Safe Haskell	None
Language	Haskell2010

Socket.Datagram.IPv4.Undestined

Contents

Types
Establish
Communicate
Exceptions
Examples

Synopsis

newtype Socket = Socket Fd
data Endpoint = Endpoint {
- address :: !IPv4
- port :: !Word16
}
withSocket :: Endpoint -> (Socket -> Word16 -> IO a) -> IO (Either SocketException a)
send :: Socket -> Endpoint -> ByteArray -> Int -> Int -> IO (Either SocketException ())
receive :: Socket -> Int -> IO (Either SocketException (Endpoint, ByteArray))
receiveMutableByteArraySlice_ :: Socket -> MutableByteArray RealWorld -> Int -> Int -> IO (Either SocketException Int)
data SocketException = SocketException {
- context :: Context
- reason :: Reason
}
data Context
- = Accept
- | Bind
- | Close
- | Connect
- | GetName
- | Listen
- | Open
- | Option
- | Receive
- | Send
- | Shutdown
data Reason
- = MessageTruncated !Int !Int
- | SocketAddressSize
- | SocketAddressFamily
- | OptionValueSize
- | NegativeBytesRequested
- | RemoteNotShutdown
- | RemoteShutdown
- | ErrorCode !CInt

Types

newtype Socket Source #

A connectionless datagram socket that may communicate with many different endpoints on a datagram-by-datagram basis.

Constructors

Socket Fd

Instances

Eq Socket Source #
Instance details Defined in Socket.Datagram.IPv4.Undestined Methods (==) :: Socket -> Socket -> Bool # (/=) :: Socket -> Socket -> Bool #
Ord Socket Source #
Instance details Defined in Socket.Datagram.IPv4.Undestined Methods compare :: Socket -> Socket -> Ordering # (<) :: Socket -> Socket -> Bool # (<=) :: Socket -> Socket -> Bool # (>) :: Socket -> Socket -> Bool # (>=) :: Socket -> Socket -> Bool # max :: Socket -> Socket -> Socket # min :: Socket -> Socket -> Socket #

data Endpoint Source #

An endpoint for an IPv4 socket, connection, or listener. Everything is in host byte order, and the user is not responisble for performing any conversions.

Constructors

Endpoint
Fields address :: !IPv4 port :: !Word16

Instances

Eq Endpoint Source #
Instance details Defined in Socket.IPv4 Methods (==) :: Endpoint -> Endpoint -> Bool # (/=) :: Endpoint -> Endpoint -> Bool #
Show Endpoint Source #
Instance details Defined in Socket.IPv4 Methods showsPrec :: Int -> Endpoint -> ShowS # show :: Endpoint -> String # showList :: [Endpoint] -> ShowS #

Establish

withSocket Source #

Arguments

:: Endpoint	Address and port to use
-> (Socket -> Word16 -> IO a)	Callback providing the socket and the chosen port
-> IO (Either SocketException a)

Open a socket and run the supplied callback on it. This closes the socket when the callback finishes or when an exception is thrown. Do not return the socket from the callback. This leads to undefined behavior. If the address 0.0.0.0 is used, the socket receives on all network interfaces. If the port 0 is used, an unused port is chosen by the operating system. The callback provides the chosen port (or if the user specified a non-zero port, the chosen port will be that value).

Communicate

send Source #

Arguments

:: Socket	Socket
-> Endpoint	Remote IPv4 address and port
-> ByteArray	Buffer (will be sliced)
-> Int	Offset into payload
-> Int	Lenth of slice into buffer
-> IO (Either SocketException ())

Send a slice of a bytearray to the specified endpoint.

receive Source #

Arguments

:: Socket	Socket
-> Int	Maximum size of datagram to receive
-> IO (Either SocketException (Endpoint, ByteArray))

Receive a datagram into a freshly allocated bytearray.

receiveMutableByteArraySlice_ Source #

Arguments

:: Socket	Socket
-> MutableByteArray RealWorld	Buffer
-> Int	Offset into buffer
-> Int	Maximum size of datagram to receive
-> IO (Either SocketException Int)

Receive a datagram into a mutable byte array, ignoring information about the remote endpoint. Returns the actual number of bytes present in the datagram. Precondition: buffer_length - offset >= max_datagram_length.

