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2 changes: 2 additions & 0 deletions ebpf/bpf/.gitignore
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cmake-build-debug/
CMakeLists.txt
58 changes: 58 additions & 0 deletions ebpf/bpf/hash.h
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// Avoid pulling in any other headers.
typedef unsigned int uint32_t;

// murmurhash2 from
// https://github.com/aappleby/smhasher/blob/92cf3702fcfaadc84eb7bef59825a23e0cd84f56/src/MurmurHash2.cpp
uint32_t MurmurHash2(const void *key, int len, uint32_t seed) {
/* 'm' and 'r' are mixing constants generated offline.
They're not really 'magic', they just happen to work well. */

const uint32_t m = 0x5bd1e995;
const int r = 24;

/* Initialize the hash to a 'random' value */

uint32_t h = seed ^ len;

/* Mix 4 bytes at a time into the hash */

const unsigned char *data = (const unsigned char *)key;
// MAX_STACK_DEPTH * 2 = 256 (because we hash 32 bits at a time).
for (int i = 0; i < 256; i++) {
if (len < 4) {
break;
}
uint32_t k = *(uint32_t *)data;

k *= m;
k ^= k >> r;
k *= m;

h *= m;
h ^= k;

data += 4;
len -= 4;
}

/* Handle the last few bytes of the input array */

switch (len) {
case 3:
h ^= data[2] << 16;
case 2:
h ^= data[1] << 8;
case 1:
h ^= data[0];
h *= m;
};

/* Do a few final mixes of the hash to ensure the last few
// bytes are well-incorporated. */

h ^= h >> 13;
h *= m;
h ^= h >> 15;

return h;
}
4 changes: 0 additions & 4 deletions ebpf/bpf/libbpf/.dockerignore
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bpf_endian.h
bpf_helper_defs.h
bpf_helpers.h
bpf_tracing.h
4 changes: 0 additions & 4 deletions ebpf/bpf/libbpf/.gitignore
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bpf_endian.h
bpf_helper_defs.h
bpf_helpers.h
bpf_tracing.h
99 changes: 99 additions & 0 deletions ebpf/bpf/libbpf/bpf_endian.h
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/* 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__ */
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