/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>

#include "alloc-util.h"
#include "argv-util.h"
#include "dropin.h"
#include "escape.h"
#include "fd-util.h"
#include "fileio.h"
#include "fstab-util.h"
#include "generator.h"
#include "initrd-util.h"
#include "log.h"
#include "mkdir.h"
#include "mountpoint-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "special.h"
#include "specifier.h"
#include "string-util.h"
#include "time-util.h"
#include "tmpfile-util.h"
#include "unit-name.h"

static int symlink_unless_exists(const char *target, const char *linkpath) {
        (void) mkdir_parents(linkpath, 0755);

        if (symlink(target, linkpath) < 0 && errno != EEXIST)
                return log_error_errno(errno, "Failed to create symlink %s: %m", linkpath);
        return 0;
}

int generator_open_unit_file_full(
                const char *dir,
                const char *source,
                const char *filename,
                FILE **ret_file,
                char **ret_final_path,
                char **ret_temp_path) {

        _cleanup_free_ char *p = NULL;
        FILE *f;
        int r;

        assert(dir);
        assert(ret_file);

        /* If <ret_temp_path> is specified, it creates a temporary unit file and also returns its
         * temporary path. */

        if (ret_temp_path) {
                r = fopen_temporary(dir, &f, &p);
                if (r < 0)
                        return log_error_errno(r, "Failed to create temporary unit file in '%s': %m", dir);

                (void) fchmod(fileno(f), 0644);

                *ret_temp_path = TAKE_PTR(p);
        } else {
                assert(filename);

                p = path_join(dir, filename);
                if (!p)
                        return log_oom();

                r = fopen_unlocked(p, "wxe", &f);
                if (r < 0) {
                        if (source && r == -EEXIST)
                                return log_error_errno(r,
                                                       "Failed to create unit file '%s', as it already exists. Duplicate entry in '%s'?",
                                                       p, source);

                        return log_error_errno(r, "Failed to create unit file '%s': %m", p);
                }
        }

        fprintf(f,
                "# Automatically generated by %s\n\n",
                program_invocation_short_name);

        *ret_file = f;

        if (ret_final_path)
                *ret_final_path = TAKE_PTR(p);

        return 0;
}

int generator_add_symlink_full(
                const char *dir,
                const char *dst,
                const char *dep_type,
                const char *src,
                const char *instance) {

        _cleanup_free_ char *dn = NULL, *fn = NULL, *instantiated = NULL, *to = NULL, *from = NULL;
        int r;

        assert(dir);
        assert(dst);
        assert(src);

        /* If 'dep_type' is specified adds a symlink from <dst>.<dep_type>/ to <src> (if src is absolute) or ../<src> (otherwise).
         *
         * If 'dep_type' is NULL, it will create a symlink to <src> (i.e. create an alias.
         *
         * If <instance> is specified, then <src> must be a template unit name, and we'll instantiate it. */

        r = path_split_prefix_filename(src, &dn, &fn);
        if (r < 0)
                return log_error_errno(r, "Failed to split '%s' into directory prefix and filename: %m", src);
        if (r == O_DIRECTORY)
                return log_error_errno(SYNTHETIC_ERRNO(EISDIR), "Expected path to regular file name, but got '%s', refusing.", src);

        if (instance) {
                r = unit_name_replace_instance(fn, instance, &instantiated);
                if (r < 0)
                        return log_error_errno(r, "Failed to instantiate '%s' for '%s': %m", fn, instance);
        }

        if (dep_type) { /* Create a .wants/ style dep */
                from = path_join(dn ?: "..", fn);
                if (!from)
                        return log_oom();

                to = strjoin(dir, "/", dst, ".", dep_type, "/", instantiated ?: fn);
        } else { /* or create an alias */
                from = dn ? path_join(dn, fn) : strdup(fn);
                if (!from)
                        return log_oom();

                to = strjoin(dir, "/", dst);
        }
        if (!to)
                return log_oom();

        return symlink_unless_exists(from, to);
}

static int generator_add_ordering(
                const char *dir,
                const char *src,
                const char *order,
                const char *dst,
                const char *instance) {

        _cleanup_free_ char *instantiated = NULL, *p = NULL, *fn = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        const char *to;
        int r;

        assert(dir);
        assert(src);
        assert(order);
        assert(dst);

