xref: /freebsd/contrib/wpa/wpa_supplicant/gas_query.c (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
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 #define GAS_QUERY_MAX_COMEBACK_DELAY 60000
34 
35 /**
36  * struct gas_query_pending - Pending GAS query
37  */
38 struct gas_query_pending {
39 	struct dl_list list;
40 	struct gas_query *gas;
41 	u8 addr[ETH_ALEN];
42 	u8 dialog_token;
43 	u8 next_frag_id;
44 	unsigned int wait_comeback:1;
45 	unsigned int offchannel_tx_started:1;
46 	unsigned int retry:1;
47 	unsigned int wildcard_bssid:1;
48 	unsigned int maintain_addr:1;
49 	int freq;
50 	u16 status_code;
51 	struct wpabuf *req;
52 	struct wpabuf *adv_proto;
53 	struct wpabuf *resp;
54 	struct os_reltime last_oper;
55 	void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
56 		   enum gas_query_result result,
57 		   const struct wpabuf *adv_proto,
58 		   const struct wpabuf *resp, u16 status_code);
59 	void *ctx;
60 	u8 sa[ETH_ALEN];
61 };
62 
63 /**
64  * struct gas_query - Internal GAS query data
65  */
66 struct gas_query {
67 	struct wpa_supplicant *wpa_s;
68 	struct dl_list pending; /* struct gas_query_pending */
69 	struct gas_query_pending *current;
70 	struct wpa_radio_work *work;
71 	struct os_reltime last_mac_addr_rand;
72 	int last_rand_sa_type;
73 	u8 rand_addr[ETH_ALEN];
74 };
75 
76 
77 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx);
78 static void gas_query_timeout(void *eloop_data, void *user_ctx);
79 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx);
80 static void gas_query_tx_initial_req(struct gas_query *gas,
81 				     struct gas_query_pending *query);
82 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst);
83 
84 
85 static int ms_from_time(struct os_reltime *last)
86 {
87 	struct os_reltime now, res;
88 
89 	os_get_reltime(&now);
90 	os_reltime_sub(&now, last, &res);
91 	return res.sec * 1000 + res.usec / 1000;
92 }
93 
94 
95 /**
96  * gas_query_init - Initialize GAS query component
97  * @wpa_s: Pointer to wpa_supplicant data
98  * Returns: Pointer to GAS query data or %NULL on failure
99  */
100 struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s)
101 {
102 	struct gas_query *gas;
103 
104 	gas = os_zalloc(sizeof(*gas));
105 	if (gas == NULL)
106 		return NULL;
107 
108 	gas->wpa_s = wpa_s;
109 	dl_list_init(&gas->pending);
110 
111 	return gas;
112 }
113 
114 
115 static const char * gas_result_txt(enum gas_query_result result)
116 {
117 	switch (result) {
118 	case GAS_QUERY_SUCCESS:
119 		return "SUCCESS";
120 	case GAS_QUERY_FAILURE:
121 		return "FAILURE";
122 	case GAS_QUERY_TIMEOUT:
123 		return "TIMEOUT";
124 	case GAS_QUERY_PEER_ERROR:
125 		return "PEER_ERROR";
126 	case GAS_QUERY_INTERNAL_ERROR:
127 		return "INTERNAL_ERROR";
128 	case GAS_QUERY_STOPPED:
129 		return "STOPPED";
130 	case GAS_QUERY_DELETED_AT_DEINIT:
131 		return "DELETED_AT_DEINIT";
132 	}
133 
134 	return "N/A";
135 }
136 
137 
138 static void gas_query_free(struct gas_query_pending *query, int del_list)
139 {
140 	struct gas_query *gas = query->gas;
141 
142 	if (del_list)
143 		dl_list_del(&query->list);
144 
145 	if (gas->work && gas->work->ctx == query) {
