Fixup compilation for kernels before 2.6.25

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>

extensions/Makefile.am

@@ -6,7 +6,8 @@ abssrcdir        = $(shell readlink -f ${srcdir})
 regular_CFLAGS  := @regular_CFLAGS@
 xtables_CFLAGS  := @xtables_CFLAGS@
 kinclude_CFLAGS := @kinclude_CFLAGS@
-AM_CFLAGS        = ${regular_CFLAGS} ${xtables_CFLAGS} ${kinclude_CFLAGS} \
+AM_CFLAGS        = ${regular_CFLAGS} -I ${top_srcdir}/include \
+                   ${xtables_CFLAGS} ${kinclude_CFLAGS} \
                    -D_INIT=$*_init
 AM_LDFLAGS       = -module -avoid-version
 xtlib_LTLIBRARIES = \

include/linux/compiler.h

@@ -0,0 +1,179 @@
+#ifndef __LINUX_COMPILER_H
+#define __LINUX_COMPILER_H
+
+#ifndef __ASSEMBLY__
+
+#ifdef __CHECKER__
+# define __user		__attribute__((noderef, address_space(1)))
+# define __kernel	/* default address space */
+# define __safe		__attribute__((safe))
+# define __force	__attribute__((force))
+# define __nocast	__attribute__((nocast))
+# define __iomem	__attribute__((noderef, address_space(2)))
+# define __acquires(x)	__attribute__((context(x,0,1)))
+# define __releases(x)	__attribute__((context(x,1,0)))
+# define __acquire(x)	__context__(x,1)
+# define __release(x)	__context__(x,-1)
+# define __cond_lock(x,c)	((c) ? ({ __acquire(x); 1; }) : 0)
+extern void __chk_user_ptr(const volatile void __user *);
+extern void __chk_io_ptr(const volatile void __iomem *);
+#else
+# define __user
+# define __kernel
+# define __safe
+# define __force
+# define __nocast
+# define __iomem
+# define __chk_user_ptr(x) (void)0
+# define __chk_io_ptr(x) (void)0
+# define __builtin_warning(x, y...) (1)
+# define __acquires(x)
+# define __releases(x)
+# define __acquire(x) (void)0
+# define __release(x) (void)0
+# define __cond_lock(x,c) (c)
+#endif
+
+#ifdef __KERNEL__
+
+#if __GNUC__ >= 4
+# include <linux/compiler-gcc4.h>
+#elif __GNUC__ == 3 && __GNUC_MINOR__ >= 2
+# include <linux/compiler-gcc3.h>
+#else
+# error Sorry, your compiler is too old/not recognized.
+#endif
+
+/* Intel compiler defines __GNUC__. So we will overwrite implementations
+ * coming from above header files here
+ */
+#ifdef __INTEL_COMPILER
+# include <linux/compiler-intel.h>
+#endif
+
+/*
+ * Generic compiler-dependent macros required for kernel
+ * build go below this comment. Actual compiler/compiler version
+ * specific implementations come from the above header files
+ */
+
+#define likely(x)	__builtin_expect(!!(x), 1)
+#define unlikely(x)	__builtin_expect(!!(x), 0)
+
+/* Optimization barrier */
+#ifndef barrier
+# define barrier() __memory_barrier()
+#endif
+
+#ifndef RELOC_HIDE
+# define RELOC_HIDE(ptr, off)					\
+  ({ unsigned long __ptr;					\
+     __ptr = (unsigned long) (ptr);				\
+    (typeof(ptr)) (__ptr + (off)); })
+#endif
+
+#endif /* __KERNEL__ */
+
+#endif /* __ASSEMBLY__ */
+
+#ifdef __KERNEL__
+/*
+ * Allow us to mark functions as 'deprecated' and have gcc emit a nice
+ * warning for each use, in hopes of speeding the functions removal.
+ * Usage is:
+ * 		int __deprecated foo(void)
+ */
+#ifndef __deprecated
+# define __deprecated		/* unimplemented */
+#endif
+
+#ifdef MODULE
+#define __deprecated_for_modules __deprecated
+#else
+#define __deprecated_for_modules
+#endif
+
+#ifndef __must_check
+#define __must_check
+#endif
+
+#ifndef CONFIG_ENABLE_MUST_CHECK
+#undef __must_check
+#define __must_check
+#endif
+#ifndef CONFIG_ENABLE_WARN_DEPRECATED
+#undef __deprecated
+#undef __deprecated_for_modules
+#define __deprecated
+#define __deprecated_for_modules
+#endif
+
+/*
+ * Allow us to avoid 'defined but not used' warnings on functions and data,
+ * as well as force them to be emitted to the assembly file.
+ *
+ * As of gcc 3.4, static functions that are not marked with attribute((used))
+ * may be elided from the assembly file.  As of gcc 3.4, static data not so
+ * marked will not be elided, but this may change in a future gcc version.
+ *
+ * NOTE: Because distributions shipped with a backported unit-at-a-time
+ * compiler in gcc 3.3, we must define __used to be __attribute__((used))
+ * for gcc >=3.3 instead of 3.4.
+ *
+ * In prior versions of gcc, such functions and data would be emitted, but
+ * would be warned about except with attribute((unused)).
+ *
+ * Mark functions that are referenced only in inline assembly as __used so
+ * the code is emitted even though it appears to be unreferenced.
+ */
+#ifndef __used
+# define __used			/* unimplemented */
+#endif
+
+#ifndef __maybe_unused
+# define __maybe_unused		/* unimplemented */
+#endif
+
+#ifndef noinline
+#define noinline
+#endif
+
+#ifndef __always_inline
+#define __always_inline inline
+#endif
+
+#endif /* __KERNEL__ */
+
+/*
+ * From the GCC manual:
+ *
+ * Many functions do not examine any values except their arguments,
+ * and have no effects except the return value.  Basically this is
+ * just slightly more strict class than the `pure' attribute above,
+ * since function is not allowed to read global memory.
+ *
+ * Note that a function that has pointer arguments and examines the
+ * data pointed to must _not_ be declared `const'.  Likewise, a
+ * function that calls a non-`const' function usually must not be
+ * `const'.  It does not make sense for a `const' function to return
+ * `void'.
+ */
+#ifndef __attribute_const__
+# define __attribute_const__	/* unimplemented */
+#endif
+
+/*
+ * Tell gcc if a function is cold. The compiler will assume any path
+ * directly leading to the call is unlikely.
+ */
+
+#ifndef __cold
+#define __cold
+#endif
+
+/* Simple shorthand for a section definition */
+#ifndef __section
+# define __section(S) __attribute__ ((__section__(#S)))
+#endif
+
+#endif /* __LINUX_COMPILER_H */

