sleep-util: split into sleep-config and hibernate-util

src/hibernate-resume/hibernate-resume.c

@@ -5,11 +5,11 @@
 
 #include "devnum-util.h"
 #include "hibernate-resume-config.h"
+#include "hibernate-util.h"
 #include "initrd-util.h"
 #include "log.h"
 #include "main-func.h"
 #include "parse-util.h"
-#include "sleep-util.h"
 #include "static-destruct.h"
 
 HibernateInfo arg_info = {};

src/login/logind-action.h

@@ -24,7 +24,7 @@ typedef struct HandleActionData HandleActionData;
 
 #include "logind-inhibit.h"
 #include "logind.h"
-#include "sleep-util.h"
+#include "sleep-config.h"
 
 static inline bool handle_action_valid(HandleAction a) {
         return a >= 0 && a < _HANDLE_ACTION_MAX;

src/login/logind-dbus.c

@@ -46,7 +46,7 @@
 #include "process-util.h"
 #include "reboot-util.h"
 #include "selinux-util.h"
-#include "sleep-util.h"
+#include "sleep-config.h"
 #include "special.h"
 #include "serialize.h"
 #include "stdio-util.h"

src/shared/hibernate-util.c

@@ -0,0 +1,512 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/***
+  Copyright © 2018 Dell Inc.
+***/
+
+#include <linux/fs.h>
+#include <linux/magic.h>
+#include <stddef.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "blockdev-util.h"
+#include "btrfs-util.h"
+#include "device-util.h"
+#include "devnum-util.h"
+#include "env-util.h"
+#include "errno-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "hibernate-util.h"
+#include "log.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+
+#define HIBERNATION_SWAP_THRESHOLD 0.98
+
+SwapEntry* swap_entry_free(SwapEntry *se) {
+        if (!se)
+                return NULL;
+
+        free(se->path);
+
+        return mfree(se);
+}
+
+HibernateLocation* hibernate_location_free(HibernateLocation *hl) {
+        if (!hl)
+                return NULL;
+
+        swap_entry_free(hl->swap);
+
+        return mfree(hl);
+}
+
+static int swap_device_to_devnum(const SwapEntry *swap, dev_t *ret_dev) {
+        _cleanup_close_ int fd = -EBADF;
+        struct stat sb;
+        int r;
+
+        assert(swap);
+        assert(swap->path);
+
+        fd = open(swap->path, O_CLOEXEC|O_PATH);
+        if (fd < 0)
+                return -errno;
+
+        if (fstat(fd, &sb) < 0)
+                return -errno;
+
+        if (swap->type == SWAP_BLOCK) {
+                if (!S_ISBLK(sb.st_mode))
+                        return -ENOTBLK;
+
+                *ret_dev = sb.st_rdev;
+                return 0;
+        }
+
+        r = stat_verify_regular(&sb);
+        if (r < 0)
+                return r;
+
+        return get_block_device_fd(fd, ret_dev);
+}
+
+/*
+ * Attempt to calculate the swap file offset on supported filesystems. On unsupported
+ * filesystems, a debug message is logged and ret_offset is set to UINT64_MAX.
+ */
+static int calculate_swap_file_offset(const SwapEntry *swap, uint64_t *ret_offset) {
+        _cleanup_close_ int fd = -EBADF;
+        _cleanup_free_ struct fiemap *fiemap = NULL;
+        int r;
+
+        assert(swap);
+        assert(swap->path);
+        assert(swap->type == SWAP_FILE);
+        assert(ret_offset);
+
+        fd = open(swap->path, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+        if (fd < 0)
+                return log_debug_errno(errno, "Failed to open swap file %s to determine on-disk offset: %m", swap->path);
+
+        r = fd_verify_regular(fd);
+        if (r < 0)
+                return log_debug_errno(r, "Selected swap file is not a regular file.");
+
+        r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC);
+        if (r < 0)
+                return log_debug_errno(r, "Error checking %s for Btrfs filesystem: %m", swap->path);
+        if (r > 0) {
+                log_debug("%s: detection of swap file offset on Btrfs is not supported", swap->path);
+                *ret_offset = UINT64_MAX;
+                return 0;
+        }
+
+        r = read_fiemap(fd, &fiemap);
+        if (r < 0)
+                return log_debug_errno(r, "Unable to read extent map for '%s': %m", swap->path);
+
+        *ret_offset = fiemap->fm_extents[0].fe_physical / page_size();
+        return 0;
+}
+
+static int read_resume_files(dev_t *ret_resume, uint64_t *ret_resume_offset) {
+        _cleanup_free_ char *resume_str = NULL, *resume_offset_str = NULL;
+        uint64_t resume_offset;
+        dev_t resume;
+        int r;
+
+        assert(ret_resume);
+        assert(ret_resume_offset);
+
+        r = read_one_line_file("/sys/power/resume", &resume_str);
+        if (r < 0)
+                return log_debug_errno(r, "Error reading /sys/power/resume: %m");
+
+        r = parse_devnum(resume_str, &resume);
+        if (r < 0)
+                return log_debug_errno(r, "Error parsing /sys/power/resume device: %s: %m", resume_str);
+
+        r = read_one_line_file("/sys/power/resume_offset", &resume_offset_str);
+        if (r == -ENOENT) {
+                log_debug_errno(r, "Kernel does not support resume_offset; swap file offset detection will be skipped.");
+                resume_offset = 0;
+        } else if (r < 0)
+                return log_debug_errno(r, "Error reading /sys/power/resume_offset: %m");
+        else {
+                r = safe_atou64(resume_offset_str, &resume_offset);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to parse value in /sys/power/resume_offset \"%s\": %m", resume_offset_str);
+        }
+
+        if (resume_offset > 0 && resume == 0)
+                log_debug("Warning: found /sys/power/resume_offset==%" PRIu64 ", but /sys/power/resume unset. Misconfiguration?",
