diff --git a/meson.build b/meson.build
index e258a65a1a..651fb30584 100644
--- a/meson.build
+++ b/meson.build
@@ -2092,6 +2092,7 @@ libsystemd_includes = [basic_includes, include_directories(
         'src/libsystemd/sd-json',
         'src/libsystemd/sd-netlink',
         'src/libsystemd/sd-network',
+        'src/libsystemd/sd-path',
         'src/libsystemd/sd-resolve',
         'src/libsystemd/sd-varlink')]
 
diff --git a/src/analyze/analyze-security.c b/src/analyze/analyze-security.c
index f7e9b94213..fb4fd654f5 100644
--- a/src/analyze/analyze-security.c
+++ b/src/analyze/analyze-security.c
@@ -26,6 +26,7 @@
 #include "nulstr-util.h"
 #include "parse-util.h"
 #include "path-util.h"
+#include "portable-util.h"
 #include "pretty-print.h"
 #include "seccomp-util.h"
 #include "service.h"
diff --git a/src/basic/meson.build b/src/basic/meson.build
index 4f83eb67a0..e02f787c75 100644
--- a/src/basic/meson.build
+++ b/src/basic/meson.build
@@ -70,7 +70,6 @@ basic_sources = files(
         'ordered-set.c',
         'os-util.c',
         'parse-util.c',
-        'path-lookup.c',
         'path-util.c',
         'percent-util.c',
         'pidref.c',
@@ -106,7 +105,6 @@ basic_sources = files(
         'uid-classification.c',
         'uid-range.c',
         'unit-def.c',
-        'unit-file.c',
         'unit-name.c',
         'user-util.c',
         'utf8.c',
diff --git a/src/basic/path-lookup.c b/src/basic/path-lookup.c
deleted file mode 100644
index 234b197394..0000000000
--- a/src/basic/path-lookup.c
+++ /dev/null
@@ -1,931 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "alloc-util.h"
-#include "fs-util.h"
-#include "log.h"
-#include "macro.h"
-#include "nulstr-util.h"
-#include "path-lookup.h"
-#include "path-util.h"
-#include "stat-util.h"
-#include "string-util.h"
-#include "strv.h"
-#include "tmpfile-util.h"
-#include "user-util.h"
-
-int xdg_user_runtime_dir(char **ret, const char *suffix) {
-        const char *e;
-        char *j;
-
-        assert(ret);
-        assert(suffix);
-
-        e = getenv("XDG_RUNTIME_DIR");
-        if (!e)
-                return -ENXIO;
-
-        j = path_join(e, suffix);
-        if (!j)
-                return -ENOMEM;
-
-        *ret = j;
-        return 0;
-}
-
-int xdg_user_config_dir(char **ret, const char *suffix) {
-        _cleanup_free_ char *j = NULL;
-        const char *e;
-        int r;
-
-        assert(ret);
-
-        e = getenv("XDG_CONFIG_HOME");
-        if (e) {
-                j = path_join(e, suffix);
-                if (!j)
-                        return -ENOMEM;
-        } else {
-                r = get_home_dir(&j);
-                if (r < 0)
-                        return r;
-
-                if (!path_extend(&j, "/.config", suffix))
-                        return -ENOMEM;
-        }
-
-        *ret = TAKE_PTR(j);
-        return 0;
-}
-
-int xdg_user_data_dir(char **ret, const char *suffix) {
-        _cleanup_free_ char *j = NULL;
-        const char *e;
-        int r;
-
-        assert(ret);
-        assert(suffix);
-
-        /* We don't treat /etc/xdg/systemd here as the spec
-         * suggests because we assume that is a link to
-         * /etc/systemd/ anyway. */
-
-        e = getenv("XDG_DATA_HOME");
-        if (e) {
-                j = path_join(e, suffix);
-                if (!j)
-                        return -ENOMEM;
-        } else {
-                r = get_home_dir(&j);
-                if (r < 0)
-                        return r;
-
-                if (!path_extend(&j, "/.local/share", suffix))
-                        return -ENOMEM;
-        }
-
-        *ret = TAKE_PTR(j);
-        return 1;
-}
-
-int runtime_directory(char **ret, RuntimeScope scope, const char *suffix) {
-        int r;
-
-        assert(ret);
-        assert(suffix);
-        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER, RUNTIME_SCOPE_GLOBAL));
-
-        /* Accept $RUNTIME_DIRECTORY as authoritative
-         * If its missing apply the suffix to /run or $XDG_RUNTIME_DIR
-         * if we are in a user runtime scope.
-         *
-         * Return value indicates whether the suffix was applied or not */
-
-        const char *e = secure_getenv("RUNTIME_DIRECTORY");
-        if (e)
-                return strdup_to(ret, e);
-
-        if (scope == RUNTIME_SCOPE_USER) {
-                r = xdg_user_runtime_dir(ret, suffix);
-                if (r < 0)
-                        return r;
-        } else {
-                char *d = path_join("/run", suffix);
-                if (!d)
-                        return -ENOMEM;
-                *ret = d;
-        }
-
-        return true;
-}
-
-static const char* const user_data_unit_paths[] = {
-        "/usr/local/lib/systemd/user",
-        "/usr/local/share/systemd/user",
-        USER_DATA_UNIT_DIR,
-        "/usr/lib/systemd/user",
-        "/usr/share/systemd/user",
-        NULL
-};
-
-static const char* const user_config_unit_paths[] = {
-        USER_CONFIG_UNIT_DIR,
-        "/etc/systemd/user",
-        NULL
-};
-
-int xdg_user_dirs(char ***ret_config_dirs, char ***ret_data_dirs) {
-        /* Implement the mechanisms defined in
-         *
-         * https://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
-         *
-         * We look in both the config and the data dirs because we
-         * want to encourage that distributors ship their unit files
-         * as data, and allow overriding as configuration.
-         */
-        const char *e;
-        _cleanup_strv_free_ char **config_dirs = NULL, **data_dirs = NULL;
-
-        e = getenv("XDG_CONFIG_DIRS");
-        if (e)
-                config_dirs = strv_split(e, ":");
-        else
-                config_dirs = strv_new("/etc/xdg");
-        if (!config_dirs)
-                return -ENOMEM;
-
-        e = getenv("XDG_DATA_DIRS");
-        if (e)
-                data_dirs = strv_split(e, ":");
-        else
-                data_dirs = strv_new("/usr/local/share",
-                                     "/usr/share");
-        if (!data_dirs)
-                return -ENOMEM;
-
-        *ret_config_dirs = TAKE_PTR(config_dirs);
-        *ret_data_dirs = TAKE_PTR(data_dirs);
-
-        return 0;
-}
-
-static char** user_dirs(
-                const char *persistent_config,
-                const char *runtime_config,
-                const char *global_persistent_config,
-                const char *global_runtime_config,
-                const char *generator,
-                const char *generator_early,
-                const char *generator_late,
-                const char *transient,
-                const char *persistent_control,
-                const char *runtime_control) {
-
-        _cleanup_strv_free_ char **config_dirs = NULL, **data_dirs = NULL;
-        _cleanup_free_ char *data_home = NULL;
-        _cleanup_strv_free_ char **res = NULL;
-        int r;
-
-        r = xdg_user_dirs(&config_dirs, &data_dirs);
-        if (r < 0)
-                return NULL;
-
-        r = xdg_user_data_dir(&data_home, "/systemd/user");
-        if (r < 0 && r != -ENXIO)
-                return NULL;
-
-        /* Now merge everything we found. */
-        if (strv_extend_many(
-                            &res,
-                            persistent_control,
-                            runtime_control,
-                            transient,
-                            generator_early,
-                            persistent_config) < 0)
-                return NULL;
-
-        if (strv_extend_strv_concat(&res, (const char* const*) config_dirs, "/systemd/user") < 0)
-                return NULL;
-
-        /* global config has lower priority than the user config of the same type */
-        if (strv_extend(&res, global_persistent_config) < 0)
-                return NULL;
-
-        if (strv_extend_strv(&res, (char**) user_config_unit_paths, false) < 0)
-                return NULL;
-
-        if (strv_extend_many(
-                            &res,
-                            runtime_config,
-                            global_runtime_config,
-                            generator,
-                            data_home) < 0)
-                return NULL;
-
-        if (strv_extend_strv_concat(&res, (const char* const*) data_dirs, "/systemd/user") < 0)
-                return NULL;
-
-        if (strv_extend_strv(&res, (char**) user_data_unit_paths, false) < 0)
-                return NULL;
-
-        if (strv_extend(&res, generator_late) < 0)
-                return NULL;
-
-        if (path_strv_make_absolute_cwd(res) < 0)
-                return NULL;
-
-        return TAKE_PTR(res);
-}
-
-bool path_is_user_data_dir(const char *path) {
-        assert(path);
-
-        return strv_contains((char**) user_data_unit_paths, path);
-}
-
-bool path_is_user_config_dir(const char *path) {
-        assert(path);
-
-        return strv_contains((char**) user_config_unit_paths, path);
-}
-
-static int acquire_generator_dirs(
-                RuntimeScope scope,
-                const char *tempdir,
-                char **generator,
-                char **generator_early,
-                char **generator_late) {
-
-        _cleanup_free_ char *x = NULL, *y = NULL, *z = NULL, *p = NULL;
-        const char *prefix;
-
-        assert(generator);
-        assert(generator_early);
-        assert(generator_late);
-        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER, RUNTIME_SCOPE_GLOBAL));
-
-        if (scope == RUNTIME_SCOPE_GLOBAL)
-                return -EOPNOTSUPP;
-
-        if (tempdir)
-                prefix = tempdir;
-        else if (scope == RUNTIME_SCOPE_SYSTEM)
-                prefix = "/run/systemd";
-        else {
-                /* RUNTIME_SCOPE_USER */
-                const char *e;
-
-                e = getenv("XDG_RUNTIME_DIR");
-                if (!e)
-                        return -ENXIO;
-
-                p = path_join(e, "/systemd");
-                if (!p)
-                        return -ENOMEM;
-
-                prefix = p;
-        }
-
-        x = path_join(prefix, "generator");
-        if (!x)
-                return -ENOMEM;
-
-        y = path_join(prefix, "generator.early");
-        if (!y)
-                return -ENOMEM;
-
-        z = path_join(prefix, "generator.late");
-        if (!z)
-                return -ENOMEM;
-
-        *generator = TAKE_PTR(x);
-        *generator_early = TAKE_PTR(y);
-        *generator_late = TAKE_PTR(z);
-
-        return 0;
-}
-
-static int acquire_transient_dir(
-                RuntimeScope scope,
-                const char *tempdir,
-                char **ret) {
-
-        char *transient;
-
-        assert(ret);
-        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER, RUNTIME_SCOPE_GLOBAL));
-
-        if (scope == RUNTIME_SCOPE_GLOBAL)
-                return -EOPNOTSUPP;
-
-        if (tempdir)
-                transient = path_join(tempdir, "transient");
-        else if (scope == RUNTIME_SCOPE_SYSTEM)
-                transient = strdup("/run/systemd/transient");
