xref: /freebsd/contrib/wpa/wpa_supplicant/mbo.c (revision 6829dae12bb055451fa467da4589c43bd03b1e64)
1 /*
2  * wpa_supplicant - MBO
3  *
4  * Copyright(c) 2015 Intel Deutschland GmbH
5  * Contact Information:
6  * Intel Linux Wireless <ilw@linux.intel.com>
7  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
8  *
9  * This software may be distributed under the terms of the BSD license.
10  * See README for more details.
11  */
12 
13 #include "utils/includes.h"
14 
15 #include "utils/common.h"
16 #include "common/ieee802_11_defs.h"
17 #include "common/gas.h"
18 #include "config.h"
19 #include "wpa_supplicant_i.h"
20 #include "driver_i.h"
21 #include "bss.h"
22 #include "scan.h"
23 
24 /* type + length + oui + oui type */
25 #define MBO_IE_HEADER 6
26 
27 
28 static int wpas_mbo_validate_non_pref_chan(u8 oper_class, u8 chan, u8 reason)
29 {
30 	if (reason > MBO_NON_PREF_CHAN_REASON_INT_INTERFERENCE)
31 		return -1;
32 
33 	/* Only checking the validity of the channel and oper_class */
34 	if (ieee80211_chan_to_freq(NULL, oper_class, chan) == -1)
35 		return -1;
36 
37 	return 0;
38 }
39 
40 
41 const u8 * mbo_attr_from_mbo_ie(const u8 *mbo_ie, enum mbo_attr_id attr)
42 {
43 	const u8 *mbo;
44 	u8 ie_len = mbo_ie[1];
45 
46 	if (ie_len < MBO_IE_HEADER - 2)
47 		return NULL;
48 	mbo = mbo_ie + MBO_IE_HEADER;
49 
50 	return get_ie(mbo, 2 + ie_len - MBO_IE_HEADER, attr);
51 }
52 
53 
54 const u8 * wpas_mbo_get_bss_attr(struct wpa_bss *bss, enum mbo_attr_id attr)
55 {
56 	const u8 *mbo, *end;
57 
58 	if (!bss)
59 		return NULL;
60 
61 	mbo = wpa_bss_get_vendor_ie(bss, MBO_IE_VENDOR_TYPE);
62 	if (!mbo)
63 		return NULL;
64 
65 	end = mbo + 2 + mbo[1];
66 	mbo += MBO_IE_HEADER;
67 
68 	return get_ie(mbo, end - mbo, attr);
69 }
70 
71 
72 static void wpas_mbo_non_pref_chan_attr_body(struct wpa_supplicant *wpa_s,
73 					     struct wpabuf *mbo,
74 					     u8 start, u8 end)
75 {
76 	u8 i;
77 
78 	wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].oper_class);
79 
80 	for (i = start; i < end; i++)
81 		wpabuf_put_u8(mbo, wpa_s->non_pref_chan[i].chan);
82 
83 	wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].preference);
84 	wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].reason);
85 }
86 
87 
88 static void wpas_mbo_non_pref_chan_attr(struct wpa_supplicant *wpa_s,
89 					struct wpabuf *mbo, u8 start, u8 end)
90 {
91 	size_t size = end - start + 3;
92 
93 	if (size + 2 > wpabuf_tailroom(mbo))
94 		return;
95 
96 	wpabuf_put_u8(mbo, MBO_ATTR_ID_NON_PREF_CHAN_REPORT);
97 	wpabuf_put_u8(mbo, size); /* Length */
98 
99 	wpas_mbo_non_pref_chan_attr_body(wpa_s, mbo, start, end);
100 }
101 
102 
103 static void wpas_mbo_non_pref_chan_subelem_hdr(struct wpabuf *mbo, u8 len)
104 {
105 	wpabuf_put_u8(mbo, WLAN_EID_VENDOR_SPECIFIC);
106 	wpabuf_put_u8(mbo, len); /* Length */
107 	wpabuf_put_be24(mbo, OUI_WFA);
108 	wpabuf_put_u8(mbo, MBO_ATTR_ID_NON_PREF_CHAN_REPORT);
109 }
110 
111 
112 static void wpas_mbo_non_pref_chan_subelement(struct wpa_supplicant *wpa_s,
