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      1 /*
      2  * Wi-Fi Direct - P2P provision discovery
      3  * Copyright (c) 2009-2010, 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 "wps/wps_defs.h"
     14 #include "p2p_i.h"
     15 #include "p2p.h"
     16 
     17 
     18 /*
     19  * Number of retries to attempt for provision discovery requests
     20  * in case the peer is not listening.
     21  */
     22 #define MAX_PROV_DISC_REQ_RETRIES 120
     23 
     24 
     25 static void p2p_build_wps_ie_config_methods(struct wpabuf *buf,
     26 					    u16 config_methods)
     27 {
     28 	u8 *len;
     29 	wpabuf_put_u8(buf, WLAN_EID_VENDOR_SPECIFIC);
     30 	len = wpabuf_put(buf, 1);
     31 	wpabuf_put_be32(buf, WPS_DEV_OUI_WFA);
     32 
     33 	/* Config Methods */
     34 	wpabuf_put_be16(buf, ATTR_CONFIG_METHODS);
     35 	wpabuf_put_be16(buf, 2);
     36 	wpabuf_put_be16(buf, config_methods);
     37 
     38 	p2p_buf_update_ie_hdr(buf, len);
     39 }
     40 
     41 
     42 static struct wpabuf * p2p_build_prov_disc_req(struct p2p_data *p2p,
     43 					       u8 dialog_token,
     44 					       u16 config_methods,
     45 					       struct p2p_device *go)
     46 {
     47 	struct wpabuf *buf;
     48 	u8 *len;
     49 	size_t extra = 0;
     50 
     51 #ifdef CONFIG_WIFI_DISPLAY
     52 	if (p2p->wfd_ie_prov_disc_req)
     53 		extra = wpabuf_len(p2p->wfd_ie_prov_disc_req);
     54 #endif /* CONFIG_WIFI_DISPLAY */
     55 
     56 	buf = wpabuf_alloc(1000 + extra);
     57 	if (buf == NULL)
     58 		return NULL;
     59 
     60 	p2p_buf_add_public_action_hdr(buf, P2P_PROV_DISC_REQ, dialog_token);
     61 
     62 	len = p2p_buf_add_ie_hdr(buf);
     63 	p2p_buf_add_capability(buf, p2p->dev_capab &
     64 			       ~P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY, 0);
     65 	p2p_buf_add_device_info(buf, p2p, NULL);
     66 	if (go) {
     67 		p2p_buf_add_group_id(buf, go->info.p2p_device_addr,
     68 				     go->oper_ssid, go->oper_ssid_len);
     69 	}
     70 	p2p_buf_update_ie_hdr(buf, len);
     71 
     72 	/* WPS IE with Config Methods attribute */
     73 	p2p_build_wps_ie_config_methods(buf, config_methods);
     74 
     75 #ifdef CONFIG_WIFI_DISPLAY
     76 	if (p2p->wfd_ie_prov_disc_req)
     77 		wpabuf_put_buf(buf, p2p->wfd_ie_prov_disc_req);
     78 #endif /* CONFIG_WIFI_DISPLAY */
     79 
     80 	return buf;
     81 }
     82 
     83 
     84 static struct wpabuf * p2p_build_prov_disc_resp(struct p2p_data *p2p,
     85 						u8 dialog_token,
     86 						u16 config_methods,
     87 						const u8 *group_id,
     88 						size_t group_id_len)
     89 {
     90 	struct wpabuf *buf;
     91 	size_t extra = 0;
     92 
     93 #ifdef CONFIG_WIFI_DISPLAY
     94 	struct wpabuf *wfd_ie = p2p->wfd_ie_prov_disc_resp;
     95 	if (wfd_ie && group_id) {
     96 		size_t i;
     97 		for (i = 0; i < p2p->num_groups; i++) {
     98 			struct p2p_group *g = p2p->groups[i];
     99 			struct wpabuf *ie;
    100 			if (!p2p_group_is_group_id_match(g, group_id,
    101 							 group_id_len))
    102 				continue;
    103 			ie = p2p_group_get_wfd_ie(g);
    104 			if (ie) {
    105 				wfd_ie = ie;
    106 				break;
    107 			}
    108 		}
    109 	}
    110 	if (wfd_ie)
    111 		extra = wpabuf_len(wfd_ie);
    112 #endif /* CONFIG_WIFI_DISPLAY */
    113 
    114 	buf = wpabuf_alloc(100 + extra);
    115 	if (buf == NULL)
    116 		return NULL;
