#!/bin/bash

if test "$1" != magic; then
	echo
	echo "Don't run this script manually, instead run:"
	echo "    make patch KERNEL=/path/to/kernel/sources"
	echo
	exit 1
fi

if test -z "$3"; then
	echo
	echo "Usage:"
	echo "    make patch KERNEL=/path/to/kernel/sources"
	echo
	exit 1
fi

KERN=$3

for x in . include/linux/netfilter/ net/netfilter/Kconfig net/netfilter/Makefile; do
	if ! test -e "$KERN"/"$x"; then
		echo "I don't recognize $KERN as a kernel source tree"
		exit 1
	fi
done

set -e

cp -v xt_RTPENGINE.h "$KERN"/include/linux/netfilter/
cp -v xt_RTPENGINE.c "$KERN"/net/netfilter/

if ! grep -q CONFIG_NETFILTER_XT_TARGET_RTPENGINE "$KERN"/net/netfilter/Makefile; then
	(
		echo
		echo "EXTRA_CFLAGS += -DRTPENGINE_VERSION=\"\\\"$4\\\"\""
		echo "obj-\$(CONFIG_NETFILTER_XT_TARGET_RTPENGINE) += xt_RTPENGINE.o"
	) >> "$KERN"/net/netfilter/Makefile
fi

if ! grep -q Kconfig\\.rtpengine "$KERN"/net/netfilter/Kconfig; then
	cat >> "$KERN"/net/netfilter/Kconfig.rtpengine << \__EOF
config NETFILTER_XT_TARGET_RTPENGINE
	tristate "Sipwise NGCP RTPENGINE target support"
	depends on IP_NF_FILTER
	help
	  Sipwise NGCP rtpengine kernel support

	  To compile it as a module, choose M here.  If unsure, say N.
__EOF
	echo 'source "net/netfilter/Kconfig.rtpengine"' >> "$KERN"/net/netfilter/Kconfig
fi