1// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2
3/*
4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
6 * Copyright (C) 2015 Huawei Inc.
7 * Copyright (C) 2017 Nicira, Inc.
8 */
9
10#undef _GNU_SOURCE
11#include <stdio.h>
12#include <string.h>
13
14#include "libbpf.h"
15#include "libbpf_internal.h"
16
17/* make sure libbpf doesn't use kernel-only integer typedefs */
18#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
19
20#define ERRNO_OFFSET(e) ((e) - __LIBBPF_ERRNO__START)
21#define ERRCODE_OFFSET(c) ERRNO_OFFSET(LIBBPF_ERRNO__##c)
22#define NR_ERRNO (__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START)
23
24static const char *libbpf_strerror_table[NR_ERRNO] = {
25 [ERRCODE_OFFSET(LIBELF)] = "Something wrong in libelf",
26 [ERRCODE_OFFSET(FORMAT)] = "BPF object format invalid",
27 [ERRCODE_OFFSET(KVERSION)] = "'version' section incorrect or lost",
28 [ERRCODE_OFFSET(ENDIAN)] = "Endian mismatch",
29 [ERRCODE_OFFSET(INTERNAL)] = "Internal error in libbpf",
30 [ERRCODE_OFFSET(RELOC)] = "Relocation failed",
31 [ERRCODE_OFFSET(VERIFY)] = "Kernel verifier blocks program loading",
32 [ERRCODE_OFFSET(PROG2BIG)] = "Program too big",
33 [ERRCODE_OFFSET(KVER)] = "Incorrect kernel version",
34 [ERRCODE_OFFSET(PROGTYPE)] = "Kernel doesn't support this program type",
35 [ERRCODE_OFFSET(WRNGPID)] = "Wrong pid in netlink message",
36 [ERRCODE_OFFSET(INVSEQ)] = "Invalid netlink sequence",
37 [ERRCODE_OFFSET(NLPARSE)] = "Incorrect netlink message parsing",
38};
39
40int libbpf_strerror(int err, char *buf, size_t size)
41{
42 int ret;
43
44 if (!buf || !size)
45 return libbpf_err(ret: -EINVAL);
46
47 err = err > 0 ? err : -err;
48
49 if (err < __LIBBPF_ERRNO__START) {
50 ret = strerror_r(err, buf, size);
51 buf[size - 1] = '\0';
52 return libbpf_err_errno(ret);
53 }
54
55 if (err < __LIBBPF_ERRNO__END) {
56 const char *msg;
57
58 msg = libbpf_strerror_table[ERRNO_OFFSET(err)];
59 ret = snprintf(buf, size, fmt: "%s", msg);
60 buf[size - 1] = '\0';
61 /* The length of the buf and msg is positive.
62 * A negative number may be returned only when the
63 * size exceeds INT_MAX. Not likely to appear.
64 */
65 if (ret >= size)
66 return libbpf_err(ret: -ERANGE);
67 return 0;
68 }
69
70 ret = snprintf(buf, size, fmt: "Unknown libbpf error %d", err);
71 buf[size - 1] = '\0';
72 if (ret >= size)
73 return libbpf_err(ret: -ERANGE);
74 return libbpf_err(ret: -ENOENT);
75}
76

source code of linux/tools/lib/bpf/libbpf_errno.c