OpenWrt – Blame information for rev 2

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1 office 1 #!/bin/sh
2 # SPDX-License-Identifier: GPL-2.0
3 #
4 # Copyright (C) 2018 Aleksandr V. Piskunov <aleksandr.v.piskunov@gmail.com>.
5 # Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
6 #
7 # This watchdog script tries to re-resolve hostnames for inactive WireGuard peers.
8 # Use it for peers with a frequently changing dynamic IP.
9 # persistent_keepalive must be set, recommended value is 25 seconds.
10 #
11 # Run this script from cron every minute:
12 # echo '* * * * * /usr/bin/wireguard_watchdog' >> /etc/crontabs/root
13  
14  
15 . /lib/functions.sh
16  
17 check_peer_activity() {
18 local cfg=$1
19 local iface=$2
20 local public_key
21 local endpoint_host
22 local endpoint_port
23 local persistent_keepalive
24 local last_handshake
25 local idle_seconds
26  
27 config_get public_key "${cfg}" "public_key"
28 config_get endpoint_host "${cfg}" "endpoint_host"
29 config_get endpoint_port "${cfg}" "endpoint_port"
30 persistent_keepalive=`wg show ${iface} persistent-keepalive | grep ${public_key} | awk '{print $2}'`
31  
32 # only process peers with endpoints and keepalive set
33 [ -z ${endpoint_host} ] && return 0;
34 [ -z ${persistent_keepalive} -o ${persistent_keepalive} = "off" ] && return 0;
35  
36 # skip IP addresses
37 # check taken from packages/net/ddns-scripts/files/dynamic_dns_functions.sh
38 local IPV4_REGEX="[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}"
39 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,\}\)"
40 local IPV4=$(echo ${endpoint_host} | grep -m 1 -o "$IPV4_REGEX$") # do not detect ip in 0.0.0.0.example.com
41 local IPV6=$(echo ${endpoint_host} | grep -m 1 -o "$IPV6_REGEX")
42 [ -n "${IPV4}" -o -n "${IPV6}" ] && return 0;
43  
44 # re-resolve endpoint hostname if not responding for too long
45 last_handshake=`wg show ${iface} latest-handshakes | grep ${public_key} | awk '{print $2}'`
46 [ -z ${last_handshake} ] && return 0;
47 idle_seconds=$((`date +%s`-${last_handshake}))
48 [ ${idle_seconds} -lt 150 ] && return 0;
49 logger -t "wireguard_monitor" "${iface} endpoint ${endpoint_host}:${endpoint_port} is not responding for ${idle_seconds} seconds, trying to re-resolve hostname"
50 wg set ${iface} peer ${public_key} endpoint "${endpoint_host}:${endpoint_port}"
51 }
52  
53 # query ubus for all active wireguard interfaces
54 wg_ifaces=`ubus -S call network.interface dump | jsonfilter -e '@.interface[@.up=true]' | jsonfilter -a -e '@[@.proto="wireguard"].interface' | tr "\n" " "`
55  
56 # check every peer in every active wireguard interface
57 config_load network
58 for iface in $wg_ifaces; do
59 config_foreach check_peer_activity "wireguard_${iface}" "${iface}"
60 done