#!/bin/sh
append DRIVERS "mac80211"
+mac80211_hostapd_setup_base() {
+ local phy="$1"
+ local ifname="$2"
+
+ cfgfile="/var/run/hostapd-$phy.conf"
+ macfile="/var/run/hostapd-$phy.maclist"
+ [ -e "$macfile" ] && rm -f "$macfile"
+
+ config_get device "$vif" device
+ config_get country "$device" country
+ config_get hwmode "$device" hwmode
+ config_get channel "$device" channel
+ config_get beacon_int "$device" beacon_int
+ config_get basic_rate_list "$device" basic_rate
+ config_get_bool noscan "$device" noscan
+
+ hostapd_set_log_options base_cfg "$device"
+
+ [ -n "$channel" -a -z "$hwmode" ] && wifi_fixup_hwmode "$device"
+
+ [ "$channel" = auto ] && {
+ channel=$(iw phy "$phy" info | \
+ sed -ne '/MHz/ { /disabled\|passive\|radar/d; s/.*\[//; s/\].*//; p; q }')
+ config_set "$device" channel "$channel"
+ }
+
+ [ -n "$hwmode" ] && {
+ config_get hwmode_11n "$device" hwmode_11n
+ [ -n "$hwmode_11n" ] && {
+ hwmode="$hwmode_11n"
+ append base_cfg "ieee80211n=1" "$N"
+ config_get htmode "$device" htmode
+ config_get ht_capab_list "$device" ht_capab
+ case "$htmode" in
+ HT20|HT40+|HT40-) ht_capab="[$htmode]";;
+ *)ht_capab=;;
+ esac
+ for cap in $ht_capab_list; do
+ ht_capab="$ht_capab[$cap]"
+ done
+ [ -n "$ht_capab" ] && append base_cfg "ht_capab=$ht_capab" "$N"
+ }
+ }
+
+ local country_ie=0
+ [ -n "$country" ] && country_ie=1
+ config_get_bool country_ie "$device" country_ie "$country_ie"
+ [ "$country_ie" -gt 0 ] && append base_cfg "ieee80211d=1" "$N"
+
+ config_get macfilter "$vif" macfilter
+ case "$macfilter" in
+ allow)
+ append base_cfg "macaddr_acl=1" "$N"
+ append base_cfg "accept_mac_file=$macfile" "$N"
+ ;;
+ deny)
+ append base_cfg "macaddr_acl=0" "$N"
+ append base_cfg "deny_mac_file=$macfile" "$N"
+ ;;
+ esac
+ config_get maclist "$vif" maclist
+ [ -n "$maclist" ] && {
+ for mac in $maclist; do
+ echo "$mac" >> $macfile
+ done
+ }
+
+ local br brval brstr
+ [ -n "$basic_rate_list" ] && {
+ for br in $basic_rate_list; do
+ brval="$(($br / 100))"
+ [ -n "$brstr" ] && brstr="$brstr "
+ brstr="$brstr$brval"
+ done
+ }
+
+ cat >> "$cfgfile" <<EOF
+ctrl_interface=/var/run/hostapd-$phy
+driver=nl80211
+wmm_ac_bk_cwmin=4
+wmm_ac_bk_cwmax=10
+wmm_ac_bk_aifs=7
+wmm_ac_bk_txop_limit=0
+wmm_ac_bk_acm=0
+wmm_ac_be_aifs=3
+wmm_ac_be_cwmin=4
+wmm_ac_be_cwmax=10
+wmm_ac_be_txop_limit=0
+wmm_ac_be_acm=0
+wmm_ac_vi_aifs=2
+wmm_ac_vi_cwmin=3
+wmm_ac_vi_cwmax=4
+wmm_ac_vi_txop_limit=94
+wmm_ac_vi_acm=0
+wmm_ac_vo_aifs=2
+wmm_ac_vo_cwmin=2
+wmm_ac_vo_cwmax=3
+wmm_ac_vo_txop_limit=47
+wmm_ac_vo_acm=0
+tx_queue_data3_aifs=7
+tx_queue_data3_cwmin=15
+tx_queue_data3_cwmax=1023
+tx_queue_data3_burst=0
+tx_queue_data2_aifs=3
+tx_queue_data2_cwmin=15
+tx_queue_data2_cwmax=63
+tx_queue_data2_burst=0
+tx_queue_data1_aifs=1
+tx_queue_data1_cwmin=7
+tx_queue_data1_cwmax=15
+tx_queue_data1_burst=3.0
+tx_queue_data0_aifs=1
+tx_queue_data0_cwmin=3
+tx_queue_data0_cwmax=7
+tx_queue_data0_burst=1.5
+${hwmode:+hw_mode=$hwmode}
+${channel:+channel=$channel}
