    {-# LINE 1 "Network/BSD.hsc" #-}
    {-# LANGUAGE CPP, ForeignFunctionInterface #-}
    {-# LINE 2 "Network/BSD.hsc" #-}
    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Network.BSD
    -- Copyright   :  (c) The University of Glasgow 2001
    -- License     :  BSD-style (see the file libraries/network/LICENSE)
    --
    -- Maintainer  :  libraries@haskell.org
    -- Stability   :  experimental
    -- Portability :  non-portable
    --
    -- The "Network.BSD" module defines Haskell bindings to network
    -- programming functionality provided by BSD Unix derivatives.
    --
    -----------------------------------------------------------------------------

    {-# LINE 18 "Network/BSD.hsc" #-}

    module Network.BSD
        (
        -- * Host names
          HostName
        , getHostName

        , HostEntry(..)
        , getHostByName
        , getHostByAddr
        , hostAddress

    {-# LINE 31 "Network/BSD.hsc" #-}
        , getHostEntries

        -- ** Low level functionality
        , setHostEntry
        , getHostEntry
        , endHostEntry

    {-# LINE 38 "Network/BSD.hsc" #-}

        -- * Service names
        , ServiceEntry(..)
        , ServiceName
        , getServiceByName
        , getServiceByPort
        , getServicePortNumber

    {-# LINE 47 "Network/BSD.hsc" #-}
        , getServiceEntries

        -- ** Low level functionality
        , getServiceEntry
        , setServiceEntry
        , endServiceEntry

    {-# LINE 54 "Network/BSD.hsc" #-}

        -- * Protocol names
        , ProtocolName
        , ProtocolNumber
        , ProtocolEntry(..)
        , getProtocolByName
        , getProtocolByNumber
        , getProtocolNumber
        , defaultProtocol

    {-# LINE 65 "Network/BSD.hsc" #-}
        , getProtocolEntries
        -- ** Low level functionality
        , setProtocolEntry
        , getProtocolEntry
        , endProtocolEntry

    {-# LINE 71 "Network/BSD.hsc" #-}

        -- * Port numbers
        , PortNumber

        -- * Network names
        , NetworkName
        , NetworkAddr
        , NetworkEntry(..)

    {-# LINE 81 "Network/BSD.hsc" #-}
        , getNetworkByName
        , getNetworkByAddr
        , getNetworkEntries
        -- ** Low level functionality
        , setNetworkEntry
        , getNetworkEntry
        , endNetworkEntry

    {-# LINE 89 "Network/BSD.hsc" #-}

    {-# LINE 91 "Network/BSD.hsc" #-}
        -- * Interface names
        , ifNameToIndex

    {-# LINE 94 "Network/BSD.hsc" #-}

        ) where

    import Network.Socket

    import Control.Concurrent (MVar, newMVar, withMVar)
    import qualified Control.Exception as E
    import Foreign.C.String (CString, peekCString, withCString)

    {-# LINE 105 "Network/BSD.hsc" #-}
    import Foreign.C.Types ( CInt(..), CUInt(..), CULong(..), CSize(..) )
    import Foreign.Ptr (Ptr, nullPtr)
    import Foreign.Storable (Storable(..))
    import Foreign.Marshal.Array (allocaArray0, peekArray0)
    import Foreign.Marshal.Utils (with, fromBool)
    import Data.Typeable
    import System.IO.Error (ioeSetErrorString, mkIOError)
    import System.IO.Unsafe (unsafePerformIO)

    import GHC.IO.Exception

    import Control.Monad (liftM)

    import Network.Socket.Internal (throwSocketErrorIfMinus1_)

    -- ---------------------------------------------------------------------------
    -- Basic Types

    type ProtocolName = String

    -- ---------------------------------------------------------------------------
    -- Service Database Access

    -- Calling getServiceByName for a given service and protocol returns
    -- the systems service entry.  This should be used to find the port
    -- numbers for standard protocols such as SMTP and FTP.  The remaining
    -- three functions should be used for browsing the service database
    -- sequentially.

