warp-3.1.10: Network/Wai/Handler/Warp/Run.hs
{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE PatternGuards #-}
{-# OPTIONS_GHC -fno-warn-deprecations #-}
module Network.Wai.Handler.Warp.Run where
#if __GLASGOW_HASKELL__ < 709
import Control.Applicative ((<$>))
#endif
import Control.Arrow (first)
import Control.Concurrent (threadDelay)
import qualified Control.Concurrent as Conc (yield)
import Control.Exception as E
import Control.Monad (when, unless, void)
import Data.ByteString (ByteString)
import qualified Data.ByteString as S
import Data.Char (chr)
import Data.IP (toHostAddress, toHostAddress6)
import Data.IORef (IORef, newIORef, readIORef, writeIORef)
import Data.Streaming.Network (bindPortTCP)
import Network (sClose, Socket)
import Network.Socket (accept, withSocketsDo, SockAddr(SockAddrInet, SockAddrInet6))
import qualified Network.Socket.ByteString as Sock
import Network.Wai
import Network.Wai.HTTP2 (HTTP2Application, promoteApplication)
import Network.Wai.Handler.Warp.Buffer
import Network.Wai.Handler.Warp.Counter
import qualified Network.Wai.Handler.Warp.Date as D
import qualified Network.Wai.Handler.Warp.FdCache as F
import qualified Network.Wai.Handler.Warp.FileInfoCache as I
import Network.Wai.Handler.Warp.HTTP2 (http2, isHTTP2)
import Network.Wai.Handler.Warp.Header
import Network.Wai.Handler.Warp.ReadInt
import Network.Wai.Handler.Warp.Recv
import Network.Wai.Handler.Warp.Request
import Network.Wai.Handler.Warp.Response
import Network.Wai.Handler.Warp.SendFile
import Network.Wai.Handler.Warp.Settings
import qualified Network.Wai.Handler.Warp.Timeout as T
import Network.Wai.Handler.Warp.Types
import Network.Wai.Internal (ResponseReceived (ResponseReceived))
import System.Environment (getEnvironment)
import System.IO.Error (isFullErrorType, ioeGetErrorType)
#if WINDOWS
import Network.Wai.Handler.Warp.Windows
#else
import System.Posix.IO (FdOption(CloseOnExec), setFdOption)
import Network.Socket (fdSocket)
#endif
-- | Creating 'Connection' for plain HTTP based on a given socket.
socketConnection :: Socket -> IO Connection
socketConnection s = do
bufferPool <- newBufferPool
writeBuf <- allocateBuffer bufferSize
let sendall = Sock.sendAll s
return Connection {
connSendMany = Sock.sendMany s
, connSendAll = sendall
, connSendFile = sendFile s writeBuf bufferSize sendall
, connClose = sClose s >> freeBuffer writeBuf
, connRecv = receive s bufferPool
, connRecvBuf = receiveBuf s
, connWriteBuffer = writeBuf
, connBufferSize = bufferSize
}
#if __GLASGOW_HASKELL__ < 702
allowInterrupt :: IO ()
allowInterrupt = unblock $ return ()
#endif
-- Composition over two arguments at once; used for runHTTP2\*.
(.:) :: (c -> d) -> (a -> b -> c) -> a -> b -> d
f .: g = curry $ f . uncurry g
-- | Run an 'Application' on the given port.
-- This calls 'runSettings' with 'defaultSettings'.
run :: Port -> Application -> IO ()
run port = runServe port . serveDefault
-- | Serve an 'HTTP2Application' and an 'Application' together on the given
-- port.
runHTTP2 :: Port -> HTTP2Application -> Application -> IO ()
runHTTP2 port = runServe port .: serveHTTP2
-- | The generalized form of 'run'.
runServe :: Port -> ServeConnection -> IO ()
runServe p = runServeSettings defaultSettings { settingsPort = p }
-- | Run an 'Application' on the port present in the @PORT@
-- environment variable. Uses the 'Port' given when the variable is unset.
-- This calls 'runSettings' with 'defaultSettings'.