+${beacon_int:+beacon_int=$beacon_int}
+${country:+country_code=$country}
+${noscan:+noscan=$noscan}
+${brstr:+basic_rates=$brstr}
+$base_cfg
+
+EOF
+}
+
+mac80211_hostapd_setup_bss() {
+ local phy="$1"
+ local vif="$2"
+
+ hostapd_cfg=
+ cfgfile="/var/run/hostapd-$phy.conf"
+ config_get ifname "$vif" ifname
+
+ if [ -f "$cfgfile" ]; then
+ append hostapd_cfg "bss=$ifname" "$N"
+ else
+ mac80211_hostapd_setup_base "$phy" "$ifname"
+ append hostapd_cfg "interface=$ifname" "$N"
+ fi
+
+ local net_cfg bridge
+ net_cfg="$(find_net_config "$vif")"
+ [ -z "$net_cfg" ] || bridge="$(bridge_interface "$net_cfg")"
+ config_set "$vif" bridge "$bridge"
+
+ hostapd_set_bss_options hostapd_cfg "$vif"
+
+ config_get_bool wds "$vif" wds 0
+ [ "$wds" -gt 0 ] && append hostapd_cfg "wds_sta=1" "$N"
+
+ local macaddr hidden maxassoc wmm
+ config_get macaddr "$vif" macaddr
+ config_get maxassoc "$vif" maxassoc
+ config_get dtim_period "$vif" dtim_period
+ config_get max_listen_int "$vif" max_listen_int
+ config_get_bool hidden "$vif" hidden 0
+ config_get_bool wmm "$vif" wmm 1
+ cat >> /var/run/hostapd-$phy.conf <<EOF
+$hostapd_cfg
+wmm_enabled=$wmm
+bssid=$macaddr
+ignore_broadcast_ssid=$hidden
+${dtim_period:+dtim_period=$dtim_period}
+${max_listen_int:+max_listen_interval=$max_listen_int}
+${maxassoc:+max_num_sta=$maxassoc}
+EOF
+}
+
+mac80211_start_vif() {
+ local vif="$1"
+ local ifname="$2"
+
+ local net_cfg
+ net_cfg="$(find_net_config "$vif")"
+ [ -z "$net_cfg" ] || start_net "$ifname" "$net_cfg"
+
+ set_wifi_up "$vif" "$ifname"
+}
+
find_mac80211_phy() {
- config_get device "$1"
+ local device="$1"
local macaddr="$(config_get "$device" macaddr | tr 'A-Z' 'a-z')"
config_get phy "$device" phy
scan_mac80211() {
local device="$1"
- local adhoc sta ap monitor mesh
+ local adhoc sta ap monitor mesh disabled
config_get vifs "$device" vifs
for vif in $vifs; do
+ config_get_bool disabled "$vif" disabled 0
+ [ $disabled = 0 ] || continue
+
config_get mode "$vif" mode
case "$mode" in
adhoc|sta|ap|monitor|mesh)
config_set "$device" vifs "${ap:+$ap }${adhoc:+$adhoc }${sta:+$sta }${monitor:+$monitor }${mesh:+$mesh}"
}
+list_phy_interfaces() {
+ local phy="$1"
+ if [ -d "/sys/class/ieee80211/${phy}/device/net" ]; then
+ ls "/sys/class/ieee80211/${phy}/device/net" 2>/dev/null;
+ else
+ ls "/sys/class/ieee80211/${phy}/device" 2>/dev/null | grep net: | sed -e 's,net:,,g'
+ fi
+}
disable_mac80211() (
local device="$1"
set_wifi_down "$device"
# kill all running hostapd and wpa_supplicant processes that
# are running on atheros/mac80211 vifs
- for pid in `pidof hostapd wpa_supplicant`; do
- grep wlan /proc/$pid/cmdline >/dev/null && \
+ for pid in `pidof hostapd`; do
+ grep -E "$phy" /proc/$pid/cmdline >/dev/null && \
kill $pid
done
include /lib/network
- for wdev in $(ls /sys/class/ieee80211/${phy}/device/net 2>/dev/null); do
+ for wdev in $(list_phy_interfaces "$phy"); do
+ [ -f "/var/run/$wdev.pid" ] && kill $(cat /var/run/$wdev.pid) >&/dev/null 2>&1
