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         unsigned int wildcard_bssid:1;
  46         int freq;
  47         u16 status_code;
  48         struct wpabuf *req;
  49         struct wpabuf *adv_proto;
  50         struct wpabuf *resp;
  51         struct os_reltime last_oper;
  52         void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
  53                    enum gas_query_result result,
  54                    const struct wpabuf *adv_proto,
  55                    const struct wpabuf *resp, u16 status_code);
  56         void *ctx;
  57         u8 sa[ETH_ALEN];
  58 };
  59
  60 /**
  61  * struct gas_query - Internal GAS query data
  62  */
  63 struct gas_query {
  64         struct wpa_supplicant *wpa_s;
  65         struct dl_list pending; /* struct gas_query_pending */
  66         struct gas_query_pending *current;
  67         struct wpa_radio_work *work;
  68         struct os_reltime last_mac_addr_rand;
  69         int last_rand_sa_type;
  70         u8 rand_addr[ETH_ALEN];
  71 };
  72
  73
  74 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx);
  75 static void gas_query_timeout(void *eloop_data, void *user_ctx);
  76 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx);
  77 static void gas_query_tx_initial_req(struct gas_query *gas,
  78                                      struct gas_query_pending *query);
  79 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst);
  80
  81
  82 static int ms_from_time(struct os_reltime *last)
  83 {
  84         struct os_reltime now, res;
  85
  86         os_get_reltime(&now);
  87         os_reltime_sub(&now, last, &res);
  88         return res.sec * 1000 + res.usec / 1000;
  89 }
  90
  91
  92 /**
  93  * gas_query_init - Initialize GAS query component
  94  * @wpa_s: Pointer to wpa_supplicant data
  95  * Returns: Pointer to GAS query data or %NULL on failure
  96  */
  97 struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s)
  98 {
  99         struct gas_query *gas;
 100
 101         gas = os_zalloc(sizeof(*gas));
 102         if (gas == NULL)
 103                 return NULL;
 104
 105         gas->wpa_s = wpa_s;
 106         dl_list_init(&gas->pending);
 107
 108         return gas;
 109 }
 110
 111
 112 static const char * gas_result_txt(enum gas_query_result result)
 113 {
 114         switch (result) {
 115         case GAS_QUERY_SUCCESS:
 116                 return "SUCCESS";
 117         case GAS_QUERY_FAILURE:
 118                 return "FAILURE";
 119         case GAS_QUERY_TIMEOUT:
 120                 return "TIMEOUT";
 121         case GAS_QUERY_PEER_ERROR:
 122                 return "PEER_ERROR";
 123         case GAS_QUERY_INTERNAL_ERROR:
 124                 return "INTERNAL_ERROR";
 125         case GAS_QUERY_STOPPED:
 126                 return "STOPPED";
 127         case GAS_QUERY_DELETED_AT_DEINIT:
 128                 return "DELETED_AT_DEINIT";
 129         }
 130
 131         return "N/A";
 132 }
 133
 134
 135 static void gas_query_free(struct gas_query_pending *query, int del_list)
 136 {
 137         struct gas_query *gas = query->gas;
 138
 139         if (del_list)
 140                 dl_list_del(&query->list);
 141
 142         if (gas->work && gas->work->ctx == query) {
 143                 radio_work_done(gas->work);
 144                 gas->work = NULL;
 145         }
 146
 147         wpabuf_free(query->req);
 148         wpabuf_free(query->adv_proto);
 149         wpabuf_free(query->resp);
 150         os_free(query);
 151 }
 152
 153
 154 static void gas_query_done(struct gas_query *gas,
 155                            struct gas_query_pending *query,
 156                            enum gas_query_result result)
 157 {
 158         wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR
 159                 " dialog_token=%u freq=%d status_code=%u result=%s",
 160                 MAC2STR(query->addr), query->dialog_token, query->freq,
 161                 query->status_code, gas_result_txt(result));
 162         if (gas->current == query)
 163                 gas->current = NULL;
 164         if (query->offchannel_tx_started)
 165                 offchannel_send_action_done(gas->wpa_s);
 166         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 167         eloop_cancel_timeout(gas_query_timeout, gas, query);
 168         eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
 169         dl_list_del(&query->list);
 170         query->cb(query->ctx, query->addr, query->dialog_token, result,
 171                   query->adv_proto, query->resp, query->status_code);
 172         gas_query_free(query, 0);
 173 }
 174
 175
 176 /**
 177  * gas_query_deinit - Deinitialize GAS query component
 178  * @gas: GAS query data from gas_query_init()
 179  */
 180 void gas_query_deinit(struct gas_query *gas)