--
-- Since 3.0.9
runEnv :: Port -> Application -> IO ()
runEnv port = runServeEnv port . serveDefault
-- | The HTTP\/2-aware form of 'runEnv'.
runHTTP2Env :: Port -> HTTP2Application -> Application -> IO ()
runHTTP2Env port = runServeEnv port .: serveHTTP2
-- | The generalized form of 'runEnv'.
runServeEnv :: Port -> ServeConnection -> IO ()
runServeEnv p serveConn = do
mp <- lookup "PORT" <$> getEnvironment
maybe (runServe p serveConn) runReadPort mp
where
runReadPort :: String -> IO ()
runReadPort sp = case reads sp of
((p', _):_) -> runServe p' serveConn
_ -> fail $ "Invalid value in $PORT: " ++ sp
-- | Run an 'Application' with the given 'Settings'.
-- This opens a listen socket on the port defined in 'Settings' and
-- calls 'runSettingsSocket'.
runSettings :: Settings -> Application -> IO ()
runSettings set = runServeSettings set . serveDefault
-- | The HTTP\/2-aware form of 'runSettings'.
runHTTP2Settings :: Settings -> HTTP2Application -> Application -> IO ()
runHTTP2Settings set = runServeSettings set .: serveHTTP2
-- | The generalized form of 'runSettings'.
runServeSettings :: Settings -> ServeConnection -> IO ()
runServeSettings set serveConn = withSocketsDo $
bracket
(bindPortTCP (settingsPort set) (settingsHost set))
sClose
(\socket -> do
setSocketCloseOnExec socket
runServeSettingsSocket set socket serveConn)
-- | This installs a shutdown handler for the given socket and
-- calls 'runSettingsConnection' with the default connection setup action
-- which handles plain (non-cipher) HTTP.
-- When the listen socket in the second argument is closed, all live
-- connections are gracefully shut down.
--
-- The supplied socket can be a Unix named socket, which
-- can be used when reverse HTTP proxying into your application.
--
-- Note that the 'settingsPort' will still be passed to 'Application's via the
-- 'serverPort' record.
runSettingsSocket :: Settings -> Socket -> Application -> IO ()
runSettingsSocket set socket = runServeSettingsSocket set socket . serveDefault
-- | The HTTP\/2-aware form of 'runSettingsSocket'.
runHTTP2SettingsSocket :: Settings
-> Socket
-> HTTP2Application
-> Application
-> IO ()
runHTTP2SettingsSocket set socket =
runServeSettingsSocket set socket .: serveHTTP2
-- | The generalized form of 'runSettingsSocket'.
runServeSettingsSocket :: Settings -> Socket -> ServeConnection -> IO ()
runServeSettingsSocket set socket serveConn = do
settingsInstallShutdownHandler set closeListenSocket
runServeSettingsConnection set getConn serveConn
where
getConn = do
#if WINDOWS
(s, sa) <- windowsThreadBlockHack $ accept socket
#else
(s, sa) <- accept socket
#endif
setSocketCloseOnExec s
conn <- socketConnection s
return (conn, sa)
closeListenSocket = sClose socket
-- | The connection setup action would be expensive. A good example
-- is initialization of TLS.
-- So, this converts the connection setup action to the connection maker
-- which will be executed after forking a new worker thread.
-- Then this calls 'runSettingsConnectionMaker' with the connection maker.
-- This allows the expensive computations to be performed
-- in a separate worker thread instead of the main server loop.
--
-- Since 1.3.5
runSettingsConnection :: Settings -> IO (Connection, SockAddr) -> Application -> IO ()
runSettingsConnection set getConn =
runServeSettingsConnection set getConn . serveDefault
-- | The generalized form of 'runSettingsConnection'.
runServeSettingsConnection :: Settings
-> IO (Connection, SockAddr)
-> ServeConnection
-> IO ()
runServeSettingsConnection set getConn serveConn =
runServeSettingsConnectionMaker set getConnMaker serveConn
where
getConnMaker = do
(conn, sa) <- getConn
return (return conn, sa)
-- | This modifies the connection maker so that it returns 'TCP' for 'Transport'
-- (i.e. plain HTTP) then calls 'runSettingsConnectionMakerSecure'.
runSettingsConnectionMaker :: Settings -> IO (IO Connection, SockAddr) -> Application -> IO ()
runSettingsConnectionMaker set getConnMaker =
runServeSettingsConnectionMaker set getConnMaker . serveDefault
-- | The generalized form of 'runSettingsConnectionMaker'.
runServeSettingsConnectionMaker :: Settings
-> IO (IO Connection, SockAddr)
-> ServeConnection
-> IO ()
runServeSettingsConnectionMaker x y =
runServeSettingsConnectionMakerSecure x (toTCP <$> y)
where
toTCP = first ((, TCP) <$>)
----------------------------------------------------------------
-- | The core run function which takes 'Settings',
-- a connection maker and 'Application'.