        /* Adds an explicit ordering dependency of type <order> from <src> to <dst>. If <instance> is
         * specified, it is inserted into <dst>. */

        if (instance) {
                r = unit_name_replace_instance(dst, instance, &instantiated);
                if (r < 0)
                        return log_error_errno(r, "Failed to instantiate '%s' for '%s': %m", dst, instance);

                to = instantiated;
        } else
                to = dst;

        fn = strjoin(src, ".d/50-order-", to, ".conf");
        if (!fn)
                return log_oom();

        p = path_join(dir, fn);
        if (!p)
                return log_oom();

        (void) mkdir_parents_label(p, 0755);

        r = fopen_unlocked(p, "wxe", &f);
        if (r < 0)
                return log_error_errno(r, "Failed to create '%s': %m", p);

        fprintf(f,
                "# Automatically generated by %s\n\n"
                "[Unit]\n"
                "%s=%s\n",
                program_invocation_short_name,
                order,
                to);

        r = fflush_and_check(f);
        if (r < 0)
                return log_error_errno(r, "Failed to write drop-in '%s': %m", p);

        return 0;
}

static int write_fsck_sysroot_service(
                const char *unit, /* Either SPECIAL_FSCK_ROOT_SERVICE or SPECIAL_FSCK_USR_SERVICE */
                const char *dir,
                const char *what,
                const char *extra_after) {

        _cleanup_free_ char *device = NULL, *escaped = NULL, *escaped2 = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        assert(unit);
        assert(dir);
        assert(what);

        /* Writes out special versions of systemd-fsck-root.service and systemd-fsck-usr.service for use in
         * the initrd. The regular statically shipped versions of these unit files use / and /usr for as
         * paths, which doesn't match what we need for the initrd (where the dirs are /sysroot/ +
         * /sysusr/usr/), hence we overwrite those versions here. */

        escaped = specifier_escape(what);
        if (!escaped)
                return log_oom();

        escaped2 = cescape(escaped);
        if (!escaped2)
                return log_oom();

        r = unit_name_from_path(what, ".device", &device);
        if (r < 0)
                return log_error_errno(r, "Failed to convert device \"%s\" to unit name: %m", what);

        r = generator_open_unit_file(dir, /* source= */ NULL, unit, &f);
        if (r < 0)
                return r;

        fprintf(f,
                "[Unit]\n"
                "Description=File System Check on %1$s\n"
                "Documentation=man:%2$s(8)\n"
                "\n"
                "DefaultDependencies=no\n"
                "BindsTo=%3$s\n"
                "Conflicts=shutdown.target\n"
                "After=%4$s%5$slocal-fs-pre.target %3$s\n"
                "Before=shutdown.target\n"
                "\n"
                "[Service]\n"
                "Type=oneshot\n"
                "RemainAfterExit=yes\n"
                "ExecStart=" SYSTEMD_FSCK_PATH " %6$s\n"
                "TimeoutSec=infinity\n"
                "ImportCredential=fsck.*\n",
                escaped,
                unit,
                device,
                strempty(extra_after),
                isempty(extra_after) ? "" : " ",
                escaped2);

        r = fflush_and_check(f);
        if (r < 0)
                return log_error_errno(r, "Failed to write unit %s: %m", unit);

        return 0;
}

int generator_write_fsck_deps(
                FILE *f,
                const char *dir,
                const char *what,
                const char *where,
                const char *fstype,
                const char *options) {

        int r;

        assert(f);
        assert(dir);
        assert(what);
        assert(where);

        /* Let's do an early exit if we are invoked for the root and /usr/ trees in the initrd, to avoid
         * generating confusing log messages. */
        if (in_initrd() && PATH_IN_SET(where, "/", "/usr")) {
                log_debug("Skipping fsck for %s in initrd.", where);
                return 0;
        }

        if (fstype) {
                if (!fstype_is_blockdev_backed(fstype)) {
                        log_debug("Skipping file system check for non-block based file system '%s'.", what);
                        return 0;
                }

                if (fstype_is_ro(fstype)) {
                        log_debug("Skipping file system check for read-only file system '%s'.", what);
                        return 0;
                }
        }

        if (fstab_test_option(options, "bind\0rbind\0")) {
                log_debug("Skipping file system check for bind mount of '%s'.", what);
                return 0;
        }

        if (!is_device_path(what)) {
                log_debug("Checking was requested for \"%s\", but it is not a device.", what);
                return 0;
        }

