dbus

package module
v5.1.0 Latest Latest
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 Go to latest Published: Feb 27, 2022 License: BSD-2-Clause Imports: 26 Imported by: 1,496

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dbus

dbus is a simple library that implements native Go client bindings for the D-Bus message bus system.

Features

  • Complete native implementation of the D-Bus message protocol
  • Go-like API (channels for signals / asynchronous method calls, Goroutine-safe connections)
  • Subpackages that help with the introspection / property interfaces

Installation

This packages requires Go 1.12 or later. It can be installed by running the command below:

go get github.com/godbus/dbus/v5

Usage

The complete package documentation and some simple examples are available at godoc.org. Also, the _examples directory gives a short overview over the basic usage.

Projects using godbus
  • fyne a cross platform GUI in Go inspired by Material Design.
  • fynedesk a full desktop environment for Linux/Unix using Fyne.
  • go-bluetooth provides a bluetooth client over bluez dbus API.
  • iwd go bindings for the internet wireless daemon "iwd".
  • notify provides desktop notifications over dbus into a library.
  • playerbm a bookmark utility for media players.

Please note that the API is considered unstable for now and may change without further notice.

License

go.dbus is available under the Simplified BSD License; see LICENSE for the full text.

Nearly all of the credit for this library goes to github.com/guelfey/go.dbus.

Documentation

Overview

Package dbus implements bindings to the D-Bus message bus system.

To use the message bus API, you first need to connect to a bus (usually the session or system bus). The acquired connection then can be used to call methods on remote objects and emit or receive signals. Using the Export method, you can arrange D-Bus methods calls to be directly translated to method calls on a Go value.

Conversion Rules

For outgoing messages, Go types are automatically converted to the corresponding D-Bus types. See the official specification at https://dbus.freedesktop.org/doc/dbus-specification.html#type-system for more information on the D-Bus type system. The following types are directly encoded as their respective D-Bus equivalents: 

Go type     | D-Bus type
------------+-----------
byte        | BYTE
bool        | BOOLEAN
int16       | INT16
uint16      | UINT16
int         | INT32
uint        | UINT32
int32       | INT32
uint32      | UINT32
int64       | INT64
uint64      | UINT64
float64     | DOUBLE
string      | STRING
ObjectPath  | OBJECT_PATH
Signature   | SIGNATURE
Variant     | VARIANT
interface{} | VARIANT
UnixFDIndex | UNIX_FD

Slices and arrays encode as ARRAYs of their element type.

Maps encode as DICTs, provided that their key type can be used as a key for a DICT.

Structs other than Variant and Signature encode as a STRUCT containing their exported fields in order. Fields whose tags contain `dbus:"-"` and unexported fields will be skipped.

Pointers encode as the value they're pointed to.

Types convertible to one of the base types above will be mapped as the base type.

Trying to encode any other type or a slice, map or struct containing an unsupported type will result in an InvalidTypeError.

For incoming messages, the inverse of these rules are used, with the exception of STRUCTs. Incoming STRUCTS are represented as a slice of empty interfaces containing the struct fields in the correct order. The Store function can be used to convert such values to Go structs.

Unix FD passing

Handling Unix file descriptors deserves special mention. To use them, you should first check that they are supported on a connection by calling SupportsUnixFDs. If it returns true, all method of Connection will translate messages containing UnixFD's to messages that are accompanied by the given file descriptors with the UnixFD values being substituted by the correct indices. Similarly, the indices of incoming messages are automatically resolved. It shouldn't be necessary to use UnixFDIndex.

Index

Examples

Constants

This section is empty.

Variables

View Source 
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"},
	}
)
View Source 
var ErrClosed = errors.New("dbus: connection closed by user")

ErrClosed is the error returned by calls on a closed connection.

Functions

func EscapeBusAddressValue added in v5.1.0 

func EscapeBusAddressValue(val string) string

EscapeBusAddressValue implements a requirement to escape the values in D-Bus server addresses, as defined by the D-Bus specification at https://dbus.freedesktop.org/doc/dbus-specification.html#addresses.

func NewDefaultHandler deprecated 

func NewDefaultHandler() *defaultHandler

NewDefaultHandler returns an instance of the default call handler. This is useful if you want to implement only one of the two handlers but not both.

Deprecated: this is the default value, don't use it, it will be unexported.

func NewDefaultSignalHandler deprecated 

func NewDefaultSignalHandler() *defaultSignalHandler

NewDefaultSignalHandler returns an instance of the default signal handler. This is useful if you want to implement only one of the two handlers but not both.

