xref: /linux/net/mac80211/spectmgmt.c (revision bca5cfbb694d66a1c482d0c347eee80f6afbc870)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * spectrum management
4  *
5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6  * Copyright 2002-2005, Instant802 Networks, Inc.
7  * Copyright 2005-2006, Devicescape Software, Inc.
8  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10  * Copyright 2007-2008, Intel Corporation
11  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
12  * Copyright (C) 2018, 2020, 2022-2024 Intel Corporation
13  */
14 
15 #include <linux/ieee80211.h>
16 #include <net/cfg80211.h>
17 #include <net/mac80211.h>
18 #include "ieee80211_i.h"
19 #include "sta_info.h"
20 #include "wme.h"
21 
22 static bool
23 wbcs_elem_to_chandef(const struct ieee80211_wide_bw_chansw_ie *wbcs_elem,
24 		     struct cfg80211_chan_def *chandef)
25 {
26 	u8 ccfs0 = wbcs_elem->new_center_freq_seg0;
27 	u8 ccfs1 = wbcs_elem->new_center_freq_seg1;
28 	u32 cf0 = ieee80211_channel_to_frequency(ccfs0, chandef->chan->band);
29 	u32 cf1 = ieee80211_channel_to_frequency(ccfs1, chandef->chan->band);
30 
31 	switch (wbcs_elem->new_channel_width) {
32 	case IEEE80211_VHT_CHANWIDTH_160MHZ:
33 		/* deprecated encoding */
34 		chandef->width = NL80211_CHAN_WIDTH_160;
35 		chandef->center_freq1 = cf0;
36 		break;
37 	case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
38 		/* deprecated encoding */
39 		chandef->width = NL80211_CHAN_WIDTH_80P80;
40 		chandef->center_freq1 = cf0;
41 		chandef->center_freq2 = cf1;
42 		break;
43 	case IEEE80211_VHT_CHANWIDTH_80MHZ:
44 		chandef->width = NL80211_CHAN_WIDTH_80;
45 		chandef->center_freq1 = cf0;
46 
47 		if (ccfs1) {
48 			u8 diff = abs(ccfs0 - ccfs1);
49 
50 			if (diff == 8) {
51 				chandef->width = NL80211_CHAN_WIDTH_160;
52 				chandef->center_freq1 = cf1;
53 			} else if (diff > 8) {
54 				chandef->width = NL80211_CHAN_WIDTH_80P80;
55 				chandef->center_freq2 = cf1;
56 			}
57 		}
58 		break;
59 	case IEEE80211_VHT_CHANWIDTH_USE_HT:
60 	default:
61 		/* If the WBCS Element is present, new channel bandwidth is
62 		 * at least 40 MHz.
63 		 */
64 		chandef->width = NL80211_CHAN_WIDTH_40;
65 		chandef->center_freq1 = cf0;
66 		break;
67 	}
68 
69 	return cfg80211_chandef_valid(chandef);
70 }
71 
72 static void
73 validate_chandef_by_ht_vht_oper(struct ieee80211_sub_if_data *sdata,
74 				struct ieee80211_conn_settings *conn,
75 				u32 vht_cap_info,
76 				struct cfg80211_chan_def *chandef)
77 {
78 	u32 control_freq, center_freq1, center_freq2;
79 	enum nl80211_chan_width chan_width;
80 	struct ieee80211_ht_operation ht_oper;
81 	struct ieee80211_vht_operation vht_oper;
82 
83 	if (conn->mode < IEEE80211_CONN_MODE_HT ||
84 	    conn->bw_limit < IEEE80211_CONN_BW_LIMIT_40) {
85 		chandef->chan = NULL;
86 		return;
87 	}
88 
89 	control_freq = chandef->chan->center_freq;
90 	center_freq1 = chandef->center_freq1;
91 	center_freq2 = chandef->center_freq2;
92 	chan_width = chandef->width;
93 
94 	ht_oper.primary_chan = ieee80211_frequency_to_channel(control_freq);
95 	if (control_freq != center_freq1)
96 		ht_oper.ht_param = control_freq > center_freq1 ?
