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>
7 * This software may be distributed under the terms of the BSD license.
8 * See README for more details.
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"
21 #include "offchannel.h"
22 #include "gas_query.h"
25 /** GAS query timeout in seconds */
26 #define GAS_QUERY_TIMEOUT_PERIOD 2
30 * struct gas_query_pending - Pending GAS query
32 struct gas_query_pending {
34 struct gas_query *gas;
38 unsigned int wait_comeback:1;
39 unsigned int offchannel_tx_started:1;
43 struct wpabuf *adv_proto;
45 void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
46 enum gas_query_result result,
47 const struct wpabuf *adv_proto,
48 const struct wpabuf *resp, u16 status_code);
53 * struct gas_query - Internal GAS query data
56 struct wpa_supplicant *wpa_s;
57 struct dl_list pending; /* struct gas_query_pending */
58 struct gas_query_pending *current;
59 struct wpa_radio_work *work;
63 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx);
64 static void gas_query_timeout(void *eloop_data, void *user_ctx);
68 * gas_query_init - Initialize GAS query component
69 * @wpa_s: Pointer to wpa_supplicant data
70 * Returns: Pointer to GAS query data or %NULL on failure
72 struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s)
74 struct gas_query *gas;
76 gas = os_zalloc(sizeof(*gas));
81 dl_list_init(&gas->pending);
87 static const char * gas_result_txt(enum gas_query_result result)
90 case GAS_QUERY_SUCCESS:
92 case GAS_QUERY_FAILURE:
94 case GAS_QUERY_TIMEOUT:
96 case GAS_QUERY_PEER_ERROR:
98 case GAS_QUERY_INTERNAL_ERROR:
99 return "INTERNAL_ERROR";
100 case GAS_QUERY_CANCELLED:
102 case GAS_QUERY_DELETED_AT_DEINIT:
103 return "DELETED_AT_DEINIT";
110 static void gas_query_free(struct gas_query_pending *query, int del_list)
112 struct gas_query *gas = query->gas;
115 dl_list_del(&query->list);
117 if (gas->work && gas->work->ctx == query) {
118 radio_work_done(gas->work);
122 wpabuf_free(query->req);
123 wpabuf_free(query->adv_proto);
124 wpabuf_free(query->resp);
129 static void gas_query_done(struct gas_query *gas,
130 struct gas_query_pending *query,
131 enum gas_query_result result)
133 wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR
134 " dialog_token=%u freq=%d status_code=%u result=%s",
135 MAC2STR(query->addr), query->dialog_token, query->freq,
136 query->status_code, gas_result_txt(result));
137 if (gas->current == query)
139 if (query->offchannel_tx_started)
140 offchannel_send_action_done(gas->wpa_s);
141 eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
142 eloop_cancel_timeout(gas_query_timeout, gas, query);
143 dl_list_del(&query->list);
144 query->cb(query->ctx, query->addr, query->dialog_token, result,
145 query->adv_proto, query->resp, query->status_code);
146 gas_query_free(query, 0);
151 * gas_query_deinit - Deinitialize GAS query component
152 * @gas: GAS query data from gas_query_init()
154 void gas_query_deinit(struct gas_query *gas)
156 struct gas_query_pending *query, *next;
161 dl_list_for_each_safe(query, next, &gas->pending,
162 struct gas_query_pending, list)
163 gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
169 static struct gas_query_pending *
170 gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token)
172 struct gas_query_pending *q;
173 dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
174 if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 &&
175 q->dialog_token == dialog_token)
182 static int gas_query_append(struct gas_query_pending *query, const u8 *data,
185 if (wpabuf_resize(&query->resp, len) < 0) {
186 wpa_printf(MSG_DEBUG, "GAS: No memory to store the response");
189 wpabuf_put_data(query->resp, data, len);
194 static void gas_query_tx_status(struct wpa_supplicant *wpa_s,
195 unsigned int freq, const u8 *dst,
196 const u8 *src, const u8 *bssid,
197 const u8 *data, size_t data_len,
198 enum offchannel_send_action_result result)
200 struct gas_query_pending *query;
201 struct gas_query *gas = wpa_s->gas;
203 if (gas->current == NULL) {
204 wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: freq=%u dst="
205 MACSTR " result=%d - no query in progress",
206 freq, MAC2STR(dst), result);
210 query = gas->current;
212 wpa_printf(MSG_DEBUG, "GAS: TX status: freq=%u dst=" MACSTR
213 " result=%d query=%p dialog_token=%u",
214 freq, MAC2STR(dst), result, query, query->dialog_token);
215 if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) {
216 wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination");
220 if (result == OFFCHANNEL_SEND_ACTION_SUCCESS) {
221 eloop_cancel_timeout(gas_query_timeout, gas, query);
222 eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
223 gas_query_timeout, gas, query);
225 if (result == OFFCHANNEL_SEND_ACTION_FAILED) {
226 eloop_cancel_timeout(gas_query_timeout, gas, query);
227 eloop_register_timeout(0, 0, gas_query_timeout, gas, query);
232 static int pmf_in_use(struct wpa_supplicant *wpa_s, const u8 *addr)
234 if (wpa_s->current_ssid == NULL ||
235 wpa_s->wpa_state < WPA_4WAY_HANDSHAKE ||
236 os_memcmp(addr, wpa_s->bssid, ETH_ALEN) != 0)
238 return wpa_sm_pmf_enabled(wpa_s->wpa);
242 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
245 int res, prot = pmf_in_use(gas->wpa_s, query->addr);
247 wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
