git-annex/Remote/WebDAV.hs
Joey Hess 2ca1d3cc01
deal with box.com horrible infinite redirect behavior
webdav: Checking if a non-existent file is present on Box.com triggered a
bug in its webdav support that generates an infinite series of redirects.

It seems to redirect foo to foo/ to foo/index.php to
foo/index.php/index.php ... Why a webdav endpoint would behave this way
who knows.

Deal with such problems by assuming such behavior means the file is not
present.

Can't simply disable following redirects, because the webdav endpoint could
legitimately be redirected to a new endpoint. So, when this happens
10 redirects have to be followed, before it gives up and assumes this means
the file does not exist.

This commit was supported by the NSF-funded DataLad project.
2017-09-12 15:13:42 -04:00

457 lines
14 KiB
Haskell

{- WebDAV remotes.
-
- Copyright 2012-2017 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE ScopedTypeVariables #-}
module Remote.WebDAV (remote, davCreds, configUrl) where
import Network.Protocol.HTTP.DAV
import qualified Data.Map as M
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString.UTF8 as B8
import qualified Data.ByteString.Lazy.UTF8 as L8
import Network.HTTP.Client (HttpException(..), RequestBody)
import Network.HTTP.Types
import System.IO.Error
import Control.Monad.Catch
import Annex.Common
import Types.Remote
import qualified Git
import Config
import Config.Cost
import Remote.Helper.Special
import Remote.Helper.Messages
import Remote.Helper.Http
import Remote.Helper.Export
import qualified Remote.Helper.Chunked.Legacy as Legacy
import Creds
import Utility.Metered
import Utility.Url (URLString, matchStatusCodeException, matchHttpExceptionContent)
import Annex.UUID
import Remote.WebDAV.DavLocation
#if MIN_VERSION_http_client(0,5,0)
import Network.HTTP.Client (HttpExceptionContent(..), responseStatus)
#endif
remote :: RemoteType
remote = RemoteType
{ typename = "webdav"
, enumerate = const (findSpecialRemotes "webdav")
, generate = gen
, setup = webdavSetup
, exportSupported = exportIsSupported
}
gen :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> Annex (Maybe Remote)
gen r u c gc = new <$> remoteCost gc expensiveRemoteCost
where
new cst = Just $ specialRemote c
(prepareDAV this $ store chunkconfig)
(prepareDAV this $ retrieve chunkconfig)
(prepareDAV this $ remove)
(prepareDAV this $ checkKey this chunkconfig)
this
where
this = Remote
{ uuid = u
, cost = cst
, name = Git.repoDescribe r
, storeKey = storeKeyDummy
, retrieveKeyFile = retreiveKeyFileDummy
, retrieveKeyFileCheap = retrieveCheap
, removeKey = removeKeyDummy
, lockContent = Nothing
, checkPresent = checkPresentDummy
, checkPresentCheap = False
, exportActions = ExportActions
{ storeExport = storeExportDav this
, retrieveExport = retrieveExportDav this
, removeExport = removeExportDav this
, checkPresentExport = checkPresentExportDav this
, renameExport = renameExportDav this
}
, whereisKey = Nothing
, remoteFsck = Nothing
, repairRepo = Nothing
, config = c
, repo = r
, gitconfig = gc
, localpath = Nothing
, readonly = False
, availability = GloballyAvailable
, remotetype = remote
, mkUnavailable = gen r u (M.insert "url" "http://!dne!/" c) gc
, getInfo = includeCredsInfo c (davCreds u) $
[("url", fromMaybe "unknown" (M.lookup "url" c))]
, claimUrl = Nothing
, checkUrl = Nothing
}
chunkconfig = getChunkConfig c
webdavSetup :: SetupStage -> Maybe UUID -> Maybe CredPair -> RemoteConfig -> RemoteGitConfig -> Annex (RemoteConfig, UUID)
webdavSetup _ mu mcreds c gc = do
u <- maybe (liftIO genUUID) return mu
url <- case M.lookup "url" c of
Nothing -> giveup "Specify url="
Just url -> return url
(c', encsetup) <- encryptionSetup c gc
creds <- maybe (getCreds c' gc u) (return . Just) mcreds
testDav url creds
gitConfigSpecialRemote u c' "webdav" "true"
c'' <- setRemoteCredPair encsetup c' gc (davCreds u) creds
return (c'', u)
-- Opens a http connection to the DAV server, which will be reused
-- each time the helper is called.