97 			IEEE80211_HT_PARAM_CHA_SEC_BELOW :
98 			IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
99 	else
100 		ht_oper.ht_param = IEEE80211_HT_PARAM_CHA_SEC_NONE;
101 
102 	ieee80211_chandef_ht_oper(&ht_oper, chandef);
103 
104 	if (conn->mode < IEEE80211_CONN_MODE_VHT)
105 		return;
106 
107 	vht_oper.center_freq_seg0_idx =
108 		ieee80211_frequency_to_channel(center_freq1);
109 	vht_oper.center_freq_seg1_idx = center_freq2 ?
110 		ieee80211_frequency_to_channel(center_freq2) : 0;
111 
112 	switch (chan_width) {
113 	case NL80211_CHAN_WIDTH_320:
114 		WARN_ON(1);
115 		break;
116 	case NL80211_CHAN_WIDTH_160:
117 		vht_oper.chan_width = IEEE80211_VHT_CHANWIDTH_80MHZ;
118 		vht_oper.center_freq_seg1_idx = vht_oper.center_freq_seg0_idx;
119 		vht_oper.center_freq_seg0_idx +=
120 			control_freq < center_freq1 ? -8 : 8;
121 		break;
122 	case NL80211_CHAN_WIDTH_80P80:
123 		vht_oper.chan_width = IEEE80211_VHT_CHANWIDTH_80MHZ;
124 		break;
125 	case NL80211_CHAN_WIDTH_80:
126 		vht_oper.chan_width = IEEE80211_VHT_CHANWIDTH_80MHZ;
127 		break;
128 	default:
129 		vht_oper.chan_width = IEEE80211_VHT_CHANWIDTH_USE_HT;
130 		break;
131 	}
132 
133 	ht_oper.operation_mode =
134 		le16_encode_bits(vht_oper.center_freq_seg1_idx,
135 				 IEEE80211_HT_OP_MODE_CCFS2_MASK);
136 
137 	if (!ieee80211_chandef_vht_oper(&sdata->local->hw, vht_cap_info,
138 					&vht_oper, &ht_oper, chandef))
139 		chandef->chan = NULL;
140 }
141 
142 static void
143 validate_chandef_by_6ghz_he_eht_oper(struct ieee80211_sub_if_data *sdata,
144 				     struct ieee80211_conn_settings *conn,
145 				     struct cfg80211_chan_def *chandef)
146 {
147 	struct ieee80211_local *local = sdata->local;
148 	u32 control_freq, center_freq1, center_freq2;
149 	enum nl80211_chan_width chan_width;
150 	DEFINE_RAW_FLEX(struct ieee80211_he_operation, he, optional,
151 			sizeof(struct ieee80211_he_6ghz_oper));
152 	struct ieee80211_he_6ghz_oper *_6ghz_oper =
153 				(struct ieee80211_he_6ghz_oper *)he->optional;
154 	DEFINE_RAW_FLEX(struct ieee80211_eht_operation, eht, optional,
155 			sizeof(struct ieee80211_eht_operation_info));
156 	struct ieee80211_eht_operation_info *_oper_info =
157 			(struct ieee80211_eht_operation_info *)eht->optional;
158 	const struct ieee80211_eht_operation *eht_oper;
159 
160 	if (conn->mode < IEEE80211_CONN_MODE_HE) {
161 		chandef->chan = NULL;
162 		return;
163 	}
164 
165 	control_freq = chandef->chan->center_freq;
166 	center_freq1 = chandef->center_freq1;
167 	center_freq2 = chandef->center_freq2;
168 	chan_width = chandef->width;
169 
170 	he->he_oper_params =
171 		le32_encode_bits(1, IEEE80211_HE_OPERATION_6GHZ_OP_INFO);
172 	_6ghz_oper->primary =
173 		ieee80211_frequency_to_channel(control_freq);
174 	_6ghz_oper->ccfs0 = ieee80211_frequency_to_channel(center_freq1);
175 	_6ghz_oper->ccfs1 = center_freq2 ?
