MSCS: Add support to send MSCS Request frames

Add support to send MSCS add/change/remove types of Action frames
to the connected AP.

Signed-off-by: Vinita S. Maloo <vmaloo@codeaurora.org>

src/common/ieee802_11_defs.h

@@ -478,6 +478,8 @@
 #define WLAN_EID_EXT_HE_6GHZ_BAND_CAP 59
 #define WLAN_EID_EXT_EDMG_CAPABILITIES 61
 #define WLAN_EID_EXT_EDMG_OPERATION 62
+#define WLAN_EID_EXT_MSCS_DESCRIPTOR 88
+#define WLAN_EID_EXT_TCLAS_MASK 89
 #define WLAN_EID_EXT_REJECTED_GROUPS 92
 #define WLAN_EID_EXT_ANTI_CLOGGING_TOKEN 93
 
@@ -562,6 +564,7 @@
 #define WLAN_EXT_CAPAB_SAE_PW_ID 81
 #define WLAN_EXT_CAPAB_SAE_PW_ID_EXCLUSIVELY 82
 #define WLAN_EXT_CAPAB_BEACON_PROTECTION 84
+#define WLAN_EXT_CAPAB_MSCS 85
 #define WLAN_EXT_CAPAB_SAE_PK_EXCLUSIVELY 88
 
 /* Extended RSN Capabilities */
@@ -2340,4 +2343,20 @@ enum edmg_bw_config {
 /* DPP Public Action frame identifiers - OUI_WFA */
 #define DPP_OUI_TYPE 0x1A
 
+/* Robust AV streaming Action field values */
+enum robust_av_streaming_action {
+	ROBUST_AV_SCS_REQ = 0,
+	ROBUST_AV_SCS_RESP = 1,
+	ROBUST_AV_GROUP_MEMBERSHIP_REQ = 2,
+	ROBUST_AV_GROUP_MEMBERSHIP_RESP = 3,
+	ROBUST_AV_MSCS_REQ = 4,
+	ROBUST_AV_MSCS_RESP = 5,
+};
+
+enum scs_request_type {
+	SCS_REQ_ADD = 0,
+	SCS_REQ_REMOVE = 1,
+	SCS_REQ_CHANGE = 2,
+};
+
 #endif /* IEEE802_11_DEFS_H */

wpa_supplicant/Android.mk

@@ -98,6 +98,7 @@ OBJS += src/utils/crc32.c
 OBJS += wmm_ac.c
 OBJS += op_classes.c
 OBJS += rrm.c
+OBJS += robust_av.c
 OBJS_p = wpa_passphrase.c
 OBJS_p += src/utils/common.c
 OBJS_p += src/utils/wpa_debug.c

wpa_supplicant/Makefile

@@ -107,6 +107,7 @@ OBJS += ../src/utils/ip_addr.o
 OBJS += ../src/utils/crc32.o
 OBJS += op_classes.o
 OBJS += rrm.o
+OBJS += robust_av.o
 OBJS_p = wpa_passphrase.o
 OBJS_p += ../src/utils/common.o
 OBJS_p += ../src/utils/wpa_debug.o

wpa_supplicant/ctrl_iface.c

@@ -8483,6 +8483,7 @@ static void wpa_supplicant_ctrl_iface_flush(struct wpa_supplicant *wpa_s)
 	wpa_s->next_scan_bssid_wildcard_ssid = 0;
 	os_free(wpa_s->select_network_scan_freqs);
 	wpa_s->select_network_scan_freqs = NULL;
+	os_memset(&wpa_s->robust_av, 0, sizeof(struct robust_av_data));
 
 	wpa_bss_flush(wpa_s);
 	if (!dl_list_empty(&wpa_s->bss)) {
@@ -8508,6 +8509,8 @@ static void wpa_supplicant_ctrl_iface_flush(struct wpa_supplicant *wpa_s)
 	wpa_supplicant_update_channel_list(wpa_s, NULL);
 
 	free_bss_tmp_disallowed(wpa_s);
+
+	os_memset(&wpa_s->robust_av, 0, sizeof(struct robust_av_data));
 }
 
 
@@ -10342,6 +10345,76 @@ static int wpas_ctrl_cmd_debug_level(const char *cmd)
 }
 
