xref: /freebsd/contrib/wpa/wpa_supplicant/mbo.c (revision 78b9f0095b4af3aca6c931b2c7b009ddb8a05125)
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 * wpas_mbo_get_bss_attr(struct wpa_bss *bss, enum mbo_attr_id attr)
42 {
43 	const u8 *mbo, *end;
44 
45 	if (!bss)
46 		return NULL;
47 
48 	mbo = wpa_bss_get_vendor_ie(bss, MBO_IE_VENDOR_TYPE);
49 	if (!mbo)
50 		return NULL;
51 
52 	end = mbo + 2 + mbo[1];
53 	mbo += MBO_IE_HEADER;
54 
55 	return get_ie(mbo, end - mbo, attr);
56 }
57 
58 
59 static void wpas_mbo_non_pref_chan_attr_body(struct wpa_supplicant *wpa_s,
60 					     struct wpabuf *mbo,
61 					     u8 start, u8 end)
62 {
63 	u8 i;
64 
65 	wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].oper_class);
66 
67 	for (i = start; i < end; i++)
68 		wpabuf_put_u8(mbo, wpa_s->non_pref_chan[i].chan);
69 
70 	wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].preference);
71 	wpabuf_put_u8(mbo, wpa_s->non_pref_chan[start].reason);
72 }
73 
74 
75 static void wpas_mbo_non_pref_chan_attr(struct wpa_supplicant *wpa_s,
76 					struct wpabuf *mbo, u8 start, u8 end)
77 {
78 	size_t size = end - start + 3;
79 
80 	if (size + 2 > wpabuf_tailroom(mbo))
81 		return;
82 
83 	wpabuf_put_u8(mbo, MBO_ATTR_ID_NON_PREF_CHAN_REPORT);
84 	wpabuf_put_u8(mbo, size); /* Length */
85 
86 	wpas_mbo_non_pref_chan_attr_body(wpa_s, mbo, start, end);
87 }
88 
89 
90 static void wpas_mbo_non_pref_chan_subelem_hdr(struct wpabuf *mbo, u8 len)
91 {
92 	wpabuf_put_u8(mbo, WLAN_EID_VENDOR_SPECIFIC);
93 	wpabuf_put_u8(mbo, len); /* Length */
94 	wpabuf_put_be24(mbo, OUI_WFA);
95 	wpabuf_put_u8(mbo, MBO_ATTR_ID_NON_PREF_CHAN_REPORT);
96 }
97 
98 
99 static void wpas_mbo_non_pref_chan_subelement(struct wpa_supplicant *wpa_s,
100 					      struct wpabuf *mbo, u8 start,
101 					      u8 end)
102 {
103 	size_t size = end - start + 7;
104 
105 	if (size + 2 > wpabuf_tailroom(mbo))
106 		return;
107 
108 	wpas_mbo_non_pref_chan_subelem_hdr(mbo, size);
109 	wpas_mbo_non_pref_chan_attr_body(wpa_s, mbo, start, end);
110 }
111 
112 
113 static void wpas_mbo_non_pref_chan_attrs(struct wpa_supplicant *wpa_s,
114 					 struct wpabuf *mbo, int subelement)
115 {
116 	u8 i, start = 0;
117 	struct wpa_mbo_non_pref_channel *start_pref;
118 
119 	if (!wpa_s->non_pref_chan || !wpa_s->non_pref_chan_num) {
120 		if (subelement)
121 			wpas_mbo_non_pref_chan_subelem_hdr(mbo, 4);
122 		return;
123 	}
124 	start_pref = &wpa_s->non_pref_chan[0];
125 
126 	for (i = 1; i <= wpa_s->non_pref_chan_num; i++) {
127 		struct wpa_mbo_non_pref_channel *non_pref = NULL;
128 
129 		if (i < wpa_s->non_pref_chan_num)
130 			non_pref = &wpa_s->non_pref_chan[i];
131 		if (!non_pref ||
132 		    non_pref->oper_class != start_pref->oper_class ||
133 		    non_pref->reason != start_pref->reason ||
134 		    non_pref->preference != start_pref->preference) {
135 			if (subelement)
136 				wpas_mbo_non_pref_chan_subelement(wpa_s, mbo,
137 								  start, i);
138 			else
139 				wpas_mbo_non_pref_chan_attr(wpa_s, mbo, start,
140 							    i);
141 
142 			if (!non_pref)
143 				return;
144 
145 			start = i;
146 			start_pref = non_pref;
147 		}
148 	}