146 		radio_work_done(gas->work);
147 		gas->work = NULL;
148 	}
149 
150 	wpabuf_free(query->req);
151 	wpabuf_free(query->adv_proto);
152 	wpabuf_free(query->resp);
153 	os_free(query);
154 }
155 
156 
157 static void gas_query_done(struct gas_query *gas,
158 			   struct gas_query_pending *query,
159 			   enum gas_query_result result)
160 {
161 	wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR
162 		" dialog_token=%u freq=%d status_code=%u result=%s",
163 		MAC2STR(query->addr), query->dialog_token, query->freq,
164 		query->status_code, gas_result_txt(result));
165 	if (gas->current == query)
166 		gas->current = NULL;
167 	if (query->offchannel_tx_started)
168 		offchannel_send_action_done(gas->wpa_s);
169 	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
170 	eloop_cancel_timeout(gas_query_timeout, gas, query);
171 	eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
172 	dl_list_del(&query->list);
173 	query->cb(query->ctx, query->addr, query->dialog_token, result,
174 		  query->adv_proto, query->resp, query->status_code);
175 	gas_query_free(query, 0);
176 }
177 
178 
179 /**
180  * gas_query_deinit - Deinitialize GAS query component
181  * @gas: GAS query data from gas_query_init()
182  */
183 void gas_query_deinit(struct gas_query *gas)
184 {
185 	struct gas_query_pending *query, *next;
186 
187 	if (gas == NULL)
188 		return;
189 
190 	dl_list_for_each_safe(query, next, &gas->pending,
191 			      struct gas_query_pending, list)
192 		gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
193 
194 	os_free(gas);
195 }
196 
197 
198 static struct gas_query_pending *
199 gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token)
200 {
201 	struct gas_query_pending *q;
202 	struct wpa_supplicant *wpa_s = gas->wpa_s;
203 
204 	dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
205 		if (ether_addr_equal(q->addr, addr) &&
206 		    q->dialog_token == dialog_token)
207 			return q;
208 		if (wpa_s->valid_links &&
209 		    ether_addr_equal(wpa_s->ap_mld_addr, addr) &&
210 		    wpas_ap_link_address(wpa_s, q->addr))
211 			return q;
212 	}
213 	return NULL;
214 }
215 
216 
217 static int gas_query_append(struct gas_query_pending *query, const u8 *data,
218 			    size_t len)
219 {
220 	if (wpabuf_resize(&query->resp, len) < 0) {
221 		wpa_printf(MSG_DEBUG, "GAS: No memory to store the response");
222 		return -1;
223 	}
224 	wpabuf_put_data(query->resp, data, len);
225 	return 0;
226 }
227 
228 
229 static void gas_query_tx_status(struct wpa_supplicant *wpa_s,
230 				unsigned int freq, const u8 *dst,
231 				const u8 *src, const u8 *bssid,
232 				const u8 *data, size_t data_len,
233 				enum offchannel_send_action_result result)
234 {
235 	struct gas_query_pending *query;
236 	struct gas_query *gas = wpa_s->gas;
237 	int dur;
238 
239 	if (gas->current == NULL) {
240 		wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: freq=%u dst="
241 			   MACSTR " result=%d - no query in progress",
242 			   freq, MAC2STR(dst), result);
243 		return;
244 	}
245 
246 	query = gas->current;
247 
248 	dur = ms_from_time(&query->last_oper);
