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| author |  Andrii Nakryiko <andriin@fb.com>
| 2020-06-30 08:21:24 -0700 |
|---|---|---|
| committer |  Daniel Borkmann <daniel@iogearbox.net>
| 2020-07-01 09:06:12 +0200 |
| commit | 30ad688094bcfe8721bfd4003f6a20c9b6ddf964 (patch) | |
| tree | 6695f0791ec2dd7d0ecbd5aa3ea60a25d847dd67 /tools/lib | |
| parent | selftests/bpf: Allow substituting custom vmlinux.h for selftests build (diff) | |
| download | linux-30ad688094bcfe8721bfd4003f6a20c9b6ddf964.tar.gz linux-30ad688094bcfe8721bfd4003f6a20c9b6ddf964.tar.bz2 linux-30ad688094bcfe8721bfd4003f6a20c9b6ddf964.zip | |
libbpf: Make bpf_endian co-exist with vmlinux.h
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
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/bpf_endian.h | 43 |
1 files changed, 35 insertions, 8 deletions
diff --git a/tools/lib/bpf/bpf_endian.h b/tools/lib/bpf/bpf_endian.h index fbe28008450f..ec9db4feca9f 100644 --- a/tools/lib/bpf/bpf_endian.h +++ b/tools/lib/bpf/bpf_endian.h @@ -2,8 +2,35 @@ #ifndef __BPF_ENDIAN__ #define __BPF_ENDIAN__ -#include <linux/stddef.h> -#include <linux/swab.h> +/* + * 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), @@ -23,16 +50,16 @@ #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) ___constant_swab16(x) -# define __bpf_constant_htons(x) ___constant_swab16(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) ___constant_swab32(x) -# define __bpf_constant_htonl(x) ___constant_swab32(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) ___constant_swab64(x) -# define __bpf_constant_cpu_to_be64(x) ___constant_swab64(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) |