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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 "common/wpa_ctrl.h"
     14 #include "wps/wps_defs.h"
     15 #include "p2p_i.h"
     16 #include "p2p.h"
     17 
     18 
     19 /*
     20  * Number of retries to attempt for provision discovery requests
     21  * in case the peer is not listening.
     22  */
     23 #define MAX_PROV_DISC_REQ_RETRIES 120
     24 
     25 
     26 static void p2p_build_wps_ie_config_methods(struct wpabuf *buf,
     27 					    u16 config_methods)
     28 {
     29 	u8 *len;
     30 	wpabuf_put_u8(buf, WLAN_EID_VENDOR_SPECIFIC);
     31 	len = wpabuf_put(buf, 1);
     32 	wpabuf_put_be32(buf, WPS_DEV_OUI_WFA);
     33 
     34 	/* Config Methods */
     35 	wpabuf_put_be16(buf, ATTR_CONFIG_METHODS);
     36 	wpabuf_put_be16(buf, 2);
     37 	wpabuf_put_be16(buf, config_methods);
     38 
     39 	p2p_buf_update_ie_hdr(buf, len);
     40 }
     41 
     42 
     43 static struct wpabuf * p2p_build_prov_disc_req(struct p2p_data *p2p,
     44 					       u8 dialog_token,
     45 					       u16 config_methods,
     46 					       struct p2p_device *go)
     47 {
     48 	struct wpabuf *buf;
     49 	u8 *len;
     50 	size_t extra = 0;
     51 
     52 #ifdef CONFIG_WIFI_DISPLAY
     53 	if (p2p->wfd_ie_prov_disc_req)
     54 		extra = wpabuf_len(p2p->wfd_ie_prov_disc_req);
     55 #endif /* CONFIG_WIFI_DISPLAY */
     56 
     57 	if (p2p->vendor_elem && p2p->vendor_elem[VENDOR_ELEM_P2P_PD_REQ])
     58 		extra += wpabuf_len(p2p->vendor_elem[VENDOR_ELEM_P2P_PD_REQ]);
     59 
     60 	buf = wpabuf_alloc(1000 + extra);
     61 	if (buf == NULL)
     62 		return NULL;
     63 
     64 	p2p_buf_add_public_action_hdr(buf, P2P_PROV_DISC_REQ, dialog_token);
     65 
     66 	len = p2p_buf_add_ie_hdr(buf);
     67 	p2p_buf_add_capability(buf, p2p->dev_capab &
     68 			       ~P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY, 0);
     69 	p2p_buf_add_device_info(buf, p2p, NULL);
     70 	if (go) {
     71 		p2p_buf_add_group_id(buf, go->info.p2p_device_addr,
     72 				     go->oper_ssid, go->oper_ssid_len);
     73 	}
     74 	p2p_buf_update_ie_hdr(buf, len);
     75 
     76 	/* WPS IE with Config Methods attribute */
     77 	p2p_build_wps_ie_config_methods(buf, config_methods);
     78 
     79 #ifdef CONFIG_WIFI_DISPLAY
     80 	if (p2p->wfd_ie_prov_disc_req)
     81 		wpabuf_put_buf(buf, p2p->wfd_ie_prov_disc_req);
     82 #endif /* CONFIG_WIFI_DISPLAY */
     83 
     84 	if (p2p->vendor_elem && p2p->vendor_elem[VENDOR_ELEM_P2P_PD_REQ])
     85 		wpabuf_put_buf(buf, p2p->vendor_elem[VENDOR_ELEM_P2P_PD_REQ]);
     86 
     87 	return buf;
     88 }
     89 
     90 
     91 static struct wpabuf * p2p_build_prov_disc_resp(struct p2p_data *p2p,
     92 						u8 dialog_token,
     93 						u16 config_methods,
     94 						const u8 *group_id,
     95 						size_t group_id_len)
     96 {
     97 	struct wpabuf *buf;
     98 	size_t extra = 0;
     99 
    100 #ifdef CONFIG_WIFI_DISPLAY
    101 	struct wpabuf *wfd_ie = p2p->wfd_ie_prov_disc_resp;
    102 	if (wfd_ie && group_id) {
    103 		size_t i;
    104 		for (i = 0; i < p2p->num_groups; i++) {
    105 			struct p2p_group *g = p2p->groups[i];
    106 			struct wpabuf *ie;
    107 			if (!p2p_group_is_group_id_match(g, group_id,
    108 							 group_id_len))
    109 				continue;
    110 			ie = p2p_group_get_wfd_ie(g);
