wpa_supplicant/gas_query.c

   1 /*
   2  * Generic advertisement service (GAS) query
   3  * Copyright (c) 2009, Atheros Communications
   4  * Copyright (c) 2011-2013, 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 "wpa_supplicant_i.h"
  19 #include "driver_i.h"
  20 #include "offchannel.h"
  21 #include "gas_query.h"
  22
  23
  24 /** GAS query timeout in seconds */
  25 #define GAS_QUERY_TIMEOUT_PERIOD 2
  26
  27
  28 /**
  29  * struct gas_query_pending - Pending GAS query
  30  */
  31 struct gas_query_pending {
  32         struct dl_list list;
  33         struct gas_query *gas;
  34         u8 addr[ETH_ALEN];
  35         u8 dialog_token;
  36         u8 next_frag_id;
  37         unsigned int wait_comeback:1;
  38         unsigned int offchannel_tx_started:1;
  39         int freq;
  40         u16 status_code;
  41         struct wpabuf *req;
  42         struct wpabuf *adv_proto;
  43         struct wpabuf *resp;
  44         void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
  45                    enum gas_query_result result,
  46                    const struct wpabuf *adv_proto,
  47                    const struct wpabuf *resp, u16 status_code);
  48         void *ctx;
  49 };
  50
  51 /**
  52  * struct gas_query - Internal GAS query data
  53  */
  54 struct gas_query {
  55         struct wpa_supplicant *wpa_s;
  56         struct dl_list pending; /* struct gas_query_pending */
  57         struct gas_query_pending *current;
  58         struct wpa_radio_work *work;
  59 };
  60
  61
  62 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx);
  63 static void gas_query_timeout(void *eloop_data, void *user_ctx);
  64
  65
  66 /**
  67  * gas_query_init - Initialize GAS query component
  68  * @wpa_s: Pointer to wpa_supplicant data
  69  * Returns: Pointer to GAS query data or %NULL on failure
  70  */
  71 struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s)
  72 {
  73         struct gas_query *gas;
  74
  75         gas = os_zalloc(sizeof(*gas));
  76         if (gas == NULL)
  77                 return NULL;
  78
  79         gas->wpa_s = wpa_s;
  80         dl_list_init(&gas->pending);
  81
  82         return gas;
  83 }
  84
  85
  86 static const char * gas_result_txt(enum gas_query_result result)
  87 {
  88         switch (result) {
  89         case GAS_QUERY_SUCCESS:
  90                 return "SUCCESS";
  91         case GAS_QUERY_FAILURE:
  92                 return "FAILURE";
  93         case GAS_QUERY_TIMEOUT:
  94                 return "TIMEOUT";
  95         case GAS_QUERY_PEER_ERROR:
  96                 return "PEER_ERROR";
  97         case GAS_QUERY_INTERNAL_ERROR:
  98                 return "INTERNAL_ERROR";
  99         case GAS_QUERY_CANCELLED:
 100                 return "CANCELLED";
 101         case GAS_QUERY_DELETED_AT_DEINIT:
 102                 return "DELETED_AT_DEINIT";
 103         }
 104
 105         return "N/A";
 106 }
 107
 108
 109 static void gas_query_free(struct gas_query_pending *query, int del_list)
 110 {
 111         struct gas_query *gas = query->gas;
 112
 113         if (del_list)
 114                 dl_list_del(&query->list);
 115
 116         if (gas->work && gas->work->ctx == query) {
 117                 radio_work_done(gas->work);
 118                 gas->work = NULL;
 119         }
 120
 121         wpabuf_free(query->req);
 122         wpabuf_free(query->adv_proto);
 123         wpabuf_free(query->resp);
 124         os_free(query);
 125 }
 126
 127
 128 static void gas_query_done(struct gas_query *gas,
 129                            struct gas_query_pending *query,
 130                            enum gas_query_result result)
 131 {
 132         wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR
 133                 " dialog_token=%u freq=%d status_code=%u result=%s",
 134                 MAC2STR(query->addr), query->dialog_token, query->freq,
 135                 query->status_code, gas_result_txt(result));
 136         if (gas->current == query)
 137                 gas->current = NULL;
 138         if (query->offchannel_tx_started)
 139                 offchannel_send_action_done(gas->wpa_s);
 140         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 141         eloop_cancel_timeout(gas_query_timeout, gas, query);
 142         dl_list_del(&query->list);
 143         query->cb(query->ctx, query->addr, query->dialog_token, result,
 144                   query->adv_proto, query->resp, query->status_code);
 145         gas_query_free(query, 0);
 146 }
 147
 148
 149 /**
 150  * gas_query_deinit - Deinitialize GAS query component
 151  * @gas: GAS query data from gas_query_init()
 152  */
 153 void gas_query_deinit(struct gas_query *gas)
 154 {
 155         struct gas_query_pending *query, *next;
 156
 157         if (gas == NULL)
 158                 return;
 159
 160         dl_list_for_each_safe(query, next, &gas->pending,
