text: /* SPDX-License-Identifier: LGPL-2.1+ */
  /***
    Copyright © 2010-2017 Canonical
    Copyright © 2018 Dell Inc.
  ***/
  
  #include <errno.h>
  #include <fcntl.h>
  #include <getopt.h>
  #include <linux/fiemap.h>
  #include <stdio.h>
  #include <sys/stat.h>
  #include <sys/types.h>
  #include <unistd.h>
  
  #include "def.h"
  #include "exec-util.h"
  #include "fd-util.h"
  #include "fileio.h"
  #include "format-util.h"
  #include "log.h"
  #include "main-func.h"
  #include "parse-util.h"
  #include "pretty-print.h"
  #include "sd-messages.h"
  #include "sleep-config.h"
  #include "stdio-util.h"
  #include "string-util.h"
  #include "strv.h"
  #include "util.h"
  
  static char* arg_verb = NULL;
  
  static int write_hibernate_location_info(void)
  {
      _cleanup_free_ char *device = NULL, *type = NULL;
      _cleanup_free_ struct fiemap* fiemap = NULL;
      char offset_str[DECIMAL_STR_MAX(uint64_t)];
      char device_str[DECIMAL_STR_MAX(uint64_t)];
      _cleanup_close_ int fd = -1;
      struct stat stb;
      uint64_t offset;
      int r;
  
      r = find_hibernate_location(&device, &type, NULL, NULL);
      if (r < 0)
          return log_debug_errno(r, "Unable to find hibernation location: %m");
  
      /* if it's a swap partition, we just write the disk to /sys/power/resume */
      if (streq(type, "partition"))
      {
          r = write_string_file("/sys/power/resume", device,
                                WRITE_STRING_FILE_DISABLE_BUFFER);
          if (r < 0)
              return log_debug_errno(
                  r,
                  "Faileed to write partitoin device to /sys/power/resume: %m");
  
          return r;
      }
      if (!streq(type, "file"))
          return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                 "Invalid hibernate type: %s", type);
  
      /* Only available in 4.17+ */
      if (access("/sys/power/resume_offset", W_OK) < 0)
      {
          if (errno == ENOENT)
          {
              log_debug(
                  "Kernel too old, can't configure resume offset, ignoring.");
              return 0;
          }
  
          return log_debug_errno(errno,
                                 "/sys/power/resume_offset not writeable: %m");
      }
  
      fd = open(device, O_RDONLY | O_CLOEXEC | O_NONBLOCK);
      if (fd < 0)
          return log_debug_errno(errno, "Unable to open '%s': %m", device);
      r = fstat(fd, &stb);
      if (r < 0)
          return log_debug_errno(errno, "Unable to stat %s: %m", device);
  
      r = read_fiemap(fd, &fiemap);
      if (r < 0)
          return log_debug_errno(r, "Unable to read extent map for '%s': %m",
                                 device);
      if (fiemap->fm_mapped_extents == 0)
          return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                 "No extents found in '%s'", device);
  
      offset = fiemap->fm_extents[0].fe_physical / page_size();
      xsprintf(offset_str, "%" PRIu64, offset);
      r = write_string_file("/sys/power/resume_offset", offset_str,
                            WRITE_STRING_FILE_DISABLE_BUFFER);
      if (r < 0)
          return log_debug_errno(r, "Failed to write offset '%s': %m",
                                 offset_str);
  
      xsprintf(device_str, "%lx", (unsigned long)stb.st_dev);
      r = write_string_file("/sys/power/resume", device_str,
                            WRITE_STRING_FILE_DISABLE_BUFFER);
      if (r < 0)
          return log_debug_errno(r, "Failed to write device '%s': %m",
                                 device_str);
  
      return 0;
  }
  
  static int write_mode(char** modes)
  {
      int r = 0;
      char** mode;
  
      STRV_FOREACH(mode, modes)
      {
          int k;
  
          k = write_string_file("/sys/power/disk", *mode,
                                WRITE_STRING_FILE_DISABLE_BUFFER);
          if (k >= 0)
              return 0;
  
          log_debug_errno(k, "Failed to write '%s' to /sys/power/disk: %m",
                          *mode);
          if (r >= 0)
              r = k;
      }
  
      return r;
  }
  
  static int write_state(FILE** f, char** states)
  {
      char** state;
      int r = 0;
  
