xref: /linux/net/mac80211/spectmgmt.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 	struct {
151 		struct ieee80211_he_operation _oper;
152 		struct ieee80211_he_6ghz_oper _6ghz_oper;
153 	} __packed he;
154 	struct {
155 		struct ieee80211_eht_operation _oper;
156 		struct ieee80211_eht_operation_info _oper_info;
157 	} __packed eht;
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._oper.he_oper_params =
171 		le32_encode_bits(1, IEEE80211_HE_OPERATION_6GHZ_OP_INFO);
172 	he._6ghz_oper.primary =
173 		ieee80211_frequency_to_channel(control_freq);
174 	he._6ghz_oper.ccfs0 = ieee80211_frequency_to_channel(center_freq1);
175 	he._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 		he._6ghz_oper.ccfs1 = he._6ghz_oper.ccfs0;
181 		he._6ghz_oper.ccfs0 += control_freq < center_freq1 ? -16 : 16;
182 		he._6ghz_oper.control = IEEE80211_EHT_OPER_CHAN_WIDTH_320MHZ;
183 		break;
184 	case NL80211_CHAN_WIDTH_160:
185 		he._6ghz_oper.ccfs1 = he._6ghz_oper.ccfs0;
186 		he._6ghz_oper.ccfs0 += control_freq < center_freq1 ? -8 : 8;
187 		fallthrough;
188 	case NL80211_CHAN_WIDTH_80P80:
189 		he._6ghz_oper.control =
190 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_160MHZ;
191 		break;
192 	case NL80211_CHAN_WIDTH_80:
193 		he._6ghz_oper.control =
194 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_80MHZ;
195 		break;
196 	case NL80211_CHAN_WIDTH_40:
197 		he._6ghz_oper.control =
198 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_40MHZ;
199 		break;
200 	default:
201 		he._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._oper.params = IEEE80211_EHT_OPER_INFO_PRESENT;
210 		eht._oper_info.control = he._6ghz_oper.control;
211 		eht._oper_info.ccfs0 = he._6ghz_oper.ccfs0;
212 		eht._oper_info.ccfs1 = he._6ghz_oper.ccfs1;
213 		eht_oper = &eht._oper;
214 	}
215 
216 	if (!ieee80211_chandef_he_6ghz_oper(local, &he._oper,
217 					    eht_oper, chandef))
218 		chandef->chan = NULL;
219 }
220 
221 int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
222 				 struct ieee802_11_elems *elems,
223 				 enum nl80211_band current_band,
224 				 u32 vht_cap_info,
225 				 struct ieee80211_conn_settings *conn,
226 				 u8 *bssid, bool unprot_action,
227 				 struct ieee80211_csa_ie *csa_ie)
228 {
229 	enum nl80211_band new_band = current_band;
230 	int new_freq;
231 	u8 new_chan_no = 0, new_op_class = 0;
232 	struct ieee80211_channel *new_chan;
233 	struct cfg80211_chan_def new_chandef = {};
234 	const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
235 	const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
236 	const struct ieee80211_bandwidth_indication *bwi;
237 	const struct ieee80211_ext_chansw_ie *ext_chansw_elem;
238 	int secondary_channel_offset = -1;
239 
240 	memset(csa_ie, 0, sizeof(*csa_ie));
241 
242 	sec_chan_offs = elems->sec_chan_offs;
243 	wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
244 	bwi = elems->bandwidth_indication;
245 	ext_chansw_elem = elems->ext_chansw_ie;
246 
247 	if (conn->mode < IEEE80211_CONN_MODE_HT ||
248 	    conn->bw_limit < IEEE80211_CONN_BW_LIMIT_40) {
249 		sec_chan_offs = NULL;
250 		wide_bw_chansw_ie = NULL;
251 	}
252 
253 	if (conn->mode < IEEE80211_CONN_MODE_VHT)
254 		wide_bw_chansw_ie = NULL;
255 
256 	if (ext_chansw_elem) {
257 		new_op_class = ext_chansw_elem->new_operating_class;
258 
259 		if (!ieee80211_operating_class_to_band(new_op_class, &new_band)) {
260 			new_op_class = 0;
261 			if (!unprot_action)
262 				sdata_info(sdata,
263 					   "cannot understand ECSA IE operating class, %d, ignoring\n",
