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linux-stable/net/mac80211/ibss.c
Koen Vandeputte 020fa0f2f0 mac80211: IBSS: avoid unneeded return value processing 
when ieee80211_ibss_csa_beacon() fails, we return it's value.
When it succeeds, we basically copy it's value and also .. return it.

Just return it immediately, simplifying the code.

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Link: https://lore.kernel.org/r/20190911141431.12498-1-koen.vandeputte@ncentric.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-10-04 13:47:12 +02:00

1876 lines
51 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* IBSS mode implementation
* Copyright 2003-2008, Jouni Malinen <j@w1.fi>
* Copyright 2004, Instant802 Networks, Inc.
* Copyright 2005, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2007, Michael Wu <flamingice@sourmilk.net>
* Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
* Copyright 2013-2014 Intel Mobile Communications GmbH
* Copyright(c) 2016 Intel Deutschland GmbH
* Copyright(c) 2018-2019 Intel Corporation
*/
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"
#define IEEE80211_SCAN_INTERVAL (2 * HZ)
#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
#define IEEE80211_IBSS_RSN_INACTIVITY_LIMIT (10 * HZ)
#define IEEE80211_IBSS_MAX_STA_ENTRIES 128
static struct beacon_data *
ieee80211_ibss_build_presp(struct ieee80211_sub_if_data *sdata,
const int beacon_int, const u32 basic_rates,
const u16 capability, u64 tsf,
struct cfg80211_chan_def *chandef,
bool *have_higher_than_11mbit,
struct cfg80211_csa_settings *csa_settings)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
int rates_n = 0, i, ri;
struct ieee80211_mgmt *mgmt;
u8 *pos;
struct ieee80211_supported_band *sband;
u32 rate_flags, rates = 0, rates_added = 0;
struct beacon_data *presp;
int frame_len;
int shift;
/* Build IBSS probe response */
frame_len = sizeof(struct ieee80211_hdr_3addr) +
12 /* struct ieee80211_mgmt.u.beacon */ +
2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
2 + 8 /* max Supported Rates */ +
3 /* max DS params */ +
4 /* IBSS params */ +
5 /* Channel Switch Announcement */ +
2 + (IEEE80211_MAX_SUPP_RATES - 8) +
2 + sizeof(struct ieee80211_ht_cap) +
2 + sizeof(struct ieee80211_ht_operation) +
2 + sizeof(struct ieee80211_vht_cap) +
2 + sizeof(struct ieee80211_vht_operation) +
ifibss->ie_len;
presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
if (!presp)
return NULL;
presp->head = (void *)(presp + 1);
mgmt = (void *) presp->head;
mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_PROBE_RESP);
eth_broadcast_addr(mgmt->da);
memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
mgmt->u.beacon.capab_info = cpu_to_le16(capability);
pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);
*pos++ = WLAN_EID_SSID;
*pos++ = ifibss->ssid_len;
memcpy(pos, ifibss->ssid, ifibss->ssid_len);
pos += ifibss->ssid_len;
sband = local->hw.wiphy->bands[chandef->chan->band];
rate_flags = ieee80211_chandef_rate_flags(chandef);
shift = ieee80211_chandef_get_shift(chandef);
rates_n = 0;
if (have_higher_than_11mbit)
*have_higher_than_11mbit = false;
for (i = 0; i < sband->n_bitrates; i++) {
if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
continue;
if (sband->bitrates[i].bitrate > 110 &&
have_higher_than_11mbit)
*have_higher_than_11mbit = true;
rates |= BIT(i);
rates_n++;
}
*pos++ = WLAN_EID_SUPP_RATES;
*pos++ = min_t(int, 8, rates_n);
for (ri = 0; ri < sband->n_bitrates; ri++) {
int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
5 * (1 << shift));
u8 basic = 0;
if (!(rates & BIT(ri)))
continue;
if (basic_rates & BIT(ri))
basic = 0x80;
*pos++ = basic | (u8) rate;
if (++rates_added == 8) {
ri++; /* continue at next rate for EXT_SUPP_RATES */
break;
}
}
if (sband->band == NL80211_BAND_2GHZ) {
*pos++ = WLAN_EID_DS_PARAMS;
*pos++ = 1;
*pos++ = ieee80211_frequency_to_channel(
chandef->chan->center_freq);
}
*pos++ = WLAN_EID_IBSS_PARAMS;
*pos++ = 2;
/* FIX: set ATIM window based on scan results */
*pos++ = 0;
*pos++ = 0;
if (csa_settings) {
*pos++ = WLAN_EID_CHANNEL_SWITCH;
*pos++ = 3;
*pos++ = csa_settings->block_tx ? 1 : 0;
*pos++ = ieee80211_frequency_to_channel(
csa_settings->chandef.chan->center_freq);
presp->csa_counter_offsets[0] = (pos - presp->head);
*pos++ = csa_settings->count;
presp->csa_current_counter = csa_settings->count;
}
/* put the remaining rates in WLAN_EID_EXT_SUPP_RATES */
if (rates_n > 8) {
*pos++ = WLAN_EID_EXT_SUPP_RATES;
*pos++ = rates_n - 8;
for (; ri < sband->n_bitrates; ri++) {
int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
5 * (1 << shift));
u8 basic = 0;
if (!(rates & BIT(ri)))
continue;
if (basic_rates & BIT(ri))
basic = 0x80;
*pos++ = basic | (u8) rate;
}
}
if (ifibss->ie_len) {
memcpy(pos, ifibss->ie, ifibss->ie_len);
