[PATCH] ieee80211: Fix problem with not decrypting broadcast packets
Zhu Yi [Thu, 19 Jan 2006 08:20:42 +0000 (16:20 +0800)]
The code for pulling the key to use for decrypt was correctly using
the host_mc_decrypt flag.  The code that actually decrypted,
however, was based on host_decrypt.  This patch changes this
behavior.

Signed-off-by: Etay Bogner <etay.bogner@gmail.com>
Signed-off-by: James Ketrenos <jketreno@linux.intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/ieee80211/ieee80211_rx.c

index 7a12180..695d047 100644 (file)
@@ -350,6 +350,7 @@ int ieee80211_rx(struct ieee80211_device *ieee, struct sk_buff *skb,
        u8 src[ETH_ALEN];
        struct ieee80211_crypt_data *crypt = NULL;
        int keyidx = 0;
+       int can_be_decrypted = 0;
 
        hdr = (struct ieee80211_hdr_4addr *)skb->data;
        stats = &ieee->stats;
@@ -410,12 +411,23 @@ int ieee80211_rx(struct ieee80211_device *ieee, struct sk_buff *skb,
                return 1;
        }
 
-       if (is_multicast_ether_addr(hdr->addr1)
-           ? ieee->host_mc_decrypt : ieee->host_decrypt) {
+       can_be_decrypted = (is_multicast_ether_addr(hdr->addr1) ||
+                           is_broadcast_ether_addr(hdr->addr2)) ?
+           ieee->host_mc_decrypt : ieee->host_decrypt;
+
+       if (can_be_decrypted) {
                int idx = 0;
-               if (skb->len >= hdrlen + 3)
+               if (skb->len >= hdrlen + 3) {
+                       /* Top two-bits of byte 3 are the key index */
                        idx = skb->data[hdrlen + 3] >> 6;
+               }
+
+               /* ieee->crypt[] is WEP_KEY (4) in length.  Given that idx
+                * is only allowed 2-bits of storage, no value of idx can
+                * be provided via above code that would result in idx
+                * being out of range */
                crypt = ieee->crypt[idx];
+
 #ifdef NOT_YET
                sta = NULL;
 
@@ -553,7 +565,7 @@ int ieee80211_rx(struct ieee80211_device *ieee, struct sk_buff *skb,
 
        /* skb: hdr + (possibly fragmented, possibly encrypted) payload */
 
-       if (ieee->host_decrypt && (fc & IEEE80211_FCTL_PROTECTED) &&
+       if ((fc & IEEE80211_FCTL_PROTECTED) && can_be_decrypted &&
            (keyidx = ieee80211_rx_frame_decrypt(ieee, skb, crypt)) < 0)
                goto rx_dropped;
 
@@ -617,7 +629,7 @@ int ieee80211_rx(struct ieee80211_device *ieee, struct sk_buff *skb,
 
        /* skb: hdr + (possible reassembled) full MSDU payload; possibly still
         * encrypted/authenticated */
-       if (ieee->host_decrypt && (fc & IEEE80211_FCTL_PROTECTED) &&
+       if ((fc & IEEE80211_FCTL_PROTECTED) && can_be_decrypted &&
            ieee80211_rx_frame_decrypt_msdu(ieee, skb, keyidx, crypt))
                goto rx_dropped;