Network.Socket

This is the main module of the network package supposed to be used with either Network.Socket.ByteString or Network.Socket.ByteString.Lazy for sending/receiving.

Here are two minimal example programs using the TCP/IP protocol:

• a server that echoes all data that it receives back
• a client using it

-- Echo server program
module Main (main) where

import Control.Concurrent (forkFinally)
import qualified Control.Exception as E
import Control.Monad (unless, forever, void)
import qualified Data.ByteString as S
import qualified Data.List.NonEmpty as NE
import Network.Socket
import Network.Socket.ByteString (recv, sendAll)

main :: IO ()
main = runTCPServer Nothing "3000" talk
  where
    talk s = do
        msg <- recv s 1024
        unless (S.null msg) $ do
          sendAll s msg
          talk s

-- from the "network-run" package.
runTCPServer :: Maybe HostName -> ServiceName -> (Socket -> IO a) -> IO a
runTCPServer mhost port server = withSocketsDo $ do
    addr <- resolve
    E.bracket (open addr) close loop
  where
    resolve = do
        let hints = defaultHints {
                addrFlags = [AI_PASSIVE]
              , addrSocketType = Stream
              }
        NE.head <$> getAddrInfo (Just hints) mhost (Just port)
    open addr = E.bracketOnError (openSocket addr) close $ \sock -> do
        setSocketOption sock ReuseAddr 1
        withFdSocket sock setCloseOnExecIfNeeded
        bind sock $ addrAddress addr
        listen sock 1024
        return sock
    loop sock = forever $ E.bracketOnError (accept sock) (close . fst)
        $ \(conn, _peer) -> void $
            -- 'forkFinally' alone is unlikely to fail thus leaking @conn@,
            -- but 'E.bracketOnError' above will be necessary if some
            -- non-atomic setups (e.g. spawning a subprocess to handle
            -- @conn@) before proper cleanup of @conn@ is your case
            forkFinally (server conn) (const $ gracefulClose conn 5000)

{-# LANGUAGE OverloadedStrings #-}
-- Echo client program
module Main (main) where

import qualified Control.Exception as E
import qualified Data.ByteString.Char8 as C
import qualified Data.List.NonEmpty as NE
import Network.Socket
import Network.Socket.ByteString (recv, sendAll)

main :: IO ()
main = runTCPClient "127.0.0.1" "3000" $ \s -> do
    sendAll s "Hello, world!"
    msg <- recv s 1024
    putStr "Received: "
    C.putStrLn msg

-- from the "network-run" package.
runTCPClient :: HostName -> ServiceName -> (Socket -> IO a) -> IO a
runTCPClient host port client = withSocketsDo $ do
    addr <- resolve
    E.bracket (open addr) close client
  where
    resolve = do
        let hints = defaultHints { addrSocketType = Stream }
        NE.head <$> getAddrInfo (Just hints) (Just host) (Just port)
    open addr = E.bracketOnError (openSocket addr) close $ \sock -> do
        connect sock $ addrAddress addr
        return sock

The proper programming model is that one Socket is handled by a single thread. If multiple threads use one Socket concurrently, unexpected things would happen. There is one exception for multiple threads vs a single Socket: one thread reads data from a Socket only and the other thread writes data to the Socket only.

Initialisation

withSocketsDo :: IO a -> IO a

With older versions of the network library (version 2.6.0.2 or earlier) on Windows operating systems, the networking subsystem must be initialised using withSocketsDo before any networking operations can be used. eg.

main = withSocketsDo $ do {...}

It is fine to nest calls to withSocketsDo, and to perform networking operations after withSocketsDo has returned.

withSocketsDo is not necessary for the current network library. However, for compatibility with older versions on Windows, it is good practice to always call withSocketsDo (it's very cheap).

Address information

getAddrInfo

Arguments

:: GetAddrInfo t

=> Maybe AddrInfo

preferred socket type or protocol

-> Maybe HostName

host name to look up

-> Maybe ServiceName

service name to look up

-> IO (t AddrInfo)

resolved addresses, with "best" first

Resolve a host or service name to one or more addresses. The AddrInfo values that this function returns contain SockAddr values that you can pass directly to connect or bind.

This function calls getaddrinfo(3), which never successfully returns with an empty list. If the query fails, getAddrInfo throws an IO exception.

For backwards-compatibility reasons, a hidden GetAddrInfo class is used to make the result polymorphic. It only has instances for [] (lists) and NonEmpty. Use of NonEmpty is recommended.

This function is protocol independent. It can return both IPv4 and IPv6 address information.

The AddrInfo argument specifies the preferred query behaviour, socket options, or protocol. You can override these conveniently using Haskell's record update syntax on defaultHints, for example as follows:

>>> let hints = defaultHints { addrFlags = [AI_NUMERICHOST], addrSocketType = Stream }

You must provide a Just value for at least one of the HostName or ServiceName arguments. HostName can be either a numeric network address (dotted quad for IPv4, colon-separated hex for IPv6) or a hostname. In the latter case, its addresses will be looked up unless AI_NUMERICHOST is specified as a hint. If you do not provide a HostName value and do not set AI_PASSIVE as a hint, network addresses in the result will contain the address of the loopback interface.

There are several reasons why a query might result in several values. For example, the queried-for host could be multihomed, or the service might be available via several protocols.

Note: the order of arguments is slightly different to that defined for getaddrinfo in RFC 2553. The AddrInfo parameter comes first to make partial application easier.

>>> import qualified Data.List.NonEmpty as NE
>>> addr <- NE.head <$> getAddrInfo (Just hints) (Just "127.0.0.1") (Just "http")
>>> addrAddress addr
127.0.0.1:80

Polymorphic version: @since 3.2.3.0

Types

type HostName = String

Either a host name e.g., "haskell.org" or a numeric host address string consisting of a dotted decimal IPv4 address or an IPv6 address e.g., "192.168.0.1".

type ServiceName = String

Either a service name e.g., "http" or a numeric port number.

data AddrInfo

Constructors

AddrInfo

Fields

• addrFlags :: [AddrInfoFlag]
• addrFamily :: Family
• addrSocketType :: SocketType
• addrProtocol :: ProtocolNumber
• addrAddress :: SockAddr
• addrCanonName :: Maybe String

Instances

Storable AddrInfo

Defined in Network.Socket.Info

Methods

sizeOf :: AddrInfo -> Int

alignment :: AddrInfo -> Int

peekElemOff :: Ptr AddrInfo -> Int -> IO AddrInfo

pokeElemOff :: Ptr AddrInfo -> Int -> AddrInfo -> IO ()

peekByteOff :: Ptr b -> Int -> IO AddrInfo

pokeByteOff :: Ptr b -> Int -> AddrInfo -> IO ()

peek :: Ptr AddrInfo -> IO AddrInfo

poke :: Ptr AddrInfo -> AddrInfo -> IO ()

Show AddrInfo

Defined in Network.Socket.Info

Methods

showsPrec :: Int -> AddrInfo -> ShowS

show :: AddrInfo -> String

showList :: [AddrInfo] -> ShowS

Eq AddrInfo

Defined in Network.Socket.Info

Methods

(==) :: AddrInfo -> AddrInfo -> Bool

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

defaultHints :: AddrInfo

Default hints for address lookup with getAddrInfo.

>>> addrFlags defaultHints
[]
>>> addrFamily defaultHints
AF_UNSPEC
>>> addrSocketType defaultHints
NoSocketType
>>> addrProtocol defaultHints
0

Flags

data AddrInfoFlag

Flags that control the querying behaviour of getAddrInfo. For more information, see https://tools.ietf.org/html/rfc3493#page-25

Constructors

AI_ADDRCONFIG

The list of returned AddrInfo values will only contain IPv4 addresses if the local system has at least one IPv4 interface configured, and likewise for IPv6. (Only some platforms support this.)

