Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3033 insertions, 0 deletions

diff --git a/src/libsystemd/sd-bus/bus-objects.c b/src/libsystemd/sd-bus/bus-objects.c
new file mode 100644
index 0000000..c25c40f
--- /dev/null
+++ b/src/libsystemd/sd-bus/bus-objects.c
@@ -0,0 +1,3033 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "alloc-util.h"
+#include "bus-internal.h"
+#include "bus-introspect.h"
+#include "bus-message.h"
+#include "bus-objects.h"
+#include "bus-signature.h"
+#include "bus-slot.h"
+#include "bus-type.h"
+#include "missing_capability.h"
+#include "string-util.h"
+#include "strv.h"
+
+static int node_vtable_get_userdata(
+                sd_bus *bus,
+                const char *path,
+                struct node_vtable *c,
+                void **userdata,
+                sd_bus_error *error) {
+
+        sd_bus_slot *s;
+        void *u, *found_u = NULL;
+        int r;
+
+        assert(bus);
+        assert(path);
+        assert(c);
+
+        s = container_of(c, sd_bus_slot, node_vtable);
+        u = s->userdata;
+        if (c->find) {
+                bus->current_slot = sd_bus_slot_ref(s);
+                bus->current_userdata = u;
+                r = c->find(bus, path, c->interface, u, &found_u, error);
+                bus->current_userdata = NULL;
+                bus->current_slot = sd_bus_slot_unref(s);
+
+                if (r < 0)
+                        return r;
+                if (sd_bus_error_is_set(error))
+                        return -sd_bus_error_get_errno(error);
+                if (r == 0)
+                        return r;
+        } else
+                found_u = u;
+
+        if (userdata)
+                *userdata = found_u;
+
+        return 1;
+}
+
+static void *vtable_method_convert_userdata(const sd_bus_vtable *p, void *u) {
+        assert(p);
+
+        if (!u || FLAGS_SET(p->flags, SD_BUS_VTABLE_ABSOLUTE_OFFSET))
+                return SIZE_TO_PTR(p->x.method.offset); /* don't add offset on NULL, to make ubsan happy */
+
+        return (uint8_t*) u + p->x.method.offset;
+}
+
+static void *vtable_property_convert_userdata(const sd_bus_vtable *p, void *u) {
+        assert(p);
+
+        if (!u || FLAGS_SET(p->flags, SD_BUS_VTABLE_ABSOLUTE_OFFSET))
+                return SIZE_TO_PTR(p->x.property.offset); /* as above */
+
+        return (uint8_t*) u + p->x.property.offset;
+}
+
+static int vtable_property_get_userdata(
+                sd_bus *bus,
+                const char *path,
+                struct vtable_member *p,
+                void **userdata,
+                sd_bus_error *error) {
+
+        void *u;
+        int r;
+
+        assert(bus);
+        assert(path);
+        assert(p);
+        assert(userdata);
+
+        r = node_vtable_get_userdata(bus, path, p->parent, &u, error);
+        if (r <= 0)
+                return r;
+        if (bus->nodes_modified)
+                return 0;
+
+        *userdata = vtable_property_convert_userdata(p->vtable, u);
+        return 1;
+}
+
+static int add_enumerated_to_set(
+                sd_bus *bus,
+                const char *prefix,
+                struct node_enumerator *first,
+                OrderedSet *s,
+                sd_bus_error *error) {
+
+        int r;
+
+        assert(bus);
+        assert(prefix);
+        assert(s);
+
+        LIST_FOREACH(enumerators, c, first) {
+                char **children = NULL;
+                sd_bus_slot *slot;
+
+                if (bus->nodes_modified)
+                        return 0;
+
+                slot = container_of(c, sd_bus_slot, node_enumerator);
+
+                bus->current_slot = sd_bus_slot_ref(slot);
+                bus->current_userdata = slot->userdata;
+                r = c->callback(bus, prefix, slot->userdata, &children, error);
+                bus->current_userdata = NULL;
+                bus->current_slot = sd_bus_slot_unref(slot);
+
+                if (r < 0)
+                        return r;
+                if (sd_bus_error_is_set(error))
+                        return -sd_bus_error_get_errno(error);
+
+                STRV_FOREACH(k, children) {
+                        if (r < 0) {
+                                free(*k);
+                                continue;
+                        }
+
+                        if (!object_path_is_valid(*k)) {
+                                free(*k);
+                                r = -EINVAL;
+                                continue;
+                        }
+
+                        if (!object_path_startswith(*k, prefix)) {
+                                free(*k);
+                                continue;
+                        }
+
+                        r = ordered_set_consume(s, *k);
+                        if (r == -EEXIST)
+                                r = 0;
+                }
+
+                free(children);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+enum {
+        /* if set, add_subtree() works recursively */
+        CHILDREN_RECURSIVE      = 1 << 0,
+        /* if set, add_subtree() scans object-manager hierarchies recursively */
+        CHILDREN_SUBHIERARCHIES = 1 << 1,
+};
+
+static int add_subtree_to_set(
+                sd_bus *bus,
+                const char *prefix,
+                struct node *n,
+                unsigned flags,
+                OrderedSet *s,
+                sd_bus_error *error) {
+
+        int r;
+
+        assert(bus);
+        assert(prefix);
+        assert(n);
+        assert(s);
+
+        r = add_enumerated_to_set(bus, prefix, n->enumerators, s, error);
+        if (r < 0)
+                return r;
+        if (bus->nodes_modified)
+                return 0;
+
+        LIST_FOREACH(siblings, i, n->child) {
+                char *t;
+
+                if (!object_path_startswith(i->path, prefix))
+                        continue;
+
+                t = strdup(i->path);
+                if (!t)
+                        return -ENOMEM;
+
+                r = ordered_set_consume(s, t);
+                if (r < 0 && r != -EEXIST)
+                        return r;
+
+                if ((flags & CHILDREN_RECURSIVE) &&
+                    ((flags & CHILDREN_SUBHIERARCHIES) || !i->object_managers)) {
+                        r = add_subtree_to_set(bus, prefix, i, flags, s, error);
+                        if (r < 0)
+                                return r;
+                        if (bus->nodes_modified)
+                                return 0;
+                }
+        }
+
+        return 0;
+}
+
+static int get_child_nodes(
+                sd_bus *bus,
+                const char *prefix,
+                struct node *n,
+                unsigned flags,
+                OrderedSet **ret,
+                sd_bus_error *error) {
+
+        _cleanup_ordered_set_free_free_ OrderedSet *s = NULL;
+        int r;
+
+        assert(bus);
+        assert(prefix);
+        assert(n);
+        assert(ret);
+
+        s = ordered_set_new(&string_hash_ops);
+        if (!s)
+                return -ENOMEM;
+
+        r = add_subtree_to_set(bus, prefix, n, flags, s, error);
+        if (r < 0)
+                return r;
+
+        *ret = TAKE_PTR(s);
+        return 0;
+}
+
+static int node_callbacks_run(
+                sd_bus *bus,
+                sd_bus_message *m,
+                struct node_callback *first,
+                bool require_fallback,
+                bool *found_object) {
+
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(found_object);
+
+        LIST_FOREACH(callbacks, c, first) {
+                _cleanup_(sd_bus_error_free) sd_bus_error error_buffer = SD_BUS_ERROR_NULL;
+                sd_bus_slot *slot;
+
+                if (bus->nodes_modified)
+                        return 0;
+
+                if (require_fallback && !c->is_fallback)
+                        continue;
+
+                *found_object = true;
+
+                if (c->last_iteration == bus->iteration_counter)
+                        continue;
+
+                c->last_iteration = bus->iteration_counter;
+
+                r = sd_bus_message_rewind(m, true);
+                if (r < 0)
+                        return r;
+
+                slot = container_of(c, sd_bus_slot, node_callback);
+
+                bus->current_slot = sd_bus_slot_ref(slot);
+                bus->current_handler = c->callback;
+                bus->current_userdata = slot->userdata;
+                r = c->callback(m, slot->userdata, &error_buffer);
+                bus->current_userdata = NULL;
+                bus->current_handler = NULL;
+                bus->current_slot = sd_bus_slot_unref(slot);
+
+                r = bus_maybe_reply_error(m, r, &error_buffer);
+                if (r != 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+#define CAPABILITY_SHIFT(x) (((x) >> __builtin_ctzll(_SD_BUS_VTABLE_CAPABILITY_MASK)) & 0xFFFF)
+
+static int check_access(sd_bus *bus, sd_bus_message *m, struct vtable_member *c, sd_bus_error *error) {
+        uint64_t cap;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(c);
+
+        /* If the entire bus is trusted let's grant access */
+        if (bus->trusted)
+                return 0;
+
+        /* If the member is marked UNPRIVILEGED let's grant access */
+        if (c->vtable->flags & SD_BUS_VTABLE_UNPRIVILEGED)
+                return 0;
+
+        /* Check that the caller has the requested capability set. Note that the flags value contains the
+         * capability number plus one, which we need to subtract here. We do this so that we have 0 as
+         * special value for the default. */
+        cap = CAPABILITY_SHIFT(c->vtable->flags);
+        if (cap == 0)
+                cap = CAPABILITY_SHIFT(c->parent->vtable[0].flags);
+        if (cap == 0)
+                cap = CAP_SYS_ADMIN;
+        else
+                cap--;
+
+        r = sd_bus_query_sender_privilege(m, cap);
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return 0;
+
+        return sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Access to %s.%s() not permitted.", c->interface, c->member);
+}
+
+static int method_callbacks_run(
+                sd_bus *bus,
+                sd_bus_message *m,
+                struct vtable_member *c,
+                bool require_fallback,
+                bool *found_object) {
+
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        const char *signature;
+        void *u;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(c);
+        assert(found_object);
+
+        if (require_fallback && !c->parent->is_fallback)
+                return 0;
+
+        if (FLAGS_SET(c->vtable->flags, SD_BUS_VTABLE_SENSITIVE)) {
+                r = sd_bus_message_sensitive(m);
+                if (r < 0)
+                        return r;
+        }
+
+        r = check_access(bus, m, c, &error);
+        if (r < 0)
+                return bus_maybe_reply_error(m, r, &error);
+
+        r = node_vtable_get_userdata(bus, m->path, c->parent, &u, &error);
+        if (r <= 0)
+                return bus_maybe_reply_error(m, r, &error);
+        if (bus->nodes_modified)
+                return 0;
+
+        u = vtable_method_convert_userdata(c->vtable, u);
+
+        *found_object = true;
+
+        if (c->last_iteration == bus->iteration_counter)
+                return 0;
+
+        c->last_iteration = bus->iteration_counter;
+
+        r = sd_bus_message_rewind(m, true);
+        if (r < 0)
+                return r;
+
+        signature = sd_bus_message_get_signature(m, true);
+        if (!signature)
+                return -EINVAL;
+
+        if (!streq(strempty(c->vtable->x.method.signature), signature))