Deprecated: this is the default value, don't use it, it will be unexported.

func Store 

func Store(src []interface{}, dest ...interface{}) error

Store copies the values contained in src to dest, which must be a slice of pointers. It converts slices of interfaces from src to corresponding structs in dest. An error is returned if the lengths of src and dest or the types of their elements don't match.

func UnescapeBusAddressValue added in v5.1.0 

func UnescapeBusAddressValue(val string) (string, error)

UnescapeBusAddressValue unescapes values in D-Bus server addresses, as defined by the D-Bus specification at https://dbus.freedesktop.org/doc/dbus-specification.html#addresses.

Types

type ArgumentDecoder 

type ArgumentDecoder interface {
	// To decode the arguments of a method the sender and message are
	// provided in case the semantics of the implementer provides access
	// to these as part of the method invocation.
	DecodeArguments(conn *Conn, sender string, msg *Message, args []interface{}) ([]interface{}, error)
}

An Argument Decoder can decode arguments using the non-standard mechanism

If a method implements this interface then the non-standard decoder will be used.

Method arguments must be decoded from the message. The mechanism for doing this will vary based on the implementation of the method. A normal approach is provided as part of this library, but may be replaced with any other decoding scheme.

type Auth 

type Auth interface {
	// Return the name of the mechanism, the argument to the first AUTH command
	// and the next status.
	FirstData() (name, resp []byte, status AuthStatus)

	// Process the given DATA command, and return the argument to the DATA
	// command and the next status. If len(resp) == 0, no DATA command is sent.
	HandleData(data []byte) (resp []byte, status AuthStatus)
}

Auth defines the behaviour of an authentication mechanism.

func AuthAnonymous 

func AuthAnonymous() Auth

AuthAnonymous returns an Auth that uses the ANONYMOUS mechanism.

func AuthCookieSha1 

func AuthCookieSha1(user, home string) Auth

AuthCookieSha1 returns an Auth that authenticates as the given user with the DBUS_COOKIE_SHA1 mechanism. The home parameter should specify the home directory of the user.

func AuthExternal 

func AuthExternal(user string) Auth

AuthExternal returns an Auth that authenticates as the given user with the EXTERNAL mechanism.

type AuthStatus 

type AuthStatus byte

AuthStatus represents the Status of an authentication mechanism. 

const (
	// AuthOk signals that authentication is finished; the next command
	// from the server should be an OK.
	AuthOk AuthStatus = iota

	// AuthContinue signals that additional data is needed; the next command
	// from the server should be a DATA.
	AuthContinue

	// AuthError signals an error; the server sent invalid data or some
	// other unexpected thing happened and the current authentication
	// process should be aborted.
	AuthError
)

type BusObject 

type BusObject interface {
	Call(method string, flags Flags, args ...interface{}) *Call
	CallWithContext(ctx context.Context, method string, flags Flags, args ...interface{}) *Call
	Go(method string, flags Flags, ch chan *Call, args ...interface{}) *Call
	GoWithContext(ctx context.Context, method string, flags Flags, ch chan *Call, args ...interface{}) *Call
	AddMatchSignal(iface, member string, options ...MatchOption) *Call
	RemoveMatchSignal(iface, member string, options ...MatchOption) *Call
	GetProperty(p string) (Variant, error)
	StoreProperty(p string, value interface{}) error
	SetProperty(p string, v interface{}) error
	Destination() string
	Path() ObjectPath
}

BusObject is the interface of a remote object on which methods can be invoked.

type Call 

type Call struct {
	Destination string
	Path        ObjectPath
	Method      string
	Args        []interface{}

	// Strobes when the call is complete.
	Done chan *Call

	// After completion, the error status. If this is non-nil, it may be an
	// error message from the peer (with Error as its type) or some other error.
	Err error

	// Holds the response once the call is done.
	Body []interface{}

	// ResponseSequence stores the sequence number of the DBus message containing
	// the call response (or error). This can be compared to the sequence number
	// of other call responses and signals on this connection to determine their
	// relative ordering on the underlying DBus connection.
	// For errors, ResponseSequence is populated only if the error came from a
	// DBusMessage that was received or if there was an error receiving. In case of
	// failure to make the call, ResponseSequence will be NoSequence.
	ResponseSequence Sequence
	// contains filtered or unexported fields
}

Call represents a pending or completed method call.

func (*Call) Context 

func (c *Call) Context() context.Context

func (*Call) ContextCancel 

func (c *Call) ContextCancel()

func (*Call) Store 

func (c *Call) Store(retvalues ...interface{}) error

Store stores the body of the reply into the provided pointers. It returns an error if the signatures of the body and retvalues don't match, or if the error status is not nil.

type Conn 

type Conn struct {
	// contains filtered or unexported fields
}

Conn represents a connection to a message bus (usually, the system or session bus).

Connections are either shared or private. Shared connections are shared between calls to the functions that return them. As a result, the methods Close, Auth and Hello must not be called on them.

Multiple goroutines may invoke methods on a connection simultaneously.

func Connect added in v5.0.4 

func Connect(address string, opts ...ConnOption) (*Conn, error)

Connect connects to the given address.

