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59962b4a AK |
1 | {-# LANGUAGE DeriveDataTypeable, ViewPatterns #-} |
2 | {-# OPTIONS_GHC -O2 -Wall #-} | |
3 | ||
51cce206 | 4 | import Prelude hiding (catch) |
59962b4a | 5 | import Control.Applicative |
59962b4a | 6 | import Control.Monad |
51cce206 | 7 | import Control.Monad.CatchIO |
59962b4a | 8 | import qualified Data.ByteString.Lazy as B |
59cbcd42 | 9 | import Data.Char |
59962b4a | 10 | import Data.Dynamic |
88f471e3 | 11 | import Data.Int |
59962b4a AK |
12 | import qualified Data.Map as M |
13 | import Data.Time.Clock.POSIX | |
14 | import Data.Time.Format | |
15 | import Network.CGI | |
16 | import Numeric | |
17 | import System.FilePath | |
18 | import System.IO | |
51cce206 | 19 | import System.IO.Error (isDoesNotExistError, isPermissionError) |
88f471e3 | 20 | import System.IO.Unsafe |
59962b4a AK |
21 | import System.Locale |
22 | import System.Posix | |
23 | import System.Posix.Handle | |
24 | ||
25 | encodings :: M.Map String String | |
26 | encodings = M.fromList [ | |
59cbcd42 | 27 | (".bz2", "bzip2"), |
59962b4a | 28 | (".gz", "gzip"), |
59cbcd42 | 29 | (".z", "compress") |
59962b4a AK |
30 | ] |
31 | ||
32 | types :: M.Map String String | |
33 | types = M.fromList [ | |
59cbcd42 AK |
34 | (".avi", "video/x-msvideo"), |
35 | (".css", "text/css"), | |
36 | (".doc", "application/msword"), | |
37 | (".gif", "image/gif"), | |
38 | (".htm", "text/html"), | |
39 | (".html", "text/html"), | |
40 | (".ico", "image/vnd.microsoft.icon"), | |
41 | (".il", "application/octet-stream"), | |
42 | (".jar", "application/java-archive"), | |
43 | (".jpeg", "image/jpeg"), | |
44 | (".jpg", "image/jpeg"), | |
45 | (".js", "application/x-javascript"), | |
46 | (".mid", "audio/midi"), | |
47 | (".midi", "audio/midi"), | |
48 | (".mov", "video/quicktime"), | |
49 | (".mp3", "audio/mpeg"), | |
50 | (".mpeg", "video/mpeg"), | |
51 | (".mpg", "video/mpeg"), | |
52 | (".pdf", "application/pdf"), | |
53 | (".png", "image/png"), | |
54 | (".ppt", "application/vnd.ms-powerpoint"), | |
55 | (".ps", "application/postscript"), | |
56 | (".svg", "image/svg+xml"), | |
57 | (".swf", "application/x-shockwave-flash"), | |
58 | (".tar", "application/x-tar"), | |
59 | (".tgz", "application/x-gzip"), | |
60 | (".tif", "image/tiff"), | |
61 | (".tiff", "image/tiff"), | |
62 | (".wav", "audio/x-wav"), | |
63 | (".wmv", "video/x-ms-wmv"), | |
64 | (".xaml", "application/xaml+xml"), | |
65 | (".xap", "application/x-silverlight-app"), | |
66 | (".xhtml", "application/xhtml+xml"), | |
67 | (".xls", "application/vnd.ms-excel"), | |
68 | (".xml", "text/xml"), | |
69 | (".xsl", "text/xml"), | |
70 | (".zip", "application/zip") | |
59962b4a AK |
71 | ] |
72 | ||
59962b4a AK |
73 | data MyError = NotModified | Forbidden | NotFound | BadMethod | BadRange |
74 | deriving (Show, Typeable) | |
75 | ||
76 | instance Exception MyError | |
77 | ||
78 | outputMyError :: MyError -> CGI CGIResult | |
79 | outputMyError NotModified = setStatus 304 "Not Modified" >> outputNothing | |
80 | outputMyError Forbidden = outputError 403 "Forbidden" [] | |
81 | outputMyError NotFound = outputError 404 "Not Found" [] | |
82 | outputMyError BadMethod = outputError 405 "Method Not Allowed" [] | |
83 | outputMyError BadRange = outputError 416 "Requested Range Not Satisfiable" [] | |
84 | ||
85 | checkExtension :: FilePath -> CGI () | |
86 | checkExtension file = do | |
87 | let (base, ext) = splitExtension file | |
59cbcd42 | 88 | ext' <- case M.lookup (map toLower ext) encodings of |
59962b4a AK |
89 | Nothing -> return ext |
90 | Just e -> do | |
91 | setHeader "Content-Encoding" e | |
92 | return $ takeExtension base | |
93 | ||
59cbcd42 | 94 | case M.lookup (map toLower ext') types of |
51cce206 | 95 | Nothing -> throw Forbidden |
59962b4a AK |
96 | Just t -> setHeader "Content-Type" t |
97 | ||
98 | checkMethod :: CGI CGIResult -> CGI CGIResult | |
99 | checkMethod rOutput = do | |
100 | m <- requestMethod | |
101 | case m of | |
102 | "HEAD" -> rOutput >> outputNothing | |
103 | "GET" -> rOutput | |
104 | "POST" -> rOutput | |
51cce206 | 105 | _ -> throw BadMethod |
59962b4a AK |
106 | |