 161                               struct gas_query_pending, list)
 162                 gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
 163
 164         os_free(gas);
 165 }
 166
 167
 168 static struct gas_query_pending *
 169 gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token)
 170 {
 171         struct gas_query_pending *q;
 172         dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
 173                 if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 &&
 174                     q->dialog_token == dialog_token)
 175                         return q;
 176         }
 177         return NULL;
 178 }
 179
 180
 181 static int gas_query_append(struct gas_query_pending *query, const u8 *data,
 182                             size_t len)
 183 {
 184         if (wpabuf_resize(&query->resp, len) < 0) {
 185                 wpa_printf(MSG_DEBUG, "GAS: No memory to store the response");
 186                 return -1;
 187         }
 188         wpabuf_put_data(query->resp, data, len);
 189         return 0;
 190 }
 191
 192
 193 static void gas_query_tx_status(struct wpa_supplicant *wpa_s,
 194                                 unsigned int freq, const u8 *dst,
 195                                 const u8 *src, const u8 *bssid,
 196                                 const u8 *data, size_t data_len,
 197                                 enum offchannel_send_action_result result)
 198 {
 199         struct gas_query_pending *query;
 200         struct gas_query *gas = wpa_s->gas;
 201
 202         if (gas->current == NULL) {
 203                 wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: freq=%u dst="
 204                            MACSTR " result=%d - no query in progress",
 205                            freq, MAC2STR(dst), result);
 206                 return;
 207         }
 208
 209         query = gas->current;
 210
 211         wpa_printf(MSG_DEBUG, "GAS: TX status: freq=%u dst=" MACSTR
 212                    " result=%d query=%p dialog_token=%u",
 213                    freq, MAC2STR(dst), result, query, query->dialog_token);
 214         if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) {
 215                 wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination");
 216                 return;
 217         }
 218
 219         if (result == OFFCHANNEL_SEND_ACTION_SUCCESS) {
 220                 eloop_cancel_timeout(gas_query_timeout, gas, query);
 221                 eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
 222                                        gas_query_timeout, gas, query);
 223         }
 224         if (result == OFFCHANNEL_SEND_ACTION_FAILED) {
 225                 eloop_cancel_timeout(gas_query_timeout, gas, query);
 226                 eloop_register_timeout(0, 0, gas_query_timeout, gas, query);
 227         }
 228 }
 229
 230
 231 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
 232                         struct wpabuf *req)
 233 {
 234         int res;
 235         wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
 236                    "freq=%d", MAC2STR(query->addr),
 237                    (unsigned int) wpabuf_len(req), query->freq);
 238         res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
 239                                      gas->wpa_s->own_addr, query->addr,
 240                                      wpabuf_head(req), wpabuf_len(req), 1000,
 241                                      gas_query_tx_status, 0);
 242         if (res == 0)
 243                 query->offchannel_tx_started = 1;
 244         return res;
 245 }
 246
 247
 248 static void gas_query_tx_comeback_req(struct gas_query *gas,
 249                                       struct gas_query_pending *query)
 250 {
 251         struct wpabuf *req;
 252
 253         req = gas_build_comeback_req(query->dialog_token);
 254         if (req == NULL) {
 255                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 256                 return;
 257         }
 258
 259         if (gas_query_tx(gas, query, req) < 0) {
 260                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 261                            MACSTR, MAC2STR(query->addr));
 262                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 263         }
 264
 265         wpabuf_free(req);
 266 }
 267
 268
 269 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
 270 {
 271         struct gas_query *gas = eloop_data;
 272         struct gas_query_pending *query = user_ctx;
 273
 274         wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
 275                    MAC2STR(query->addr));
 276         gas_query_tx_comeback_req(gas, query);
 277 }
 278
 279
 280 static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
 281                                             struct gas_query_pending *query,
 282                                             u16 comeback_delay)
 283 {
 284         unsigned int secs, usecs;
