mac80211: ibss: fix ignored channel parameter

my earlier patch "mac80211: change IBSS channel state to chandef"
created a regression by ignoring the channel parameter in
__ieee80211_sta_join_ibss, which breaks IBSS channel selection. This
patch fixes this situation by using the right channel and adopting the
selected bandwidth mode.

Cc: stable@vger.kernel.org
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 29 insertions, 4 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 5e8bb3bee3c2..2d45643c964e 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -36,7 +36,7 @@
 
 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
                                       const u8 *bssid, const int beacon_int,
-                                      struct ieee80211_channel *chan,
+                                      struct cfg80211_chan_def *req_chandef,
                                       const u32 basic_rates,
                                       const u16 capability, u64 tsf,
                                       bool creator)
@@ -51,6 +51,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
         u32 bss_change;
         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
         struct cfg80211_chan_def chandef;
+        struct ieee80211_channel *chan;
         struct beacon_data *presp;
         int frame_len;
 
@@ -81,7 +82,9 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 
         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 
-        chandef = ifibss->chandef;
+        /* make a copy of the chandef, it could be modified below. */
+        chandef = *req_chandef;
+        chan = chandef.chan;
         if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
                 chandef.width = NL80211_CHAN_WIDTH_20;
                 chandef.center_freq1 = chan->center_freq;
@@ -259,10 +262,12 @@ static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
         struct cfg80211_bss *cbss =
                 container_of((void *)bss, struct cfg80211_bss, priv);
         struct ieee80211_supported_band *sband;
+        struct cfg80211_chan_def chandef;
         u32 basic_rates;
         int i, j;
         u16 beacon_int = cbss->beacon_interval;
         const struct cfg80211_bss_ies *ies;
+        enum nl80211_channel_type chan_type;
         u64 tsf;
 
         sdata_assert_lock(sdata);
@@ -270,6 +275,26 @@ static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
         if (beacon_int < 10)
                 beacon_int = 10;
 
+        switch (sdata->u.ibss.chandef.width) {
+        case NL80211_CHAN_WIDTH_20_NOHT:
+        case NL80211_CHAN_WIDTH_20:
+        case NL80211_CHAN_WIDTH_40:
+                chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
+                cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
+                break;
+        case NL80211_CHAN_WIDTH_5:
+        case NL80211_CHAN_WIDTH_10:
+                cfg80211_chandef_create(&chandef, cbss->channel,
+                                        NL80211_CHAN_WIDTH_20_NOHT);
+                chandef.width = sdata->u.ibss.chandef.width;
+                break;
+        default:
+                /* fall back to 20 MHz for unsupported modes */
+                cfg80211_chandef_create(&chandef, cbss->channel,
+                                        NL80211_CHAN_WIDTH_20_NOHT);
+                break;
+        }
+
         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
 
         basic_rates = 0;
@@ -294,7 +319,7 @@ static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
 
         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
                                   beacon_int,
-                                  cbss->channel,
+                                  &chandef,
                                   basic_rates,
                                   cbss->capability,
                                   tsf, false);
@@ -736,7 +761,7 @@ static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
                 sdata->drop_unencrypted = 0;
 
         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
-                                  ifibss->chandef.chan, ifibss->basic_rates,
+                                  &ifibss->chandef, ifibss->basic_rates,
                                   capability, 0, true);
 }