1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 2#ifndef __BPF_ENDIAN__ 3#define __BPF_ENDIAN__ 4 5/* 6 * Isolate byte #n and put it into byte #m, for __u##b type. 7 * E.g., moving byte #6 (nnnnnnnn) into byte #1 (mmmmmmmm) for __u64: 8 * 1) xxxxxxxx nnnnnnnn xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx mmmmmmmm xxxxxxxx 9 * 2) nnnnnnnn xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx mmmmmmmm xxxxxxxx 00000000 10 * 3) 00000000 00000000 00000000 00000000 00000000 00000000 00000000 nnnnnnnn 11 * 4) 00000000 00000000 00000000 00000000 00000000 00000000 nnnnnnnn 00000000 12 */ 13#define ___bpf_mvb(x, b, n, m) ((__u##b)(x) << (b-(n+1)*8) >> (b-8) << (m*8)) 14 15#define ___bpf_swab16(x) ((__u16)( \ 16 ___bpf_mvb(x, 16, 0, 1) | \ 17 ___bpf_mvb(x, 16, 1, 0))) 18 19#define ___bpf_swab32(x) ((__u32)( \ 20 ___bpf_mvb(x, 32, 0, 3) | \ 21 ___bpf_mvb(x, 32, 1, 2) | \ 22 ___bpf_mvb(x, 32, 2, 1) | \ 23 ___bpf_mvb(x, 32, 3, 0))) 24 25#define ___bpf_swab64(x) ((__u64)( \ 26 ___bpf_mvb(x, 64, 0, 7) | \ 27 ___bpf_mvb(x, 64, 1, 6) | \ 28 ___bpf_mvb(x, 64, 2, 5) | \ 29 ___bpf_mvb(x, 64, 3, 4) | \ 30 ___bpf_mvb(x, 64, 4, 3) | \ 31 ___bpf_mvb(x, 64, 5, 2) | \ 32 ___bpf_mvb(x, 64, 6, 1) | \ 33 ___bpf_mvb(x, 64, 7, 0))) 34 35/* LLVM's BPF target selects the endianness of the CPU 36 * it compiles on, or the user specifies (bpfel/bpfeb), 37 * respectively. The used __BYTE_ORDER__ is defined by 38 * the compiler, we cannot rely on __BYTE_ORDER from 39 * libc headers, since it doesn't reflect the actual 40 * requested byte order. 41 * 42 * Note, LLVM's BPF target has different __builtin_bswapX() 43 * semantics. It does map to BPF_ALU | BPF_END | BPF_TO_BE 44 * in bpfel and bpfeb case, which means below, that we map 45 * to cpu_to_be16(). We could use it unconditionally in BPF 46 * case, but better not rely on it, so that this header here 47 * can be used from application and BPF program side, which 48 * use different targets. 49 */ 50#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ 51# define __bpf_ntohs(x) __builtin_bswap16(x) 52# define __bpf_htons(x) __builtin_bswap16(x) 53# define __bpf_constant_ntohs(x) ___bpf_swab16(x) 54# define __bpf_constant_htons(x) ___bpf_swab16(x) 55# define __bpf_ntohl(x) __builtin_bswap32(x) 56# define __bpf_htonl(x) __builtin_bswap32(x) 57# define __bpf_constant_ntohl(x) ___bpf_swab32(x) 58# define __bpf_constant_htonl(x) ___bpf_swab32(x) 59# define __bpf_be64_to_cpu(x) __builtin_bswap64(x) 60# define __bpf_cpu_to_be64(x) __builtin_bswap64(x) 61# define __bpf_constant_be64_to_cpu(x) ___bpf_swab64(x) 62# define __bpf_constant_cpu_to_be64(x) ___bpf_swab64(x) 63#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ 64# define __bpf_ntohs(x) (x) 65# define __bpf_htons(x) (x) 66# define __bpf_constant_ntohs(x) (x) 67# define __bpf_constant_htons(x) (x) 68# define __bpf_ntohl(x) (x) 69# define __bpf_htonl(x) (x) 70# define __bpf_constant_ntohl(x) (x) 71# define __bpf_constant_htonl(x) (x) 72# define __bpf_be64_to_cpu(x) (x) 73# define __bpf_cpu_to_be64(x) (x) 74# define __bpf_constant_be64_to_cpu(x) (x) 75# define __bpf_constant_cpu_to_be64(x) (x) 76#else 77# error "Fix your compiler's __BYTE_ORDER__?!" 78#endif 79 80#define bpf_htons(x) \ 81 (__builtin_constant_p(x) ? \ 82 __bpf_constant_htons(x) : __bpf_htons(x)) 83#define bpf_ntohs(x) \ 84 (__builtin_constant_p(x) ? \ 85 __bpf_constant_ntohs(x) : __bpf_ntohs(x)) 86#define bpf_htonl(x) \ 87 (__builtin_constant_p(x) ? \ 88 __bpf_constant_htonl(x) : __bpf_htonl(x)) 89#define bpf_ntohl(x) \ 90 (__builtin_constant_p(x) ? \ 91 __bpf_constant_ntohl(x) : __bpf_ntohl(x)) 92#define bpf_cpu_to_be64(x) \ 93 (__builtin_constant_p(x) ? \ 94 __bpf_constant_cpu_to_be64(x) : __bpf_cpu_to_be64(x)) 95#define bpf_be64_to_cpu(x) \ 96 (__builtin_constant_p(x) ? \ 97 __bpf_constant_be64_to_cpu(x) : __bpf_be64_to_cpu(x)) 98 99#endif /* __BPF_ENDIAN__ */ 100