+                          resume_offset);
+
+        *ret_resume = resume;
+        *ret_resume_offset = resume_offset;
+        return 0;
+}
+
+/*
+ * Determine if the HibernateLocation matches the resume= (device) and resume_offset= (file).
+ */
+static bool location_is_resume_device(const HibernateLocation *location, dev_t sys_resume, uint64_t sys_offset) {
+        if (!location)
+                return false;
+
+        return  sys_resume > 0 &&
+                sys_resume == location->devno &&
+                (sys_offset == location->offset || (sys_offset > 0 && location->offset == UINT64_MAX));
+}
+
+/*
+ * Attempt to find the hibernation location by parsing /proc/swaps, /sys/power/resume, and
+ * /sys/power/resume_offset.
+ *
+ * Beware:
+ *  Never use a device or file as location that hasn't been somehow specified by a user that would also be
+ *  entrusted with full system memory access (for example via /sys/power/resume) or that isn't an already
+ *  active swap area!
+ *  Otherwise various security attacks might become possible, for example an attacker could silently attach
+ *  such a device and circumvent full disk encryption when it would be automatically used for hibernation.
+ *  Also, having a swap area on top of encryption is not per se enough to protect from all such attacks.
+ *
+ * Returns:
+ *  1 - Values are set in /sys/power/resume and /sys/power/resume_offset.
+ *      ret_hibernate_location will represent matching /proc/swap entry if identified or NULL if not.
+ *
+ *  0 - No values are set in /sys/power/resume and /sys/power/resume_offset.
+        ret_hibernate_location will represent the highest priority swap with most remaining space discovered in /proc/swaps.
+ *
+ *  Negative value in the case of error.
+ */
+int find_hibernate_location(HibernateLocation **ret_hibernate_location) {
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_(hibernate_location_freep) HibernateLocation *hibernate_location = NULL;
+        dev_t sys_resume = 0; /* Unnecessary initialization to appease gcc */
+        uint64_t sys_offset = 0;
+        bool resume_match = false;
+        int r;
+
+        /* read the /sys/power/resume & /sys/power/resume_offset values */
+        r = read_resume_files(&sys_resume, &sys_offset);
+        if (r < 0)
+                return r;
+
+        f = fopen("/proc/swaps", "re");
+        if (!f) {
+                log_debug_errno(errno, "Failed to open /proc/swaps: %m");
+                return errno == ENOENT ? -EOPNOTSUPP : -errno; /* Convert swap not supported to a recognizable error */
+        }
+
+        (void) fscanf(f, "%*s %*s %*s %*s %*s\n");
+        for (unsigned i = 1;; i++) {
+                _cleanup_(swap_entry_freep) SwapEntry *swap = NULL;
+                _cleanup_free_ char *type = NULL;
+                uint64_t swap_offset = 0;
+                int k;
+
+                swap = new(SwapEntry, 1);
+                if (!swap)
+                        return -ENOMEM;
+
+                *swap = (SwapEntry) {
+                        .type = _SWAP_TYPE_INVALID,
+                };
+
+                k = fscanf(f,
+                           "%ms "       /* device/file path */
+                           "%ms "       /* type of swap */
+                           "%" PRIu64   /* swap size */
+                           "%" PRIu64   /* used */
+                           "%i\n",      /* priority */
+                           &swap->path, &type, &swap->size, &swap->used, &swap->priority);
+                if (k == EOF)
+                        break;
+                if (k != 5) {
+                        log_debug("Failed to parse /proc/swaps:%u, ignoring", i);
+                        continue;
+                }
+
+                if (streq(type, "file")) {
+
+                        if (endswith(swap->path, "\\040(deleted)")) {
+                                log_debug("Ignoring deleted swap file '%s'.", swap->path);
+                                continue;
+                        }
+
+                        swap->type = SWAP_FILE;
+
+                        r = calculate_swap_file_offset(swap, &swap_offset);
+                        if (r < 0)
+                                return r;
+
+                } else if (streq(type, "partition")) {
+                        const char *fn;
+
+                        fn = path_startswith(swap->path, "/dev/");
+                        if (fn && startswith(fn, "zram")) {
+                                log_debug("%s: ignoring zram swap", swap->path);
+                                continue;
+                        }
+
+                        swap->type = SWAP_BLOCK;
+
+                } else {
+                        log_debug("%s: swap type %s is unsupported for hibernation, ignoring", swap->path, type);
+                        continue;
+                }
+
+                /* prefer resume device or highest priority swap with most remaining space */
+                if (sys_resume == 0) {
+                        if (hibernate_location && swap->priority < hibernate_location->swap->priority) {
+                                log_debug("%s: ignoring device with lower priority", swap->path);
+                                continue;
+                        }
+                        if (hibernate_location &&
+                            (swap->priority == hibernate_location->swap->priority
+                             && swap->size - swap->used < hibernate_location->swap->size - hibernate_location->swap->used)) {
+                                log_debug("%s: ignoring device with lower usable space", swap->path);
