aboutsummaryrefslogtreecommitdiffstats
path: root/wpa_supplicant/gas_query.c
blob: e4c3b1b96444f6717c07ae10622eecb99685e402 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
/*
 * Generic advertisement service (GAS) query
 * Copyright (c) 2009, Atheros Communications
 * Copyright (c) 2011-2014, Qualcomm Atheros, Inc.
 * Copyright (c) 2011-2014, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#include "includes.h"

#include "common.h"
#include "utils/eloop.h"
#include "common/ieee802_11_defs.h"
#include "common/gas.h"
#include "common/wpa_ctrl.h"
#include "rsn_supp/wpa.h"
#include "wpa_supplicant_i.h"
#include "config.h"
#include "driver_i.h"
#include "offchannel.h"
#include "gas_query.h"


/** GAS query timeout in seconds */
#define GAS_QUERY_TIMEOUT_PERIOD 2

/* GAS query wait-time / duration in ms */
#define GAS_QUERY_WAIT_TIME_INITIAL 1000
#define GAS_QUERY_WAIT_TIME_COMEBACK 150

/**
 * struct gas_query_pending - Pending GAS query
 */
struct gas_query_pending {
	struct dl_list list;
	struct gas_query *gas;
	u8 addr[ETH_ALEN];
	u8 dialog_token;
	u8 next_frag_id;
	unsigned int wait_comeback:1;
	unsigned int offchannel_tx_started:1;
	unsigned int retry:1;
	int freq;
	u16 status_code;
	struct wpabuf *req;
	struct wpabuf *adv_proto;
	struct wpabuf *resp;
	struct os_reltime last_oper;
	void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
		   enum gas_query_result result,
		   const struct wpabuf *adv_proto,
		   const struct wpabuf *resp, u16 status_code);
	void *ctx;
	u8 sa[ETH_ALEN];
};

/**
 * struct gas_query - Internal GAS query data
 */
struct gas_query {
	struct wpa_supplicant *wpa_s;
	struct dl_list pending; /* struct gas_query_pending */
	struct gas_query_pending *current;
	struct wpa_radio_work *work;
	struct os_reltime last_mac_addr_rand;
	int last_rand_sa_type;
	u8 rand_addr[ETH_ALEN];
};


static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx);
static void gas_query_timeout(void *eloop_data, void *user_ctx);
static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx);
static void gas_query_tx_initial_req(struct gas_query *gas,
				     struct gas_query_pending *query);
static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst);


static int ms_from_time(struct os_reltime *last)
{
	struct os_reltime now, res;

	os_get_reltime(&now);
	os_reltime_sub(&now, last, &res);
	return res.sec * 1000 + res.usec / 1000;
}


/**
 * gas_query_init - Initialize GAS query component
 * @wpa_s: Pointer to wpa_supplicant data
 * Returns: Pointer to GAS query data or %NULL on failure
 */
struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s)
{
	struct gas_query *gas;

	gas = os_zalloc(sizeof(*gas));
	if (gas == NULL)
		return NULL;

	gas->wpa_s = wpa_s;
	dl_list_init(&gas->pending);

	return gas;
}


static const char * gas_result_txt(enum gas_query_result result)
{
	switch (result) {
	case GAS_QUERY_SUCCESS:
		return "SUCCESS";
	case GAS_QUERY_FAILURE:
		return "FAILURE";
	case GAS_QUERY_TIMEOUT:
		return "TIMEOUT";
	case GAS_QUERY_PEER_ERROR:
		return "PEER_ERROR";
	case GAS_QUERY_INTERNAL_ERROR:
		return "INTERNAL_ERROR";
	case GAS_QUERY_STOPPED:
		return "STOPPED";
	case GAS_QUERY_DELETED_AT_DEINIT:
		return "DELETED_AT_DEINIT";
	}

	return "N/A";
}


static void gas_query_free(struct gas_query_pending *query, int del_list)
{
	struct gas_query *gas = query->gas;

	if (del_list)
		dl_list_del(&query->list);

	if (gas->work && gas->work->ctx == query) {
		radio_work_done(gas->work);
		gas->work = NULL;
	}

	wpabuf_free(query->req);
	wpabuf_free(query->adv_proto);
	wpabuf_free(query->resp);
	os_free(query);
}


