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      1 /*
      2  * Wi-Fi Direct - P2P service discovery
      3  * Copyright (c) 2009, Atheros Communications
      4  *
      5  * This software may be distributed under the terms of the BSD license.
      6  * See README for more details.
      7  */
      8 
      9 #include "includes.h"
     10 
     11 #include "common.h"
     12 #include "common/ieee802_11_defs.h"
     13 #include "common/gas.h"
     14 #include "p2p_i.h"
     15 #include "p2p.h"
     16 
     17 
     18 #ifdef CONFIG_WIFI_DISPLAY
     19 static int wfd_wsd_supported(struct wpabuf *wfd)
     20 {
     21 	const u8 *pos, *end;
     22 	u8 subelem;
     23 	u16 len;
     24 
     25 	if (wfd == NULL)
     26 		return 0;
     27 
     28 	pos = wpabuf_head(wfd);
     29 	end = pos + wpabuf_len(wfd);
     30 
     31 	while (pos + 3 <= end) {
     32 		subelem = *pos++;
     33 		len = WPA_GET_BE16(pos);
     34 		pos += 2;
     35 		if (pos + len > end)
     36 			break;
     37 
     38 		if (subelem == WFD_SUBELEM_DEVICE_INFO && len >= 6) {
     39 			u16 info = WPA_GET_BE16(pos);
     40 			return !!(info & 0x0040);
     41 		}
     42 
     43 		pos += len;
     44 	}
     45 
     46 	return 0;
     47 }
     48 #endif /* CONFIG_WIFI_DISPLAY */
     49 
     50 struct p2p_sd_query * p2p_pending_sd_req(struct p2p_data *p2p,
     51 					 struct p2p_device *dev)
     52 {
     53 	struct p2p_sd_query *q;
     54 	int wsd = 0;
     55 	int count = 0;
     56 
     57 	if (!(dev->info.dev_capab & P2P_DEV_CAPAB_SERVICE_DISCOVERY))
     58 		return NULL; /* peer does not support SD */
     59 #ifdef CONFIG_WIFI_DISPLAY
     60 	if (wfd_wsd_supported(dev->info.wfd_subelems))
     61 		wsd = 1;
     62 #endif /* CONFIG_WIFI_DISPLAY */
     63 
     64 	for (q = p2p->sd_queries; q; q = q->next) {
     65 		/* Use WSD only if the peer indicates support or it */
     66 		if (q->wsd && !wsd)
     67 			continue;
     68 		/* if the query is a broadcast query */
     69 		if (q->for_all_peers) {
     70 			/*
     71 			 * check if there are any broadcast queries pending for
     72 			 * this device
     73 			 */
     74 			if (dev->sd_pending_bcast_queries <= 0)
     75 				return NULL;
     76 			/* query number that needs to be send to the device */
     77 			if (count == dev->sd_pending_bcast_queries - 1)
     78 				goto found;
     79 			count++;
     80 		}
     81 		if (!q->for_all_peers &&
     82 		    os_memcmp(q->peer, dev->info.p2p_device_addr, ETH_ALEN) ==
     83 		    0)
     84 			goto found;
     85 	}
     86 
     87 	return NULL;
     88 
     89 found:
     90 	if (dev->sd_reqs > 100) {
     91 		p2p_dbg(p2p, "Too many SD request attempts to " MACSTR
     92 			" - skip remaining queries",
     93 			MAC2STR(dev->info.p2p_device_addr));
     94 		return NULL;
     95 	}
     96 	return q;
     97 }
     98 
     99 
    100 static void p2p_decrease_sd_bc_queries(struct p2p_data *p2p, int query_number)
    101 {
    102 	struct p2p_device *dev;
    103 
    104 	p2p->num_p2p_sd_queries--;
    105 	dl_list_for_each(dev, &p2p->devices, struct p2p_device, list) {
    106 		if (query_number <= dev->sd_pending_bcast_queries - 1) {
    107 			/*
    108 			 * Query not yet sent to the device and it is to be
    109 			 * removed, so update the pending count.
