1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
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 xxxxxxxx
9 * 2) nnnnnnnn xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx mmmmmmmm xxxxxxxx 00000000
10 * 3) 00000000 00000000 00000000 00000000 00000000 00000000 00000000 nnnnnnnn
11 * 4) 00000000 00000000 00000000 00000000 00000000 00000000 nnnnnnnn 00000000
13 #define ___bpf_mvb(x, b, n, m) ((__u##b)(x) << (b-(n+1)*8) >> (b-8) << (m*8))
15 #define ___bpf_swab16(x) ((__u16)( \
16 ___bpf_mvb(x, 16, 0, 1) | \
17 ___bpf_mvb(x, 16, 1, 0)))
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)))
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)))
35 /* LLVM's BPF target selects the endianness of the CPU
36 * it compiles on, or the user specifies (bpfel/bpfeb),
37 * respectively. The used __BYTE_ORDER__ is defined by
38 * the compiler, we cannot rely on __BYTE_ORDER from
39 * libc headers, since it doesn't reflect the actual
40 * requested byte order.
42 * Note, LLVM's BPF target has different __builtin_bswapX()
43 * semantics. It does map to BPF_ALU | BPF_END | BPF_TO_BE
44 * in bpfel and bpfeb case, which means below, that we map
45 * to cpu_to_be16(). We could use it unconditionally in BPF
46 * case, but better not rely on it, so that this header here
47 * can be used from application and BPF program side, which
48 * use different targets.
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)
77 # error "Fix your compiler's __BYTE_ORDER__?!"
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))
99 #endif /* __BPF_ENDIAN__ */