AI_ALL

If AI_ALL is specified, return all matching IPv6 and IPv4 addresses. Otherwise, this flag has no effect. (Only some platforms support this.)

AI_CANONNAME

The addrCanonName field of the first returned AddrInfo will contain the "canonical name" of the host.

AI_NUMERICHOST

The HostName argument must be a numeric address in string form, and network name lookups will not be attempted.

AI_NUMERICSERV

The ServiceName argument must be a port number in string form, and service name lookups will not be attempted. (Only some platforms support this.)

AI_PASSIVE

If no HostName value is provided, the network address in each SockAddr will be left as a "wild card". This is useful for server applications that will accept connections from any client.

AI_V4MAPPED

If an IPv6 lookup is performed, and no IPv6 addresses are found, IPv6-mapped IPv4 addresses will be returned. (Only some platforms support this.)

Instances

Read AddrInfoFlag

Defined in Network.Socket.Info

Methods

readsPrec :: Int -> ReadS AddrInfoFlag

readList :: ReadS [AddrInfoFlag]

readPrec :: ReadPrec AddrInfoFlag

readListPrec :: ReadPrec [AddrInfoFlag]

Show AddrInfoFlag

Defined in Network.Socket.Info

Methods

showsPrec :: Int -> AddrInfoFlag -> ShowS

show :: AddrInfoFlag -> String

showList :: [AddrInfoFlag] -> ShowS

Eq AddrInfoFlag

Defined in Network.Socket.Info

Methods

(==) :: AddrInfoFlag -> AddrInfoFlag -> Bool

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

addrInfoFlagImplemented :: AddrInfoFlag -> Bool

Indicate whether the given AddrInfoFlag will have any effect on this system.

Socket operations

connect :: Socket -> SockAddr -> IO ()

Connect to a remote socket at address.

bind :: Socket -> SockAddr -> IO ()

Bind the socket to an address. The socket must not already be bound. The Family passed to bind must be the same as that passed to socket. If the special port number defaultPort is passed then the system assigns the next available use port.

listen :: Socket -> Int -> IO ()

Listen for connections made to the socket. The second argument specifies the maximum number of queued connections and should be at least 1; the maximum value is system-dependent (usually 5).

accept :: Socket -> IO (Socket, SockAddr)

Accept a connection. The socket must be bound to an address and listening for connections. The return value is a pair (conn, address) where conn is a new socket object usable to send and receive data on the connection, and address is the address bound to the socket on the other end of the connection. On Unix, FD_CLOEXEC is set to the new Socket.

Closing

close :: Socket -> IO ()

Close the socket. This function does not throw exceptions even if the underlying system call returns errors.

If multiple threads use the same socket and one uses unsafeFdSocket and the other use close, unexpected behavior may happen. For more information, please refer to the documentation of unsafeFdSocket.

close' :: Socket -> IO ()

Close the socket. This function throws exceptions if the underlying system call returns errors.

gracefulClose :: Socket -> Int -> IO ()

Closing a socket gracefully. This sends TCP FIN and check if TCP FIN is received from the peer. The second argument is time out to receive TCP FIN in millisecond. In both normal cases and error cases, socket is deallocated finally.

Since: 3.1.1.0

shutdown :: Socket -> ShutdownCmd -> IO ()

Shut down one or both halves of the connection, depending on the second argument to the function. If the second argument is ShutdownReceive, further receives are disallowed. If it is ShutdownSend, further sends are disallowed. If it is ShutdownBoth, further sends and receives are disallowed.

data ShutdownCmd

Constructors

ShutdownReceive

ShutdownSend

ShutdownBoth

Socket options

data SocketOption

Socket options for use with setSocketOption and getSocketOption.

The existence of a constructor does not imply that the relevant option is supported on your system: see isSupportedSocketOption

Constructors

SockOpt

Fields

• CInt

  Option Level

• CInt

  Option Name

Bundled Patterns

pattern UnsupportedSocketOption :: SocketOption

pattern Debug :: SocketOption

SO_DEBUG

pattern ReuseAddr :: SocketOption

SO_REUSEADDR

pattern SoDomain :: SocketOption

SO_DOMAIN, read-only

pattern Type :: SocketOption

SO_TYPE, read-only

pattern SoProtocol :: SocketOption

SO_PROTOCOL, read-only

pattern SoError :: SocketOption

SO_ERROR

pattern DontRoute :: SocketOption

SO_DONTROUTE

pattern Broadcast :: SocketOption

SO_BROADCAST

pattern SendBuffer :: SocketOption

SO_SNDBUF

pattern RecvBuffer :: SocketOption

SO_RCVBUF

pattern KeepAlive :: SocketOption

SO_KEEPALIVE

pattern OOBInline :: SocketOption

SO_OOBINLINE

pattern TimeToLive :: SocketOption

IP_TTL

pattern MaxSegment :: SocketOption

TCP_MAXSEG

pattern NoDelay :: SocketOption

TCP_NODELAY

pattern Cork :: SocketOption

TCP_CORK

pattern Linger :: SocketOption

SO_LINGER: timeout in seconds, 0 means disabling/disabled.

pattern ReusePort :: SocketOption

SO_REUSEPORT

pattern RecvLowWater :: SocketOption

SO_RCVLOWAT

pattern SendLowWater :: SocketOption

SO_SNDLOWAT

pattern RecvTimeOut :: SocketOption

SO_RCVTIMEO: timeout in microseconds. This option is not useful in the normal case where sockets are non-blocking.

pattern SendTimeOut :: SocketOption

SO_SNDTIMEO: timeout in microseconds. This option is not useful in the normal case where sockets are non-blocking.

pattern UseLoopBack :: SocketOption

SO_USELOOPBACK

pattern UserTimeout :: SocketOption

TCP_USER_TIMEOUT

pattern IPv6Only :: SocketOption

IPV6_V6ONLY: don't use this on OpenBSD.

pattern RecvIPv4TTL :: SocketOption

Receiving IPv4 TTL.

pattern RecvIPv4TOS :: SocketOption

Receiving IPv4 TOS.

pattern RecvIPv4PktInfo :: SocketOption

Receiving IP_PKTINFO (struct in_pktinfo).

pattern RecvIPv6HopLimit :: SocketOption

Receiving IPv6 hop limit.

pattern RecvIPv6TClass :: SocketOption

Receiving IPv6 traffic class.

pattern RecvIPv6PktInfo :: SocketOption

Receiving IPV6_PKTINFO (struct in6_pktinfo).

Instances

Read SocketOption

Defined in Network.Socket.Options

Methods

readsPrec :: Int -> ReadS SocketOption

readList :: ReadS [SocketOption]

readPrec :: ReadPrec SocketOption

readListPrec :: ReadPrec [SocketOption]

Show SocketOption

Defined in Network.Socket.Options

Methods

showsPrec :: Int -> SocketOption -> ShowS

show :: SocketOption -> String

showList :: [SocketOption] -> ShowS

Eq SocketOption

Defined in Network.Socket.Options

Methods

(==) :: SocketOption -> SocketOption -> Bool

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

isSupportedSocketOption :: SocketOption -> Bool

Does the SocketOption exist on this system?

whenSupported :: SocketOption -> IO a -> IO ()

Execute the given action only when the specified socket option is supported. Any return value is ignored.

getSocketOption :: Socket -> SocketOption -> IO Int

Get a socket option that gives an Int value.

setSocketOption :: Socket -> SocketOption -> Int -> IO ()

Set a socket option that expects an Int value.

General socket options

data StructLinger

Low level SO_LINGER option value, which can be used with setSockOpt or setSockOptValue . SockOptValue.