    110 			*/
    111 			dev->sd_pending_bcast_queries--;
    112 		}
    113 	}
    114 }
    115 
    116 
    117 static int p2p_unlink_sd_query(struct p2p_data *p2p,
    118 			       struct p2p_sd_query *query)
    119 {
    120 	struct p2p_sd_query *q, *prev;
    121 	int query_number = 0;
    122 
    123 	q = p2p->sd_queries;
    124 	prev = NULL;
    125 	while (q) {
    126 		if (q == query) {
    127 			/* If the query is a broadcast query, decrease one from
    128 			 * all the devices */
    129 			if (query->for_all_peers)
    130 				p2p_decrease_sd_bc_queries(p2p, query_number);
    131 			if (prev)
    132 				prev->next = q->next;
    133 			else
    134 				p2p->sd_queries = q->next;
    135 			if (p2p->sd_query == query)
    136 				p2p->sd_query = NULL;
    137 			return 1;
    138 		}
    139 		if (q->for_all_peers)
    140 			query_number++;
    141 		prev = q;
    142 		q = q->next;
    143 	}
    144 	return 0;
    145 }
    146 
    147 
    148 static void p2p_free_sd_query(struct p2p_sd_query *q)
    149 {
    150 	if (q == NULL)
    151 		return;
    152 	wpabuf_free(q->tlvs);
    153 	os_free(q);
    154 }
    155 
    156 
    157 void p2p_free_sd_queries(struct p2p_data *p2p)
    158 {
    159 	struct p2p_sd_query *q, *prev;
    160 	q = p2p->sd_queries;
    161 	p2p->sd_queries = NULL;
    162 	while (q) {
    163 		prev = q;
    164 		q = q->next;
    165 		p2p_free_sd_query(prev);
    166 	}
    167 	p2p->num_p2p_sd_queries = 0;
    168 }
    169 
    170 
    171 static struct wpabuf * p2p_build_sd_query(u16 update_indic,
    172 					  struct wpabuf *tlvs)
    173 {
    174 	struct wpabuf *buf;
    175 	u8 *len_pos;
    176 
    177 	buf = gas_anqp_build_initial_req(0, 100 + wpabuf_len(tlvs));
    178 	if (buf == NULL)
    179 		return NULL;
    180 
    181 	/* ANQP Query Request Frame */
    182 	len_pos = gas_anqp_add_element(buf, ANQP_VENDOR_SPECIFIC);
    183 	wpabuf_put_be32(buf, P2P_IE_VENDOR_TYPE);
    184 	wpabuf_put_le16(buf, update_indic); /* Service Update Indicator */
    185 	wpabuf_put_buf(buf, tlvs);
    186 	gas_anqp_set_element_len(buf, len_pos);
    187 
    188 	gas_anqp_set_len(buf);
    189 
    190 	return buf;
    191 }
    192 
    193 
    194 static void p2p_send_gas_comeback_req(struct p2p_data *p2p, const u8 *dst,
    195 				      u8 dialog_token, int freq)
    196 {
    197 	struct wpabuf *req;
    198 
    199 	req = gas_build_comeback_req(dialog_token);
    200 	if (req == NULL)
    201 		return;
    202 
    203 	p2p->pending_action_state = P2P_NO_PENDING_ACTION;
    204 	if (p2p_send_action(p2p, freq, dst, p2p->cfg->dev_addr, dst,
    205 			    wpabuf_head(req), wpabuf_len(req), 200) < 0)
    206 		p2p_dbg(p2p, "Failed to send Action frame");
    207 
    208 	wpabuf_free(req);
    209 }
    210 
    211 
    212 static struct wpabuf * p2p_build_sd_response(u8 dialog_token, u16 status_code,
    213 					     u16 comeback_delay,
    214 					     u16 update_indic,
    215 					     const struct wpabuf *tlvs)
    216 {
    217 	struct wpabuf *buf;
    218 	u8 *len_pos;
    219 
    220 	buf = gas_anqp_build_initial_resp(dialog_token, status_code,
    221 					  comeback_delay,
    222 					  100 + (tlvs ? wpabuf_len(tlvs) : 0));
    223 	if (buf == NULL)
    224 		return NULL;
    225 
    226 	if (tlvs) {
    227 		/* ANQP Query Response Frame */
    228 		len_pos = gas_anqp_add_element(buf, ANQP_VENDOR_SPECIFIC);
    229 		wpabuf_put_be32(buf, P2P_IE_VENDOR_TYPE);
    230 		 /* Service Update Indicator */
    231 		wpabuf_put_le16(buf, update_indic);
    232 		wpabuf_put_buf(buf, tlvs);