static void gas_query_done(struct gas_query *gas,
			   struct gas_query_pending *query,
			   enum gas_query_result result)
{
	wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR
		" dialog_token=%u freq=%d status_code=%u result=%s",
		MAC2STR(query->addr), query->dialog_token, query->freq,
		query->status_code, gas_result_txt(result));
	if (gas->current == query)
		gas->current = NULL;
	if (query->offchannel_tx_started)
		offchannel_send_action_done(gas->wpa_s);
	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
	eloop_cancel_timeout(gas_query_timeout, gas, query);
	eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
	dl_list_del(&query->list);
	query->cb(query->ctx, query->addr, query->dialog_token, result,
		  query->adv_proto, query->resp, query->status_code);
	gas_query_free(query, 0);
}


/**
 * gas_query_deinit - Deinitialize GAS query component
 * @gas: GAS query data from gas_query_init()
 */
void gas_query_deinit(struct gas_query *gas)
{
	struct gas_query_pending *query, *next;

	if (gas == NULL)
		return;

	dl_list_for_each_safe(query, next, &gas->pending,
			      struct gas_query_pending, list)
		gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);

	os_free(gas);
}


static struct gas_query_pending *
gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token)
{
	struct gas_query_pending *q;
	dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
		if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 &&
		    q->dialog_token == dialog_token)
			return q;
	}
	return NULL;
}


static int gas_query_append(struct gas_query_pending *query, const u8 *data,
			    size_t len)
{
	if (wpabuf_resize(&query->resp, len) < 0) {
		wpa_printf(MSG_DEBUG, "GAS: No memory to store the response");
		return -1;
	}
	wpabuf_put_data(query->resp, data, len);
	return 0;
}


static void gas_query_tx_status(struct wpa_supplicant *wpa_s,
				unsigned int freq, const u8 *dst,
				const u8 *src, const u8 *bssid,
				const u8 *data, size_t data_len,
				enum offchannel_send_action_result result)
{
	struct gas_query_pending *query;
	struct gas_query *gas = wpa_s->gas;
	int dur;

	if (gas->current == NULL) {
		wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: freq=%u dst="
			   MACSTR " result=%d - no query in progress",
			   freq, MAC2STR(dst), result);
		return;
	}

	query = gas->current;

	dur = ms_from_time(&query->last_oper);
	wpa_printf(MSG_DEBUG, "GAS: TX status: freq=%u dst=" MACSTR
		   " result=%d query=%p dialog_token=%u dur=%d ms",
		   freq, MAC2STR(dst), result, query, query->dialog_token, dur);
	if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) {
		wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination");
		return;
	}
	os_get_reltime(&query->last_oper);

	if (result == OFFCHANNEL_SEND_ACTION_SUCCESS ||
	    result == OFFCHANNEL_SEND_ACTION_NO_ACK) {
		eloop_cancel_timeout(gas_query_timeout, gas, query);
		if (result == OFFCHANNEL_SEND_ACTION_NO_ACK) {
			wpa_printf(MSG_DEBUG, "GAS: No ACK to GAS request");
			eloop_register_timeout(0, 250000,
					       gas_query_timeout, gas, query);
		} else {
			eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
					       gas_query_timeout, gas, query);
		}
		if (query->wait_comeback && !query->retry) {
			eloop_cancel_timeout(gas_query_rx_comeback_timeout,
					     gas, query);
			eloop_register_timeout(
				0, (GAS_QUERY_WAIT_TIME_COMEBACK + 10) * 1000,
				gas_query_rx_comeback_timeout, gas, query);
		}
	}
	if (result == OFFCHANNEL_SEND_ACTION_FAILED) {
		eloop_cancel_timeout(gas_query_timeout, gas, query);
		eloop_register_timeout(0, 0, gas_query_timeout, gas, query);
	}
}


static int pmf_in_use(struct wpa_supplicant *wpa_s, const u8 *addr)
{
	if (wpa_s->current_ssid == NULL ||
	    wpa_s->wpa_state < WPA_4WAY_HANDSHAKE ||
	    os_memcmp(addr, wpa_s->bssid, ETH_ALEN) != 0)
		return 0;
	return wpa_sm_pmf_enabled(wpa_s->wpa);
}