264 					   ext_chansw_elem->new_operating_class);
265 		} else {
266 			new_chan_no = ext_chansw_elem->new_ch_num;
267 			csa_ie->count = ext_chansw_elem->count;
268 			csa_ie->mode = ext_chansw_elem->mode;
269 		}
270 	}
271 
272 	if (!new_op_class && elems->ch_switch_ie) {
273 		new_chan_no = elems->ch_switch_ie->new_ch_num;
274 		csa_ie->count = elems->ch_switch_ie->count;
275 		csa_ie->mode = elems->ch_switch_ie->mode;
276 	}
277 
278 	/* nothing here we understand */
279 	if (!new_chan_no)
280 		return 1;
281 
282 	/* Mesh Channel Switch Parameters Element */
283 	if (elems->mesh_chansw_params_ie) {
284 		csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
285 		csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
286 		csa_ie->pre_value = le16_to_cpu(
287 				elems->mesh_chansw_params_ie->mesh_pre_value);
288 
289 		if (elems->mesh_chansw_params_ie->mesh_flags &
290 				WLAN_EID_CHAN_SWITCH_PARAM_REASON)
291 			csa_ie->reason_code = le16_to_cpu(
292 				elems->mesh_chansw_params_ie->mesh_reason);
293 	}
294 
295 	new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
296 	new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
297 	if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
298 		if (!unprot_action)
299 			sdata_info(sdata,
300 				   "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
301 				   bssid, new_freq);
302 		return -EINVAL;
303 	}
304 
305 	if (sec_chan_offs) {
306 		secondary_channel_offset = sec_chan_offs->sec_chan_offs;
307 	} else if (conn->mode >= IEEE80211_CONN_MODE_HT) {
308 		/* If the secondary channel offset IE is not present,
309 		 * we can't know what's the post-CSA offset, so the
310 		 * best we can do is use 20MHz.
311 		*/
312 		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
313 	}
314 
315 	switch (secondary_channel_offset) {
316 	default:
317 		/* secondary_channel_offset was present but is invalid */
318 	case IEEE80211_HT_PARAM_CHA_SEC_NONE:
319 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
320 					NL80211_CHAN_HT20);
321 		break;
322 	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
323 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
324 					NL80211_CHAN_HT40PLUS);
325 		break;
326 	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
327 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
328 					NL80211_CHAN_HT40MINUS);
329 		break;
330 	case -1:
331 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
332 					NL80211_CHAN_NO_HT);
333 		/* keep width for 5/10 MHz channels */
334 		switch (sdata->vif.bss_conf.chanreq.oper.width) {
335 		case NL80211_CHAN_WIDTH_5:
336 		case NL80211_CHAN_WIDTH_10:
337 			csa_ie->chanreq.oper.width =
338 				sdata->vif.bss_conf.chanreq.oper.width;
339 			break;
340 		default:
341 			break;
342 		}
343 		break;
344 	}
345 
346 	/* capture the AP configuration */
347 	csa_ie->chanreq.ap = csa_ie->chanreq.oper;
348 
349 	/* parse one of the Elements to build a new chandef */
350 	memset(&new_chandef, 0, sizeof(new_chandef));
351 	new_chandef.chan = new_chan;
352 	if (bwi) {
353 		/* start with the CSA one */
354 		new_chandef = csa_ie->chanreq.oper;
355 		/* and update the width accordingly */
356 		ieee80211_chandef_eht_oper(&bwi->info, &new_chandef);
357 
358 		if (bwi->params & IEEE80211_BW_IND_DIS_SUBCH_PRESENT)
359 			new_chandef.punctured =
360 				get_unaligned_le16(bwi->info.optional);
361 	} else if (!wide_bw_chansw_ie || !wbcs_elem_to_chandef(wide_bw_chansw_ie,
362 							       &new_chandef)) {