249 	wpa_printf(MSG_DEBUG, "GAS: TX status: freq=%u dst=" MACSTR
250 		   " result=%d query=%p dialog_token=%u dur=%d ms",
251 		   freq, MAC2STR(dst), result, query, query->dialog_token, dur);
252 	if (!ether_addr_equal(dst, query->addr)) {
253 		wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination");
254 		return;
255 	}
256 	os_get_reltime(&query->last_oper);
257 
258 	if (result == OFFCHANNEL_SEND_ACTION_SUCCESS ||
259 	    result == OFFCHANNEL_SEND_ACTION_NO_ACK) {
260 		eloop_cancel_timeout(gas_query_timeout, gas, query);
261 		if (result == OFFCHANNEL_SEND_ACTION_NO_ACK) {
262 			wpa_printf(MSG_DEBUG, "GAS: No ACK to GAS request");
263 			eloop_register_timeout(0, 250000,
264 					       gas_query_timeout, gas, query);
265 		} else {
266 			eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
267 					       gas_query_timeout, gas, query);
268 		}
269 		if (query->wait_comeback && !query->retry) {
270 			eloop_cancel_timeout(gas_query_rx_comeback_timeout,
271 					     gas, query);
272 			eloop_register_timeout(
273 				0, (GAS_QUERY_WAIT_TIME_COMEBACK + 10) * 1000,
274 				gas_query_rx_comeback_timeout, gas, query);
275 		}
276 	}
277 	if (result == OFFCHANNEL_SEND_ACTION_FAILED) {
278 		eloop_cancel_timeout(gas_query_timeout, gas, query);
279 		eloop_register_timeout(0, 0, gas_query_timeout, gas, query);
280 	}
281 }
282 
283 
284 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
285 			struct wpabuf *req, unsigned int wait_time)
286 {
287 	int res, prot = pmf_in_use(gas->wpa_s, query->addr);
288 	const u8 *bssid;
289 	const u8 wildcard_bssid[ETH_ALEN] = {
290 		0xff, 0xff, 0xff, 0xff, 0xff, 0xff
291 	};
292 
293 	wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
294 		   "freq=%d prot=%d using src addr " MACSTR,
295 		   MAC2STR(query->addr), (unsigned int) wpabuf_len(req),
296 		   query->freq, prot, MAC2STR(query->sa));
297 	if (prot) {
298 		u8 *categ = wpabuf_mhead_u8(req);
299 		*categ = WLAN_ACTION_PROTECTED_DUAL;
300 	}
301 	os_get_reltime(&query->last_oper);
302 	if (gas->wpa_s->max_remain_on_chan &&
303 	    wait_time > gas->wpa_s->max_remain_on_chan)
304 		wait_time = gas->wpa_s->max_remain_on_chan;
305 	if (!query->wildcard_bssid &&
306 	    (!gas->wpa_s->conf->gas_address3 ||
307 	     (gas->wpa_s->current_ssid &&
308 	      gas->wpa_s->wpa_state >= WPA_ASSOCIATED &&
309 	      ether_addr_equal(query->addr, gas->wpa_s->bssid))))
310 		bssid = query->addr;
311 	else
312 		bssid = wildcard_bssid;
313 
314 	res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
315 				     query->sa, bssid, wpabuf_head(req),
316 				     wpabuf_len(req), wait_time,
317 				     gas_query_tx_status, 0);
318 
319 	if (res == 0)
320 		query->offchannel_tx_started = 1;
321 	return res;
322 }
323 
324 
325 static void gas_query_tx_comeback_req(struct gas_query *gas,
326 				      struct gas_query_pending *query)
327 {
328 	struct wpabuf *req;
329 	unsigned int wait_time;
330 
331 	req = gas_build_comeback_req(query->dialog_token);
332 	if (req == NULL) {
333 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
334 		return;
335 	}
336 
337 	wait_time = (query->retry || !query->offchannel_tx_started) ?
