mirror of
https://github.com/torvalds/linux.git
synced 2025-10-31 08:38:45 +02:00
30ad688094
Make bpf_endian.h compatible with vmlinux.h. It is a frequent request from users wanting to use bpf_endian.h in their BPF applications using CO-RE and vmlinux.h. To achieve that, re-implement byte swap macros and drop all the header includes. This way it can be used both with linux header includes, as well as with a vmlinux.h. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200630152125.3631920-2-andriin@fb.com
99 lines
3.7 KiB
C
99 lines
3.7 KiB
C
/* 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__ */
|