107 | httpDate :: String | |
108 | httpDate = "%a, %d %b %Y %H:%M:%S %Z" | |
109 | formatHTTPDate :: EpochTime -> String | |
110 | formatHTTPDate = formatTime defaultTimeLocale httpDate . | |
111 | posixSecondsToUTCTime . realToFrac | |
112 | parseHTTPDate :: String -> Maybe EpochTime | |
113 | parseHTTPDate = (fromInteger . floor . utcTimeToPOSIXSeconds <$>) . | |
114 | parseTime defaultTimeLocale httpDate | |
115 | ||
116 | checkModified :: EpochTime -> CGI () | |
117 | checkModified mTime = do | |
118 | setHeader "Last-Modified" $ formatHTTPDate mTime | |
119 | (requestHeader "If-Modified-Since" >>=) $ maybe (return ()) $ \ims -> | |
51cce206 | 120 | when (parseHTTPDate ims >= Just mTime) $ throw NotModified |
59962b4a AK |
121 | |
122 | checkIfRange :: EpochTime -> CGI (Maybe ()) | |
123 | checkIfRange mTime = do | |
124 | (requestHeader "If-Range" >>=) $ maybe (return $ Just ()) $ \ir -> | |
125 | return $ if parseHTTPDate ir == Just mTime then Just () else Nothing | |
126 | ||
127 | parseRange :: String -> FileOffset -> Maybe (FileOffset, FileOffset) | |
30782664 AK |
128 | parseRange (splitAt 6 -> ("bytes=", '-':(readDec -> [(len, "")]))) size = |
129 | Just (max 0 (size - len), size - 1) | |
59962b4a AK |
130 | parseRange (splitAt 6 -> ("bytes=", readDec -> [(a, "-")])) size = |
131 | Just (a, size - 1) | |
374d09ff AK |
132 | parseRange (splitAt 6 -> ("bytes=", readDec -> [(a, '-':(readDec -> [(b, "")]))])) size = |
133 | Just (a, min (size - 1) b) | |
59962b4a AK |
134 | parseRange _ _ = Nothing |
135 | ||
136 | checkRange :: EpochTime -> FileOffset -> CGI (Maybe (FileOffset, FileOffset)) | |
137 | checkRange mTime size = do | |
138 | setHeader "Accept-Ranges" "bytes" | |
139 | (requestHeader "Range" >>=) $ maybe (return Nothing) $ \range -> do | |
140 | (checkIfRange mTime >>=) $ maybe (return Nothing) $ \() -> do | |
141 | case parseRange range size of | |
142 | Just (a, b) | a <= b -> return $ Just (a, b) | |
9b3cd5c2 AK |
143 | Just _ -> throw BadRange |
144 | Nothing -> return Nothing | |
59962b4a | 145 | |
1cb5cdb0 AK |
146 | outputAll :: Handle -> FileOffset -> CGI CGIResult |
147 | outputAll h size = do | |
148 | setHeader "Content-Length" $ show size | |
149 | outputFPS =<< liftIO (B.hGetContents h) | |
150 | ||
88f471e3 AK |
151 | -- | Lazily read a given number of bytes from the handle into a |
152 | -- 'ByteString', then close the handle. | |
153 | hGetClose :: Handle -> Int64 -> IO B.ByteString | |
154 | hGetClose h len = do | |
155 | contents <- B.hGetContents h | |
156 | end <- unsafeInterleaveIO (hClose h >> return B.empty) | |
157 | return (B.append (B.take len contents) end) | |
158 | ||
1cb5cdb0 AK |
159 | outputRange :: Handle -> FileOffset -> Maybe (FileOffset, FileOffset) -> CGI CGIResult |
160 | outputRange h size Nothing = outputAll h size | |
161 | outputRange h size (Just (a, b)) = do | |
162 | let len = b - a + 1 | |
163 | ||
164 | setStatus 206 "Partial Content" | |
165 | setHeader "Content-Range" $ | |
166 | "bytes " ++ show a ++ "-" ++ show b ++ "/" ++ show size | |
167 | setHeader "Content-Length" $ show len | |
168 | liftIO $ hSeek h AbsoluteSeek (fromIntegral a) | |
88f471e3 | 169 | outputFPS =<< liftIO (hGetClose h (fromIntegral len)) |
1cb5cdb0 | 170 | |
59962b4a | 171 | serveFile :: FilePath -> CGI CGIResult |
51cce206 | 172 | serveFile file = (`catch` outputMyError) $ do |
59962b4a AK |
173 | checkExtension file |
174 | ||
175 | checkMethod $ do | |
176 | ||
cee07ba6 | 177 | let handleOpenError e = |
51cce206 AK |
178 | if isDoesNotExistError e then throw NotFound |
179 | else if isPermissionError e then throw Forbidden | |
180 | else throw e | |
181 | h <- liftIO (openBinaryFile file ReadMode) `catch` handleOpenError | |
182 | (`onException` liftIO (hClose h)) $ do | |
59962b4a AK |
183 | |
184 | status <- liftIO $ hGetStatus h | |
185 | let mTime = modificationTime status | |
186 | size = fileSize status | |
187 | checkModified mTime | |
188 | ||
1cb5cdb0 AK |
189 | range <- checkRange mTime size |
190 | outputRange h size range | |
59962b4a AK |
191 | |
192 | main :: IO () | |
193 | main = runCGI $ handleErrors $ serveFile =<< pathTranslated |