+                        return TXRX_DROP; /* TODO: count this? */
 
-                        if (!rx->key) {
-                                if (!rx->u.rx.ra_match)
-                                        return TXRX_DROP;
-                                if (net_ratelimit())
-                                        printk(KERN_DEBUG "%s: RX WEP frame "
-                                               "with unknown keyidx %d "
-                                               "(A1=" MAC_FMT
-                                               " A2=" MAC_FMT
-                                               " A3=" MAC_FMT ")\n",
-                                               rx->dev->name, keyidx,
-                                               MAC_ARG(hdr->addr1),
-                                               MAC_ARG(hdr->addr2),
-                                               MAC_ARG(hdr->addr3));
-                                /*
-                                 * TODO: notify userspace about this
-                                 * via cfg/nl80211
-                                 */
-                                return TXRX_DROP;
-                        }
-                }
+                /*
+                 * 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;
+
+                rx->key = rx->sdata->keys[keyidx];
+
+                /*
+                 * RSNA-protected unicast frames should always be sent with
+                 * pairwise or station-to-station keys, but for WEP we allow
+                 * using a key index as well.
+                 */
+                if (rx->key && rx->key->alg != ALG_WEP &&
+                    !is_multicast_ether_addr(hdr->addr1))
+                        rx->key = NULL;
         }
 
-        if (rx->fc & IEEE80211_FCTL_PROTECTED && rx->key && rx->u.rx.ra_match) {
+        if (rx->key) {
                 rx->key->tx_rx_count++;
                 if (unlikely(rx->local->key_tx_rx_threshold &&
                              rx->key->tx_rx_count >
@@ -516,10 +541,6 @@ ieee80211_rx_h_wep_weak_iv_detection(struct ieee80211_txrx_data *rx)
 static ieee80211_txrx_result
 ieee80211_rx_h_wep_decrypt(struct ieee80211_txrx_data *rx)
 {
-        /* If the device handles decryption totally, skip this test */
-        if (rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP)
-                return TXRX_CONTINUE;
-
         if ((rx->key && rx->key->alg != ALG_WEP) ||
             !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
             ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA &&
@@ -871,8 +892,14 @@ ieee80211_rx_h_802_1x_pae(struct ieee80211_txrx_data *rx)
 static ieee80211_txrx_result
 ieee80211_rx_h_drop_unencrypted(struct ieee80211_txrx_data *rx)
 {
-        /*  If the device handles decryption totally, skip this test */
-        if (rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP)
+        /*
+         * Pass through unencrypted frames if the hardware might have
+         * decrypted them already without telling us, but that can only
+         * be true if we either didn't find a key or the found key is
+         * uploaded to the hardware.
+         */
+        if ((rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) &&
+            (!rx->key || !rx->key->force_sw_encrypt))
                 return TXRX_CONTINUE;
 
         /* Drop unencrypted frames if key is set. */
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 783af32c6911..f5723ea15aae 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -137,9 +137,10 @@ ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx)
 
         fc = rx->fc;
 
-        /* If device handles decryption totally, skip this check */
-        if ((rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) ||
-            (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC))
+        /*
+         * No way to verify the MIC if the hardware stripped it
+         */
+        if (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC)
                 return TXRX_CONTINUE;
 
         if (!rx->key || rx->key->alg != ALG_TKIP ||