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 "driver_i.h"
21 #include "offchannel.h"
22 #include "gas_query.h"
23 
24 
25 /** GAS query timeout in seconds */
26 #define GAS_QUERY_TIMEOUT_PERIOD 2
27 
28 
29 /**
30  * struct gas_query_pending - Pending GAS query
31  */
32 struct gas_query_pending {
33 	struct dl_list list;
34 	struct gas_query *gas;
35 	u8 addr[ETH_ALEN];
36 	u8 dialog_token;
37 	u8 next_frag_id;
38 	unsigned int wait_comeback:1;
39 	unsigned int offchannel_tx_started:1;
40 	int freq;
41 	u16 status_code;
42 	struct wpabuf *req;
43 	struct wpabuf *adv_proto;
44 	struct wpabuf *resp;
45 	struct os_reltime last_oper;
46 	void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
47 		   enum gas_query_result result,
48 		   const struct wpabuf *adv_proto,
49 		   const struct wpabuf *resp, u16 status_code);
50 	void *ctx;
51 };
52 
53 /**
54  * struct gas_query - Internal GAS query data
55  */
56 struct gas_query {
57 	struct wpa_supplicant *wpa_s;
58 	struct dl_list pending; /* struct gas_query_pending */
59 	struct gas_query_pending *current;
60 	struct wpa_radio_work *work;
61 };
62 
63 
64 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx);
65 static void gas_query_timeout(void *eloop_data, void *user_ctx);
66 
67 
ms_from_time(struct os_reltime * last)68 static int ms_from_time(struct os_reltime *last)
69 {
70 	struct os_reltime now, res;
71 
72 	os_get_reltime(&now);
73 	os_reltime_sub(&now, last, &res);
74 	return res.sec * 1000 + res.usec / 1000;
75 }
76 
77 
78 /**
79  * gas_query_init - Initialize GAS query component
80  * @wpa_s: Pointer to wpa_supplicant data
81  * Returns: Pointer to GAS query data or %NULL on failure
82  */
gas_query_init(struct wpa_supplicant * wpa_s)83 struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s)
84 {
85 	struct gas_query *gas;
86 
87 	gas = os_zalloc(sizeof(*gas));
88 	if (gas == NULL)
89 		return NULL;
90 
91 	gas->wpa_s = wpa_s;
92 	dl_list_init(&gas->pending);
93 
94 	return gas;
95 }
96 
97 
gas_result_txt(enum gas_query_result result)98 static const char * gas_result_txt(enum gas_query_result result)
99 {
100 	switch (result) {
101 	case GAS_QUERY_SUCCESS:
102 		return "SUCCESS";
103 	case GAS_QUERY_FAILURE:
104 		return "FAILURE";
105 	case GAS_QUERY_TIMEOUT:
106 		return "TIMEOUT";
107 	case GAS_QUERY_PEER_ERROR:
108 		return "PEER_ERROR";
109 	case GAS_QUERY_INTERNAL_ERROR:
110 		return "INTERNAL_ERROR";
111 	case GAS_QUERY_CANCELLED:
112 		return "CANCELLED";
113 	case GAS_QUERY_DELETED_AT_DEINIT:
114 		return "DELETED_AT_DEINIT";
115 	}
116 
117 	return "N/A";
118 }
119 
120 
gas_query_free(struct gas_query_pending * query,int del_list)121 static void gas_query_free(struct gas_query_pending *query, int del_list)
122 {
123 	struct gas_query *gas = query->gas;
124 
125 	if (del_list)
126 		dl_list_del(&query->list);
127 
128 	if (gas->work && gas->work->ctx == query) {
129 		radio_work_done(gas->work);
130 		gas->work = NULL;
131 	}
132 
133 	wpabuf_free(query->req);
134 	wpabuf_free(query->adv_proto);
135 	wpabuf_free(query->resp);
136 	os_free(query);
137 }
138 
139 
gas_query_done(struct gas_query * gas,struct gas_query_pending * query,enum gas_query_result result)140 static void gas_query_done(struct gas_query *gas,
141 			   struct gas_query_pending *query,
142 			   enum gas_query_result result)
143 {
144 	wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR
145 		" dialog_token=%u freq=%d status_code=%u result=%s",
146 		MAC2STR(query->addr), query->dialog_token, query->freq,
147 		query->status_code, gas_result_txt(result));
148 	if (gas->current == query)
149 		gas->current = NULL;
150 	if (query->offchannel_tx_started)
151 		offchannel_send_action_done(gas->wpa_s);
152 	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