+                                continue;
+                        }
+                }
+
+                dev_t swap_devno;
+                r = swap_device_to_devnum(swap, &swap_devno);
+                if (r < 0)
+                        return log_debug_errno(r, "%s: failed to query device number: %m", swap->path);
+                if (swap_devno == 0)
+                        return log_debug_errno(SYNTHETIC_ERRNO(ENODEV), "%s: not backed by block device.", swap->path);
+
+                hibernate_location = hibernate_location_free(hibernate_location);
+                hibernate_location = new(HibernateLocation, 1);
+                if (!hibernate_location)
+                        return -ENOMEM;
+
+                *hibernate_location = (HibernateLocation) {
+                        .devno = swap_devno,
+                        .offset = swap_offset,
+                        .swap = TAKE_PTR(swap),
+                };
+
+                /* if the swap is the resume device, stop the loop */
+                if (location_is_resume_device(hibernate_location, sys_resume, sys_offset)) {
+                        log_debug("%s: device matches configured resume settings.", hibernate_location->swap->path);
+                        resume_match = true;
+                        break;
+                }
+
+                log_debug("%s: is a candidate device.", hibernate_location->swap->path);
+        }
+
+        /* We found nothing at all */
+        if (!hibernate_location)
+                return log_debug_errno(SYNTHETIC_ERRNO(ENOSYS),
+                                       "No possible swap partitions or files suitable for hibernation were found in /proc/swaps.");
+
+        /* resume= is set but a matching /proc/swaps entry was not found */
+        if (sys_resume != 0 && !resume_match)
+                return log_debug_errno(SYNTHETIC_ERRNO(ENOSYS),
+                                       "No swap partitions or files matching resume config were found in /proc/swaps.");
+
+        if (hibernate_location->offset == UINT64_MAX) {
+                if (sys_offset == 0)
+                        return log_debug_errno(SYNTHETIC_ERRNO(ENOSYS), "Offset detection failed and /sys/power/resume_offset is not set.");
+
+                hibernate_location->offset = sys_offset;
+        }
+
+        if (resume_match)
+                log_debug("Hibernation will attempt to use swap entry with path: %s, device: %u:%u, offset: %" PRIu64 ", priority: %i",
+                          hibernate_location->swap->path, major(hibernate_location->devno), minor(hibernate_location->devno),
+                          hibernate_location->offset, hibernate_location->swap->priority);
+        else
+                log_debug("/sys/power/resume is not configured; attempting to hibernate with path: %s, device: %u:%u, offset: %" PRIu64 ", priority: %i",
+                          hibernate_location->swap->path, major(hibernate_location->devno), minor(hibernate_location->devno),
+                          hibernate_location->offset, hibernate_location->swap->priority);
+
+        *ret_hibernate_location = TAKE_PTR(hibernate_location);
+
+        if (resume_match)
+                return 1;
+
+        return 0;
+}
+
+bool enough_swap_for_hibernation(void) {
+        _cleanup_free_ char *active = NULL;
+        _cleanup_(hibernate_location_freep) HibernateLocation *hibernate_location = NULL;
+        unsigned long long act = 0;
+        int r;
+
+        if (getenv_bool("SYSTEMD_BYPASS_HIBERNATION_MEMORY_CHECK") > 0)
+                return true;
+
+        r = find_hibernate_location(&hibernate_location);
+        if (r < 0)
+                return false;
+
+        /* If /sys/power/{resume,resume_offset} is configured but a matching entry
+         * could not be identified in /proc/swaps, user is likely using Btrfs with a swapfile;
+         * return true and let the system attempt hibernation.
+         */
+        if (r > 0 && !hibernate_location) {
+                log_debug("Unable to determine remaining swap space; hibernation may fail");
+                return true;
+        }
+
+        if (!hibernate_location)
+                return false;
+
+        r = get_proc_field("/proc/meminfo", "Active(anon)", WHITESPACE, &active);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to retrieve Active(anon) from /proc/meminfo: %m");
+                return false;
+        }
+
+        r = safe_atollu(active, &act);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to parse Active(anon) from /proc/meminfo: %s: %m", active);
+                return false;
+        }
+
+        r = act <= (hibernate_location->swap->size - hibernate_location->swap->used) * HIBERNATION_SWAP_THRESHOLD;
+        log_debug("%s swap for hibernation, Active(anon)=%llu kB, size=%" PRIu64 " kB, used=%" PRIu64 " kB, threshold=%.2g%%",
+                  r ? "Enough" : "Not enough", act, hibernate_location->swap->size, hibernate_location->swap->used, 100*HIBERNATION_SWAP_THRESHOLD);
+
+        return r;
+}
+
+int read_fiemap(int fd, struct fiemap **ret) {
+        _cleanup_free_ struct fiemap *fiemap = NULL, *result_fiemap = NULL;
+        struct stat statinfo;
+        uint32_t result_extents = 0;
+        uint64_t fiemap_start = 0, fiemap_length;
+        const size_t n_extra = DIV_ROUND_UP(sizeof(struct fiemap), sizeof(struct fiemap_extent));
+
+        if (fstat(fd, &statinfo) < 0)
+                return log_debug_errno(errno, "Cannot determine file size: %m");
+        if (!S_ISREG(statinfo.st_mode))