prepareDAV :: Remote -> (Maybe DavHandle -> helper) -> Preparer helper
prepareDAV = resourcePrepare . const . withDAVHandle
store :: ChunkConfig -> Maybe DavHandle -> Storer
store _ Nothing = byteStorer $ \_k _b _p -> return False
store (LegacyChunks chunksize) (Just dav) = fileStorer $ \k f p -> liftIO $
withMeteredFile f p $ storeLegacyChunked chunksize k dav
store _ (Just dav) = httpStorer $ \k reqbody -> liftIO $ goDAV dav $ do
let tmp = keyTmpLocation k
let dest = keyLocation k
storeHelper dav tmp dest reqbody
return True
storeHelper :: DavHandle -> DavLocation -> DavLocation -> RequestBody -> DAVT IO ()
storeHelper dav tmp dest reqbody = do
void $ mkColRecursive tmpDir
inLocation tmp $
putContentM' (contentType, reqbody)
finalizeStore dav tmp dest
finalizeStore :: DavHandle -> DavLocation -> DavLocation -> DAVT IO ()
finalizeStore dav tmp dest = do
inLocation dest $ void $ safely $ delContentM
maybe noop (void . mkColRecursive) (locationParent dest)
moveDAV (baseURL dav) tmp dest
retrieveCheap :: Key -> AssociatedFile -> FilePath -> Annex Bool
retrieveCheap _ _ _ = return False
retrieve :: ChunkConfig -> Maybe DavHandle -> Retriever
retrieve _ Nothing = giveup "unable to connect"
retrieve (LegacyChunks _) (Just dav) = retrieveLegacyChunked dav
retrieve _ (Just dav) = fileRetriever $ \d k p -> liftIO $
goDAV dav $ retrieveHelper (keyLocation k) d p
retrieveHelper :: DavLocation -> FilePath -> MeterUpdate -> DAVT IO ()
retrieveHelper loc d p = inLocation loc $
withContentM $ httpBodyRetriever d p
remove :: Maybe DavHandle -> Remover
remove Nothing _ = return False
remove (Just dav) k = liftIO $ goDAV dav $
-- Delete the key's whole directory, including any
-- legacy chunked files, etc, in a single action.
removeHelper (keyDir k)
removeHelper :: DavLocation -> DAVT IO Bool
removeHelper d = do
v <- safely $ inLocation d delContentM
case v of
Just _ -> return True
Nothing -> do
v' <- existsDAV d
case v' of
Right False -> return True
_ -> return False
checkKey :: Remote -> ChunkConfig -> Maybe DavHandle -> CheckPresent
checkKey r _ Nothing _ = giveup $ name r ++ " not configured"
checkKey r chunkconfig (Just dav) k = do
showChecking r
case chunkconfig of
LegacyChunks _ -> checkKeyLegacyChunked dav k
_ -> do
v <- liftIO $ goDAV dav $
existsDAV (keyLocation k)
either giveup return v
storeExportDav :: Remote -> FilePath -> Key -> ExportLocation -> MeterUpdate -> Annex Bool
storeExportDav r f _k loc p = runExport r $ \dav -> do
reqbody <- liftIO $ httpBodyStorer f p
storeHelper dav (exportTmpLocation loc) (exportLocation loc) reqbody
return True
retrieveExportDav :: Remote -> Key -> ExportLocation -> FilePath -> MeterUpdate -> Annex Bool
retrieveExportDav r _k loc d p = runExport r $ \_dav -> do
retrieveHelper (exportLocation loc) d p
return True
removeExportDav :: Remote -> Key -> ExportLocation -> Annex Bool
removeExportDav r _k loc = runExport r $ \_dav ->
removeHelper (exportLocation loc)
checkPresentExportDav :: Remote -> Key -> ExportLocation -> Annex Bool
checkPresentExportDav r _k loc = withDAVHandle r $ \mh -> case mh of
Nothing -> giveup $ name r ++ " not configured"
Just h -> liftIO $ do
v <- goDAV h $ existsDAV (exportLocation loc)
either giveup return v
renameExportDav :: Remote -> Key -> ExportLocation -> ExportLocation -> Annex Bool
renameExportDav r _k src dest = runExport r $ \dav -> do
moveDAV (baseURL dav) (exportLocation src) (exportLocation dest)
return True
runExport :: Remote -> (DavHandle -> DAVT IO Bool) -> Annex Bool
runExport r a = withDAVHandle r $ \mh -> case mh of
Nothing -> return False
Just h -> fromMaybe False <$> liftIO (goDAV h $ safely (a h))
configUrl :: Remote -> Maybe URLString
configUrl r = fixup <$> M.lookup "url" (config r)
where
-- box.com DAV url changed
fixup = replace "https://www.box.com/dav/" "https://dav.box.com/dav/"
type DavUser = B8.ByteString
type DavPass = B8.ByteString
baseURL :: DavHandle -> URLString
baseURL (DavHandle _ _ _ u) = u
toDavUser :: String -> DavUser
toDavUser = B8.fromString
toDavPass :: String -> DavPass
toDavPass = B8.fromString
{- Test if a WebDAV store is usable, by writing to a test file, and then
- deleting the file.