153 	eloop_cancel_timeout(gas_query_timeout, gas, query);
154 	dl_list_del(&query->list);
155 	query->cb(query->ctx, query->addr, query->dialog_token, result,
156 		  query->adv_proto, query->resp, query->status_code);
157 	gas_query_free(query, 0);
158 }
159 
160 
161 /**
162  * gas_query_deinit - Deinitialize GAS query component
163  * @gas: GAS query data from gas_query_init()
164  */
gas_query_deinit(struct gas_query * gas)165 void gas_query_deinit(struct gas_query *gas)
166 {
167 	struct gas_query_pending *query, *next;
168 
169 	if (gas == NULL)
170 		return;
171 
172 	dl_list_for_each_safe(query, next, &gas->pending,
173 			      struct gas_query_pending, list)
174 		gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
175 
176 	os_free(gas);
177 }
178 
179 
180 static struct gas_query_pending *
gas_query_get_pending(struct gas_query * gas,const u8 * addr,u8 dialog_token)181 gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token)
182 {
183 	struct gas_query_pending *q;
184 	dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
185 		if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 &&
186 		    q->dialog_token == dialog_token)
187 			return q;
188 	}
189 	return NULL;
190 }
191 
192 
gas_query_append(struct gas_query_pending * query,const u8 * data,size_t len)193 static int gas_query_append(struct gas_query_pending *query, const u8 *data,
194 			    size_t len)
195 {
196 	if (wpabuf_resize(&query->resp, len) < 0) {
197 		wpa_printf(MSG_DEBUG, "GAS: No memory to store the response");
198 		return -1;
199 	}
200 	wpabuf_put_data(query->resp, data, len);
201 	return 0;
202 }
203 
204 
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)205 static void gas_query_tx_status(struct wpa_supplicant *wpa_s,
206 				unsigned int freq, const u8 *dst,
207 				const u8 *src, const u8 *bssid,
208 				const u8 *data, size_t data_len,
209 				enum offchannel_send_action_result result)
210 {
211 	struct gas_query_pending *query;
212 	struct gas_query *gas = wpa_s->gas;
213 	int dur;
214 
215 	if (gas->current == NULL) {
216 		wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: freq=%u dst="
217 			   MACSTR " result=%d - no query in progress",
218 			   freq, MAC2STR(dst), result);
219 		return;
220 	}
221 
222 	query = gas->current;
223 
224 	dur = ms_from_time(&query->last_oper);
225 	wpa_printf(MSG_DEBUG, "GAS: TX status: freq=%u dst=" MACSTR
226 		   " result=%d query=%p dialog_token=%u dur=%d ms",
227 		   freq, MAC2STR(dst), result, query, query->dialog_token, dur);
228 	if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) {
229 		wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination");
230 		return;
231 	}
232 	os_get_reltime(&query->last_oper);
233 
234 	if (result == OFFCHANNEL_SEND_ACTION_SUCCESS) {
235 		eloop_cancel_timeout(gas_query_timeout, gas, query);
236 		eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
237 				       gas_query_timeout, gas, query);
238 	}
239 	if (result == OFFCHANNEL_SEND_ACTION_FAILED) {
240 		eloop_cancel_timeout(gas_query_timeout, gas, query);
241 		eloop_register_timeout(0, 0, gas_query_timeout, gas, query);
242 	}
243 }
244 
245 
pmf_in_use(struct wpa_supplicant * wpa_s,const u8 * addr)246 static int pmf_in_use(struct wpa_supplicant *wpa_s, const u8 *addr)
247 {
248 	if (wpa_s->current_ssid == NULL ||
249 	    wpa_s->wpa_state < WPA_4WAY_HANDSHAKE ||
250 	    os_memcmp(addr, wpa_s->bssid, ETH_ALEN) != 0)
251 		return 0;
252 	return wpa_sm_pmf_enabled(wpa_s->wpa);
253 }
254 
255 
gas_query_tx(struct gas_query * gas,struct gas_query_pending * query,struct wpabuf * req)256 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
257 			struct wpabuf *req)
258 {
259 	unsigned int wait_time;
260 	int res, prot = pmf_in_use(gas->wpa_s, query->addr);
261 
262 	wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