pos += ifibss->ie_len;
}
/* add HT capability and information IEs */
if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT &&
chandef->width != NL80211_CHAN_WIDTH_5 &&
chandef->width != NL80211_CHAN_WIDTH_10 &&
sband->ht_cap.ht_supported) {
struct ieee80211_sta_ht_cap ht_cap;
memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
ieee80211_apply_htcap_overrides(sdata, &ht_cap);
pos = ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
/*
* Note: According to 802.11n-2009 9.13.3.1, HT Protection
* field and RIFS Mode are reserved in IBSS mode, therefore
* keep them at 0
*/
pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
chandef, 0, false);
/* add VHT capability and information IEs */
if (chandef->width != NL80211_CHAN_WIDTH_20 &&
chandef->width != NL80211_CHAN_WIDTH_40 &&
sband->vht_cap.vht_supported) {
pos = ieee80211_ie_build_vht_cap(pos, &sband->vht_cap,
sband->vht_cap.cap);
pos = ieee80211_ie_build_vht_oper(pos, &sband->vht_cap,
chandef);
}
}
if (local->hw.queues >= IEEE80211_NUM_ACS)
pos = ieee80211_add_wmm_info_ie(pos, 0); /* U-APSD not in use */
presp->head_len = pos - presp->head;
if (WARN_ON(presp->head_len > frame_len))
goto error;
return presp;
error:
kfree(presp);
return NULL;
}
static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const int beacon_int,
struct cfg80211_chan_def *req_chandef,
const u32 basic_rates,
const u16 capability, u64 tsf,
bool creator)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct ieee80211_mgmt *mgmt;
struct cfg80211_bss *bss;
u32 bss_change;
struct cfg80211_chan_def chandef;
struct ieee80211_channel *chan;
struct beacon_data *presp;
struct cfg80211_inform_bss bss_meta = {};
bool have_higher_than_11mbit;
bool radar_required;
int err;
sdata_assert_lock(sdata);
/* Reset own TSF to allow time synchronization work. */
drv_reset_tsf(local, sdata);
if (!ether_addr_equal(ifibss->bssid, bssid))
sta_info_flush(sdata);
/* if merging, indicate to driver that we leave the old IBSS */
if (sdata->vif.bss_conf.ibss_joined) {
sdata->vif.bss_conf.ibss_joined = false;
sdata->vif.bss_conf.ibss_creator = false;
sdata->vif.bss_conf.enable_beacon = false;
netif_carrier_off(sdata->dev);
ieee80211_bss_info_change_notify(sdata,
BSS_CHANGED_IBSS |
BSS_CHANGED_BEACON_ENABLED);
drv_leave_ibss(local, sdata);
}
presp = rcu_dereference_protected(ifibss->presp,
lockdep_is_held(&sdata->wdev.mtx));
RCU_INIT_POINTER(ifibss->presp, NULL);
if (presp)
kfree_rcu(presp, rcu_head);
/* make a copy of the chandef, it could be modified below. */
chandef = *req_chandef;
chan = chandef.chan;
if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
NL80211_IFTYPE_ADHOC)) {
if (chandef.width == NL80211_CHAN_WIDTH_5 ||
chandef.width == NL80211_CHAN_WIDTH_10 ||
chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
chandef.width == NL80211_CHAN_WIDTH_20) {
sdata_info(sdata,
"Failed to join IBSS, beacons forbidden\n");
return;
}
chandef.width = NL80211_CHAN_WIDTH_20;
chandef.center_freq1 = chan->center_freq;
/* check again for downgraded chandef */
if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
NL80211_IFTYPE_ADHOC)) {
sdata_info(sdata,
"Failed to join IBSS, beacons forbidden\n");
return;
}
}
err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
&chandef, NL80211_IFTYPE_ADHOC);
if (err < 0) {
sdata_info(sdata,
"Failed to join IBSS, invalid chandef\n");
return;
}
if (err > 0 && !ifibss->userspace_handles_dfs) {
sdata_info(sdata,
"Failed to join IBSS, DFS channel without control program\n");
return;
}
radar_required = err;
mutex_lock(&local->mtx);
if (ieee80211_vif_use_channel(sdata, &chandef,
ifibss->fixed_channel ?
IEEE80211_CHANCTX_SHARED :
IEEE80211_CHANCTX_EXCLUSIVE)) {
sdata_info(sdata, "Failed to join IBSS, no channel context\n");
mutex_unlock(&local->mtx);
return;
}
sdata->radar_required = radar_required;
mutex_unlock(&local->mtx);
memcpy(ifibss->bssid, bssid, ETH_ALEN);
presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
capability, tsf, &chandef,
&have_higher_than_11mbit, NULL);
if (!presp)
return;
rcu_assign_pointer(ifibss->presp, presp);
mgmt = (void *)presp->head;
sdata->vif.bss_conf.enable_beacon = true;
sdata->vif.bss_conf.beacon_int = beacon_int;
sdata->vif.bss_conf.basic_rates = basic_rates;
sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
bss_change = BSS_CHANGED_BEACON_INT;
bss_change |= ieee80211_reset_erp_info(sdata);
bss_change |= BSS_CHANGED_BSSID;
bss_change |= BSS_CHANGED_BEACON;
bss_change |= BSS_CHANGED_BEACON_ENABLED;
bss_change |= BSS_CHANGED_BASIC_RATES;
bss_change |= BSS_CHANGED_HT;
bss_change |= BSS_CHANGED_IBSS;
bss_change |= BSS_CHANGED_SSID;
/*
* In 5 GHz/802.11a, we can always use short slot time.
* (IEEE 802.11-2012 18.3.8.7)
*
* In 2.4GHz, we must always use long slots in IBSS for compatibility
* reasons.
