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
24int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
25				 struct ieee802_11_elems *elems,
26				 enum ieee80211_band current_band,
27				 u32 sta_flags, u8 *bssid,
28				 struct ieee80211_csa_ie *csa_ie)
29{
30	enum ieee80211_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		new_vht_chandef.chan = new_chan;
133		new_vht_chandef.center_freq1 =
134			ieee80211_channel_to_frequency(
135				wide_bw_chansw_ie->new_center_freq_seg0,
136				new_band);
137
138		switch (wide_bw_chansw_ie->new_channel_width) {
139		default:
140			/* hmmm, ignore VHT and use HT if present */
141		case IEEE80211_VHT_CHANWIDTH_USE_HT:
142			new_vht_chandef.chan = NULL;
143			break;
144		case IEEE80211_VHT_CHANWIDTH_80MHZ:
145			new_vht_chandef.width = NL80211_CHAN_WIDTH_80;
146			break;
147		case IEEE80211_VHT_CHANWIDTH_160MHZ:
148			new_vht_chandef.width = NL80211_CHAN_WIDTH_160;
149			break;
150		case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
151			/* field is otherwise reserved */
152			new_vht_chandef.center_freq2 =
153				ieee80211_channel_to_frequency(
154					wide_bw_chansw_ie->new_center_freq_seg1,
155					new_band);
156			new_vht_chandef.width = NL80211_CHAN_WIDTH_80P80;
157			break;
158		}
159		if (sta_flags & IEEE80211_STA_DISABLE_80P80MHZ &&
160		    new_vht_chandef.width == NL80211_CHAN_WIDTH_80P80)
161			ieee80211_chandef_downgrade(&new_vht_chandef);
162		if (sta_flags & IEEE80211_STA_DISABLE_160MHZ &&
163		    new_vht_chandef.width == NL80211_CHAN_WIDTH_160)
164			ieee80211_chandef_downgrade(&new_vht_chandef);
165		if (sta_flags & IEEE80211_STA_DISABLE_40MHZ &&
166		    new_vht_chandef.width > NL80211_CHAN_WIDTH_20)
167			ieee80211_chandef_downgrade(&new_vht_chandef);
168	}
169
170	/* if VHT data is there validate & use it */
171	if (new_vht_chandef.chan) {
172		if (!cfg80211_chandef_compatible(&new_vht_chandef,
173						 &csa_ie->chandef)) {
174			sdata_info(sdata,
175				   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
176				   bssid);
177			return -EINVAL;
178		}
179		csa_ie->chandef = new_vht_chandef;
180	}
181
182	return 0;
183}
184
185static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
186					struct ieee80211_msrment_ie *request_ie,
187					const u8 *da, const u8 *bssid,
188					u8 dialog_token)
189{
190	struct ieee80211_local *local = sdata->local;
191	struct sk_buff *skb;
192	struct ieee80211_mgmt *msr_report;
193
194	skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
195				sizeof(struct ieee80211_msrment_ie));
196	if (!skb)
197		return;
198
199	skb_reserve(skb, local->hw.extra_tx_headroom);
200	msr_report = (struct ieee80211_mgmt *)skb_put(skb, 24);
201	memset(msr_report, 0, 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
228void 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