Returned connection is ready to use and doesn't require calling Auth and Hello methods to make it usable.

func ConnectSessionBus added in v5.0.4 

func ConnectSessionBus(opts ...ConnOption) (*Conn, error)

ConnectSessionBus connects to the session bus.

func ConnectSystemBus added in v5.0.4 

func ConnectSystemBus(opts ...ConnOption) (*Conn, error)

ConnectSystemBus connects to the system bus.

func Dial 

func Dial(address string, opts ...ConnOption) (*Conn, error)

Dial establishes a new private connection to the message bus specified by address.

func DialHandler deprecated 

func DialHandler(address string, handler Handler, signalHandler SignalHandler) (*Conn, error)

DialHandler establishes a new private connection to the message bus specified by address, using the supplied handlers.

Deprecated: use Dial with options instead.

func NewConn 

func NewConn(conn io.ReadWriteCloser, opts ...ConnOption) (*Conn, error)

NewConn creates a new private *Conn from an already established connection.

func NewConnHandler deprecated 

func NewConnHandler(conn io.ReadWriteCloser, handler Handler, signalHandler SignalHandler) (*Conn, error)

NewConnHandler creates a new private *Conn from an already established connection, using the supplied handlers.

Deprecated: use NewConn with options instead.

func SessionBus 

func SessionBus() (conn *Conn, err error)

SessionBus returns a shared connection to the session bus, connecting to it if not already done.

func SessionBusPrivate 

func SessionBusPrivate(opts ...ConnOption) (*Conn, error)

SessionBusPrivate returns a new private connection to the session bus.

func SessionBusPrivateHandler deprecated 

func SessionBusPrivateHandler(handler Handler, signalHandler SignalHandler) (*Conn, error)

SessionBusPrivate returns a new private connection to the session bus.

Deprecated: use SessionBusPrivate with options instead.

func SessionBusPrivateNoAutoStartup added in v5.0.6 

func SessionBusPrivateNoAutoStartup(opts ...ConnOption) (*Conn, error)

SessionBusPrivate returns a new private connection to the session bus. If the session bus is not already open, do not attempt to launch it.

func SystemBus 

func SystemBus() (conn *Conn, err error)

SystemBus returns a shared connection to the system bus, connecting to it if not already done.

func SystemBusPrivate 

func SystemBusPrivate(opts ...ConnOption) (*Conn, error)

SystemBusPrivate returns a new private connection to the system bus. Note: this connection is not ready to use. One must perform Auth and Hello on the connection before it is usable.

func SystemBusPrivateHandler deprecated 

func SystemBusPrivateHandler(handler Handler, signalHandler SignalHandler) (*Conn, error)

SystemBusPrivateHandler returns a new private connection to the system bus, using the provided handlers.

Deprecated: use SystemBusPrivate with options instead.

func (*Conn) AddMatchSignal 

func (conn *Conn) AddMatchSignal(options ...MatchOption) error

AddMatchSignal registers the given match rule to receive broadcast signals based on their contents.

func (*Conn) AddMatchSignalContext added in v5.0.4 

func (conn *Conn) AddMatchSignalContext(ctx context.Context, options ...MatchOption) error

AddMatchSignalContext acts like AddMatchSignal but takes a context.

func (*Conn) Auth 

func (conn *Conn) Auth(methods []Auth) error

Auth authenticates the connection, trying the given list of authentication mechanisms (in that order). If nil is passed, the EXTERNAL and DBUS_COOKIE_SHA1 mechanisms are tried for the current user. For private connections, this method must be called before sending any messages to the bus. Auth must not be called on shared connections.

func (*Conn) BusObject 

func (conn *Conn) BusObject() BusObject

BusObject returns the object owned by the bus daemon which handles administrative requests.

func (*Conn) Close 

func (conn *Conn) Close() error

Close closes the connection. Any blocked operations will return with errors and the channels passed to Eavesdrop and Signal are closed. This method must not be called on shared connections.

func (*Conn) Connected added in v5.0.4 

func (conn *Conn) Connected() bool

Connected returns whether conn is connected

func (*Conn) Context added in v5.0.3 

func (conn *Conn) Context() context.Context

Context returns the context associated with the connection. The context will be cancelled when the connection is closed.

func (*Conn) Eavesdrop 

func (conn *Conn) Eavesdrop(ch chan<- *Message)

Eavesdrop causes conn to send all incoming messages to the given channel without further processing. Method replies, errors and signals will not be sent to the appropriate channels and method calls will not be handled. If nil is passed, the normal behaviour is restored.

The caller has to make sure that ch is sufficiently buffered; if a message arrives when a write to ch is not possible, the message is discarded.

func (*Conn) Emit 

func (conn *Conn) Emit(path ObjectPath, name string, values ...interface{}) error

Emit emits the given signal on the message bus. The name parameter must be formatted as "interface.member", e.g., "org.freedesktop.DBus.NameLost".

