From 0e096632c53b746b9f4b4c0249d9e5a18c1c543d Mon Sep 17 00:00:00 2001 From: Tanu Kaskinen Date: Sun, 30 Aug 2009 19:52:22 +0300 Subject: dbus: Do message argument type checking early, centrally. --- src/pulsecore/protocol-dbus.c | 336 +++++++++++++++++++++++++++--------------- 1 file changed, 220 insertions(+), 116 deletions(-) (limited to 'src/pulsecore/protocol-dbus.c') diff --git a/src/pulsecore/protocol-dbus.c b/src/pulsecore/protocol-dbus.c index d1e19ff3..91022511 100644 --- a/src/pulsecore/protocol-dbus.c +++ b/src/pulsecore/protocol-dbus.c @@ -257,37 +257,90 @@ static void update_introspection(struct object_entry *oe) { oe->introspection = pa_strbuf_tostring_free(buf); } +/* Return value of find_handler() and its subfunctions. */ enum find_result_t { - FOUND_METHOD, + /* The received message is a valid .Get call. */ FOUND_GET_PROPERTY, + + /* The received message is a valid .Set call. */ FOUND_SET_PROPERTY, + + /* The received message is a valid .GetAll call. */ FOUND_GET_ALL, + + /* The received message is a valid method call. */ + FOUND_METHOD, + + /* The interface of the received message hasn't been registered for the + * destination object. */ + NO_SUCH_INTERFACE, + + /* No property handler was found for the received .Get or .Set call. */ + NO_SUCH_PROPERTY, + + /* The interface argument of a property call didn't match any registered + * interface. */ + NO_SUCH_PROPERTY_INTERFACE, + + /* The received message called .Get or .Set for a property whose access + * mode doesn't match the call. */ PROPERTY_ACCESS_DENIED, + + /* The new value signature of a .Set call didn't match the expexted + * signature. */ + INVALID_PROPERTY_SIG, + + /* No method handler was found for the received message. */ NO_SUCH_METHOD, - NO_SUCH_PROPERTY, - INVALID_MESSAGE_ARGUMENTS + + /* The signature of the received message didn't match the expected + * signature. Despite the name, this can also be returned for a property + * call if its message signature is invalid. */ + INVALID_METHOD_SIG }; -static enum find_result_t find_handler_by_property(struct object_entry *obj_entry, - DBusMessage *msg, - const char *property, - struct interface_entry **iface_entry, - pa_dbus_property_handler **property_handler) { +/* Data for resolving the correct reaction to a received message. */ +struct call_info { + DBusMessage *message; /* The received message. */ + struct object_entry *obj_entry; + const char *interface; /* Destination interface name (extracted from the message). */ + struct interface_entry *iface_entry; + + const char *property; /* Property name (extracted from the message). */ + const char *property_interface; /* The interface argument of a property call is stored here. */ + pa_dbus_property_handler *property_handler; + const char *expected_property_sig; /* Property signature from the introspection data. */ + const char *property_sig; /* The signature of the new value in the received .Set message. */ + DBusMessageIter variant_iter; /* Iterator pointing to the beginning of the new value variant of a .Set call. */ + + const char *method; /* Method name (extracted from the message). */ + pa_dbus_method_handler *method_handler; + const char *expected_method_sig; /* Method signature from the introspection data. */ + const char *method_sig; /* The signature of the received message. */ +}; + +/* Called when call_info->property has been set and the property interface has + * not been given. In case of a Set call, call_info->property_sig is also set, + * which is checked against the expected value in this function. */ +static enum find_result_t find_handler_by_property(struct call_info *call_info) { void *state = NULL; - pa_assert(obj_entry); - pa_assert(msg); - pa_assert(property); - pa_assert(iface_entry); - pa_assert(property_handler); - - PA_HASHMAP_FOREACH(*iface_entry, obj_entry->interfaces, state) { - if ((*property_handler = pa_hashmap_get((*iface_entry)->property_handlers, property))) { - if (dbus_message_has_member(msg, "Get")) - return (*property_handler)->get_cb ? FOUND_GET_PROPERTY : PROPERTY_ACCESS_DENIED; - else if (dbus_message_has_member(msg, "Set")) - return (*property_handler)->set_cb ? FOUND_SET_PROPERTY : PROPERTY_ACCESS_DENIED; - else + pa_assert(call_info); + + PA_HASHMAP_FOREACH(call_info->iface_entry, call_info->obj_entry->interfaces, state) { + if ((call_info->property_handler = pa_hashmap_get(call_info->iface_entry->property_handlers, call_info->property))) { + if (pa_streq(call_info->method, "Get")) + return call_info->property_handler->get_cb ? FOUND_GET_PROPERTY : PROPERTY_ACCESS_DENIED; + + else if (pa_streq(call_info->method, "Set")) { + call_info->expected_property_sig = call_info->property_handler->type; + + if (pa_streq(call_info->property_sig, call_info->expected_property_sig)) + return call_info->property_handler->set_cb ? FOUND_SET_PROPERTY : PROPERTY_ACCESS_DENIED; + else + return INVALID_PROPERTY_SIG; + + } else pa_assert_not_reached(); } } @@ -295,120 +348,138 @@ static enum find_result_t find_handler_by_property(struct object_entry *obj_entr return NO_SUCH_PROPERTY; } -static enum find_result_t find_handler_by_method(struct object_entry *obj_entry, - const char *method, - struct interface_entry **iface_entry, - pa_dbus_method_handler **method_handler) { +static enum find_result_t find_handler_by_method(struct call_info *call_info) { void *state = NULL; - pa_assert(obj_entry); - pa_assert(method); - pa_assert(iface_entry); - pa_assert(method_handler); + pa_assert(call_info); - PA_HASHMAP_FOREACH(*iface_entry, obj_entry->interfaces, state) { - if ((*method_handler = pa_hashmap_get((*iface_entry)->method_handlers, method))) + PA_HASHMAP_FOREACH(call_info->iface_entry, call_info->obj_entry->interfaces, state) { + if ((call_info->method_handler = pa_hashmap_get(call_info->iface_entry->method_handlers, call_info->method))) return FOUND_METHOD; } return NO_SUCH_METHOD; } -static enum find_result_t find_handler_from_properties_call(struct object_entry *obj_entry, - DBusMessage *msg, - struct interface_entry **iface_entry, - pa_dbus_property_handler **property_handler, - const char **attempted_property) { - const char *interface; +static enum find_result_t find_handler_from_properties_call(struct call_info *call_info) { + pa_assert(call_info); - pa_assert(obj_entry); - pa_assert(msg); - pa_assert(iface_entry); + if (pa_streq(call_info->method, "GetAll")) { + call_info->expected_method_sig = "s"; + if (!pa_streq(call_info->method_sig, call_info->expected_method_sig)) + return INVALID_METHOD_SIG; - if (dbus_message_has_member(msg, "GetAll")) { - if (!dbus_message_get_args(msg, NULL, DBUS_TYPE_STRING, &interface, DBUS_TYPE_INVALID)) - return INVALID_MESSAGE_ARGUMENTS; + pa_assert_se(dbus_message_get_args(call_info->message, NULL, + DBUS_TYPE_STRING, &call_info->property_interface, + DBUS_TYPE_INVALID)); - if (*interface) { - if ((*iface_entry = pa_hashmap_get(obj_entry->interfaces, interface))) + if (*call_info->property_interface) { + if ((call_info->iface_entry = pa_hashmap_get(call_info->obj_entry->interfaces, call_info->property_interface))) return FOUND_GET_ALL; - else { - return NO_SUCH_METHOD; /* XXX: NO_SUCH_INTERFACE or something like that might be more accurate. */ - } + else + return NO_SUCH_PROPERTY_INTERFACE; + } else { - pa_assert_se((*iface_entry = pa_hashmap_first(obj_entry->interfaces))); + pa_assert_se(call_info->iface_entry = pa_hashmap_first(call_info->obj_entry->interfaces)); return FOUND_GET_ALL; } - } else { - if (!dbus_message_get_args(msg, NULL, DBUS_TYPE_STRING, &interface, DBUS_TYPE_STRING, attempted_property, DBUS_TYPE_INVALID)) - return INVALID_MESSAGE_ARGUMENTS; - - if (*interface) { - if ((*iface_entry = pa_hashmap_get(obj_entry->interfaces, interface)) && - (*property_handler = pa_hashmap_get((*iface_entry)->property_handlers, *attempted_property))) { - if (dbus_message_has_member(msg, "Get")) - return (*property_handler)->get_cb ? FOUND_GET_PROPERTY : PROPERTY_ACCESS_DENIED; - else if (dbus_message_has_member(msg, "Set")) - return (*property_handler)->set_cb ? FOUND_SET_PROPERTY : PROPERTY_ACCESS_DENIED; + + } else if (pa_streq(call_info->method, "Get")) { + call_info->expected_method_sig = "ss"; + if (!pa_streq(call_info->method_sig, call_info->expected_method_sig)) + return INVALID_METHOD_SIG; + + pa_assert_se(dbus_message_get_args(call_info->message, NULL, + DBUS_TYPE_STRING, &call_info->property_interface, + DBUS_TYPE_STRING, &call_info->property, + DBUS_TYPE_INVALID)); + + if (*call_info->property_interface) { + if (!(call_info->iface_entry = pa_hashmap_get(call_info->obj_entry->interfaces, call_info->property_interface))) + return NO_SUCH_PROPERTY_INTERFACE; + else if ((call_info->property_handler = + pa_hashmap_get(call_info->iface_entry->property_handlers, call_info->property))) + return FOUND_GET_PROPERTY; + else + return NO_SUCH_PROPERTY; + + } else + return find_handler_by_property(call_info); + + } else if (pa_streq(call_info->method, "Set")) { + DBusMessageIter msg_iter; + + call_info->expected_method_sig = "ssv"; + if (!pa_streq(call_info->method_sig, call_info->expected_method_sig)) + return INVALID_METHOD_SIG; + + pa_assert_se(dbus_message_iter_init(call_info->message, &msg_iter)); + + dbus_message_iter_get_basic(&msg_iter, &call_info->property_interface); + pa_assert_se(dbus_message_iter_next(&msg_iter)); + dbus_message_iter_get_basic(&msg_iter, &call_info->property); + pa_assert_se(dbus_message_iter_next(&msg_iter)); + + dbus_message_iter_recurse(&msg_iter, &call_info->variant_iter); + + call_info->property_sig = dbus_message_iter_get_signature(&call_info->variant_iter); + + if (*call_info->property_interface) { + if (!(call_info->iface_entry = pa_hashmap_get(call_info->obj_entry->interfaces, call_info->property_interface))) + return NO_SUCH_PROPERTY_INTERFACE; + + else if ((call_info->property_handler = + pa_hashmap_get(call_info->iface_entry->property_handlers, call_info->property))) { + call_info->expected_property_sig = call_info->property_handler->type; + + if (pa_streq(call_info->property_sig, call_info->expected_property_sig)) + return FOUND_SET_PROPERTY; else - pa_assert_not_reached(); + return INVALID_PROPERTY_SIG; + } else return NO_SUCH_PROPERTY; + } else - return find_handler_by_property(obj_entry, msg, *attempted_property, iface_entry, property_handler); - } -} + return find_handler_by_property(call_info); -static enum find_result_t find_handler(struct object_entry *obj_entry, - DBusMessage *msg, - struct interface_entry **iface_entry, - pa_dbus_method_handler **method_handler, - pa_dbus_property_handler **property_handler, - const char **attempted_property) { - const char *interface; + } else + pa_assert_not_reached(); +} - pa_assert(obj_entry); - pa_assert(msg); - pa_assert(iface_entry); - pa_assert(method_handler); - pa_assert(property_handler); - pa_assert(attempted_property); +static enum find_result_t find_handler(struct call_info *call_info) { + pa_assert(call_info); - *iface_entry = NULL; - *method_handler = NULL; + if (call_info->interface) { + if (pa_streq(call_info->interface, DBUS_INTERFACE_PROPERTIES)) + return find_handler_from_properties_call(call_info); - if (dbus_message_has_interface(msg, DBUS_INTERFACE_PROPERTIES)) - return find_handler_from_properties_call(obj_entry, msg, iface_entry, property_handler, attempted_property); + else if (!