263 		   "freq=%d prot=%d", MAC2STR(query->addr),
264 		   (unsigned int) wpabuf_len(req), query->freq, prot);
265 	if (prot) {
266 		u8 *categ = wpabuf_mhead_u8(req);
267 		*categ = WLAN_ACTION_PROTECTED_DUAL;
268 	}
269 	os_get_reltime(&query->last_oper);
270 	wait_time = 1000;
271 	if (gas->wpa_s->max_remain_on_chan &&
272 	    wait_time > gas->wpa_s->max_remain_on_chan)
273 		wait_time = gas->wpa_s->max_remain_on_chan;
274 	res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
275 				     gas->wpa_s->own_addr, query->addr,
276 				     wpabuf_head(req), wpabuf_len(req),
277 				     wait_time, gas_query_tx_status, 0);
278 	if (res == 0)
279 		query->offchannel_tx_started = 1;
280 	return res;
281 }
282 
283 
gas_query_tx_comeback_req(struct gas_query * gas,struct gas_query_pending * query)284 static void gas_query_tx_comeback_req(struct gas_query *gas,
285 				      struct gas_query_pending *query)
286 {
287 	struct wpabuf *req;
288 
289 	req = gas_build_comeback_req(query->dialog_token);
290 	if (req == NULL) {
291 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
292 		return;
293 	}
294 
295 	if (gas_query_tx(gas, query, req) < 0) {
296 		wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
297 			   MACSTR, MAC2STR(query->addr));
298 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
299 	}
300 
301 	wpabuf_free(req);
302 }
303 
304 
gas_query_tx_comeback_timeout(void * eloop_data,void * user_ctx)305 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
306 {
307 	struct gas_query *gas = eloop_data;
308 	struct gas_query_pending *query = user_ctx;
309 
310 	wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
311 		   MAC2STR(query->addr));
312 	gas_query_tx_comeback_req(gas, query);
313 }
314 
315 
gas_query_tx_comeback_req_delay(struct gas_query * gas,struct gas_query_pending * query,u16 comeback_delay)316 static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
317 					    struct gas_query_pending *query,
318 					    u16 comeback_delay)
319 {
320 	unsigned int secs, usecs;
321 
322 	secs = (comeback_delay * 1024) / 1000000;
323 	usecs = comeback_delay * 1024 - secs * 1000000;
324 	wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
325 		   " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
326 	eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
327 	eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
328 			       gas, query);
329 }
330 
331 
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)332 static void gas_query_rx_initial(struct gas_query *gas,
333 				 struct gas_query_pending *query,
334 				 const u8 *adv_proto, const u8 *resp,
335 				 size_t len, u16 comeback_delay)
336 {
337 	wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
338 		   MACSTR " (dialog_token=%u comeback_delay=%u)",
339 		   MAC2STR(query->addr), query->dialog_token, comeback_delay);
340 
341 	query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]);
342 	if (query->adv_proto == NULL) {
343 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
344 		return;
345 	}
346 
347 	if (comeback_delay) {
348 		query->wait_comeback = 1;
349 		gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
350 		return;
351 	}
352 
353 	/* Query was completed without comeback mechanism */
354 	if (gas_query_append(query, resp, len) < 0) {
355 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
356 		return;
357 	}
358 
359 	gas_query_done(gas, query, GAS_QUERY_SUCCESS);
360 }
361 
362 
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)363 static void gas_query_rx_comeback(struct gas_query *gas,
364 				  struct gas_query_pending *query,
365 				  const u8 *adv_proto, const u8 *resp,
366 				  size_t len, u8 frag_id, u8 more_frags,
367 				  u16 comeback_delay)
368 {
369 	wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
