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