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 /* GAS query wait-time / duration in ms */
  29 #define GAS_QUERY_WAIT_TIME_INITIAL 1000
  30 #define GAS_QUERY_WAIT_TIME_COMEBACK 150
  31
  32 /**
  33  * struct gas_query_pending - Pending GAS query
  34  */
  35 struct gas_query_pending {
  36         struct dl_list list;
  37         struct gas_query *gas;
  38         u8 addr[ETH_ALEN];
  39         u8 dialog_token;
  40         u8 next_frag_id;
  41         unsigned int wait_comeback:1;
  42         unsigned int offchannel_tx_started:1;
  43         unsigned int retry:1;
  44         int freq;
  45         u16 status_code;
  46         struct wpabuf *req;
  47         struct wpabuf *adv_proto;
  48         struct wpabuf *resp;
  49         struct os_reltime last_oper;
  50         void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
  51                    enum gas_query_result result,
  52                    const struct wpabuf *adv_proto,
  53                    const struct wpabuf *resp, u16 status_code);
  54         void *ctx;
  55 };
  56
  57 /**
  58  * struct gas_query - Internal GAS query data
  59  */
  60 struct gas_query {
  61         struct wpa_supplicant *wpa_s;
  62         struct dl_list pending; /* struct gas_query_pending */
  63         struct gas_query_pending *current;
  64         struct wpa_radio_work *work;
  65 };
  66
  67
  68 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx);
  69 static void gas_query_timeout(void *eloop_data, void *user_ctx);
  70 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx);
  71 static void gas_query_tx_initial_req(struct gas_query *gas,
  72                                      struct gas_query_pending *query);
  73 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst);
  74
  75
  76 static int ms_from_time(struct os_reltime *last)
  77 {
  78         struct os_reltime now, res;
  79
  80         os_get_reltime(&now);
  81         os_reltime_sub(&now, last, &res);
  82         return res.sec * 1000 + res.usec / 1000;
  83 }
  84
  85
  86 /**
  87  * gas_query_init - Initialize GAS query component
  88  * @wpa_s: Pointer to wpa_supplicant data
  89  * Returns: Pointer to GAS query data or %NULL on failure
  90  */
  91 struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s)
  92 {
  93         struct gas_query *gas;
  94
  95         gas = os_zalloc(sizeof(*gas));
  96         if (gas == NULL)
  97                 return NULL;
  98
  99         gas->wpa_s = wpa_s;
 100         dl_list_init(&gas->pending);
 101
 102         return gas;
 103 }
 104
 105
 106 static const char * gas_result_txt(enum gas_query_result result)
 107 {
 108         switch (result) {
 109         case GAS_QUERY_SUCCESS:
 110                 return "SUCCESS";
 111         case GAS_QUERY_FAILURE:
 112                 return "FAILURE";
 113         case GAS_QUERY_TIMEOUT:
 114                 return "TIMEOUT";
 115         case GAS_QUERY_PEER_ERROR:
 116                 return "PEER_ERROR";
 117         case GAS_QUERY_INTERNAL_ERROR:
 118                 return "INTERNAL_ERROR";
 119         case GAS_QUERY_CANCELLED:
 120                 return "CANCELLED";
 121         case GAS_QUERY_DELETED_AT_DEINIT:
 122                 return "DELETED_AT_DEINIT";
 123         }
 124
 125         return "N/A";
 126 }
 127
 128
 129 static void gas_query_free(struct gas_query_pending *query, int del_list)
 130 {
 131         struct gas_query *gas = query->gas;
 132
 133         if (del_list)
 134                 dl_list_del(&query->list);
 135
 136         if (gas->work && gas->work->ctx == query) {
 137                 radio_work_done(gas->work);
 138                 gas->work = NULL;
 139         }
 140
 141         wpabuf_free(query->req);
 142         wpabuf_free(query->adv_proto);
 143         wpabuf_free(query->resp);
 144         os_free(query);
 145 }
 146
 147
 148 static void gas_query_done(struct gas_query *gas,
 149                            struct gas_query_pending *query,
 150                            enum gas_query_result result)
 151 {
 152         wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR
 153                 " dialog_token=%u freq=%d status_code=%u result=%s",
 154                 MAC2STR(query->addr), query->dialog_token, query->freq,
 155                 query->status_code, gas_result_txt(result));
 156         if (gas->current == query)
 157                 gas->current = NULL;
 158         if (query->offchannel_tx_started)
 159                 offchannel_send_action_done(gas->wpa_s);
 160         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 161         eloop_cancel_timeout(gas_query_timeout, gas, query);
 162         eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
 163         dl_list_del(&query->list);
 164         query->cb(query->ctx, query->addr, query->dialog_token, result,
 165                   query->adv_proto, query->resp, query->status_code);
 166         gas_query_free(query, 0);
 167 }
 168
 169
 170 /**
 171  * gas_query_deinit - Deinitialize GAS query component
