wireguard-tools/src/wg-quick.bash

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#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
#
set -e -o pipefail
shopt -s extglob
export LC_ALL=C
SELF="$(readlink -f "${BASH_SOURCE[0]}")"
export PATH="${SELF%/*}:$PATH"
WG_CONFIG=""
INTERFACE=""
ADDRESSES=( )
MTU=""
DNS=( )
TABLE=""
PRE_UP=( )
POST_UP=( )
PRE_DOWN=( )
POST_DOWN=( )
SAVE_CONFIG=0
CONFIG_FILE=""
PROGRAM="${0##*/}"
ARGS=( "$@" )
parse_options() {
local interface_section=0 line key value stripped
CONFIG_FILE="$1"
[[ $CONFIG_FILE =~ ^[a-zA-Z0-9_=+.-]{1,15}$ ]] && CONFIG_FILE="/etc/wireguard/$CONFIG_FILE.conf"
[[ -e $CONFIG_FILE ]] || die "\`$CONFIG_FILE' does not exist"
[[ $CONFIG_FILE =~ (^|/)([a-zA-Z0-9_=+.-]{1,15})\.conf$ ]] || die "The config file must be a valid interface name, followed by .conf"
CONFIG_FILE="$(readlink -f "$CONFIG_FILE")"
((($(stat -c '0%#a' "$CONFIG_FILE") & $(stat -c '0%#a' "${CONFIG_FILE%/*}") & 0007) == 0)) || echo "Warning: \`$CONFIG_FILE' is world accessible" >&2
INTERFACE="${BASH_REMATCH[2]}"
shopt -s nocasematch
while read -r line || [[ -n $line ]]; do
stripped="${line%%\#*}"
key="${stripped%%=*}"; key="${key##*([[:space:]])}"; key="${key%%*([[:space:]])}"
value="${stripped#*=}"; value="${value##*([[:space:]])}"; value="${value%%*([[:space:]])}"
[[ $key == "["* ]] && interface_section=0
[[ $key == "[Interface]" ]] && interface_section=1
if [[ $interface_section -eq 1 ]]; then
case "$key" in
Address) ADDRESSES+=( ${value//,/ } ); continue ;;
MTU) MTU="$value"; continue ;;
DNS) DNS+=( ${value//,/ } ); continue ;;
Table) TABLE="$value"; continue ;;
PreUp) PRE_UP+=( "$value" ); continue ;;
PreDown) PRE_DOWN+=( "$value" ); continue ;;
PostUp) POST_UP+=( "$value" ); continue ;;
PostDown) POST_DOWN+=( "$value" ); continue ;;
SaveConfig) read_bool SAVE_CONFIG "$value"; continue ;;
esac
fi
WG_CONFIG+="$line"$'\n'
done < "$CONFIG_FILE"
shopt -u nocasematch
}
read_bool() {
case "$2" in
true) printf -v "$1" 1 ;;
false) printf -v "$1" 0 ;;
*) die "\`$2' is neither true nor false"
esac
}
cmd() {
echo "[#] $*" >&2
"$@"
}
die() {
echo "$PROGRAM: $*" >&2
exit 1
}
auto_su() {
[[ $UID == 0 ]] || exec sudo -p "$PROGRAM must be run as root. Please enter the password for %u to continue: " "$SELF" "${ARGS[@]}"
}
add_if() {
cmd ip link add "$INTERFACE" type wireguard
}
del_if() {
local fwmark
[[ $HAVE_SET_DNS -eq 0 ]] || unset_dns
fwmark="$(wg show "$INTERFACE" fwmark)"
DEFAULT_TABLE=0
[[ $fwmark != off ]] && DEFAULT_TABLE=$(( fwmark ))
if [[ $DEFAULT_TABLE -ne 0 ]]; then
while [[ $(ip -4 rule show) == *"lookup $DEFAULT_TABLE"* ]]; do
cmd ip -4 rule delete table $DEFAULT_TABLE
done
while [[ $(ip -4 rule show) == *"from all lookup main suppress_prefixlength 0"* ]]; do
cmd ip -4 rule delete table main suppress_prefixlength 0
done
while [[ $(ip -6 rule show) == *"lookup $DEFAULT_TABLE"* ]]; do
cmd ip -6 rule delete table $DEFAULT_TABLE
done
while [[ $(ip -6 rule show) == *"from all lookup main suppress_prefixlength 0"* ]]; do
cmd ip -6 rule delete table main suppress_prefixlength 0
done
fi
cmd ip link delete dev "$INTERFACE"
}
up_if() {
cmd ip link set "$INTERFACE" up
}
add_addr() {
cmd ip address add "$1" dev "$INTERFACE"
}
set_mtu() {
local mtu=0 endpoint output
