100 lines · c
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 xxxxxxxx9 * 2) nnnnnnnn xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx mmmmmmmm xxxxxxxx 0000000010 * 3) 00000000 00000000 00000000 00000000 00000000 00000000 00000000 nnnnnnnn11 * 4) 00000000 00000000 00000000 00000000 00000000 00000000 nnnnnnnn 0000000012 */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 CPU36 * it compiles on, or the user specifies (bpfel/bpfeb),37 * respectively. The used __BYTE_ORDER__ is defined by38 * the compiler, we cannot rely on __BYTE_ORDER from39 * libc headers, since it doesn't reflect the actual40 * 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_BE44 * in bpfel and bpfeb case, which means below, that we map45 * to cpu_to_be16(). We could use it unconditionally in BPF46 * case, but better not rely on it, so that this header here47 * can be used from application and BPF program side, which48 * 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#else77# error "Fix your compiler's __BYTE_ORDER__?!"78#endif79 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