1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef __BPF_UTIL__
 3#define __BPF_UTIL__
 4
 5#include <stdio.h>
 6#include <stdlib.h>
 7#include <string.h>
 8#include <errno.h>
 9#include <syscall.h>
10#include <bpf/libbpf.h> /* libbpf_num_possible_cpus */
11
12static inline unsigned int bpf_num_possible_cpus(void)
13{
14	int possible_cpus = libbpf_num_possible_cpus();
15
16	if (possible_cpus < 0) {
17		printf("Failed to get # of possible cpus: '%s'!\n",
18		       strerror(-possible_cpus));
19		exit(1);
20	}
21	return possible_cpus;
22}
23
24/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
25 * is zero-terminated string no matter what (unless sz == 0, in which case
26 * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
27 * in what is returned. Given this is internal helper, it's trivial to extend
28 * this, when necessary. Use this instead of strncpy inside libbpf source code.
29 */
30static inline void bpf_strlcpy(char *dst, const char *src, size_t sz)
31{
32	size_t i;
33
34	if (sz == 0)
35		return;
36
37	sz--;
38	for (i = 0; i < sz && src[i]; i++)
39		dst[i] = src[i];
40	dst[i] = '\0';
41}
42
43#define __bpf_percpu_val_align	__attribute__((__aligned__(8)))
44
45#define BPF_DECLARE_PERCPU(type, name)				\
46	struct { type v; /* padding */ } __bpf_percpu_val_align	\
47		name[bpf_num_possible_cpus()]
48#define bpf_percpu(name, cpu) name[(cpu)].v
49
50#ifndef ARRAY_SIZE
51# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
52#endif
53
54#ifndef sizeof_field
55#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
56#endif
57
58#ifndef offsetofend
59#define offsetofend(TYPE, MEMBER) \
60	(offsetof(TYPE, MEMBER)	+ sizeof_field(TYPE, MEMBER))
61#endif
62
63/* Availability of gettid across glibc versions is hit-and-miss, therefore
64 * fallback to syscall in this macro and use it everywhere.
65 */
66#ifndef sys_gettid
67#define sys_gettid() syscall(SYS_gettid)
68#endif
69
70#ifndef ENOTSUPP
71#define ENOTSUPP 524
72#endif
73
74#endif /* __BPF_UTIL__ */