* (IEEE 802.11-2012 19.4.5)
*
* HT follows these specifications (IEEE 802.11-2012 20.3.18)
*/
sdata->vif.bss_conf.use_short_slot = chan->band == NL80211_BAND_5GHZ;
bss_change |= BSS_CHANGED_ERP_SLOT;
/* cf. IEEE 802.11 9.2.12 */
if (chan->band == NL80211_BAND_2GHZ && have_higher_than_11mbit)
sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
else
sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
ieee80211_set_wmm_default(sdata, true, false);
sdata->vif.bss_conf.ibss_joined = true;
sdata->vif.bss_conf.ibss_creator = creator;
err = drv_join_ibss(local, sdata);
if (err) {
sdata->vif.bss_conf.ibss_joined = false;
sdata->vif.bss_conf.ibss_creator = false;
sdata->vif.bss_conf.enable_beacon = false;
sdata->vif.bss_conf.ssid_len = 0;
RCU_INIT_POINTER(ifibss->presp, NULL);
kfree_rcu(presp, rcu_head);
mutex_lock(&local->mtx);
ieee80211_vif_release_channel(sdata);
mutex_unlock(&local->mtx);
sdata_info(sdata, "Failed to join IBSS, driver failure: %d\n",
err);
return;
}
ieee80211_bss_info_change_notify(sdata, bss_change);
ifibss->state = IEEE80211_IBSS_MLME_JOINED;
mod_timer(&ifibss->timer,
round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
bss_meta.chan = chan;
bss_meta.scan_width = cfg80211_chandef_to_scan_width(&chandef);
bss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta, mgmt,
presp->head_len, GFP_KERNEL);
cfg80211_put_bss(local->hw.wiphy, bss);
netif_carrier_on(sdata->dev);
cfg80211_ibss_joined(sdata->dev, ifibss->bssid, chan, GFP_KERNEL);
}
static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
struct ieee80211_bss *bss)
{
struct cfg80211_bss *cbss =
container_of((void *)bss, struct cfg80211_bss, priv);
struct ieee80211_supported_band *sband;
struct cfg80211_chan_def chandef;
u32 basic_rates;
int i, j;
u16 beacon_int = cbss->beacon_interval;
const struct cfg80211_bss_ies *ies;
enum nl80211_channel_type chan_type;
u64 tsf;
u32 rate_flags;
int shift;
sdata_assert_lock(sdata);
if (beacon_int < 10)
beacon_int = 10;
switch (sdata->u.ibss.chandef.width) {
case NL80211_CHAN_WIDTH_20_NOHT:
case NL80211_CHAN_WIDTH_20:
case NL80211_CHAN_WIDTH_40:
chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
break;
case NL80211_CHAN_WIDTH_5:
case NL80211_CHAN_WIDTH_10:
cfg80211_chandef_create(&chandef, cbss->channel,
NL80211_CHAN_NO_HT);
chandef.width = sdata->u.ibss.chandef.width;
break;
case NL80211_CHAN_WIDTH_80:
case NL80211_CHAN_WIDTH_80P80:
case NL80211_CHAN_WIDTH_160:
chandef = sdata->u.ibss.chandef;
chandef.chan = cbss->channel;
break;
default:
/* fall back to 20 MHz for unsupported modes */
cfg80211_chandef_create(&chandef, cbss->channel,
NL80211_CHAN_NO_HT);
break;
}
sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
rate_flags = ieee80211_chandef_rate_flags(&sdata->u.ibss.chandef);
shift = ieee80211_vif_get_shift(&sdata->vif);
basic_rates = 0;
for (i = 0; i < bss->supp_rates_len; i++) {
int rate = bss->supp_rates[i] & 0x7f;
bool is_basic = !!(bss->supp_rates[i] & 0x80);
for (j = 0; j < sband->n_bitrates; j++) {
int brate;
if ((rate_flags & sband->bitrates[j].flags)
!= rate_flags)
continue;
brate = DIV_ROUND_UP(sband->bitrates[j].bitrate,
5 * (1 << shift));
if (brate == rate) {
if (is_basic)
basic_rates |= BIT(j);
break;
}
}
}
rcu_read_lock();
ies = rcu_dereference(cbss->ies);
tsf = ies->tsf;
rcu_read_unlock();
__ieee80211_sta_join_ibss(sdata, cbss->bssid,
beacon_int,
&chandef,
basic_rates,
cbss->capability,
tsf, false);
}
int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
struct cfg80211_csa_settings *csa_settings)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct beacon_data *presp, *old_presp;
struct cfg80211_bss *cbss;
const struct cfg80211_bss_ies *ies;
u16 capability = WLAN_CAPABILITY_IBSS;
u64 tsf;
int ret = 0;
sdata_assert_lock(sdata);
if (ifibss->privacy)
capability |= WLAN_CAPABILITY_PRIVACY;
cbss = cfg80211_get_bss(sdata->local->hw.wiphy, ifibss->chandef.chan,
ifibss->bssid, ifibss->ssid,
ifibss->ssid_len, IEEE80211_BSS_TYPE_IBSS,
IEEE80211_PRIVACY(ifibss->privacy));
if (WARN_ON(!cbss)) {
ret = -EINVAL;
goto out;
}
rcu_read_lock();
ies = rcu_dereference(cbss->ies);
tsf = ies->tsf;
rcu_read_unlock();
cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
old_presp = rcu_dereference_protected(ifibss->presp,
lockdep_is_held(&sdata->wdev.mtx));
presp = ieee80211_ibss_build_presp(sdata,
sdata->vif.bss_conf.beacon_int,
sdata->vif.bss_conf.basic_rates,
capability, tsf, &ifibss->chandef,
NULL, csa_settings);
if (!presp) {
ret = -ENOMEM;
goto out;
}
rcu_assign_pointer(ifibss->presp, presp);
if (old_presp)
kfree_rcu(old_presp, rcu_head);
return BSS_CHANGED_BEACON;
out:
return ret;
}
int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct cfg80211_bss *cbss;
sdata_assert_lock(sdata);
/* update cfg80211 bss information with the new channel */
if (!is_zero_ether_addr(ifibss->bssid)) {
cbss = cfg80211_get_bss(sdata->local->hw.wiphy,
ifibss->chandef.chan,
ifibss->bssid, ifibss->ssid,
ifibss->ssid_len,
IEEE80211_BSS_TYPE_IBSS,
IEEE80211_PRIVACY(ifibss->privacy));
/* XXX: should not really modify cfg80211 data */
if (cbss) {
cbss->channel = sdata->csa_chandef.chan;
cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
}
}
ifibss->chandef = sdata->csa_chandef;
/* generate the beacon */
return ieee80211_ibss_csa_beacon(sdata, NULL);
}
void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
cancel_work_sync(&ifibss->csa_connection_drop_work);
}
static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
__acquires(RCU)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
u8 addr[ETH_ALEN];
memcpy(addr, sta->sta.addr, ETH_ALEN);
ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
/* authorize the station only if the network is not RSN protected. If
* not wait for the userspace to authorize it */
if (!sta->sdata->u.ibss.control_port)
sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
rate_control_rate_init(sta);
/* If it fails, maybe we raced another insertion? */
if (sta_info_insert_rcu(sta))
return sta_info_get(sdata, addr);
return sta;
}
static struct sta_info *
ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
const u8 *addr, u32 supp_rates)
__acquires(RCU)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
struct ieee80211_chanctx_conf *chanctx_conf;
struct ieee80211_supported_band *sband;
enum nl80211_bss_scan_width scan_width;
int band;
/*
* XXX: Consider removing the least recently used entry and
* allow new one to be added.
