xref: /linux/net/mac80211/spectmgmt.c (revision 576d7fed09c7edbae7600f29a8a3ed6c1ead904f)
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 int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
23 				 struct ieee802_11_elems *elems,
24 				 enum nl80211_band current_band,
25 				 u32 vht_cap_info,
26 				 ieee80211_conn_flags_t conn_flags, u8 *bssid,
27 				 struct ieee80211_csa_ie *csa_ie)
28 {
29 	enum nl80211_band new_band = current_band;
30 	int new_freq;
31 	u8 new_chan_no;
32 	struct ieee80211_channel *new_chan;
33 	struct cfg80211_chan_def new_vht_chandef = {};
34 	const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
35 	const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
36 	const struct ieee80211_bandwidth_indication *bwi;
37 	int secondary_channel_offset = -1;
38 
39 	memset(csa_ie, 0, sizeof(*csa_ie));
40 
41 	sec_chan_offs = elems->sec_chan_offs;
42 	wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
43 	bwi = elems->bandwidth_indication;
44 
45 	if (conn_flags & (IEEE80211_CONN_DISABLE_HT |
46 			  IEEE80211_CONN_DISABLE_40MHZ)) {
47 		sec_chan_offs = NULL;
48 		wide_bw_chansw_ie = NULL;
49 	}
50 
51 	if (conn_flags & IEEE80211_CONN_DISABLE_VHT)
52 		wide_bw_chansw_ie = NULL;
53 
54 	if (elems->ext_chansw_ie) {
55 		if (!ieee80211_operating_class_to_band(
56 				elems->ext_chansw_ie->new_operating_class,
57 				&new_band)) {
58 			sdata_info(sdata,
59 				   "cannot understand ECSA IE operating class, %d, ignoring\n",
60 				   elems->ext_chansw_ie->new_operating_class);
61 		}
62 		new_chan_no = elems->ext_chansw_ie->new_ch_num;
63 		csa_ie->count = elems->ext_chansw_ie->count;
64 		csa_ie->mode = elems->ext_chansw_ie->mode;
65 	} else if (elems->ch_switch_ie) {
66 		new_chan_no = elems->ch_switch_ie->new_ch_num;
67 		csa_ie->count = elems->ch_switch_ie->count;
68 		csa_ie->mode = elems->ch_switch_ie->mode;
69 	} else {
70 		/* nothing here we understand */
71 		return 1;
72 	}
73 
74 	/* Mesh Channel Switch Parameters Element */
75 	if (elems->mesh_chansw_params_ie) {
76 		csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
77 		csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
78 		csa_ie->pre_value = le16_to_cpu(
79 				elems->mesh_chansw_params_ie->mesh_pre_value);
80 
81 		if (elems->mesh_chansw_params_ie->mesh_flags &
82 				WLAN_EID_CHAN_SWITCH_PARAM_REASON)
83 			csa_ie->reason_code = le16_to_cpu(
84 				elems->mesh_chansw_params_ie->mesh_reason);
85 	}
86 
87 	new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
88 	new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
89 	if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
90 		sdata_info(sdata,
91 			   "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
92 			   bssid, new_freq);
93 		return -EINVAL;
94 	}
95 
96 	if (sec_chan_offs) {
97 		secondary_channel_offset = sec_chan_offs->sec_chan_offs;
98 	} else if (!(conn_flags & IEEE80211_CONN_DISABLE_HT)) {
99 		/* If the secondary channel offset IE is not present,
100 		 * we can't know what's the post-CSA offset, so the
101 		 * best we can do is use 20MHz.