+                return -ENOTTY;
+        fiemap_length = statinfo.st_size;
+
+        /* Zero this out in case we run on a file with no extents */
+        fiemap = calloc(n_extra, sizeof(struct fiemap_extent));
+        if (!fiemap)
+                return -ENOMEM;
+
+        result_fiemap = malloc_multiply(n_extra, sizeof(struct fiemap_extent));
+        if (!result_fiemap)
+                return -ENOMEM;
+
+        /*  XFS filesystem has incorrect implementation of fiemap ioctl and
+         *  returns extents for only one block-group at a time, so we need
+         *  to handle it manually, starting the next fiemap call from the end
+         *  of the last extent
+         */
+        while (fiemap_start < fiemap_length) {
+                *fiemap = (struct fiemap) {
+                        .fm_start = fiemap_start,
+                        .fm_length = fiemap_length,
+                        .fm_flags = FIEMAP_FLAG_SYNC,
+                };
+
+                /* Find out how many extents there are */
+                if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0)
+                        return log_debug_errno(errno, "Failed to read extents: %m");
+
+                /* Nothing to process */
+                if (fiemap->fm_mapped_extents == 0)
+                        break;
+
+                /* Resize fiemap to allow us to read in the extents, result fiemap has to hold all
+                 * the extents for the whole file. Add space for the initial struct fiemap. */
+                if (!greedy_realloc0((void**) &fiemap, n_extra + fiemap->fm_mapped_extents, sizeof(struct fiemap_extent)))
+                        return -ENOMEM;
+
+                fiemap->fm_extent_count = fiemap->fm_mapped_extents;
+                fiemap->fm_mapped_extents = 0;
+
+                if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0)
+                        return log_debug_errno(errno, "Failed to read extents: %m");
+
+                /* Resize result_fiemap to allow us to copy in the extents */
+                if (!greedy_realloc((void**) &result_fiemap,
+                                    n_extra + result_extents + fiemap->fm_mapped_extents, sizeof(struct fiemap_extent)))
+                        return -ENOMEM;
+
+                memcpy(result_fiemap->fm_extents + result_extents,
+                       fiemap->fm_extents,
+                       sizeof(struct fiemap_extent) * fiemap->fm_mapped_extents);
+
+                result_extents += fiemap->fm_mapped_extents;
+
+                /* Highly unlikely that it is zero */
+                if (_likely_(fiemap->fm_mapped_extents > 0)) {
+                        uint32_t i = fiemap->fm_mapped_extents - 1;
+
+                        fiemap_start = fiemap->fm_extents[i].fe_logical +
+                                       fiemap->fm_extents[i].fe_length;
+
+                        if (fiemap->fm_extents[i].fe_flags & FIEMAP_EXTENT_LAST)
+                                break;
+                }
+        }
+
+        memcpy(result_fiemap, fiemap, sizeof(struct fiemap));
+        result_fiemap->fm_mapped_extents = result_extents;
+        *ret = TAKE_PTR(result_fiemap);
+        return 0;
+}
+
+int write_resume_config(dev_t devno, uint64_t offset, const char *device) {
+        char offset_str[DECIMAL_STR_MAX(uint64_t)];
+        _cleanup_free_ char *path = NULL;
+        const char *devno_str;
+        int r;
+
+        devno_str = FORMAT_DEVNUM(devno);
+        xsprintf(offset_str, "%" PRIu64, offset);
+
+        if (!device) {
+                r = device_path_make_canonical(S_IFBLK, devno, &path);
+                if (r < 0)
+                        return log_error_errno(r,
+                                               "Failed to format canonical device path for devno '" DEVNUM_FORMAT_STR "': %m",
+                                               DEVNUM_FORMAT_VAL(devno));
+                device = path;
+        }
+
+        /* We write the offset first since it's safer. Note that this file is only available in 4.17+, so
+         * fail gracefully if it doesn't exist and we're only overwriting it with 0. */
+        r = write_string_file("/sys/power/resume_offset", offset_str, WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r == -ENOENT) {
+                if (offset != 0)
+                        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
+                                               "Can't configure hibernation offset %" PRIu64 ", kernel does not support /sys/power/resume_offset. Refusing.",
+                                               offset);
+
+                log_warning_errno(r, "/sys/power/resume_offset is unavailable, skipping writing swap file offset.");
+        } else if (r < 0)
+                return log_error_errno(r,
+                                       "Failed to write swap file offset %s to /sys/power/resume_offset for device '%s': %m",
+                                       offset_str, device);
+        else
+                log_debug("Wrote resume_offset=%s for device '%s' to /sys/power/resume_offset.",
+                          offset_str, device);
+
+        r = write_string_file("/sys/power/resume", devno_str, WRITE_STRING_FILE_DISABLE_BUFFER);
+        if (r < 0)
+                return log_error_errno(r,
+                                       "Failed to write device '%s' (%s) to /sys/power/resume: %m",
+                                       device, devno_str);
+        log_debug("Wrote resume=%s for device '%s' to /sys/power/resume.", devno_str, device);
+
+        return 0;
+}

