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