src/basic/verbs.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2014 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <getopt.h>
  22 #include <stdbool.h>
  23 #include <stddef.h>
  24
  25 #include "log.h"
  26 #include "macro.h"
  27 #include "string-util.h"
  28 #include "verbs.h"
  29 #include "virt.h"
  30
  31 int dispatch_verb(int argc, char *argv[], const Verb verbs[], void *userdata) {
  32         const Verb *verb;
  33         const char *name;
  34         unsigned i;
  35         int left;
  36
  37         assert(verbs);
  38         assert(verbs[0].dispatch);
  39         assert(argc >= 0);
  40         assert(argv);
  41         assert(argc >= optind);
  42
  43         left = argc - optind;
  44         name = argv[optind];
  45
  46         for (i = 0;; i++) {
  47                 bool found;
  48
  49                 /* At the end of the list? */
  50                 if (!verbs[i].dispatch) {
  51                         if (name)
  52                                 log_error("Unknown operation %s.", name);
  53                         else
  54                                 log_error("Requires operation parameter.");
  55                         return -EINVAL;
  56                 }
  57
  58                 if (name)
  59                         found = streq(name, verbs[i].verb);
  60                 else
  61                         found = !!(verbs[i].flags & VERB_DEFAULT);
  62
  63                 if (found) {
  64                         verb = &verbs[i];
  65                         break;
  66                 }
  67         }
  68
  69         assert(verb);
  70
  71         if (!name)
  72                 left = 1;
  73
  74         if (verb->min_args != VERB_ANY &&
  75             (unsigned) left < verb->min_args) {
  76                 log_error("Too few arguments.");
  77                 return -EINVAL;
  78         }
  79
  80         if (verb->max_args != VERB_ANY &&
  81             (unsigned) left > verb->max_args) {
  82                 log_error("Too many arguments.");
  83                 return -EINVAL;
  84         }
  85
  86         if ((verb->flags & VERB_NOCHROOT) && running_in_chroot() > 0) {
  87                 log_info("Running in chroot, ignoring request.");
  88                 return 0;
  89         }
  90
  91         if (name)
  92                 return verb->dispatch(left, argv + optind, userdata);
  93         else {
  94                 char* fake[2] = {
  95                         (char*) verb->verb,
  96                         NULL
  97                 };
  98
  99                 return verb->dispatch(1, fake, userdata);
 100         }
 101 }