+                return sd_bus_reply_method_errorf(
+                                m,
+                                SD_BUS_ERROR_INVALID_ARGS,
+                                "Invalid arguments '%s' to call %s.%s(), expecting '%s'.",
+                                signature, c->interface, c->member, strempty(c->vtable->x.method.signature));
+
+        /* Keep track what the signature of the reply to this message
+         * should be, so that this can be enforced when sealing the
+         * reply. */
+        m->enforced_reply_signature = strempty(c->vtable->x.method.result);
+
+        if (c->vtable->x.method.handler) {
+                sd_bus_slot *slot;
+
+                slot = container_of(c->parent, sd_bus_slot, node_vtable);
+
+                bus->current_slot = sd_bus_slot_ref(slot);
+                bus->current_handler = c->vtable->x.method.handler;
+                bus->current_userdata = u;
+                r = c->vtable->x.method.handler(m, u, &error);
+                bus->current_userdata = NULL;
+                bus->current_handler = NULL;
+                bus->current_slot = sd_bus_slot_unref(slot);
+
+                return bus_maybe_reply_error(m, r, &error);
+        }
+
+        /* If the method callback is NULL, make this a successful NOP */
+        r = sd_bus_reply_method_return(m, NULL);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+static int invoke_property_get(
+                sd_bus *bus,
+                sd_bus_slot *slot,
+                const sd_bus_vtable *v,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        const void *p;
+        int r;
+
+        assert(bus);
+        assert(slot);
+        assert(v);
+        assert(path);
+        assert(interface);
+        assert(property);
+        assert(reply);
+
+        if (v->x.property.get) {
+
+                bus->current_slot = sd_bus_slot_ref(slot);
+                bus->current_userdata = userdata;
+                r = v->x.property.get(bus, path, interface, property, reply, userdata, error);
+                bus->current_userdata = NULL;
+                bus->current_slot = sd_bus_slot_unref(slot);
+
+                if (r < 0)
+                        return r;
+                if (sd_bus_error_is_set(error))
+                        return -sd_bus_error_get_errno(error);
+                return r;
+        }
+
+        /* Automatic handling if no callback is defined. */
+
+        if (streq(v->x.property.signature, "as"))
+                return sd_bus_message_append_strv(reply, *(char***) userdata);
+
+        assert(signature_is_single(v->x.property.signature, false));
+        assert(bus_type_is_basic(v->x.property.signature[0]));
+
+        switch (v->x.property.signature[0]) {
+
+        case SD_BUS_TYPE_STRING:
+        case SD_BUS_TYPE_SIGNATURE:
+                p = strempty(*(char**) userdata);
+                break;
+
+        case SD_BUS_TYPE_OBJECT_PATH:
+                p = *(char**) userdata;
+                assert(p);
+                break;
+
+        default:
+                p = userdata;
+                break;
+        }
+
+        return sd_bus_message_append_basic(reply, v->x.property.signature[0], p);
+}
+
+static int invoke_property_set(
+                sd_bus *bus,
+                sd_bus_slot *slot,
+                const sd_bus_vtable *v,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *value,
+                void *userdata,
+                sd_bus_error *error) {
+
+        int r;
+
+        assert(bus);
+        assert(slot);
+        assert(v);
+        assert(path);
+        assert(interface);
+        assert(property);
+        assert(value);
+
+        if (v->x.property.set) {
+
+                bus->current_slot = sd_bus_slot_ref(slot);
+                bus->current_userdata = userdata;
+                r = v->x.property.set(bus, path, interface, property, value, userdata, error);
+                bus->current_userdata = NULL;
+                bus->current_slot = sd_bus_slot_unref(slot);
+
+                if (r < 0)
+                        return r;
+                if (sd_bus_error_is_set(error))
+                        return -sd_bus_error_get_errno(error);
+                return r;
+        }
+
+        /*  Automatic handling if no callback is defined. */
+
+        assert(signature_is_single(v->x.property.signature, false));
+        assert(bus_type_is_basic(v->x.property.signature[0]));
+
+        switch (v->x.property.signature[0]) {
+
+        case SD_BUS_TYPE_STRING:
+        case SD_BUS_TYPE_OBJECT_PATH:
+        case SD_BUS_TYPE_SIGNATURE: {
+                const char *p;
+                char *n;
+
+                r = sd_bus_message_read_basic(value, v->x.property.signature[0], &p);
+                if (r < 0)
+                        return r;
+
+                n = strdup(p);
+                if (!n)
+                        return -ENOMEM;
+
+                free(*(char**) userdata);
+                *(char**) userdata = n;
+
+                break;
+        }
+
+        default:
+                r = sd_bus_message_read_basic(value, v->x.property.signature[0], userdata);
+                if (r < 0)
+                        return r;
+
+                break;
+        }
+
+        return 1;
+}
+
+static int property_get_set_callbacks_run(
+                sd_bus *bus,
+                sd_bus_message *m,
+                struct vtable_member *c,
+                bool require_fallback,
+                bool is_get,
+                bool *found_object) {
+
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        sd_bus_slot *slot;
+        void *u = NULL;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(c);
+        assert(found_object);
+
+        if (require_fallback && !c->parent->is_fallback)
+                return 0;
+
+        if (FLAGS_SET(c->vtable->flags, SD_BUS_VTABLE_SENSITIVE)) {
+                r = sd_bus_message_sensitive(m);
+                if (r < 0)
+                        return r;
+        }
+
+        r = vtable_property_get_userdata(bus, m->path, c, &u, &error);
+        if (r <= 0)
+                return bus_maybe_reply_error(m, r, &error);
+        if (bus->nodes_modified)
+                return 0;
+
+        slot = container_of(c->parent, sd_bus_slot, node_vtable);
+
+        *found_object = true;
+
+        r = sd_bus_message_new_method_return(m, &reply);
+        if (r < 0)
+                return r;
+
+        if (FLAGS_SET(c->vtable->flags, SD_BUS_VTABLE_SENSITIVE)) {
+                r = sd_bus_message_sensitive(reply);
+                if (r < 0)
+                        return r;
+        }
+
+        if (is_get) {
+                /* Note that we do not protect against reexecution
+                 * here (using the last_iteration check, see below),
+                 * should the node tree have changed and we got called
+                 * again. We assume that property Get() calls are
+                 * ultimately without side-effects or if they aren't
+                 * then at least idempotent. */
+
+                r = sd_bus_message_open_container(reply, 'v', c->vtable->x.property.signature);
+                if (r < 0)
+                        return r;
+
+                /* Note that we do not do an access check here. Read
+                 * access to properties is always unrestricted, since
+                 * PropertiesChanged signals broadcast contents
+                 * anyway. */
+
+                r = invoke_property_get(bus, slot, c->vtable, m->path, c->interface, c->member, reply, u, &error);
+                if (r < 0)
+                        return bus_maybe_reply_error(m, r, &error);
+
+                if (bus->nodes_modified)
+                        return 0;
+
+                r = sd_bus_message_close_container(reply);
+                if (r < 0)
+                        return r;
+
+        } else {
+                const char *signature = NULL;
+                char type = 0;
+
+                if (c->vtable->type != _SD_BUS_VTABLE_WRITABLE_PROPERTY)
+                        return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_PROPERTY_READ_ONLY, "Property '%s' is not writable.", c->member);
+
+                /* Avoid that we call the set routine more than once
+                 * if the processing of this message got restarted
+                 * because the node tree changed. */
+                if (c->last_iteration == bus->iteration_counter)
+                        return 0;
+
+                c->last_iteration = bus->iteration_counter;
+
+                r = sd_bus_message_peek_type(m, &type, &signature);
+                if (r < 0)
+                        return r;
+
+                if (type != 'v')
+                        return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_INVALID_SIGNATURE,
+                                                          "Incorrect signature when setting property '%s', expected 'v', got '%c'.",
+                                                          c->member, type);
+                if (!streq(strempty(signature), strempty(c->vtable->x.property.signature)))
+                        return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_INVALID_ARGS,
+                                                          "Incorrect parameters for property '%s', expected '%s', got '%s'.",
+                                                          c->member, strempty(c->vtable->x.property.signature), strempty(signature));
+
+                r = sd_bus_message_enter_container(m, 'v', c->vtable->x.property.signature);
+                if (r < 0)
+                        return r;
+
+                r = check_access(bus, m, c, &error);
+                if (r < 0)
+                        return bus_maybe_reply_error(m, r, &error);
+
+                r = invoke_property_set(bus, slot, c->vtable, m->path, c->interface, c->member, m, u, &error);
+                if (r < 0)
+                        return bus_maybe_reply_error(m, r, &error);
+
+                if (bus->nodes_modified)
+                        return 0;
+
+                r = sd_bus_message_exit_container(m);
+                if (r < 0)
+                        return r;
+        }
+
+        r = sd_bus_send(bus, reply, NULL);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+static int vtable_append_one_property(
+                sd_bus *bus,
+                sd_bus_message *reply,
+                const char *path,
+                struct node_vtable *c,
+                const sd_bus_vtable *v,
+                void *userdata,
+                sd_bus_error *error) {
+
+        sd_bus_slot *slot;
+        int r;
+
+        assert(bus);
+        assert(reply);
+        assert(path);
+        assert(c);
+        assert(v);
+
+        if (FLAGS_SET(c->vtable->flags, SD_BUS_VTABLE_SENSITIVE)) {
+                r = sd_bus_message_sensitive(reply);
+                if (r < 0)
+                        return r;
+        }
+
+        r = sd_bus_message_open_container(reply, 'e', "sv");
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append(reply, "s", v->x.property.member);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_open_container(reply, 'v', v->x.property.signature);
+        if (r < 0)
+                return r;
+
+        slot = container_of(c, sd_bus_slot, node_vtable);
+
+        r = invoke_property_get(bus, slot, v, path, c->interface, v->x.property.member, reply, vtable_property_convert_userdata(v, userdata), error);
+        if (r < 0)
+                return r;
+        if (bus->nodes_modified)
+                return 0;
+
+        r = sd_bus_message_close_container(reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_close_container(reply);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+static int vtable_append_all_properties(
