p2p_group.c revision c5ec7f57ead87efa365800228aa0b09a12d9e6c4
1/*
2 * Wi-Fi Direct - P2P group operations
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 "common/ieee802_11_common.h"
14#include "wps/wps_defs.h"
15#include "wps/wps_i.h"
16#include "p2p_i.h"
17#include "p2p.h"
18
19
20struct p2p_group_member {
21	struct p2p_group_member *next;
22	u8 addr[ETH_ALEN]; /* P2P Interface Address */
23	u8 dev_addr[ETH_ALEN]; /* P2P Device Address */
24	struct wpabuf *p2p_ie;
25	struct wpabuf *client_info;
26	u8 dev_capab;
27};
28
29/**
30 * struct p2p_group - Internal P2P module per-group data
31 */
32struct p2p_group {
33	struct p2p_data *p2p;
34	struct p2p_group_config *cfg;
35	struct p2p_group_member *members;
36	unsigned int num_members;
37	int group_formation;
38	int beacon_update;
39	struct wpabuf *noa;
40};
41
42
43static void p2p_group_update_ies(struct p2p_group *group);
44
45
46struct p2p_group * p2p_group_init(struct p2p_data *p2p,
47				  struct p2p_group_config *config)
48{
49	struct p2p_group *group, **groups;
50
51	group = os_zalloc(sizeof(*group));
52	if (group == NULL)
53		return NULL;
54
55	groups = os_realloc(p2p->groups, (p2p->num_groups + 1) *
56			    sizeof(struct p2p_group *));
57	if (groups == NULL) {
58		os_free(group);
59		return NULL;
60	}
61	groups[p2p->num_groups++] = group;
62	p2p->groups = groups;
63
64	group->p2p = p2p;
65	group->cfg = config;
66	group->group_formation = 1;
67	group->beacon_update = 1;
68	p2p_group_update_ies(group);
69	group->cfg->idle_update(group->cfg->cb_ctx, 1);
70
71	return group;
72}
73
74
75static void p2p_group_free_member(struct p2p_group_member *m)
76{
77	wpabuf_free(m->p2p_ie);
78	wpabuf_free(m->client_info);
79	os_free(m);
80}
81
82
83static void p2p_group_free_members(struct p2p_group *group)
84{
85	struct p2p_group_member *m, *prev;
86	m = group->members;
87	group->members = NULL;
88	group->num_members = 0;
89	while (m) {
90		prev = m;
91		m = m->next;
92		p2p_group_free_member(prev);
93	}
94}
95
96
97void p2p_group_deinit(struct p2p_group *group)
98{
99	size_t g;
100	struct p2p_data *p2p;
101
102	if (group == NULL)
103		return;
104
105	p2p = group->p2p;
106
107	for (g = 0; g < p2p->num_groups; g++) {
108		if (p2p->groups[g] == group) {
109			while (g + 1 < p2p->num_groups) {
110				p2p->groups[g] = p2p->groups[g + 1];
111				g++;
112			}
113			p2p->num_groups--;
114			break;
115		}
116	}
117
118	p2p_group_free_members(group);
119	os_free(group->cfg);
120	wpabuf_free(group->noa);
121	os_free(group);
122}
123
124
125static void p2p_client_info(struct wpabuf *ie, struct p2p_group_member *m)
126{
127	if (m->client_info == NULL)
128		return;
129	if (wpabuf_tailroom(ie) < wpabuf_len(m->client_info) + 1)
130		return;
131	wpabuf_put_buf(ie, m->client_info);
132}
133
134
135static void p2p_group_add_common_ies(struct p2p_group *group,
136				     struct wpabuf *ie)
137{
138	u8 dev_capab = 0, group_capab = 0;
139
140	/* P2P Capability */
141	dev_capab |= P2P_DEV_CAPAB_SERVICE_DISCOVERY;
142	dev_capab |= P2P_DEV_CAPAB_INVITATION_PROCEDURE;
143	group_capab |= P2P_GROUP_CAPAB_GROUP_OWNER;
144	if (group->cfg->persistent_group) {
145		group_capab |= P2P_GROUP_CAPAB_PERSISTENT_GROUP;
146		if (group->cfg->persistent_group == 2)
147			group_capab |= P2P_GROUP_CAPAB_PERSISTENT_RECONN;