    233 		gas_anqp_set_element_len(buf, len_pos);
    234 	}
    235 
    236 	gas_anqp_set_len(buf);
    237 
    238 	return buf;
    239 }
    240 
    241 
    242 static struct wpabuf * p2p_build_gas_comeback_resp(u8 dialog_token,
    243 						   u16 status_code,
    244 						   u16 update_indic,
    245 						   const u8 *data, size_t len,
    246 						   u8 frag_id, u8 more,
    247 						   u16 total_len)
    248 {
    249 	struct wpabuf *buf;
    250 
    251 	buf = gas_anqp_build_comeback_resp(dialog_token, status_code, frag_id,
    252 					   more, 0, 100 + len);
    253 	if (buf == NULL)
    254 		return NULL;
    255 
    256 	if (frag_id == 0) {
    257 		/* ANQP Query Response Frame */
    258 		wpabuf_put_le16(buf, ANQP_VENDOR_SPECIFIC); /* Info ID */
    259 		wpabuf_put_le16(buf, 3 + 1 + 2 + total_len);
    260 		wpabuf_put_be32(buf, P2P_IE_VENDOR_TYPE);
    261 		/* Service Update Indicator */
    262 		wpabuf_put_le16(buf, update_indic);
    263 	}
    264 
    265 	wpabuf_put_data(buf, data, len);
    266 	gas_anqp_set_len(buf);
    267 
    268 	return buf;
    269 }
    270 
    271 
    272 int p2p_start_sd(struct p2p_data *p2p, struct p2p_device *dev)
    273 {
    274 	struct wpabuf *req;
    275 	int ret = 0;
    276 	struct p2p_sd_query *query;
    277 	int freq;
    278 	unsigned int wait_time;
    279 
    280 	freq = dev->listen_freq > 0 ? dev->listen_freq : dev->oper_freq;
    281 	if (freq <= 0) {
    282 		p2p_dbg(p2p, "No Listen/Operating frequency known for the peer "
    283 			MACSTR " to send SD Request",
    284 			MAC2STR(dev->info.p2p_device_addr));
    285 		return -1;
    286 	}
    287 
    288 	query = p2p_pending_sd_req(p2p, dev);
    289 	if (query == NULL)
    290 		return -1;
    291 
    292 	p2p_dbg(p2p, "Start Service Discovery with " MACSTR,
    293 		MAC2STR(dev->info.p2p_device_addr));
    294 
    295 	req = p2p_build_sd_query(p2p->srv_update_indic, query->tlvs);
    296 	if (req == NULL)
    297 		return -1;
    298 
    299 	dev->sd_reqs++;
    300 	p2p->sd_peer = dev;
    301 	p2p->sd_query = query;
    302 	p2p->pending_action_state = P2P_PENDING_SD;
    303 
    304 	wait_time = 5000;
    305 	if (p2p->cfg->max_listen && wait_time > p2p->cfg->max_listen)
    306 		wait_time = p2p->cfg->max_listen;
    307 	if (p2p_send_action(p2p, freq, dev->info.p2p_device_addr,
    308 			    p2p->cfg->dev_addr, dev->info.p2p_device_addr,
    309 			    wpabuf_head(req), wpabuf_len(req), wait_time) < 0) {
    310 		p2p_dbg(p2p, "Failed to send Action frame");
    311 		ret = -1;
    312 	}
    313 
    314 	wpabuf_free(req);
    315 
    316 	return ret;
    317 }
    318 
    319 
    320 void p2p_rx_gas_initial_req(struct p2p_data *p2p, const u8 *sa,
    321 			    const u8 *data, size_t len, int rx_freq)
    322 {
    323 	const u8 *pos = data;
    324 	const u8 *end = data + len;
    325 	const u8 *next;
    326 	u8 dialog_token;
    327 	u16 slen;
    328 	int freq;
    329 	u16 update_indic;
    330 
    331 
    332 	if (p2p->cfg->sd_request == NULL)
    333 		return;
    334 
    335 	if (rx_freq > 0)
    336 		freq = rx_freq;
    337 	else
    338 		freq = p2p_channel_to_freq(p2p->cfg->reg_class,
    339 					   p2p->cfg->channel);
    340 	if (freq < 0)
    341 		return;
    342 
    343 	if (len < 1 + 2)
    344 		return;
    345 
    346 	dialog_token = *pos++;
    347 	p2p_dbg(p2p, "GAS Initial Request from " MACSTR
    348 		" (dialog token %u, freq %d)",
    349 		MAC2STR(sa), dialog_token, rx_freq);
    350 
    351 	if (*pos != WLAN_EID_ADV_PROTO) {
    352 		p2p_dbg(p2p, "Unexpected IE in GAS Initial Request: %u", *pos);