    -- Calling setServiceEntry with True indicates that the service
    -- database should be left open between calls to getServiceEntry.  To
    -- close the database a call to endServiceEntry is required.  This
    -- database file is usually stored in the file /etc/services.

    data ServiceEntry  =
      ServiceEntry  {
         serviceName     :: ServiceName,    -- Official Name
         serviceAliases  :: [ServiceName],  -- aliases
         servicePort     :: PortNumber,     -- Port Number  ( network byte order )
         serviceProtocol :: ProtocolName    -- Protocol
      } deriving (Show, Typeable)

    instance Storable ServiceEntry where
       sizeOf    _ = 32
    {-# LINE 149 "Network/BSD.hsc" #-}
       alignment _ = alignment (undefined :: CInt) -- ???

       peek p = do
            s_name    <- ((\hsc_ptr -> peekByteOff hsc_ptr 0)) p >>= peekCString
    {-# LINE 153 "Network/BSD.hsc" #-}
            s_aliases <- ((\hsc_ptr -> peekByteOff hsc_ptr 8)) p
    {-# LINE 154 "Network/BSD.hsc" #-}
                               >>= peekArray0 nullPtr
                               >>= mapM peekCString
            s_port    <- ((\hsc_ptr -> peekByteOff hsc_ptr 16)) p
    {-# LINE 157 "Network/BSD.hsc" #-}
            s_proto   <- ((\hsc_ptr -> peekByteOff hsc_ptr 24)) p >>= peekCString
    {-# LINE 158 "Network/BSD.hsc" #-}
            return (ServiceEntry {
                            serviceName     = s_name,
                            serviceAliases  = s_aliases,

    {-# LINE 164 "Network/BSD.hsc" #-}
                               -- s_port is already in network byte order, but it
                               -- might be the wrong size.
                            servicePort     = (fromIntegral (s_port :: CInt)),

    {-# LINE 168 "Network/BSD.hsc" #-}
                            serviceProtocol = s_proto
                    })

       poke = throwUnsupportedOperationPoke "ServiceEntry"

    -- | Get service by name.
    getServiceByName :: ServiceName         -- Service Name
                     -> ProtocolName        -- Protocol Name
                     -> IO ServiceEntry     -- Service Entry
    getServiceByName name proto = withLock $ do
     withCString name  $ \ cstr_name  -> do
     withCString proto $ \ cstr_proto -> do
     throwNoSuchThingIfNull "Network.BSD.getServiceByName" "no such service entry"
       $ c_getservbyname cstr_name cstr_proto
     >>= peek

    foreign import CALLCONV unsafe "getservbyname"
      c_getservbyname :: CString -> CString -> IO (Ptr ServiceEntry)

    -- | Get the service given a 'PortNumber' and 'ProtocolName'.
    getServiceByPort :: PortNumber -> ProtocolName -> IO ServiceEntry
    getServiceByPort port proto = withLock $ do
     withCString proto $ \ cstr_proto -> do
     throwNoSuchThingIfNull "Network.BSD.getServiceByPort" "no such service entry"
       $ c_getservbyport (fromIntegral port) cstr_proto
     >>= peek

    foreign import CALLCONV unsafe "getservbyport"
      c_getservbyport :: CInt -> CString -> IO (Ptr ServiceEntry)

    -- | Get the 'PortNumber' corresponding to the 'ServiceName'.
    getServicePortNumber :: ServiceName -> IO PortNumber
    getServicePortNumber name = do
        (ServiceEntry _ _ port _) <- getServiceByName name "tcp"
        return port

    {-# LINE 206 "Network/BSD.hsc" #-}
    getServiceEntry :: IO ServiceEntry
    getServiceEntry = withLock $ do
     throwNoSuchThingIfNull "Network.BSD.getServiceEntry" "no such service entry"
       $ c_getservent
     >>= peek

    foreign import ccall unsafe "getservent" c_getservent :: IO (Ptr ServiceEntry)

    setServiceEntry :: Bool -> IO ()
    setServiceEntry flg = withLock $ c_setservent (fromBool flg)

    foreign import ccall unsafe  "setservent" c_setservent :: CInt -> IO ()

    endServiceEntry :: IO ()
    endServiceEntry = withLock $ c_endservent

    foreign import ccall unsafe  "endservent" c_endservent :: IO ()

    getServiceEntries :: Bool -> IO [ServiceEntry]
    getServiceEntries stayOpen = do
      setServiceEntry stayOpen
      getEntries (getServiceEntry) (endServiceEntry)