370 		   MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
371 		   "comeback_delay=%u)",
372 		   MAC2STR(query->addr), query->dialog_token, frag_id,
373 		   more_frags, comeback_delay);
374 
375 	if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) ||
376 	    os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
377 		      wpabuf_len(query->adv_proto)) != 0) {
378 		wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
379 			   "between initial and comeback response from "
380 			   MACSTR, MAC2STR(query->addr));
381 		gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
382 		return;
383 	}
384 
385 	if (comeback_delay) {
386 		if (frag_id) {
387 			wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
388 				   "with non-zero frag_id and comeback_delay "
389 				   "from " MACSTR, MAC2STR(query->addr));
390 			gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
391 			return;
392 		}
393 		gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
394 		return;
395 	}
396 
397 	if (frag_id != query->next_frag_id) {
398 		wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
399 			   "from " MACSTR, MAC2STR(query->addr));
400 		if (frag_id + 1 == query->next_frag_id) {
401 			wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
402 				   "retry of previous fragment");
403 			return;
404 		}
405 		gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
406 		return;
407 	}
408 	query->next_frag_id++;
409 
410 	if (gas_query_append(query, resp, len) < 0) {
411 		gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
412 		return;
413 	}
414 
415 	if (more_frags) {
416 		gas_query_tx_comeback_req(gas, query);
417 		return;
418 	}
419 
420 	gas_query_done(gas, query, GAS_QUERY_SUCCESS);
421 }
422 
423 
424 /**
425  * gas_query_rx - Indicate reception of a Public Action or Protected Dual frame
426  * @gas: GAS query data from gas_query_init()
427  * @da: Destination MAC address of the Action frame
428  * @sa: Source MAC address of the Action frame
429  * @bssid: BSSID of the Action frame
430  * @categ: Category of the Action frame
431  * @data: Payload of the Action frame
432  * @len: Length of @data
433  * @freq: Frequency (in MHz) on which the frame was received
434  * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
435  */
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)436 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
437 		 const u8 *bssid, u8 categ, const u8 *data, size_t len,
438 		 int freq)
439 {
440 	struct gas_query_pending *query;
441 	u8 action, dialog_token, frag_id = 0, more_frags = 0;
442 	u16 comeback_delay, resp_len;
443 	const u8 *pos, *adv_proto;
444 	int prot, pmf;
445 	unsigned int left;
446 
447 	if (gas == NULL || len < 4)
448 		return -1;
449 
450 	prot = categ == WLAN_ACTION_PROTECTED_DUAL;
451 	pmf = pmf_in_use(gas->wpa_s, bssid);
452 	if (prot && !pmf) {
453 		wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled");
454 		return 0;
455 	}
456 	if (!prot && pmf) {
457 		wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled");
458 		return 0;
459 	}
460 
461 	pos = data;
462 	action = *pos++;
463 	dialog_token = *pos++;
464 
465 	if (action != WLAN_PA_GAS_INITIAL_RESP &&
466 	    action != WLAN_PA_GAS_COMEBACK_RESP)
467 		return -1; /* Not a GAS response */
468 
469 	query = gas_query_get_pending(gas, sa, dialog_token);
470 	if (query == NULL) {
471 		wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR
472 			   " dialog token %u", MAC2STR(sa), dialog_token);
473 		return -1;
474 	}
475 
476 	wpa_printf(MSG_DEBUG, "GAS: Response in %d ms from " MACSTR,
477 		   ms_from_time(&query->last_oper), MAC2STR(sa));
478 
479 	if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) {
480 		wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from "
