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1 /*
2  * Wi-Fi Direct - P2P provision discovery
3  * Copyright (c) 2009-2010, Atheros Communications
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "includes.h"
10 
11 #include "common.h"
12 #include "common/ieee802_11_defs.h"
13 #include "wps/wps_defs.h"
14 #include "p2p_i.h"
15 #include "p2p.h"
16 
17 
18 /*
19  * Number of retries to attempt for provision discovery requests
20  * in case the peer is not listening.
21  */
22 #define MAX_PROV_DISC_REQ_RETRIES 10
23 
24 
p2p_build_wps_ie_config_methods(struct wpabuf * buf,u16 config_methods)25 static void p2p_build_wps_ie_config_methods(struct wpabuf *buf,
26 					    u16 config_methods)
27 {
28 	u8 *len;
29 	wpabuf_put_u8(buf, WLAN_EID_VENDOR_SPECIFIC);
30 	len = wpabuf_put(buf, 1);
31 	wpabuf_put_be32(buf, WPS_DEV_OUI_WFA);
32 
33 	/* Config Methods */
34 	wpabuf_put_be16(buf, ATTR_CONFIG_METHODS);
35 	wpabuf_put_be16(buf, 2);
36 	wpabuf_put_be16(buf, config_methods);
37 
38 	p2p_buf_update_ie_hdr(buf, len);
39 }
40 
41 
p2p_build_prov_disc_req(struct p2p_data * p2p,u8 dialog_token,u16 config_methods,struct p2p_device * go)42 static struct wpabuf * p2p_build_prov_disc_req(struct p2p_data *p2p,
43 					       u8 dialog_token,
44 					       u16 config_methods,
45 					       struct p2p_device *go)
46 {
47 	struct wpabuf *buf;
48 	u8 *len;
49 	size_t extra = 0;
50 
51 #ifdef CONFIG_WIFI_DISPLAY
52 	if (p2p->wfd_ie_prov_disc_req)
53 		extra = wpabuf_len(p2p->wfd_ie_prov_disc_req);
54 #endif /* CONFIG_WIFI_DISPLAY */
55 
56 	buf = wpabuf_alloc(1000 + extra);
57 	if (buf == NULL)
58 		return NULL;
59 
60 	p2p_buf_add_public_action_hdr(buf, P2P_PROV_DISC_REQ, dialog_token);
61 
62 	len = p2p_buf_add_ie_hdr(buf);
63 	p2p_buf_add_capability(buf, p2p->dev_capab &
64 			       ~P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY, 0);
65 	p2p_buf_add_device_info(buf, p2p, NULL);
66 	if (go) {
67 		p2p_buf_add_group_id(buf, go->info.p2p_device_addr,
68 				     go->oper_ssid, go->oper_ssid_len);
69 	}
70 	p2p_buf_update_ie_hdr(buf, len);
71 
72 	/* WPS IE with Config Methods attribute */
73 	p2p_build_wps_ie_config_methods(buf, config_methods);
74 
75 #ifdef CONFIG_WIFI_DISPLAY
76 	if (p2p->wfd_ie_prov_disc_req)
77 		wpabuf_put_buf(buf, p2p->wfd_ie_prov_disc_req);
78 #endif /* CONFIG_WIFI_DISPLAY */
79 
80 	return buf;
81 }
82 
83 
p2p_build_prov_disc_resp(struct p2p_data * p2p,u8 dialog_token,u16 config_methods,const u8 * group_id,size_t group_id_len)84 static struct wpabuf * p2p_build_prov_disc_resp(struct p2p_data *p2p,
85 						u8 dialog_token,
86 						u16 config_methods,
87 						const u8 *group_id,
88 						size_t group_id_len)
89 {
90 	struct wpabuf *buf;
91 	size_t extra = 0;
92 
93 #ifdef CONFIG_WIFI_DISPLAY
94 	struct wpabuf *wfd_ie = p2p->wfd_ie_prov_disc_resp;
95 	if (wfd_ie && group_id) {
96 		size_t i;
97 		for (i = 0; i < p2p->num_groups; i++) {
98 			struct p2p_group *g = p2p->groups[i];
99 			struct wpabuf *ie;
100 			if (!p2p_group_is_group_id_match(g, group_id,
101 							 group_id_len))
102 				continue;
103 			ie = p2p_group_get_wfd_ie(g);
104 			if (ie) {
105 				wfd_ie = ie;
106 				break;
