samples/bpf/ibumad_user.c

   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 }