-
- Also ensures that the path of the url exists, trying to create it if not.
-
- Throws an error if store is not usable.
-}
testDav :: URLString -> Maybe CredPair -> Annex ()
testDav url (Just (u, p)) = do
showAction "testing WebDAV server"
test $ liftIO $ evalDAVT url $ do
prepDAV user pass
makeParentDirs
void $ mkColRecursive tmpDir
inLocation (tmpLocation "git-annex-test") $ do
putContentM (Nothing, L8.fromString "test")
delContentM
where
test a = liftIO $
either (\e -> throwIO $ "WebDAV test failed: " ++ show e)
(const noop)
=<< tryNonAsync a
user = toDavUser u
pass = toDavPass p
testDav _ Nothing = error "Need to configure webdav username and password."
{- Tries to make all the parent directories in the WebDAV urls's path,
- right down to the root.
-
- Ignores any failures, which can occur for reasons including the WebDAV
- server only serving up WebDAV in a subdirectory. -}
makeParentDirs :: DAVT IO ()
makeParentDirs = go
where
go = do
l <- getDAVLocation
case locationParent l of
Nothing -> noop
Just p -> void $ safely $ inDAVLocation (const p) go
void $ safely mkCol
{- Checks if the directory exists. If not, tries to create its
- parent directories, all the way down to the root, and finally creates
- it. -}
mkColRecursive :: DavLocation -> DAVT IO Bool
mkColRecursive d = go =<< existsDAV d
where
go (Right True) = return True
go _ = ifM (inLocation d mkCol)
( return True
, do
case locationParent d of
Nothing -> makeParentDirs
Just parent -> void (mkColRecursive parent)
inLocation d mkCol
)
getCreds :: RemoteConfig -> RemoteGitConfig -> UUID -> Annex (Maybe CredPair)
getCreds c gc u = getRemoteCredPairFor "webdav" c gc (davCreds u)
davCreds :: UUID -> CredPairStorage
davCreds u = CredPairStorage
{ credPairFile = fromUUID u
, credPairEnvironment = ("WEBDAV_USERNAME", "WEBDAV_PASSWORD")
, credPairRemoteKey = Just "davcreds"
}
{- Content-Type to use for files uploaded to WebDAV. -}
contentType :: Maybe B8.ByteString
contentType = Just $ B8.fromString "application/octet-stream"
throwIO :: String -> IO a
throwIO msg = ioError $ mkIOError userErrorType msg Nothing Nothing
moveDAV :: URLString -> DavLocation -> DavLocation -> DAVT IO ()
moveDAV baseurl src dest = inLocation src $ moveContentM newurl
where
newurl = B8.fromString (locationUrl baseurl dest)
existsDAV :: DavLocation -> DAVT IO (Either String Bool)
existsDAV l = inLocation l check `catchNonAsync` (\e -> return (Left $ show e))
where
check = do
-- Some DAV services only support depth of 1, and
-- more depth is certainly not needed to check if a
-- location exists.