static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
			struct wpabuf *req, unsigned int wait_time)
{
	int res, prot = pmf_in_use(gas->wpa_s, query->addr);
	const u8 *bssid;
	const u8 wildcard_bssid[ETH_ALEN] = {
		0xff, 0xff, 0xff, 0xff, 0xff, 0xff
	};

	wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
		   "freq=%d prot=%d using src addr " MACSTR,
		   MAC2STR(query->addr), (unsigned int) wpabuf_len(req),
		   query->freq, prot, MAC2STR(query->sa));
	if (prot) {
		u8 *categ = wpabuf_mhead_u8(req);
		*categ = WLAN_ACTION_PROTECTED_DUAL;
	}
	os_get_reltime(&query->last_oper);
	if (gas->wpa_s->max_remain_on_chan &&
	    wait_time > gas->wpa_s->max_remain_on_chan)
		wait_time = gas->wpa_s->max_remain_on_chan;
	if (!gas->wpa_s->conf->gas_address3 ||
	    (gas->wpa_s->current_ssid &&
	     gas->wpa_s->wpa_state >= WPA_ASSOCIATED &&
	     os_memcmp(query->addr, gas->wpa_s->bssid, ETH_ALEN) == 0))
		bssid = query->addr;
	else
		bssid = wildcard_bssid;

	res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
				     query->sa, bssid, wpabuf_head(req),
				     wpabuf_len(req), wait_time,
				     gas_query_tx_status, 0);

	if (res == 0)
		query->offchannel_tx_started = 1;
	return res;
}


static void gas_query_tx_comeback_req(struct gas_query *gas,
				      struct gas_query_pending *query)
{
	struct wpabuf *req;
	unsigned int wait_time;

	req = gas_build_comeback_req(query->dialog_token);
	if (req == NULL) {
		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
		return;
	}

	wait_time = (query->retry || !query->offchannel_tx_started) ?
		GAS_QUERY_WAIT_TIME_INITIAL : GAS_QUERY_WAIT_TIME_COMEBACK;

	if (gas_query_tx(gas, query, req, wait_time) < 0) {
		wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
			   MACSTR, MAC2STR(query->addr));
		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
	}

	wpabuf_free(req);
}


static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx)
{
	struct gas_query *gas = eloop_data;
	struct gas_query_pending *query = user_ctx;
	int dialog_token;

	wpa_printf(MSG_DEBUG,
		   "GAS: No response to comeback request received (retry=%u)",
		   query->retry);
	if (gas->current != query || query->retry)
		return;
	dialog_token = gas_query_new_dialog_token(gas, query->addr);
	if (dialog_token < 0)
		return;
	wpa_printf(MSG_DEBUG,
		   "GAS: Retry GAS query due to comeback response timeout");
	query->retry = 1;
	query->dialog_token = dialog_token;
	*(wpabuf_mhead_u8(query->req) + 2) = dialog_token;
	query->wait_comeback = 0;
	query->next_frag_id = 0;
	wpabuf_free(query->adv_proto);
	query->adv_proto = NULL;
	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
	eloop_cancel_timeout(gas_query_timeout, gas, query);
	gas_query_tx_initial_req(gas, query);
}


static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
{
	struct gas_query *gas = eloop_data;
	struct gas_query_pending *query = user_ctx;

	wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
		   MAC2STR(query->addr));
	gas_query_tx_comeback_req(gas, query);
}


static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
					    struct gas_query_pending *query,
					    u16 comeback_delay)
{
	unsigned int secs, usecs;

	if (comeback_delay > 1 && query->offchannel_tx_started) {
		offchannel_send_action_done(gas->wpa_s);
		query->offchannel_tx_started = 0;
	}

	secs = (comeback_delay * 1024) / 1000000;
	usecs = comeback_delay * 1024 - secs * 1000000;
	wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
		   " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
	eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
			       gas, query);
}


static void gas_query_rx_initial(struct gas_query *gas,
				 struct gas_query_pending *query,
				 const u8 *adv_proto, const u8 *resp,
				 size_t len, u16 comeback_delay)
{
	wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
		   MACSTR " (dialog_token=%u comeback_delay=%u)",
		   MAC2STR(query->addr), query->dialog_token, comeback_delay);

	query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]);
	if (query->adv_proto == NULL) {
		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
		return;
	}

	if (comeback_delay) {
		eloop_cancel_timeout(gas_query_timeout, gas, query);
		query->wait_comeback = 1;
		gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
		return;
	}