+                sd_bus *bus,
+                sd_bus_message *reply,
+                const char *path,
+                struct node_vtable *c,
+                void *userdata,
+                sd_bus_error *error) {
+
+        const sd_bus_vtable *v;
+        int r;
+
+        assert(bus);
+        assert(reply);
+        assert(path);
+        assert(c);
+
+        if (c->vtable[0].flags & SD_BUS_VTABLE_HIDDEN)
+                return 1;
+
+        v = c->vtable;
+        for (v = bus_vtable_next(c->vtable, v); v->type != _SD_BUS_VTABLE_END; v = bus_vtable_next(c->vtable, v)) {
+                if (!IN_SET(v->type, _SD_BUS_VTABLE_PROPERTY, _SD_BUS_VTABLE_WRITABLE_PROPERTY))
+                        continue;
+
+                if (v->flags & SD_BUS_VTABLE_HIDDEN)
+                        continue;
+
+                /* Let's not include properties marked as "explicit" in any message that contains a generic
+                 * dump of properties, but only in those generated as a response to an explicit request. */
+                if (v->flags & SD_BUS_VTABLE_PROPERTY_EXPLICIT)
+                        continue;
+
+                /* Let's not include properties marked only for invalidation on change (i.e. in contrast to
+                 * those whose new values are included in PropertiesChanges message) in any signals. This is
+                 * useful to ensure they aren't included in InterfacesAdded messages. */
+                if (reply->header->type != SD_BUS_MESSAGE_METHOD_RETURN &&
+                    FLAGS_SET(v->flags, SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION))
+                        continue;
+
+                r = vtable_append_one_property(bus, reply, path, c, v, userdata, error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        return 1;
+}
+
+static int property_get_all_callbacks_run(
+                sd_bus *bus,
+                sd_bus_message *m,
+                struct node_vtable *first,
+                bool require_fallback,
+                const char *iface,
+                bool *found_object) {
+
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        bool found_interface;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(found_object);
+
+        r = sd_bus_message_new_method_return(m, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_open_container(reply, 'a', "{sv}");
+        if (r < 0)
+                return r;
+
+        found_interface = !iface || STR_IN_SET(iface,
+                                               "org.freedesktop.DBus.Properties",
+                                               "org.freedesktop.DBus.Peer",
+                                               "org.freedesktop.DBus.Introspectable");
+
+        LIST_FOREACH(vtables, c, first) {
+                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+                void *u;
+
+                if (require_fallback && !c->is_fallback)
+                        continue;
+
+                r = node_vtable_get_userdata(bus, m->path, c, &u, &error);
+                if (r < 0)
+                        return bus_maybe_reply_error(m, r, &error);
+                if (bus->nodes_modified)
+                        return 0;
+                if (r == 0)
+                        continue;
+
+                *found_object = true;
+
+                if (iface && !streq(c->interface, iface))
+                        continue;
+                found_interface = true;
+
+                r = vtable_append_all_properties(bus, reply, m->path, c, u, &error);
+                if (r < 0)
+                        return bus_maybe_reply_error(m, r, &error);
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        if (!*found_object)
+                return 0;
+
+        if (!found_interface) {
+                r = sd_bus_reply_method_errorf(
+                                m,
+                                SD_BUS_ERROR_UNKNOWN_INTERFACE,
+                                "Unknown interface '%s'.", iface);
+                if (r < 0)
+                        return r;
+
+                return 1;
+        }
+
+        r = sd_bus_message_close_container(reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_send(bus, reply, NULL);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+static int bus_node_exists(
+                sd_bus *bus,
+                struct node *n,
+                const char *path,
+                bool require_fallback) {
+
+        int r;
+
+        assert(bus);
+        assert(n);
+        assert(path);
+
+        /* Tests if there's anything attached directly to this node
+         * for the specified path */
+
+        if (!require_fallback && (n->enumerators || n->object_managers))
+                return true;
+
+        LIST_FOREACH(callbacks, k, n->callbacks) {
+                if (require_fallback && !k->is_fallback)
+                        continue;
+
+                return 1;
+        }
+
+        LIST_FOREACH(vtables, c, n->vtables) {
+                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+
+                if (require_fallback && !c->is_fallback)
+                        continue;
+
+                r = node_vtable_get_userdata(bus, path, c, NULL, &error);
+                if (r != 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        return 0;
+}
+
+int introspect_path(
+                sd_bus *bus,
+                const char *path,
+                struct node *n,
+                bool require_fallback,
+                bool ignore_nodes_modified,
+                bool *found_object,
+                char **ret,
+                sd_bus_error *error) {
+
+        _cleanup_ordered_set_free_free_ OrderedSet *s = NULL;
+        _cleanup_(introspect_done) struct introspect intro = {};
+        bool empty;
+        int r;
+
+        if (!n) {
+                n = hashmap_get(bus->nodes, path);
+                if (!n)
+                        return -ENOENT;
+        }
+
+        r = get_child_nodes(bus, path, n, 0, &s, error);
+        if (r < 0)
+                return r;
+        if (bus->nodes_modified && !ignore_nodes_modified)
+                return 0;
+
+        r = introspect_begin(&intro, bus->trusted);
+        if (r < 0)
+                return r;
+
+        r = introspect_write_default_interfaces(&intro, !require_fallback && n->object_managers);
+        if (r < 0)
+                return r;
+
+        empty = ordered_set_isempty(s);
+
+        LIST_FOREACH(vtables, c, n->vtables) {
+                if (require_fallback && !c->is_fallback)
+                        continue;
+
+                r = node_vtable_get_userdata(bus, path, c, NULL, error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified && !ignore_nodes_modified)
+                        return 0;
+                if (r == 0)
+                        continue;
+
+                empty = false;
+
+                if (c->vtable[0].flags & SD_BUS_VTABLE_HIDDEN)
+                        continue;
+
+                r = introspect_write_interface(&intro, c->interface, c->vtable);
+                if (r < 0)
+                        return r;
+        }
+
+        if (empty) {
+                /* Nothing?, let's see if we exist at all, and if not
+                 * refuse to do anything */
+                r = bus_node_exists(bus, n, path, require_fallback);
+                if (r <= 0)
+                        return r;
+                if (bus->nodes_modified && !ignore_nodes_modified)
+                        return 0;
+        }
+
+        if (found_object)
+                *found_object = true;
+
+        r = introspect_write_child_nodes(&intro, s, path);
+        if (r < 0)
+                return r;
+
+        r = introspect_finish(&intro, ret);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+static int process_introspect(
+                sd_bus *bus,
+                sd_bus_message *m,
+                struct node *n,
+                bool require_fallback,
+                bool *found_object) {
+
+        _cleanup_free_ char *s = NULL;
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(n);
+        assert(found_object);
+
+        r = introspect_path(bus, m->path, n, require_fallback, false, found_object, &s, &error);
+        if (r < 0)
+                return bus_maybe_reply_error(m, r, &error);
+        if (r == 0)
+                /* nodes_modified == true */
+                return 0;
+
+        r = sd_bus_message_new_method_return(m, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append(reply, "s", s);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_send(bus, reply, NULL);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+static int object_manager_serialize_path(
+                sd_bus *bus,
+                sd_bus_message *reply,
+                const char *prefix,
+                const char *path,
+                bool require_fallback,
+                bool *found_object_manager,
+                sd_bus_error *error) {
+
+        const char *previous_interface = NULL;
+        bool found_something = false;
+        struct node *n;
+        int r;
+
+        assert(bus);
+        assert(reply);
+        assert(prefix);
+        assert(path);
+        assert(found_object_manager);
+        assert(error);
+
+        n = hashmap_get(bus->nodes, prefix);
+        if (!n)
+                return 0;
+
+        if (!require_fallback && n->object_managers)
+                *found_object_manager = true;
+
+        LIST_FOREACH(vtables, i, n->vtables) {
+                void *u;
+
+                if (require_fallback && !i->is_fallback)
+                        continue;
+
+                r = node_vtable_get_userdata(bus, path, i, &u, error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+                if (r == 0)
+                        continue;
+
+                if (!found_something) {
+
+                        /* Open the object part */
+
+                        r = sd_bus_message_open_container(reply, 'e', "oa{sa{sv}}");
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_append(reply, "o", path);
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_open_container(reply, 'a', "{sa{sv}}");
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_append(reply, "{sa{sv}}", "org.freedesktop.DBus.Peer", 0);
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_append(reply, "{sa{sv}}", "org.freedesktop.DBus.Introspectable", 0);
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_append(reply, "{sa{sv}}", "org.freedesktop.DBus.Properties", 0);
+                        if (r < 0)
+                                return r;
+
+                        if (*found_object_manager) {
+                                r = sd_bus_message_append(
+                                                reply, "{sa{sv}}", "org.freedesktop.DBus.ObjectManager", 0);
+                                if (r < 0)
+                                        return r;
+                        }
+
+                        found_something = true;
+                }
+
+                if (!streq_ptr(previous_interface, i->interface)) {
+
+                        /* Maybe close the previous interface part */
+
+                        if (previous_interface) {
+                                r = sd_bus_message_close_container(reply);
+                                if (r < 0)
+                                        return r;
+
+                                r = sd_bus_message_close_container(reply);
+                                if (r < 0)
+                                        return r;
+                        }
+
+                        /* Open the new interface part */
