module Network.HTTP.Lucu.StaticFile
- (
+ ( staticFile
+ , handleStaticFile
+
+ , staticDir
+ , handleStaticDir
+
+ , generateETagFromFile
)
where
+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 Network.HTTP.Lucu.Utils
+import System.Directory
+import System.Posix.Files
+import Text.Printf
+
staticFile :: FilePath -> ResourceDef
staticFile path
= ResourceDef {
resUsesNativeThread = False
, resIsGreedy = False
- , resGet
- = Just $ do
\ No newline at end of file
+ , resGet = Just $ handleStaticFile path
+ , resHead = Nothing
+ , resPost = Nothing
+ , resPut = Nothing
+ , resDelete = Nothing
+ }
+
+
+handleStaticFile :: FilePath -> Resource ()
+handleStaticFile path
+ = do isFile <- liftIO $ doesFileExist path
+ if isFile 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
+
+ -- 讀める
+ tag <- liftIO $ generateETagFromFile path
+ lastMod <- liftIO $ getModificationTime path
+ foundEntity tag lastMod
+
+ -- MIME Type を推定
+ conf <- getConfig
+ case guessTypeByFileName (cnfExtToMIMEType conf) path of
+ Nothing -> return ()
+ Just mime -> setContentType mime
+
+ -- 實際にファイルを讀んで送る
+ (liftIO $ B.readFile path) >>= outputBS
+ else
+ do isDir <- liftIO $ doesDirectoryExist path
+ if isDir then
+ abort Forbidden [] Nothing
+ else
+ foundNoEntity Nothing
+
+
+-- |Computation @'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 strict strong ETag from a
+-- file since 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
+
+
+staticDir :: FilePath -> ResourceDef
+staticDir path
+ = ResourceDef {
+ resUsesNativeThread = False
+ , resIsGreedy = True
+ , resGet = Just $ handleStaticDir path
+ , resHead = Nothing
+ , resPost = Nothing
+ , resPut = Nothing
+ , resDelete = Nothing
+ }
+
+
+handleStaticDir :: FilePath -> Resource ()
+handleStaticDir basePath
+ = do extraPath <- getPathInfo
+ securityCheck extraPath
+ let path = basePath ++ "/" ++ joinWith "/" extraPath
+
+ handleStaticFile path
+ where
+ securityCheck :: Monad m => [String] -> m ()
+ securityCheck pathElems
+ = when (any (== "..") pathElems) $ fail ("security error: "
+ ++ joinWith "/" pathElems)