#!/bin/sh
NAGIOS_CMD=/var/lib/nagios4/rw/nagios.cmd
NAGIOS_HOST=${1:?host name required}
NAGIOS_SERVICE=${2:-SNMP Trap}

read trap_host
read trap_transport
trap_sender=$trap_transport
case "$trap_transport" in
    *'['*']:'*)
        trap_sender=${trap_transport#*[}
        trap_sender=${trap_sender%%]*}
        ;;
esac

trap_oid=unknown
while IFS= read -r line; do
    case "$line" in
        *snmpTrapOID.0*|*1.3.6.1.6.3.1.1.4.1.0*|*iso.3.6.1.6.3.1.1.4.1.0*)
            trap_oid=${line##* }
            ;;
    esac
done

now=$(date +%s)
printf '[%s] PROCESS_SERVICE_CHECK_RESULT;%s;%s;1;WARNING - SNMP trap %s from %s\n' \
    "$now" "$NAGIOS_HOST" "$NAGIOS_SERVICE" "$trap_oid" "$trap_sender" > "$NAGIOS_CMD"