    111 			if (ie) {
    112 				wfd_ie = ie;
    113 				break;
    114 			}
    115 		}
    116 	}
    117 	if (wfd_ie)
    118 		extra = wpabuf_len(wfd_ie);
    119 #endif /* CONFIG_WIFI_DISPLAY */
    120 
    121 	if (p2p->vendor_elem && p2p->vendor_elem[VENDOR_ELEM_P2P_PD_RESP])
    122 		extra += wpabuf_len(p2p->vendor_elem[VENDOR_ELEM_P2P_PD_RESP]);
    123 
    124 	buf = wpabuf_alloc(100 + extra);
    125 	if (buf == NULL)
    126 		return NULL;
    127 
    128 	p2p_buf_add_public_action_hdr(buf, P2P_PROV_DISC_RESP, dialog_token);
    129 
    130 	/* WPS IE with Config Methods attribute */
    131 	p2p_build_wps_ie_config_methods(buf, config_methods);
    132 
    133 #ifdef CONFIG_WIFI_DISPLAY
    134 	if (wfd_ie)
    135 		wpabuf_put_buf(buf, wfd_ie);
    136 #endif /* CONFIG_WIFI_DISPLAY */
    137 
    138 	if (p2p->vendor_elem && p2p->vendor_elem[VENDOR_ELEM_P2P_PD_RESP])
    139 		wpabuf_put_buf(buf, p2p->vendor_elem[VENDOR_ELEM_P2P_PD_RESP]);
    140 
    141 	return buf;
    142 }
    143 
    144 
    145 void p2p_process_prov_disc_req(struct p2p_data *p2p, const u8 *sa,
    146 			       const u8 *data, size_t len, int rx_freq)
    147 {
    148 	struct p2p_message msg;
    149 	struct p2p_device *dev;
    150 	int freq;
    151 	int reject = 1;
    152 	struct wpabuf *resp;
    153 
    154 	if (p2p_parse(data, len, &msg))
    155 		return;
    156 
    157 	p2p_dbg(p2p, "Received Provision Discovery Request from " MACSTR
    158 		" with config methods 0x%x (freq=%d)",
    159 		MAC2STR(sa), msg.wps_config_methods, rx_freq);
    160 
    161 	dev = p2p_get_device(p2p, sa);
    162 	if (dev == NULL || (dev->flags & P2P_DEV_PROBE_REQ_ONLY)) {
    163 		p2p_dbg(p2p, "Provision Discovery Request from unknown peer "
    164 			MACSTR, MAC2STR(sa));
    165 
    166 		if (p2p_add_device(p2p, sa, rx_freq, NULL, 0, data + 1, len - 1,
    167 				   0)) {
    168 			p2p_dbg(p2p, "Provision Discovery Request add device failed "
    169 				MACSTR, MAC2STR(sa));
    170 		}
    171 	} else if (msg.wfd_subelems) {
    172 		wpabuf_free(dev->info.wfd_subelems);
    173 		dev->info.wfd_subelems = wpabuf_dup(msg.wfd_subelems);
    174 	}
    175 
    176 	if (!(msg.wps_config_methods &
    177 	      (WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD |
    178 	       WPS_CONFIG_PUSHBUTTON))) {
    179 		p2p_dbg(p2p, "Unsupported Config Methods in Provision Discovery Request");
    180 		goto out;
    181 	}
    182 
    183 	if (msg.group_id) {
    184 		size_t i;
    185 		for (i = 0; i < p2p->num_groups; i++) {
    186 			if (p2p_group_is_group_id_match(p2p->groups[i],
    187 							msg.group_id,
    188 							msg.group_id_len))
    189 				break;
    190 		}
    191 		if (i == p2p->num_groups) {
    192 			p2p_dbg(p2p, "PD request for unknown P2P Group ID - reject");
    193 			goto out;
    194 		}
    195 	}
    196 
    197 	if (dev)
    198 		dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
    199 				P2P_DEV_PD_PEER_KEYPAD);
    200 	if (msg.wps_config_methods & WPS_CONFIG_DISPLAY) {
    201 		p2p_dbg(p2p, "Peer " MACSTR
    202 			" requested us to show a PIN on display", MAC2STR(sa));
    203 		if (dev)
    204 			dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
    205 	} else if (msg.wps_config_methods & WPS_CONFIG_KEYPAD) {
    206 		p2p_dbg(p2p, "Peer " MACSTR
    207 			" requested us to write its PIN using keypad",
    208 			MAC2STR(sa));