	/* Query was completed without comeback mechanism */
	if (gas_query_append(query, resp, len) < 0) {
		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
		return;
	}

	gas_query_done(gas, query, GAS_QUERY_SUCCESS);
}


static void gas_query_rx_comeback(struct gas_query *gas,
				  struct gas_query_pending *query,
				  const u8 *adv_proto, const u8 *resp,
				  size_t len, u8 frag_id, u8 more_frags,
				  u16 comeback_delay)
{
	wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
		   MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
		   "comeback_delay=%u)",
		   MAC2STR(query->addr), query->dialog_token, frag_id,
		   more_frags, comeback_delay);
	eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);

	if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) ||
	    os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
		      wpabuf_len(query->adv_proto)) != 0) {
		wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
			   "between initial and comeback response from "
			   MACSTR, MAC2STR(query->addr));
		gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
		return;
	}

	if (comeback_delay) {
		if (frag_id) {
			wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
				   "with non-zero frag_id and comeback_delay "
				   "from " MACSTR, MAC2STR(query->addr));
			gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
			return;
		}
		gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
		return;
	}

	if (frag_id != query->next_frag_id) {
		wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
			   "from " MACSTR, MAC2STR(query->addr));
		if (frag_id + 1 == query->next_frag_id) {
			wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
				   "retry of previous fragment");
			return;
		}
		gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
		return;
	}
	query->next_frag_id++;

	if (gas_query_append(query, resp, len) < 0) {
		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
		return;
	}

	if (more_frags) {
		gas_query_tx_comeback_req(gas, query);
		return;
	}

	gas_query_done(gas, query, GAS_QUERY_SUCCESS);
}


/**
 * gas_query_rx - Indicate reception of a Public Action or Protected Dual frame
 * @gas: GAS query data from gas_query_init()
 * @da: Destination MAC address of the Action frame
 * @sa: Source MAC address of the Action frame
 * @bssid: BSSID of the Action frame
 * @categ: Category of the Action frame
 * @data: Payload of the Action frame
 * @len: Length of @data
 * @freq: Frequency (in MHz) on which the frame was received
 * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
 */
int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
		 const u8 *bssid, u8 categ, const u8 *data, size_t len,
		 int freq)
{
	struct gas_query_pending *query;
	u8 action, dialog_token, frag_id = 0, more_frags = 0;
	u16 comeback_delay, resp_len;
	const u8 *pos, *adv_proto;
	int prot, pmf;
	unsigned int left;

	if (gas == NULL || len < 4)
		return -1;

	pos = data;
	action = *pos++;
	dialog_token = *pos++;

	if (action != WLAN_PA_GAS_INITIAL_RESP &&
	    action != WLAN_PA_GAS_COMEBACK_RESP)
		return -1; /* Not a GAS response */

	prot = categ == WLAN_ACTION_PROTECTED_DUAL;
	pmf = pmf_in_use(gas->wpa_s, sa);
	if (prot && !pmf) {
		wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled");
		return 0;
	}
	if (!prot && pmf) {
		wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled");
		return 0;
	}

	query = gas_query_get_pending(gas, sa, dialog_token);
	if (query == NULL) {
		wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR
			   " dialog token %u", MAC2STR(sa), dialog_token);
		return -1;
	}

	wpa_printf(MSG_DEBUG, "GAS: Response in %d ms from " MACSTR,
		   ms_from_time(&query->last_oper), MAC2STR(sa));

	if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) {
		wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from "
			   MACSTR " dialog token %u when waiting for comeback "
			   "response", MAC2STR(sa), dialog_token);
		return 0;
	}

	if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) {
		wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from "
			   MACSTR " dialog token %u when waiting for initial "
			   "response", MAC2STR(sa), dialog_token);
		return 0;
	}

	query->status_code = WPA_GET_LE16(pos);
	pos += 2;