    {-# LINE 229 "Network/BSD.hsc" #-}

    -- ---------------------------------------------------------------------------
    -- Protocol Entries

    -- The following relate directly to the corresponding UNIX C
    -- calls for returning the protocol entries. The protocol entry is
    -- represented by the Haskell type ProtocolEntry.

    -- As for setServiceEntry above, calling setProtocolEntry.
    -- determines whether or not the protocol database file, usually
    -- @/etc/protocols@, is to be kept open between calls of
    -- getProtocolEntry. Similarly,

    data ProtocolEntry =
      ProtocolEntry  {
         protoName    :: ProtocolName,      -- Official Name
         protoAliases :: [ProtocolName],    -- aliases
         protoNumber  :: ProtocolNumber     -- Protocol Number
      } deriving (Read, Show, Typeable)

    instance Storable ProtocolEntry where
       sizeOf    _ = 24
    {-# LINE 251 "Network/BSD.hsc" #-}
       alignment _ = alignment (undefined :: CInt) -- ???

       peek p = do
            p_name    <- ((\hsc_ptr -> peekByteOff hsc_ptr 0)) p >>= peekCString
    {-# LINE 255 "Network/BSD.hsc" #-}
            p_aliases <- ((\hsc_ptr -> peekByteOff hsc_ptr 8)) p
    {-# LINE 256 "Network/BSD.hsc" #-}
                               >>= peekArray0 nullPtr
                               >>= mapM peekCString

    {-# LINE 265 "Network/BSD.hsc" #-}
            p_proto        <- ((\hsc_ptr -> peekByteOff hsc_ptr 16)) p
    {-# LINE 266 "Network/BSD.hsc" #-}

    {-# LINE 267 "Network/BSD.hsc" #-}
            return (ProtocolEntry {
                            protoName    = p_name,
                            protoAliases = p_aliases,
                            protoNumber  = p_proto
                    })

       poke = throwUnsupportedOperationPoke "ProtocolEntry"

    getProtocolByName :: ProtocolName -> IO ProtocolEntry
    getProtocolByName name = withLock $ do
     withCString name $ \ name_cstr -> do
     throwNoSuchThingIfNull "Network.BSD.getProtocolByName" ("no such protocol name: " ++ name)
       $ c_getprotobyname name_cstr
     >>= peek

    foreign import  CALLCONV unsafe  "getprotobyname"
       c_getprotobyname :: CString -> IO (Ptr ProtocolEntry)

    getProtocolByNumber :: ProtocolNumber -> IO ProtocolEntry
    getProtocolByNumber num = withLock $ do
     throwNoSuchThingIfNull "Network.BSD.getProtocolByNumber" ("no such protocol number: " ++ show num)
       $ c_getprotobynumber (fromIntegral num)
     >>= peek

    foreign import CALLCONV unsafe  "getprotobynumber"
       c_getprotobynumber :: CInt -> IO (Ptr ProtocolEntry)

    getProtocolNumber :: ProtocolName -> IO ProtocolNumber
    getProtocolNumber proto = do
     (ProtocolEntry _ _ num) <- getProtocolByName proto
     return num