148	}
149	if (group->p2p->cfg->p2p_intra_bss)
150		group_capab |= P2P_GROUP_CAPAB_INTRA_BSS_DIST;
151	if (group->group_formation)
152		group_capab |= P2P_GROUP_CAPAB_GROUP_FORMATION;
153	if (group->p2p->cross_connect)
154		group_capab |= P2P_GROUP_CAPAB_CROSS_CONN;
155	if (group->num_members >= group->cfg->max_clients)
156		group_capab |= P2P_GROUP_CAPAB_GROUP_LIMIT;
157	p2p_buf_add_capability(ie, dev_capab, group_capab);
158}
159
160
161static void p2p_group_add_noa(struct wpabuf *ie, struct wpabuf *noa)
162{
163	if (noa == NULL)
164		return;
165	/* Notice of Absence */
166	wpabuf_put_u8(ie, P2P_ATTR_NOTICE_OF_ABSENCE);
167	wpabuf_put_le16(ie, wpabuf_len(noa));
168	wpabuf_put_buf(ie, noa);
169}
170
171
172static struct wpabuf * p2p_group_build_beacon_ie(struct p2p_group *group)
173{
174	struct wpabuf *ie;
175	u8 *len;
176
177	ie = wpabuf_alloc(257);
178	if (ie == NULL)
179		return NULL;
180
181	len = p2p_buf_add_ie_hdr(ie);
182	p2p_group_add_common_ies(group, ie);
183	p2p_buf_add_device_id(ie, group->p2p->cfg->dev_addr);
184	p2p_group_add_noa(ie, group->noa);
185	p2p_buf_update_ie_hdr(ie, len);
186
187	return ie;
188}
189
190
191static struct wpabuf * p2p_group_build_probe_resp_ie(struct p2p_group *group)
192{
193	u8 *group_info;
194	struct wpabuf *ie;
195	struct p2p_group_member *m;
196	u8 *len;
197
198	ie = wpabuf_alloc(257);
199	if (ie == NULL)
200		return NULL;
201
202	len = p2p_buf_add_ie_hdr(ie);
203
204	p2p_group_add_common_ies(group, ie);
205	p2p_group_add_noa(ie, group->noa);
206
207	/* P2P Device Info */
208	p2p_buf_add_device_info(ie, group->p2p, NULL);
209
210	/* P2P Group Info */
211	group_info = wpabuf_put(ie, 0);
212	wpabuf_put_u8(ie, P2P_ATTR_GROUP_INFO);
213	wpabuf_put_le16(ie, 0); /* Length to be filled */
214	for (m = group->members; m; m = m->next)
215		p2p_client_info(ie, m);
216	WPA_PUT_LE16(group_info + 1,
217		     (u8 *) wpabuf_put(ie, 0) - group_info - 3);
218
219	p2p_buf_update_ie_hdr(ie, len);
220	return ie;
221}
222
223
224static void p2p_group_update_ies(struct p2p_group *group)
225{
226	struct wpabuf *beacon_ie;
227	struct wpabuf *probe_resp_ie;
228
229	probe_resp_ie = p2p_group_build_probe_resp_ie(group);
230	if (probe_resp_ie == NULL)
231		return;
232	wpa_hexdump_buf(MSG_MSGDUMP, "P2P: Update GO Probe Response P2P IE",
233			probe_resp_ie);
234
235	if (group->beacon_update) {
236		beacon_ie = p2p_group_build_beacon_ie(group);
237		if (beacon_ie)
238			group->beacon_update = 0;
239		wpa_hexdump_buf(MSG_MSGDUMP, "P2P: Update GO Beacon P2P IE",
240				beacon_ie);
241	} else
242		beacon_ie = NULL;
243
244	group->cfg->ie_update(group->cfg->cb_ctx, beacon_ie, probe_resp_ie);
245}
246
247
248/**
249 * p2p_build_client_info - Build P2P Client Info Descriptor
250 * @addr: MAC address of the peer device
251 * @p2p_ie: P2P IE from (Re)Association Request
252 * @dev_capab: Buffer for returning Device Capability
253 * @dev_addr: Buffer for returning P2P Device Address
254 * Returns: P2P Client Info Descriptor or %NULL on failure
255 *
256 * This function builds P2P Client Info Descriptor based on the information
257 * available from (Re)Association Request frame. Group owner can use this to
258 * build the P2P Group Info attribute for Probe Response frames.
