LXR linux/tools/lib/bpf/bpf

   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__ */
  73