root/tools/lib/bpf/libbpf_utils.c
// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)

/*
 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
 * Copyright (C) 2015 Huawei Inc.
 * Copyright (C) 2017 Nicira, Inc.
 */

#undef _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <inttypes.h>
#include <linux/kernel.h>

#include "libbpf.h"
#include "libbpf_internal.h"

#ifndef ENOTSUPP
#define ENOTSUPP        524
#endif

/* make sure libbpf doesn't use kernel-only integer typedefs */
#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64

#define ERRNO_OFFSET(e)         ((e) - __LIBBPF_ERRNO__START)
#define ERRCODE_OFFSET(c)       ERRNO_OFFSET(LIBBPF_ERRNO__##c)
#define NR_ERRNO        (__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START)

static const char *libbpf_strerror_table[NR_ERRNO] = {
        [ERRCODE_OFFSET(LIBELF)]        = "Something wrong in libelf",
        [ERRCODE_OFFSET(FORMAT)]        = "BPF object format invalid",
        [ERRCODE_OFFSET(KVERSION)]      = "'version' section incorrect or lost",
        [ERRCODE_OFFSET(ENDIAN)]        = "Endian mismatch",
        [ERRCODE_OFFSET(INTERNAL)]      = "Internal error in libbpf",
        [ERRCODE_OFFSET(RELOC)]         = "Relocation failed",
        [ERRCODE_OFFSET(VERIFY)]        = "Kernel verifier blocks program loading",
        [ERRCODE_OFFSET(PROG2BIG)]      = "Program too big",
        [ERRCODE_OFFSET(KVER)]          = "Incorrect kernel version",
        [ERRCODE_OFFSET(PROGTYPE)]      = "Kernel doesn't support this program type",
        [ERRCODE_OFFSET(WRNGPID)]       = "Wrong pid in netlink message",
        [ERRCODE_OFFSET(INVSEQ)]        = "Invalid netlink sequence",
        [ERRCODE_OFFSET(NLPARSE)]       = "Incorrect netlink message parsing",
};

int libbpf_strerror(int err, char *buf, size_t size)
{
        int ret;

        if (!buf || !size)
                return libbpf_err(-EINVAL);

        err = err > 0 ? err : -err;

        if (err < __LIBBPF_ERRNO__START) {
                ret = strerror_r(err, buf, size);
                buf[size - 1] = '\0';
                return libbpf_err_errno(ret);
        }

        if (err < __LIBBPF_ERRNO__END) {
                const char *msg;

                msg = libbpf_strerror_table[ERRNO_OFFSET(err)];
                ret = snprintf(buf, size, "%s", msg);
                buf[size - 1] = '\0';
                /* The length of the buf and msg is positive.
                 * A negative number may be returned only when the
                 * size exceeds INT_MAX. Not likely to appear.
                 */
                if (ret >= size)
                        return libbpf_err(-ERANGE);
                return 0;
        }

        ret = snprintf(buf, size, "Unknown libbpf error %d", err);
        buf[size - 1] = '\0';
        if (ret >= size)
                return libbpf_err(-ERANGE);
        return libbpf_err(-ENOENT);
}

const char *libbpf_errstr(int err)
{
        static __thread char buf[12];

        if (err > 0)
                err = -err;

        switch (err) {
        case -E2BIG:            return "-E2BIG";
        case -EACCES:           return "-EACCES";
        case -EADDRINUSE:       return "-EADDRINUSE";
        case -EADDRNOTAVAIL:    return "-EADDRNOTAVAIL";
        case -EAGAIN:           return "-EAGAIN";
        case -EALREADY:         return "-EALREADY";
        case -EBADF:            return "-EBADF";
        case -EBADFD:           return "-EBADFD";
        case -EBUSY:            return "-EBUSY";
        case -ECANCELED:        return "-ECANCELED";
        case -ECHILD:           return "-ECHILD";
        case -EDEADLK:          return "-EDEADLK";
        case -EDOM:             return "-EDOM";
        case -EEXIST:           return "-EEXIST";
        case -EFAULT:           return "-EFAULT";
        case -EFBIG:            return "-EFBIG";
        case -EILSEQ:           return "-EILSEQ";
        case -EINPROGRESS:      return "-EINPROGRESS";
        case -EINTR:            return "-EINTR";
        case -EINVAL:           return "-EINVAL";
        case -EIO:              return "-EIO";
        case -EISDIR:           return "-EISDIR";
        case -ELOOP:            return "-ELOOP";
        case -EMFILE:           return "-EMFILE";
        case -EMLINK:           return "-EMLINK";
        case -EMSGSIZE:         return "-EMSGSIZE";
        case -ENAMETOOLONG:     return "-ENAMETOOLONG";
        case -ENFILE:           return "-ENFILE";
        case -ENODATA:          return "-ENODATA";
        case -ENODEV:           return "-ENODEV";
        case -ENOENT:           return "-ENOENT";
        case -ENOEXEC:          return "-ENOEXEC";
        case -ENOLINK:          return "-ENOLINK";
        case -ENOMEM:           return "-ENOMEM";
        case -ENOSPC:           return "-ENOSPC";
        case -ENOTBLK:          return "-ENOTBLK";
        case -ENOTDIR:          return "-ENOTDIR";
        case -ENOTSUPP:         return "-ENOTSUPP";
        case -ENOTTY:           return "-ENOTTY";
        case -ENXIO:            return "-ENXIO";
        case -EOPNOTSUPP:       return "-EOPNOTSUPP";
        case -EOVERFLOW:        return "-EOVERFLOW";
        case -EPERM:            return "-EPERM";
        case -EPIPE:            return "-EPIPE";
        case -EPROTO:           return "-EPROTO";
        case -EPROTONOSUPPORT:  return "-EPROTONOSUPPORT";
        case -ERANGE:           return "-ERANGE";
        case -EROFS:            return "-EROFS";
        case -ESPIPE:           return "-ESPIPE";
        case -ESRCH:            return "-ESRCH";
        case -ETXTBSY:          return "-ETXTBSY";
        case -EUCLEAN:          return "-EUCLEAN";
        case -EXDEV:            return "-EXDEV";
        default:
                snprintf(buf, sizeof(buf), "%d", err);
                return buf;
        }
}