*/
if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
sdata->name, addr);
rcu_read_lock();
return NULL;
}
if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
rcu_read_lock();
return NULL;
}
if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
rcu_read_lock();
return NULL;
}
rcu_read_lock();
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
if (WARN_ON_ONCE(!chanctx_conf))
return NULL;
band = chanctx_conf->def.chan->band;
scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
rcu_read_unlock();
sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
if (!sta) {
rcu_read_lock();
return NULL;
}
/* make sure mandatory rates are always added */
sband = local->hw.wiphy->bands[band];
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(sband, scan_width);
return ieee80211_ibss_finish_sta(sta);
}
static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
int active = 0;
struct sta_info *sta;
sdata_assert_lock(sdata);
rcu_read_lock();
list_for_each_entry_rcu(sta, &local->sta_list, list) {
unsigned long last_active = ieee80211_sta_last_active(sta);
if (sta->sdata == sdata &&
time_is_after_jiffies(last_active +
IEEE80211_IBSS_MERGE_INTERVAL)) {
active++;
break;
}
}
rcu_read_unlock();
return active;
}
static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct cfg80211_bss *cbss;
struct beacon_data *presp;
struct sta_info *sta;
if (!is_zero_ether_addr(ifibss->bssid)) {
cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
ifibss->bssid, ifibss->ssid,
ifibss->ssid_len,
IEEE80211_BSS_TYPE_IBSS,
IEEE80211_PRIVACY(ifibss->privacy));
if (cbss) {
cfg80211_unlink_bss(local->hw.wiphy, cbss);
cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
}
}
ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
sta_info_flush(sdata);
spin_lock_bh(&ifibss->incomplete_lock);
while (!list_empty(&ifibss->incomplete_stations)) {
sta = list_first_entry(&ifibss->incomplete_stations,
struct sta_info, list);
list_del(&sta->list);
spin_unlock_bh(&ifibss->incomplete_lock);
sta_info_free(local, sta);
spin_lock_bh(&ifibss->incomplete_lock);
}
spin_unlock_bh(&ifibss->incomplete_lock);
netif_carrier_off(sdata->dev);
sdata->vif.bss_conf.ibss_joined = false;
sdata->vif.bss_conf.ibss_creator = false;
sdata->vif.bss_conf.enable_beacon = false;
sdata->vif.bss_conf.ssid_len = 0;
/* remove beacon */
presp = rcu_dereference_protected(ifibss->presp,
lockdep_is_held(&sdata->wdev.mtx));
RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
if (presp)
kfree_rcu(presp, rcu_head);
clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
BSS_CHANGED_IBSS);
drv_leave_ibss(local, sdata);
mutex_lock(&local->mtx);
ieee80211_vif_release_channel(sdata);
mutex_unlock(&local->mtx);
}
static void ieee80211_csa_connection_drop_work(struct work_struct *work)
{
struct ieee80211_sub_if_data *sdata =
container_of(work, struct ieee80211_sub_if_data,
u.ibss.csa_connection_drop_work);
sdata_lock(sdata);
ieee80211_ibss_disconnect(sdata);
synchronize_rcu();
skb_queue_purge(&sdata->skb_queue);
/* trigger a scan to find another IBSS network to join */
ieee80211_queue_work(&sdata->local->hw, &sdata->work);
sdata_unlock(sdata);
}
static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
int err;
/* if the current channel is a DFS channel, mark the channel as
* unavailable.
*/
err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
&ifibss->chandef,
NL80211_IFTYPE_ADHOC);
if (err > 0)
cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
GFP_ATOMIC);
}
static bool
ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
struct ieee802_11_elems *elems,
bool beacon)
{
struct cfg80211_csa_settings params;
struct ieee80211_csa_ie csa_ie;
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
enum nl80211_channel_type ch_type;
int err;
u32 sta_flags;
sdata_assert_lock(sdata);
sta_flags = IEEE80211_STA_DISABLE_VHT;
switch (ifibss->chandef.width) {
case NL80211_CHAN_WIDTH_5:
case NL80211_CHAN_WIDTH_10:
case NL80211_CHAN_WIDTH_20_NOHT:
sta_flags |= IEEE80211_STA_DISABLE_HT;
/* fall through */
case NL80211_CHAN_WIDTH_20:
sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
break;
default:
break;
}
memset(&params, 0, sizeof(params));
err = ieee80211_parse_ch_switch_ie(sdata, elems,
ifibss->chandef.chan->band,
sta_flags, ifibss->bssid, &csa_ie);
/* can't switch to destination channel, fail */
if (err < 0)
goto disconnect;
/* did not contain a CSA */
if (err)
return false;
/* channel switch is not supported, disconnect */
if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
goto disconnect;
params.count = csa_ie.count;
params.chandef = csa_ie.chandef;
switch (ifibss->chandef.width) {
case NL80211_CHAN_WIDTH_20_NOHT:
case NL80211_CHAN_WIDTH_20:
case NL80211_CHAN_WIDTH_40:
/* keep our current HT mode (HT20/HT40+/HT40-), even if
* another mode has been announced. The mode is not adopted
* within the beacon while doing CSA and we should therefore
* keep the mode which we announce.
