wpa_supplicant/gas_query.c

   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
  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  */
  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
  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
 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
 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  */
 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 *
 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
 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
 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
 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
 256 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
 257                         struct wpabuf *req)
 258 {
 259         int res, prot = pmf_in_use(gas->wpa_s, query->addr);
 260
 261         wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
 262                    "freq=%d prot=%d", MAC2STR(query->addr),
 263                    (unsigned int) wpabuf_len(req), query->freq, prot);
 264         if (prot) {
 265                 u8 *categ = wpabuf_mhead_u8(req);
 266                 *categ = WLAN_ACTION_PROTECTED_DUAL;
 267         }
 268         os_get_reltime(&query->last_oper);
 269         res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
 270                                      gas->wpa_s->own_addr, query->addr,
 271                                      wpabuf_head(req), wpabuf_len(req), 1000,
 272                                      gas_query_tx_status, 0);
 273         if (res == 0)
 274                 query->offchannel_tx_started = 1;
 275         return res;
 276 }
 277
 278
 279 static void gas_query_tx_comeback_req(struct gas_query *gas,
 280                                       struct gas_query_pending *query)
 281 {
 282         struct wpabuf *req;
 283
 284         req = gas_build_comeback_req(query->dialog_token);
 285         if (req == NULL) {
 286                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 287                 return;
 288         }
 289
 290         if (gas_query_tx(gas, query, req) < 0) {
 291                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 292                            MACSTR, MAC2STR(query->addr));
 293                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 294         }
 295
 296         wpabuf_free(req);
 297 }
 298
 299
 300 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
 301 {
 302         struct gas_query *gas = eloop_data;
 303         struct gas_query_pending *query = user_ctx;
 304
 305         wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
 306                    MAC2STR(query->addr));
 307         gas_query_tx_comeback_req(gas, query);
 308 }
 309
 310
 311 static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
 312                                             struct gas_query_pending *query,
 313                                             u16 comeback_delay)
 314 {
 315         unsigned int secs, usecs;
 316
 317         secs = (comeback_delay * 1024) / 1000000;
 318         usecs = comeback_delay * 1024 - secs * 1000000;
 319         wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
 320                    " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
 321         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 322         eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
 323                                gas, query);
 324 }
 325
 326
 327 static void gas_query_rx_initial(struct gas_query *gas,
 328                                  struct gas_query_pending *query,
 329                                  const u8 *adv_proto, const u8 *resp,
 330                                  size_t len, u16 comeback_delay)
 331 {
 332         wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
 333                    MACSTR " (dialog_token=%u comeback_delay=%u)",
 334                    MAC2STR(query->addr), query->dialog_token, comeback_delay);
 335
 336         query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]);
 337         if (query->adv_proto == NULL) {
 338                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 339                 return;
 340         }
 341
 342         if (comeback_delay) {
 343                 query->wait_comeback = 1;
 344                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 345                 return;
 346         }
 347
 348         /* Query was completed without comeback mechanism */
 349         if (gas_query_append(query, resp, len) < 0) {
 350                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 351                 return;
 352         }
 353
 354         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 355 }
 356
 357
 358 static void gas_query_rx_comeback(struct gas_query *gas,
 359                                   struct gas_query_pending *query,
 360                                   const u8 *adv_proto, const u8 *resp,
 361                                   size_t len, u8 frag_id, u8 more_frags,
 362                                   u16 comeback_delay)
 363 {
 364         wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
 365                    MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
 366                    "comeback_delay=%u)",
 367                    MAC2STR(query->addr), query->dialog_token, frag_id,
 368                    more_frags, comeback_delay);
 369
 370         if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) ||
 371             os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
 372                       wpabuf_len(query->adv_proto)) != 0) {
 373                 wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
 374                            "between initial and comeback response from "
 375                            MACSTR, MAC2STR(query->addr));
 376                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 377                 return;
 378         }
 379
 380         if (comeback_delay) {
 381                 if (frag_id) {
 382                         wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
 383                                    "with non-zero frag_id and comeback_delay "