 
+static int wpas_ctrl_iface_configure_mscs(struct wpa_supplicant *wpa_s,
+					  const char *cmd)
+{
+	size_t frame_classifier_len;
+	const char *pos, *end;
+	struct robust_av_data *robust_av = &wpa_s->robust_av;
+	int val;
+
+	/*
+	 * format:
+	 * <add|remove|change> [up_bitmap=<hex byte>] [up_limit=<integer>]
+	 * [stream_timeout=<in TUs>] [frame_classifier=<hex bytes>]
+	 */
+	os_memset(robust_av, 0, sizeof(struct robust_av_data));
+	if (os_strncmp(cmd, "add ", 4) == 0) {
+		robust_av->request_type = SCS_REQ_ADD;
+	} else if (os_strcmp(cmd, "remove") == 0) {
+		robust_av->request_type = SCS_REQ_REMOVE;
+		robust_av->valid_config = false;
+		return wpas_send_mscs_req(wpa_s);
+	} else if (os_strncmp(cmd, "change ", 7) == 0) {
+		robust_av->request_type = SCS_REQ_CHANGE;
+	} else {
+		return -1;
+	}
+
+	pos = os_strstr(cmd, "up_bitmap=");
+	if (!pos)
+		return -1;
+
+	val = hex2byte(pos + 10);
+	if (val < 0)
+		return -1;
+	robust_av->up_bitmap = val;
+
+	pos = os_strstr(cmd, "up_limit=");
+	if (!pos)
+		return -1;
+
+	robust_av->up_limit = atoi(pos + 9);
+
+	pos = os_strstr(cmd, "stream_timeout=");
+	if (!pos)
+		return -1;
+
+	robust_av->stream_timeout = atoi(pos + 15);
+	if (robust_av->stream_timeout == 0)
+		return -1;
+
+	pos = os_strstr(cmd, "frame_classifier=");
+	if (!pos)
+		return -1;
+
+	pos += 17;
+	end = os_strchr(pos, ' ');
+	if (!end)
+		end = pos + os_strlen(pos);
+
+	frame_classifier_len = (end - pos) / 2;
+	if (frame_classifier_len > sizeof(robust_av->frame_classifier) ||
+	    hexstr2bin(pos, robust_av->frame_classifier, frame_classifier_len))
+		return -1;
+
+	robust_av->frame_classifier_len = frame_classifier_len;
+	robust_av->valid_config = true;
+
+	return wpas_send_mscs_req(wpa_s);
+}
+
+
 char * wpa_supplicant_ctrl_iface_process(struct wpa_supplicant *wpa_s,
 					 char *buf, size_t *resp_len)
 {
@@ -11233,6 +11306,9 @@ char * wpa_supplicant_ctrl_iface_process(struct wpa_supplicant *wpa_s,
 			reply_len = -1;
 #endif /* CONFIG_DPP2 */
 #endif /* CONFIG_DPP */
+	} else if (os_strncmp(buf, "MSCS ", 5) == 0) {
+		if (wpas_ctrl_iface_configure_mscs(wpa_s, buf + 5))
+			reply_len = -1;
 	} else {
 		os_memcpy(reply, "UNKNOWN COMMAND\n", 16);
 		reply_len = 16;

