/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ #ifndef __BPF_ENDIAN__ #define __BPF_ENDIAN__ /* * Isolate byte #n and put it into byte #m, for __u##b type. * E.g., moving byte #6 (nnnnnnnn) into byte #1 (mmmmmmmm) for __u64: * 1) xxxxxxxx nnnnnnnn xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx mmmmmmmm xxxxxxxx * 2) nnnnnnnn xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx mmmmmmmm xxxxxxxx 00000000 * 3) 00000000 00000000 00000000 00000000 00000000 00000000 00000000 nnnnnnnn * 4) 00000000 00000000 00000000 00000000 00000000 00000000 nnnnnnnn 00000000 */ #define ___bpf_mvb(x, b, n, m) ((__u##b)(x) << (b-(n+1)*8) >> (b-8) << (m*8)) #define ___bpf_swab16(x) ((__u16)( \ ___bpf_mvb(x, 16, 0, 1) | \ ___bpf_mvb(x, 16, 1, 0))) #define ___bpf_swab32(x) ((__u32)( \ ___bpf_mvb(x, 32, 0, 3) | \ ___bpf_mvb(x, 32, 1, 2) | \ ___bpf_mvb(x, 32, 2, 1) | \ ___bpf_mvb(x, 32, 3, 0))) #define ___bpf_swab64(x) ((__u64)( \ ___bpf_mvb(x, 64, 0, 7) | \ ___bpf_mvb(x, 64, 1, 6) | \ ___bpf_mvb(x, 64, 2, 5) | \ ___bpf_mvb(x, 64, 3, 4) | \ ___bpf_mvb(x, 64, 4, 3) | \ ___bpf_mvb(x, 64, 5, 2) | \ ___bpf_mvb(x, 64, 6, 1) | \ ___bpf_mvb(x, 64, 7, 0))) /* LLVM's BPF target selects the endianness of the CPU * it compiles on, or the user specifies (bpfel/bpfeb), * respectively. The used __BYTE_ORDER__ is defined by * the compiler, we cannot rely on __BYTE_ORDER from * libc headers, since it doesn't reflect the actual * requested byte order. * * Note, LLVM's BPF target has different __builtin_bswapX() * semantics. It does map to BPF_ALU | BPF_END | BPF_TO_BE * in bpfel and bpfeb case, which means below, that we map * to cpu_to_be16(). We could use it unconditionally in BPF * case, but better not rely on it, so that this header here * can be used from application and BPF program side, which * use different targets. */ #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ # define __bpf_ntohs(x) __builtin_bswap16(x) # define __bpf_htons(x) __builtin_bswap16(x) # define __bpf_constant_ntohs(x) ___bpf_swab16(x) # define __bpf_constant_htons(x) ___bpf_swab16(x) # define __bpf_ntohl(x) __builtin_bswap32(x) # define __bpf_htonl(x) __builtin_bswap32(x) # define __bpf_constant_ntohl(x) ___bpf_swab32(x) # define __bpf_constant_htonl(x) ___bpf_swab32(x) # define __bpf_be64_to_cpu(x) __builtin_bswap64(x) # define __bpf_cpu_to_be64(x) __builtin_bswap64(x) # define __bpf_constant_be64_to_cpu(x) ___bpf_swab64(x) # define __bpf_constant_cpu_to_be64(x) ___bpf_swab64(x) #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ # define __bpf_ntohs(x) (x) # define __bpf_htons(x) (x) # define __bpf_constant_ntohs(x) (x) # define __bpf_constant_htons(x) (x) # define __bpf_ntohl(x) (x) # define __bpf_htonl(x) (x) # define __bpf_constant_ntohl(x) (x) # define __bpf_constant_htonl(x) (x) # define __bpf_be64_to_cpu(x) (x) # define __bpf_cpu_to_be64(x) (x) # define __bpf_constant_be64_to_cpu(x) (x) # define __bpf_constant_cpu_to_be64(x) (x) #else # error "Fix your compiler's __BYTE_ORDER__?!" #endif #define bpf_htons(x) \ (__builtin_constant_p(x) ? \ __bpf_constant_htons(x) : __bpf_htons(x)) #define bpf_ntohs(x) \ (__builtin_constant_p(x) ? \ __bpf_constant_ntohs(x) : __bpf_ntohs(x)) #define bpf_htonl(x) \ (__builtin_constant_p(x) ? \ __bpf_constant_htonl(x) : __bpf_htonl(x)) #define bpf_ntohl(x) \ (__builtin_constant_p(x) ? \ __bpf_constant_ntohl(x) : __bpf_ntohl(x)) #define bpf_cpu_to_be64(x) \ (__builtin_constant_p(x) ? \ __bpf_constant_cpu_to_be64(x) : __bpf_cpu_to_be64(x)) #define bpf_be64_to_cpu(x) \ (__builtin_constant_p(x) ? \ __bpf_constant_be64_to_cpu(x) : __bpf_be64_to_cpu(x)) #endif /* __BPF_ENDIAN__ */