    209 		if (dev)
    210 			dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
    211 	}
    212 
    213 	reject = 0;
    214 
    215 out:
    216 	resp = p2p_build_prov_disc_resp(p2p, msg.dialog_token,
    217 					reject ? 0 : msg.wps_config_methods,
    218 					msg.group_id, msg.group_id_len);
    219 	if (resp == NULL) {
    220 		p2p_parse_free(&msg);
    221 		return;
    222 	}
    223 	p2p_dbg(p2p, "Sending Provision Discovery Response");
    224 	if (rx_freq > 0)
    225 		freq = rx_freq;
    226 	else
    227 		freq = p2p_channel_to_freq(p2p->cfg->reg_class,
    228 					   p2p->cfg->channel);
    229 	if (freq < 0) {
    230 		p2p_dbg(p2p, "Unknown regulatory class/channel");
    231 		wpabuf_free(resp);
    232 		p2p_parse_free(&msg);
    233 		return;
    234 	}
    235 	p2p->pending_action_state = P2P_NO_PENDING_ACTION;
    236 	if (p2p_send_action(p2p, freq, sa, p2p->cfg->dev_addr,
    237 			    p2p->cfg->dev_addr,
    238 			    wpabuf_head(resp), wpabuf_len(resp), 200) < 0) {
    239 		p2p_dbg(p2p, "Failed to send Action frame");
    240 	} else
    241 		p2p->send_action_in_progress = 1;
    242 
    243 	wpabuf_free(resp);
    244 
    245 	if (!reject && p2p->cfg->prov_disc_req) {
    246 		const u8 *dev_addr = sa;
    247 		if (msg.p2p_device_addr)
    248 			dev_addr = msg.p2p_device_addr;
    249 		p2p->cfg->prov_disc_req(p2p->cfg->cb_ctx, sa,
    250 					msg.wps_config_methods,
    251 					dev_addr, msg.pri_dev_type,
    252 					msg.device_name, msg.config_methods,
    253 					msg.capability ? msg.capability[0] : 0,
    254 					msg.capability ? msg.capability[1] :
    255 					0,
    256 					msg.group_id, msg.group_id_len);
    257 	}
    258 	p2p_parse_free(&msg);
    259 }
    260 
    261 
    262 void p2p_process_prov_disc_resp(struct p2p_data *p2p, const u8 *sa,
    263 				const u8 *data, size_t len)
    264 {
    265 	struct p2p_message msg;
    266 	struct p2p_device *dev;
    267 	u16 report_config_methods = 0, req_config_methods;
    268 	int success = 0;
    269 
    270 	if (p2p_parse(data, len, &msg))
    271 		return;
    272 
    273 	p2p_dbg(p2p, "Received Provision Discovery Response from " MACSTR
    274 		" with config methods 0x%x",
    275 		MAC2STR(sa), msg.wps_config_methods);
    276 
    277 	dev = p2p_get_device(p2p, sa);
    278 	if (dev == NULL || !dev->req_config_methods) {
    279 		p2p_dbg(p2p, "Ignore Provision Discovery Response from " MACSTR
    280 			" with no pending request", MAC2STR(sa));
    281 		p2p_parse_free(&msg);
    282 		return;
    283 	}
    284 
    285 	if (dev->dialog_token != msg.dialog_token) {
    286 		p2p_dbg(p2p, "Ignore Provision Discovery Response with unexpected Dialog Token %u (expected %u)",
    287 			msg.dialog_token, dev->dialog_token);
    288 		p2p_parse_free(&msg);
    289 		return;
    290 	}
    291 
    292 	if (p2p->pending_action_state == P2P_PENDING_PD) {
    293 		os_memset(p2p->pending_pd_devaddr, 0, ETH_ALEN);
    294 		p2p->pending_action_state = P2P_NO_PENDING_ACTION;
    295 	}
    296 
    297 	/*
    298 	 * Use a local copy of the requested config methods since
    299 	 * p2p_reset_pending_pd() can clear this in the peer entry.
    300 	 */
    301 	req_config_methods = dev->req_config_methods;
    302 
    303 	/*
    304 	 * If the response is from the peer to whom a user initiated request
    305 	 * was sent earlier, we reset that state info here.