481 			   MACSTR " dialog token %u when waiting for comeback "
482 			   "response", MAC2STR(sa), dialog_token);
483 		return 0;
484 	}
485 
486 	if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) {
487 		wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from "
488 			   MACSTR " dialog token %u when waiting for initial "
489 			   "response", MAC2STR(sa), dialog_token);
490 		return 0;
491 	}
492 
493 	query->status_code = WPA_GET_LE16(pos);
494 	pos += 2;
495 
496 	if (query->status_code == WLAN_STATUS_QUERY_RESP_OUTSTANDING &&
497 	    action == WLAN_PA_GAS_COMEBACK_RESP) {
498 		wpa_printf(MSG_DEBUG, "GAS: Allow non-zero status for outstanding comeback response");
499 	} else if (query->status_code != WLAN_STATUS_SUCCESS) {
500 		wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token "
501 			   "%u failed - status code %u",
502 			   MAC2STR(sa), dialog_token, query->status_code);
503 		gas_query_done(gas, query, GAS_QUERY_FAILURE);
504 		return 0;
505 	}
506 
507 	if (action == WLAN_PA_GAS_COMEBACK_RESP) {
508 		if (pos + 1 > data + len)
509 			return 0;
510 		frag_id = *pos & 0x7f;
511 		more_frags = (*pos & 0x80) >> 7;
512 		pos++;
513 	}
514 
515 	/* Comeback Delay */
516 	if (pos + 2 > data + len)
517 		return 0;
518 	comeback_delay = WPA_GET_LE16(pos);
519 	pos += 2;
520 
521 	/* Advertisement Protocol element */
522 	if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) {
523 		wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
524 			   "Protocol element in the response from " MACSTR,
525 			   MAC2STR(sa));
526 		return 0;
527 	}
528 
529 	if (*pos != WLAN_EID_ADV_PROTO) {
530 		wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
531 			   "Protocol element ID %u in response from " MACSTR,
532 			   *pos, MAC2STR(sa));
533 		return 0;
534 	}
535 
536 	adv_proto = pos;
537 	pos += 2 + pos[1];
538 
539 	/* Query Response Length */
540 	if (pos + 2 > data + len) {
541 		wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
542 		return 0;
543 	}
544 	resp_len = WPA_GET_LE16(pos);
545 	pos += 2;
546 
547 	left = data + len - pos;
548 	if (resp_len > left) {
549 		wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
550 			   "response from " MACSTR, MAC2STR(sa));
551 		return 0;
552 	}
553 
554 	if (resp_len < left) {
555 		wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
556 			   "after Query Response from " MACSTR,
557 			   left - resp_len, MAC2STR(sa));
558 	}
559 
560 	if (action == WLAN_PA_GAS_COMEBACK_RESP)
561 		gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len,
562 				      frag_id, more_frags, comeback_delay);
563 	else
564 		gas_query_rx_initial(gas, query, adv_proto, pos, resp_len,
565 				     comeback_delay);
566 
567 	return 0;
568 }
569 
570 
gas_query_timeout(void * eloop_data,void * user_ctx)571 static void gas_query_timeout(void *eloop_data, void *user_ctx)
572 {
573 	struct gas_query *gas = eloop_data;
574 	struct gas_query_pending *query = user_ctx;
575 
576 	wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
577 		   " dialog token %u",
578 		   MAC2STR(query->addr), query->dialog_token);
579 	gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
580 }
581 
582 
gas_query_dialog_token_available(struct gas_query * gas,const u8 * dst,u8 dialog_token)583 static int gas_query_dialog_token_available(struct gas_query *gas,
584 					    const u8 *dst, u8 dialog_token)
585 {
586 	struct gas_query_pending *q;
587 	dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
588 		if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 &&
589 		    dialog_token == q->dialog_token)
590 			return 0;
591 	}
592 
593 	return 1;
594 }
595 
596 
gas_query_start_cb(struct wpa_radio_work * work,int deinit)597 static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
598 {
