1 /* 2 * Generic advertisement service (GAS) query (hostapd) 3 * Copyright (c) 2009, Atheros Communications 4 * Copyright (c) 2011-2017, Qualcomm Atheros, Inc. 5 * Copyright (c) 2011-2014, Jouni Malinen <j (at) 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 "utils/list.h" 16 #include "common/ieee802_11_defs.h" 17 #include "common/gas.h" 18 #include "common/wpa_ctrl.h" 19 #include "hostapd.h" 20 #include "sta_info.h" 21 #include "ap_drv_ops.h" 22 #include "gas_query_ap.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_ap *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_ap_result result, 52 const struct wpabuf *adv_proto, 53 const struct wpabuf *resp, u16 status_code); 54 void *ctx; 55 u8 sa[ETH_ALEN]; 56 }; 57 58 /** 59 * struct gas_query_ap - Internal GAS query data 60 */ 61 struct gas_query_ap { 62 struct hostapd_data *hapd; 63 void *msg_ctx; 64 struct dl_list pending; /* struct gas_query_pending */ 65 struct gas_query_pending *current; 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_ap *gas, 73 struct gas_query_pending *query); 74 static int gas_query_new_dialog_token(struct gas_query_ap *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_ap_init - Initialize GAS query component 89 * @hapd: Pointer to hostapd data 90 * Returns: Pointer to GAS query data or %NULL on failure 91 */ 92 struct gas_query_ap * gas_query_ap_init(struct hostapd_data *hapd, 93 void *msg_ctx) 94 { 95 struct gas_query_ap *gas; 96 97 gas = os_zalloc(sizeof(*gas)); 98 if (!gas) 99 return NULL; 100 101 gas->hapd = hapd; 102 gas->msg_ctx = msg_ctx; 103 dl_list_init(&gas->pending); 104 105 return gas; 106 } 107 108 109 static const char * gas_result_txt(enum gas_query_ap_result result) 110 { 111 switch (result) { 112 case GAS_QUERY_AP_SUCCESS: 113 return "SUCCESS"; 114 case GAS_QUERY_AP_FAILURE: 115 return "FAILURE"; 116 case GAS_QUERY_AP_TIMEOUT: 117 return "TIMEOUT"; 118 case GAS_QUERY_AP_PEER_ERROR: 119 return "PEER_ERROR"; 120 case GAS_QUERY_AP_INTERNAL_ERROR: 121 return "INTERNAL_ERROR"; 122 case GAS_QUERY_AP_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 if (del_list) 133 dl_list_del(&query->list); 134 135 wpabuf_free(query->req); 136 wpabuf_free(query->adv_proto); 137 wpabuf_free(query->resp); 138 os_free(query); 139 } 140 141 142 static void gas_query_done(struct gas_query_ap *gas, 143 struct gas_query_pending *query, 144 enum gas_query_ap_result result) 145 { 146 wpa_msg(gas->msg_ctx, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR 147 " dialog_token=%u freq=%d status_code=%u result=%s", 148 MAC2STR(query->addr), query->dialog_token, query->freq, 149 query->status_code, gas_result_txt(result)); 150 if (gas->current == query) 151 gas->current = NULL; 152 eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query); 153 eloop_cancel_timeout(gas_query_timeout, gas, query); 154 eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query); 155 dl_list_del(&query->list); 156 query->cb(query->ctx, query->addr, query->dialog_token, result, 157 query->adv_proto, query->resp, query->status_code); 158 gas_query_free(query, 0); 159 } 160 161 162 /** 163 * gas_query_ap_deinit - Deinitialize GAS query component 164 * @gas: GAS query data from gas_query_init() 165 */ 166 void gas_query_ap_deinit(struct gas_query_ap *gas) 167 { 168 struct gas_query_pending *query, *next; 169 170 if (gas == NULL) 171 return; 172 173 dl_list_for_each_safe(query, next, &gas->pending, 174 struct gas_query_pending, list) 175 gas_query_done(gas, query, GAS_QUERY_AP_DELETED_AT_DEINIT); 176 177 os_free(gas); 178 } 179 180 181 static struct gas_query_pending * 182 gas_query_get_pending(struct gas_query_ap *gas, const u8 *addr, u8 dialog_token) 183 { 184 struct gas_query_pending *q; 185 dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) { 186 if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 && 187 q->dialog_token == dialog_token) 188 return q; 189 } 190 return NULL; 191 } 192 193 194 static int gas_query_append(struct gas_query_pending *query, const