mac80211: fix ibss scanning
Stanislaw Gruszka [Tue, 11 Dec 2012 09:48:23 +0000 (10:48 +0100)]
commit 34bcf71502413f8903ade93746f2d0f04b937a78 upstream.

Do not scan on no-IBSS and disabled channels in IBSS mode. Doing this
can trigger Microcode errors on iwlwifi and iwlegacy drivers.

Also rename ieee80211_request_internal_scan() function since it is only
used in IBSS mode and simplify calling it from ieee80211_sta_find_ibss().

This patch should address:
https://bugzilla.redhat.com/show_bug.cgi?id=883414
https://bugzilla.kernel.org/show_bug.cgi?id=49411

Reported-by: Jesse Kahtava <jesse_kahtava@f-m.fm>
Reported-by: Mikko Rapeli  <mikko.rapeli@iki.fi>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/mac80211/ibss.c
net/mac80211/ieee80211_i.h
net/mac80211/scan.c

index 7c51bae..50191a3 100644 (file)
@@ -664,8 +664,8 @@ static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
        printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
               "IBSS networks with same SSID (merge)\n", sdata->name);
 
-       ieee80211_request_internal_scan(sdata,
-                       ifibss->ssid, ifibss->ssid_len, NULL);
+       ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
+                                   NULL);
 }
 
 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
@@ -772,9 +772,8 @@ static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
                printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
                       "join\n", sdata->name);
 
-               ieee80211_request_internal_scan(sdata,
-                               ifibss->ssid, ifibss->ssid_len,
-                               ifibss->fixed_channel ? ifibss->channel : NULL);
+               ieee80211_request_ibss_scan(sdata, ifibss->ssid,
+                                           ifibss->ssid_len, chan);
        } else {
                int interval = IEEE80211_SCAN_INTERVAL;
 
index 498e87b..f8b5e75 100644 (file)
@@ -1233,9 +1233,9 @@ void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 
 /* scan/BSS handling */
 void ieee80211_scan_work(struct work_struct *work);
-int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
-                                   const u8 *ssid, u8 ssid_len,
-                                   struct ieee80211_channel *chan);
+int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
+                               const u8 *ssid, u8 ssid_len,
+                               struct ieee80211_channel *chan);
 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
                           struct cfg80211_scan_request *req);
 void ieee80211_scan_cancel(struct ieee80211_local *local);
index c70e176..e95d494 100644 (file)
@@ -761,9 +761,9 @@ int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
        return res;
 }
 
-int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
-                                   const u8 *ssid, u8 ssid_len,
-                                   struct ieee80211_channel *chan)
+int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
+                               const u8 *ssid, u8 ssid_len,
+                               struct ieee80211_channel *chan)
 {
        struct ieee80211_local *local = sdata->local;
        int ret = -EBUSY;
@@ -777,22 +777,36 @@ int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
 
        /* fill internal scan request */
        if (!chan) {
-               int i, nchan = 0;
+               int i, max_n;
+               int n_ch = 0;
 
                for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
                        if (!local->hw.wiphy->bands[band])
                                continue;
-                       for (i = 0;
-                            i < local->hw.wiphy->bands[band]->n_channels;
-                            i++) {
-                               local->int_scan_req->channels[nchan] =
+
+                       max_n = local->hw.wiphy->bands[band]->n_channels;
+                       for (i = 0; i < max_n; i++) {
+                               struct ieee80211_channel *tmp_ch =
                                    &local->hw.wiphy->bands[band]->channels[i];
-                               nchan++;
+
+                               if (tmp_ch->flags & (IEEE80211_CHAN_NO_IBSS |
+                                                    IEEE80211_CHAN_DISABLED))
+                                       continue;
+
+                               local->int_scan_req->channels[n_ch] = tmp_ch;
+                               n_ch++;
                        }
                }
 
-               local->int_scan_req->n_channels = nchan;
+               if (WARN_ON_ONCE(n_ch == 0))
+                       goto unlock;
+
+               local->int_scan_req->n_channels = n_ch;
        } else {
+               if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IBSS |
+                                               IEEE80211_CHAN_DISABLED)))
+                       goto unlock;
+
                local->int_scan_req->channels[0] = chan;
                local->int_scan_req->n_channels = 1;
        }