+ for pid in `pidof wpa_supplicant`; do
+ grep "$wdev" /proc/$pid/cmdline >/dev/null && \
+ kill $pid
+ done
ifconfig "$wdev" down 2>/dev/null
unbridge "$dev"
iw dev "$wdev" del
return 0
)
+
get_freq() {
local phy="$1"
local chan="$2"
iw "$phy" info | grep -E -m1 "(\* ${chan:-....} MHz${chan:+|\\[$chan\\]})" | grep MHz | awk '{print $2}'
}
+
+mac80211_generate_mac() {
+ local off="$1"
+ local mac="$2"
+ local oIFS="$IFS"; IFS=":"; set -- $mac; IFS="$oIFS"
+
+ local b2mask=0x00
+ [ $off -gt 0 ] && b2mask=0x02
+
+ printf "%02x:%s:%s:%s:%02x:%02x" \
+ $(( 0x$1 | $b2mask )) $2 $3 $4 \
+ $(( (0x$5 + ($off / 0x100)) % 0x100 )) \
+ $(( (0x$6 + $off) % 0x100 ))
+}
+
enable_mac80211() {
local device="$1"
config_get channel "$device" channel
config_get vifs "$device" vifs
config_get txpower "$device" txpower
config_get country "$device" country
+ config_get distance "$device" distance
+ config_get txantenna "$device" txantenna all
+ config_get rxantenna "$device" rxantenna all
+ config_get frag "$device" frag
+ config_get rts "$device" rts
find_mac80211_phy "$device" || return 0
config_get phy "$device" phy
local i=0
+ local macidx=0
+ local apidx=0
fixed=""
+ local hostapd_ctrl=""
+
+ [ -n "$country" ] && {
+ iw reg get | grep -q "^country $country:" || {
+ iw reg set "$country"
+ sleep 1
+ }
+ }
+
+ config_get ath9k_chanbw "$device" ath9k_chanbw
+ [ -n "$ath9k_chanbw" -a -d /sys/kernel/debug/ieee80211/$phy/ath9k ] && echo "$ath9k_chanbw" > /sys/kernel/debug/ieee80211/$phy/ath9k/chanbw
[ -n "$country" ] && iw reg set "$country"
[ "$channel" = "auto" -o "$channel" = "0" ] || {
fixed=1
}
+ iw phy "$phy" set antenna $txantenna $rxantenna >/dev/null 2>&1
+
+ [ -n "$distance" ] && iw phy "$phy" set distance "$distance"
+ [ -n "$frag" ] && iw phy "$phy" set frag "${frag%%.*}"
+ [ -n "$rts" ] && iw phy "$phy" set rts "${rts%%.*}"
+
export channel fixed
# convert channel to frequency
local freq="$(get_freq "$phy" "${fixed:+$channel}")"
wifi_fixup_hwmode "$device" "g"
for vif in $vifs; do
- while [ -d "/sys/class/net/wlan$i" ]; do
- i=$(($i + 1))
- done
-
config_get ifname "$vif" ifname
[ -n "$ifname" ] || {
- ifname="wlan$i"
+ [ $i -gt 0 ] && ifname="wlan${phy#phy}-$i" || ifname="wlan${phy#phy}"
}
config_set "$vif" ifname "$ifname"
- config_get enc "$vif" encryption
config_get mode "$vif" mode
config_get ssid "$vif" ssid
- config_get_bool wds "$vif" wds 0
# It is far easier to delete and create the desired interface
case "$mode" in
ap)
# Hostapd will handle recreating the interface and
# it's accompanying monitor
- iw phy "$phy" interface add "$ifname" type managed
+ apidx="$(($apidx + 1))"
+ [ "$apidx" -gt 1 ] || iw phy "$phy" interface add "$ifname" type managed
;;
mesh)
config_get mesh_id "$vif" mesh_id
;;
sta)
local wdsflag
+ config_get_bool wds "$vif" wds 0
[ "$wds" -gt 0 ] && wdsflag="4addr on"
iw phy "$phy" interface add "$ifname" type managed $wdsflag
config_get_bool powersave "$vif" powersave 0
[ "$powersave" -gt 0 ] && powersave="on" || powersave="off"
