src/hibernate-resume/hibernate-resume-generator.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2014 Ivan Shapovalov
   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 <stdio.h>
  22
  23 #include "alloc-util.h"
  24 #include "fstab-util.h"
  25 #include "log.h"
  26 #include "mkdir.h"
  27 #include "proc-cmdline.h"
  28 #include "special.h"
  29 #include "string-util.h"
  30 #include "unit-name.h"
  31 #include "util.h"
  32
  33 static const char *arg_dest = "/tmp";
  34 static char *arg_resume_device = NULL;
  35
  36 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
  37
  38         if (streq(key, "resume")) {
  39                 char *s;
  40
  41                 if (proc_cmdline_value_missing(key, value))
  42                         return 0;
  43
  44                 s = fstab_node_to_udev_node(value);
  45                 if (!s)
  46                         return log_oom();
  47
  48                 free(arg_resume_device);
  49                 arg_resume_device = s;
  50         }
  51
  52         return 0;
  53 }
  54
  55 static int process_resume(void) {
  56         _cleanup_free_ char *name = NULL, *lnk = NULL;
  57         int r;
  58
  59         if (!arg_resume_device)
  60                 return 0;
  61
  62         r = unit_name_from_path_instance("systemd-hibernate-resume", arg_resume_device, ".service", &name);
  63         if (r < 0)
  64                 return log_error_errno(r, "Failed to generate unit name: %m");
  65
  66         lnk = strjoin(arg_dest, "/" SPECIAL_SYSINIT_TARGET ".wants/", name);
  67         if (!lnk)
  68                 return log_oom();
  69
  70         mkdir_parents_label(lnk, 0755);
  71         if (symlink(SYSTEM_DATA_UNIT_PATH "/systemd-hibernate-resume@.service", lnk) < 0)
  72                 return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
  73
  74         return 0;
  75 }
  76
  77 int main(int argc, char *argv[]) {
  78         int r = 0;
  79
  80         if (argc > 1 && argc != 4) {
  81                 log_error("This program takes three or no arguments.");
  82                 return EXIT_FAILURE;
  83         }
  84
  85         if (argc > 1)
  86                 arg_dest = argv[1];
  87
  88         log_set_target(LOG_TARGET_SAFE);
  89         log_parse_environment();
  90         log_open();
  91
  92         umask(0022);
  93
  94         /* Don't even consider resuming outside of initramfs. */
  95         if (!in_initrd())
  96                 return EXIT_SUCCESS;
  97
  98         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
  99         if (r < 0)
 100                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 101
 102         r = process_resume();
 103         free(arg_resume_device);
 104
 105         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 106 }