        if (!isempty(fstype) && !streq(fstype, "auto")) {
                r = fsck_exists_for_fstype(fstype);
                if (r < 0)
                        log_warning_errno(r, "Checking was requested for %s, but couldn't detect if fsck.%s may be used, proceeding: %m", what, fstype);
                else if (r == 0) {
                        /* treat missing check as essentially OK */
                        log_debug("Checking was requested for %s, but fsck.%s does not exist.", what, fstype);
                        return 0;
                }
        } else {
                r = fsck_exists();
                if (r < 0)
                        log_warning_errno(r, "Checking was requested for %s, but couldn't detect if the fsck command may be used, proceeding: %m", what);
                else if (r == 0) {
                        /* treat missing fsck as essentially OK */
                        log_debug("Checking was requested for %s, but the fsck command does not exist.", what);
                        return 0;
                }
        }

        if (path_equal(where, "/")) {
                /* We support running the fsck instance for the root fs while it is already mounted, for
                 * compatibility with non-initrd boots. It's ugly, but it is how it is. Since – unlike for
                 * regular file systems – this means the ordering is reversed (i.e. mount *before* fsck) we
                 * have a separate fsck unit for this, independent of systemd-fsck@.service. */

                const char *lnk = strjoina(dir, "/" SPECIAL_LOCAL_FS_TARGET ".wants/" SPECIAL_FSCK_ROOT_SERVICE);

                r = symlink_unless_exists(SYSTEM_DATA_UNIT_DIR "/" SPECIAL_FSCK_ROOT_SERVICE, lnk);
                if (r < 0)
                        return r;
        } else {
                _cleanup_free_ char *_fsck = NULL;
                const char *fsck, *dep;

                if (in_initrd() && path_equal(where, "/sysroot")) {
                        r = write_fsck_sysroot_service(SPECIAL_FSCK_ROOT_SERVICE, dir, what, SPECIAL_INITRD_ROOT_DEVICE_TARGET);
                        if (r < 0)
                                return r;

                        fsck = SPECIAL_FSCK_ROOT_SERVICE;
                        dep = "Requires";

                } else if (in_initrd() && path_equal(where, "/sysusr/usr")) {
                        r = write_fsck_sysroot_service(SPECIAL_FSCK_USR_SERVICE, dir, what, NULL);
                        if (r < 0)
                                return r;

                        fsck = SPECIAL_FSCK_USR_SERVICE;
                        dep = "Requires";
                } else {
                        /* When this is /usr, then let's add a Wants= dependency, otherwise a Requires=
                         * dependency. Why? We can't possibly unmount /usr during shutdown, but if we have a
                         * Requires= from /usr onto a fsck@.service unit and that unit is shut down, then
                         * we'd have to unmount /usr too.  */

                        dep = path_equal(where, "/usr") ? "Wants" : "Requires";

                        r = unit_name_from_path_instance("systemd-fsck", what, ".service", &_fsck);
                        if (r < 0)
                                return log_error_errno(r, "Failed to create fsck service name: %m");

                        fsck = _fsck;
                }

                fprintf(f,
                        "%1$s=%2$s\n"
                        "After=%2$s\n",
                        dep, fsck);
        }

        return 0;
}

int generator_write_device_timeout(
                const char *dir,
                const char *what,
                const char *opts,
                char **filtered) {

        /* Configure how long we wait for a device that backs a mount point or a
         * swap partition to show up. This is useful to support endless device timeouts
         * for devices that show up only after user input, like crypto devices. */

        _cleanup_free_ char *node = NULL, *unit = NULL, *timeout = NULL;
        usec_t u;
        int r;

        assert(dir);
        assert(what);

        r = fstab_filter_options(opts, "comment=systemd.device-timeout\0"
                                       "x-systemd.device-timeout\0",
                                 NULL, &timeout, NULL, filtered);
        if (r < 0) {
                log_warning_errno(r, "Failed to parse fstab options, ignoring: %m");
                return 0;
        }
        if (r == 0)
                return 0;

        r = parse_sec_fix_0(timeout, &u);
        if (r < 0) {
                log_warning("Failed to parse timeout for device '%s', ignoring: %s", what, timeout);
                return 0;
        }

        node = fstab_node_to_udev_node(what);
        if (!node)
                return log_oom();
        if (!is_device_path(node)) {
                log_warning("'%s' is not a device path, ignoring x-systemd.device-timeout= option.", node);
                return 0;
        }

        r = unit_name_from_path(node, ".device", &unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from device path '%s': %m", node);

        r = write_drop_in_format(dir, unit, 50, "device-timeout",
                                 "# Automatically generated by %s\n"
                                 "# from supplied options \"%s\"\n\n"
                                 "[Unit]\n"
                                 "JobRunningTimeoutSec=%s",
                                 program_invocation_short_name,
                                 opts,
                                 timeout);
        if (r < 0)
                return r;

        return 1;
}

int generator_write_unit_timeout(
                FILE *f,
                const char *where,
                const char *opts,
                const char *filter,
                const char *unit_setting) {