    {-# LINE 303 "Network/BSD.hsc" #-}
    getProtocolEntry :: IO ProtocolEntry    -- Next Protocol Entry from DB
    getProtocolEntry = withLock $ do
     ent <- throwNoSuchThingIfNull "Network.BSD.getProtocolEntry" "no such protocol entry"
                    $ c_getprotoent
     peek ent

    foreign import ccall unsafe  "getprotoent" c_getprotoent :: IO (Ptr ProtocolEntry)

    setProtocolEntry :: Bool -> IO ()       -- Keep DB Open ?
    setProtocolEntry flg = withLock $ c_setprotoent (fromBool flg)

    foreign import ccall unsafe "setprotoent" c_setprotoent :: CInt -> IO ()

    endProtocolEntry :: IO ()
    endProtocolEntry = withLock $ c_endprotoent

    foreign import ccall unsafe "endprotoent" c_endprotoent :: IO ()

    getProtocolEntries :: Bool -> IO [ProtocolEntry]
    getProtocolEntries stayOpen = withLock $ do
      setProtocolEntry stayOpen
      getEntries (getProtocolEntry) (endProtocolEntry)

    {-# LINE 326 "Network/BSD.hsc" #-}

    -- ---------------------------------------------------------------------------
    -- Host lookups

    data HostEntry =
      HostEntry  {
         hostName      :: HostName,         -- Official Name
         hostAliases   :: [HostName],       -- aliases
         hostFamily    :: Family,           -- Host Type (currently AF_INET)
         hostAddresses :: [HostAddress]     -- Set of Network Addresses  (in network byte order)
      } deriving (Read, Show, Typeable)

    instance Storable HostEntry where
       sizeOf    _ = 32
    {-# LINE 340 "Network/BSD.hsc" #-}
       alignment _ = alignment (undefined :: CInt) -- ???

       peek p = do
            h_name       <- ((\hsc_ptr -> peekByteOff hsc_ptr 0)) p >>= peekCString
    {-# LINE 344 "Network/BSD.hsc" #-}
            h_aliases    <- ((\hsc_ptr -> peekByteOff hsc_ptr 8)) p
    {-# LINE 345 "Network/BSD.hsc" #-}
                                    >>= peekArray0 nullPtr
                                    >>= mapM peekCString
            h_addrtype   <- ((\hsc_ptr -> peekByteOff hsc_ptr 16)) p
    {-# LINE 348 "Network/BSD.hsc" #-}
            -- h_length       <- (#peek struct hostent, h_length) p
            h_addr_list  <- ((\hsc_ptr -> peekByteOff hsc_ptr 24)) p
    {-# LINE 350 "Network/BSD.hsc" #-}
                                    >>= peekArray0 nullPtr
                                    >>= mapM peek
            return (HostEntry {
                            hostName       = h_name,
                            hostAliases    = h_aliases,

    {-# LINE 358 "Network/BSD.hsc" #-}
                            hostFamily     = unpackFamily h_addrtype,

    {-# LINE 360 "Network/BSD.hsc" #-}
                            hostAddresses  = h_addr_list
                    })

       poke = throwUnsupportedOperationPoke "HostEntry"

    -- convenience function:
    hostAddress :: HostEntry -> HostAddress
    hostAddress (HostEntry nm _ _ ls) =
     case ls of
       []    -> error $ "Network.BSD.hostAddress: empty network address list for " ++ nm
       (x:_) -> x

    -- getHostByName must use the same lock as the *hostent functions
    -- may cause problems if called concurrently.

    -- | Resolve a 'HostName' to IPv4 address.
    getHostByName :: HostName -> IO HostEntry
    getHostByName name = withLock $ do
      withCString name $ \ name_cstr -> do
       ent <- throwNoSuchThingIfNull "Network.BSD.getHostByName" "no such host entry"
                    $ c_gethostbyname name_cstr
       peek ent

    foreign import CALLCONV safe "gethostbyname"
       c_gethostbyname :: CString -> IO (Ptr HostEntry)

    -- The locking of gethostbyaddr is similar to gethostbyname.
    -- | Get a 'HostEntry' corresponding to the given address and family.
    -- Note that only IPv4 is currently supported.
    getHostByAddr :: Family -> HostAddress -> IO HostEntry
    getHostByAddr family addr = do
     with addr $ \ ptr_addr -> withLock $ do
     throwNoSuchThingIfNull "Network.BSD.getHostByAddr" "no such host entry"
       $ c_gethostbyaddr ptr_addr (fromIntegral (sizeOf addr)) (packFamily family)
     >>= peek

    foreign import CALLCONV safe "gethostbyaddr"
       c_gethostbyaddr :: Ptr HostAddress -> CInt -> CInt -> IO (Ptr HostEntry)

