module Network.Wai.Application.Classic.CGI (
cgiApp
) where
import Blaze.ByteString.Builder.ByteString
import Control.Applicative
import Control.Exception
import Control.Monad (when)
import Control.Monad.IO.Class (liftIO)
import Data.ByteString (ByteString)
import qualified Data.ByteString as BS hiding (unpack)
import qualified Data.ByteString.Char8 as BS (readInt, unpack)
import Data.CaseInsensitive hiding (map)
import Data.Enumerator hiding (map, filter, drop, break)
import qualified Data.Enumerator.Binary as EB
import qualified Data.Enumerator.List as EL
import Network.HTTP.Types
import Network.Wai
import Network.Wai.Application.Classic.EnumLine as ENL
import Network.Wai.Application.Classic.Field
import Network.Wai.Application.Classic.Header
import Network.Wai.Application.Classic.Types
import Network.Wai.Application.Classic.Utils
import Network.Wai.Logger.Utils
import System.IO
import System.Process
type ENVVARS = [(String,String)]
gatewayInterface :: String
gatewayInterface = "CGI/1.1"
cgiApp :: AppSpec -> CgiRoute -> Application
cgiApp spec cgii req = case method of
"GET" -> cgiApp' False spec cgii req
"POST" -> cgiApp' True spec cgii req
_ -> return $ responseLBS statusNotAllowed textPlain "Method Not Allowed\r\n"
where
method = requestMethod req
cgiApp' :: Bool -> AppSpec -> CgiRoute -> Application
cgiApp' body spec cgii req = do
(rhdl,whdl,pid) <- liftIO $ execProcess spec cgii req
let cleanup = do
hClose whdl
hClose rhdl
terminateProcess pid
toCGI whdl body `catchError` const (liftIO cleanup)
liftIO $ hClose whdl
respEnumerator $ \hdrMaker ->
fromCGI rhdl spec req hdrMaker `finally` cleanup
where
respEnumerator = return . ResponseEnumerator
toCGI :: Handle -> Bool -> Iteratee ByteString IO ()
toCGI whdl body = when body $ EL.consume >>= liftIO . mapM_ (BS.hPutStr whdl)
fromCGI :: Handle -> AppSpec -> Request -> ResponseEnumerator a
fromCGI rhdl spec req hdrMaker = run_ $ EB.enumHandle 4096 rhdl $$ do
m <- (>>= check) <$> parseHeader
let (st, hdr, hasBody) = case m of
Nothing -> (status500,[],False)
Just (s,h) -> (s,h,True)
hdr' = addHeader hdr
liftIO $ logger spec req st Nothing
if hasBody
then response st hdr'
else emptyBody $$ response st hdr'
where
toBuilder = EL.map fromByteString
emptyBody = enumEOF
response status hs = toBuilder =$ hdrMaker status hs
check hs = lookup fkContentType hs >> case lookup "status" hs of
Nothing -> Just (status200, hs)
Just l -> toStatus l >>= \s -> Just (s,hs')
where
hs' = filter (\(k,_) -> k /= "status") hs
toStatus s = BS.readInt s >>= \x -> Just (Status (fst x) s)
addHeader hdr = ("Server", softwareName spec) : hdr
parseHeader :: Iteratee ByteString IO (Maybe RequestHeaders)
parseHeader = takeHeader >>= maybe (return Nothing)
(return . Just . map parseField)
where
parseField bs = (mk key, val)
where
(key,val) = case BS.breakByte 58 bs of
kv@(_,"") -> kv
(k,v) -> let v' = BS.dropWhile (==32) $ BS.tail v in (k,v')
takeHeader :: Iteratee ByteString IO (Maybe [ByteString])
takeHeader = ENL.head >>= maybe (return Nothing) $. \l ->
if l == ""
then return (Just [])
else takeHeader >>= maybe (return Nothing) (return . Just . (l:))
execProcess :: AppSpec -> CgiRoute -> Request -> IO (Handle, Handle, ProcessHandle)
execProcess spec cgii req = do
let naddr = showSockAddr . remoteHost $ req
(Just whdl,Just rhdl,_,pid) <- createProcess . proSpec $ naddr
hSetEncoding rhdl latin1
hSetEncoding whdl latin1
return (rhdl, whdl, pid)
where
proSpec naddr = CreateProcess {
cmdspec = RawCommand prog []
, cwd = Nothing
, env = Just (makeEnv req naddr scriptName pathinfo (softwareName spec))
, std_in = CreatePipe
, std_out = CreatePipe
, std_err = Inherit
, close_fds = True
#if __GLASGOW_HASKELL__ >= 702
, create_group = True
#endif
}
(prog, scriptName, pathinfo) = pathinfoToCGI (cgiSrc cgii)
(cgiDst cgii)
(rawPathInfo req)
makeEnv :: Request -> NumericAddress -> String -> String -> ByteString -> ENVVARS
makeEnv req naddr scriptName pathinfo sname = addLength . addType . addCookie $ baseEnv
where
baseEnv = [
("GATEWAY_INTERFACE", gatewayInterface)
, ("SCRIPT_NAME", scriptName)
, ("REQUEST_METHOD", BS.unpack . requestMethod $ req)
, ("SERVER_NAME", BS.unpack . serverName $ req)
, ("SERVER_PORT", show . serverPort $ req)
, ("REMOTE_ADDR", naddr)
, ("SERVER_PROTOCOL", show . httpVersion $ req)
, ("SERVER_SOFTWARE", BS.unpack sname)
, ("PATH_INFO", pathinfo)
, ("QUERY_STRING", query req)
]
headers = requestHeaders req
addLength = addEnv "CONTENT_LENGTH" $ lookup fkContentLength headers
addType = addEnv "CONTENT_TYPE" $ lookup fkContentType headers
addCookie = addEnv "HTTP_COOKIE" $ lookup fkCookie headers
query = BS.unpack . safeTail . rawQueryString
where
safeTail "" = ""
safeTail bs = BS.tail bs
addEnv :: String -> Maybe ByteString -> ENVVARS -> ENVVARS
addEnv _ Nothing envs = envs
addEnv key (Just val) envs = (key,BS.unpack val) : envs
pathinfoToCGI :: ByteString -> ByteString -> ByteString -> (FilePath, String, String)
pathinfoToCGI src dst path = (prog, scriptName, pathinfo)
where
path' = BS.drop (BS.length src) path
(prog',pathinfo') = BS.breakByte pathSep path'
prog = BS.unpack (dst </> prog')
scriptName = BS.unpack (src </> prog')
pathinfo = BS.unpack pathinfo'
infixr 6 $.
($.) :: (a -> b) -> a -> b
($.) = ($)