xref: /linux/net/mac80211/spectmgmt.c (revision 40d269c000bda9fcd276a0412a9cebd3f6e344c5)
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, 2022-2023 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 
159 	if (conn->mode < IEEE80211_CONN_MODE_HE) {
160 		chandef->chan = NULL;
161 		return;
162 	}
163 
164 	control_freq = chandef->chan->center_freq;
165 	center_freq1 = chandef->center_freq1;
166 	center_freq2 = chandef->center_freq2;
167 	chan_width = chandef->width;
168 
169 	he._oper.he_oper_params =
170 		le32_encode_bits(1, IEEE80211_HE_OPERATION_6GHZ_OP_INFO);
171 	he._6ghz_oper.primary =
172 		ieee80211_frequency_to_channel(control_freq);
173 	he._6ghz_oper.ccfs0 = ieee80211_frequency_to_channel(center_freq1);
174 	he._6ghz_oper.ccfs1 = center_freq2 ?
175 		ieee80211_frequency_to_channel(center_freq2) : 0;
176 
177 	switch (chan_width) {
178 	case NL80211_CHAN_WIDTH_320:
179 		he._6ghz_oper.ccfs1 = he._6ghz_oper.ccfs0;
180 		he._6ghz_oper.ccfs0 += control_freq < center_freq1 ? -16 : 16;
181 		he._6ghz_oper.control = IEEE80211_EHT_OPER_CHAN_WIDTH_320MHZ;
182 		break;
183 	case NL80211_CHAN_WIDTH_160:
184 		he._6ghz_oper.ccfs1 = he._6ghz_oper.ccfs0;
185 		he._6ghz_oper.ccfs0 += control_freq < center_freq1 ? -8 : 8;
186 		fallthrough;
187 	case NL80211_CHAN_WIDTH_80P80:
188 		he._6ghz_oper.control =
189 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_160MHZ;
190 		break;
191 	case NL80211_CHAN_WIDTH_80:
192 		he._6ghz_oper.control =
193 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_80MHZ;
194 		break;
195 	case NL80211_CHAN_WIDTH_40:
196 		he._6ghz_oper.control =
197 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_40MHZ;
198 		break;
199 	default:
200 		he._6ghz_oper.control =
201 			IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_20MHZ;
202 		break;
203 	}
204 
205 	if (conn->mode < IEEE80211_CONN_MODE_EHT) {
206 		if (!ieee80211_chandef_he_6ghz_oper(local, &he._oper,
207 						    NULL, chandef))
208 			chandef->chan = NULL;
209 	} else {
210 		eht._oper.params = IEEE80211_EHT_OPER_INFO_PRESENT;
211 		eht._oper_info.control = he._6ghz_oper.control;
212 		eht._oper_info.ccfs0 = he._6ghz_oper.ccfs0;
213 		eht._oper_info.ccfs1 = he._6ghz_oper.ccfs1;
214 
215 		if (!ieee80211_chandef_he_6ghz_oper(local, &he._oper,
216 						    &eht._oper, chandef))
217 			chandef->chan = NULL;
218 	}
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,
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 			sdata_info(sdata, "cannot understand ECSA IE operating class, %d, ignoring\n",
262 				   ext_chansw_elem->new_operating_class);
263 		} else {
264 			new_chan_no = ext_chansw_elem->new_ch_num;
265 			csa_ie->count = ext_chansw_elem->count;
266 			csa_ie->mode = ext_chansw_elem->mode;
267 		}
268 	}
269 
270 	if (!new_op_class && elems->ch_switch_ie) {
271 		new_chan_no = elems->ch_switch_ie->new_ch_num;
272 		csa_ie->count = elems->ch_switch_ie->count;
273 		csa_ie->mode = elems->ch_switch_ie->mode;
274 	}
275 
276 	/* nothing here we understand */
277 	if (!new_chan_no)
278 		return 1;
279 
280 	/* Mesh Channel Switch Parameters Element */
281 	if (elems->mesh_chansw_params_ie) {
282 		csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
283 		csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
284 		csa_ie->pre_value = le16_to_cpu(
285 				elems->mesh_chansw_params_ie->mesh_pre_value);
286 
287 		if (elems->mesh_chansw_params_ie->mesh_flags &
288 				WLAN_EID_CHAN_SWITCH_PARAM_REASON)
289 			csa_ie->reason_code = le16_to_cpu(
290 				elems->mesh_chansw_params_ie->mesh_reason);
291 	}
292 
293 	new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
294 	new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
295 	if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
296 		sdata_info(sdata,
297 			   "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
298 			   bssid, new_freq);
299 		return -EINVAL;
300 	}
301 
302 	if (sec_chan_offs) {
303 		secondary_channel_offset = sec_chan_offs->sec_chan_offs;
304 	} else if (conn->mode >= IEEE80211_CONN_MODE_HT) {
305 		/* If the secondary channel offset IE is not present,
306 		 * we can't know what's the post-CSA offset, so the
307 		 * best we can do is use 20MHz.
