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_dev = NULL;
  35
  36 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
  37
  38         if (streq(key, "resume") && value) {
  39                 free(arg_resume_dev);
  40                 arg_resume_dev = fstab_node_to_udev_node(value);
  41                 if (!arg_resume_dev)
  42                         return log_oom();
  43         }
  44
  45         return 0;
  46 }
  47
  48 static int process_resume(void) {
  49         _cleanup_free_ char *name = NULL, *lnk = NULL;
  50         int r;
  51
  52         if (!arg_resume_dev)
  53                 return 0;
  54
  55         r = unit_name_from_path_instance("systemd-hibernate-resume", arg_resume_dev, ".service", &name);
  56         if (r < 0)
  57                 return log_error_errno(r, "Failed to generate unit name: %m");
  58
  59         lnk = strjoin(arg_dest, "/" SPECIAL_SYSINIT_TARGET ".wants/", name);
  60         if (!lnk)
  61                 return log_oom();
  62
  63         mkdir_parents_label(lnk, 0755);
  64         if (symlink(SYSTEM_DATA_UNIT_PATH "/systemd-hibernate-resume@.service", lnk) < 0)
  65                 return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
  66
  67         return 0;
  68 }
  69
  70 int main(int argc, char *argv[]) {
  71         int r = 0;
  72
  73         if (argc > 1 && argc != 4) {
  74                 log_error("This program takes three or no arguments.");
  75                 return EXIT_FAILURE;
  76         }
  77
  78         if (argc > 1)
  79                 arg_dest = argv[1];
  80
  81         log_set_target(LOG_TARGET_SAFE);
  82         log_parse_environment();
  83         log_open();
  84
  85         umask(0022);
  86
  87         /* Don't even consider resuming outside of initramfs. */
  88         if (!in_initrd())
  89                 return EXIT_SUCCESS;
  90
  91         r = parse_proc_cmdline(parse_proc_cmdline_item, NULL, false);
  92         if (r < 0)
  93                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
  94
  95         r = process_resume();
  96         free(arg_resume_dev);
  97
  98         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
  99 }