linux-hardened/net/mac80211/spectmgmt.c
Ilan Peer 191da271ac mac80211: Do not disconnect on invalid operating class
Some APs include a non global operating class in their extended channel
switch information element. In such a case, as the operating class is not
known, mac80211 would decide to disconnect.

However the specification states that the operating class needs to be
taken from Annex E, but it does not specify from which table it should be
taken, so it is valid for an AP to use a non global operating class.

To avoid possibly unneeded disconnection, in such a case ignore the
operating class and assume that the current band is used, and if the
resulting channel and band configuration is invalid disconnect.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-02-19 14:53:14 +01:00

237 lines
7.5 KiB
C

/*
* 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 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#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 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) {
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 =
wide_bw_chansw_ie->new_center_freq_seg1,
/* .basic_mcs_set doesn't matter */
};
/* 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(&vht_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;
}
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);
}