-        else
-                return xdg_user_runtime_dir(ret, "/systemd/transient");
-
-        if (!transient)
-                return -ENOMEM;
-        *ret = transient;
-        return 0;
-}
-
-static int acquire_config_dirs(RuntimeScope scope, char **persistent, char **runtime) {
-        _cleanup_free_ char *a = NULL, *b = NULL;
-        int r;
-
-        assert(persistent);
-        assert(runtime);
-
-        switch (scope) {
-
-        case RUNTIME_SCOPE_SYSTEM:
-                a = strdup(SYSTEM_CONFIG_UNIT_DIR);
-                b = strdup("/run/systemd/system");
-                break;
-
-        case RUNTIME_SCOPE_GLOBAL:
-                a = strdup(USER_CONFIG_UNIT_DIR);
-                b = strdup("/run/systemd/user");
-                break;
-
-        case RUNTIME_SCOPE_USER:
-                r = xdg_user_config_dir(&a, "/systemd/user");
-                if (r < 0 && r != -ENXIO)
-                        return r;
-
-                r = xdg_user_runtime_dir(runtime, "/systemd/user");
-                if (r < 0) {
-                        if (r != -ENXIO)
-                                return r;
-
-                        /* If XDG_RUNTIME_DIR is not set, don't consider that fatal, simply initialize the runtime
-                         * directory to NULL */
-                        *runtime = NULL;
-                }
-
-                *persistent = TAKE_PTR(a);
-
-                return 0;
-
-        default:
-                assert_not_reached();
-        }
-
-        if (!a || !b)
-                return -ENOMEM;
-
-        *persistent = TAKE_PTR(a);
-        *runtime = TAKE_PTR(b);
-
-        return 0;
-}
-
-static int acquire_control_dirs(RuntimeScope scope, char **persistent, char **runtime) {
-        _cleanup_free_ char *a = NULL;
-        int r;
-
-        assert(persistent);
-        assert(runtime);
-
-        switch (scope) {
-
-        case RUNTIME_SCOPE_SYSTEM:  {
-                _cleanup_free_ char *b = NULL;
-
-                a = strdup("/etc/systemd/system.control");
-                if (!a)
-                        return -ENOMEM;
-
-                b = strdup("/run/systemd/system.control");
-                if (!b)
-                        return -ENOMEM;
-
-                *runtime = TAKE_PTR(b);
-
-                break;
-        }
-
-        case RUNTIME_SCOPE_USER:
-                r = xdg_user_config_dir(&a, "/systemd/user.control");
-                if (r < 0 && r != -ENXIO)
-                        return r;
-
-                r = xdg_user_runtime_dir(runtime, "/systemd/user.control");
-                if (r < 0) {
-                        if (r != -ENXIO)
-                                return r;
-
-                        /* If XDG_RUNTIME_DIR is not set, don't consider this fatal, simply initialize the directory to
-                         * NULL */
-                        *runtime = NULL;
-                }
-
-                break;
-
-        case RUNTIME_SCOPE_GLOBAL:
-                return -EOPNOTSUPP;
-
-        default:
-                assert_not_reached();
-        }
-
-        *persistent = TAKE_PTR(a);
-
-        return 0;
-}
-
-static int acquire_attached_dirs(
-                RuntimeScope scope,
-                char **ret_persistent,
-                char **ret_runtime) {
-
-        _cleanup_free_ char *a = NULL, *b = NULL;
-
-        assert(ret_persistent);
-        assert(ret_runtime);
-
-        /* Portable services are not available to regular users for now. */
-        if (scope != RUNTIME_SCOPE_SYSTEM)
-                return -EOPNOTSUPP;
-
-        a = strdup("/etc/systemd/system.attached");
-        if (!a)
-                return -ENOMEM;
-
-        b = strdup("/run/systemd/system.attached");
-        if (!b)
-                return -ENOMEM;
-
-        *ret_persistent = TAKE_PTR(a);
-        *ret_runtime = TAKE_PTR(b);
-
-        return 0;
-}
-
-static int patch_root_prefix(char **p, const char *root_dir) {
-        char *c;
-
-        assert(p);
-
-        if (!*p)
-                return 0;
-
-        c = path_join(root_dir, *p);
-        if (!c)
-                return -ENOMEM;
-
-        free_and_replace(*p, c);
-        return 0;
-}
-
-static int patch_root_prefix_strv(char **l, const char *root_dir) {
-        int r;
-
-        if (!root_dir)
-                return 0;
-
-        STRV_FOREACH(i, l) {
-                r = patch_root_prefix(i, root_dir);
-                if (r < 0)
-                        return r;
-        }
-
-        return 0;
-}
-
-static int get_paths_from_environ(const char *var, char ***paths, bool *append) {
-        const char *e;
-        int r;
-
-        assert(var);
-        assert(paths);
-        assert(append);
-
-        *append = false;
-
-        e = getenv(var);
-        if (e) {
-                const char *k;
-
-                k = endswith(e, ":");
-                if (k) {
-                        e = strndupa_safe(e, k - e);
-                        *append = true;
-                }
-
-                /* FIXME: empty components in other places should be rejected. */
-
-                r = path_split_and_make_absolute(e, paths);
-                if (r < 0)
-                        return r;
-        }
-
-        return 0;
-}
-
-int lookup_paths_init(
-                LookupPaths *lp,
-                RuntimeScope scope,
-                LookupPathsFlags flags,
-                const char *root_dir) {
-
-        _cleanup_(rmdir_and_freep) char *tempdir = NULL;
-        _cleanup_free_ char
-                *root = NULL,
-                *persistent_config = NULL, *runtime_config = NULL,
-                *global_persistent_config = NULL, *global_runtime_config = NULL,
-                *generator = NULL, *generator_early = NULL, *generator_late = NULL,
-                *transient = NULL,
-                *persistent_control = NULL, *runtime_control = NULL,
-                *persistent_attached = NULL, *runtime_attached = NULL;
-        bool append = false; /* Add items from SYSTEMD_UNIT_PATH before normal directories */
-        _cleanup_strv_free_ char **paths = NULL;
-        int r;
-
-        assert(lp);
-        assert(scope >= 0);
-        assert(scope < _RUNTIME_SCOPE_MAX);
-
-        if (!empty_or_root(root_dir)) {
-                if (scope == RUNTIME_SCOPE_USER)
-                        return -EINVAL;
-
-                r = is_dir(root_dir, true);
-                if (r < 0)
-                        return r;
-                if (r == 0)
-                        return -ENOTDIR;
-
-                root = strdup(root_dir);
-                if (!root)
-                        return -ENOMEM;
-        }
-
-        if (flags & LOOKUP_PATHS_TEMPORARY_GENERATED) {
-                r = mkdtemp_malloc("/tmp/systemd-temporary-XXXXXX", &tempdir);
-                if (r < 0)
-                        return log_debug_errno(r, "Failed to create temporary directory: %m");
-        }
-
-        /* Note: when XDG_RUNTIME_DIR is not set this will not return -ENXIO, but simply set runtime_config to NULL */
-        r = acquire_config_dirs(scope, &persistent_config, &runtime_config);
-        if (r < 0)
-                return r;
-
-        if (scope == RUNTIME_SCOPE_USER) {
-                r = acquire_config_dirs(RUNTIME_SCOPE_GLOBAL, &global_persistent_config, &global_runtime_config);
-                if (r < 0)
-                        return r;
-        }
-
-        if ((flags & LOOKUP_PATHS_EXCLUDE_GENERATED) == 0) {
-                /* Note: if XDG_RUNTIME_DIR is not set, this will fail completely with ENXIO */
-                r = acquire_generator_dirs(scope, tempdir,
-                                           &generator, &generator_early, &generator_late);
-                if (r < 0 && !IN_SET(r, -EOPNOTSUPP, -ENXIO))
-                        return r;
-        }
-
-        /* Note: if XDG_RUNTIME_DIR is not set, this will fail completely with ENXIO */
-        r = acquire_transient_dir(scope, tempdir, &transient);
-        if (r < 0 && !IN_SET(r, -EOPNOTSUPP, -ENXIO))
-                return r;
-
-        /* Note: when XDG_RUNTIME_DIR is not set this will not return -ENXIO, but simply set runtime_control to NULL */
-        r = acquire_control_dirs(scope, &persistent_control, &runtime_control);
-        if (r < 0 && r != -EOPNOTSUPP)
-                return r;
-
-        r = acquire_attached_dirs(scope, &persistent_attached, &runtime_attached);
-        if (r < 0 && r != -EOPNOTSUPP)
-                return r;
-
-        /* First priority is whatever has been passed to us via env vars */
-        r = get_paths_from_environ("SYSTEMD_UNIT_PATH", &paths, &append);
-        if (r < 0)
-                return r;
-
-        if (!paths || append) {
-                /* Let's figure something out. */
-
-                _cleanup_strv_free_ char **add = NULL;
-
-                /* For the user units we include share/ in the search
-                 * path in order to comply with the XDG basedir spec.
-                 * For the system stuff we avoid such nonsense. OTOH
-                 * we include /lib in the search path for the system
-                 * stuff but avoid it for user stuff. */
-
-                switch (scope) {
-
-                case RUNTIME_SCOPE_SYSTEM:
-                        add = strv_new(
-                                        /* If you modify this you also want to modify
-                                         * systemdsystemunitpath= in systemd.pc.in! */
-                                        STRV_IFNOTNULL(persistent_control),
-                                        STRV_IFNOTNULL(runtime_control),
-                                        STRV_IFNOTNULL(transient),
-                                        STRV_IFNOTNULL(generator_early),
-                                        persistent_config,
-                                        SYSTEM_CONFIG_UNIT_DIR,
-                                        "/etc/systemd/system",
-                                        STRV_IFNOTNULL(persistent_attached),
-                                        runtime_config,
-                                        "/run/systemd/system",
-                                        STRV_IFNOTNULL(runtime_attached),
-                                        STRV_IFNOTNULL(generator),
-                                        "/usr/local/lib/systemd/system",
-                                        SYSTEM_DATA_UNIT_DIR,
-                                        "/usr/lib/systemd/system",
-                                        /* To be used ONLY for images which might be legacy split-usr */
-                                        STRV_IFNOTNULL(flags & LOOKUP_PATHS_SPLIT_USR ? "/lib/systemd/system" : NULL),
-                                        STRV_IFNOTNULL(generator_late));
-                        break;
-
-                case RUNTIME_SCOPE_GLOBAL:
-                        add = strv_new(
-                                        /* If you modify this you also want to modify
