xref: /freebsd/contrib/wpa/wpa_supplicant/gas_query.c (revision 36712a94975f5bd0d26c85377283b49a2369c82f)
1 /*
2  * Generic advertisement service (GAS) query
3  * Copyright (c) 2009, Atheros Communications
4  * Copyright (c) 2011-2014, Qualcomm Atheros, Inc.
5  * Copyright (c) 2011-2014, Jouni Malinen <j@w1.fi>
6  *
7  * This software may be distributed under the terms of the BSD license.
8  * See README for more details.
9  */
10 
11 #include "includes.h"
12 
13 #include "common.h"
14 #include "utils/eloop.h"
15 #include "common/ieee802_11_defs.h"
16 #include "common/gas.h"
17 #include "common/wpa_ctrl.h"
18 #include "rsn_supp/wpa.h"
19 #include "wpa_supplicant_i.h"
20 #include "config.h"
21 #include "driver_i.h"
22 #include "offchannel.h"
23 #include "gas_query.h"
24 
25 
26 /** GAS query timeout in seconds */
27 #define GAS_QUERY_TIMEOUT_PERIOD 2
28 
29 /* GAS query wait-time / duration in ms */
30 #define GAS_QUERY_WAIT_TIME_INITIAL 1000
31 #define GAS_QUERY_WAIT_TIME_COMEBACK 150
32 
33 /**
34  * struct gas_query_pending - Pending GAS query
35  */
36 struct gas_query_pending {
37 	struct dl_list list;
38 	struct gas_query *gas;
39 	u8 addr[ETH_ALEN];
40 	u8 dialog_token;
41 	u8 next_frag_id;
42 	unsigned int wait_comeback:1;
43 	unsigned int offchannel_tx_started:1;
44 	unsigned int retry:1;
45 	unsigned int wildcard_bssid:1;
46 	int freq;
47 	u16 status_code;
48 	struct wpabuf *req;
49 	struct wpabuf *adv_proto;
50 	struct wpabuf *resp;
51 	struct os_reltime last_oper;
52 	void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
53 		   enum gas_query_result result,
54 		   const struct wpabuf *adv_proto,
55 		   const struct wpabuf *resp, u16 status_code);
56 	void *ctx;
57 	u8 sa[ETH_ALEN];
58 };
59 
60 /**
61  * struct gas_query - Internal GAS query data
62  */
63 struct gas_query {
64 	struct wpa_supplicant *wpa_s;
65 	struct dl_list pending; /* struct gas_query_pending */
66 	struct gas_query_pending *current;
67 	struct wpa_radio_work *work;
68 	struct os_reltime last_mac_addr_rand;
69 	int last_rand_sa_type;
70 	u8 rand_addr[ETH_ALEN];
71 };
72 
73 
74 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx);
75 static void gas_query_timeout(void *eloop_data, void *user_ctx);
76 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx);
77 static void gas_query_tx_initial_req(struct gas_query *gas,
78 				     struct gas_query_pending *query);
79 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst);
80 
81 
82 static int ms_from_time(struct os_reltime *last)
83 {
84 	struct os_reltime now, res;
85 
86 	os_get_reltime(&now);
87 	os_reltime_sub(&now, last, &res);
88 	return res.sec * 1000 + res.usec / 1000;
89 }
90 
91 
92 /**
93  * gas_query_init - Initialize GAS query component
94  * @wpa_s: Pointer to wpa_supplicant data
95  * Returns: Pointer to GAS query data or %NULL on failure
96  */
97 struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s)
98 {
99 	struct gas_query *gas;
100 
101 	gas = os_zalloc(sizeof(*gas));
102 	if (gas == NULL)
103 		return NULL;
104 
105 	gas->wpa_s = wpa_s;
106 	dl_list_init(&gas->pending);
107 
108 	return gas;
109 }
110 
111 
112 static const char * gas_result_txt(enum gas_query_result result)
113 {
114 	switch (result) {
115 	case GAS_QUERY_SUCCESS:
116 		return "SUCCESS";
117 	case GAS_QUERY_FAILURE:
118 		return "FAILURE";
119 	case GAS_QUERY_TIMEOUT:
120 		return "TIMEOUT";
121 	case GAS_QUERY_PEER_ERROR:
122 		return "PEER_ERROR";
