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
  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_section_name;
  20 char *cfg_path_name;
  21
  22 static void load_and_attach_program(void)
  23 {
  24         struct bpf_program *prog, *main_prog;
  25         struct bpf_map *prog_array;
  26         int i, fd, prog_fd, ret;
  27         struct bpf_object *obj;
  28         int prog_array_fd;
  29
  30         ret = bpf_prog_load(cfg_path_name, BPF_PROG_TYPE_FLOW_DISSECTOR, &obj,
  31                             &prog_fd);
  32         if (ret)
  33                 error(1, 0, "bpf_prog_load %s", cfg_path_name);
  34
  35         main_prog = bpf_object__find_program_by_title(obj, cfg_section_name);
  36         if (!main_prog)
  37                 error(1, 0, "bpf_object__find_program_by_title %s",
  38                       cfg_section_name);
  39
  40         prog_fd = bpf_program__fd(main_prog);
  41         if (prog_fd < 0)
  42                 error(1, 0, "bpf_program__fd");
  43
  44         prog_array = bpf_object__find_map_by_name(obj, cfg_map_name);
  45         if (!prog_array)
  46                 error(1, 0, "bpf_object__find_map_by_name %s", cfg_map_name);
  47
  48         prog_array_fd = bpf_map__fd(prog_array);
  49         if (prog_array_fd < 0)
  50                 error(1, 0, "bpf_map__fd %s", cfg_map_name);
  51
  52         i = 0;
  53         bpf_object__for_each_program(prog, obj) {
  54                 fd = bpf_program__fd(prog);
  55                 if (fd < 0)
  56                         error(1, 0, "bpf_program__fd");
  57
  58                 if (fd != prog_fd) {
  59                         printf("%d: %s\n", i, bpf_program__title(prog, false));
  60                         bpf_map_update_elem(prog_array_fd, &i, &fd, BPF_ANY);
  61                         ++i;
  62                 }
  63         }
  64
  65         ret = bpf_prog_attach(prog_fd, 0 /* Ignore */, BPF_FLOW_DISSECTOR, 0);
  66         if (ret)
  67                 error(1, 0, "bpf_prog_attach %s", cfg_path_name);
  68
  69         ret = bpf_object__pin(obj, cfg_pin_path);
  70         if (ret)
  71                 error(1, 0, "bpf_object__pin %s", cfg_pin_path);
  72
  73 }
  74
  75 static void detach_program(void)
  76 {
  77         char command[64];
  78         int ret;
  79
  80         ret = bpf_prog_detach(0, BPF_FLOW_DISSECTOR);
  81         if (ret)
  82                 error(1, 0, "bpf_prog_detach");
  83
  84         /* To unpin, it is necessary and sufficient to just remove this dir */
  85         sprintf(command, "rm -r %s", cfg_pin_path);
  86         ret = system(command);
  87         if (ret)
  88                 error(1, errno, command);
  89 }
  90
  91 static void parse_opts(int argc, char **argv)
  92 {
  93         bool attach = false;
  94         bool detach = false;
  95         int c;
  96
  97         while ((c = getopt(argc, argv, "adp:s:")) != -1) {
  98                 switch (c) {
  99                 case 'a':
 100                         if (detach)
 101                                 error(1, 0, "attach/detach are exclusive");
 102                         attach = true;
 103                         break;
 104                 case 'd':
 105                         if (attach)
 106                                 error(1, 0, "attach/detach are exclusive");
 107                         detach = true;
 108                         break;
 109                 case 'p':
 110                         if (cfg_path_name)
 111                                 error(1, 0, "only one prog name can be given");
 112
 113                         cfg_path_name = optarg;
 114                         break;
 115                 case 's':
 116                         if (cfg_section_name)
 117                                 error(1, 0, "only one section can be given");
 118
 119                         cfg_section_name = optarg;
 120                         break;
 121                 }
 122         }
 123
 124         if (detach)
 125                 cfg_attach = false;
 126
 127         if (cfg_attach && !cfg_path_name)
 128                 error(1, 0, "must provide a path to the BPF program");
 129
 130         if (cfg_attach && !cfg_section_name)
 131                 error(1, 0, "must provide a section name");
 132 }
 133
 134 int main(int argc, char **argv)
 135 {
 136         parse_opts(argc, argv);
 137         if (cfg_attach)
 138                 load_and_attach_program();
 139         else
 140                 detach_program();
 141         return 0;
 142 }