dbus: add infrastructure for changing multiple properties at once on units and hook some cgroup attributes up to it

This introduces two bus calls to make runtime changes to selected bus
properties, optionally with persistence.

This currently hooks this up only for three cgroup atributes, but this
brings the infrastructure to add more changable attributes.

This allows setting multiple attributes at once, and takes an array
rather than a dictionary of properties, in order to implement simple
resetting of lists using the same approach as when they are sourced from
unit files. This means, that list properties are appended to by this
call, unless they are first reset via assigning the empty list.

1 files changed, 38 insertions, 4 deletions

diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
index c081ff5d16..353cb22867 100644
--- a/src/core/dbus-manager.c
+++ b/src/core/dbus-manager.c
@@ -228,12 +228,17 @@
         "   <arg name=\"runtime\" type=\"b\" direction=\"in\"/>\n"      \
         "   <arg name=\"changes\" type=\"a(sss)\" direction=\"out\"/>\n" \
         "  </method>\n"                                                 \
-        "  <method name=\"SetDefaultTarget\">\n"                         \
+        "  <method name=\"SetDefaultTarget\">\n"                        \
         "   <arg name=\"files\" type=\"as\" direction=\"in\"/>\n"       \
         "   <arg name=\"changes\" type=\"a(sss)\" direction=\"out\"/>\n" \
         "  </method>\n"                                                 \
-        "  <method name=\"GetDefaultTarget\">\n"                         \
-        "   <arg name=\"name\" type=\"s\" direction=\"out\"/>\n" \
+        "  <method name=\"GetDefaultTarget\">\n"                        \
+        "   <arg name=\"name\" type=\"s\" direction=\"out\"/>\n"        \
+        "  </method>\n"                                                 \
+        "  <method name=\"SetUnitProperties\">\n"                       \
+        "   <arg name=\"name\" type=\"s\" direction=\"out\"/>\n"        \
+        "   <arg name=\"runtime\" type=\"b\" direction=\"in\"/>\n"      \
+        "   <arg name=\"properties\" type=\"a(sv)\" direction=\"in\"/>\n" \
         "  </method>\n"
 
 #define BUS_MANAGER_INTERFACE_SIGNALS                                   \
@@ -1725,13 +1730,42 @@ static DBusHandlerResult bus_manager_message_handler(DBusConnection *connection,
                         goto oom;
 
                 r = unit_file_get_default(scope, NULL, &default_target);
-
                 if (r < 0)
                         return bus_send_error_reply(connection, message, NULL, r);
 
                 if (!dbus_message_append_args(reply, DBUS_TYPE_STRING, &default_target, DBUS_TYPE_INVALID)) {
                         goto oom;
                 }
+
+        } else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Manager", "SetUnitProperties")) {
+                DBusMessageIter iter;
+                dbus_bool_t runtime;
+                const char *name;
+                Unit *u;
+
+                if (!dbus_message_iter_init(message, &iter))
+                        goto oom;
+
+                if (bus_iter_get_basic_and_next(&iter, DBUS_TYPE_STRING, &name, true) < 0 ||
+                    bus_iter_get_basic_and_next(&iter, DBUS_TYPE_BOOLEAN, &runtime, true) < 0)
+                        return bus_send_error_reply(connection, message, NULL, -EINVAL);
+
+                u = manager_get_unit(m, name);
+                if (!u) {
+                        dbus_set_error(&error, BUS_ERROR_NO_SUCH_UNIT, "Unit %s is not loaded.", name);
+                        return bus_send_error_reply(connection, message, &error, -ENOENT);
+                }
+
+                SELINUX_UNIT_ACCESS_CHECK(u, connection, message, "start");
+
+                r = bus_unit_set_properties(u, &iter, runtime ? UNIT_RUNTIME : UNIT_PERSISTENT, &error);
+                if (r < 0)
+                        return bus_send_error_reply(connection, message, &error, r);
+
+                reply = dbus_message_new_method_return(message);
+                if (!reply)
+                        goto oom;
+
         } else {
                 const BusBoundProperties bps[] = {
                         { "org.freedesktop.systemd1.Manager", bus_systemd_properties, systemd_property_string },