Constructors

StructLinger

Fields

• sl_onoff :: CInt

  Set the linger option on.

• sl_linger :: CInt

  Linger timeout.

Instances

Storable StructLinger

Defined in Network.Socket.Options

Methods

sizeOf :: StructLinger -> Int

alignment :: StructLinger -> Int

peekElemOff :: Ptr StructLinger -> Int -> IO StructLinger

pokeElemOff :: Ptr StructLinger -> Int -> StructLinger -> IO ()

peekByteOff :: Ptr b -> Int -> IO StructLinger

pokeByteOff :: Ptr b -> Int -> StructLinger -> IO ()

peek :: Ptr StructLinger -> IO StructLinger

poke :: Ptr StructLinger -> StructLinger -> IO ()

Show StructLinger

Defined in Network.Socket.Options

Methods

showsPrec :: Int -> StructLinger -> ShowS

show :: StructLinger -> String

showList :: [StructLinger] -> ShowS

Eq StructLinger

Defined in Network.Socket.Options

Methods

(==) :: StructLinger -> StructLinger -> Bool

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

Ord StructLinger

Defined in Network.Socket.Options

Methods

compare :: StructLinger -> StructLinger -> Ordering

(<) :: StructLinger -> StructLinger -> Bool

(<=) :: StructLinger -> StructLinger -> Bool

(>) :: StructLinger -> StructLinger -> Bool

(>=) :: StructLinger -> StructLinger -> Bool

max :: StructLinger -> StructLinger -> StructLinger

min :: StructLinger -> StructLinger -> StructLinger

newtype SocketTimeout

Timeout in microseconds. This will be converted into struct timeval on Unix and DWORD (as milliseconds) on Windows.

Constructors

SocketTimeout Word32

Instances

Storable SocketTimeout

Defined in Network.Socket.Options

Methods

sizeOf :: SocketTimeout -> Int

alignment :: SocketTimeout -> Int

peekElemOff :: Ptr SocketTimeout -> Int -> IO SocketTimeout

pokeElemOff :: Ptr SocketTimeout -> Int -> SocketTimeout -> IO ()

peekByteOff :: Ptr b -> Int -> IO SocketTimeout

pokeByteOff :: Ptr b -> Int -> SocketTimeout -> IO ()

peek :: Ptr SocketTimeout -> IO SocketTimeout

poke :: Ptr SocketTimeout -> SocketTimeout -> IO ()

Show SocketTimeout

Defined in Network.Socket.Options

Methods

showsPrec :: Int -> SocketTimeout -> ShowS

show :: SocketTimeout -> String

showList :: [SocketTimeout] -> ShowS

Eq SocketTimeout

Defined in Network.Socket.Options

Methods

(==) :: SocketTimeout -> SocketTimeout -> Bool

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

Ord SocketTimeout

Defined in Network.Socket.Options

Methods

compare :: SocketTimeout -> SocketTimeout -> Ordering

(<) :: SocketTimeout -> SocketTimeout -> Bool

(<=) :: SocketTimeout -> SocketTimeout -> Bool

(>) :: SocketTimeout -> SocketTimeout -> Bool

(>=) :: SocketTimeout -> SocketTimeout -> Bool

max :: SocketTimeout -> SocketTimeout -> SocketTimeout

min :: SocketTimeout -> SocketTimeout -> SocketTimeout

getSockOpt :: forall a. Storable a => Socket -> SocketOption -> IO a

Get a socket option.

setSockOpt :: Storable a => Socket -> SocketOption -> a -> IO ()

Set a socket option.

Integrated socket options

data SockOptValue where

A type that can hold any Storable socket option value (e.g. StructLinger and CInt)

See setSocOptValue

Constructors

SockOptValue :: Storable a => a -> SockOptValue

setSockOptValue :: Socket -> SocketOption -> SockOptValue -> IO ()

Set a socket option value

The existential SockOptValue enables things like:

mapM_ (uncurry $ setSockOptValue sock) [
      (NoDelay, SockOptValue @Int 1)
    , (Linger, SockOptValue (StructLinger 1 0))
    ]

Socket

data Socket

Basic type for a socket.

Instances

Show Socket

Defined in Network.Socket.Types

Methods

showsPrec :: Int -> Socket -> ShowS

show :: Socket -> String

showList :: [Socket] -> ShowS

Eq Socket

Defined in Network.Socket.Types

Methods

(==) :: Socket -> Socket -> Bool

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

socket :: Family -> SocketType -> ProtocolNumber -> IO Socket

Create a new socket using the given address family, socket type and protocol number. The address family is usually AF_INET, AF_INET6, or AF_UNIX. The socket type is usually Stream or Datagram. The protocol number is usually defaultProtocol. If AF_INET6 is used and the socket type is Stream or Datagram, the IPv6Only socket option is set to 0 so that both IPv4 and IPv6 can be handled with one socket.

>>> import Network.Socket
>>> import qualified Data.List.NonEmpty as NE
>>> let hints = defaultHints { addrFlags = [AI_NUMERICHOST, AI_NUMERICSERV], addrSocketType = Stream }
>>> addr <- NE.head <$> getAddrInfo (Just hints) (Just "127.0.0.1") (Just "5000")
>>> sock <- socket (addrFamily addr) (addrSocketType addr) (addrProtocol addr)
>>> Network.Socket.bind sock (addrAddress addr)
>>> getSocketName sock
127.0.0.1:5000

openSocket :: AddrInfo -> IO Socket

A utility function to open a socket with AddrInfo. This is a just wrapper for the following code:

\addr -> socket (addrFamily addr) (addrSocketType addr) (addrProtocol addr)

withFdSocket :: Socket -> (CInt -> IO r) -> IO r

Get a file descriptor from a Socket. The socket will never be closed automatically before withFdSocket completes, but it may still be closed by an explicit call to close or close', either before or during the call.

The file descriptor must not be used after withFdSocket returns, because the Socket may have been garbage-collected, invalidating the file descriptor.

Since: 3.1.0.0

unsafeFdSocket :: Socket -> IO CInt

Getting a file descriptor from a socket.

If a Socket is shared with multiple threads and one uses unsafeFdSocket, unexpected issues may happen. Consider the following scenario:

1) Thread A acquires a Fd from Socket by unsafeFdSocket.

2) Thread B close the Socket.

3) Thread C opens a new Socket. Unfortunately it gets the same Fd number which thread A is holding.

In this case, it is safer for Thread A to clone Fd by dup. But this would still suffer from a race condition between unsafeFdSocket and close.

If you use this function, you need to guarantee that the Socket does not get garbage-collected until after you finish using the file descriptor. touchSocket can be used for this purpose.

A safer option is to use withFdSocket instead.

touchSocket :: Socket -> IO ()

Ensure that the given Socket stays alive (i.e. not garbage-collected) at the given place in the sequence of IO actions. This function can be used in conjunction with unsafeFdSocket to guarantee that the file descriptor is not prematurely freed.

fd <- unsafeFdSocket sock
-- using fd with blocking operations such as accept(2)
touchSocket sock

socketToFd :: Socket -> IO CInt

Socket is closed and a duplicated file descriptor is returned. The duplicated descriptor is no longer subject to the possibility of unexpectedly being closed if the socket is finalized. It is now the caller's responsibility to ultimately close the duplicated file descriptor.

fdSocket :: Socket -> IO CInt

Deprecated: Use withFdSocket or unsafeFdSocket instead

Currently, this is an alias of unsafeFdSocket.

mkSocket :: CInt -> IO Socket

Creating a socket from a file descriptor.

socketToHandle :: Socket -> IOMode -> IO Handle

Turns a Socket into an Handle. By default, the new handle is unbuffered. Use hSetBuffering to change the buffering.