149 }
150 
151 
152 int wpas_mbo_ie(struct wpa_supplicant *wpa_s, u8 *buf, size_t len)
153 {
154 	struct wpabuf *mbo;
155 	int res;
156 
157 	if (len < MBO_IE_HEADER + 3 + 7)
158 		return 0;
159 
160 	/* Leave room for the MBO IE header */
161 	mbo = wpabuf_alloc(len - MBO_IE_HEADER);
162 	if (!mbo)
163 		return 0;
164 
165 	/* Add non-preferred channels attribute */
166 	wpas_mbo_non_pref_chan_attrs(wpa_s, mbo, 0);
167 
168 	/*
169 	 * Send cellular capabilities attribute even if AP does not advertise
170 	 * cellular capabilities.
171 	 */
172 	wpabuf_put_u8(mbo, MBO_ATTR_ID_CELL_DATA_CAPA);
173 	wpabuf_put_u8(mbo, 1);
174 	wpabuf_put_u8(mbo, wpa_s->conf->mbo_cell_capa);
175 
176 	res = mbo_add_ie(buf, len, wpabuf_head_u8(mbo), wpabuf_len(mbo));
177 	if (!res)
178 		wpa_printf(MSG_ERROR, "Failed to add MBO IE");
179 
180 	wpabuf_free(mbo);
181 	return res;
182 }
183 
184 
185 static void wpas_mbo_send_wnm_notification(struct wpa_supplicant *wpa_s,
186 					   const u8 *data, size_t len)
187 {
188 	struct wpabuf *buf;
189 	int res;
190 
191 	/*
192 	 * Send WNM-Notification Request frame only in case of a change in
193 	 * non-preferred channels list during association, if the AP supports
194 	 * MBO.
195 	 */
196 	if (wpa_s->wpa_state != WPA_COMPLETED || !wpa_s->current_bss ||
197 	    !wpa_bss_get_vendor_ie(wpa_s->current_bss, MBO_IE_VENDOR_TYPE))
198 		return;
199 
200 	buf = wpabuf_alloc(4 + len);
201 	if (!buf)
202 		return;
203 
204 	wpabuf_put_u8(buf, WLAN_ACTION_WNM);
205 	wpabuf_put_u8(buf, WNM_NOTIFICATION_REQ);
206 	wpa_s->mbo_wnm_token++;
207 	if (wpa_s->mbo_wnm_token == 0)
208 		wpa_s->mbo_wnm_token++;
209 	wpabuf_put_u8(buf, wpa_s->mbo_wnm_token);
210 	wpabuf_put_u8(buf, WLAN_EID_VENDOR_SPECIFIC); /* Type */
211 
212 	wpabuf_put_data(buf, data, len);
213 
214 	res = wpa_drv_send_action(wpa_s, wpa_s->assoc_freq, 0, wpa_s->bssid,
215 				  wpa_s->own_addr, wpa_s->bssid,
216 				  wpabuf_head(buf), wpabuf_len(buf), 0);
217 	if (res < 0)
218 		wpa_printf(MSG_DEBUG,
219 			   "Failed to send WNM-Notification Request frame with non-preferred channel list");
220 
221 	wpabuf_free(buf);
222 }
223 
224 
225 static void wpas_mbo_non_pref_chan_changed(struct wpa_supplicant *wpa_s)
226 {
227 	struct wpabuf *buf;
228 
229 	buf = wpabuf_alloc(512);
230 	if (!buf)
231 		return;
232 
233 	wpas_mbo_non_pref_chan_attrs(wpa_s, buf, 1);
234 	wpas_mbo_send_wnm_notification(wpa_s, wpabuf_head_u8(buf),
235 				       wpabuf_len(buf));
236 	wpabuf_free(buf);
237 }
238 
239 
240 static int wpa_non_pref_chan_is_eq(struct wpa_mbo_non_pref_channel *a,
241 				   struct wpa_mbo_non_pref_channel *b)
242 {
243 	return a->oper_class == b->oper_class && a->chan == b->chan;
244 }
245 
246 
247 /*
248  * wpa_non_pref_chan_cmp - Compare two channels for sorting
249  *
250  * In MBO IE non-preferred channel subelement we can put many channels in an
251  * attribute if they are in the same operating class and have the same
252  * preference and reason. To make it easy for the functions that build
253  * the IE attributes and WNM Request subelements, save the channels sorted
254  * by their oper_class and reason.
