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