    353 		return;
    354 	}
    355 	pos++;
    356 
    357 	slen = *pos++;
    358 	next = pos + slen;
    359 	if (next > end || slen < 2) {
    360 		p2p_dbg(p2p, "Invalid IE in GAS Initial Request");
    361 		return;
    362 	}
    363 	pos++; /* skip QueryRespLenLimit and PAME-BI */
    364 
    365 	if (*pos != ACCESS_NETWORK_QUERY_PROTOCOL) {
    366 		p2p_dbg(p2p, "Unsupported GAS advertisement protocol id %u",
    367 			*pos);
    368 		return;
    369 	}
    370 
    371 	pos = next;
    372 	/* Query Request */
    373 	if (pos + 2 > end)
    374 		return;
    375 	slen = WPA_GET_LE16(pos);
    376 	pos += 2;
    377 	if (pos + slen > end)
    378 		return;
    379 	end = pos + slen;
    380 
    381 	/* ANQP Query Request */
    382 	if (pos + 4 > end)
    383 		return;
    384 	if (WPA_GET_LE16(pos) != ANQP_VENDOR_SPECIFIC) {
    385 		p2p_dbg(p2p, "Unsupported ANQP Info ID %u", WPA_GET_LE16(pos));
    386 		return;
    387 	}
    388 	pos += 2;
    389 
    390 	slen = WPA_GET_LE16(pos);
    391 	pos += 2;
    392 	if (pos + slen > end || slen < 3 + 1) {
    393 		p2p_dbg(p2p, "Invalid ANQP Query Request length");
    394 		return;
    395 	}
    396 
    397 	if (WPA_GET_BE32(pos) != P2P_IE_VENDOR_TYPE) {
    398 		p2p_dbg(p2p, "Unsupported ANQP vendor OUI-type %08x",
    399 			WPA_GET_BE32(pos));
    400 		return;
    401 	}
    402 	pos += 4;
    403 
    404 	if (pos + 2 > end)
    405 		return;
    406 	update_indic = WPA_GET_LE16(pos);
    407 	p2p_dbg(p2p, "Service Update Indicator: %u", update_indic);
    408 	pos += 2;
    409 
    410 	p2p->cfg->sd_request(p2p->cfg->cb_ctx, freq, sa, dialog_token,
    411 			     update_indic, pos, end - pos);
    412 	/* the response will be indicated with a call to p2p_sd_response() */
    413 }
    414 
    415 
    416 void p2p_sd_response(struct p2p_data *p2p, int freq, const u8 *dst,
    417 		     u8 dialog_token, const struct wpabuf *resp_tlvs)
    418 {
    419 	struct wpabuf *resp;
    420 
    421 	/* TODO: fix the length limit to match with the maximum frame length */
    422 	if (wpabuf_len(resp_tlvs) > 1400) {
    423 		p2p_dbg(p2p, "SD response long enough to require fragmentation");
    424 		if (p2p->sd_resp) {
    425 			/*
    426 			 * TODO: Could consider storing the fragmented response
    427 			 * separately for each peer to avoid having to drop old
    428 			 * one if there is more than one pending SD query.
    429 			 * Though, that would eat more memory, so there are
    430 			 * also benefits to just using a single buffer.
    431 			 */
    432 			p2p_dbg(p2p, "Drop previous SD response");
    433 			wpabuf_free(p2p->sd_resp);
    434 		}
    435 		p2p->sd_resp = wpabuf_dup(resp_tlvs);
    436 		if (p2p->sd_resp == NULL) {
    437 			p2p_err(p2p, "Failed to allocate SD response fragmentation area");
    438 			return;
    439 		}
    440 		os_memcpy(p2p->sd_resp_addr, dst, ETH_ALEN);
    441 		p2p->sd_resp_dialog_token = dialog_token;
    442 		p2p->sd_resp_pos = 0;
    443 		p2p->sd_frag_id = 0;
    444 		resp = p2p_build_sd_response(dialog_token, WLAN_STATUS_SUCCESS,
    445 					     1, p2p->srv_update_indic, NULL);
    446 	} else {
    447 		p2p_dbg(p2p, "SD response fits in initial response");
    448 		resp = p2p_build_sd_response(dialog_token,
    449 					     WLAN_STATUS_SUCCESS, 0,
    450 					     p2p->srv_update_indic, resp_tlvs);
    451 	}
    452 	if (resp == NULL)
    453 		return;
    454 
    455 	p2p->pending_action_state = P2P_NO_PENDING_ACTION;
    456 	if (p2p_send_action(p2p, freq, dst, p2p->cfg->dev_addr,
    457 			    p2p->cfg->dev_addr,