-- The connection maker can return a connection of either plain HTTP
-- or HTTP over TLS.
--
-- Since 2.1.4
runSettingsConnectionMakerSecure :: Settings -> IO (IO (Connection, Transport), SockAddr) -> Application -> IO ()
runSettingsConnectionMakerSecure set getConnMaker =
runServeSettingsConnectionMakerSecure set getConnMaker . serveDefault
-- | The generalized form of 'runSettingsConnectionMakerSecure'.
runServeSettingsConnectionMakerSecure :: Settings
-> IO (IO (Connection, Transport), SockAddr)
-> ServeConnection
-> IO ()
runServeSettingsConnectionMakerSecure set getConnMaker serveConn = do
settingsBeforeMainLoop set
counter <- newCounter
withII $ acceptConnection set getConnMaker serveConn counter
where
withII action =
D.withDateCache $ \dc ->
F.withFdCache fdCacheDurationInSeconds $ \fc ->
I.withFileInfoCache fdFileInfoDurationInSeconds $ \get ->
withTimeoutManager $ \tm -> do
let ii0 = InternalInfo undefined tm fc get dc -- fixme: undefined
action ii0
fdCacheDurationInSeconds = settingsFdCacheDuration set * 1000000
fdFileInfoDurationInSeconds = settingsFileInfoCacheDuration set * 1000000
withTimeoutManager f = case settingsManager set of
Just tm -> f tm
Nothing -> bracket
(T.initialize $ settingsTimeout set * 1000000)
T.stopManager
f
-- Note that there is a thorough discussion of the exception safety of the
-- following code at: https://github.com/yesodweb/wai/issues/146
--
-- We need to make sure of two things:
--
-- 1. Asynchronous exceptions are not blocked entirely in the main loop.
-- Doing so would make it impossible to kill the Warp thread.
--
-- 2. Once a connection maker is received via acceptNewConnection, the
-- connection is guaranteed to be closed, even in the presence of
-- async exceptions.
--
-- Our approach is explained in the comments below.
acceptConnection :: Settings
-> IO (IO (Connection, Transport), SockAddr)
-> ServeConnection
-> Counter
-> InternalInfo
-> IO ()
acceptConnection set getConnMaker serveConn counter ii0 = do
-- First mask all exceptions in acceptLoop. This is necessary to
-- ensure that no async exception is throw between the call to
-- acceptNewConnection and the registering of connClose.
void $ mask_ acceptLoop
gracefulShutdown counter
where
acceptLoop = do
-- Allow async exceptions before receiving the next connection maker.
allowInterrupt
-- acceptNewConnection will try to receive the next incoming
-- request. It returns a /connection maker/, not a connection,
-- since in some circumstances creating a working connection
-- from a raw socket may be an expensive operation, and this
-- expensive work should not be performed in the main event
-- loop. An example of something expensive would be TLS
-- negotiation.
mx <- acceptNewConnection
case mx of
Nothing -> return ()
Just (mkConn, addr) -> do
fork set mkConn addr serveConn counter ii0
acceptLoop
acceptNewConnection = do
ex <- try getConnMaker
case ex of
Right x -> return $ Just x
Left e -> do
settingsOnException set Nothing $ toException e
if isFullErrorType (ioeGetErrorType e) then do
-- "resource exhausted (Too many open files)" may
-- happen by accept(). Wait a second hoping that
-- resource will be available.
threadDelay 1000000
acceptNewConnection
else
-- Assuming the listen socket is closed.
return Nothing
-- Fork a new worker thread for this connection maker, and ask for a
-- function to unmask (i.e., allow async exceptions to be thrown).
fork :: Settings
-> IO (Connection, Transport)
-> SockAddr
-> ServeConnection
-> Counter
-> InternalInfo
-> IO ()
fork set mkConn addr serveConn counter ii0 = settingsFork set $ \ unmask ->
-- Run the connection maker to get a new connection, and ensure
-- that the connection is closed. If the mkConn call throws an
-- exception, we will leak the connection. If the mkConn call is
-- vulnerable to attacks (e.g., Slowloris), we do nothing to
-- protect the server. It is therefore vital that mkConn is well
-- vetted.
