diff options
Diffstat (limited to 'vendor/github.com/godbus/dbus/export.go')
-rw-r--r-- | vendor/github.com/godbus/dbus/export.go | 413 |
1 files changed, 413 insertions, 0 deletions
diff --git a/vendor/github.com/godbus/dbus/export.go b/vendor/github.com/godbus/dbus/export.go new file mode 100644 index 000000000..aae970881 --- /dev/null +++ b/vendor/github.com/godbus/dbus/export.go @@ -0,0 +1,413 @@ +package dbus + +import ( + "errors" + "fmt" + "reflect" + "strings" +) + +var ( + ErrMsgInvalidArg = Error{ + "org.freedesktop.DBus.Error.InvalidArgs", + []interface{}{"Invalid type / number of args"}, + } + ErrMsgNoObject = Error{ + "org.freedesktop.DBus.Error.NoSuchObject", + []interface{}{"No such object"}, + } + ErrMsgUnknownMethod = Error{ + "org.freedesktop.DBus.Error.UnknownMethod", + []interface{}{"Unknown / invalid method"}, + } + ErrMsgUnknownInterface = Error{ + "org.freedesktop.DBus.Error.UnknownInterface", + []interface{}{"Object does not implement the interface"}, + } +) + +func MakeFailedError(err error) *Error { + return &Error{ + "org.freedesktop.DBus.Error.Failed", + []interface{}{err.Error()}, + } +} + +// Sender is a type which can be used in exported methods to receive the message +// sender. +type Sender string + +func computeMethodName(name string, mapping map[string]string) string { + newname, ok := mapping[name] + if ok { + name = newname + } + return name +} + +func getMethods(in interface{}, mapping map[string]string) map[string]reflect.Value { + if in == nil { + return nil + } + methods := make(map[string]reflect.Value) + val := reflect.ValueOf(in) + typ := val.Type() + for i := 0; i < typ.NumMethod(); i++ { + methtype := typ.Method(i) + method := val.Method(i) + t := method.Type() + // only track valid methods must return *Error as last arg + // and must be exported + if t.NumOut() == 0 || + t.Out(t.NumOut()-1) != reflect.TypeOf(&ErrMsgInvalidArg) || + methtype.PkgPath != "" { + continue + } + // map names while building table + methods[computeMethodName(methtype.Name, mapping)] = method + } + return methods +} + +func standardMethodArgumentDecode(m Method, sender string, msg *Message, body []interface{}) ([]interface{}, error) { + pointers := make([]interface{}, m.NumArguments()) + decode := make([]interface{}, 0, len(body)) + + for i := 0; i < m.NumArguments(); i++ { + tp := reflect.TypeOf(m.ArgumentValue(i)) + val := reflect.New(tp) + pointers[i] = val.Interface() + if tp == reflect.TypeOf((*Sender)(nil)).Elem() { + val.Elem().SetString(sender) + } else if tp == reflect.TypeOf((*Message)(nil)).Elem() { + val.Elem().Set(reflect.ValueOf(*msg)) + } else { + decode = append(decode, pointers[i]) + } + } + + if len(decode) != len(body) { + return nil, ErrMsgInvalidArg + } + + if err := Store(body, decode...); err != nil { + return nil, ErrMsgInvalidArg + } + + return pointers, nil +} + +func (conn *Conn) decodeArguments(m Method, sender string, msg *Message) ([]interface{}, error) { + if decoder, ok := m.(ArgumentDecoder); ok { + return decoder.DecodeArguments(conn, sender, msg, msg.Body) + } + return standardMethodArgumentDecode(m, sender, msg, msg.Body) +} + +// handleCall handles the given method call (i.e. looks if it's one of the +// pre-implemented ones and searches for a corresponding handler if not). +func (conn *Conn) handleCall(msg *Message) { + name := msg.Headers[FieldMember].value.(string) + path := msg.Headers[FieldPath].value.(ObjectPath) + ifaceName, _ := msg.Headers[FieldInterface].value.(string) + sender, hasSender := msg.Headers[FieldSender].value.(string) + serial := msg.serial + if ifaceName == "org.freedesktop.DBus.Peer" { + switch name { + case "Ping": + conn.sendReply(sender, serial) + case "GetMachineId": + conn.sendReply(sender, serial, conn.uuid) + default: + conn.sendError(ErrMsgUnknownMethod, sender, serial) + } + return + } + if len(name) == 0 { + conn.sendError(ErrMsgUnknownMethod, sender, serial) + } + + object, ok := conn.handler.LookupObject(path) + if !ok { + conn.sendError(ErrMsgNoObject, sender, serial) + return + } + + iface, exists := object.LookupInterface(ifaceName) + if !exists { + conn.sendError(ErrMsgUnknownInterface, sender, serial) + return + } + + m, exists := iface.LookupMethod(name) + if !exists { + conn.sendError(ErrMsgUnknownMethod, sender, serial) + return + } + args, err := conn.decodeArguments(m, sender, msg) + if err != nil { + conn.sendError(err, sender, serial) + return + } + + ret, err := m.Call(args...) + if err != nil { + conn.sendError(err, sender, serial) + return + } + + if