113 					      struct wpabuf *mbo, u8 start,
114 					      u8 end)
115 {
116 	size_t size = end - start + 7;
117 
118 	if (size + 2 > wpabuf_tailroom(mbo))
119 		return;
120 
121 	wpas_mbo_non_pref_chan_subelem_hdr(mbo, size);
122 	wpas_mbo_non_pref_chan_attr_body(wpa_s, mbo, start, end);
123 }
124 
125 
126 static void wpas_mbo_non_pref_chan_attrs(struct wpa_supplicant *wpa_s,
127 					 struct wpabuf *mbo, int subelement)
128 {
129 	u8 i, start = 0;
130 	struct wpa_mbo_non_pref_channel *start_pref;
131 
132 	if (!wpa_s->non_pref_chan || !wpa_s->non_pref_chan_num) {
133 		if (subelement)
134 			wpas_mbo_non_pref_chan_subelem_hdr(mbo, 4);
135 		return;
136 	}
137 	start_pref = &wpa_s->non_pref_chan[0];
138 
139 	for (i = 1; i <= wpa_s->non_pref_chan_num; i++) {
140 		struct wpa_mbo_non_pref_channel *non_pref = NULL;
141 
142 		if (i < wpa_s->non_pref_chan_num)
143 			non_pref = &wpa_s->non_pref_chan[i];
144 		if (!non_pref ||
145 		    non_pref->oper_class != start_pref->oper_class ||
146 		    non_pref->reason != start_pref->reason ||
147 		    non_pref->preference != start_pref->preference) {
148 			if (subelement)
149 				wpas_mbo_non_pref_chan_subelement(wpa_s, mbo,
150 								  start, i);
151 			else
152 				wpas_mbo_non_pref_chan_attr(wpa_s, mbo, start,
153 							    i);
154 
155 			if (!non_pref)
156 				return;
157 
158 			start = i;
159 			start_pref = non_pref;
160 		}
161 	}
162 }
163 
164 
165 int wpas_mbo_ie(struct wpa_supplicant *wpa_s, u8 *buf, size_t len,
166 		int add_oce_capa)
167 {
168 	struct wpabuf *mbo;
169 	int res;
170 
171 	if (len < MBO_IE_HEADER + 3 + 7 +
172 	    ((wpa_s->enable_oce & OCE_STA) ? 3 : 0))
173 		return 0;
174 
175 	/* Leave room for the MBO IE header */
176 	mbo = wpabuf_alloc(len - MBO_IE_HEADER);
177 	if (!mbo)
178 		return 0;
179 
180 	/* Add non-preferred channels attribute */
181 	wpas_mbo_non_pref_chan_attrs(wpa_s, mbo, 0);
182 
183 	/*
184 	 * Send cellular capabilities attribute even if AP does not advertise
185 	 * cellular capabilities.
186 	 */
187 	wpabuf_put_u8(mbo, MBO_ATTR_ID_CELL_DATA_CAPA);
188 	wpabuf_put_u8(mbo, 1);
189 	wpabuf_put_u8(mbo, wpa_s->conf->mbo_cell_capa);
190 
191 	/* Add OCE capability indication attribute if OCE is enabled */
192 	if ((wpa_s->enable_oce & OCE_STA) && add_oce_capa) {
193 		wpabuf_put_u8(mbo, OCE_ATTR_ID_CAPA_IND);
194 		wpabuf_put_u8(mbo, 1);
195 		wpabuf_put_u8(mbo, OCE_RELEASE);
196 	}
197 
198 	res = mbo_add_ie(buf, len, wpabuf_head_u8(mbo), wpabuf_len(mbo));
199 	if (!res)
200 		wpa_printf(MSG_ERROR, "Failed to add MBO/OCE IE");
201 
202 	wpabuf_free(mbo);
203 	return res;
204 }
205 
206 
207 static void wpas_mbo_send_wnm_notification(struct wpa_supplicant *wpa_s,
208 					   const u8 *data, size_t len)
209 {
210 	struct wpabuf *buf;
211 	int res;
212 
213 	/*
214 	 * Send WNM-Notification Request frame only in case of a change in
215 	 * non-preferred channels list during association, if the AP supports
216 	 * MBO.
