SCS: Add support for QoS Characteristics in SCS request

Add support to configure the mandatory QoS Characteristics parameters
per IEEE P802.11be/D4.0, 9.4.2.316 (QoS Characteristics element), in SCS
request:
 - Minimum Service Interval
 - Maximum Service Interval
 - Minimum Data Rate
 - Delay Bound

Enable STA SCS traffic descriptor support for EHT connection when the
connected EHT AP advertises SCS traffic descriptor capability in the EHT
Capabilities element.

Signed-off-by: Purushottam Kushwaha <quic_pkushwah@quicinc.com>

src/common/ieee802_11_defs.h

@@ -501,6 +501,7 @@
 #define WLAN_EID_EXT_EHT_CAPABILITIES 108
 #define WLAN_EID_EXT_TID_TO_LINK_MAPPING 109
 #define WLAN_EID_EXT_MULTI_LINK_TRAFFIC_INDICATION 110
+#define WLAN_EID_EXT_QOS_CHARACTERISTICS 113
 #define WLAN_EID_EXT_AKM_SUITE_SELECTOR 114
 
 /* Extended Capabilities field */
@@ -2768,6 +2769,26 @@ enum scs_request_type {
 	SCS_REQ_CHANGE = 2,
 };
 
+/*
+ * IEEE P802.11be/D4.0, 9.4.2.316 QoS Characteristics element,
+ * Table 9-404s (Direction subfield encoding)
+ */
+enum scs_direction {
+	SCS_DIRECTION_UP = 0,
+	SCS_DIRECTION_DOWN = 1,
+	SCS_DIRECTION_DIRECT = 2,
+};
+
+/*
+ * IEEE P802.11be/D4.0, 9.4.2.316 QoS Characteristics element,
+ * Figure 9-1001av (Control Info field format)
+ */
+#define EHT_QOS_CONTROL_INFO_DIRECTION_OFFSET		0
+#define EHT_QOS_CONTROL_INFO_TID_OFFSET			2
+#define EHT_QOS_CONTROL_INFO_USER_PRIORITY_OFFSET	6
+#define EHT_QOS_CONTROL_INFO_PRESENCE_MASK_OFFSET	9
+#define EHT_QOS_CONTROL_INFO_LINK_ID_OFFSET		25
+
 /* Optional subelement IDs for MSCS Descriptor element */
 enum mscs_description_subelem {
 	MCSC_SUBELEM_STATUS = 1,

wpa_supplicant/ctrl_iface.c

@@ -11528,7 +11528,11 @@ static int wpas_ctrl_iface_configure_scs(struct wpa_supplicant *wpa_s,
 	 * [scs_id=<decimal number>] <add|remove|change> [scs_up=<0-7>]
 	 * [classifier_type=<4|10>]
 	 * [classifier params based on classifier type]
-	 * [tclas_processing=<0|1>] [scs_id=<decimal number>] ...
+	 * [tclas_processing=<0|1>]
+	 * [qos_characteristics] <up/down/direct> [min_si=<decimal number>]
+	 * [max_si=<decimal number>] [min_data_rate=<decimal number>]
+	 * [delay_bound=<decimal number>]
+	 * [scs_id=<decimal number>] ...
 	 */
 	pos1 = os_strstr(cmd, "scs_id=");
 	if (!pos1) {
@@ -11543,7 +11547,8 @@ static int wpas_ctrl_iface_configure_scs(struct wpa_supplicant *wpa_s,
 		struct active_scs_elem *active_scs_desc;
 		char *next_scs_desc;
 		unsigned int num_tclas_elem = 0;
-		bool scsid_active = false;
+		bool scsid_active = false, tclas_present = false;
+		struct qos_characteristics *qos_elem = &desc_elem.qos_char_elem;
 
 		desc_elem.scs_id = atoi(pos1 + 7);
 		pos1 += 7;
@@ -11619,8 +11624,9 @@ static int wpas_ctrl_iface_configure_scs(struct wpa_supplicant *wpa_s,
 		pos = os_strstr(pos1, "classifier_type=");
 		if (!pos) {
 			wpa_printf(MSG_ERROR, "classifier type empty");
-			goto free_scs_desc;
+			goto qos_characteristics;
 		}
+		tclas_present = true;
 
 		while (pos) {
 			struct tclas_element elem = { 0 }, *n;
@@ -11684,6 +11690,68 @@ static int wpas_ctrl_iface_configure_scs(struct wpa_supplicant *wpa_s,
 			desc_elem.tclas_processing = val;
 		}
 
