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(-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, "%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(-ERANGE);
67		return 0;
68	}
69
70	ret = snprintf(buf, size, "Unknown libbpf error %d", err);
71	buf[size - 1] = '\0';
72	if (ret >= size)
73		return libbpf_err(-ERANGE);
74	return libbpf_err(-ENOENT);
75}
76