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 <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 }