 172  * @gas: GAS query data from gas_query_init()
 173  */
 174 void gas_query_deinit(struct gas_query *gas)
 175 {
 176         struct gas_query_pending *query, *next;
 177
 178         if (gas == NULL)
 179                 return;
 180
 181         dl_list_for_each_safe(query, next, &gas->pending,
 182                               struct gas_query_pending, list)
 183                 gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
 184
 185         os_free(gas);
 186 }
 187
 188
 189 static struct gas_query_pending *
 190 gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token)
 191 {
 192         struct gas_query_pending *q;
 193         dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
 194                 if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 &&
 195                     q->dialog_token == dialog_token)
 196                         return q;
 197         }
 198         return NULL;
 199 }
 200
 201
 202 static int gas_query_append(struct gas_query_pending *query, const u8 *data,
 203                             size_t len)
 204 {
 205         if (wpabuf_resize(&query->resp, len) < 0) {
 206                 wpa_printf(MSG_DEBUG, "GAS: No memory to store the response");
 207                 return -1;
 208         }
 209         wpabuf_put_data(query->resp, data, len);
 210         return 0;
 211 }
 212
 213
 214 static void gas_query_tx_status(struct wpa_supplicant *wpa_s,
 215                                 unsigned int freq, const u8 *dst,
 216                                 const u8 *src, const u8 *bssid,
 217                                 const u8 *data, size_t data_len,
 218                                 enum offchannel_send_action_result result)
 219 {
 220         struct gas_query_pending *query;
 221         struct gas_query *gas = wpa_s->gas;
 222         int dur;
 223
 224         if (gas->current == NULL) {
 225                 wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: freq=%u dst="
 226                            MACSTR " result=%d - no query in progress",
 227                            freq, MAC2STR(dst), result);
 228                 return;
 229         }
 230
 231         query = gas->current;
 232
 233         dur = ms_from_time(&query->last_oper);
 234         wpa_printf(MSG_DEBUG, "GAS: TX status: freq=%u dst=" MACSTR
 235                    " result=%d query=%p dialog_token=%u dur=%d ms",
 236                    freq, MAC2STR(dst), result, query, query->dialog_token, dur);
 237         if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) {
 238                 wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination");
 239                 return;
 240         }
 241         os_get_reltime(&query->last_oper);
 242
 243         if (result == OFFCHANNEL_SEND_ACTION_SUCCESS) {
 244                 eloop_cancel_timeout(gas_query_timeout, gas, query);
 245                 eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
 246                                        gas_query_timeout, gas, query);
 247                 if (query->wait_comeback && !query->retry) {
 248                         eloop_cancel_timeout(gas_query_rx_comeback_timeout,
 249                                              gas, query);
 250                         eloop_register_timeout(
 251                                 0, (GAS_QUERY_WAIT_TIME_COMEBACK + 10) * 1000,
 252                                 gas_query_rx_comeback_timeout, gas, query);
 253                 }
 254         }
 255         if (result == OFFCHANNEL_SEND_ACTION_FAILED) {
 256                 eloop_cancel_timeout(gas_query_timeout, gas, query);
 257                 eloop_register_timeout(0, 0, gas_query_timeout, gas, query);
 258         }
 259 }
 260
 261
 262 static int pmf_in_use(struct wpa_supplicant *wpa_s, const u8 *addr)
 263 {
 264         if (wpa_s->current_ssid == NULL ||
 265             wpa_s->wpa_state < WPA_4WAY_HANDSHAKE ||
 266             os_memcmp(addr, wpa_s->bssid, ETH_ALEN) != 0)
 267                 return 0;
 268         return wpa_sm_pmf_enabled(wpa_s->wpa);
 269 }
 270
 271
 272 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
 273                         struct wpabuf *req, unsigned int wait_time)
 274 {
 275         int res, prot = pmf_in_use(gas->wpa_s, query->addr);
 276
 277         wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
 278                    "freq=%d prot=%d", MAC2STR(query->addr),
 279                    (unsigned int) wpabuf_len(req), query->freq, prot);
 280         if (prot) {
 281                 u8 *categ = wpabuf_mhead_u8(req);
 282                 *categ = WLAN_ACTION_PROTECTED_DUAL;
 283         }
 284         os_get_reltime(&query->last_oper);
 285         if (gas->wpa_s->max_remain_on_chan &&
 286             wait_time > gas->wpa_s->max_remain_on_chan)
 287                 wait_time = gas->wpa_s->max_remain_on_chan;
 288         res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
 289                                      gas->wpa_s->own_addr, query->addr,