123 	case GAS_QUERY_INTERNAL_ERROR:
124 		return "INTERNAL_ERROR";
125 	case GAS_QUERY_STOPPED:
126 		return "STOPPED";
127 	case GAS_QUERY_DELETED_AT_DEINIT:
128 		return "DELETED_AT_DEINIT";
129 	}
130 
131 	return "N/A";
132 }
133 
134 
135 static void gas_query_free(struct gas_query_pending *query, int del_list)
136 {
137 	struct gas_query *gas = query->gas;
138 
139 	if (del_list)
140 		dl_list_del(&query->list);
141 
142 	if (gas->work && gas->work->ctx == query) {
143 		radio_work_done(gas->work);
144 		gas->work = NULL;
145 	}
146 
147 	wpabuf_free(query->req);
148 	wpabuf_free(query->adv_proto);
149 	wpabuf_free(query->resp);
150 	os_free(query);
151 }
152 
153 
154 static void gas_query_done(struct gas_query *gas,
155 			   struct gas_query_pending *query,
156 			   enum gas_query_result result)
157 {
158 	wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR
159 		" dialog_token=%u freq=%d status_code=%u result=%s",
160 		MAC2STR(query->addr), query->dialog_token, query->freq,
161 		query->status_code, gas_result_txt(result));
162 	if (gas->current == query)
163 		gas->current = NULL;
164 	if (query->offchannel_tx_started)
165 		offchannel_send_action_done(gas->wpa_s);
166 	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
167 	eloop_cancel_timeout(gas_query_timeout, gas, query);
168 	eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
169 	dl_list_del(&query->list);
170 	query->cb(query->ctx, query->addr, query->dialog_token, result,
171 		  query->adv_proto, query->resp, query->status_code);
172 	gas_query_free(query, 0);
173 }
174 
175 
176 /**
177  * gas_query_deinit - Deinitialize GAS query component
178  * @gas: GAS query data from gas_query_init()
179  */
180 void gas_query_deinit(struct gas_query *gas)
181 {
182 	struct gas_query_pending *query, *next;
183 
184 	if (gas == NULL)
185 		return;
186 
187 	dl_list_for_each_safe(query, next, &gas->pending,
188 			      struct gas_query_pending, list)
189 		gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
190 
191 	os_free(gas);
192 }
193 
194 
195 static struct gas_query_pending *
196 gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token)
197 {
198 	struct gas_query_pending *q;
199 	dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
200 		if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 &&
201 		    q->dialog_token == dialog_token)
202 			return q;
203 	}
204 	return NULL;
205 }
206 
207 
208 static int gas_query_append(struct gas_query_pending *query, const u8 *data,
209 			    size_t len)
210 {
211 	if (wpabuf_resize(&query->resp, len) < 0) {
212 		wpa_printf(MSG_DEBUG, "GAS: No memory to store the response");
213 		return -1;
214 	}
215 	wpabuf_put_data(query->resp, data, len);
216 	return 0;
217 }
218 
219 
220 static void gas_query_tx_status(struct wpa_supplicant *wpa_s,
221 				unsigned int freq, const u8 *dst,
222 				const u8 *src, const u8 *bssid,
223 				const u8 *data, size_t data_len,
224 				enum offchannel_send_action_result result)
225 {
226 	struct gas_query_pending *query;
227 	struct gas_query *gas = wpa_s->gas;
228 	int dur;
229 
230 	if (gas->current == NULL) {
231 		wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: freq=%u dst="
232 			   MACSTR " result=%d - no query in progress",
233 			   freq, MAC2STR(dst), result);
234 		return;
235 	}
236 
237 	query = gas->current;
238 
239 	dur = ms_from_time(&query->last_oper);
240 	wpa_printf(MSG_DEBUG, "GAS: TX status: freq=%u dst=" MACSTR