wpa_supplicant/robust_av.c

@@ -0,0 +1,98 @@
+/*
+ * wpa_supplicant - Robust AV procedures
+ * Copyright (c) 2020, The Linux Foundation
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#include "utils/includes.h"
+#include "utils/common.h"
+#include "common/wpa_ctrl.h"
+#include "wpa_supplicant_i.h"
+#include "driver_i.h"
+#include "bss.h"
+
+
+void wpas_populate_mscs_descriptor_ie(struct robust_av_data *robust_av,
+				      struct wpabuf *buf)
+{
+	u8 *len, *len1;
+
+	/* MSCS descriptor element */
+	wpabuf_put_u8(buf, WLAN_EID_EXTENSION);
+	len = wpabuf_put(buf, 1);
+	wpabuf_put_u8(buf, WLAN_EID_EXT_MSCS_DESCRIPTOR);
+	wpabuf_put_u8(buf, robust_av->request_type);
+	wpabuf_put_u8(buf, robust_av->up_bitmap);
+	wpabuf_put_u8(buf, robust_av->up_limit);
+	wpabuf_put_le32(buf, robust_av->stream_timeout);
+
+	if (robust_av->request_type != SCS_REQ_REMOVE) {
+		/* TCLAS mask element */
+		wpabuf_put_u8(buf, WLAN_EID_EXTENSION);
+		len1 = wpabuf_put(buf, 1);
+		wpabuf_put_u8(buf, WLAN_EID_EXT_TCLAS_MASK);
+
+		/* Frame classifier */
+		wpabuf_put_data(buf, robust_av->frame_classifier,
+				robust_av->frame_classifier_len);
+		*len1 = (u8 *) wpabuf_put(buf, 0) - len1 - 1;
+	}
+
+	*len = (u8 *) wpabuf_put(buf, 0) - len - 1;
+}
+
+
+int wpas_send_mscs_req(struct wpa_supplicant *wpa_s)
+{
+	struct wpabuf *buf;
+	const u8 *ext_capab = NULL;
+	size_t buf_len;
+	int ret;
+
+	if (wpa_s->wpa_state != WPA_COMPLETED || !wpa_s->current_ssid)
+		return 0;
+
+	if (wpa_s->current_bss)
+		ext_capab = wpa_bss_get_ie(wpa_s->current_bss,
+					   WLAN_EID_EXT_CAPAB);
+
+	if (!ext_capab || ext_capab[1] < 11 || !(ext_capab[12] & 0x20)) {
+		wpa_dbg(wpa_s, MSG_INFO,
+			"AP does not support MSCS - could not send MSCS Req");
+		return -1;
+	}
+
+	buf_len = 3 +	/* Action frame header */
+		  3 +	/* MSCS descriptor IE header */
+		  1 +	/* Request type */
+		  2 +	/* User priority control */
+		  4 +	/* Stream timeout */
+		  3 +	/* TCLAS Mask IE header */
+		  wpa_s->robust_av.frame_classifier_len;
+
+	buf = wpabuf_alloc(buf_len);
+	if (!buf) {
+		wpa_printf(MSG_ERROR, "Failed to allocate MSCS req");
+		return -1;
+	}
+
+	wpabuf_put_u8(buf, WLAN_ACTION_ROBUST_AV_STREAMING);
+	wpabuf_put_u8(buf, ROBUST_AV_MSCS_REQ);
+	wpa_s->robust_av.dialog_token++;
+	wpabuf_put_u8(buf, wpa_s->robust_av.dialog_token);
+
+	/* MSCS descriptor element */
+	wpas_populate_mscs_descriptor_ie(&wpa_s->robust_av, buf);
+
+	wpa_hexdump_buf(MSG_MSGDUMP, "MSCS Request", wpabuf_head(buf));
+	ret = wpa_drv_send_action(wpa_s, wpa_s->assoc_freq, 0, wpa_s->bssid,
+				  wpa_s->own_addr, wpa_s->bssid,
+				  wpabuf_head(buf), wpabuf_len(buf), 0);
+	if (ret < 0)
+		wpa_dbg(wpa_s, MSG_INFO, "MSCS: Failed to send MSCS Request");
+
+	wpabuf_free(buf);
+	return ret;
+}

wpa_supplicant/wpa_supplicant.c

@@ -1899,6 +1899,9 @@ static void wpas_ext_capab_byte(struct wpa_supplicant *wpa_s, u8 *pos, int idx)
 			*pos |= 0x01;
 #endif /* CONFIG_FILS */
 		break;
+	case 10: /* Bits 80-87 */
+		*pos |= 0x20; /* Bit 85 - Mirrored SCS */
+		break;
 	}
 }
 
@@ -1906,7 +1909,7 @@ static void wpas_ext_capab_byte(struct wpa_supplicant *wpa_s, u8 *pos, int idx)
 int wpas_build_ext_capab(struct wpa_supplicant *wpa_s, u8 *buf, size_t buflen)
 {
 	u8 *pos = buf;
-	u8 len = 10, i;
+	u8 len = 11, i;
 
 	if (len < wpa_s->extended_capa_len)
 		len = wpa_s->extended_capa_len;

wpa_supplicant/wpa_supplicant_i.h

@@ -491,6 +491,17 @@ struct driver_signal_override {
 	int scan_level;
 };
 
+struct robust_av_data {
+	u8 dialog_token;
+	enum scs_request_type request_type;
+	u8 up_bitmap;
+	u8 up_limit;
+	u32 stream_timeout;
+	u8 frame_classifier[48];
+	size_t frame_classifier_len;
+	bool valid_config;
+};
+
 /**
  * struct wpa_supplicant - Internal data for wpa_supplicant interface
  *
@@ -1315,6 +1326,7 @@ struct wpa_supplicant {
 	unsigned int multi_ap_ie:1;
 	unsigned int multi_ap_backhaul:1;
 	unsigned int multi_ap_fronthaul:1;
+	struct robust_av_data robust_av;
 };
 
 
@@ -1623,4 +1635,8 @@ int wpa_is_fils_sk_pfs_supported(struct wpa_supplicant *wpa_s);
 
 void wpas_clear_driver_signal_override(struct wpa_supplicant *wpa_s);
 
+int wpas_send_mscs_req(struct wpa_supplicant *wpa_s);
+void wpas_populate_mscs_descriptor_ie(struct robust_av_data *robust_av,
+				      struct wpabuf *buf);
+
 #endif /* WPA_SUPPLICANT_I_H */