#!/bin/bash # # Copyright (C) 2016-2017 Jason A. Donenfeld . All Rights Reserved. # set -e -o pipefail shopt -s extglob SELF="$(readlink -f "${BASH_SOURCE[0]}")" export PATH="${SELF%/*}:$PATH" WG_CONFIG="" INTERFACE="" ADDRESSES=( ) 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 CONFIG_FILE="$1" [[ $CONFIG_FILE =~ ^[a-zA-Z0-9_=+.-]{1,16}$ ]] && CONFIG_FILE="/etc/wireguard/$CONFIG_FILE.conf" [[ -e $CONFIG_FILE ]] || die "\`$CONFIG_FILE' does not exist" [[ $CONFIG_FILE =~ /?([a-zA-Z0-9_=+.-]{1,16})\.conf$ ]] || die "The config file must be a valid interface name, followed by .conf" ((($(stat -c '%#a' "$CONFIG_FILE") & 0007) == 0)) || echo "Warning: \`$CONFIG_FILE' is world accessible" >&2 INTERFACE="${BASH_REMATCH[1]}" shopt -s nocasematch while read -r line; do key="${line%%=*}"; key="${key##*( )}"; key="${key%%*( )}" value="${line#*=}"; value="${value##*( )}"; value="${value%%*( )}" [[ $key == "["* ]] && interface_section=0 [[ $key == "[Interface]" ]] && interface_section=1 if [[ $interface_section -eq 1 ]]; then case "$key" in Address) ADDRESSES+=( ${value//,/ } ); continue ;; PreUp) PRE_UP="$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() { local -n out="$1" case "$2" in true) out=1 ;; false) out=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 "$INTERFACE" type wireguard } del_if() { DEFAULT_TABLE=$(("$(wg show "$INTERFACE" fwmark)")) if [[ $DEFAULT_TABLE -ne 0 ]]; then while [[ -n $(ip -4 rule show table $DEFAULT_TABLE) ]]; do cmd ip -4 rule delete table $DEFAULT_TABLE [[ $(ip -4 rule show table main) == *"from all lookup main suppress_prefixlength 0"* ]] && cmd ip -4 rule delete table main suppress_prefixlength 0 done while [[ -n $(ip -6 rule show table $DEFAULT_TABLE) ]]; do cmd ip -6 rule delete table $DEFAULT_TABLE [[ $(ip -6 rule show table main) == *"from all lookup main suppress_prefixlength 0"* ]] && cmd ip -6 rule delete table main suppress_prefixlength 0 done fi cmd ip link delete dev "$INTERFACE" } up_if() { cmd ip link set "$INTERFACE" up } add_addr() { cmd ip address add "$1" dev "$INTERFACE" } add_route() { if [[ $1 == 0.0.0.0/0 || $1 == ::/0 ]]; then add_default "$1" else cmd ip route add "$1" dev "$INTERFACE" fi } DEFAULT_TABLE= add_default() { if [[ -z $DEFAULT_TABLE ]]; then DEFAULT_TABLE=51820 while [[ -n $(ip 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 equals value while read -r key equals 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 [[ $(ip -all -brief address show dev "$INTERFACE") =~ ^$INTERFACE\ +\ [A-Z]+\ +(.+)$ ]] || true new_config=$'[Interface]\n' for address in ${BASH_REMATCH[1]}; do new_config+="Address = $address"$'\n' done [[ $SAVE_CONFIG -eq 0 ]] || new_config+=$'SaveConfig = true\n' [[ -z $PRE_UP ]] || new_config+="PreUp = $PRE_UP"$'\n' [[ -z $POST_UP ]] || new_config+="PostUp = $POST_UP"$'\n' [[ -z $PRE_DOWN ]] || new_config+="PreDown = $PRE_DOWN"$'\n' [[ -z $POST_DOWN ]] || new_config+="PostDown = $POST_DOWN"$'\n' 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}" > "$CONFIG_FILE.tmp" || die "Could not write configuration file" mv "$CONFIG_FILE.tmp" "$CONFIG_FILE" || die "Could not move configuration file" trap - INT TERM EXIT umask "$old_umask" } execute_hook() { [[ -n $1 ]] || return 0 local hook="${1//%i/$INTERFACE}" echo "[#] $hook" >&2 (eval "$hook") } cmd_usage() { cat >&2 <<-_EOF Usage: $PROGRAM [ up | down ] [ 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. - 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 "\`$INTERFACE' already exists" trap 'del_if; exit' INT TERM EXIT execute_hook "$PRE_UP" add_if set_config for i in "${ADDRESSES[@]}"; do add_addr "$i" done up_if for i in $(wg show "$INTERFACE" allowed-ips | grep -Po '(?<=[\t ])[0-9.:/a-f]+' | sort -nr -k 2 -t /); do [[ $(ip route get "$i" 2>/dev/null) == *dev\ $INTERFACE\ * ]] || add_route "$i" done execute_hook "$POST_UP" trap - INT TERM EXIT } cmd_down() { [[ -n $(ip link show dev "$INTERFACE" type wireguard 2>/dev/null) ]] || die "\`$INTERFACE' is not a WireGuard interface" execute_hook "$PRE_DOWN" [[ $SAVE_CONFIG -eq 0 ]] || save_config del_if execute_hook "$POST_DOWN" } 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 else cmd_usage exit 1 fi exit 0