xref: /openbmc/linux/net/mac80211/spectmgmt.c (revision fcc8487d)
1 /*
2  * spectrum management
3  *
4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5  * Copyright 2002-2005, Instant802 Networks, Inc.
6  * Copyright 2005-2006, Devicescape Software, Inc.
7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9  * Copyright 2007-2008, Intel Corporation
10  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16 
17 #include <linux/ieee80211.h>
18 #include <net/cfg80211.h>
19 #include <net/mac80211.h>
20 #include "ieee80211_i.h"
21 #include "sta_info.h"
22 #include "wme.h"
23 
24 int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
25 				 struct ieee802_11_elems *elems,
26 				 enum nl80211_band current_band,
27 				 u32 sta_flags, u8 *bssid,
28 				 struct ieee80211_csa_ie *csa_ie)
29 {
30 	enum nl80211_band new_band;
31 	int new_freq;
32 	u8 new_chan_no;
33 	struct ieee80211_channel *new_chan;
34 	struct cfg80211_chan_def new_vht_chandef = {};
35 	const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
36 	const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
37 	int secondary_channel_offset = -1;
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, disconnecting\n",
57 				   elems->ext_chansw_ie->new_operating_class);
58 			return -EINVAL;
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_band = current_band;
65 		new_chan_no = elems->ch_switch_ie->new_ch_num;
66 		csa_ie->count = elems->ch_switch_ie->count;
67 		csa_ie->mode = elems->ch_switch_ie->mode;
68 	} else {
69 		/* nothing here we understand */
70 		return 1;
71 	}
72 
73 	/* Mesh Channel Switch Parameters Element */
74 	if (elems->mesh_chansw_params_ie) {
75 		csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
76 		csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
77 		csa_ie->pre_value = le16_to_cpu(
78 				elems->mesh_chansw_params_ie->mesh_pre_value);
79 	}
80 
81 	new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
82 	new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
83 	if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
84 		sdata_info(sdata,
85 			   "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
86 			   bssid, new_freq);
87 		return -EINVAL;
88 	}
89 
90 	if (sec_chan_offs) {
91 		secondary_channel_offset = sec_chan_offs->sec_chan_offs;
92 	} else if (!(sta_flags & IEEE80211_STA_DISABLE_HT)) {
93 		/* If the secondary channel offset IE is not present,
94 		 * we can't know what's the post-CSA offset, so the
95 		 * best we can do is use 20MHz.
96 		*/
97 		secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
98 	}
99 
100 	switch (secondary_channel_offset) {
101 	default:
102 		/* secondary_channel_offset was present but is invalid */
103 	case IEEE80211_HT_PARAM_CHA_SEC_NONE:
104 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
105 					NL80211_CHAN_HT20);
106 		break;
107 	case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
108 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
109 					NL80211_CHAN_HT40PLUS);
110 		break;
111 	case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
112 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
113 					NL80211_CHAN_HT40MINUS);
114 		break;
115 	case -1:
116 		cfg80211_chandef_create(&csa_ie->chandef, new_chan,
117 					NL80211_CHAN_NO_HT);
118 		/* keep width for 5/10 MHz channels */
119 		switch (sdata->vif.bss_conf.chandef.width) {
120 		case NL80211_CHAN_WIDTH_5:
121 		case NL80211_CHAN_WIDTH_10:
122 			csa_ie->chandef.width =
123 				sdata->vif.bss_conf.chandef.width;
124 			break;
125 		default:
126 			break;
127 		}
128 		break;
129 	}
130 
131 	if (wide_bw_chansw_ie) {
132 		struct ieee80211_vht_operation vht_oper = {
133 			.chan_width =
134 				wide_bw_chansw_ie->new_channel_width,
135 			.center_freq_seg0_idx =
136 				wide_bw_chansw_ie->new_center_freq_seg0,
137 			.center_freq_seg1_idx =
138 				wide_bw_chansw_ie->new_center_freq_seg1,
139 			/* .basic_mcs_set doesn't matter */
140 		};
141 
142 		/* default, for the case of IEEE80211_VHT_CHANWIDTH_USE_HT,
143 		 * to the previously parsed chandef
144 		 */
145 		new_vht_chandef = csa_ie->chandef;
146 
147 		/* ignore if parsing fails */
148 		if (!ieee80211_chandef_vht_oper(&vht_oper, &new_vht_chandef))
149 			new_vht_chandef.chan = NULL;
150 
151 		if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
152 		    new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
153 			ieee80211_chandef_downgrade(&new_vht_chandef);
154 		if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
155 		    new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
156 			ieee80211_chandef_downgrade(&new_vht_chandef);
157 	}
158 
159 	/* if VHT data is there validate & use it */
160 	if (new_vht_chandef.chan) {
161 		if (!cfg80211_chandef_compatible(&new_vht_chandef,
162 						 &csa_ie->chandef)) {
163 			sdata_info(sdata,
164 				   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
165 				   bssid);
166 			return -EINVAL;
167 		}
168 		csa_ie->chandef = new_vht_chandef;
169 	}
170 
171 	return 0;
172 }
173 
174 static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
175 					struct ieee80211_msrment_ie *request_ie,
176 					const u8 *da, const u8 *bssid,
177 					u8 dialog_token)
178 {
179 	struct ieee80211_local *local = sdata->local;
180 	struct sk_buff *skb;
181 	struct ieee80211_mgmt *msr_report;
182 
183 	skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
184 				sizeof(struct ieee80211_msrment_ie));
185 	if (!skb)
186 		return;
187 
188 	skb_reserve(skb, local->hw.extra_tx_headroom);
189 	msr_report = (struct ieee80211_mgmt *)skb_put(skb, 24);
190 	memset(msr_report, 0, 24);
191 	memcpy(msr_report->da, da, ETH_ALEN);
192 	memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
193 	memcpy(msr_report->bssid, bssid, ETH_ALEN);
194 	msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
195 						IEEE80211_STYPE_ACTION);
196 
197 	skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
198 	msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
199 	msr_report->u.action.u.measurement.action_code =
200 				WLAN_ACTION_SPCT_MSR_RPRT;
201 	msr_report->u.action.u.measurement.dialog_token = dialog_token;
202 
203 	msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
204 	msr_report->u.action.u.measurement.length =
205 			sizeof(struct ieee80211_msrment_ie);
206 
207 	memset(&msr_report->u.action.u.measurement.msr_elem, 0,
208 		sizeof(struct ieee80211_msrment_ie));
209 	msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
210 	msr_report->u.action.u.measurement.msr_elem.mode |=
211 			IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
212 	msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;
213 
214 	ieee80211_tx_skb(sdata, skb);
215 }
216 
217 void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
218 				       struct ieee80211_mgmt *mgmt,
219 				       size_t len)
220 {
221 	/*
222 	 * Ignoring measurement request is spec violation.
223 	 * Mandatory measurements must be reported optional
224 	 * measurements might be refused or reported incapable
225 	 * For now just refuse
226 	 * TODO: Answer basic measurement as unmeasured
227 	 */
228 	ieee80211_send_refuse_measurement_request(sdata,
229 			&mgmt->u.action.u.measurement.msr_elem,
230 			mgmt->sa, mgmt->bssid,
231 			mgmt->u.action.u.measurement.dialog_token);
232 }
233