102 		*/
103 		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
104 	}
105 
106 	switch (secondary_channel_offset) {
107 	default:
108 		/* secondary_channel_offset was present but is invalid */
109 	case IEEE80211_HT_PARAM_CHA_SEC_NONE:
110 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
111 					NL80211_CHAN_HT20);
112 		break;
113 	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
114 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
115 					NL80211_CHAN_HT40PLUS);
116 		break;
117 	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
118 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
119 					NL80211_CHAN_HT40MINUS);
120 		break;
121 	case -1:
122 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
123 					NL80211_CHAN_NO_HT);
124 		/* keep width for 5/10 MHz channels */
125 		switch (sdata->vif.bss_conf.chandef.width) {
126 		case NL80211_CHAN_WIDTH_5:
127 		case NL80211_CHAN_WIDTH_10:
128 			csa_ie->chandef.width =
129 				sdata->vif.bss_conf.chandef.width;
130 			break;
131 		default:
132 			break;
133 		}
134 		break;
135 	}
136 
137 	if (bwi) {
138 		/* start with the CSA one */
139 		new_vht_chandef = csa_ie->chandef;
140 		/* and update the width accordingly */
141 		/* FIXME: support 160/320 */
142 		ieee80211_chandef_eht_oper(&bwi->info, true, true,
143 					   &new_vht_chandef);
144 	} else if (wide_bw_chansw_ie) {
145 		u8 new_seg1 = wide_bw_chansw_ie->new_center_freq_seg1;
146 		struct ieee80211_vht_operation vht_oper = {
147 			.chan_width =
148 				wide_bw_chansw_ie->new_channel_width,
149 			.center_freq_seg0_idx =
150 				wide_bw_chansw_ie->new_center_freq_seg0,
151 			.center_freq_seg1_idx = new_seg1,
152 			/* .basic_mcs_set doesn't matter */
153 		};
154 		struct ieee80211_ht_operation ht_oper = {
155 			.operation_mode =
156 				cpu_to_le16(new_seg1 <<
157 					    IEEE80211_HT_OP_MODE_CCFS2_SHIFT),
158 		};
159 
160 		/* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
161 		 * to the previously parsed chandef
162 		 */
163 		new_vht_chandef = csa_ie->chandef;
164 
165 		/* ignore if parsing fails */
166 		if (!ieee80211_chandef_vht_oper(&sdata->local->hw,
167 						vht_cap_info,
168 						&vht_oper, &ht_oper,
169 						&new_vht_chandef))
170 			new_vht_chandef.chan = NULL;
171 
172 		if (conn_flags & IEEE80211_CONN_DISABLE_80P80MHZ &&
173 		    new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
174 			ieee80211_chandef_downgrade(&new_vht_chandef);
175 		if (conn_flags & IEEE80211_CONN_DISABLE_160MHZ &&
176 		    new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
177 			ieee80211_chandef_downgrade(&new_vht_chandef);
178 	}
179 
180 	/* if VHT data is there validate & use it */
181 	if (new_vht_chandef.chan) {
182 		if (!cfg80211_chandef_compatible(&new_vht_chandef,
183 						 &csa_ie->chandef)) {
184 			sdata_info(sdata,
185 				   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
186 				   bssid);
187 			return -EINVAL;
188 		}
189 		csa_ie->chandef = new_vht_chandef;
190 	}
191 
192 	if (elems->max_channel_switch_time)
193 		csa_ie->max_switch_time =
194 			(elems->max_channel_switch_time[0] << 0) |
195 			(elems->max_channel_switch_time[1] <<  8) |
196 			(elems->max_channel_switch_time[2] << 16);
197 
198 	return 0;
199 }
200 
201 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
202 					struct ieee80211_msrment_ie *request_ie,
203 					const u8 *da, const u8 *bssid,
204 					u8 dialog_token)
205 {
206 	struct ieee80211_local *local = sdata->local;
207 	struct sk_buff *skb;
208 	struct ieee80211_mgmt *msr_report;
209 
210 	skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
211 				sizeof(struct ieee80211_msrment_ie));
212 	if (!skb)
213 		return;
214 
215 	skb_reserve(skb, local->hw.extra_tx_headroom);
216 	msr_report = skb_put_zero(skb, 24);
217 	memcpy(msr_report->da, da, ETH_ALEN);
218 	memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
219 	memcpy(msr_report->bssid, bssid, ETH_ALEN);
220 	msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
221 						IEEE80211_STYPE_ACTION);
222 
223 	skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
224 	msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
225 	msr_report->u.action.u.measurement.action_code =
226 				WLAN_ACTION_SPCT_MSR_RPRT;
227 	msr_report->u.action.u.measurement.dialog_token = dialog_token;
228 
229 	msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
230 	msr_report->u.action.u.measurement.length =
231 			sizeof(struct ieee80211_msrment_ie);
232 
233 	memset(&msr_report->u.action.u.measurement.msr_elem, 0,
234 		sizeof(struct ieee80211_msrment_ie));
235 	msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
236 	msr_report->u.action.u.measurement.msr_elem.mode |=
237 			IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
238 	msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
239 
240 	ieee80211_tx_skb(sdata, skb);
241 }
242 
243 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
244 				       struct ieee80211_mgmt *mgmt,
245 				       size_t len)
246 {
247 	/*
248 	 * Ignoring measurement request is spec violation.
249 	 * Mandatory measurements must be reported optional
250 	 * measurements might be refused or reported incapable
251 	 * For now just refuse
252 	 * TODO: Answer basic measurement as unmeasured
253 	 */
254 	ieee80211_send_refuse_measurement_request(sdata,
255 			&mgmt->u.action.u.measurement.msr_elem,
256 			mgmt->sa, mgmt->bssid,
257 			mgmt->u.action.u.measurement.dialog_token);
258 }
259