{-# LINE 1 "Network/Socket/Internal.hsc" #-}
{-# LANGUAGE CPP, ForeignFunctionInterface #-}
{-# LINE 2 "Network/Socket/Internal.hsc" #-}
-----------------------------------------------------------------------------
-- |
-- Module      :  Network.Socket.Internal
-- Copyright   :  (c) The University of Glasgow 2001
-- License     :  BSD-style (see the file libraries/network/LICENSE)
--
-- Maintainer  :  libraries@haskell.org
-- Stability   :  provisional
-- Portability :  portable
--
-- A module containing semi-public 'Network.Socket' internals.
-- Modules which extend the 'Network.Socket' module will need to use
-- this module while ideally most users will be able to make do with
-- the public interface.
--
-----------------------------------------------------------------------------


{-# LINE 20 "Network/Socket/Internal.hsc" #-}

module Network.Socket.Internal
    (
      -- * Socket addresses
      HostAddress,

{-# LINE 26 "Network/Socket/Internal.hsc" #-}
      HostAddress6,
      FlowInfo,
      ScopeID,

{-# LINE 30 "Network/Socket/Internal.hsc" #-}
      PortNumber(..),
      SockAddr(..),

      peekSockAddr,
      pokeSockAddr,
      sizeOfSockAddr,
      sizeOfSockAddrByFamily,
      withSockAddr,
      withNewSockAddr,

      -- * Protocol families
      Family(..),

      -- * Socket error functions

{-# LINE 47 "Network/Socket/Internal.hsc" #-}
      throwSocketError,

      -- * Guards for socket operations that may fail
      throwSocketErrorIfMinus1_,
      throwSocketErrorIfMinus1Retry,
      throwSocketErrorIfMinus1RetryMayBlock,

      -- * Initialization
      withSocketsDo,

      -- * Low-level helpers
      zeroMemory,
    ) where

import Data.Bits ( (.|.), shiftL, shiftR )
import Data.Word ( Word8, Word16, Word32 )
import Foreign.C.Error (throwErrno, throwErrnoIfMinus1Retry,
                        throwErrnoIfMinus1RetryMayBlock, throwErrnoIfMinus1_)
import Foreign.C.String ( castCharToCChar, peekCString )
import Foreign.C.Types ( CInt, CSize )
import Foreign.Marshal.Alloc ( allocaBytes )
import Foreign.Marshal.Array ( pokeArray, pokeArray0 )
import Foreign.Ptr ( Ptr, castPtr, plusPtr )
import Foreign.Storable ( Storable(..) )


{-# LINE 80 "Network/Socket/Internal.hsc" #-}

------------------------------------------------------------------------

type HostAddress = Word32


{-# LINE 86 "Network/Socket/Internal.hsc" #-}
type HostAddress6 = (Word32, Word32, Word32, Word32)

-- The peek32 and poke32 functions work around the fact that the RFCs
-- don't require 32-bit-wide address fields to be present.  We can
-- only portably rely on an 8-bit field, s6_addr.

s6_addr_offset :: Int
s6_addr_offset = ((0))
{-# LINE 94 "Network/Socket/Internal.hsc" #-}

peek32 :: Ptr a -> Int -> IO Word32
peek32 p i = do
    let i' = i * 4
        peekByte n = peekByteOff p (s6_addr_offset + i' + n) :: IO Word8
        a `sl` i = fromIntegral a `shiftL` i
    a0 <- peekByte 0
    a1 <- peekByte 1
    a2 <- peekByte 2
    a3 <- peekByte 3
    return ((a0 `sl` 24) .|. (a1 `sl` 16) .|. (a2 `sl` 8) .|. (a3 `sl` 0))

poke32 :: Ptr a -> Int -> Word32 -> IO ()
poke32 p i a = do
    let i' = i * 4
        pokeByte n = pokeByteOff p (s6_addr_offset + i' + n)
        a `sr` i = fromIntegral (a `shiftR` i) :: Word8
    pokeByte 0 (a `sr` 24)
    pokeByte 1 (a `sr` 16)
    pokeByte 2 (a `sr`  8)
    pokeByte 3 (a `sr`  0)

instance Storable HostAddress6 where
    sizeOf _    = (16)
{-# LINE 118 "Network/Socket/Internal.hsc" #-}
    alignment _ = alignment (undefined :: CInt)

    peek p = do
        a <- peek32 p 0
        b <- peek32 p 1
        c <- peek32 p 2
        d <- peek32 p 3
        return (a, b, c, d)

    poke p (a, b, c, d) = do
        poke32 p 0 a
        poke32 p 1 b
        poke32 p 2 c
        poke32 p 3 d

{-# LINE 133 "Network/Socket/Internal.hsc" #-}

------------------------------------------------------------------------
-- Port Numbers
--
-- newtyped to prevent accidental use of sane-looking
-- port numbers that haven't actually been converted to
-- network-byte-order first.
--

newtype PortNumber = PortNum Word16 deriving ( Eq, Ord )

------------------------------------------------------------------------
-- Socket addresses

-- The scheme used for addressing sockets is somewhat quirky. The
-- calls in the BSD socket API that need to know the socket address
-- all operate in terms of struct sockaddr, a `virtual' type of
-- socket address.