338 		GAS_QUERY_WAIT_TIME_INITIAL : GAS_QUERY_WAIT_TIME_COMEBACK;
339 
340 	if (gas_query_tx(gas, query, req, wait_time) < 0) {
341 		wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
342 			   MACSTR, MAC2STR(query->addr));
343 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
344 	}
345 
346 	wpabuf_free(req);
347 }
348 
349 
350 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx)
351 {
352 	struct gas_query *gas = eloop_data;
353 	struct gas_query_pending *query = user_ctx;
354 	int dialog_token;
355 
356 	wpa_printf(MSG_DEBUG,
357 		   "GAS: No response to comeback request received (retry=%u)",
358 		   query->retry);
359 	if (gas->current != query || query->retry)
360 		return;
361 	dialog_token = gas_query_new_dialog_token(gas, query->addr);
362 	if (dialog_token < 0)
363 		return;
364 	wpa_printf(MSG_DEBUG,
365 		   "GAS: Retry GAS query due to comeback response timeout");
366 	query->retry = 1;
367 	query->dialog_token = dialog_token;
368 	*(wpabuf_mhead_u8(query->req) + 2) = dialog_token;
369 	query->wait_comeback = 0;
370 	query->next_frag_id = 0;
371 	wpabuf_free(query->adv_proto);
372 	query->adv_proto = NULL;
373 	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
374 	eloop_cancel_timeout(gas_query_timeout, gas, query);
375 	gas_query_tx_initial_req(gas, query);
376 }
377 
378 
379 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
380 {
381 	struct gas_query *gas = eloop_data;
382 	struct gas_query_pending *query = user_ctx;
383 
384 	wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
385 		   MAC2STR(query->addr));
386 	gas_query_tx_comeback_req(gas, query);
387 }
388 
389 
390 static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
391 					    struct gas_query_pending *query,
392 					    u16 comeback_delay)
393 {
394 	unsigned int secs, usecs;
395 
396 	if (comeback_delay > 1 && query->offchannel_tx_started) {
397 		offchannel_send_action_done(gas->wpa_s);
398 		query->offchannel_tx_started = 0;
399 	}
400 
401 	secs = (comeback_delay * 1024) / 1000000;
402 	usecs = comeback_delay * 1024 - secs * 1000000;
403 	wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
404 		   " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
405 	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
406 	eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
407 			       gas, query);
408 }
409 
410 
411 static void gas_query_rx_initial(struct gas_query *gas,
412 				 struct gas_query_pending *query,
413 				 const u8 *adv_proto, size_t adv_proto_len,
414 				 const u8 *resp, size_t len, u16 comeback_delay)
415 {
416 	wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
417 		   MACSTR " (dialog_token=%u comeback_delay=%u)",
418 		   MAC2STR(query->addr), query->dialog_token, comeback_delay);
419 
420 	query->adv_proto = wpabuf_alloc_copy(adv_proto, adv_proto_len);
421 	if (query->adv_proto == NULL) {
422 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
423 		return;
424 	}
425 
426 	if (comeback_delay) {
427 		eloop_cancel_timeout(gas_query_timeout, gas, query);
428 		query->wait_comeback = 1;
429 		gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
430 		return;
431 	}
432 
433 	/* Query was completed without comeback mechanism */
434 	if (gas_query_append(query, resp, len) < 0) {
435 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
436 		return;
437 	}
438 
439 	gas_query_done(gas, query, GAS_QUERY_SUCCESS);
440 }
441 
442 
443 static void gas_query_rx_comeback(struct gas_query *gas,
444 				  struct gas_query_pending *query,
445 				  const u8 *adv_proto, size_t adv_proto_len,
446 				  const u8 *resp, size_t len, u8 frag_id,
447 				  u8 more_frags, u16 comeback_delay)
448 {
449 	wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
450 		   MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
451 		   "comeback_delay=%u)",
452 		   MAC2STR(query->addr), query->dialog_token, frag_id,
453 		   more_frags, comeback_delay);
454 	eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
455 
456 	if (adv_proto_len != wpabuf_len(query->adv_proto) ||