+
+                        r = sd_bus_message_open_container(reply, 'e', "sa{sv}");
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_append(reply, "s", i->interface);
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_open_container(reply, 'a', "{sv}");
+                        if (r < 0)
+                                return r;
+                }
+
+                r = vtable_append_all_properties(bus, reply, path, i, u, error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+
+                previous_interface = i->interface;
+        }
+
+        if (previous_interface) {
+                r = sd_bus_message_close_container(reply);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_close_container(reply);
+                if (r < 0)
+                        return r;
+        }
+
+        if (found_something) {
+                r = sd_bus_message_close_container(reply);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_close_container(reply);
+                if (r < 0)
+                        return r;
+        }
+
+        return 1;
+}
+
+static int object_manager_serialize_path_and_fallbacks(
+                sd_bus *bus,
+                sd_bus_message *reply,
+                const char *path,
+                sd_bus_error *error) {
+
+        _cleanup_free_ char *prefix = NULL;
+        size_t pl;
+        int r;
+        bool found_object_manager = false;
+
+        assert(bus);
+        assert(reply);
+        assert(path);
+        assert(error);
+
+        /* First, add all vtables registered for this path */
+        r = object_manager_serialize_path(bus, reply, path, path, false, &found_object_manager, error);
+        if (r < 0)
+                return r;
+        if (bus->nodes_modified)
+                return 0;
+
+        /* Second, add fallback vtables registered for any of the prefixes */
+        pl = strlen(path);
+        assert(pl <= BUS_PATH_SIZE_MAX);
+        prefix = new(char, pl + 1);
+        if (!prefix)
+                return -ENOMEM;
+
+        OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
+                r = object_manager_serialize_path(bus, reply, prefix, path, true, &found_object_manager, error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        return 0;
+}
+
+static int process_get_managed_objects(
+                sd_bus *bus,
+                sd_bus_message *m,
+                struct node *n,
+                bool require_fallback,
+                bool *found_object) {
+
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        _cleanup_ordered_set_free_free_ OrderedSet *s = NULL;
+        char *path;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(n);
+        assert(found_object);
+
+        /* Spec says, GetManagedObjects() is only implemented on the root of a
+         * sub-tree. Therefore, we require a registered object-manager on
+         * exactly the queried path, otherwise, we refuse to respond. */
+
+        if (require_fallback || !n->object_managers)
+                return 0;
+
+        r = get_child_nodes(bus, m->path, n, CHILDREN_RECURSIVE, &s, &error);
+        if (r < 0)
+                return bus_maybe_reply_error(m, r, &error);
+        if (bus->nodes_modified)
+                return 0;
+
+        r = sd_bus_message_new_method_return(m, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_open_container(reply, 'a', "{oa{sa{sv}}}");
+        if (r < 0)
+                return r;
+
+        ORDERED_SET_FOREACH(path, s) {
+                r = object_manager_serialize_path_and_fallbacks(bus, reply, path, &error);
+                if (r < 0)
+                        return bus_maybe_reply_error(m, r, &error);
+
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        r = sd_bus_message_close_container(reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_send(bus, reply, NULL);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+static int object_find_and_run(
+                sd_bus *bus,
+                sd_bus_message *m,
+                const char *p,
+                bool require_fallback,
+                bool *found_object) {
+
+        struct node *n;
+        struct vtable_member vtable_key, *v;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(p);
+        assert(found_object);
+
+        n = hashmap_get(bus->nodes, p);
+        if (!n)
+                return 0;
+
+        /* First, try object callbacks */
+        r = node_callbacks_run(bus, m, n->callbacks, require_fallback, found_object);
+        if (r != 0)
+                return r;
+        if (bus->nodes_modified)
+                return 0;
+
+        if (!m->interface || !m->member)
+                return 0;
+
+        /* Then, look for a known method */
+        vtable_key.path = (char*) p;
+        vtable_key.interface = m->interface;
+        vtable_key.member = m->member;
+
+        v = hashmap_get(bus->vtable_methods, &vtable_key);
+        if (v) {
+                r = method_callbacks_run(bus, m, v, require_fallback, found_object);
+                if (r != 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        /* Then, look for a known property */
+        if (streq(m->interface, "org.freedesktop.DBus.Properties")) {
+                bool get = false;
+
+                get = streq(m->member, "Get");
+
+                if (get || streq(m->member, "Set")) {
+
+                        r = sd_bus_message_rewind(m, true);
+                        if (r < 0)
+                                return r;
+
+                        vtable_key.path = (char*) p;
+
+                        r = sd_bus_message_read(m, "ss", &vtable_key.interface, &vtable_key.member);
+                        if (r < 0)
+                                return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_INVALID_ARGS, "Expected interface and member parameters");
+
+                        v = hashmap_get(bus->vtable_properties, &vtable_key);
+                        if (v) {
+                                r = property_get_set_callbacks_run(bus, m, v, require_fallback, get, found_object);
+                                if (r != 0)
+                                        return r;
+                        }
+
+                } else if (streq(m->member, "GetAll")) {
+                        const char *iface;
+
+                        r = sd_bus_message_rewind(m, true);
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_read(m, "s", &iface);
+                        if (r < 0)
+                                return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_INVALID_ARGS, "Expected interface parameter");
+
+                        if (iface[0] == 0)
+                                iface = NULL;
+
+                        r = property_get_all_callbacks_run(bus, m, n->vtables, require_fallback, iface, found_object);
+                        if (r != 0)
+                                return r;
+                }
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Introspectable", "Introspect")) {
+
+                if (!isempty(sd_bus_message_get_signature(m, true)))
+                        return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_INVALID_ARGS, "Expected no parameters");
+
+                r = process_introspect(bus, m, n, require_fallback, found_object);
+                if (r != 0)
+                        return r;
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus.ObjectManager", "GetManagedObjects")) {
+
+                if (!isempty(sd_bus_message_get_signature(m, true)))
+                        return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_INVALID_ARGS, "Expected no parameters");
+
+                r = process_get_managed_objects(bus, m, n, require_fallback, found_object);
+                if (r != 0)
+                        return r;
+        }
+
+        if (bus->nodes_modified)
+                return 0;
+
+        if (!*found_object) {
+                r = bus_node_exists(bus, n, m->path, require_fallback);
+                if (r < 0)
+                        return bus_maybe_reply_error(m, r, NULL);
+                if (bus->nodes_modified)
+                        return 0;
+                if (r > 0)
+                        *found_object = true;
+        }
+
+        return 0;
+}
+
+int bus_process_object(sd_bus *bus, sd_bus_message *m) {
+        _cleanup_free_ char *prefix = NULL;
+        int r;
+        size_t pl;
+        bool found_object = false;
+
+        assert(bus);
+        assert(m);
+
+        if (bus->is_monitor)
+                return 0;
+
+        if (m->header->type != SD_BUS_MESSAGE_METHOD_CALL)
+                return 0;
+
+        if (hashmap_isempty(bus->nodes))
+                return 0;
+
+        /* Never respond to broadcast messages */
+        if (bus->bus_client && !m->destination)
+                return 0;
+
+        assert(m->path);
+        assert(m->member);
+
+        pl = strlen(m->path);
+        assert(pl <= BUS_PATH_SIZE_MAX);
+        prefix = new(char, pl + 1);
+        if (!prefix)
+                return -ENOMEM;
+
+        do {
+                bus->nodes_modified = false;
+
+                r = object_find_and_run(bus, m, m->path, false, &found_object);
+                if (r != 0)
+                        return r;
+
+                /* Look for fallback prefixes */
+                OBJECT_PATH_FOREACH_PREFIX(prefix, m->path) {
+
+                        if (bus->nodes_modified)
+                                break;
+
+                        r = object_find_and_run(bus, m, prefix, true, &found_object);
+                        if (r != 0)
+                                return r;
+                }
+
+        } while (bus->nodes_modified);
+
+        if (!found_object)
+                return 0;
+
+        if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Properties", "Get") ||
+            sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Properties", "Set")) {
+                const char *interface = NULL, *property = NULL;
+
+                (void) sd_bus_message_rewind(m, true);
+                (void) sd_bus_message_read_basic(m, 's', &interface);
+                (void) sd_bus_message_read_basic(m, 's', &property);
+
+                r = sd_bus_reply_method_errorf(
+                                m,
+                                SD_BUS_ERROR_UNKNOWN_PROPERTY,
+                                "Unknown interface %s or property %s.", strnull(interface), strnull(property));
+        } else
+                r = sd_bus_reply_method_errorf(
+                                m,
+                                SD_BUS_ERROR_UNKNOWN_METHOD,
+                                "Unknown method %s or interface %s.", m->member, m->interface);
+
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+static struct node* bus_node_allocate(sd_bus *bus, const char *path) {
+        struct node *n, *parent;
+        const char *e;
+        _cleanup_free_ char *s = NULL;
+        char *p;
+        int r;
+
+        assert(bus);
+        assert(path);
+        assert(path[0] == '/');
+
+        n = hashmap_get(bus->nodes, path);
+        if (n)
+                return n;
+
+        r = hashmap_ensure_allocated(&bus->nodes, &string_hash_ops);
+        if (r < 0)
+                return NULL;
+
+        s = strdup(path);
+        if (!s)
+                return NULL;
+
+        if (streq(path, "/"))
+                parent = NULL;
+        else {
+                assert_se(e = strrchr(path, '/'));
+
+                p = strndupa_safe(path, MAX(1, e - path));
+
+                parent = bus_node_allocate(bus, p);
+                if (!parent)
+                        return NULL;
+        }
+