src/shared/hibernate-util.h

@@ -4,30 +4,6 @@
 #include <linux/fiemap.h>
 #include <sys/types.h>
 
-#include "time-util.h"
-
-#define DEFAULT_SUSPEND_ESTIMATION_USEC (1 * USEC_PER_HOUR)
-
-typedef enum SleepOperation {
-        SLEEP_SUSPEND,
-        SLEEP_HIBERNATE,
-        SLEEP_HYBRID_SLEEP,
-        SLEEP_SUSPEND_THEN_HIBERNATE,
-        _SLEEP_OPERATION_MAX,
-        _SLEEP_OPERATION_INVALID = -EINVAL,
-} SleepOperation;
-
-typedef struct SleepConfig {
-        bool allow[_SLEEP_OPERATION_MAX];
-        char **modes[_SLEEP_OPERATION_MAX];
-        char **states[_SLEEP_OPERATION_MAX];
-        usec_t hibernate_delay_usec;
-        usec_t suspend_estimation_usec;
-} SleepConfig;
-
-SleepConfig* free_sleep_config(SleepConfig *sc);
-DEFINE_TRIVIAL_CLEANUP_FUNC(SleepConfig*, free_sleep_config);
-
 typedef enum SwapType {
         SWAP_BLOCK,
         SWAP_FILE,
@@ -61,13 +37,6 @@ HibernateLocation* hibernate_location_free(HibernateLocation *hl);
 DEFINE_TRIVIAL_CLEANUP_FUNC(HibernateLocation*, hibernate_location_free);
 
 int read_fiemap(int fd, struct fiemap **ret);
-int parse_sleep_config(SleepConfig **sleep_config);
 int find_hibernate_location(HibernateLocation **ret_hibernate_location);
 int write_resume_config(dev_t devno, uint64_t offset, const char *device);
-
-int can_sleep(SleepOperation operation);
-int can_sleep_disk(char **types);
-int can_sleep_state(char **types);
-
-const char* sleep_operation_to_string(SleepOperation s) _const_;
-SleepOperation sleep_operation_from_string(const char *s) _pure_;
+bool enough_swap_for_hibernation(void);

src/shared/meson.build

@@ -79,6 +79,7 @@ shared_sources = files(
         'geneve-util.c',
         'gpt.c',
         'group-record.c',
+        'hibernate-util.c',
         'hostname-setup.c',
         'hwdb-util.c',
         'id128-print.c',
@@ -146,7 +147,7 @@ shared_sources = files(
         'selinux-util.c',
         'serialize.c',
         'service-util.c',
-        'sleep-util.c',
+        'sleep-config.c',
         'smack-util.c',
         'socket-label.c',
         'socket-netlink.c',