 181 {
 182         struct gas_query_pending *query, *next;
 183
 184         if (gas == NULL)
 185                 return;
 186
 187         dl_list_for_each_safe(query, next, &gas->pending,
 188                               struct gas_query_pending, list)
 189                 gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
 190
 191         os_free(gas);
 192 }
 193
 194
 195 static struct gas_query_pending *
 196 gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token)
 197 {
 198         struct gas_query_pending *q;
 199         dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
 200                 if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 &&
 201                     q->dialog_token == dialog_token)
 202                         return q;
 203         }
 204         return NULL;
 205 }
 206
 207
 208 static int gas_query_append(struct gas_query_pending *query, const u8 *data,
 209                             size_t len)
 210 {
 211         if (wpabuf_resize(&query->resp, len) < 0) {
 212                 wpa_printf(MSG_DEBUG, "GAS: No memory to store the response");
 213                 return -1;
 214         }
 215         wpabuf_put_data(query->resp, data, len);
 216         return 0;
 217 }
 218
 219
 220 static void gas_query_tx_status(struct wpa_supplicant *wpa_s,
 221                                 unsigned int freq, const u8 *dst,
 222                                 const u8 *src, const u8 *bssid,
 223                                 const u8 *data, size_t data_len,
 224                                 enum offchannel_send_action_result result)
 225 {
 226         struct gas_query_pending *query;
 227         struct gas_query *gas = wpa_s->gas;
 228         int dur;
 229
 230         if (gas->current == NULL) {
 231                 wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: freq=%u dst="
 232                            MACSTR " result=%d - no query in progress",
 233                            freq, MAC2STR(dst), result);
 234                 return;
 235         }
 236
 237         query = gas->current;
 238
 239         dur = ms_from_time(&query->last_oper);
 240         wpa_printf(MSG_DEBUG, "GAS: TX status: freq=%u dst=" MACSTR
 241                    " result=%d query=%p dialog_token=%u dur=%d ms",
 242                    freq, MAC2STR(dst), result, query, query->dialog_token, dur);
 243         if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) {
 244                 wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination");
 245                 return;
 246         }
 247         os_get_reltime(&query->last_oper);
 248
 249         if (result == OFFCHANNEL_SEND_ACTION_SUCCESS ||
 250             result == OFFCHANNEL_SEND_ACTION_NO_ACK) {
 251                 eloop_cancel_timeout(gas_query_timeout, gas, query);
 252                 if (result == OFFCHANNEL_SEND_ACTION_NO_ACK) {
 253                         wpa_printf(MSG_DEBUG, "GAS: No ACK to GAS request");
 254                         eloop_register_timeout(0, 250000,
 255                                                gas_query_timeout, gas, query);
 256                 } else {
 257                         eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
 258                                                gas_query_timeout, gas, query);
 259                 }
 260                 if (query->wait_comeback && !query->retry) {
 261                         eloop_cancel_timeout(gas_query_rx_comeback_timeout,
 262                                              gas, query);
 263                         eloop_register_timeout(
 264                                 0, (GAS_QUERY_WAIT_TIME_COMEBACK + 10) * 1000,
 265                                 gas_query_rx_comeback_timeout, gas, query);
 266                 }
 267         }
 268         if (result == OFFCHANNEL_SEND_ACTION_FAILED) {
 269                 eloop_cancel_timeout(gas_query_timeout, gas, query);
 270                 eloop_register_timeout(0, 0, gas_query_timeout, gas, query);
 271         }
 272 }
 273
 274
 275 int pmf_in_use(struct wpa_supplicant *wpa_s, const u8 *addr)
 276 {
 277         if (wpa_s->current_ssid == NULL ||
 278             wpa_s->wpa_state < WPA_4WAY_HANDSHAKE ||
 279             os_memcmp(addr, wpa_s->bssid, ETH_ALEN) != 0)
 280                 return 0;
 281         return wpa_sm_pmf_enabled(wpa_s->wpa);
 282 }
 283
 284
 285 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query,
 286                         struct wpabuf *req, unsigned int wait_time)
 287 {
 288         int res, prot = pmf_in_use(gas->wpa_s, query->addr);
 289         const u8 *bssid;
 290         const u8 wildcard_bssid[ETH_ALEN] = {
 291                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
 292         };
 293
