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

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <stdio.h>
   5
   6 #include "alloc-util.h"
   7 #include "fstab-util.h"
   8 #include "log.h"
   9 #include "mkdir.h"
  10 #include "proc-cmdline.h"
  11 #include "special.h"
  12 #include "string-util.h"
  13 #include "unit-name.h"
  14 #include "util.h"
  15
  16 static const char *arg_dest = "/tmp";
  17 static char *arg_resume_device = NULL;
  18 static bool arg_noresume = false;
  19
  20 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
  21
  22         if (streq(key, "resume")) {
  23                 char *s;
  24
  25                 if (proc_cmdline_value_missing(key, value))
  26                         return 0;
  27
  28                 s = fstab_node_to_udev_node(value);
  29                 if (!s)
  30                         return log_oom();
  31
  32                 free_and_replace(arg_resume_device, s);
  33
  34         } else if (streq(key, "noresume")) {
  35                 if (value) {
  36                         log_warning("\"noresume\" kernel command line switch specified with an argument, ignoring.");
  37                         return 0;
  38                 }
  39
  40                 arg_noresume = true;
  41         }
  42
  43         return 0;
  44 }
  45
  46 static int process_resume(void) {
  47         _cleanup_free_ char *name = NULL, *lnk = NULL;
  48         int r;
  49
  50         if (!arg_resume_device)
  51                 return 0;
  52
  53         r = unit_name_from_path_instance("systemd-hibernate-resume", arg_resume_device, ".service", &name);
  54         if (r < 0)
  55                 return log_error_errno(r, "Failed to generate unit name: %m");
  56
  57         lnk = strjoin(arg_dest, "/" SPECIAL_SYSINIT_TARGET ".wants/", name);
  58         if (!lnk)
  59                 return log_oom();
  60
  61         mkdir_parents_label(lnk, 0755);
  62         if (symlink(SYSTEM_DATA_UNIT_PATH "/systemd-hibernate-resume@.service", lnk) < 0)
  63                 return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
  64
  65         return 0;
  66 }
  67
  68 int main(int argc, char *argv[]) {
  69         int r = 0;
  70
  71         log_set_prohibit_ipc(true);
  72         log_set_target(LOG_TARGET_AUTO);
  73         log_parse_environment();
  74         log_open();
  75
  76         umask(0022);
  77
  78         if (argc > 1 && argc != 4) {
  79                 log_error("This program takes three or no arguments.");
  80                 return EXIT_FAILURE;
  81         }
  82
  83         if (argc > 1)
  84                 arg_dest = argv[1];
  85
  86         /* Don't even consider resuming outside of initramfs. */
  87         if (!in_initrd()) {
  88                 log_debug("Not running in an initrd, quitting.");
  89                 return EXIT_SUCCESS;
  90         }
  91
  92         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
  93         if (r < 0)
  94                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
  95
  96         if (arg_noresume) {
  97                 log_notice("Found \"noresume\" on the kernel command line, quitting.");
  98                 r = 0;
  99                 goto finish;
 100         }
 101
 102         r = process_resume();
 103
 104 finish:
 105         free(arg_resume_device);
 106
 107         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 108 }