-- The Internet family of sockets are addressed as struct sockaddr_in,
-- so when calling functions that operate on struct sockaddr, we have
-- to type cast the Internet socket address into a struct sockaddr.
-- Instances of the structure for different families might *not* be
-- the same size. Same casting is required of other families of
-- sockets such as Xerox NS. Similarly for Unix domain sockets.

-- To represent these socket addresses in Haskell-land, we do what BSD
-- didn't do, and use a union/algebraic type for the different
-- families. Currently only Unix domain sockets and the Internet
-- families are supported.


{-# LINE 165 "Network/Socket/Internal.hsc" #-}
type FlowInfo = Word32
type ScopeID = Word32

{-# LINE 168 "Network/Socket/Internal.hsc" #-}

data SockAddr       -- C Names
  = SockAddrInet
    PortNumber  -- sin_port  (network byte order)
    HostAddress -- sin_addr  (ditto)

{-# LINE 174 "Network/Socket/Internal.hsc" #-}
  | SockAddrInet6
        PortNumber      -- sin6_port (network byte order)
        FlowInfo        -- sin6_flowinfo (ditto)
        HostAddress6    -- sin6_addr (ditto)
        ScopeID         -- sin6_scope_id (ditto)

{-# LINE 180 "Network/Socket/Internal.hsc" #-}

{-# LINE 181 "Network/Socket/Internal.hsc" #-}
  | SockAddrUnix
        String          -- sun_path

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  deriving (Eq)


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type CSaFamily = (Word16)
{-# LINE 192 "Network/Socket/Internal.hsc" #-}

{-# LINE 193 "Network/Socket/Internal.hsc" #-}

-- | Computes the storage requirements (in bytes) of the given
-- 'SockAddr'.  This function differs from 'Foreign.Storable.sizeOf'
-- in that the value of the argument /is/ used.
sizeOfSockAddr :: SockAddr -> Int

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sizeOfSockAddr (SockAddrUnix path) =
    case path of
        '\0':_ -> (2) + length path
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        _      -> 110
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sizeOfSockAddr (SockAddrInet _ _) = 16
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sizeOfSockAddr (SockAddrInet6 _ _ _ _) = 28
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-- | Computes the storage requirements (in bytes) required for a
-- 'SockAddr' with the given 'Family'.
sizeOfSockAddrByFamily :: Family -> Int

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sizeOfSockAddrByFamily AF_UNIX  = 110
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sizeOfSockAddrByFamily AF_INET6 = 28
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sizeOfSockAddrByFamily AF_INET  = 16
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-- | Use a 'SockAddr' with a function requiring a pointer to a
-- 'SockAddr' and the length of that 'SockAddr'.
withSockAddr :: SockAddr -> (Ptr SockAddr -> Int -> IO a) -> IO a
withSockAddr addr f = do
    let sz = sizeOfSockAddr addr
    allocaBytes sz $ \p -> pokeSockAddr p addr >> f (castPtr p) sz

-- | Create a new 'SockAddr' for use with a function requiring a
-- pointer to a 'SockAddr' and the length of that 'SockAddr'.
withNewSockAddr :: Family -> (Ptr SockAddr -> Int -> IO a) -> IO a
withNewSockAddr family f = do
    let sz = sizeOfSockAddrByFamily family
    allocaBytes sz $ \ptr -> f ptr sz

-- We can't write an instance of 'Storable' for 'SockAddr' because
-- @sockaddr@ is a sum type of variable size but
-- 'Foreign.Storable.sizeOf' is required to be constant.

-- Note that on Darwin, the sockaddr structure must be zeroed before
-- use.