 384                                    "from " MACSTR, MAC2STR(query->addr));
 385                         gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 386                         return;
 387                 }
 388                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 389                 return;
 390         }
 391
 392         if (frag_id != query->next_frag_id) {
 393                 wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
 394                            "from " MACSTR, MAC2STR(query->addr));
 395                 if (frag_id + 1 == query->next_frag_id) {
 396                         wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
 397                                    "retry of previous fragment");
 398                         return;
 399                 }
 400                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 401                 return;
 402         }
 403         query->next_frag_id++;
 404
 405         if (gas_query_append(query, resp, len) < 0) {
 406                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 407                 return;
 408         }
 409
 410         if (more_frags) {
 411                 gas_query_tx_comeback_req(gas, query);
 412                 return;
 413         }
 414
 415         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 416 }
 417
 418
 419 /**
 420  * gas_query_rx - Indicate reception of a Public Action or Protected Dual frame
 421  * @gas: GAS query data from gas_query_init()
 422  * @da: Destination MAC address of the Action frame
 423  * @sa: Source MAC address of the Action frame
 424  * @bssid: BSSID of the Action frame
 425  * @categ: Category of the Action frame
 426  * @data: Payload of the Action frame
 427  * @len: Length of @data
 428  * @freq: Frequency (in MHz) on which the frame was received
 429  * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
 430  */
 431 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
 432                  const u8 *bssid, u8 categ, const u8 *data, size_t len,
 433                  int freq)
 434 {
 435         struct gas_query_pending *query;
 436         u8 action, dialog_token, frag_id = 0, more_frags = 0;
 437         u16 comeback_delay, resp_len;
 438         const u8 *pos, *adv_proto;
 439         int prot, pmf;
 440
 441         if (gas == NULL || len < 4)
 442                 return -1;
 443
 444         prot = categ == WLAN_ACTION_PROTECTED_DUAL;
 445         pmf = pmf_in_use(gas->wpa_s, bssid);
 446         if (prot && !pmf) {
 447                 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled");
 448                 return 0;
 449         }
 450         if (!prot && pmf) {
 451                 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled");
 452                 return 0;
 453         }
 454
 455         pos = data;
 456         action = *pos++;
 457         dialog_token = *pos++;
 458
 459         if (action != WLAN_PA_GAS_INITIAL_RESP &&
 460             action != WLAN_PA_GAS_COMEBACK_RESP)
 461                 return -1; /* Not a GAS response */
 462
 463         query = gas_query_get_pending(gas, sa, dialog_token);
 464         if (query == NULL) {
 465                 wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR
 466                            " dialog token %u", MAC2STR(sa), dialog_token);
 467                 return -1;
 468         }
 469
 470         wpa_printf(MSG_DEBUG, "GAS: Response in %d ms from " MACSTR,
 471                    ms_from_time(&query->last_oper), MAC2STR(sa));
 472
 473         if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) {
 474                 wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from "
 475                            MACSTR " dialog token %u when waiting for comeback "
 476                            "response", MAC2STR(sa), dialog_token);
 477                 return 0;
 478         }
 479
 480         if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) {
 481                 wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from "
 482                            MACSTR " dialog token %u when waiting for initial "
 483                            "response", MAC2STR(sa), dialog_token);
 484                 return 0;
 485         }
 486
 487         query->status_code = WPA_GET_LE16(pos);
 488         pos += 2;
 489
 490         if (query->status_code != WLAN_STATUS_SUCCESS) {
 491                 wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token "
 492                            "%u failed - status code %u",
 493                            MAC2STR(sa), dialog_token, query->status_code);
 494                 gas_query_done(gas, query, GAS_QUERY_FAILURE);
 495                 return 0;
 496         }
 497
 498         if (action == WLAN_PA_GAS_COMEBACK_RESP) {
 499                 if (pos + 1 > data + len)
 500                         return 0;
 501                 frag_id = *pos & 0x7f;
 502                 more_frags = (*pos & 0x80) >> 7;
 503                 pos++;
 504         }
 505
 506         /* Comeback Delay */
 507         if (pos + 2 > data + len)
 508                 return 0;
 509         comeback_delay = WPA_GET_LE16(pos);
 510         pos += 2;
 511
 512         /* Advertisement Protocol element */
 513         if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) {
 514                 wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
 515                            "Protocol element in the response from " MACSTR,
 516                            MAC2STR(sa));
 517                 return 0;
 518         }
 519
 520         if (*pos != WLAN_EID_ADV_PROTO) {
 521                 wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
 522                            "Protocol element ID %u in response from " MACSTR,
 523                            *pos, MAC2STR(sa));
 524                 return 0;
 525         }
 526
 527         adv_proto = pos;
 528         pos += 2 + pos[1];
 529
 530         /* Query Response Length */
 531         if (pos + 2 > data + len) {
 532                 wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
 533                 return 0;
 534         }
 535         resp_len = WPA_GET_LE16(pos);
 536         pos += 2;
 537
 538         if (pos + resp_len > data + len) {