+        n = new0(struct node, 1);
+        if (!n)
+                return NULL;
+
+        n->parent = parent;
+        n->path = TAKE_PTR(s);
+
+        r = hashmap_put(bus->nodes, n->path, n);
+        if (r < 0) {
+                free(n->path);
+                return mfree(n);
+        }
+
+        if (parent)
+                LIST_PREPEND(siblings, parent->child, n);
+
+        return n;
+}
+
+void bus_node_gc(sd_bus *b, struct node *n) {
+        assert(b);
+
+        if (!n)
+                return;
+
+        if (n->child ||
+            n->callbacks ||
+            n->vtables ||
+            n->enumerators ||
+            n->object_managers)
+                return;
+
+        assert_se(hashmap_remove(b->nodes, n->path) == n);
+
+        if (n->parent)
+                LIST_REMOVE(siblings, n->parent->child, n);
+
+        free(n->path);
+        bus_node_gc(b, n->parent);
+        free(n);
+}
+
+static int bus_find_parent_object_manager(sd_bus *bus, struct node **out, const char *path, bool* path_has_object_manager) {
+        struct node *n;
+
+        assert(bus);
+        assert(path);
+        assert(path_has_object_manager);
+
+        n = hashmap_get(bus->nodes, path);
+
+        if (n)
+                *path_has_object_manager = n->object_managers;
+
+        if (!n) {
+                _cleanup_free_ char *prefix = NULL;
+                size_t pl;
+
+                pl = strlen(path);
+                assert(pl <= BUS_PATH_SIZE_MAX);
+                prefix = new(char, pl + 1);
+                if (!prefix)
+                        return -ENOMEM;
+
+                OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
+                        n = hashmap_get(bus->nodes, prefix);
+                        if (n)
+                                break;
+                }
+        }
+
+        while (n && !n->object_managers)
+                n = n->parent;
+
+        if (out)
+                *out = n;
+        return !!n;
+}
+
+static int bus_add_object(
+                sd_bus *bus,
+                sd_bus_slot **slot,
+                bool fallback,
+                const char *path,
+                sd_bus_message_handler_t callback,
+                void *userdata) {
+
+        sd_bus_slot *s;
+        struct node *n;
+        int r;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(callback, -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        n = bus_node_allocate(bus, path);
+        if (!n)
+                return -ENOMEM;
+
+        s = bus_slot_allocate(bus, !slot, BUS_NODE_CALLBACK, sizeof(struct node_callback), userdata);
+        if (!s) {
+                r = -ENOMEM;
+                goto fail;
+        }
+
+        s->node_callback.callback = callback;
+        s->node_callback.is_fallback = fallback;
+
+        s->node_callback.node = n;
+        LIST_PREPEND(callbacks, n->callbacks, &s->node_callback);
+        bus->nodes_modified = true;
+
+        if (slot)
+                *slot = s;
+
+        return 0;
+
+fail:
+        sd_bus_slot_unref(s);
+        bus_node_gc(bus, n);
+
+        return r;
+}
+
+_public_ int sd_bus_add_object(
+                sd_bus *bus,
+                sd_bus_slot **slot,
+                const char *path,
+                sd_bus_message_handler_t callback,
+                void *userdata) {
+
+        return bus_add_object(bus, slot, false, path, callback, userdata);
+}
+
+_public_ int sd_bus_add_fallback(
+                sd_bus *bus,
+                sd_bus_slot **slot,
+                const char *prefix,
+                sd_bus_message_handler_t callback,
+                void *userdata) {
+
+        return bus_add_object(bus, slot, true, prefix, callback, userdata);
+}
+
+static void vtable_member_hash_func(const struct vtable_member *m, struct siphash *state) {
+        assert(m);
+
+        string_hash_func(m->path, state);
+        string_hash_func(m->interface, state);
+        string_hash_func(m->member, state);
+}
+
+static int vtable_member_compare_func(const struct vtable_member *x, const struct vtable_member *y) {
+        int r;
+
+        assert(x);
+        assert(y);
+
+        r = strcmp(x->path, y->path);
+        if (r != 0)
+                return r;
+
+        r = strcmp(x->interface, y->interface);
+        if (r != 0)
+                return r;
+
+        return strcmp(x->member, y->member);
+}
+
+DEFINE_PRIVATE_HASH_OPS(vtable_member_hash_ops, struct vtable_member, vtable_member_hash_func, vtable_member_compare_func);
+
+typedef enum {
+        NAMES_FIRST_PART        = 1 << 0, /* first part of argument name list (input names). It is reset by names_are_valid() */
+        NAMES_PRESENT           = 1 << 1, /* at least one argument name is present, so the names will checked.
+                                             This flag is set and used internally by names_are_valid(), but needs to be stored across calls for 2-parts list  */
+        NAMES_SINGLE_PART       = 1 << 2, /* argument name list consisting of a single part */
+} names_flags;
+
+static bool names_are_valid(const char *signature, const char **names, names_flags *flags) {
+        int r;
+
+        if ((*flags & NAMES_FIRST_PART || *flags & NAMES_SINGLE_PART) && **names != '\0')
+                *flags |= NAMES_PRESENT;
+
+        for (;*flags & NAMES_PRESENT;) {
+                size_t l;
+
+                if (!*signature)
+                        break;
+
+                r = signature_element_length(signature, &l);
+                if (r < 0)
+                        return false;
+
+                if (**names != '\0') {
+                        if (!member_name_is_valid(*names))
+                                return false;
+                        *names += strlen(*names) + 1;
+                } else if (*flags & NAMES_PRESENT)
+                        return false;
+
+                signature += l;
+        }
+        /* let's check if there are more argument names specified than the signature allows */
+        if (*flags & NAMES_PRESENT && **names != '\0' && !(*flags & NAMES_FIRST_PART))
+                return false;
+        *flags &= ~NAMES_FIRST_PART;
+        return true;
+}
+
+/* the current version of this struct is defined in sd-bus-vtable.h, but we need to list here the historical versions
+   to make sure the calling code is compatible with one of these */
+struct sd_bus_vtable_221 {
+        uint8_t type:8;
+        uint64_t flags:56;
+        union {
+                struct {
+                        size_t element_size;
+                } start;
+                struct {
+                        const char *member;
+                        const char *signature;
+                        const char *result;
+                        sd_bus_message_handler_t handler;
+                        size_t offset;
+                } method;
+                struct {
+                        const char *member;
+                        const char *signature;
+                } signal;
+                struct {
+                        const char *member;
+                        const char *signature;
+                        sd_bus_property_get_t get;
+                        sd_bus_property_set_t set;
+                        size_t offset;
+                } property;
+        } x;
+};
+/* Structure size up to v241 */
+#define VTABLE_ELEMENT_SIZE_221 sizeof(struct sd_bus_vtable_221)
+
+/* Size of the structure when "features" field was added. If the structure definition is augmented, a copy of
+ * the structure definition will need to be made (similarly to the sd_bus_vtable_221 above), and this
+ * definition updated to refer to it. */
+#define VTABLE_ELEMENT_SIZE_242 sizeof(struct sd_bus_vtable)
+
+static int vtable_features(const sd_bus_vtable *vtable) {
+        if (vtable[0].x.start.element_size < VTABLE_ELEMENT_SIZE_242 ||
+            !vtable[0].x.start.vtable_format_reference)
+                return 0;
+        return vtable[0].x.start.features;
+}
+
+bool bus_vtable_has_names(const sd_bus_vtable *vtable) {
+        return vtable_features(vtable) & _SD_BUS_VTABLE_PARAM_NAMES;
+}
+
+const sd_bus_vtable* bus_vtable_next(const sd_bus_vtable *vtable, const sd_bus_vtable *v) {
+        return (const sd_bus_vtable*) ((char*) v + vtable[0].x.start.element_size);
+}
+
+static int add_object_vtable_internal(
+                sd_bus *bus,
+                sd_bus_slot **slot,
+                const char *path,
+                const char *interface,
+                const sd_bus_vtable *vtable,
+                bool fallback,
+                sd_bus_object_find_t find,
+                void *userdata) {
+
+        sd_bus_slot *s = NULL;
+        struct node_vtable *existing = NULL;
+        const sd_bus_vtable *v;
+        struct node *n;
+        int r;
+        const char *names = "";
+        names_flags nf;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(interface_name_is_valid(interface), -EINVAL);
+        assert_return(vtable, -EINVAL);
+        assert_return(vtable[0].type == _SD_BUS_VTABLE_START, -EINVAL);
+        assert_return(vtable[0].x.start.element_size == VTABLE_ELEMENT_SIZE_221 ||
+                      vtable[0].x.start.element_size >= VTABLE_ELEMENT_SIZE_242,
+                      -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+        assert_return(!streq(interface, "org.freedesktop.DBus.Properties") &&
+                      !streq(interface, "org.freedesktop.DBus.Introspectable") &&
+                      !streq(interface, "org.freedesktop.DBus.Peer") &&
+                      !streq(interface, "org.freedesktop.DBus.ObjectManager"), -EINVAL);
+
+        r = hashmap_ensure_allocated(&bus->vtable_methods, &vtable_member_hash_ops);
+        if (r < 0)
+                return r;
+
+        r = hashmap_ensure_allocated(&bus->vtable_properties, &vtable_member_hash_ops);
+        if (r < 0)
+                return r;
+
+        n = bus_node_allocate(bus, path);
+        if (!n)
+                return -ENOMEM;
+
+        LIST_FOREACH(vtables, i, n->vtables) {
+                if (i->is_fallback != fallback) {
+                        r = -EPROTOTYPE;
+                        goto fail;
+                }
+
+                if (streq(i->interface, interface)) {
+
+                        if (i->vtable == vtable) {
+                                r = -EEXIST;
+                                goto fail;
+                        }
+
+                        existing = i;
+                }
+        }
+
+        s = bus_slot_allocate(bus, !slot, BUS_NODE_VTABLE, sizeof(struct node_vtable), userdata);
+        if (!s) {
+                r = -ENOMEM;
+                goto fail;
+        }
+
+        s->node_vtable.is_fallback = fallback;
+        s->node_vtable.vtable = vtable;
+        s->node_vtable.find = find;
+
+        s->node_vtable.interface = strdup(interface);
+        if (!s->node_vtable.interface) {
+                r = -ENOMEM;
+                goto fail;
+        }
+
+        v = s->node_vtable.vtable;
+        for (v = bus_vtable_next(vtable, v); v->type != _SD_BUS_VTABLE_END; v = bus_vtable_next(vtable, v)) {
+
+                switch (v->type) {
+
+                case _SD_BUS_VTABLE_METHOD: {
+                        struct vtable_member *m;
+                        nf = NAMES_FIRST_PART;
+
+                        if (bus_vtable_has_names(vtable))
+                                names = strempty(v->x.method.names);
+
+                        if (!member_name_is_valid(v->x.method.member) ||
+                            !signature_is_valid(strempty(v->x.method.signature), false) ||
+                            !signature_is_valid(strempty(v->x.method.result), false) ||
