1// SPDX-License-Identifier: GPL-2.0-only
2#include <stdio.h>
3#include <fcntl.h>
4#include <poll.h>
5#include <time.h>
6#include <signal.h>
7#include <bpf/libbpf.h>
8
9static __u64 time_get_ns(void)
10{
11	struct timespec ts;
12
13	clock_gettime(CLOCK_MONOTONIC, &ts);
14	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
15}
16
17static __u64 start_time;
18static __u64 cnt;
19
20#define MAX_CNT 100000ll
21
22static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
23{
24	struct {
25		__u64 pid;
26		__u64 cookie;
27	} *e = data;
28
29	if (e->cookie != 0x12345678) {
30		printf("BUG pid %llx cookie %llx sized %d\n",
31		       e->pid, e->cookie, size);
32		return;
33	}
34
35	cnt++;
36
37	if (cnt == MAX_CNT) {
38		printf("recv %lld events per sec\n",
39		       MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
40		return;
41	}
42}
43
44int main(int argc, char **argv)
45{
46	struct perf_buffer_opts pb_opts = {};
47	struct bpf_link *link = NULL;
48	struct bpf_program *prog;
49	struct perf_buffer *pb;
50	struct bpf_object *obj;
51	int map_fd, ret = 0;
52	char filename[256];
53	FILE *f;
54
55	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
56	obj = bpf_object__open_file(filename, NULL);
57	if (libbpf_get_error(obj)) {
58		fprintf(stderr, "ERROR: opening BPF object file failed\n");
59		return 0;
60	}
61
62	/* load BPF program */
63	if (bpf_object__load(obj)) {
64		fprintf(stderr, "ERROR: loading BPF object file failed\n");
65		goto cleanup;
66	}
67
68	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
69	if (map_fd < 0) {
70		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
71		goto cleanup;
72	}
73
74	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
75	if (libbpf_get_error(prog)) {
76		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
77		goto cleanup;
78	}
79
80	link = bpf_program__attach(prog);
81	if (libbpf_get_error(link)) {
82		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
83		link = NULL;
84		goto cleanup;
85	}
86
87	pb_opts.sample_cb = print_bpf_output;
88	pb = perf_buffer__new(map_fd, 8, &pb_opts);
89	ret = libbpf_get_error(pb);
90	if (ret) {
91		printf("failed to setup perf_buffer: %d\n", ret);
92		return 1;
93	}
94
95	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
96	(void) f;
97
98	start_time = time_get_ns();
99	while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
100	}
101	kill(0, SIGINT);
102
103cleanup:
104	bpf_link__destroy(link);
105	bpf_object__close(obj);
106	return ret;
107}
108