        _cleanup_free_ char *timeout = NULL;
        usec_t u;
        int r;

        assert(f);
        assert(where);
        assert(filter);
        assert(unit_setting);

        r = fstab_filter_options(opts, filter, NULL, &timeout, NULL, NULL);
        if (r < 0)
                return log_error_errno(r, "Failed to parse options for '%s': %m", where);
        if (r == 0)
                return 0;

        r = parse_sec_fix_0(timeout, &u);
        if (r < 0) {
                log_warning_errno(r, "Failed to parse timeout '%s' for '%s', ignoring: %m", timeout, where);
                return 0;
        }

        fprintf(f, "%s=%s\n", unit_setting, FORMAT_TIMESPAN(u, 0));

        return 0;
}

int generator_write_network_device_deps(
                const char *dir,
                const char *what,
                const char *where,
                const char *opts) {

        /* fstab records that specify _netdev option should apply the network
         * ordering on the actual device depending on network connection. If we
         * are not mounting real device (NFS, CIFS), we rely on _netdev effect
         * on the mount unit itself. */

        _cleanup_free_ char *node = NULL, *unit = NULL;
        int r;

        assert(dir);
        assert(what);

        if (where && fstab_is_extrinsic(where, opts))
                return 0;

        if (!fstab_test_option(opts, "_netdev\0"))
                return 0;

        node = fstab_node_to_udev_node(what);
        if (!node)
                return log_oom();

        /* Nothing to apply dependencies to. */
        if (!is_device_path(node))
                return 0;

        r = unit_name_from_path(node, ".device", &unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from path \"%s\": %m", node);

        /* See mount_add_default_dependencies for explanation why we create such
         * dependencies. */
        return write_drop_in_format(dir, unit, 50, "netdev-dependencies",
                                    "# Automatically generated by %s\n\n"
                                    "[Unit]\n"
                                    "After=" SPECIAL_NETWORK_ONLINE_TARGET " " SPECIAL_NETWORK_TARGET "\n"
                                    "Wants=" SPECIAL_NETWORK_ONLINE_TARGET "\n",
                                    program_invocation_short_name);
}

int generator_write_initrd_root_device_deps(const char *dir, const char *what) {
        _cleanup_free_ char *unit = NULL;
        int r;

        r = unit_name_from_path(what, ".device", &unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from path \"%s\": %m",
                                       what);

        return write_drop_in_format(dir, SPECIAL_INITRD_ROOT_DEVICE_TARGET, 50, "root-device",
                                    "# Automatically generated by %s\n\n"
                                    "[Unit]\n"
                                    "Requires=%s\n"
                                    "After=%s",
                                    program_invocation_short_name,
                                    unit,
                                    unit);
}

int generator_hook_up_mkswap(
                const char *dir,
                const char *what) {

        _cleanup_free_ char *node = NULL, *unit = NULL, *escaped = NULL, *where_unit = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        assert(dir);
        assert(what);

        node = fstab_node_to_udev_node(what);
        if (!node)
                return log_oom();

        /* Nothing to work on. */
        if (!is_device_path(node))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Cannot format something that is not a device node: %s",
                                       node);

        r = unit_name_from_path_instance("systemd-mkswap", node, ".service", &unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit instance name from path \"%s\": %m",
                                       node);

        escaped = cescape(node);
        if (!escaped)
                return log_oom();

        r = unit_name_from_path(what, ".swap", &where_unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from path \"%s\": %m",
                                       what);

        r = generator_open_unit_file(dir, /* source= */ NULL, unit, &f);
        if (r < 0)
                return r;

        fprintf(f,
                "[Unit]\n"
                "Description=Make Swap on %%f\n"
                "Documentation=man:systemd-mkswap@.service(8)\n"
                "\n"
                "DefaultDependencies=no\n"
                "BindsTo=%%i.device\n"
                "After=%%i.device\n"
                "Before=%s\n"
                "Conflicts=shutdown.target\n"
                "Before=shutdown.target\n"
                "\n"
                "[Service]\n"
                "Type=oneshot\n"
                "RemainAfterExit=yes\n"
                "ExecStart="SYSTEMD_MAKEFS_PATH " swap %s\n"
                "TimeoutSec=infinity\n",
                where_unit,
                escaped);

        r = fflush_and_check(f);
        if (r < 0)
                return log_error_errno(r, "Failed to write unit %s: %m", unit);

        return generator_add_symlink(dir, where_unit, "requires", unit);
}

int generator_hook_up_mkfs(
                const char *dir,
                const char *what,
                const char *where,
                const char *type) {