      STRV_FOREACH(state, states)
      {
          int k;
  
          k = write_string_stream(*f, *state, WRITE_STRING_FILE_DISABLE_BUFFER);
          if (k >= 0)
              return 0;
          log_debug_errno(k, "Failed to write '%s' to /sys/power/state: %m",
                          *state);
          if (r >= 0)
              r = k;
  
          fclose(*f);
          *f = fopen("/sys/power/state", "we");
          if (!*f)
              return -errno;
      }
  
      return r;
  }
  
  static int execute(char** modes, char** states)
  {
      char* arguments[] = {NULL, (char*)"pre", arg_verb, NULL};
      static const char* const dirs[] = {SYSTEM_SLEEP_PATH, NULL};
  
      int r;
      _cleanup_fclose_ FILE* f = NULL;
  
      /* This file is opened first, so that if we hit an error,
       * we can abort before modifying any state. */
      f = fopen("/sys/power/state", "we");
      if (!f)
          return log_error_errno(errno, "Failed to open /sys/power/state: %m");
  
      setvbuf(f, NULL, _IONBF, 0);
  
      /* Configure the hibernation mode */
      if (!strv_isempty(modes))
      {
          r = write_hibernate_location_info();
          if (r < 0)
              return log_error_errno(
                  r, "Failed to write hibernation disk offset: %m");
          r = write_mode(modes);
          if (r < 0)
              return log_error_errno(
                  r, "Failed to write mode to /sys/power/disk: %m");
          ;
      }
  
      (void)execute_directories(dirs, DEFAULT_TIMEOUT_USEC, NULL, NULL, arguments,
                                NULL, EXEC_DIR_PARALLEL | EXEC_DIR_IGNORE_ERRORS);
  
      log_struct(LOG_INFO, "MESSAGE_ID=" SD_MESSAGE_SLEEP_START_STR,
                 LOG_MESSAGE("Suspending system..."), "SLEEP=%s", arg_verb);
  
      r = write_state(&f, states);
      if (r < 0)
          log_struct_errno(
              LOG_ERR, r, "MESSAGE_ID=" SD_MESSAGE_SLEEP_STOP_STR,
              LOG_MESSAGE("Failed to suspend system. System resumed again: %m"),
              "SLEEP=%s", arg_verb);
      else
          log_struct(LOG_INFO, "MESSAGE_ID=" SD_MESSAGE_SLEEP_STOP_STR,
                     LOG_MESSAGE("System resumed."), "SLEEP=%s", arg_verb);
  
      arguments[1] = (char*)"post";
      (void)execute_directories(dirs, DEFAULT_TIMEOUT_USEC, NULL, NULL, arguments,
                                NULL, EXEC_DIR_PARALLEL | EXEC_DIR_IGNORE_ERRORS);
  
      return r;
  }
  
  static int rtc_read_time(uint64_t* ret_sec)
  {
      _cleanup_free_ char* t = NULL;
      int r;
  
      r = read_one_line_file("/sys/class/rtc/rtc0/since_epoch", &t);
      if (r < 0)
          return log_error_errno(r, "Failed to read RTC time: %m");
  
      r = safe_atou64(t, ret_sec);
      if (r < 0)
          return log_error_errno(r, "Failed to parse RTC time '%s': %m", t);
  
      return 0;
  }
  
  static int rtc_write_wake_alarm(uint64_t sec)
  {
      char buf[DECIMAL_STR_MAX(uint64_t)];
      int r;
  
      xsprintf(buf, "%" PRIu64, sec);
  
      r = write_string_file("/sys/class/rtc/rtc0/wakealarm", buf,
                            WRITE_STRING_FILE_DISABLE_BUFFER);
      if (r < 0)
          return log_error_errno(
              r, "Failed to write '%s' to /sys/class/rtc/rtc0/wakealarm: %m",
              buf);
  
      return 0;
  }
  
  static int execute_s2h(usec_t hibernate_delay_sec)
  {
  
      _cleanup_strv_free_ char **hibernate_modes = NULL,
                               **hibernate_states = NULL, **suspend_modes = NULL,
                               **suspend_states = NULL;
      usec_t original_time, wake_time, cmp_time;
      int r;
  
