samples/bpf/ibumad_user.c

0001 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
0002
0003 /*
0004  * ibumad BPF sample user side
0005  *
0006  * This program is free software; you can redistribute it and/or
0007  * modify it under the terms of version 2 of the GNU General Public
0008  * License as published by the Free Software Foundation.
0009  *
0010  * Copyright(c) 2018 Ira Weiny, Intel Corporation
0011  */
0012
0013 #include <linux/bpf.h>
0014 #include <signal.h>
0015 #include <stdio.h>
0016 #include <stdlib.h>
0017 #include <string.h>
0018 #include <unistd.h>
0019 #include <sys/types.h>
0020 #include <limits.h>
0021
0022 #include <getopt.h>
0023 #include <net/if.h>
0024
0025 #include <bpf/bpf.h>
0026 #include "bpf_util.h"
0027 #include <bpf/libbpf.h>
0028
0029 static struct bpf_link *tp_links[3];
0030 static struct bpf_object *obj;
0031 static int map_fd[2];
0032 static int tp_cnt;
0033
0034 static void dump_counts(int fd)
0035 {
0036     __u32 key;
0037     __u64 value;
0038
0039     for (key = 0; key < 256; key++) {
0040         if (bpf_map_lookup_elem(fd, &key, &value)) {
0041             printf("failed to read key %u\n", key);
0042             continue;
0043         }
0044         if (value)
0045             printf("0x%02x : %llu\n", key, value);
0046     }
0047 }
0048
0049 static void dump_all_counts(void)
0050 {
0051     printf("Read 'Class : count'\n");
0052     dump_counts(map_fd[0]);
0053     printf("Write 'Class : count'\n");
0054     dump_counts(map_fd[1]);
0055 }
0056
0057 static void dump_exit(int sig)
0058 {
0059     dump_all_counts();
0060     /* Detach tracepoints */
0061     while (tp_cnt)
0062         bpf_link__destroy(tp_links[--tp_cnt]);
0063
0064     bpf_object__close(obj);
0065     exit(0);
0066 }
0067
0068 static const struct option long_options[] = {
0069     {"help",      no_argument,       NULL, 'h'},
0070     {"delay",     required_argument, NULL, 'd'},
0071 };
0072
0073 static void usage(char *cmd)
0074 {
0075     printf("eBPF test program to count packets from various IP addresses\n"
0076         "Usage: %s <options>\n"
0077         "       --help,   -h  this menu\n"
0078         "       --delay,  -d  <delay>  wait <delay> sec between prints [1 - 1000000]\n"
0079         , cmd
0080         );
0081 }
0082
0083 int main(int argc, char **argv)
0084 {
0085     struct bpf_program *prog;
0086     unsigned long delay = 5;
0087     char filename[256];
0088     int longindex = 0;
0089     int opt, err = -1;
0090
0091     while ((opt = getopt_long(argc, argv, "hd:rSw",
0092                   long_options, &longindex)) != -1) {
0093         switch (opt) {
0094         case 'd':
0095             delay = strtoul(optarg, NULL, 0);
0096             if (delay == ULONG_MAX || delay < 0 ||
0097                 delay > 1000000) {
0098                 fprintf(stderr, "ERROR: invalid delay : %s\n",
0099                     optarg);
0100                 usage(argv[0]);
0101                 return 1;
0102             }
0103             break;
0104         default:
0105         case 'h':
0106             usage(argv[0]);
0107             return 1;
0108         }
0109     }
0110
0111     /* Do one final dump when exiting */
0112     signal(SIGINT, dump_exit);
0113     signal(SIGTERM, dump_exit);
0114
0115     snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
0116     obj = bpf_object__open_file(filename, NULL);
0117     if (libbpf_get_error(obj)) {
0118         fprintf(stderr, "ERROR: opening BPF object file failed\n");
0119         return err;
0120     }
0121
0122     /* load BPF program */
0123     if (bpf_object__load(obj)) {
0124         fprintf(stderr, "ERROR: loading BPF object file failed\n");
0125         goto cleanup;
0126     }
0127
0128     map_fd[0] = bpf_object__find_map_fd_by_name(obj, "read_count");
0129     map_fd[1] = bpf_object__find_map_fd_by_name(obj, "write_count");
0130     if (map_fd[0] < 0 || map_fd[1] < 0) {
0131         fprintf(stderr, "ERROR: finding a map in obj file failed\n");
0132         goto cleanup;
0133     }
0134
0135     bpf_object__for_each_program(prog, obj) {
0136         tp_links[tp_cnt] = bpf_program__attach(prog);
0137         if (libbpf_get_error(tp_links[tp_cnt])) {
0138             fprintf(stderr, "ERROR: bpf_program__attach failed\n");
0139             tp_links[tp_cnt] = NULL;
0140             goto cleanup;
0141         }
0142         tp_cnt++;
0143     }
0144
0145     while (1) {
0146         sleep(delay);
0147         dump_all_counts();
0148     }
0149     err = 0;
0150
0151 cleanup:
0152     /* Detach tracepoints */
0153     while (tp_cnt)
0154         bpf_link__destroy(tp_links[--tp_cnt]);
0155
0156     bpf_object__close(obj);
0157     return err;
0158 }