{-# LANGUAGE CPP, ForeignFunctionInterface #-}
-----------------------------------------------------------------------------
-- |
-- 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.
--
-----------------------------------------------------------------------------
#include "HsNet.h"
module Network.BSD
(
-- * Host names
HostName
, getHostName
, HostEntry(..)
, getHostByName
, getHostByAddr
, hostAddress
#if defined(HAVE_GETHOSTENT) && !defined(mingw32_HOST_OS)
, getHostEntries
-- ** Low level functionality
, setHostEntry
, getHostEntry
, endHostEntry
#endif
-- * Service names
, ServiceEntry(..)
, ServiceName
, getServiceByName
, getServiceByPort
, getServicePortNumber
#if !defined(mingw32_HOST_OS)
, getServiceEntries
-- ** Low level functionality
, getServiceEntry
, setServiceEntry
, endServiceEntry
#endif
-- * Protocol names
, ProtocolName
, ProtocolNumber
, ProtocolEntry(..)
, getProtocolByName
, getProtocolByNumber
, getProtocolNumber
, defaultProtocol
#if !defined(mingw32_HOST_OS)
, getProtocolEntries
-- ** Low level functionality
, setProtocolEntry
, getProtocolEntry
, endProtocolEntry
#endif
-- * Port numbers
, PortNumber
-- * Network names
, NetworkName
, NetworkAddr
, NetworkEntry(..)
#if !defined(mingw32_HOST_OS)
, getNetworkByName
, getNetworkByAddr
, getNetworkEntries
-- ** Low level functionality
, setNetworkEntry
, getNetworkEntry
, endNetworkEntry
#endif
#if defined(HAVE_IF_NAMETOINDEX)
-- * Interface names
, ifNameToIndex
#endif
) where
import Network.Socket
import Control.Concurrent (MVar, newMVar, withMVar)
import qualified Control.Exception as E
import Foreign.C.String (CString, peekCString, withCString)
#if defined(HAVE_WINSOCK2_H)
import Foreign.C.Types ( CShort )
#endif
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 _ = #const sizeof(struct servent)
alignment _ = alignment (undefined :: CInt) -- ???
peek p = do
s_name <- (#peek struct servent, s_name) p >>= peekCString
s_aliases <- (#peek struct servent, s_aliases) p
>>= peekArray0 nullPtr
>>= mapM peekCString
s_port <- (#peek struct servent, s_port) p
s_proto <- (#peek struct servent, s_proto) p >>= peekCString
return (ServiceEntry {
serviceName = s_name,
serviceAliases = s_aliases,
#if defined(HAVE_WINSOCK2_H)
servicePort = (fromIntegral (s_port :: CShort)),
#else
-- s_port is already in network byte order, but it
-- might be the wrong size.
servicePort = (fromIntegral (s_port :: CInt)),
#endif
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
#if !defined(mingw32_HOST_OS)
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)
#endif
-- ---------------------------------------------------------------------------
-- 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 _ = #const sizeof(struct protoent)
alignment _ = alignment (undefined :: CInt) -- ???
peek p = do
p_name <- (#peek struct protoent, p_name) p >>= peekCString
p_aliases <- (#peek struct protoent, p_aliases) p
>>= peekArray0 nullPtr
>>= mapM peekCString
#if defined(HAVE_WINSOCK2_H)
-- With WinSock, the protocol number is only a short;
-- hoist it in as such, but represent it on the Haskell side
-- as a CInt.
p_proto_short <- (#peek struct protoent, p_proto) p
let p_proto = fromIntegral (p_proto_short :: CShort)
#else
p_proto <- (#peek struct protoent, p_proto) p
#endif
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
#if !defined(mingw32_HOST_OS)
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)
#endif
-- ---------------------------------------------------------------------------
-- 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 _ = #const sizeof(struct hostent)
alignment _ = alignment (undefined :: CInt) -- ???
peek p = do
h_name <- (#peek struct hostent, h_name) p >>= peekCString
h_aliases <- (#peek struct hostent, h_aliases) p
>>= peekArray0 nullPtr
>>= mapM peekCString
h_addrtype <- (#peek struct hostent, h_addrtype) p
-- h_length <- (#peek struct hostent, h_length) p
h_addr_list <- (#peek struct hostent, h_addr_list) p
>>= peekArray0 nullPtr
>>= mapM peek
return (HostEntry {
hostName = h_name,
hostAliases = h_aliases,
#if defined(HAVE_WINSOCK2_H)
hostFamily = unpackFamily (fromIntegral (h_addrtype :: CShort)),
#else
hostFamily = unpackFamily h_addrtype,
#endif
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)
#if defined(HAVE_GETHOSTENT) && !defined(mingw32_HOST_OS)
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)
#endif
-- ---------------------------------------------------------------------------
-- 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 _ = #const sizeof(struct hostent)
alignment _ = alignment (undefined :: CInt) -- ???
peek p = do
n_name <- (#peek struct netent, n_name) p >>= peekCString
n_aliases <- (#peek struct netent, n_aliases) p
>>= peekArray0 nullPtr
>>= mapM peekCString
n_addrtype <- (#peek struct netent, n_addrtype) p
n_net <- (#peek struct netent, n_net) p
return (NetworkEntry {
networkName = n_name,
networkAliases = n_aliases,
networkFamily = unpackFamily (fromIntegral
(n_addrtype :: CInt)),
networkAddress = n_net
})
poke = throwUnsupportedOperationPoke "NetworkEntry"
#if !defined(mingw32_HOST_OS)
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)
#endif
-- ---------------------------------------------------------------------------
-- Interface names
#if defined(HAVE_IF_NAMETOINDEX)
-- 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
#endif
-- 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