599 	struct gas_query_pending *query = work->ctx;
600 	struct gas_query *gas = query->gas;
601 	struct wpa_supplicant *wpa_s = gas->wpa_s;
602 
603 	if (deinit) {
604 		if (work->started) {
605 			gas->work = NULL;
606 			gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
607 			return;
608 		}
609 
610 		gas_query_free(query, 1);
611 		return;
612 	}
613 
614 	if (wpas_update_random_addr_disassoc(wpa_s) < 0) {
615 		wpa_msg(wpa_s, MSG_INFO,
616 			"Failed to assign random MAC address for GAS");
617 		gas_query_free(query, 1);
618 		radio_work_done(work);
619 		return;
620 	}
621 
622 	gas->work = work;
623 
624 	if (gas_query_tx(gas, query, query->req) < 0) {
625 		wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
626 			   MACSTR, MAC2STR(query->addr));
627 		gas_query_free(query, 1);
628 		return;
629 	}
630 	gas->current = query;
631 
632 	wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
633 		   query->dialog_token);
634 	eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
635 			       gas_query_timeout, gas, query);
636 
637 }
638 
639 
640 /**
641  * gas_query_req - Request a GAS query
642  * @gas: GAS query data from gas_query_init()
643  * @dst: Destination MAC address for the query
644  * @freq: Frequency (in MHz) for the channel on which to send the query
645  * @req: GAS query payload (to be freed by gas_query module in case of success
646  *	return)
647  * @cb: Callback function for reporting GAS query result and response
648  * @ctx: Context pointer to use with the @cb call
649  * Returns: dialog token (>= 0) on success or -1 on failure
650  */
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)651 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
652 		  struct wpabuf *req,
653 		  void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
654 			     enum gas_query_result result,
655 			     const struct wpabuf *adv_proto,
656 			     const struct wpabuf *resp, u16 status_code),
657 		  void *ctx)
658 {
659 	struct gas_query_pending *query;
660 	int dialog_token;
661 	static int next_start = 0;
662 
663 	if (wpabuf_len(req) < 3)
664 		return -1;
665 
666 	for (dialog_token = 0; dialog_token < 256; dialog_token++) {
667 		if (gas_query_dialog_token_available(
668 			    gas, dst, (next_start + dialog_token) % 256))
669 			break;
670 	}
671 	if (dialog_token == 256)
672 		return -1; /* Too many pending queries */
673 	dialog_token = (next_start + dialog_token) % 256;
674 	next_start = (dialog_token + 1) % 256;
675 
676 	query = os_zalloc(sizeof(*query));
677 	if (query == NULL)
678 		return -1;
679 
680 	query->gas = gas;
681 	os_memcpy(query->addr, dst, ETH_ALEN);
682 	query->dialog_token = dialog_token;
683 	query->freq = freq;
684 	query->cb = cb;
685 	query->ctx = ctx;
686 	query->req = req;
687 	dl_list_add(&gas->pending, &query->list);
688 
689 	*(wpabuf_mhead_u8(req) + 2) = dialog_token;
690 
691 	wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
692 		" dialog_token=%u freq=%d",
693 		MAC2STR(query->addr), query->dialog_token, query->freq);
694 
695 	if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
696 			   query) < 0) {
697 		gas_query_free(query, 1);
698 		return -1;
699 	}
700 
701 	return dialog_token;
702 }
703 
704 
705 /**
706  * gas_query_cancel - Cancel a pending GAS query
707  * @gas: GAS query data from gas_query_init()
708  * @dst: Destination MAC address for the query
709  * @dialog_token: Dialog token from gas_query_req()
710  */
gas_query_cancel(struct gas_query * gas,const u8 * dst,u8 dialog_token)711 void gas_query_cancel(struct gas_query *gas, const u8 *dst, u8 dialog_token)
712 {
713 	struct gas_query_pending *query;
714 
715 	query = gas_query_get_pending(gas, dst, dialog_token);
716 	if (query)
717 		gas_query_done(gas, query, GAS_QUERY_CANCELLED);
718 
719 }
720