#!/system/xbin/bash # # Copyright (C) 2016-2017 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="" NETID=0 ADDRESSES=( ) MTU="" DNS=( ) 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="/data/misc/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 || [[ -n $line ]]; do key="${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+=( ${value//,/ } ); continue ;; MTU) MTU="$value"; continue ;; DNS) DNS+=( ${value//,/ } ); continue ;; esac fi WG_CONFIG+="$line"$'\n' done < "$CONFIG_FILE" shopt -u nocasematch } cmd() { echo "[#] $*" >&2 "$@" } cndc() { local out="$(cmd ndc "$@")" [[ $out == *200\ 0* ]] || { echo "$out"; return 1; } } die() { echo "$PROGRAM: $*" >&2 exit 1 } auto_su() { [[ $UID == 0 ]] || exec su -p -c "'$SELF' ${ARGS[*]}" } add_if() { cmd ip link add "$INTERFACE" type wireguard } del_if() { cmd ip link del "$INTERFACE" [[ $(ip rule show) =~ 0xc([0-9a-f]+)/0xcffff\ lookup\ $INTERFACE ]] && cndc network destroy $(( 0x${BASH_REMATCH[1]} )); } up_if() { while [[ $NETID -lt 4096 ]]; do NETID="$RANDOM" done cmd wg set "$INTERFACE" fwmark 0x20000 cndc interface setcfg "$INTERFACE" up cndc network create "$NETID" vpn 1 1 cndc network interface add "$NETID" "$INTERFACE" cndc network users add "$NETID" 0-99999 } set_dns() { [[ ${#DNS[@]} -eq 0 ]] || cndc resolver setnetdns "$NETID" "" "${DNS[@]}" } add_addr() { if [[ $1 == *:* ]]; then cndc interface ipv6 "$INTERFACE" enable cmd ip -6 addr add "$1" dev "$INTERFACE" else local ip="${1%%/*}" mask=32 [[ $1 == */* ]] && mask="${1##*/}" cndc interface setcfg "$INTERFACE" "$ip" "$mask" fi } set_mtu() { local mtu=0 endpoint output if [[ -n $MTU ]]; then cndc interface setmtu "$INTERFACE" "$MTU" 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 [[ $mtu -gt 0 ]] || mtu=1500 cndc interface setmtu "$INTERFACE" $(( mtu - 80 )) } add_route() { cndc network route add "$NETID" "$INTERFACE" "$1" } set_config() { cmd wg setconf "$INTERFACE" <(echo "$WG_CONFIG") } 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 /data/misc/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. - MTU: an optional MTU for the interface; if unspecified, auto-calculated. - DNS: an optional DNS server to use while the device is up. See wg-quick(8) for more info and examples. _EOF } cmd_up() { local i [[ -z $(ip link show dev "$INTERFACE" 2>/dev/null) ]] || die "\`$INTERFACE' already exists" trap 'del_if; exit' INT TERM EXIT add_if set_config set_mtu for i in "${ADDRESSES[@]}"; do add_addr "$i" done 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 [[ $(ip route get "$i" 2>/dev/null) == *dev\ $INTERFACE\ * ]] || add_route "$i" done trap - INT TERM EXIT } cmd_down() { [[ -n $(ip link show dev "$INTERFACE" type wireguard 2>/dev/null) ]] || die "\`$INTERFACE' is not a WireGuard interface" del_if } 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