107 			}
108 		}
109 	}
110 	if (wfd_ie)
111 		extra = wpabuf_len(wfd_ie);
112 #endif /* CONFIG_WIFI_DISPLAY */
113 
114 	buf = wpabuf_alloc(100 + extra);
115 	if (buf == NULL)
116 		return NULL;
117 
118 	p2p_buf_add_public_action_hdr(buf, P2P_PROV_DISC_RESP, dialog_token);
119 
120 	/* WPS IE with Config Methods attribute */
121 	p2p_build_wps_ie_config_methods(buf, config_methods);
122 
123 #ifdef CONFIG_WIFI_DISPLAY
124 	if (wfd_ie)
125 		wpabuf_put_buf(buf, wfd_ie);
126 #endif /* CONFIG_WIFI_DISPLAY */
127 
128 	return buf;
129 }
130 
131 
p2p_process_prov_disc_req(struct p2p_data * p2p,const u8 * sa,const u8 * data,size_t len,int rx_freq)132 void p2p_process_prov_disc_req(struct p2p_data *p2p, const u8 *sa,
133 			       const u8 *data, size_t len, int rx_freq)
134 {
135 	struct p2p_message msg;
136 	struct p2p_device *dev;
137 	int freq;
138 	int reject = 1;
139 	struct wpabuf *resp;
140 
141 	if (p2p_parse(data, len, &msg))
142 		return;
143 
144 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
145 		"P2P: Received Provision Discovery Request from " MACSTR
146 		" with config methods 0x%x (freq=%d)",
147 		MAC2STR(sa), msg.wps_config_methods, rx_freq);
148 
149 	dev = p2p_get_device(p2p, sa);
150 	if (dev == NULL || (dev->flags & P2P_DEV_PROBE_REQ_ONLY)) {
151 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
152 			"P2P: Provision Discovery Request from "
153 			"unknown peer " MACSTR, MAC2STR(sa));
154 		if (p2p_add_device(p2p, sa, rx_freq, 0, data + 1, len - 1, 0))
155 		{
156 			wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
157 			        "P2P: Provision Discovery Request add device "
158 				"failed " MACSTR, MAC2STR(sa));
159 		}
160 	} else if (msg.wfd_subelems) {
161 		wpabuf_free(dev->info.wfd_subelems);
162 		dev->info.wfd_subelems = wpabuf_dup(msg.wfd_subelems);
163 	}
164 
165 	if (!(msg.wps_config_methods &
166 	      (WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD |
167 	       WPS_CONFIG_PUSHBUTTON))) {
168 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Unsupported "
169 			"Config Methods in Provision Discovery Request");
170 		goto out;
171 	}
172 
173 	if (msg.group_id) {
174 		size_t i;
175 		for (i = 0; i < p2p->num_groups; i++) {
176 			if (p2p_group_is_group_id_match(p2p->groups[i],
177 							msg.group_id,
178 							msg.group_id_len))
179 				break;
180 		}
181 		if (i == p2p->num_groups) {
182 			wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: PD "
183 				"request for unknown P2P Group ID - reject");
184 			goto out;
185 		}
186 	}
187 
188 	if (dev)
189 		dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
190 				P2P_DEV_PD_PEER_KEYPAD);
191 	if (msg.wps_config_methods & WPS_CONFIG_DISPLAY) {
192 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
193 			" requested us to show a PIN on display", MAC2STR(sa));
194 		if (dev)
195 			dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
196 	} else if (msg.wps_config_methods & WPS_CONFIG_KEYPAD) {
197 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
198 			" requested us to write its PIN using keypad",
199 			MAC2STR(sa));
200 		if (dev)
201 			dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