    117 
    118 	p2p_buf_add_public_action_hdr(buf, P2P_PROV_DISC_RESP, dialog_token);
    119 
    120 	/* WPS IE with Config Methods attribute */
    121 	p2p_build_wps_ie_config_methods(buf, config_methods);
    122 
    123 #ifdef CONFIG_WIFI_DISPLAY
    124 	if (wfd_ie)
    125 		wpabuf_put_buf(buf, wfd_ie);
    126 #endif /* CONFIG_WIFI_DISPLAY */
    127 
    128 	return buf;
    129 }
    130 
    131 
    132 void p2p_process_prov_disc_req(struct p2p_data *p2p, const u8 *sa,
    133 			       const u8 *data, size_t len, int rx_freq)
    134 {
    135 	struct p2p_message msg;
    136 	struct p2p_device *dev;
    137 	int freq;
    138 	int reject = 1;
    139 	struct wpabuf *resp;
    140 
    141 	if (p2p_parse(data, len, &msg))
    142 		return;
    143 
    144 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    145 		"P2P: Received Provision Discovery Request from " MACSTR
    146 		" with config methods 0x%x (freq=%d)",
    147 		MAC2STR(sa), msg.wps_config_methods, rx_freq);
    148 
    149 	dev = p2p_get_device(p2p, sa);
    150 	if (dev == NULL || (dev->flags & P2P_DEV_PROBE_REQ_ONLY)) {
    151 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    152 			"P2P: Provision Discovery Request from "
    153 			"unknown peer " MACSTR, MAC2STR(sa));
    154 
    155 		if (p2p_add_device(p2p, sa, rx_freq, NULL, 0, data + 1, len - 1,
    156 				   0)) {
    157 			wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    158 			        "P2P: Provision Discovery Request add device "
    159 				"failed " MACSTR, MAC2STR(sa));
    160 		}
    161 	} else if (msg.wfd_subelems) {
    162 		wpabuf_free(dev->info.wfd_subelems);
    163 		dev->info.wfd_subelems = wpabuf_dup(msg.wfd_subelems);
    164 	}
    165 
    166 	if (!(msg.wps_config_methods &
    167 	      (WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD |
    168 	       WPS_CONFIG_PUSHBUTTON))) {
    169 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Unsupported "
    170 			"Config Methods in Provision Discovery Request");
    171 		goto out;
    172 	}
    173 
    174 	if (msg.group_id) {
    175 		size_t i;
    176 		for (i = 0; i < p2p->num_groups; i++) {
    177 			if (p2p_group_is_group_id_match(p2p->groups[i],
    178 							msg.group_id,
    179 							msg.group_id_len))
    180 				break;
    181 		}
    182 		if (i == p2p->num_groups) {
    183 			wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: PD "
    184 				"request for unknown P2P Group ID - reject");
    185 			goto out;
    186 		}
    187 	}
    188 
    189 	if (dev)
    190 		dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
    191 				P2P_DEV_PD_PEER_KEYPAD);
    192 	if (msg.wps_config_methods & WPS_CONFIG_DISPLAY) {
    193 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
    194 			" requested us to show a PIN on display", MAC2STR(sa));
    195 		if (dev)
    196 			dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
    197 	} else if (msg.wps_config_methods & WPS_CONFIG_KEYPAD) {
    198 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
    199 			" requested us to write its PIN using keypad",
    200 			MAC2STR(sa));
    201 		if (dev)
    202 			dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
    203 	}
    204 
    205 	reject = 0;
    206 
    207 out:
    208 	resp = p2p_build_prov_disc_resp(p2p, msg.dialog_token,
    209 					reject ? 0 : msg.wps_config_methods,
    210 					msg.group_id, msg.group_id_len);