        _cleanup_free_ char *node = NULL, *unit = NULL, *escaped = NULL, *where_unit = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        const char *fsck_unit;
        int r;

        assert(dir);
        assert(what);
        assert(where);

        node = fstab_node_to_udev_node(what);
        if (!node)
                return log_oom();

        /* Nothing to work on. */
        if (!is_device_path(node))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Cannot format something that is not a device node: %s",
                                       node);

        if (!type || streq(type, "auto"))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Cannot format partition %s, filesystem type is not specified",
                                       node);

        r = unit_name_from_path_instance("systemd-makefs", node, ".service", &unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit instance name from path \"%s\": %m",
                                       node);

        if (in_initrd() && path_equal(where, "/sysroot"))
                fsck_unit = SPECIAL_FSCK_ROOT_SERVICE;
        else if (in_initrd() && path_equal(where, "/sysusr/usr"))
                fsck_unit = SPECIAL_FSCK_USR_SERVICE;
        else
                fsck_unit = "systemd-fsck@%i.service";

        escaped = cescape(node);
        if (!escaped)
                return log_oom();

        r = unit_name_from_path(where, ".mount", &where_unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from path \"%s\": %m",
                                       where);

        r = generator_open_unit_file(dir, /* source= */ NULL, unit, &f);
        if (r < 0)
                return r;

        fprintf(f,
                "[Unit]\n"
                "Description=Make File System on %%f\n"
                "Documentation=man:systemd-makefs@.service(8)\n"
                "\n"
                "DefaultDependencies=no\n"
                "BindsTo=%%i.device\n"
                "After=%%i.device\n"
                /* fsck might or might not be used, so let's be safe and order
                 * ourselves before both systemd-fsck@.service and the mount unit. */
                "Before=%s %s\n"
                "Conflicts=shutdown.target\n"
                "Before=shutdown.target\n"
                "\n"
                "[Service]\n"
                "Type=oneshot\n"
                "RemainAfterExit=yes\n"
                "ExecStart="SYSTEMD_MAKEFS_PATH " %s %s\n"
                "TimeoutSec=infinity\n",
                fsck_unit,
                where_unit,
                type,
                escaped);
        // XXX: what about local-fs-pre.target?

        r = fflush_and_check(f);
        if (r < 0)
                return log_error_errno(r, "Failed to write unit %s: %m", unit);

        return generator_add_symlink(dir, where_unit, "requires", unit);
}

int generator_hook_up_growfs(
                const char *dir,
                const char *where,
                const char *target) {

        const char *growfs_unit, *growfs_unit_path;
        _cleanup_free_ char *where_unit = NULL, *instance = NULL;
        int r;

        assert(dir);
        assert(where);

        r = unit_name_from_path(where, ".mount", &where_unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from path '%s': %m", where);

        if (empty_or_root(where)) {
                growfs_unit = SPECIAL_GROWFS_ROOT_SERVICE;
                growfs_unit_path = SYSTEM_DATA_UNIT_DIR "/" SPECIAL_GROWFS_ROOT_SERVICE;
        } else {
                growfs_unit = SPECIAL_GROWFS_SERVICE;
                growfs_unit_path = SYSTEM_DATA_UNIT_DIR "/" SPECIAL_GROWFS_SERVICE;

                r = unit_name_path_escape(where, &instance);
                if (r < 0)
                        return log_error_errno(r, "Failed to escape path '%s': %m", where);
        }

        if (target) {
                r = generator_add_ordering(dir, target, "After", growfs_unit, instance);
                if (r < 0)
                        return r;
        }

        return generator_add_symlink_full(dir, where_unit, "wants", growfs_unit_path, instance);
}

int generator_hook_up_pcrfs(
                const char *dir,
                const char *where,
                const char *target) {

        const char *pcrfs_unit, *pcrfs_unit_path;
        _cleanup_free_ char *where_unit = NULL, *instance = NULL;
        int r;

        assert(dir);
        assert(where);

        r = unit_name_from_path(where, ".mount", &where_unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from path '%s': %m", where);

        if (empty_or_root(where)) {
                pcrfs_unit = SPECIAL_PCRFS_ROOT_SERVICE;
                pcrfs_unit_path = SYSTEM_DATA_UNIT_DIR "/" SPECIAL_PCRFS_ROOT_SERVICE;
        } else {
                pcrfs_unit = SPECIAL_PCRFS_SERVICE;
                pcrfs_unit_path = SYSTEM_DATA_UNIT_DIR "/" SPECIAL_PCRFS_SERVICE;

                r = unit_name_path_escape(where, &instance);
                if (r < 0)
                        return log_error_errno(r, "Failed to escape path '%s': %m", where);
        }

        if (target) {
                r = generator_add_ordering(dir, target, "After", pcrfs_unit, instance);
                if (r < 0)
                        return r;
        }

        return generator_add_symlink_full(dir, where_unit, "wants", pcrfs_unit_path, instance);
}

int generator_hook_up_validatefs(
                const char *dir,
                const char *where,
                const char *target) {

