1 /* 2 * Generic advertisement service (GAS) query 3 * Copyright (c) 2009, Atheros Communications 4 * Copyright (c) 2011, Qualcomm Atheros 5 * 6 * This software may be distributed under the terms of the BSD license. 7 * See README for more details. 8 */ 9 10 #include "includes.h" 11 12 #include "common.h" 13 #include "utils/eloop.h" 14 #include "common/ieee802_11_defs.h" 15 #include "common/gas.h" 16 #include "wpa_supplicant_i.h" 17 #include "driver_i.h" 18 #include "offchannel.h" 19 #include "gas_query.h" 20 21 22 #define GAS_QUERY_TIMEOUT 5 23 24 25 struct gas_query_pending { 26 struct dl_list list; 27 u8 addr[ETH_ALEN]; 28 u8 dialog_token; 29 u8 next_frag_id; 30 unsigned int wait_comeback:1; 31 unsigned int offchannel_tx_started:1; 32 int freq; 33 u16 status_code; 34 struct wpabuf *adv_proto; 35 struct wpabuf *resp; 36 void (*cb)(void *ctx, const u8 *dst, u8 dialog_token, 37 enum gas_query_result result, 38 const struct wpabuf *adv_proto, 39 const struct wpabuf *resp, u16 status_code); 40 void *ctx; 41 }; 42 43 struct gas_query { 44 struct wpa_supplicant *wpa_s; 45 struct dl_list pending; /* struct gas_query_pending */ 46 }; 47 48 49 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx); 50 static void gas_query_timeout(void *eloop_data, void *user_ctx); 51 52 53 struct gas_query * gas_query_init(struct wpa_supplicant *wpa_s) 54 { 55 struct gas_query *gas; 56 57 gas = os_zalloc(sizeof(*gas)); 58 if (gas == NULL) 59 return NULL; 60 61 gas->wpa_s = wpa_s; 62 dl_list_init(&gas->pending); 63 64 return gas; 65 } 66 67 68 static void gas_query_done(struct gas_query *gas, 69 struct gas_query_pending *query, 70 enum gas_query_result result) 71 { 72 if (query->offchannel_tx_started) 73 offchannel_send_action_done(gas->wpa_s); 74 eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query); 75 eloop_cancel_timeout(gas_query_timeout, gas, query); 76 dl_list_del(&query->list); 77 query->cb(query->ctx, query->addr, query->dialog_token, result, 78 query->adv_proto, query->resp, query->status_code); 79 wpabuf_free(query->adv_proto); 80 wpabuf_free(query->resp); 81 os_free(query); 82 } 83 84 85 void gas_query_deinit(struct gas_query *gas) 86 { 87 struct gas_query_pending *query, *next; 88 89 if (gas == NULL) 90 return; 91 92 dl_list_for_each_safe(query, next, &gas->pending, 93 struct gas_query_pending, list) 94 gas_query_done(gas, query, GAS_QUERY_DELETED_AT_DEINIT); 95 96 os_free(gas); 97 } 98 99 100 static struct gas_query_pending * 101 gas_query_get_pending(struct gas_query *gas, const u8 *addr, u8 dialog_token) 102 { 103 struct gas_query_pending *q; 104 dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) { 105 if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 && 106 q->dialog_token == dialog_token) 107 return q; 108 } 109 return NULL; 110 } 111 112 113 static int gas_query_append(struct gas_query_pending *query, const u8 *data, 114 size_t len) 115 { 116 if (wpabuf_resize(&query->resp, len) < 0) { 117 wpa_printf(MSG_DEBUG, "GAS: No memory to store the response"); 118 return -1; 119 } 120 wpabuf_put_data(query->resp, data, len); 121 return 0; 122 } 123 124 125 static int gas_query_tx(struct gas_query *gas, struct gas_query_pending *query, 126 struct wpabuf *req) 127 { 128 int res; 129 wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u " 130 "freq=%d", MAC2STR(query->addr), 131 (unsigned int) wpabuf_len(req), query->freq); 132 res = offchannel_send_action(gas->wpa_s, query->freq, query->addr, 133 gas->wpa_s->own_addr, query->addr, 134 wpabuf_head(req), wpabuf_len(req), 1000, 135 NULL, 0); 136 if (res == 0) 137 query->offchannel_tx_started = 1; 138 return res; 139 } 140 141 142 static void gas_query_tx_comeback_req(struct gas_query *gas, 143 struct gas_query_pending *query) 144 { 145 struct wpabuf *req; 146 147 req = gas_build_comeback_req(query->dialog_token); 148 if (req == NULL) { 149 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR); 150 return; 151 } 152 153 if (gas_query_tx(gas, query, req) < 0) { 154 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to " 155 MACSTR, MAC2STR(query->addr)); 156 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR); 157 } 158 159 wpabuf_free(req); 160 } 161 162 163 static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx) 164 { 165 struct gas_query *gas = eloop_data; 166 struct gas_query_pending *query = user_ctx; 167 168 wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR, 169 MAC2STR(query->addr)); 170 gas_query_tx_comeback_req(gas, query); 