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
ms_from_time(struct os_reltime * last)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 */
gas_query_init(struct wpa_supplicant * wpa_s)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
gas_result_txt(enum gas_query_result result)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
gas_query_free(struct gas_query_pending * query,int del_list)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
gas_query_done(struct gas_query * gas,struct gas_query_pending * query,enum gas_query_result result)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 */
gas_query_deinit(struct gas_query * gas)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 *
gas_query_get_pending(struct gas_query * gas,const u8 * addr,u8 dialog_token)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
gas_query_append(struct gas_query_pending * query,const u8 * data,size_t len)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
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)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
pmf_in_use(struct wpa_supplicant * wpa_s,const u8 * addr)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
gas_query_tx(struct gas_query * gas,struct gas_query_pending * query,struct wpabuf * req,unsigned int wait_time)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
gas_query_tx_comeback_req(struct gas_query * gas,struct gas_query_pending * query)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
gas_query_rx_comeback_timeout(void * eloop_data,void * user_ctx)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
gas_query_tx_comeback_timeout(void * eloop_data,void * user_ctx)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
gas_query_tx_comeback_req_delay(struct gas_query * gas,struct gas_query_pending * query,u16 comeback_delay)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
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)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
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)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 */
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)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
gas_query_timeout(void * eloop_data,void * user_ctx)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
gas_query_dialog_token_available(struct gas_query * gas,const u8 * dst,u8 dialog_token)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
gas_query_start_cb(struct wpa_radio_work * work,int deinit)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
gas_query_tx_initial_req(struct gas_query * gas,struct gas_query_pending * query)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
gas_query_new_dialog_token(struct gas_query * gas,const u8 * dst)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
gas_query_set_sa(struct gas_query * gas,struct gas_query_pending * query)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 */
gas_query_req(struct gas_query * gas,const u8 * dst,int freq,int wildcard_bssid,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)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
gas_query_stop(struct gas_query * gas,u8 dialog_token)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