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 "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         int freq;
  46         u16 status_code;
  47         struct wpabuf *req;
  48         struct wpabuf *adv_proto;
  49         struct wpabuf *resp;
  50         struct os_reltime last_oper;
  51         void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
  52                    enum gas_query_result result,
  53                    const struct wpabuf *adv_proto,
  54                    const struct wpabuf *resp, u16 status_code);
  55         void *ctx;
  56 };
  57
  58 /**
  59  * struct gas_query - Internal GAS query data
  60  */
  61 struct gas_query {
  62         struct wpa_supplicant *wpa_s;
  63         struct dl_list pending; /* struct gas_query_pending */
  64         struct gas_query_pending *current;
  65         struct wpa_radio_work *work;
  66 };
  67
  68
  69 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx);
  70 static void gas_query_timeout(void *eloop_data, void *user_ctx);
  71 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx);
  72 static void gas_query_tx_initial_req(struct gas_query *gas,
  73                                      struct gas_query_pending *query);
  74 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst);
  75
  76
  77 static int ms_from_time(struct os_reltime *last)
  78 {
  79         struct os_reltime now, res;
  80
  81         os_get_reltime(&now);
  82         os_reltime_sub(&now, last, &res);
  83         return res.sec * 1000 + res.usec / 1000;
  84 }
  85
  86
  87 /**
  88  * gas_query_init - Initialize GAS query component
  89  * @wpa_s: Pointer to wpa_supplicant data
  90  * Returns: Pointer to GAS query data or %NULL on failure
  91  */
  92 struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s)
  93 {
  94         struct gas_query *gas;
  95
  96         gas = os_zalloc(sizeof(*gas));
  97         if (gas == NULL)
  98                 return NULL;
  99
 100         gas->wpa_s = wpa_s;
 101         dl_list_init(&gas->pending);
 102
 103         return gas;
 104 }
 105
 106
 107 static const char * gas_result_txt(enum gas_query_result result)
 108 {
 109         switch (result) {
 110         case GAS_QUERY_SUCCESS:
 111                 return "SUCCESS";
 112         case GAS_QUERY_FAILURE:
 113                 return "FAILURE";
 114         case GAS_QUERY_TIMEOUT:
 115                 return "TIMEOUT";
 116         case GAS_QUERY_PEER_ERROR:
 117                 return "PEER_ERROR";
 118         case GAS_QUERY_INTERNAL_ERROR:
 119                 return "INTERNAL_ERROR";
 120         case GAS_QUERY_CANCELLED:
 121                 return "CANCELLED";
 122         case GAS_QUERY_DELETED_AT_DEINIT:
 123                 return "DELETED_AT_DEINIT";
 124         }
 125
 126         return "N/A";
 127 }
 128
 129
 130 static void gas_query_free(struct gas_query_pending *query, int del_list)
 131 {
 132         struct gas_query *gas = query->gas;
 133
 134         if (del_list)
 135                 dl_list_del(&query->list);
 136
 137         if (gas->work && gas->work->ctx == query) {
 138                 radio_work_done(gas->work);
 139                 gas->work = NULL;
 140         }
 141
 142         wpabuf_free(query->req);
 143         wpabuf_free(query->adv_proto);
 144         wpabuf_free(query->resp);
 145         os_free(query);
 146 }
 147
 148
 149 static void gas_query_done(struct gas_query *gas,
 150                            struct gas_query_pending *query,
 151                            enum gas_query_result result)
 152 {
 153         wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR
 154                 " dialog_token=%u freq=%d status_code=%u result=%s",
 155                 MAC2STR(query->addr), query->dialog_token, query->freq,
 156                 query->status_code, gas_result_txt(result));
 157         if (gas->current == query)
 158                 gas->current = NULL;
 159         if (query->offchannel_tx_started)
 160                 offchannel_send_action_done(gas->wpa_s);
 161         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 162         eloop_cancel_timeout(gas_query_timeout, gas, query);
 163         eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
 164         dl_list_del(&query->list);
 165         query->cb(query->ctx, query->addr, query->dialog_token, result,
 166                   query->adv_proto, query->resp, query->status_code);
 167         gas_query_free(query, 0);
 168 }
 169
 170
 171 /**
 172  * gas_query_deinit - Deinitialize GAS query component
 173  * @gas: GAS query data from gas_query_init()
 174  */
 175 void gas_query_deinit(struct gas_query *gas)
 176 {
 177         struct gas_query_pending *query, *next;
 178
 179         if (gas == NULL)
 180                 return;
 181
 182         dl_list_for_each_safe(query, next, &gas->pending,
 183                               struct gas_query_pending, list)
 184                 gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
 185
 186         os_free(gas);
 187 }
 188