217 	 */
218 	if (wpa_s->wpa_state != WPA_COMPLETED || !wpa_s->current_bss ||
219 	    !wpa_bss_get_vendor_ie(wpa_s->current_bss, MBO_IE_VENDOR_TYPE))
220 		return;
221 
222 	buf = wpabuf_alloc(4 + len);
223 	if (!buf)
224 		return;
225 
226 	wpabuf_put_u8(buf, WLAN_ACTION_WNM);
227 	wpabuf_put_u8(buf, WNM_NOTIFICATION_REQ);
228 	wpa_s->mbo_wnm_token++;
229 	if (wpa_s->mbo_wnm_token == 0)
230 		wpa_s->mbo_wnm_token++;
231 	wpabuf_put_u8(buf, wpa_s->mbo_wnm_token);
232 	wpabuf_put_u8(buf, WLAN_EID_VENDOR_SPECIFIC); /* Type */
233 
234 	wpabuf_put_data(buf, data, len);
235 
236 	res = wpa_drv_send_action(wpa_s, wpa_s->assoc_freq, 0, wpa_s->bssid,
237 				  wpa_s->own_addr, wpa_s->bssid,
238 				  wpabuf_head(buf), wpabuf_len(buf), 0);
239 	if (res < 0)
240 		wpa_printf(MSG_DEBUG,
241 			   "Failed to send WNM-Notification Request frame with non-preferred channel list");
242 
243 	wpabuf_free(buf);
244 }
245 
246 
247 static void wpas_mbo_non_pref_chan_changed(struct wpa_supplicant *wpa_s)
248 {
249 	struct wpabuf *buf;
250 
251 	buf = wpabuf_alloc(512);
252 	if (!buf)
253 		return;
254 
255 	wpas_mbo_non_pref_chan_attrs(wpa_s, buf, 1);
256 	wpas_mbo_send_wnm_notification(wpa_s, wpabuf_head_u8(buf),
257 				       wpabuf_len(buf));
258 	wpabuf_free(buf);
259 }
260 
261 
262 static int wpa_non_pref_chan_is_eq(struct wpa_mbo_non_pref_channel *a,
263 				   struct wpa_mbo_non_pref_channel *b)
264 {
265 	return a->oper_class == b->oper_class && a->chan == b->chan;
266 }
267 
268 
269 /*
270  * wpa_non_pref_chan_cmp - Compare two channels for sorting
271  *
272  * In MBO IE non-preferred channel subelement we can put many channels in an
273  * attribute if they are in the same operating class and have the same
274  * preference and reason. To make it easy for the functions that build
275  * the IE attributes and WNM Request subelements, save the channels sorted
276  * by their oper_class and reason.
277  */
278 static int wpa_non_pref_chan_cmp(const void *_a, const void *_b)
279 {
280 	const struct wpa_mbo_non_pref_channel *a = _a, *b = _b;
281 
282 	if (a->oper_class != b->oper_class)
283 		return a->oper_class - b->oper_class;
284 	if (a->reason != b->reason)
285 		return a->reason - b->reason;
286 	return a->preference - b->preference;
287 }
288 
289 
290 int wpas_mbo_update_non_pref_chan(struct wpa_supplicant *wpa_s,
291 				  const char *non_pref_chan)
292 {
293 	char *cmd, *token, *context = NULL;
294 	struct wpa_mbo_non_pref_channel *chans = NULL, *tmp_chans;
295 	size_t num = 0, size = 0;
296 	unsigned i;
297 
298 	wpa_printf(MSG_DEBUG, "MBO: Update non-preferred channels, non_pref_chan=%s",
299 		   non_pref_chan ? non_pref_chan : "N/A");
300 
301 	/*
302 	 * The shortest channel configuration is 7 characters - 3 colons and
303 	 * 4 values.