	if (query->status_code == WLAN_STATUS_QUERY_RESP_OUTSTANDING &&
	    action == WLAN_PA_GAS_COMEBACK_RESP) {
		wpa_printf(MSG_DEBUG, "GAS: Allow non-zero status for outstanding comeback response");
	} else if (query->status_code != WLAN_STATUS_SUCCESS) {
		wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token "
			   "%u failed - status code %u",
			   MAC2STR(sa), dialog_token, query->status_code);
		gas_query_done(gas, query, GAS_QUERY_FAILURE);
		return 0;
	}

	if (action == WLAN_PA_GAS_COMEBACK_RESP) {
		if (pos + 1 > data + len)
			return 0;
		frag_id = *pos & 0x7f;
		more_frags = (*pos & 0x80) >> 7;
		pos++;
	}

	/* Comeback Delay */
	if (pos + 2 > data + len)
		return 0;
	comeback_delay = WPA_GET_LE16(pos);
	pos += 2;

	/* Advertisement Protocol element */
	if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) {
		wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
			   "Protocol element in the response from " MACSTR,
			   MAC2STR(sa));
		return 0;
	}

	if (*pos != WLAN_EID_ADV_PROTO) {
		wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
			   "Protocol element ID %u in response from " MACSTR,
			   *pos, MAC2STR(sa));
		return 0;
	}

	adv_proto = pos;
	pos += 2 + pos[1];

	/* Query Response Length */
	if (pos + 2 > data + len) {
		wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
		return 0;
	}
	resp_len = WPA_GET_LE16(pos);
	pos += 2;

	left = data + len - pos;
	if (resp_len > left) {
		wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
			   "response from " MACSTR, MAC2STR(sa));
		return 0;
	}

	if (resp_len < left) {
		wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
			   "after Query Response from " MACSTR,
			   left - resp_len, MAC2STR(sa));
	}

	if (action == WLAN_PA_GAS_COMEBACK_RESP)
		gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len,
				      frag_id, more_frags, comeback_delay);
	else
		gas_query_rx_initial(gas, query, adv_proto, pos, resp_len,
				     comeback_delay);

	return 0;
}


static void gas_query_timeout(void *eloop_data, void *user_ctx)
{
	struct gas_query *gas = eloop_data;
	struct gas_query_pending *query = user_ctx;

	wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
		   " dialog token %u",
		   MAC2STR(query->addr), query->dialog_token);
	gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
}


static int gas_query_dialog_token_available(struct gas_query *gas,
					    const u8 *dst, u8 dialog_token)
{
	struct gas_query_pending *q;
	dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
		if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 &&
		    dialog_token == q->dialog_token)
			return 0;
	}

	return 1;
}


static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
{
	struct gas_query_pending *query = work->ctx;
	struct gas_query *gas = query->gas;
	struct wpa_supplicant *wpa_s = gas->wpa_s;

	if (deinit) {
		if (work->started) {
			gas->work = NULL;
			gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
			return;
		}

		gas_query_free(query, 1);
		return;
	}

	if (wpas_update_random_addr_disassoc(wpa_s) < 0) {
		wpa_msg(wpa_s, MSG_INFO,
			"Failed to assign random MAC address for GAS");
		gas_query_free(query, 1);
		radio_work_done(work);
		return;
	}

	gas->work = work;
	gas_query_tx_initial_req(gas, query);
}


static void gas_query_tx_initial_req(struct gas_query *gas,
				     struct gas_query_pending *query)
{
	if (gas_query_tx(gas, query, query->req,
			 GAS_QUERY_WAIT_TIME_INITIAL) < 0) {
		wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
			   MACSTR, MAC2STR(query->addr));
		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
		return;
	}
	gas->current = query;

	wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
		   query->dialog_token);
	eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
			       gas_query_timeout, gas, query);
}


static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst)
{
	static int next_start = 0;
	int dialog_token;

	for (dialog_token = 0; dialog_token < 256; dialog_token++) {
		if (gas_query_dialog_token_available(
			    gas, dst, (next_start + dialog_token) % 256))
			break;
	}
	if (dialog_token == 256)
		return -1; /* Too many pending queries */
	dialog_token = (next_start + dialog_token) % 256;
	next_start = (dialog_token + 1) % 256;
	return dialog_token;
}