-                                         * systemduserunitpath= in systemd.pc.in, and
-                                         * the arrays in user_dirs() above! */
-                                        STRV_IFNOTNULL(persistent_control),
-                                        STRV_IFNOTNULL(runtime_control),
-                                        STRV_IFNOTNULL(transient),
-                                        STRV_IFNOTNULL(generator_early),
-                                        persistent_config,
-                                        USER_CONFIG_UNIT_DIR,
-                                        "/etc/systemd/user",
-                                        runtime_config,
-                                        "/run/systemd/user",
-                                        STRV_IFNOTNULL(generator),
-                                        "/usr/local/share/systemd/user",
-                                        "/usr/share/systemd/user",
-                                        "/usr/local/lib/systemd/user",
-                                        USER_DATA_UNIT_DIR,
-                                        "/usr/lib/systemd/user",
-                                        STRV_IFNOTNULL(generator_late));
-                        break;
-
-                case RUNTIME_SCOPE_USER:
-                        add = user_dirs(persistent_config, runtime_config,
-                                        global_persistent_config, global_runtime_config,
-                                        generator, generator_early, generator_late,
-                                        transient,
-                                        persistent_control, runtime_control);
-                        break;
-
-                default:
-                        assert_not_reached();
-                }
-
-                if (!add)
-                        return -ENOMEM;
-
-                if (paths) {
-                        r = strv_extend_strv(&paths, add, true);
-                        if (r < 0)
-                                return r;
-                } else
-                        /* Small optimization: if paths is NULL (and it usually is), we can simply assign 'add' to it,
-                         * and don't have to copy anything */
-                        paths = TAKE_PTR(add);
-        }
-
-        r = patch_root_prefix(&persistent_config, root);
-        if (r < 0)
-                return r;
-        r = patch_root_prefix(&runtime_config, root);
-        if (r < 0)
-                return r;
-
-        r = patch_root_prefix(&generator, root);
-        if (r < 0)
-                return r;
-        r = patch_root_prefix(&generator_early, root);
-        if (r < 0)
-                return r;
-        r = patch_root_prefix(&generator_late, root);
-        if (r < 0)
-                return r;
-
-        r = patch_root_prefix(&transient, root);
-        if (r < 0)
-                return r;
-
-        r = patch_root_prefix(&persistent_control, root);
-        if (r < 0)
-                return r;
-        r = patch_root_prefix(&runtime_control, root);
-        if (r < 0)
-                return r;
-
-        r = patch_root_prefix(&persistent_attached, root);
-        if (r < 0)
-                return r;
-        r = patch_root_prefix(&runtime_attached, root);
-        if (r < 0)
-                return r;
-
-        r = patch_root_prefix_strv(paths, root);
-        if (r < 0)
-                return -ENOMEM;
-
-        *lp = (LookupPaths) {
-                .search_path = strv_uniq(TAKE_PTR(paths)),
-
-                .persistent_config = TAKE_PTR(persistent_config),
-                .runtime_config = TAKE_PTR(runtime_config),
-
-                .generator = TAKE_PTR(generator),
-                .generator_early = TAKE_PTR(generator_early),
-                .generator_late = TAKE_PTR(generator_late),
-
-                .transient = TAKE_PTR(transient),
-
-                .persistent_control = TAKE_PTR(persistent_control),
-                .runtime_control = TAKE_PTR(runtime_control),
-
-                .persistent_attached = TAKE_PTR(persistent_attached),
-                .runtime_attached = TAKE_PTR(runtime_attached),
-
-                .root_dir = TAKE_PTR(root),
-                .temporary_dir = TAKE_PTR(tempdir),
-        };
-
-        return 0;
-}
-
-int lookup_paths_init_or_warn(LookupPaths *lp, RuntimeScope scope, LookupPathsFlags flags, const char *root_dir) {
-        int r;
-
-        r = lookup_paths_init(lp, scope, flags, root_dir);
-        if (r < 0)
-                return log_error_errno(r, "Failed to initialize unit search paths%s%s: %m",
-                                       isempty(root_dir) ? "" : " for root directory ", strempty(root_dir));
-        return r;
-}
-
-void lookup_paths_done(LookupPaths *lp) {
-        assert(lp);
-
-        lp->search_path = strv_free(lp->search_path);
-
-        lp->persistent_config = mfree(lp->persistent_config);
-        lp->runtime_config = mfree(lp->runtime_config);
-
-        lp->persistent_attached = mfree(lp->persistent_attached);
-        lp->runtime_attached = mfree(lp->runtime_attached);
-
-        lp->generator = mfree(lp->generator);
-        lp->generator_early = mfree(lp->generator_early);
-        lp->generator_late = mfree(lp->generator_late);
-
-        lp->transient = mfree(lp->transient);
-
-        lp->persistent_control = mfree(lp->persistent_control);
-        lp->runtime_control = mfree(lp->runtime_control);
-
-        lp->root_dir = mfree(lp->root_dir);
-        lp->temporary_dir = mfree(lp->temporary_dir);
-}
-
-void lookup_paths_log(LookupPaths *lp) {
-        assert(lp);
-
-        if (strv_isempty(lp->search_path)) {
-                log_debug("Ignoring unit files.");
-                lp->search_path = strv_free(lp->search_path);
-        } else {
-                _cleanup_free_ char *t = NULL;
-
-                t = strv_join(lp->search_path, "\n\t");
-                log_debug("Looking for unit files in (higher priority first):\n\t%s", strna(t));
-        }
-}
-
-char **generator_binary_paths(RuntimeScope scope) {
-        bool append = false; /* Add items from SYSTEMD_GENERATOR_PATH before normal directories */
-        _cleanup_strv_free_ char **paths = NULL;
-        int r;
-
-        /* First priority is whatever has been passed to us via env vars */
-        r = get_paths_from_environ("SYSTEMD_GENERATOR_PATH", &paths, &append);
-        if (r < 0)
-                return NULL;
-
-        if (!paths || append) {
-                _cleanup_strv_free_ char **add = NULL;
-
-                switch (scope) {
-
-                case RUNTIME_SCOPE_SYSTEM:
-                        add = strv_new("/run/systemd/system-generators",
-                                       "/etc/systemd/system-generators",
-                                       "/usr/local/lib/systemd/system-generators",
-                                       SYSTEM_GENERATOR_DIR);
-                        break;
-
-                case RUNTIME_SCOPE_GLOBAL:
-                case RUNTIME_SCOPE_USER:
-                        add = strv_new("/run/systemd/user-generators",
-                                       "/etc/systemd/user-generators",
-                                       "/usr/local/lib/systemd/user-generators",
-                                       USER_GENERATOR_DIR);
-                        break;
-
-                default:
-                        assert_not_reached();
-                }
-                if (!add)
-                        return NULL;
-
-                if (paths) {
-                        r = strv_extend_strv(&paths, add, true);
-                        if (r < 0)
-                                return NULL;
-                } else
-                        /* Small optimization: if paths is NULL (and it usually is), we can simply assign 'add' to it,
-                         * and don't have to copy anything */
-                        paths = TAKE_PTR(add);
-        }
-
-        return TAKE_PTR(paths);
-}
-
-char **env_generator_binary_paths(RuntimeScope runtime_scope) {
-        _cleanup_strv_free_ char **paths = NULL, **add = NULL;
-        bool append = false; /* Add items from SYSTEMD_ENVIRONMENT_GENERATOR_PATH before normal directories */
-        int r;
-
-        /* First priority is whatever has been passed to us via env vars */
-        r = get_paths_from_environ("SYSTEMD_ENVIRONMENT_GENERATOR_PATH", &paths, &append);
-        if (r < 0)
-                return NULL;
-
-        if (!paths || append) {
-                switch (runtime_scope) {
-
-                case RUNTIME_SCOPE_SYSTEM:
-                        add = strv_new("/run/systemd/system-environment-generators",
-                                        "/etc/systemd/system-environment-generators",
-                                        "/usr/local/lib/systemd/system-environment-generators",
-                                        SYSTEM_ENV_GENERATOR_DIR);
-                        break;
-
-                case RUNTIME_SCOPE_USER:
-                        add = strv_new("/run/systemd/user-environment-generators",
-                                       "/etc/systemd/user-environment-generators",
-                                       "/usr/local/lib/systemd/user-environment-generators",
-                                       USER_ENV_GENERATOR_DIR);
-                        break;
-
-                default:
-                        assert_not_reached();
-                }
-                if (!add)
-                        return NULL;
-        }
-
-        if (paths) {
-                r = strv_extend_strv(&paths, add, true);
-                if (r < 0)
-                        return NULL;
-        } else
-                /* Small optimization: if paths is NULL (and it usually is), we can simply assign 'add' to it,
-                 * and don't have to copy anything */
-                paths = TAKE_PTR(add);
-
-        return TAKE_PTR(paths);
-}
-
-int find_portable_profile(const char *name, const char *unit, char **ret_path) {
-        const char *dot;
-        int r;
-
-        assert(name);
-        assert(ret_path);
-
-        assert_se(dot = strrchr(unit, '.'));
-
-        NULSTR_FOREACH(p, PORTABLE_PROFILE_DIRS) {
-                _cleanup_free_ char *joined = NULL;
-
-                joined = strjoin(p, "/", name, "/", dot + 1, ".conf");
-                if (!joined)
-                        return -ENOMEM;
-
-                r = access_nofollow(joined, F_OK);
-                if (r >= 0) {
-                        *ret_path = TAKE_PTR(joined);
-                        return 0;
-                }
-                if (r != -ENOENT)
-                        return r;
-        }
-
-        return -ENOENT;
-}
diff --git a/src/core/main.c b/src/core/main.c
index e526c37e6a..0c171a788d 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -182,7 +182,7 @@ static int manager_find_user_config_paths(char ***ret_files, char ***ret_dirs) {
         _cleanup_strv_free_ char **files = NULL, **dirs = NULL;
         int r;
 
