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@Menci
Last active February 20, 2023 06:44
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wg_keep_alive, A bash script to workaround NAT bugs
# When there's a upstream NAT bug, WireGuard will never succeed senting packets
# and will never receive any packets then. Detect sent increase while receive not change
# Change a random port for it.
function wg_keep_alive() {
# Wait init
sleep 10
# Configuration
CHECK_INTERVAL=3
MAX_FAILED_CHECKS=3
PORT_MIN=24000
PORT_MAX=30000
RESET_WAIT=10
function wg_reset_port() {
while true; do
((NEW_PORT=RANDOM%(PORT_MAX-PORT_MIN)+PORT_MIN))
if ! ss -ulpn | grep "$NEW_PORT" >/dev/null 2>/dev/null; then
break
fi
done
wg set "$1" listen-port "$NEW_PORT"
}
declare -A PEER_RECEIVED_BYTES
declare -A PEER_SENT_BYTES
declare -A PEER_FAILED_CHECKES
while true; do
while read PEER RECEIVED_BYTES SENT_BYTES; do
if [[ "$PEER" == "" ]]; then
break
fi
if [[ "${PEER_RECEIVED_BYTES["$PEER"]}" != "$RECEIVED_BYTES" ]]; then
PEER_RECEIVED_BYTES["$PEER"]="$RECEIVED_BYTES"
PEER_SENT_BYTES["$PEER"]="$SENT_BYTES"
PEER_FAILED_CHECKES["$PEER"]="0"
elif [[ "${PEER_SENT_BYTES["$PEER"]}" != "$SENT_BYTES" ]]; then
FAILED_CHECKES="${PEER_FAILED_CHECKES["$PEER"]}"
((FAILED_CHECKES=FAILED_CHECKES+1))
echo wg_keep_alive: check failed! current fails = $FAILED_CHECKES
if [[ "$FAILED_CHECKES" == "$MAX_FAILED_CHECKS" ]]; then
wg_reset_port "$1"
sleep "$RESET_WAIT"
PEER_FAILED_CHECKES["$PEER"]=0
break
fi
PEER_FAILED_CHECKES["$PEER"]="$FAILED_CHECKES"
fi
done <<< "$(wg show "$1" transfer)"
sleep "$CHECK_INTERVAL"
done
}
# wg_keep_alive <wg-interface-name>
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