 294         wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u "
 295                    "freq=%d prot=%d using src addr " MACSTR,
 296                    MAC2STR(query->addr), (unsigned int) wpabuf_len(req),
 297                    query->freq, prot, MAC2STR(query->sa));
 298         if (prot) {
 299                 u8 *categ = wpabuf_mhead_u8(req);
 300                 *categ = WLAN_ACTION_PROTECTED_DUAL;
 301         }
 302         os_get_reltime(&query->last_oper);
 303         if (gas->wpa_s->max_remain_on_chan &&
 304             wait_time > gas->wpa_s->max_remain_on_chan)
 305                 wait_time = gas->wpa_s->max_remain_on_chan;
 306         if (!query->wildcard_bssid &&
 307             (!gas->wpa_s->conf->gas_address3 ||
 308              (gas->wpa_s->current_ssid &&
 309               gas->wpa_s->wpa_state >= WPA_ASSOCIATED &&
 310               os_memcmp(query->addr, gas->wpa_s->bssid, ETH_ALEN) == 0)))
 311                 bssid = query->addr;
 312         else
 313                 bssid = wildcard_bssid;
 314
 315         res = offchannel_send_action(gas->wpa_s, query->freq, query->addr,
 316                                      query->sa, bssid, wpabuf_head(req),
 317                                      wpabuf_len(req), wait_time,
 318                                      gas_query_tx_status, 0);
 319
 320         if (res == 0)
 321                 query->offchannel_tx_started = 1;
 322         return res;
 323 }
 324
 325
 326 static void gas_query_tx_comeback_req(struct gas_query *gas,
 327                                       struct gas_query_pending *query)
 328 {
 329         struct wpabuf *req;
 330         unsigned int wait_time;
 331
 332         req = gas_build_comeback_req(query->dialog_token);
 333         if (req == NULL) {
 334                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 335                 return;
 336         }
 337
 338         wait_time = (query->retry || !query->offchannel_tx_started) ?
 339                 GAS_QUERY_WAIT_TIME_INITIAL : GAS_QUERY_WAIT_TIME_COMEBACK;
 340
 341         if (gas_query_tx(gas, query, req, wait_time) < 0) {
 342                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 343                            MACSTR, MAC2STR(query->addr));
 344                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 345         }
 346
 347         wpabuf_free(req);
 348 }
 349
 350
 351 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx)
 352 {
 353         struct gas_query *gas = eloop_data;
 354         struct gas_query_pending *query = user_ctx;
 355         int dialog_token;
 356
 357         wpa_printf(MSG_DEBUG,
 358                    "GAS: No response to comeback request received (retry=%u)",
 359                    query->retry);
 360         if (gas->current != query || query->retry)
 361                 return;
 362         dialog_token = gas_query_new_dialog_token(gas, query->addr);
 363         if (dialog_token < 0)
 364                 return;
 365         wpa_printf(MSG_DEBUG,
 366                    "GAS: Retry GAS query due to comeback response timeout");
 367         query->retry = 1;
 368         query->dialog_token = dialog_token;
 369         *(wpabuf_mhead_u8(query->req) + 2) = dialog_token;
 370         query->wait_comeback = 0;
 371         query->next_frag_id = 0;
 372         wpabuf_free(query->adv_proto);
 373         query->adv_proto = NULL;
 374         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 375         eloop_cancel_timeout(gas_query_timeout, gas, query);
 376         gas_query_tx_initial_req(gas, query);
 377 }
 378
 379
 380 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx)
 381 {
 382         struct gas_query *gas = eloop_data;
 383         struct gas_query_pending *query = user_ctx;
 384
 385         wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR,
 386                    MAC2STR(query->addr));
 387         gas_query_tx_comeback_req(gas, query);
 388 }
 389
 390
 391 static void gas_query_tx_comeback_req_delay(struct gas_query *gas,
 392                                             struct gas_query_pending *query,
 393                                             u16 comeback_delay)
 394 {
 395         unsigned int secs, usecs;
 396
 397         if (comeback_delay > 1 && query->offchannel_tx_started) {
 398                 offchannel_send_action_done(gas->wpa_s);
 399                 query->offchannel_tx_started = 0;
 400         }
 401
 402         secs = (comeback_delay * 1024) / 1000000;
 403         usecs = comeback_delay * 1024 - secs * 1000000;
 404         wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR
 405                    " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs);
 406         eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query);
