1/*
2 * Wi-Fi Direct - P2P Invitation procedure
3 * Copyright (c) 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 "p2p_i.h"
14#include "p2p.h"
15
16
17static struct wpabuf * p2p_build_invitation_req(struct p2p_data *p2p,
18						struct p2p_device *peer,
19						const u8 *go_dev_addr)
20{
21	struct wpabuf *buf;
22	u8 *len;
23	const u8 *dev_addr;
24	size_t extra = 0;
25
26#ifdef CONFIG_WIFI_DISPLAY
27	struct wpabuf *wfd_ie = p2p->wfd_ie_invitation;
28	if (wfd_ie && p2p->inv_role == P2P_INVITE_ROLE_ACTIVE_GO) {
29		size_t i;
30		for (i = 0; i < p2p->num_groups; i++) {
31			struct p2p_group *g = p2p->groups[i];
32			struct wpabuf *ie;
33			if (os_memcmp(p2p_group_get_interface_addr(g),
34				      p2p->inv_bssid, ETH_ALEN) != 0)
35				continue;
36			ie = p2p_group_get_wfd_ie(g);
37			if (ie) {
38				wfd_ie = ie;
39				break;
40			}
41		}
42	}
43	if (wfd_ie)
44		extra = wpabuf_len(wfd_ie);
45#endif /* CONFIG_WIFI_DISPLAY */
46
47	buf = wpabuf_alloc(1000 + extra);
48	if (buf == NULL)
49		return NULL;
50
51	peer->dialog_token++;
52	if (peer->dialog_token == 0)
53		peer->dialog_token = 1;
54	p2p_buf_add_public_action_hdr(buf, P2P_INVITATION_REQ,
55				      peer->dialog_token);
56
57	len = p2p_buf_add_ie_hdr(buf);
58	if (p2p->inv_role == P2P_INVITE_ROLE_ACTIVE_GO || !p2p->inv_persistent)
59		p2p_buf_add_config_timeout(buf, 0, 0);
60	else
61		p2p_buf_add_config_timeout(buf, p2p->go_timeout,
62					   p2p->client_timeout);
63	p2p_buf_add_invitation_flags(buf, p2p->inv_persistent ?
64				     P2P_INVITATION_FLAGS_TYPE : 0);
65	if (p2p->inv_role != P2P_INVITE_ROLE_CLIENT ||
66	    !(peer->flags & P2P_DEV_NO_PREF_CHAN))
67		p2p_buf_add_operating_channel(buf, p2p->cfg->country,
68					      p2p->op_reg_class,
69					      p2p->op_channel);
70	if (p2p->inv_bssid_set)
71		p2p_buf_add_group_bssid(buf, p2p->inv_bssid);
72	p2p_buf_add_channel_list(buf, p2p->cfg->country, &p2p->channels);
73	if (go_dev_addr)
74		dev_addr = go_dev_addr;
75	else if (p2p->inv_role == P2P_INVITE_ROLE_CLIENT)
76		dev_addr = peer->info.p2p_device_addr;
77	else
78		dev_addr = p2p->cfg->dev_addr;
79	p2p_buf_add_group_id(buf, dev_addr, p2p->inv_ssid, p2p->inv_ssid_len);
80	p2p_buf_add_device_info(buf, p2p, peer);
81	p2p_buf_update_ie_hdr(buf, len);
82
83#ifdef CONFIG_WIFI_DISPLAY
84	if (wfd_ie)
85		wpabuf_put_buf(buf, wfd_ie);
86#endif /* CONFIG_WIFI_DISPLAY */
87
88	return buf;
89}
90
91
92static struct wpabuf * p2p_build_invitation_resp(struct p2p_data *p2p,
93						 struct p2p_device *peer,
94						 u8 dialog_token, u8 status,
95						 const u8 *group_bssid,
96						 u8 reg_class, u8 channel,
97						 struct p2p_channels *channels)
98{
99	struct wpabuf *buf;
100	u8 *len;
101	size_t extra = 0;
102
103#ifdef CONFIG_WIFI_DISPLAY
104	struct wpabuf *wfd_ie = p2p->wfd_ie_invitation;
105	if (wfd_ie && group_bssid) {
106		size_t i;
107		for (i = 0; i < p2p->num_groups; i++) {
108			struct p2p_group *g = p2p->groups[i];
109			struct wpabuf *ie;