    211 	if (resp == NULL) {
    212 		p2p_parse_free(&msg);
    213 		return;
    214 	}
    215 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    216 		"P2P: Sending Provision Discovery Response");
    217 	if (rx_freq > 0)
    218 		freq = rx_freq;
    219 	else
    220 		freq = p2p_channel_to_freq(p2p->cfg->country,
    221 					   p2p->cfg->reg_class,
    222 					   p2p->cfg->channel);
    223 	if (freq < 0) {
    224 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    225 			"P2P: Unknown regulatory class/channel");
    226 		wpabuf_free(resp);
    227 		p2p_parse_free(&msg);
    228 		return;
    229 	}
    230 	p2p->pending_action_state = P2P_NO_PENDING_ACTION;
    231 	if (p2p_send_action(p2p, freq, sa, p2p->cfg->dev_addr,
    232 			    p2p->cfg->dev_addr,
    233 			    wpabuf_head(resp), wpabuf_len(resp), 200) < 0) {
    234 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    235 			"P2P: Failed to send Action frame");
    236 	}
    237 
    238 	wpabuf_free(resp);
    239 
    240 	if (!reject && p2p->cfg->prov_disc_req) {
    241 		const u8 *dev_addr = sa;
    242 		if (msg.p2p_device_addr)
    243 			dev_addr = msg.p2p_device_addr;
    244 		p2p->cfg->prov_disc_req(p2p->cfg->cb_ctx, sa,
    245 					msg.wps_config_methods,
    246 					dev_addr, msg.pri_dev_type,
    247 					msg.device_name, msg.config_methods,
    248 					msg.capability ? msg.capability[0] : 0,
    249 					msg.capability ? msg.capability[1] :
    250 					0,
    251 					msg.group_id, msg.group_id_len);
    252 	}
    253 	p2p_parse_free(&msg);
    254 }
    255 
    256 
    257 void p2p_process_prov_disc_resp(struct p2p_data *p2p, const u8 *sa,
    258 				const u8 *data, size_t len)
    259 {
    260 	struct p2p_message msg;
    261 	struct p2p_device *dev;
    262 	u16 report_config_methods = 0, req_config_methods;
    263 	int success = 0;
    264 
    265 	if (p2p_parse(data, len, &msg))
    266 		return;
    267 
    268 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    269 		"P2P: Received Provision Discovery Response from " MACSTR
    270 		" with config methods 0x%x",
    271 		MAC2STR(sa), msg.wps_config_methods);
    272 
    273 	dev = p2p_get_device(p2p, sa);
    274 	if (dev == NULL || !dev->req_config_methods) {
    275 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    276 			"P2P: Ignore Provision Discovery Response from "
    277 			MACSTR " with no pending request", MAC2STR(sa));
    278 		p2p_parse_free(&msg);
    279 		return;
    280 	}
    281 
    282 	if (dev->dialog_token != msg.dialog_token) {
    283 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    284 			"P2P: Ignore Provision Discovery Response with "
    285 			"unexpected Dialog Token %u (expected %u)",
    286 			msg.dialog_token, dev->dialog_token);
    287 		p2p_parse_free(&msg);
    288 		return;
    289 	}
    290 
    291 	if (p2p->pending_action_state == P2P_PENDING_PD) {
    292 		os_memset(p2p->pending_pd_devaddr, 0, ETH_ALEN);
    293 		p2p->pending_action_state = P2P_NO_PENDING_ACTION;
    294 	}
    295 
    296 	/*
    297 	 * Use a local copy of the requested config methods since
    298 	 * p2p_reset_pending_pd() can clear this in the peer entry.
    299 	 */
    300 	req_config_methods = dev->req_config_methods;
    301 
    302 	/*
    303 	 * If the response is from the peer to whom a user initiated request
    304 	 * was sent earlier, we reset that state info here.