    458 			    wpabuf_head(resp), wpabuf_len(resp), 200) < 0)
    459 		p2p_dbg(p2p, "Failed to send Action frame");
    460 
    461 	wpabuf_free(resp);
    462 }
    463 
    464 
    465 void p2p_rx_gas_initial_resp(struct p2p_data *p2p, const u8 *sa,
    466 			     const u8 *data, size_t len, int rx_freq)
    467 {
    468 	const u8 *pos = data;
    469 	const u8 *end = data + len;
    470 	const u8 *next;
    471 	u8 dialog_token;
    472 	u16 status_code;
    473 	u16 comeback_delay;
    474 	u16 slen;
    475 	u16 update_indic;
    476 
    477 	if (p2p->state != P2P_SD_DURING_FIND || p2p->sd_peer == NULL ||
    478 	    os_memcmp(sa, p2p->sd_peer->info.p2p_device_addr, ETH_ALEN) != 0) {
    479 		p2p_dbg(p2p, "Ignore unexpected GAS Initial Response from "
    480 			MACSTR, MAC2STR(sa));
    481 		return;
    482 	}
    483 	p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
    484 	p2p_clear_timeout(p2p);
    485 
    486 	p2p_dbg(p2p, "Received GAS Initial Response from " MACSTR " (len=%d)",
    487 		MAC2STR(sa), (int) len);
    488 
    489 	if (len < 5 + 2) {
    490 		p2p_dbg(p2p, "Too short GAS Initial Response frame");
    491 		return;
    492 	}
    493 
    494 	dialog_token = *pos++;
    495 	/* TODO: check dialog_token match */
    496 	status_code = WPA_GET_LE16(pos);
    497 	pos += 2;
    498 	comeback_delay = WPA_GET_LE16(pos);
    499 	pos += 2;
    500 	p2p_dbg(p2p, "dialog_token=%u status_code=%u comeback_delay=%u",
    501 		dialog_token, status_code, comeback_delay);
    502 	if (status_code) {
    503 		p2p_dbg(p2p, "Service Discovery failed: status code %u",
    504 			status_code);
    505 		return;
    506 	}
    507 
    508 	if (*pos != WLAN_EID_ADV_PROTO) {
    509 		p2p_dbg(p2p, "Unexpected IE in GAS Initial Response: %u", *pos);
    510 		return;
    511 	}
    512 	pos++;
    513 
    514 	slen = *pos++;
    515 	next = pos + slen;
    516 	if (next > end || slen < 2) {
    517 		p2p_dbg(p2p, "Invalid IE in GAS Initial Response");
    518 		return;
    519 	}
    520 	pos++; /* skip QueryRespLenLimit and PAME-BI */
    521 
    522 	if (*pos != ACCESS_NETWORK_QUERY_PROTOCOL) {
    523 		p2p_dbg(p2p, "Unsupported GAS advertisement protocol id %u",
    524 			*pos);
    525 		return;
    526 	}
    527 
    528 	pos = next;
    529 	/* Query Response */
    530 	if (pos + 2 > end) {
    531 		p2p_dbg(p2p, "Too short Query Response");
    532 		return;
    533 	}
    534 	slen = WPA_GET_LE16(pos);
    535 	pos += 2;
    536 	p2p_dbg(p2p, "Query Response Length: %d", slen);
    537 	if (pos + slen > end) {
    538 		p2p_dbg(p2p, "Not enough Query Response data");
    539 		return;
    540 	}
    541 	end = pos + slen;
    542 
    543 	if (comeback_delay) {
    544 		p2p_dbg(p2p, "Fragmented response - request fragments");
    545 		if (p2p->sd_rx_resp) {
    546 			p2p_dbg(p2p, "Drop old SD reassembly buffer");
    547 			wpabuf_free(p2p->sd_rx_resp);
    548 			p2p->sd_rx_resp = NULL;
    549 		}
    550 		p2p_send_gas_comeback_req(p2p, sa, dialog_token, rx_freq);
    551 		return;
    552 	}
    553 
    554 	/* ANQP Query Response */
    555 	if (pos + 4 > end)
    556 		return;
    557 	if (WPA_GET_LE16(pos) != ANQP_VENDOR_SPECIFIC) {
    558 		p2p_dbg(p2p, "Unsupported ANQP Info ID %u", WPA_GET_LE16(pos));
    559 		return;
    560 	}
    561 	pos += 2;
    562 
    563 	slen = WPA_GET_LE16(pos);
    564 	pos += 2;
    565 	if (pos + slen > end || slen < 3 + 1) {
    566 		p2p_dbg(p2p, "Invalid ANQP Query Response length");
    567 		return;
    568 	}
    569 
    570 	if (WPA_GET_BE32(pos) != P2P_IE_VENDOR_TYPE) {