 407         eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout,
 408                                gas, query);
 409 }
 410
 411
 412 static void gas_query_rx_initial(struct gas_query *gas,
 413                                  struct gas_query_pending *query,
 414                                  const u8 *adv_proto, const u8 *resp,
 415                                  size_t len, u16 comeback_delay)
 416 {
 417         wpa_printf(MSG_DEBUG, "GAS: Received initial response from "
 418                    MACSTR " (dialog_token=%u comeback_delay=%u)",
 419                    MAC2STR(query->addr), query->dialog_token, comeback_delay);
 420
 421         query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]);
 422         if (query->adv_proto == NULL) {
 423                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 424                 return;
 425         }
 426
 427         if (comeback_delay) {
 428                 eloop_cancel_timeout(gas_query_timeout, gas, query);
 429                 query->wait_comeback = 1;
 430                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 431                 return;
 432         }
 433
 434         /* Query was completed without comeback mechanism */
 435         if (gas_query_append(query, resp, len) < 0) {
 436                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 437                 return;
 438         }
 439
 440         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 441 }
 442
 443
 444 static void gas_query_rx_comeback(struct gas_query *gas,
 445                                   struct gas_query_pending *query,
 446                                   const u8 *adv_proto, const u8 *resp,
 447                                   size_t len, u8 frag_id, u8 more_frags,
 448                                   u16 comeback_delay)
 449 {
 450         wpa_printf(MSG_DEBUG, "GAS: Received comeback response from "
 451                    MACSTR " (dialog_token=%u frag_id=%u more_frags=%u "
 452                    "comeback_delay=%u)",
 453                    MAC2STR(query->addr), query->dialog_token, frag_id,
 454                    more_frags, comeback_delay);
 455         eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query);
 456
 457         if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) ||
 458             os_memcmp(adv_proto, wpabuf_head(query->adv_proto),
 459                       wpabuf_len(query->adv_proto)) != 0) {
 460                 wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed "
 461                            "between initial and comeback response from "
 462                            MACSTR, MAC2STR(query->addr));
 463                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 464                 return;
 465         }
 466
 467         if (comeback_delay) {
 468                 if (frag_id) {
 469                         wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response "
 470                                    "with non-zero frag_id and comeback_delay "
 471                                    "from " MACSTR, MAC2STR(query->addr));
 472                         gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 473                         return;
 474                 }
 475                 gas_query_tx_comeback_req_delay(gas, query, comeback_delay);
 476                 return;
 477         }
 478
 479         if (frag_id != query->next_frag_id) {
 480                 wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response "
 481                            "from " MACSTR, MAC2STR(query->addr));
 482                 if (frag_id + 1 == query->next_frag_id) {
 483                         wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible "
 484                                    "retry of previous fragment");
 485                         return;
 486                 }
 487                 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR);
 488                 return;
 489         }
 490         query->next_frag_id++;
 491
 492         if (gas_query_append(query, resp, len) < 0) {
 493                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 494                 return;
 495         }
 496
 497         if (more_frags) {
 498                 gas_query_tx_comeback_req(gas, query);
 499                 return;
 500         }
 501
 502         gas_query_done(gas, query, GAS_QUERY_SUCCESS);
 503 }
 504
 505
 506 /**
 507  * gas_query_rx - Indicate reception of a Public Action or Protected Dual frame
 508  * @gas: GAS query data from gas_query_init()
 509  * @da: Destination MAC address of the Action frame
 510  * @sa: Source MAC address of the Action frame
 511  * @bssid: BSSID of the Action frame
 512  * @categ: Category of the Action frame
 513  * @data: Payload of the Action frame