 539                 wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
 540                            "response from " MACSTR, MAC2STR(sa));
 541                 return 0;
 542         }
 543
 544         if (pos + resp_len < data + len) {
 545                 wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
 546                            "after Query Response from " MACSTR,
 547                            (unsigned int) (data + len - pos - resp_len),
 548                            MAC2STR(sa));
 549         }
 550
 551         if (action == WLAN_PA_GAS_COMEBACK_RESP)
 552                 gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len,
 553                                       frag_id, more_frags, comeback_delay);
 554         else
 555                 gas_query_rx_initial(gas, query, adv_proto, pos, resp_len,
 556                                      comeback_delay);
 557
 558         return 0;
 559 }
 560
 561
 562 static void gas_query_timeout(void *eloop_data, void *user_ctx)
 563 {
 564         struct gas_query *gas = eloop_data;
 565         struct gas_query_pending *query = user_ctx;
 566
 567         wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
 568                    " dialog token %u",
 569                    MAC2STR(query->addr), query->dialog_token);
 570         gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
 571 }
 572
 573
 574 static int gas_query_dialog_token_available(struct gas_query *gas,
 575                                             const u8 *dst, u8 dialog_token)
 576 {
 577         struct gas_query_pending *q;
 578         dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
 579                 if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 &&
 580                     dialog_token == q->dialog_token)
 581                         return 0;
 582         }
 583
 584         return 1;
 585 }
 586
 587
 588 static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
 589 {
 590         struct gas_query_pending *query = work->ctx;
 591         struct gas_query *gas = query->gas;
 592
 593         if (deinit) {
 594                 if (work->started) {
 595                         gas->work = NULL;
 596                         gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
 597                         return;
 598                 }
 599
 600                 gas_query_free(query, 1);
 601                 return;
 602         }
 603
 604         gas->work = work;
 605
 606         if (gas_query_tx(gas, query, query->req) < 0) {
 607                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 608                            MACSTR, MAC2STR(query->addr));
 609                 gas_query_free(query, 1);
 610                 return;
 611         }
 612         gas->current = query;
 613
 614         wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
 615                    query->dialog_token);
 616         eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
 617                                gas_query_timeout, gas, query);
 618
 619 }
 620
 621
 622 /**
 623  * gas_query_req - Request a GAS query
 624  * @gas: GAS query data from gas_query_init()
 625  * @dst: Destination MAC address for the query
 626  * @freq: Frequency (in MHz) for the channel on which to send the query
 627  * @req: GAS query payload (to be freed by gas_query module in case of success
 628  *      return)
 629  * @cb: Callback function for reporting GAS query result and response
 630  * @ctx: Context pointer to use with the @cb call
 631  * Returns: dialog token (>= 0) on success or -1 on failure
 632  */
 633 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
 634                   struct wpabuf *req,
 635                   void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
 636                              enum gas_query_result result,
 637                              const struct wpabuf *adv_proto,
 638                              const struct wpabuf *resp, u16 status_code),
 639                   void *ctx)
 640 {
 641         struct gas_query_pending *query;
 642         int dialog_token;
 643         static int next_start = 0;
 644
 645         if (wpabuf_len(req) < 3)
 646                 return -1;
 647
 648         for (dialog_token = 0; dialog_token < 256; dialog_token++) {
 649                 if (gas_query_dialog_token_available(
 650                             gas, dst, (next_start + dialog_token) % 256))
 651                         break;
 652         }
 653         if (dialog_token == 256)
 654                 return -1; /* Too many pending queries */
 655         dialog_token = (next_start + dialog_token) % 256;
 656         next_start = (dialog_token + 1) % 256;
 657
 658         query = os_zalloc(sizeof(*query));
 659         if (query == NULL)
 660                 return -1;
 661
 662         query->gas = gas;
 663         os_memcpy(query->addr, dst, ETH_ALEN);
 664         query->dialog_token = dialog_token;
 665         query->freq = freq;
 666         query->cb = cb;
 667         query->ctx = ctx;
 668         query->req = req;
 669         dl_list_add(&gas->pending, &query->list);
 670
 671         *(wpabuf_mhead_u8(req) + 2) = dialog_token;
 672
 673         wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
 674                 " dialog_token=%u freq=%d",
 675                 MAC2STR(query->addr), query->dialog_token, query->freq);
 676
 677         if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
 678                            query) < 0) {
 679                 gas_query_free(query, 1);
 680                 return -1;
 681         }
 682
 683         return dialog_token;
 684 }
 685
 686
 687 /**
 688  * gas_query_cancel - Cancel a pending GAS query
 689  * @gas: GAS query data from gas_query_init()
 690  * @dst: Destination MAC address for the query
 691  * @dialog_token: Dialog token from gas_query_req()
 692  */
 693 void gas_query_cancel(struct gas_query *gas, const u8 *dst, u8 dialog_token)
 694 {
 695         struct gas_query_pending *query;
 696
 697         query = gas_query_get_pending(gas, dst, dialog_token);
 698         if (query)
 699                 gas_query_done(gas, query, GAS_QUERY_CANCELLED);
 700
 701 }