241 		   " result=%d query=%p dialog_token=%u dur=%d ms",
242 		   freq, MAC2STR(dst), result, query, query->dialog_token, dur);
243 	if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) {
244 		wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination");
245 		return;
246 	}
247 	os_get_reltime(&query->last_oper);
248 
249 	if (result == OFFCHANNEL_SEND_ACTION_SUCCESS ||
250 	    result == OFFCHANNEL_SEND_ACTION_NO_ACK) {
251 		eloop_cancel_timeout(gas_query_timeout, gas, query);
252 		if (result == OFFCHANNEL_SEND_ACTION_NO_ACK) {
253 			wpa_printf(MSG_DEBUG, "GAS: No ACK to GAS request");
254 			eloop_register_timeout(0, 250000,
255 					       gas_query_timeout, gas, query);
256 		} else {
257 			eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
258 					       gas_query_timeout, gas, query);
259 		}
260 		if (query->wait_comeback && !query->retry) {
261 			eloop_cancel_timeout(gas_query_rx_comeback_timeout,
262 					     gas, query);
263 			eloop_register_timeout(
264 				0, (GAS_QUERY_WAIT_TIME_COMEBACK + 10) * 1000,
265 				gas_query_rx_comeback_timeout, gas, query);
266 		}
267 	}
268 	if (result == OFFCHANNEL_SEND_ACTION_FAILED) {
269 		eloop_cancel_timeout(gas_query_timeout, gas, query);
270 		eloop_register_timeout(0, 0, gas_query_timeout, gas, query);
271 	}
272 }
273 
274 
275 int pmf_in_use(struct wpa_supplicant *wpa_s, const u8 *addr)
276 {
277 	if (wpa_s->current_ssid == NULL ||
278 	    wpa_s->wpa_state < WPA_4WAY_HANDSHAKE ||
279 	    os_memcmp(addr, wpa_s->bssid, ETH_ALEN) != 0)
280 		return 0;
281 	return wpa_sm_pmf_enabled(wpa_s->wpa);
282 }
283 
284 
285 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
286 			struct wpabuf *req, unsigned int wait_time)
287 {
288 	int res, prot = pmf_in_use(gas->wpa_s, query->addr);
289 	const u8 *bssid;
290 	const u8 wildcard_bssid[ETH_ALEN] = {
291 		0xff, 0xff, 0xff, 0xff, 0xff, 0xff
292 	};
293 
294 	wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
295 		   "freq=%d prot=%d using src addr " MACSTR,
296 		   MAC2STR(query->addr), (unsigned int) wpabuf_len(req),
297 		   query->freq, prot, MAC2STR(query->sa));
298 	if (prot) {
299 		u8 *categ = wpabuf_mhead_u8(req);
300 		*categ = WLAN_ACTION_PROTECTED_DUAL;
301 	}
302 	os_get_reltime(&query->last_oper);
303 	if (gas->wpa_s->max_remain_on_chan &&
304 	    wait_time > gas->wpa_s->max_remain_on_chan)
305 		wait_time = gas->wpa_s->max_remain_on_chan;
306 	if (!query->wildcard_bssid &&
307 	    (!gas->wpa_s->conf->gas_address3 ||
308 	     (gas->wpa_s->current_ssid &&
309 	      gas->wpa_s->wpa_state >= WPA_ASSOCIATED &&
310 	      os_memcmp(query->addr, gas->wpa_s->bssid, ETH_ALEN) == 0)))
311 		bssid = query->addr;
312 	else
313 		bssid = wildcard_bssid;
314 
315 	res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
316 				     query->sa, bssid, wpabuf_head(req),
317 				     wpabuf_len(req), wait_time,
318 				     gas_query_tx_status, 0);
319 
320 	if (res == 0)
321 		query->offchannel_tx_started = 1;
322 	return res;
323 }
324 
325 
326 static void gas_query_tx_comeback_req(struct gas_query *gas,
327 				      struct gas_query_pending *query)
328 {
329 	struct wpabuf *req;
330 	unsigned int wait_time;
331 
332 	req = gas_build_comeback_req(query->dialog_token);
333 	if (req == NULL) {
334 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
335 		return;
336 	}
337 
338 	wait_time = (query->retry || !query->offchannel_tx_started) ?