-- | Write the given 'SockAddr' to the given memory location.
pokeSockAddr :: Ptr a -> SockAddr -> IO ()

{-# LINE 244 "Network/Socket/Internal.hsc" #-}
pokeSockAddr p (SockAddrUnix path) = do

{-# LINE 248 "Network/Socket/Internal.hsc" #-}

{-# LINE 251 "Network/Socket/Internal.hsc" #-}
    ((\hsc_ptr -> pokeByteOff hsc_ptr 0)) p ((1) :: CSaFamily)
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    let pathC = map castCharToCChar path
        poker = case path of ('\0':_) -> pokeArray; _ -> pokeArray0 0
    poker (((\hsc_ptr -> hsc_ptr `plusPtr` 2)) p) pathC
{-# LINE 255 "Network/Socket/Internal.hsc" #-}

{-# LINE 256 "Network/Socket/Internal.hsc" #-}
pokeSockAddr p (SockAddrInet (PortNum port) addr) = do

{-# LINE 260 "Network/Socket/Internal.hsc" #-}

{-# LINE 263 "Network/Socket/Internal.hsc" #-}
    ((\hsc_ptr -> pokeByteOff hsc_ptr 0)) p ((2) :: CSaFamily)
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    ((\hsc_ptr -> pokeByteOff hsc_ptr 2)) p port
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    ((\hsc_ptr -> pokeByteOff hsc_ptr 4)) p addr
{-# LINE 266 "Network/Socket/Internal.hsc" #-}

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pokeSockAddr p (SockAddrInet6 (PortNum port) flow addr scope) = do

{-# LINE 271 "Network/Socket/Internal.hsc" #-}

{-# LINE 274 "Network/Socket/Internal.hsc" #-}
    ((\hsc_ptr -> pokeByteOff hsc_ptr 0)) p ((10) :: CSaFamily)
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    ((\hsc_ptr -> pokeByteOff hsc_ptr 2)) p port
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    ((\hsc_ptr -> pokeByteOff hsc_ptr 4)) p flow
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    ((\hsc_ptr -> pokeByteOff hsc_ptr 8)) p addr
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    ((\hsc_ptr -> pokeByteOff hsc_ptr 24)) p scope
{-# LINE 279 "Network/Socket/Internal.hsc" #-}

{-# LINE 280 "Network/Socket/Internal.hsc" #-}

-- | Read a 'SockAddr' from the given memory location.
peekSockAddr :: Ptr SockAddr -> IO SockAddr
peekSockAddr p = do
  family <- ((\hsc_ptr -> peekByteOff hsc_ptr 0)) p
{-# LINE 285 "Network/Socket/Internal.hsc" #-}
  case family :: CSaFamily of

{-# LINE 287 "Network/Socket/Internal.hsc" #-}
    (1) -> do
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        str <- peekCString (((\hsc_ptr -> hsc_ptr `plusPtr` 2)) p)
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        return (SockAddrUnix str)

{-# LINE 291 "Network/Socket/Internal.hsc" #-}
    (2) -> do
{-# LINE 292 "Network/Socket/Internal.hsc" #-}
        addr <- ((\hsc_ptr -> peekByteOff hsc_ptr 4)) p
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        port <- ((\hsc_ptr -> peekByteOff hsc_ptr 2)) p
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        return (SockAddrInet (PortNum port) addr)

{-# LINE 296 "Network/Socket/Internal.hsc" #-}
    (10) -> do
{-# LINE 297 "Network/Socket/Internal.hsc" #-}
        port <- ((\hsc_ptr -> peekByteOff hsc_ptr 2)) p
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        flow <- ((\hsc_ptr -> peekByteOff hsc_ptr 4)) p
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        addr <- ((\hsc_ptr -> peekByteOff hsc_ptr 8)) p
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        scope <- ((\hsc_ptr -> peekByteOff hsc_ptr 24)) p
{-# LINE 301 "Network/Socket/Internal.hsc" #-}
        return (SockAddrInet6 (PortNum port) flow addr scope)

{-# LINE 303 "Network/Socket/Internal.hsc" #-}

------------------------------------------------------------------------
-- Protocol Families.

-- | This data type might have different constructors depending on
-- what is supported by the operating system.
data Family
    = AF_UNSPEC           -- unspecified

{-# LINE 312 "Network/Socket/Internal.hsc" #-}
    | AF_UNIX             -- local to host (pipes, portals

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    | AF_INET             -- internetwork: UDP, TCP, etc

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    | AF_INET6            -- Internet Protocol version 6

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    | AF_SNA              -- IBM SNA

{-# LINE 347 "Network/Socket/Internal.hsc" #-}

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    | AF_DECnet           -- DECnet

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    | AF_APPLETALK        -- Apple Talk

{-# LINE 362 "Network/Socket/Internal.hsc" #-}

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    | AF_ROUTE            -- Internal Routing Protocol

