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      1 /*
      2  * wpa_supplicant - Wi-Fi Display
      3  * Copyright (c) 2011, Atheros Communications, Inc.
      4  * Copyright (c) 2011-2012, Qualcomm Atheros, Inc.
      5  *
      6  * This software may be distributed under the terms of the BSD license.
      7  * See README for more details.
      8  */
      9 
     10 #include "includes.h"
     11 
     12 #include "common.h"
     13 #include "p2p/p2p.h"
     14 #include "common/ieee802_11_defs.h"
     15 #include "wpa_supplicant_i.h"
     16 #include "wifi_display.h"
     17 
     18 
     19 #define WIFI_DISPLAY_SUBELEM_HEADER_LEN 3
     20 
     21 
     22 int wifi_display_init(struct wpa_global *global)
     23 {
     24 	global->wifi_display = 1;
     25 	return 0;
     26 }
     27 
     28 
     29 void wifi_display_deinit(struct wpa_global *global)
     30 {
     31 	int i;
     32 	for (i = 0; i < MAX_WFD_SUBELEMS; i++) {
     33 		wpabuf_free(global->wfd_subelem[i]);
     34 		global->wfd_subelem[i] = NULL;
     35 	}
     36 }
     37 
     38 
     39 struct wpabuf * wifi_display_get_wfd_ie(struct wpa_global *global)
     40 {
     41 	struct wpabuf *ie;
     42 	size_t len;
     43 	int i;
     44 
     45 	if (global->p2p == NULL)
     46 		return NULL;
     47 
     48 	len = 0;
     49 	for (i = 0; i < MAX_WFD_SUBELEMS; i++) {
     50 		if (global->wfd_subelem[i])
     51 			len += wpabuf_len(global->wfd_subelem[i]);
     52 	}
     53 
     54 	ie = wpabuf_alloc(len);
     55 	if (ie == NULL)
     56 		return NULL;
     57 
     58 	for (i = 0; i < MAX_WFD_SUBELEMS; i++) {
     59 		if (global->wfd_subelem[i])
     60 			wpabuf_put_buf(ie, global->wfd_subelem[i]);
     61 	}
     62 
     63 	return ie;
     64 }
     65 
     66 
     67 static int wifi_display_update_wfd_ie(struct wpa_global *global)
     68 {
     69 	struct wpabuf *ie, *buf;
     70 	size_t len, plen;
     71 
     72 	if (global->p2p == NULL)
     73 		return 0;
     74 
     75 	wpa_printf(MSG_DEBUG, "WFD: Update WFD IE");
     76 
     77 	if (!global->wifi_display) {
     78 		wpa_printf(MSG_DEBUG, "WFD: Wi-Fi Display disabled - do not "
     79 			   "include WFD IE");
     80 		p2p_set_wfd_ie_beacon(global->p2p, NULL);
     81 		p2p_set_wfd_ie_probe_req(global->p2p, NULL);
     82 		p2p_set_wfd_ie_probe_resp(global->p2p, NULL);
     83 		p2p_set_wfd_ie_assoc_req(global->p2p, NULL);
     84 		p2p_set_wfd_ie_invitation(global->p2p, NULL);
     85 		p2p_set_wfd_ie_prov_disc_req(global->p2p, NULL);
     86 		p2p_set_wfd_ie_prov_disc_resp(global->p2p, NULL);
     87 		p2p_set_wfd_ie_go_neg(global->p2p, NULL);
     88 		p2p_set_wfd_dev_info(global->p2p, NULL);
     89 		p2p_set_wfd_assoc_bssid(global->p2p, NULL);
     90 		p2p_set_wfd_coupled_sink_info(global->p2p, NULL);
     91 		return 0;
     92 	}
     93 
     94 	p2p_set_wfd_dev_info(global->p2p,
     95 			     global->wfd_subelem[WFD_SUBELEM_DEVICE_INFO]);
     96 	p2p_set_wfd_assoc_bssid(
     97 		global->p2p,
     98 		global->wfd_subelem[WFD_SUBELEM_ASSOCIATED_BSSID]);
     99 	p2p_set_wfd_coupled_sink_info(
    100 		global->p2p, global->wfd_subelem[WFD_SUBELEM_COUPLED_SINK]);
    101 
    102 	/*
    103 	 * WFD IE is included in number of management frames. Two different
    104 	 * sets of subelements are included depending on the frame:
    105 	 *