259 */
260static struct wpabuf * p2p_build_client_info(const u8 *addr,
261					     struct wpabuf *p2p_ie,
262					     u8 *dev_capab, u8 *dev_addr)
263{
264	const u8 *spos;
265	struct p2p_message msg;
266	u8 *len_pos;
267	struct wpabuf *buf;
268
269	if (p2p_ie == NULL)
270		return NULL;
271
272	os_memset(&msg, 0, sizeof(msg));
273	if (p2p_parse_p2p_ie(p2p_ie, &msg) ||
274	    msg.capability == NULL || msg.p2p_device_info == NULL)
275		return NULL;
276
277	buf = wpabuf_alloc(ETH_ALEN + 1 + 1 + msg.p2p_device_info_len);
278	if (buf == NULL)
279		return NULL;
280
281	*dev_capab = msg.capability[0];
282	os_memcpy(dev_addr, msg.p2p_device_addr, ETH_ALEN);
283
284	spos = msg.p2p_device_info; /* P2P Device address */
285
286	/* P2P Client Info Descriptor */
287	/* Length to be set */
288	len_pos = wpabuf_put(buf, 1);
289	/* P2P Device address */
290	wpabuf_put_data(buf, spos, ETH_ALEN);
291	/* P2P Interface address */
292	wpabuf_put_data(buf, addr, ETH_ALEN);
293	/* Device Capability Bitmap */
294	wpabuf_put_u8(buf, msg.capability[0]);
295	/*
296	 * Config Methods, Primary Device Type, Number of Secondary Device
297	 * Types, Secondary Device Type List, Device Name copied from
298	 * Device Info
299	 */
300	wpabuf_put_data(buf, spos + ETH_ALEN,
301			msg.p2p_device_info_len - ETH_ALEN);
302
303	*len_pos = wpabuf_len(buf) - 1;
304
305
306	return buf;
307}
308
309
310static int p2p_group_remove_member(struct p2p_group *group, const u8 *addr)
311{
312	struct p2p_group_member *m, *prev;
313
314	if (group == NULL)
315		return 0;
316
317	m = group->members;
318	prev = NULL;
319	while (m) {
320		if (os_memcmp(m->addr, addr, ETH_ALEN) == 0)
321			break;
322		prev = m;
323		m = m->next;
324	}
325
326	if (m == NULL)
327		return 0;
328
329	if (prev)
330		prev->next = m->next;
331	else
332		group->members = m->next;
333	p2p_group_free_member(m);
334	group->num_members--;
335
336	return 1;
337}
338
339
340int p2p_group_notif_assoc(struct p2p_group *group, const u8 *addr,
341			  const u8 *ie, size_t len)
342{
343	struct p2p_group_member *m;
344
345	if (group == NULL)
346		return -1;
347
348	m = os_zalloc(sizeof(*m));
349	if (m == NULL)
350		return -1;
351	os_memcpy(m->addr, addr, ETH_ALEN);
352	m->p2p_ie = ieee802_11_vendor_ie_concat(ie, len, P2P_IE_VENDOR_TYPE);
353	if (m->p2p_ie) {
354		m->client_info = p2p_build_client_info(addr, m->p2p_ie,
355						       &m->dev_capab,
356						       m->dev_addr);
357	}
358
359	p2p_group_remove_member(group, addr);
360
361	m->next = group->members;
362	group->members = m;
363	group->num_members++;
364	wpa_msg(group->p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Add client " MACSTR
365		" to group (p2p=%d client_info=%d); num_members=%u/%u",
366		MAC2STR(addr), m->p2p_ie ? 1 : 0, m->client_info ? 1 : 0,
367		group->num_members, group->cfg->max_clients);
368	if (group->num_members == group->cfg->max_clients)
369		group->beacon_update = 1;
370	p2p_group_update_ies(group);
371	if (group->num_members == 1)
372		group->cfg->idle_update(group->cfg->cb_ctx, 0);
373
374	return 0;
375}
376
377
378struct wpabuf * p2p_group_assoc_resp_ie(struct p2p_group *group, u8 status)