static inline __u32 get_unaligned_be32(const void *p)
{
        __be32 val;

        memcpy(&val, p, sizeof(val));
        return be32_to_cpu(val);
}

static inline void put_unaligned_be32(__u32 val, void *p)
{
        __be32 be_val = cpu_to_be32(val);

        memcpy(p, &be_val, sizeof(be_val));
}

#define SHA256_BLOCK_LENGTH 64
#define Ch(x, y, z) (((x) & (y)) ^ (~(x) & (z)))
#define Maj(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
#define Sigma_0(x) (ror32((x), 2) ^ ror32((x), 13) ^ ror32((x), 22))
#define Sigma_1(x) (ror32((x), 6) ^ ror32((x), 11) ^ ror32((x), 25))
#define sigma_0(x) (ror32((x), 7) ^ ror32((x), 18) ^ ((x) >> 3))
#define sigma_1(x) (ror32((x), 17) ^ ror32((x), 19) ^ ((x) >> 10))

static const __u32 sha256_K[64] = {
        0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
        0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
        0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
        0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
        0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
        0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
        0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
        0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
        0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
        0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
        0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
};

#define SHA256_ROUND(i, a, b, c, d, e, f, g, h)                                \
        {                                                                      \
                __u32 tmp = h + Sigma_1(e) + Ch(e, f, g) + sha256_K[i] + w[i]; \
                d += tmp;                                                      \
                h = tmp + Sigma_0(a) + Maj(a, b, c);                           \
        }

static void sha256_blocks(__u32 state[8], const __u8 *data, size_t nblocks)
{
        while (nblocks--) {
                __u32 a = state[0];
                __u32 b = state[1];
                __u32 c = state[2];
                __u32 d = state[3];
                __u32 e = state[4];
                __u32 f = state[5];
                __u32 g = state[6];
                __u32 h = state[7];
                __u32 w[64];
                int i;

                for (i = 0; i < 16; i++)
                        w[i] = get_unaligned_be32(&data[4 * i]);
                for (; i < ARRAY_SIZE(w); i++)
                        w[i] = sigma_1(w[i - 2]) + w[i - 7] +
                               sigma_0(w[i - 15]) + w[i - 16];
                for (i = 0; i < ARRAY_SIZE(w); i += 8) {
                        SHA256_ROUND(i + 0, a, b, c, d, e, f, g, h);
                        SHA256_ROUND(i + 1, h, a, b, c, d, e, f, g);
                        SHA256_ROUND(i + 2, g, h, a, b, c, d, e, f);
                        SHA256_ROUND(i + 3, f, g, h, a, b, c, d, e);
                        SHA256_ROUND(i + 4, e, f, g, h, a, b, c, d);
                        SHA256_ROUND(i + 5, d, e, f, g, h, a, b, c);
                        SHA256_ROUND(i + 6, c, d, e, f, g, h, a, b);
                        SHA256_ROUND(i + 7, b, c, d, e, f, g, h, a);
                }
                state[0] += a;
                state[1] += b;
                state[2] += c;
                state[3] += d;
                state[4] += e;
                state[5] += f;
                state[6] += g;
                state[7] += h;
                data += SHA256_BLOCK_LENGTH;
        }
}

void libbpf_sha256(const void *data, size_t len, __u8 out[SHA256_DIGEST_LENGTH])
{
        __u32 state[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
                           0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 };
        const __be64 bitcount = cpu_to_be64((__u64)len * 8);
        __u8 final_data[2 * SHA256_BLOCK_LENGTH] = { 0 };
        size_t final_len = len % SHA256_BLOCK_LENGTH;
        int i;

        sha256_blocks(state, data, len / SHA256_BLOCK_LENGTH);

        memcpy(final_data, data + len - final_len, final_len);
        final_data[final_len] = 0x80;
        final_len = roundup(final_len + 9, SHA256_BLOCK_LENGTH);
        memcpy(&final_data[final_len - 8], &bitcount, 8);

        sha256_blocks(state, final_data, final_len / SHA256_BLOCK_LENGTH);

        for (i = 0; i < ARRAY_SIZE(state); i++)
                put_unaligned_be32(state[i], &out[4 * i]);
}