Example 
conn, err := ConnectSystemBus()
if err != nil {
	panic(err)
}
defer conn.Close()

if err := conn.Emit("/foo/bar", "foo.bar.Baz", uint32(0xDAEDBEEF)); err != nil {
	panic(err)
}

Output:

func (*Conn) Export 

func (conn *Conn) Export(v interface{}, path ObjectPath, iface string) error

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) ExportAll added in v5.0.4 

func (conn *Conn) ExportAll(v interface{}, path ObjectPath, iface string) error

ExportAll registers all exported methods defined by the given object on the message bus.

Unlike Export there is no requirement to have the last parameter as type *Error. If you want to be able to return error then you can append an error type parameter to your method signature. If the error returned 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.

func (*Conn) ExportMethodTable 

func (conn *Conn) ExportMethodTable(methods map[string]interface{}, path ObjectPath, iface string) error

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) ExportSubtree 

func (conn *Conn) ExportSubtree(v interface{}, path ObjectPath, iface string) error

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) ExportSubtreeMethodTable 

func (conn *Conn) ExportSubtreeMethodTable(methods map[string]interface{}, path ObjectPath, iface string) error

Like ExportSubtree, but with the same caveats as ExportMethodTable.

func (*Conn) ExportSubtreeWithMap 

func (conn *Conn) ExportSubtreeWithMap(v interface{}, mapping map[string]string, path ObjectPath, iface string) error

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) ExportWithMap 

func (conn *Conn) ExportWithMap(v interface{}, mapping map[string]string, path ObjectPath, iface string) error

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) Hello 

func (conn *Conn) Hello() error

Hello sends the initial org.freedesktop.DBus.Hello call. This method must be called after authentication, but before sending any other messages to the bus. Hello must not be called for shared connections.

func (*Conn) Names 

func (conn *Conn) Names() []string

Names returns the list of all names that are currently owned by this connection. The slice is always at least one element long, the first element being the unique name of the connection.

func (*Conn) Object 

func (conn *Conn) Object(dest string, path ObjectPath) BusObject

Object returns the object identified by the given destination name and path.

func (*Conn) ReleaseName 

func (conn *Conn) ReleaseName(name string) (ReleaseNameReply, error)

ReleaseName calls org.freedesktop.DBus.ReleaseName and awaits a response.

func (*Conn) RemoveMatchSignal 

func (conn *Conn) RemoveMatchSignal(options ...MatchOption) error

RemoveMatchSignal removes the first rule that matches previously registered with AddMatchSignal.

func (*Conn) RemoveMatchSignalContext added in v5.0.4 

func (conn *Conn) RemoveMatchSignalContext(ctx context.Context, options ...MatchOption) error

RemoveMatchSignalContext acts like RemoveMatchSignal but takes a context.

func (*Conn) RemoveSignal 

func (conn *Conn) RemoveSignal(ch chan<- *Signal)

RemoveSignal removes the given channel from the list of the registered channels.

Panics if the signal handler is not a `SignalRegistrar`.

func (*Conn) RequestName 

func (conn *Conn) RequestName(name string, flags RequestNameFlags) (RequestNameReply, error)

RequestName calls org.freedesktop.DBus.RequestName and awaits a response.

func (*Conn) Send 

func (conn *Conn) Send(msg *Message, ch chan *Call) *Call

Send sends the given message to the message bus. You usually don't need to use this; use the higher-level equivalents (Call / Go, Emit and Export) instead. If msg is a method call and NoReplyExpected is not set, a non-nil call is returned and the same value is sent to ch (which must be buffered) once the call is complete. Otherwise, ch is ignored and a Call structure is returned of which only the Err member is valid.

func (*Conn) SendWithContext 

func (conn *Conn) SendWithContext(ctx context.Context, msg *Message, ch chan *Call) *Call

SendWithContext acts like Send but takes a context

func (*Conn) Signal 

func (conn *Conn) Signal(ch chan<- *Signal)

Signal registers the given channel to be passed all received signal messages.

Multiple of these channels can be registered at the same time. The channel is closed if the Conn is closed; it should not be closed by the caller before RemoveSignal was called on it.

These channels are "overwritten" by Eavesdrop; i.e., if there currently is a channel for eavesdropped messages, this channel receives all signals, and none of the channels passed to Signal will receive any signals.