202 	}
203 
204 	reject = 0;
205 
206 out:
207 	resp = p2p_build_prov_disc_resp(p2p, msg.dialog_token,
208 					reject ? 0 : msg.wps_config_methods,
209 					msg.group_id, msg.group_id_len);
210 	if (resp == NULL) {
211 		p2p_parse_free(&msg);
212 		return;
213 	}
214 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
215 		"P2P: Sending Provision Discovery Response");
216 	if (rx_freq > 0)
217 		freq = rx_freq;
218 	else
219 		freq = p2p_channel_to_freq(p2p->cfg->country,
220 					   p2p->cfg->reg_class,
221 					   p2p->cfg->channel);
222 	if (freq < 0) {
223 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
224 			"P2P: Unknown regulatory class/channel");
225 		wpabuf_free(resp);
226 		p2p_parse_free(&msg);
227 		return;
228 	}
229 	p2p->pending_action_state = P2P_NO_PENDING_ACTION;
230 	if (p2p_send_action(p2p, freq, sa, p2p->cfg->dev_addr,
231 			    p2p->cfg->dev_addr,
232 			    wpabuf_head(resp), wpabuf_len(resp), 200) < 0) {
233 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
234 			"P2P: Failed to send Action frame");
235 	}
236 
237 	wpabuf_free(resp);
238 
239 	if (!reject && p2p->cfg->prov_disc_req) {
240 		const u8 *dev_addr = sa;
241 		if (msg.p2p_device_addr)
242 			dev_addr = msg.p2p_device_addr;
243 		p2p->cfg->prov_disc_req(p2p->cfg->cb_ctx, sa,
244 					msg.wps_config_methods,
245 					dev_addr, msg.pri_dev_type,
246 					msg.device_name, msg.config_methods,
247 					msg.capability ? msg.capability[0] : 0,
248 					msg.capability ? msg.capability[1] :
249 					0,
250 					msg.group_id, msg.group_id_len);
251 	}
252 	p2p_parse_free(&msg);
253 }
254 
255 
p2p_process_prov_disc_resp(struct p2p_data * p2p,const u8 * sa,const u8 * data,size_t len)256 void p2p_process_prov_disc_resp(struct p2p_data *p2p, const u8 *sa,
257 				const u8 *data, size_t len)
258 {
259 	struct p2p_message msg;
260 	struct p2p_device *dev;
261 	u16 report_config_methods = 0;
262 	int success = 0;
263 
264 	if (p2p_parse(data, len, &msg))
265 		return;
266 
267 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
268 		"P2P: Received Provision Discovery Response from " MACSTR
269 		" with config methods 0x%x",
270 		MAC2STR(sa), msg.wps_config_methods);
271 
272 	dev = p2p_get_device(p2p, sa);
273 	if (dev == NULL || !dev->req_config_methods) {
274 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
275 			"P2P: Ignore Provision Discovery Response from "
276 			MACSTR " with no pending request", MAC2STR(sa));
277 		p2p_parse_free(&msg);
278 		return;
279 	}
280 
281 	if (dev->dialog_token != msg.dialog_token) {
282 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
283 			"P2P: Ignore Provision Discovery Response with "
284 			"unexpected Dialog Token %u (expected %u)",
285 			msg.dialog_token, dev->dialog_token);
286 		p2p_parse_free(&msg);
287 		return;
288 	}
289 
290 	if (p2p->pending_action_state == P2P_PENDING_PD) {
291 		os_memset(p2p->pending_pd_devaddr, 0, ETH_ALEN);
292 		p2p->pending_action_state = P2P_NO_PENDING_ACTION;
293 	}
294 
295 	/*
296 	 * If the response is from the peer to whom a user initiated request
297 	 * was sent earlier, we reset that state info here.