 189
 190 static struct gas_query_pending *
 191 gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token)
 192 {
 193         struct gas_query_pending *q;
 194         dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
 195                 if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 &&
 196                     q->dialog_token == dialog_token)
 197                         return q;
 198         }
 199         return NULL;
 200 }
 201
 202
 203 static int gas_query_append(struct gas_query_pending *query, const u8 *data,
 204                             size_t len)
 205 {
 206         if (wpabuf_resize(&query->resp, len) < 0) {
 207                 wpa_printf(MSG_DEBUG, "GAS: No memory to store the response");
 208                 return -1;
 209         }
 210         wpabuf_put_data(query->resp, data, len);
 211         return 0;
 212 }
 213
 214
 215 static void gas_query_tx_status(struct wpa_supplicant *wpa_s,
 216                                 unsigned int freq, const u8 *dst,
 217                                 const u8 *src, const u8 *bssid,
 218                                 const u8 *data, size_t data_len,
 219                                 enum offchannel_send_action_result result)
 220 {
 221         struct gas_query_pending *query;
 222         struct gas_query *gas = wpa_s->gas;
 223         int dur;
 224
 225         if (gas->current == NULL) {
 226                 wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: freq=%u dst="
 227                            MACSTR " result=%d - no query in progress",
 228                            freq, MAC2STR(dst), result);
 229                 return;
 230         }
 231
 232         query = gas->current;
 233
 234         dur = ms_from_time(&query->last_oper);
 235         wpa_printf(MSG_DEBUG, "GAS: TX status: freq=%u dst=" MACSTR
 236                    " result=%d query=%p dialog_token=%u dur=%d ms",
 237                    freq, MAC2STR(dst), result, query, query->dialog_token, dur);
 238         if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) {
 239                 wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination");
 240                 return;
 241         }
 242         os_get_reltime(&query->last_oper);
 243
 244         if (result == OFFCHANNEL_SEND_ACTION_SUCCESS) {
 245                 eloop_cancel_timeout(gas_query_timeout, gas, query);
 246                 eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
 247                                        gas_query_timeout, gas, query);
 248                 if (query->wait_comeback && !query->retry) {
 249                         eloop_cancel_timeout(gas_query_rx_comeback_timeout,
 250                                              gas, query);
 251                         eloop_register_timeout(
 252                                 0, (GAS_QUERY_WAIT_TIME_COMEBACK + 10) * 1000,
 253                                 gas_query_rx_comeback_timeout, gas, query);
 254                 }
 255         }
 256         if (result == OFFCHANNEL_SEND_ACTION_FAILED) {
 257                 eloop_cancel_timeout(gas_query_timeout, gas, query);
 258                 eloop_register_timeout(0, 0, gas_query_timeout, gas, query);
 259         }
 260 }
 261
 262
 263 static int pmf_in_use(struct wpa_supplicant *wpa_s, const u8 *addr)
 264 {
 265         if (wpa_s->current_ssid == NULL ||
 266             wpa_s->wpa_state < WPA_4WAY_HANDSHAKE ||
 267             os_memcmp(addr, wpa_s->bssid, ETH_ALEN) != 0)
 268                 return 0;
 269         return wpa_sm_pmf_enabled(wpa_s->wpa);
 270 }
 271
 272
 273 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
 274                         struct wpabuf *req, unsigned int wait_time)
 275 {
 276         int res, prot = pmf_in_use(gas->wpa_s, query->addr);
 277         const u8 *bssid;
 278         const u8 wildcard_bssid[ETH_ALEN] = {
 279                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
 280         };
 281
 282         wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
 283                    "freq=%d prot=%d", MAC2STR(query->addr),
 284                    (unsigned int) wpabuf_len(req), query->freq, prot);
 285         if (prot) {
 286                 u8 *categ = wpabuf_mhead_u8(req);
 287                 *categ = WLAN_ACTION_PROTECTED_DUAL;
 288         }
 289         os_get_reltime(&query->last_oper);
 290         if (gas->wpa_s->max_remain_on_chan &&
 291             wait_time > gas->wpa_s->max_remain_on_chan)
 292                 wait_time = gas->wpa_s->max_remain_on_chan;
 293         if (!gas->wpa_s->conf->gas_address3 ||
 294             (gas->wpa_s->current_ssid &&
 295              gas->wpa_s->wpa_state >= WPA_ASSOCIATED &&
 296              os_memcmp(query->addr, gas->wpa_s->bssid, ETH_ALEN) == 0))
 297                 bssid = query->addr;
 298         else
 299                 bssid = wildcard_bssid;
 300         res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
 301                                      gas->wpa_s->own_addr, bssid,
