ldap-client/src/Ldap/Client.hs

337 lines
11 KiB
Haskell

{-# LANGUAGE CPP #-}
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE ScopedTypeVariables #-}
-- | This module is intended to be imported qualified
--
-- @
-- import qualified Ldap.Client as Ldap
-- @
module Ldap.Client
( with
, with'
, runsIn
, runsInEither
, open
, close
, Host(..)
, defaultTlsSettings
, insecureTlsSettings
, PortNumber
, Ldap
, LdapH
, LdapError(..)
, ResponseError(..)
, Type.ResultCode(..)
-- * Bind
, Password(..)
, bind
, externalBind
-- * Search
, search
, SearchEntry(..)
-- ** Search modifiers
, Search
, Mod
, Type.Scope(..)
, scope
, size
, time
, typesOnly
, Type.DerefAliases(..)
, derefAliases
, Filter(..)
-- * Modify
, modify
, Operation(..)
-- * Add
, add
-- * Delete
, delete
-- * ModifyDn
, RelativeDn(..)
, modifyDn
-- * Compare
, compare
-- * Extended
, Oid(..)
, extended
-- * Miscellanous
, Dn(..)
, Attr(..)
, AttrValue
, AttrList
-- * Re-exports
, NonEmpty
) where
#if __GLASGOW_HASKELL__ < 710
import Control.Applicative ((<$>))
#endif
import qualified Control.Concurrent.Async as Async
import Control.Concurrent.STM (atomically, throwSTM)
import Control.Concurrent.STM.TMVar (putTMVar)
import Control.Concurrent.STM.TQueue (TQueue, newTQueueIO, writeTQueue, readTQueue)
import Control.Exception (Exception, bracket, throwIO, SomeException, fromException, throw, Handler(..))
import Control.Monad (forever)
import Data.Void (Void)
import qualified Data.ASN1.BinaryEncoding as Asn1
import qualified Data.ASN1.Encoding as Asn1
import qualified Data.ASN1.Error as Asn1
import qualified Data.ByteString as ByteString
import qualified Data.ByteString.Lazy as ByteString.Lazy
import Data.Foldable (asum)
import Data.Function (fix)
import Data.List.NonEmpty (NonEmpty((:|)))
import qualified Data.Map.Strict as Map
import Data.Monoid (Endo(appEndo))
import Data.Text (Text)
#if __GLASGOW_HASKELL__ < 710
import Data.Traversable (traverse)
#endif
import Data.Typeable (Typeable)
import Network.Connection (Connection)
import qualified Network.Connection as Conn
import Prelude hiding (compare)
import qualified System.IO.Error as IO
import Ldap.Asn1.ToAsn1 (ToAsn1(toAsn1))
import Ldap.Asn1.FromAsn1 (FromAsn1, parseAsn1)
import qualified Ldap.Asn1.Type as Type
import Ldap.Client.Internal
import Ldap.Client.Bind (Password(..), bind, externalBind)
import Ldap.Client.Search
( search
, Search
, Mod
, scope
, size
, time
, typesOnly
, derefAliases
, Filter(..)
, SearchEntry(..)
)
import Ldap.Client.Modify (Operation(..), modify, RelativeDn(..), modifyDn)
import Ldap.Client.Add (add)
import Ldap.Client.Delete (delete)
import Ldap.Client.Compare (compare)
import Ldap.Client.Extended (Oid(..), extended, noticeOfDisconnectionOid)
{-# ANN module ("HLint: ignore Use first" :: String) #-}
-- | Various failures that can happen when working with LDAP.
data LdapError
= IOError !IOError -- ^ Network failure.
| ParseError !Asn1.ASN1Error -- ^ Invalid ASN.1 data received from the server.
| ResponseError !ResponseError -- ^ An LDAP operation failed.
| DisconnectError !Disconnect -- ^ Notice of Disconnection has been received.
deriving (Show, Eq)
instance Exception LdapError
data Disconnect = Disconnect !Type.ResultCode !Dn !Text
deriving (Show, Eq, Typeable)
instance Exception Disconnect
newtype LdapH = LdapH Ldap
-- | Provide a 'LdapH' to a function needing an 'Ldap' handle.
runsIn :: (Ldap -> IO a)
-> LdapH
-> IO a
runsIn act (LdapH ldap) = do
actor <- Async.async (act ldap)
r <- Async.waitEitherCatch (workers ldap) actor
case r of
Left (Right _a) -> error "Unreachable"
Left (Left e) -> throwIO =<< catchesHandler workerErr e
Right (Right r') -> pure r'
Right (Left e) -> throwIO =<< catchesHandler respErr e
-- | Provide a 'LdapH' to a function needing an 'Ldap' handle
runsInEither :: (Ldap -> IO a)
-> LdapH
-> IO (Either LdapError a)
runsInEither act (LdapH ldap) = do
actor <- Async.async (act ldap)
r <- Async.waitEitherCatch (workers ldap) actor
case r of
Left (Right _a) -> error "Unreachable"
Left (Left e) -> do Left <$> catchesHandler workerErr e
Right (Right r') -> pure (Right r')
Right (Left e) -> do Left <$> catchesHandler respErr e
workerErr :: [Handler LdapError]
workerErr = [ Handler (\(ex :: IOError) -> pure (IOError ex))
, Handler (\(ex :: Asn1.ASN1Error) -> pure (ParseError ex))
, Handler (\(ex :: Disconnect) -> pure (DisconnectError ex))
]
respErr :: [Handler LdapError]
respErr = [ Handler (\(ex :: ResponseError) -> pure (ResponseError ex))
]
catchesHandler :: [Handler a] -> SomeException -> IO a
catchesHandler handlers e = foldr tryHandler (throw e) handlers
where tryHandler (Handler handler) res
= case fromException e of
Just e' -> handler e'
Nothing -> res
-- | The entrypoint into LDAP.