Panics if the signal handler is not a `SignalRegistrar`.

func (*Conn) SupportsUnixFDs 

func (conn *Conn) SupportsUnixFDs() bool

SupportsUnixFDs returns whether the underlying transport supports passing of unix file descriptors. If this is false, method calls containing unix file descriptors will return an error and emitted signals containing them will not be sent.

type ConnOption 

type ConnOption func(conn *Conn) error

ConnOption is a connection option.

func WithAuth added in v5.0.4 

func WithAuth(methods ...Auth) ConnOption

WithAuth sets authentication methods for the auth conversation.

func WithContext added in v5.0.3 

func WithContext(ctx context.Context) ConnOption

WithContext overrides the default context for the connection.

func WithHandler 

func WithHandler(handler Handler) ConnOption

WithHandler overrides the default handler.

func WithIncomingInterceptor added in v5.0.3 

func WithIncomingInterceptor(interceptor Interceptor) ConnOption

WithIncomingInterceptor sets the given interceptor for incoming messages.

func WithOutgoingInterceptor added in v5.0.3 

func WithOutgoingInterceptor(interceptor Interceptor) ConnOption

WithOutgoingInterceptor sets the given interceptor for outgoing messages.

func WithSerialGenerator 

func WithSerialGenerator(gen SerialGenerator) ConnOption

WithSerialGenerator overrides the default signals generator.

func WithSignalHandler 

func WithSignalHandler(handler SignalHandler) ConnOption

WithSignalHandler overrides the default signal handler.

type DBusError 

type DBusError interface {
	DBusError() (string, []interface{})
}

A DBusError is used to convert a generic object to a D-Bus error.

Any custom error mechanism may implement this interface to provide a custom encoding of the error on D-Bus. By default if a normal error is returned, it will be encoded as the generic "org.freedesktop.DBus.Error.Failed" error. By implementing this interface as well a custom encoding may be provided.

type Error 

type Error struct {
	Name string
	Body []interface{}
}

Error represents a D-Bus message of type Error.

func MakeFailedError 

func MakeFailedError(err error) *Error

func MakeNoObjectError added in v5.0.5 

func MakeNoObjectError(path ObjectPath) Error

func MakeUnknownInterfaceError added in v5.0.5 

func MakeUnknownInterfaceError(ifaceName string) Error

func MakeUnknownMethodError added in v5.0.5 

func MakeUnknownMethodError(methodName string) Error

func NewError 

func NewError(name string, body []interface{}) *Error

func (Error) Error 

func (e Error) Error() string

type Flags 

type Flags byte

Flags represents the possible flags of a D-Bus message. 

const (
	// FlagNoReplyExpected signals that the message is not expected to generate
	// a reply. If this flag is set on outgoing messages, any possible reply
	// will be discarded.
	FlagNoReplyExpected Flags = 1 << iota
	// FlagNoAutoStart signals that the message bus should not automatically
	// start an application when handling this message.
	FlagNoAutoStart
	// FlagAllowInteractiveAuthorization may be set on a method call
	// message to inform the receiving side that the caller is prepared
	// to wait for interactive authorization, which might take a
	// considerable time to complete. For instance, if this flag is set,
	// it would be appropriate to query the user for passwords or
	// confirmation via Polkit or a similar framework.
	FlagAllowInteractiveAuthorization
)

type FormatError 

type FormatError string

A FormatError is an error in the wire format.

func (FormatError) Error 

func (e FormatError) Error() string

type Handler 

type Handler interface {
	LookupObject(path ObjectPath) (ServerObject, bool)
}

Handler is the representation of a D-Bus Application.

The Handler must have a way to lookup objects given an ObjectPath. The returned object must implement the ServerObject interface.

type HeaderField 

type HeaderField byte

HeaderField represents the possible byte codes for the headers of a D-Bus message. 

const (
	FieldPath HeaderField = 1 + iota
	FieldInterface
	FieldMember
	FieldErrorName
	FieldReplySerial
	FieldDestination
	FieldSender
	FieldSignature
	FieldUnixFDs
)

type Interceptor added in v5.0.3 

type Interceptor func(msg *Message)

Interceptor intercepts incoming and outgoing messages.

type Interface 

type Interface interface {
	LookupMethod(name string) (Method, bool)
}

An Interface is the representation of a D-Bus Interface.

Interfaces are a grouping of methods implemented by the Objects. Interfaces are responsible for routing method calls.

type InvalidMessageError 

type InvalidMessageError string

An InvalidMessageError describes the reason why a D-Bus message is regarded as invalid.

func (InvalidMessageError) Error 

func (e InvalidMessageError) Error() string

type InvalidTypeError 

type InvalidTypeError struct {
	Type reflect.Type
}

An InvalidTypeError signals that a value which cannot be represented in the D-Bus wire format was passed to a function.

func (InvalidTypeError) Error 

func (e InvalidTypeError) Error() string

type MatchOption 

type MatchOption struct {
	// contains filtered or unexported fields
}

MatchOption specifies option for dbus routing match rule. Options can be constructed with WithMatch* helpers. For full list of available options consult https://dbus.freedesktop.org/doc/dbus-specification.html#message-bus-routing-match-rules

func WithMatchArg added in v5.0.4 

func WithMatchArg(argIdx int, value string) MatchOption

WithMatchArg sets argN match option, range of N is 0 to 63.