110			if (os_memcmp(p2p_group_get_interface_addr(g),
111				      group_bssid, ETH_ALEN) != 0)
112				continue;
113			ie = p2p_group_get_wfd_ie(g);
114			if (ie) {
115				wfd_ie = ie;
116				break;
117			}
118		}
119	}
120	if (wfd_ie)
121		extra = wpabuf_len(wfd_ie);
122#endif /* CONFIG_WIFI_DISPLAY */
123
124	buf = wpabuf_alloc(1000 + extra);
125	if (buf == NULL)
126		return NULL;
127
128	p2p_buf_add_public_action_hdr(buf, P2P_INVITATION_RESP,
129				      dialog_token);
130
131	len = p2p_buf_add_ie_hdr(buf);
132	p2p_buf_add_status(buf, status);
133	p2p_buf_add_config_timeout(buf, 0, 0); /* FIX */
134	if (reg_class && channel)
135		p2p_buf_add_operating_channel(buf, p2p->cfg->country,
136					      reg_class, channel);
137	if (group_bssid)
138		p2p_buf_add_group_bssid(buf, group_bssid);
139	if (channels)
140		p2p_buf_add_channel_list(buf, p2p->cfg->country, channels);
141	p2p_buf_update_ie_hdr(buf, len);
142
143#ifdef CONFIG_WIFI_DISPLAY
144	if (wfd_ie)
145		wpabuf_put_buf(buf, wfd_ie);
146#endif /* CONFIG_WIFI_DISPLAY */
147
148	return buf;
149}
150
151
152void p2p_process_invitation_req(struct p2p_data *p2p, const u8 *sa,
153				const u8 *data, size_t len, int rx_freq)
154{
155	struct p2p_device *dev;
156	struct p2p_message msg;
157	struct wpabuf *resp = NULL;
158	u8 status = P2P_SC_FAIL_INFO_CURRENTLY_UNAVAILABLE;
159	int freq;
160	int go = 0;
161	u8 group_bssid[ETH_ALEN], *bssid;
162	int op_freq = 0;
163	u8 reg_class = 0, channel = 0;
164	struct p2p_channels intersection, *channels = NULL;
165	int persistent;
166
167	os_memset(group_bssid, 0, sizeof(group_bssid));
168
169	p2p_dbg(p2p, "Received Invitation Request from " MACSTR " (freq=%d)",
170		MAC2STR(sa), rx_freq);
171
172	if (p2p_parse(data, len, &msg))
173		return;
174
175	dev = p2p_get_device(p2p, sa);
176	if (dev == NULL || (dev->flags & P2P_DEV_PROBE_REQ_ONLY)) {
177		p2p_dbg(p2p, "Invitation Request from unknown peer " MACSTR,
178			MAC2STR(sa));
179
180		if (p2p_add_device(p2p, sa, rx_freq, NULL, 0, data + 1, len - 1,
181				   0)) {
182			p2p_dbg(p2p, "Invitation Request add device failed "
183				MACSTR, MAC2STR(sa));
184			status = P2P_SC_FAIL_INFO_CURRENTLY_UNAVAILABLE;
185			goto fail;
186		}
187
188		dev = p2p_get_device(p2p, sa);
189		if (dev == NULL) {
190			p2p_dbg(p2p, "Reject Invitation Request from unknown peer "
191				MACSTR, MAC2STR(sa));
192			status = P2P_SC_FAIL_INFO_CURRENTLY_UNAVAILABLE;
193			goto fail;
194		}
195	}
196
197	if (!msg.group_id || !msg.channel_list) {
198		p2p_dbg(p2p, "Mandatory attribute missing in Invitation Request from "
199			MACSTR, MAC2STR(sa));
200		status = P2P_SC_FAIL_INVALID_PARAMS;
201		goto fail;
202	}
203
204	if (msg.invitation_flags)
205		persistent = *msg.invitation_flags & P2P_INVITATION_FLAGS_TYPE;
206	else {
207		/* Invitation Flags is a mandatory attribute starting from P2P
208		 * spec 1.06. As a backwards compatibility mechanism, assume
209		 * the request was for a persistent group if the attribute is
210		 * missing.