248 "freq=%d prot=%d", MAC2STR(query->addr),
249 (unsigned int) wpabuf_len(req), query->freq, prot);
251 u8 *categ = wpabuf_mhead_u8(req);
252 *categ = WLAN_ACTION_PROTECTED_DUAL;
254 res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
255 gas->wpa_s->own_addr, query->addr,
256 wpabuf_head(req), wpabuf_len(req), 1000,
257 gas_query_tx_status, 0);
259 query->offchannel_tx_started = 1;
264 static void gas_query_tx_comeback_req(struct gas_query *gas,
265 struct gas_query_pending *query)
269 req = gas_build_comeback_req(query->dialog_token);
271 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
275 if (gas_query_tx(gas, query, req) < 0) {
276 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
277 MACSTR, MAC2STR(query->addr));
278 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
285 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
287 struct gas_query *gas = eloop_data;
288 struct gas_query_pending *query = user_ctx;
290 wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
291 MAC2STR(query->addr));
292 gas_query_tx_comeback_req(gas, query);
296 static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
297 struct gas_query_pending *query,
300 unsigned int secs, usecs;
302 secs = (comeback_delay * 1024) / 1000000;
303 usecs = comeback_delay * 1024 - secs * 1000000;
304 wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
305 " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
306 eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
307 eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
312 static void gas_query_rx_initial(struct gas_query *gas,
313 struct gas_query_pending *query,
314 const u8 *adv_proto, const u8 *resp,
315 size_t len, u16 comeback_delay)
317 wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
318 MACSTR " (dialog_token=%u comeback_delay=%u)",
319 MAC2STR(query->addr), query->dialog_token, comeback_delay);
321 query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]);
322 if (query->adv_proto == NULL) {
323 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
327 if (comeback_delay) {
328 query->wait_comeback = 1;
329 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
333 /* Query was completed without comeback mechanism */
334 if (gas_query_append(query, resp, len) < 0) {
335 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
339 gas_query_done(gas, query, GAS_QUERY_SUCCESS);
343 static void gas_query_rx_comeback(struct gas_query *gas,
344 struct gas_query_pending *query,
345 const u8 *adv_proto, const u8 *resp,
346 size_t len, u8 frag_id, u8 more_frags,
349 wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
350 MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
351 "comeback_delay=%u)",
352 MAC2STR(query->addr), query->dialog_token, frag_id,
353 more_frags, comeback_delay);
355 if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) ||
356 os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
357 wpabuf_len(query->adv_proto)) != 0) {
358 wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
359 "between initial and comeback response from "
360 MACSTR, MAC2STR(query->addr));
361 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
365 if (comeback_delay) {
367 wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
368 "with non-zero frag_id and comeback_delay "
369 "from " MACSTR, MAC2STR(query->addr));
370 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
373 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
377 if (frag_id != query->next_frag_id) {
378 wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
379 "from " MACSTR, MAC2STR(query->addr));
380 if (frag_id + 1 == query->next_frag_id) {
381 wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
382 "retry of previous fragment");
385 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
388 query->next_frag_id++;
390 if (gas_query_append(query, resp, len) < 0) {
391 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
396 gas_query_tx_comeback_req(gas, query);
400 gas_query_done(gas, query, GAS_QUERY_SUCCESS);
405 * gas_query_rx - Indicate reception of a Public Action or Protected Dual frame
406 * @gas: GAS query data from gas_query_init()
407 * @da: Destination MAC address of the Action frame
408 * @sa: Source MAC address of the Action frame
409 * @bssid: BSSID of the Action frame
410 * @categ: Category of the Action frame
411 * @data: Payload of the Action frame
412 * @len: Length of @data
413 * @freq: Frequency (in MHz) on which the frame was received
414 * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
416 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
417 const u8 *bssid, u8 categ, const u8 *data, size_t len,
420 struct gas_query_pending *query;
421 u8 action, dialog_token, frag_id = 0, more_frags = 0;
422 u16 comeback_delay, resp_len;
423 const u8 *pos, *adv_proto;
426 if (gas == NULL || len < 4)
429 prot = categ == WLAN_ACTION_PROTECTED_DUAL;
430 pmf = pmf_in_use(gas->wpa_s, bssid);
432 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled");
436 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled");
442 dialog_token = *pos++;
444 if (action != WLAN_PA_GAS_INITIAL_RESP &&
445 action != WLAN_PA_GAS_COMEBACK_RESP)
446 return -1; /* Not a GAS response */
448 query = gas_query_get_pending(gas, sa, dialog_token);
450 wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR
