#!/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

KEY="<Redacted>"
SECRET="<Redacted>"
RULE_ID="XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"
WAN_INTERFACE="igc0"
HOST=localhost

WAN_PREFIX=$(curl -sk -u "$KEY:$SECRET" "https://$HOST/api/interfaces/overview/get_interface/$WAN_INTERFACE" \
  | jq -r '.message["ifctl.prefix"].value[0]')

[ -z "$WAN_PREFIX" ] && exit 0

CURRENT_DEST_NET=$(curl -sk -u "$KEY:$SECRET" "https://$HOST/api/firewall/npt/get_rule/$RULE_ID" \
  | jq -r '.rule.destination_net')

[ "$WAN_PREFIX" = "$CURRENT_DEST_NET" ] && exit 0

exit 1  # Prefix has changed