+                            !names_are_valid(strempty(v->x.method.signature), &names, &nf) ||
+                            !names_are_valid(strempty(v->x.method.result), &names, &nf) ||
+                            !(v->x.method.handler || (isempty(v->x.method.signature) && isempty(v->x.method.result))) ||
+                            v->flags & (SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE|SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION)) {
+                                r = -EINVAL;
+                                goto fail;
+                        }
+
+                        m = new0(struct vtable_member, 1);
+                        if (!m) {
+                                r = -ENOMEM;
+                                goto fail;
+                        }
+
+                        m->parent = &s->node_vtable;
+                        m->path = n->path;
+                        m->interface = s->node_vtable.interface;
+                        m->member = v->x.method.member;
+                        m->vtable = v;
+
+                        r = hashmap_put(bus->vtable_methods, m, m);
+                        if (r < 0) {
+                                free(m);
+                                goto fail;
+                        }
+
+                        break;
+                }
+
+                case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
+
+                        if (!(v->x.property.set || bus_type_is_basic(v->x.property.signature[0]))) {
+                                r = -EINVAL;
+                                goto fail;
+                        }
+
+                        if (v->flags & SD_BUS_VTABLE_PROPERTY_CONST) {
+                                r = -EINVAL;
+                                goto fail;
+                        }
+
+                        _fallthrough_;
+                case _SD_BUS_VTABLE_PROPERTY: {
+                        struct vtable_member *m;
+
+                        if (!member_name_is_valid(v->x.property.member) ||
+                            !signature_is_single(v->x.property.signature, false) ||
+                            !(v->x.property.get || bus_type_is_basic(v->x.property.signature[0]) || streq(v->x.property.signature, "as")) ||
+                            (v->flags & SD_BUS_VTABLE_METHOD_NO_REPLY) ||
+                            (!!(v->flags & SD_BUS_VTABLE_PROPERTY_CONST) + !!(v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE) + !!(v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION)) > 1 ||
+                            ((v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE) && (v->flags & SD_BUS_VTABLE_PROPERTY_EXPLICIT)) ||
+                            (v->flags & SD_BUS_VTABLE_UNPRIVILEGED && v->type == _SD_BUS_VTABLE_PROPERTY)) {
+                                r = -EINVAL;
+                                goto fail;
+                        }
+
+                        m = new0(struct vtable_member, 1);
+                        if (!m) {
+                                r = -ENOMEM;
+                                goto fail;
+                        }
+
+                        m->parent = &s->node_vtable;
+                        m->path = n->path;
+                        m->interface = s->node_vtable.interface;
+                        m->member = v->x.property.member;
+                        m->vtable = v;
+
+                        r = hashmap_put(bus->vtable_properties, m, m);
+                        if (r < 0) {
+                                free(m);
+                                goto fail;
+                        }
+
+                        break;
+                }
+
+                case _SD_BUS_VTABLE_SIGNAL:
+                        nf = NAMES_SINGLE_PART;
+
+                        if (bus_vtable_has_names(vtable))
+                                names = strempty(v->x.signal.names);
+
+                        if (!member_name_is_valid(v->x.signal.member) ||
+                            !signature_is_valid(strempty(v->x.signal.signature), false) ||
+                            !names_are_valid(strempty(v->x.signal.signature), &names, &nf) ||
+                            v->flags & SD_BUS_VTABLE_UNPRIVILEGED) {
+                                r = -EINVAL;
+                                goto fail;
+                        }
+
+                        break;
+
+                default:
+                        r = -EINVAL;
+                        goto fail;
+                }
+        }
+
+        s->node_vtable.node = n;
+        LIST_INSERT_AFTER(vtables, n->vtables, existing, &s->node_vtable);
+        bus->nodes_modified = true;
+
+        if (slot)
+                *slot = s;
+
+        return 0;
+
+fail:
+        sd_bus_slot_unref(s);
+        bus_node_gc(bus, n);
+
+        return r;
+}
+
+/* This symbol exists solely to tell the linker that the "new" vtable format is used. */
+_public_ const unsigned sd_bus_object_vtable_format = 242;
+
+_public_ int sd_bus_add_object_vtable(
+                sd_bus *bus,
+                sd_bus_slot **slot,
+                const char *path,
+                const char *interface,
+                const sd_bus_vtable *vtable,
+                void *userdata) {
+
+        return add_object_vtable_internal(bus, slot, path, interface, vtable, false, NULL, userdata);
+}
+
+_public_ int sd_bus_add_fallback_vtable(
+                sd_bus *bus,
+                sd_bus_slot **slot,
+                const char *prefix,
+                const char *interface,
+                const sd_bus_vtable *vtable,
+                sd_bus_object_find_t find,
+                void *userdata) {
+
+        return add_object_vtable_internal(bus, slot, prefix, interface, vtable, true, find, userdata);
+}
+
+_public_ int sd_bus_add_node_enumerator(
+                sd_bus *bus,
+                sd_bus_slot **slot,
+                const char *path,
+                sd_bus_node_enumerator_t callback,
+                void *userdata) {
+
+        sd_bus_slot *s;
+        struct node *n;
+        int r;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(callback, -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        n = bus_node_allocate(bus, path);
+        if (!n)
+                return -ENOMEM;
+
+        s = bus_slot_allocate(bus, !slot, BUS_NODE_ENUMERATOR, sizeof(struct node_enumerator), userdata);
+        if (!s) {
+                r = -ENOMEM;
+                goto fail;
+        }
+
+        s->node_enumerator.callback = callback;
+
+        s->node_enumerator.node = n;
+        LIST_PREPEND(enumerators, n->enumerators, &s->node_enumerator);
+        bus->nodes_modified = true;
+
+        if (slot)
+                *slot = s;
+
+        return 0;
+
+fail:
+        sd_bus_slot_unref(s);
+        bus_node_gc(bus, n);
+
+        return r;
+}
+
+static int emit_properties_changed_on_interface(
+                sd_bus *bus,
+                const char *prefix,
+                const char *path,
+                const char *interface,
+                bool require_fallback,
+                bool *found_interface,
+                char **names) {
+
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
+        bool has_invalidating = false, has_changing = false;
+        struct vtable_member key = {};
+        struct node *n;
+        void *u = NULL;
+        int r;
+
+        assert(bus);
+        assert(prefix);
+        assert(path);
+        assert(interface);
+        assert(found_interface);
+
+        n = hashmap_get(bus->nodes, prefix);
+        if (!n)
+                return 0;
+
+        r = sd_bus_message_new_signal(bus, &m, path, "org.freedesktop.DBus.Properties", "PropertiesChanged");
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append(m, "s", interface);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_open_container(m, 'a', "{sv}");
+        if (r < 0)
+                return r;
+
+        key.path = prefix;
+        key.interface = interface;
+
+        LIST_FOREACH(vtables, c, n->vtables) {
+                if (require_fallback && !c->is_fallback)
+                        continue;
+
+                if (!streq(c->interface, interface))
+                        continue;
+
+                r = node_vtable_get_userdata(bus, path, c, &u, &error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+                if (r == 0)
+                        continue;
+
+                *found_interface = true;
+
+                if (names) {
+                        /* If the caller specified a list of
+                         * properties we include exactly those in the
+                         * PropertiesChanged message */
+
+                        STRV_FOREACH(property, names) {
+                                struct vtable_member *v;
+
+                                assert_return(member_name_is_valid(*property), -EINVAL);
+
+                                key.member = *property;
+                                v = hashmap_get(bus->vtable_properties, &key);
+                                if (!v)
+                                        return -ENOENT;
+
+                                /* If there are two vtables for the same
+                                 * interface, let's handle this property when
+                                 * we come to that vtable. */
+                                if (c != v->parent)
+                                        continue;
+
+                                assert_return(v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE ||
+                                              v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION, -EDOM);
+
+                                assert_return(!(v->vtable->flags & SD_BUS_VTABLE_HIDDEN), -EDOM);
+
+                                if (v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION) {
+                                        has_invalidating = true;
+                                        continue;
+                                }
+
+                                has_changing = true;
+
+                                r = vtable_append_one_property(bus, m, m->path, c, v->vtable, u, &error);
+                                if (r < 0)
+                                        return r;
+                                if (bus->nodes_modified)
+                                        return 0;
+                        }
+                } else {
+                        const sd_bus_vtable *v;
+
+                        /* If the caller specified no properties list
+                         * we include all properties that are marked
+                         * as changing in the message. */
+
+                        v = c->vtable;
+                        for (v = bus_vtable_next(c->vtable, v); v->type != _SD_BUS_VTABLE_END; v = bus_vtable_next(c->vtable, v)) {
+                                if (!IN_SET(v->type, _SD_BUS_VTABLE_PROPERTY, _SD_BUS_VTABLE_WRITABLE_PROPERTY))
+                                        continue;
+
+                                if (v->flags & SD_BUS_VTABLE_HIDDEN)
+                                        continue;
+
+                                if (v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION) {
+                                        has_invalidating = true;
+                                        continue;
+                                }
+
+                                if (!(v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))
+                                        continue;
+
+                                has_changing = true;
+
+                                r = vtable_append_one_property(bus, m, m->path, c, v, u, &error);
+                                if (r < 0)