+	qos_characteristics:
+		pos1 = os_strstr(pos1, "qos_characteristics");
+		if (!pos1 && !tclas_present)
+			goto free_scs_desc;
+		if (!pos1)
+			goto scs_desc_end;
+
+		qos_elem->available = true;
+		if (os_strstr(pos1, "up ")) {
+			qos_elem->direction = SCS_DIRECTION_UP;
+			if (tclas_present) {
+				wpa_printf(MSG_ERROR,
+					   "TCLAS with direction:UP not allowed");
+				goto free_scs_desc;
+			}
+		} else if (os_strstr(pos1, "down ")) {
+			qos_elem->direction = SCS_DIRECTION_DOWN;
+		} else if (os_strstr(pos1, "direct ")) {
+			qos_elem->direction = SCS_DIRECTION_DIRECT;
+		}
+
+		pos1 = os_strstr(pos1, "min_si=");
+		if (!pos1) {
+			wpa_printf(MSG_ERROR, "Min SI is required");
+			goto free_scs_desc;
+		}
+		qos_elem->min_si = atoi(pos1 + 7);
+
+		pos1 = os_strstr(pos1, "max_si=");
+		if (!pos1) {
+			wpa_printf(MSG_ERROR, "Max SI is required");
+			goto free_scs_desc;
+		}
+		qos_elem->max_si = atoi(pos1 + 7);
+
+		if (qos_elem->min_si && qos_elem->max_si &&
+		    qos_elem->max_si < qos_elem->min_si) {
+			wpa_printf(MSG_ERROR, "Invalid Max SI");
+			goto free_scs_desc;
+		}
+
+		pos1 = os_strstr(pos1, "min_data_rate=");
+		if (!pos1) {
+			wpa_printf(MSG_ERROR, "Min data rate is required");
+			goto free_scs_desc;
+		}
+		qos_elem->min_data_rate = atoi(pos1 + 14);
+
+		pos1 = os_strstr(pos1, "delay_bound=");
+		if (!pos1) {
+			wpa_printf(MSG_ERROR, "Delay Bound is required");
+			goto free_scs_desc;
+		}
+		qos_elem->delay_bound = atoi(pos1 + 12);
+
+		if (qos_elem->min_data_rate >= BIT(24) ||
+		    qos_elem->delay_bound >= BIT(24)) {
+			wpa_printf(MSG_ERROR,
+				   "Invalid min_data_rate or delay_bound");
+			goto free_scs_desc;
+		}
+
 scs_desc_end:
 		n1 = os_realloc(scs_data->scs_desc_elems, (num_scs_desc + 1) *
 				sizeof(struct scs_desc_elem));

wpa_supplicant/robust_av.c

@@ -97,12 +97,27 @@ static int wpas_populate_type10_classifier(struct type10_params *type10_param,
 }
 
 
+static bool tclas_elem_required(const struct qos_characteristics *qos_elem)
+{
+	if (!qos_elem || !qos_elem->available)
+		return true;
+
+	if (qos_elem->direction == SCS_DIRECTION_DOWN)
+		return true;
+
+	return false;
+}
+
+
 static int wpas_populate_scs_descriptor_ie(struct scs_desc_elem *desc_elem,
-					   struct wpabuf *buf)
+					   struct wpabuf *buf,
+					   bool allow_scs_traffic_desc)
 {
 	u8 *len, *len1;
 	struct tclas_element *tclas_elem;
 	unsigned int i;
+	struct qos_characteristics *qos_elem;
+	u32 control_info = 0;
 