255  */
256 static int wpa_non_pref_chan_cmp(const void *_a, const void *_b)
257 {
258 	const struct wpa_mbo_non_pref_channel *a = _a, *b = _b;
259 
260 	if (a->oper_class != b->oper_class)
261 		return a->oper_class - b->oper_class;
262 	if (a->reason != b->reason)
263 		return a->reason - b->reason;
264 	return a->preference - b->preference;
265 }
266 
267 
268 int wpas_mbo_update_non_pref_chan(struct wpa_supplicant *wpa_s,
269 				  const char *non_pref_chan)
270 {
271 	char *cmd, *token, *context = NULL;
272 	struct wpa_mbo_non_pref_channel *chans = NULL, *tmp_chans;
273 	size_t num = 0, size = 0;
274 	unsigned i;
275 
276 	wpa_printf(MSG_DEBUG, "MBO: Update non-preferred channels, non_pref_chan=%s",
277 		   non_pref_chan ? non_pref_chan : "N/A");
278 
279 	/*
280 	 * The shortest channel configuration is 10 characters - commas, 3
281 	 * colons, and 4 values that one of them (oper_class) is 2 digits or
282 	 * more.
283 	 */
284 	if (!non_pref_chan || os_strlen(non_pref_chan) < 10)
285 		goto update;
286 
287 	cmd = os_strdup(non_pref_chan);
288 	if (!cmd)
289 		return -1;
290 
291 	while ((token = str_token(cmd, " ", &context))) {
292 		struct wpa_mbo_non_pref_channel *chan;
293 		int ret;
294 		unsigned int _oper_class;
295 		unsigned int _chan;
296 		unsigned int _preference;
297 		unsigned int _reason;
298 
299 		if (num == size) {
300 			size = size ? size * 2 : 1;
301 			tmp_chans = os_realloc_array(chans, size,
302 						     sizeof(*chans));
303 			if (!tmp_chans) {
304 				wpa_printf(MSG_ERROR,
305 					   "Couldn't reallocate non_pref_chan");
306 				goto fail;
307 			}
308 			chans = tmp_chans;
309 		}
310 
311 		chan = &chans[num];
312 
313 		ret = sscanf(token, "%u:%u:%u:%u", &_oper_class,
314 			     &_chan, &_preference, &_reason);
315 		if (ret != 4 ||
316 		    _oper_class > 255 || _chan > 255 ||
317 		    _preference > 255 || _reason > 65535 ) {
318 			wpa_printf(MSG_ERROR, "Invalid non-pref chan input %s",
319 				   token);
320 			goto fail;
321 		}
322 		chan->oper_class = _oper_class;
323 		chan->chan = _chan;
324 		chan->preference = _preference;
325 		chan->reason = _reason;
326 
327 		if (wpas_mbo_validate_non_pref_chan(chan->oper_class,
328 						    chan->chan, chan->reason)) {
329 			wpa_printf(MSG_ERROR,
330 				   "Invalid non_pref_chan: oper class %d chan %d reason %d",
331 				   chan->oper_class, chan->chan, chan->reason);
332 			goto fail;
333 		}
334 
335 		for (i = 0; i < num; i++)
336 			if (wpa_non_pref_chan_is_eq(chan, &chans[i]))
337 				break;
338 		if (i != num) {
339 			wpa_printf(MSG_ERROR,
340 				   "oper class %d chan %d is duplicated",
341 				   chan->oper_class, chan->chan);
342 			goto fail;
343 		}
344 
345 		num++;
346 	}
347 
348 	os_free(cmd);
349 
350 	if (chans) {
351 		qsort(chans, num, sizeof(struct wpa_mbo_non_pref_channel),
352 		      wpa_non_pref_chan_cmp);
353 	}
354 
355 update:
356 	os_free(wpa_s->non_pref_chan);
357 	wpa_s->non_pref_chan = chans;