304 	 */
305 	if (!non_pref_chan || os_strlen(non_pref_chan) < 7)
306 		goto update;
307 
308 	cmd = os_strdup(non_pref_chan);
309 	if (!cmd)
310 		return -1;
311 
312 	while ((token = str_token(cmd, " ", &context))) {
313 		struct wpa_mbo_non_pref_channel *chan;
314 		int ret;
315 		unsigned int _oper_class;
316 		unsigned int _chan;
317 		unsigned int _preference;
318 		unsigned int _reason;
319 
320 		if (num == size) {
321 			size = size ? size * 2 : 1;
322 			tmp_chans = os_realloc_array(chans, size,
323 						     sizeof(*chans));
324 			if (!tmp_chans) {
325 				wpa_printf(MSG_ERROR,
326 					   "Couldn't reallocate non_pref_chan");
327 				goto fail;
328 			}
329 			chans = tmp_chans;
330 		}
331 
332 		chan = &chans[num];
333 
334 		ret = sscanf(token, "%u:%u:%u:%u", &_oper_class,
335 			     &_chan, &_preference, &_reason);
336 		if (ret != 4 ||
337 		    _oper_class > 255 || _chan > 255 ||
338 		    _preference > 255 || _reason > 65535 ) {
339 			wpa_printf(MSG_ERROR, "Invalid non-pref chan input %s",
340 				   token);
341 			goto fail;
342 		}
343 		chan->oper_class = _oper_class;
344 		chan->chan = _chan;
345 		chan->preference = _preference;
346 		chan->reason = _reason;
347 
348 		if (wpas_mbo_validate_non_pref_chan(chan->oper_class,
349 						    chan->chan, chan->reason)) {
350 			wpa_printf(MSG_ERROR,
351 				   "Invalid non_pref_chan: oper class %d chan %d reason %d",
352 				   chan->oper_class, chan->chan, chan->reason);
353 			goto fail;
354 		}
355 
356 		for (i = 0; i < num; i++)
357 			if (wpa_non_pref_chan_is_eq(chan, &chans[i]))
358 				break;
359 		if (i != num) {
360 			wpa_printf(MSG_ERROR,
361 				   "oper class %d chan %d is duplicated",
362 				   chan->oper_class, chan->chan);
363 			goto fail;
364 		}
365 
366 		num++;
367 	}
368 
369 	os_free(cmd);
370 
371 	if (chans) {
372 		qsort(chans, num, sizeof(struct wpa_mbo_non_pref_channel),
373 		      wpa_non_pref_chan_cmp);
374 	}
375 
376 update:
377 	os_free(wpa_s->non_pref_chan);
378 	wpa_s->non_pref_chan = chans;
379 	wpa_s->non_pref_chan_num = num;
380 	wpas_mbo_non_pref_chan_changed(wpa_s);
381 
382 	return 0;
383 
384 fail:
385 	os_free(chans);
386 	os_free(cmd);
387 	return -1;
388 }
389 
390 
391 void wpas_mbo_scan_ie(struct wpa_supplicant *wpa_s, struct wpabuf *ie)
392 {
393 	u8 *len;
394 
395 	wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
396 	len = wpabuf_put(ie, 1);
397 
398 	wpabuf_put_be24(ie, OUI_WFA);
399 	wpabuf_put_u8(ie, MBO_OUI_TYPE);
400 
401 	wpabuf_put_u8(ie, MBO_ATTR_ID_CELL_DATA_CAPA);
402 	wpabuf_put_u8(ie, 1);
403 	wpabuf_put_u8(ie, wpa_s->conf->mbo_cell_capa);
404 	if (wpa_s->enable_oce & OCE_STA) {
405 		wpabuf_put_u8(ie, OCE_ATTR_ID_CAPA_IND);
406 		wpabuf_put_u8(ie, 1);
407 		wpabuf_put_u8(ie, OCE_RELEASE);
408 	}
409 	*len = (u8 *) wpabuf_put(ie, 0) - len - 1;