    106 	 * Beacon, (Re)Association Request, GO Negotiation Req/Resp/Conf,
    107 	 * Provision Discovery Req:
    108 	 * WFD Device Info
    109 	 * [Associated BSSID]
    110 	 * [Coupled Sink Info]
    111 	 *
    112 	 * Probe Request:
    113 	 * WFD Device Info
    114 	 * [Associated BSSID]
    115 	 * [Coupled Sink Info]
    116 	 * [WFD Extended Capability]
    117 	 *
    118 	 * Probe Response:
    119 	 * WFD Device Info
    120 	 * [Associated BSSID]
    121 	 * [Coupled Sink Info]
    122 	 * [WFD Extended Capability]
    123 	 * [WFD Session Info]
    124 	 *
    125 	 * (Re)Association Response, P2P Invitation Req/Resp,
    126 	 * Provision Discovery Resp:
    127 	 * WFD Device Info
    128 	 * [Associated BSSID]
    129 	 * [Coupled Sink Info]
    130 	 * [WFD Session Info]
    131 	 */
    132 	len = 0;
    133 	if (global->wfd_subelem[WFD_SUBELEM_DEVICE_INFO])
    134 		len += wpabuf_len(global->wfd_subelem[
    135 					  WFD_SUBELEM_DEVICE_INFO]);
    136 	if (global->wfd_subelem[WFD_SUBELEM_ASSOCIATED_BSSID])
    137 		len += wpabuf_len(global->wfd_subelem[
    138 					  WFD_SUBELEM_ASSOCIATED_BSSID]);
    139 	if (global->wfd_subelem[WFD_SUBELEM_COUPLED_SINK])
    140 		len += wpabuf_len(global->wfd_subelem[
    141 					  WFD_SUBELEM_COUPLED_SINK]);
    142 	if (global->wfd_subelem[WFD_SUBELEM_SESSION_INFO])
    143 		len += wpabuf_len(global->wfd_subelem[
    144 					  WFD_SUBELEM_SESSION_INFO]);
    145 	if (global->wfd_subelem[WFD_SUBELEM_EXT_CAPAB])
    146 		len += wpabuf_len(global->wfd_subelem[WFD_SUBELEM_EXT_CAPAB]);
    147 	buf = wpabuf_alloc(len);
    148 	if (buf == NULL)
    149 		return -1;
    150 
    151 	if (global->wfd_subelem[WFD_SUBELEM_DEVICE_INFO])
    152 		wpabuf_put_buf(buf,
    153 			       global->wfd_subelem[WFD_SUBELEM_DEVICE_INFO]);
    154 	if (global->wfd_subelem[WFD_SUBELEM_ASSOCIATED_BSSID])
    155 		wpabuf_put_buf(buf, global->wfd_subelem[
    156 				       WFD_SUBELEM_ASSOCIATED_BSSID]);
    157 	if (global->wfd_subelem[WFD_SUBELEM_COUPLED_SINK])
    158 		wpabuf_put_buf(buf,
    159 			       global->wfd_subelem[WFD_SUBELEM_COUPLED_SINK]);
    160 
    161 	ie = wifi_display_encaps(buf);
    162 	wpa_hexdump_buf(MSG_DEBUG, "WFD: WFD IE for Beacon", ie);
    163 	p2p_set_wfd_ie_beacon(global->p2p, ie);
    164 
    165 	ie = wifi_display_encaps(buf);
    166 	wpa_hexdump_buf(MSG_DEBUG, "WFD: WFD IE for (Re)Association Request",
    167 			ie);
    168 	p2p_set_wfd_ie_assoc_req(global->p2p, ie);
    169 
    170 	ie = wifi_display_encaps(buf);
    171 	wpa_hexdump_buf(MSG_DEBUG, "WFD: WFD IE for GO Negotiation", ie);
    172 	p2p_set_wfd_ie_go_neg(global->p2p, ie);
    173 
    174 	ie = wifi_display_encaps(buf);
    175 	wpa_hexdump_buf(MSG_DEBUG, "WFD: WFD IE for Provision Discovery "
    176 			"Request", ie);
    177 	p2p_set_wfd_ie_prov_disc_req(global->p2p, ie);
    178 
    179 	plen = buf->used;
    180 	if (global->wfd_subelem[WFD_SUBELEM_EXT_CAPAB])
    181 		wpabuf_put_buf(buf,
    182 			       global->wfd_subelem[WFD_SUBELEM_EXT_CAPAB]);
    183 
    184 	ie = wifi_display_encaps(buf);
    185 	wpa_hexdump_buf(MSG_DEBUG, "WFD: WFD IE for Probe Request", ie);
    186 	p2p_set_wfd_ie_probe_req(global->p2p, ie);
    187 
    188 	if (global->wfd_subelem[WFD_SUBELEM_SESSION_INFO])
    189 		wpabuf_put_buf(buf,
    190 			       global->wfd_subelem[WFD_SUBELEM_SESSION_INFO]);
    191 	ie = wifi_display_encaps(buf);