if [[ -n $MTU ]]; then
cmd ip link set mtu "$MTU" dev "$INTERFACE"
return
fi
while read -r _ endpoint; do
[[ $endpoint =~ ^\[?([a-z0-9:.]+)\]?:[0-9]+$ ]] || continue
output="$(ip route get "${BASH_REMATCH[1]}" || true)"
[[ ( $output =~ mtu\ ([0-9]+) || ( $output =~ dev\ ([^ ]+) && $(ip link show dev "${BASH_REMATCH[1]}") =~ mtu\ ([0-9]+) ) ) && ${BASH_REMATCH[1]} -gt $mtu ]] && mtu="${BASH_REMATCH[1]}"
done < <(wg show "$INTERFACE" endpoints)
if [[ $mtu -eq 0 ]]; then
read -r output < <(ip route show default || true) || true
[[ ( $output =~ mtu\ ([0-9]+) || ( $output =~ dev\ ([^ ]+) && $(ip link show dev "${BASH_REMATCH[1]}") =~ mtu\ ([0-9]+) ) ) && ${BASH_REMATCH[1]} -gt $mtu ]] && mtu="${BASH_REMATCH[1]}"
fi
[[ $mtu -gt 0 ]] || mtu=1500
cmd ip link set mtu $(( mtu - 80 )) dev "$INTERFACE"
}
resolvconf_iface_prefix() {
[[ -f /etc/resolvconf/interface-order ]] || return 0
local iface
while read -r iface; do
[[ $iface =~ ^([A-Za-z0-9-]+)\*$ ]] || continue
echo "${BASH_REMATCH[1]}." && return 0
done < /etc/resolvconf/interface-order
}
HAVE_SET_DNS=0
set_dns() {
[[ ${#DNS[@]} -gt 0 ]] || return 0
printf 'nameserver %s\n' "${DNS[@]}" | cmd resolvconf -a "$(resolvconf_iface_prefix)$INTERFACE" -m 0 -x
HAVE_SET_DNS=1
}
unset_dns() {
[[ ${#DNS[@]} -gt 0 ]] || return 0
cmd resolvconf -d "$(resolvconf_iface_prefix)$INTERFACE"
}
add_route() {
[[ $TABLE != off ]] || return 0
if [[ -n $TABLE && $TABLE != auto ]]; then
cmd ip route add "$1" dev "$INTERFACE" table "$TABLE"
elif [[ $1 == */0 ]]; then
add_default "$1"
else
[[ $(ip route get "$i" 2>/dev/null) == *dev\ $INTERFACE\ * ]] || cmd ip route add "$1" dev "$INTERFACE"
fi
}
DEFAULT_TABLE=
add_default() {
if [[ -z $DEFAULT_TABLE ]]; then
DEFAULT_TABLE=51820
while [[ -n $(ip -4 route show table $DEFAULT_TABLE) || -n $(ip -6 route show table $DEFAULT_TABLE) ]]; do
((DEFAULT_TABLE++))
done
fi
local proto=-4
[[ $1 == *:* ]] && proto=-6
cmd wg set "$INTERFACE" fwmark $DEFAULT_TABLE
cmd ip $proto route add "$1" dev "$INTERFACE" table $DEFAULT_TABLE
cmd ip $proto rule add not fwmark $DEFAULT_TABLE table $DEFAULT_TABLE
cmd ip $proto rule add table main suppress_prefixlength 0
local key value
while read -r key _ value; do
[[ $value -eq 1 ]] && sysctl -q "$key=2"
done < <(sysctl -a -r '^net\.ipv4.conf\.[^ .=]+\.rp_filter$')
return 0
}
set_config() {
cmd wg setconf "$INTERFACE" <(echo "$WG_CONFIG")
}
save_config() {
local old_umask new_config current_config address cmd
[[ $(ip -all -brief address show dev "$INTERFACE") =~ ^$INTERFACE\ +\ [A-Z]+\ +(.+)$ ]] || true
new_config=$'[Interface]\n'
for address in ${BASH_REMATCH[1]}; do
new_config+="Address = $address"$'\n'
done
while read -r address; do
[[ $address =~ ^nameserver\ ([a-zA-Z0-9_=+:%.-]+)$ ]] && new_config+="DNS = ${BASH_REMATCH[1]}"$'\n'
done < <(resolvconf -l "$(resolvconf_iface_prefix)$INTERFACE" 2>/dev/null || cat "/etc/resolvconf/run/interface/$(resolvconf_iface_prefix)$INTERFACE")
[[ -n $MTU && $(ip link show dev "$INTERFACE") =~ mtu\ ([0-9]+) ]] && new_config+="MTU = ${BASH_REMATCH[1]}"$'\n'
[[ -n $TABLE ]] && new_config+="Table = $TABLE"$'\n'
[[ $SAVE_CONFIG -eq 0 ]] || new_config+=$'SaveConfig = true\n'
for cmd in "${PRE_UP[@]}"; do
new_config+="PreUp = $cmd"$'\n'
done