211		 */
212		p2p_dbg(p2p, "Mandatory Invitation Flags attribute missing from Invitation Request");
213		persistent = 1;
214	}
215
216	if (p2p_peer_channels_check(p2p, &p2p->cfg->channels, dev,
217				    msg.channel_list, msg.channel_list_len) <
218	    0) {
219		p2p_dbg(p2p, "No common channels found");
220		status = P2P_SC_FAIL_NO_COMMON_CHANNELS;
221		goto fail;
222	}
223
224	p2p_channels_intersect(&p2p->cfg->channels, &dev->channels,
225			       &intersection);
226
227	if (p2p->cfg->invitation_process) {
228		status = p2p->cfg->invitation_process(
229			p2p->cfg->cb_ctx, sa, msg.group_bssid, msg.group_id,
230			msg.group_id + ETH_ALEN, msg.group_id_len - ETH_ALEN,
231			&go, group_bssid, &op_freq, persistent, &intersection);
232	}
233
234	if (op_freq) {
235		p2p_dbg(p2p, "Invitation processing forced frequency %d MHz",
236			op_freq);
237		if (p2p_freq_to_channel(op_freq, &reg_class, &channel) < 0) {
238			p2p_dbg(p2p, "Unknown forced freq %d MHz from invitation_process()",
239				op_freq);
240			status = P2P_SC_FAIL_NO_COMMON_CHANNELS;
241			goto fail;
242		}
243
244		if (!p2p_channels_includes(&intersection, reg_class, channel))
245		{
246			p2p_dbg(p2p, "forced freq %d MHz not in the supported channels interaction",
247				op_freq);
248			status = P2P_SC_FAIL_NO_COMMON_CHANNELS;
249			goto fail;
250		}
251
252		if (status == P2P_SC_SUCCESS)
253			channels = &intersection;
254	} else {
255		p2p_dbg(p2p, "No forced channel from invitation processing - figure out best one to use");
256
257		/* Default to own configuration as a starting point */
258		p2p->op_reg_class = p2p->cfg->op_reg_class;
259		p2p->op_channel = p2p->cfg->op_channel;
260		p2p_dbg(p2p, "Own default op_class %d channel %d",
261			p2p->op_reg_class, p2p->op_channel);
262
263		/* Use peer preference if specified and compatible */
264		if (msg.operating_channel) {
265			int req_freq;
266			req_freq = p2p_channel_to_freq(
267				msg.operating_channel[3],
268				msg.operating_channel[4]);
269			p2p_dbg(p2p, "Peer operating channel preference: %d MHz",
270				req_freq);
271			if (req_freq > 0 &&
272			    p2p_channels_includes(&intersection,
273						  msg.operating_channel[3],
274						  msg.operating_channel[4])) {
275				p2p->op_reg_class = msg.operating_channel[3];
276				p2p->op_channel = msg.operating_channel[4];
277				p2p_dbg(p2p, "Use peer preference op_class %d channel %d",
278					p2p->op_reg_class, p2p->op_channel);
279			} else {
280				p2p_dbg(p2p, "Cannot use peer channel preference");
281			}
282		}
283
284		if (!p2p_channels_includes(&intersection, p2p->op_reg_class,
285					   p2p->op_channel)) {
286			p2p_dbg(p2p, "Initially selected channel (op_class %d channel %d) not in channel intersection - try to reselect",
287				p2p->op_reg_class, p2p->op_channel);
288			p2p_reselect_channel(p2p, &intersection);
289			p2p_dbg(p2p, "Re-selection result: op_class %d channel %d",
290				p2p->op_reg_class, p2p->op_channel);
291			if (!p2p_channels_includes(&intersection,
292						   p2p->op_reg_class,