339 		GAS_QUERY_WAIT_TIME_INITIAL : GAS_QUERY_WAIT_TIME_COMEBACK;
340 
341 	if (gas_query_tx(gas, query, req, wait_time) < 0) {
342 		wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
343 			   MACSTR, MAC2STR(query->addr));
344 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
345 	}
346 
347 	wpabuf_free(req);
348 }
349 
350 
351 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx)
352 {
353 	struct gas_query *gas = eloop_data;
354 	struct gas_query_pending *query = user_ctx;
355 	int dialog_token;
356 
357 	wpa_printf(MSG_DEBUG,
358 		   "GAS: No response to comeback request received (retry=%u)",
359 		   query->retry);
360 	if (gas->current != query || query->retry)
361 		return;
362 	dialog_token = gas_query_new_dialog_token(gas, query->addr);
363 	if (dialog_token < 0)
364 		return;
365 	wpa_printf(MSG_DEBUG,
366 		   "GAS: Retry GAS query due to comeback response timeout");
367 	query->retry = 1;
368 	query->dialog_token = dialog_token;
369 	*(wpabuf_mhead_u8(query->req) + 2) = dialog_token;
370 	query->wait_comeback = 0;
371 	query->next_frag_id = 0;
372 	wpabuf_free(query->adv_proto);
373 	query->adv_proto = NULL;
374 	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
375 	eloop_cancel_timeout(gas_query_timeout, gas, query);
376 	gas_query_tx_initial_req(gas, query);
377 }
378 
379 
380 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
381 {
382 	struct gas_query *gas = eloop_data;
383 	struct gas_query_pending *query = user_ctx;
384 
385 	wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
386 		   MAC2STR(query->addr));
387 	gas_query_tx_comeback_req(gas, query);
388 }
389 
390 
391 static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
392 					    struct gas_query_pending *query,
393 					    u16 comeback_delay)
394 {
395 	unsigned int secs, usecs;
396 
397 	if (comeback_delay > 1 && query->offchannel_tx_started) {
398 		offchannel_send_action_done(gas->wpa_s);
399 		query->offchannel_tx_started = 0;
400 	}
401 
402 	secs = (comeback_delay * 1024) / 1000000;
403 	usecs = comeback_delay * 1024 - secs * 1000000;
404 	wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
405 		   " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
406 	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
407 	eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
408 			       gas, query);
409 }
410 
411 
412 static void gas_query_rx_initial(struct gas_query *gas,
413 				 struct gas_query_pending *query,
414 				 const u8 *adv_proto, const u8 *resp,
415 				 size_t len, u16 comeback_delay)
416 {
417 	wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
418 		   MACSTR " (dialog_token=%u comeback_delay=%u)",
419 		   MAC2STR(query->addr), query->dialog_token, comeback_delay);
420 
421 	query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]);
422 	if (query->adv_proto == NULL) {
423 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
424 		return;
425 	}
426 
427 	if (comeback_delay) {
428 		eloop_cancel_timeout(gas_query_timeout, gas, query);
429 		query->wait_comeback = 1;
430 		gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
431 		return;
432 	}
433 
434 	/* Query was completed without comeback mechanism */
435 	if (gas_query_append(query, resp, len) < 0) {
436 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
437 		return;
438 	}
439 
440 	gas_query_done(gas, query, GAS_QUERY_SUCCESS);
441 }
442 
443 
444 static void gas_query_rx_comeback(struct gas_query *gas,
445 				  struct gas_query_pending *query,
446 				  const u8 *adv_proto, const u8 *resp,
447 				  size_t len, u8 frag_id, u8 more_frags,
448 				  u16 comeback_delay)
449 {
450 	wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
451 		   MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
452 		   "comeback_delay=%u)",
453 		   MAC2STR(query->addr), query->dialog_token, frag_id,
454 		   more_frags, comeback_delay);
455 	eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
456 
457 	if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) ||
458 	    os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
459 		      wpabuf_len(query->adv_proto)) != 0) {
460 		wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
461 			   "between initial and comeback response from "
462 			   MACSTR, MAC2STR(query->addr));
463 		gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
464 		return;
465 	}
466 