 302                                      wpabuf_head(req), wpabuf_len(req),
 303                                      wait_time, gas_query_tx_status, 0);
 304         if (res == 0)
 305                 query->offchannel_tx_started = 1;
 306         return res;
 307 }
 308
 309
 310 static void gas_query_tx_comeback_req(struct gas_query *gas,
 311                                       struct gas_query_pending *query)
 312 {
 313         struct wpabuf *req;
 314         unsigned int wait_time;
 315
 316         req = gas_build_comeback_req(query->dialog_token);
 317         if (req == NULL) {
 318                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 319                 return;
 320         }
 321
 322         wait_time = (query->retry || !query->offchannel_tx_started) ?
 323                 GAS_QUERY_WAIT_TIME_INITIAL : GAS_QUERY_WAIT_TIME_COMEBACK;
 324
 325         if (gas_query_tx(gas, query, req, wait_time) < 0) {
 326                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 327                            MACSTR, MAC2STR(query->addr));
 328                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 329         }
 330
 331         wpabuf_free(req);
 332 }
 333
 334
 335 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx)
 336 {
 337         struct gas_query *gas = eloop_data;
 338         struct gas_query_pending *query = user_ctx;
 339         int dialog_token;
 340
 341         wpa_printf(MSG_DEBUG,
 342                    "GAS: No response to comeback request received (retry=%u)",
 343                    query->retry);
 344         if (gas->current != query || query->retry)
 345                 return;
 346         dialog_token = gas_query_new_dialog_token(gas, query->addr);
 347         if (dialog_token < 0)
 348                 return;
 349         wpa_printf(MSG_DEBUG,
 350                    "GAS: Retry GAS query due to comeback response timeout");
 351         query->retry = 1;
 352         query->dialog_token = dialog_token;
 353         *(wpabuf_mhead_u8(query->req) + 2) = dialog_token;
 354         query->wait_comeback = 0;
 355         query->next_frag_id = 0;
 356         wpabuf_free(query->adv_proto);
 357         query->adv_proto = NULL;
 358         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 359         eloop_cancel_timeout(gas_query_timeout, gas, query);
 360         gas_query_tx_initial_req(gas, query);
 361 }
 362
 363
 364 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
 365 {
 366         struct gas_query *gas = eloop_data;
 367         struct gas_query_pending *query = user_ctx;
 368
 369         wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
 370                    MAC2STR(query->addr));
 371         gas_query_tx_comeback_req(gas, query);
 372 }
 373
 374
 375 static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
 376                                             struct gas_query_pending *query,
 377                                             u16 comeback_delay)
 378 {
 379         unsigned int secs, usecs;
 380
 381         if (comeback_delay > 1 && query->offchannel_tx_started) {
 382                 offchannel_send_action_done(gas->wpa_s);
 383                 query->offchannel_tx_started = 0;
 384         }
 385
 386         secs = (comeback_delay * 1024) / 1000000;
 387         usecs = comeback_delay * 1024 - secs * 1000000;
 388         wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
 389                    " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
 390         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 391         eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
 392                                gas, query);
 393 }
 394
 395
 396 static void gas_query_rx_initial(struct gas_query *gas,
 397                                  struct gas_query_pending *query,
 398                                  const u8 *adv_proto, const u8 *resp,
 399                                  size_t len, u16 comeback_delay)
 400 {
 401         wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
 402                    MACSTR " (dialog_token=%u comeback_delay=%u)",
 403                    MAC2STR(query->addr), query->dialog_token, comeback_delay);
 404
 405         query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]);
 406         if (query->adv_proto == NULL) {
 407                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 408                 return;
 409         }
 410
 411         if (comeback_delay) {
 412                 query->wait_comeback = 1;
 413                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 414                 return;
 415         }
 416
 417         /* Query was completed without comeback mechanism */
 418         if (gas_query_append(query, resp, len) < 0) {
 419                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 420                 return;
 421         }
 422
 423         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 424 }
 425
 426
 427 static void gas_query_rx_comeback(struct gas_query *gas,