msg.Flags&FlagNoReplyExpected == 0 { + reply := new(Message) + reply.Type = TypeMethodReply + reply.serial = conn.getSerial() + reply.Headers = make(map[HeaderField]Variant) + if hasSender { + reply.Headers[FieldDestination] = msg.Headers[FieldSender] + } + reply.Headers[FieldReplySerial] = MakeVariant(msg.serial) + reply.Body = make([]interface{}, len(ret)) + for i := 0; i < len(ret); i++ { + reply.Body[i] = ret[i] + } + reply.Headers[FieldSignature] = MakeVariant(SignatureOf(reply.Body...)) + conn.outLck.RLock() + if !conn.closed { + conn.out <- reply + } + conn.outLck.RUnlock() + } +} + +// Emit emits the given signal on the message bus. The name parameter must be +// formatted as "interface.member", e.g., "org.freedesktop.DBus.NameLost". +func (conn *Conn) Emit(path ObjectPath, name string, values ...interface{}) error { + if !path.IsValid() { + return errors.New("dbus: invalid object path") + } + i := strings.LastIndex(name, ".") + if i == -1 { + return errors.New("dbus: invalid method name") + } + iface := name[:i] + member := name[i+1:] + if !isValidMember(member) { + return errors.New("dbus: invalid method name") + } + if !isValidInterface(iface) { + return errors.New("dbus: invalid interface name") + } + msg := new(Message) + msg.Type = TypeSignal + msg.serial = conn.getSerial() + msg.Headers = make(map[HeaderField]Variant) + msg.Headers[FieldInterface] = MakeVariant(iface) + msg.Headers[FieldMember] = MakeVariant(member) + msg.Headers[FieldPath] = MakeVariant(path) + msg.Body = values + if len(values) > 0 { + msg.Headers[FieldSignature] = MakeVariant(SignatureOf(values...)) + } + conn.outLck.RLock() + defer conn.outLck.RUnlock() + if conn.closed { + return ErrClosed + } + conn.out <- msg + return nil +} + +// Export registers the given value to be exported as an object on the +// message bus. +// +// If a method call on the given path and interface is received, an exported +// method with the same name is called with v as the receiver if the +// parameters match and the last return value is of type *Error. If this +// *Error is not nil, it is sent back to the caller as an error. +// Otherwise, a method reply is sent with the other return values as its body. +// +// Any parameters with the special type Sender are set to the sender of the +// dbus message when the method is called. Parameters of this type do not +// contribute to the dbus signature of the method (i.e. the method is exposed +// as if the parameters of type Sender were not there). +// +// Similarly, any parameters with the type Message are set to the raw message +// received on the bus. Again, parameters of this type do not contribute to the +// dbus signature of the method. +// +// Every method call is executed in a new goroutine, so the method may be called +// in multiple goroutines at once. +// +// Method calls on the interface org.freedesktop.DBus.Peer will be automatically +// handled for every object. +// +// Passing nil as the first parameter will cause conn to cease handling calls on +// the given combination of path and interface. +// +// Export returns an error if path is not a valid path name. +func (conn *Conn) Export(v interface{}, path ObjectPath, iface string) error { + return conn.ExportWithMap(v, nil, path, iface) +} + +// ExportWithMap works exactly like Export but provides the ability to remap +// method names (e.g. export a lower-case method). +// +// The keys in the map are the real method names (exported on the struct), and +// the values are the method names to be exported on DBus. +func (conn *Conn) ExportWithMap(v interface{}, mapping map[string]string, path ObjectPath, iface string) error { + return conn.export(getMethods(v, mapping), path, iface, false) +} + +// ExportSubtree works exactly like Export but registers the given value for +// an entire subtree rather under the root path provided. +// +// In order to make this useful, one parameter in each of the value's exported +// methods should be a Message, in which case it will contain the raw message +// (allowing one to get access to the path that caused the method to be called). +// +// Note that more specific export paths take precedence over less specific. For +// example, a method call using the ObjectPath /foo/bar/baz will call a method +// exported on /foo/bar before a method exported on /foo. +func (conn *Conn) ExportSubtree(v interface{}, path ObjectPath, iface string) error { + return conn.ExportSubtreeWithMap(v, nil, path, iface) +} + +// ExportSubtreeWithMap works exactly like ExportSubtree but provides