u8 *data, 195 size_t len) 196 { 197 if (wpabuf_resize(&query->resp, len) < 0) { 198 wpa_printf(MSG_DEBUG, "GAS: No memory to store the response"); 199 return -1; 200 } 201 wpabuf_put_data(query->resp, data, len); 202 return 0; 203 } 204 205 206 void gas_query_ap_tx_status(struct gas_query_ap *gas, const u8 *dst, 207 const u8 *data, size_t data_len, int ok) 208 { 209 struct gas_query_pending *query; 210 int dur; 211 212 if (!gas || !gas->current) { 213 wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: dst=" MACSTR 214 " ok=%d - no query in progress", MAC2STR(dst), ok); 215 return; 216 } 217 218 query = gas->current; 219 220 dur = ms_from_time(&query->last_oper); 221 wpa_printf(MSG_DEBUG, "GAS: TX status: dst=" MACSTR 222 " ok=%d query=%p dialog_token=%u dur=%d ms", 223 MAC2STR(dst), ok, query, query->dialog_token, dur); 224 if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) { 225 wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination"); 226 return; 227 } 228 os_get_reltime(&query->last_oper); 229 230 eloop_cancel_timeout(gas_query_timeout, gas, query); 231 if (!ok) { 232 wpa_printf(MSG_DEBUG, "GAS: No ACK to GAS request"); 233 eloop_register_timeout(0, 250000, gas_query_timeout, 234 gas, query); 235 } else { 236 eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0, 237 gas_query_timeout, gas, query); 238 } 239 if (query->wait_comeback && !query->retry) { 240 eloop_cancel_timeout(gas_query_rx_comeback_timeout, 241 gas, query); 242 eloop_register_timeout( 243 0, (GAS_QUERY_WAIT_TIME_COMEBACK + 10) * 1000, 244 gas_query_rx_comeback_timeout, gas, query); 245 } 246 } 247 248 249 static int pmf_in_use(struct hostapd_data *hapd, const u8 *addr) 250 { 251 struct sta_info *sta; 252 253 sta = ap_get_sta(hapd, addr); 254 return sta && (sta->flags & WLAN_STA_MFP); 255 } 256 257 258 static int gas_query_tx(struct gas_query_ap *gas, 259 struct gas_query_pending *query, 260 struct wpabuf *req, unsigned int wait_time) 261 { 262 int res, prot = pmf_in_use(gas->hapd, query->addr); 263 264 wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u " 265 "freq=%d prot=%d using src addr " MACSTR, 266 MAC2STR(query->addr), (unsigned int) wpabuf_len(req), 267 query->freq, prot, MAC2STR(query->sa)); 268 if (prot) { 269 u8 *categ = wpabuf_mhead_u8(req); 270 *categ = WLAN_ACTION_PROTECTED_DUAL; 271 } 272 os_get_reltime(&query->last_oper); 273 res = hostapd_drv_send_action(gas->hapd, query->freq, wait_time, 274 query->addr, wpabuf_head(req), 275 wpabuf_len(req)); 276 return res; 277 } 278 279 280 static void gas_query_tx_comeback_req(struct gas_query_ap *gas, 281 struct gas_query_pending *query) 282 { 283 struct wpabuf *req; 284 unsigned int wait_time; 285 286 req = gas_build_comeback_req(query->dialog_token); 287 if (req == NULL) { 288 gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); 289 return; 290 } 291 292 wait_time = (query->retry || !query->offchannel_tx_started) ? 293 GAS_QUERY_WAIT_TIME_INITIAL : GAS_QUERY_WAIT_TIME_COMEBACK; 294 295 if (gas_query_tx(gas, query, req, wait_time) < 0) { 296 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to " 297 MACSTR, MAC2STR(query->addr)); 298 gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); 299 } 300 301 wpabuf_free(req); 302 } 303 304 305 static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx) 306 { 307 struct gas_query_ap *gas = eloop_data; 308 struct gas_query_pending *query = user_ctx; 309 int dialog_token; 310 311 wpa_printf(MSG_DEBUG, 312 "GAS: No response to comeback request received (retry=%u)", 313 query->retry); 314 if (gas->current != query || query->retry) 315 return; 316 dialog_token = gas_query_new_dialog_token(gas, query->addr); 317 if (dialog_token < 0) 318 return; 319 wpa_printf(MSG_DEBUG, 320 "GAS: Retry GAS query due to comeback response timeout"); 321 query->retry = 1; 322 query->dialog_token = dialog_token; 323 *(wpabuf_mhead_u8(query->req) + 2) = dialog_token; 324 query->wait_comeback = 0; 325 query->next_frag_id = 0; 326 wpabuf_free(query->adv_proto); 