457 	    os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
458 		      wpabuf_len(query->adv_proto)) != 0) {
459 		wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
460 			   "between initial and comeback response from "
461 			   MACSTR, MAC2STR(query->addr));
462 		gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
463 		return;
464 	}
465 
466 	if (comeback_delay) {
467 		if (frag_id) {
468 			wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
469 				   "with non-zero frag_id and comeback_delay "
470 				   "from " MACSTR, MAC2STR(query->addr));
471 			gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
472 			return;
473 		}
474 		gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
475 		return;
476 	}
477 
478 	if (frag_id != query->next_frag_id) {
479 		wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
480 			   "from " MACSTR, MAC2STR(query->addr));
481 		if (frag_id + 1 == query->next_frag_id) {
482 			wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
483 				   "retry of previous fragment");
484 			return;
485 		}
486 		gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
487 		return;
488 	}
489 	query->next_frag_id++;
490 
491 	if (gas_query_append(query, resp, len) < 0) {
492 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
493 		return;
494 	}
495 
496 	if (more_frags) {
497 		gas_query_tx_comeback_req(gas, query);
498 		return;
499 	}
500 
501 	gas_query_done(gas, query, GAS_QUERY_SUCCESS);
502 }
503 
504 
505 /**
506  * gas_query_rx - Indicate reception of a Public Action or Protected Dual frame
507  * @gas: GAS query data from gas_query_init()
508  * @da: Destination MAC address of the Action frame
509  * @sa: Source MAC address of the Action frame
510  * @bssid: BSSID of the Action frame
511  * @categ: Category of the Action frame
512  * @data: Payload of the Action frame
513  * @len: Length of @data
514  * @freq: Frequency (in MHz) on which the frame was received
515  * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
516  */
517 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
518 		 const u8 *bssid, u8 categ, const u8 *data, size_t len,
519 		 int freq)
520 {
521 	struct gas_query_pending *query;
522 	u8 action, dialog_token, frag_id = 0, more_frags = 0;
523 	u16 comeback_delay, resp_len;
524 	const u8 *pos, *adv_proto;
525 	size_t adv_proto_len;
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 	if (comeback_delay > GAS_QUERY_MAX_COMEBACK_DELAY)
602 		comeback_delay = GAS_QUERY_MAX_COMEBACK_DELAY;
603 	pos += 2;
604 
605 	/* Advertisement Protocol element */
606 	adv_proto = pos;
607 	left = data + len - adv_proto;
608 	if (left < 2 || adv_proto[1] > left - 2) {
609 		wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
610 			   "Protocol element in the response from " MACSTR,
611 			   MAC2STR(sa));
612 		return 0;
613 	}
614 
615 	if (*adv_proto != WLAN_EID_ADV_PROTO) {
616 		wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
617 			   "Protocol element ID %u in response from " MACSTR,
618 			   *adv_proto, MAC2STR(sa));
619 		return 0;
620 	}
621 	adv_proto_len = 2 + adv_proto[1];
622 	if (adv_proto_len > (size_t) (data + len - pos))
623 		return 0; /* unreachable due to an earlier check */
624 
625 	pos += adv_proto_len;
626 
627 	/* Query Response Length */
628 	if (pos + 2 > data + len) {
629 		wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
630 		return 0;
631 	}
632 	resp_len = WPA_GET_LE16(pos);
633 	pos += 2;
634 
635 	left = data + len - pos;
636 	if (resp_len > left) {
637 		wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
638 			   "response from " MACSTR, MAC2STR(sa));
639 		return 0;
640 	}
641 
642 	if (resp_len < left) {
643 		wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
644 			   "after Query Response from " MACSTR,
645 			   left - resp_len, MAC2STR(sa));
646 	}
647 
648 	if (action == WLAN_PA_GAS_COMEBACK_RESP)
649 		gas_query_rx_comeback(gas, query, adv_proto, adv_proto_len,
650 				      pos, resp_len, frag_id, more_frags,