    306 	 */
    307 	if (p2p->user_initiated_pd &&
    308 	    os_memcmp(p2p->pending_pd_devaddr, sa, ETH_ALEN) == 0)
    309 		p2p_reset_pending_pd(p2p);
    310 
    311 	if (msg.wps_config_methods != req_config_methods) {
    312 		p2p_dbg(p2p, "Peer rejected our Provision Discovery Request (received config_methods 0x%x expected 0x%x",
    313 			msg.wps_config_methods, req_config_methods);
    314 		if (p2p->cfg->prov_disc_fail)
    315 			p2p->cfg->prov_disc_fail(p2p->cfg->cb_ctx, sa,
    316 						 P2P_PROV_DISC_REJECTED);
    317 		p2p_parse_free(&msg);
    318 		goto out;
    319 	}
    320 
    321 	report_config_methods = req_config_methods;
    322 	dev->flags &= ~(P2P_DEV_PD_PEER_DISPLAY |
    323 			P2P_DEV_PD_PEER_KEYPAD);
    324 	if (req_config_methods & WPS_CONFIG_DISPLAY) {
    325 		p2p_dbg(p2p, "Peer " MACSTR
    326 			" accepted to show a PIN on display", MAC2STR(sa));
    327 		dev->flags |= P2P_DEV_PD_PEER_DISPLAY;
    328 	} else if (msg.wps_config_methods & WPS_CONFIG_KEYPAD) {
    329 		p2p_dbg(p2p, "Peer " MACSTR
    330 			" accepted to write our PIN using keypad",
    331 			MAC2STR(sa));
    332 		dev->flags |= P2P_DEV_PD_PEER_KEYPAD;
    333 	}
    334 
    335 	/* Store the provisioning info */
    336 	dev->wps_prov_info = msg.wps_config_methods;
    337 
    338 	p2p_parse_free(&msg);
    339 	success = 1;
    340 
    341 out:
    342 	dev->req_config_methods = 0;
    343 	p2p->cfg->send_action_done(p2p->cfg->cb_ctx);
    344 	if (dev->flags & P2P_DEV_PD_BEFORE_GO_NEG) {
    345 		p2p_dbg(p2p, "Start GO Neg after the PD-before-GO-Neg workaround with "
    346 			MACSTR, MAC2STR(dev->info.p2p_device_addr));
    347 		dev->flags &= ~P2P_DEV_PD_BEFORE_GO_NEG;
    348 		p2p_connect_send(p2p, dev);
    349 		return;
    350 	}
    351 	if (success && p2p->cfg->prov_disc_resp)
    352 		p2p->cfg->prov_disc_resp(p2p->cfg->cb_ctx, sa,
    353 					 report_config_methods);
    354 
    355 	if (p2p->state == P2P_PD_DURING_FIND) {
    356 		p2p_clear_timeout(p2p);
    357 		p2p_continue_find(p2p);
    358 	}
    359 }
    360 
    361 
    362 int p2p_send_prov_disc_req(struct p2p_data *p2p, struct p2p_device *dev,
    363 			   int join, int force_freq)
    364 {
    365 	struct wpabuf *req;
    366 	int freq;
    367 
    368 	if (force_freq > 0)
    369 		freq = force_freq;
    370 	else
    371 		freq = dev->listen_freq > 0 ? dev->listen_freq :
    372 			dev->oper_freq;
    373 	if (freq <= 0) {
    374 		p2p_dbg(p2p, "No Listen/Operating frequency known for the peer "
    375 			MACSTR " to send Provision Discovery Request",
    376 			MAC2STR(dev->info.p2p_device_addr));
    377 		return -1;
    378 	}
    379 
    380 	if (dev->flags & P2P_DEV_GROUP_CLIENT_ONLY) {
    381 		if (!(dev->info.dev_capab &
    382 		      P2P_DEV_CAPAB_CLIENT_DISCOVERABILITY)) {
    383 			p2p_dbg(p2p, "Cannot use PD with P2P Device " MACSTR
    384 				" that is in a group and is not discoverable",
    385 				MAC2STR(dev->info.p2p_device_addr));
    386 			return -1;
    387 		}
    388 		/* TODO: use device discoverability request through GO */
    389 	}
    390 
    391 	req = p2p_build_prov_disc_req(p2p, dev->dialog_token,
    392 				      dev->req_config_methods,
    393 				      join ? dev : NULL);
    394 	if (req == NULL)