410 }
411 
412 
413 void wpas_mbo_ie_trans_req(struct wpa_supplicant *wpa_s, const u8 *mbo_ie,
414 			   size_t len)
415 {
416 	const u8 *pos, *cell_pref = NULL;
417 	u8 id, elen;
418 	u16 disallowed_sec = 0;
419 
420 	if (len <= 4 || WPA_GET_BE24(mbo_ie) != OUI_WFA ||
421 	    mbo_ie[3] != MBO_OUI_TYPE)
422 		return;
423 
424 	pos = mbo_ie + 4;
425 	len -= 4;
426 
427 	while (len >= 2) {
428 		id = *pos++;
429 		elen = *pos++;
430 		len -= 2;
431 
432 		if (elen > len)
433 			goto fail;
434 
435 		switch (id) {
436 		case MBO_ATTR_ID_CELL_DATA_PREF:
437 			if (elen != 1)
438 				goto fail;
439 
440 			if (wpa_s->conf->mbo_cell_capa ==
441 			    MBO_CELL_CAPA_AVAILABLE)
442 				cell_pref = pos;
443 			else
444 				wpa_printf(MSG_DEBUG,
445 					   "MBO: Station does not support Cellular data connection");
446 			break;
447 		case MBO_ATTR_ID_TRANSITION_REASON:
448 			if (elen != 1)
449 				goto fail;
450 
451 			wpa_s->wnm_mbo_trans_reason_present = 1;
452 			wpa_s->wnm_mbo_transition_reason = *pos;
453 			break;
454 		case MBO_ATTR_ID_ASSOC_RETRY_DELAY:
455 			if (elen != 2)
456 				goto fail;
457 
458 			if (wpa_s->wnm_mode &
459 			    WNM_BSS_TM_REQ_BSS_TERMINATION_INCLUDED) {
460 				wpa_printf(MSG_DEBUG,
461 					   "MBO: Unexpected association retry delay, BSS is terminating");
462 				goto fail;
463 			} else if (wpa_s->wnm_mode &
464 				   WNM_BSS_TM_REQ_DISASSOC_IMMINENT) {
465 				disallowed_sec = WPA_GET_LE16(pos);
466 				wpa_printf(MSG_DEBUG,
467 					   "MBO: Association retry delay: %u",
468 					   disallowed_sec);
469 			} else {
470 				wpa_printf(MSG_DEBUG,
471 					   "MBO: Association retry delay attribute not in disassoc imminent mode");
472 			}
473 
474 			break;
475 		case MBO_ATTR_ID_AP_CAPA_IND:
476 		case MBO_ATTR_ID_NON_PREF_CHAN_REPORT:
477 		case MBO_ATTR_ID_CELL_DATA_CAPA:
478 		case MBO_ATTR_ID_ASSOC_DISALLOW:
479 		case MBO_ATTR_ID_TRANSITION_REJECT_REASON:
480 			wpa_printf(MSG_DEBUG,
481 				   "MBO: Attribute %d should not be included in BTM Request frame",
482 				   id);
483 			break;
484 		default:
485 			wpa_printf(MSG_DEBUG, "MBO: Unknown attribute id %u",
486 				   id);
487 			return;
488 		}
489 
490 		pos += elen;
491 		len -= elen;
492 	}
493 
494 	if (cell_pref)
495 		wpa_msg(wpa_s, MSG_INFO, MBO_CELL_PREFERENCE "preference=%u",
496 			*cell_pref);
497 
498 	if (wpa_s->wnm_mbo_trans_reason_present)
499 		wpa_msg(wpa_s, MSG_INFO, MBO_TRANSITION_REASON "reason=%u",
500 			wpa_s->wnm_mbo_transition_reason);
501 
502 	if (disallowed_sec && wpa_s->current_bss)
503 		wpa_bss_tmp_disallow(wpa_s, wpa_s->current_bss->bssid,
504 				     disallowed_sec);
505 
506 	return;
507 fail:
508 	wpa_printf(MSG_DEBUG, "MBO IE parsing failed (id=%u len=%u left=%zu)",
509 		   id, elen, len);
510 }
511 
512 