*/
ch_type = cfg80211_get_chandef_type(&ifibss->chandef);
cfg80211_chandef_create(&params.chandef, params.chandef.chan,
ch_type);
break;
case NL80211_CHAN_WIDTH_5:
case NL80211_CHAN_WIDTH_10:
if (params.chandef.width != ifibss->chandef.width) {
sdata_info(sdata,
"IBSS %pM received channel switch from incompatible channel width (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
ifibss->bssid,
params.chandef.chan->center_freq,
params.chandef.width,
params.chandef.center_freq1,
params.chandef.center_freq2);
goto disconnect;
}
break;
default:
/* should not happen, sta_flags should prevent VHT modes. */
WARN_ON(1);
goto disconnect;
}
if (!cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
NL80211_IFTYPE_ADHOC)) {
sdata_info(sdata,
"IBSS %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
ifibss->bssid,
params.chandef.chan->center_freq,
params.chandef.width,
params.chandef.center_freq1,
params.chandef.center_freq2);
goto disconnect;
}
err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
&params.chandef,
NL80211_IFTYPE_ADHOC);
if (err < 0)
goto disconnect;
if (err > 0 && !ifibss->userspace_handles_dfs) {
/* IBSS-DFS only allowed with a control program */
goto disconnect;
}
params.radar_required = err;
if (cfg80211_chandef_identical(&params.chandef,
&sdata->vif.bss_conf.chandef)) {
ibss_dbg(sdata,
"received csa with an identical chandef, ignoring\n");
return true;
}
/* all checks done, now perform the channel switch. */
ibss_dbg(sdata,
"received channel switch announcement to go to channel %d MHz\n",
params.chandef.chan->center_freq);
params.block_tx = !!csa_ie.mode;
if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
&params))
goto disconnect;
ieee80211_ibss_csa_mark_radar(sdata);
return true;
disconnect:
ibss_dbg(sdata, "Can't handle channel switch, disconnect\n");
ieee80211_queue_work(&sdata->local->hw,
&ifibss->csa_connection_drop_work);
ieee80211_ibss_csa_mark_radar(sdata);
return true;
}
static void
ieee80211_rx_mgmt_spectrum_mgmt(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_rx_status *rx_status,
struct ieee802_11_elems *elems)
{
int required_len;
if (len < IEEE80211_MIN_ACTION_SIZE + 1)
return;
/* CSA is the only action we handle for now */
if (mgmt->u.action.u.measurement.action_code !=
WLAN_ACTION_SPCT_CHL_SWITCH)
return;
required_len = IEEE80211_MIN_ACTION_SIZE +
sizeof(mgmt->u.action.u.chan_switch);
if (len < required_len)
return;
if (!sdata->vif.csa_active)
ieee80211_ibss_process_chanswitch(sdata, elems, false);
}
static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len)
{
u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
if (len < IEEE80211_DEAUTH_FRAME_LEN)
return;
ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM\n", mgmt->sa, mgmt->da);
ibss_dbg(sdata, "\tBSSID=%pM (reason: %d)\n", mgmt->bssid, reason);
sta_info_destroy_addr(sdata, mgmt->sa);
}
static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len)
{
u16 auth_alg, auth_transaction;
sdata_assert_lock(sdata);
if (len < 24 + 6)
return;
auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
ibss_dbg(sdata, "RX Auth SA=%pM DA=%pM\n", mgmt->sa, mgmt->da);
ibss_dbg(sdata, "\tBSSID=%pM (auth_transaction=%d)\n",
mgmt->bssid, auth_transaction);
if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
return;
/*
* IEEE 802.11 standard does not require authentication in IBSS
* networks and most implementations do not seem to use it.
* However, try to reply to authentication attempts if someone
* has actually implemented this.
*/
ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
}
static void ieee80211_update_sta_info(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_rx_status *rx_status,
struct ieee802_11_elems *elems,
struct ieee80211_channel *channel)
{
struct sta_info *sta;
enum nl80211_band band = rx_status->band;
enum nl80211_bss_scan_width scan_width;
struct ieee80211_local *local = sdata->local;
struct ieee80211_supported_band *sband;
bool rates_updated = false;
u32 supp_rates = 0;
if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
return;
if (!ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid))
return;
sband = local->hw.wiphy->bands[band];
if (WARN_ON(!sband))
return;
rcu_read_lock();
sta = sta_info_get(sdata, mgmt->sa);
if (elems->supp_rates) {
supp_rates = ieee80211_sta_get_rates(sdata, elems,
band, NULL);
if (sta) {
u32 prev_rates;
prev_rates = sta->sta.supp_rates[band];
/* make sure mandatory rates are always added */
scan_width = NL80211_BSS_CHAN_WIDTH_20;
if (rx_status->bw == RATE_INFO_BW_5)
scan_width = NL80211_BSS_CHAN_WIDTH_5;
else if (rx_status->bw == RATE_INFO_BW_10)
scan_width = NL80211_BSS_CHAN_WIDTH_10;
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(sband, scan_width);
if (sta->sta.supp_rates[band] != prev_rates) {
ibss_dbg(sdata,
"updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
sta->sta.addr, prev_rates,
sta->sta.supp_rates[band]);
rates_updated = true;
}
} else {
rcu_read_unlock();
sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
mgmt->sa, supp_rates);
}
}
if (sta && !sta->sta.wme &&
elems->wmm_info && local->hw.queues >= IEEE80211_NUM_ACS) {
sta->sta.wme = true;
ieee80211_check_fast_xmit(sta);
}
if (sta && elems->ht_operation && elems->ht_cap_elem &&
sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 &&
sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) {
/* we both use HT */
struct ieee80211_ht_cap htcap_ie;
struct cfg80211_chan_def chandef;
enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
cfg80211_chandef_create(&chandef, channel, NL80211_CHAN_NO_HT);
ieee80211_chandef_ht_oper(elems->ht_operation, &chandef);
memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
&htcap_ie,
sta);
if (elems->vht_operation && elems->vht_cap_elem &&
sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20 &&
sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_40) {
/* we both use VHT */
struct ieee80211_vht_cap cap_ie;
struct ieee80211_sta_vht_cap cap = sta->sta.vht_cap;
ieee80211_chandef_vht_oper(&local->hw,
elems->vht_operation,
elems->ht_operation,
&chandef);
memcpy(&cap_ie, elems->vht_cap_elem, sizeof(cap_ie));
ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
&cap_ie, sta);
if (memcmp(&cap, &sta->sta.vht_cap, sizeof(cap)))
rates_updated |= true;
}
if (bw != sta->sta.bandwidth)
rates_updated |= true;
if (!cfg80211_chandef_compatible(&sdata->u.ibss.chandef,
&chandef))
WARN_ON_ONCE(1);
}
if (sta && rates_updated) {
u32 changed = IEEE80211_RC_SUPP_RATES_CHANGED;
u8 rx_nss = sta->sta.rx_nss;
/* Force rx_nss recalculation */
sta->sta.rx_nss = 0;
rate_control_rate_init(sta);
if (sta->sta.rx_nss != rx_nss)