467 	if (comeback_delay) {
468 		if (frag_id) {
469 			wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
470 				   "with non-zero frag_id and comeback_delay "
471 				   "from " MACSTR, MAC2STR(query->addr));
472 			gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
473 			return;
474 		}
475 		gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
476 		return;
477 	}
478 
479 	if (frag_id != query->next_frag_id) {
480 		wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
481 			   "from " MACSTR, MAC2STR(query->addr));
482 		if (frag_id + 1 == query->next_frag_id) {
483 			wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
484 				   "retry of previous fragment");
485 			return;
486 		}
487 		gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
488 		return;
489 	}
490 	query->next_frag_id++;
491 
492 	if (gas_query_append(query, resp, len) < 0) {
493 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
494 		return;
495 	}
496 
497 	if (more_frags) {
498 		gas_query_tx_comeback_req(gas, query);
499 		return;
500 	}
501 
502 	gas_query_done(gas, query, GAS_QUERY_SUCCESS);
503 }
504 
505 
506 /**
507  * gas_query_rx - Indicate reception of a Public Action or Protected Dual frame
508  * @gas: GAS query data from gas_query_init()
509  * @da: Destination MAC address of the Action frame
510  * @sa: Source MAC address of the Action frame
511  * @bssid: BSSID of the Action frame
512  * @categ: Category of the Action frame
513  * @data: Payload of the Action frame
514  * @len: Length of @data
515  * @freq: Frequency (in MHz) on which the frame was received
516  * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
517  */
518 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
519 		 const u8 *bssid, u8 categ, const u8 *data, size_t len,
520 		 int freq)
521 {
522 	struct gas_query_pending *query;
523 	u8 action, dialog_token, frag_id = 0, more_frags = 0;
524 	u16 comeback_delay, resp_len;
525 	const u8 *pos, *adv_proto;
526 	int prot, pmf;
527 	unsigned int left;
528 
529 	if (gas == NULL || len < 4)
530 		return -1;
531 
532 	pos = data;
533 	action = *pos++;
534 	dialog_token = *pos++;
535 
536 	if (action != WLAN_PA_GAS_INITIAL_RESP &&
537 	    action != WLAN_PA_GAS_COMEBACK_RESP)
538 		return -1; /* Not a GAS response */
539 
540 	prot = categ == WLAN_ACTION_PROTECTED_DUAL;
541 	pmf = pmf_in_use(gas->wpa_s, sa);
542 	if (prot && !pmf) {
543 		wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled");
544 		return 0;
545 	}
546 	if (!prot && pmf) {
547 		wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled");
548 		return 0;
549 	}
550 
551 	query = gas_query_get_pending(gas, sa, dialog_token);
552 	if (query == NULL) {
553 		wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR
554 			   " dialog token %u", MAC2STR(sa), dialog_token);
555 		return -1;
556 	}
557 
558 	wpa_printf(MSG_DEBUG, "GAS: Response in %d ms from " MACSTR,
559 		   ms_from_time(&query->last_oper), MAC2STR(sa));
560 
561 	if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) {
562 		wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from "
563 			   MACSTR " dialog token %u when waiting for comeback "
564 			   "response", MAC2STR(sa), dialog_token);
565 		return 0;
566 	}
567 
568 	if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) {
569 		wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from "
570 			   MACSTR " dialog token %u when waiting for initial "
571 			   "response", MAC2STR(sa), dialog_token);
572 		return 0;
573 	}
574 
575 	query->status_code = WPA_GET_LE16(pos);
576 	pos += 2;
577 
578 	if (query->status_code == WLAN_STATUS_QUERY_RESP_OUTSTANDING &&
579 	    action == WLAN_PA_GAS_COMEBACK_RESP) {
580 		wpa_printf(MSG_DEBUG, "GAS: Allow non-zero status for outstanding comeback response");
581 	} else if (query->status_code != WLAN_STATUS_SUCCESS) {
582 		wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token "
583 			   "%u failed - status code %u",
584 			   MAC2STR(sa), dialog_token, query->status_code);
585 		gas_query_done(gas, query, GAS_QUERY_FAILURE);
586 		return 0;
587 	}
588 
589 	if (action == WLAN_PA_GAS_COMEBACK_RESP) {
590 		if (pos + 1 > data + len)
591 			return 0;
592 		frag_id = *pos & 0x7f;
593 		more_frags = (*pos & 0x80) >> 7;
594 		pos++;
595 	}
596 
597 	/* Comeback Delay */
598 	if (pos + 2 > data + len)
599 		return 0;
600 	comeback_delay = WPA_GET_LE16(pos);