include/linux/netfilter.h

@@ -0,0 +1,48 @@
+#ifndef __LINUX_NETFILTER_H
+#define __LINUX_NETFILTER_H
+
+#include <linux/compiler.h>
+
+/* Responses from hook functions. */
+#define NF_DROP 0
+#define NF_ACCEPT 1
+#define NF_STOLEN 2
+#define NF_QUEUE 3
+#define NF_REPEAT 4
+#define NF_STOP 5
+#define NF_MAX_VERDICT NF_STOP
+
+/* we overload the higher bits for encoding auxiliary data such as the queue
+ * number. Not nice, but better than additional function arguments. */
+#define NF_VERDICT_MASK 0x0000ffff
+#define NF_VERDICT_BITS 16
+
+#define NF_VERDICT_QMASK 0xffff0000
+#define NF_VERDICT_QBITS 16
+
+#define NF_QUEUE_NR(x) (((x << NF_VERDICT_QBITS) & NF_VERDICT_QMASK) | NF_QUEUE)
+
+/* only for userspace compatibility */
+/* Generic cache responses from hook functions.
+   <= 0x2000 is used for protocol-flags. */
+#define NFC_UNKNOWN 0x4000
+#define NFC_ALTERED 0x8000
+
+enum nf_inet_hooks {
+	NF_INET_PRE_ROUTING,
+	NF_INET_LOCAL_IN,
+	NF_INET_FORWARD,
+	NF_INET_LOCAL_OUT,
+	NF_INET_POST_ROUTING,
+	NF_INET_NUMHOOKS
+};
+
+union nf_inet_addr {
+	u_int32_t	all[4];
+	__be32		ip;
+	__be32		ip6[4];
+	struct in_addr	in;
+	struct in6_addr	in6;
+};
+
+#endif /*__LINUX_NETFILTER_H*/