static int gas_query_set_sa(struct gas_query *gas,
			    struct gas_query_pending *query)
{
	struct wpa_supplicant *wpa_s = gas->wpa_s;
	struct os_reltime now;

	if (!wpa_s->conf->gas_rand_mac_addr ||
	    !(wpa_s->current_bss ?
	      (wpa_s->drv_flags &
	       WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA_CONNECTED) :
	      (wpa_s->drv_flags & WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA))) {
		/* Use own MAC address as the transmitter address */
		os_memcpy(query->sa, wpa_s->own_addr, ETH_ALEN);
		return 0;
	}

	os_get_reltime(&now);

	if (wpa_s->conf->gas_rand_mac_addr == gas->last_rand_sa_type &&
	    gas->last_mac_addr_rand.sec != 0 &&
	    !os_reltime_expired(&now, &gas->last_mac_addr_rand,
				wpa_s->conf->gas_rand_addr_lifetime)) {
		wpa_printf(MSG_DEBUG,
			   "GAS: Use the previously selected random transmitter address "
			   MACSTR, MAC2STR(gas->rand_addr));
		os_memcpy(query->sa, gas->rand_addr, ETH_ALEN);
		return 0;
	}

	if (wpa_s->conf->gas_rand_mac_addr == 1 &&
	    random_mac_addr(gas->rand_addr) < 0) {
		wpa_printf(MSG_ERROR, "GAS: Failed to get random address");
		return -1;
	}

	if (wpa_s->conf->gas_rand_mac_addr == 2 &&
	    random_mac_addr_keep_oui(gas->rand_addr) < 0) {
		wpa_printf(MSG_ERROR,
			   "GAS: Failed to get random address with same OUI");
		return -1;
	}

	wpa_printf(MSG_DEBUG, "GAS: Use a new random transmitter address "
		   MACSTR, MAC2STR(gas->rand_addr));
	os_memcpy(query->sa, gas->rand_addr, ETH_ALEN);
	os_get_reltime(&gas->last_mac_addr_rand);
	gas->last_rand_sa_type = wpa_s->conf->gas_rand_mac_addr;

	return 0;
}


/**
 * gas_query_req - Request a GAS query
 * @gas: GAS query data from gas_query_init()
 * @dst: Destination MAC address for the query
 * @freq: Frequency (in MHz) for the channel on which to send the query
 * @req: GAS query payload (to be freed by gas_query module in case of success
 *	return)
 * @cb: Callback function for reporting GAS query result and response
 * @ctx: Context pointer to use with the @cb call
 * Returns: dialog token (>= 0) on success or -1 on failure
 */
int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
		  struct wpabuf *req,
		  void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
			     enum gas_query_result result,
			     const struct wpabuf *adv_proto,
			     const struct wpabuf *resp, u16 status_code),
		  void *ctx)
{
	struct gas_query_pending *query;
	int dialog_token;

	if (wpabuf_len(req) < 3)
		return -1;

	dialog_token = gas_query_new_dialog_token(gas, dst);
	if (dialog_token < 0)
		return -1;

	query = os_zalloc(sizeof(*query));
	if (query == NULL)
		return -1;

	query->gas = gas;
	if (gas_query_set_sa(gas, query)) {
		os_free(query);
		return -1;
	}
	os_memcpy(query->addr, dst, ETH_ALEN);
	query->dialog_token = dialog_token;
	query->freq = freq;
	query->cb = cb;
	query->ctx = ctx;
	query->req = req;
	dl_list_add(&gas->pending, &query->list);

	*(wpabuf_mhead_u8(req) + 2) = dialog_token;

	wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
		" dialog_token=%u freq=%d",
		MAC2STR(query->addr), query->dialog_token, query->freq);

	if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
			   query) < 0) {
		query->req = NULL; /* caller will free this in error case */
		gas_query_free(query, 1);
		return -1;
	}

	return dialog_token;
}


int gas_query_stop(struct gas_query *gas, u8 dialog_token)
{
	struct gas_query_pending *query;

	dl_list_for_each(query, &gas->pending, struct gas_query_pending, list) {
		if (query->dialog_token == dialog_token) {
			gas_query_done(gas, query, GAS_QUERY_STOPPED);
			return 0;
		}
	}

	return -1;
}