[ 087/171] mac80211: fix ibss scanning

Greg Kroah-Hartman
2013-01-15T23:39:52Z

From: Stanislaw Gruszka <sgruszka@redhat.com>

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 | 9 ++++-----
net/mac80211/ieee80211_i.h | 6 +++---
net/mac80211/scan.c | 34 ++++++++++++++++++++++++----------
3 files changed, 31 insertions(+), 18 deletions(-)

--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -664,8 +664,8 @@ static void ieee80211_sta_merge_ibss(str
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(stru
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;

--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1233,9 +1233,9 @@ void ieee80211_mesh_rx_queued_mgmt(struc

/* 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);
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -761,9 +761,9 @@ int ieee80211_request_scan(struct ieee80
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(stru

/* 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;
}