- iwconfig "$ifname" power "$powersave"
+ iw "$ifname" set power_save "$powersave"
;;
esac
# which can either be explicitly set in the device
# section, or automatically generated
config_get macaddr "$device" macaddr
- local mac_1="${macaddr%%:*}"
- local mac_2="${macaddr#*:}"
-
config_get vif_mac "$vif" macaddr
[ -n "$vif_mac" ] || {
- if [ "$i" -gt 0 ]; then
- offset="$(( 2 + $i * 4 ))"
- else
- offset="0"
- fi
- vif_mac="$( printf %02x $((0x$mac_1 + $offset)) ):$mac_2"
+ vif_mac="$(mac80211_generate_mac $macidx $macaddr)"
+ macidx="$(($macidx + 1))"
}
- ifconfig "$ifname" hw ether "$vif_mac"
-
- # We attempt to set teh channel for all interfaces, although
- # mac80211 may not support it or the driver might not yet
- [ -n "$fixed" -a -n "$channel" ] && iw dev "$ifname" set channel "$channel"
-
- local key keystring
+ [ "$mode" = "ap" ] || ifconfig "$ifname" hw ether "$vif_mac"
+ config_set "$vif" macaddr "$vif_mac"
- # Valid values are:
- # wpa / wep / none
- #
# !! ap !!
#
# ALL ap functionality will be passed to hostapd
#
- # !! mesh / adhoc / station !!
- # none -> NO encryption
+ # !! station !!
#
- # wep + keymgmt = '' -> we use iw to connect to the
- # network.
+ # ALL station functionality will be passed to wpa_supplicant
#
- # wep + keymgmt = 'NONE' -> wpa_supplicant will be
- # configured to handle the wep connection
if [ ! "$mode" = "ap" ]; then
- case "$enc" in
- *wep*)
- config_get keymgmt "$vif" keymgmt
- if [ -z "$keymgmt" ]; then
- config_get key "$vif" key
- key="${key:-1}"
- case "$key" in
- [1234])
- for idx in 1 2 3 4; do
- local zidx
- zidx=$(($idx - 1))
- config_get ckey "$vif" "key${idx}"
- if [ -n "$ckey" ]; then
- [ $idx -eq $key ] && zidx="d:${zidx}"
- append keystring "${zidx}:$(prepare_key_wep "$ckey")"
- fi
- done
- ;;
- *)
- keystring="d:0:$(prepare_key_wep "$key")"
- ;;
- esac
- fi
- ;;
- *psk*|*wpa*)
- config_get key "$vif" key
- ;;
- esac
+ # We attempt to set the channel for all interfaces, although
+ # mac80211 may not support it or the driver might not yet
+ # for ap mode this is handled by hostapd
+ [ -n "$fixed" -a -n "$channel" ] && iw dev "$ifname" set channel "$channel"
fi
- # txpower is not yet implemented in iw
+ i=$(($i + 1))
+ done
+
+ local start_hostapd=
+ rm -f /var/run/hostapd-$phy.conf
+ for vif in $vifs; do
+ config_get mode "$vif" mode
+ [ "$mode" = "ap" ] || continue
+ mac80211_hostapd_setup_bss "$phy" "$vif"
+ start_hostapd=1
+ done
+
+ [ -n "$start_hostapd" ] && {
+ hostapd -P /var/run/wifi-$phy.pid -B /var/run/hostapd-$phy.conf || {
+ echo "Failed to start hostapd for $phy"
+ return
+ }
+ sleep 2
+
+ for vif in $vifs; do
+ config_get mode "$vif" mode
+ config_get ifname "$vif" ifname
+ [ "$mode" = "ap" ] || continue
+ hostapd_ctrl="${hostapd_ctrl:-/var/run/hostapd-$phy/$ifname}"
+ mac80211_start_vif "$vif" "$ifname"
+ done
+ }
+
+ for vif in $vifs; do
+ config_get mode "$vif" mode
+ config_get ifname "$vif" ifname
+ [ ! "$mode" = "ap" ] || continue
+ ifconfig "$ifname" up