379{
380	struct wpabuf *resp;
381	u8 *rlen;
382
383	/*
384	 * (Re)Association Response - P2P IE
385	 * Status attribute (shall be present when association request is
386	 *	denied)
387	 * Extended Listen Timing (may be present)
388	 */
389	resp = wpabuf_alloc(20);
390	if (resp == NULL)
391		return NULL;
392	rlen = p2p_buf_add_ie_hdr(resp);
393	if (status != P2P_SC_SUCCESS)
394		p2p_buf_add_status(resp, status);
395	p2p_buf_update_ie_hdr(resp, rlen);
396
397	return resp;
398}
399
400
401void p2p_group_notif_disassoc(struct p2p_group *group, const u8 *addr)
402{
403	if (p2p_group_remove_member(group, addr)) {
404		wpa_msg(group->p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Remove "
405			"client " MACSTR " from group; num_members=%u/%u",
406			MAC2STR(addr), group->num_members,
407			group->cfg->max_clients);
408		if (group->num_members == group->cfg->max_clients - 1)
409			group->beacon_update = 1;
410		p2p_group_update_ies(group);
411		if (group->num_members == 0)
412			group->cfg->idle_update(group->cfg->cb_ctx, 1);
413	}
414}
415
416
417/**
418 * p2p_match_dev_type_member - Match client device type with requested type
419 * @m: Group member
420 * @wps: WPS TLVs from Probe Request frame (concatenated WPS IEs)
421 * Returns: 1 on match, 0 on mismatch
422 *
423 * This function can be used to match the Requested Device Type attribute in
424 * WPS IE with the device types of a group member for deciding whether a GO
425 * should reply to a Probe Request frame.
426 */
427static int p2p_match_dev_type_member(struct p2p_group_member *m,
428				     struct wpabuf *wps)
429{
430	const u8 *pos, *end;
431	struct wps_parse_attr attr;
432	u8 num_sec;
433
434	if (m->client_info == NULL || wps == NULL)
435		return 0;
436
437	pos = wpabuf_head(m->client_info);
438	end = pos + wpabuf_len(m->client_info);
439
440	pos += 1 + 2 * ETH_ALEN + 1 + 2;
441	if (end - pos < WPS_DEV_TYPE_LEN + 1)
442		return 0;
443
444	if (wps_parse_msg(wps, &attr))
445		return 1; /* assume no Requested Device Type attributes */
446
447	if (attr.num_req_dev_type == 0)
448		return 1; /* no Requested Device Type attributes -> match */
449
450	if (dev_type_list_match(pos, attr.req_dev_type, attr.num_req_dev_type))
451		return 1; /* Match with client Primary Device Type */
452
453	pos += WPS_DEV_TYPE_LEN;
454	num_sec = *pos++;
455	if (end - pos < num_sec * WPS_DEV_TYPE_LEN)
456		return 0;
457	while (num_sec > 0) {
458		num_sec--;
459		if (dev_type_list_match(pos, attr.req_dev_type,
460					attr.num_req_dev_type))
461			return 1; /* Match with client Secondary Device Type */
462		pos += WPS_DEV_TYPE_LEN;
463	}
464
465	/* No matching device type found */
466	return 0;
467}
468
469
470int p2p_group_match_dev_type(struct p2p_group *group, struct wpabuf *wps)
471{
472	struct p2p_group_member *m;
473
474	if (p2p_match_dev_type(group->p2p, wps))
475		return 1; /* Match with own device type */
476
477	for (m = group->members; m; m = m->next) {
478		if (p2p_match_dev_type_member(m, wps))
479			return 1; /* Match with group client device type */
480	}
481
482	/* No match with Requested Device Type */
483	return 0;