 514  * @len: Length of @data
 515  * @freq: Frequency (in MHz) on which the frame was received
 516  * Returns: 0 if the Public Action frame was a GAS frame or -1 if not
 517  */
 518 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa,
 519                  const u8 *bssid, u8 categ, const u8 *data, size_t len,
 520                  int freq)
 521 {
 522         struct gas_query_pending *query;
 523         u8 action, dialog_token, frag_id = 0, more_frags = 0;
 524         u16 comeback_delay, resp_len;
 525         const u8 *pos, *adv_proto;
 526         int prot, pmf;
 527         unsigned int left;
 528
 529         if (gas == NULL || len < 4)
 530                 return -1;
 531
 532         pos = data;
 533         action = *pos++;
 534         dialog_token = *pos++;
 535
 536         if (action != WLAN_PA_GAS_INITIAL_RESP &&
 537             action != WLAN_PA_GAS_COMEBACK_RESP)
 538                 return -1; /* Not a GAS response */
 539
 540         prot = categ == WLAN_ACTION_PROTECTED_DUAL;
 541         pmf = pmf_in_use(gas->wpa_s, sa);
 542         if (prot && !pmf) {
 543                 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled");
 544                 return 0;
 545         }
 546         if (!prot && pmf) {
 547                 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled");
 548                 return 0;
 549         }
 550
 551         query = gas_query_get_pending(gas, sa, dialog_token);
 552         if (query == NULL) {
 553                 wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR
 554                            " dialog token %u", MAC2STR(sa), dialog_token);
 555                 return -1;
 556         }
 557
 558         wpa_printf(MSG_DEBUG, "GAS: Response in %d ms from " MACSTR,
 559                    ms_from_time(&query->last_oper), MAC2STR(sa));
 560
 561         if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) {
 562                 wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from "
 563                            MACSTR " dialog token %u when waiting for comeback "
 564                            "response", MAC2STR(sa), dialog_token);
 565                 return 0;
 566         }
 567
 568         if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) {
 569                 wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from "
 570                            MACSTR " dialog token %u when waiting for initial "
 571                            "response", MAC2STR(sa), dialog_token);
 572                 return 0;
 573         }
 574
 575         query->status_code = WPA_GET_LE16(pos);
 576         pos += 2;
 577
 578         if (query->status_code == WLAN_STATUS_QUERY_RESP_OUTSTANDING &&
 579             action == WLAN_PA_GAS_COMEBACK_RESP) {
 580                 wpa_printf(MSG_DEBUG, "GAS: Allow non-zero status for outstanding comeback response");
 581         } else if (query->status_code != WLAN_STATUS_SUCCESS) {
 582                 wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token "
 583                            "%u failed - status code %u",
 584                            MAC2STR(sa), dialog_token, query->status_code);
 585                 gas_query_done(gas, query, GAS_QUERY_FAILURE);
 586                 return 0;
 587         }
 588
 589         if (action == WLAN_PA_GAS_COMEBACK_RESP) {
 590                 if (pos + 1 > data + len)
 591                         return 0;
 592                 frag_id = *pos & 0x7f;
 593                 more_frags = (*pos & 0x80) >> 7;
 594                 pos++;
 595         }
 596
 597         /* Comeback Delay */
 598         if (pos + 2 > data + len)
 599                 return 0;
 600         comeback_delay = WPA_GET_LE16(pos);
 601         pos += 2;
 602
 603         /* Advertisement Protocol element */
 604         if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) {
 605                 wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement "
 606                            "Protocol element in the response from " MACSTR,
 607                            MAC2STR(sa));
 608                 return 0;
 609         }
 610
 611         if (*pos != WLAN_EID_ADV_PROTO) {
 612                 wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement "
 613                            "Protocol element ID %u in response from " MACSTR,
 614                            *pos, MAC2STR(sa));
 615                 return 0;
 616         }
 617
 618         adv_proto = pos;
 619         pos += 2 + pos[1];
 620
 621         /* Query Response Length */
 622         if (pos + 2 > data + len) {
 623                 wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length");
 624                 return 0;
 625         }
 626         resp_len = WPA_GET_LE16(pos);
 627         pos += 2;