changed |= IEEE80211_RC_NSS_CHANGED;
drv_sta_rc_update(local, sdata, &sta->sta, changed);
}
rcu_read_unlock();
}
static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_rx_status *rx_status,
struct ieee802_11_elems *elems)
{
struct ieee80211_local *local = sdata->local;
struct cfg80211_bss *cbss;
struct ieee80211_bss *bss;
struct ieee80211_channel *channel;
u64 beacon_timestamp, rx_timestamp;
u32 supp_rates = 0;
enum nl80211_band band = rx_status->band;
channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
if (!channel)
return;
ieee80211_update_sta_info(sdata, mgmt, len, rx_status, elems, channel);
bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, channel);
if (!bss)
return;
cbss = container_of((void *)bss, struct cfg80211_bss, priv);
/* same for beacon and probe response */
beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
/* check if we need to merge IBSS */
/* not an IBSS */
if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
goto put_bss;
/* different channel */
if (sdata->u.ibss.fixed_channel &&
sdata->u.ibss.chandef.chan != cbss->channel)
goto put_bss;
/* different SSID */
if (elems->ssid_len != sdata->u.ibss.ssid_len ||
memcmp(elems->ssid, sdata->u.ibss.ssid,
sdata->u.ibss.ssid_len))
goto put_bss;
/* process channel switch */
if (sdata->vif.csa_active ||
ieee80211_ibss_process_chanswitch(sdata, elems, true))
goto put_bss;
/* same BSSID */
if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
goto put_bss;
/* we use a fixed BSSID */
if (sdata->u.ibss.fixed_bssid)
goto put_bss;
if (ieee80211_have_rx_timestamp(rx_status)) {
/* time when timestamp field was received */
rx_timestamp =
ieee80211_calculate_rx_timestamp(local, rx_status,
len + FCS_LEN, 24);
} else {
/*
* second best option: get current TSF
* (will return -1 if not supported)
*/
rx_timestamp = drv_get_tsf(local, sdata);
}
ibss_dbg(sdata, "RX beacon SA=%pM BSSID=%pM TSF=0x%llx\n",
mgmt->sa, mgmt->bssid,
(unsigned long long)rx_timestamp);
ibss_dbg(sdata, "\tBCN=0x%llx diff=%lld @%lu\n",
(unsigned long long)beacon_timestamp,
(unsigned long long)(rx_timestamp - beacon_timestamp),
jiffies);
if (beacon_timestamp > rx_timestamp) {
ibss_dbg(sdata,
"beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
mgmt->bssid);
ieee80211_sta_join_ibss(sdata, bss);
supp_rates = ieee80211_sta_get_rates(sdata, elems, band, NULL);
ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
supp_rates);
rcu_read_unlock();
}
put_bss:
ieee80211_rx_bss_put(local, bss);
}
void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
const u8 *bssid, const u8 *addr,
u32 supp_rates)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
struct ieee80211_chanctx_conf *chanctx_conf;
struct ieee80211_supported_band *sband;
enum nl80211_bss_scan_width scan_width;
int band;
/*
* XXX: Consider removing the least recently used entry and
* allow new one to be added.
*/
if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
sdata->name, addr);
return;
}
if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
return;
if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
return;
rcu_read_lock();
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
if (WARN_ON_ONCE(!chanctx_conf)) {
rcu_read_unlock();
return;
}
band = chanctx_conf->def.chan->band;
scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
rcu_read_unlock();
sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
if (!sta)
return;
/* make sure mandatory rates are always added */
sband = local->hw.wiphy->bands[band];
sta->sta.supp_rates[band] = supp_rates |
ieee80211_mandatory_rates(sband, scan_width);
spin_lock(&ifibss->incomplete_lock);
list_add(&sta->list, &ifibss->incomplete_stations);
spin_unlock(&ifibss->incomplete_lock);
ieee80211_queue_work(&local->hw, &sdata->work);
}
static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct sta_info *sta, *tmp;
unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
unsigned long exp_rsn = IEEE80211_IBSS_RSN_INACTIVITY_LIMIT;
mutex_lock(&local->sta_mtx);
list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
unsigned long last_active = ieee80211_sta_last_active(sta);
if (sdata != sta->sdata)
continue;
if (time_is_before_jiffies(last_active + exp_time) ||
(time_is_before_jiffies(last_active + exp_rsn) &&
sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
sta->sta_state != IEEE80211_STA_AUTHORIZED ?
"not authorized " : "", sta->sta.addr);
ieee80211_send_deauth_disassoc(sdata, sta->sta.addr,
ifibss->bssid,
IEEE80211_STYPE_DEAUTH,
WLAN_REASON_DEAUTH_LEAVING,
true, frame_buf);
WARN_ON(__sta_info_destroy(sta));
}
}
mutex_unlock(&local->sta_mtx);
}
/*
* This function is called with state == IEEE80211_IBSS_MLME_JOINED
*/
static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
enum nl80211_bss_scan_width scan_width;
sdata_assert_lock(sdata);
mod_timer(&ifibss->timer,
round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
ieee80211_ibss_sta_expire(sdata);
if (time_before(jiffies, ifibss->last_scan_completed +
IEEE80211_IBSS_MERGE_INTERVAL))
return;
if (ieee80211_sta_active_ibss(sdata))
return;
if (ifibss->fixed_channel)
return;
sdata_info(sdata,
"No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
NULL, 0, scan_width);
}
static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
u8 bssid[ETH_ALEN];
u16 capability;
int i;
sdata_assert_lock(sdata);
if (ifibss->fixed_bssid) {
memcpy(bssid, ifibss->bssid, ETH_ALEN);
} else {
/* Generate random, not broadcast, locally administered BSSID. Mix in
* own MAC address to make sure that devices that do not have proper
* random number generator get different BSSID. */
get_random_bytes(bssid, ETH_ALEN);
for (i = 0; i < ETH_ALEN; i++)
bssid[i] ^= sdata->vif.addr[i];
bssid[0] &= ~0x01;
bssid[0] |= 0x02;
}
sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
capability = WLAN_CAPABILITY_IBSS;
if (ifibss->privacy)
capability |= WLAN_CAPABILITY_PRIVACY;
__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
&ifibss->chandef, ifibss->basic_rates,
capability, 0, true);
}
static unsigned ibss_setup_channels(struct wiphy *wiphy,
struct ieee80211_channel **channels,
unsigned int channels_max,
u32 center_freq, u32 width)
{
struct ieee80211_channel *chan = NULL;
unsigned int n_chan = 0;
u32 start_freq, end_freq, freq;
if (width <= 20) {
start_freq = center_freq;
end_freq = center_freq;
} else {
start_freq = center_freq - width / 2 + 10;
end_freq = center_freq + width / 2 - 10;
}
for (freq = start_freq; freq <= end_freq; freq += 20) {
chan = ieee80211_get_channel(wiphy, freq);
if (!chan)
continue;
if (n_chan >= channels_max)
return n_chan;
channels[n_chan] = chan;
n_chan++;
}
return n_chan;