    {-# LINE 402 "Network/BSD.hsc" #-}
    getHostEntry :: IO HostEntry
    getHostEntry = withLock $ do
     throwNoSuchThingIfNull "Network.BSD.getHostEntry" "unable to retrieve host entry"
       $ c_gethostent
     >>= peek

    foreign import ccall unsafe "gethostent" c_gethostent :: IO (Ptr HostEntry)

    setHostEntry :: Bool -> IO ()
    setHostEntry flg = withLock $ c_sethostent (fromBool flg)

    foreign import ccall unsafe "sethostent" c_sethostent :: CInt -> IO ()

    endHostEntry :: IO ()
    endHostEntry = withLock $ c_endhostent

    foreign import ccall unsafe "endhostent" c_endhostent :: IO ()

    getHostEntries :: Bool -> IO [HostEntry]
    getHostEntries stayOpen = do
      setHostEntry stayOpen
      getEntries (getHostEntry) (endHostEntry)

    {-# LINE 425 "Network/BSD.hsc" #-}

    -- ---------------------------------------------------------------------------
    -- Accessing network information

    -- Same set of access functions as for accessing host,protocol and
    -- service system info, this time for the types of networks supported.

    -- network addresses are represented in host byte order.
    type NetworkAddr = CULong

    type NetworkName = String

    data NetworkEntry =
      NetworkEntry {
         networkName        :: NetworkName,   -- official name
         networkAliases     :: [NetworkName], -- aliases
         networkFamily      :: Family,         -- type
         networkAddress     :: NetworkAddr
       } deriving (Read, Show, Typeable)

    instance Storable NetworkEntry where
       sizeOf    _ = 32
    {-# LINE 447 "Network/BSD.hsc" #-}
       alignment _ = alignment (undefined :: CInt) -- ???

       peek p = do
            n_name         <- ((\hsc_ptr -> peekByteOff hsc_ptr 0)) p >>= peekCString
    {-# LINE 451 "Network/BSD.hsc" #-}
            n_aliases      <- ((\hsc_ptr -> peekByteOff hsc_ptr 8)) p
    {-# LINE 452 "Network/BSD.hsc" #-}
                                    >>= peekArray0 nullPtr
                                    >>= mapM peekCString
            n_addrtype     <- ((\hsc_ptr -> peekByteOff hsc_ptr 16)) p
    {-# LINE 455 "Network/BSD.hsc" #-}
            n_net          <- ((\hsc_ptr -> peekByteOff hsc_ptr 20)) p
    {-# LINE 456 "Network/BSD.hsc" #-}
            return (NetworkEntry {
                            networkName      = n_name,
                            networkAliases   = n_aliases,
                            networkFamily    = unpackFamily (fromIntegral
                                                            (n_addrtype :: CInt)),
                            networkAddress   = n_net
                    })

       poke = throwUnsupportedOperationPoke "NetworkEntry"

    {-# LINE 468 "Network/BSD.hsc" #-}
    getNetworkByName :: NetworkName -> IO NetworkEntry
    getNetworkByName name = withLock $ do
     withCString name $ \ name_cstr -> do
      throwNoSuchThingIfNull "Network.BSD.getNetworkByName" "no such network entry"
        $ c_getnetbyname name_cstr
      >>= peek

    foreign import ccall unsafe "getnetbyname"
       c_getnetbyname  :: CString -> IO (Ptr NetworkEntry)

    getNetworkByAddr :: NetworkAddr -> Family -> IO NetworkEntry
    getNetworkByAddr addr family = withLock $ do
     throwNoSuchThingIfNull "Network.BSD.getNetworkByAddr" "no such network entry"
       $ c_getnetbyaddr addr (packFamily family)
     >>= peek

    foreign import ccall unsafe "getnetbyaddr"
       c_getnetbyaddr  :: NetworkAddr -> CInt -> IO (Ptr NetworkEntry)

    getNetworkEntry :: IO NetworkEntry
    getNetworkEntry = withLock $ do
     throwNoSuchThingIfNull "Network.BSD.getNetworkEntry" "no more network entries"
              $ c_getnetent
     >>= peek

    foreign import ccall unsafe "getnetent" c_getnetent :: IO (Ptr NetworkEntry)