 628
 629         left = data + len - pos;
 630         if (resp_len > left) {
 631                 wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in "
 632                            "response from " MACSTR, MAC2STR(sa));
 633                 return 0;
 634         }
 635
 636         if (resp_len < left) {
 637                 wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data "
 638                            "after Query Response from " MACSTR,
 639                            left - resp_len, MAC2STR(sa));
 640         }
 641
 642         if (action == WLAN_PA_GAS_COMEBACK_RESP)
 643                 gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len,
 644                                       frag_id, more_frags, comeback_delay);
 645         else
 646                 gas_query_rx_initial(gas, query, adv_proto, pos, resp_len,
 647                                      comeback_delay);
 648
 649         return 0;
 650 }
 651
 652
 653 static void gas_query_timeout(void *eloop_data, void *user_ctx)
 654 {
 655         struct gas_query *gas = eloop_data;
 656         struct gas_query_pending *query = user_ctx;
 657
 658         wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR
 659                    " dialog token %u",
 660                    MAC2STR(query->addr), query->dialog_token);
 661         gas_query_done(gas, query, GAS_QUERY_TIMEOUT);
 662 }
 663
 664
 665 static int gas_query_dialog_token_available(struct gas_query *gas,
 666                                             const u8 *dst, u8 dialog_token)
 667 {
 668         struct gas_query_pending *q;
 669         dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) {
 670                 if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 &&
 671                     dialog_token == q->dialog_token)
 672                         return 0;
 673         }
 674
 675         return 1;
 676 }
 677
 678
 679 static void gas_query_start_cb(struct wpa_radio_work *work, int deinit)
 680 {
 681         struct gas_query_pending *query = work->ctx;
 682         struct gas_query *gas = query->gas;
 683         struct wpa_supplicant *wpa_s = gas->wpa_s;
 684
 685         if (deinit) {
 686                 if (work->started) {
 687                         gas->work = NULL;
 688                         gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT);
 689                         return;
 690                 }
 691
 692                 gas_query_free(query, 1);
 693                 return;
 694         }
 695
 696         if (wpas_update_random_addr_disassoc(wpa_s) < 0) {
 697                 wpa_msg(wpa_s, MSG_INFO,
 698                         "Failed to assign random MAC address for GAS");
 699                 gas_query_free(query, 1);
 700                 radio_work_done(work);
 701                 return;
 702         }
 703
 704         gas->work = work;
 705         gas_query_tx_initial_req(gas, query);
 706 }
 707
 708
 709 static void gas_query_tx_initial_req(struct gas_query *gas,
 710                                      struct gas_query_pending *query)
 711 {
 712         if (gas_query_tx(gas, query, query->req,
 713                          GAS_QUERY_WAIT_TIME_INITIAL) < 0) {
 714                 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to "
 715                            MACSTR, MAC2STR(query->addr));
 716                 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR);
 717                 return;
 718         }
 719         gas->current = query;
 720
 721         wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u",
 722                    query->dialog_token);
 723         eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0,
 724                                gas_query_timeout, gas, query);
 725 }
 726
 727
 728 static int gas_query_new_dialog_token(struct gas_query *gas, const u8 *dst)
 729 {
 730         static int next_start = 0;
 731         int dialog_token;
 732
 733         for (dialog_token = 0; dialog_token < 256; dialog_token++) {
 734                 if (gas_query_dialog_token_available(
 735                             gas, dst, (next_start + dialog_token) % 256))
 736                         break;
 737         }
 738         if (dialog_token == 256)
 739                 return -1; /* Too many pending queries */
 740         dialog_token = (next_start + dialog_token) % 256;
 741         next_start = (dialog_token + 1) % 256;
 742         return dialog_token;
 743 }
 744
 745
 746 static int gas_query_set_sa(struct gas_query *gas,
 747                             struct gas_query_pending *query)
 748 {
 749         struct wpa_supplicant *wpa_s = gas->wpa_s;
 750         struct os_reltime now;
 751
 752         if (!wpa_s->conf->gas_rand_mac_addr ||
 753             !(wpa_s->current_bss ?