Exceptions

data SocketException Source #

Represents any unexpected behaviors that a function working on a socket, connection, or listener can exhibit.

Constructors

SocketException
Fields context :: Context reason :: Reason

Instances

Eq SocketException Source #
Instance details Defined in Socket Methods (==) :: SocketException -> SocketException -> Bool # (/=) :: SocketException -> SocketException -> Bool #
Show SocketException Source #
Instance details Defined in Socket Methods showsPrec :: Int -> SocketException -> ShowS # show :: SocketException -> String # showList :: [SocketException] -> ShowS #
Exception SocketException Source #
Instance details Defined in Socket Methods toException :: SocketException -> SomeException # fromException :: SomeException -> Maybe SocketException # displayException :: SocketException -> String #

data Context Source #

The function that behaved unexpectedly.

Constructors

Accept
Bind
Close
Connect
GetName
Listen
Open
Option
Receive
Send
Shutdown

Instances

Eq Context Source #
Instance details Defined in Socket Methods (==) :: Context -> Context -> Bool # (/=) :: Context -> Context -> Bool #
Show Context Source #
Instance details Defined in Socket Methods showsPrec :: Int -> Context -> ShowS # show :: Context -> String # showList :: [Context] -> ShowS #

data Reason Source #

A description of the unexpected behavior.

Constructors

MessageTruncated !Int !Int	The datagram did not fit in the buffer. This can happen while sending or receiving. Fields: buffer size, datagram size.
SocketAddressSize	The socket address was not the expected size. This exception indicates a bug in this library or (less likely) in the operating system.
SocketAddressFamily	The socket address had an unexpected family. This exception indicates a bug in this library or (less likely) in the operating system.
OptionValueSize	The option value was not the expected size. This exception indicates a bug in this library or (less likely) in the operating system.
NegativeBytesRequested	The user requested a negative number of bytes in a call to a receive function.
RemoteNotShutdown	The remote end sent more data when it was expected to send a shutdown.
RemoteShutdown	The remote end has shutdown its side of the full-duplex connection. This can happen `receive` is called on a stream socket. This is not necessarily a bad thing. Many protocols use shutdown to indicate that no more data is available. These protocols can be contrasted with protocols that send a length representing a number of expected bytes.
ErrorCode !CInt	Any error code from the operating system that this library does not expect or recognize. Consult your operating system manual for details about the error code.

Instances

Eq Reason Source #
Instance details Defined in Socket Methods (==) :: Reason -> Reason -> Bool # (/=) :: Reason -> Reason -> Bool #
Show Reason Source #
Instance details Defined in Socket Methods showsPrec :: Int -> Reason -> ShowS # show :: Reason -> String # showList :: [Reason] -> ShowS #

Examples

Print every UDP packet that we receive. This terminates, closing the socket, after receiving ten packets. This code throws any exception that happens. This is commonly a useful behavior since most exceptions cannot be handled gracefully.

import qualified Data.ByteString.Char8 as BC
import Control.Monad (replicateM_)
import qualified Data.ByteString.Short.Internal as SB

udpStdoutServer :: IO ()
udpStdoutServer = do
  unhandled $ withSocket (Endpoint IPv4.loopback 0) $ \sock port -> do
    BC.putStrLn ("Receiving datagrams on 127.0.0.1:" <> BC.pack (show port))
    replicateM_ 10 $ do
      (remote,ByteArray payload) <- unhandled (receive sock 1024)
      BC.putStrLn ("Datagram from " <> BC.pack (show remote))
      BC.putStr (SB.fromShort (SB.SBS payload))

unhandled :: Exception e => IO (Either e a) -> IO a
unhandled action = action >>= either throwIO pure