xref: /openbmc/linux/samples/bpf/ibumad_user.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 
3 /*
4  * ibumad BPF sample user side
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of version 2 of the GNU General Public
8  * License as published by the Free Software Foundation.
9  *
10  * Copyright(c) 2018 Ira Weiny, Intel Corporation
11  */
12 
13 #include <linux/bpf.h>
14 #include <signal.h>
15 #include <stdio.h>
16 #include <stdlib.h>
17 #include <string.h>
18 #include <unistd.h>
19 #include <sys/types.h>
20 #include <limits.h>
21 
22 #include <sys/resource.h>
23 #include <getopt.h>
24 #include <net/if.h>
25 
26 #include <bpf/bpf.h>
27 #include "bpf_util.h"
28 #include <bpf/libbpf.h>
29 
30 static struct bpf_link *tp_links[3];
31 static struct bpf_object *obj;
32 static int map_fd[2];
33 static int tp_cnt;
34 
35 static void dump_counts(int fd)
36 {
37 	__u32 key;
38 	__u64 value;
39 
40 	for (key = 0; key < 256; key++) {
41 		if (bpf_map_lookup_elem(fd, &key, &value)) {
42 			printf("failed to read key %u\n", key);
43 			continue;
44 		}
45 		if (value)
46 			printf("0x%02x : %llu\n", key, value);
47 	}
48 }
49 
50 static void dump_all_counts(void)
51 {
52 	printf("Read 'Class : count'\n");
53 	dump_counts(map_fd[0]);
54 	printf("Write 'Class : count'\n");
55 	dump_counts(map_fd[1]);
56 }
57 
58 static void dump_exit(int sig)
59 {
60 	dump_all_counts();
61 	/* Detach tracepoints */
62 	while (tp_cnt)
63 		bpf_link__destroy(tp_links[--tp_cnt]);
64 
65 	bpf_object__close(obj);
66 	exit(0);
67 }
68 
69 static const struct option long_options[] = {
70 	{"help",      no_argument,       NULL, 'h'},
71 	{"delay",     required_argument, NULL, 'd'},
72 };
73 
74 static void usage(char *cmd)
75 {
76 	printf("eBPF test program to count packets from various IP addresses\n"
77 		"Usage: %s <options>\n"
78 		"       --help,   -h  this menu\n"
79 		"       --delay,  -d  <delay>  wait <delay> sec between prints [1 - 1000000]\n"
80 		, cmd
81 		);
82 }
83 
84 int main(int argc, char **argv)
85 {
86 	struct bpf_program *prog;
87 	unsigned long delay = 5;
88 	char filename[256];
89 	int longindex = 0;
90 	int opt, err = -1;
91 
92 	while ((opt = getopt_long(argc, argv, "hd:rSw",
93 				  long_options, &longindex)) != -1) {
94 		switch (opt) {
95 		case 'd':
96 			delay = strtoul(optarg, NULL, 0);
97 			if (delay == ULONG_MAX || delay < 0 ||
98 			    delay > 1000000) {
99 				fprintf(stderr, "ERROR: invalid delay : %s\n",
100 					optarg);
101 				usage(argv[0]);
102 				return 1;
103 			}
104 			break;
105 		default:
106 		case 'h':
107 			usage(argv[0]);
108 			return 1;
109 		}
110 	}
111 
112 	/* Do one final dump when exiting */
113 	signal(SIGINT, dump_exit);
114 	signal(SIGTERM, dump_exit);
115 
116 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
117 	obj = bpf_object__open_file(filename, NULL);
118 	if (libbpf_get_error(obj)) {
119 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
120 		return err;
121 	}
122 
123 	/* load BPF program */
124 	if (bpf_object__load(obj)) {
125 		fprintf(stderr, "ERROR: loading BPF object file failed\n");
126 		goto cleanup;
127 	}
128 
129 	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "read_count");
130 	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "write_count");
131 	if (map_fd[0] < 0 || map_fd[1] < 0) {
132 		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
133 		goto cleanup;
134 	}
135 
136 	bpf_object__for_each_program(prog, obj) {
137 		tp_links[tp_cnt] = bpf_program__attach(prog);
138 		if (libbpf_get_error(tp_links[tp_cnt])) {
139 			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
140 			tp_links[tp_cnt] = NULL;
141 			goto cleanup;
142 		}
143 		tp_cnt++;
144 	}
145 
146 	while (1) {
147 		sleep(delay);
148 		dump_all_counts();
149 	}
150 	err = 0;
151 
152 cleanup:
153 	/* Detach tracepoints */
154 	while (tp_cnt)
155 		bpf_link__destroy(tp_links[--tp_cnt]);
156 
157 	bpf_object__close(obj);
158 	return err;
159 }
160