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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 
wifi_display_init(struct wpa_global * global)22 int wifi_display_init(struct wpa_global *global)
23 {
24 	global->wifi_display = 1;
25 	return 0;
26 }
27 
28 
wifi_display_deinit(struct wpa_global * global)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 
wifi_display_get_wfd_ie(struct wpa_global * global)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 
wifi_display_update_wfd_ie(struct wpa_global * global)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 
wifi_display_enable(struct wpa_global * global,int enabled)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 
wifi_display_subelem_set(struct wpa_global * global,char * cmd)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 
wifi_display_subelem_set_from_ies(struct wpa_global * global,struct wpabuf * ie)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 
wifi_display_subelem_get(struct wpa_global * global,char * cmd,char * buf,size_t buflen)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 
wifi_display_subelem_hex(const struct wpabuf * wfd_subelems,u8 id)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