-        r = xdg_user_config_dir(&base, "/systemd");
+        r = xdg_user_config_dir("/systemd", &base);
         if (r < 0)
                 return r;
 
@@ -2479,7 +2479,7 @@ static int initialize_runtime(
                 /* Create the runtime directory and place the inaccessible device nodes there, if we run in
                  * user mode. In system mode mount_setup() already did that. */
 
-                r = xdg_user_runtime_dir(&p, "/systemd");
+                r = xdg_user_runtime_dir("/systemd", &p);
                 if (r < 0) {
                         *ret_error_message = "$XDG_RUNTIME_DIR is not set";
                         return log_struct_errno(LOG_EMERG, r,
diff --git a/src/core/manager.c b/src/core/manager.c
index 2dddc79722..18fb8fdaf8 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1031,7 +1031,7 @@ int manager_new(RuntimeScope runtime_scope, ManagerTestRunFlags test_run_flags,
                         r = mkdir_label("/run/systemd/units", 0755);
                 else {
                         _cleanup_free_ char *units_path = NULL;
-                        r = xdg_user_runtime_dir(&units_path, "/systemd/units");
+                        r = xdg_user_runtime_dir("/systemd/units", &units_path);
                         if (r < 0)
                                 return r;
 
diff --git a/src/core/unit.c b/src/core/unit.c
index ae3cefcdde..c303ce9282 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -5576,12 +5576,13 @@ static int unit_get_invocation_path(Unit *u, char **ret) {
                 p = strjoin("/run/systemd/units/invocation:", u->id);
         else {
                 _cleanup_free_ char *user_path = NULL;
-                r = xdg_user_runtime_dir(&user_path, "/systemd/units/invocation:");
+
+                r = xdg_user_runtime_dir("/systemd/units/invocation:", &user_path);
                 if (r < 0)
                         return r;
+
                 p = strjoin(user_path, u->id);
         }
-
         if (!p)
                 return -ENOMEM;
 
diff --git a/src/libsystemd/meson.build b/src/libsystemd/meson.build
index d73c3a8974..fa28aa09fb 100644
--- a/src/libsystemd/meson.build
+++ b/src/libsystemd/meson.build
@@ -44,7 +44,7 @@ sd_journal_sources += [audit_type_to_name]
 
 ############################################################
 
-id128_sources = files(
+sd_id128_sources = files(
         'sd-id128/id128-util.c',
         'sd-id128/sd-id128.c',
 )
@@ -62,6 +62,41 @@ sd_event_sources = files(
 
 ############################################################
 
+sd_bus_sources = files(
+        'sd-bus/bus-common-errors.c',
+        'sd-bus/bus-container.c',
+        'sd-bus/bus-control.c',
+        'sd-bus/bus-convenience.c',
+        'sd-bus/bus-creds.c',
+        'sd-bus/bus-dump.c',
+        'sd-bus/bus-error.c',
+        'sd-bus/bus-internal.c',
+        'sd-bus/bus-introspect.c',
+        'sd-bus/bus-kernel.c',
+        'sd-bus/bus-match.c',
+        'sd-bus/bus-message.c',
+        'sd-bus/bus-objects.c',
+        'sd-bus/bus-signature.c',
+        'sd-bus/bus-slot.c',
+        'sd-bus/bus-socket.c',
+        'sd-bus/bus-track.c',
+        'sd-bus/bus-type.c',
+        'sd-bus/sd-bus.c',
+)
+
+############################################################
+
+sd_device_sources = files(
+        'sd-device/device-enumerator.c',
+        'sd-device/device-filter.c',
+        'sd-device/device-monitor.c',
+        'sd-device/device-private.c',
+        'sd-device/device-util.c',
+        'sd-device/sd-device.c',
+)
+
+############################################################
+
 sd_login_sources = files('sd-login/sd-login.c')
 
 ############################################################
@@ -83,33 +118,14 @@ sd_varlink_sources = files(
 
 ############################################################
 
-libsystemd_sources = files(
-        'sd-bus/bus-common-errors.c',
-        'sd-bus/bus-container.c',
-        'sd-bus/bus-control.c',
-        'sd-bus/bus-convenience.c',
-        'sd-bus/bus-creds.c',
-        'sd-bus/bus-dump.c',
-        'sd-bus/bus-error.c',
-        'sd-bus/bus-internal.c',
-        'sd-bus/bus-introspect.c',
-        'sd-bus/bus-kernel.c',
-        'sd-bus/bus-match.c',
-        'sd-bus/bus-message.c',
-        'sd-bus/bus-objects.c',
-        'sd-bus/bus-signature.c',
-        'sd-bus/bus-slot.c',
-        'sd-bus/bus-socket.c',
-        'sd-bus/bus-track.c',
-        'sd-bus/bus-type.c',
-        'sd-bus/sd-bus.c',
-        'sd-device/device-enumerator.c',
-        'sd-device/device-filter.c',
-        'sd-device/device-monitor.c',
-        'sd-device/device-private.c',
-        'sd-device/device-util.c',
-        'sd-device/sd-device.c',
-        'sd-hwdb/sd-hwdb.c',
+sd_path_sources = files(
+        'sd-path/path-lookup.c',
+        'sd-path/sd-path.c',
+)
+
+############################################################
+
+sd_netlink_sources = files(
         'sd-netlink/netlink-genl.c',
         'sd-netlink/netlink-message-nfnl.c',
         'sd-netlink/netlink-message-rtnl.c',
@@ -122,11 +138,24 @@ libsystemd_sources = files(
         'sd-netlink/netlink-types.c',
         'sd-netlink/netlink-util.c',
         'sd-netlink/sd-netlink.c',
+)
+
+############################################################
+
+sd_network_sources = files(
         'sd-network/network-util.c',
         'sd-network/sd-network.c',
-        'sd-path/sd-path.c',
+)
+
+############################################################
+
+libsystemd_sources = files(
+        'sd-hwdb/sd-hwdb.c',
         'sd-resolve/sd-resolve.c',
-) + sd_journal_sources + id128_sources + sd_daemon_sources + sd_event_sources + sd_login_sources + sd_json_sources + sd_varlink_sources
+) + sd_journal_sources + sd_id128_sources + sd_daemon_sources \
+  + sd_event_sources + sd_bus_sources + sd_device_sources \
+  + sd_login_sources + sd_json_sources + sd_varlink_sources \
+  + sd_path_sources + sd_netlink_sources + sd_network_sources
 
 libsystemd_c_args = ['-fvisibility=default']
 
diff --git a/src/libsystemd/sd-network/network-util.h b/src/libsystemd/sd-network/network-util.h
index 6fc6015902..14c6f6819d 100644
--- a/src/libsystemd/sd-network/network-util.h
+++ b/src/libsystemd/sd-network/network-util.h
@@ -4,8 +4,12 @@
 #include <errno.h>
 #include <stdbool.h>
 
+#include "constants.h"
 #include "macro.h"
 
+#define NETWORK_DIRS ((const char* const*) CONF_PATHS_STRV("systemd/network"))
+#define NETWORK_DIRS_NULSTR CONF_PATHS_NULSTR("systemd/network")
+
 bool network_is_online(void);
 
