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 
9 static __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 
17 static __u64 start_time;
18 static __u64 cnt;
19 
20 #define MAX_CNT 100000ll
21 
22 static 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 
44 int 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 
103 cleanup:
104 	bpf_link__destroy(link);
105 	bpf_object__close(obj);
106 	return ret;
107 }
108