293						   p2p->op_channel)) {
294				p2p_dbg(p2p, "Peer does not support selected operating channel (reg_class=%u channel=%u)",
295					p2p->op_reg_class, p2p->op_channel);
296				status = P2P_SC_FAIL_NO_COMMON_CHANNELS;
297				goto fail;
298			}
299		} else if (!(dev->flags & P2P_DEV_FORCE_FREQ) &&
300			   !p2p->cfg->cfg_op_channel) {
301			p2p_dbg(p2p, "Try to reselect channel selection with peer information received; previously selected op_class %u channel %u",
302				p2p->op_reg_class, p2p->op_channel);
303			p2p_reselect_channel(p2p, &intersection);
304		}
305
306		op_freq = p2p_channel_to_freq(p2p->op_reg_class,
307					      p2p->op_channel);
308		if (op_freq < 0) {
309			p2p_dbg(p2p, "Unknown operational channel (country=%c%c reg_class=%u channel=%u)",
310				p2p->cfg->country[0], p2p->cfg->country[1],
311				p2p->op_reg_class, p2p->op_channel);
312			status = P2P_SC_FAIL_NO_COMMON_CHANNELS;
313			goto fail;
314		}
315		p2p_dbg(p2p, "Selected operating channel - %d MHz", op_freq);
316
317		if (status == P2P_SC_SUCCESS) {
318			reg_class = p2p->op_reg_class;
319			channel = p2p->op_channel;
320			channels = &intersection;
321		}
322	}
323
324fail:
325	if (go && status == P2P_SC_SUCCESS && !is_zero_ether_addr(group_bssid))
326		bssid = group_bssid;
327	else
328		bssid = NULL;
329	resp = p2p_build_invitation_resp(p2p, dev, msg.dialog_token, status,
330					 bssid, reg_class, channel, channels);
331
332	if (resp == NULL)
333		goto out;
334
335	if (rx_freq > 0)
336		freq = rx_freq;
337	else
338		freq = p2p_channel_to_freq(p2p->cfg->reg_class,
339					   p2p->cfg->channel);
340	if (freq < 0) {
341		p2p_dbg(p2p, "Unknown regulatory class/channel");
342		goto out;
343	}
344
345	/*
346	 * Store copy of invitation data to be used when processing TX status
347	 * callback for the Acton frame.
348	 */
349	os_memcpy(p2p->inv_sa, sa, ETH_ALEN);
350	if (msg.group_bssid) {
351		os_memcpy(p2p->inv_group_bssid, msg.group_bssid, ETH_ALEN);
352		p2p->inv_group_bssid_ptr = p2p->inv_group_bssid;
353	} else
354		p2p->inv_group_bssid_ptr = NULL;
355	if (msg.group_id_len - ETH_ALEN <= 32) {
356		os_memcpy(p2p->inv_ssid, msg.group_id + ETH_ALEN,
357			  msg.group_id_len - ETH_ALEN);
358		p2p->inv_ssid_len = msg.group_id_len - ETH_ALEN;
359	}
360	os_memcpy(p2p->inv_go_dev_addr, msg.group_id, ETH_ALEN);
361	p2p->inv_status = status;
362	p2p->inv_op_freq = op_freq;
363
364	p2p->pending_action_state = P2P_PENDING_INVITATION_RESPONSE;
365	if (p2p_send_action(p2p, freq, sa, p2p->cfg->dev_addr,
366			    p2p->cfg->dev_addr,
367			    wpabuf_head(resp), wpabuf_len(resp), 200) < 0) {
368		p2p_dbg(p2p, "Failed to send Action frame");
369	}
370
371out:
372	wpabuf_free(resp);
373	p2p_parse_free(&msg);
374}
375
376
377void p2p_process_invitation_resp(struct p2p_data *p2p, const u8 *sa,
378				 const u8 *data, size_t len)
379{
380	struct p2p_device *dev;
381	struct p2p_message msg;
382	struct p2p_channels intersection, *channels = NULL;
383
384	p2p_dbg(p2p, "Received Invitation Response from " MACSTR,
385		MAC2STR(sa));
386