+                                        return r;
+                                if (bus->nodes_modified)
+                                        return 0;
+                        }
+                }
+        }
+
+        if (!has_invalidating && !has_changing)
+                return 0;
+
+        r = sd_bus_message_close_container(m);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_open_container(m, 'a', "s");
+        if (r < 0)
+                return r;
+
+        if (has_invalidating) {
+                LIST_FOREACH(vtables, c, n->vtables) {
+                        if (require_fallback && !c->is_fallback)
+                                continue;
+
+                        if (!streq(c->interface, interface))
+                                continue;
+
+                        r = node_vtable_get_userdata(bus, path, c, &u, &error);
+                        if (r < 0)
+                                return r;
+                        if (bus->nodes_modified)
+                                return 0;
+                        if (r == 0)
+                                continue;
+
+                        if (names) {
+                                STRV_FOREACH(property, names) {
+                                        struct vtable_member *v;
+
+                                        key.member = *property;
+                                        assert_se(v = hashmap_get(bus->vtable_properties, &key));
+                                        assert(c == v->parent);
+
+                                        if (!(v->vtable->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION))
+                                                continue;
+
+                                        r = sd_bus_message_append(m, "s", *property);
+                                        if (r < 0)
+                                                return r;
+                                }
+                        } else {
+                                const sd_bus_vtable *v;
+
+                                v = c->vtable;
+                                for (v = bus_vtable_next(c->vtable, v); v->type != _SD_BUS_VTABLE_END; v = bus_vtable_next(c->vtable, v)) {
+                                        if (!IN_SET(v->type, _SD_BUS_VTABLE_PROPERTY, _SD_BUS_VTABLE_WRITABLE_PROPERTY))
+                                                continue;
+
+                                        if (v->flags & SD_BUS_VTABLE_HIDDEN)
+                                                continue;
+
+                                        if (!(v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION))
+                                                continue;
+
+                                        r = sd_bus_message_append(m, "s", v->x.property.member);
+                                        if (r < 0)
+                                                return r;
+                                }
+                        }
+                }
+        }
+
+        r = sd_bus_message_close_container(m);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_send(bus, m, NULL);
+        if (r < 0)
+                return r;
+
+        return 1;
+}
+
+_public_ int sd_bus_emit_properties_changed_strv(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                char **names) {
+
+        _cleanup_free_ char *prefix = NULL;
+        bool found_interface = false;
+        size_t pl;
+        int r;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(interface_name_is_valid(interface), -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        if (!BUS_IS_OPEN(bus->state))
+                return -ENOTCONN;
+
+        /* A non-NULL but empty names list means nothing needs to be
+           generated. A NULL list OTOH indicates that all properties
+           that are set to EMITS_CHANGE or EMITS_INVALIDATION shall be
+           included in the PropertiesChanged message. */
+        if (names && names[0] == NULL)
+                return 0;
+
+        BUS_DONT_DESTROY(bus);
+
+        pl = strlen(path);
+        assert(pl <= BUS_PATH_SIZE_MAX);
+        prefix = new(char, pl + 1);
+        if (!prefix)
+                return -ENOMEM;
+
+        do {
+                bus->nodes_modified = false;
+
+                r = emit_properties_changed_on_interface(bus, path, path, interface, false, &found_interface, names);
+                if (r != 0)
+                        return r;
+                if (bus->nodes_modified)
+                        continue;
+
+                OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
+                        r = emit_properties_changed_on_interface(bus, prefix, path, interface, true, &found_interface, names);
+                        if (r != 0)
+                                return r;
+                        if (bus->nodes_modified)
+                                break;
+                }
+
+        } while (bus->nodes_modified);
+
+        return found_interface ? 0 : -ENOENT;
+}
+
+_public_ int sd_bus_emit_properties_changed(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *name, ...)  {
+
+        char **names;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(interface_name_is_valid(interface), -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        if (!BUS_IS_OPEN(bus->state))
+                return -ENOTCONN;
+
+        if (!name)
+                return 0;
+
+        names = strv_from_stdarg_alloca(name);
+
+        return sd_bus_emit_properties_changed_strv(bus, path, interface, names);
+}
+
+static int object_added_append_all_prefix(
+                sd_bus *bus,
+                sd_bus_message *m,
+                OrderedSet *s,
+                const char *prefix,
+                const char *path,
+                bool require_fallback) {
+
+        const char *previous_interface = NULL;
+        struct node *n;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(s);
+        assert(prefix);
+        assert(path);
+
+        n = hashmap_get(bus->nodes, prefix);
+        if (!n)
+                return 0;
+
+        LIST_FOREACH(vtables, c, n->vtables) {
+                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+                void *u = NULL;
+
+                if (require_fallback && !c->is_fallback)
+                        continue;
+
+                r = node_vtable_get_userdata(bus, path, c, &u, &error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+                if (r == 0)
+                        continue;
+
+                if (!streq_ptr(c->interface, previous_interface)) {
+                        /* If a child-node already handled this interface, we
+                         * skip it on any of its parents. The child vtables
+                         * always fully override any conflicting vtables of
+                         * any parent node. */
+                        if (ordered_set_get(s, c->interface))
+                                continue;
+
+                        r = ordered_set_put(s, c->interface);
+                        if (r < 0)
+                                return r;
+
+                        if (previous_interface) {
+                                r = sd_bus_message_close_container(m);
+                                if (r < 0)
+                                        return r;
+                                r = sd_bus_message_close_container(m);
+                                if (r < 0)
+                                        return r;
+                        }
+
+                        r = sd_bus_message_open_container(m, 'e', "sa{sv}");
+                        if (r < 0)
+                                return r;
+                        r = sd_bus_message_append(m, "s", c->interface);
+                        if (r < 0)
+                                return r;
+                        r = sd_bus_message_open_container(m, 'a', "{sv}");
+                        if (r < 0)
+                                return r;
+
+                        previous_interface = c->interface;
+                }
+
+                r = vtable_append_all_properties(bus, m, path, c, u, &error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        if (previous_interface) {
+                r = sd_bus_message_close_container(m);
+                if (r < 0)
+                        return r;
+                r = sd_bus_message_close_container(m);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+static int object_added_append_all(sd_bus *bus, sd_bus_message *m, const char *path, bool path_has_object_manager) {
+        _cleanup_ordered_set_free_ OrderedSet *s = NULL;
+        _cleanup_free_ char *prefix = NULL;
+        size_t pl;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(path);
+
+        /*
+         * This appends all interfaces registered on path @path. We first add
+         * the builtin interfaces, which are always available and handled by
+         * sd-bus. Then, we add all interfaces registered on the exact node,
+         * followed by all fallback interfaces registered on any parent prefix.
+         *
+         * If an interface is registered multiple times on the same node with
+         * different vtables, we merge all the properties across all vtables.
+         * However, if a child node has the same interface registered as one of
+         * its parent nodes has as fallback, we make the child overwrite the
+         * parent instead of extending it. Therefore, we keep a "Set" of all
+         * handled interfaces during parent traversal, so we skip interfaces on
+         * a parent that were overwritten by a child.
+         */
+
+        s = ordered_set_new(&string_hash_ops);
+        if (!s)
+                return -ENOMEM;
+
+        r = sd_bus_message_append(m, "{sa{sv}}", "org.freedesktop.DBus.Peer", 0);
+        if (r < 0)
+                return r;
+        r = sd_bus_message_append(m, "{sa{sv}}", "org.freedesktop.DBus.Introspectable", 0);
+        if (r < 0)
+                return r;
+        r = sd_bus_message_append(m, "{sa{sv}}", "org.freedesktop.DBus.Properties", 0);
+        if (r < 0)
+                return r;
+        if (path_has_object_manager){
+                r = sd_bus_message_append(m, "{sa{sv}}", "org.freedesktop.DBus.ObjectManager", 0);
+                if (r < 0)
+                        return r;
+        }
+
+        r = object_added_append_all_prefix(bus, m, s, path, path, false);
+        if (r < 0)
+                return r;
+        if (bus->nodes_modified)
+                return 0;
+
+        pl = strlen(path);
+        assert(pl <= BUS_PATH_SIZE_MAX);
+        prefix = new(char, pl + 1);
+        if (!prefix)
+                return -ENOMEM;
+
+        OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
+                r = object_added_append_all_prefix(bus, m, s, prefix, path, true);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        return 0;
+}
+
+_public_ int sd_bus_emit_object_added(sd_bus *bus, const char *path) {
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
+        struct node *object_manager;
+        int r;
+
+        /*
+         * This emits an InterfacesAdded signal on the given path, by iterating
+         * all registered vtables and fallback vtables on the path. All
+         * properties are queried and included in the signal.
+         * This call is equivalent to sd_bus_emit_interfaces_added() with an
+         * explicit list of registered interfaces. However, unlike
+         * interfaces_added(), this call can figure out the list of supported
+         * interfaces itself. Furthermore, it properly adds the builtin
+         * org.freedesktop.DBus.* interfaces.