 428                                   struct gas_query_pending *query,
 429                                   const u8 *adv_proto, const u8 *resp,
 430                                   size_t len, u8 frag_id, u8 more_frags,
 431                                   u16 comeback_delay)
 432 {
 433         wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
 434                    MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
 435                    "comeback_delay=%u)",
 436                    MAC2STR(query->addr), query->dialog_token, frag_id,
 437                    more_frags, comeback_delay);
 438         eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
 439
 440         if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) ||
 441             os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
 442                       wpabuf_len(query->adv_proto)) != 0) {
 443                 wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
 444                            "between initial and comeback response from "
 445                            MACSTR, MAC2STR(query->addr));
 446                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 447                 return;
 448         }
 449
 450         if (comeback_delay) {
 451                 if (frag_id) {
 452                         wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
 453                                    "with non-zero frag_id and comeback_delay "
 454                                    "from " MACSTR, MAC2STR(query->addr));
 455                         gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 456                         return;
 457                 }
 458                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 459                 return;
 460         }
 461
 462         if (frag_id != query->next_frag_id) {
 463                 wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
 464                            "from " MACSTR, MAC2STR(query->addr));
 465                 if (frag_id + 1 == query->next_frag_id) {
 466                         wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
 467                                    "retry of previous fragment");
 468                         return;
 469                 }
 470                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 471                 return;
 472         }
 473         query->next_frag_id++;
 474
 475         if (gas_query_append(query, resp, len) < 0) {
 476                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 477                 return;
 478         }
 479
 480         if (more_frags) {
 481                 gas_query_tx_comeback_req(gas, query);
 482                 return;
 483         }
 484
 485         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 486 }
 487
 488
 489 /**
 490  * gas_query_rx - Indicate reception of a Public Action or Protected Dual frame
 491  * @gas: GAS query data from gas_query_init()
 492  * @da: Destination MAC address of the Action frame
 493  * @sa: Source MAC address of the Action frame
 494  * @bssid: BSSID of the Action frame
 495  * @categ: Category of the Action frame
 496  * @data: Payload of the Action frame
 497  * @len: Length of @data
 498  * @freq: Frequency (in MHz) on which the frame was received
 499  * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
 500  */
 501 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
 502                  const u8 *bssid, u8 categ, const u8 *data, size_t len,
 503                  int freq)
 504 {
 505         struct gas_query_pending *query;
 506         u8 action, dialog_token, frag_id = 0, more_frags = 0;
 507         u16 comeback_delay, resp_len;
 508         const u8 *pos, *adv_proto;
 509         int prot, pmf;
 510         unsigned int left;
 511
 512         if (gas == NULL || len < 4)
 513                 return -1;
 514
 515         pos = data;
 516         action = *pos++;
 517         dialog_token = *pos++;
 518
 519         if (action != WLAN_PA_GAS_INITIAL_RESP &&
 520             action != WLAN_PA_GAS_COMEBACK_RESP)
 521                 return -1; /* Not a GAS response */
 522
 523         prot = categ == WLAN_ACTION_PROTECTED_DUAL;
 524         pmf = pmf_in_use(gas->wpa_s, sa);
 525         if (prot && !pmf) {
 526                 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled");
 527                 return 0;
 528         }
 529         if (!prot && pmf) {
 530                 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled");
 531                 return 0;
 532         }
 533
 534         query = gas_query_get_pending(gas, sa, dialog_token);
 535         if (query == NULL) {
 536                 wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR
 537                            " dialog token %u", MAC2STR(sa), dialog_token);
 538                 return -1;
 539         }
 540
 541         wpa_printf(MSG_DEBUG, "GAS: Response in %d ms from " MACSTR,
 542                    ms_from_time(&query->last_oper), MAC2STR(sa));
 543
