mac80211: IBSS fix scan request

In case of wide bandwidth (wider than 20MHz) used by IBSS,
scan all channels in chandef to be able to find neighboring
IBSS netwqworks that use the same overall channels but a different
control channel.

Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 6da4e72f81788dae0dbfb161dd32d489bfaf68a8..8f8391e008ed585f0d0862a533bf809c937c03f8 100644 (file)
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -1270,7 +1270,7 @@ static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
 
        scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
        ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
-                                   NULL, scan_width);
+                                   NULL, 0, scan_width);
 }
 
 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
@@ -1307,6 +1307,76 @@ static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
                                  capability, 0, true);
 }
 
+static unsigned ibss_setup_channels(struct wiphy *wiphy,
+                                   struct ieee80211_channel **channels,
+                                   unsigned int channels_max,
+                                   u32 center_freq, u32 width)
+{
+       struct ieee80211_channel *chan = NULL;
+       unsigned int n_chan = 0;
+       u32 start_freq, end_freq, freq;
+
+       if (width <= 20) {
+               start_freq = center_freq;
+               end_freq = center_freq;
+       } else {
+               start_freq = center_freq - width / 2 + 10;
+               end_freq = center_freq + width / 2 - 10;
+       }
+
+       for (freq = start_freq; freq <= end_freq; freq += 20) {
+               chan = ieee80211_get_channel(wiphy, freq);
+               if (!chan)
+                       continue;
+               if (n_chan >= channels_max)
+                       return n_chan;
+
+               channels[n_chan] = chan;
+               n_chan++;
+       }
+
+       return n_chan;
+}
+
+static unsigned int
+ieee80211_ibss_setup_scan_channels(struct wiphy *wiphy,
+                                  const struct cfg80211_chan_def *chandef,
+                                  struct ieee80211_channel **channels,
+                                  unsigned int channels_max)
+{
+       unsigned int n_chan = 0;
+       u32 width, cf1, cf2 = 0;
+
+       switch (chandef->width) {
+       case NL80211_CHAN_WIDTH_40:
+               width = 40;
+               break;
+       case NL80211_CHAN_WIDTH_80P80:
+               cf2 = chandef->center_freq2;
+               /* fall through */
+       case NL80211_CHAN_WIDTH_80:
+               width = 80;
+               break;
+       case NL80211_CHAN_WIDTH_160:
+               width = 160;
+               break;
+       default:
+               width = 20;
+               break;
+       }
+
+       cf1 = chandef->center_freq1;
+
+       n_chan = ibss_setup_channels(wiphy, channels, channels_max, cf1, width);
+
+       if (cf2)
+               n_chan += ibss_setup_channels(wiphy, &channels[n_chan],
+                                             channels_max - n_chan, cf2,
+                                             width);
+
+       return n_chan;
+}
+
 /*
  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
  */
@@ -1372,11 +1442,18 @@ static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
        /* Selected IBSS not found in current scan results - try to scan */
        if (time_after(jiffies, ifibss->last_scan_completed +
                                        IEEE80211_SCAN_INTERVAL)) {
+               struct ieee80211_channel *channels[8];
+               unsigned int num;
+
                sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
 
+               num = ieee80211_ibss_setup_scan_channels(local->hw.wiphy,
+                                                        &ifibss->chandef,
+                                                        channels,
+                                                        ARRAY_SIZE(channels));
                scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
                ieee80211_request_ibss_scan(sdata, ifibss->ssid,
-                                           ifibss->ssid_len, chan,
+                                           ifibss->ssid_len, channels, num,
                                            scan_width);
        } else {
                int interval = IEEE80211_SCAN_INTERVAL;

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 3e3cfe8da4efbb84b8fc1bb19f2f8891ccf64242..3331c62b443359ab3a0a0d726b93aa6549ed8f0e 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1529,7 +1529,8 @@ int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata);
 void ieee80211_scan_work(struct work_struct *work);
 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
                                const u8 *ssid, u8 ssid_len,
-                               struct ieee80211_channel *chan,
+                               struct ieee80211_channel **channels,
+                               unsigned int n_channels,
                                enum nl80211_bss_scan_width scan_width);
 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
                           struct cfg80211_scan_request *req);

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 05f0d711b6d8666701e91262141fb67711d9dad7..7bb6a9383f58ec01b3f9c68964aac3f44f3e5beb 100644 (file)
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -928,11 +928,12 @@ int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
 
 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
                                const u8 *ssid, u8 ssid_len,
-                               struct ieee80211_channel *chan,
+                               struct ieee80211_channel **channels,
+                               unsigned int n_channels,
                                enum nl80211_bss_scan_width scan_width)
 {
        struct ieee80211_local *local = sdata->local;
-       int ret = -EBUSY;
+       int ret = -EBUSY, i, n_ch = 0;
        enum ieee80211_band band;
 
        mutex_lock(&local->mtx);
@@ -942,9 +943,8 @@ int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
                goto unlock;
 
        /* fill internal scan request */
-       if (!chan) {
-               int i, max_n;
-               int n_ch = 0;
+       if (!channels) {
+               int max_n;
 
                for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
                        if (!local->hw.wiphy->bands[band])
@@ -969,12 +969,19 @@ int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
 
                local->int_scan_req->n_channels = n_ch;
        } else {
-               if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IR |
-                                               IEEE80211_CHAN_DISABLED)))
+               for (i = 0; i < n_channels; i++) {
+                       if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
+                                                 IEEE80211_CHAN_DISABLED))
+                               continue;
+
+                       local->int_scan_req->channels[n_ch] = channels[i];
+                       n_ch++;
+               }
+
+               if (WARN_ON_ONCE(n_ch == 0))
                        goto unlock;
 
-               local->int_scan_req->channels[0] = chan;
-               local->int_scan_req->n_channels = 1;
+               local->int_scan_req->n_channels = n_ch;
        }
 
        local->int_scan_req->ssids = &local->scan_ssid;