484}
485
486
487int p2p_group_match_dev_id(struct p2p_group *group, struct wpabuf *p2p)
488{
489	struct p2p_group_member *m;
490	struct p2p_message msg;
491
492	os_memset(&msg, 0, sizeof(msg));
493	if (p2p_parse_p2p_ie(p2p, &msg))
494		return 1; /* Failed to parse - assume no filter on Device ID */
495
496	if (!msg.device_id)
497		return 1; /* No filter on Device ID */
498
499	if (os_memcmp(msg.device_id, group->p2p->cfg->dev_addr, ETH_ALEN) == 0)
500		return 1; /* Match with our P2P Device Address */
501
502	for (m = group->members; m; m = m->next) {
503		if (os_memcmp(msg.device_id, m->dev_addr, ETH_ALEN) == 0)
504			return 1; /* Match with group client P2P Device Address */
505	}
506
507	/* No match with Device ID */
508	return 0;
509}
510
511
512void p2p_group_notif_formation_done(struct p2p_group *group)
513{
514	if (group == NULL)
515		return;
516	group->group_formation = 0;
517	group->beacon_update = 1;
518	p2p_group_update_ies(group);
519}
520
521
522int p2p_group_notif_noa(struct p2p_group *group, const u8 *noa,
523			size_t noa_len)
524{
525	if (noa == NULL) {
526		wpabuf_free(group->noa);
527		group->noa = NULL;
528	} else {
529		if (group->noa) {
530			if (wpabuf_size(group->noa) >= noa_len) {
531				group->noa->used = 0;
532				wpabuf_put_data(group->noa, noa, noa_len);
533			} else {
534				wpabuf_free(group->noa);
535				group->noa = NULL;
536			}
537		}
538
539		if (!group->noa) {
540			group->noa = wpabuf_alloc_copy(noa, noa_len);
541			if (group->noa == NULL)
542				return -1;
543		}
544	}
545
546	group->beacon_update = 1;
547	p2p_group_update_ies(group);
548	return 0;
549}
550
551
552static struct p2p_group_member * p2p_group_get_client(struct p2p_group *group,
553						      const u8 *dev_id)
554{
555	struct p2p_group_member *m;
556
557	for (m = group->members; m; m = m->next) {
558		if (os_memcmp(dev_id, m->dev_addr, ETH_ALEN) == 0)
559			return m;
560	}
561
562	return NULL;
563}
564
565
566static struct p2p_group_member * p2p_group_get_client_iface(
567	struct p2p_group *group, const u8 *interface_addr)
568{
569	struct p2p_group_member *m;
570
571	for (m = group->members; m; m = m->next) {
572		if (os_memcmp(interface_addr, m->addr, ETH_ALEN) == 0)
573			return m;
574	}
575
576	return NULL;
577}
578
579
580const u8 * p2p_group_get_dev_addr(struct p2p_group *group, const u8 *addr)
581{
582	struct p2p_group_member *m;
583
584	if (group == NULL)
585		return NULL;
586	m = p2p_group_get_client_iface(group, addr);
587	if (m && !is_zero_ether_addr(m->dev_addr))
588		return m->dev_addr;
589	return NULL;
590}
591
592
593static struct wpabuf * p2p_build_go_disc_req(void)
594{
595	struct wpabuf *buf;
596
597	buf = wpabuf_alloc(100);
598	if (buf == NULL)
599		return NULL;
600
601	p2p_buf_add_action_hdr(buf, P2P_GO_DISC_REQ, 0);
602
603	return buf;
604}
605
606
607int p2p_group_go_discover(struct p2p_group *group, const u8 *dev_id,
608			  const u8 *searching_dev, int rx_freq)
609{
610	struct p2p_group_member *m;
611	struct wpabuf *req;
612	struct p2p_data *p2p = group->p2p;
613	int freq;
614
615	m = p2p_group_get_client(group, dev_id);
616	if (m == NULL || m->client_info == NULL) {
