openwrt/package/network/utils/wireguard-tools/files/wireguard_watchdog
Jo-Philipp Wich 039f8a1241 wireguard-tools: avoid redundant jsonfilter calls
Use a single jsonfilter expression to yield the list of logical wireguard
interface names in shell compatible notation.

Supersedes: #12344
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
2024-01-23 09:19:35 +01:00

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#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
#
# Copyright (C) 2018 Aleksandr V. Piskunov <aleksandr.v.piskunov@gmail.com>.
# Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
#
# This watchdog script tries to re-resolve hostnames for inactive WireGuard peers.
# Use it for peers with a frequently changing dynamic IP.
# persistent_keepalive must be set, recommended value is 25 seconds.
#
# Run this script from cron every minute:
# echo '* * * * * /usr/bin/wireguard_watchdog' >> /etc/crontabs/root
. /lib/functions.sh
check_peer_activity() {
local cfg=$1
local iface=$2
local disabled
local public_key
local endpoint_host
local endpoint_port
local persistent_keepalive
local last_handshake
local idle_seconds
config_get_bool disabled "${cfg}" "disabled" 0
config_get public_key "${cfg}" "public_key"
config_get endpoint_host "${cfg}" "endpoint_host"
config_get endpoint_port "${cfg}" "endpoint_port"
if [ "${disabled}" -eq 1 ]; then
# skip disabled peers
return 0
fi
persistent_keepalive=$(wg show ${iface} persistent-keepalive | grep ${public_key} | awk '{print $2}')
# only process peers with endpoints and keepalive set
[ -z ${endpoint_host} ] && return 0;
[ -z ${persistent_keepalive} -o ${persistent_keepalive} = "off" ] && return 0;
# skip IP addresses
# check taken from packages/net/ddns-scripts/files/dynamic_dns_functions.sh
local IPV4_REGEX="[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}"
local IPV6_REGEX="\(\([0-9A-Fa-f]\{1,4\}:\)\{1,\}\)\(\([0-9A-Fa-f]\{1,4\}\)\{0,1\}\)\(\(:[0-9A-Fa-f]\{1,4\}\)\{1,\}\)"
local IPV4=$(echo ${endpoint_host} | grep -m 1 -o "$IPV4_REGEX$") # do not detect ip in 0.0.0.0.example.com
local IPV6=$(echo ${endpoint_host} | grep -m 1 -o "$IPV6_REGEX")
[ -n "${IPV4}" -o -n "${IPV6}" ] && return 0;
# re-resolve endpoint hostname if not responding for too long
last_handshake=$(wg show ${iface} latest-handshakes | grep ${public_key} | awk '{print $2}')
[ -z ${last_handshake} ] && return 0;
idle_seconds=$(($(date +%s)-${last_handshake}))
[ ${idle_seconds} -lt 150 ] && return 0;
logger -t "wireguard_monitor" "${iface} endpoint ${endpoint_host}:${endpoint_port} is not responding for ${idle_seconds} seconds, trying to re-resolve hostname"
wg set ${iface} peer ${public_key} endpoint "${endpoint_host}:${endpoint_port}"
}
# query ubus for all active wireguard interfaces
eval $(ubus -S call network.interface dump | jsonfilter -e 'wg_ifaces=@.interface[@.up=true && @.proto="wireguard"].interface')
# check every peer in every active wireguard interface
config_load network
for iface in $wg_ifaces; do
config_foreach check_peer_activity "wireguard_${iface}" "${iface}"
done