tools/testing/selftests/bpf/flow_dissector_load.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <error.h>
   3 #include <errno.h>
   4 #include <getopt.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <sys/stat.h>
   9 #include <fcntl.h>
  10 #include <unistd.h>
  11 #include <bpf/bpf.h>
  12 #include <bpf/libbpf.h>
  13
  14 #include "bpf_rlimit.h"
  15 #include "flow_dissector_load.h"
  16
  17 const char *cfg_pin_path = "/sys/fs/bpf/flow_dissector";
  18 const char *cfg_map_name = "jmp_table";
  19 bool cfg_attach = true;
  20 char *cfg_section_name;
  21 char *cfg_path_name;
  22
  23 static void load_and_attach_program(void)
  24 {
  25         int prog_fd, ret;
  26         struct bpf_object *obj;
  27
  28         ret = bpf_flow_load(&obj, cfg_path_name, cfg_section_name,
  29                             cfg_map_name, NULL, &prog_fd, NULL);
  30         if (ret)
  31                 error(1, 0, "bpf_flow_load %s", cfg_path_name);
  32
  33         ret = bpf_prog_attach(prog_fd, 0 /* Ignore */, BPF_FLOW_DISSECTOR, 0);
  34         if (ret)
  35                 error(1, 0, "bpf_prog_attach %s", cfg_path_name);
  36
  37         ret = bpf_object__pin(obj, cfg_pin_path);
  38         if (ret)
  39                 error(1, 0, "bpf_object__pin %s", cfg_pin_path);
  40 }
  41
  42 static void detach_program(void)
  43 {
  44         char command[64];
  45         int ret;
  46
  47         ret = bpf_prog_detach(0, BPF_FLOW_DISSECTOR);
  48         if (ret)
  49                 error(1, 0, "bpf_prog_detach");
  50
  51         /* To unpin, it is necessary and sufficient to just remove this dir */
  52         sprintf(command, "rm -r %s", cfg_pin_path);
  53         ret = system(command);
  54         if (ret)
  55                 error(1, errno, "%s", command);
  56 }
  57
  58 static void parse_opts(int argc, char **argv)
  59 {
  60         bool attach = false;
  61         bool detach = false;
  62         int c;
  63
  64         while ((c = getopt(argc, argv, "adp:s:")) != -1) {
  65                 switch (c) {
  66                 case 'a':
  67                         if (detach)
  68                                 error(1, 0, "attach/detach are exclusive");
  69                         attach = true;
  70                         break;
  71                 case 'd':
  72                         if (attach)
  73                                 error(1, 0, "attach/detach are exclusive");
  74                         detach = true;
  75                         break;
  76                 case 'p':
  77                         if (cfg_path_name)
  78                                 error(1, 0, "only one prog name can be given");
  79
  80                         cfg_path_name = optarg;
  81                         break;
  82                 case 's':
  83                         if (cfg_section_name)
  84                                 error(1, 0, "only one section can be given");
  85
  86                         cfg_section_name = optarg;
  87                         break;
  88                 }
  89         }
  90
  91         if (detach)
  92                 cfg_attach = false;
  93
  94         if (cfg_attach && !cfg_path_name)
  95                 error(1, 0, "must provide a path to the BPF program");
  96
  97         if (cfg_attach && !cfg_section_name)
  98                 error(1, 0, "must provide a section name");
  99 }
 100
 101 int main(int argc, char **argv)
 102 {
 103         parse_opts(argc, argv);
 104         if (cfg_attach)
 105                 load_and_attach_program();
 106         else
 107                 detach_program();
 108         return 0;
 109 }