for cmd in "${POST_UP[@]}"; do
new_config+="PostUp = $cmd"$'\n'
done
for cmd in "${PRE_DOWN[@]}"; do
new_config+="PreDown = $cmd"$'\n'
done
for cmd in "${POST_DOWN[@]}"; do
new_config+="PostDown = $cmd"$'\n'
done
old_umask="$(umask)"
umask 077
current_config="$(cmd wg showconf "$INTERFACE")"
trap 'rm -f "$CONFIG_FILE.tmp"; exit' INT TERM EXIT
echo "${current_config/\[Interface\]$'\n'/$new_config}" > "$CONFIG_FILE.tmp" || die "Could not write configuration file"
sync "$CONFIG_FILE.tmp"
mv "$CONFIG_FILE.tmp" "$CONFIG_FILE" || die "Could not move configuration file"
trap - INT TERM EXIT
umask "$old_umask"
}
execute_hooks() {
local hook
for hook in "$@"; do
hook="${hook//%i/$INTERFACE}"
echo "[#] $hook" >&2
(eval "$hook")
done
}
cmd_usage() {
cat >&2 <<-_EOF
Usage: $PROGRAM [ up | down | save ] [ CONFIG_FILE | INTERFACE ]
CONFIG_FILE is a configuration file, whose filename is the interface name
followed by \`.conf'. Otherwise, INTERFACE is an interface name, with
configuration found at /etc/wireguard/INTERFACE.conf. It is to be readable
by wg(8)'s \`setconf' sub-command, with the exception of the following additions
to the [Interface] section, which are handled by $PROGRAM:
- Address: may be specified one or more times and contains one or more
IP addresses (with an optional CIDR mask) to be set for the interface.
- DNS: an optional DNS server to use while the device is up.
- MTU: an optional MTU for the interface; if unspecified, auto-calculated.
- Table: an optional routing table to which routes will be added; if
unspecified or \`auto', the default table is used. If \`off', no routes
are added.
- PreUp, PostUp, PreDown, PostDown: script snippets which will be executed
by bash(1) at the corresponding phases of the link, most commonly used
to configure DNS. The string \`%i' is expanded to INTERFACE.
- SaveConfig: if set to \`true', the configuration is saved from the current
state of the interface upon shutdown.
See wg-quick(8) for more info and examples.
_EOF
}
cmd_up() {
local i
[[ -z $(ip link show dev "$INTERFACE" 2>/dev/null) ]] || die "\`$INTERFACE' already exists"
trap 'del_if; exit' INT TERM EXIT
execute_hooks "${PRE_UP[@]}"
add_if
set_config
for i in "${ADDRESSES[@]}"; do
add_addr "$i"
done
set_mtu
up_if
set_dns
for i in $(while read -r _ i; do for i in $i; do [[ $i =~ ^[0-9a-z:.]+/[0-9]+$ ]] && echo "$i"; done; done < <(wg show "$INTERFACE" allowed-ips) | sort -nr -k 2 -t /); do
add_route "$i"
done
execute_hooks "${POST_UP[@]}"
trap - INT TERM EXIT
}
cmd_down() {
[[ " $(wg show interfaces) " == *" $INTERFACE "* ]] || die "\`$INTERFACE' is not a WireGuard interface"
execute_hooks "${PRE_DOWN[@]}"
[[ $SAVE_CONFIG -eq 0 ]] || save_config
del_if
unset_dns
execute_hooks "${POST_DOWN[@]}"
}
cmd_save() {
[[ " $(wg show interfaces) " == *" $INTERFACE "* ]] || die "\`$INTERFACE' is not a WireGuard interface"
save_config
}
# ~~ function override insertion point ~~
if [[ $# -eq 1 && ( $1 == --help || $1 == -h || $1 == help ) ]]; then
cmd_usage
elif [[ $# -eq 2 && $1 == up ]]; then
auto_su
parse_options "$2"
cmd_up
elif [[ $# -eq 2 && $1 == down ]]; then
auto_su
parse_options "$2"
cmd_down
elif [[ $# -eq 2 && $1 == save ]]; then
auto_su
parse_options "$2"
cmd_save
else
cmd_usage
exit 1
fi
exit 0