298 	 */
299 	if (p2p->user_initiated_pd &&
300 	    os_memcmp(p2p->pending_pd_devaddr, sa, ETH_ALEN) == 0)
301 		p2p_reset_pending_pd(p2p);
302 
303 	if (msg.wps_config_methods != dev->req_config_methods) {
304 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer rejected "
305 			"our Provision Discovery Request");
306 		if (p2p->cfg->prov_disc_fail)
307 			p2p->cfg->prov_disc_fail(p2p->cfg->cb_ctx, sa,
308 						 P2P_PROV_DISC_REJECTED);
309 		p2p_parse_free(&msg);
310 		goto out;
311 	}
312 
313 	report_config_methods = dev->req_config_methods;
314 	dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
315 			P2P_DEV_PD_PEER_KEYPAD);
316 	if (dev->req_config_methods & WPS_CONFIG_DISPLAY) {
317 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
318 			" accepted to show a PIN on display", MAC2STR(sa));
319 		dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
320 	} else if (msg.wps_config_methods & WPS_CONFIG_KEYPAD) {
321 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
322 			" accepted to write our PIN using keypad",
323 			MAC2STR(sa));
324 		dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
325 	}
326 
327 	/* Store the provisioning info */
328 	dev->wps_prov_info = msg.wps_config_methods;
329 
330 	p2p_parse_free(&msg);
331 	success = 1;
332 
333 out:
334 	dev->req_config_methods = 0;
335 	p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
336 	if (dev->flags & P2P_DEV_PD_BEFORE_GO_NEG) {
337 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
338 			"P2P: Start GO Neg after the PD-before-GO-Neg "
339 			"workaround with " MACSTR,
340 			MAC2STR(dev->info.p2p_device_addr));
341 		dev->flags &= ~P2P_DEV_PD_BEFORE_GO_NEG;
342 		p2p_connect_send(p2p, dev);
343 		return;
344 	}
345 	if (success && p2p->cfg->prov_disc_resp)
346 		p2p->cfg->prov_disc_resp(p2p->cfg->cb_ctx, sa,
347 					 report_config_methods);
348 }
349 
350 
p2p_send_prov_disc_req(struct p2p_data * p2p,struct p2p_device * dev,int join,int force_freq)351 int p2p_send_prov_disc_req(struct p2p_data *p2p, struct p2p_device *dev,
352 			   int join, int force_freq)
353 {
354 	struct wpabuf *req;
355 	int freq;
356 
357 	if (force_freq > 0)
358 		freq = force_freq;
359 	else
360 		freq = dev->listen_freq > 0 ? dev->listen_freq :
361 			dev->oper_freq;
362 	if (freq <= 0) {
363 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
364 			"P2P: No Listen/Operating frequency known for the "
365 			"peer " MACSTR " to send Provision Discovery Request",
366 			MAC2STR(dev->info.p2p_device_addr));
367 		return -1;
368 	}
369 
370 	if (dev->flags & P2P_DEV_GROUP_CLIENT_ONLY) {
371 		if (!(dev->info.dev_capab &
372 		      P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY)) {
373 			wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
374 				"P2P: Cannot use PD with P2P Device " MACSTR
375 				" that is in a group and is not discoverable",
376 				MAC2STR(dev->info.p2p_device_addr));
377 			return -1;
378 		}
379 		/* TODO: use device discoverability request through GO */
380 	}
381 
382 	dev->dialog_token++;
383 	if (dev->dialog_token == 0)
384 		dev->dialog_token = 1;
385 	req = p2p_build_prov_disc_req(p2p, dev->dialog_token,