308 		*/
309 		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
310 	}
311 
312 	switch (secondary_channel_offset) {
313 	default:
314 		/* secondary_channel_offset was present but is invalid */
315 	case IEEE80211_HT_PARAM_CHA_SEC_NONE:
316 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
317 					NL80211_CHAN_HT20);
318 		break;
319 	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
320 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
321 					NL80211_CHAN_HT40PLUS);
322 		break;
323 	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
324 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
325 					NL80211_CHAN_HT40MINUS);
326 		break;
327 	case -1:
328 		cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
329 					NL80211_CHAN_NO_HT);
330 		/* keep width for 5/10 MHz channels */
331 		switch (sdata->vif.bss_conf.chanreq.oper.width) {
332 		case NL80211_CHAN_WIDTH_5:
333 		case NL80211_CHAN_WIDTH_10:
334 			csa_ie->chanreq.oper.width =
335 				sdata->vif.bss_conf.chanreq.oper.width;
336 			break;
337 		default:
338 			break;
339 		}
340 		break;
341 	}
342 
343 	/* parse one of the Elements to build a new chandef */
344 	memset(&new_chandef, 0, sizeof(new_chandef));
345 	new_chandef.chan = new_chan;
346 	if (bwi) {
347 		/* start with the CSA one */
348 		new_chandef = csa_ie->chanreq.oper;
349 		/* and update the width accordingly */
350 		ieee80211_chandef_eht_oper(&bwi->info, &new_chandef);
351 	} else if (!wide_bw_chansw_ie || !wbcs_elem_to_chandef(wide_bw_chansw_ie,
352 							       &new_chandef)) {
353 		if (!ieee80211_operating_class_to_chandef(new_op_class, new_chan,
354 							  &new_chandef))
355 			new_chandef = csa_ie->chanreq.oper;
356 	}
357 
358 	/* check if the new chandef fits the capabilities */
359 	if (new_band == NL80211_BAND_6GHZ)
360 		validate_chandef_by_6ghz_he_eht_oper(sdata, conn, &new_chandef);
361 	else
362 		validate_chandef_by_ht_vht_oper(sdata, conn, vht_cap_info,
363 						&new_chandef);
364 
365 	/* if data is there validate the bandwidth & use it */
366 	if (new_chandef.chan) {
367 		if (conn->bw_limit < IEEE80211_CONN_BW_LIMIT_320 &&
368 		    new_chandef.width == NL80211_CHAN_WIDTH_320)
369 			ieee80211_chandef_downgrade(&new_chandef, NULL);
370 
371 		if (conn->bw_limit < IEEE80211_CONN_BW_LIMIT_160 &&
372 		    (new_chandef.width == NL80211_CHAN_WIDTH_80P80 ||
373 		     new_chandef.width == NL80211_CHAN_WIDTH_160))
374 			ieee80211_chandef_downgrade(&new_chandef, NULL);
375 
376 		if (!cfg80211_chandef_compatible(&new_chandef,
377 						 &csa_ie->chanreq.oper)) {
378 			sdata_info(sdata,
379 				   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
380 				   bssid);
381 			return -EINVAL;
382 		}
383 
384 		csa_ie->chanreq.oper = new_chandef;
385 	}
386 
387 	if (elems->max_channel_switch_time)
388 		csa_ie->max_switch_time =
389 			(elems->max_channel_switch_time[0] << 0) |
390 			(elems->max_channel_switch_time[1] <<  8) |
391 			(elems->max_channel_switch_time[2] << 16);
392 
393 	return 0;
394 }
395 
396 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
397 					struct ieee80211_msrment_ie *request_ie,
398 					const u8 *da, const u8 *bssid,
399 					u8 dialog_token)
400 {
401 	struct ieee80211_local *local = sdata->local;
402 	struct sk_buff *skb;
403 	struct ieee80211_mgmt *msr_report;
404 
405 	skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
406 				sizeof(struct ieee80211_msrment_ie));
407 	if (!skb)
408 		return;
409 
410 	skb_reserve(skb, local->hw.extra_tx_headroom);
411 	msr_report = skb_put_zero(skb, 24);
412 	memcpy(msr_report->da, da, ETH_ALEN);
413 	memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
414 	memcpy(msr_report->bssid, bssid, ETH_ALEN);
415 	msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
416 						IEEE80211_STYPE_ACTION);
417 
418 	skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
419 	msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
420 	msr_report->u.action.u.measurement.action_code =
421 				WLAN_ACTION_SPCT_MSR_RPRT;
422 	msr_report->u.action.u.measurement.dialog_token = dialog_token;
423 
424 	msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
425 	msr_report->u.action.u.measurement.length =
426 			sizeof(struct ieee80211_msrment_ie);
427 
428 	memset(&msr_report->u.action.u.measurement.msr_elem, 0,
429 		sizeof(struct ieee80211_msrment_ie));
430 	msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
431 	msr_report->u.action.u.measurement.msr_elem.mode |=
432 			IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
433 	msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
434 
435 	ieee80211_tx_skb(sdata, skb);
436 }
437 
438 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
439 				       struct ieee80211_mgmt *mgmt,
440 				       size_t len)
441 {
442 	/*
443 	 * Ignoring measurement request is spec violation.
444 	 * Mandatory measurements must be reported optional
445 	 * measurements might be refused or reported incapable
446 	 * For now just refuse
447 	 * TODO: Answer basic measurement as unmeasured
448 	 */
449 	ieee80211_send_refuse_measurement_request(sdata,
450 			&mgmt->u.action.u.measurement.msr_elem,
451 			mgmt->sa, mgmt->bssid,
452 			mgmt->u.action.u.measurement.dialog_token);
453 }
454