601 	pos += 2;
602 
603 	/* Advertisement Protocol element */
604 	if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) {
605 		wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
606 			   "Protocol element in the response from " MACSTR,
607 			   MAC2STR(sa));
608 		return 0;
609 	}
610 
611 	if (*pos != WLAN_EID_ADV_PROTO) {
612 		wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
613 			   "Protocol element ID %u in response from " MACSTR,
614 			   *pos, MAC2STR(sa));
615 		return 0;
616 	}
617 
618 	adv_proto = pos;
619 	pos += 2 + pos[1];
620 
621 	/* Query Response Length */
622 	if (pos + 2 > data + len) {
623 		wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
624 		return 0;
625 	}
626 	resp_len = WPA_GET_LE16(pos);
627 	pos += 2;
628 
629 	left = data + len - pos;
630 	if (resp_len > left) {
631 		wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
632 			   "response from " MACSTR, MAC2STR(sa));
633 		return 0;
634 	}
635 
636 	if (resp_len < left) {
637 		wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
638 			   "after Query Response from " MACSTR,
639 			   left - resp_len, MAC2STR(sa));
640 	}
641 
642 	if (action == WLAN_PA_GAS_COMEBACK_RESP)
643 		gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len,
644 				      frag_id, more_frags, comeback_delay);
645 	else
646 		gas_query_rx_initial(gas, query, adv_proto, pos, resp_len,
647 				     comeback_delay);
648 
649 	return 0;
650 }
651 
652 
653 static void gas_query_timeout(void *eloop_data, void *user_ctx)
654 {
655 	struct gas_query *gas = eloop_data;
656 	struct gas_query_pending *query = user_ctx;
657 
658 	wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
659 		   " dialog token %u",
660 		   MAC2STR(query->addr), query->dialog_token);
661 	gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
662 }
663 
664 
665 static int gas_query_dialog_token_available(struct gas_query *gas,
666 					    const u8 *dst, u8 dialog_token)
667 {
668 	struct gas_query_pending *q;
669 	dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
670 		if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 &&
671 		    dialog_token == q->dialog_token)
672 			return 0;
673 	}
674 
675 	return 1;
676 }
677 
678 
679 static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
680 {
681 	struct gas_query_pending *query = work->ctx;
682 	struct gas_query *gas = query->gas;
683 	struct wpa_supplicant *wpa_s = gas->wpa_s;
684 
685 	if (deinit) {
686 		if (work->started) {
687 			gas->work = NULL;
688 			gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
689 			return;
690 		}
691 
692 		gas_query_free(query, 1);
693 		return;
694 	}
695 
696 	if (wpas_update_random_addr_disassoc(wpa_s) < 0) {
697 		wpa_msg(wpa_s, MSG_INFO,
698 			"Failed to assign random MAC address for GAS");
699 		gas_query_free(query, 1);
700 		radio_work_done(work);
701 		return;
702 	}
703 
704 	gas->work = work;
705 	gas_query_tx_initial_req(gas, query);
706 }
707 
708 
709 static void gas_query_tx_initial_req(struct gas_query *gas,
710 				     struct gas_query_pending *query)
711 {
712 	if (gas_query_tx(gas, query, query->req,
713 			 GAS_QUERY_WAIT_TIME_INITIAL) < 0) {
714 		wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
715 			   MACSTR, MAC2STR(query->addr));
716 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
717 		return;
718 	}
719 	gas->current = query;
720 
721 	wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
722 		   query->dialog_token);
723 	eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
724 			       gas_query_timeout, gas, query);
725 }
726 
727 
728 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst)
729 {
730 	static int next_start = 0;
731 	int dialog_token;
732 
733 	for (dialog_token = 0; dialog_token < 256; dialog_token++) {
734 		if (gas_query_dialog_token_available(
735 			    gas, dst, (next_start + dialog_token) % 256))
736 			break;
737 	}
738 	if (dialog_token == 256)
739 		return -1; /* Too many pending queries */
740 	dialog_token = (next_start + dialog_token) % 256;
741 	next_start = (dialog_token + 1) % 256;
742 	return dialog_token;
743 }
744 
745 
746 static int gas_query_set_sa(struct gas_query *gas,
747 			    struct gas_query_pending *query)
748 {
749 	struct wpa_supplicant *wpa_s = gas->wpa_s;
750 	struct os_reltime now;
751 
752 	if (!wpa_s->conf->gas_rand_mac_addr ||
753 	    !(wpa_s->current_bss ?