 544         if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) {
 545                 wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from "
 546                            MACSTR " dialog token %u when waiting for comeback "
 547                            "response", MAC2STR(sa), dialog_token);
 548                 return 0;
 549         }
 550
 551         if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) {
 552                 wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from "
 553                            MACSTR " dialog token %u when waiting for initial "
 554                            "response", MAC2STR(sa), dialog_token);
 555                 return 0;
 556         }
 557
 558         query->status_code = WPA_GET_LE16(pos);
 559         pos += 2;
 560
 561         if (query->status_code == WLAN_STATUS_QUERY_RESP_OUTSTANDING &&
 562             action == WLAN_PA_GAS_COMEBACK_RESP) {
 563                 wpa_printf(MSG_DEBUG, "GAS: Allow non-zero status for outstanding comeback response");
 564         } else if (query->status_code != WLAN_STATUS_SUCCESS) {
 565                 wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token "
 566                            "%u failed - status code %u",
 567                            MAC2STR(sa), dialog_token, query->status_code);
 568                 gas_query_done(gas, query, GAS_QUERY_FAILURE);
 569                 return 0;
 570         }
 571
 572         if (action == WLAN_PA_GAS_COMEBACK_RESP) {
 573                 if (pos + 1 > data + len)
 574                         return 0;
 575                 frag_id = *pos & 0x7f;
 576                 more_frags = (*pos & 0x80) >> 7;
 577                 pos++;
 578         }
 579
 580         /* Comeback Delay */
 581         if (pos + 2 > data + len)
 582                 return 0;
 583         comeback_delay = WPA_GET_LE16(pos);
 584         pos += 2;
 585
 586         /* Advertisement Protocol element */
 587         if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) {
 588                 wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
 589                            "Protocol element in the response from " MACSTR,
 590                            MAC2STR(sa));
 591                 return 0;
 592         }
 593
 594         if (*pos != WLAN_EID_ADV_PROTO) {
 595                 wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
 596                            "Protocol element ID %u in response from " MACSTR,
 597                            *pos, MAC2STR(sa));
 598                 return 0;
 599         }
 600
 601         adv_proto = pos;
 602         pos += 2 + pos[1];
 603
 604         /* Query Response Length */
 605         if (pos + 2 > data + len) {
 606                 wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
 607                 return 0;
 608         }
 609         resp_len = WPA_GET_LE16(pos);
 610         pos += 2;
 611
 612         left = data + len - pos;
 613         if (resp_len > left) {
 614                 wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
 615                            "response from " MACSTR, MAC2STR(sa));
 616                 return 0;
 617         }
 618
 619         if (resp_len < left) {
 620                 wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
 621                            "after Query Response from " MACSTR,
 622                            left - resp_len, MAC2STR(sa));
 623         }
 624
 625         if (action == WLAN_PA_GAS_COMEBACK_RESP)
 626                 gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len,
 627                                       frag_id, more_frags, comeback_delay);
 628         else
 629                 gas_query_rx_initial(gas, query, adv_proto, pos, resp_len,
 630                                      comeback_delay);
 631
 632         return 0;
 633 }
 634
 635
 636 static void gas_query_timeout(void *eloop_data, void *user_ctx)
 637 {
 638         struct gas_query *gas = eloop_data;
 639         struct gas_query_pending *query = user_ctx;
 640
 641         wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
 642                    " dialog token %u",
 643                    MAC2STR(query->addr), query->dialog_token);
 644         gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
 645 }
 646
 647
 648 static int gas_query_dialog_token_available(struct gas_query *gas,
 649                                             const u8 *dst, u8 dialog_token)
 650 {
 651         struct gas_query_pending *q;
 652         dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
 653                 if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 &&
 654                     dialog_token == q->dialog_token)
 655                         return 0;
 656         }
 657
 658         return 1;
 659 }
 660
 661
 662 static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
 663 {
 664         struct gas_query_pending *query = work->ctx;
 665         struct gas_query *gas = query->gas;
 666         struct wpa_supplicant *wpa_s = gas->wpa_s;