src/shared/sleep-config.c

@@ -0,0 +1,259 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "conf-parser.h"
+#include "constants.h"
+#include "device-util.h"
+#include "devnum-util.h"
+#include "errno-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "hibernate-util.h"
+#include "log.h"
+#include "macro.h"
+#include "path-util.h"
+#include "sleep-config.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+
+int parse_sleep_config(SleepConfig **ret_sleep_config) {
+        _cleanup_(free_sleep_configp) SleepConfig *sc = NULL;
+        int allow_suspend = -1, allow_hibernate = -1,
+            allow_s2h = -1, allow_hybrid_sleep = -1;
+
+        sc = new(SleepConfig, 1);
+        if (!sc)
+                return log_oom();
+
+        *sc = (SleepConfig) {
+                .hibernate_delay_usec = USEC_INFINITY,
+        };
+
+        const ConfigTableItem items[] = {
+                { "Sleep", "AllowSuspend",              config_parse_tristate, 0, &allow_suspend                  },
+                { "Sleep", "AllowHibernation",          config_parse_tristate, 0, &allow_hibernate                },
+                { "Sleep", "AllowSuspendThenHibernate", config_parse_tristate, 0, &allow_s2h                      },
+                { "Sleep", "AllowHybridSleep",          config_parse_tristate, 0, &allow_hybrid_sleep             },
+
+                { "Sleep", "SuspendMode",               config_parse_strv,     0, sc->modes + SLEEP_SUSPEND       },
+                { "Sleep", "SuspendState",              config_parse_strv,     0, sc->states + SLEEP_SUSPEND      },
+                { "Sleep", "HibernateMode",             config_parse_strv,     0, sc->modes + SLEEP_HIBERNATE     },
+                { "Sleep", "HibernateState",            config_parse_strv,     0, sc->states + SLEEP_HIBERNATE    },
+                { "Sleep", "HybridSleepMode",           config_parse_strv,     0, sc->modes + SLEEP_HYBRID_SLEEP  },
+                { "Sleep", "HybridSleepState",          config_parse_strv,     0, sc->states + SLEEP_HYBRID_SLEEP },
+
+                { "Sleep", "HibernateDelaySec",         config_parse_sec,      0, &sc->hibernate_delay_usec       },
+                { "Sleep", "SuspendEstimationSec",      config_parse_sec,      0, &sc->suspend_estimation_usec    },
+                {}
+        };
+
+        (void) config_parse_config_file("sleep.conf", "Sleep\0",
+                                        config_item_table_lookup, items,
+                                        CONFIG_PARSE_WARN, NULL);
+
+        /* use default values unless set */
+        sc->allow[SLEEP_SUSPEND] = allow_suspend != 0;
+        sc->allow[SLEEP_HIBERNATE] = allow_hibernate != 0;
+        sc->allow[SLEEP_HYBRID_SLEEP] = allow_hybrid_sleep >= 0 ? allow_hybrid_sleep
+                : (allow_suspend != 0 && allow_hibernate != 0);
+        sc->allow[SLEEP_SUSPEND_THEN_HIBERNATE] = allow_s2h >= 0 ? allow_s2h
+                : (allow_suspend != 0 && allow_hibernate != 0);
+
+        if (!sc->states[SLEEP_SUSPEND])
+                sc->states[SLEEP_SUSPEND] = strv_new("mem", "standby", "freeze");
+        if (!sc->modes[SLEEP_HIBERNATE])
+                sc->modes[SLEEP_HIBERNATE] = strv_new("platform", "shutdown");
+        if (!sc->states[SLEEP_HIBERNATE])
+                sc->states[SLEEP_HIBERNATE] = strv_new("disk");
+        if (!sc->modes[SLEEP_HYBRID_SLEEP])
+                sc->modes[SLEEP_HYBRID_SLEEP] = strv_new("suspend", "platform", "shutdown");
+        if (!sc->states[SLEEP_HYBRID_SLEEP])
+                sc->states[SLEEP_HYBRID_SLEEP] = strv_new("disk");
+        if (sc->suspend_estimation_usec == 0)
+                sc->suspend_estimation_usec = DEFAULT_SUSPEND_ESTIMATION_USEC;
+
+        /* Ensure values set for all required fields */
+        if (!sc->states[SLEEP_SUSPEND] || !sc->modes[SLEEP_HIBERNATE]
+            || !sc->states[SLEEP_HIBERNATE] || !sc->modes[SLEEP_HYBRID_SLEEP] || !sc->states[SLEEP_HYBRID_SLEEP])
+                return log_oom();
+
+        *ret_sleep_config = TAKE_PTR(sc);
+
+        return 0;
+}
+
+int can_sleep_state(char **requested_types) {
+        _cleanup_free_ char *text = NULL;
+        int r;
+
+        if (strv_isempty(requested_types))
+                return true;
+
+        /* If /sys is read-only we cannot sleep */
+        if (access("/sys/power/state", W_OK) < 0) {
+                log_debug_errno(errno, "/sys/power/state is not writable, cannot sleep: %m");
+                return false;
+        }
+
+        r = read_one_line_file("/sys/power/state", &text);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to read /sys/power/state, cannot sleep: %m");
+                return false;
+        }
+
+        const char *found;
+        r = string_contains_word_strv(text, NULL, requested_types, &found);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to parse /sys/power/state: %m");
+        if (r > 0)
+                log_debug("Sleep mode \"%s\" is supported by the kernel.", found);
+        else if (DEBUG_LOGGING) {
+                _cleanup_free_ char *t = strv_join(requested_types, "/");
+                log_debug("Sleep mode %s not supported by the kernel, sorry.", strnull(t));
+        }
+        return r;
+}
+
+int can_sleep_disk(char **types) {
+        _cleanup_free_ char *text = NULL;
+        int r;
+
+        if (strv_isempty(types))
+                return true;
+
+        /* If /sys is read-only we cannot sleep */
+        if (access("/sys/power/disk", W_OK) < 0) {
+                log_debug_errno(errno, "/sys/power/disk is not writable: %m");
+                return false;
+        }
+
+        r = read_one_line_file("/sys/power/disk", &text);
+        if (r < 0) {
+                log_debug_errno(r, "Couldn't read /sys/power/disk: %m");
+                return false;
+        }
+
+        for (const char *p = text;;) {
+                _cleanup_free_ char *word = NULL;
+
+                r = extract_first_word(&p, &word, NULL, 0);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to parse /sys/power/disk: %m");
+                if (r == 0)
+                        break;
+
+                char *s = word;
+                size_t l = strlen(s);
+                if (s[0] == '[' && s[l-1] == ']') {
+                        s[l-1] = '\0';
+                        s++;
+                }
+
+                if (strv_contains(types, s)) {
+                        log_debug("Disk sleep mode \"%s\" is supported by the kernel.", s);
+                        return true;
+                }
+        }
+
+        if (DEBUG_LOGGING) {
+                _cleanup_free_ char *t = strv_join(types, "/");
+                log_debug("Disk sleep mode %s not supported by the kernel, sorry.", strnull(t));
+        }
+        return false;
+}
+
+static int can_sleep_internal(const SleepConfig *sleep_config, SleepOperation operation, bool check_allowed);
+
+static bool can_s2h(const SleepConfig *sleep_config) {
+
+        static const SleepOperation operations[] = {
+                SLEEP_SUSPEND,
+                SLEEP_HIBERNATE,
+        };
+
+        int r;
+
+        if (!clock_supported(CLOCK_BOOTTIME_ALARM)) {
+                log_debug("CLOCK_BOOTTIME_ALARM is not supported.");
+                return false;
+        }
+
+        for (size_t i = 0; i < ELEMENTSOF(operations); i++) {
+                r = can_sleep_internal(sleep_config, operations[i], false);
+                if (IN_SET(r, 0, -ENOSPC)) {
+                        log_debug("Unable to %s system.", sleep_operation_to_string(operations[i]));
+                        return false;
+                }
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to check if %s is possible: %m", sleep_operation_to_string(operations[i]));
+        }
+
+        return true;
+}
+
+static int can_sleep_internal(
+                const SleepConfig *sleep_config,
+                SleepOperation operation,
+                bool check_allowed) {
+
+        assert(operation >= 0);
+        assert(operation < _SLEEP_OPERATION_MAX);
+
+        if (check_allowed && !sleep_config->allow[operation]) {
+                log_debug("Sleep mode \"%s\" is disabled by configuration.", sleep_operation_to_string(operation));
+                return false;
+        }
+
+        if (operation == SLEEP_SUSPEND_THEN_HIBERNATE)
+                return can_s2h(sleep_config);
+
+        if (can_sleep_state(sleep_config->states[operation]) <= 0 ||
+            can_sleep_disk(sleep_config->modes[operation]) <= 0)
+                return false;
+
+        if (operation == SLEEP_SUSPEND)
+                return true;
+
+        if (!enough_swap_for_hibernation())
+                return -ENOSPC;
+
+        return true;
+}
+
+int can_sleep(SleepOperation operation) {
+        _cleanup_(free_sleep_configp) SleepConfig *sleep_config = NULL;
+        int r;
+
+        r = parse_sleep_config(&sleep_config);
+        if (r < 0)
+                return r;
+
+        return can_sleep_internal(sleep_config, operation, true);
+}
+
+SleepConfig* free_sleep_config(SleepConfig *sc) {
+        if (!sc)
+                return NULL;
+
+        for (SleepOperation i = 0; i < _SLEEP_OPERATION_MAX; i++) {
+                strv_free(sc->modes[i]);
+                strv_free(sc->states[i]);
+        }
+
+        return mfree(sc);
+}
+
+static const char* const sleep_operation_table[_SLEEP_OPERATION_MAX] = {
+        [SLEEP_SUSPEND]                = "suspend",
+        [SLEEP_HIBERNATE]              = "hibernate",
+        [SLEEP_HYBRID_SLEEP]           = "hybrid-sleep",
+        [SLEEP_SUSPEND_THEN_HIBERNATE] = "suspend-then-hibernate",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(sleep_operation, SleepOperation);