176 		ieee80211_frequency_to_channel(center_freq2) : 0;
177 
178 	switch (chan_width) {
179 	case NL80211_CHAN_WIDTH_320:
180 		_6ghz_oper->ccfs1 = _6ghz_oper->ccfs0;
181 		_6ghz_oper->ccfs0 += control_freq < center_freq1 ? -16 : 16;
182 		_6ghz_oper->control = IEEE80211_EHT_OPER_CHAN_WIDTH_320MHZ;
183 		break;
184 	case NL80211_CHAN_WIDTH_160:
185 		_6ghz_oper->ccfs1 = _6ghz_oper->ccfs0;
186 		_6ghz_oper->ccfs0 += control_freq < center_freq1 ? -8 : 8;
187 		fallthrough;
188 	case NL80211_CHAN_WIDTH_80P80:
189 		_6ghz_oper->control =
190 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_160MHZ;
191 		break;
192 	case NL80211_CHAN_WIDTH_80:
193 		_6ghz_oper->control =
194 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_80MHZ;
195 		break;
196 	case NL80211_CHAN_WIDTH_40:
197 		_6ghz_oper->control =
198 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_40MHZ;
199 		break;
200 	default:
201 		_6ghz_oper->control =
202 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_20MHZ;
203 		break;
204 	}
205 
206 	if (conn->mode < IEEE80211_CONN_MODE_EHT) {
207 		eht_oper = NULL;
208 	} else {
209 		eht->params = IEEE80211_EHT_OPER_INFO_PRESENT;
210 		_oper_info->control = _6ghz_oper->control;
211 		_oper_info->ccfs0 = _6ghz_oper->ccfs0;
212 		_oper_info->ccfs1 = _6ghz_oper->ccfs1;
213 		eht_oper = eht;
214 	}
215 
216 	if (!ieee80211_chandef_he_6ghz_oper(local, he, eht_oper, chandef))
217 		chandef->chan = NULL;
218 }
219 
220 int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
221 				 struct ieee802_11_elems *elems,
222 				 enum nl80211_band current_band,
223 				 u32 vht_cap_info,
224 				 struct ieee80211_conn_settings *conn,
225 				 u8 *bssid, bool unprot_action,
226 				 struct ieee80211_csa_ie *csa_ie)
227 {
228 	enum nl80211_band new_band = current_band;
229 	int new_freq;
230 	u8 new_chan_no = 0, new_op_class = 0;
231 	struct ieee80211_channel *new_chan;
232 	struct cfg80211_chan_def new_chandef = {};
233 	const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
234 	const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
235 	const struct ieee80211_bandwidth_indication *bwi;
236 	const struct ieee80211_ext_chansw_ie *ext_chansw_elem;
237 	int secondary_channel_offset = -1;
238 
239 	memset(csa_ie, 0, sizeof(*csa_ie));
240 
241 	sec_chan_offs = elems->sec_chan_offs;
242 	wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
243 	bwi = elems->bandwidth_indication;
244 	ext_chansw_elem = elems->ext_chansw_ie;
245 
246 	if (conn->mode < IEEE80211_CONN_MODE_HT ||
247 	    conn->bw_limit < IEEE80211_CONN_BW_LIMIT_40) {
248 		sec_chan_offs = NULL;
249 		wide_bw_chansw_ie = NULL;
250 	}
251 
252 	if (conn->mode < IEEE80211_CONN_MODE_VHT)
253 		wide_bw_chansw_ie = NULL;
254 
255 	if (ext_chansw_elem) {
256 		new_op_class = ext_chansw_elem->new_operating_class;
257 
258 		if (!ieee80211_operating_class_to_band(new_op_class, &new_band)) {
259 			new_op_class = 0;
260 			if (!unprot_action)
261 				sdata_info(sdata,
262 					   "cannot understand ECSA IE operating class, %d, ignoring\n",
263 					   ext_chansw_elem->new_operating_class);
264 		} else {
265 			new_chan_no = ext_chansw_elem->new_ch_num;
266 			csa_ie->count = ext_chansw_elem->count;
267 			csa_ie->mode = ext_chansw_elem->mode;
268 		}
269 	}
270 
271 	if (!new_op_class && elems->ch_switch_ie) {
272 		new_chan_no = elems->ch_switch_ie->new_ch_num;
