mac80211: push michael MIC report after DA check

When we receive a michael MIC failure report from the
hardware we currently do not check whether it is actually
reported on a frame that is destined to us. It shouldn't
be possible to get a michael MIC failure report on other
frames, but it also doesn't hurt to verify.

Also, since we then don't need the station struct that
early, move looking it up a bit later in the RX path.

Finally, while at it, a few code cleanups in the area.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 6bce97e..68d9e9c 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1818,11 +1818,11 @@ static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
                 * Some hardware seem to generate incorrect Michael MIC
                 * reports; ignore them to avoid triggering countermeasures.
                 */
-               goto ignore;
+               return;
        }
 
        if (!ieee80211_has_protected(hdr->frame_control))
-               goto ignore;
+               return;
 
        if (rx->sdata->vif.type == NL80211_IFTYPE_AP && keyidx) {
                /*
@@ -1831,18 +1831,15 @@ static void ieee80211_rx_michael_mic_report(struct ieee80211_hdr *hdr,
                 * group keys and only the AP is sending real multicast
                 * frames in the BSS.
                 */
-               goto ignore;
+               return;
        }
 
        if (!ieee80211_is_data(hdr->frame_control) &&
            !ieee80211_is_auth(hdr->frame_control))
-               goto ignore;
+               return;
 
        mac80211_ev_michael_mic_failure(rx->sdata, keyidx, hdr, NULL,
                                        GFP_ATOMIC);
- ignore:
-       dev_kfree_skb(rx->skb);
-       rx->skb = NULL;
 }
 
 /* TODO: use IEEE80211_RX_FRAGMENTED */
@@ -2064,8 +2061,6 @@ static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
                        return 0;
                break;
        case NL80211_IFTYPE_MONITOR:
-               /* take everything */
-               break;
        case NL80211_IFTYPE_UNSPECIFIED:
        case __NL80211_IFTYPE_AFTER_LAST:
                /* should never get here */
@@ -2097,24 +2092,12 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
        memset(&rx, 0, sizeof(rx));
        rx.skb = skb;
        rx.local = local;
-
        rx.status = status;
        rx.rate = rate;
 
        if (ieee80211_is_data(hdr->frame_control) || ieee80211_is_mgmt(hdr->frame_control))
                local->dot11ReceivedFragmentCount++;
 
-       rx.sta = sta_info_get(local, hdr->addr2);
-       if (rx.sta) {
-               rx.sdata = rx.sta->sdata;
-               rx.dev = rx.sta->sdata->dev;
-       }
-
-       if ((status->flag & RX_FLAG_MMIC_ERROR)) {
-               ieee80211_rx_michael_mic_report(hdr, &rx);
-               return;
-       }
-
        if (unlikely(test_bit(SCAN_HW_SCANNING, &local->scanning) ||
                     test_bit(SCAN_OFF_CHANNEL, &local->scanning)))
                rx.flags |= IEEE80211_RX_IN_SCAN;
@@ -2122,13 +2105,22 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
        ieee80211_parse_qos(&rx);
        ieee80211_verify_alignment(&rx);
 
-       skb = rx.skb;
+       rx.sta = sta_info_get(local, hdr->addr2);
+       if (rx.sta) {
+               rx.sdata = rx.sta->sdata;
+               rx.dev = rx.sta->sdata->dev;
+       }
 
        if (rx.sdata && ieee80211_is_data(hdr->frame_control)) {
                rx.flags |= IEEE80211_RX_RA_MATCH;
                prepares = prepare_for_handlers(rx.sdata, &rx, hdr);
-               if (prepares)
-                       prev = rx.sdata;
+               if (prepares) {
+                       if (status->flag & RX_FLAG_MMIC_ERROR) {
+                               if (rx.flags & IEEE80211_RX_RA_MATCH)
+                                       ieee80211_rx_michael_mic_report(hdr, &rx);
+                       } else
+                               prev = rx.sdata;
+               }
        } else list_for_each_entry_rcu(sdata, &local->interfaces, list) {
                if (!netif_running(sdata->dev))
                        continue;
@@ -2143,6 +2135,13 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
                if (!prepares)
                        continue;
 
+               if (status->flag & RX_FLAG_MMIC_ERROR) {
+                       rx.sdata = sdata;
+                       if (rx.flags & IEEE80211_RX_RA_MATCH)
+                               ieee80211_rx_michael_mic_report(hdr, &rx);
+                       continue;
+               }
+
                /*
                 * frame is destined for this interface, but if it's not
                 * also for the previous one we handle that after the