xref: /openbmc/linux/net/mac80211/spectmgmt.c (revision a44e4f3a)
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        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 sta_flags, u8 *bssid,
26 				 struct ieee80211_csa_ie *csa_ie)
27 {
28 	enum nl80211_band new_band = current_band;
29 	int new_freq;
30 	u8 new_chan_no;
31 	struct ieee80211_channel *new_chan;
32 	struct cfg80211_chan_def new_vht_chandef = {};
33 	const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
34 	const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
35 	int secondary_channel_offset = -1;
36 
37 	memset(csa_ie, 0, sizeof(*csa_ie));
38 
39 	sec_chan_offs = elems->sec_chan_offs;
40 	wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
41 
42 	if (sta_flags & (IEEE80211_STA_DISABLE_HT |
43 			 IEEE80211_STA_DISABLE_40MHZ)) {
44 		sec_chan_offs = NULL;
45 		wide_bw_chansw_ie = NULL;
46 	}
47 
48 	if (sta_flags & IEEE80211_STA_DISABLE_VHT)
49 		wide_bw_chansw_ie = NULL;
50 
51 	if (elems->ext_chansw_ie) {
52 		if (!ieee80211_operating_class_to_band(
53 				elems->ext_chansw_ie->new_operating_class,
54 				&new_band)) {
55 			sdata_info(sdata,
56 				   "cannot understand ECSA IE operating class, %d, ignoring\n",
57 				   elems->ext_chansw_ie->new_operating_class);
58 		}
59 		new_chan_no = elems->ext_chansw_ie->new_ch_num;
60 		csa_ie->count = elems->ext_chansw_ie->count;
61 		csa_ie->mode = elems->ext_chansw_ie->mode;
62 	} else if (elems->ch_switch_ie) {
63 		new_chan_no = elems->ch_switch_ie->new_ch_num;
64 		csa_ie->count = elems->ch_switch_ie->count;
65 		csa_ie->mode = elems->ch_switch_ie->mode;
66 	} else {
67 		/* nothing here we understand */
68 		return 1;
69 	}
70 
71 	/* Mesh Channel Switch Parameters Element */
72 	if (elems->mesh_chansw_params_ie) {
73 		csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
74 		csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
75 		csa_ie->pre_value = le16_to_cpu(
76 				elems->mesh_chansw_params_ie->mesh_pre_value);
77 
78 		if (elems->mesh_chansw_params_ie->mesh_flags &
79 				WLAN_EID_CHAN_SWITCH_PARAM_REASON)
80 			csa_ie->reason_code = le16_to_cpu(
81 				elems->mesh_chansw_params_ie->mesh_reason);
82 	}
83 
84 	new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
85 	new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
86 	if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
87 		sdata_info(sdata,
88 			   "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
89 			   bssid, new_freq);
90 		return -EINVAL;
91 	}
92 
93 	if (sec_chan_offs) {
94 		secondary_channel_offset = sec_chan_offs->sec_chan_offs;
95 	} else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
96 		/* If the secondary channel offset IE is not present,
97 		 * we can't know what's the post-CSA offset, so the
98 		 * best we can do is use 20MHz.