    305 	 */
    306 	if (p2p->user_initiated_pd &&
    307 	    os_memcmp(p2p->pending_pd_devaddr, sa, ETH_ALEN) == 0)
    308 		p2p_reset_pending_pd(p2p);
    309 
    310 	if (msg.wps_config_methods != req_config_methods) {
    311 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer rejected "
    312 			"our Provision Discovery Request (received "
    313 			"config_methods 0x%x expected 0x%x",
    314 			msg.wps_config_methods, req_config_methods);
    315 		if (p2p->cfg->prov_disc_fail)
    316 			p2p->cfg->prov_disc_fail(p2p->cfg->cb_ctx, sa,
    317 						 P2P_PROV_DISC_REJECTED);
    318 		p2p_parse_free(&msg);
    319 		goto out;
    320 	}
    321 
    322 	report_config_methods = req_config_methods;
    323 	dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
    324 			P2P_DEV_PD_PEER_KEYPAD);
    325 	if (req_config_methods & WPS_CONFIG_DISPLAY) {
    326 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
    327 			" accepted to show a PIN on display", MAC2STR(sa));
    328 		dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
    329 	} else if (msg.wps_config_methods & WPS_CONFIG_KEYPAD) {
    330 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Peer " MACSTR
    331 			" accepted to write our PIN using keypad",
    332 			MAC2STR(sa));
    333 		dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
    334 	}
    335 
    336 	/* Store the provisioning info */
    337 	dev->wps_prov_info = msg.wps_config_methods;
    338 
    339 	p2p_parse_free(&msg);
    340 	success = 1;
    341 
    342 out:
    343 	dev->req_config_methods = 0;
    344 	p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
    345 	if (dev->flags & P2P_DEV_PD_BEFORE_GO_NEG) {
    346 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    347 			"P2P: Start GO Neg after the PD-before-GO-Neg "
    348 			"workaround with " MACSTR,
    349 			MAC2STR(dev->info.p2p_device_addr));
    350 		dev->flags &= ~P2P_DEV_PD_BEFORE_GO_NEG;
    351 		p2p_connect_send(p2p, dev);
    352 		return;
    353 	}
    354 	if (success && p2p->cfg->prov_disc_resp)
    355 		p2p->cfg->prov_disc_resp(p2p->cfg->cb_ctx, sa,
    356 					 report_config_methods);
    357 
    358 	if (p2p->state == P2P_PD_DURING_FIND) {
    359 		p2p_clear_timeout(p2p);
    360 		p2p_continue_find(p2p);
    361 	}
    362 }
    363 
    364 
    365 int p2p_send_prov_disc_req(struct p2p_data *p2p, struct p2p_device *dev,
    366 			   int join, int force_freq)
    367 {
    368 	struct wpabuf *req;
    369 	int freq;
    370 
    371 	if (force_freq > 0)
    372 		freq = force_freq;
    373 	else
    374 		freq = dev->listen_freq > 0 ? dev->listen_freq :
    375 			dev->oper_freq;
    376 	if (freq <= 0) {
    377 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    378 			"P2P: No Listen/Operating frequency known for the "
    379 			"peer " MACSTR " to send Provision Discovery Request",
    380 			MAC2STR(dev->info.p2p_device_addr));
    381 		return -1;
    382 	}
    383 
    384 	if (dev->flags & P2P_DEV_GROUP_CLIENT_ONLY) {
    385 		if (!(dev->info.dev_capab &
    386 		      P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY)) {
    387 			wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    388 				"P2P: Cannot use PD with P2P Device " MACSTR
    389 				" that is in a group and is not discoverable",
    390 				MAC2STR(dev->info.p2p_device_addr));
    391 			return -1;
    392 		}
    393 		/* TODO: use device discoverability request through GO */
    394 	}
    395 
    396 	req = p2p_build_prov_disc_req(p2p, dev->dialog_token,