    571 		p2p_dbg(p2p, "Unsupported ANQP vendor OUI-type %08x",
    572 			WPA_GET_BE32(pos));
    573 		return;
    574 	}
    575 	pos += 4;
    576 
    577 	if (pos + 2 > end)
    578 		return;
    579 	update_indic = WPA_GET_LE16(pos);
    580 	p2p_dbg(p2p, "Service Update Indicator: %u", update_indic);
    581 	pos += 2;
    582 
    583 	p2p->sd_peer = NULL;
    584 
    585 	if (p2p->sd_query) {
    586 		if (!p2p->sd_query->for_all_peers) {
    587 			struct p2p_sd_query *q;
    588 			p2p_dbg(p2p, "Remove completed SD query %p",
    589 				p2p->sd_query);
    590 			q = p2p->sd_query;
    591 			p2p_unlink_sd_query(p2p, p2p->sd_query);
    592 			p2p_free_sd_query(q);
    593 		}
    594 		p2p->sd_query = NULL;
    595 	}
    596 
    597 	if (p2p->cfg->sd_response)
    598 		p2p->cfg->sd_response(p2p->cfg->cb_ctx, sa, update_indic,
    599 				      pos, end - pos);
    600 	p2p_continue_find(p2p);
    601 }
    602 
    603 
    604 void p2p_rx_gas_comeback_req(struct p2p_data *p2p, const u8 *sa,
    605 			     const u8 *data, size_t len, int rx_freq)
    606 {
    607 	struct wpabuf *resp;
    608 	u8 dialog_token;
    609 	size_t frag_len;
    610 	int more = 0;
    611 
    612 	wpa_hexdump(MSG_DEBUG, "P2P: RX GAS Comeback Request", data, len);
    613 	if (len < 1)
    614 		return;
    615 	dialog_token = *data;
    616 	p2p_dbg(p2p, "Dialog Token: %u", dialog_token);
    617 	if (dialog_token != p2p->sd_resp_dialog_token) {
    618 		p2p_dbg(p2p, "No pending SD response fragment for dialog token %u",
    619 			dialog_token);
    620 		return;
    621 	}
    622 
    623 	if (p2p->sd_resp == NULL) {
    624 		p2p_dbg(p2p, "No pending SD response fragment available");
    625 		return;
    626 	}
    627 	if (os_memcmp(sa, p2p->sd_resp_addr, ETH_ALEN) != 0) {
    628 		p2p_dbg(p2p, "No pending SD response fragment for " MACSTR,
    629 			MAC2STR(sa));
    630 		return;
    631 	}
    632 
    633 	frag_len = wpabuf_len(p2p->sd_resp) - p2p->sd_resp_pos;
    634 	if (frag_len > 1400) {
    635 		frag_len = 1400;
    636 		more = 1;
    637 	}
    638 	resp = p2p_build_gas_comeback_resp(dialog_token, WLAN_STATUS_SUCCESS,
    639 					   p2p->srv_update_indic,
    640 					   wpabuf_head_u8(p2p->sd_resp) +
    641 					   p2p->sd_resp_pos, frag_len,
    642 					   p2p->sd_frag_id, more,
    643 					   wpabuf_len(p2p->sd_resp));
    644 	if (resp == NULL)
    645 		return;
    646 	p2p_dbg(p2p, "Send GAS Comeback Response (frag_id %d more=%d frag_len=%d)",
    647 		p2p->sd_frag_id, more, (int) frag_len);
    648 	p2p->sd_frag_id++;
    649 	p2p->sd_resp_pos += frag_len;
    650 
    651 	if (more) {
    652 		p2p_dbg(p2p, "%d more bytes remain to be sent",
    653 			(int) (wpabuf_len(p2p->sd_resp) - p2p->sd_resp_pos));
    654 	} else {
    655 		p2p_dbg(p2p, "All fragments of SD response sent");
    656 		wpabuf_free(p2p->sd_resp);
    657 		p2p->sd_resp = NULL;
    658 	}
    659 
    660 	p2p->pending_action_state = P2P_NO_PENDING_ACTION;
    661 	if (p2p_send_action(p2p, rx_freq, sa, p2p->cfg->dev_addr,
    662 			    p2p->cfg->dev_addr,
    663 			    wpabuf_head(resp), wpabuf_len(resp), 200) < 0)
    664 		p2p_dbg(p2p, "Failed to send Action frame");
    665 
    666 	wpabuf_free(resp);
    667 }
    668 
    669 
    670 void p2p_rx_gas_comeback_resp(struct p2p_data *p2p, const u8 *sa,
    671 			      const u8 *data, size_t len, int rx_freq)
    672 {
    673 	const u8 *pos = data;
    674 	const u8 *end = data + len;
    675 	const u8 *next;
    676 	u8 dialog_token;
    677 	u16 status_code;
    678 	u8 frag_id;
    679 	u8 more_frags;
    680 	u16 comeback_delay;