}
static unsigned int
ieee80211_ibss_setup_scan_channels(struct wiphy *wiphy,
const struct cfg80211_chan_def *chandef,
struct ieee80211_channel **channels,
unsigned int channels_max)
{
unsigned int n_chan = 0;
u32 width, cf1, cf2 = 0;
switch (chandef->width) {
case NL80211_CHAN_WIDTH_40:
width = 40;
break;
case NL80211_CHAN_WIDTH_80P80:
cf2 = chandef->center_freq2;
/* fall through */
case NL80211_CHAN_WIDTH_80:
width = 80;
break;
case NL80211_CHAN_WIDTH_160:
width = 160;
break;
default:
width = 20;
break;
}
cf1 = chandef->center_freq1;
n_chan = ibss_setup_channels(wiphy, channels, channels_max, cf1, width);
if (cf2)
n_chan += ibss_setup_channels(wiphy, &channels[n_chan],
channels_max - n_chan, cf2,
width);
return n_chan;
}
/*
* This function is called with state == IEEE80211_IBSS_MLME_SEARCH
*/
static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct cfg80211_bss *cbss;
struct ieee80211_channel *chan = NULL;
const u8 *bssid = NULL;
enum nl80211_bss_scan_width scan_width;
int active_ibss;
sdata_assert_lock(sdata);
active_ibss = ieee80211_sta_active_ibss(sdata);
ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
if (active_ibss)
return;
if (ifibss->fixed_bssid)
bssid = ifibss->bssid;
if (ifibss->fixed_channel)
chan = ifibss->chandef.chan;
if (!is_zero_ether_addr(ifibss->bssid))
bssid = ifibss->bssid;
cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
ifibss->ssid, ifibss->ssid_len,
IEEE80211_BSS_TYPE_IBSS,
IEEE80211_PRIVACY(ifibss->privacy));
if (cbss) {
struct ieee80211_bss *bss;
bss = (void *)cbss->priv;
ibss_dbg(sdata,
"sta_find_ibss: selected %pM current %pM\n",
cbss->bssid, ifibss->bssid);
sdata_info(sdata,
"Selected IBSS BSSID %pM based on configured SSID\n",
cbss->bssid);
ieee80211_sta_join_ibss(sdata, bss);
ieee80211_rx_bss_put(local, bss);
return;
}
/* if a fixed bssid and a fixed freq have been provided create the IBSS
* directly and do not waste time scanning
*/
if (ifibss->fixed_bssid && ifibss->fixed_channel) {
sdata_info(sdata, "Created IBSS using preconfigured BSSID %pM\n",
bssid);
ieee80211_sta_create_ibss(sdata);
return;
}
ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
/* Selected IBSS not found in current scan results - try to scan */
if (time_after(jiffies, ifibss->last_scan_completed +
IEEE80211_SCAN_INTERVAL)) {
struct ieee80211_channel *channels[8];
unsigned int num;
sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
if (ifibss->fixed_channel) {
num = ieee80211_ibss_setup_scan_channels(local->hw.wiphy,
&ifibss->chandef,
channels,
ARRAY_SIZE(channels));
ieee80211_request_ibss_scan(sdata, ifibss->ssid,
ifibss->ssid_len, channels,
num, scan_width);
} else {
ieee80211_request_ibss_scan(sdata, ifibss->ssid,
ifibss->ssid_len, NULL,
0, scan_width);
}
} else {
int interval = IEEE80211_SCAN_INTERVAL;
if (time_after(jiffies, ifibss->ibss_join_req +
IEEE80211_IBSS_JOIN_TIMEOUT))
ieee80211_sta_create_ibss(sdata);
mod_timer(&ifibss->timer,
round_jiffies(jiffies + interval));
}
}
static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
struct sk_buff *req)
{
struct ieee80211_mgmt *mgmt = (void *)req->data;
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
int tx_last_beacon, len = req->len;
struct sk_buff *skb;
struct beacon_data *presp;
u8 *pos, *end;
sdata_assert_lock(sdata);
presp = rcu_dereference_protected(ifibss->presp,
lockdep_is_held(&sdata->wdev.mtx));
if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
len < 24 + 2 || !presp)
return;
tx_last_beacon = drv_tx_last_beacon(local);
ibss_dbg(sdata, "RX ProbeReq SA=%pM DA=%pM\n", mgmt->sa, mgmt->da);
ibss_dbg(sdata, "\tBSSID=%pM (tx_last_beacon=%d)\n",
mgmt->bssid, tx_last_beacon);
if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
return;
if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
!is_broadcast_ether_addr(mgmt->bssid))
return;
end = ((u8 *) mgmt) + len;
pos = mgmt->u.probe_req.variable;
if (pos[0] != WLAN_EID_SSID ||
pos + 2 + pos[1] > end) {
ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
mgmt->sa);
return;
}
if (pos[1] != 0 &&
(pos[1] != ifibss->ssid_len ||
memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
/* Ignore ProbeReq for foreign SSID */
return;
}
/* Reply with ProbeResp */
skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
if (!skb)
return;
skb_reserve(skb, local->tx_headroom);
skb_put_data(skb, presp->head, presp->head_len);
memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
/* avoid excessive retries for probe request to wildcard SSIDs */
if (pos[1] == 0)
IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_NO_ACK;
ieee80211_tx_skb(sdata, skb);
}
static
void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_rx_status *rx_status)
{
size_t baselen;
struct ieee802_11_elems elems;
BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
offsetof(typeof(mgmt->u.beacon), variable));
/*
* either beacon or probe_resp but the variable field is at the
* same offset
*/
baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
if (baselen > len)
return;
ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
false, &elems, mgmt->bssid, NULL);
ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
}
void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_rx_status *rx_status;
struct ieee80211_mgmt *mgmt;
u16 fc;
struct ieee802_11_elems elems;
int ies_len;
rx_status = IEEE80211_SKB_RXCB(skb);
mgmt = (struct ieee80211_mgmt *) skb->data;
fc = le16_to_cpu(mgmt->frame_control);
sdata_lock(sdata);
if (!sdata->u.ibss.ssid_len)
goto mgmt_out; /* not ready to merge yet */
switch (fc & IEEE80211_FCTL_STYPE) {
case IEEE80211_STYPE_PROBE_REQ:
ieee80211_rx_mgmt_probe_req(sdata, skb);
break;
case IEEE80211_STYPE_PROBE_RESP:
case IEEE80211_STYPE_BEACON:
ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
rx_status);
break;
case IEEE80211_STYPE_AUTH:
ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
break;
case IEEE80211_STYPE_DEAUTH:
ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
break;
case IEEE80211_STYPE_ACTION:
switch (mgmt->u.action.category) {
case WLAN_CATEGORY_SPECTRUM_MGMT:
ies_len = skb->len -
offsetof(struct ieee80211_mgmt,
u.action.u.chan_switch.variable);
if (ies_len < 0)
break;
ieee802_11_parse_elems(
mgmt->u.action.u.chan_switch.variable,
ies_len, true, &elems, mgmt->bssid, NULL);
if (elems.parse_error)
break;
ieee80211_rx_mgmt_spectrum_mgmt(sdata, mgmt, skb->len,
rx_status, &elems);
break;
}
}
mgmt_out:
sdata_unlock(sdata);
}
void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct sta_info *sta;
sdata_lock(sdata);
/*
* Work could be scheduled after scan or similar
* when we aren't even joined (or trying) with a
* network.