171 } 172 173 174 static void gas_query_tx_comeback_req_delay(struct gas_query *gas, 175 struct gas_query_pending *query, 176 u16 comeback_delay) 177 { 178 unsigned int secs, usecs; 179 180 secs = (comeback_delay * 1024) / 1000000; 181 usecs = comeback_delay * 1024 - secs * 1000000; 182 wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR 183 " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs); 184 eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query); 185 eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout, 186 gas, query); 187 } 188 189 190 static void gas_query_rx_initial(struct gas_query *gas, 191 struct gas_query_pending *query, 192 const u8 *adv_proto, const u8 *resp, 193 size_t len, u16 comeback_delay) 194 { 195 wpa_printf(MSG_DEBUG, "GAS: Received initial response from " 196 MACSTR " (dialog_token=%u comeback_delay=%u)", 197 MAC2STR(query->addr), query->dialog_token, comeback_delay); 198 199 query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]); 200 if (query->adv_proto == NULL) { 201 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR); 202 return; 203 } 204 205 if (comeback_delay) { 206 query->wait_comeback = 1; 207 gas_query_tx_comeback_req_delay(gas, query, comeback_delay); 208 return; 209 } 210 211 /* Query was completed without comeback mechanism */ 212 if (gas_query_append(query, resp, len) < 0) { 213 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR); 214 return; 215 } 216 217 gas_query_done(gas, query, GAS_QUERY_SUCCESS); 218 } 219 220 221 static void gas_query_rx_comeback(struct gas_query *gas, 222 struct gas_query_pending *query, 223 const u8 *adv_proto, const u8 *resp, 224 size_t len, u8 frag_id, u8 more_frags, 225 u16 comeback_delay) 226 { 227 wpa_printf(MSG_DEBUG, "GAS: Received comeback response from " 228 MACSTR " (dialog_token=%u frag_id=%u more_frags=%u " 229 "comeback_delay=%u)", 230 MAC2STR(query->addr), query->dialog_token, frag_id, 231 more_frags, comeback_delay); 232 233 if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) || 234 os_memcmp(adv_proto, wpabuf_head(query->adv_proto), 235 wpabuf_len(query->adv_proto)) != 0) { 236 wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed " 237 "between initial and comeback response from " 238 MACSTR, MAC2STR(query->addr)); 239 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR); 240 return; 241 } 242 243 if (comeback_delay) { 244 if (frag_id) { 245 wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response " 246 "with non-zero frag_id and comeback_delay " 247 "from " MACSTR, MAC2STR(query->addr)); 248 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR); 249 return; 250 } 251 gas_query_tx_comeback_req_delay(gas, query, comeback_delay); 252 return; 253 } 254 255 if (frag_id != query->next_frag_id) { 256 wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response " 257 "from " MACSTR, MAC2STR(query->addr)); 258 gas_query_done(gas, query, GAS_QUERY_PEER_ERROR); 259 return; 260 } 261 query->next_frag_id++; 262 263 if (gas_query_append(query, resp, len) < 0) { 264 gas_query_done(gas, query, GAS_QUERY_INTERNAL_ERROR); 265 return; 266 } 267 268 if (more_frags) { 269 gas_query_tx_comeback_req(gas, query); 270 return; 271 } 272 273 gas_query_done(gas, query, GAS_QUERY_SUCCESS); 274 } 275 276 277 int gas_query_rx(struct gas_query *gas, const u8 *da, const u8 *sa, 278 const u8 *bssid, const u8 *data, size_t len, int freq) 279 { 280 struct gas_query_pending *query; 281 u8 action, dialog_token, frag_id = 0, more_frags = 0; 282 u16 comeback_delay, resp_len; 283 const u8 *pos, *adv_proto; 284 285 if (gas == NULL || len < 4) 286 return -1; 287 288 pos = data; 289 action = *pos++; 290 dialog_token = *pos++; 291 292 if (action != WLAN_PA_GAS_INITIAL_RESP && 293 action != WLAN_PA_GAS_COMEBACK_RESP) 294 return -1; /* Not a GAS response */ 295 296 query = gas_query_get_pending(gas, sa, dialog_token); 297 if (query == NULL) { 298 wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR 299 " dialog token %u", MAC2STR(sa), dialog_token); 300 return -1; 301 } 302 303 if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) { 304 wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from " 305 MACSTR " dialog token %u when waiting for comeback " 306 "response", MAC2STR(sa), dialog_token); 307 return 0; 308 } 309 310 if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) { 311 wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from " 312 MACSTR " dialog token %u