+
config_get vif_txpower "$vif" txpower
# use vif_txpower (from wifi-iface) to override txpower (from
# wifi-device) if the latter doesn't exist
txpower="${txpower:-$vif_txpower}"
- [ -z "$txpower" ] || iwconfig "$ifname" txpower "${txpower%%.*}"
+ [ -z "$txpower" ] || iw dev "$ifname" set txpower fixed "${txpower%%.*}00"
- config_get frag "$vif" frag
- if [ -n "$frag" ]; then
- iw phy "$phy" set frag "${frag%%.*}"
- fi
-
- config_get rts "$vif" rts
- if [ -n "$rts" ]; then
- iw phy "$phy" set rts "${rts%%.*}"
- fi
-
- ifconfig "$ifname" up
+ if [ ! "$mode" = "ap" ]; then
+ ifconfig "$ifname" up
+ case "$mode" in
+ adhoc)
+ config_get bssid "$vif" bssid
+ config_get ssid "$vif" ssid
+ config_get beacon_int "$device" beacon_int
+ config_get basic_rate_list "$device" basic_rate
+ config_get encryption "$vif" encryption
+ config_get key "$vif" key 1
+ config_get mcast_rate "$vif" mcast_rate
+
+ local keyspec=""
+ [ "$encryption" == "wep" ] && {
+ case "$key" in
+ [1234])
+ local idx
+ for idx in 1 2 3 4; do
+ local ikey
+ config_get ikey "$vif" "key$idx"
+
+ [ -n "$ikey" ] && {
+ ikey="$(($idx - 1)):$(prepare_key_wep "$ikey")"
+ [ $idx -eq $key ] && ikey="d:$ikey"
+ append keyspec "$ikey"
+ }
+ done
+ ;;
+ *) append keyspec "d:0:$(prepare_key_wep "$key")" ;;
+ esac
+ }
- local net_cfg bridge
- net_cfg="$(find_net_config "$vif")"
- [ -z "$net_cfg" ] || {
- bridge="$(bridge_interface "$net_cfg")"
- config_set "$vif" bridge "$bridge"
- start_net "$ifname" "$net_cfg"
- }
+ local br brval brsub brstr
+ [ -n "$basic_rate_list" ] && {
+ for br in $basic_rate_list; do
+ brval="$(($br / 1000))"
+ brsub="$((($br / 100) % 10))"
+ [ "$brsub" -gt 0 ] && brval="$brval.$brsub"
+ [ -n "$brstr" ] && brstr="$brstr,"
+ brstr="$brstr$brval"
+ done
+ }
- set_wifi_up "$vif" "$ifname"
- case "$mode" in
- ap)
- if eval "type hostapd_setup_vif" 2>/dev/null >/dev/null; then
- hostapd_setup_vif "$vif" nl80211 || {
- echo "enable_mac80211($device): Failed to set up wpa for interface $ifname" >&2
- # make sure this wifi interface won't accidentally stay open without encryption
- ifconfig "$ifname" down
- continue
+ local mcval=""
+ [ -n "$mcast_rate" ] && {
+ mcval="$(($mcast_rate / 1000))"
+ mcsub="$(( ($mcast_rate / 100) % 10 ))"
+ [ "$mcsub" -gt 0 ] && mcval="$mcval.$mcsub"
}
- fi
- ;;
- adhoc)
- config_get bssid "$vif" bssid
- iw dev "$ifname" ibss join "$ssid" $freq ${fixed:+fixed-freq} $bssid
- ;;
- sta|mesh)
- config_get bssid "$vif" bssid
- case "$enc" in
- *wep*)
- if [ -z "$keymgmt" ]; then
- [ -n "$keystring" ] &&
- iw dev "$ifname" connect "$ssid" ${fixed:+$freq} $bssid key $keystring
- else
- if eval "type wpa_supplicant_setup_vif" 2>/dev/null >/dev/null; then
- wpa_supplicant_setup_vif "$vif" wext || {
- echo "enable_mac80211($device): Failed to set up wpa_supplicant for interface $ifname" >&2
- # make sure this wifi interface won't accidentally stay open without encryption
- ifconfig "$ifname" down
- continue
- }
- fi
- fi
- ;;
- *wpa*|*psk*)