 typedef enum AddressFamily {
diff --git a/src/libsystemd/sd-path/path-lookup.c b/src/libsystemd/sd-path/path-lookup.c
new file mode 100644
index 0000000000..a3b09208cb
--- /dev/null
+++ b/src/libsystemd/sd-path/path-lookup.c
@@ -0,0 +1,724 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "alloc-util.h"
+#include "fs-util.h"
+#include "log.h"
+#include "macro.h"
+#include "nulstr-util.h"
+#include "path-lookup.h"
+#include "path-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "tmpfile-util.h"
+#include "user-util.h"
+
+int user_search_dirs(const char *suffix, char ***ret_config_dirs, char ***ret_data_dirs) {
+        _cleanup_strv_free_ char **config_dirs = NULL, **data_dirs = NULL;
+        int r;
+
+        assert(ret_config_dirs);
+        assert(ret_data_dirs);
+
+        r = sd_path_lookup_strv(SD_PATH_SEARCH_CONFIGURATION, suffix, &config_dirs);
+        if (r < 0)
+                return r;
+
+        r = sd_path_lookup_strv(SD_PATH_SEARCH_SHARED, suffix, &data_dirs);
+        if (r < 0)
+                return r;
+
+        *ret_config_dirs = TAKE_PTR(config_dirs);
+        *ret_data_dirs = TAKE_PTR(data_dirs);
+
+        return 0;
+}
+
+int runtime_directory(RuntimeScope scope, const char *suffix, char **ret) {
+        int r;
+
+        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER));
+        assert(suffix);
+        assert(ret);
+
+        /* Accept $RUNTIME_DIRECTORY as authoritative
+         * If it's missing, apply the suffix to /run/, or $XDG_RUNTIME_DIR if we are in a user runtime scope.
+         *
+         * Return value indicates whether the suffix was applied or not */
+
+        const char *e = secure_getenv("RUNTIME_DIRECTORY");
+        if (e)
+                return strdup_to(ret, e);
+
+        if (scope == RUNTIME_SCOPE_USER) {
+                r = xdg_user_runtime_dir(suffix, ret);
+                if (r < 0)
+                        return r;
+        } else {
+                char *d = path_join("/run", suffix);
+                if (!d)
+                        return -ENOMEM;
+                *ret = d;
+        }
+
+        return 1;
+}
+
+static const char* const user_data_unit_paths[] = {
+        "/usr/local/lib/systemd/user",
+        "/usr/local/share/systemd/user",
+        USER_DATA_UNIT_DIR,
+        "/usr/lib/systemd/user",
+        "/usr/share/systemd/user",
+        NULL
+};
+
+static const char* const user_config_unit_paths[] = {
+        USER_CONFIG_UNIT_DIR,
+        "/etc/systemd/user",
+        NULL
+};
+
+bool path_is_user_data_dir(const char *path) {
+        assert(path);
+
+        return path_strv_contains((char* const*) user_data_unit_paths, path);
+}
+
+bool path_is_user_config_dir(const char *path) {
+        assert(path);
+
+        return path_strv_contains((char* const*) user_config_unit_paths, path);
+}
+
+static int acquire_generator_dirs(
+                RuntimeScope scope,
+                const char *tempdir,
+                char **ret,
+                char **ret_early,
+                char **ret_late) {
+
+        _cleanup_free_ char *prefix_alloc = NULL, *g = NULL, *early = NULL, *late = NULL;
+        const char *prefix;
+        int r;
+
+        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER, RUNTIME_SCOPE_GLOBAL));
+        assert(ret);
+        assert(ret_early);
+        assert(ret_late);
+
+        if (scope == RUNTIME_SCOPE_GLOBAL)
+                return -EOPNOTSUPP;
+
+        if (tempdir)
+                prefix = tempdir;
+        else if (scope == RUNTIME_SCOPE_SYSTEM)
+                prefix = "/run/systemd";
+        else { /* RUNTIME_SCOPE_USER */
+                r = xdg_user_runtime_dir("/systemd", &prefix_alloc);
+                if (r < 0)
+                        return r;
+
+                prefix = prefix_alloc;
+        }
+
+        g = path_join(prefix, "generator");
+        if (!g)
+                return -ENOMEM;
+
+        early = path_join(prefix, "generator.early");
+        if (!early)
+                return -ENOMEM;
+
+        late = path_join(prefix, "generator.late");
+        if (!late)
+                return -ENOMEM;
+
+        *ret = TAKE_PTR(g);
+        *ret_early = TAKE_PTR(early);
+        *ret_late = TAKE_PTR(late);
+
+        return 0;
+}
+
+static int acquire_transient_dir(RuntimeScope scope, const char *tempdir, char **ret) {
+        char *transient;
+
+        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER, RUNTIME_SCOPE_GLOBAL));
+        assert(ret);
+
+        if (scope == RUNTIME_SCOPE_GLOBAL)
+                return -EOPNOTSUPP;
+
+        if (tempdir)
+                transient = path_join(tempdir, "transient");
+        else if (scope == RUNTIME_SCOPE_SYSTEM)
+                transient = strdup("/run/systemd/transient");
+        else /* RUNTIME_SCOPE_USER */
+                return xdg_user_runtime_dir("/systemd/transient", ret);
+
+        if (!transient)
+                return -ENOMEM;
+
+        *ret = transient;
+        return 0;
+}
+
+typedef enum LookupDirType {
+        LOOKUP_DIR_CONFIG,
+        LOOKUP_DIR_CONTROL,
+        LOOKUP_DIR_ATTACHED,
+        _LOOKUP_DIR_MAX,
+        _LOOKUP_DIR_INVALID = -EINVAL,
+} LookupDirType;
+
+static int acquire_lookup_dirs(
+                LookupDirType type,
+                RuntimeScope scope,
+                char **ret_persistent,
+                char **ret_runtime) {
+
+        /* RUNTIME_SCOPE_USER dirs are relative to XDG_CONFIG_DIR and XDG_RUNTIME_DIR, respectively */
+        static const struct {
+                const char *persistent;
+                const char *runtime;
+        } dirs[_LOOKUP_DIR_MAX][_RUNTIME_SCOPE_MAX] = {
+                [LOOKUP_DIR_CONFIG] = {
+                        [RUNTIME_SCOPE_SYSTEM] = { SYSTEM_CONFIG_UNIT_DIR, "/run/systemd/system" },
+                        [RUNTIME_SCOPE_GLOBAL] = { USER_CONFIG_UNIT_DIR,   "/run/systemd/user"   },
+                        [RUNTIME_SCOPE_USER]   = { "systemd/user",         "systemd/user"        },
+                },
+                [LOOKUP_DIR_CONTROL] = {
+                        [RUNTIME_SCOPE_SYSTEM] = { "/etc/systemd/system.control", "/run/systemd/system.control" },
+                        [RUNTIME_SCOPE_USER]   = { "systemd/user.control",        "systemd/user.control"        },
+                },
+                [LOOKUP_DIR_ATTACHED] = {
+                        [RUNTIME_SCOPE_SYSTEM] = { "/etc/systemd/system.attached", "/run/systemd/system.attached" },
+                        /* Portable services are not available to regular users for now. */
+                },
+        };
+
+        _cleanup_free_ char *a = NULL, *b = NULL;
+        int r;
+
+        assert(type >= 0 && type < _LOOKUP_DIR_MAX);
+        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER, RUNTIME_SCOPE_GLOBAL));
+        assert(ret_persistent);
+        assert(ret_runtime);
+
+        const char *persistent = dirs[type][scope].persistent;
+        const char *runtime = dirs[type][scope].runtime;
+        assert(!persistent == !runtime);
+
+        if (!persistent)
+                return -EOPNOTSUPP;
+
+        switch (scope) {
+
+        case RUNTIME_SCOPE_SYSTEM:
+        case RUNTIME_SCOPE_GLOBAL:
+                a = strdup(persistent);
+                b = strdup(runtime);
+                if (!a || !b)
+                        return -ENOMEM;
+
+                *ret_persistent = TAKE_PTR(a);
+                *ret_runtime = TAKE_PTR(b);
+
+                return 0;
+
+        case RUNTIME_SCOPE_USER:
+                r = xdg_user_config_dir(persistent, &a);
+                if (r < 0)
+                        return r;
+
+                r = xdg_user_runtime_dir(runtime, ret_runtime);
+                if (r < 0) {
+                        if (r != -ENXIO)
+                                return r;
+
+                        /* If XDG_RUNTIME_DIR is not set, don't consider that fatal, simply initialize
+                         * the runtime directory to NULL. */
+                        *ret_runtime = NULL;
+                }
+
+                *ret_persistent = TAKE_PTR(a);
+
+                return 0;
+
+        default:
+                assert_not_reached();
+        }
+}
+
+static int patch_root_prefix(char **p, const char *root_dir) {
+        char *c;
+
+        assert(p);
+
+        if (!root_dir)
+                return 0;
+
+        if (!*p)
+                return 0;
+
+        c = path_join(root_dir, *p);
+        if (!c)
+                return -ENOMEM;
+
+        free_and_replace(*p, c);
+        return 0;
+}
+
+static int patch_root_prefix_strv(char **l, const char *root_dir) {
+        int r;
+
+        if (!root_dir)
+                return 0;
+
+        STRV_FOREACH(i, l) {
+                r = patch_root_prefix(i, root_dir);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+static int get_paths_from_environ(const char *var, char ***ret) {
+        const char *e;
+        int r;
+
+        assert(var);
+        assert(ret);
+
+        e = getenv(var);
+        if (!e) {
+                *ret = NULL;
+                return 0;
+        }
+
+        bool append = endswith(e, ":"); /* Whether to append the normal search paths after what's obtained
+                                           from envvar */
+
+        /* FIXME: empty components in other places should be rejected. */
+
+        r = path_split_and_make_absolute(e, ret);
+        if (r < 0)
+                return r;
+
+        return append;
+}
+
+static char** user_unit_search_dirs(
+                const char *persistent_config,
+                const char *runtime_config,
+                const char *global_persistent_config,
+                const char *global_runtime_config,
+                const char *generator,
+                const char *generator_early,
+                const char *generator_late,
+                const char *transient,
+                const char *persistent_control,
+                const char *runtime_control) {
+
+        _cleanup_strv_free_ char **paths = NULL, **config_dirs = NULL, **data_dirs = NULL;
+
+        /* The returned strv might contain duplicates, and we expect caller to filter them. */
+
+        assert(persistent_config);
+        assert(global_persistent_config);
+        assert(global_runtime_config);
+        assert(persistent_control);
+
+        if (user_search_dirs("/systemd/user", &config_dirs, &data_dirs) < 0)
+                return NULL;
+
+        paths = strv_new(persistent_control,
+                         STRV_IFNOTNULL(runtime_control),
+                         STRV_IFNOTNULL(transient),
+                         STRV_IFNOTNULL(generator_early),
+                         persistent_config);
+        if (!paths)
+                return NULL;
+
+        if (strv_extend_strv_consume(&paths, TAKE_PTR(config_dirs), /* filter_duplicates = */ false) < 0)
+                return NULL;
+
+        /* global config has lower priority than the user config of the same type */
+        if (strv_extend(&paths, global_persistent_config) < 0)
+                return NULL;
+
+        if (strv_extend_strv(&paths, (char* const*) user_config_unit_paths, /* filter_duplicates = */ false) < 0)
+                return NULL;
+
+        /* strv_extend_many() can deal with NULL-s in arguments */
+        if (strv_extend_many(&paths,
+                             runtime_config,
+                             global_runtime_config,
+                             generator) < 0)
+                return NULL;
+
+        if (strv_extend_strv_consume(&paths, TAKE_PTR(data_dirs), /* filter_duplicates = */ false) < 0)
+                return NULL;
+
+        if (strv_extend_strv(&paths, (char* const*) user_data_unit_paths, false) < 0)
+                return NULL;
+
+        if (strv_extend(&paths, generator_late) < 0)
+                return NULL;
+
+        if (path_strv_make_absolute_cwd(paths) < 0)
+                return NULL;
+
+        return TAKE_PTR(paths);
+}
+
+int lookup_paths_init(
+                LookupPaths *lp,
+                RuntimeScope scope,
+                LookupPathsFlags flags,
+                const char *root_dir) {
+
+        _cleanup_(rmdir_and_freep) char *tempdir = NULL;
+        _cleanup_free_ char
+                *root = NULL,
+                *persistent_config = NULL, *runtime_config = NULL,
+                *global_persistent_config = NULL, *global_runtime_config = NULL,
+                *generator = NULL, *generator_early = NULL, *generator_late = NULL,
+                *transient = NULL,
+                *persistent_control = NULL, *runtime_control = NULL,
+                *persistent_attached = NULL, *runtime_attached = NULL;
+        _cleanup_strv_free_ char **paths = NULL;
+        int r;
+
+        assert(lp);
+        assert(scope >= 0);
+        assert(scope < _RUNTIME_SCOPE_MAX);
+        assert(!FLAGS_SET(flags, LOOKUP_PATHS_EXCLUDE_GENERATED|LOOKUP_PATHS_TEMPORARY_GENERATED));
+
+        if (!empty_or_root(root_dir)) {
+                if (scope == RUNTIME_SCOPE_USER)
+                        return -EINVAL;