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    | AF_X25              -- CCITT X.25

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    | AF_AX25

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    | AF_IPX              -- Novell Internet Protocol

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    | AF_ISDN             -- Integrated Services Digital Network

{-# LINE 437 "Network/Socket/Internal.hsc" #-}

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    | AF_NETROM           -- Amateur radio NetROM

{-# LINE 464 "Network/Socket/Internal.hsc" #-}

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    | AF_BRIDGE           -- multiprotocol bridge

{-# LINE 467 "Network/Socket/Internal.hsc" #-}

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    | AF_ATMPVC           -- ATM PVCs

{-# LINE 470 "Network/Socket/Internal.hsc" #-}

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    | AF_ROSE             -- Amateur Radio X.25 PLP

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    | AF_NETBEUI          -- 802.2LLC

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    | AF_SECURITY         -- Security callback pseudo AF

{-# LINE 479 "Network/Socket/Internal.hsc" #-}

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    | AF_PACKET           -- Packet family

{-# LINE 482 "Network/Socket/Internal.hsc" #-}

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    | AF_ASH              -- Ash

{-# LINE 485 "Network/Socket/Internal.hsc" #-}

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    | AF_ECONET           -- Acorn Econet

{-# LINE 488 "Network/Socket/Internal.hsc" #-}

{-# LINE 489 "Network/Socket/Internal.hsc" #-}
    | AF_ATMSVC           -- ATM SVCs

{-# LINE 491 "Network/Socket/Internal.hsc" #-}

{-# LINE 492 "Network/Socket/Internal.hsc" #-}
    | AF_IRDA             -- IRDA sockets

{-# LINE 494 "Network/Socket/Internal.hsc" #-}

{-# LINE 495 "Network/Socket/Internal.hsc" #-}
    | AF_PPPOX            -- PPPoX sockets

{-# LINE 497 "Network/Socket/Internal.hsc" #-}

{-# LINE 498 "Network/Socket/Internal.hsc" #-}
    | AF_WANPIPE          -- Wanpipe API sockets

{-# LINE 500 "Network/Socket/Internal.hsc" #-}

{-# LINE 501 "Network/Socket/Internal.hsc" #-}
    | AF_BLUETOOTH        -- bluetooth sockets

{-# LINE 503 "Network/Socket/Internal.hsc" #-}
      deriving (Eq, Ord, Read, Show)

-- ---------------------------------------------------------------------
-- Guards for socket operations that may fail

-- | Throw an 'IOError' corresponding to the current socket error.
throwSocketError :: String  -- ^ textual description of the error location
                 -> IO a

-- | 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.
throwSocketErrorIfMinus1_
    :: Num a => String  -- ^ textual description of the location
    -> IO a             -- ^ the 'IO' operation to be executed
    -> IO ()

{-# SPECIALIZE throwSocketErrorIfMinus1_ :: String -> IO CInt -> IO () #-}

-- | 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.
throwSocketErrorIfMinus1Retry
    :: Num a => String  -- ^ textual description of the location
    -> IO a             -- ^ the 'IO' operation to be executed
    -> IO a

{-# SPECIALIZE throwSocketErrorIfMinus1Retry :: String -> IO CInt -> IO CInt #-}

-- | 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.
throwSocketErrorIfMinus1RetryMayBlock
    :: 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

{-# SPECIALIZE throwSocketErrorIfMinus1RetryMayBlock
        :: String -> IO b -> IO CInt -> IO CInt #-}


{-# LINE 547 "Network/Socket/Internal.hsc" #-}

throwSocketErrorIfMinus1RetryMayBlock name on_block act =
    throwErrnoIfMinus1RetryMayBlock name act on_block

throwSocketErrorIfMinus1Retry = throwErrnoIfMinus1Retry

throwSocketErrorIfMinus1_ = throwErrnoIfMinus1_

throwSocketError = throwErrno


{-# LINE 604 "Network/Socket/Internal.hsc" #-}

-- ---------------------------------------------------------------------------
-- WinSock support

{-| 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.
-}
withSocketsDo :: IO a -> IO a

{-# LINE 620 "Network/Socket/Internal.hsc" #-}
withSocketsDo x = x

{-# LINE 632 "Network/Socket/Internal.hsc" #-}

------------------------------------------------------------------------
-- Helper functions

foreign import ccall unsafe "string.h" memset :: Ptr a -> CInt -> CSize -> IO ()

-- | Zero a structure.
zeroMemory :: Ptr a -> CSize -> IO ()
zeroMemory dest nbytes = memset dest 0 (fromIntegral nbytes)