diff options
author | David Herrmann <dh.herrmann@gmail.com> | 2015-09-05 19:43:29 +0200 |
---|---|---|
committer | David Herrmann <dh.herrmann@gmail.com> | 2015-09-05 19:43:29 +0200 |
commit | 44eb1adda98f6733264c0e8fbc569656c6ff2de0 (patch) | |
tree | c4c1e07ea77907e2c4fd9adaa4b53a1fbfb2d048 /src/libsystemd/sd-bus/bus-objects.c | |
parent | b47c788854600ca691382d222ffeac335f619da9 (diff) |
sd-bus: make introspection data non-recursive
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.
Diffstat (limited to 'src/libsystemd/sd-bus/bus-objects.c')
-rw-r--r-- | src/libsystemd/sd-bus/bus-objects.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/src/libsystemd/sd-bus/bus-objects.c b/src/libsystemd/sd-bus/bus-objects.c index 0593aa658a..1d061cb9cf 100644 --- a/src/libsystemd/sd-bus/bus-objects.c +++ b/src/libsystemd/sd-bus/bus-objects.c @@ -169,11 +169,18 @@ static int add_enumerated_to_set( return 0; } +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, - bool skip_subhierarchies, + unsigned int flags, Set *s, sd_bus_error *error) { @@ -205,8 +212,9 @@ static int add_subtree_to_set( 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) @@ -221,7 +229,7 @@ static int get_child_nodes( sd_bus *bus, const char *prefix, struct node *n, - bool skip_subhierarchies, + unsigned int flags, Set **_s, sd_bus_error *error) { @@ -237,7 +245,7 @@ static int get_child_nodes( if (!s) return -ENOMEM; - 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; @@ -907,7 +915,7 @@ static int process_introspect( 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) @@ -1173,7 +1181,7 @@ static int process_get_managed_objects( 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) |