    -- | Open the network name database. The parameter specifies
    -- whether a connection is maintained open between various
    -- networkEntry calls
    setNetworkEntry :: Bool -> IO ()
    setNetworkEntry flg = withLock $ c_setnetent (fromBool flg)

    foreign import ccall unsafe "setnetent" c_setnetent :: CInt -> IO ()

    -- | Close the connection to the network name database.
    endNetworkEntry :: IO ()
    endNetworkEntry = withLock $ c_endnetent

    foreign import ccall unsafe "endnetent" c_endnetent :: IO ()

    -- | Get the list of network entries.
    getNetworkEntries :: Bool -> IO [NetworkEntry]
    getNetworkEntries stayOpen = do
      setNetworkEntry stayOpen
      getEntries (getNetworkEntry) (endNetworkEntry)

    {-# LINE 515 "Network/BSD.hsc" #-}

    -- ---------------------------------------------------------------------------
    -- Interface names

    {-# LINE 520 "Network/BSD.hsc" #-}

    -- returns the index of the network interface corresponding to the name ifname.
    ifNameToIndex :: String -> IO (Maybe Int)
    ifNameToIndex ifname = do
      index <- withCString ifname c_if_nametoindex
      -- On failure zero is returned. We'll return Nothing.
      return $ if index == 0 then Nothing else Just $ fromIntegral index

    foreign import CALLCONV safe "if_nametoindex"
       c_if_nametoindex :: CString -> IO CUInt

    {-# LINE 532 "Network/BSD.hsc" #-}

    -- Mutex for name service lockdown

    {-# NOINLINE lock #-}
    lock :: MVar ()
    lock = unsafePerformIO $ withSocketsDo $ newMVar ()

    withLock :: IO a -> IO a
    withLock act = withMVar lock (\_ -> act)

    -- ---------------------------------------------------------------------------
    -- Miscellaneous Functions

    -- | Calling getHostName returns the standard host name for the current
    -- processor, as set at boot time.

    getHostName :: IO HostName
    getHostName = do
      let size = 256
      allocaArray0 size $ \ cstr -> do
        throwSocketErrorIfMinus1_ "Network.BSD.getHostName" $ c_gethostname cstr (fromIntegral size)
        peekCString cstr

    foreign import CALLCONV unsafe "gethostname"
       c_gethostname :: CString -> CSize -> IO CInt

    -- Helper function used by the exported functions that provides a
    -- Haskellised view of the enumerator functions:

    getEntries :: IO a  -- read
               -> IO () -- at end
               -> IO [a]
    getEntries getOne atEnd = loop
      where
        loop = do
          vv <- E.catch (liftM Just getOne)
                (\ e -> let _types = e :: IOException in return Nothing)
          case vv of
            Nothing -> return []
            Just v  -> loop >>= \ vs -> atEnd >> return (v:vs)

    throwNoSuchThingIfNull :: String -> String -> IO (Ptr a) -> IO (Ptr a)
    throwNoSuchThingIfNull loc desc act = do
      ptr <- act
      if (ptr == nullPtr)
       then ioError (ioeSetErrorString (mkIOError NoSuchThing loc Nothing Nothing) desc)
       else return ptr

    throwUnsupportedOperationPoke :: String -> Ptr a -> a -> IO ()
    throwUnsupportedOperationPoke typ _ _ =
      ioError $ ioeSetErrorString ioe "Operation not implemented"
      where
        ioe = mkIOError UnsupportedOperation
                        ("Network.BSD: instance Storable " ++ typ ++ ": poke")
                        Nothing
                        Nothing