Network.DNS.MDNSResponder.Client

Managing connections

data Connection

A connection to the daemon.

connect

Arguments

:: SockAddr

The address of the daemon.

You probably want defaultAddr. In any case, the implementation currently only works for AF_UNIX-based daemons, even though there are AF_INET-based daemons in existence.

-> AsyncConnectionErrorHandler

-> IO (Either DNSServiceErrorType Connection)

Connect to the daemon.

disconnect :: Connection -> IO ()

Disconnect from the daemon.

It is an error to use the passed in Connection during or after this call, though it is safe to call this again if it fails due to an asynchronous exception.

defaultAddr :: IO SockAddr

The default address for the daemon.

data AsyncConnectionError

An error communicating with the daemon.

Constructors

AsyncConnectionIOError !IOError

An IOError occured while using the socket.

AsyncConnectionClosedError

The daemon closed the socket unexpectedly.

AsyncConnectionBadDaemonVersionError !Word32

The daemon reported a version we can't handle.

Instances

Show AsyncConnectionError

Methods

showsPrec :: Int -> AsyncConnectionError -> ShowS

show :: AsyncConnectionError -> String

showList :: [AsyncConnectionError] -> ShowS

Exception AsyncConnectionError

Methods

toException :: AsyncConnectionError -> SomeException

fromException :: SomeException -> Maybe AsyncConnectionError

displayException :: AsyncConnectionError -> String

type AsyncConnectionErrorHandler = AsyncConnectionError -> IO ()

Handle a generic error communicating with the daemon.

These errors may occur at any time, are not associated with any particular request, and are not generally recoverable. You should still call disconnect to clean up resources after recieving an error.

The handler is called in its own thread.

Data types

type NullFreeByteString = ByteString

A ByteString with no null characters.

This invariant must be maintained by the caller.

Flags

data DNSServiceFlags

Flag type for API calls.

Instances

Eq DNSServiceFlags

Methods

(==) :: DNSServiceFlags -> DNSServiceFlags -> Bool

(/=) :: DNSServiceFlags -> DNSServiceFlags -> Bool

Monoid DNSServiceFlags

Methods

mempty :: DNSServiceFlags

mappend :: DNSServiceFlags -> DNSServiceFlags -> DNSServiceFlags

mconcat :: [DNSServiceFlags] -> DNSServiceFlags

Bits DNSServiceFlags

Methods

(.&.) :: DNSServiceFlags -> DNSServiceFlags -> DNSServiceFlags

(.|.) :: DNSServiceFlags -> DNSServiceFlags -> DNSServiceFlags

xor :: DNSServiceFlags -> DNSServiceFlags -> DNSServiceFlags

complement :: DNSServiceFlags -> DNSServiceFlags

shift :: DNSServiceFlags -> Int -> DNSServiceFlags

rotate :: DNSServiceFlags -> Int -> DNSServiceFlags

zeroBits :: DNSServiceFlags

bit :: Int -> DNSServiceFlags

setBit :: DNSServiceFlags -> Int -> DNSServiceFlags

clearBit :: DNSServiceFlags -> Int -> DNSServiceFlags

complementBit :: DNSServiceFlags -> Int -> DNSServiceFlags

testBit :: DNSServiceFlags -> Int -> Bool

bitSizeMaybe :: DNSServiceFlags -> Maybe Int

bitSize :: DNSServiceFlags -> Int

isSigned :: DNSServiceFlags -> Bool

shiftL :: DNSServiceFlags -> Int -> DNSServiceFlags

unsafeShiftL :: DNSServiceFlags -> Int -> DNSServiceFlags

shiftR :: DNSServiceFlags -> Int -> DNSServiceFlags

unsafeShiftR :: DNSServiceFlags -> Int -> DNSServiceFlags

rotateL :: DNSServiceFlags -> Int -> DNSServiceFlags

rotateR :: DNSServiceFlags -> Int -> DNSServiceFlags

popCount :: DNSServiceFlags -> Int

Error codes

data DNSServiceErrorType

Error codes returned by the daemon.

Instances

Eq DNSServiceErrorType

Methods

(==) :: DNSServiceErrorType -> DNSServiceErrorType -> Bool

(/=) :: DNSServiceErrorType -> DNSServiceErrorType -> Bool

Show DNSServiceErrorType

Methods

showsPrec :: Int -> DNSServiceErrorType -> ShowS

show :: DNSServiceErrorType -> String

showList :: [DNSServiceErrorType] -> ShowS

kDNSServiceErr_NoError :: DNSServiceErrorType

There was no error.

kDNSServiceErr_ServiceNotRunning :: DNSServiceErrorType

The daemon is not running/closed the connection.

