samples/bpf/xdp1_user.c

   1 /* Copyright (c) 2016 PLUMgrid
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of version 2 of the GNU General Public
   5  * License as published by the Free Software Foundation.
   6  */
   7 #include <linux/bpf.h>
   8 #include <linux/if_link.h>
   9 #include <assert.h>
  10 #include <errno.h>
  11 #include <signal.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <unistd.h>
  16 #include <libgen.h>
  17
  18 #include "bpf_load.h"
  19 #include "bpf_util.h"
  20 #include "libbpf.h"
  21
  22 static int ifindex;
  23 static __u32 xdp_flags;
  24
  25 static void int_exit(int sig)
  26 {
  27         set_link_xdp_fd(ifindex, -1, xdp_flags);
  28         exit(0);
  29 }
  30
  31 /* simple per-protocol drop counter
  32  */
  33 static void poll_stats(int interval)
  34 {
  35         unsigned int nr_cpus = bpf_num_possible_cpus();
  36         const unsigned int nr_keys = 256;
  37         __u64 values[nr_cpus], prev[nr_keys][nr_cpus];
  38         __u32 key;
  39         int i;
  40
  41         memset(prev, 0, sizeof(prev));
  42
  43         while (1) {
  44                 sleep(interval);
  45
  46                 for (key = 0; key < nr_keys; key++) {
  47                         __u64 sum = 0;
  48
  49                         assert(bpf_map_lookup_elem(map_fd[0], &key, values) == 0);
  50                         for (i = 0; i < nr_cpus; i++)
  51                                 sum += (values[i] - prev[key][i]);
  52                         if (sum)
  53                                 printf("proto %u: %10llu pkt/s\n",
  54                                        key, sum / interval);
  55                         memcpy(prev[key], values, sizeof(values));
  56                 }
  57         }
  58 }
  59
  60 static void usage(const char *prog)
  61 {
  62         fprintf(stderr,
  63                 "usage: %s [OPTS] IFINDEX\n\n"
  64                 "OPTS:\n"
  65                 "    -S    use skb-mode\n"
  66                 "    -N    enforce native mode\n",
  67                 prog);
  68 }
  69
  70 int main(int argc, char **argv)
  71 {
  72         const char *optstr = "SN";
  73         char filename[256];
  74         int opt;
  75
  76         while ((opt = getopt(argc, argv, optstr)) != -1) {
  77                 switch (opt) {
  78                 case 'S':
  79                         xdp_flags |= XDP_FLAGS_SKB_MODE;
  80                         break;
  81                 case 'N':
  82                         xdp_flags |= XDP_FLAGS_DRV_MODE;
  83                         break;
  84                 default:
  85                         usage(basename(argv[0]));
  86                         return 1;
  87                 }
  88         }
  89
  90         if (optind == argc) {
  91                 usage(basename(argv[0]));
  92                 return 1;
  93         }
  94         ifindex = strtoul(argv[optind], NULL, 0);
  95
  96         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
  97
  98         if (load_bpf_file(filename)) {
  99                 printf("%s", bpf_log_buf);
 100                 return 1;
 101         }
 102
 103         if (!prog_fd[0]) {
 104                 printf("load_bpf_file: %s\n", strerror(errno));
 105                 return 1;
 106         }
 107
 108         signal(SIGINT, int_exit);
 109         signal(SIGTERM, int_exit);
 110
 111         if (set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {
 112                 printf("link set xdp fd failed\n");
 113                 return 1;
 114         }
 115
 116         poll_stats(2);
 117
 118         return 0;
 119 }