651 				      comeback_delay);
652 	else
653 		gas_query_rx_initial(gas, query, adv_proto, adv_proto_len,
654 				     pos, resp_len, comeback_delay);
655 
656 	return 0;
657 }
658 
659 
660 static void gas_query_timeout(void *eloop_data, void *user_ctx)
661 {
662 	struct gas_query *gas = eloop_data;
663 	struct gas_query_pending *query = user_ctx;
664 
665 	wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
666 		   " dialog token %u",
667 		   MAC2STR(query->addr), query->dialog_token);
668 	gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
669 }
670 
671 
672 static int gas_query_dialog_token_available(struct gas_query *gas,
673 					    const u8 *dst, u8 dialog_token)
674 {
675 	struct gas_query_pending *q;
676 	dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
677 		if (ether_addr_equal(dst, q->addr) &&
678 		    dialog_token == q->dialog_token)
679 			return 0;
680 	}
681 
682 	return 1;
683 }
684 
685 
686 static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
687 {
688 	struct gas_query_pending *query = work->ctx;
689 	struct gas_query *gas = query->gas;
690 	struct wpa_supplicant *wpa_s = gas->wpa_s;
691 
692 	if (deinit) {
693 		if (work->started) {
694 			gas->work = NULL;
695 			gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
696 			return;
697 		}
698 
699 		gas_query_free(query, 1);
700 		return;
701 	}
702 
703 	if (!query->maintain_addr && !wpa_s->conf->gas_rand_mac_addr) {
704 		if (wpas_update_random_addr_disassoc(wpa_s) < 0) {
705 			wpa_msg(wpa_s, MSG_INFO,
706 				"Failed to assign random MAC address for GAS");
707 			gas_query_free(query, 1);
708 			radio_work_done(work);
709 			return;
710 		}
711 		os_memcpy(query->sa, wpa_s->own_addr, ETH_ALEN);
712 	}
713 
714 	gas->work = work;
715 	gas_query_tx_initial_req(gas, query);
716 }
717 
718 
719 static void gas_query_tx_initial_req(struct gas_query *gas,
720 				     struct gas_query_pending *query)
721 {
722 	if (gas_query_tx(gas, query, query->req,
723 			 GAS_QUERY_WAIT_TIME_INITIAL) < 0) {
724 		wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
725 			   MACSTR, MAC2STR(query->addr));
726 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
727 		return;
728 	}
729 	gas->current = query;
730 
731 	wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
732 		   query->dialog_token);
733 	eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
734 			       gas_query_timeout, gas, query);
735 }
736 
737 
738 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst)
739 {
740 	u8 dialog_token;
741 	int i;
742 
743 	/* There should never be more than couple active GAS queries in
744 	 * progress, so it should be very likely to find an available dialog
745 	 * token by checking random values. Use a limit on the number of
746 	 * iterations to handle the unexpected case of large number of pending
747 	 * queries cleanly. */
748 	for (i = 0; i < 256; i++) {
749 		/* Get a random number and check if the slot is available */
750 		if (os_get_random(&dialog_token, sizeof(dialog_token)) < 0)
751 			break;
752 		if (gas_query_dialog_token_available(gas, dst, dialog_token))
753 			return dialog_token;
754 	}
755 
756 	/* No dialog token value available */
757 	return -1;
758 }
759 
760 
761 static int gas_query_set_sa(struct gas_query *gas,
762 			    struct gas_query_pending *query)
763 {
764 	struct wpa_supplicant *wpa_s = gas->wpa_s;
765 	struct os_reltime now;
766 
767 	if (query->maintain_addr ||
768 	    !wpa_s->conf->gas_rand_mac_addr ||
769 	    !(wpa_s->current_bss ?
770 	      (wpa_s->drv_flags &
771 	       WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA_CONNECTED) :
772 	      (wpa_s->drv_flags & WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA))) {
773 		/* Use own MAC address as the transmitter address */
774 		wpa_printf(MSG_DEBUG,
775 			   "GAS: Use own MAC address as the transmitter address%s%s%s",
776 			   query->maintain_addr ? " (maintain_addr)" : "",
777 			   !wpa_s->conf->gas_rand_mac_addr ? " (no gas_rand_mac_adr set)" : "",
778 			   !(wpa_s->current_bss ?
