Currently, our introspection data looks like this:
<node>
<interface name="org.freedesktop.DBus.Peer">
...
</interface>
<interface name="org.freedesktop.DBus.Introspectable">
...
</interface>
<interface name="org.freedesktop.DBus.Properties">
...
</interface>
<node name="org"/>
<node name="org/freedesktop"/>
<node name="org/freedesktop/login1"/>
<node name="org/freedesktop/login1/user"/>
<node name="org/freedesktop/login1/user/self"/>
<node name="org/freedesktop/login1/user/_1000"/>
<node name="org/freedesktop/login1/seat"/>
<node name="org/freedesktop/login1/seat/self"/>
<node name="org/freedesktop/login1/seat/seat0"/>
<node name="org/freedesktop/login1/session"/>
<node name="org/freedesktop/login1/session/self"/>
<node name="org/freedesktop/login1/session/c1"/>
</node>
(ordered alphabetically for better visibility)
This is grossly incorrect. The spec says that we're allowed to return
non-directed children, however, it does not allow us to return data
recursively in multiple parents. If we return "org", then we must not
return anything else that starts with "org/".
It is unclear, whether we can include child-nodes as a tree. Moreover, it
is usually not what the caller wants. Hence, this patch changes sd-bus to
never return introspection data recursively. Instead, only a single
child-layer is returned.
This patch relies on enumerators to never return hierarchies. If someone
registers an enumerator via sd_bus_add_enumerator, they better register
sub-enumerators if they support *TRUE* hierarchies. Each enumerator is
treated as a single layer and not filtered.
Enumerators are still allowed to return nested data. However, that data
is still required to be a single hierarchy. For instance, returning
"/org/foo" and "/com/bar" is fine, but including "/com" or "/org" in that
dataset is not.
This should be the default for enumerators and I see no reason to filter
in sd-bus. Moreover, filtering that data-set would require to sort the
strv by path and then do prefix-filtering. This is O(n log n), which
would be fine, but still better to avoid.
Fixes #664.
+enum {
+ /* if set, add_subtree() works recursively */
+ CHILDREN_RECURSIVE = (1U << 1),
+ /* if set, add_subtree() scans object-manager hierarchies recursively */
+ CHILDREN_SUBHIERARCHIES = (1U << 0),
+};
+
static int add_subtree_to_set(
sd_bus *bus,
const char *prefix,
struct node *n,
static int add_subtree_to_set(
sd_bus *bus,
const char *prefix,
struct node *n,
- bool skip_subhierarchies,
Set *s,
sd_bus_error *error) {
Set *s,
sd_bus_error *error) {
if (r < 0 && r != -EEXIST)
return r;
if (r < 0 && r != -EEXIST)
return r;
- if (!skip_subhierarchies || !i->object_managers) {
- r = add_subtree_to_set(bus, prefix, i, skip_subhierarchies, s, error);
+ 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)
if (r < 0)
return r;
if (bus->nodes_modified)
sd_bus *bus,
const char *prefix,
struct node *n,
sd_bus *bus,
const char *prefix,
struct node *n,
- bool skip_subhierarchies,
Set **_s,
sd_bus_error *error) {
Set **_s,
sd_bus_error *error) {
- r = add_subtree_to_set(bus, prefix, n, skip_subhierarchies, s, error);
+ r = add_subtree_to_set(bus, prefix, n, flags, s, error);
if (r < 0) {
set_free_free(s);
return r;
if (r < 0) {
set_free_free(s);
return r;
assert(n);
assert(found_object);
assert(n);
assert(found_object);
- r = get_child_nodes(bus, m->path, n, false, &s, &error);
+ r = get_child_nodes(bus, m->path, n, 0, &s, &error);
if (r < 0)
return bus_maybe_reply_error(m, r, &error);
if (bus->nodes_modified)
if (r < 0)
return bus_maybe_reply_error(m, r, &error);
if (bus->nodes_modified)
if (require_fallback || !n->object_managers)
return 0;
if (require_fallback || !n->object_managers)
return 0;
- r = get_child_nodes(bus, m->path, n, true, &s, &error);
+ r = get_child_nodes(bus, m->path, n, CHILDREN_RECURSIVE, &s, &error);
if (r < 0)
return r;
if (bus->nodes_modified)
if (r < 0)
return r;
if (bus->nodes_modified)