    397 				      dev->req_config_methods,
    398 				      join ? dev : NULL);
    399 	if (req == NULL)
    400 		return -1;
    401 
    402 	if (p2p->state != P2P_IDLE)
    403 		p2p_stop_listen_for_freq(p2p, freq);
    404 	p2p->pending_action_state = P2P_PENDING_PD;
    405 	if (p2p_send_action(p2p, freq, dev->info.p2p_device_addr,
    406 			    p2p->cfg->dev_addr, dev->info.p2p_device_addr,
    407 			    wpabuf_head(req), wpabuf_len(req), 200) < 0) {
    408 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG,
    409 			"P2P: Failed to send Action frame");
    410 		wpabuf_free(req);
    411 		return -1;
    412 	}
    413 
    414 	os_memcpy(p2p->pending_pd_devaddr, dev->info.p2p_device_addr, ETH_ALEN);
    415 
    416 	wpabuf_free(req);
    417 	return 0;
    418 }
    419 
    420 
    421 int p2p_prov_disc_req(struct p2p_data *p2p, const u8 *peer_addr,
    422 		      u16 config_methods, int join, int force_freq,
    423 		      int user_initiated_pd)
    424 {
    425 	struct p2p_device *dev;
    426 
    427 	dev = p2p_get_device(p2p, peer_addr);
    428 	if (dev == NULL)
    429 		dev = p2p_get_device_interface(p2p, peer_addr);
    430 	if (dev == NULL || (dev->flags & P2P_DEV_PROBE_REQ_ONLY)) {
    431 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Provision "
    432 			"Discovery Request destination " MACSTR
    433 			" not yet known", MAC2STR(peer_addr));
    434 		return -1;
    435 	}
    436 
    437 	wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Provision Discovery "
    438 		"Request with " MACSTR " (config methods 0x%x)",
    439 		MAC2STR(peer_addr), config_methods);
    440 	if (config_methods == 0)
    441 		return -1;
    442 
    443 	/* Reset provisioning info */
    444 	dev->wps_prov_info = 0;
    445 
    446 	dev->req_config_methods = config_methods;
    447 	if (join)
    448 		dev->flags |= P2P_DEV_PD_FOR_JOIN;
    449 	else
    450 		dev->flags &= ~P2P_DEV_PD_FOR_JOIN;
    451 
    452 	if (p2p->state != P2P_IDLE && p2p->state != P2P_SEARCH &&
    453 	    p2p->state != P2P_LISTEN_ONLY) {
    454 		wpa_msg(p2p->cfg->msg_ctx, MSG_DEBUG, "P2P: Busy with other "
    455 			"operations; postpone Provision Discovery Request "
    456 			"with " MACSTR " (config methods 0x%x)",
    457 			MAC2STR(peer_addr), config_methods);
    458 		return 0;
    459 	}
    460 
    461 	p2p->user_initiated_pd = user_initiated_pd;
    462 
    463 	if (p2p->user_initiated_pd)
    464 		p2p->pd_retries = MAX_PROV_DISC_REQ_RETRIES;
    465 
    466 	/*
    467 	 * Assign dialog token here to use the same value in each retry within
    468 	 * the same PD exchange.
    469 	 */
    470 	dev->dialog_token++;
    471 	if (dev->dialog_token == 0)
    472 		dev->dialog_token = 1;
    473 
    474 	return p2p_send_prov_disc_req(p2p, dev, join, force_freq);
    475 }
    476 
    477 
    478 void p2p_reset_pending_pd(struct p2p_data *p2p)
    479 {
    480 	struct p2p_device *dev;
    481 
    482 	dl_list_for_each(dev, &p2p->devices, struct p2p_device, list) {
    483 		if (os_memcmp(p2p->pending_pd_devaddr,
    484 			      dev->info.p2p_device_addr, ETH_ALEN))
    485 			continue;
    486 		if (!dev->req_config_methods)
    487 			continue;
    488 		if (dev->flags & P2P_DEV_PD_FOR_JOIN)
    489 			continue;
    490 		/* Reset the config methods of the device */
    491 		dev->req_config_methods = 0;
    492 	}
    493 
    494 	p2p->user_initiated_pd = 0;
    495 	os_memset(p2p->pending_pd_devaddr, 0, ETH_ALEN);
    496 	p2p->pd_retries = 0;
    497 }
    498