779 			     (wpa_s->drv_flags &
780 			      WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA_CONNECTED) :
781 			     (wpa_s->drv_flags &
782 			      WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA)) ?
783 			   " (no driver rand capa" : "");
784 		os_memcpy(query->sa, wpa_s->own_addr, ETH_ALEN);
785 		return 0;
786 	}
787 
788 	os_get_reltime(&now);
789 
790 	if (wpa_s->conf->gas_rand_mac_addr == gas->last_rand_sa_type &&
791 	    gas->last_mac_addr_rand.sec != 0 &&
792 	    !os_reltime_expired(&now, &gas->last_mac_addr_rand,
793 				wpa_s->conf->gas_rand_addr_lifetime)) {
794 		wpa_printf(MSG_DEBUG,
795 			   "GAS: Use the previously selected random transmitter address "
796 			   MACSTR, MAC2STR(gas->rand_addr));
797 		os_memcpy(query->sa, gas->rand_addr, ETH_ALEN);
798 		return 0;
799 	}
800 
801 	if (wpa_s->conf->gas_rand_mac_addr == 1 &&
802 	    random_mac_addr(gas->rand_addr) < 0) {
803 		wpa_printf(MSG_ERROR, "GAS: Failed to get random address");
804 		return -1;
805 	}
806 
807 	if (wpa_s->conf->gas_rand_mac_addr == 2 &&
808 	    random_mac_addr_keep_oui(gas->rand_addr) < 0) {
809 		wpa_printf(MSG_ERROR,
810 			   "GAS: Failed to get random address with same OUI");
811 		return -1;
812 	}
813 
814 	wpa_printf(MSG_DEBUG, "GAS: Use a new random transmitter address "
815 		   MACSTR, MAC2STR(gas->rand_addr));
816 	os_memcpy(query->sa, gas->rand_addr, ETH_ALEN);
817 	os_get_reltime(&gas->last_mac_addr_rand);
818 	gas->last_rand_sa_type = wpa_s->conf->gas_rand_mac_addr;
819 
820 	return 0;
821 }
822 
823 
824 /**
825  * gas_query_req - Request a GAS query
826  * @gas: GAS query data from gas_query_init()
827  * @dst: Destination MAC address for the query
828  * @freq: Frequency (in MHz) for the channel on which to send the query
829  * @wildcard_bssid: Force use of wildcard BSSID value
830  * @maintain_addr: Maintain own MAC address for exchange (i.e., ignore MAC
831  *	address randomization rules)
832  * @req: GAS query payload (to be freed by gas_query module in case of success
833  *	return)
834  * @cb: Callback function for reporting GAS query result and response
835  * @ctx: Context pointer to use with the @cb call
836  * Returns: dialog token (>= 0) on success or -1 on failure
837  */
838 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
839 		  int wildcard_bssid, int maintain_addr, struct wpabuf *req,
840 		  void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
841 			     enum gas_query_result result,
842 			     const struct wpabuf *adv_proto,
843 			     const struct wpabuf *resp, u16 status_code),
844 		  void *ctx)
845 {
846 	struct gas_query_pending *query;
847 	int dialog_token;
848 
849 	if (wpabuf_len(req) < 3)
850 		return -1;
851 
852 	dialog_token = gas_query_new_dialog_token(gas, dst);
853 	if (dialog_token < 0)
854 		return -1;
855 
856 	query = os_zalloc(sizeof(*query));
857 	if (query == NULL)
858 		return -1;
859 
860 	query->gas = gas;
861 	query->maintain_addr = !!maintain_addr;
862 	if (gas_query_set_sa(gas, query)) {
863 		os_free(query);
864 		return -1;
865 	}
866 	os_memcpy(query->addr, dst, ETH_ALEN);
867 	query->dialog_token = dialog_token;
868 	query->wildcard_bssid = !!wildcard_bssid;
869 	query->freq = freq;
870 	query->cb = cb;
871 	query->ctx = ctx;
872 	query->req = req;
873 	dl_list_add(&gas->pending, &query->list);
874 
875 	*(wpabuf_mhead_u8(req) + 2) = dialog_token;
876 
877 	wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
878 		" dialog_token=%u freq=%d",
879 		MAC2STR(query->addr), query->dialog_token, query->freq);
880 
881 	if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
882 			   query) < 0) {
883 		query->req = NULL; /* caller will free this in error case */
884 		gas_query_free(query, 1);
885 		return -1;
886 	}
887 
888 	return dialog_token;
889 }
890 
891 
892 int gas_query_stop(struct gas_query *gas, u8 dialog_token)
893 {
894 	struct gas_query_pending *query;
895 
896 	dl_list_for_each(query, &gas->pending, struct gas_query_pending, list) {
897 		if (query->dialog_token == dialog_token) {
898 			if (!gas->work) {
899 				/* The pending radio work has not yet been
900 				 * started, but the pending entry has a
901 				 * reference to the soon to be freed query.
902 				 * Need to remove that radio work now to avoid
903 				 * leaving behind a reference to freed memory.
904 				 */
905 				radio_remove_pending_work(gas->wpa_s, query);
906 			}
907 			gas_query_done(gas, query, GAS_QUERY_STOPPED);
908 			return 0;
909 		}
910 	}
911 
912 	return -1;
913 }
914