+
+                r = is_dir(root_dir, true);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        return -ENOTDIR;
+
+                root = strdup(root_dir);
+                if (!root)
+                        return -ENOMEM;
+        }
+
+        if (FLAGS_SET(flags, LOOKUP_PATHS_TEMPORARY_GENERATED)) {
+                r = mkdtemp_malloc("/tmp/systemd-temporary-XXXXXX", &tempdir);
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to create temporary directory: %m");
+        }
+
+        /* Note: when XDG_RUNTIME_DIR is not set this will not return -ENXIO, but simply set runtime_config to NULL */
+        r = acquire_lookup_dirs(LOOKUP_DIR_CONFIG, scope, &persistent_config, &runtime_config);
+        if (r < 0)
+                return r;
+
+        if (scope == RUNTIME_SCOPE_USER) {
+                r = acquire_lookup_dirs(LOOKUP_DIR_CONFIG, RUNTIME_SCOPE_GLOBAL, &global_persistent_config, &global_runtime_config);
+                if (r < 0)
+                        return r;
+        }
+
+        r = acquire_lookup_dirs(LOOKUP_DIR_CONTROL, scope, &persistent_control, &runtime_control);
+        if (r < 0 && r != -EOPNOTSUPP)
+                return r;
+
+        r = acquire_lookup_dirs(LOOKUP_DIR_ATTACHED, scope, &persistent_attached, &runtime_attached);
+        if (r < 0 && r != -EOPNOTSUPP)
+                return r;
+
+        if (!FLAGS_SET(flags, LOOKUP_PATHS_EXCLUDE_GENERATED)) {
+                /* Note: if XDG_RUNTIME_DIR is not set, this will fail completely with ENXIO */
+                r = acquire_generator_dirs(scope, tempdir,
+                                           &generator, &generator_early, &generator_late);
+                if (r < 0 && !IN_SET(r, -EOPNOTSUPP, -ENXIO))
+                        return r;
+        }
+
+        /* Note: if XDG_RUNTIME_DIR is not set, this will fail completely with ENXIO */
+        r = acquire_transient_dir(scope, tempdir, &transient);
+        if (r < 0 && !IN_SET(r, -EOPNOTSUPP, -ENXIO))
+                return r;
+
+        /* First priority is whatever has been passed to us via env vars */
+        r = get_paths_from_environ("SYSTEMD_UNIT_PATH", &paths);
+        if (r < 0)
+                return r;
+
+        if (!paths || r > 0) {
+                /* Let's figure something out. */
+
+                _cleanup_strv_free_ char **add = NULL;
+
+                /* For the user units we include share/ in the search paths in order to comply with
+                 * the XDG basedir spec. For the system stuff we avoid such nonsense. OTOH we include (/usr/)lib/
+                 * in the search paths for the system stuff but avoid it for user stuff. */
+
+                assert(persistent_config);
+
+                switch (scope) {
+
+                case RUNTIME_SCOPE_SYSTEM:
+                        /* If you modify this you also want to modify systemdsystemunitpath= in systemd.pc.in! */
+                        add = strv_new(ASSERT_PTR(persistent_control),
+                                       ASSERT_PTR(runtime_control),
+                                       ASSERT_PTR(transient),
+                                       STRV_IFNOTNULL(generator_early),
+                                       persistent_config,
+                                       SYSTEM_CONFIG_UNIT_DIR,
+                                       "/etc/systemd/system",
+                                       ASSERT_PTR(persistent_attached),
+                                       ASSERT_PTR(runtime_config),
+                                       "/run/systemd/system",
+                                       ASSERT_PTR(runtime_attached),
+                                       STRV_IFNOTNULL(generator),
+                                       "/usr/local/lib/systemd/system",
+                                       SYSTEM_DATA_UNIT_DIR,
+                                       "/usr/lib/systemd/system",
+                                       /* To be used ONLY for images which might be legacy split-usr */
+                                       FLAGS_SET(flags, LOOKUP_PATHS_SPLIT_USR) ? "/lib/systemd/system" : STRV_IGNORE,
+                                       STRV_IFNOTNULL(generator_late));
+                        break;
+
+                case RUNTIME_SCOPE_GLOBAL:
+                        /* If you modify this you also want to modify systemduserunitpath= in systemd.pc.in,
+                         * and RUNTIME_SCOPE_USER search paths below! */
+
+                        assert(!persistent_control);
+                        assert(!runtime_control);
+                        assert(!transient);
+                        assert(!generator_early);
+                        assert(!generator);
+                        assert(!generator_late);
+
+                        add = strv_new(persistent_config,
+                                       USER_CONFIG_UNIT_DIR,
+                                       "/etc/systemd/user",
+                                       ASSERT_PTR(runtime_config),
+                                       "/run/systemd/user",
+                                       "/usr/local/share/systemd/user",
+                                       "/usr/share/systemd/user",
+                                       "/usr/local/lib/systemd/user",
+                                       USER_DATA_UNIT_DIR,
+                                       "/usr/lib/systemd/user");
+                        break;
+
+                case RUNTIME_SCOPE_USER:
+                        add = user_unit_search_dirs(persistent_config, runtime_config,
+                                                    global_persistent_config, global_runtime_config,
+                                                    generator, generator_early, generator_late,
+                                                    transient,
+                                                    persistent_control, runtime_control);
+                        break;
+
+                default:
+                        assert_not_reached();
+                }
+
+                if (!add)
+                        return -ENOMEM;
+
+                /* strv_uniq() below would filter all duplicates against the final strv */
+                r = strv_extend_strv_consume(&paths, TAKE_PTR(add), /* filter_duplicates = */ false);
+                if (r < 0)
+                        return r;
+        }
+
+        r = patch_root_prefix(&persistent_config, root);
+        if (r < 0)
+                return r;
+        r = patch_root_prefix(&runtime_config, root);
+        if (r < 0)
+                return r;
+
+        r = patch_root_prefix(&generator, root);
+        if (r < 0)
+                return r;
+        r = patch_root_prefix(&generator_early, root);
+        if (r < 0)
+                return r;
+        r = patch_root_prefix(&generator_late, root);
+        if (r < 0)
+                return r;
+
+        r = patch_root_prefix(&transient, root);
+        if (r < 0)
+                return r;
+
+        r = patch_root_prefix(&persistent_control, root);
+        if (r < 0)
+                return r;
+        r = patch_root_prefix(&runtime_control, root);
+        if (r < 0)
+                return r;
+
+        r = patch_root_prefix(&persistent_attached, root);
+        if (r < 0)
+                return r;
+        r = patch_root_prefix(&runtime_attached, root);
+        if (r < 0)
+                return r;
+
+        r = patch_root_prefix_strv(paths, root);
+        if (r < 0)
+                return -ENOMEM;
+
+        *lp = (LookupPaths) {
+                .search_path = strv_uniq(TAKE_PTR(paths)),
+
+                .persistent_config = TAKE_PTR(persistent_config),
+                .runtime_config = TAKE_PTR(runtime_config),
+
+                .generator = TAKE_PTR(generator),
+                .generator_early = TAKE_PTR(generator_early),
+                .generator_late = TAKE_PTR(generator_late),
+
+                .transient = TAKE_PTR(transient),
+
+                .persistent_control = TAKE_PTR(persistent_control),
+                .runtime_control = TAKE_PTR(runtime_control),
+
+                .persistent_attached = TAKE_PTR(persistent_attached),
+                .runtime_attached = TAKE_PTR(runtime_attached),
+
+                .root_dir = TAKE_PTR(root),
+                .temporary_dir = TAKE_PTR(tempdir),
+        };
+
+        return 0;
+}
+
+int lookup_paths_init_or_warn(LookupPaths *lp, RuntimeScope scope, LookupPathsFlags flags, const char *root_dir) {
+        int r;
+
+        r = lookup_paths_init(lp, scope, flags, root_dir);
+        if (r < 0)
+                return log_error_errno(r, "Failed to initialize unit search paths%s%s: %m",
+                                       isempty(root_dir) ? "" : " for root directory ", strempty(root_dir));
+        return r;
+}
+
+void lookup_paths_done(LookupPaths *lp) {
+        assert(lp);
+
+        lp->search_path = strv_free(lp->search_path);
+
+        lp->persistent_config = mfree(lp->persistent_config);
+        lp->runtime_config = mfree(lp->runtime_config);
+
+        lp->persistent_attached = mfree(lp->persistent_attached);
+        lp->runtime_attached = mfree(lp->runtime_attached);
+
+        lp->generator = mfree(lp->generator);
+        lp->generator_early = mfree(lp->generator_early);
+        lp->generator_late = mfree(lp->generator_late);
+
+        lp->transient = mfree(lp->transient);
+
+        lp->persistent_control = mfree(lp->persistent_control);
+        lp->runtime_control = mfree(lp->runtime_control);
+
+        lp->root_dir = mfree(lp->root_dir);
+        lp->temporary_dir = mfree(lp->temporary_dir);
+}
+
+void lookup_paths_log(LookupPaths *lp) {
+        assert(lp);
+
+        if (strv_isempty(lp->search_path)) {
+                log_debug("Ignoring unit files.");
+                lp->search_path = strv_free(lp->search_path);
+        } else {
+                _cleanup_free_ char *t = NULL;
+
+                t = strv_join(lp->search_path, "\n\t");
+                log_debug("Looking for unit files in (higher priority first):\n\t%s", strna(t));
+        }
+}
+
+static const char* const system_generator_paths[] = {
+        "/run/systemd/system-generators",
+        "/etc/systemd/system-generators",
+        "/usr/local/lib/systemd/system-generators",
+        SYSTEM_GENERATOR_DIR,
+        NULL,
+};
+
+static const char* const user_generator_paths[] = {
+        "/run/systemd/user-generators",
+        "/etc/systemd/user-generators",
+        "/usr/local/lib/systemd/user-generators",
+        USER_GENERATOR_DIR,
+        NULL,
+};
+
+static const char* const system_env_generator_paths[] = {
+        "/run/systemd/system-environment-generators",
+        "/etc/systemd/system-environment-generators",
+        "/usr/local/lib/systemd/system-environment-generators",
+        SYSTEM_ENV_GENERATOR_DIR,
+        NULL,
+};
+
+static const char* const user_env_generator_paths[] = {
+        "/run/systemd/user-environment-generators",
+        "/etc/systemd/user-environment-generators",
+        "/usr/local/lib/systemd/user-environment-generators",
+        USER_ENV_GENERATOR_DIR,
+        NULL,
+};
+
+char** generator_binary_paths_internal(RuntimeScope scope, bool env_generator) {
+
+        static const struct {
+                const char *env_name;
+                const char * const *paths[_RUNTIME_SCOPE_MAX];
+        } unit_generator = {
+                "SYSTEMD_GENERATOR_PATH",
+                {
+                        [RUNTIME_SCOPE_SYSTEM] = system_generator_paths,
+                        [RUNTIME_SCOPE_USER]   = user_generator_paths,
+                }
+        }, environment_generator = {
+                "SYSTEMD_ENVIRONMENT_GENERATOR_PATH",
+                {
+                        [RUNTIME_SCOPE_SYSTEM] = system_env_generator_paths,
+                        [RUNTIME_SCOPE_USER]   = user_env_generator_paths,
+                }
+        };
+
+        _cleanup_strv_free_ char **paths = NULL;
+        int r;
+
+        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER));
+
+        const char *env_name = ASSERT_PTR((env_generator ? environment_generator : unit_generator).env_name);
+        const char * const *generator_paths = ASSERT_PTR((env_generator ? environment_generator : unit_generator).paths[scope]);
+
+        /* First priority is whatever has been passed to us via env vars */
+        r = get_paths_from_environ(env_name, &paths);
+        if (r < 0)
+                return NULL;
+
+        if (!paths || r > 0) {
+                r = strv_extend_strv(&paths, (char* const*) generator_paths, /* filter_duplicates = */ true);
+                if (r < 0)
+                        return NULL;
+        }
+
+        return TAKE_PTR(paths);
+}
diff --git a/src/basic/path-lookup.h b/src/libsystemd/sd-path/path-lookup.h
similarity index 69%
rename from src/basic/path-lookup.h
rename to src/libsystemd/sd-path/path-lookup.h
index 0db2c5a98c..819c4cdb15 100644
--- a/src/basic/path-lookup.h
+++ b/src/libsystemd/sd-path/path-lookup.h
@@ -3,8 +3,8 @@
 
