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

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <stdio.h>
   5 #include <unistd.h>
   6
   7 #include "alloc-util.h"
   8 #include "fstab-util.h"
   9 #include "generator.h"
  10 #include "log.h"
  11 #include "main-func.h"
  12 #include "mkdir.h"
  13 #include "proc-cmdline.h"
  14 #include "special.h"
  15 #include "string-util.h"
  16 #include "unit-name.h"
  17
  18 static const char *arg_dest = "/tmp";
  19 static char *arg_resume_device = NULL;
  20 static bool arg_noresume = false;
  21
  22 STATIC_DESTRUCTOR_REGISTER(arg_resume_device, freep);
  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_and_replace(arg_resume_device, s);
  37
  38         } else if (streq(key, "noresume")) {
  39                 if (value) {
  40                         log_warning("\"noresume\" kernel command line switch specified with an argument, ignoring.");
  41                         return 0;
  42                 }
  43
  44                 arg_noresume = true;
  45         }
  46
  47         return 0;
  48 }
  49
  50 static int process_resume(void) {
  51         _cleanup_free_ char *name = NULL, *lnk = NULL;
  52         int r;
  53
  54         if (!arg_resume_device)
  55                 return 0;
  56
  57         r = unit_name_from_path_instance("systemd-hibernate-resume", arg_resume_device, ".service", &name);
  58         if (r < 0)
  59                 return log_error_errno(r, "Failed to generate unit name: %m");
  60
  61         lnk = strjoin(arg_dest, "/" SPECIAL_SYSINIT_TARGET ".wants/", name);
  62         if (!lnk)
  63                 return log_oom();
  64
  65         mkdir_parents_label(lnk, 0755);
  66         if (symlink(SYSTEM_DATA_UNIT_PATH "/systemd-hibernate-resume@.service", lnk) < 0)
  67                 return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
  68
  69         return 0;
  70 }
  71
  72 static int run(int argc, char *argv[]) {
  73         int r = 0;
  74
  75         log_setup_generator();
  76
  77         if (argc > 1 && argc != 4)
  78                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
  79                                        "This program takes three or no arguments.");
  80
  81         if (argc > 1)
  82                 arg_dest = argv[1];
  83
  84         /* Don't even consider resuming outside of initramfs. */
  85         if (!in_initrd()) {
  86                 log_debug("Not running in an initrd, quitting.");
  87                 return 0;
  88         }
  89
  90         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
  91         if (r < 0)
  92                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
  93
  94         if (arg_noresume) {
  95                 log_notice("Found \"noresume\" on the kernel command line, quitting.");
  96                 return 0;
  97         }
  98
  99         return process_resume();
 100 }
 101
 102 DEFINE_MAIN_FUNCTION(run);