 754               (wpa_s->drv_flags &
 755                WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA_CONNECTED) :
 756               (wpa_s->drv_flags & WPA_DRIVER_FLAGS_MGMT_TX_RANDOM_TA))) {
 757                 /* Use own MAC address as the transmitter address */
 758                 os_memcpy(query->sa, wpa_s->own_addr, ETH_ALEN);
 759                 return 0;
 760         }
 761
 762         os_get_reltime(&now);
 763
 764         if (wpa_s->conf->gas_rand_mac_addr == gas->last_rand_sa_type &&
 765             gas->last_mac_addr_rand.sec != 0 &&
 766             !os_reltime_expired(&now, &gas->last_mac_addr_rand,
 767                                 wpa_s->conf->gas_rand_addr_lifetime)) {
 768                 wpa_printf(MSG_DEBUG,
 769                            "GAS: Use the previously selected random transmitter address "
 770                            MACSTR, MAC2STR(gas->rand_addr));
 771                 os_memcpy(query->sa, gas->rand_addr, ETH_ALEN);
 772                 return 0;
 773         }
 774
 775         if (wpa_s->conf->gas_rand_mac_addr == 1 &&
 776             random_mac_addr(gas->rand_addr) < 0) {
 777                 wpa_printf(MSG_ERROR, "GAS: Failed to get random address");
 778                 return -1;
 779         }
 780
 781         if (wpa_s->conf->gas_rand_mac_addr == 2 &&
 782             random_mac_addr_keep_oui(gas->rand_addr) < 0) {
 783                 wpa_printf(MSG_ERROR,
 784                            "GAS: Failed to get random address with same OUI");
 785                 return -1;
 786         }
 787
 788         wpa_printf(MSG_DEBUG, "GAS: Use a new random transmitter address "
 789                    MACSTR, MAC2STR(gas->rand_addr));
 790         os_memcpy(query->sa, gas->rand_addr, ETH_ALEN);
 791         os_get_reltime(&gas->last_mac_addr_rand);
 792         gas->last_rand_sa_type = wpa_s->conf->gas_rand_mac_addr;
 793
 794         return 0;
 795 }
 796
 797
 798 /**
 799  * gas_query_req - Request a GAS query
 800  * @gas: GAS query data from gas_query_init()
 801  * @dst: Destination MAC address for the query
 802  * @freq: Frequency (in MHz) for the channel on which to send the query
 803  * @req: GAS query payload (to be freed by gas_query module in case of success
 804  *      return)
 805  * @cb: Callback function for reporting GAS query result and response
 806  * @ctx: Context pointer to use with the @cb call
 807  * Returns: dialog token (>= 0) on success or -1 on failure
 808  */
 809 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq,
 810                   int wildcard_bssid, struct wpabuf *req,
 811                   void (*cb)(void *ctx, const u8 *dst, u8 dialog_token,
 812                              enum gas_query_result result,
 813                              const struct wpabuf *adv_proto,
 814                              const struct wpabuf *resp, u16 status_code),
 815                   void *ctx)
 816 {
 817         struct gas_query_pending *query;
 818         int dialog_token;
 819
 820         if (wpabuf_len(req) < 3)
 821                 return -1;
 822
 823         dialog_token = gas_query_new_dialog_token(gas, dst);
 824         if (dialog_token < 0)
 825                 return -1;
 826
 827         query = os_zalloc(sizeof(*query));
 828         if (query == NULL)
 829                 return -1;
 830
 831         query->gas = gas;
 832         if (gas_query_set_sa(gas, query)) {
 833                 os_free(query);
 834                 return -1;
 835         }
 836         os_memcpy(query->addr, dst, ETH_ALEN);
 837         query->dialog_token = dialog_token;
 838         query->wildcard_bssid = !!wildcard_bssid;
 839         query->freq = freq;
 840         query->cb = cb;
 841         query->ctx = ctx;
 842         query->req = req;
 843         dl_list_add(&gas->pending, &query->list);
 844
 845         *(wpabuf_mhead_u8(req) + 2) = dialog_token;
 846
 847         wpa_msg(gas->wpa_s, MSG_INFO, GAS_QUERY_START "addr=" MACSTR
 848                 " dialog_token=%u freq=%d",
 849                 MAC2STR(query->addr), query->dialog_token, query->freq);
 850
 851         if (radio_add_work(gas->wpa_s, freq, "gas-query", 0, gas_query_start_cb,
 852                            query) < 0) {
 853                 query->req = NULL; /* caller will free this in error case */
 854                 gas_query_free(query, 1);
 855                 return -1;
 856         }
 857
 858         return dialog_token;
 859 }
 860
 861
 862 int gas_query_stop(struct gas_query *gas, u8 dialog_token)
 863 {
 864         struct gas_query_pending *query;
 865
 866         dl_list_for_each(query, &gas->pending, struct gas_query_pending, list) {
 867                 if (query->dialog_token == dialog_token) {
 868                         if (!gas->work) {
 869                                 /* The pending radio work has not yet been
 870                                  * started, but the pending entry has a
 871                                  * reference to the soon to be freed query.
 872                                  * Need to remove that radio work now to avoid
 873                                  * leaving behind a reference to freed memory.
 874                                  */
 875                                 radio_remove_pending_work(gas->wpa_s, query);
 876                         }
 877                         gas_query_done(gas, query, GAS_QUERY_STOPPED);
 878                         return 0;
 879                 }
 880         }
 881
 882         return -1;
 883 }