 	/* SCS Descriptor element */
 	wpabuf_put_u8(buf, WLAN_EID_SCS_DESCRIPTOR);
@@ -112,6 +127,9 @@ static int wpas_populate_scs_descriptor_ie(struct scs_desc_elem *desc_elem,
 	if (desc_elem->request_type == SCS_REQ_REMOVE)
 		goto end;
 
+	if (!tclas_elem_required(&desc_elem->qos_char_elem))
+		goto skip_tclas_elem;
+
 	if (desc_elem->intra_access_priority || desc_elem->scs_up_avail) {
 		wpabuf_put_u8(buf, WLAN_EID_INTRA_ACCESS_CATEGORY_PRIORITY);
 		wpabuf_put_u8(buf, 1);
@@ -164,6 +182,40 @@ static int wpas_populate_scs_descriptor_ie(struct scs_desc_elem *desc_elem,
 		wpabuf_put_u8(buf, desc_elem->tclas_processing);
 	}
 
+skip_tclas_elem:
+	if (allow_scs_traffic_desc && desc_elem->qos_char_elem.available) {
+		qos_elem = &desc_elem->qos_char_elem;
+		/* Element ID, Length, and Element ID Extension */
+		wpabuf_put_u8(buf, WLAN_EID_EXTENSION);
+		len1 = wpabuf_put(buf, 1);
+		wpabuf_put_u8(buf, WLAN_EID_EXT_QOS_CHARACTERISTICS);
+
+		/* IEEE P802.11be/D4.0, 9.4.2.316 QoS Characteristics element,
+		 * Figure 9-1001av (Control Info field format)
+		 */
+		control_info = ((u32) qos_elem->direction <<
+				EHT_QOS_CONTROL_INFO_DIRECTION_OFFSET);
+		control_info |= ((u32) desc_elem->intra_access_priority <<
+				 EHT_QOS_CONTROL_INFO_TID_OFFSET);
+		control_info |= ((u32) desc_elem->intra_access_priority <<
+				 EHT_QOS_CONTROL_INFO_USER_PRIORITY_OFFSET);
+		control_info |= ((u32) qos_elem->mask <<
+				 EHT_QOS_CONTROL_INFO_PRESENCE_MASK_OFFSET);
+
+		/* Control Info */
+		wpabuf_put_le32(buf, control_info);
+		/* Minimum Service Interval */
+		wpabuf_put_le32(buf, qos_elem->min_si);
+		/* Maximum Service Interval */
+		wpabuf_put_le32(buf, qos_elem->max_si);
+		/* Minimum Data Rate */
+		wpabuf_put_le24(buf, qos_elem->min_data_rate);
+		/* Delay Bound */
+		wpabuf_put_le24(buf, qos_elem->delay_bound);
+
+		*len1 = (u8 *) wpabuf_put(buf, 0) - len1 - 1;
+	}
+
 end:
 	*len = (u8 *) wpabuf_put(buf, 0) - len - 1;
 	return 0;
@@ -273,8 +325,26 @@ static size_t tclas_elem_len(const struct tclas_element *elem)
 }
 
 
+static size_t qos_char_len(const struct qos_characteristics *qos_elem)
+{
+	size_t buf_len = 0;
+
+	buf_len += 1 +	/* Element ID */
+		1 +	/* Length */
+		1 +	/* Element ID Extension */
+		4 +	/* Control Info */
+		4 +	/* Minimum Service Interval */
+		4 +	/* Maximum Service Interval */
+		3 +	/* Minimum Data Rate */
+		3;	/* Delay Bound */
+
+	return buf_len;
+}
+
+
 static struct wpabuf * allocate_scs_buf(struct scs_desc_elem *desc_elem,
-					unsigned int num_scs_desc)
+					unsigned int num_scs_desc,
+					bool allow_scs_traffic_desc)
 {
 	struct wpabuf *buf;
 	size_t buf_len = 0;
@@ -292,6 +362,13 @@ static struct wpabuf * allocate_scs_buf(struct scs_desc_elem *desc_elem,
 		if (desc_elem->request_type == SCS_REQ_REMOVE)
 			continue;
 
