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
  19 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
  20
  21         if (streq(key, "resume")) {
  22                 char *s;
  23
  24                 if (proc_cmdline_value_missing(key, value))
  25                         return 0;
  26
  27                 s = fstab_node_to_udev_node(value);
  28                 if (!s)
  29                         return log_oom();
  30
  31                 free(arg_resume_device);
  32                 arg_resume_device = s;
  33         }
  34
  35         return 0;
  36 }
  37
  38 static int process_resume(void) {
  39         _cleanup_free_ char *name = NULL, *lnk = NULL;
  40         int r;
  41
  42         if (!arg_resume_device)
  43                 return 0;
  44
  45         r = unit_name_from_path_instance("systemd-hibernate-resume", arg_resume_device, ".service", &name);
  46         if (r < 0)
  47                 return log_error_errno(r, "Failed to generate unit name: %m");
  48
  49         lnk = strjoin(arg_dest, "/" SPECIAL_SYSINIT_TARGET ".wants/", name);
  50         if (!lnk)
  51                 return log_oom();
  52
  53         mkdir_parents_label(lnk, 0755);
  54         if (symlink(SYSTEM_DATA_UNIT_PATH "/systemd-hibernate-resume@.service", lnk) < 0)
  55                 return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
  56
  57         return 0;
  58 }
  59
  60 int main(int argc, char *argv[]) {
  61         int r = 0;
  62
  63         if (argc > 1 && argc != 4) {
  64                 log_error("This program takes three or no arguments.");
  65                 return EXIT_FAILURE;
  66         }
  67
  68         if (argc > 1)
  69                 arg_dest = argv[1];
  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         /* Don't even consider resuming outside of initramfs. */
  79         if (!in_initrd())
  80                 return EXIT_SUCCESS;
  81
  82         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
  83         if (r < 0)
  84                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
  85
  86         r = process_resume();
  87         free(arg_resume_device);
  88
  89         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
  90 }