*/
if (!ifibss->ssid_len)
goto out;
spin_lock_bh(&ifibss->incomplete_lock);
while (!list_empty(&ifibss->incomplete_stations)) {
sta = list_first_entry(&ifibss->incomplete_stations,
struct sta_info, list);
list_del(&sta->list);
spin_unlock_bh(&ifibss->incomplete_lock);
ieee80211_ibss_finish_sta(sta);
rcu_read_unlock();
spin_lock_bh(&ifibss->incomplete_lock);
}
spin_unlock_bh(&ifibss->incomplete_lock);
switch (ifibss->state) {
case IEEE80211_IBSS_MLME_SEARCH:
ieee80211_sta_find_ibss(sdata);
break;
case IEEE80211_IBSS_MLME_JOINED:
ieee80211_sta_merge_ibss(sdata);
break;
default:
WARN_ON(1);
break;
}
out:
sdata_unlock(sdata);
}
static void ieee80211_ibss_timer(struct timer_list *t)
{
struct ieee80211_sub_if_data *sdata =
from_timer(sdata, t, u.ibss.timer);
ieee80211_queue_work(&sdata->local->hw, &sdata->work);
}
void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
timer_setup(&ifibss->timer, ieee80211_ibss_timer, 0);
INIT_LIST_HEAD(&ifibss->incomplete_stations);
spin_lock_init(&ifibss->incomplete_lock);
INIT_WORK(&ifibss->csa_connection_drop_work,
ieee80211_csa_connection_drop_work);
}
/* scan finished notification */
void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
{
struct ieee80211_sub_if_data *sdata;
mutex_lock(&local->iflist_mtx);
list_for_each_entry(sdata, &local->interfaces, list) {
if (!ieee80211_sdata_running(sdata))
continue;
if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
continue;
sdata->u.ibss.last_scan_completed = jiffies;
}
mutex_unlock(&local->iflist_mtx);
}
int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
struct cfg80211_ibss_params *params)
{
u32 changed = 0;
u32 rate_flags;
struct ieee80211_supported_band *sband;
enum ieee80211_chanctx_mode chanmode;
struct ieee80211_local *local = sdata->local;
int radar_detect_width = 0;
int i;
int ret;
ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
&params->chandef,
sdata->wdev.iftype);
if (ret < 0)
return ret;
if (ret > 0) {
if (!params->userspace_handles_dfs)
return -EINVAL;
radar_detect_width = BIT(params->chandef.width);
}
chanmode = (params->channel_fixed && !ret) ?
IEEE80211_CHANCTX_SHARED : IEEE80211_CHANCTX_EXCLUSIVE;
mutex_lock(&local->chanctx_mtx);
ret = ieee80211_check_combinations(sdata, &params->chandef, chanmode,
radar_detect_width);
mutex_unlock(&local->chanctx_mtx);
if (ret < 0)
return ret;
if (params->bssid) {
memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
sdata->u.ibss.fixed_bssid = true;
} else
sdata->u.ibss.fixed_bssid = false;
sdata->u.ibss.privacy = params->privacy;
sdata->u.ibss.control_port = params->control_port;
sdata->u.ibss.userspace_handles_dfs = params->userspace_handles_dfs;
sdata->u.ibss.basic_rates = params->basic_rates;
sdata->u.ibss.last_scan_completed = jiffies;
/* fix basic_rates if channel does not support these rates */
rate_flags = ieee80211_chandef_rate_flags(&params->chandef);
sband = local->hw.wiphy->bands[params->chandef.chan->band];
for (i = 0; i < sband->n_bitrates; i++) {
if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
sdata->u.ibss.basic_rates &= ~BIT(i);
}
memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
sizeof(params->mcast_rate));
sdata->vif.bss_conf.beacon_int = params->beacon_interval;
sdata->u.ibss.chandef = params->chandef;
sdata->u.ibss.fixed_channel = params->channel_fixed;
if (params->ie) {
sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
GFP_KERNEL);
if (sdata->u.ibss.ie)
sdata->u.ibss.ie_len = params->ie_len;
}
sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
sdata->u.ibss.ibss_join_req = jiffies;
memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
sdata->u.ibss.ssid_len = params->ssid_len;
memcpy(&sdata->u.ibss.ht_capa, &params->ht_capa,
sizeof(sdata->u.ibss.ht_capa));
memcpy(&sdata->u.ibss.ht_capa_mask, &params->ht_capa_mask,
sizeof(sdata->u.ibss.ht_capa_mask));
/*
* 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
* reserved, but an HT STA shall protect HT transmissions as though
* the HT Protection field were set to non-HT mixed mode.
*
* In an IBSS, the RIFS Mode field of the HT Operation element is
* also reserved, but an HT STA shall operate as though this field
* were set to 1.
*/
sdata->vif.bss_conf.ht_operation_mode |=
IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
| IEEE80211_HT_PARAM_RIFS_MODE;
changed |= BSS_CHANGED_HT | BSS_CHANGED_MCAST_RATE;
ieee80211_bss_info_change_notify(sdata, changed);
sdata->smps_mode = IEEE80211_SMPS_OFF;
sdata->needed_rx_chains = local->rx_chains;
sdata->control_port_over_nl80211 = params->control_port_over_nl80211;
ieee80211_queue_work(&local->hw, &sdata->work);
return 0;
}
int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
ieee80211_ibss_disconnect(sdata);
ifibss->ssid_len = 0;
eth_zero_addr(ifibss->bssid);
/* remove beacon */
kfree(sdata->u.ibss.ie);
/* on the next join, re-program HT parameters */
memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
synchronize_rcu();
skb_queue_purge(&sdata->skb_queue);
del_timer_sync(&sdata->u.ibss.timer);
return 0;
}
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