358 	wpa_s->non_pref_chan_num = num;
359 	wpas_mbo_non_pref_chan_changed(wpa_s);
360 
361 	return 0;
362 
363 fail:
364 	os_free(chans);
365 	os_free(cmd);
366 	return -1;
367 }
368 
369 
370 void wpas_mbo_scan_ie(struct wpa_supplicant *wpa_s, struct wpabuf *ie)
371 {
372 	wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
373 	wpabuf_put_u8(ie, 7);
374 	wpabuf_put_be24(ie, OUI_WFA);
375 	wpabuf_put_u8(ie, MBO_OUI_TYPE);
376 
377 	wpabuf_put_u8(ie, MBO_ATTR_ID_CELL_DATA_CAPA);
378 	wpabuf_put_u8(ie, 1);
379 	wpabuf_put_u8(ie, wpa_s->conf->mbo_cell_capa);
380 }
381 
382 
383 enum chan_allowed {
384 	NOT_ALLOWED, ALLOWED
385 };
386 
387 static enum chan_allowed allow_channel(struct hostapd_hw_modes *mode, u8 chan,
388 				       unsigned int *flags)
389 {
390 	int i;
391 
392 	for (i = 0; i < mode->num_channels; i++) {
393 		if (mode->channels[i].chan == chan)
394 			break;
395 	}
396 
397 	if (i == mode->num_channels ||
398 	    (mode->channels[i].flag & HOSTAPD_CHAN_DISABLED))
399 		return NOT_ALLOWED;
400 
401 	if (flags)
402 		*flags = mode->channels[i].flag;
403 
404 	return ALLOWED;
405 }
406 
407 
408 static int get_center_80mhz(struct hostapd_hw_modes *mode, u8 channel)
409 {
410 	u8 center_channels[] = {42, 58, 106, 122, 138, 155};
411 	size_t i;
412 
413 	if (mode->mode != HOSTAPD_MODE_IEEE80211A)
414 		return 0;
415 
416 	for (i = 0; i < ARRAY_SIZE(center_channels); i++) {
417 		/*
418 		 * In 80 MHz, the bandwidth "spans" 12 channels (e.g., 36-48),
419 		 * so the center channel is 6 channels away from the start/end.
420 		 */
421 		if (channel >= center_channels[i] - 6 &&
422 		    channel <= center_channels[i] + 6)
423 			return center_channels[i];
424 	}
425 
426 	return 0;
427 }
428 
429 
430 static enum chan_allowed verify_80mhz(struct hostapd_hw_modes *mode, u8 channel)
431 {
432 	u8 center_chan;
433 	unsigned int i;
434 
435 	center_chan = get_center_80mhz(mode, channel);
436 	if (!center_chan)
437 		return NOT_ALLOWED;
438 
439 	/* check all the channels are available */
440 	for (i = 0; i < 4; i++) {
441 		unsigned int flags;
442 		u8 adj_chan = center_chan - 6 + i * 4;
443 
444 		if (allow_channel(mode, adj_chan, &flags) == NOT_ALLOWED)
445 			return NOT_ALLOWED;
446 
447 		if ((i == 0 && !(flags & HOSTAPD_CHAN_VHT_10_70)) ||
448 		    (i == 1 && !(flags & HOSTAPD_CHAN_VHT_30_50)) ||
449 		    (i == 2 && !(flags & HOSTAPD_CHAN_VHT_50_30)) ||
450 		    (i == 3 && !(flags & HOSTAPD_CHAN_VHT_70_10)))
451 			return NOT_ALLOWED;
452 	}
453 
454 	return ALLOWED;
455 }
456 
457 
458 static int get_center_160mhz(struct hostapd_hw_modes *mode, u8 channel)
459 {
460 	u8 center_channels[] = { 50, 114 };
461 	unsigned int i;
462 
463 	if (mode->mode != HOSTAPD_MODE_IEEE80211A)
464 		return 0;
465 
466 	for (i = 0; i < ARRAY_SIZE(center_channels); i++) {
467 		/*
468 		 * In 160 MHz, the bandwidth "spans" 28 channels (e.g., 36-64),
469 		 * so the center channel is 14 channels away from the start/end.
