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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 during IDLE
20  * state 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 
50 	buf = wpabuf_alloc(1000);
51 	if (buf == NULL)
52 		return NULL;
53 
54 	p2p_buf_add_public_action_hdr(buf, P2P_PROV_DISC_REQ, dialog_token);
55 
56 	len = p2p_buf_add_ie_hdr(buf);
57 	p2p_buf_add_capability(buf, p2p->dev_capab, 0);
58 	p2p_buf_add_device_info(buf, p2p, NULL);
59 	if (go) {
60 		p2p_buf_add_group_id(buf, go->info.p2p_device_addr,
61 				     go->oper_ssid, go->oper_ssid_len);
62 	}
63 	p2p_buf_update_ie_hdr(buf, len);
64 
65 	/* WPS IE with Config Methods attribute */
66 	p2p_build_wps_ie_config_methods(buf, config_methods);
67 
68 	return buf;
69 }
70 
71 
p2p_build_prov_disc_resp(struct p2p_data * p2p,u8 dialog_token,u16 config_methods)72 static struct wpabuf * p2p_build_prov_disc_resp(struct p2p_data *p2p,
73 						u8 dialog_token,
74 						u16 config_methods)
75 {
76 	struct wpabuf *buf;
77 
78 	buf = wpabuf_alloc(100);
79 	if (buf == NULL)
80 		return NULL;
81 
82 	p2p_buf_add_public_action_hdr(buf, P2P_PROV_DISC_RESP, dialog_token);
83 
84 	/* WPS IE with Config Methods attribute */
85 	p2p_build_wps_ie_config_methods(buf, config_methods);
86 
87 	return buf;
88 }
89 
90 
p2p_process_prov_disc_req(struct p2p_data * p2p,const u8 * sa,const u8 * data,size_t len,int rx_freq)91 void p2p_process_prov_disc_req(struct p2p_data *p2p, const u8 *sa,
92 			       const u8 *data, size_t len, int rx_freq)
93 {
94 	struct p2p_message msg;
95 	struct p2p_device *dev;
96 	int freq;
97 	int reject = 1;
98 	struct wpabuf *resp;
99 
100 	if (p2p_parse(data, len, &msg))
101 		return;
102 
103 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
104 		"P2P: Received Provision Discovery Request from " MACSTR
105 		" with config methods 0x%x (freq=%d)",
106 		MAC2STR(sa), msg.wps_config_methods, rx_freq);
107 
108 	dev = p2p_get_device(p2p, sa);
109 	if (dev == NULL || (dev->flags & P2P_DEV_PROBE_REQ_ONLY)) {
110 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
111 			"P2P: Provision Discovery Request from "
112 			"unknown peer " MACSTR, MAC2STR(sa));
113 		if (p2p_add_device(p2p, sa, rx_freq, 0, data + 1, len - 1)) {
114 			wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
115 			        "P2P: Provision Discovery Request add device "
116 				"failed " MACSTR, MAC2STR(sa));
117 		}
118 	}
119 
120 	if (!(msg.wps_config_methods &
121 	      (WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD |
122 	       WPS_CONFIG_PUSHBUTTON))) {
123 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Unsupported "
124 			"Config Methods in Provision Discovery Request");
125 		goto out;
126 	}
127 
128 	if (dev)
129 		dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
130 				P2P_DEV_PD_PEER_KEYPAD);
131 	if (msg.wps_config_methods & WPS_CONFIG_DISPLAY) {
132 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
133 			" requested us to show a PIN on display", MAC2STR(sa));
134 		if (dev)
135 			dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
136 	} else if (msg.wps_config_methods & WPS_CONFIG_KEYPAD) {
137 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
138 			" requested us to write its PIN using keypad",
139 			MAC2STR(sa));
140 		if (dev)
141 			dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
142 	}
143 
144 	reject = 0;
145 
146 out:
147 	resp = p2p_build_prov_disc_resp(p2p, msg.dialog_token,
148 					reject ? 0 : msg.wps_config_methods);
149 	if (resp == NULL) {
150 		p2p_parse_free(&msg);
151 		return;
152 	}
153 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
154 		"P2P: Sending Provision Discovery Response");
155 	if (rx_freq > 0)
156 		freq = rx_freq;
157 	else
158 		freq = p2p_channel_to_freq(p2p->cfg->country,
159 					   p2p->cfg->reg_class,
160 					   p2p->cfg->channel);
161 	if (freq < 0) {
162 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
163 			"P2P: Unknown regulatory class/channel");
164 		wpabuf_free(resp);
165 		p2p_parse_free(&msg);
166 		return;
167 	}
168 	p2p->pending_action_state = P2P_NO_PENDING_ACTION;