 #include <stdbool.h>
 
-#include "constants.h"
-#include "macro.h"
+#include "sd-path.h"
+
 #include "runtime-scope.h"
 
 typedef enum LookupPathsFlags {
@@ -55,23 +55,32 @@ typedef struct LookupPaths {
 int lookup_paths_init(LookupPaths *lp, RuntimeScope scope, LookupPathsFlags flags, const char *root_dir);
 int lookup_paths_init_or_warn(LookupPaths *lp, RuntimeScope scope, LookupPathsFlags flags, const char *root_dir);
 
-int xdg_user_dirs(char ***ret_config_dirs, char ***ret_data_dirs);
-int xdg_user_runtime_dir(char **ret, const char *suffix);
-int xdg_user_config_dir(char **ret, const char *suffix);
-int xdg_user_data_dir(char **ret, const char *suffix);
-int runtime_directory(char **ret, RuntimeScope scope, const char *suffix);
+void lookup_paths_log(LookupPaths *p);
+void lookup_paths_done(LookupPaths *p);
+
+int runtime_directory(RuntimeScope scope, const char *suffix, char **ret);
+
+/* We don't treat /etc/xdg/systemd/ in these functions as the xdg base dir spec suggests because we assume
+ * that is a link to /etc/systemd/ anyway. */
+
+int user_search_dirs(const char *suffix, char ***ret_config_dirs, char ***ret_data_dirs);
+static inline int xdg_user_runtime_dir(const char *suffix, char **ret) {
+        return sd_path_lookup(SD_PATH_USER_RUNTIME, suffix, ret);
+}
+static inline int xdg_user_config_dir(const char *suffix, char **ret) {
+        return sd_path_lookup(SD_PATH_USER_CONFIGURATION, suffix, ret);
+}
+static inline int xdg_user_data_dir(const char *suffix, char **ret) {
+        return sd_path_lookup(SD_PATH_USER_SHARED, suffix, ret);
+}
 
 bool path_is_user_data_dir(const char *path);
 bool path_is_user_config_dir(const char *path);
 
-void lookup_paths_log(LookupPaths *p);
-void lookup_paths_done(LookupPaths *p);
-
-char **generator_binary_paths(RuntimeScope scope);
-char **env_generator_binary_paths(RuntimeScope scope);
-
-#define NETWORK_DIRS ((const char* const*) CONF_PATHS_STRV("systemd/network"))
-#define NETWORK_DIRS_NULSTR CONF_PATHS_NULSTR("systemd/network")
-
-#define PORTABLE_PROFILE_DIRS CONF_PATHS_NULSTR("systemd/portable/profile")
-int find_portable_profile(const char *name, const char *unit, char **ret_path);
+char** generator_binary_paths_internal(RuntimeScope scope, bool env_generator);
+static inline char** generator_binary_paths(RuntimeScope runtime_scope) {
+        return generator_binary_paths_internal(runtime_scope, false);
+}
+static inline char** env_generator_binary_paths(RuntimeScope runtime_scope) {
+        return generator_binary_paths_internal(runtime_scope, true);
+}
diff --git a/src/libsystemd/sd-path/sd-path.c b/src/libsystemd/sd-path/sd-path.c
index ebeeec1194..9f495f3051 100644
--- a/src/libsystemd/sd-path/sd-path.c
+++ b/src/libsystemd/sd-path/sd-path.c
@@ -7,6 +7,7 @@
 #include "fd-util.h"
 #include "fileio.h"
 #include "fs-util.h"
+#include "network-util.h"
 #include "nulstr-util.h"
 #include "path-lookup.h"
 #include "path-util.h"
@@ -580,25 +581,16 @@ static int get_search(uint64_t type, char ***ret) {
         }
 
         case SD_PATH_SYSTEMD_SEARCH_SYSTEM_GENERATOR:
-        case SD_PATH_SYSTEMD_SEARCH_USER_GENERATOR: {
-                RuntimeScope scope = type == SD_PATH_SYSTEMD_SEARCH_SYSTEM_GENERATOR ?
-                        RUNTIME_SCOPE_SYSTEM : RUNTIME_SCOPE_USER;
-                char **t;
-
-                t = generator_binary_paths(scope);
-                if (!t)
-                        return -ENOMEM;
-
-                *ret = t;
-                return 0;
-        }
-
+        case SD_PATH_SYSTEMD_SEARCH_USER_GENERATOR:
         case SD_PATH_SYSTEMD_SEARCH_SYSTEM_ENVIRONMENT_GENERATOR:
         case SD_PATH_SYSTEMD_SEARCH_USER_ENVIRONMENT_GENERATOR: {
-                char **t;
+                RuntimeScope scope = IN_SET(type, SD_PATH_SYSTEMD_SEARCH_SYSTEM_GENERATOR,
+                                                  SD_PATH_SYSTEMD_SEARCH_SYSTEM_ENVIRONMENT_GENERATOR) ?
+                                     RUNTIME_SCOPE_SYSTEM : RUNTIME_SCOPE_USER;
+                bool env_generator = IN_SET(type, SD_PATH_SYSTEMD_SEARCH_SYSTEM_ENVIRONMENT_GENERATOR,
+                                                  SD_PATH_SYSTEMD_SEARCH_USER_ENVIRONMENT_GENERATOR);
 
-                t = env_generator_binary_paths(type == SD_PATH_SYSTEMD_SEARCH_SYSTEM_ENVIRONMENT_GENERATOR ?
-                                               RUNTIME_SCOPE_SYSTEM : RUNTIME_SCOPE_USER);
+                char **t = generator_binary_paths_internal(scope, env_generator);
                 if (!t)
                         return -ENOMEM;
 
diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index 53f74f6e8b..8e58a1ae12 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -29,6 +29,7 @@
 #include "netdevsim.h"
 #include "netif-util.h"
 #include "netlink-util.h"
+#include "network-util.h"
 #include "networkd-manager.h"
 #include "networkd-queue.h"
 #include "networkd-setlink.h"
diff --git a/src/network/networkctl-config-file.c b/src/network/networkctl-config-file.c
index eeddfb2281..7ef7668f30 100644
--- a/src/network/networkctl-config-file.c
+++ b/src/network/networkctl-config-file.c
@@ -15,6 +15,7 @@
 #include "edit-util.h"
 #include "mkdir-label.h"
 #include "netlink-util.h"
+#include "network-util.h"
 #include "networkctl.h"
 #include "networkctl-config-file.h"
 #include "networkctl-util.h"
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index b6d34c4a9c..1fff264036 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -15,6 +15,7 @@
 #include "in-addr-util.h"
 #include "net-condition.h"
 #include "netdev/macvlan.h"
+#include "network-util.h"
 #include "networkd-address-label.h"
 #include "networkd-address.h"
 #include "networkd-bridge-fdb.h"
diff --git a/src/portable/portable.c b/src/portable/portable.c
index f0c508c306..b1055aa8c3 100644
--- a/src/portable/portable.c
+++ b/src/portable/portable.c
@@ -32,6 +32,7 @@
 #include "os-util.h"
 #include "path-lookup.h"
 #include "portable.h"
+#include "portable-util.h"
 #include "process-util.h"
 #include "rm-rf.h"
 #include "selinux-util.h"
diff --git a/src/shared/meson.build b/src/shared/meson.build
index 8fc39429e5..e759293364 100644
--- a/src/shared/meson.build
+++ b/src/shared/meson.build
@@ -144,6 +144,7 @@ shared_sources = files(
         'pkcs11-util.c',
         'plymouth-util.c',
         'polkit-agent.c',
+        'portable-util.c',
         'pretty-print.c',
         'capsule-util.c',
         'ptyfwd.c',
@@ -170,6 +171,7 @@ shared_sources = files(
         'tpm2-util.c',
         'tpm2-event-log.c',
         'udev-util.c',
+        'unit-file.c',
         'user-record-nss.c',
         'user-record-show.c',
         'user-record.c',
diff --git a/src/shared/portable-util.c b/src/shared/portable-util.c
new file mode 100644
index 0000000000..85c128a1b4
--- /dev/null
+++ b/src/shared/portable-util.c
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "fs-util.h"
+#include "nulstr-util.h"
+#include "portable-util.h"
+#include "string-util.h"
+
+int find_portable_profile(const char *name, const char *unit, char **ret_path) {
+        const char *dot;
+        int r;
+
+        assert(name);
+        assert(ret_path);
+
+        assert_se(dot = strrchr(unit, '.'));
+
+        NULSTR_FOREACH(p, PORTABLE_PROFILE_DIRS) {
+                _cleanup_free_ char *joined = NULL;
+
+                joined = strjoin(p, "/", name, "/", dot + 1, ".conf");
+                if (!joined)
+                        return -ENOMEM;
+
+                r = access_nofollow(joined, F_OK);
+                if (r >= 0) {
+                        *ret_path = TAKE_PTR(joined);
+                        return 0;
+                }
+                if (r != -ENOENT)
+                        return r;
+        }
+
+        return -ENOENT;
+}
diff --git a/src/shared/portable-util.h b/src/shared/portable-util.h
new file mode 100644
index 0000000000..2c89fe3eb8
--- /dev/null
+++ b/src/shared/portable-util.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "constants.h"
+#include "macro.h"
+
+#define PORTABLE_PROFILE_DIRS CONF_PATHS_NULSTR("systemd/portable/profile")
+
+int find_portable_profile(const char *name, const char *unit, char **ret_path);
diff --git a/src/basic/unit-file.c b/src/shared/unit-file.c
similarity index 98%
rename from src/basic/unit-file.c
rename to src/shared/unit-file.c
index ca2686b209..5bb580285c 100644
--- a/src/basic/unit-file.c
+++ b/src/shared/unit-file.c
@@ -16,25 +16,6 @@
 #include "strv.h"
 #include "unit-file.h"
 