the +// ability to remap method names (e.g. export a lower-case method). +// +// The keys in the map are the real method names (exported on the struct), and +// the values are the method names to be exported on DBus. +func (conn *Conn) ExportSubtreeWithMap(v interface{}, mapping map[string]string, path ObjectPath, iface string) error { + return conn.export(getMethods(v, mapping), path, iface, true) +} + +// ExportMethodTable like Export registers the given methods as an object +// on the message bus. Unlike Export the it uses a method table to define +// the object instead of a native go object. +// +// The method table is a map from method name to function closure +// representing the method. This allows an object exported on the bus to not +// necessarily be a native go object. It can be useful for generating exposed +// methods on the fly. +// +// Any non-function objects in the method table are ignored. +func (conn *Conn) ExportMethodTable(methods map[string]interface{}, path ObjectPath, iface string) error { + return conn.exportMethodTable(methods, path, iface, false) +} + +// Like ExportSubtree, but with the same caveats as ExportMethodTable. +func (conn *Conn) ExportSubtreeMethodTable(methods map[string]interface{}, path ObjectPath, iface string) error { + return conn.exportMethodTable(methods, path, iface, true) +} + +func (conn *Conn) exportMethodTable(methods map[string]interface{}, path ObjectPath, iface string, includeSubtree bool) error { + out := make(map[string]reflect.Value) + for name, method := range methods { + rval := reflect.ValueOf(method) + if rval.Kind() != reflect.Func { + continue + } + t := rval.Type() + // only track valid methods must return *Error as last arg + if t.NumOut() == 0 || + t.Out(t.NumOut()-1) != reflect.TypeOf(&ErrMsgInvalidArg) { + continue + } + out[name] = rval + } + return conn.export(out, path, iface, includeSubtree) +} + +func (conn *Conn) unexport(h *defaultHandler, path ObjectPath, iface string) error { + if h.PathExists(path) { + obj := h.objects[path] + obj.DeleteInterface(iface) + if len(obj.interfaces) == 0 { + h.DeleteObject(path) + } + } + return nil +} + +// exportWithMap is the worker function for all exports/registrations. +func (conn *Conn) export(methods map[string]reflect.Value, path ObjectPath, iface string, includeSubtree bool) error { + h, ok := conn.handler.(*defaultHandler) + if !ok { + return fmt.Errorf( + `dbus: export only allowed on the default hander handler have %T"`, + conn.handler) + } + + if !path.IsValid() { + return fmt.Errorf(`dbus: Invalid path name: "%s"`, path) + } + + // Remove a previous export if the interface is nil + if methods == nil { + return conn.unexport(h, path, iface) + } + + // If this is the first handler for this path, make a new map to hold all + // handlers for this path. + if !h.PathExists(path) { + h.AddObject(path, newExportedObject()) + } + + exportedMethods := make(map[string]Method) + for name, method := range methods { + exportedMethods[name] = exportedMethod{method} + } + + // Finally, save this handler + obj := h.objects[path] + obj.AddInterface(iface, newExportedIntf(exportedMethods, includeSubtree)) + + return nil +} + +// ReleaseName calls org.freedesktop.DBus.ReleaseName and awaits a response. +func (conn *Conn) ReleaseName(name string) (ReleaseNameReply, error) { + var r uint32 + err := conn.busObj.Call("org.freedesktop.DBus.ReleaseName", 0, name).Store(&r) + if err != nil { + return 0, err + } + return ReleaseNameReply(r), nil +} + +// RequestName calls org.freedesktop.DBus.RequestName and awaits a response. +func (conn *Conn) RequestName(name string, flags RequestNameFlags) (RequestNameReply, error) { + var r uint32 + err := conn.busObj.Call("org.freedesktop.DBus.RequestName", 0, name, flags).Store(&r) + if err != nil { + return 0, err + } + return RequestNameReply(r), nil +} + +// ReleaseNameReply is the reply to a ReleaseName call. +type ReleaseNameReply uint32 + +const ( + ReleaseNameReplyReleased ReleaseNameReply = 1 + iota + ReleaseNameReplyNonExistent + ReleaseNameReplyNotOwner +) + +// RequestNameFlags represents the possible flags for a RequestName call. +type RequestNameFlags uint32 + +const ( + NameFlagAllowReplacement RequestNameFlags = 1 << iota + NameFlagReplaceExisting + NameFlagDoNotQueue +) + +// RequestNameReply is the reply to a RequestName call. +type RequestNameReply uint32 + +const ( + RequestNameReplyPrimaryOwner RequestNameReply = 1 + iota + RequestNameReplyInQueue + RequestNameReplyExists + RequestNameReplyAlreadyOwner +) |