      r = parse_sleep_config("suspend", NULL, &suspend_modes, &suspend_states,
                             NULL);
      if (r < 0)
          return r;
  
      r = parse_sleep_config("hibernate", NULL, &hibernate_modes,
                             &hibernate_states, NULL);
      if (r < 0)
          return r;
  
      r = rtc_read_time(&original_time);
      if (r < 0)
          return r;
  
      wake_time = original_time + DIV_ROUND_UP(hibernate_delay_sec, USEC_PER_SEC);
      r = rtc_write_wake_alarm(wake_time);
      if (r < 0)
          return r;
  
      log_debug("Set RTC wake alarm for %" PRIu64, wake_time);
  
      r = execute(suspend_modes, suspend_states);
      if (r < 0)
          return r;
  
      /* Reset RTC right-away */
      r = rtc_write_wake_alarm(0);
      if (r < 0)
          return r;
  
      r = rtc_read_time(&cmp_time);
      if (r < 0)
          return r;
  
      log_debug("Woke up at %" PRIu64, cmp_time);
  
      if (cmp_time <
          wake_time) /* We woke up before the alarm time, we are done. */
          return 0;
  
      /* If woken up after alarm time, hibernate */
      r = execute(hibernate_modes, hibernate_states);
      if (r < 0)
      {
          log_notice("Couldn't hibernate, will try to suspend again.");
          r = execute(suspend_modes, suspend_states);
          if (r < 0)
          {
              log_notice("Could neither hibernate nor suspend again, giving up.");
              return r;
          }
      }
  
      return 0;
  }
  
  static int help(void)
  {
      _cleanup_free_ char* link = NULL;
      int r;
  
      r = terminal_urlify_man("systemd-suspend.service", "8", &link);
      if (r < 0)
          return log_oom();
  
      printf("%s COMMAND\n\n"
             "Suspend the system, hibernate the system, or both.\n\n"
             "  -h --help              Show this help and exit\n"
             "  --version              Print version string and exit\n"
             "\nCommands:\n"
             "  suspend                Suspend the system\n"
             "  hibernate              Hibernate the system\n"
             "  hybrid-sleep           Both hibernate and suspend the system\n"
             "  suspend-then-hibernate Initially suspend and then hibernate\n"
             "                         the system after a fixed period of time\n"
             "\nSee the %s for details.\n",
             program_invocation_short_name, link);
  
      return 0;
  }
  
  static int parse_argv(int argc, char* argv[])
  {
      enum
      {
          ARG_VERSION = 0x100,
      };
  
      static const struct option options[] = {
          {"help", no_argument, NULL, 'h'},
          {"version", no_argument, NULL, ARG_VERSION},
          {}};
  
      int c;
  
      assert(argc >= 0);
      assert(argv);
  
      while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
          switch (c)
          {
              case 'h':
                  return help();
  
              case ARG_VERSION:
                  return version();
  
              case '?':
                  return -EINVAL;
  
              default:
                  assert_not_reached("Unhandled option");
          }
  
      if (argc - optind != 1)
          return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Usage: %s COMMAND",
                                 program_invocation_short_name);
  
      arg_verb = argv[optind];
  
      if (!STR_IN_SET(arg_verb, "suspend", "hibernate", "hybrid-sleep",
                      "suspend-then-hibernate"))
          return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown command '%s'.",
                                 arg_verb);
  
      return 1 /* work to do */;
  }
  
  static int run(int argc, char* argv[])
  {
      bool allow;
      _cleanup_strv_free_ char **modes = NULL, **states = NULL;
      usec_t delay = 0;
      int r;
  
      log_setup_service();
  
      r = parse_argv(argc, argv);
      if (r <= 0)
          return r;
  
      r = parse_sleep_config(arg_verb, &allow, &modes, &states, &delay);
      if (r < 0)
          return r;
  
      if (!allow)
          return log_error_errno(
              SYNTHETIC_ERRNO(EACCES),
              "Sleep mode \"%s\" is disabled by configuration, refusing.",
              arg_verb);
  
      if (streq(arg_verb, "suspend-then-hibernate"))
          return execute_s2h(delay);
      else
          return execute(modes, states);
  }
  
  DEFINE_MAIN_FUNCTION(run);
  