Note that since a Handle is automatically closed by a finalizer when it is no longer referenced, you should avoid doing any more operations on the Socket after calling socketToHandle. To close the Socket after socketToHandle, call hClose on the Handle.

Caveat Handle is not recommended for network programming in Haskell, e.g. merely performing hClose on a TCP socket won't cooperate with peer's gracefulClose, i.e. proper shutdown sequence with appropriate handshakes specified by the protocol.

Types of Socket

data SocketType where

Socket Types.

Some of the defined patterns may be unsupported on some systems: see isSupportedSocketType.

Bundled Patterns

pattern GeneralSocketType :: CInt -> SocketType

Pattern for a general socket type.

pattern UnsupportedSocketType :: SocketType

Unsupported socket type, equal to any other types not supported on this system.

pattern NoSocketType :: SocketType

Used in getAddrInfo hints, for example.

pattern Stream :: SocketType

pattern Datagram :: SocketType

pattern Raw :: SocketType

pattern RDM :: SocketType

pattern SeqPacket :: SocketType

Instances

Read SocketType

Defined in Network.Socket.Types

Methods

readsPrec :: Int -> ReadS SocketType

readList :: ReadS [SocketType]

readPrec :: ReadPrec SocketType

readListPrec :: ReadPrec [SocketType]

Show SocketType

Defined in Network.Socket.Types

Methods

showsPrec :: Int -> SocketType -> ShowS

show :: SocketType -> String

showList :: [SocketType] -> ShowS

Eq SocketType

Defined in Network.Socket.Types

Methods

(==) :: SocketType -> SocketType -> Bool

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

Ord SocketType

Defined in Network.Socket.Types

Methods

compare :: SocketType -> SocketType -> Ordering

(<) :: SocketType -> SocketType -> Bool

(<=) :: SocketType -> SocketType -> Bool

(>) :: SocketType -> SocketType -> Bool

(>=) :: SocketType -> SocketType -> Bool

max :: SocketType -> SocketType -> SocketType

min :: SocketType -> SocketType -> SocketType

isSupportedSocketType :: SocketType -> Bool

Is the SOCK_xxxxx constant corresponding to the given SocketType known on this system? GeneralSocketType values, not equal to any of the named patterns or UnsupportedSocketType, will return True even when not known on this system.

getSocketType :: Socket -> IO SocketType

Get the SocketType of an active socket.

Since: 3.0.1.0

Family

data Family where

Address families. The AF_xxxxx constants are widely used as synonyms for the corresponding PF_xxxxx protocol family values, to which they are numerically equal in mainstream socket API implementations.

Strictly correct usage would be to pass the PF_xxxxx constants as the first argument when creating a Socket, while the AF_xxxxx constants should be used as addrFamily values with getAddrInfo. For now only the AF_xxxxx constants are provided.

Some of the defined patterns may be unsupported on some systems: see isSupportedFamily.

Bundled Patterns

pattern GeneralFamily :: CInt -> Family

Pattern for a general protocol family (a.k.a. address family).

Since: 3.2.0.0

pattern UnsupportedFamily :: Family

Unsupported address family, equal to any other families that are not supported on the system.

Since: 3.2.0.0

pattern AF_UNSPEC :: Family

unspecified

pattern AF_UNIX :: Family

UNIX-domain

pattern AF_INET :: Family

Internet Protocol version 4

pattern AF_INET6 :: Family

Internet Protocol version 6

pattern AF_IMPLINK :: Family

Arpanet imp addresses

pattern AF_PUP :: Family

pup protocols: e.g. BSP

pattern AF_CHAOS :: Family

mit CHAOS protocols

pattern AF_NS :: Family

XEROX NS protocols

pattern AF_NBS :: Family

nbs protocols

pattern AF_ECMA :: Family

european computer manufacturers

pattern AF_DATAKIT :: Family

datakit protocols

pattern AF_CCITT :: Family

CCITT protocols, X.25 etc

pattern AF_SNA :: Family

IBM SNA

pattern AF_DECnet :: Family

DECnet

pattern AF_DLI :: Family

Direct data link interface

pattern AF_LAT :: Family

LAT

pattern AF_HYLINK :: Family

NSC Hyperchannel

pattern AF_APPLETALK :: Family

Apple Talk

pattern AF_ROUTE :: Family

Internal Routing Protocol (aka AF_NETLINK)

pattern AF_NETBIOS :: Family

NetBios-style addresses

pattern AF_NIT :: Family

Network Interface Tap

pattern AF_802 :: Family

IEEE 802.2, also ISO 8802

pattern AF_ISO :: Family

ISO protocols

pattern AF_OSI :: Family

umbrella of all families used by OSI

pattern AF_NETMAN :: Family

DNA Network Management

pattern AF_X25 :: Family

CCITT X.25

pattern AF_AX25 :: Family

AX25

pattern AF_OSINET :: Family

AFI

pattern AF_GOSSIP :: Family

US Government OSI

pattern AF_IPX :: Family

Novell Internet Protocol

pattern Pseudo_AF_XTP :: Family

eXpress Transfer Protocol (no AF)

pattern AF_CTF :: Family

Common Trace Facility

pattern AF_WAN :: Family

Wide Area Network protocols

pattern AF_SDL :: Family

SGI Data Link for DLPI

pattern AF_NETWARE :: Family

Netware

pattern AF_NDD :: Family

NDD

pattern AF_INTF :: Family

Debugging use only

pattern AF_COIP :: Family

connection-oriented IP, aka ST II

pattern AF_CNT :: Family

Computer Network Technology

pattern Pseudo_AF_RTIP :: Family

Help Identify RTIP packets

pattern Pseudo_AF_PIP :: Family

Help Identify PIP packets

pattern AF_SIP :: Family

Simple Internet Protocol

pattern AF_ISDN :: Family

Integrated Services Digital Network

pattern Pseudo_AF_KEY :: Family

Internal key-management function

pattern AF_NATM :: Family

native ATM access

pattern AF_ARP :: Family

ARP (RFC 826)

pattern Pseudo_AF_HDRCMPLT :: Family

Used by BPF to not rewrite hdrs in iface output

pattern AF_ENCAP :: Family

ENCAP

pattern AF_LINK :: Family

Link layer interface

pattern AF_RAW :: Family

Link layer interface

pattern AF_RIF :: Family

raw interface

pattern AF_NETROM :: Family

Amateur radio NetROM

pattern AF_BRIDGE :: Family

multiprotocol bridge

pattern AF_ATMPVC :: Family

ATM PVCs

pattern AF_ROSE :: Family

Amateur Radio X.25 PLP

pattern AF_NETBEUI :: Family

Netbeui 802.2LLC

pattern AF_SECURITY :: Family

Security callback pseudo AF

pattern AF_PACKET :: Family

Packet family

pattern AF_ASH :: Family

Ash

pattern AF_ECONET :: Family

Acorn Econet

pattern AF_ATMSVC :: Family

ATM SVCs

pattern AF_IRDA :: Family

IRDA sockets

pattern AF_PPPOX :: Family

PPPoX sockets

pattern AF_WANPIPE :: Family

Wanpipe API sockets

pattern AF_BLUETOOTH :: Family

bluetooth sockets

pattern AF_CAN :: Family

Controller Area Network

Instances

Read Family

Defined in Network.Socket.Types

Methods

readsPrec :: Int -> ReadS Family

readList :: ReadS [Family]

readPrec :: ReadPrec Family

readListPrec :: ReadPrec [Family]

Show Family

Defined in Network.Socket.Types

Methods

showsPrec :: Int -> Family -> ShowS

show :: Family -> String

showList :: [Family] -> ShowS

Eq Family

Defined in Network.Socket.Types

Methods

(==) :: Family -> Family -> Bool

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

Ord Family

Defined in Network.Socket.Types

Methods

compare :: Family -> Family -> Ordering

(<) :: Family -> Family -> Bool

(<=) :: Family -> Family -> Bool

(>) :: Family -> Family -> Bool

(>=) :: Family -> Family -> Bool

max :: Family -> Family -> Family

min :: Family -> Family -> Family

isSupportedFamily :: Family -> Bool

Does one of the AF_ constants correspond to a known address family on this system. GeneralFamily values, not equal to any of the named AF_xxxxx patterns or UnsupportedFamily, will return True even when not known on this system.

packFamily :: Family -> CInt

unpackFamily :: CInt -> Family

Convert CInt to Family.