(call_info->iface_entry = pa_hashmap_get(call_info->obj_entry->interfaces, call_info->interface))) + return NO_SUCH_INTERFACE; - else if ((interface = dbus_message_get_interface(msg))) { - if ((*iface_entry = pa_hashmap_get(obj_entry->interfaces, interface)) && - (*method_handler = pa_hashmap_get((*iface_entry)->method_handlers, dbus_message_get_member(msg)))) + else if ((call_info->method_handler = pa_hashmap_get(call_info->iface_entry->method_handlers, call_info->method))) return FOUND_METHOD; - else { - pa_log("Message has unknown interface or there's no method handler."); + + else return NO_SUCH_METHOD; - } } else { /* The method call doesn't contain an interface. */ - if (dbus_message_has_member(msg, "Get") || dbus_message_has_member(msg, "Set") || dbus_message_has_member(msg, "GetAll")) { - if (find_handler_by_method(obj_entry, dbus_message_get_member(msg), iface_entry, method_handler) == FOUND_METHOD) - return FOUND_METHOD; /* The object has a method named Get, Set or GetAll in some other interface than .Properties. */ + if (pa_streq(call_info->method, "Get") || pa_streq(call_info->method, "Set") || pa_streq(call_info->method, "GetAll")) { + if (find_handler_by_method(call_info) == FOUND_METHOD) + /* The object has a method named Get, Set or GetAll in some other interface than .Properties. */ + return FOUND_METHOD; else /* Assume this is a .Properties call. */ - return find_handler_from_properties_call(obj_entry, msg, iface_entry, property_handler, attempted_property); + return find_handler_from_properties_call(call_info); } else /* This is not a .Properties call. */ - return find_handler_by_method(obj_entry, dbus_message_get_member(msg), iface_entry, method_handler); + return find_handler_by_method(call_info); } } static DBusHandlerResult handle_message_cb(DBusConnection *connection, DBusMessage *message, void *user_data) { pa_dbus_protocol *p = user_data; - struct object_entry *obj_entry = NULL; - struct interface_entry *iface_entry = NULL; - pa_dbus_method_handler *method_handler = NULL; - pa_dbus_property_handler *property_handler = NULL; - const char *attempted_property = NULL; + struct call_info call_info; pa_assert(connection); pa_assert(message); @@ -423,49 +494,72 @@ static DBusHandlerResult handle_message_cb(DBusConnection *connection, DBusMessa dbus_message_get_interface(message), dbus_message_get_member(message)); - pa_assert_se((obj_entry = pa_hashmap_get(p->objects, dbus_message_get_path(message)))); + call_info.message = message; + pa_assert_se(call_info.obj_entry = pa_hashmap_get(p->objects, dbus_message_get_path(message))); + call_info.interface = dbus_message_get_interface(message); + pa_assert_se(call_info.method = dbus_message_get_member(message)); + pa_assert_se(call_info.method_sig = dbus_message_get_signature(message)); if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Introspectable", "Introspect") || (!dbus_message_get_interface(message) && dbus_message_has_member(message, "Introspect"))) { - pa_dbus_send_basic_value_reply(connection, message, DBUS_TYPE_STRING, &obj_entry->introspection); + pa_dbus_send_basic_value_reply(connection, message, DBUS_TYPE_STRING, &call_info.obj_entry->introspection); goto finish; } - switch (find_handler(obj_entry, message, &iface_entry, &method_handler, &property_handler, &attempted_property)) { - case FOUND_METHOD: - method_handler->receive_cb(connection, message, iface_entry->userdata); - break; - + switch (find_handler(&call_info)) { case FOUND_GET_PROPERTY: - property_handler->get_cb(connection, message, iface_entry->userdata); + call_info.property_handler->get_cb(connection, message, call_info.iface_entry->userdata); break; case FOUND_SET_PROPERTY: - property_handler->set_cb(connection, message, iface_entry->userdata); + call_info.property_handler->set_cb(connection, message, &call_info.variant_iter, call_info.iface_entry->userdata); + break; + + case FOUND_METHOD: + call_info.method_handler->receive_cb(connection, message, call_info.iface_entry->userdata); break; case FOUND_GET_ALL: - if (iface_entry->get_all_properties_cb) - iface_entry->get_all_properties_cb(connection, message, iface_entry->userdata); - /* TODO: Write an else branch where a dummy response is sent. */ + if (call_info.iface_entry->get_all_properties_cb) + call_info.iface_entry->get_all_properties_cb(connection, message, call_info.iface_entry->userdata); + else { + DBusMessage *dummy_reply = NULL; + DBusMessageIter msg_iter; + DBusMessageIter dict_iter; + + pa_assert_se(dummy_reply = dbus_message_new_method_return(message)); + dbus_message_iter_init_append(dummy_reply, &msg_iter); + pa_assert_se(dbus_message_iter_open_container(&msg_iter, DBUS_TYPE_ARRAY, "{sv}", &dict_iter)); + pa_assert_se(dbus_message_iter_close_container(&msg_iter, &dict_iter)); + pa_assert_se(dbus_connection_send(connection, dummy_reply, NULL)); + dbus_message_unref(dummy_reply); + } break; case PROPERTY_ACCESS_DENIED: - pa_dbus_send_error(connection, message, DBUS_ERROR_ACCESS_DENIED, "%s access denied for property %s", dbus_message_get_member(message), attempted_property); + pa_dbus_send_error(connection, message, DBUS_ERROR_ACCESS_DENIED, + "%s access denied for property %s", call_info.method, call_info.property); break; case NO_SUCH_METHOD: - pa_dbus_send_error(connection, message, DBUS_ERROR_UNKNOWN_METHOD, "%s: No such method", dbus_message_get_member(message)); + pa_dbus_send_error(connection, message, DBUS_ERROR_UNKNOWN_METHOD, "No such method: %s", call_info.method); break; case NO_SUCH_PROPERTY: - pa_dbus_send_error(connection, message, PA_DBUS_ERROR_NO_SUCH_PROPERTY, "%s: No such property", attempted_property); + pa_dbus_send_error(connection, message, PA_DBUS_ERROR_NO_SUCH_PROPERTY, "No such property: %s", call_info.property); break; - case INVALID_MESSAGE_ARGUMENTS: - pa_dbus_send_error(connection, message, DBUS_ERROR_INVALID_ARGS, "Invalid arguments for %s", dbus_message_get_member(message)); + case INVALID_METHOD_SIG: + pa_dbus_send_error(connection, message, DBUS_ERROR_INVALID_ARGS, + "Invalid signature for method %s: '%s'. Expected '%s'.", + call_info.method, call_info.method_sig, call_info.expected_method_sig); break; + case INVALID_PROPERTY_SIG: + pa_dbus_send_error(connection, message, DBUS_ERROR_INVALID_ARGS, + "Invalid signature for property %s: '%s'. Expected '%s'.", + call_info.property, call_info.property_sig, call_info.expected_property_sig); + default: pa_assert_not_reached(); } @@ -821,7 +915,12 @@ pa_client *pa_dbus_protocol_get_client(pa_dbus_protocol *p, DBusConnection *conn return conn_entry->client; } -void pa_dbus_protocol_add_signal_listener(pa_dbus_protocol *p, DBusConnection *conn, const char *signal, char **objects, unsigned n_objects) { +void pa_dbus_protocol_add_signal_listener( + pa_dbus_protocol *p, + DBusConnection *conn, + const char *signal, + char **objects, + unsigned n_objects) { struct connection_entry *conn_entry; pa_idxset *object_set; char *object_path; @@ -981,7 +1080,12 @@ int pa_dbus_protocol_unregister_extension(pa_dbus_protocol *p, const char *name) return 0; } -pa_hook_slot *pa_dbus_protocol_hook_connect(pa_dbus_protocol *p, pa_dbus_protocol_hook_t hook, pa_hook_priority_t prio, pa_hook_cb_t cb, void *data) { +pa_hook_slot *pa_dbus_protocol_hook_connect( + pa_dbus_protocol *p, + pa_dbus_protocol_hook_t hook, + pa_hook_priority_t prio, + pa_hook_cb_t cb, + void *data) { pa_assert(p); pa_assert(hook < PA_DBUS_PROTOCOL_HOOK_MAX); pa_assert(cb); -- cgit