network-2.4.1.2: Low-level networking interface

Portabilityportable
Stabilityprovisional
Maintainerlibraries@haskell.org
Safe HaskellNone

Network.Socket.Internal

Contents

Description

A module containing semi-public Socket internals. Modules which extend the Socket module will need to use this module while ideally most users will be able to make do with the public interface.

Synopsis

Socket addresses

type HostAddress = Word32Source

Network byte order.

type HostAddress6 = (Word32, Word32, Word32, Word32)Source

Host byte order.

type FlowInfo = Word32Source

type ScopeID = Word32Source

newtype PortNumber Source

Constructors

PortNum Word16 

Instances

Enum PortNumber 
Eq PortNumber 
Integral PortNumber 
Num PortNumber 
Ord PortNumber 
Real PortNumber 
Show PortNumber 
Typeable PortNumber 
Storable PortNumber 

peekSockAddr :: Ptr SockAddr -> IO SockAddrSource

Read a SockAddr from the given memory location.

pokeSockAddr :: Ptr a -> SockAddr -> IO ()Source

Write the given SockAddr to the given memory location.

sizeOfSockAddr :: SockAddr -> IntSource

Computes the storage requirements (in bytes) of the given SockAddr. This function differs from sizeOf in that the value of the argument is used.

sizeOfSockAddrByFamily :: Family -> IntSource

Computes the storage requirements (in bytes) required for a SockAddr with the given Family.

withSockAddr :: SockAddr -> (Ptr SockAddr -> Int -> IO a) -> IO aSource

Use a SockAddr with a function requiring a pointer to a SockAddr and the length of that SockAddr.

withNewSockAddr :: Family -> (Ptr SockAddr -> Int -> IO a) -> IO aSource

Create a new SockAddr for use with a function requiring a pointer to a SockAddr and the length of that SockAddr.

Protocol families

Socket error functions

throwSocketErrorSource

Arguments

:: String

textual description of the error location

-> IO a 

Throw an IOError corresponding to the current socket error.

throwSocketErrorCode :: String -> CInt -> IO aSource

Like throwSocketError, but the error code is supplied as an argument.

On Windows, do not use errno. Use a system error code instead.

Guards for socket operations that may fail

throwSocketErrorIfMinus1_Source

Arguments

:: (Eq a, Num a) 
=> String

textual description of the location

-> IO a

the IO operation to be executed

-> IO () 

Throw an IOError corresponding to the current socket error if the IO action returns a result of -1. Discards the result of the IO action after error handling.

throwSocketErrorIfMinus1RetrySource

Arguments

:: (Eq a, Num a) 
=> String

textual description of the location

-> IO a

the IO operation to be executed

-> IO a 

Throw an IOError corresponding to the current socket error if the IO action returns a result of -1, but retries in case of an interrupted operation.

throwSocketErrorIfMinus1RetryMayBlockSource

Arguments

:: (Eq a, Num a) 
=> String

textual description of the location

-> IO b

action to execute before retrying if an immediate retry would block

-> IO a

the IO operation to be executed

-> IO a 

Throw an IOError corresponding to the current socket error if the IO action returns a result of -1, but retries in case of an interrupted operation. Checks for operations that would block and executes an alternative action before retrying in that case.

Guards that wait and retry if the operation would block

These guards are based on throwSocketErrorIfMinus1RetryMayBlock. They wait for socket readiness if the action fails with EWOULDBLOCK or similar.

throwSocketErrorWaitRead :: (Eq a, Num a) => Socket -> String -> IO a -> IO aSource

Like throwSocketErrorIfMinus1Retry, but if the action fails with EWOULDBLOCK or similar, wait for the socket to be read-ready, and try again.

throwSocketErrorWaitWrite :: (Eq a, Num a) => Socket -> String -> IO a -> IO aSource

Like throwSocketErrorIfMinus1Retry, but if the action fails with EWOULDBLOCK or similar, wait for the socket to be write-ready, and try again.

Initialization

withSocketsDo :: IO a -> IO aSource

On Windows operating systems, the networking subsystem has to be initialised using withSocketsDo before any networking operations can be used. eg.

 main = withSocketsDo $ do {...}

Although this is only strictly necessary on Windows platforms, it is harmless on other platforms, so for portability it is good practice to use it all the time.

Low-level helpers

zeroMemory :: Ptr a -> CSize -> IO ()Source

Zero a structure.