Protocol number

type ProtocolNumber = CInt

Protocol number.

defaultProtocol :: ProtocolNumber

This is the default protocol for a given service.

>>> defaultProtocol
0

Basic socket address type

data SockAddr

Socket addresses. The existence of a constructor does not necessarily imply that that socket address type is supported on your system: see isSupportedSockAddr.

Constructors

SockAddrInet PortNumber HostAddress

SockAddrInet6 PortNumber FlowInfo HostAddress6 ScopeID

SockAddrUnix String

The path must have fewer than 104 characters. All of these characters must have code points less than 256.

Instances

Show SockAddr

>>> SockAddrInet6 80 0 (0,0,0xffff,0x01020304) 0
[::ffff:1.2.3.4]:80

Defined in Network.Socket.Info

Methods

showsPrec :: Int -> SockAddr -> ShowS

show :: SockAddr -> String

showList :: [SockAddr] -> ShowS

NFData SockAddr

Defined in Network.Socket.Types

Methods

rnf :: SockAddr -> ()

Eq SockAddr

Defined in Network.Socket.Types

Methods

(==) :: SockAddr -> SockAddr -> Bool

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

Ord SockAddr

Defined in Network.Socket.Types

Methods

compare :: SockAddr -> SockAddr -> Ordering

(<) :: SockAddr -> SockAddr -> Bool

(<=) :: SockAddr -> SockAddr -> Bool

(>) :: SockAddr -> SockAddr -> Bool

(>=) :: SockAddr -> SockAddr -> Bool

max :: SockAddr -> SockAddr -> SockAddr

min :: SockAddr -> SockAddr -> SockAddr

SocketAddress SockAddr

Defined in Network.Socket.Types

Methods

sizeOfSocketAddress :: SockAddr -> Int

peekSocketAddress :: Ptr SockAddr -> IO SockAddr

pokeSocketAddress :: Ptr a -> SockAddr -> IO ()

isSupportedSockAddr :: SockAddr -> Bool

Is the socket address type supported on this system?

getPeerName :: Socket -> IO SockAddr

Getting peer's SockAddr.

getSocketName :: Socket -> IO SockAddr

Getting my SockAddr.

Host address

type HostAddress = Word32

The raw network byte order number is read using host byte order. Therefore on little-endian architectures the byte order is swapped. For example 127.0.0.1 is represented as 0x0100007f on little-endian hosts and as 0x7f000001 on big-endian hosts.

For direct manipulation prefer hostAddressToTuple and tupleToHostAddress.

hostAddressToTuple :: HostAddress -> (Word8, Word8, Word8, Word8)

Converts HostAddress to representation-independent IPv4 quadruple. For example for 127.0.0.1 the function will return (0x7f, 0, 0, 1) regardless of host endianness.

tupleToHostAddress :: (Word8, Word8, Word8, Word8) -> HostAddress

Converts IPv4 quadruple to HostAddress.

Host address6

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

Independent of endianness. For example ::1 is stored as (0, 0, 0, 1).

For direct manipulation prefer hostAddress6ToTuple and tupleToHostAddress6.

hostAddress6ToTuple :: HostAddress6 -> (Word16, Word16, Word16, Word16, Word16, Word16, Word16, Word16)

Converts HostAddress6 to representation-independent IPv6 octuple.

tupleToHostAddress6 :: (Word16, Word16, Word16, Word16, Word16, Word16, Word16, Word16) -> HostAddress6

Converts IPv6 octuple to HostAddress6.

Flow Info

type FlowInfo = Word32

Flow information.

Scope ID

type ScopeID = Word32

Scope identifier.

ifNameToIndex :: String -> IO (Maybe Int)

Returns the index corresponding to the interface name.

Since 2.7.0.0.

ifIndexToName :: Int -> IO (Maybe String)

Returns the interface name corresponding to the index.

Since 2.7.0.0.

Port number

data PortNumber

Port number. Use the Num instance (i.e. use a literal) to create a PortNumber value.

>>> 1 :: PortNumber
1
>>> read "1" :: PortNumber
1
>>> show (12345 :: PortNumber)
"12345"
>>> 50000 < (51000 :: PortNumber)
True
>>> 50000 < (52000 :: PortNumber)
True
>>> 50000 + (10000 :: PortNumber)
60000

Instances

Storable PortNumber

Defined in Network.Socket.Types

Methods

sizeOf :: PortNumber -> Int

alignment :: PortNumber -> Int

peekElemOff :: Ptr PortNumber -> Int -> IO PortNumber

pokeElemOff :: Ptr PortNumber -> Int -> PortNumber -> IO ()

peekByteOff :: Ptr b -> Int -> IO PortNumber

pokeByteOff :: Ptr b -> Int -> PortNumber -> IO ()

peek :: Ptr PortNumber -> IO PortNumber

poke :: Ptr PortNumber -> PortNumber -> IO ()

Bounded PortNumber

Defined in Network.Socket.Types

Methods

minBound :: PortNumber

maxBound :: PortNumber

Enum PortNumber

Defined in Network.Socket.Types

Methods

succ :: PortNumber -> PortNumber

pred :: PortNumber -> PortNumber

toEnum :: Int -> PortNumber

fromEnum :: PortNumber -> Int

enumFrom :: PortNumber -> [PortNumber]

enumFromThen :: PortNumber -> PortNumber -> [PortNumber]

enumFromTo :: PortNumber -> PortNumber -> [PortNumber]

enumFromThenTo :: PortNumber -> PortNumber -> PortNumber -> [PortNumber]

Num PortNumber

Defined in Network.Socket.Types

Methods

(+) :: PortNumber -> PortNumber -> PortNumber

(-) :: PortNumber -> PortNumber -> PortNumber

(*) :: PortNumber -> PortNumber -> PortNumber

negate :: PortNumber -> PortNumber

abs :: PortNumber -> PortNumber

signum :: PortNumber -> PortNumber

fromInteger :: Integer -> PortNumber

Read PortNumber

Defined in Network.Socket.Types

Methods

readsPrec :: Int -> ReadS PortNumber

readList :: ReadS [PortNumber]

readPrec :: ReadPrec PortNumber

readListPrec :: ReadPrec [PortNumber]

Integral PortNumber

Defined in Network.Socket.Types

Methods

quot :: PortNumber -> PortNumber -> PortNumber

rem :: PortNumber -> PortNumber -> PortNumber

div :: PortNumber -> PortNumber -> PortNumber

mod :: PortNumber -> PortNumber -> PortNumber

quotRem :: PortNumber -> PortNumber -> (PortNumber, PortNumber)

divMod :: PortNumber -> PortNumber -> (PortNumber, PortNumber)

toInteger :: PortNumber -> Integer

Real PortNumber

Defined in Network.Socket.Types

Methods

toRational :: PortNumber -> Rational

Show PortNumber

Defined in Network.Socket.Types

Methods

showsPrec :: Int -> PortNumber -> ShowS

show :: PortNumber -> String

showList :: [PortNumber] -> ShowS

Eq PortNumber

Defined in Network.Socket.Types

Methods

(==) :: PortNumber -> PortNumber -> Bool

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

Ord PortNumber

Defined in Network.Socket.Types

Methods

compare :: PortNumber -> PortNumber -> Ordering

(<) :: PortNumber -> PortNumber -> Bool

(<=) :: PortNumber -> PortNumber -> Bool

(>) :: PortNumber -> PortNumber -> Bool

(>=) :: PortNumber -> PortNumber -> Bool

max :: PortNumber -> PortNumber -> PortNumber

min :: PortNumber -> PortNumber -> PortNumber

defaultPort :: PortNumber

Default port number.