273 		csa_ie->count = elems->ch_switch_ie->count;
274 		csa_ie->mode = elems->ch_switch_ie->mode;
275 	}
276 
277 	/* nothing here we understand */
278 	if (!new_chan_no)
279 		return 1;
280 
281 	/* Mesh Channel Switch Parameters Element */
282 	if (elems->mesh_chansw_params_ie) {
283 		csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
284 		csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
285 		csa_ie->pre_value = le16_to_cpu(
286 				elems->mesh_chansw_params_ie->mesh_pre_value);
287 
288 		if (elems->mesh_chansw_params_ie->mesh_flags &
289 				WLAN_EID_CHAN_SWITCH_PARAM_REASON)
290 			csa_ie->reason_code = le16_to_cpu(
291 				elems->mesh_chansw_params_ie->mesh_reason);
292 	}
293 
294 	new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
295 	new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
296 	if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
297 		if (!unprot_action)
298 			sdata_info(sdata,
299 				   "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
300 				   bssid, new_freq);
301 		return -EINVAL;
302 	}
303 
304 	if (sec_chan_offs) {
305 		secondary_channel_offset = sec_chan_offs->sec_chan_offs;
306 	} else if (conn->mode >= IEEE80211_CONN_MODE_HT) {
307 		/* If the secondary channel offset IE is not present,
308 		 * we can't know what's the post-CSA offset, so the
309 		 * best we can do is use 20MHz.
310 		*/
311 		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
312 	}
313 
314 	switch (secondary_channel_offset) {
315 	default:
316 		/* secondary_channel_offset was present but is invalid */
317 	case IEEE80211_HT_PARAM_CHA_SEC_NONE:
318 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
319 					NL80211_CHAN_HT20);
320 		break;
321 	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
322 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
323 					NL80211_CHAN_HT40PLUS);
324 		break;
325 	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
326 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
327 					NL80211_CHAN_HT40MINUS);
328 		break;
329 	case -1:
330 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
331 					NL80211_CHAN_NO_HT);
332 		/* keep width for 5/10 MHz channels */
333 		switch (sdata->vif.bss_conf.chanreq.oper.width) {
334 		case NL80211_CHAN_WIDTH_5:
335 		case NL80211_CHAN_WIDTH_10:
336 			csa_ie->chanreq.oper.width =
337 				sdata->vif.bss_conf.chanreq.oper.width;
338 			break;
339 		default:
340 			break;
341 		}
342 		break;
343 	}
344 
345 	/* capture the AP configuration */
346 	csa_ie->chanreq.ap = csa_ie->chanreq.oper;
347 
348 	/* parse one of the Elements to build a new chandef */
349 	memset(&new_chandef, 0, sizeof(new_chandef));
350 	new_chandef.chan = new_chan;
351 	if (bwi) {
352 		/* start with the CSA one */
353 		new_chandef = csa_ie->chanreq.oper;
354 		/* and update the width accordingly */
355 		ieee80211_chandef_eht_oper(&bwi->info, &new_chandef);
356 
357 		if (bwi->params & IEEE80211_BW_IND_DIS_SUBCH_PRESENT)
358 			new_chandef.punctured =
359 				get_unaligned_le16(bwi->info.optional);
360 	} else if (!wide_bw_chansw_ie || !wbcs_elem_to_chandef(wide_bw_chansw_ie,
361 							       &new_chandef)) {
362 		if (!ieee80211_operating_class_to_chandef(new_op_class, new_chan,
363 							  &new_chandef))
364 			new_chandef = csa_ie->chanreq.oper;
365 	}
366 
367 	/* check if the new chandef fits the capabilities */
