mac80211: TDLS: add proper HT-oper IE

When 11n peers performs a TDLS connection on a legacy BSS, the HT
operation IE must be specified according to IEEE802.11-2012 section
9.23.3.2. Otherwise HT-protection is compromised and the medium becomes
noisy for both the TDLS and the BSS links.

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>

5 files changed, 18 insertions, 7 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 2001555d49cb..3b5874e0174f 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -188,7 +188,7 @@ ieee80211_ibss_build_presp(struct ieee80211_sub_if_data *sdata,
                  * keep them at 0
                  */
                 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
-                                                 chandef, 0);
+                                                 chandef, 0, false);
 
                 /* add VHT capability and information IEs */
                 if (chandef->width != NL80211_CHAN_WIDTH_20 &&
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 68680ad04cef..5c76ba7aaf57 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1962,7 +1962,7 @@ u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_sta_ht_cap *ht_cap,
                               u16 cap);
 u8 *ieee80211_ie_build_ht_oper(u8 *pos, struct ieee80211_sta_ht_cap *ht_cap,
                                const struct cfg80211_chan_def *chandef,
-                               u16 prot_mode);
+                               u16 prot_mode, bool rifs_mode);
 u8 *ieee80211_ie_build_vht_cap(u8 *pos, struct ieee80211_sta_vht_cap *vht_cap,
                                u32 cap);
 u8 *ieee80211_ie_build_vht_oper(u8 *pos, struct ieee80211_sta_vht_cap *vht_cap,
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 626e8de70842..fa28500f28fd 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -466,7 +466,8 @@ int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
 
         pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
         ieee80211_ie_build_ht_oper(pos, ht_cap, &sdata->vif.bss_conf.chandef,
-                                   sdata->vif.bss_conf.ht_operation_mode);
+                                   sdata->vif.bss_conf.ht_operation_mode,
+                                   false);
 
         return 0;
 }
diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index ecc5e2a8f80b..c9eeb3f12808 100644
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -591,12 +591,19 @@ ieee80211_tdls_add_setup_cfm_ies(struct ieee80211_sub_if_data *sdata,
                 offset = noffset;
         }
 
-        /* if HT support is only added in TDLS, we need an HT-operation IE */
+        /*
+         * if HT support is only added in TDLS, we need an HT-operation IE.
+         * add the IE as required by IEEE802.11-2012 9.23.3.2.
+         */
         if (!ap_sta->sta.ht_cap.ht_supported && sta->sta.ht_cap.ht_supported) {
+                u16 prot = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED |
+                           IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT |
+                           IEEE80211_HT_OP_MODE_NON_HT_STA_PRSNT;
+
                 pos = skb_put(skb, 2 + sizeof(struct ieee80211_ht_operation));
-                /* send an empty HT operation IE */
                 ieee80211_ie_build_ht_oper(pos, &sta->sta.ht_cap,
-                                           &sdata->vif.bss_conf.chandef, 0);
+                                           &sdata->vif.bss_conf.chandef, prot,
+                                           true);
         }
 
         ieee80211_tdls_add_link_ie(sdata, skb, peer, initiator);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index d38daf0181e8..8802aa4da2a4 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2292,7 +2292,7 @@ u8 *ieee80211_ie_build_vht_cap(u8 *pos, struct ieee80211_sta_vht_cap *vht_cap,
 
 u8 *ieee80211_ie_build_ht_oper(u8 *pos, struct ieee80211_sta_ht_cap *ht_cap,
                                const struct cfg80211_chan_def *chandef,
-                               u16 prot_mode)
+                               u16 prot_mode, bool rifs_mode)
 {
         struct ieee80211_ht_operation *ht_oper;
         /* Build HT Information */
@@ -2320,6 +2320,9 @@ u8 *ieee80211_ie_build_ht_oper(u8 *pos, struct ieee80211_sta_ht_cap *ht_cap,
             chandef->width != NL80211_CHAN_WIDTH_20)
                 ht_oper->ht_param |= IEEE80211_HT_PARAM_CHAN_WIDTH_ANY;
 
+        if (rifs_mode)
+                ht_oper->ht_param |= IEEE80211_HT_PARAM_RIFS_MODE;
+
         ht_oper->operation_mode = cpu_to_le16(prot_mode);
         ht_oper->stbc_param = 0x0000;