func WithMatchArg0Namespace added in v5.0.4 

func WithMatchArg0Namespace(arg0Namespace string) MatchOption

WithMatchArg0Namespace sets arg0namespace match option.

func WithMatchArgPath added in v5.0.4 

func WithMatchArgPath(argIdx int, path string) MatchOption

WithMatchArgPath sets argN path match option, range of N is 0 to 63.

func WithMatchDestination 

func WithMatchDestination(destination string) MatchOption

WithMatchDestination sets destination match option.

func WithMatchEavesdrop added in v5.0.4 

func WithMatchEavesdrop(eavesdrop bool) MatchOption

WithMatchEavesdrop sets eavesdrop match option.

func WithMatchInterface 

func WithMatchInterface(iface string) MatchOption

WithMatchSender sets interface match option.

func WithMatchMember 

func WithMatchMember(member string) MatchOption

WithMatchMember sets member match option.

func WithMatchObjectPath 

func WithMatchObjectPath(path ObjectPath) MatchOption

WithMatchObjectPath creates match option that filters events based on given path

func WithMatchOption 

func WithMatchOption(key, value string) MatchOption

WithMatchOption creates match option with given key and value

func WithMatchPathNamespace 

func WithMatchPathNamespace(namespace ObjectPath) MatchOption

WithMatchPathNamespace sets path_namespace match option.

func WithMatchSender 

func WithMatchSender(sender string) MatchOption

WithMatchSender sets sender match option.

type Message 

type Message struct {
	Type
	Flags
	Headers map[HeaderField]Variant
	Body    []interface{}
	// contains filtered or unexported fields
}

Message represents a single D-Bus message.

func DecodeMessage 

func DecodeMessage(rd io.Reader) (msg *Message, err error)

DecodeMessage tries to decode a single message in the D-Bus wire format from the given reader. The byte order is figured out from the first byte. The possibly returned error can be an error of the underlying reader, an InvalidMessageError or a FormatError.

func DecodeMessageWithFDs added in v5.0.5 

func DecodeMessageWithFDs(rd io.Reader, fds []int) (msg *Message, err error)

func (*Message) CountFds added in v5.0.5 

func (msg *Message) CountFds() (int, error)

func (*Message) EncodeTo 

func (msg *Message) EncodeTo(out io.Writer, order binary.ByteOrder) (err error)

EncodeTo encodes and sends a message to the given writer. The byte order must be either binary.LittleEndian or binary.BigEndian. If the message is not valid or an error occurs when writing, an error is returned.

func (*Message) EncodeToWithFDs added in v5.0.5 

func (msg *Message) EncodeToWithFDs(out io.Writer, order binary.ByteOrder) (fds []int, err error)

func (*Message) IsValid 

func (msg *Message) IsValid() error

IsValid checks whether msg is a valid message and returns an InvalidMessageError or FormatError if it is not.

func (*Message) Serial 

func (msg *Message) Serial() uint32

Serial returns the message's serial number. The returned value is only valid for messages received by eavesdropping.

func (*Message) String 

func (msg *Message) String() string

String returns a string representation of a message similar to the format of dbus-monitor.

type Method 

type Method interface {
	// Call requires that all arguments are decoded before being passed to it.
	Call(args ...interface{}) ([]interface{}, error)
	NumArguments() int
	NumReturns() int
	// ArgumentValue returns a representative value for the argument at position
	// it should be of the proper type. reflect.Zero would be a good mechanism
	// to use for this Value.
	ArgumentValue(position int) interface{}
	// ReturnValue returns a representative value for the return at position
	// it should be of the proper type. reflect.Zero would be a good mechanism
	// to use for this Value.
	ReturnValue(position int) interface{}
}

A Method represents the exposed methods on D-Bus.

type Object 

type Object struct {
	// contains filtered or unexported fields
}

Object represents a remote object on which methods can be invoked.

func (*Object) AddMatchSignal deprecated 

func (o *Object) AddMatchSignal(iface, member string, options ...MatchOption) *Call

AddMatchSignal subscribes BusObject to signals from specified interface, method (member). Additional filter rules can be added via WithMatch* option constructors. Note: To filter events by object path you have to specify this path via an option.

Deprecated: use (*Conn) AddMatchSignal instead.

func (*Object) Call 

func (o *Object) Call(method string, flags Flags, args ...interface{}) *Call

Call calls a method with (*Object).Go and waits for its reply.