        _cleanup_free_ char *where_unit = NULL, *instance = NULL;
        const char *validatefs_unit, *validatefs_unit_path;
        int r;

        assert(dir);
        assert(where);

        /* never hook this in for the actual root fs, because it's too late then, we already are running from
         * the root fs, it makes no sense to validate it anymore */
        if (empty_or_root(where))
                return 0;

        r = unit_name_from_path(where, ".mount", &where_unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from path '%s': %m", where);

        validatefs_unit = SPECIAL_VALIDATEFS_SERVICE;
        validatefs_unit_path = SYSTEM_DATA_UNIT_DIR "/" SPECIAL_VALIDATEFS_SERVICE;

        r = unit_name_path_escape(where, &instance);
        if (r < 0)
                return log_error_errno(r, "Failed to escape path '%s': %m", where);

        if (target) {
                r = generator_add_ordering(dir, target, "After", validatefs_unit, instance);
                if (r < 0)
                        return r;
        }

        return generator_add_symlink_full(dir, where_unit, "wants", validatefs_unit_path, instance);
}

int generator_hook_up_quotacheck(
                const char *dir,
                const char *what,
                const char *where,
                const char *target,
                const char *fstype) {

        _cleanup_free_ char *where_unit = NULL, *instance = NULL;
        int r;

        assert(dir);
        assert(where);

        if (isempty(fstype) || streq(fstype, "auto"))
                return log_warning_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Couldn't determine filesystem type for %s, quota cannot be activated", what);
        if (fstype_has_internal_quota(fstype)) {
                log_debug("%s handles quotas internally, skipping quotacheck/quotaon setup for %s", fstype, what);
                return 0;
        }
        if (!fstype_needs_quota(fstype))
                return log_warning_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Quota was requested for %s, but not supported, ignoring: %s", what, fstype);

        /* quotacheck unit for system root */
        if (path_equal(where, "/")) {
                r = generator_add_symlink(dir, SPECIAL_LOCAL_FS_TARGET, "wants", SYSTEM_DATA_UNIT_DIR "/" SPECIAL_QUOTACHECK_ROOT_SERVICE);
                return r < 0 ? r : 1;
        }

        r = unit_name_path_escape(where, &instance);
        if (r < 0)
                return log_error_errno(r, "Failed to escape path '%s': %m", where);

        if (target) {
                r = generator_add_ordering(dir, target, "After", SPECIAL_QUOTACHECK_SERVICE, instance);
                if (r < 0)
                        return r;
        }

        r = unit_name_from_path(where, ".mount", &where_unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from path '%s': %m", where);

        r = generator_add_symlink_full(dir, where_unit, "wants", SYSTEM_DATA_UNIT_DIR "/" SPECIAL_QUOTACHECK_SERVICE, instance);
        return r < 0 ? r : 1;
}

int generator_hook_up_quotaon(
                const char *dir,
                const char *where,
                const char *target) {

        _cleanup_free_ char *where_unit = NULL, *instance = NULL;
        int r;

        assert(dir);
        assert(where);

        /* quotaon unit for system root is not instantiated */
        if (path_equal(where, "/"))
                return generator_add_symlink(dir,  SPECIAL_LOCAL_FS_TARGET, "wants", SYSTEM_DATA_UNIT_DIR "/" SPECIAL_QUOTAON_ROOT_SERVICE);

        r = unit_name_path_escape(where, &instance);
        if (r < 0)
                return log_error_errno(r, "Failed to escape path '%s': %m", where);

        if (target) {
                r = generator_add_ordering(dir, target, "After", SPECIAL_QUOTAON_SERVICE, instance);
                if (r < 0)
                        return r;
        }

        r = unit_name_from_path(where, ".mount", &where_unit);
        if (r < 0)
                return log_error_errno(r, "Failed to make unit name from path '%s': %m", where);

        return generator_add_symlink_full(dir, where_unit, "wants", SYSTEM_DATA_UNIT_DIR "/" SPECIAL_QUOTAON_SERVICE, instance);
}