- config_get key "$vif" key
- if eval "type wpa_supplicant_setup_vif" 2>/dev/null >/dev/null; then
- wpa_supplicant_setup_vif "$vif" wext || {
- echo "enable_mac80211($device): Failed to set up wpa_supplicant for interface $ifname" >&2
- # make sure this wifi interface won't accidentally stay open without encryption
- ifconfig "$ifname" down
- continue
- }
- fi
- ;;
- *)
- iw dev "$ifname" connect "$ssid" ${fixed:+$freq} $bssid
- ;;
- esac
- ;;
- esac
+ config_get htmode "$device" htmode
+ case "$htmode" in
+ HT20|HT40+|HT40-) ;;
+ *) htmode= ;;
+ esac
+
+ iw dev "$ifname" ibss join "$ssid" $freq $htmode \
+ ${fixed:+fixed-freq} $bssid \
+ ${beacon_int:+beacon-interval $beacon_int} \
+ ${brstr:+basic-rates $brstr} \
+ ${mcval:+mcast-rate $mcval} \
+ ${keyspec:+keys $keyspec}
+ ;;
+ sta)
+ if eval "type wpa_supplicant_setup_vif" 2>/dev/null >/dev/null; then
+ wpa_supplicant_setup_vif "$vif" nl80211 "${hostapd_ctrl:+-H $hostapd_ctrl}" || {
+ echo "enable_mac80211($device): Failed to set up wpa_supplicant for interface $ifname" >&2
+ # make sure this wifi interface won't accidentally stay open without encryption
+ ifconfig "$ifname" down
+ continue
+ }
+ fi
+ ;;
+ esac
+ mac80211_start_vif "$vif" "$ifname"
+ fi
done
+
}
-check_device() {
+check_mac80211_device() {
config_get phy "$1" phy
[ -z "$phy" ] && {
find_mac80211_phy "$1" >/dev/null || return 0
done
for dev in $(ls /sys/class/ieee80211); do
found=0
- config_foreach check_device wifi-device
+ config_foreach check_mac80211_device wifi-device
[ "$found" -gt 0 ] && continue
mode_11n=""
mode_band="g"
- channel="5"
+ channel="11"
ht_cap=0
- for cap in $(iw phy "$dev" info | grep 'HT capabilities' | cut -d: -f2); do
+ for cap in $(iw phy "$dev" info | grep 'Capabilities:' | cut -d: -f2); do
ht_cap="$(($ht_cap | $cap))"
done
ht_capab="";
[ "$ht_cap" -gt 0 ] && {
mode_11n="n"
+ append ht_capab " option htmode HT20" "$N"
+
list=" list ht_capab"
[ "$(($ht_cap & 1))" -eq 1 ] && append ht_capab "$list LDPC" "$N"
- [ "$(($ht_cap & 2))" -eq 2 ] && append ht_capab "$list HT40-" "$N"
+ [ "$(($ht_cap & 16))" -eq 16 ] && append ht_capab "$list GF" "$N"
[ "$(($ht_cap & 32))" -eq 32 ] && append ht_capab "$list SHORT-GI-20" "$N"
[ "$(($ht_cap & 64))" -eq 64 ] && append ht_capab "$list SHORT-GI-40" "$N"
+ [ "$(($ht_cap & 128))" -eq 128 ] && append ht_capab "$list TX-STBC" "$N"
+ [ "$(($ht_cap & 768))" -eq 256 ] && append ht_capab "$list RX-STBC1" "$N"
+ [ "$(($ht_cap & 768))" -eq 512 ] && append ht_capab "$list RX-STBC12" "$N"
+ [ "$(($ht_cap & 768))" -eq 768 ] && append ht_capab "$list RX-STBC123" "$N"
[ "$(($ht_cap & 4096))" -eq 4096 ] && append ht_capab "$list DSSS_CCK-40" "$N"
}
iw phy "$dev" info | grep -q '2412 MHz' || { mode_band="a"; channel="36"; }
option channel ${channel}
option macaddr $(cat /sys/class/ieee80211/${dev}/macaddress)
option hwmode 11${mode_11n}${mode_band}
+$ht_capab
# REMOVE THIS LINE TO ENABLE WIFI:
option disabled 1
-$ht_capab
config wifi-iface
option device radio$devidx