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 #include <sys/resource.h>
  18
  19 #include "bpf_load.h"
  20 #include "bpf_util.h"
  21 #include "libbpf.h"
  22
  23 static int ifindex;
  24 static __u32 xdp_flags;
  25
  26 static void int_exit(int sig)
  27 {
  28         bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
  29         exit(0);
  30 }
  31
  32 /* simple per-protocol drop counter
  33  */
  34 static void poll_stats(int interval)
  35 {
  36         unsigned int nr_cpus = bpf_num_possible_cpus();
  37         const unsigned int nr_keys = 256;
  38         __u64 values[nr_cpus], prev[nr_keys][nr_cpus];
  39         __u32 key;
  40         int i;
  41
  42         memset(prev, 0, sizeof(prev));
  43
  44         while (1) {
  45                 sleep(interval);
  46
  47                 for (key = 0; key < nr_keys; key++) {
  48                         __u64 sum = 0;
  49
  50                         assert(bpf_map_lookup_elem(map_fd[0], &key, values) == 0);
  51                         for (i = 0; i < nr_cpus; i++)
  52                                 sum += (values[i] - prev[key][i]);
  53                         if (sum)
  54                                 printf("proto %u: %10llu pkt/s\n",
  55                                        key, sum / interval);
  56                         memcpy(prev[key], values, sizeof(values));
  57                 }
  58         }
  59 }
  60
  61 static void usage(const char *prog)
  62 {
  63         fprintf(stderr,
  64                 "usage: %s [OPTS] IFINDEX\n\n"
  65                 "OPTS:\n"
  66                 "    -S    use skb-mode\n"
  67                 "    -N    enforce native mode\n",
  68                 prog);
  69 }
  70
  71 int main(int argc, char **argv)
  72 {
  73         struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
  74         const char *optstr = "SN";
  75         char filename[256];
  76         int opt;
  77
  78         while ((opt = getopt(argc, argv, optstr)) != -1) {
  79                 switch (opt) {
  80                 case 'S':
  81                         xdp_flags |= XDP_FLAGS_SKB_MODE;
  82                         break;
  83                 case 'N':
  84                         xdp_flags |= XDP_FLAGS_DRV_MODE;
  85                         break;
  86                 default:
  87                         usage(basename(argv[0]));
  88                         return 1;
  89                 }
  90         }
  91
  92         if (optind == argc) {
  93                 usage(basename(argv[0]));
  94                 return 1;
  95         }
  96
  97         if (setrlimit(RLIMIT_MEMLOCK, &r)) {
  98                 perror("setrlimit(RLIMIT_MEMLOCK)");
  99                 return 1;
 100         }
 101
 102         ifindex = strtoul(argv[optind], NULL, 0);
 103
 104         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 105
 106         if (load_bpf_file(filename)) {
 107                 printf("%s", bpf_log_buf);
 108                 return 1;
 109         }
 110
 111         if (!prog_fd[0]) {
 112                 printf("load_bpf_file: %s\n", strerror(errno));
 113                 return 1;
 114         }
 115
 116         signal(SIGINT, int_exit);
 117         signal(SIGTERM, int_exit);
 118
 119         if (bpf_set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {
 120                 printf("link set xdp fd failed\n");
 121                 return 1;
 122         }
 123
 124         poll_stats(2);
 125
 126         return 0;
 127 }