387	dev = p2p_get_device(p2p, sa);
388	if (dev == NULL) {
389		p2p_dbg(p2p, "Ignore Invitation Response from unknown peer "
390			MACSTR, MAC2STR(sa));
391		return;
392	}
393
394	if (dev != p2p->invite_peer) {
395		p2p_dbg(p2p, "Ignore unexpected Invitation Response from peer "
396			MACSTR, MAC2STR(sa));
397		return;
398	}
399
400	if (p2p_parse(data, len, &msg))
401		return;
402
403	if (!msg.status) {
404		p2p_dbg(p2p, "Mandatory Status attribute missing in Invitation Response from "
405			MACSTR, MAC2STR(sa));
406		p2p_parse_free(&msg);
407		return;
408	}
409
410	if (!msg.channel_list) {
411		p2p_dbg(p2p, "Mandatory Channel List attribute missing in Invitation Response from "
412			MACSTR, MAC2STR(sa));
413#ifdef CONFIG_P2P_STRICT
414		p2p_parse_free(&msg);
415		return;
416#endif /* CONFIG_P2P_STRICT */
417		/* Try to survive without peer channel list */
418		channels = &p2p->channels;
419	} else if (p2p_peer_channels_check(p2p, &p2p->channels, dev,
420					   msg.channel_list,
421					   msg.channel_list_len) < 0) {
422		p2p_dbg(p2p, "No common channels found");
423		p2p_parse_free(&msg);
424		return;
425	} else {
426		p2p_channels_intersect(&p2p->channels, &dev->channels,
427				       &intersection);
428		channels = &intersection;
429	}
430
431	if (p2p->cfg->invitation_result)
432		p2p->cfg->invitation_result(p2p->cfg->cb_ctx, *msg.status,
433					    msg.group_bssid, channels, sa);
434
435	p2p_parse_free(&msg);
436
437	p2p_clear_timeout(p2p);
438	p2p_set_state(p2p, P2P_IDLE);
439	p2p->invite_peer = NULL;
440}
441
442
443int p2p_invite_send(struct p2p_data *p2p, struct p2p_device *dev,
444		    const u8 *go_dev_addr)
445{
446	struct wpabuf *req;
447	int freq;
448
449	freq = dev->listen_freq > 0 ? dev->listen_freq : dev->oper_freq;
450	if (freq <= 0) {
451		p2p_dbg(p2p, "No Listen/Operating frequency known for the peer "
452			MACSTR " to send Invitation Request",
453			MAC2STR(dev->info.p2p_device_addr));
454		return -1;
455	}
456
457	req = p2p_build_invitation_req(p2p, dev, go_dev_addr);
458	if (req == NULL)
459		return -1;
460	if (p2p->state != P2P_IDLE)
461		p2p_stop_listen_for_freq(p2p, freq);
462	p2p_dbg(p2p, "Sending Invitation Request");
463	p2p_set_state(p2p, P2P_INVITE);
464	p2p->pending_action_state = P2P_PENDING_INVITATION_REQUEST;
465	p2p->invite_peer = dev;
466	dev->invitation_reqs++;
467	if (p2p_send_action(p2p, freq, dev->info.p2p_device_addr,
468			    p2p->cfg->dev_addr, dev->info.p2p_device_addr,
469			    wpabuf_head(req), wpabuf_len(req), 200) < 0) {
470		p2p_dbg(p2p, "Failed to send Action frame");
471		/* Use P2P find to recover and retry */
472		p2p_set_timeout(p2p, 0, 0);
473	}
474
475	wpabuf_free(req);
476
477	return 0;
478}
479
480
481void p2p_invitation_req_cb(struct p2p_data *p2p, int success)
482{
483	p2p_dbg(p2p, "Invitation Request TX callback: success=%d", success);
484
485	if (p2p->invite_peer == NULL) {
486		p2p_dbg(p2p, "No pending Invite");
487		return;
488	}
489
490	/*
491	 * Use P2P find, if needed, to find the other device from its listen
492	 * channel.