src/shared/sleep-config.h

@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "time-util.h"
+
+#define DEFAULT_SUSPEND_ESTIMATION_USEC (1 * USEC_PER_HOUR)
+
+typedef enum SleepOperation {
+        SLEEP_SUSPEND,
+        SLEEP_HIBERNATE,
+        SLEEP_HYBRID_SLEEP,
+        SLEEP_SUSPEND_THEN_HIBERNATE,
+        _SLEEP_OPERATION_MAX,
+        _SLEEP_OPERATION_INVALID = -EINVAL,
+} SleepOperation;
+
+typedef struct SleepConfig {
+        bool allow[_SLEEP_OPERATION_MAX];
+        char **modes[_SLEEP_OPERATION_MAX];
+        char **states[_SLEEP_OPERATION_MAX];
+        usec_t hibernate_delay_usec;
+        usec_t suspend_estimation_usec;
+} SleepConfig;
+
+SleepConfig* free_sleep_config(SleepConfig *sc);
+DEFINE_TRIVIAL_CLEANUP_FUNC(SleepConfig*, free_sleep_config);
+
+int parse_sleep_config(SleepConfig **sleep_config);
+
+int can_sleep(SleepOperation operation);
+int can_sleep_disk(char **types);
+int can_sleep_state(char **types);
+
+const char* sleep_operation_to_string(SleepOperation s) _const_;
+SleepOperation sleep_operation_from_string(const char *s) _pure_;

src/sleep/sleep.c

@@ -34,6 +34,7 @@
 #include "fd-util.h"
 #include "fileio.h"
 #include "format-util.h"
+#include "hibernate-util.h"
 #include "id128-util.h"
 #include "io-util.h"
 #include "json.h"
@@ -42,7 +43,7 @@
 #include "os-util.h"
 #include "parse-util.h"
 #include "pretty-print.h"
-#include "sleep-util.h"
+#include "sleep-config.h"
 #include "special.h"
 #include "stdio-util.h"
 #include "string-util.h"

