Add a rudimentary routine to patch the module into a full kernel tree

kernel-module/Makefile

@@ -1,13 +1,21 @@
 PWD    := $(shell pwd)
 KSRC   ?= /lib/modules/$(shell uname -r)/build
 KBUILD := $(KSRC)
-MEDIAPROXY_VERSION = $(shell dpkg-parsechangelog -l$(M)/../debian/changelog | awk '/^Version: / {print $$2}')
-EXTRA_CFLAGS += -DMEDIAPROXY_VERSION="\"$(MEDIAPROXY_VERSION)\""
+ifeq ($(origin MEDIAPROXY_VERSION), undefined)
+MEDIAPROXY_VERSION := $(shell dpkg-parsechangelog -l../debian/changelog | awk '/^Version: / {print $$2}')
+export MEDIAPROXY_VERSION
+endif
+EXTRA_CFLAGS += -DMEDIAPROXY_VERSION="\"$(MEDIAPROXY_VERSION)\"" -D__MP_EXTERNAL
 
 obj-m        += xt_MEDIAPROXY.o
 
+.PHONY:		modules clean patch
+
 modules:
 		make -C $(KBUILD) M=$(PWD) O=$(KBUILD) modules
 
 clean:
 		make -C $(KBUILD) M=$(PWD) clean
+
+patch:
+		../utils/patch-kernel magic "$(PWD)" "$(KERNEL)" "$(MEDIAPROXY_VERSION)"

kernel-module/xt_MEDIAPROXY.c

@@ -17,7 +17,11 @@
 #include <linux/netfilter_ipv4.h>
 #include <linux/netfilter_ipv6.h>
 #include <linux/netfilter/x_tables.h>
+#ifndef __MP_EXTERNAL
+#include <linux/netfilter/xt_MEDIAPROXY.h>
+#else
 #include "xt_MEDIAPROXY.h"
+#endif
 
 MODULE_LICENSE("GPL");
 

utils/patch-kernel

@@ -0,0 +1,52 @@
+#!/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 $KERN as a kernel source tree"
+		exit 1
+	fi
+done
+
+set -e
+
+cp -v xt_MEDIAPROXY.h "$KERN"/include/linux/netfilter/
+cp -v xt_MEDIAPROXY.c "$KERN"/net/netfilter/
+
+if ! grep -q CONFIG_NETFILTER_XT_TARGET_MEDIAPROXY "$KERN"/net/netfilter/Makefile; then
+	(
+		echo
+		echo "EXTRA_CFLAGS += -DMEDIAPROXY_VERSION=\"\\\"$4\\\"\""
+		echo 'obj-$(CONFIG_NETFILTER_XT_TARGET_MEDIAPROXY) += xt_MEDIAPROXY.o'
+	) >> "$KERN"/net/netfilter/Makefile
+fi
+
+if ! grep -q Kconfig\\.mediaproxy-ng "$KERN"/net/netfilter/Kconfig; then
+	cat >> "$KERN"/net/netfilter/Kconfig.mediaproxy-ng << \__EOF
+config NETFILTER_XT_TARGET_MEDIAPROXY
+	tristate "Sipwise NGCP MEDIAPROXY target support"
+	depends on IP_NF_FILTER
+	help
+	  Sipwise NGCP mediaproxy-ng kernel support
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+__EOF
+	echo 'source "net/netfilter/Kconfig.mediaproxy-ng"' >> "$KERN"/net/netfilter/Kconfig
+fi