 285
 286         secs = (comeback_delay * 1024) / 1000000;
 287         usecs = comeback_delay * 1024 - secs * 1000000;
 288         wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
 289                    " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
 290         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 291         eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
 292                                gas, query);
 293 }
 294
 295
 296 static void gas_query_rx_initial(struct gas_query *gas,
 297                                  struct gas_query_pending *query,
 298                                  const u8 *adv_proto, const u8 *resp,
 299                                  size_t len, u16 comeback_delay)
 300 {
 301         wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
 302                    MACSTR " (dialog_token=%u comeback_delay=%u)",
 303                    MAC2STR(query->addr), query->dialog_token, comeback_delay);
 304
 305         query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]);
 306         if (query->adv_proto == NULL) {
 307                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 308                 return;
 309         }
 310
 311         if (comeback_delay) {
 312                 query->wait_comeback = 1;
 313                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 314                 return;
 315         }
 316
 317         /* Query was completed without comeback mechanism */
 318         if (gas_query_append(query, resp, len) < 0) {
 319                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 320                 return;
 321         }
 322
 323         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 324 }
 325
 326
 327 static void gas_query_rx_comeback(struct gas_query *gas,
 328                                   struct gas_query_pending *query,
 329                                   const u8 *adv_proto, const u8 *resp,
 330                                   size_t len, u8 frag_id, u8 more_frags,
 331                                   u16 comeback_delay)
 332 {
 333         wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
 334                    MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
 335                    "comeback_delay=%u)",
 336                    MAC2STR(query->addr), query->dialog_token, frag_id,
 337                    more_frags, comeback_delay);
 338
 339         if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) ||
 340             os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
 341                       wpabuf_len(query->adv_proto)) != 0) {
 342                 wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
 343                            "between initial and comeback response from "
 344                            MACSTR, MAC2STR(query->addr));
 345                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 346                 return;
 347         }
 348
 349         if (comeback_delay) {
 350                 if (frag_id) {
 351                         wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
 352                                    "with non-zero frag_id and comeback_delay "
 353                                    "from " MACSTR, MAC2STR(query->addr));
 354                         gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 355                         return;
 356                 }
 357                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 358                 return;
 359         }
 360
 361         if (frag_id != query->next_frag_id) {
 362                 wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
 363                            "from " MACSTR, MAC2STR(query->addr));
 364                 if (frag_id + 1 == query->next_frag_id) {
 365                         wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
 366                                    "retry of previous fragment");
 367                         return;
 368                 }
 369                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 370                 return;
 371         }
 372         query->next_frag_id++;
 373
 374         if (gas_query_append(query, resp, len) < 0) {
 375                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 376                 return;
 377         }
 378
 379         if (more_frags) {
 380                 gas_query_tx_comeback_req(gas, query);
 381                 return;
 382         }
 383
 384         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 385 }
 386
 387
 388 /**
 389  * gas_query_rx - Indicate reception of a Public Action frame
 390  * @gas: GAS query data from gas_query_init()
 391  * @da: Destination MAC address of the Action frame
 392  * @sa: Source MAC address of the Action frame
 393  * @bssid: BSSID of the Action frame
 394  * @data: Payload of the Action frame
 395  * @len: Length of @data
