[PATCH] HT: Check remote peer HT Operation IE

[Masashi Honma]

The remote mesh STA which had configuration disable_ht40=1 could have
HT Capabilities IE which includes Supported Channel Width Set = 1 (both
20 MHz and 40 MHz operation is supported) even though it had HT
Operation IE which includes STA Channel Width = 0 (20 MHz channel width
only). Previously, local peer recognized such a remote peer as 40MHz
band width enabled STA because local peer only checked HT Capabilities
IE. This could cause disconnection between disable_ht40=1 mesh STA and
disable_ht40=0 mesh STA (they could be established but could not ping
with ath9k_htc device). This patch fixes the issue by refering HT
Operation IE.

Signed-off-by: Masashi Honma <masashi.honma at gmail.com>
---
 src/common/hw_features_common.c | 13 +++++++++++++
 src/common/hw_features_common.h |  2 ++
 wpa_supplicant/mesh_mpm.c       | 14 ++++++++++++++
 wpa_supplicant/wpa_supplicant.c | 12 ++----------
 4 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/src/common/hw_features_common.c b/src/common/hw_features_common.c
index 9c37ea6..b1eb995 100644
--- a/src/common/hw_features_common.c
+++ b/src/common/hw_features_common.c
@@ -453,3 +453,16 @@ int hostapd_set_freq_params(struct hostapd_freq_params *data,
 
 	return 0;
 }
+
+void set_disable_ht40(struct ieee80211_ht_capabilities *htcaps,
+		      int disabled)
+{
+	/* Masking these out disables HT40 */
+	le16 msk = host_to_le16(HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET |
+				HT_CAP_INFO_SHORT_GI40MHZ);
+
+	if (disabled)
+		htcaps->ht_capabilities_info &= ~msk;
+	else
+		htcaps->ht_capabilities_info |= msk;
+}
diff --git a/src/common/hw_features_common.h b/src/common/hw_features_common.h
index 7360b4e..234b7bf 100644
--- a/src/common/hw_features_common.h
+++ b/src/common/hw_features_common.h
@@ -35,5 +35,7 @@ int hostapd_set_freq_params(struct hostapd_freq_params *data,
 			    int vht_enabled, int sec_channel_offset,
 			    int vht_oper_chwidth, int center_segment0,
 			    int center_segment1, u32 vht_caps);
+void set_disable_ht40(struct ieee80211_ht_capabilities *htcaps,
+		      int disabled);
 
 #endif /* HW_FEATURES_COMMON_H */
diff --git a/wpa_supplicant/mesh_mpm.c b/wpa_supplicant/mesh_mpm.c
index 6c3fa14..39a4ee8 100644
--- a/wpa_supplicant/mesh_mpm.c
+++ b/wpa_supplicant/mesh_mpm.c
@@ -11,6 +11,7 @@
 #include "utils/common.h"
 #include "utils/eloop.h"
 #include "common/ieee802_11_defs.h"
+#include "common/hw_features_common.h"
 #include "ap/hostapd.h"
 #include "ap/sta_info.h"
 #include "ap/ieee802_11.h"
@@ -646,6 +647,9 @@ static struct sta_info * mesh_mpm_add_peer(struct wpa_supplicant *wpa_s,
 	struct mesh_conf *conf = wpa_s->ifmsh->mconf;
 	struct hostapd_data *data = wpa_s->ifmsh->bss[0];
 	struct sta_info *sta;
+#ifdef CONFIG_IEEE80211N
+	struct ieee80211_ht_operation *oper;
+#endif /* CONFIG_IEEE80211N */
 	int ret;
 
 	if (elems->mesh_config_len >= 7 &&
@@ -677,6 +681,16 @@ static struct sta_info * mesh_mpm_add_peer(struct wpa_supplicant *wpa_s,
 
 #ifdef CONFIG_IEEE80211N
 	copy_sta_ht_capab(data, sta, elems->ht_capabilities);
+
+	oper = (struct ieee80211_ht_operation *)elems->ht_operation;
+	if (oper &&
+	    !(oper->ht_param & HT_INFO_HT_PARAM_STA_CHNL_WIDTH)) {
+		wpa_msg(wpa_s, MSG_DEBUG, MACSTR
+			" does not supports 40MHz band width",
+			MAC2STR(sta->addr));
+		set_disable_ht40(sta->ht_capabilities, 1);
+	}
+
 	update_ht_state(data, sta);
 #endif /* CONFIG_IEEE80211N */
 
diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c
index bc59c67..6a3e02a 100644
--- a/wpa_supplicant/wpa_supplicant.c
+++ b/wpa_supplicant/wpa_supplicant.c
@@ -3857,18 +3857,10 @@ static int wpa_set_disable_ht40(struct wpa_supplicant *wpa_s,
 				struct ieee80211_ht_capabilities *htcaps_mask,
 				int disabled)
 {
-	/* Masking these out disables HT40 */
-	le16 msk = host_to_le16(HT_CAP_INFO_SUPP_CHANNEL_WIDTH_SET |
-				HT_CAP_INFO_SHORT_GI40MHZ);
-
 	wpa_msg(wpa_s, MSG_DEBUG, "set_disable_ht40: %d", disabled);
 
-	if (disabled)
-		htcaps->ht_capabilities_info &= ~msk;
-	else
-		htcaps->ht_capabilities_info |= msk;
-
-	htcaps_mask->ht_capabilities_info |= msk;
+	set_disable_ht40(htcaps, disabled);
+	set_disable_ht40(htcaps_mask, 1);
 
 	return 0;
 }
-- 
2.7.4