    395 		return -1;
    396 
    397 	if (p2p->state != P2P_IDLE)
    398 		p2p_stop_listen_for_freq(p2p, freq);
    399 	p2p->pending_action_state = P2P_PENDING_PD;
    400 	if (p2p_send_action(p2p, freq, dev->info.p2p_device_addr,
    401 			    p2p->cfg->dev_addr, dev->info.p2p_device_addr,
    402 			    wpabuf_head(req), wpabuf_len(req), 200) < 0) {
    403 		p2p_dbg(p2p, "Failed to send Action frame");
    404 		wpabuf_free(req);
    405 		return -1;
    406 	}
    407 
    408 	os_memcpy(p2p->pending_pd_devaddr, dev->info.p2p_device_addr, ETH_ALEN);
    409 
    410 	wpabuf_free(req);
    411 	return 0;
    412 }
    413 
    414 
    415 int p2p_prov_disc_req(struct p2p_data *p2p, const u8 *peer_addr,
    416 		      u16 config_methods, int join, int force_freq,
    417 		      int user_initiated_pd)
    418 {
    419 	struct p2p_device *dev;
    420 
    421 	dev = p2p_get_device(p2p, peer_addr);
    422 	if (dev == NULL)
    423 		dev = p2p_get_device_interface(p2p, peer_addr);
    424 	if (dev == NULL || (dev->flags & P2P_DEV_PROBE_REQ_ONLY)) {
    425 		p2p_dbg(p2p, "Provision Discovery Request destination " MACSTR
    426 			" not yet known", MAC2STR(peer_addr));
    427 		return -1;
    428 	}
    429 
    430 	p2p_dbg(p2p, "Provision Discovery Request with " MACSTR
    431 		" (config methods 0x%x)",
    432 		MAC2STR(peer_addr), config_methods);
    433 	if (config_methods == 0)
    434 		return -1;
    435 
    436 	/* Reset provisioning info */
    437 	dev->wps_prov_info = 0;
    438 
    439 	dev->req_config_methods = config_methods;
    440 	if (join)
    441 		dev->flags |= P2P_DEV_PD_FOR_JOIN;
    442 	else
    443 		dev->flags &= ~P2P_DEV_PD_FOR_JOIN;
    444 
    445 	if (p2p->state != P2P_IDLE && p2p->state != P2P_SEARCH &&
    446 	    p2p->state != P2P_LISTEN_ONLY) {
    447 		p2p_dbg(p2p, "Busy with other operations; postpone Provision Discovery Request with "
    448 			MACSTR " (config methods 0x%x)",
    449 			MAC2STR(peer_addr), config_methods);
    450 		return 0;
    451 	}
    452 
    453 	p2p->user_initiated_pd = user_initiated_pd;
    454 	p2p->pd_force_freq = force_freq;
    455 
    456 	if (p2p->user_initiated_pd)
    457 		p2p->pd_retries = MAX_PROV_DISC_REQ_RETRIES;
    458 
    459 	/*
    460 	 * Assign dialog token here to use the same value in each retry within
    461 	 * the same PD exchange.
    462 	 */
    463 	dev->dialog_token++;
    464 	if (dev->dialog_token == 0)
    465 		dev->dialog_token = 1;
    466 
    467 	return p2p_send_prov_disc_req(p2p, dev, join, force_freq);
    468 }
    469 
    470 
    471 void p2p_reset_pending_pd(struct p2p_data *p2p)
    472 {
    473 	struct p2p_device *dev;
    474 
    475 	dl_list_for_each(dev, &p2p->devices, struct p2p_device, list) {
    476 		if (os_memcmp(p2p->pending_pd_devaddr,
    477 			      dev->info.p2p_device_addr, ETH_ALEN))
    478 			continue;
    479 		if (!dev->req_config_methods)
    480 			continue;
    481 		if (dev->flags & P2P_DEV_PD_FOR_JOIN)
    482 			continue;
    483 		/* Reset the config methods of the device */
    484 		dev->req_config_methods = 0;
    485 	}
    486 
    487 	p2p->user_initiated_pd = 0;
    488 	os_memset(p2p->pending_pd_devaddr, 0, ETH_ALEN);
    489 	p2p->pd_retries = 0;
    490 	p2p->pd_force_freq = 0;
    491 }
    492