with' :: Host -> PortNumber -> (Ldap -> IO a) -> IO a
with' host port act = bracket (open host port) close (runsIn act)
with :: Host -> PortNumber -> (Ldap -> IO a) -> IO (Either LdapError a)
with host port act = bracket (open host port) close (runsInEither act)
-- | Creates an LDAP handle. This action is useful for creating your own resource
-- management, such as with 'resource-pool'. The handle must be manually closed
-- with 'close'.
open :: Host -> PortNumber -> IO (LdapH)
open host port = do
context <- Conn.initConnectionContext
conn <- Conn.connectTo context params
reqQ <- newTQueueIO
inQ <- newTQueueIO
outQ <- newTQueueIO
-- The input worker that reads data off the network.
(inW :: Async.Async Void) <- Async.async (input inQ conn)
-- The output worker that sends data onto the network.
(outW :: Async.Async Void) <- Async.async (output outQ conn)
-- The dispatch worker that sends data between the three queues.
(dispW :: Async.Async Void) <- Async.async (dispatch reqQ inQ outQ)
-- We use this to propagate exceptions between the workers. The `workers` Async is just a tool to
-- exchange exceptions between the entire worker group and another thread.
workers <- Async.async (snd <$> Async.waitAnyCancel [inW, outW, dispW])
pure (LdapH (Ldap reqQ workers conn))
where
params = Conn.ConnectionParams
{ Conn.connectionHostname =
case host of
Plain h -> h
Tls h _ -> h
, Conn.connectionPort = port
, Conn.connectionUseSecure =
case host of
Plain _ -> Nothing
Tls _ settings -> pure settings
, Conn.connectionUseSocks = Nothing
}
-- | Closes an LDAP connection.
-- This is to be used in together with 'open'.
close :: LdapH -> IO ()
close (LdapH ldap) = do
unbindAsync ldap
Conn.connectionClose (conn ldap)
Async.cancel (workers ldap)
defaultTlsSettings :: Conn.TLSSettings
defaultTlsSettings = Conn.TLSSettingsSimple
{ Conn.settingDisableCertificateValidation = False
, Conn.settingDisableSession = False
, Conn.settingUseServerName = False
}
insecureTlsSettings :: Conn.TLSSettings
insecureTlsSettings = Conn.TLSSettingsSimple
{ Conn.settingDisableCertificateValidation = True
, Conn.settingDisableSession = False
, Conn.settingUseServerName = False
}
-- | Reads Asn1 BER encoded chunks off a connection into a TQueue.
input :: FromAsn1 a => TQueue a -> Connection -> IO b
input inq conn = loop []
where
loop chunks = do
chunk <- Conn.connectionGet conn 8192
case ByteString.length chunk of
0 -> throwIO (IO.mkIOError IO.eofErrorType "Ldap.Client.input" Nothing Nothing)
_ -> do
let chunks' = chunk : chunks
case Asn1.decodeASN1 Asn1.BER (ByteString.Lazy.fromChunks (reverse chunks')) of
Left Asn1.ParsingPartial
-> loop chunks'
Left e -> throwIO e
Right asn1 -> do
flip fix asn1 $ \loop' asn1' ->
case parseAsn1 asn1' of
Nothing -> return ()
Just (asn1'', a) -> do
atomically (writeTQueue inq a)
loop' asn1''
loop []
-- | Transmits Asn1 DER encoded data from a TQueue into a Connection.
output :: ToAsn1 a => TQueue a -> Connection -> IO b
output out conn = forever $ do
msg <- atomically (readTQueue out)
Conn.connectionPut conn (encode (toAsn1 msg))
where
encode x = Asn1.encodeASN1' Asn1.DER (appEndo x [])
dispatch
:: TQueue ClientMessage
-> TQueue (Type.LdapMessage Type.ProtocolServerOp)
-> TQueue (Type.LdapMessage Request)
-> IO a
dispatch reqq inq outq = loop (Map.empty, 1)
where
saveUp mid op res = return (Map.adjust (\(stack, var) -> (op : stack, var)) mid res)
loop (!req, !counter) =
loop =<< atomically (asum
[ do New new var <- readTQueue reqq
writeTQueue outq (Type.LdapMessage (Type.Id counter) new Nothing)
return (Map.insert (Type.Id counter) ([], var) req, counter + 1)
, do Type.LdapMessage mid op _
<- readTQueue inq
res <- case op of
Type.BindResponse {} -> done mid op req
Type.SearchResultEntry {} -> saveUp mid op req
Type.SearchResultReference {} -> return req
Type.SearchResultDone {} -> done mid op req
Type.ModifyResponse {} -> done mid op req
Type.AddResponse {} -> done mid op req
Type.DeleteResponse {} -> done mid op req
Type.ModifyDnResponse {} -> done mid op req
Type.CompareResponse {} -> done mid op req
Type.ExtendedResponse {} -> probablyDisconnect mid op req
Type.IntermediateResponse {} -> saveUp mid op req
return (res, counter)
])
done mid op req =
case Map.lookup mid req of
Nothing -> return req
Just (stack, var) -> do
putTMVar var (op :| stack)
return (Map.delete mid req)
probablyDisconnect (Type.Id 0)
(Type.ExtendedResponse
(Type.LdapResult code
(Type.LdapDn (Type.LdapString dn))
(Type.LdapString reason)
_)
moid _)
req =
case moid of
Just (Type.LdapOid oid)
| Oid oid == noticeOfDisconnectionOid -> throwSTM (Disconnect code (Dn dn) reason)
_ -> return req
probablyDisconnect mid op req = done mid op req