src/test/meson.build

@@ -83,6 +83,7 @@ simple_tests += files(
         'test-exit-status.c',
         'test-extract-word.c',
         'test-fdset.c',
+        'test-fiemap.c',
         'test-fileio.c',
         'test-firewall-util.c',
         'test-format-table.c',
@@ -153,7 +154,7 @@ simple_tests += files(
         'test-sigbus.c',
         'test-signal-util.c',
         'test-siphash24.c',
-        'test-sleep.c',
+        'test-sleep-config.c',
         'test-socket-netlink.c',
         'test-socket-util.c',
         'test-specifier.c',

src/test/test-fiemap.c

@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <linux/fiemap.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "errno-util.h"
+#include "fd-util.h"
+#include "log.h"
+#include "hibernate-util.h"
+#include "tests.h"
+
+static int test_fiemap_one(const char *path) {
+        _cleanup_free_ struct fiemap *fiemap = NULL;
+        _cleanup_close_ int fd = -EBADF;
+        int r;
+
+        log_info("/* %s */", __func__);
+
+        fd = open(path, O_RDONLY | O_CLOEXEC | O_NONBLOCK);
+        if (fd < 0)
+                return log_error_errno(errno, "failed to open %s: %m", path);
+        r = read_fiemap(fd, &fiemap);
+        if (r == -EOPNOTSUPP)
+                exit(log_tests_skipped("Not supported"));
+        if (r < 0)
+                return log_error_errno(r, "Unable to read extent map for '%s': %m", path);
+        log_info("extent map information for %s:", path);
+        log_info("\t start: %" PRIu64, (uint64_t) fiemap->fm_start);
+        log_info("\t length: %" PRIu64, (uint64_t) fiemap->fm_length);
+        log_info("\t flags: %" PRIu32, fiemap->fm_flags);
+        log_info("\t number of mapped extents: %" PRIu32, fiemap->fm_mapped_extents);
+        log_info("\t extent count: %" PRIu32, fiemap->fm_extent_count);
+        if (fiemap->fm_extent_count > 0)
+                log_info("\t first extent location: %" PRIu64,
+                         (uint64_t) (fiemap->fm_extents[0].fe_physical / page_size()));
+
+        return 0;
+}
+
+TEST_RET(fiemap) {
+        int r = 0;
+
+        assert_se(test_fiemap_one(saved_argv[0]) == 0);
+        for (int i = 1; i < saved_argc; i++) {
+                int k = test_fiemap_one(saved_argv[i]);
+                if (r == 0)
+                        r = k;
+        }
+
+        return r;
+}
+
+static int intro(void) {
+        if (getuid() != 0)
+                log_warning("This program is unlikely to work for unprivileged users");
+
+        return EXIT_SUCCESS;
+}
+
+DEFINE_TEST_MAIN_WITH_INTRO(LOG_DEBUG, intro);

src/test/test-sleep-config.c

@@ -1,18 +1,11 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-#include <fcntl.h>
-#include <inttypes.h>
-#include <linux/fiemap.h>
-#include <stdio.h>
-#include <sys/types.h>
 #include <unistd.h>
 
 #include "efivars.h"
 #include "errno-util.h"
-#include "fd-util.h"
 #include "log.h"
-#include "memory-util.h"
-#include "sleep-util.h"
+#include "sleep-config.h"
 #include "strv.h"
 #include "tests.h"
 
@@ -41,47 +34,6 @@ TEST(parse_sleep_config) {
         log_debug("        states: %s", hys);
 }
 
-static int test_fiemap_one(const char *path) {
-        _cleanup_free_ struct fiemap *fiemap = NULL;
-        _cleanup_close_ int fd = -EBADF;
-        int r;
-
-        log_info("/* %s */", __func__);
-
-        fd = open(path, O_RDONLY | O_CLOEXEC | O_NONBLOCK);
-        if (fd < 0)
-                return log_error_errno(errno, "failed to open %s: %m", path);
-        r = read_fiemap(fd, &fiemap);
-        if (r == -EOPNOTSUPP)
-                exit(log_tests_skipped("Not supported"));
-        if (r < 0)
-                return log_error_errno(r, "Unable to read extent map for '%s': %m", path);
-        log_info("extent map information for %s:", path);
-        log_info("\t start: %" PRIu64, (uint64_t) fiemap->fm_start);
-        log_info("\t length: %" PRIu64, (uint64_t) fiemap->fm_length);
-        log_info("\t flags: %" PRIu32, fiemap->fm_flags);
-        log_info("\t number of mapped extents: %" PRIu32, fiemap->fm_mapped_extents);
-        log_info("\t extent count: %" PRIu32, fiemap->fm_extent_count);
-        if (fiemap->fm_extent_count > 0)
-                log_info("\t first extent location: %" PRIu64,
-                         (uint64_t) (fiemap->fm_extents[0].fe_physical / page_size()));
-
-        return 0;
-}
-
-TEST_RET(fiemap) {
-        int r = 0;
-
-        assert_se(test_fiemap_one(saved_argv[0]) == 0);
-        for (int i = 1; i < saved_argc; i++) {
-                int k = test_fiemap_one(saved_argv[i]);
-                if (r == 0)
-                        r = k;
-        }
-
-        return r;
-}
-
 TEST(sleep) {
         _cleanup_strv_free_ char
                 **standby = strv_new("standby"),