Example 
var list []string

conn, err := ConnectSessionBus()
if err != nil {
	panic(err)
}
defer conn.Close()

err = conn.BusObject().Call("org.freedesktop.DBus.ListNames", 0).Store(&list)
if err != nil {
	panic(err)
}
for _, v := range list {
	fmt.Println(v)
}

Output:

func (*Object) CallWithContext 

func (o *Object) CallWithContext(ctx context.Context, method string, flags Flags, args ...interface{}) *Call

CallWithContext acts like Call but takes a context

func (*Object) Destination 

func (o *Object) Destination() string

Destination returns the destination that calls on (o *Object) are sent to.

func (*Object) GetProperty 

func (o *Object) GetProperty(p string) (Variant, error)

GetProperty calls org.freedesktop.DBus.Properties.Get on the given object. The property name must be given in interface.member notation.

func (*Object) Go 

func (o *Object) Go(method string, flags Flags, ch chan *Call, args ...interface{}) *Call

Go calls a method with the given arguments asynchronously. It returns a Call structure representing this method call. The passed channel will return the same value once the call is done. If ch is nil, a new channel will be allocated. Otherwise, ch has to be buffered or Go will panic.

If the flags include FlagNoReplyExpected, ch is ignored and a Call structure is returned with any error in Err and a closed channel in Done containing the returned Call as it's one entry.

If the method parameter contains a dot ('.'), the part before the last dot specifies the interface on which the method is called.

Example 
conn, err := ConnectSessionBus()
if err != nil {
	panic(err)
}
defer conn.Close()

ch := make(chan *Call, 10)
conn.BusObject().Go("org.freedesktop.DBus.ListActivatableNames", 0, ch)
select {
case call := <-ch:
	if call.Err != nil {
		panic(err)
	}
	list := call.Body[0].([]string)
	for _, v := range list {
		fmt.Println(v)
	}
	// put some other cases here
}

Output:

func (*Object) GoWithContext 

func (o *Object) GoWithContext(ctx context.Context, method string, flags Flags, ch chan *Call, args ...interface{}) *Call

GoWithContext acts like Go but takes a context

func (*Object) Path 

func (o *Object) Path() ObjectPath

Path returns the path that calls on (o *Object") are sent to.

func (*Object) RemoveMatchSignal deprecated 

func (o *Object) RemoveMatchSignal(iface, member string, options ...MatchOption) *Call

RemoveMatchSignal unsubscribes BusObject from signals from specified interface, method (member). Additional filter rules can be added via WithMatch* option constructors

Deprecated: use (*Conn) RemoveMatchSignal instead.

func (*Object) SetProperty 

func (o *Object) SetProperty(p string, v interface{}) error

SetProperty calls org.freedesktop.DBus.Properties.Set on the given object. The property name must be given in interface.member notation.

func (*Object) StoreProperty added in v5.0.4 

func (o *Object) StoreProperty(p string, value interface{}) error

StoreProperty calls org.freedesktop.DBus.Properties.Get on the given object. The property name must be given in interface.member notation. It stores the returned property into the provided value.

type ObjectPath 

type ObjectPath string

An ObjectPath is an object path as defined by the D-Bus spec.

func (ObjectPath) IsValid 

func (o ObjectPath) IsValid() bool

IsValid returns whether the object path is valid.

type ReleaseNameReply 

type ReleaseNameReply uint32

ReleaseNameReply is the reply to a ReleaseName call. 

const (
	ReleaseNameReplyReleased ReleaseNameReply = 1 + iota
	ReleaseNameReplyNonExistent
	ReleaseNameReplyNotOwner
)

type RequestNameFlags 

type RequestNameFlags uint32

RequestNameFlags represents the possible flags for a RequestName call. 

const (
	NameFlagAllowReplacement RequestNameFlags = 1 << iota
	NameFlagReplaceExisting
	NameFlagDoNotQueue
)

type RequestNameReply 

type RequestNameReply uint32

RequestNameReply is the reply to a RequestName call. 

const (
	RequestNameReplyPrimaryOwner RequestNameReply = 1 + iota
	RequestNameReplyInQueue
	RequestNameReplyExists
	RequestNameReplyAlreadyOwner
)

type Sender 

type Sender string

Sender is a type which can be used in exported methods to receive the message sender.

type Sequence added in v5.0.4 

type Sequence uint64

Sequence represents the value of a monotonically increasing counter. 

const (
	// NoSequence indicates the absence of a sequence value.
	NoSequence Sequence = 0
)

type SerialGenerator 

type SerialGenerator interface {
	GetSerial() uint32
	RetireSerial(serial uint32)
}

SerialGenerator is responsible for serials generation.

Different approaches for the serial generation can be used, maintaining a map guarded with a mutex (the standard way) or simply increment an atomic counter.

type ServerObject 

type ServerObject interface {
	LookupInterface(name string) (Interface, bool)
}

ServerObject is the representation of an D-Bus Object.