451 " dialog token %u", MAC2STR(sa), dialog_token);
455 if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) {
456 wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from "
457 MACSTR " dialog token %u when waiting for comeback "
458 "response", MAC2STR(sa), dialog_token);
462 if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) {
463 wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from "
464 MACSTR " dialog token %u when waiting for initial "
465 "response", MAC2STR(sa), dialog_token);
469 query->status_code = WPA_GET_LE16(pos);
472 if (query->status_code != WLAN_STATUS_SUCCESS) {
473 wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token "
474 "%u failed - status code %u",
475 MAC2STR(sa), dialog_token, query->status_code);
476 gas_query_done(gas, query, GAS_QUERY_FAILURE);
480 if (action == WLAN_PA_GAS_COMEBACK_RESP) {
481 if (pos + 1 > data + len)
483 frag_id = *pos & 0x7f;
484 more_frags = (*pos & 0x80) >> 7;
489 if (pos + 2 > data + len)
491 comeback_delay = WPA_GET_LE16(pos);
494 /* Advertisement Protocol element */
495 if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) {
496 wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
497 "Protocol element in the response from " MACSTR,
502 if (*pos != WLAN_EID_ADV_PROTO) {
503 wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
504 "Protocol element ID %u in response from " MACSTR,
512 /* Query Response Length */
513 if (pos + 2 > data + len) {
514 wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
517 resp_len = WPA_GET_LE16(pos);
520 if (pos + resp_len > data + len) {
521 wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
522 "response from " MACSTR, MAC2STR(sa));
526 if (pos + resp_len < data + len) {
527 wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
528 "after Query Response from " MACSTR,
529 (unsigned int) (data + len - pos - resp_len),
533 if (action == WLAN_PA_GAS_COMEBACK_RESP)
534 gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len,
535 frag_id, more_frags, comeback_delay);
537 gas_query_rx_initial(gas, query, adv_proto, pos, resp_len,
544 static void gas_query_timeout(void *eloop_data, void *user_ctx)
546 struct gas_query *gas = eloop_data;
547 struct gas_query_pending *query = user_ctx;
549 wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
551 MAC2STR(query->addr), query->dialog_token);
552 gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
556 static int gas_query_dialog_token_available(struct gas_query *gas,
557 const u8 *dst, u8 dialog_token)
559 struct gas_query_pending *q;
560 dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
561 if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 &&
562 dialog_token == q->dialog_token)
570 static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
572 struct gas_query_pending *query = work->ctx;
573 struct gas_query *gas = query->gas;
576 gas_query_free(query, 1);
582 if (gas_query_tx(gas, query, query->req) < 0) {
583 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
584 MACSTR, MAC2STR(query->addr));
585 gas_query_free(query, 1);
588 gas->current = query;
590 wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
591 query->dialog_token);
592 eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
593 gas_query_timeout, gas, query);
599 * gas_query_req - Request a GAS query
600 * @gas: GAS query data from gas_query_init()
601 * @dst: Destination MAC address for the query
602 * @freq: Frequency (in MHz) for the channel on which to send the query
603 * @req: GAS query payload (to be freed by gas_query module in case of success
605 * @cb: Callback function for reporting GAS query result and response
606 * @ctx: Context pointer to use with the @cb call
607 * Returns: dialog token (>= 0) on success or -1 on failure
609 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
611 void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
612 enum gas_query_result result,
613 const struct wpabuf *adv_proto,
614 const struct wpabuf *resp, u16 status_code),
617 struct gas_query_pending *query;
619 static int next_start = 0;
621 if (wpabuf_len(req) < 3)
624 for (dialog_token = 0; dialog_token < 256; dialog_token++) {
625 if (gas_query_dialog_token_available(
626 gas, dst, (next_start + dialog_token) % 256))
629 if (dialog_token == 256)
630 return -1; /* Too many pending queries */
631 dialog_token = (next_start + dialog_token) % 256;
632 next_start = (dialog_token + 1) % 256;
634 query = os_zalloc(sizeof(*query));
639 os_memcpy(query->addr, dst, ETH_ALEN);
640 query->dialog_token = dialog_token;
645 dl_list_add(&gas->pending, &query->list);
647 *(wpabuf_mhead_u8(req) + 2) = dialog_token;
649 wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
650 " dialog_token=%u freq=%d",
651 MAC2STR(query->addr), query->dialog_token, query->freq);
653 if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
655 gas_query_free(query, 1);
664 * gas_query_cancel - Cancel a pending GAS query
665 * @gas: GAS query data from gas_query_init()
666 * @dst: Destination MAC address for the query
667 * @dialog_token: Dialog token from gas_query_req()
669 void gas_query_cancel(struct gas_query *gas, const u8 *dst, u8 dialog_token)
671 struct gas_query_pending *query;
673 query = gas_query_get_pending(gas, dst, dialog_token);
675 gas_query_done(gas, query, GAS_QUERY_CANCELLED);