[PATCH 18/26] ap: Advertise supported operating classes IE

[Ilan Peer]

From: Andrei Otcheretianski <andrei.otcheretianski at intel.com>

Advertise current operating class in beacons and probe responses. This IE is
required by the spec when extended channel switch is supported. However, since
this IE doesn't reflect correctly the sub-band spectrum breakdown and can't be
effectively used by clients, publish only the minimal required part which
is the current op. class.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski at intel.com>
---
 src/ap/beacon.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/ap/beacon.c b/src/ap/beacon.c
index 32e054e..3887f4a 100644
--- a/src/ap/beacon.c
+++ b/src/ap/beacon.c
@@ -328,6 +328,34 @@ static u8 *hostapd_eid_ecsa(struct hostapd_data *hapd, u8 *eid)
 }
 
 
+static u8 *hostapd_eid_supported_op_classes(struct hostapd_data *hapd, u8 *eid)
+{
+	u8 op_class, channel;
+
+	if (!(hapd->iface->drv_flags & WPA_DRIVER_FLAGS_AP_CSA) ||
+	    !hapd->iface->freq)
+		return eid;
+
+	if (ieee80211_freq_to_channel_ext(hapd->iface->freq,
+					  hapd->iconf->secondary_channel,
+					  hapd->iconf->vht_oper_chwidth,
+					  &op_class, &channel) ==
+	    NUM_HOSTAPD_MODES)
+		return eid;
+
+	*eid++ = WLAN_EID_SUPPORTED_OPERATING_CLASSES;
+	*eid++ = 2;
+
+	/* Current op. class must be first */
+	*eid++ = op_class;
+
+	/* TODO: advertise all the supported op. classes */
+	*eid++ = 0;
+
+	return eid;
+}
+
+
 static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd,
 				   const struct ieee80211_mgmt *req,
 				   int is_p2p, size_t *resp_len)
@@ -419,6 +447,7 @@ static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd,
 		hapd->cs_c_off_ecsa_proberesp = csa_pos - (u8 *)resp - 1;
 
 	pos = csa_pos;
+	pos = hostapd_eid_supported_op_classes(hapd, pos);
 
 #ifdef CONFIG_IEEE80211N
 	/* Secondary channel IE */
@@ -1005,6 +1034,8 @@ int ieee802_11_build_ap_params(struct hostapd_data *hapd,
 
 	tailpos = csa_pos;
 
+	tailpos = hostapd_eid_supported_op_classes(hapd, tailpos);
+
 #ifdef CONFIG_IEEE80211N
 	/* Secondary Channel IE */
 	/* TODO: The spec doesn't specify secondary channel IE position */
-- 
1.9.1