363 		if (!ieee80211_operating_class_to_chandef(new_op_class, new_chan,
364 							  &new_chandef))
365 			new_chandef = csa_ie->chanreq.oper;
366 	}
367 
368 	/* check if the new chandef fits the capabilities */
369 	if (new_band == NL80211_BAND_6GHZ)
370 		validate_chandef_by_6ghz_he_eht_oper(sdata, conn, &new_chandef);
371 	else
372 		validate_chandef_by_ht_vht_oper(sdata, conn, vht_cap_info,
373 						&new_chandef);
374 
375 	/* if data is there validate the bandwidth & use it */
376 	if (new_chandef.chan) {
377 		/* capture the AP chandef before (potential) downgrading */
378 		csa_ie->chanreq.ap = new_chandef;
379 
380 		while (conn->bw_limit <
381 			       ieee80211_min_bw_limit_from_chandef(&new_chandef))
382 			ieee80211_chandef_downgrade(&new_chandef, NULL);
383 
384 		if (!cfg80211_chandef_compatible(&new_chandef,
385 						 &csa_ie->chanreq.oper)) {
386 			sdata_info(sdata,
387 				   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
388 				   bssid);
389 			return -EINVAL;
390 		}
391 
392 		csa_ie->chanreq.oper = new_chandef;
393 	}
394 
395 	if (elems->max_channel_switch_time)
396 		csa_ie->max_switch_time =
397 			(elems->max_channel_switch_time[0] << 0) |
398 			(elems->max_channel_switch_time[1] <<  8) |
399 			(elems->max_channel_switch_time[2] << 16);
400 
401 	return 0;
402 }
403 
404 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
405 					struct ieee80211_msrment_ie *request_ie,
406 					const u8 *da, const u8 *bssid,
407 					u8 dialog_token)
408 {
409 	struct ieee80211_local *local = sdata->local;
410 	struct sk_buff *skb;
411 	struct ieee80211_mgmt *msr_report;
412 
413 	skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
414 				sizeof(struct ieee80211_msrment_ie));
415 	if (!skb)
416 		return;
417 
418 	skb_reserve(skb, local->hw.extra_tx_headroom);
419 	msr_report = skb_put_zero(skb, 24);
420 	memcpy(msr_report->da, da, ETH_ALEN);
421 	memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
422 	memcpy(msr_report->bssid, bssid, ETH_ALEN);
423 	msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
424 						IEEE80211_STYPE_ACTION);
425 
426 	skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
427 	msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
428 	msr_report->u.action.u.measurement.action_code =
429 				WLAN_ACTION_SPCT_MSR_RPRT;
430 	msr_report->u.action.u.measurement.dialog_token = dialog_token;
431 
432 	msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
433 	msr_report->u.action.u.measurement.length =
434 			sizeof(struct ieee80211_msrment_ie);
435 
436 	memset(&msr_report->u.action.u.measurement.msr_elem, 0,
437 		sizeof(struct ieee80211_msrment_ie));
438 	msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
439 	msr_report->u.action.u.measurement.msr_elem.mode |=
440 			IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
441 	msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
442 
443 	ieee80211_tx_skb(sdata, skb);
444 }
445 
446 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
447 				       struct ieee80211_mgmt *mgmt,
448 				       size_t len)
449 {
450 	/*
451 	 * Ignoring measurement request is spec violation.
452 	 * Mandatory measurements must be reported optional
453 	 * measurements might be refused or reported incapable
454 	 * For now just refuse
455 	 * TODO: Answer basic measurement as unmeasured
456 	 */
457 	ieee80211_send_refuse_measurement_request(sdata,
458 			&mgmt->u.action.u.measurement.msr_elem,
459 			mgmt->sa, mgmt->bssid,
460 			mgmt->u.action.u.measurement.dialog_token);
461 }
462