int generator_enable_remount_fs_service(const char *dir) {
        /* Pull in systemd-remount-fs.service */
        return generator_add_symlink(dir, SPECIAL_LOCAL_FS_TARGET, "wants",
                                     SYSTEM_DATA_UNIT_DIR "/" SPECIAL_REMOUNT_FS_SERVICE);
}

int generator_write_blockdev_dependency(FILE *f, const char *what) {
        _cleanup_free_ char *escaped = NULL;
        int r;

        assert(f);
        assert(what);

        if (!path_startswith(what, "/dev/"))
                return 0;

        r = unit_name_path_escape(what, &escaped);
        if (r < 0)
                return log_error_errno(r, "Failed to escape device node path %s: %m", what);

        fprintf(f,
                "After=blockdev@%s.target\n",
                escaped);

        return 0;
}

int generator_write_cryptsetup_unit_section(FILE *f, const char *source) {
        assert(f);

        fprintf(f,
                "[Unit]\n"
                "Description=Cryptography Setup for %%I\n"
                "Documentation=man:crypttab(5) man:systemd-cryptsetup-generator(8) man:systemd-cryptsetup@.service(8)\n");

        if (source)
                fprintf(f, "SourcePath=%s\n", source);

        fprintf(f,
                "\n"
                "DefaultDependencies=no\n"
                /* The ordering against systemd-udevd.service is mostly about shutdown, not startup: on stop
                 * the device is detached via a device-mapper ioctl that carries a udev cookie, and we block in
                 * dm_udev_wait() until udev releases it (see 95-dm-notify.rules). Ordering After= it means we
                 * are stopped first, while udevd is still around to service that cookie; otherwise during
                 * soft-reboot/shutdown udevd may exit first and the detach hangs until the job timeout. */
                "After=cryptsetup-pre.target systemd-udevd-kernel.socket systemd-udevd.service systemd-tpm2-setup-early.service\n"
                "Before=blockdev@dev-mapper-%%i.target\n"
                "Wants=blockdev@dev-mapper-%%i.target\n"
                "IgnoreOnIsolate=true\n");

        return 0;
}

int generator_write_cryptsetup_service_section(
                FILE *f,
                const char *name,
                const char *what,
                const char *key_file,
                const char *options) {

        _cleanup_free_ char *name_escaped = NULL, *what_escaped = NULL, *key_file_escaped = NULL, *options_escaped = NULL;

        assert(f);
        assert(name);
        assert(what);

        name_escaped = specifier_escape(name);
        if (!name_escaped)
                return log_oom();

        what_escaped = specifier_escape(what);
        if (!what_escaped)
                return log_oom();

        if (key_file) {
                key_file_escaped = specifier_escape(key_file);
                if (!key_file_escaped)
                        return log_oom();
        }

        if (options) {
                options_escaped = specifier_escape(options);
                if (!options_escaped)
                        return log_oom();
        }

        fprintf(f,
                "\n"
                "[Service]\n"
                "Type=oneshot\n"
                "RemainAfterExit=yes\n"
                "TimeoutSec=infinity\n"   /* The binary handles timeouts on its own */
                "KeyringMode=shared\n"    /* Make sure we can share cached keys among instances */
                "OOMScoreAdjust=500\n"    /* Unlocking can allocate a lot of memory if Argon2 is used */
                "ImportCredential=cryptsetup.*\n"
                "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '%s' '%s'\n"
                "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
                name_escaped, what_escaped, strempty(key_file_escaped), strempty(options_escaped),
                name_escaped);

        return 0;
}

int generator_write_veritysetup_unit_section(FILE *f, const char *source) {
        assert(f);

        fprintf(f,
                "[Unit]\n"
                "Description=Integrity Protection Setup for %%I\n"
                "Documentation=man:veritytab(5) man:systemd-veritysetup-generator(8) man:systemd-veritysetup@.service(8)\n");

        if (source)
                fprintf(f, "SourcePath=%s\n", source);

        fprintf(f,
                "DefaultDependencies=no\n"
                "IgnoreOnIsolate=true\n"
                /* The systemd-udevd.service ordering is mostly about shutdown, not startup: on stop the dm
                 * device is detached via an ioctl carrying a udev cookie that blocks in dm_udev_wait() until
                 * udev releases it (95-dm-notify.rules). Stopping before udevd keeps it around to service the
                 * cookie; otherwise during soft-reboot/shutdown udevd may exit first and the detach hangs. */
                "After=veritysetup-pre.target systemd-udevd-kernel.socket systemd-udevd.service\n"
                "Before=blockdev@dev-mapper-%%i.target\n"
                "Wants=blockdev@dev-mapper-%%i.target\n");

        return 0;
}

int generator_write_veritysetup_service_section(
                FILE *f,
                const char *name,
                const char *data_what,
                const char *hash_what,
                const char *roothash,
                const char *options) {