470 		 */
471 		if (channel >= center_channels[i] - 14 &&
472 		    channel <= center_channels[i] + 14)
473 			return center_channels[i];
474 	}
475 
476 	return 0;
477 }
478 
479 
480 static enum chan_allowed verify_160mhz(struct hostapd_hw_modes *mode,
481 				       u8 channel)
482 {
483 	u8 center_chan;
484 	unsigned int i;
485 
486 	center_chan = get_center_160mhz(mode, channel);
487 	if (!center_chan)
488 		return NOT_ALLOWED;
489 
490 	/* Check all the channels are available */
491 	for (i = 0; i < 8; i++) {
492 		unsigned int flags;
493 		u8 adj_chan = center_chan - 14 + i * 4;
494 
495 		if (allow_channel(mode, adj_chan, &flags) == NOT_ALLOWED)
496 			return NOT_ALLOWED;
497 
498 		if ((i == 0 && !(flags & HOSTAPD_CHAN_VHT_10_150)) ||
499 		    (i == 1 && !(flags & HOSTAPD_CHAN_VHT_30_130)) ||
500 		    (i == 2 && !(flags & HOSTAPD_CHAN_VHT_50_110)) ||
501 		    (i == 3 && !(flags & HOSTAPD_CHAN_VHT_70_90)) ||
502 		    (i == 4 && !(flags & HOSTAPD_CHAN_VHT_90_70)) ||
503 		    (i == 5 && !(flags & HOSTAPD_CHAN_VHT_110_50)) ||
504 		    (i == 6 && !(flags & HOSTAPD_CHAN_VHT_130_30)) ||
505 		    (i == 7 && !(flags & HOSTAPD_CHAN_VHT_150_10)))
506 			return NOT_ALLOWED;
507 	}
508 
509 	return ALLOWED;
510 }
511 
512 
513 static enum chan_allowed verify_channel(struct hostapd_hw_modes *mode,
514 					u8 channel, u8 bw)
515 {
516 	unsigned int flag = 0;
517 	enum chan_allowed res, res2;
518 
519 	res2 = res = allow_channel(mode, channel, &flag);
520 	if (bw == BW40MINUS) {
521 		if (!(flag & HOSTAPD_CHAN_HT40MINUS))
522 			return NOT_ALLOWED;
523 		res2 = allow_channel(mode, channel - 4, NULL);
524 	} else if (bw == BW40PLUS) {
525 		if (!(flag & HOSTAPD_CHAN_HT40PLUS))
526 			return NOT_ALLOWED;
527 		res2 = allow_channel(mode, channel + 4, NULL);
528 	} else if (bw == BW80) {
529 		/*
530 		 * channel is a center channel and as such, not necessarily a
531 		 * valid 20 MHz channels. Override earlier allow_channel()
532 		 * result and use only the 80 MHz specific version.
533 		 */
534 		res2 = res = verify_80mhz(mode, channel);
535 	} else if (bw == BW160) {
536 		/*
537 		 * channel is a center channel and as such, not necessarily a
538 		 * valid 20 MHz channels. Override earlier allow_channel()
539 		 * result and use only the 160 MHz specific version.