617		wpa_printf(MSG_DEBUG, "P2P: Requested client was not in this "
618			   "group " MACSTR,
619			   MAC2STR(group->cfg->interface_addr));
620		return -1;
621	}
622
623	if (!(m->dev_capab & P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY)) {
624		wpa_printf(MSG_DEBUG, "P2P: Requested client does not support "
625			   "client discoverability");
626		return -1;
627	}
628
629	wpa_printf(MSG_DEBUG, "P2P: Schedule GO Discoverability Request to be "
630		   "sent to " MACSTR, MAC2STR(dev_id));
631
632	req = p2p_build_go_disc_req();
633	if (req == NULL)
634		return -1;
635
636	/* TODO: Should really use group operating frequency here */
637	freq = rx_freq;
638
639	p2p->pending_action_state = P2P_PENDING_GO_DISC_REQ;
640	if (p2p->cfg->send_action(p2p->cfg->cb_ctx, freq, m->addr,
641				  group->cfg->interface_addr,
642				  group->cfg->interface_addr,
643				  wpabuf_head(req), wpabuf_len(req), 200) < 0)
644	{
645		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
646			"P2P: Failed to send Action frame");
647	}
648
649	wpabuf_free(req);
650
651	return 0;
652}
653
654
655const u8 * p2p_group_get_interface_addr(struct p2p_group *group)
656{
657	return group->cfg->interface_addr;
658}
659
660
661u8 p2p_group_presence_req(struct p2p_group *group,
662			  const u8 *client_interface_addr,
663			  const u8 *noa, size_t noa_len)
664{
665	struct p2p_group_member *m;
666	u8 curr_noa[50];
667	int curr_noa_len;
668
669	m = p2p_group_get_client_iface(group, client_interface_addr);
670	if (m == NULL || m->client_info == NULL) {
671		wpa_printf(MSG_DEBUG, "P2P: Client was not in this group");
672		return P2P_SC_FAIL_UNABLE_TO_ACCOMMODATE;
673	}
674
675	wpa_hexdump(MSG_DEBUG, "P2P: Presence Request NoA", noa, noa_len);
676
677	if (group->p2p->cfg->get_noa)
678		curr_noa_len = group->p2p->cfg->get_noa(
679			group->p2p->cfg->cb_ctx, group->cfg->interface_addr,
680			curr_noa, sizeof(curr_noa));
681	else
682		curr_noa_len = -1;
683	if (curr_noa_len < 0)
684		wpa_printf(MSG_DEBUG, "P2P: Failed to fetch current NoA");
685	else if (curr_noa_len == 0)
686		wpa_printf(MSG_DEBUG, "P2P: No NoA being advertized");
687	else
688		wpa_hexdump(MSG_DEBUG, "P2P: Current NoA", curr_noa,
689			    curr_noa_len);
690
691	/* TODO: properly process request and store copy */
692	if (curr_noa_len > 0 || curr_noa_len == -1)
693		return P2P_SC_FAIL_UNABLE_TO_ACCOMMODATE;
694
695	return P2P_SC_SUCCESS;
696}
697
698
699unsigned int p2p_get_group_num_members(struct p2p_group *group)
700{
701	return group->num_members;
702}
703
704
705const u8 * p2p_iterate_group_members(struct p2p_group *group, void **next)
706{
707	struct p2p_group_member *iter = *next;
708
709	if (!iter)
710		iter = group->members;
711	else
712		iter = iter->next;
713
714	*next = iter;
715
716	if (!iter)
717		return NULL;
718
719	return iter->addr;
720}
721
722
723int p2p_group_is_client_connected(struct p2p_group *group, const u8 *dev_addr)
724{
725	struct p2p_group_member *m;
726
727	for (m = group->members; m; m = m->next) {
728		if (os_memcmp(m->dev_addr, dev_addr, ETH_ALEN) == 0)
729			return 1;
730	}
731
732	return 0;
733}
734