--
-- We grab the connection before registering timeouts since the
-- timeouts will be useless during connection creation, due to the
-- fact that async exceptions are still masked.
bracket mkConn closeConn $ \(conn, transport) ->
-- We need to register a timeout handler for this thread, and
-- cancel that handler as soon as we exit.
bracket (T.registerKillThread (timeoutManager ii0)) T.cancel $ \th ->
let ii = ii0 { threadHandle = th }
-- We now have fully registered a connection close handler
-- in the case of all exceptions, so it is safe to one
-- again allow async exceptions.
in unmask .
-- Call the user-supplied on exception code if any
-- exceptions are thrown.
handle (settingsOnException set Nothing) .
-- Call the user-supplied code for connection open and close events
bracket (onOpen addr) (onClose addr) $ \goingon ->
-- Actually serve this connection.
-- bracket with closeConn above ensures the connection is closed.
when goingon $ serveConn conn ii addr transport set
where
closeConn (conn, _transport) = connClose conn
onOpen adr = increase counter >> settingsOnOpen set adr
onClose adr _ = decrease counter >> settingsOnClose set adr
-- The type of a function to serve a fully-prepared connection.
type ServeConnection = Connection
-> InternalInfo
-> SockAddr
-> Transport
-> Settings
-> IO ()
-- Serve an HTTP\/2-unaware Application to a connection over any HTTP version.
serveDefault :: Application -> ServeConnection
serveDefault app = serveHTTP2 (promoteApplication app) app
-- Serve an HTTP\/2-aware application over HTTP\/2 or a backup 'Application'
-- over HTTP\/1.1 or HTTP\/1.
serveHTTP2 :: HTTP2Application -> Application -> ServeConnection
serveHTTP2 app2 app conn ii origAddr transport settings = do
-- fixme: Upgrading to HTTP/2 should be supported.
(h2,bs) <- if isHTTP2 transport then
return (True, "")
else do
bs0 <- connRecv conn
if S.length bs0 >= 4 && "PRI " `S.isPrefixOf` bs0 then
return (True, bs0)
else
return (False, bs0)
if settingsHTTP2Enabled settings && h2 then do
recvN <- makeReceiveN bs (connRecv conn) (connRecvBuf conn)
-- fixme: origAddr
http2 conn ii origAddr transport settings recvN app2
else do
istatus <- newIORef False
src <- mkSource (wrappedRecv conn th istatus (settingsSlowlorisSize settings))
writeIORef istatus True
leftoverSource src bs
addr <- getProxyProtocolAddr src
http1 addr istatus src `E.catch` \e -> do
sendErrorResponse addr istatus e
throwIO (e :: SomeException)
where
getProxyProtocolAddr src =
case settingsProxyProtocol settings of
ProxyProtocolNone ->
return origAddr
ProxyProtocolRequired -> do
seg <- readSource src
parseProxyProtocolHeader src seg
ProxyProtocolOptional -> do
seg <- readSource src
if S.isPrefixOf "PROXY " seg
then parseProxyProtocolHeader src seg
else do leftoverSource src seg
return origAddr
parseProxyProtocolHeader src seg = do
let (header,seg') = S.break (== 0x0d) seg -- 0x0d == CR
maybeAddr = case S.split 0x20 header of -- 0x20 == space
["PROXY","TCP4",clientAddr,_,clientPort,_] ->
case [x | (x, t) <- reads (decodeAscii clientAddr), null t] of
[a] -> Just (SockAddrInet (readInt clientPort)
(toHostAddress a))
_ -> Nothing
["PROXY","TCP6",clientAddr,_,clientPort,_] ->
case [x | (x, t) <- reads (decodeAscii clientAddr), null t] of
[a] -> Just (SockAddrInet6 (readInt clientPort)
0
(toHostAddress6 a)
0)
_ -> Nothing
("PROXY":"UNKNOWN":_) ->
Just origAddr
_ ->
Nothing
case maybeAddr of
Nothing -> throwIO (BadProxyHeader (decodeAscii header))
Just a -> do leftoverSource src (S.drop 2 seg') -- drop CRLF
return a
decodeAscii = map (chr . fromEnum) . S.unpack
th = threadHandle ii
shouldSendErrorResponse se
| Just ConnectionClosedByPeer <- fromException se = False
| otherwise = True
sendErrorResponse addr istatus e = do
status <- readIORef istatus
when (shouldSendErrorResponse e && status) $ void $
sendResponse settings conn ii (dummyreq addr) defaultIndexRequestHeader (return S.empty) (errorResponse e)
dummyreq addr = defaultRequest { remoteHost = addr }
errorResponse e = settingsOnExceptionResponse settings e
http1 addr istatus src = do
(req', mremainingRef, idxhdr, nextBodyFlush) <- recvRequest settings conn ii addr src
let req = req' { isSecure = isTransportSecure transport }
keepAlive <- processRequest istatus src req mremainingRef idxhdr nextBodyFlush
`E.catch` \e -> do
-- Call the user-supplied exception handlers, passing the request.