    681 	u16 slen;
    682 
    683 	wpa_hexdump(MSG_DEBUG, "P2P: RX GAS Comeback Response", data, len);
    684 
    685 	if (p2p->state != P2P_SD_DURING_FIND || p2p->sd_peer == NULL ||
    686 	    os_memcmp(sa, p2p->sd_peer->info.p2p_device_addr, ETH_ALEN) != 0) {
    687 		p2p_dbg(p2p, "Ignore unexpected GAS Comeback Response from "
    688 			MACSTR, MAC2STR(sa));
    689 		return;
    690 	}
    691 	p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
    692 	p2p_clear_timeout(p2p);
    693 
    694 	p2p_dbg(p2p, "Received GAS Comeback Response from " MACSTR " (len=%d)",
    695 		MAC2STR(sa), (int) len);
    696 
    697 	if (len < 6 + 2) {
    698 		p2p_dbg(p2p, "Too short GAS Comeback Response frame");
    699 		return;
    700 	}
    701 
    702 	dialog_token = *pos++;
    703 	/* TODO: check dialog_token match */
    704 	status_code = WPA_GET_LE16(pos);
    705 	pos += 2;
    706 	frag_id = *pos & 0x7f;
    707 	more_frags = (*pos & 0x80) >> 7;
    708 	pos++;
    709 	comeback_delay = WPA_GET_LE16(pos);
    710 	pos += 2;
    711 	p2p_dbg(p2p, "dialog_token=%u status_code=%u frag_id=%d more_frags=%d "
    712 		"comeback_delay=%u",
    713 		dialog_token, status_code, frag_id, more_frags,
    714 		comeback_delay);
    715 	/* TODO: check frag_id match */
    716 	if (status_code) {
    717 		p2p_dbg(p2p, "Service Discovery failed: status code %u",
    718 			status_code);
    719 		return;
    720 	}
    721 
    722 	if (*pos != WLAN_EID_ADV_PROTO) {
    723 		p2p_dbg(p2p, "Unexpected IE in GAS Comeback Response: %u",
    724 			*pos);
    725 		return;
    726 	}
    727 	pos++;
    728 
    729 	slen = *pos++;
    730 	next = pos + slen;
    731 	if (next > end || slen < 2) {
    732 		p2p_dbg(p2p, "Invalid IE in GAS Comeback Response");
    733 		return;
    734 	}
    735 	pos++; /* skip QueryRespLenLimit and PAME-BI */
    736 
    737 	if (*pos != ACCESS_NETWORK_QUERY_PROTOCOL) {
    738 		p2p_dbg(p2p, "Unsupported GAS advertisement protocol id %u",
    739 			*pos);
    740 		return;
    741 	}
    742 
    743 	pos = next;
    744 	/* Query Response */
    745 	if (pos + 2 > end) {
    746 		p2p_dbg(p2p, "Too short Query Response");
    747 		return;
    748 	}
    749 	slen = WPA_GET_LE16(pos);
    750 	pos += 2;
    751 	p2p_dbg(p2p, "Query Response Length: %d", slen);
    752 	if (pos + slen > end) {
    753 		p2p_dbg(p2p, "Not enough Query Response data");
    754 		return;
    755 	}
    756 	if (slen == 0) {
    757 		p2p_dbg(p2p, "No Query Response data");
    758 		return;
    759 	}
    760 	end = pos + slen;
    761 
    762 	if (p2p->sd_rx_resp) {
    763 		 /*
    764 		  * ANQP header is only included in the first fragment; rest of
    765 		  * the fragments start with continue TLVs.
    766 		  */
    767 		goto skip_nqp_header;
    768 	}
    769 
    770 	/* ANQP Query Response */
    771 	if (pos + 4 > end)
    772 		return;
    773 	if (WPA_GET_LE16(pos) != ANQP_VENDOR_SPECIFIC) {
    774 		p2p_dbg(p2p, "Unsupported ANQP Info ID %u", WPA_GET_LE16(pos));
    775 		return;
    776 	}
    777 	pos += 2;
    778 
    779 	slen = WPA_GET_LE16(pos);
    780 	pos += 2;
    781 	p2p_dbg(p2p, "ANQP Query Response length: %u", slen);
    782 	if (slen < 3 + 1) {
    783 		p2p_dbg(p2p, "Invalid ANQP Query Response length");
    784 		return;
    785 	}
    786 	if (pos + 4 > end)
    787 		return;
    788 
    789 	if (WPA_GET_BE32(pos) != P2P_IE_VENDOR_TYPE) {
    790 		p2p_dbg(p2p, "Unsupported ANQP vendor OUI-type %08x",
    791 			WPA_GET_BE32(pos));
    792 		return;
    793 	}
    794 	pos += 4;
    795 
    796 	if (pos + 2 > end)
