xref: /linux/samples/bpf/ibumad_user.c (revision e80a48bade619ec5a92230b3d4ae84bfc2746822)
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 <getopt.h>
23 #include <net/if.h>
24 
25 #include <bpf/bpf.h>
26 #include "bpf_util.h"
27 #include <bpf/libbpf.h>
28 
29 static struct bpf_link *tp_links[3];
30 static struct bpf_object *obj;
31 static int map_fd[2];
32 static int tp_cnt;
33 
34 static void dump_counts(int fd)
35 {
36 	__u32 key;
37 	__u64 value;
38 
39 	for (key = 0; key < 256; key++) {
40 		if (bpf_map_lookup_elem(fd, &key, &value)) {
41 			printf("failed to read key %u\n", key);
42 			continue;
43 		}
44 		if (value)
45 			printf("0x%02x : %llu\n", key, value);
46 	}
47 }
48 
49 static void dump_all_counts(void)
50 {
51 	printf("Read 'Class : count'\n");
52 	dump_counts(map_fd[0]);
53 	printf("Write 'Class : count'\n");
54 	dump_counts(map_fd[1]);
55 }
56 
57 static void dump_exit(int sig)
58 {
59 	dump_all_counts();
60 	/* Detach tracepoints */
61 	while (tp_cnt)
62 		bpf_link__destroy(tp_links[--tp_cnt]);
63 
64 	bpf_object__close(obj);
65 	exit(0);
66 }
67 
68 static const struct option long_options[] = {
69 	{"help",      no_argument,       NULL, 'h'},
70 	{"delay",     required_argument, NULL, 'd'},
71 };
72 
73 static void usage(char *cmd)
74 {
75 	printf("eBPF test program to count packets from various IP addresses\n"
76 		"Usage: %s <options>\n"
77 		"       --help,   -h  this menu\n"
78 		"       --delay,  -d  <delay>  wait <delay> sec between prints [1 - 1000000]\n"
79 		, cmd
80 		);
81 }
82 
83 int main(int argc, char **argv)
84 {
85 	struct bpf_program *prog;
86 	unsigned long delay = 5;
87 	char filename[256];
88 	int longindex = 0;
89 	int opt, err = -1;
90 
91 	while ((opt = getopt_long(argc, argv, "hd:rSw",
92 				  long_options, &longindex)) != -1) {
93 		switch (opt) {
94 		case 'd':
95 			delay = strtoul(optarg, NULL, 0);
96 			if (delay == ULONG_MAX || delay < 0 ||
97 			    delay > 1000000) {
98 				fprintf(stderr, "ERROR: invalid delay : %s\n",
99 					optarg);
100 				usage(argv[0]);
101 				return 1;
102 			}
103 			break;
104 		default:
105 		case 'h':
106 			usage(argv[0]);
107 			return 1;
108 		}
109 	}
110 
111 	/* Do one final dump when exiting */
112 	signal(SIGINT, dump_exit);
113 	signal(SIGTERM, dump_exit);
114 
115 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
116 	obj = bpf_object__open_file(filename, NULL);
117 	if (libbpf_get_error(obj)) {
118 		fprintf(stderr, "ERROR: opening BPF object file failed\n");
119 		return err;
120 	}
121 
122 	/* load BPF program */
123 	if (bpf_object__load(obj)) {
124 		fprintf(stderr, "ERROR: loading BPF object file failed\n");
125 		goto cleanup;
126 	}
127 
128 	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "read_count");
129 	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "write_count");
130 	if (map_fd[0] < 0 || map_fd[1] < 0) {
131 		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
132 		goto cleanup;
133 	}
134 
135 	bpf_object__for_each_program(prog, obj) {
136 		tp_links[tp_cnt] = bpf_program__attach(prog);
137 		if (libbpf_get_error(tp_links[tp_cnt])) {
138 			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
139 			tp_links[tp_cnt] = NULL;
140 			goto cleanup;
141 		}
142 		tp_cnt++;
143 	}
144 
145 	while (1) {
146 		sleep(delay);
147 		dump_all_counts();
148 	}
149 	err = 0;
150 
151 cleanup:
152 	/* Detach tracepoints */
153 	while (tp_cnt)
154 		bpf_link__destroy(tp_links[--tp_cnt]);
155 
156 	bpf_object__close(obj);
157 	return err;
158 }
159