169 	if (p2p_send_action(p2p, freq, sa, p2p->cfg->dev_addr,
170 			    p2p->cfg->dev_addr,
171 			    wpabuf_head(resp), wpabuf_len(resp), 200) < 0) {
172 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
173 			"P2P: Failed to send Action frame");
174 	}
175 
176 	wpabuf_free(resp);
177 
178 	if (!reject && p2p->cfg->prov_disc_req) {
179 		const u8 *dev_addr = sa;
180 		if (msg.p2p_device_addr)
181 			dev_addr = msg.p2p_device_addr;
182 		p2p->cfg->prov_disc_req(p2p->cfg->cb_ctx, sa,
183 					msg.wps_config_methods,
184 					dev_addr, msg.pri_dev_type,
185 					msg.device_name, msg.config_methods,
186 					msg.capability ? msg.capability[0] : 0,
187 					msg.capability ? msg.capability[1] :
188 					0,
189 					msg.group_id, msg.group_id_len);
190 	}
191 	p2p_parse_free(&msg);
192 }
193 
194 
p2p_process_prov_disc_resp(struct p2p_data * p2p,const u8 * sa,const u8 * data,size_t len)195 void p2p_process_prov_disc_resp(struct p2p_data *p2p, const u8 *sa,
196 				const u8 *data, size_t len)
197 {
198 	struct p2p_message msg;
199 	struct p2p_device *dev;
200 	u16 report_config_methods = 0;
201 
202 	if (p2p_parse(data, len, &msg))
203 		return;
204 
205 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
206 		"P2P: Received Provision Discovery Response from " MACSTR
207 		" with config methods 0x%x",
208 		MAC2STR(sa), msg.wps_config_methods);
209 
210 	dev = p2p_get_device(p2p, sa);
211 	if (dev == NULL || !dev->req_config_methods) {
212 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
213 			"P2P: Ignore Provision Discovery Response from "
214 			MACSTR " with no pending request", MAC2STR(sa));
215 		p2p_parse_free(&msg);
216 		return;
217 	}
218 
219 	if (p2p->pending_action_state == P2P_PENDING_PD) {
220 		os_memset(p2p->pending_pd_devaddr, 0, ETH_ALEN);
221 		p2p->pending_action_state = P2P_NO_PENDING_ACTION;
222 	}
223 
224 	if (dev->dialog_token != msg.dialog_token) {
225 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
226 			"P2P: Ignore Provision Discovery Response with "
227 			"unexpected Dialog Token %u (expected %u)",
228 			msg.dialog_token, dev->dialog_token);
229 		p2p_parse_free(&msg);
230 		return;
231 	}
232 
233 	/*
234 	 * If the response is from the peer to whom a user initiated request
235 	 * was sent earlier, we reset that state info here.
236 	 */
237 	if (p2p->user_initiated_pd &&
238 	    os_memcmp(p2p->pending_pd_devaddr, sa, ETH_ALEN) == 0)
239 		p2p_reset_pending_pd(p2p);
240 
241 	if (msg.wps_config_methods != dev->req_config_methods) {
242 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer rejected "
243 			"our Provision Discovery Request");
244 		if (p2p->cfg->prov_disc_fail)
245 			p2p->cfg->prov_disc_fail(p2p->cfg->cb_ctx, sa,
246 						 P2P_PROV_DISC_REJECTED);
247 		p2p_parse_free(&msg);
248 		goto out;
249 	}
250 
251 	report_config_methods = dev->req_config_methods;
252 	dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
253 			P2P_DEV_PD_PEER_KEYPAD);
254 	if (dev->req_config_methods & WPS_CONFIG_DISPLAY) {
255 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
256 			" accepted to show a PIN on display", MAC2STR(sa));
257 		dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
258 	} else if (msg.wps_config_methods & WPS_CONFIG_KEYPAD) {
259 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
260 			" accepted to write our PIN using keypad",
261 			MAC2STR(sa));
262 		dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
263 	}
264 
265 	/* Store the provisioning info */
266 	dev->wps_prov_info = msg.wps_config_methods;
267 
268 	p2p_parse_free(&msg);
269 
270 out:
271 	dev->req_config_methods = 0;
272 	p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
273 	if (p2p->cfg->prov_disc_resp)
274 		p2p->cfg->prov_disc_resp(p2p->cfg->cb_ctx, sa,
275 					 report_config_methods);
276 }
277 
278 
p2p_send_prov_disc_req(struct p2p_data * p2p,struct p2p_device * dev,int join,int force_freq)279 int p2p_send_prov_disc_req(struct p2p_data *p2p, struct p2p_device *dev,
280 			   int join, int force_freq)
281 {
282 	struct wpabuf *req;
283 	int freq;
284 
285 	if (force_freq > 0)
286 		freq = force_freq;
287 	else