 290                                      wpabuf_head(req), wpabuf_len(req),
 291                                      wait_time, gas_query_tx_status, 0);
 292         if (res == 0)
 293                 query->offchannel_tx_started = 1;
 294         return res;
 295 }
 296
 297
 298 static void gas_query_tx_comeback_req(struct gas_query *gas,
 299                                       struct gas_query_pending *query)
 300 {
 301         struct wpabuf *req;
 302         unsigned int wait_time;
 303
 304         req = gas_build_comeback_req(query->dialog_token);
 305         if (req == NULL) {
 306                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 307                 return;
 308         }
 309
 310         wait_time = (query->retry || !query->offchannel_tx_started) ?
 311                 GAS_QUERY_WAIT_TIME_INITIAL : GAS_QUERY_WAIT_TIME_COMEBACK;
 312
 313         if (gas_query_tx(gas, query, req, wait_time) < 0) {
 314                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 315                            MACSTR, MAC2STR(query->addr));
 316                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 317         }
 318
 319         wpabuf_free(req);
 320 }
 321
 322
 323 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx)
 324 {
 325         struct gas_query *gas = eloop_data;
 326         struct gas_query_pending *query = user_ctx;
 327         int dialog_token;
 328
 329         wpa_printf(MSG_DEBUG,
 330                    "GAS: No response to comeback request received (retry=%u)",
 331                    query->retry);
 332         if (gas->current != query || query->retry)
 333                 return;
 334         dialog_token = gas_query_new_dialog_token(gas, query->addr);
 335         if (dialog_token < 0)
 336                 return;
 337         wpa_printf(MSG_DEBUG,
 338                    "GAS: Retry GAS query due to comeback response timeout");
 339         query->retry = 1;
 340         query->dialog_token = dialog_token;
 341         *(wpabuf_mhead_u8(query->req) + 2) = dialog_token;
 342         query->wait_comeback = 0;
 343         query->next_frag_id = 0;
 344         wpabuf_free(query->adv_proto);
 345         query->adv_proto = NULL;
 346         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 347         eloop_cancel_timeout(gas_query_timeout, gas, query);
 348         gas_query_tx_initial_req(gas, query);
 349 }
 350
 351
 352 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
 353 {
 354         struct gas_query *gas = eloop_data;
 355         struct gas_query_pending *query = user_ctx;
 356
 357         wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
 358                    MAC2STR(query->addr));
 359         gas_query_tx_comeback_req(gas, query);
 360 }
 361
 362
 363 static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
 364                                             struct gas_query_pending *query,
 365                                             u16 comeback_delay)
 366 {
 367         unsigned int secs, usecs;
 368
 369         if (comeback_delay > 1 && query->offchannel_tx_started) {
 370                 offchannel_send_action_done(gas->wpa_s);
 371                 query->offchannel_tx_started = 0;
 372         }
 373
 374         secs = (comeback_delay * 1024) / 1000000;
 375         usecs = comeback_delay * 1024 - secs * 1000000;
 376         wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
 377                    " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
 378         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 379         eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
 380                                gas, query);
 381 }
 382
 383
 384 static void gas_query_rx_initial(struct gas_query *gas,
 385                                  struct gas_query_pending *query,
 386                                  const u8 *adv_proto, const u8 *resp,
 387                                  size_t len, u16 comeback_delay)
 388 {
 389         wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
 390                    MACSTR " (dialog_token=%u comeback_delay=%u)",
 391                    MAC2STR(query->addr), query->dialog_token, comeback_delay);
 392
 393         query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]);
 394         if (query->adv_proto == NULL) {
 395                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 396                 return;
 397         }
 398
 399         if (comeback_delay) {
 400                 query->wait_comeback = 1;
 401                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 402                 return;
 403         }
 404
 405         /* Query was completed without comeback mechanism */
 406         if (gas_query_append(query, resp, len) < 0) {
 407                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 408                 return;
 409         }
 410
 411         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 412 }
 413
 414
 415 static void gas_query_rx_comeback(struct gas_query *gas,
