+{-# LANGUAGE
+ DoAndIfThenElse
+ , OverloadedStrings
+ , UnicodeSyntax
+ #-}
+-- | Handling static files on the filesystem.
module Network.HTTP.Lucu.StaticFile
- ( staticFile -- FilePath -> ResourceDef
- , handleStaticFile -- FilePath -> Resource ()
+ ( staticFile
+ , staticDir
+
+ , generateETagFromFile
)
where
+import qualified Blaze.ByteString.Builder.ByteString as BB
+import qualified Blaze.Text.Int as BT
+import Control.Monad
+import Control.Monad.Unicode
+import Control.Monad.Trans
+import qualified Data.Ascii as A
+import Data.ByteString (ByteString)
+import qualified Data.ByteString.Lazy.Char8 as LBS
+import Data.Monoid.Unicode
+import Data.String
+import qualified Data.Text as T
+import qualified Data.Text.Encoding as T
+import Data.Time.Clock.POSIX
+import Network.HTTP.Lucu.Abortion
+import Network.HTTP.Lucu.Config
+import Network.HTTP.Lucu.ETag
+import Network.HTTP.Lucu.MIMEType
+import Network.HTTP.Lucu.MIMEType.Guess
+import Network.HTTP.Lucu.Resource
+import Network.HTTP.Lucu.Resource.Internal
+import Network.HTTP.Lucu.Response
+import Prelude.Unicode
+import System.FilePath
+import System.Posix.Files
-import Control.Monad
-import Control.Monad.Trans
-import qualified Data.ByteString.Lazy.Char8 as B
-import Data.ByteString.Lazy.Char8 (ByteString)
-import Network.HTTP.Lucu.Abortion
-import Network.HTTP.Lucu.Config
-import Network.HTTP.Lucu.ETag
-import Network.HTTP.Lucu.MIMEType.Guess
-import Network.HTTP.Lucu.Resource
-import Network.HTTP.Lucu.Resource.Tree
-import Network.HTTP.Lucu.Response
-import System.Directory
-import System.Posix.Files
-import Text.Printf
-
-
-staticFile :: FilePath -> ResourceDef
+-- | @'staticFile' fpath@ is a 'ResourceDef' which serves the file at
+-- @fpath@ on the filesystem.
+staticFile ∷ FilePath → ResourceDef
staticFile path
- = ResourceDef {
- resUsesNativeThread = False
- , resIsGreedy = False
- , resGet = Just $ handleStaticFile path
- , resHead = Nothing
- , resPost = Nothing
- , resPut = Nothing
- , resDelete = Nothing
+ = emptyResource {
+ resGet = Just $ handleStaticFile True path
+ , resHead = Just $ handleStaticFile False path
}
+octetStream ∷ MIMEType
+{-# NOINLINE octetStream #-}
+octetStream = parseMIMEType "application/octet-stream"
-handleStaticFile :: FilePath -> Resource ()
-handleStaticFile path
- = do exist <- liftIO $ fileExist path
- if exist then
- -- 存在はした。讀めるかどうかは知らない。
- do readable <- liftIO $ fileAccess path True False False
- unless readable
- -- 讀めない
- $ abort Forbidden [] Nothing
+handleStaticFile ∷ Bool → FilePath → Resource ()
+handleStaticFile sendContent path
+ = do exists ← liftIO $ fileExist path
+ unless exists
+ foundNoEntity'
- -- 讀める
- tag <- liftIO $ generateETagFromFile path
- lastMod <- liftIO $ getModificationTime path
- foundEntity tag lastMod
+ readable ← liftIO $ fileAccess path True False False
+ unless readable
+ $ abort
+ $ mkAbortion Forbidden [] Nothing
- -- MIME Type を推定
- conf <- getConfig
- case guessTypeByFileName (cnfExtToMIMEType conf) path of
- Nothing -> return ()
- Just mime -> setContentType mime
+ stat ← liftIO $ getFileStatus path
+ when (isDirectory stat)
+ $ abort
+ $ mkAbortion Forbidden [] Nothing
- -- 實際にファイルを讀んで送る
- (liftIO $ B.readFile path) >>= outputBS
- else
- foundNoEntity Nothing
+ tag ← liftIO $ generateETagFromFile path
+ let lastMod = posixSecondsToUTCTime
+ $ fromRational
+ $ toRational
+ $ modificationTime stat
+ foundEntity tag lastMod
+ conf ← getConfig
+ case guessTypeByFileName (cnfExtToMIMEType conf) path of
+ Nothing → setContentType octetStream
+ Just mime → setContentType mime
--- inode-size-lastmod
-generateETagFromFile :: FilePath -> IO ETag
+ when sendContent
+ $ liftIO (LBS.readFile path) ≫= putChunks
+
+-- |@'generateETagFromFile' fpath@ generates a strong entity tag from
+-- a file. The file doesn't necessarily have to be a regular file; it
+-- may be a FIFO or a device file. The tag is made of inode ID, size
+-- and modification time.
+--
+-- Note that the tag is not strictly strong because the file could be
+-- modified twice at a second without changing inode ID or size, but
+-- it's not really possible to generate a strictly strong ETag from a
+-- file as we don't want to simply grab the entire file and use it as
+-- an ETag. It is indeed possible to hash it with SHA-1 or MD5 to
+-- increase strictness, but it's too inefficient if the file is really
+-- large (say, 1 TiB).
+generateETagFromFile ∷ FilePath → IO ETag
generateETagFromFile path
- = do stat <- getFileStatus path
- let inode = fromEnum $ fileID stat
- size = fromEnum $ fileSize stat
- lastmod = fromEnum $ modificationTime stat
- return $ strongETag $ printf "%x-%x-%x" inode size lastmod
+ = do stat ← getFileStatus path
+ let inode = fileID stat
+ size = fileSize stat
+ lastMod = fromEnum $ modificationTime stat
+ tag = A.fromAsciiBuilder
+ $ A.unsafeFromBuilder
+ $ BT.integral inode
+ ⊕ BB.fromByteString "-"
+ ⊕ BT.integral size
+ ⊕ BB.fromByteString "-"
+ ⊕ BT.integral lastMod
+ return $ strongETag tag
+
+-- | @'staticDir' dir@ is a 'ResourceDef' which maps all files in
+-- @dir@ and its subdirectories on the filesystem to the
+-- 'Network.HTTP.Lucu.Resource.Tree.ResTree'.
+--
+-- Note that 'staticDir' currently doesn't have a directory-listing
+-- capability. Requesting the content of a directory will end up being
+-- replied with /403 Forbidden/.
+staticDir ∷ FilePath → ResourceDef
+staticDir path
+ = emptyResource {
+ resIsGreedy = True
+ , resGet = Just $ handleStaticDir True path
+ , resHead = Just $ handleStaticDir False path
+ }
+
+-- TODO: implement directory listing.
+handleStaticDir ∷ Bool → FilePath → Resource ()
+handleStaticDir sendContent basePath
+ = do extraPath ← getPathInfo
+ securityCheck extraPath
+ let path = basePath </> joinPath (map dec8 extraPath)
+ handleStaticFile sendContent path
+ where
+ dec8 ∷ ByteString → String
+ dec8 = T.unpack ∘ T.decodeUtf8
+
+securityCheck ∷ (Eq s, Show s, IsString s, Monad m) ⇒ [s] → m ()
+securityCheck pathElems
+ = when (any (≡ "..") pathElems)
+ $ fail ("security error: " ⧺ show pathElems)