bpf: Move endianness BPF helpers out of bpf_util.h

We do not want to include things like stdio.h and friends into
eBPF program builds.  bpf_util.h is for host compiled programs,
so eBPF C-code helpers don't really belong there.

Add a new bpf_endian.h as a quick fix for this for now.
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/bpf/bpf_endian.h

+#ifndef __BPF_ENDIAN__
+#define __BPF_ENDIAN__
+
+#include <asm/byteorder.h>
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+# define __bpf_ntohs(x)		__builtin_bswap16(x)
+# define __bpf_htons(x)		__builtin_bswap16(x)
+#elif __BYTE_ORDER == __BIG_ENDIAN
+# define __bpf_ntohs(x)		(x)
+# define __bpf_htons(x)		(x)
+#else
+# error "Fix your __BYTE_ORDER?!"
+#endif
+
+#define bpf_htons(x)				\
+	(__builtin_constant_p(x) ?		\
+	 __constant_htons(x) : __bpf_htons(x))
+#define bpf_ntohs(x)				\
+	(__builtin_constant_p(x) ?		\
+	 __constant_ntohs(x) : __bpf_ntohs(x))
+
+#endif

tools/testing/selftests/bpf/bpf_util.h

@@ -6,25 +6,6 @@
 #include <string.h>
 #include <errno.h>
 
-#include <asm/byteorder.h>
-
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-# define __bpf_ntohs(x)		__builtin_bswap16(x)
-# define __bpf_htons(x)		__builtin_bswap16(x)
-#elif __BYTE_ORDER == __BIG_ENDIAN
-# define __bpf_ntohs(x)		(x)
-# define __bpf_htons(x)		(x)
-#else
-# error "Fix your __BYTE_ORDER?!"
-#endif
-
-#define bpf_htons(x)				\
-	(__builtin_constant_p(x) ?		\
-	 __constant_htons(x) : __bpf_htons(x))
-#define bpf_ntohs(x)				\
-	(__builtin_constant_p(x) ?		\
-	 __constant_ntohs(x) : __bpf_ntohs(x))
-
 static inline unsigned int bpf_num_possible_cpus(void)
 {
 	static const char *fcpu = "/sys/devices/system/cpu/possible";

tools/testing/selftests/bpf/test_l4lb.c

@@ -19,7 +19,7 @@
 #include <linux/udp.h>
 #include "bpf_helpers.h"
 #include "test_iptunnel_common.h"
-#include "bpf_util.h"
+#include "bpf_endian.h"
 
 int _version SEC("version") = 1;
 

tools/testing/selftests/bpf/test_pkt_access.c

@@ -14,7 +14,7 @@
 #include <linux/tcp.h>
 #include <linux/pkt_cls.h>
 #include "bpf_helpers.h"
-#include "bpf_util.h"
+#include "bpf_endian.h"
 
 #define barrier() __asm__ __volatile__("": : :"memory")
 int _version SEC("version") = 1;