754 	      (wpa_s->drv_flags &
755 	       WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA_CONNECTED) :
756 	      (wpa_s->drv_flags & WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA))) {
757 		/* Use own MAC address as the transmitter address */
758 		os_memcpy(query->sa, wpa_s->own_addr, ETH_ALEN);
759 		return 0;
760 	}
761 
762 	os_get_reltime(&now);
763 
764 	if (wpa_s->conf->gas_rand_mac_addr == gas->last_rand_sa_type &&
765 	    gas->last_mac_addr_rand.sec != 0 &&
766 	    !os_reltime_expired(&now, &gas->last_mac_addr_rand,
767 				wpa_s->conf->gas_rand_addr_lifetime)) {
768 		wpa_printf(MSG_DEBUG,
769 			   "GAS: Use the previously selected random transmitter address "
770 			   MACSTR, MAC2STR(gas->rand_addr));
771 		os_memcpy(query->sa, gas->rand_addr, ETH_ALEN);
772 		return 0;
773 	}
774 
775 	if (wpa_s->conf->gas_rand_mac_addr == 1 &&
776 	    random_mac_addr(gas->rand_addr) < 0) {
777 		wpa_printf(MSG_ERROR, "GAS: Failed to get random address");
778 		return -1;
779 	}
780 
781 	if (wpa_s->conf->gas_rand_mac_addr == 2 &&
782 	    random_mac_addr_keep_oui(gas->rand_addr) < 0) {
783 		wpa_printf(MSG_ERROR,
784 			   "GAS: Failed to get random address with same OUI");
785 		return -1;
786 	}
787 
788 	wpa_printf(MSG_DEBUG, "GAS: Use a new random transmitter address "
789 		   MACSTR, MAC2STR(gas->rand_addr));
790 	os_memcpy(query->sa, gas->rand_addr, ETH_ALEN);
791 	os_get_reltime(&gas->last_mac_addr_rand);
792 	gas->last_rand_sa_type = wpa_s->conf->gas_rand_mac_addr;
793 
794 	return 0;
795 }
796 
797 
798 /**
799  * gas_query_req - Request a GAS query
800  * @gas: GAS query data from gas_query_init()
801  * @dst: Destination MAC address for the query
802  * @freq: Frequency (in MHz) for the channel on which to send the query
803  * @req: GAS query payload (to be freed by gas_query module in case of success
804  *	return)
805  * @cb: Callback function for reporting GAS query result and response
806  * @ctx: Context pointer to use with the @cb call
807  * Returns: dialog token (>= 0) on success or -1 on failure
808  */
809 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
810 		  int wildcard_bssid, struct wpabuf *req,
811 		  void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
812 			     enum gas_query_result result,
813 			     const struct wpabuf *adv_proto,
814 			     const struct wpabuf *resp, u16 status_code),
815 		  void *ctx)
816 {
817 	struct gas_query_pending *query;
818 	int dialog_token;
819 
820 	if (wpabuf_len(req) < 3)
821 		return -1;
822 
823 	dialog_token = gas_query_new_dialog_token(gas, dst);
824 	if (dialog_token < 0)
825 		return -1;
826 
827 	query = os_zalloc(sizeof(*query));
828 	if (query == NULL)
829 		return -1;
830 
831 	query->gas = gas;
832 	if (gas_query_set_sa(gas, query)) {
833 		os_free(query);
834 		return -1;
835 	}
836 	os_memcpy(query->addr, dst, ETH_ALEN);
837 	query->dialog_token = dialog_token;
838 	query->wildcard_bssid = !!wildcard_bssid;
839 	query->freq = freq;
840 	query->cb = cb;
841 	query->ctx = ctx;
842 	query->req = req;
843 	dl_list_add(&gas->pending, &query->list);
844 
845 	*(wpabuf_mhead_u8(req) + 2) = dialog_token;
846 
847 	wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
848 		" dialog_token=%u freq=%d",
849 		MAC2STR(query->addr), query->dialog_token, query->freq);
850 
851 	if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
852 			   query) < 0) {
853 		query->req = NULL; /* caller will free this in error case */
854 		gas_query_free(query, 1);
855 		return -1;
856 	}
857 
858 	return dialog_token;
859 }
860 
861 
862 int gas_query_stop(struct gas_query *gas, u8 dialog_token)
863 {
864 	struct gas_query_pending *query;
865 
866 	dl_list_for_each(query, &gas->pending, struct gas_query_pending, list) {
867 		if (query->dialog_token == dialog_token) {
868 			if (!gas->work) {
869 				/* The pending radio work has not yet been
870 				 * started, but the pending entry has a
871 				 * reference to the soon to be freed query.
872 				 * Need to remove that radio work now to avoid
873 				 * leaving behind a reference to freed memory.
874 				 */
875 				radio_remove_pending_work(gas->wpa_s, query);
876 			}
877 			gas_query_done(gas, query, GAS_QUERY_STOPPED);
878 			return 0;
879 		}
880 	}
881 
882 	return -1;
883 }
884