-bool unit_type_may_alias(UnitType type) {
-        return IN_SET(type,
-                      UNIT_SERVICE,
-                      UNIT_SOCKET,
-                      UNIT_TARGET,
-                      UNIT_DEVICE,
-                      UNIT_TIMER,
-                      UNIT_PATH);
-}
-
-bool unit_type_may_template(UnitType type) {
-        return IN_SET(type,
-                      UNIT_SERVICE,
-                      UNIT_SOCKET,
-                      UNIT_TARGET,
-                      UNIT_TIMER,
-                      UNIT_PATH);
-}
-
 int unit_symlink_name_compatible(const char *symlink, const char *target, bool instance_propagation) {
         _cleanup_free_ char *template = NULL;
         int r, un_type1, un_type2;
diff --git a/src/basic/unit-file.h b/src/shared/unit-file.h
similarity index 76%
rename from src/basic/unit-file.h
rename to src/shared/unit-file.h
index 1c43861f00..1c89a92c7d 100644
--- a/src/basic/unit-file.h
+++ b/src/shared/unit-file.h
@@ -28,8 +28,24 @@ enum UnitFileState {
         _UNIT_FILE_STATE_INVALID = -EINVAL,
 };
 
-bool unit_type_may_alias(UnitType type) _const_;
-bool unit_type_may_template(UnitType type) _const_;
+static inline bool unit_type_may_alias(UnitType type) {
+        return IN_SET(type,
+                      UNIT_SERVICE,
+                      UNIT_SOCKET,
+                      UNIT_TARGET,
+                      UNIT_DEVICE,
+                      UNIT_TIMER,
+                      UNIT_PATH);
+}
+
+static inline bool unit_type_may_template(UnitType type) {
+        return IN_SET(type,
+                      UNIT_SERVICE,
+                      UNIT_SOCKET,
+                      UNIT_TARGET,
+                      UNIT_TIMER,
+                      UNIT_PATH);
+}
 
 int unit_symlink_name_compatible(const char *symlink, const char *target, bool instance_propagation);
 int unit_validate_alias_symlink_or_warn(int log_level, const char *filename, const char *target);
diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index a7655aad1c..421e465d71 100644
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -349,49 +349,35 @@ static int log_unresolvable_specifier(const char *filename, unsigned line) {
                  arg_dry_run ? (would) : (doing),       \
                  __VA_ARGS__)
 
-static int user_config_paths(char*** ret) {
+static int user_config_paths(char ***ret) {
         _cleanup_strv_free_ char **config_dirs = NULL, **data_dirs = NULL;
-        _cleanup_free_ char *persistent_config = NULL, *runtime_config = NULL, *data_home = NULL;
-        _cleanup_strv_free_ char **res = NULL;
+        _cleanup_free_ char *runtime_config = NULL;
         int r;
 
-        r = xdg_user_dirs(&config_dirs, &data_dirs);
+        assert(ret);
+
+        /* Combined user-specific and global dirs */
+        r = user_search_dirs("/user-tmpfiles.d", &config_dirs, &data_dirs);
         if (r < 0)
                 return r;
 
-        r = xdg_user_config_dir(&persistent_config, "/user-tmpfiles.d");
+        r = xdg_user_runtime_dir("/user-tmpfiles.d", &runtime_config);
         if (r < 0 && !ERRNO_IS_NEG_NOINFO(r))
                 return r;
 
-        r = xdg_user_runtime_dir(&runtime_config, "/user-tmpfiles.d");
-        if (r < 0 && !ERRNO_IS_NEG_NOINFO(r))
-                return r;
-
-        r = xdg_user_data_dir(&data_home, "/user-tmpfiles.d");
-        if (r < 0 && !ERRNO_IS_NEG_NOINFO(r))
-                return r;
-
-        r = strv_extend_strv_concat(&res, (const char* const*) config_dirs, "/user-tmpfiles.d");
+        r = strv_consume(&config_dirs, TAKE_PTR(runtime_config));
         if (r < 0)
                 return r;
 
-        r = strv_extend_many(
-                        &res,
-                        persistent_config,
-                        runtime_config,
-                        data_home);
+        r = strv_extend_strv_consume(&config_dirs, TAKE_PTR(data_dirs), /* filter_duplicates = */ true);
         if (r < 0)
                 return r;
 
-        r = strv_extend_strv_concat(&res, (const char* const*) data_dirs, "/user-tmpfiles.d");
+        r = path_strv_make_absolute_cwd(config_dirs);
         if (r < 0)
                 return r;
 
-        r = path_strv_make_absolute_cwd(res);
-        if (r < 0)
-                return r;
-
-        *ret = TAKE_PTR(res);
+        *ret = TAKE_PTR(config_dirs);
         return 0;
 }
 
diff --git a/src/udev/net/link-config.c b/src/udev/net/link-config.c
index 645c7f840a..edfbb38ad8 100644
--- a/src/udev/net/link-config.c
+++ b/src/udev/net/link-config.c
@@ -27,6 +27,7 @@
 #include "netif-sriov.h"
 #include "netif-util.h"
 #include "netlink-util.h"
+#include "network-util.h"
 #include "parse-util.h"
 #include "path-lookup.h"
 #include "path-util.h"
diff --git a/src/vmspawn/vmspawn-util.c b/src/vmspawn/vmspawn-util.c
index 8a6122dd9d..22cfa289fa 100644
--- a/src/vmspawn/vmspawn-util.c
+++ b/src/vmspawn/vmspawn-util.c
@@ -212,7 +212,7 @@ static int get_firmware_search_dirs(char ***ret) {
          * Prioritising entries in "more specific" directories */
 
         _cleanup_free_ char *user_firmware_dir = NULL;
-        r = xdg_user_config_dir(&user_firmware_dir, "/qemu/firmware");
+        r = xdg_user_config_dir("/qemu/firmware", &user_firmware_dir);
         if (r < 0)
                 return r;
 
diff --git a/src/vmspawn/vmspawn.c b/src/vmspawn/vmspawn.c
index 7474b301f3..9d7f943200 100644
--- a/src/vmspawn/vmspawn.c
+++ b/src/vmspawn/vmspawn.c
@@ -1488,11 +1488,11 @@ static int run_virtual_machine(int kvm_device_fd, int vhost_device_fd) {
 
         /* if we are going to be starting any units with state then create our runtime dir */
         if (arg_tpm != 0 || arg_directory || arg_runtime_mounts.n_mounts != 0) {
-                r = runtime_directory(&arg_runtime_directory, arg_privileged ? RUNTIME_SCOPE_SYSTEM : RUNTIME_SCOPE_USER, "systemd/vmspawn");
+                r = runtime_directory(arg_privileged ? RUNTIME_SCOPE_SYSTEM : RUNTIME_SCOPE_USER, "systemd/vmspawn",
+                                      &arg_runtime_directory);
                 if (r < 0)
                         return log_error_errno(r, "Failed to lookup runtime directory: %m");
-                if (r) {
-                        /* r > 0 means we need to create our own runtime dir */
+                if (r > 0) { /* We need to create our own runtime dir */
                         r = mkdir_p(arg_runtime_directory, 0755);
                         if (r < 0)
                                 return log_error_errno(r, "Failed to create runtime directory: %m");
diff --git a/src/xdg-autostart-generator/xdg-autostart-generator.c b/src/xdg-autostart-generator/xdg-autostart-generator.c
index 71e1a66435..47252c2e36 100644
--- a/src/xdg-autostart-generator/xdg-autostart-generator.c
+++ b/src/xdg-autostart-generator/xdg-autostart-generator.c
@@ -20,6 +20,39 @@
 
 DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(xdgautostartservice_hash_ops, char, string_hash_func, string_compare_func, XdgAutostartService, xdg_autostart_service_free);
 
+static int xdg_base_dirs(char ***ret_config_dirs, char ***ret_data_dirs) {
+        _cleanup_strv_free_ char **config_dirs = NULL, **data_dirs = NULL;
+        const char *e;
+
+        /* Implement the mechanisms defined in
+         * https://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html */
+
+        assert(ret_config_dirs);
+        assert(ret_data_dirs);
+
+        e = getenv("XDG_CONFIG_DIRS");
+        if (e)
+                config_dirs = strv_split(e, ":");
+        else
+                config_dirs = strv_new("/etc/xdg");
+        if (!config_dirs)
+                return -ENOMEM;
+
+        e = getenv("XDG_DATA_DIRS");
+        if (e)
+                data_dirs = strv_split(e, ":");
+        else
+                data_dirs = strv_new("/usr/local/share",
+                                     "/usr/share");
+        if (!data_dirs)
+                return -ENOMEM;
+
+        *ret_config_dirs = TAKE_PTR(config_dirs);
+        *ret_data_dirs = TAKE_PTR(data_dirs);
+
+        return 0;
+}
+
 static int enumerate_xdg_autostart(Hashmap *all_services) {
         _cleanup_strv_free_ char **autostart_dirs = NULL;
         _cleanup_strv_free_ char **config_dirs = NULL;
@@ -27,14 +60,14 @@ static int enumerate_xdg_autostart(Hashmap *all_services) {
         _cleanup_free_ char *user_config_autostart_dir = NULL;
         int r;
 
-        r = xdg_user_config_dir(&user_config_autostart_dir, "/autostart");
+        r = xdg_user_config_dir("/autostart", &user_config_autostart_dir);
         if (r < 0)
                 return r;
         r = strv_extend(&autostart_dirs, user_config_autostart_dir);
         if (r < 0)
                 return r;
 
-        r = xdg_user_dirs(&config_dirs, &data_dirs);
+        r = xdg_base_dirs(&config_dirs, &data_dirs);
         if (r < 0)
                 return r;
         r = strv_extend_strv_concat(&autostart_dirs, (const char* const*) config_dirs, "/autostart");