cfg/mac80211: add regulatory classes IE during TDLS setup

Seems Broadcom TDLS peers (Nexus 5, Xperia Z3) refuse to allow TDLS
connection when channel-switching is supported but the regulatory
classes IE is missing from the setup request.
Add a chandef to reg-class translation function to cfg80211 and use it
to add the required IE during setup. For now add only the current
regulatory class as supported - it is enough to resolve the
compatibility issue.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 161 insertions, 0 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 12a6121ea76e..c4d873b8f32d 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4903,6 +4903,17 @@ void cfg80211_ch_switch_started_notify(struct net_device *dev,
 bool ieee80211_operating_class_to_band(u8 operating_class,
                                        enum ieee80211_band *band);
 
+/**
+ * ieee80211_chandef_to_operating_class - convert chandef to operation class
+ *
+ * @chandef: the chandef to convert
+ * @op_class: a pointer to the resulting operating class
+ *
+ * Returns %true if the conversion was successful, %false otherwise.
+ */
+bool ieee80211_chandef_to_operating_class(struct cfg80211_chan_def *chandef,
+                                          u8 *op_class);
+
 /*
  * cfg80211_tdls_oper_request - request userspace to perform TDLS operation
  * @dev: the device on which the operation is requested
diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index bc7e4049896f..79ed59acf0d4 100644
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -136,6 +136,24 @@ ieee80211_tdls_add_supp_channels(struct ieee80211_sub_if_data *sdata,
         *pos = 2 * subband_cnt;
 }
 
+static void ieee80211_tdls_add_oper_classes(struct ieee80211_sub_if_data *sdata,
+                                            struct sk_buff *skb)
+{
+        u8 *pos;
+        u8 op_class;
+
+        if (!ieee80211_chandef_to_operating_class(&sdata->vif.bss_conf.chandef,
+                                                  &op_class))
+                return;
+
+        pos = skb_put(skb, 4);
+        *pos++ = WLAN_EID_SUPPORTED_REGULATORY_CLASSES;
+        *pos++ = 2; /* len */
+
+        *pos++ = op_class;
+        *pos++ = op_class; /* give current operating class as alternate too */
+}
+
 static void ieee80211_tdls_add_bss_coex_ie(struct sk_buff *skb)
 {
         u8 *pos = (void *)skb_put(skb, 3);
@@ -350,6 +368,8 @@ ieee80211_tdls_add_setup_start_ies(struct ieee80211_sub_if_data *sdata,
                 }
         }
 
+        ieee80211_tdls_add_oper_classes(sdata, skb);
+
         /*
          * with TDLS we can switch channels, and HT-caps are not necessarily
          * the same on all bands. The specification limits the setup to a
@@ -786,6 +806,7 @@ ieee80211_tdls_build_mgmt_packet_data(struct ieee80211_sub_if_data *sdata,
                                50 + /* supported channels */
                                3 + /* 40/20 BSS coex */
                                4 + /* AID */
+                               4 + /* oper classes */
                                extra_ies_len +
                                sizeof(struct ieee80211_tdls_lnkie));
         if (!skb)
diff --git a/net/wireless/util.c b/net/wireless/util.c
index f7b35980af69..f218b151530a 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1314,6 +1314,135 @@ bool ieee80211_operating_class_to_band(u8 operating_class,
 }
 EXPORT_SYMBOL(ieee80211_operating_class_to_band);
 
+bool ieee80211_chandef_to_operating_class(struct cfg80211_chan_def *chandef,
+                                          u8 *op_class)
+{
+        u8 vht_opclass;
+        u16 freq = chandef->center_freq1;
+
+        if (freq >= 2412 && freq <= 2472) {
+                if (chandef->width > NL80211_CHAN_WIDTH_40)
+                        return false;
+
+                /* 2.407 GHz, channels 1..13 */
+                if (chandef->width == NL80211_CHAN_WIDTH_40) {
+                        if (freq > chandef->chan->center_freq)
+                                *op_class = 83; /* HT40+ */
+                        else
+                                *op_class = 84; /* HT40- */
+                } else {
+                        *op_class = 81;
+                }
+
+                return true;
+        }
+
+        if (freq == 2484) {
+                if (chandef->width > NL80211_CHAN_WIDTH_40)
+                        return false;
+
+                *op_class = 82; /* channel 14 */
+                return true;
+        }
+
+        switch (chandef->width) {
+        case NL80211_CHAN_WIDTH_80:
+                vht_opclass = 128;
+                break;
+        case NL80211_CHAN_WIDTH_160:
+                vht_opclass = 129;
+                break;
+        case NL80211_CHAN_WIDTH_80P80:
+                vht_opclass = 130;
+                break;
+        case NL80211_CHAN_WIDTH_10:
+        case NL80211_CHAN_WIDTH_5:
+                return false; /* unsupported for now */
+        default:
+                vht_opclass = 0;
+                break;
+        }
+
+        /* 5 GHz, channels 36..48 */
+        if (freq >= 5180 && freq <= 5240) {
+                if (vht_opclass) {
+                        *op_class = vht_opclass;
+                } else if (chandef->width == NL80211_CHAN_WIDTH_40) {
+                        if (freq > chandef->chan->center_freq)
+                                *op_class = 116;
+                        else
+                                *op_class = 117;
+                } else {
+                        *op_class = 115;
+                }
+
+                return true;
+        }
+
+        /* 5 GHz, channels 52..64 */
+        if (freq >= 5260 && freq <= 5320) {
+                if (vht_opclass) {
+                        *op_class = vht_opclass;
+                } else if (chandef->width == NL80211_CHAN_WIDTH_40) {
+                        if (freq > chandef->chan->center_freq)
+                                *op_class = 119;
+                        else
+                                *op_class = 120;
+                } else {
+                        *op_class = 118;
+                }
+
+                return true;
+        }
+
+        /* 5 GHz, channels 100..144 */
+        if (freq >= 5500 && freq <= 5720) {
+                if (vht_opclass) {
+                        *op_class = vht_opclass;
+                } else if (chandef->width == NL80211_CHAN_WIDTH_40) {
+                        if (freq > chandef->chan->center_freq)
+                                *op_class = 122;
+                        else
+                                *op_class = 123;
+                } else {
+                        *op_class = 121;
+                }
+
+                return true;
+        }
+
+        /* 5 GHz, channels 149..169 */
+        if (freq >= 5745 && freq <= 5845) {
+                if (vht_opclass) {
+                        *op_class = vht_opclass;
+                } else if (chandef->width == NL80211_CHAN_WIDTH_40) {
+                        if (freq > chandef->chan->center_freq)
+                                *op_class = 126;
+                        else
+                                *op_class = 127;
+                } else if (freq <= 5805) {
+                        *op_class = 124;
+                } else {
+                        *op_class = 125;
+                }
+
+                return true;
+        }
+
+        /* 56.16 GHz, channel 1..4 */
+        if (freq >= 56160 + 2160 * 1 && freq <= 56160 + 2160 * 4) {
+                if (chandef->width >= NL80211_CHAN_WIDTH_40)
+                        return false;
+
+                *op_class = 180;
+                return true;
+        }
+
+        /* not supported yet */
+        return false;
+}
+EXPORT_SYMBOL(ieee80211_chandef_to_operating_class);
+
 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
                                  u32 beacon_int)
 {