mac80211: track AP and peer STA TDLS chan-switch support

The AP or peer can prohibit TDLS channel switch via a bit in the
extended capabilities IE. Parse the IE and track this bit. Set an
appropriate STA flag if both the AP and peer STA support TDLS
channel-switching.

Add the new STA flag and the missing TDLS_INITIATOR to debugfs.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

6 files changed, 23 insertions, 2 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 3ecbf68dadf1..8195e65d8a91 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1042,6 +1042,13 @@ static int sta_apply_parameters(struct ieee80211_local *local,
                         clear_sta_flag(sta, WLAN_STA_TDLS_PEER);
         }
 
+        /* mark TDLS channel switch support, if the AP allows it */
+        if (test_sta_flag(sta, WLAN_STA_TDLS_PEER) &&
+            !sdata->u.mgd.tdls_chan_switch_prohibited &&
+            params->ext_capab_len >= 4 &&
+            params->ext_capab[3] & WLAN_EXT_CAPA4_TDLS_CHAN_SWITCH)
+                set_sta_flag(sta, WLAN_STA_TDLS_CHAN_SWITCH);
+
         if (params->sta_modify_mask & STATION_PARAM_APPLY_UAPSD) {
                 sta->sta.uapsd_queues = params->uapsd_queues;
                 sta->sta.max_sp = params->max_sp;
diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index bafe48916229..2ba7f53746da 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -74,7 +74,7 @@ static ssize_t sta_flags_read(struct file *file, char __user *userbuf,
         test_sta_flag(sta, WLAN_STA_##flg) ? #flg "\n" : ""
 
         int res = scnprintf(buf, sizeof(buf),
-                            "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
+                            "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
                             TEST(AUTH), TEST(ASSOC), TEST(PS_STA),
                             TEST(PS_DRIVER), TEST(AUTHORIZED),
                             TEST(SHORT_PREAMBLE),
@@ -82,7 +82,8 @@ static ssize_t sta_flags_read(struct file *file, char __user *userbuf,
                             TEST(WDS), TEST(CLEAR_PS_FILT),
                             TEST(MFP), TEST(BLOCK_BA), TEST(PSPOLL),
                             TEST(UAPSD), TEST(SP), TEST(TDLS_PEER),
-                            TEST(TDLS_PEER_AUTH), TEST(4ADDR_EVENT),
+                            TEST(TDLS_PEER_AUTH), TEST(TDLS_INITIATOR),
+                            TEST(TDLS_CHAN_SWITCH), TEST(4ADDR_EVENT),
                             TEST(INSERTED), TEST(RATE_CONTROL),
                             TEST(TOFFSET_KNOWN), TEST(MPSP_OWNER),
                             TEST(MPSP_RECIPIENT));
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 53eb41fad033..4b3a7e7ec2a0 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -531,6 +531,7 @@ struct ieee80211_if_managed {
         struct sk_buff *orig_teardown_skb; /* The original teardown skb */
         struct sk_buff *teardown_skb; /* A copy to send through the AP */
         spinlock_t teardown_lock; /* To lock changing teardown_skb */
+        bool tdls_chan_switch_prohibited;
 
         /* WMM-AC TSPEC support */
         struct ieee80211_sta_tx_tspec tx_tspec[IEEE80211_NUM_ACS];
@@ -1399,6 +1400,7 @@ struct ieee802_11_elems {
         size_t total_len;
 
         /* pointers to IEs */
+        const u8 *ext_capab;
         const u8 *ssid;
         const u8 *supp_rates;
         const u8 *ds_params;
@@ -1433,6 +1435,7 @@ struct ieee802_11_elems {
         const struct ieee80211_mesh_chansw_params_ie *mesh_chansw_params_ie;
 
         /* length of them, respectively */
+        u8 ext_capab_len;
         u8 ssid_len;
         u8 supp_rates_len;
         u8 tim_len;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 11a937f3fdeb..45490a202d9c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2802,6 +2802,9 @@ static bool ieee80211_assoc_success(struct ieee80211_sub_if_data *sdata,
         }
 
         ifmgd->aid = aid;
+        ifmgd->tdls_chan_switch_prohibited =
+                elems.ext_capab && elems.ext_capab_len >= 5 &&
+                (elems.ext_capab[4] & WLAN_EXT_CAPA5_TDLS_CH_SW_PROHIBITED);
 
         /*
          * Some APs are erroneously not including some information in their
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index bcda2ac7d844..b6702c810ad3 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -49,6 +49,7 @@
  *      packets. This means the link is enabled.
  * @WLAN_STA_TDLS_INITIATOR: We are the initiator of the TDLS link with this
  *      station.
+ * @WLAN_STA_TDLS_CHAN_SWITCH: This TDLS peer supports TDLS channel-switching
  * @WLAN_STA_UAPSD: Station requested unscheduled SP while driver was
  *      keeping station in power-save mode, reply when the driver
  *      unblocks the station.
@@ -78,6 +79,7 @@ enum ieee80211_sta_info_flags {
         WLAN_STA_TDLS_PEER,
         WLAN_STA_TDLS_PEER_AUTH,
         WLAN_STA_TDLS_INITIATOR,
+        WLAN_STA_TDLS_CHAN_SWITCH,
         WLAN_STA_UAPSD,
         WLAN_STA_SP,
         WLAN_STA_4ADDR_EVENT,
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index f9319a5dca64..3ca0c2e725ff 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -831,6 +831,7 @@ u32 ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,
                 case WLAN_EID_SECONDARY_CHANNEL_OFFSET:
                 case WLAN_EID_WIDE_BW_CHANNEL_SWITCH:
                 case WLAN_EID_CHAN_SWITCH_PARAM:
+                case WLAN_EID_EXT_CAPABILITY:
                 /*
                  * not listing WLAN_EID_CHANNEL_SWITCH_WRAPPER -- it seems possible
                  * that if the content gets bigger it might be needed more than once
@@ -850,6 +851,10 @@ u32 ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,
                 elem_parse_failed = false;
 
                 switch (id) {
+                case WLAN_EID_EXT_CAPABILITY:
+                        elems->ext_capab = pos;
+                        elems->ext_capab_len = elen;
+                        break;
                 case WLAN_EID_SSID:
                         elems->ssid = pos;
                         elems->ssid_len = elen;