327 query->adv_proto = NULL; 328 eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query); 329 eloop_cancel_timeout(gas_query_timeout, gas, query); 330 gas_query_tx_initial_req(gas, query); 331 } 332 333 334 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx) 335 { 336 struct gas_query_ap *gas = eloop_data; 337 struct gas_query_pending *query = user_ctx; 338 339 wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR, 340 MAC2STR(query->addr)); 341 gas_query_tx_comeback_req(gas, query); 342 } 343 344 345 static void gas_query_tx_comeback_req_delay(struct gas_query_ap *gas, 346 struct gas_query_pending *query, 347 u16 comeback_delay) 348 { 349 unsigned int secs, usecs; 350 351 secs = (comeback_delay * 1024) / 1000000; 352 usecs = comeback_delay * 1024 - secs * 1000000; 353 wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR 354 " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs); 355 eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query); 356 eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout, 357 gas, query); 358 } 359 360 361 static void gas_query_rx_initial(struct gas_query_ap *gas, 362 struct gas_query_pending *query, 363 const u8 *adv_proto, const u8 *resp, 364 size_t len, u16 comeback_delay) 365 { 366 wpa_printf(MSG_DEBUG, "GAS: Received initial response from " 367 MACSTR " (dialog_token=%u comeback_delay=%u)", 368 MAC2STR(query->addr), query->dialog_token, comeback_delay); 369 370 query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]); 371 if (query->adv_proto == NULL) { 372 gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); 373 return; 374 } 375 376 if (comeback_delay) { 377 eloop_cancel_timeout(gas_query_timeout, gas, query); 378 query->wait_comeback = 1; 379 gas_query_tx_comeback_req_delay(gas, query, comeback_delay); 380 return; 381 } 382 383 /* Query was completed without comeback mechanism */ 384 if (gas_query_append(query, resp, len) < 0) { 385 gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); 386 return; 387 } 388 389 gas_query_done(gas, query, GAS_QUERY_AP_SUCCESS); 390 } 391 392 393 static void gas_query_rx_comeback(struct gas_query_ap *gas, 394 struct gas_query_pending *query, 395 const u8 *adv_proto, const u8 *resp, 396 size_t len, u8 frag_id, u8 more_frags, 397 u16 comeback_delay) 398 { 399 wpa_printf(MSG_DEBUG, "GAS: Received comeback response from " 400 MACSTR " (dialog_token=%u frag_id=%u more_frags=%u " 401 "comeback_delay=%u)", 402 MAC2STR(query->addr), query->dialog_token, frag_id, 403 more_frags, comeback_delay); 404 eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query); 405 406 if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) || 407 os_memcmp(adv_proto, wpabuf_head(query->adv_proto), 408 wpabuf_len(query->adv_proto)) != 0) { 409 wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed " 410 "between initial and comeback response from " 411 MACSTR, MAC2STR(query->addr)); 412 gas_query_done(gas, query, GAS_QUERY_AP_PEER_ERROR); 413 return; 414 } 415 416 if (comeback_delay) { 417 if (frag_id) { 418 wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response " 419 "with non-zero frag_id and comeback_delay " 420 "from " MACSTR, MAC2STR(query->addr)); 421 gas_query_done(gas, query, GAS_QUERY_AP_PEER_ERROR); 422 return; 423 } 424 gas_query_tx_comeback_req_delay(gas, query, comeback_delay); 425 return; 426 } 427 428 if (frag_id != query->next_frag_id) { 429 wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response " 430 "from " MACSTR, MAC2STR(query->addr)); 431 if (frag_id + 1 == query->next_frag_id) { 432 wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible " 433 "retry of previous fragment"); 434 return; 435 } 436 gas_query_done(gas, query, GAS_QUERY_AP_PEER_ERROR); 437 return; 438 } 439 query->next_frag_id++; 440 441 if (gas_query_append(query, resp, len) < 0) { 442 gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); 443 return; 444 } 445 446 if (more_frags) { 447 gas_query_tx_comeback_req(gas, query); 448 