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 "flow_dissector_load.h"
  15
  16 const char *cfg_pin_path = "/sys/fs/bpf/flow_dissector";
  17 const char *cfg_map_name = "jmp_table";
  18 bool cfg_attach = true;
  19 char *cfg_prog_name;
  20 char *cfg_path_name;
  21
  22 static void load_and_attach_program(void)
  23 {
  24         int prog_fd, ret;
  25         struct bpf_object *obj;
  26
  27         /* Use libbpf 1.0 API mode */
  28         libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
  29
  30         ret = bpf_flow_load(&obj, cfg_path_name, cfg_prog_name,
  31                             cfg_map_name, NULL, &prog_fd, NULL);
  32         if (ret)
  33                 error(1, 0, "bpf_flow_load %s", cfg_path_name);
  34
  35         ret = bpf_prog_attach(prog_fd, 0 /* Ignore */, BPF_FLOW_DISSECTOR, 0);
  36         if (ret)
  37                 error(1, 0, "bpf_prog_attach %s", cfg_path_name);
  38
  39         ret = bpf_object__pin(obj, cfg_pin_path);
  40         if (ret)
  41                 error(1, 0, "bpf_object__pin %s", cfg_pin_path);
  42 }
  43
  44 static void detach_program(void)
  45 {
  46         char command[64];
  47         int ret;
  48
  49         ret = bpf_prog_detach(0, BPF_FLOW_DISSECTOR);
  50         if (ret)
  51                 error(1, 0, "bpf_prog_detach");
  52
  53         /* To unpin, it is necessary and sufficient to just remove this dir */
  54         sprintf(command, "rm -r %s", cfg_pin_path);
  55         ret = system(command);
  56         if (ret)
  57                 error(1, errno, "%s", command);
  58 }
  59
  60 static void parse_opts(int argc, char **argv)
  61 {
  62         bool attach = false;
  63         bool detach = false;
  64         int c;
  65
  66         while ((c = getopt(argc, argv, "adp:s:")) != -1) {
  67                 switch (c) {
  68                 case 'a':
  69                         if (detach)
  70                                 error(1, 0, "attach/detach are exclusive");
  71                         attach = true;
  72                         break;
  73                 case 'd':
  74                         if (attach)
  75                                 error(1, 0, "attach/detach are exclusive");
  76                         detach = true;
  77                         break;
  78                 case 'p':
  79                         if (cfg_path_name)
  80                                 error(1, 0, "only one path can be given");
  81
  82                         cfg_path_name = optarg;
  83                         break;
  84                 case 's':
  85                         if (cfg_prog_name)
  86                                 error(1, 0, "only one prog can be given");
  87
  88                         cfg_prog_name = optarg;
  89                         break;
  90                 }
  91         }
  92
  93         if (detach)
  94                 cfg_attach = false;
  95
  96         if (cfg_attach && !cfg_path_name)
  97                 error(1, 0, "must provide a path to the BPF program");
  98
  99         if (cfg_attach && !cfg_prog_name)
 100                 error(1, 0, "must provide a section name");
 101 }
 102
 103 int main(int argc, char **argv)
 104 {
 105         parse_opts(argc, argv);
 106         if (cfg_attach)
 107                 load_and_attach_program();
 108         else
 109                 detach_program();
 110         return 0;
 111 }