540 		 */
541 		res2 = res = verify_160mhz(mode, channel);
542 	} else if (bw == BW80P80) {
543 		/*
544 		 * channel is a center channel and as such, not necessarily a
545 		 * valid 20 MHz channels. Override earlier allow_channel()
546 		 * result and use only the 80 MHz specific version.
547 		 */
548 		res2 = res = verify_80mhz(mode, channel);
549 	}
550 
551 	if (res == NOT_ALLOWED || res2 == NOT_ALLOWED)
552 		return NOT_ALLOWED;
553 
554 	return ALLOWED;
555 }
556 
557 
558 static int wpas_op_class_supported(struct wpa_supplicant *wpa_s,
559 				   const struct oper_class_map *op_class)
560 {
561 	int chan;
562 	size_t i;
563 	struct hostapd_hw_modes *mode;
564 	int found;
565 
566 	mode = get_mode(wpa_s->hw.modes, wpa_s->hw.num_modes, op_class->mode);
567 	if (!mode)
568 		return 0;
569 
570 	if (op_class->op_class == 128) {
571 		u8 channels[] = { 42, 58, 106, 122, 138, 155 };
572 
573 		for (i = 0; i < ARRAY_SIZE(channels); i++) {
574 			if (verify_channel(mode, channels[i], op_class->bw) ==
575 			    ALLOWED)
576 				return 1;
577 		}
578 
579 		return 0;
580 	}
581 
582 	if (op_class->op_class == 129) {
583 		/* Check if either 160 MHz channels is allowed */
584 		return verify_channel(mode, 50, op_class->bw) == ALLOWED ||
585 			verify_channel(mode, 114, op_class->bw) == ALLOWED;
586 	}
587 
588 	if (op_class->op_class == 130) {
589 		/* Need at least two non-contiguous 80 MHz segments */
590 		found = 0;
591 
592 		if (verify_channel(mode, 42, op_class->bw) == ALLOWED ||
593 		    verify_channel(mode, 58, op_class->bw) == ALLOWED)
594 			found++;
595 		if (verify_channel(mode, 106, op_class->bw) == ALLOWED ||
596 		    verify_channel(mode, 122, op_class->bw) == ALLOWED ||
597 		    verify_channel(mode, 138, op_class->bw) == ALLOWED)
598 			found++;
599 		if (verify_channel(mode, 106, op_class->bw) == ALLOWED &&
600 		    verify_channel(mode, 138, op_class->bw) == ALLOWED)
601 			found++;
602 		if (verify_channel(mode, 155, op_class->bw) == ALLOWED)
603 			found++;
604 
605 		if (found >= 2)
606 			return 1;
607 
608 		return 0;
609 	}
610 
611 	found = 0;
612 	for (chan = op_class->min_chan; chan <= op_class->max_chan;
613 	     chan += op_class->inc) {
614 		if (verify_channel(mode, chan, op_class->bw) == ALLOWED) {
615 			found = 1;
616 			break;
617 		}
618 	}
619 
620 	return found;
621 }
622 
623 
624 int wpas_mbo_supp_op_class_ie(struct wpa_supplicant *wpa_s, int freq, u8 *pos,
625 			      size_t len)
626 {
627 	struct wpabuf *buf;
628 	u8 op, current, chan;
629 	u8 *ie_len;
630 	int res;
631 
632 	/*
633 	 * Assume 20 MHz channel for now.
634 	 * TODO: Use the secondary channel and VHT channel width that will be
635 	 * used after association.
636 	 */
637 	if (ieee80211_freq_to_channel_ext(freq, 0, VHT_CHANWIDTH_USE_HT,
638 					  &current, &chan) == NUM_HOSTAPD_MODES)
639 		return 0;
640 
641 	/*
642 	 * Need 3 bytes for EID, length, and current operating class, plus
643 	 * 1 byte for every other supported operating class.