368 	if (new_band == NL80211_BAND_6GHZ)
369 		validate_chandef_by_6ghz_he_eht_oper(sdata, conn, &new_chandef);
370 	else
371 		validate_chandef_by_ht_vht_oper(sdata, conn, vht_cap_info,
372 						&new_chandef);
373 
374 	/* if data is there validate the bandwidth & use it */
375 	if (new_chandef.chan) {
376 		/* capture the AP chandef before (potential) downgrading */
377 		csa_ie->chanreq.ap = new_chandef;
378 
379 		while (conn->bw_limit <
380 			       ieee80211_min_bw_limit_from_chandef(&new_chandef))
381 			ieee80211_chandef_downgrade(&new_chandef, NULL);
382 
383 		if (!cfg80211_chandef_compatible(&new_chandef,
384 						 &csa_ie->chanreq.oper)) {
385 			sdata_info(sdata,
386 				   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
387 				   bssid);
388 			return -EINVAL;
389 		}
390 
391 		csa_ie->chanreq.oper = new_chandef;
392 	}
393 
394 	if (elems->max_channel_switch_time)
395 		csa_ie->max_switch_time =
396 			(elems->max_channel_switch_time[0] << 0) |
397 			(elems->max_channel_switch_time[1] <<  8) |
398 			(elems->max_channel_switch_time[2] << 16);
399 
400 	return 0;
401 }
402 
403 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
404 					struct ieee80211_msrment_ie *request_ie,
405 					const u8 *da, const u8 *bssid,
406 					u8 dialog_token)
407 {
408 	struct ieee80211_local *local = sdata->local;
409 	struct sk_buff *skb;
410 	struct ieee80211_mgmt *msr_report;
411 
412 	skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
413 				sizeof(struct ieee80211_msrment_ie));
414 	if (!skb)
415 		return;
416 
417 	skb_reserve(skb, local->hw.extra_tx_headroom);
418 	msr_report = skb_put_zero(skb, 24);
419 	memcpy(msr_report->da, da, ETH_ALEN);
420 	memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
421 	memcpy(msr_report->bssid, bssid, ETH_ALEN);
422 	msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
423 						IEEE80211_STYPE_ACTION);
424 
425 	skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
426 	msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
427 	msr_report->u.action.u.measurement.action_code =
428 				WLAN_ACTION_SPCT_MSR_RPRT;
429 	msr_report->u.action.u.measurement.dialog_token = dialog_token;
430 
431 	msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
432 	msr_report->u.action.u.measurement.length =
433 			sizeof(struct ieee80211_msrment_ie);
434 
435 	memset(&msr_report->u.action.u.measurement.msr_elem, 0,
436 		sizeof(struct ieee80211_msrment_ie));
437 	msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
438 	msr_report->u.action.u.measurement.msr_elem.mode |=
439 			IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
440 	msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
441 
442 	ieee80211_tx_skb(sdata, skb);
443 }
444 
445 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
446 				       struct ieee80211_mgmt *mgmt,
447 				       size_t len)
448 {
449 	/*
450 	 * Ignoring measurement request is spec violation.
451 	 * Mandatory measurements must be reported optional
452 	 * measurements might be refused or reported incapable
453 	 * For now just refuse
454 	 * TODO: Answer basic measurement as unmeasured
455 	 */
456 	ieee80211_send_refuse_measurement_request(sdata,
457 			&mgmt->u.action.u.measurement.msr_elem,
458 			mgmt->sa, mgmt->bssid,
459 			mgmt->u.action.u.measurement.dialog_token);
460 }
461