 416                                   struct gas_query_pending *query,
 417                                   const u8 *adv_proto, const u8 *resp,
 418                                   size_t len, u8 frag_id, u8 more_frags,
 419                                   u16 comeback_delay)
 420 {
 421         wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
 422                    MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
 423                    "comeback_delay=%u)",
 424                    MAC2STR(query->addr), query->dialog_token, frag_id,
 425                    more_frags, comeback_delay);
 426         eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
 427
 428         if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) ||
 429             os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
 430                       wpabuf_len(query->adv_proto)) != 0) {
 431                 wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
 432                            "between initial and comeback response from "
 433                            MACSTR, MAC2STR(query->addr));
 434                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 435                 return;
 436         }
 437
 438         if (comeback_delay) {
 439                 if (frag_id) {
 440                         wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
 441                                    "with non-zero frag_id and comeback_delay "
 442                                    "from " MACSTR, MAC2STR(query->addr));
 443                         gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 444                         return;
 445                 }
 446                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 447                 return;
 448         }
 449
 450         if (frag_id != query->next_frag_id) {
 451                 wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
 452                            "from " MACSTR, MAC2STR(query->addr));
 453                 if (frag_id + 1 == query->next_frag_id) {
 454                         wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
 455                                    "retry of previous fragment");
 456                         return;
 457                 }
 458                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 459                 return;
 460         }
 461         query->next_frag_id++;
 462
 463         if (gas_query_append(query, resp, len) < 0) {
 464                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 465                 return;
 466         }
 467
 468         if (more_frags) {
 469                 gas_query_tx_comeback_req(gas, query);
 470                 return;
 471         }
 472
 473         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 474 }
 475
 476
 477 /**
 478  * gas_query_rx - Indicate reception of a Public Action or Protected Dual frame
 479  * @gas: GAS query data from gas_query_init()
 480  * @da: Destination MAC address of the Action frame
 481  * @sa: Source MAC address of the Action frame
 482  * @bssid: BSSID of the Action frame
 483  * @categ: Category of the Action frame
 484  * @data: Payload of the Action frame
 485  * @len: Length of @data
 486  * @freq: Frequency (in MHz) on which the frame was received
 487  * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
 488  */
 489 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
 490                  const u8 *bssid, u8 categ, const u8 *data, size_t len,
 491                  int freq)
 492 {
 493         struct gas_query_pending *query;
 494         u8 action, dialog_token, frag_id = 0, more_frags = 0;
 495         u16 comeback_delay, resp_len;
 496         const u8 *pos, *adv_proto;
 497         int prot, pmf;
 498         unsigned int left;
 499
 500         if (gas == NULL || len < 4)
 501                 return -1;
 502
 503         prot = categ == WLAN_ACTION_PROTECTED_DUAL;
 504         pmf = pmf_in_use(gas->wpa_s, bssid);
 505         if (prot && !pmf) {
 506                 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled");
 507                 return 0;
 508         }
 509         if (!prot && pmf) {
 510                 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled");
 511                 return 0;
 512         }
 513
 514         pos = data;
 515         action = *pos++;
 516         dialog_token = *pos++;
 517
 518         if (action != WLAN_PA_GAS_INITIAL_RESP &&
 519             action != WLAN_PA_GAS_COMEBACK_RESP)
 520                 return -1; /* Not a GAS response */
 521
 522         query = gas_query_get_pending(gas, sa, dialog_token);
 523         if (query == NULL) {
 524                 wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR
 525                            " dialog token %u", MAC2STR(sa), dialog_token);
 526                 return -1;
 527         }
 528
 529         wpa_printf(MSG_DEBUG, "GAS: Response in %d ms from " MACSTR,
 530                    ms_from_time(&query->last_oper), MAC2STR(sa));
 531