386 				      dev->req_config_methods,
387 				      join ? dev : NULL);
388 	if (req == NULL)
389 		return -1;
390 
391 	if (p2p->state != P2P_IDLE)
392 		p2p_stop_listen_for_freq(p2p, freq);
393 	p2p->pending_action_state = P2P_PENDING_PD;
394 	if (p2p_send_action(p2p, freq, dev->info.p2p_device_addr,
395 			    p2p->cfg->dev_addr, dev->info.p2p_device_addr,
396 			    wpabuf_head(req), wpabuf_len(req), 200) < 0) {
397 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
398 			"P2P: Failed to send Action frame");
399 		wpabuf_free(req);
400 		return -1;
401 	}
402 
403 	os_memcpy(p2p->pending_pd_devaddr, dev->info.p2p_device_addr, ETH_ALEN);
404 
405 	wpabuf_free(req);
406 	return 0;
407 }
408 
409 
p2p_prov_disc_req(struct p2p_data * p2p,const u8 * peer_addr,u16 config_methods,int join,int force_freq)410 int p2p_prov_disc_req(struct p2p_data *p2p, const u8 *peer_addr,
411 		      u16 config_methods, int join, int force_freq)
412 {
413 	struct p2p_device *dev;
414 
415 	dev = p2p_get_device(p2p, peer_addr);
416 	if (dev == NULL)
417 		dev = p2p_get_device_interface(p2p, peer_addr);
418 	if (dev == NULL || (dev->flags & P2P_DEV_PROBE_REQ_ONLY)) {
419 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Provision "
420 			"Discovery Request destination " MACSTR
421 			" not yet known", MAC2STR(peer_addr));
422 		return -1;
423 	}
424 
425 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Provision Discovery "
426 		"Request with " MACSTR " (config methods 0x%x)",
427 		MAC2STR(peer_addr), config_methods);
428 	if (config_methods == 0)
429 		return -1;
430 
431 	/* Reset provisioning info */
432 	dev->wps_prov_info = 0;
433 
434 	dev->req_config_methods = config_methods;
435 	if (join)
436 		dev->flags |= P2P_DEV_PD_FOR_JOIN;
437 	else
438 		dev->flags &= ~P2P_DEV_PD_FOR_JOIN;
439 
440 	if (p2p->state != P2P_IDLE && p2p->state != P2P_SEARCH &&
441 	    p2p->state != P2P_LISTEN_ONLY) {
442 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Busy with other "
443 			"operations; postpone Provision Discovery Request "
444 			"with " MACSTR " (config methods 0x%x)",
445 			MAC2STR(peer_addr), config_methods);
446 		return 0;
447 	}
448 
449 	/*
450 	 * We use the join param as a cue to differentiate between user
451 	 * initiated PD request and one issued during finds (internal).
452 	 */
453 	p2p->user_initiated_pd = !join;
454 
455 	if (p2p->user_initiated_pd)
456 		p2p->pd_retries = MAX_PROV_DISC_REQ_RETRIES;
457 
458 	return p2p_send_prov_disc_req(p2p, dev, join, force_freq);
459 }
460 
461 
p2p_reset_pending_pd(struct p2p_data * p2p)462 void p2p_reset_pending_pd(struct p2p_data *p2p)
463 {
464 	struct p2p_device *dev;
465 
466 	dl_list_for_each(dev, &p2p->devices, struct p2p_device, list) {
467 		if (os_memcmp(p2p->pending_pd_devaddr,
468 			      dev->info.p2p_device_addr, ETH_ALEN))
469 			continue;
470 		if (!dev->req_config_methods)
471 			continue;
472 		if (dev->flags & P2P_DEV_PD_FOR_JOIN)
473 			continue;
474 		/* Reset the config methods of the device */
475 		dev->req_config_methods = 0;
476 	}
477 
478 	p2p->user_initiated_pd = 0;
479 	os_memset(p2p->pending_pd_devaddr, 0, ETH_ALEN);
480 	p2p->pd_retries = 0;
481 }
482