493	 */
494	p2p_set_state(p2p, P2P_INVITE);
495	p2p_set_timeout(p2p, 0, success ? 350000 : 100000);
496}
497
498
499void p2p_invitation_resp_cb(struct p2p_data *p2p, int success)
500{
501	p2p_dbg(p2p, "Invitation Response TX callback: success=%d", success);
502	p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
503
504	if (!success)
505		p2p_dbg(p2p, "Assume Invitation Response was actually received by the peer even though Ack was not reported");
506
507	if (p2p->cfg->invitation_received) {
508		p2p->cfg->invitation_received(p2p->cfg->cb_ctx,
509					      p2p->inv_sa,
510					      p2p->inv_group_bssid_ptr,
511					      p2p->inv_ssid, p2p->inv_ssid_len,
512					      p2p->inv_go_dev_addr,
513					      p2p->inv_status,
514					      p2p->inv_op_freq);
515	}
516}
517
518
519int p2p_invite(struct p2p_data *p2p, const u8 *peer, enum p2p_invite_role role,
520	       const u8 *bssid, const u8 *ssid, size_t ssid_len,
521	       unsigned int force_freq, const u8 *go_dev_addr,
522	       int persistent_group, unsigned int pref_freq)
523{
524	struct p2p_device *dev;
525
526	p2p_dbg(p2p, "Request to invite peer " MACSTR " role=%d persistent=%d "
527		"force_freq=%u",
528		MAC2STR(peer), role, persistent_group, force_freq);
529	if (bssid)
530		p2p_dbg(p2p, "Invitation for BSSID " MACSTR, MAC2STR(bssid));
531	if (go_dev_addr) {
532		p2p_dbg(p2p, "Invitation for GO Device Address " MACSTR,
533			MAC2STR(go_dev_addr));
534		os_memcpy(p2p->invite_go_dev_addr_buf, go_dev_addr, ETH_ALEN);
535		p2p->invite_go_dev_addr = p2p->invite_go_dev_addr_buf;
536	} else
537		p2p->invite_go_dev_addr = NULL;
538	wpa_hexdump_ascii(MSG_DEBUG, "Invitation for SSID",
539			  ssid, ssid_len);
540
541	dev = p2p_get_device(p2p, peer);
542	if (dev == NULL || (dev->listen_freq <= 0 && dev->oper_freq <= 0)) {
543		p2p_dbg(p2p, "Cannot invite unknown P2P Device " MACSTR,
544			MAC2STR(peer));
545		return -1;
546	}
547
548	if (p2p_prepare_channel(p2p, dev, force_freq, pref_freq) < 0)
549		return -1;
550
551	if (persistent_group && role == P2P_INVITE_ROLE_CLIENT && !force_freq &&
552	    !pref_freq)
553		dev->flags |= P2P_DEV_NO_PREF_CHAN;
554	else
555		dev->flags &= ~P2P_DEV_NO_PREF_CHAN;
556
557	if (dev->flags & P2P_DEV_GROUP_CLIENT_ONLY) {
558		if (!(dev->info.dev_capab &
559		      P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY)) {
560			p2p_dbg(p2p, "Cannot invite a P2P Device " MACSTR
561				" that is in a group and is not discoverable",
562				MAC2STR(peer));
563		}
564		/* TODO: use device discoverability request through GO */
565	}
566
567	dev->invitation_reqs = 0;
568
569	if (p2p->state != P2P_IDLE)
570		p2p_stop_find(p2p);
571
572	p2p->inv_role = role;
573	p2p->inv_bssid_set = bssid != NULL;
574	if (bssid)
575		os_memcpy(p2p->inv_bssid, bssid, ETH_ALEN);
576	os_memcpy(p2p->inv_ssid, ssid, ssid_len);
577	p2p->inv_ssid_len = ssid_len;
578	p2p->inv_persistent = persistent_group;
579	return p2p_invite_send(p2p, dev, go_dev_addr);
580}
581