644 	 */
645 	buf = wpabuf_alloc(global_op_class_size + 3);
646 	if (!buf)
647 		return 0;
648 
649 	wpabuf_put_u8(buf, WLAN_EID_SUPPORTED_OPERATING_CLASSES);
650 	/* Will set the length later, putting a placeholder */
651 	ie_len = wpabuf_put(buf, 1);
652 	wpabuf_put_u8(buf, current);
653 
654 	for (op = 0; global_op_class[op].op_class; op++) {
655 		if (wpas_op_class_supported(wpa_s, &global_op_class[op]))
656 			wpabuf_put_u8(buf, global_op_class[op].op_class);
657 	}
658 
659 	*ie_len = wpabuf_len(buf) - 2;
660 	if (*ie_len < 2 || wpabuf_len(buf) > len) {
661 		wpa_printf(MSG_ERROR,
662 			   "Failed to add supported operating classes IE");
663 		res = 0;
664 	} else {
665 		os_memcpy(pos, wpabuf_head(buf), wpabuf_len(buf));
666 		res = wpabuf_len(buf);
667 		wpa_hexdump_buf(MSG_DEBUG,
668 				"MBO: Added supported operating classes IE",
669 				buf);
670 	}
671 
672 	wpabuf_free(buf);
673 	return res;
674 }
675 
676 
677 void wpas_mbo_ie_trans_req(struct wpa_supplicant *wpa_s, const u8 *mbo_ie,
678 			   size_t len)
679 {
680 	const u8 *pos, *cell_pref = NULL, *reason = NULL;
681 	u8 id, elen;
682 	u16 disallowed_sec = 0;
683 
684 	if (len <= 4 || WPA_GET_BE24(mbo_ie) != OUI_WFA ||
685 	    mbo_ie[3] != MBO_OUI_TYPE)
686 		return;
687 
688 	pos = mbo_ie + 4;
689 	len -= 4;
690 
691 	while (len >= 2) {
692 		id = *pos++;
693 		elen = *pos++;
694 		len -= 2;
695 
696 		if (elen > len)
697 			goto fail;
698 
699 		switch (id) {
700 		case MBO_ATTR_ID_CELL_DATA_PREF:
701 			if (elen != 1)
702 				goto fail;
703 
704 			if (wpa_s->conf->mbo_cell_capa ==
705 			    MBO_CELL_CAPA_AVAILABLE)
706 				cell_pref = pos;
707 			else
708 				wpa_printf(MSG_DEBUG,
709 					   "MBO: Station does not support Cellular data connection");
710 			break;
711 		case MBO_ATTR_ID_TRANSITION_REASON:
712 			if (elen != 1)
713 				goto fail;
714 
715 			reason = pos;
716 			break;
717 		case MBO_ATTR_ID_ASSOC_RETRY_DELAY:
718 			if (elen != 2)
719 				goto fail;
720 
721 			if (wpa_s->wnm_mode &
722 			    WNM_BSS_TM_REQ_BSS_TERMINATION_INCLUDED) {
723 				wpa_printf(MSG_DEBUG,
724 					   "MBO: Unexpected association retry delay, BSS is terminating");
725 				goto fail;
726 			} else if (wpa_s->wnm_mode &
727 				   WNM_BSS_TM_REQ_DISASSOC_IMMINENT) {
728 				disallowed_sec = WPA_GET_LE16(pos);
729 			} else {
730 				wpa_printf(MSG_DEBUG,
731 					   "MBO: Association retry delay attribute not in disassoc imminent mode");
732 			}
733 
734 			break;
735 		case MBO_ATTR_ID_AP_CAPA_IND:
736 		case MBO_ATTR_ID_NON_PREF_CHAN_REPORT:
737 		case MBO_ATTR_ID_CELL_DATA_CAPA:
738 		case MBO_ATTR_ID_ASSOC_DISALLOW:
739 		case MBO_ATTR_ID_TRANSITION_REJECT_REASON:
740 			wpa_printf(MSG_DEBUG,
741 				   "MBO: Attribute %d should not be included in BTM Request frame",
742 				   id);
743 			break;
744 		default:
745 			wpa_printf(MSG_DEBUG, "MBO: Unknown attribute id %u",
746 				   id);
747 			return;
748 		}
749 
750 		pos += elen;
751 		len -= elen;
752 	}
753 
754 	if (cell_pref)
755 		wpa_msg(wpa_s, MSG_INFO, MBO_CELL_PREFERENCE "preference=%u",
756 			*cell_pref);
757 
758 	if (reason)
759 		wpa_msg(wpa_s, MSG_INFO, MBO_TRANSITION_REASON "reason=%u",
760 			*reason);
761 
762 	if (disallowed_sec && wpa_s->current_bss)
763 		wpa_bss_tmp_disallow(wpa_s, wpa_s->current_bss->bssid,
764 				     disallowed_sec);
765 
766 	return;
767 fail:
768 	wpa_printf(MSG_DEBUG, "MBO IE parsing failed (id=%u len=%u left=%zu)",
769 		   id, elen, len);
770 }
771 
772 
773 size_t wpas_mbo_ie_bss_trans_reject(struct wpa_supplicant *wpa_s, u8 *pos,
774 				    size_t len,
775 				    enum mbo_transition_reject_reason reason)
776 {
777 	u8 reject_attr[3];
778 
779 	reject_attr[0] = MBO_ATTR_ID_TRANSITION_REJECT_REASON;
780 	reject_attr[1] = 1;
781 	reject_attr[2] = reason;
782 
783 	return mbo_add_ie(pos, len, reject_attr, sizeof(reject_attr));
784 }
785 
786 
787 void wpas_mbo_update_cell_capa(struct wpa_supplicant *wpa_s, u8 mbo_cell_capa)
788 {
789 	u8 cell_capa[7];
790 
791 	if (wpa_s->conf->mbo_cell_capa == mbo_cell_capa) {
792 		wpa_printf(MSG_DEBUG,
793 			   "MBO: Cellular capability already set to %u",
794 			   mbo_cell_capa);
795 		return;
796 	}
797 
798 	wpa_s->conf->mbo_cell_capa = mbo_cell_capa;
799 
800 	cell_capa[0] = WLAN_EID_VENDOR_SPECIFIC;
801 	cell_capa[1] = 5; /* Length */
802 	WPA_PUT_BE24(cell_capa + 2, OUI_WFA);
803 	cell_capa[5] = MBO_ATTR_ID_CELL_DATA_CAPA;
804 	cell_capa[6] = mbo_cell_capa;
805 
806 	wpas_mbo_send_wnm_notification(wpa_s, cell_capa, 7);
807 	wpa_supplicant_set_default_scan_ies(wpa_s);
808 }
809 
810 
811 struct wpabuf * mbo_build_anqp_buf(struct wpa_supplicant *wpa_s,
812 				   struct wpa_bss *bss)
813 {
814 	struct wpabuf *anqp_buf;
815 	u8 *len_pos;
816 
817 	if (!wpa_bss_get_vendor_ie(bss, MBO_IE_VENDOR_TYPE)) {
818 		wpa_printf(MSG_INFO, "MBO: " MACSTR
819 			   " does not support MBO - cannot request MBO ANQP elements from it",
820 			   MAC2STR(bss->bssid));
821 		return NULL;
822 	}
823 
824 	anqp_buf = wpabuf_alloc(10);
825 	if (!anqp_buf)
826 		return NULL;
827 
828 	len_pos = gas_anqp_add_element(anqp_buf, ANQP_VENDOR_SPECIFIC);
829 	wpabuf_put_be24(anqp_buf, OUI_WFA);
830 	wpabuf_put_u8(anqp_buf, MBO_ANQP_OUI_TYPE);
831 
832 	wpabuf_put_u8(anqp_buf, MBO_ANQP_SUBTYPE_CELL_CONN_PREF);
833 	gas_anqp_set_element_len(anqp_buf, len_pos);
834 
835 	return anqp_buf;
836 }
837