>>> defaultPort
0

socketPortSafe :: Socket -> IO (Maybe PortNumber)

Getting the port of socket.

socketPort :: Socket -> IO PortNumber

Getting the port of socket. IOError is thrown if a port is not available.

UNIX-domain socket

isUnixDomainSocketAvailable :: Bool

Whether or not UNIX-domain sockets are available. AF_UNIX is supported on Windows since 3.1.3.0. So, this variable is True on all platforms.

Since 2.7.0.0.

socketPair :: Family -> SocketType -> ProtocolNumber -> IO (Socket, Socket)

Build a pair of connected socket objects. On Windows, this function emulates socketpair() using AF_UNIX and a temporary file will remain.

sendFd :: Socket -> CInt -> IO ()

Send a file descriptor over a UNIX-domain socket. This function does not work on Windows.

recvFd :: Socket -> IO CInt

Receive a file descriptor over a UNIX-domain socket. Note that the resulting file descriptor may have to be put into non-blocking mode in order to be used safely. See setNonBlockIfNeeded. This function does not work on Windows.

getPeerCredential :: Socket -> IO (Maybe CUInt, Maybe CUInt, Maybe CUInt)

Getting process ID, user ID and group ID for UNIX-domain sockets.

This is implemented with SO_PEERCRED on Linux and getpeereid() on BSD variants. Unfortunately, on some BSD variants getpeereid() returns unexpected results, rather than an error, for AF_INET sockets. It is the user's responsibility to make sure that the socket is a UNIX-domain socket. Also, on some BSD variants, getpeereid() does not return credentials for sockets created via socketPair, only separately created and then explicitly connected UNIX-domain sockets work on such systems.

Since 2.7.0.0.

Name information

getNameInfo

Arguments

:: [NameInfoFlag]

flags to control lookup behaviour

-> Bool

whether to look up a hostname

-> Bool

whether to look up a service name

-> SockAddr

the address to look up

-> IO (Maybe HostName, Maybe ServiceName)

Resolve an address to a host or service name. This function is protocol independent. The list of NameInfoFlag values controls query behaviour.

If a host or service's name cannot be looked up, then the numeric form of the address or service will be returned.

If the query fails, this function throws an IO exception.

>>> addr:_ <- getAddrInfo (Just defaultHints) (Just "127.0.0.1") (Just "http")
>>> getNameInfo [NI_NUMERICHOST, NI_NUMERICSERV] True True $ addrAddress addr
(Just "127.0.0.1",Just "80")

data NameInfoFlag

Flags that control the querying behaviour of getNameInfo. For more information, see https://tools.ietf.org/html/rfc3493#page-30

Constructors

NI_DGRAM

Resolve a datagram-based service name. This is required only for the few protocols that have different port numbers for their datagram-based versions than for their stream-based versions.

NI_NAMEREQD

If the hostname cannot be looked up, an IO error is thrown.

NI_NOFQDN

If a host is local, return only the hostname part of the FQDN.

NI_NUMERICHOST

The name of the host is not looked up. Instead, a numeric representation of the host's address is returned. For an IPv4 address, this will be a dotted-quad string. For IPv6, it will be colon-separated hexadecimal.

NI_NUMERICSERV

The name of the service is not looked up. Instead, a numeric representation of the service is returned.

Instances

Read NameInfoFlag

Defined in Network.Socket.Info

Methods

readsPrec :: Int -> ReadS NameInfoFlag

readList :: ReadS [NameInfoFlag]

readPrec :: ReadPrec NameInfoFlag

readListPrec :: ReadPrec [NameInfoFlag]

Show NameInfoFlag

Defined in Network.Socket.Info

Methods

showsPrec :: Int -> NameInfoFlag -> ShowS

show :: NameInfoFlag -> String

showList :: [NameInfoFlag] -> ShowS

Eq NameInfoFlag

Defined in Network.Socket.Info

Methods

(==) :: NameInfoFlag -> NameInfoFlag -> Bool

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

Low level

socket operations

setCloseOnExecIfNeeded :: CInt -> IO ()

Set the close_on_exec flag on Unix. On Windows, nothing is done.

Since 2.7.0.0.

getCloseOnExec :: CInt -> IO Bool

Get the close_on_exec flag. On Windows, this function always returns False.

Since 2.7.0.0.

setNonBlockIfNeeded :: CInt -> IO ()

Set the nonblocking flag on Unix. On Windows, nothing is done.

getNonBlock :: CInt -> IO Bool

Get the nonblocking flag. On Windows, this function always returns False.

Since 2.7.0.0.

Sending and receiving data

sendBuf :: Socket -> Ptr Word8 -> Int -> IO Int

Send data to the socket. The socket must be connected to a remote socket. Returns the number of bytes sent. Applications are responsible for ensuring that all data has been sent.

recvBuf :: Socket -> Ptr Word8 -> Int -> IO Int

Receive data from the socket. The socket must be in a connected state. This function may return fewer bytes than specified. If the message is longer than the specified length, it may be discarded depending on the type of socket. This function may block until a message arrives.

Considering hardware and network realities, the maximum number of bytes to receive should be a small power of 2, e.g., 4096.

The return value is the length of received data. Zero means EOF. Historical note: Version 2.8.x.y or earlier, an EOF error was thrown. This was changed in version 3.0.

sendBufTo :: Socket -> Ptr a -> Int -> SockAddr -> IO Int

Send data to the socket. The recipient can be specified explicitly, so the socket need not be in a connected state. Returns the number of bytes sent. Applications are responsible for ensuring that all data has been sent.

recvBufFrom :: Socket -> Ptr a -> Int -> IO (Int, SockAddr)

Receive data from the socket, writing it into buffer instead of creating a new string. The socket need not be in a connected state. Returns (nbytes, address) where nbytes is the number of bytes received and address is a SockAddr representing the address of the sending socket.

If the first return value is zero, it means EOF.

For Stream sockets, the second return value would be invalid.

NOTE: blocking on Windows unless you compile with -threaded (see GHC ticket #1129)

Advanced IO

sendBufMsg

Arguments

:: Socket

Socket

-> SockAddr

Destination address

-> [(Ptr Word8, Int)]

Data to be sent

-> [Cmsg]

Control messages

-> MsgFlag

Message flags

-> IO Int

The length actually sent

Send data to the socket using sendmsg(2).

recvBufMsg

Arguments

:: Socket

Socket

-> [(Ptr Word8, Int)]

A list of a pair of buffer and its size. If the total length is not large enough, MSG_TRUNC is returned

-> Int

The buffer size for control messages. If the length is not large enough, MSG_CTRUNC is returned

-> MsgFlag

Message flags

-> IO (SockAddr, Int, [Cmsg], MsgFlag)

Source address, received data, control messages and message flags

Receive data from the socket using recvmsg(2).

data MsgFlag where

Message flags. To combine flags, use (<>).

Bundled Patterns

pattern MSG_OOB :: MsgFlag

Send or receive OOB(out-of-bound) data.

pattern MSG_DONTROUTE :: MsgFlag

Bypass routing table lookup.

pattern MSG_PEEK :: MsgFlag

Peek at incoming message without removing it from the queue.

pattern MSG_EOR :: MsgFlag

End of record.

pattern MSG_TRUNC :: MsgFlag

Received data is truncated. More data exist.

pattern MSG_CTRUNC :: MsgFlag

Received control message is truncated. More control message exist.

pattern MSG_WAITALL :: MsgFlag

Wait until the requested number of bytes have been read.