99 		*/
100 		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
101 	}
102 
103 	switch (secondary_channel_offset) {
104 	default:
105 		/* secondary_channel_offset was present but is invalid */
106 	case IEEE80211_HT_PARAM_CHA_SEC_NONE:
107 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
108 					NL80211_CHAN_HT20);
109 		break;
110 	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
111 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
112 					NL80211_CHAN_HT40PLUS);
113 		break;
114 	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
115 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
116 					NL80211_CHAN_HT40MINUS);
117 		break;
118 	case -1:
119 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
120 					NL80211_CHAN_NO_HT);
121 		/* keep width for 5/10 MHz channels */
122 		switch (sdata->vif.bss_conf.chandef.width) {
123 		case NL80211_CHAN_WIDTH_5:
124 		case NL80211_CHAN_WIDTH_10:
125 			csa_ie->chandef.width =
126 				sdata->vif.bss_conf.chandef.width;
127 			break;
128 		default:
129 			break;
130 		}
131 		break;
132 	}
133 
134 	if (wide_bw_chansw_ie) {
135 		struct ieee80211_vht_operation vht_oper = {
136 			.chan_width =
137 				wide_bw_chansw_ie->new_channel_width,
138 			.center_freq_seg0_idx =
139 				wide_bw_chansw_ie->new_center_freq_seg0,
140 			.center_freq_seg1_idx =
141 				wide_bw_chansw_ie->new_center_freq_seg1,
142 			/* .basic_mcs_set doesn't matter */
143 		};
144 		struct ieee80211_ht_operation ht_oper = {};
145 
146 		/* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
147 		 * to the previously parsed chandef
148 		 */
149 		new_vht_chandef = csa_ie->chandef;
150 
151 		/* ignore if parsing fails */
152 		if (!ieee80211_chandef_vht_oper(&sdata->local->hw,
153 						&vht_oper, &ht_oper,
154 						&new_vht_chandef))
155 			new_vht_chandef.chan = NULL;
156 
157 		if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
158 		    new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
159 			ieee80211_chandef_downgrade(&new_vht_chandef);
160 		if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
161 		    new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
162 			ieee80211_chandef_downgrade(&new_vht_chandef);
163 	}
164 
165 	/* if VHT data is there validate & use it */
166 	if (new_vht_chandef.chan) {
167 		if (!cfg80211_chandef_compatible(&new_vht_chandef,
168 						 &csa_ie->chandef)) {
169 			sdata_info(sdata,
170 				   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
171 				   bssid);
172 			return -EINVAL;
173 		}
174 		csa_ie->chandef = new_vht_chandef;
175 	}
176 
177 	if (elems->max_channel_switch_time)
178 		csa_ie->max_switch_time =
179 			(elems->max_channel_switch_time[0] << 0) |
180 			(elems->max_channel_switch_time[1] <<  8) |
181 			(elems->max_channel_switch_time[2] << 16);
182 
183 	return 0;
184 }
185 
186 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
187 					struct ieee80211_msrment_ie *request_ie,
188 					const u8 *da, const u8 *bssid,
189 					u8 dialog_token)
190 {
191 	struct ieee80211_local *local = sdata->local;
192 	struct sk_buff *skb;
193 	struct ieee80211_mgmt *msr_report;
194 
195 	skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
196 				sizeof(struct ieee80211_msrment_ie));
197 	if (!skb)
198 		return;
199 
200 	skb_reserve(skb, local->hw.extra_tx_headroom);
201 	msr_report = skb_put_zero(skb, 24);
202 	memcpy(msr_report->da, da, ETH_ALEN);
203 	memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
204 	memcpy(msr_report->bssid, bssid, ETH_ALEN);
205 	msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
206 						IEEE80211_STYPE_ACTION);
207 
208 	skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
209 	msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
210 	msr_report->u.action.u.measurement.action_code =
211 				WLAN_ACTION_SPCT_MSR_RPRT;
212 	msr_report->u.action.u.measurement.dialog_token = dialog_token;
213 
214 	msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
215 	msr_report->u.action.u.measurement.length =
216 			sizeof(struct ieee80211_msrment_ie);
217 
218 	memset(&msr_report->u.action.u.measurement.msr_elem, 0,
219 		sizeof(struct ieee80211_msrment_ie));
220 	msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
221 	msr_report->u.action.u.measurement.msr_elem.mode |=
222 			IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
223 	msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
224 
225 	ieee80211_tx_skb(sdata, skb);
226 }
227 
228 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
229 				       struct ieee80211_mgmt *mgmt,
230 				       size_t len)
231 {
232 	/*
233 	 * Ignoring measurement request is spec violation.
234 	 * Mandatory measurements must be reported optional
235 	 * measurements might be refused or reported incapable
236 	 * For now just refuse
237 	 * TODO: Answer basic measurement as unmeasured
238 	 */
239 	ieee80211_send_refuse_measurement_request(sdata,
240 			&mgmt->u.action.u.measurement.msr_elem,
241 			mgmt->sa, mgmt->bssid,
242 			mgmt->u.action.u.measurement.dialog_token);
243 }
244