513 size_t wpas_mbo_ie_bss_trans_reject(struct wpa_supplicant *wpa_s, u8 *pos,
514 				    size_t len,
515 				    enum mbo_transition_reject_reason reason)
516 {
517 	u8 reject_attr[3];
518 
519 	reject_attr[0] = MBO_ATTR_ID_TRANSITION_REJECT_REASON;
520 	reject_attr[1] = 1;
521 	reject_attr[2] = reason;
522 
523 	return mbo_add_ie(pos, len, reject_attr, sizeof(reject_attr));
524 }
525 
526 
527 void wpas_mbo_update_cell_capa(struct wpa_supplicant *wpa_s, u8 mbo_cell_capa)
528 {
529 	u8 cell_capa[7];
530 
531 	if (wpa_s->conf->mbo_cell_capa == mbo_cell_capa) {
532 		wpa_printf(MSG_DEBUG,
533 			   "MBO: Cellular capability already set to %u",
534 			   mbo_cell_capa);
535 		return;
536 	}
537 
538 	wpa_s->conf->mbo_cell_capa = mbo_cell_capa;
539 
540 	cell_capa[0] = WLAN_EID_VENDOR_SPECIFIC;
541 	cell_capa[1] = 5; /* Length */
542 	WPA_PUT_BE24(cell_capa + 2, OUI_WFA);
543 	cell_capa[5] = MBO_ATTR_ID_CELL_DATA_CAPA;
544 	cell_capa[6] = mbo_cell_capa;
545 
546 	wpas_mbo_send_wnm_notification(wpa_s, cell_capa, 7);
547 	wpa_supplicant_set_default_scan_ies(wpa_s);
548 }
549 
550 
551 struct wpabuf * mbo_build_anqp_buf(struct wpa_supplicant *wpa_s,
552 				   struct wpa_bss *bss, u32 mbo_subtypes)
553 {
554 	struct wpabuf *anqp_buf;
555 	u8 *len_pos;
556 	u8 i;
557 
558 	if (!wpa_bss_get_vendor_ie(bss, MBO_IE_VENDOR_TYPE)) {
559 		wpa_printf(MSG_INFO, "MBO: " MACSTR
560 			   " does not support MBO - cannot request MBO ANQP elements from it",
561 			   MAC2STR(bss->bssid));
562 		return NULL;
563 	}
564 
565 	/* Allocate size for the maximum case - all MBO subtypes are set */
566 	anqp_buf = wpabuf_alloc(9 + MAX_MBO_ANQP_SUBTYPE);
567 	if (!anqp_buf)
568 		return NULL;
569 
570 	len_pos = gas_anqp_add_element(anqp_buf, ANQP_VENDOR_SPECIFIC);
571 	wpabuf_put_be24(anqp_buf, OUI_WFA);
572 	wpabuf_put_u8(anqp_buf, MBO_ANQP_OUI_TYPE);
573 
574 	wpabuf_put_u8(anqp_buf, MBO_ANQP_SUBTYPE_QUERY_LIST);
575 
576 	/* The first valid MBO subtype is 1 */
577 	for (i = 1; i <= MAX_MBO_ANQP_SUBTYPE; i++) {
578 		if (mbo_subtypes & BIT(i))
579 			wpabuf_put_u8(anqp_buf, i);
580 	}
581 
582 	gas_anqp_set_element_len(anqp_buf, len_pos);
583 
584 	return anqp_buf;
585 }
586 
587 
588 void mbo_parse_rx_anqp_resp(struct wpa_supplicant *wpa_s,
589 			    struct wpa_bss *bss, const u8 *sa,
590 			    const u8 *data, size_t slen)
591 {
592 	const u8 *pos = data;
593 	u8 subtype;
594 
595 	if (slen < 1)
596 		return;
597 
598 	subtype = *pos++;
599 	slen--;
600 
601 	switch (subtype) {
602 	case MBO_ANQP_SUBTYPE_CELL_CONN_PREF:
603 		if (slen < 1)
604 			break;
605 		wpa_msg(wpa_s, MSG_INFO, RX_MBO_ANQP MACSTR
606 			" cell_conn_pref=%u", MAC2STR(sa), *pos);
607 		break;
608 	default:
609 		wpa_printf(MSG_DEBUG, "MBO: Unsupported ANQP subtype %u",
610 			   subtype);
611 		break;
612 	}
613 }
614