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

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2014 Ivan Shapovalov
   6 ***/
   7
   8 #include <errno.h>
   9 #include <stdio.h>
  10
  11 #include "alloc-util.h"
  12 #include "fstab-util.h"
  13 #include "log.h"
  14 #include "mkdir.h"
  15 #include "proc-cmdline.h"
  16 #include "special.h"
  17 #include "string-util.h"
  18 #include "unit-name.h"
  19 #include "util.h"
  20
  21 static const char *arg_dest = "/tmp";
  22 static char *arg_resume_device = NULL;
  23
  24 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
  25
  26         if (streq(key, "resume")) {
  27                 char *s;
  28
  29                 if (proc_cmdline_value_missing(key, value))
  30                         return 0;
  31
  32                 s = fstab_node_to_udev_node(value);
  33                 if (!s)
  34                         return log_oom();
  35
  36                 free(arg_resume_device);
  37                 arg_resume_device = s;
  38         }
  39
  40         return 0;
  41 }
  42
  43 static int process_resume(void) {
  44         _cleanup_free_ char *name = NULL, *lnk = NULL;
  45         int r;
  46
  47         if (!arg_resume_device)
  48                 return 0;
  49
  50         r = unit_name_from_path_instance("systemd-hibernate-resume", arg_resume_device, ".service", &name);
  51         if (r < 0)
  52                 return log_error_errno(r, "Failed to generate unit name: %m");
  53
  54         lnk = strjoin(arg_dest, "/" SPECIAL_SYSINIT_TARGET ".wants/", name);
  55         if (!lnk)
  56                 return log_oom();
  57
  58         mkdir_parents_label(lnk, 0755);
  59         if (symlink(SYSTEM_DATA_UNIT_PATH "/systemd-hibernate-resume@.service", lnk) < 0)
  60                 return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
  61
  62         return 0;
  63 }
  64
  65 int main(int argc, char *argv[]) {
  66         int r = 0;
  67
  68         if (argc > 1 && argc != 4) {
  69                 log_error("This program takes three or no arguments.");
  70                 return EXIT_FAILURE;
  71         }
  72
  73         if (argc > 1)
  74                 arg_dest = argv[1];
  75
  76         log_set_prohibit_ipc(true);
  77         log_set_target(LOG_TARGET_AUTO);
  78         log_parse_environment();
  79         log_open();
  80
  81         umask(0022);
  82
  83         /* Don't even consider resuming outside of initramfs. */
  84         if (!in_initrd())
  85                 return EXIT_SUCCESS;
  86
  87         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
  88         if (r < 0)
  89                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
  90
  91         r = process_resume();
  92         free(arg_resume_device);
  93
  94         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
  95 }