Objects are registered at a path for a given Handler. The Objects implement D-Bus interfaces. The semantics of Interface lookup is up to the implementation of the ServerObject. The ServerObject implementation may choose to implement empty string as a valid interface represeting all methods or not per the D-Bus specification.

type Signal 

type Signal struct {
	Sender   string
	Path     ObjectPath
	Name     string
	Body     []interface{}
	Sequence Sequence
}

Signal represents a D-Bus message of type Signal. The name member is given in "interface.member" notation, e.g. org.freedesktop.D-Bus.NameLost.

type SignalHandler 

type SignalHandler interface {
	DeliverSignal(iface, name string, signal *Signal)
}

A SignalHandler is responsible for delivering a signal.

Signal delivery may be changed from the default channel based approach by Handlers implementing the SignalHandler interface.

func NewSequentialSignalHandler added in v5.0.4 

func NewSequentialSignalHandler() SignalHandler

NewSequentialSignalHandler returns an instance of a new signal handler that guarantees sequential processing of signals. It is a guarantee of this signal handler that signals will be written to channels in the order they are received on the DBus connection.

type SignalRegistrar 

type SignalRegistrar interface {
	AddSignal(ch chan<- *Signal)
	RemoveSignal(ch chan<- *Signal)
}

SignalRegistrar manages signal delivery channels.

This is an optional set of methods for `SignalHandler`.

type Signature 

type Signature struct {
	// contains filtered or unexported fields
}

Signature represents a correct type signature as specified by the D-Bus specification. The zero value represents the empty signature, "".

func ParseSignature 

func ParseSignature(s string) (sig Signature, err error)

ParseSignature returns the signature represented by this string, or a SignatureError if the string is not a valid signature.

func ParseSignatureMust 

func ParseSignatureMust(s string) Signature

ParseSignatureMust behaves like ParseSignature, except that it panics if s is not valid.

func SignatureOf 

func SignatureOf(vs ...interface{}) Signature

SignatureOf returns the concatenation of all the signatures of the given values. It panics if one of them is not representable in D-Bus.

func SignatureOfType 

func SignatureOfType(t reflect.Type) Signature

SignatureOfType returns the signature of the given type. It panics if the type is not representable in D-Bus.

func (Signature) Empty 

func (s Signature) Empty() bool

Empty returns whether the signature is the empty signature.

func (Signature) Single 

func (s Signature) Single() bool

Single returns whether the signature represents a single, complete type.

func (Signature) String 

func (s Signature) String() string

String returns the signature's string representation.

type SignatureError 

type SignatureError struct {
	Sig    string
	Reason string
}

A SignatureError indicates that a signature passed to a function or received on a connection is not a valid signature.

func (SignatureError) Error 

func (e SignatureError) Error() string

type Terminator 

type Terminator interface {
	Terminate()
}

Terminator allows a handler to implement a shutdown mechanism that is called when the connection terminates.

type Type 

type Type byte

Type represents the possible types of a D-Bus message. 

const (
	TypeMethodCall Type = 1 + iota
	TypeMethodReply
	TypeError
	TypeSignal
)

func (Type) String 

func (t Type) String() string

type UnixFD 

type UnixFD int32

A UnixFD is a Unix file descriptor sent over the wire. See the package-level documentation for more information about Unix file descriptor passsing.

type UnixFDIndex 

type UnixFDIndex uint32

A UnixFDIndex is the representation of a Unix file descriptor in a message.

type Variant 

type Variant struct {
	// contains filtered or unexported fields
}

Variant represents the D-Bus variant type.

func MakeVariant 

func MakeVariant(v interface{}) Variant

MakeVariant converts the given value to a Variant. It panics if v cannot be represented as a D-Bus type.

func MakeVariantWithSignature 

func MakeVariantWithSignature(v interface{}, s Signature) Variant

MakeVariantWithSignature converts the given value to a Variant.

func ParseVariant 

func ParseVariant(s string, sig Signature) (Variant, error)

ParseVariant parses the given string as a variant as described at https://developer.gnome.org/glib/stable/gvariant-text.html. If sig is not empty, it is taken to be the expected signature for the variant.

func (Variant) Signature 

func (v Variant) Signature() Signature

Signature returns the D-Bus signature of the underlying value of v.

func (Variant) Store added in v5.0.4 

func (v Variant) Store(value interface{}) error

Store converts the variant into a native go type using the same mechanism as the "Store" function.

func (Variant) String 

func (v Variant) String() string

String returns the string representation of the underlying value of v as described at https://developer.gnome.org/glib/stable/gvariant-text.html.

func (Variant) Value 

func (v Variant) Value() interface{}

Value returns the underlying value of v.

Source Files

View all Source files

Directories

Path Synopsis
Package introspect provides some utilities for dealing with the DBus introspection format.
 Package introspect provides some utilities for dealing with the DBus introspection format.
Package prop provides the Properties struct which can be used to implement org.freedesktop.DBus.Properties.
 Package prop provides the Properties struct which can be used to implement org.freedesktop.DBus.Properties.

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