Instances

Monoid MsgFlag

Defined in Network.Socket.Flag

Methods

mempty :: MsgFlag

mappend :: MsgFlag -> MsgFlag -> MsgFlag

mconcat :: [MsgFlag] -> MsgFlag

Semigroup MsgFlag

Defined in Network.Socket.Flag

Methods

(<>) :: MsgFlag -> MsgFlag -> MsgFlag

sconcat :: NonEmpty MsgFlag -> MsgFlag

stimes :: Integral b => b -> MsgFlag -> MsgFlag

Bits MsgFlag

Defined in Network.Socket.Flag

Methods

(.&.) :: MsgFlag -> MsgFlag -> MsgFlag

(.|.) :: MsgFlag -> MsgFlag -> MsgFlag

xor :: MsgFlag -> MsgFlag -> MsgFlag

complement :: MsgFlag -> MsgFlag

shift :: MsgFlag -> Int -> MsgFlag

rotate :: MsgFlag -> Int -> MsgFlag

zeroBits :: MsgFlag

bit :: Int -> MsgFlag

setBit :: MsgFlag -> Int -> MsgFlag

clearBit :: MsgFlag -> Int -> MsgFlag

complementBit :: MsgFlag -> Int -> MsgFlag

testBit :: MsgFlag -> Int -> Bool

bitSizeMaybe :: MsgFlag -> Maybe Int

bitSize :: MsgFlag -> Int

isSigned :: MsgFlag -> Bool

shiftL :: MsgFlag -> Int -> MsgFlag

unsafeShiftL :: MsgFlag -> Int -> MsgFlag

shiftR :: MsgFlag -> Int -> MsgFlag

unsafeShiftR :: MsgFlag -> Int -> MsgFlag

rotateL :: MsgFlag -> Int -> MsgFlag

rotateR :: MsgFlag -> Int -> MsgFlag

popCount :: MsgFlag -> Int

Num MsgFlag

Defined in Network.Socket.Flag

Methods

(+) :: MsgFlag -> MsgFlag -> MsgFlag

(-) :: MsgFlag -> MsgFlag -> MsgFlag

(*) :: MsgFlag -> MsgFlag -> MsgFlag

negate :: MsgFlag -> MsgFlag

abs :: MsgFlag -> MsgFlag

signum :: MsgFlag -> MsgFlag

fromInteger :: Integer -> MsgFlag

Show MsgFlag

Defined in Network.Socket.Flag

Methods

showsPrec :: Int -> MsgFlag -> ShowS

show :: MsgFlag -> String

showList :: [MsgFlag] -> ShowS

Eq MsgFlag

Defined in Network.Socket.Flag

Methods

(==) :: MsgFlag -> MsgFlag -> Bool

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

Ord MsgFlag

Defined in Network.Socket.Flag

Methods

compare :: MsgFlag -> MsgFlag -> Ordering

(<) :: MsgFlag -> MsgFlag -> Bool

(<=) :: MsgFlag -> MsgFlag -> Bool

(>) :: MsgFlag -> MsgFlag -> Bool

(>=) :: MsgFlag -> MsgFlag -> Bool

max :: MsgFlag -> MsgFlag -> MsgFlag

min :: MsgFlag -> MsgFlag -> MsgFlag

Control message (ancillary data)

data Cmsg

Control message (ancillary data) including a pair of level and type.

Constructors

Cmsg

Fields

• cmsgId :: CmsgId
• cmsgData :: ByteString

Instances

Show Cmsg

Defined in Network.Socket.Posix.Cmsg

Methods

showsPrec :: Int -> Cmsg -> ShowS

show :: Cmsg -> String

showList :: [Cmsg] -> ShowS

Eq Cmsg

Defined in Network.Socket.Posix.Cmsg

Methods

(==) :: Cmsg -> Cmsg -> Bool

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

data CmsgId

Identifier of control message (ancillary data).

Constructors

CmsgId CInt CInt

Bundled Patterns

pattern CmsgIdIPv4TTL :: CmsgId

The identifier for IPv4TTL.

pattern CmsgIdIPv6HopLimit :: CmsgId

The identifier for IPv6HopLimit.

pattern CmsgIdIPv4TOS :: CmsgId

The identifier for IPv4TOS.

pattern CmsgIdIPv6TClass :: CmsgId

The identifier for IPv6TClass.

pattern CmsgIdIPv4PktInfo :: CmsgId

The identifier for IPv4PktInfo.

pattern CmsgIdIPv6PktInfo :: CmsgId

The identifier for IPv6PktInfo.

pattern CmsgIdFds :: CmsgId

The identifier for Fds.

pattern UnsupportedCmsgId :: CmsgId

Unsupported identifier

Instances

Read CmsgId

Defined in Network.Socket.Posix.Cmsg

Methods

readsPrec :: Int -> ReadS CmsgId

readList :: ReadS [CmsgId]

readPrec :: ReadPrec CmsgId

readListPrec :: ReadPrec [CmsgId]

Show CmsgId

Defined in Network.Socket.Posix.Cmsg

Methods

showsPrec :: Int -> CmsgId -> ShowS

show :: CmsgId -> String

showList :: [CmsgId] -> ShowS

Eq CmsgId

Defined in Network.Socket.Posix.Cmsg

Methods

(==) :: CmsgId -> CmsgId -> Bool

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

APIs for control message

lookupCmsg :: CmsgId -> [Cmsg] -> Maybe Cmsg

Locate a control message of the given type in a list of control messages. The following shows an example usage:

(lookupCmsg CmsgIdIPv4TOS cmsgs >>= decodeCmsg) :: Maybe IPv4TOS

filterCmsg :: CmsgId -> [Cmsg] -> [Cmsg]

Filtering control message.

Class and types for control message

class ControlMessage a where

Control message type class. Each control message type has a numeric CmsgId and encode and decode functions.

Methods

controlMessageId :: CmsgId

encodeCmsg :: a -> Cmsg

decodeCmsg :: Cmsg -> Maybe a

Instances

ControlMessage IPv4PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv4PktInfo -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv4PktInfo

ControlMessage IPv4TOS

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv4TOS -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv4TOS

ControlMessage IPv4TTL

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv4TTL -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv4TTL

ControlMessage IPv6HopLimit

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv6HopLimit -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv6HopLimit

ControlMessage IPv6PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv6PktInfo -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv6PktInfo

ControlMessage IPv6TClass

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv6TClass -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv6TClass

ControlMessage [Fd]

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: [Fd] -> Cmsg

decodeCmsg :: Cmsg -> Maybe [Fd]

newtype IPv4TTL

Time to live of IPv4.

Constructors

IPv4TTL CInt

Instances

Storable IPv4TTL

Defined in Network.Socket.Posix.Cmsg

Methods

sizeOf :: IPv4TTL -> Int

alignment :: IPv4TTL -> Int

peekElemOff :: Ptr IPv4TTL -> Int -> IO IPv4TTL

pokeElemOff :: Ptr IPv4TTL -> Int -> IPv4TTL -> IO ()

peekByteOff :: Ptr b -> Int -> IO IPv4TTL

pokeByteOff :: Ptr b -> Int -> IPv4TTL -> IO ()

peek :: Ptr IPv4TTL -> IO IPv4TTL

poke :: Ptr IPv4TTL -> IPv4TTL -> IO ()

Show IPv4TTL

Defined in Network.Socket.Posix.Cmsg

Methods

showsPrec :: Int -> IPv4TTL -> ShowS

show :: IPv4TTL -> String

showList :: [IPv4TTL] -> ShowS

Eq IPv4TTL

Defined in Network.Socket.Posix.Cmsg

Methods

(==) :: IPv4TTL -> IPv4TTL -> Bool

(/=) :: IPv4TTL -> IPv4TTL -> Bool

ControlMessage IPv4TTL

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv4TTL -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv4TTL

newtype IPv6HopLimit

Hop limit of IPv6.