 396  * @freq: Frequency (in MHz) on which the frame was received
 397  * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
 398  */
 399 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
 400                  const u8 *bssid, const u8 *data, size_t len, int freq)
 401 {
 402         struct gas_query_pending *query;
 403         u8 action, dialog_token, frag_id = 0, more_frags = 0;
 404         u16 comeback_delay, resp_len;
 405         const u8 *pos, *adv_proto;
 406
 407         if (gas == NULL || len < 4)
 408                 return -1;
 409
 410         pos = data;
 411         action = *pos++;
 412         dialog_token = *pos++;
 413
 414         if (action != WLAN_PA_GAS_INITIAL_RESP &&
 415             action != WLAN_PA_GAS_COMEBACK_RESP)
 416                 return -1; /* Not a GAS response */
 417
 418         query = gas_query_get_pending(gas, sa, dialog_token);
 419         if (query == NULL) {
 420                 wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR
 421                            " dialog token %u", MAC2STR(sa), dialog_token);
 422                 return -1;
 423         }
 424
 425         if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) {
 426                 wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from "
 427                            MACSTR " dialog token %u when waiting for comeback "
 428                            "response", MAC2STR(sa), dialog_token);
 429                 return 0;
 430         }
 431
 432         if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) {
 433                 wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from "
 434                            MACSTR " dialog token %u when waiting for initial "
 435                            "response", MAC2STR(sa), dialog_token);
 436                 return 0;
 437         }
 438
 439         query->status_code = WPA_GET_LE16(pos);
 440         pos += 2;
 441
 442         if (query->status_code != WLAN_STATUS_SUCCESS) {
 443                 wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token "
 444                            "%u failed - status code %u",
 445                            MAC2STR(sa), dialog_token, query->status_code);
 446                 gas_query_done(gas, query, GAS_QUERY_FAILURE);
 447                 return 0;
 448         }
 449
 450         if (action == WLAN_PA_GAS_COMEBACK_RESP) {
 451                 if (pos + 1 > data + len)
 452                         return 0;
 453                 frag_id = *pos & 0x7f;
 454                 more_frags = (*pos & 0x80) >> 7;
 455                 pos++;
 456         }
 457
 458         /* Comeback Delay */
 459         if (pos + 2 > data + len)
 460                 return 0;
 461         comeback_delay = WPA_GET_LE16(pos);
 462         pos += 2;
 463
 464         /* Advertisement Protocol element */
 465         if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) {
 466                 wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
 467                            "Protocol element in the response from " MACSTR,
 468                            MAC2STR(sa));
 469                 return 0;
 470         }
 471
 472         if (*pos != WLAN_EID_ADV_PROTO) {
 473                 wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
 474                            "Protocol element ID %u in response from " MACSTR,
 475                            *pos, MAC2STR(sa));
 476                 return 0;
 477         }
 478
 479         adv_proto = pos;
 480         pos += 2 + pos[1];
 481
 482         /* Query Response Length */
 483         if (pos + 2 > data + len) {
 484                 wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
 485                 return 0;
 486         }
 487         resp_len = WPA_GET_LE16(pos);
 488         pos += 2;
 489
 490         if (pos + resp_len > data + len) {
 491                 wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
 492                            "response from " MACSTR, MAC2STR(sa));
 493                 return 0;
 494         }
 495
 496         if (pos + resp_len < data + len) {
 497                 wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
 498                            "after Query Response from " MACSTR,
 499                            (unsigned int) (data + len - pos - resp_len),
 500                            MAC2STR(sa));
 501         }
 502
 503         if (action == WLAN_PA_GAS_COMEBACK_RESP)
 504                 gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len,
 505                                       frag_id, more_frags, comeback_delay);
 506         else
 507                 gas_query_rx_initial(gas, query, adv_proto, pos, resp_len,
 508                                      comeback_delay);
 509
 510         return 0;
 511 }
 512
 513
 514 static void gas_query_timeout(void *eloop_data, void *user_ctx)
 515 {
 516         struct gas_query *gas = eloop_data;