 667
 668         if (deinit) {
 669                 if (work->started) {
 670                         gas->work = NULL;
 671                         gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
 672                         return;
 673                 }
 674
 675                 gas_query_free(query, 1);
 676                 return;
 677         }
 678
 679         if (wpas_update_random_addr_disassoc(wpa_s) < 0) {
 680                 wpa_msg(wpa_s, MSG_INFO,
 681                         "Failed to assign random MAC address for GAS");
 682                 gas_query_free(query, 1);
 683                 radio_work_done(work);
 684                 return;
 685         }
 686
 687         gas->work = work;
 688         gas_query_tx_initial_req(gas, query);
 689 }
 690
 691
 692 static void gas_query_tx_initial_req(struct gas_query *gas,
 693                                      struct gas_query_pending *query)
 694 {
 695         if (gas_query_tx(gas, query, query->req,
 696                          GAS_QUERY_WAIT_TIME_INITIAL) < 0) {
 697                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 698                            MACSTR, MAC2STR(query->addr));
 699                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 700                 return;
 701         }
 702         gas->current = query;
 703
 704         wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
 705                    query->dialog_token);
 706         eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
 707                                gas_query_timeout, gas, query);
 708 }
 709
 710
 711 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst)
 712 {
 713         static int next_start = 0;
 714         int dialog_token;
 715
 716         for (dialog_token = 0; dialog_token < 256; dialog_token++) {
 717                 if (gas_query_dialog_token_available(
 718                             gas, dst, (next_start + dialog_token) % 256))
 719                         break;
 720         }
 721         if (dialog_token == 256)
 722                 return -1; /* Too many pending queries */
 723         dialog_token = (next_start + dialog_token) % 256;
 724         next_start = (dialog_token + 1) % 256;
 725         return dialog_token;
 726 }
 727
 728
 729 /**
 730  * gas_query_req - Request a GAS query
 731  * @gas: GAS query data from gas_query_init()
 732  * @dst: Destination MAC address for the query
 733  * @freq: Frequency (in MHz) for the channel on which to send the query
 734  * @req: GAS query payload (to be freed by gas_query module in case of success
 735  *      return)
 736  * @cb: Callback function for reporting GAS query result and response
 737  * @ctx: Context pointer to use with the @cb call
 738  * Returns: dialog token (>= 0) on success or -1 on failure
 739  */
 740 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
 741                   struct wpabuf *req,
 742                   void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
 743                              enum gas_query_result result,
 744                              const struct wpabuf *adv_proto,
 745                              const struct wpabuf *resp, u16 status_code),
 746                   void *ctx)
 747 {
 748         struct gas_query_pending *query;
 749         int dialog_token;
 750
 751         if (wpabuf_len(req) < 3)
 752                 return -1;
 753
 754         dialog_token = gas_query_new_dialog_token(gas, dst);
 755         if (dialog_token < 0)
 756                 return -1;
 757
 758         query = os_zalloc(sizeof(*query));
 759         if (query == NULL)
 760                 return -1;
 761
 762         query->gas = gas;
 763         os_memcpy(query->addr, dst, ETH_ALEN);
 764         query->dialog_token = dialog_token;
 765         query->freq = freq;
 766         query->cb = cb;
 767         query->ctx = ctx;
 768         query->req = req;
 769         dl_list_add(&gas->pending, &query->list);
 770
 771         *(wpabuf_mhead_u8(req) + 2) = dialog_token;
 772
 773         wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
 774                 " dialog_token=%u freq=%d",
 775                 MAC2STR(query->addr), query->dialog_token, query->freq);
 776
 777         if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
 778                            query) < 0) {
 779                 gas_query_free(query, 1);
 780                 return -1;
 781         }
 782
 783         return dialog_token;
 784 }
 785
 786
 787 /**
 788  * gas_query_cancel - Cancel a pending GAS query
 789  * @gas: GAS query data from gas_query_init()
 790  * @dst: Destination MAC address for the query
 791  * @dialog_token: Dialog token from gas_query_req()
 792  */
 793 void gas_query_cancel(struct gas_query *gas, const u8 *dst, u8 dialog_token)
 794 {
 795         struct gas_query_pending *query;
 796
 797         query = gas_query_get_pending(gas, dst, dialog_token);
 798         if (query)
 799                 gas_query_done(gas, query, GAS_QUERY_CANCELLED);
 800
 801 }