Constructors

IPv6HopLimit CInt

Instances

Storable IPv6HopLimit

Defined in Network.Socket.Posix.Cmsg

Methods

sizeOf :: IPv6HopLimit -> Int

alignment :: IPv6HopLimit -> Int

peekElemOff :: Ptr IPv6HopLimit -> Int -> IO IPv6HopLimit

pokeElemOff :: Ptr IPv6HopLimit -> Int -> IPv6HopLimit -> IO ()

peekByteOff :: Ptr b -> Int -> IO IPv6HopLimit

pokeByteOff :: Ptr b -> Int -> IPv6HopLimit -> IO ()

peek :: Ptr IPv6HopLimit -> IO IPv6HopLimit

poke :: Ptr IPv6HopLimit -> IPv6HopLimit -> IO ()

Show IPv6HopLimit

Defined in Network.Socket.Posix.Cmsg

Methods

showsPrec :: Int -> IPv6HopLimit -> ShowS

show :: IPv6HopLimit -> String

showList :: [IPv6HopLimit] -> ShowS

Eq IPv6HopLimit

Defined in Network.Socket.Posix.Cmsg

Methods

(==) :: IPv6HopLimit -> IPv6HopLimit -> Bool

(/=) :: IPv6HopLimit -> IPv6HopLimit -> Bool

ControlMessage IPv6HopLimit

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv6HopLimit -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv6HopLimit

newtype IPv4TOS

TOS of IPv4.

Constructors

IPv4TOS CChar

Instances

Storable IPv4TOS

Defined in Network.Socket.Posix.Cmsg

Methods

sizeOf :: IPv4TOS -> Int

alignment :: IPv4TOS -> Int

peekElemOff :: Ptr IPv4TOS -> Int -> IO IPv4TOS

pokeElemOff :: Ptr IPv4TOS -> Int -> IPv4TOS -> IO ()

peekByteOff :: Ptr b -> Int -> IO IPv4TOS

pokeByteOff :: Ptr b -> Int -> IPv4TOS -> IO ()

peek :: Ptr IPv4TOS -> IO IPv4TOS

poke :: Ptr IPv4TOS -> IPv4TOS -> IO ()

Show IPv4TOS

Defined in Network.Socket.Posix.Cmsg

Methods

showsPrec :: Int -> IPv4TOS -> ShowS

show :: IPv4TOS -> String

showList :: [IPv4TOS] -> ShowS

Eq IPv4TOS

Defined in Network.Socket.Posix.Cmsg

Methods

(==) :: IPv4TOS -> IPv4TOS -> Bool

(/=) :: IPv4TOS -> IPv4TOS -> Bool

ControlMessage IPv4TOS

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv4TOS -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv4TOS

newtype IPv6TClass

Traffic class of IPv6.

Constructors

IPv6TClass CInt

Instances

Storable IPv6TClass

Defined in Network.Socket.Posix.Cmsg

Methods

sizeOf :: IPv6TClass -> Int

alignment :: IPv6TClass -> Int

peekElemOff :: Ptr IPv6TClass -> Int -> IO IPv6TClass

pokeElemOff :: Ptr IPv6TClass -> Int -> IPv6TClass -> IO ()

peekByteOff :: Ptr b -> Int -> IO IPv6TClass

pokeByteOff :: Ptr b -> Int -> IPv6TClass -> IO ()

peek :: Ptr IPv6TClass -> IO IPv6TClass

poke :: Ptr IPv6TClass -> IPv6TClass -> IO ()

Show IPv6TClass

Defined in Network.Socket.Posix.Cmsg

Methods

showsPrec :: Int -> IPv6TClass -> ShowS

show :: IPv6TClass -> String

showList :: [IPv6TClass] -> ShowS

Eq IPv6TClass

Defined in Network.Socket.Posix.Cmsg

Methods

(==) :: IPv6TClass -> IPv6TClass -> Bool

(/=) :: IPv6TClass -> IPv6TClass -> Bool

ControlMessage IPv6TClass

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv6TClass -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv6TClass

data IPv4PktInfo

Network interface ID and local IPv4 address.

Constructors

IPv4PktInfo Int HostAddress HostAddress

Instances

Storable IPv4PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

sizeOf :: IPv4PktInfo -> Int

alignment :: IPv4PktInfo -> Int

peekElemOff :: Ptr IPv4PktInfo -> Int -> IO IPv4PktInfo

pokeElemOff :: Ptr IPv4PktInfo -> Int -> IPv4PktInfo -> IO ()

peekByteOff :: Ptr b -> Int -> IO IPv4PktInfo

pokeByteOff :: Ptr b -> Int -> IPv4PktInfo -> IO ()

peek :: Ptr IPv4PktInfo -> IO IPv4PktInfo

poke :: Ptr IPv4PktInfo -> IPv4PktInfo -> IO ()

Show IPv4PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

showsPrec :: Int -> IPv4PktInfo -> ShowS

show :: IPv4PktInfo -> String

showList :: [IPv4PktInfo] -> ShowS

Eq IPv4PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

(==) :: IPv4PktInfo -> IPv4PktInfo -> Bool

(/=) :: IPv4PktInfo -> IPv4PktInfo -> Bool

ControlMessage IPv4PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv4PktInfo -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv4PktInfo

data IPv6PktInfo

Network interface ID and local IPv4 address.

Constructors

IPv6PktInfo Int HostAddress6

Instances

Storable IPv6PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

sizeOf :: IPv6PktInfo -> Int

alignment :: IPv6PktInfo -> Int

peekElemOff :: Ptr IPv6PktInfo -> Int -> IO IPv6PktInfo

pokeElemOff :: Ptr IPv6PktInfo -> Int -> IPv6PktInfo -> IO ()

peekByteOff :: Ptr b -> Int -> IO IPv6PktInfo

pokeByteOff :: Ptr b -> Int -> IPv6PktInfo -> IO ()

peek :: Ptr IPv6PktInfo -> IO IPv6PktInfo

poke :: Ptr IPv6PktInfo -> IPv6PktInfo -> IO ()

Show IPv6PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

showsPrec :: Int -> IPv6PktInfo -> ShowS

show :: IPv6PktInfo -> String

showList :: [IPv6PktInfo] -> ShowS

Eq IPv6PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

(==) :: IPv6PktInfo -> IPv6PktInfo -> Bool

(/=) :: IPv6PktInfo -> IPv6PktInfo -> Bool

ControlMessage IPv6PktInfo

Defined in Network.Socket.Posix.Cmsg

Methods

controlMessageId :: CmsgId

encodeCmsg :: IPv6PktInfo -> Cmsg

decodeCmsg :: Cmsg -> Maybe IPv6PktInfo

Special constants

maxListenQueue :: Int

This is the value of SOMAXCONN, typically 128. 128 is good enough for normal network servers but is too small for high performance servers.

STM to check read and write

waitReadSocketSTM :: Socket -> IO (STM ())

STM action to wait until the socket is ready for reading.

waitAndCancelReadSocketSTM :: Socket -> IO (STM (), IO ())

STM action to wait until the socket is ready for reading and STM action to cancel the waiting.

waitWriteSocketSTM :: Socket -> IO (STM ())

STM action to wait until the socket is ready for writing.

waitAndCancelWriteSocketSTM :: Socket -> IO (STM (), IO ())

STM action to wait until the socket is ready for writing and STM action to cancel the waiting.