1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
 2#ifndef __BPF_ENDIAN__
 3#define __BPF_ENDIAN__
 4
 5#include <linux/stddef.h>
 6#include <linux/swab.h>
 7
 8/* LLVM's BPF target selects the endianness of the CPU
 9 * it compiles on, or the user specifies (bpfel/bpfeb),
10 * respectively. The used __BYTE_ORDER__ is defined by
11 * the compiler, we cannot rely on __BYTE_ORDER from
12 * libc headers, since it doesn't reflect the actual
13 * requested byte order.
14 *
15 * Note, LLVM's BPF target has different __builtin_bswapX()
16 * semantics. It does map to BPF_ALU | BPF_END | BPF_TO_BE
17 * in bpfel and bpfeb case, which means below, that we map
18 * to cpu_to_be16(). We could use it unconditionally in BPF
19 * case, but better not rely on it, so that this header here
20 * can be used from application and BPF program side, which
21 * use different targets.
22 */
23#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
24# define __bpf_ntohs(x)			__builtin_bswap16(x)
25# define __bpf_htons(x)			__builtin_bswap16(x)
26# define __bpf_constant_ntohs(x)	___constant_swab16(x)
27# define __bpf_constant_htons(x)	___constant_swab16(x)
28# define __bpf_ntohl(x)			__builtin_bswap32(x)
29# define __bpf_htonl(x)			__builtin_bswap32(x)
30# define __bpf_constant_ntohl(x)	___constant_swab32(x)
31# define __bpf_constant_htonl(x)	___constant_swab32(x)
32# define __bpf_be64_to_cpu(x)		__builtin_bswap64(x)
33# define __bpf_cpu_to_be64(x)		__builtin_bswap64(x)
34# define __bpf_constant_be64_to_cpu(x)	___constant_swab64(x)
35# define __bpf_constant_cpu_to_be64(x)	___constant_swab64(x)
36#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
37# define __bpf_ntohs(x)			(x)
38# define __bpf_htons(x)			(x)
39# define __bpf_constant_ntohs(x)	(x)
40# define __bpf_constant_htons(x)	(x)
41# define __bpf_ntohl(x)			(x)
42# define __bpf_htonl(x)			(x)
43# define __bpf_constant_ntohl(x)	(x)
44# define __bpf_constant_htonl(x)	(x)
45# define __bpf_be64_to_cpu(x)		(x)
46# define __bpf_cpu_to_be64(x)		(x)
47# define __bpf_constant_be64_to_cpu(x)  (x)
48# define __bpf_constant_cpu_to_be64(x)  (x)
49#else
50# error "Fix your compiler's __BYTE_ORDER__?!"
51#endif
52
53#define bpf_htons(x)				\
54	(__builtin_constant_p(x) ?		\
55	 __bpf_constant_htons(x) : __bpf_htons(x))
56#define bpf_ntohs(x)				\
57	(__builtin_constant_p(x) ?		\
58	 __bpf_constant_ntohs(x) : __bpf_ntohs(x))
59#define bpf_htonl(x)				\
60	(__builtin_constant_p(x) ?		\
61	 __bpf_constant_htonl(x) : __bpf_htonl(x))
62#define bpf_ntohl(x)				\
63	(__builtin_constant_p(x) ?		\
64	 __bpf_constant_ntohl(x) : __bpf_ntohl(x))
65#define bpf_cpu_to_be64(x)			\
66	(__builtin_constant_p(x) ?		\
67	 __bpf_constant_cpu_to_be64(x) : __bpf_cpu_to_be64(x))
68#define bpf_be64_to_cpu(x)			\
69	(__builtin_constant_p(x) ?		\
70	 __bpf_constant_be64_to_cpu(x) : __bpf_be64_to_cpu(x))
71
72#endif /* __BPF_ENDIAN__ */