        _cleanup_free_ char *name_escaped = NULL, *data_what_escaped = NULL, *hash_what_escaped = NULL,
                            *roothash_escaped = NULL, *options_escaped = NULL;

        assert(f);
        assert(name);
        assert(data_what);
        assert(hash_what);

        name_escaped = specifier_escape(name);
        if (!name_escaped)
                return log_oom();

        data_what_escaped = specifier_escape(data_what);
        if (!data_what_escaped)
                return log_oom();

        hash_what_escaped = specifier_escape(hash_what);
        if (!hash_what_escaped)
                return log_oom();

        if (roothash) {
                roothash_escaped = specifier_escape(roothash);
                if (!roothash_escaped)
                        return log_oom();
        }

        if (options) {
                options_escaped = specifier_escape(options);
                if (!options_escaped)
                        return log_oom();
        }

        fprintf(f,
                "\n"
                "[Service]\n"
                "Type=oneshot\n"
                "RemainAfterExit=yes\n"
                "ExecStart=" SYSTEMD_VERITYSETUP_PATH " attach '%s' '%s' '%s' '%s' '%s'\n"
                "ExecStop=" SYSTEMD_VERITYSETUP_PATH " detach '%s'\n",
                name_escaped, data_what_escaped, hash_what_escaped, empty_to_dash(roothash_escaped), strempty(options_escaped),
                name_escaped);

        return 0;
}

void log_setup_generator(void) {
        if (invoked_by_systemd()) {
                /* Disable talking to syslog/journal (i.e. the two IPC-based loggers) if we run in system context. */
                if (streq_ptr(getenv("SYSTEMD_SCOPE"), "system"))
                        log_set_prohibit_ipc(true);

                /* This effectively means: journal for per-user service manager generators, kmsg for per-system service manager generators */
                log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
        } else
                log_set_target(LOG_TARGET_AUTO);

        log_parse_environment();
        log_open();
}

bool generator_soft_rebooted(void) {
        static int cached = -1;
        int r;

        if (cached >= 0)
                return cached;

        const char *e = secure_getenv("SYSTEMD_SOFT_REBOOTS_COUNT");
        if (!e)
                return (cached = false);

        unsigned u;

        r = safe_atou(e, &u);
        if (r < 0) {
                log_debug_errno(r, "Failed to parse $SYSTEMD_SOFT_REBOOTS_COUNT, assuming the system hasn't soft-rebooted: %m");
                return (cached = false);
        }

        return (cached = (u > 0));
}

GptAutoRoot parse_gpt_auto_root(const char *switch_name, const char *value) {
        assert(switch_name);
        assert(value);

        /* Parses the 'gpt-auto'/'gpt-auto-root'/'dissect'/'dissect-force' parameters to root=
         *
         * note that we are not using a regular string table here, because the mode names don't fully match
         * the parameter names. And root= being something else is not an error. */

        if (streq(value, "gpt-auto")) {
                log_debug("Enabling partition auto-detection (respecting factory reset mode), %s is explicitly set to 'gpt-auto'.", switch_name);
                return GPT_AUTO_ROOT_ON;
        }

        if (streq(value, "gpt-auto-force")) {
                log_debug("Enabling partition auto-detection (ignoring factory reset mode), %s is explicitly set to 'gpt-auto-force'.", switch_name);
                return GPT_AUTO_ROOT_FORCE;
        }

        if (streq(value, "dissect")) {
                log_debug("Enabling partition auto-detection via full image dissection (respecting factory reset mode), %s is explicitly set to 'dissect'.", switch_name);
                return GPT_AUTO_ROOT_DISSECT;
        }

        if (streq(value, "dissect-force")) {
                log_debug("Enabling partition auto-detection via full image dissection (ignoring factory reset mode), %s is explicitly set to 'dissect-force'.", switch_name);
                return GPT_AUTO_ROOT_DISSECT_FORCE;
        }

        if (streq(value, "off"))
                log_debug("Disabling partition auto-detection, %s handling is explicitly turned off.", switch_name);
        else
                log_debug("Disabling partition auto-detection, %s is neither unset, nor set to 'gpt-auto', 'gpt-auto-force', 'dissect' or 'dissect-force'.", switch_name);

        return GPT_AUTO_ROOT_OFF;
}
