aboutsummaryrefslogtreecommitdiff
path: root/net/mac80211/spectmgmt.c
blob: 76747bfdaddd08ec02e207a0fb603976b443dafe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
// SPDX-License-Identifier: GPL-2.0-only
/*
 * spectrum management
 *
 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 * Copyright 2007-2008, Intel Corporation
 * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
 * Copyright (C) 2018, 2020 Intel Corporation
 */

#include <linux/ieee80211.h>
#include <net/cfg80211.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "sta_info.h"
#include "wme.h"

int 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,
				 u32 sta_flags, u8 *bssid,
				 struct ieee80211_csa_ie *csa_ie)
{
	enum nl80211_band new_band = current_band;
	int new_freq;
	u8 new_chan_no;
	struct ieee80211_channel *new_chan;
	struct cfg80211_chan_def new_vht_chandef = {};
	const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
	const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
	int secondary_channel_offset = -1;

	memset(csa_ie, 0, sizeof(*csa_ie));

	sec_chan_offs = elems->sec_chan_offs;
	wide_bw_chansw_ie = elems->wide_bw_chansw_ie;

	if (sta_flags & (IEEE80211_STA_DISABLE_HT |
			 IEEE80211_STA_DISABLE_40MHZ)) {
		sec_chan_offs = NULL;
		wide_bw_chansw_ie = NULL;
	}

	if (sta_flags & IEEE80211_STA_DISABLE_VHT)
		wide_bw_chansw_ie = NULL;

	if (elems->ext_chansw_ie) {
		if (!ieee80211_operating_class_to_band(
				elems->ext_chansw_ie->new_operating_class,
				&new_band)) {
			sdata_info(sdata,
				   "cannot understand ECSA IE operating class, %d, ignoring\n",
				   elems->ext_chansw_ie->new_operating_class);
		}
		new_chan_no = elems->ext_chansw_ie->new_ch_num;
		csa_ie->count = elems->ext_chansw_ie->count;
		csa_ie->mode = elems->ext_chansw_ie->mode;
	} else if (elems->ch_switch_ie) {
		new_chan_no = elems->ch_switch_ie->new_ch_num;
		csa_ie->count = elems->ch_switch_ie->count;
		csa_ie->mode = elems->ch_switch_ie->mode;
	} else {
		/* nothing here we understand */
		return 1;
	}

	/* Mesh Channel Switch Parameters Element */
	if (elems->mesh_chansw_params_ie) {
		csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
		csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
		csa_ie->pre_value = le16_to_cpu(
				elems->mesh_chansw_params_ie->mesh_pre_value);

		if (elems->mesh_chansw_params_ie->mesh_flags &
				WLAN_EID_CHAN_SWITCH_PARAM_REASON)
			csa_ie->reason_code = le16_to_cpu(
				elems->mesh_chansw_params_ie->mesh_reason);
	}

	new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
	new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
	if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
		sdata_info(sdata,
			   "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
			   bssid, new_freq);
		return -EINVAL;
	}

	if (sec_chan_offs) {
		secondary_channel_offset = sec_chan_offs->sec_chan_offs;
	} else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
		/* If the secondary channel offset IE is not present,
		 * we can't know what's the post-CSA offset, so the
		 * best we can do is use 20MHz.
		*/
		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
	}

	switch (secondary_channel_offset) {
	default:
		/* secondary_channel_offset was present but is invalid */
	case IEEE80211_HT_PARAM_CHA_SEC_NONE:
		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
					NL80211_CHAN_HT20);
		break;
	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
					NL80211_CHAN_HT40PLUS);
		break;
	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
					NL80211_CHAN_HT40MINUS);
		break;
	case -1:
		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
					NL80211_CHAN_NO_HT);
		/* keep width for 5/10 MHz channels */
		switch (sdata->vif.bss_conf.chandef.width) {
		case NL80211_CHAN_WIDTH_5:
		case NL80211_CHAN_WIDTH_10:
			csa_ie->chandef.width =
				sdata->vif.bss_conf.chandef.width;
			break;
		default:
			break;
		}
		break;
	}

	if (wide_bw_chansw_ie) {
		u8 new_seg1 = wide_bw_chansw_ie->new_center_freq_seg1;
		struct ieee80211_vht_operation vht_oper = {
			.chan_width =
				wide_bw_chansw_ie->new_channel_width,
			.center_freq_seg0_idx =
				wide_bw_chansw_ie->new_center_freq_seg0,
			.center_freq_seg1_idx = new_seg1,
			/* .basic_mcs_set doesn't matter */
		};
		struct ieee80211_ht_operation ht_oper = {
			.operation_mode =
				cpu_to_le16(new_seg1 <<
					    IEEE80211_HT_OP_MODE_CCFS2_SHIFT),
		};

		/* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
		 * to the previously parsed chandef
		 */
		new_vht_chandef = csa_ie->chandef;

		/* ignore if parsing fails */
		if (!ieee80211_chandef_vht_oper(&sdata->local->hw,
						vht_cap_info,
						&vht_oper, &ht_oper,
						&new_vht_chandef))
			new_vht_chandef.chan = NULL;

		if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
		    new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
			ieee80211_chandef_downgrade(&new_vht_chandef);
		if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
		    new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
			ieee80211_chandef_downgrade(&new_vht_chandef);
	}

	/* if VHT data is there validate & use it */
	if (new_vht_chandef.chan) {
		if (!cfg80211_chandef_compatible(&new_vht_chandef,
						 &csa_ie->chandef)) {
			sdata_info(sdata,
				   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
				   bssid);
			return -EINVAL;
		}
		csa_ie->chandef = new_vht_chandef;
	}

	if (elems->max_channel_switch_time)
		csa_ie->max_switch_time =
			(elems->max_channel_switch_time[0] << 0) |
			(elems->max_channel_switch_time[1] <<  8) |
			(elems->max_channel_switch_time[2] << 16);

	return 0;
}

static void 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)
{
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_mgmt *msr_report;

	skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
				sizeof(struct ieee80211_msrment_ie));
	if (!skb)
		return;

	skb_reserve(skb, local->hw.extra_tx_headroom);
	msr_report = skb_put_zero(skb, 24);
	memcpy(msr_report->da, da, ETH_ALEN);
	memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
	memcpy(msr_report->bssid, bssid, ETH_ALEN);
	msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
						IEEE80211_STYPE_ACTION);

	skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
	msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
	msr_report->u.action.u.measurement.action_code =
				WLAN_ACTION_SPCT_MSR_RPRT;
	msr_report->u.action.u.measurement.dialog_token = dialog_token;

	msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
	msr_report->u.action.u.measurement.length =
			sizeof(struct ieee80211_msrment_ie);

	memset(&msr_report->u.action.u.measurement.msr_elem, 0,
		sizeof(struct ieee80211_msrment_ie));
	msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
	msr_report->u.action.u.measurement.msr_elem.mode |=
			IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
	msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;

	ieee80211_tx_skb(sdata, skb);
}

void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
				       struct ieee80211_mgmt *mgmt,
				       size_t len)
{
	/*
	 * Ignoring measurement request is spec violation.
	 * Mandatory measurements must be reported optional
	 * measurements might be refused or reported incapable
	 * For now just refuse
	 * TODO: Answer basic measurement as unmeasured
	 */
	ieee80211_send_refuse_measurement_request(sdata,
			&mgmt->u.action.u.measurement.msr_elem,
			mgmt->sa, mgmt->bssid,
			mgmt->u.action.u.measurement.dialog_token);
}