setDepth (Just Depth1)
catchJust missinghttpstatus
(getPropsM >> ispresent True)
(const $ ispresent False)
ispresent = return . Right
missinghttpstatus e =
matchStatusCodeException (== notFound404) e
<|> matchHttpExceptionContent toomanyredirects e
toomanyredirects (TooManyRedirects _) = True
toomanyredirects _ = False
safely :: DAVT IO a -> DAVT IO (Maybe a)
safely = eitherToMaybe <$$> tryNonAsync
choke :: IO (Either String a) -> IO a
choke f = do
x <- f
case x of
Left e -> error e
Right r -> return r
data DavHandle = DavHandle DAVContext DavUser DavPass URLString
withDAVHandle :: Remote -> (Maybe DavHandle -> Annex a) -> Annex a
withDAVHandle r a = do
mcreds <- getCreds (config r) (gitconfig r) (uuid r)
case (mcreds, configUrl r) of
(Just (user, pass), Just baseurl) ->
withDAVContext baseurl $ \ctx ->
a (Just (DavHandle ctx (toDavUser user) (toDavPass pass) baseurl))
_ -> a Nothing
goDAV :: DavHandle -> DAVT IO a -> IO a
goDAV (DavHandle ctx user pass _) a = choke $ run $ prettifyExceptions $ do
prepDAV user pass
a
where
run = fst <$$> runDAVContext ctx
{- Catch StatusCodeException and trim it to only the statusMessage part,
- eliminating a lot of noise, which can include the whole request that
- failed. The rethrown exception is no longer a StatusCodeException. -}
#if MIN_VERSION_http_client(0,5,0)
prettifyExceptions :: DAVT IO a -> DAVT IO a
prettifyExceptions a = catchJust (matchStatusCodeException (const True)) a go
where
go (HttpExceptionRequest _ (StatusCodeException response message)) = error $ unwords
[ "DAV failure:"
, show (responseStatus response)
, show (message)
]
go e = throwM e
#else
prettifyExceptions :: DAVT IO a -> DAVT IO a
prettifyExceptions a = catchJust (matchStatusCodeException (const True)) a go
where
go (StatusCodeException status _ _) = error $ unwords
[ "DAV failure:"
, show (statusCode status)
, show (statusMessage status)
]
go e = throwM e
#endif
prepDAV :: DavUser -> DavPass -> DAVT IO ()
prepDAV user pass = do
setResponseTimeout Nothing -- disable default (5 second!) timeout
setCreds user pass
--
-- Legacy chunking code, to be removed eventually.
--
storeLegacyChunked :: ChunkSize -> Key -> DavHandle -> L.ByteString -> IO Bool
storeLegacyChunked chunksize k dav b =
Legacy.storeChunks k tmp dest storer recorder finalizer
where
storehttp l b' = void $ goDAV dav $ do
maybe noop (void . mkColRecursive) (locationParent l)
inLocation l $ putContentM (contentType, b')
storer locs = Legacy.storeChunked chunksize locs storehttp b
recorder l s = storehttp l (L8.fromString s)
finalizer tmp' dest' = goDAV dav $
finalizeStore dav tmp' (fromJust $ locationParent dest')
tmp = addTrailingPathSeparator $ keyTmpLocation k
dest = keyLocation k
retrieveLegacyChunked :: DavHandle -> Retriever
retrieveLegacyChunked dav = fileRetriever $ \d k p -> liftIO $
withStoredFilesLegacyChunked k dav onerr $ \locs ->
Legacy.meteredWriteFileChunks p d locs $ \l ->
goDAV dav $
inLocation l $
snd <$> getContentM
where
onerr = error "download failed"
checkKeyLegacyChunked :: DavHandle -> CheckPresent
checkKeyLegacyChunked dav k = liftIO $
either error id <$> withStoredFilesLegacyChunked k dav onerr check
where
check [] = return $ Right True
check (l:ls) = do
v <- goDAV dav $ existsDAV l
if v == Right True
then check ls
else return v
{- Failed to read the chunkcount file; see if it's missing,
- or if there's a problem accessing it,
- or perhaps this was an intermittent error. -}
onerr f = do
v <- goDAV dav $ existsDAV f
return $ if v == Right True
then Left $ "failed to read " ++ f
else v
withStoredFilesLegacyChunked
:: Key
-> DavHandle
-> (DavLocation -> IO a)
-> ([DavLocation] -> IO a)
-> IO a
withStoredFilesLegacyChunked k dav onerr a = do
let chunkcount = keyloc ++ Legacy.chunkCount
v <- goDAV dav $ safely $
inLocation chunkcount $
snd <$> getContentM
case v of
Just s -> a $ Legacy.listChunks keyloc $ L8.toString s
Nothing -> do
chunks <- Legacy.probeChunks keyloc $ \f ->
(== Right True) <$> goDAV dav (existsDAV f)
if null chunks
then onerr chunkcount
else a chunks
where
keyloc = keyLocation k