sendErrorResponse addr istatus e
settingsOnException settings (Just req) e
-- Don't throw the error again to prevent calling settingsOnException twice.
return False
when keepAlive $ http1 addr istatus src
processRequest istatus src req mremainingRef idxhdr nextBodyFlush = do
-- Let the application run for as long as it wants
T.pause th
-- In the event that some scarce resource was acquired during
-- creating the request, we need to make sure that we don't get
-- an async exception before calling the ResponseSource.
keepAliveRef <- newIORef $ error "keepAliveRef not filled"
_ <- app req $ \res -> do
T.resume th
-- FIXME consider forcing evaluation of the res here to
-- send more meaningful error messages to the user.
-- However, it may affect performance.
writeIORef istatus False
keepAlive <- sendResponse settings conn ii req idxhdr (readSource src) res
writeIORef keepAliveRef keepAlive
return ResponseReceived
keepAlive <- readIORef keepAliveRef
-- We just send a Response and it takes a time to
-- receive a Request again. If we immediately call recv,
-- it is likely to fail and the IO manager works.
-- It is very costly. So, we yield to another Haskell
-- thread hoping that the next Request will arrive
-- when this Haskell thread will be re-scheduled.
-- This improves performance at least when
-- the number of cores is small.
Conc.yield
if not keepAlive then
return False
else
-- If there is an unknown or large amount of data to still be read
-- from the request body, simple drop this connection instead of
-- reading it all in to satisfy a keep-alive request.
case settingsMaximumBodyFlush settings of
Nothing -> do
flushEntireBody nextBodyFlush
T.resume th
return True
Just maxToRead -> do
let tryKeepAlive = do
-- flush the rest of the request body
isComplete <- flushBody nextBodyFlush maxToRead
if isComplete then do
T.resume th
return True
else
return False
case mremainingRef of
Just ref -> do
remaining <- readIORef ref
if remaining <= maxToRead then
tryKeepAlive
else
return False
Nothing -> tryKeepAlive
flushEntireBody :: IO ByteString -> IO ()
flushEntireBody src =
loop
where
loop = do
bs <- src
unless (S.null bs) loop
flushBody :: IO ByteString -- ^ get next chunk
-> Int -- ^ maximum to flush
-> IO Bool -- ^ True == flushed the entire body, False == we didn't
flushBody src =
loop
where
loop toRead = do
bs <- src
let toRead' = toRead - S.length bs
case () of
()
| S.null bs -> return True
| toRead' >= 0 -> loop toRead'
| otherwise -> return False
wrappedRecv :: Connection -> T.Handle -> IORef Bool -> Int -> IO ByteString
wrappedRecv Connection { connRecv = recv } th istatus slowlorisSize = do
bs <- recv
unless (S.null bs) $ do
writeIORef istatus True
when (S.length bs >= slowlorisSize) $ T.tickle th
return bs
-- Copied from: https://github.com/mzero/plush/blob/master/src/Plush/Server/Warp.hs
setSocketCloseOnExec :: Socket -> IO ()
#if WINDOWS
setSocketCloseOnExec _ = return ()
#else
setSocketCloseOnExec socket =
setFdOption (fromIntegral $ fdSocket socket) CloseOnExec True
#endif
gracefulShutdown :: Counter -> IO ()
gracefulShutdown counter = waitForZero counter