+		if (allow_scs_traffic_desc &&
+		    desc_elem->qos_char_elem.available)
+			buf_len += qos_char_len(&desc_elem->qos_char_elem);
+
+		if (!tclas_elem_required(&desc_elem->qos_char_elem))
+			continue;
+
 		if (desc_elem->intra_access_priority || desc_elem->scs_up_avail)
 			buf_len += 3;
 
@@ -369,8 +446,11 @@ int wpas_send_scs_req(struct wpa_supplicant *wpa_s)
 {
 	struct wpabuf *buf = NULL;
 	struct scs_desc_elem *desc_elem = NULL;
+	const struct ieee80211_eht_capabilities *eht;
+	const u8 *eht_ie;
 	int ret = -1;
 	unsigned int i;
+	bool allow_scs_traffic_desc = false;
 
 	if (wpa_s->wpa_state != WPA_COMPLETED || !wpa_s->current_ssid)
 		return -1;
@@ -385,8 +465,28 @@ int wpas_send_scs_req(struct wpa_supplicant *wpa_s)
 	if (!desc_elem)
 		return -1;
 
+	if (wpa_is_non_eht_scs_traffic_desc_supported(wpa_s->current_bss))
+		allow_scs_traffic_desc = true;
+
+	/* Allow SCS Traffic descriptor support for EHT connection */
+	eht_ie = wpa_bss_get_ie_ext(wpa_s->current_bss,
+				    WLAN_EID_EXT_EHT_CAPABILITIES);
+	if (wpa_s->connection_eht && eht_ie &&
+	    eht_ie[1] >= 1 + IEEE80211_EHT_CAPAB_MIN_LEN) {
+		eht = (const struct ieee80211_eht_capabilities *) &eht_ie[3];
+		if (eht->mac_cap & EHT_MACCAP_SCS_TRAFFIC_DESC)
+			allow_scs_traffic_desc = true;
+	}
+
+	if (!allow_scs_traffic_desc && desc_elem->qos_char_elem.available) {
+		wpa_dbg(wpa_s, MSG_INFO,
+			"Connection does not support EHT/non-EHT SCS Traffic Description - could not send SCS Request with QoS Characteristics");
+		return -1;
+	}
+
 	buf = allocate_scs_buf(desc_elem,
-			       wpa_s->scs_robust_av_req.num_scs_desc);
+			       wpa_s->scs_robust_av_req.num_scs_desc,
+			       allow_scs_traffic_desc);
 	if (!buf)
 		return -1;
 
@@ -400,7 +500,8 @@ int wpas_send_scs_req(struct wpa_supplicant *wpa_s)
 	for (i = 0; i < wpa_s->scs_robust_av_req.num_scs_desc;
 	     i++, desc_elem++) {
 		/* SCS Descriptor element */
-		if (wpas_populate_scs_descriptor_ie(desc_elem, buf) < 0)
+		if (wpas_populate_scs_descriptor_ie(desc_elem, buf,
+						    allow_scs_traffic_desc) < 0)
 			goto end;
 	}
 

wpa_supplicant/wpa_supplicant_i.h

@@ -596,6 +596,24 @@ struct tclas_element {
 };
 
 
+struct qos_characteristics {
+	bool available;
+
+	/* Control Info Direction */
+	u8 direction;
+	/* Presence Bitmap Of Additional Parameters */
+	u16 mask;
+	/* Minimum Service Interval */
+	u32 min_si;
+	/* Maximum Service Interval */
+	u32 max_si;
+	/* Minimum Data Rate */
+	u32 min_data_rate;
+	/* Delay Bound */
+	u32 delay_bound;
+};
+
+
 struct scs_desc_elem {
 	u8 scs_id;
 	enum scs_request_type request_type;
@@ -604,6 +622,7 @@ struct scs_desc_elem {
 	struct tclas_element *tclas_elems;
 	unsigned int num_tclas_elem;
 	u8 tclas_processing;
+	struct qos_characteristics qos_char_elem;
 };