return; 449 } 450 451 gas_query_done(gas, query, GAS_QUERY_AP_SUCCESS); 452 } 453 454 455 /** 456 * gas_query_ap_rx - Indicate reception of a Public Action or Protected Dual 457 * frame 458 * @gas: GAS query data from gas_query_init() 459 * @sa: Source MAC address of the Action frame 460 * @categ: Category of the Action frame 461 * @data: Payload of the Action frame 462 * @len: Length of @data 463 * @freq: Frequency (in MHz) on which the frame was received 464 * Returns: 0 if the Public Action frame was a GAS frame or -1 if not 465 */ 466 int gas_query_ap_rx(struct gas_query_ap *gas, const u8 *sa, u8 categ, 467 const u8 *data, size_t len, int freq) 468 { 469 struct gas_query_pending *query; 470 u8 action, dialog_token, frag_id = 0, more_frags = 0; 471 u16 comeback_delay, resp_len; 472 const u8 *pos, *adv_proto; 473 int prot, pmf; 474 unsigned int left; 475 476 if (!gas || len < 4) 477 return -1; 478 479 pos = data; 480 action = *pos++; 481 dialog_token = *pos++; 482 483 if (action != WLAN_PA_GAS_INITIAL_RESP && 484 action != WLAN_PA_GAS_COMEBACK_RESP) 485 return -1; /* Not a GAS response */ 486 487 prot = categ == WLAN_ACTION_PROTECTED_DUAL; 488 pmf = pmf_in_use(gas->hapd, sa); 489 if (prot && !pmf) { 490 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled"); 491 return 0; 492 } 493 if (!prot && pmf) { 494 wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled"); 495 return 0; 496 } 497 498 query = gas_query_get_pending(gas, sa, dialog_token); 499 if (query == NULL) { 500 wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR 501 " dialog token %u", MAC2STR(sa), dialog_token); 502 return -1; 503 } 504 505 wpa_printf(MSG_DEBUG, "GAS: Response in %d ms from " MACSTR, 506 ms_from_time(&query->last_oper), MAC2STR(sa)); 507 508 if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) { 509 wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from " 510 MACSTR " dialog token %u when waiting for comeback " 511 "response", MAC2STR(sa), dialog_token); 512 return 0; 513 } 514 515 if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) { 516 wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from " 517 MACSTR " dialog token %u when waiting for initial " 518 "response", MAC2STR(sa), dialog_token); 519 return 0; 520 } 521 522 query->status_code = WPA_GET_LE16(pos); 523 pos += 2; 524 525 if (query->status_code == WLAN_STATUS_QUERY_RESP_OUTSTANDING && 526 action == WLAN_PA_GAS_COMEBACK_RESP) { 527 wpa_printf(MSG_DEBUG, "GAS: Allow non-zero status for outstanding comeback response"); 528 } else if (query->status_code != WLAN_STATUS_SUCCESS) { 529 wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token " 530 "%u failed - status code %u", 531 MAC2STR(sa), dialog_token, query->status_code); 532 gas_query_done(gas, query, GAS_QUERY_AP_FAILURE); 533 return 0; 534 } 535 536 if (action == WLAN_PA_GAS_COMEBACK_RESP) { 537 if (pos + 1 > data + len) 538 return 0; 539 frag_id = *pos & 0x7f; 540 more_frags = (*pos & 0x80) >> 7; 541 pos++; 542 } 543 544 /* Comeback Delay */ 545 if (pos + 2 > data + len) 546 return 0; 547 comeback_delay = WPA_GET_LE16(pos); 548 pos += 2; 549 550 /* Advertisement Protocol element */ 551 if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) { 552 wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement " 553 "Protocol element in the response from " MACSTR, 554 MAC2STR(sa)); 555 return 0; 556 } 557 558 if (*pos != WLAN_EID_ADV_PROTO) { 559 wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement " 560 "Protocol element ID %u in response from " MACSTR, 561 *pos, MAC2STR(sa)); 562 return 0; 563 } 564 565 adv_proto = pos; 566 pos += 2 + pos[1]; 567 568 /* Query Response Length */ 569 if (pos + 2 > data + len) { 570 wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length"); 571 return 0; 572 } 573 resp_len = WPA_GET_LE16(pos); 574 pos += 2; 575 576 left = data + len - pos; 577 if (resp_len > left) { 578 wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in " 579 "response from " MACSTR, MAC2STR(sa)); 