    797 		return;
    798 	p2p->sd_rx_update_indic = WPA_GET_LE16(pos);
    799 	p2p_dbg(p2p, "Service Update Indicator: %u", p2p->sd_rx_update_indic);
    800 	pos += 2;
    801 
    802 skip_nqp_header:
    803 	if (wpabuf_resize(&p2p->sd_rx_resp, end - pos) < 0)
    804 		return;
    805 	wpabuf_put_data(p2p->sd_rx_resp, pos, end - pos);
    806 	p2p_dbg(p2p, "Current SD reassembly buffer length: %u",
    807 		(unsigned int) wpabuf_len(p2p->sd_rx_resp));
    808 
    809 	if (more_frags) {
    810 		p2p_dbg(p2p, "More fragments remains");
    811 		/* TODO: what would be a good size limit? */
    812 		if (wpabuf_len(p2p->sd_rx_resp) > 64000) {
    813 			wpabuf_free(p2p->sd_rx_resp);
    814 			p2p->sd_rx_resp = NULL;
    815 			p2p_dbg(p2p, "Too long SD response - drop it");
    816 			return;
    817 		}
    818 		p2p_send_gas_comeback_req(p2p, sa, dialog_token, rx_freq);
    819 		return;
    820 	}
    821 
    822 	p2p->sd_peer = NULL;
    823 
    824 	if (p2p->sd_query) {
    825 		if (!p2p->sd_query->for_all_peers) {
    826 			struct p2p_sd_query *q;
    827 			p2p_dbg(p2p, "Remove completed SD query %p",
    828 				p2p->sd_query);
    829 			q = p2p->sd_query;
    830 			p2p_unlink_sd_query(p2p, p2p->sd_query);
    831 			p2p_free_sd_query(q);
    832 		}
    833 		p2p->sd_query = NULL;
    834 	}
    835 
    836 	if (p2p->cfg->sd_response)
    837 		p2p->cfg->sd_response(p2p->cfg->cb_ctx, sa,
    838 				      p2p->sd_rx_update_indic,
    839 				      wpabuf_head(p2p->sd_rx_resp),
    840 				      wpabuf_len(p2p->sd_rx_resp));
    841 	wpabuf_free(p2p->sd_rx_resp);
    842 	p2p->sd_rx_resp = NULL;
    843 
    844 	p2p_continue_find(p2p);
    845 }
    846 
    847 
    848 void * p2p_sd_request(struct p2p_data *p2p, const u8 *dst,
    849 		      const struct wpabuf *tlvs)
    850 {
    851 	struct p2p_sd_query *q;
    852 
    853 	q = os_zalloc(sizeof(*q));
    854 	if (q == NULL)
    855 		return NULL;
    856 
    857 	if (dst)
    858 		os_memcpy(q->peer, dst, ETH_ALEN);
    859 	else
    860 		q->for_all_peers = 1;
    861 
    862 	q->tlvs = wpabuf_dup(tlvs);
    863 	if (q->tlvs == NULL) {
    864 		p2p_free_sd_query(q);
    865 		return NULL;
    866 	}
    867 
    868 	q->next = p2p->sd_queries;
    869 	p2p->sd_queries = q;
    870 	p2p_dbg(p2p, "Added SD Query %p", q);
    871 
    872 	if (dst == NULL) {
    873 		struct p2p_device *dev;
    874 
    875 		p2p->num_p2p_sd_queries++;
    876 
    877 		/* Update all the devices for the newly added broadcast query */
    878 		dl_list_for_each(dev, &p2p->devices, struct p2p_device, list) {
    879 			if (dev->sd_pending_bcast_queries <= 0)
    880 				dev->sd_pending_bcast_queries = 1;
    881 			else
    882 				dev->sd_pending_bcast_queries++;
    883 		}
    884 	}
    885 
    886 	return q;
    887 }
    888 
    889 
    890 #ifdef CONFIG_WIFI_DISPLAY
    891 void * p2p_sd_request_wfd(struct p2p_data *p2p, const u8 *dst,
    892 			  const struct wpabuf *tlvs)
    893 {
    894 	struct p2p_sd_query *q;
    895 	q = p2p_sd_request(p2p, dst, tlvs);
    896 	if (q)
    897 		q->wsd = 1;
    898 	return q;
    899 }
    900 #endif /* CONFIG_WIFI_DISPLAY */
    901 
    902 
    903 void p2p_sd_service_update(struct p2p_data *p2p)
    904 {
    905 	p2p->srv_update_indic++;
    906 }
    907 
    908 
    909 int p2p_sd_cancel_request(struct p2p_data *p2p, void *req)
    910 {
    911 	if (p2p_unlink_sd_query(p2p, req)) {
    912 		p2p_dbg(p2p, "Cancel pending SD query %p", req);
    913 		p2p_free_sd_query(req);
    914 		return 0;
    915 	}
    916 	return -1;
    917 }
    918