You should still call disconnect to clean up resources!

kDNSServiceErr_ShortResponse :: DNSServiceErrorType

The response sent by the daemon was too short.

This is not an upstream error code, the official Apple client just declines to call the callback in this case. It is outside of the documented range for mDNS error codes.

Interface indices

data InterfaceIndex

An index to specify on which interface a service exists.

kDNSServiceInterfaceIndexAny :: InterfaceIndex

The service is served on any interface.

kDNSServiceInterfaceIndexLocalOnly :: InterfaceIndex

The service is only served to the local host.

Requests

data Request a where

A request to the mDNSResponder daemon.

Parameterized by the type of the response.

Constructor fields documented with the constructor due to https://ghc.haskell.org/trac/ghc/ticket/12050

See also the documentation for these requests in dns_sd.h

Constructors

ServiceRegister :: !DNSServiceFlags -> !InterfaceIndex -> !NullFreeByteString -> !NullFreeByteString -> !NullFreeByteString -> !NullFreeByteString -> !PortNumber -> !ByteString -> Request NTDResponse

Register a service.

Fields:

1. flags: Indicate behavior on name conflict.
2. index: The interface(s) on which to register the service.
3. name: The service name to be registered, or empty for the default.
4. type: The service type followed by the protocol, separated by a dot.
5. domain: The domain on which to advertise, or empty for the default domains.
6. host: The SRV target host name, or empty for the default host name(s).
7. port: The port the service listens on.
8. txt: The text record data, or empty for none.

ServiceBrowse :: !InterfaceIndex -> !NullFreeByteString -> !NullFreeByteString -> Request NTDResponse

Browse for a service.

Fields:

1. index: The interface(s) on which to browse.
2. regtype: The service type being browsed for followed by the protocol, with optional subtypes or group IDs.
3. domain: The domain on which to browse, or empty for the default.

ServiceResolve :: !DNSServiceFlags -> !InterfaceIndex -> !NullFreeByteString -> !NullFreeByteString -> !NullFreeByteString -> Request ResolveResponse

Resolve a service.

You probably want to populate the name, regtype, and domain from the results of a ServiceBrowse request.

Fields:

1. flags: Specify multicast behavior.
2. index: The interface(s) on which to resolve.
3. name: The name of the service to be resolved.
4. regtype: The type of the service to be resolved.
5. domain: The domain of the service to be resolved.

request

Arguments

:: PeekableResponse a

=> Connection

-> Request a

-> AsyncResponseHandler a

-> IO DNSServiceErrorType

The immediate error from the daemon, if any. Even if kDNSServiceErr_NoError is returned here, there still may be asynchronous errors for this request.

Send a request to the daemon.

The PeekableResponse constraint is an implementation detail, all Requests have a type appropriate for request. Unfortunately, it doesn't seem possible to hide this constraint from the haddock docs.

Responses

type AsyncResponseHandler a = Either DNSServiceErrorType (Response a) -> IO ()

Handle asynchronous responses to a request.

Some requests result in multiple responses.

The handler is called on its own thread.

data ResponseHeader

The shared header for daemon responses.

The header also contains an error code on the wire, but it's always kDNSServiceErr_NoError on code paths that get passed a header.

Constructors

ResponseHeader

Fields

• reshdr_flags :: !DNSServiceFlags

  Flags applicable to the response.

• reshdr_ifi :: !InterfaceIndex

  The interface in question.

data Response a

A response with its header.

Constructors

Response !ResponseHeader !a

data NTDResponse

A response containing a name, registration type, and domain.

Constructors

NTDResponse

Fields

• ntd_name :: !NullFreeByteString

  The service name.

• ntd_regtype :: !NullFreeByteString

  The service registration type.

• ntd_domain :: !NullFreeByteString

  The domain on which the service is registered.

data ResolveResponse

A response to a ServiceResolve request.

Constructors

ResolveResponse

Fields

• resolve_fullname :: !NullFreeByteString

  The full service domain name.

• resolve_hosttarget :: !NullFreeByteString

  The hostname of the machine providing the service.

• resolve_port :: !PortNumber

  The port number the service is served on.

• resolve_txt :: !ByteString

  The primary TXT record for the service.