580 return 0; 581 } 582 583 if (resp_len < left) { 584 wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data " 585 "after Query Response from " MACSTR, 586 left - resp_len, MAC2STR(sa)); 587 } 588 589 if (action == WLAN_PA_GAS_COMEBACK_RESP) 590 gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len, 591 frag_id, more_frags, comeback_delay); 592 else 593 gas_query_rx_initial(gas, query, adv_proto, pos, resp_len, 594 comeback_delay); 595 596 return 0; 597 } 598 599 600 static void gas_query_timeout(void *eloop_data, void *user_ctx) 601 { 602 struct gas_query_ap *gas = eloop_data; 603 struct gas_query_pending *query = user_ctx; 604 605 wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR 606 " dialog token %u", 607 MAC2STR(query->addr), query->dialog_token); 608 gas_query_done(gas, query, GAS_QUERY_AP_TIMEOUT); 609 } 610 611 612 static int gas_query_dialog_token_available(struct gas_query_ap *gas, 613 const u8 *dst, u8 dialog_token) 614 { 615 struct gas_query_pending *q; 616 dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) { 617 if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 && 618 dialog_token == q->dialog_token) 619 return 0; 620 } 621 622 return 1; 623 } 624 625 626 static void gas_query_tx_initial_req(struct gas_query_ap *gas, 627 struct gas_query_pending *query) 628 { 629 if (gas_query_tx(gas, query, query->req, 630 GAS_QUERY_WAIT_TIME_INITIAL) < 0) { 631 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to " 632 MACSTR, MAC2STR(query->addr)); 633 gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); 634 return; 635 } 636 gas->current = query; 637 638 wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u", 639 query->dialog_token); 640 eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0, 641 gas_query_timeout, gas, query); 642 } 643 644 645 static int gas_query_new_dialog_token(struct gas_query_ap *gas, const u8 *dst) 646 { 647 static int next_start = 0; 648 int dialog_token; 649 650 for (dialog_token = 0; dialog_token < 256; dialog_token++) { 651 if (gas_query_dialog_token_available( 652 gas, dst, (next_start + dialog_token) % 256)) 653 break; 654 } 655 if (dialog_token == 256) 656 return -1; /* Too many pending queries */ 657 dialog_token = (next_start + dialog_token) % 256; 658 next_start = (dialog_token + 1) % 256; 659 return dialog_token; 660 } 661 662 663 /** 664 * gas_query_ap_req - Request a GAS query 665 * @gas: GAS query data from gas_query_init() 666 * @dst: Destination MAC address for the query 667 * @freq: Frequency (in MHz) for the channel on which to send the query 668 * @req: GAS query payload (to be freed by gas_query module in case of success 669 * return) 670 * @cb: Callback function for reporting GAS query result and response 671 * @ctx: Context pointer to use with the @cb call 672 * Returns: dialog token (>= 0) on success or -1 on failure 673 */ 674 int gas_query_ap_req(struct gas_query_ap *gas, const u8 *dst, int freq, 675 struct wpabuf *req, 676 void (*cb)(void *ctx, const u8 *dst, u8 dialog_token, 677 enum gas_query_ap_result result, 678 const struct wpabuf *adv_proto, 679 const struct wpabuf *resp, u16 status_code), 680 void *ctx) 681 { 682 struct gas_query_pending *query; 683 int dialog_token; 684 685 if (!gas || wpabuf_len(req) < 3) 686 return -1; 687 688 dialog_token = gas_query_new_dialog_token(gas, dst); 689 if (dialog_token < 0) 690 return -1; 691 692 query = os_zalloc(sizeof(*query)); 693 if (query == NULL) 694 return -1; 695 696 query->gas = gas; 697 os_memcpy(query->addr, dst, ETH_ALEN); 698 query->dialog_token = dialog_token; 699 query->freq = freq; 700 query->cb = cb; 701 query->ctx = ctx; 702 query->req = req; 703 dl_list_add(&gas->pending, &query->list); 704 705 *(wpabuf_mhead_u8(req) + 2) = dialog_token; 706 707 wpa_msg(gas->msg_ctx, MSG_INFO, GAS_QUERY_START "addr=" MACSTR 708 " dialog_token=%u freq=%d", 709 MAC2STR(query->addr), query->dialog_token, query->freq); 710 711 gas_query_tx_initial_req(gas, query); 712 713 return dialog_token; 714 } 715