 532         if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) {
 533                 wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from "
 534                            MACSTR " dialog token %u when waiting for comeback "
 535                            "response", MAC2STR(sa), dialog_token);
 536                 return 0;
 537         }
 538
 539         if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) {
 540                 wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from "
 541                            MACSTR " dialog token %u when waiting for initial "
 542                            "response", MAC2STR(sa), dialog_token);
 543                 return 0;
 544         }
 545
 546         query->status_code = WPA_GET_LE16(pos);
 547         pos += 2;
 548
 549         if (query->status_code == WLAN_STATUS_QUERY_RESP_OUTSTANDING &&
 550             action == WLAN_PA_GAS_COMEBACK_RESP) {
 551                 wpa_printf(MSG_DEBUG, "GAS: Allow non-zero status for outstanding comeback response");
 552         } else if (query->status_code != WLAN_STATUS_SUCCESS) {
 553                 wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token "
 554                            "%u failed - status code %u",
 555                            MAC2STR(sa), dialog_token, query->status_code);
 556                 gas_query_done(gas, query, GAS_QUERY_FAILURE);
 557                 return 0;
 558         }
 559
 560         if (action == WLAN_PA_GAS_COMEBACK_RESP) {
 561                 if (pos + 1 > data + len)
 562                         return 0;
 563                 frag_id = *pos & 0x7f;
 564                 more_frags = (*pos & 0x80) >> 7;
 565                 pos++;
 566         }
 567
 568         /* Comeback Delay */
 569         if (pos + 2 > data + len)
 570                 return 0;
 571         comeback_delay = WPA_GET_LE16(pos);
 572         pos += 2;
 573
 574         /* Advertisement Protocol element */
 575         if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) {
 576                 wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
 577                            "Protocol element in the response from " MACSTR,
 578                            MAC2STR(sa));
 579                 return 0;
 580         }
 581
 582         if (*pos != WLAN_EID_ADV_PROTO) {
 583                 wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
 584                            "Protocol element ID %u in response from " MACSTR,
 585                            *pos, MAC2STR(sa));
 586                 return 0;
 587         }
 588
 589         adv_proto = pos;
 590         pos += 2 + pos[1];
 591
 592         /* Query Response Length */
 593         if (pos + 2 > data + len) {
 594                 wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
 595                 return 0;
 596         }
 597         resp_len = WPA_GET_LE16(pos);
 598         pos += 2;
 599
 600         left = data + len - pos;
 601         if (resp_len > left) {
 602                 wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
 603                            "response from " MACSTR, MAC2STR(sa));
 604                 return 0;
 605         }
 606
 607         if (resp_len < left) {
 608                 wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
 609                            "after Query Response from " MACSTR,
 610                            left - resp_len, MAC2STR(sa));
 611         }
 612
 613         if (action == WLAN_PA_GAS_COMEBACK_RESP)
 614                 gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len,
 615                                       frag_id, more_frags, comeback_delay);
 616         else
 617                 gas_query_rx_initial(gas, query, adv_proto, pos, resp_len,
 618                                      comeback_delay);
 619
 620         return 0;
 621 }
 622
 623
 624 static void gas_query_timeout(void *eloop_data, void *user_ctx)
 625 {
 626         struct gas_query *gas = eloop_data;
 627         struct gas_query_pending *query = user_ctx;
 628
 629         wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
 630                    " dialog token %u",
 631                    MAC2STR(query->addr), query->dialog_token);
 632         gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
 633 }
 634
 635
 636 static int gas_query_dialog_token_available(struct gas_query *gas,
 637                                             const u8 *dst, u8 dialog_token)
 638 {
 639         struct gas_query_pending *q;
 640         dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
 641                 if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 &&
 642                     dialog_token == q->dialog_token)
 643                         return 0;
 644         }
 645
 646         return 1;
 647 }
 648
 649
 650 static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
 651 {
 652         struct gas_query_pending *query = work->ctx;
 653         struct gas_query *gas = query->gas;
 654         struct wpa_supplicant *wpa_s = gas->wpa_s;