 517         struct gas_query_pending *query = user_ctx;
 518
 519         wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
 520                    " dialog token %u",
 521                    MAC2STR(query->addr), query->dialog_token);
 522         gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
 523 }
 524
 525
 526 static int gas_query_dialog_token_available(struct gas_query *gas,
 527                                             const u8 *dst, u8 dialog_token)
 528 {
 529         struct gas_query_pending *q;
 530         dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
 531                 if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 &&
 532                     dialog_token == q->dialog_token)
 533                         return 0;
 534         }
 535
 536         return 1;
 537 }
 538
 539
 540 static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
 541 {
 542         struct gas_query_pending *query = work->ctx;
 543         struct gas_query *gas = query->gas;
 544
 545         if (deinit) {
 546                 gas_query_free(query, 1);
 547                 return;
 548         }
 549
 550         gas->work = work;
 551
 552         if (gas_query_tx(gas, query, query->req) < 0) {
 553                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 554                            MACSTR, MAC2STR(query->addr));
 555                 gas_query_free(query, 1);
 556                 return;
 557         }
 558         gas->current = query;
 559
 560         wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
 561                    query->dialog_token);
 562         eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
 563                                gas_query_timeout, gas, query);
 564
 565 }
 566
 567
 568 /**
 569  * gas_query_req - Request a GAS query
 570  * @gas: GAS query data from gas_query_init()
 571  * @dst: Destination MAC address for the query
 572  * @freq: Frequency (in MHz) for the channel on which to send the query
 573  * @req: GAS query payload (to be freed by gas_query module in case of success
 574  *      return)
 575  * @cb: Callback function for reporting GAS query result and response
 576  * @ctx: Context pointer to use with the @cb call
 577  * Returns: dialog token (>= 0) on success or -1 on failure
 578  */
 579 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
 580                   struct wpabuf *req,
 581                   void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
 582                              enum gas_query_result result,
 583                              const struct wpabuf *adv_proto,
 584                              const struct wpabuf *resp, u16 status_code),
 585                   void *ctx)
 586 {
 587         struct gas_query_pending *query;
 588         int dialog_token;
 589         static int next_start = 0;
 590
 591         if (wpabuf_len(req) < 3)
 592                 return -1;
 593
 594         for (dialog_token = 0; dialog_token < 256; dialog_token++) {
 595                 if (gas_query_dialog_token_available(
 596                             gas, dst, (next_start + dialog_token) % 256))
 597                         break;
 598         }
 599         if (dialog_token == 256)
 600                 return -1; /* Too many pending queries */
 601         dialog_token = (next_start + dialog_token) % 256;
 602         next_start = (dialog_token + 1) % 256;
 603
 604         query = os_zalloc(sizeof(*query));
 605         if (query == NULL)
 606                 return -1;
 607
 608         query->gas = gas;
 609         os_memcpy(query->addr, dst, ETH_ALEN);
 610         query->dialog_token = dialog_token;
 611         query->freq = freq;
 612         query->cb = cb;
 613         query->ctx = ctx;
 614         query->req = req;
 615         dl_list_add(&gas->pending, &query->list);
 616
 617         *(wpabuf_mhead_u8(req) + 2) = dialog_token;
 618
 619         wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
 620                 " dialog_token=%u freq=%d",
 621                 MAC2STR(query->addr), query->dialog_token, query->freq);
 622
 623         if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
 624                            query) < 0) {
 625                 gas_query_free(query, 1);
 626                 return -1;
 627         }
 628
 629         return dialog_token;
 630 }
 631
 632
 633 /**
 634  * gas_query_cancel - Cancel a pending GAS query
 635  * @gas: GAS query data from gas_query_init()
 636  * @dst: Destination MAC address for the query
 637  * @dialog_token: Dialog token from gas_query_req()
 638  */
 639 void gas_query_cancel(struct gas_query *gas, const u8 *dst, u8 dialog_token)
 640 {
 641         struct gas_query_pending *query;
 642
 643         query = gas_query_get_pending(gas, dst, dialog_token);
 644         if (query)
 645                 gas_query_done(gas, query, GAS_QUERY_CANCELLED);
 646
 647 }