    192 	wpa_hexdump_buf(MSG_DEBUG, "WFD: WFD IE for Probe Response", ie);
    193 	p2p_set_wfd_ie_probe_resp(global->p2p, ie);
    194 
    195 	/* Remove WFD Extended Capability from buffer */
    196 	buf->used = plen;
    197 	if (global->wfd_subelem[WFD_SUBELEM_SESSION_INFO])
    198 		wpabuf_put_buf(buf,
    199 			       global->wfd_subelem[WFD_SUBELEM_SESSION_INFO]);
    200 
    201 	ie = wifi_display_encaps(buf);
    202 	wpa_hexdump_buf(MSG_DEBUG, "WFD: WFD IE for P2P Invitation", ie);
    203 	p2p_set_wfd_ie_invitation(global->p2p, ie);
    204 
    205 	ie = wifi_display_encaps(buf);
    206 	wpa_hexdump_buf(MSG_DEBUG, "WFD: WFD IE for Provision Discovery "
    207 			"Response", ie);
    208 	p2p_set_wfd_ie_prov_disc_resp(global->p2p, ie);
    209 
    210 	wpabuf_free(buf);
    211 
    212 	return 0;
    213 }
    214 
    215 
    216 void wifi_display_enable(struct wpa_global *global, int enabled)
    217 {
    218 	wpa_printf(MSG_DEBUG, "WFD: Wi-Fi Display %s",
    219 		   enabled ? "enabled" : "disabled");
    220 	global->wifi_display = enabled;
    221 	wifi_display_update_wfd_ie(global);
    222 }
    223 
    224 
    225 int wifi_display_subelem_set(struct wpa_global *global, char *cmd)
    226 {
    227 	char *pos;
    228 	int subelem;
    229 	size_t len;
    230 	struct wpabuf *e;
    231 
    232 	pos = os_strchr(cmd, ' ');
    233 	if (pos == NULL)
    234 		return -1;
    235 	*pos++ = '\0';
    236 
    237 	len = os_strlen(pos);
    238 	if (len & 1)
    239 		return -1;
    240 	len /= 2;
    241 
    242 	if (os_strcmp(cmd, "all") == 0) {
    243 		int res;
    244 
    245 		e = wpabuf_alloc(len);
    246 		if (e == NULL)
    247 			return -1;
    248 		if (hexstr2bin(pos, wpabuf_put(e, len), len) < 0) {
    249 			wpabuf_free(e);
    250 			return -1;
    251 		}
    252 		res = wifi_display_subelem_set_from_ies(global, e);
    253 		wpabuf_free(e);
    254 		return res;
    255 	}
    256 
    257 	subelem = atoi(cmd);
    258 	if (subelem < 0 || subelem >= MAX_WFD_SUBELEMS)
    259 		return -1;
    260 
    261 	if (len == 0) {
    262 		/* Clear subelement */
    263 		e = NULL;
    264 		wpa_printf(MSG_DEBUG, "WFD: Clear subelement %d", subelem);
    265 	} else {
    266 		e = wpabuf_alloc(1 + len);
    267 		if (e == NULL)
    268 			return -1;
    269 		wpabuf_put_u8(e, subelem);
    270 		if (hexstr2bin(pos, wpabuf_put(e, len), len) < 0) {
    271 			wpabuf_free(e);
    272 			return -1;
    273 		}
    274 		wpa_printf(MSG_DEBUG, "WFD: Set subelement %d", subelem);
    275 	}
    276 
    277 	wpabuf_free(global->wfd_subelem[subelem]);
    278 	global->wfd_subelem[subelem] = e;
    279 	wifi_display_update_wfd_ie(global);
    280 
    281 	return 0;
    282 }
    283 
    284 
    285 int wifi_display_subelem_set_from_ies(struct wpa_global *global,
    286 				      struct wpabuf *ie)
    287 {
    288 	int subelements[MAX_WFD_SUBELEMS] = {};
    289 	const u8 *pos, *end;
    290 	unsigned int len, subelem;
    291 	struct wpabuf *e;
    292 
    293 	wpa_printf(MSG_DEBUG, "WFD IEs set: %p - %lu",
    294 		   ie, ie ? (unsigned long) wpabuf_len(ie) : 0);
    295 
    296 	if (ie == NULL || wpabuf_len(ie) < 6)
    297 		return -1;
    298 
    299 	pos = wpabuf_head(ie);
    300 	end = pos + wpabuf_len(ie);
    301 
    302 	while (end > pos) {
    303 		if (pos + 3 > end)
    304 			break;
    305 