when waiting for initial " 313 "response", MAC2STR(sa), dialog_token); 314 return 0; 315 } 316 317 query->status_code = WPA_GET_LE16(pos); 318 pos += 2; 319 320 if (query->status_code != WLAN_STATUS_SUCCESS) { 321 wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token " 322 "%u failed - status code %u", 323 MAC2STR(sa), dialog_token, query->status_code); 324 gas_query_done(gas, query, GAS_QUERY_FAILURE); 325 return 0; 326 } 327 328 if (action == WLAN_PA_GAS_COMEBACK_RESP) { 329 if (pos + 1 > data + len) 330 return 0; 331 frag_id = *pos & 0x7f; 332 more_frags = (*pos & 0x80) >> 7; 333 pos++; 334 } 335 336 /* Comeback Delay */ 337 if (pos + 2 > data + len) 338 return 0; 339 comeback_delay = WPA_GET_LE16(pos); 340 pos += 2; 341 342 /* Advertisement Protocol element */ 343 if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) { 344 wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement " 345 "Protocol element in the response from " MACSTR, 346 MAC2STR(sa)); 347 return 0; 348 } 349 350 if (*pos != WLAN_EID_ADV_PROTO) { 351 wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement " 352 "Protocol element ID %u in response from " MACSTR, 353 *pos, MAC2STR(sa)); 354 return 0; 355 } 356 357 adv_proto = pos; 358 pos += 2 + pos[1]; 359 360 /* Query Response Length */ 361 if (pos + 2 > data + len) { 362 wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length"); 363 return 0; 364 } 365 resp_len = WPA_GET_LE16(pos); 366 pos += 2; 367 368 if (pos + resp_len > data + len) { 369 wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in " 370 "response from " MACSTR, MAC2STR(sa)); 371 return 0; 372 } 373 374 if (pos + resp_len < data + len) { 375 wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data " 376 "after Query Response from " MACSTR, 377 (unsigned int) (data + len - pos - resp_len), 378 MAC2STR(sa)); 379 } 380 381 if (action == WLAN_PA_GAS_COMEBACK_RESP) 382 gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len, 383 frag_id, more_frags, comeback_delay); 384 else 385 gas_query_rx_initial(gas, query, adv_proto, pos, resp_len, 386 comeback_delay); 387 388 return 0; 389 } 390 391 392 static void gas_query_timeout(void *eloop_data, void *user_ctx) 393 { 394 struct gas_query *gas = eloop_data; 395 struct gas_query_pending *query = user_ctx; 396 397 wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR, 398 MAC2STR(query->addr)); 399 gas_query_done(gas, query, GAS_QUERY_TIMEOUT); 400 } 401 402 403 static int gas_query_dialog_token_available(struct gas_query *gas, 404 const u8 *dst, u8 dialog_token) 405 { 406 struct gas_query_pending *q; 407 dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) { 408 if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 && 409 dialog_token == q->dialog_token) 410 return 0; 411 } 412 413 return 1; 414 } 415 416 417 int gas_query_req(struct gas_query *gas, const u8 *dst, int freq, 418 struct wpabuf *req, 419 void (*cb)(void *ctx, const u8 *dst, u8 dialog_token, 420 enum gas_query_result result, 421 const struct wpabuf *adv_proto, 422 const struct wpabuf *resp, u16 status_code), 423 void *ctx) 424 { 425 struct gas_query_pending *query; 426 int dialog_token; 427 428 if (wpabuf_len(req) < 3) 429 return -1; 430 431 for (dialog_token = 0; dialog_token < 256; dialog_token++) { 432 if (gas_query_dialog_token_available(gas, dst, dialog_token)) 433 break; 434 } 435 if (dialog_token == 256) 436 return -1; /* Too many pending queries */ 437 438 query = os_zalloc(sizeof(*query)); 439 if (query == NULL) 440 return -1; 441 442 os_memcpy(query->addr, dst, ETH_ALEN); 443 query->dialog_token = dialog_token; 444 query->freq = freq; 445 query->cb = cb; 446 query->ctx = ctx; 447 dl_list_add(&gas->pending, &query->list); 448 449 *(wpabuf_mhead_u8(req) + 2) = dialog_token; 450 451 wpa_printf(MSG_DEBUG, "GAS: Starting request for " MACSTR 452 " dialog_token %u", MAC2STR(dst), dialog_token); 453 if (gas_query_tx(gas, query, req) < 0) { 454 wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to " 455 MACSTR, MAC2STR(query->addr)); 456 os_free(query); 457 return -1; 458 } 459 460 eloop_register_timeout(GAS_QUERY_TIMEOUT, 0, gas_query_timeout, 461 gas, query); 462 463 return dialog_token; 464 } 465 466 467 void gas_query_cancel(struct gas_query *gas, const u8 *dst, u8 dialog_token) 468 { 469 struct gas_query_pending *query; 470 471 query = gas_query_get_pending(gas, dst, dialog_token); 472 if (query) 473 gas_query_done(gas, query, GAS_QUERY_CANCELLED); 474 475 } 476
