| package dbus |
| |
| import ( |
| "errors" |
| "reflect" |
| "strings" |
| "unicode" |
| ) |
| |
| 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"}, |
| } |
| ) |
| |
| // Sender is a type which can be used in exported methods to receive the message |
| // sender. |
| type Sender string |
| |
| func exportedMethod(v interface{}, name string) reflect.Value { |
| if v == nil { |
| return reflect.Value{} |
| } |
| m := reflect.ValueOf(v).MethodByName(name) |
| if !m.IsValid() { |
| return reflect.Value{} |
| } |
| t := m.Type() |
| if t.NumOut() == 0 || |
| t.Out(t.NumOut()-1) != reflect.TypeOf(&errmsgInvalidArg) { |
| |
| return reflect.Value{} |
| } |
| return m |
| } |
| |
| // 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, hasIface := 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 || unicode.IsLower([]rune(name)[0]) { |
| conn.sendError(errmsgUnknownMethod, sender, serial) |
| } |
| var m reflect.Value |
| if hasIface { |
| conn.handlersLck.RLock() |
| obj, ok := conn.handlers[path] |
| if !ok { |
| conn.sendError(errmsgNoObject, sender, serial) |
| conn.handlersLck.RUnlock() |
| return |
| } |
| iface := obj[ifaceName] |
| conn.handlersLck.RUnlock() |
| m = exportedMethod(iface, name) |
| } else { |
| conn.handlersLck.RLock() |
| if _, ok := conn.handlers[path]; !ok { |
| conn.sendError(errmsgNoObject, sender, serial) |
| conn.handlersLck.RUnlock() |
| return |
| } |
| for _, v := range conn.handlers[path] { |
| m = exportedMethod(v, name) |
| if m.IsValid() { |
| break |
| } |
| } |
| conn.handlersLck.RUnlock() |
| } |
| if !m.IsValid() { |
| conn.sendError(errmsgUnknownMethod, sender, serial) |
| return |
| } |
| t := m.Type() |
| vs := msg.Body |
| pointers := make([]interface{}, t.NumIn()) |
| decode := make([]interface{}, 0, len(vs)) |
| for i := 0; i < t.NumIn(); i++ { |
| tp := t.In(i) |
| val := reflect.New(tp) |
| pointers[i] = val.Interface() |
| if tp == reflect.TypeOf((*Sender)(nil)).Elem() { |
| val.Elem().SetString(sender) |
| } else { |
| decode = append(decode, pointers[i]) |
| } |
| } |
| if len(decode) != len(vs) { |
| conn.sendError(errmsgInvalidArg, sender, serial) |
| return |
| } |
| if err := Store(vs, decode...); err != nil { |
| conn.sendError(errmsgInvalidArg, sender, serial) |
| return |
| } |
| params := make([]reflect.Value, len(pointers)) |
| for i := 0; i < len(pointers); i++ { |
| params[i] = reflect.ValueOf(pointers[i]).Elem() |
| } |
| ret := m.Call(params) |
| if em := ret[t.NumOut()-1].Interface().(*Error); em != nil { |
| conn.sendError(*em, 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)-1) |
| for i := 0; i < len(ret)-1; i++ { |
| reply.Body[i] = ret[i].Interface() |
| } |
| if len(ret) != 1 { |
| 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). |
| // |
| // 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 { |
| if !path.IsValid() { |
| return errors.New("dbus: invalid path name") |
| } |
| conn.handlersLck.Lock() |
| if v == nil { |
| if _, ok := conn.handlers[path]; ok { |
| delete(conn.handlers[path], iface) |
| if len(conn.handlers[path]) == 0 { |
| delete(conn.handlers, path) |
| } |
| } |
| return nil |
| } |
| if _, ok := conn.handlers[path]; !ok { |
| conn.handlers[path] = make(map[string]interface{}) |
| } |
| conn.handlers[path][iface] = v |
| conn.handlersLck.Unlock() |
| return nil |
| } |
| |
| // ReleaseName calls org.freedesktop.DBus.ReleaseName. You should use only this |
| // method to release a name (see below). |
| 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 |
| } |
| if r == uint32(ReleaseNameReplyReleased) { |
| conn.namesLck.Lock() |
| for i, v := range conn.names { |
| if v == name { |
| copy(conn.names[i:], conn.names[i+1:]) |
| conn.names = conn.names[:len(conn.names)-1] |
| } |
| } |
| conn.namesLck.Unlock() |
| } |
| return ReleaseNameReply(r), nil |
| } |
| |
| // RequestName calls org.freedesktop.DBus.RequestName. You should use only this |
| // method to request a name because package dbus needs to keep track of all |
| // names that the connection has. |
| 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 |
| } |
| if r == uint32(RequestNameReplyPrimaryOwner) { |
| conn.namesLck.Lock() |
| conn.names = append(conn.names, name) |
| conn.namesLck.Unlock() |
| } |
| 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 |
| ) |