    306 		len = WPA_GET_BE16(pos + 1) + 3;
    307 
    308 		wpa_printf(MSG_DEBUG, "WFD Sub-Element ID %d - len %d",
    309 			   *pos, len - 3);
    310 
    311 		if (len > (unsigned int) (end - pos))
    312 			break;
    313 
    314 		subelem = *pos;
    315 		if (subelem < MAX_WFD_SUBELEMS && subelements[subelem] == 0) {
    316 			e = wpabuf_alloc_copy(pos, len);
    317 			if (e == NULL)
    318 				return -1;
    319 
    320 			wpabuf_free(global->wfd_subelem[subelem]);
    321 			global->wfd_subelem[subelem] = e;
    322 			subelements[subelem] = 1;
    323 		}
    324 
    325 		pos += len;
    326 	}
    327 
    328 	for (subelem = 0; subelem < MAX_WFD_SUBELEMS; subelem++) {
    329 		if (subelements[subelem] == 0) {
    330 			wpabuf_free(global->wfd_subelem[subelem]);
    331 			global->wfd_subelem[subelem] = NULL;
    332 		}
    333 	}
    334 
    335 	return wifi_display_update_wfd_ie(global);
    336 }
    337 
    338 
    339 int wifi_display_subelem_get(struct wpa_global *global, char *cmd,
    340 			     char *buf, size_t buflen)
    341 {
    342 	int subelem;
    343 
    344 	if (os_strcmp(cmd, "all") == 0) {
    345 		struct wpabuf *ie;
    346 		int res;
    347 
    348 		ie = wifi_display_get_wfd_ie(global);
    349 		if (ie == NULL)
    350 			return 0;
    351 		res = wpa_snprintf_hex(buf, buflen, wpabuf_head(ie),
    352 				       wpabuf_len(ie));
    353 		wpabuf_free(ie);
    354 		return res;
    355 	}
    356 
    357 	subelem = atoi(cmd);
    358 	if (subelem < 0 || subelem >= MAX_WFD_SUBELEMS)
    359 		return -1;
    360 
    361 	if (global->wfd_subelem[subelem] == NULL)
    362 		return 0;
    363 
    364 	return wpa_snprintf_hex(buf, buflen,
    365 				wpabuf_head_u8(global->wfd_subelem[subelem]) +
    366 				1,
    367 				wpabuf_len(global->wfd_subelem[subelem]) - 1);
    368 }
    369 
    370 
    371 char * wifi_display_subelem_hex(const struct wpabuf *wfd_subelems, u8 id)
    372 {
    373 	char *subelem = NULL;
    374 	const u8 *buf;
    375 	size_t buflen;
    376 	size_t i = 0;
    377 	u16 elen;
    378 
    379 	if (!wfd_subelems)
    380 		return NULL;
    381 
    382 	buf = wpabuf_head_u8(wfd_subelems);
    383 	if (!buf)
    384 		return NULL;
    385 
    386 	buflen = wpabuf_len(wfd_subelems);
    387 
    388 	while (i + WIFI_DISPLAY_SUBELEM_HEADER_LEN < buflen) {
    389 		elen = WPA_GET_BE16(buf + i + 1);
    390 		if (i + WIFI_DISPLAY_SUBELEM_HEADER_LEN + elen > buflen)
    391 			break; /* truncated subelement */
    392 
    393 		if (buf[i] == id) {
    394 			/*
    395 			 * Limit explicitly to an arbitrary length to avoid
    396 			 * unnecessarily large allocations. In practice, this
    397 			 * is limited to maximum frame length anyway, so the
    398 			 * maximum memory allocation here is not really that
    399 			 * large. Anyway, the Wi-Fi Display subelements that
    400 			 * are fetched with this function are even shorter.
    401 			 */
    402 			if (elen > 1000)
    403 				break;
    404 			subelem = os_zalloc(2 * elen + 1);
    405 			if (!subelem)
    406 				return NULL;
    407 			wpa_snprintf_hex(subelem, 2 * elen + 1,
    408 					 buf + i +
    409 					 WIFI_DISPLAY_SUBELEM_HEADER_LEN,
    410 					 elen);
    411 			break;
    412 		}
    413 
    414 		i += elen + WIFI_DISPLAY_SUBELEM_HEADER_LEN;
    415 	}
    416 
    417 	return subelem;
    418 }
    419