288 		freq = dev->listen_freq > 0 ? dev->listen_freq :
289 			dev->oper_freq;
290 	if (freq <= 0) {
291 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
292 			"P2P: No Listen/Operating frequency known for the "
293 			"peer " MACSTR " to send Provision Discovery Request",
294 			MAC2STR(dev->info.p2p_device_addr));
295 		return -1;
296 	}
297 
298 	if (dev->flags & P2P_DEV_GROUP_CLIENT_ONLY) {
299 		if (!(dev->info.dev_capab &
300 		      P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY)) {
301 			wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
302 				"P2P: Cannot use PD with P2P Device " MACSTR
303 				" that is in a group and is not discoverable",
304 				MAC2STR(dev->info.p2p_device_addr));
305 			return -1;
306 		}
307 		/* TODO: use device discoverability request through GO */
308 	}
309 
310 	dev->dialog_token++;
311 	if (dev->dialog_token == 0)
312 		dev->dialog_token = 1;
313 	req = p2p_build_prov_disc_req(p2p, dev->dialog_token,
314 				      dev->req_config_methods,
315 				      join ? dev : NULL);
316 	if (req == NULL)
317 		return -1;
318 
319 	p2p->pending_action_state = P2P_PENDING_PD;
320 	if (p2p_send_action(p2p, freq, dev->info.p2p_device_addr,
321 			    p2p->cfg->dev_addr, dev->info.p2p_device_addr,
322 			    wpabuf_head(req), wpabuf_len(req), 200) < 0) {
323 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
324 			"P2P: Failed to send Action frame");
325 		wpabuf_free(req);
326 		return -1;
327 	}
328 
329 	os_memcpy(p2p->pending_pd_devaddr, dev->info.p2p_device_addr, ETH_ALEN);
330 
331 	wpabuf_free(req);
332 	return 0;
333 }
334 
335 
p2p_prov_disc_req(struct p2p_data * p2p,const u8 * peer_addr,u16 config_methods,int join,int force_freq)336 int p2p_prov_disc_req(struct p2p_data *p2p, const u8 *peer_addr,
337 		      u16 config_methods, int join, int force_freq)
338 {
339 	struct p2p_device *dev;
340 
341 	dev = p2p_get_device(p2p, peer_addr);
342 	if (dev == NULL)
343 		dev = p2p_get_device_interface(p2p, peer_addr);
344 	if (dev == NULL || (dev->flags & P2P_DEV_PROBE_REQ_ONLY)) {
345 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Provision "
346 			"Discovery Request destination " MACSTR
347 			" not yet known", MAC2STR(peer_addr));
348 		return -1;
349 	}
350 
351 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Provision Discovery "
352 		"Request with " MACSTR " (config methods 0x%x)",
353 		MAC2STR(peer_addr), config_methods);
354 	if (config_methods == 0)
355 		return -1;
356 
357 	/* Reset provisioning info */
358 	dev->wps_prov_info = 0;
359 
360 	dev->req_config_methods = config_methods;
361 	if (join)
362 		dev->flags |= P2P_DEV_PD_FOR_JOIN;
363 	else
364 		dev->flags &= ~P2P_DEV_PD_FOR_JOIN;
365 
366 	if (p2p->state != P2P_IDLE && p2p->state != P2P_SEARCH &&
367 	    p2p->state != P2P_LISTEN_ONLY) {
368 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Busy with other "
369 			"operations; postpone Provision Discovery Request "
370 			"with " MACSTR " (config methods 0x%x)",
371 			MAC2STR(peer_addr), config_methods);
372 		return 0;
373 	}
374 
375 	/*
376 	 * We use the join param as a cue to differentiate between user
377 	 * initiated PD request and one issued during finds (internal).
378 	 */
379 	p2p->user_initiated_pd = !join;
380 
381 	/* Also set some retries to attempt in case of IDLE state */
382 	if (p2p->user_initiated_pd && p2p->state == P2P_IDLE)
383 		p2p->pd_retries = MAX_PROV_DISC_REQ_RETRIES;
384 
385 	return p2p_send_prov_disc_req(p2p, dev, join, force_freq);
386 }
387 
388 
p2p_reset_pending_pd(struct p2p_data * p2p)389 void p2p_reset_pending_pd(struct p2p_data *p2p)
390 {
391 	struct p2p_device *dev;
392 
393 	dl_list_for_each(dev, &p2p->devices, struct p2p_device, list) {
394 		if (os_memcmp(p2p->pending_pd_devaddr,
395 			      dev->info.p2p_device_addr, ETH_ALEN))
396 			continue;
397 		if (!dev->req_config_methods)
398 			continue;
399 		if (dev->flags & P2P_DEV_PD_FOR_JOIN)
400 			continue;
401 		/* Reset the config methods of the device */
402 		dev->req_config_methods = 0;
403 	}
404 
405 	p2p->user_initiated_pd = 0;
406 	os_memset(p2p->pending_pd_devaddr, 0, ETH_ALEN);
407 	p2p->pd_retries = 0;
408 }
409