 655
 656         if (deinit) {
 657                 if (work->started) {
 658                         gas->work = NULL;
 659                         gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
 660                         return;
 661                 }
 662
 663                 gas_query_free(query, 1);
 664                 return;
 665         }
 666
 667         if (wpas_update_random_addr_disassoc(wpa_s) < 0) {
 668                 wpa_msg(wpa_s, MSG_INFO,
 669                         "Failed to assign random MAC address for GAS");
 670                 gas_query_free(query, 1);
 671                 radio_work_done(work);
 672                 return;
 673         }
 674
 675         gas->work = work;
 676         gas_query_tx_initial_req(gas, query);
 677 }
 678
 679
 680 static void gas_query_tx_initial_req(struct gas_query *gas,
 681                                      struct gas_query_pending *query)
 682 {
 683         if (gas_query_tx(gas, query, query->req,
 684                          GAS_QUERY_WAIT_TIME_INITIAL) < 0) {
 685                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 686                            MACSTR, MAC2STR(query->addr));
 687                 gas_query_free(query, 1);
 688                 return;
 689         }
 690         gas->current = query;
 691
 692         wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
 693                    query->dialog_token);
 694         eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
 695                                gas_query_timeout, gas, query);
 696 }
 697
 698
 699 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst)
 700 {
 701         static int next_start = 0;
 702         int dialog_token;
 703
 704         for (dialog_token = 0; dialog_token < 256; dialog_token++) {
 705                 if (gas_query_dialog_token_available(
 706                             gas, dst, (next_start + dialog_token) % 256))
 707                         break;
 708         }
 709         if (dialog_token == 256)
 710                 return -1; /* Too many pending queries */
 711         dialog_token = (next_start + dialog_token) % 256;
 712         next_start = (dialog_token + 1) % 256;
 713         return dialog_token;
 714 }
 715
 716
 717 /**
 718  * gas_query_req - Request a GAS query
 719  * @gas: GAS query data from gas_query_init()
 720  * @dst: Destination MAC address for the query
 721  * @freq: Frequency (in MHz) for the channel on which to send the query
 722  * @req: GAS query payload (to be freed by gas_query module in case of success
 723  *      return)
 724  * @cb: Callback function for reporting GAS query result and response
 725  * @ctx: Context pointer to use with the @cb call
 726  * Returns: dialog token (>= 0) on success or -1 on failure
 727  */
 728 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
 729                   struct wpabuf *req,
 730                   void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
 731                              enum gas_query_result result,
 732                              const struct wpabuf *adv_proto,
 733                              const struct wpabuf *resp, u16 status_code),
 734                   void *ctx)
 735 {
 736         struct gas_query_pending *query;
 737         int dialog_token;
 738
 739         if (wpabuf_len(req) < 3)
 740                 return -1;
 741
 742         dialog_token = gas_query_new_dialog_token(gas, dst);
 743         if (dialog_token < 0)
 744                 return -1;
 745
 746         query = os_zalloc(sizeof(*query));
 747         if (query == NULL)
 748                 return -1;
 749
 750         query->gas = gas;
 751         os_memcpy(query->addr, dst, ETH_ALEN);
 752         query->dialog_token = dialog_token;
 753         query->freq = freq;
 754         query->cb = cb;
 755         query->ctx = ctx;
 756         query->req = req;
 757         dl_list_add(&gas->pending, &query->list);
 758
 759         *(wpabuf_mhead_u8(req) + 2) = dialog_token;
 760
 761         wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
 762                 " dialog_token=%u freq=%d",
 763                 MAC2STR(query->addr), query->dialog_token, query->freq);
 764
 765         if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
 766                            query) < 0) {
 767                 gas_query_free(query, 1);
 768                 return -1;
 769         }
 770
 771         return dialog_token;
 772 }
 773
 774
 775 /**
 776  * gas_query_cancel - Cancel a pending GAS query
 777  * @gas: GAS query data from gas_query_init()
 778  * @dst: Destination MAC address for the query
 779  * @dialog_token: Dialog token from gas_query_req()
 780  */
 781 void gas_query_cancel(struct gas_query *gas, const u8 *dst, u8 dialog_token)
 782 {
 783         struct gas_query_pending *query;
 784
 785         query = gas_query_get_pending(gas, dst, dialog_token);
 786         if (query)
 787                 gas_query_done(gas, query, GAS_QUERY_CANCELLED);
 788
 789 }