+         */
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        if (!BUS_IS_OPEN(bus->state))
+                return -ENOTCONN;
+
+        bool path_has_object_manager = false;
+        r = bus_find_parent_object_manager(bus, &object_manager, path, &path_has_object_manager);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -ESRCH;
+
+        BUS_DONT_DESTROY(bus);
+
+        do {
+                bus->nodes_modified = false;
+                m = sd_bus_message_unref(m);
+
+                r = sd_bus_message_new_signal(bus, &m, object_manager->path, "org.freedesktop.DBus.ObjectManager", "InterfacesAdded");
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_append_basic(m, 'o', path);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_open_container(m, 'a', "{sa{sv}}");
+                if (r < 0)
+                        return r;
+
+                r = object_added_append_all(bus, m, path, path_has_object_manager);
+                if (r < 0)
+                        return r;
+
+                if (bus->nodes_modified)
+                        continue;
+
+                r = sd_bus_message_close_container(m);
+                if (r < 0)
+                        return r;
+
+        } while (bus->nodes_modified);
+
+        return sd_bus_send(bus, m, NULL);
+}
+
+static int object_removed_append_all_prefix(
+                sd_bus *bus,
+                sd_bus_message *m,
+                OrderedSet *s,
+                const char *prefix,
+                const char *path,
+                bool require_fallback) {
+
+        const char *previous_interface = NULL;
+        struct node *n;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(s);
+        assert(prefix);
+        assert(path);
+
+        n = hashmap_get(bus->nodes, prefix);
+        if (!n)
+                return 0;
+
+        LIST_FOREACH(vtables, c, n->vtables) {
+                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+                void *u = NULL;
+
+                if (require_fallback && !c->is_fallback)
+                        continue;
+                if (streq_ptr(c->interface, previous_interface))
+                        continue;
+
+                /* If a child-node already handled this interface, we
+                 * skip it on any of its parents. The child vtables
+                 * always fully override any conflicting vtables of
+                 * any parent node. */
+                if (ordered_set_get(s, c->interface))
+                        continue;
+
+                r = node_vtable_get_userdata(bus, path, c, &u, &error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+                if (r == 0)
+                        continue;
+
+                r = ordered_set_put(s, c->interface);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_append(m, "s", c->interface);
+                if (r < 0)
+                        return r;
+
+                previous_interface = c->interface;
+        }
+
+        return 0;
+}
+
+static int object_removed_append_all(sd_bus *bus, sd_bus_message *m, const char *path, bool path_has_object_manager) {
+        _cleanup_ordered_set_free_ OrderedSet *s = NULL;
+        _cleanup_free_ char *prefix = NULL;
+        size_t pl;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(path);
+
+        /* see sd_bus_emit_object_added() for details */
+
+        s = ordered_set_new(&string_hash_ops);
+        if (!s)
+                return -ENOMEM;
+
+        r = sd_bus_message_append(m, "s", "org.freedesktop.DBus.Peer");
+        if (r < 0)
+                return r;
+        r = sd_bus_message_append(m, "s", "org.freedesktop.DBus.Introspectable");
+        if (r < 0)
+                return r;
+        r = sd_bus_message_append(m, "s", "org.freedesktop.DBus.Properties");
+        if (r < 0)
+                return r;
+
+        if (path_has_object_manager){
+                r = sd_bus_message_append(m, "s", "org.freedesktop.DBus.ObjectManager");
+                if (r < 0)
+                        return r;
+        }
+
+        r = object_removed_append_all_prefix(bus, m, s, path, path, false);
+        if (r < 0)
+                return r;
+        if (bus->nodes_modified)
+                return 0;
+
+        pl = strlen(path);
+        assert(pl <= BUS_PATH_SIZE_MAX);
+        prefix = new(char, pl + 1);
+        if (!prefix)
+                return -ENOMEM;
+
+        OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
+                r = object_removed_append_all_prefix(bus, m, s, prefix, path, true);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        return 0;
+}
+
+_public_ int sd_bus_emit_object_removed(sd_bus *bus, const char *path) {
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
+        struct node *object_manager;
+        int r;
+
+        /*
+         * This is like sd_bus_emit_object_added(), but emits an
+         * InterfacesRemoved signal on the given path. This only includes any
+         * registered interfaces but skips the properties. Note that this will
+         * call into the find() callbacks of any registered vtable. Therefore,
+         * you must call this function before destroying/unlinking your object.
+         * Otherwise, the list of interfaces will be incomplete. However, note
+         * that this will *NOT* call into any property callback. Therefore, the
+         * object might be in an "destructed" state, as long as we can find it.
+         */
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        if (!BUS_IS_OPEN(bus->state))
+                return -ENOTCONN;
+
+        bool path_has_object_manager = false;
+        r = bus_find_parent_object_manager(bus, &object_manager, path, &path_has_object_manager);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -ESRCH;
+
+        BUS_DONT_DESTROY(bus);
+
+        do {
+                bus->nodes_modified = false;
+                m = sd_bus_message_unref(m);
+
+                r = sd_bus_message_new_signal(bus, &m, object_manager->path, "org.freedesktop.DBus.ObjectManager", "InterfacesRemoved");
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_append_basic(m, 'o', path);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_open_container(m, 'a', "s");
+                if (r < 0)
+                        return r;
+
+                r = object_removed_append_all(bus, m, path, path_has_object_manager);
+                if (r < 0)
+                        return r;
+
+                if (bus->nodes_modified)
+                        continue;
+
+                r = sd_bus_message_close_container(m);
+                if (r < 0)
+                        return r;
+
+        } while (bus->nodes_modified);
+
+        return sd_bus_send(bus, m, NULL);
+}
+
+static int interfaces_added_append_one_prefix(
+                sd_bus *bus,
+                sd_bus_message *m,
+                const char *prefix,
+                const char *path,
+                const char *interface,
+                bool require_fallback) {
+
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        bool found_interface = false;
+        struct node *n;
+        void *u = NULL;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(prefix);
+        assert(path);
+        assert(interface);
+
+        n = hashmap_get(bus->nodes, prefix);
+        if (!n)
+                return 0;
+
+        LIST_FOREACH(vtables, c, n->vtables) {
+                if (require_fallback && !c->is_fallback)
+                        continue;
+
+                if (!streq(c->interface, interface))
+                        continue;
+
+                r = node_vtable_get_userdata(bus, path, c, &u, &error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+                if (r == 0)
+                        continue;
+
+                if (!found_interface) {
+                        r = sd_bus_message_append_basic(m, 's', interface);
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_open_container(m, 'a', "{sv}");
+                        if (r < 0)
+                                return r;
+
+                        found_interface = true;
+                }
+
+                r = vtable_append_all_properties(bus, m, path, c, u, &error);
+                if (r < 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        if (found_interface) {
+                r = sd_bus_message_close_container(m);
+                if (r < 0)
+                        return r;
+        }
+
+        return found_interface;
+}
+
+static int interfaces_added_append_one(
+                sd_bus *bus,
+                sd_bus_message *m,
+                const char *path,
+                const char *interface) {
+
+        _cleanup_free_ char *prefix = NULL;
+        size_t pl;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(path);
+        assert(interface);
+
+        r = interfaces_added_append_one_prefix(bus, m, path, path, interface, false);
+        if (r != 0)
+                return r;
+        if (bus->nodes_modified)
+                return 0;
+
+        pl = strlen(path);
+        assert(pl <= BUS_PATH_SIZE_MAX);
+        prefix = new(char, pl + 1);
+        if (!prefix)
+                return -ENOMEM;
+
+        OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
+                r = interfaces_added_append_one_prefix(bus, m, prefix, path, interface, true);
+                if (r != 0)
+                        return r;
+                if (bus->nodes_modified)
+                        return 0;
+        }
+
+        return -ENOENT;
+}
+
+_public_ int sd_bus_emit_interfaces_added_strv(sd_bus *bus, const char *path, char **interfaces) {
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
+        struct node *object_manager;
+        int r;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        if (!BUS_IS_OPEN(bus->state))
+                return -ENOTCONN;
+
+        if (strv_isempty(interfaces))
+                return 0;
+
+        bool path_has_object_manager = false;
+        r = bus_find_parent_object_manager(bus, &object_manager, path, &path_has_object_manager);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -ESRCH;
+
+        BUS_DONT_DESTROY(bus);
+
+        do {
+                bus->nodes_modified = false;
+                m = sd_bus_message_unref(m);
+
+                r = sd_bus_message_new_signal(bus, &m, object_manager->path, "org.freedesktop.DBus.ObjectManager", "InterfacesAdded");
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_append_basic(m, 'o', path);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_open_container(m, 'a', "{sa{sv}}");
+                if (r < 0)
+                        return r;
+
+                STRV_FOREACH(i, interfaces) {
+                        assert_return(interface_name_is_valid(*i), -EINVAL);
+
+                        r = sd_bus_message_open_container(m, 'e', "sa{sv}");
+                        if (r < 0)
+                                return r;
+
+                        r = interfaces_added_append_one(bus, m, path, *i);
+                        if (r < 0)
+                                return r;
+
+                        if (bus->nodes_modified)
+                                break;
+
+                        r = sd_bus_message_close_container(m);
+                        if (r < 0)
+                                return r;
+                }
+
+                if (bus->nodes_modified)
+                        continue;
+
+                r = sd_bus_message_close_container(m);
+                if (r < 0)
+                        return r;
+
+        } while (bus->nodes_modified);
+
+        return sd_bus_send(bus, m, NULL);
+}
+
+_public_ int sd_bus_emit_interfaces_added(sd_bus *bus, const char *path, const char *interface, ...) {
+        char **interfaces;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        if (!BUS_IS_OPEN(bus->state))
+                return -ENOTCONN;
+
+        interfaces = strv_from_stdarg_alloca(interface);
+
+        return sd_bus_emit_interfaces_added_strv(bus, path, interfaces);
+}
+
+_public_ int sd_bus_emit_interfaces_removed_strv(sd_bus *bus, const char *path, char **interfaces) {
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
+        struct node *object_manager;
+        int r;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        if (!BUS_IS_OPEN(bus->state))
+                return -ENOTCONN;
+
+        if (strv_isempty(interfaces))
+                return 0;
+
+        bool path_has_object_manager = false;
+        r = bus_find_parent_object_manager(bus, &object_manager, path, &path_has_object_manager);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -ESRCH;
+
+        r = sd_bus_message_new_signal(bus, &m, object_manager->path, "org.freedesktop.DBus.ObjectManager", "InterfacesRemoved");
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append_basic(m, 'o', path);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append_strv(m, interfaces);
+        if (r < 0)
+                return r;
+
+        return sd_bus_send(bus, m, NULL);
+}
+
+_public_ int sd_bus_emit_interfaces_removed(sd_bus *bus, const char *path, const char *interface, ...) {
+        char **interfaces;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        if (!BUS_IS_OPEN(bus->state))
+                return -ENOTCONN;
+
+        interfaces = strv_from_stdarg_alloca(interface);
+
+        return sd_bus_emit_interfaces_removed_strv(bus, path, interfaces);
+}
+
+_public_ int sd_bus_add_object_manager(sd_bus *bus, sd_bus_slot **slot, const char *path) {
+        sd_bus_slot *s;
+        struct node *n;
+        int r;
+
+        assert_return(bus, -EINVAL);
+        assert_return(bus = bus_resolve(bus), -ENOPKG);
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(!bus_origin_changed(bus), -ECHILD);
+
+        n = bus_node_allocate(bus, path);
+        if (!n)
+                return -ENOMEM;
+
+        s = bus_slot_allocate(bus, !slot, BUS_NODE_OBJECT_MANAGER, sizeof(struct node_object_manager), NULL);
+        if (!s) {
+                r = -ENOMEM;
+                goto fail;
+        }
+
+        s->node_object_manager.node = n;
+        LIST_PREPEND(object_managers, n->object_managers, &s->node_object_manager);
+        bus->nodes_modified = true;
+
+        if (slot)
+                *slot = s;
+
+        return 0;
+
+fail:
+        sd_bus_slot_unref(s);
+        bus_node_gc(bus, n);
+
+        return r;
+}