git-annex/Annex/Perms.hs
Joey Hess e423190b11 fix
2013-02-24 17:40:14 -04:00

100 lines
3 KiB
Haskell

{- git-annex file permissions
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.Perms (
setAnnexPerm,
annexFileMode,
createAnnexDirectory,
noUmask,
createContentDir,
freezeContentDir,
) where
import Common.Annex
import Utility.FileMode
import Git.SharedRepository
import qualified Annex
import Config
import System.Posix.Types
withShared :: (SharedRepository -> Annex a) -> Annex a
withShared a = maybe startup a =<< Annex.getState Annex.shared
where
startup = do
shared <- fromRepo getSharedRepository
Annex.changeState $ \s -> s { Annex.shared = Just shared }
a shared
{- Sets appropriate file mode for a file or directory in the annex,
- other than the content files and content directory. Normally,
- use the default mode, but with core.sharedRepository set,
- allow the group to write, etc. -}
setAnnexPerm :: FilePath -> Annex ()
setAnnexPerm file = unlessM crippledFileSystem $
withShared $ liftIO . go
where
go GroupShared = groupWriteRead file
go AllShared = modifyFileMode file $ addModes $
[ ownerWriteMode, groupWriteMode ] ++ readModes
go _ = noop
{- Gets the appropriate mode to use for creating a file in the annex
- (other than content files, which are locked down more). -}
annexFileMode :: Annex FileMode
annexFileMode = withShared $ return . go
where
go GroupShared = sharedmode
go AllShared = combineModes (sharedmode:readModes)
go _ = stdFileMode
sharedmode = combineModes
[ ownerWriteMode, groupWriteMode
, ownerReadMode, groupReadMode
]
{- Creates a directory inside the gitAnnexDir, including any parent
- directories. Makes directories with appropriate permissions. -}
createAnnexDirectory :: FilePath -> Annex ()
createAnnexDirectory dir = traverse dir [] =<< top
where
top = parentDir <$> fromRepo gitAnnexDir
traverse d below stop
| d `equalFilePath` stop = done
| otherwise = ifM (liftIO $ doesDirectoryExist d)
( done
, traverse (parentDir d) (d:below) stop
)
where
done = forM_ below $ \p -> do
liftIO $ createDirectoryIfMissing True p
setAnnexPerm p
{- Blocks writing to the directory an annexed file is in, to prevent the
- file accidentially being deleted. However, if core.sharedRepository
- is set, this is not done, since the group must be allowed to delete the
- file.
-}
freezeContentDir :: FilePath -> Annex ()
freezeContentDir file = unlessM crippledFileSystem $
liftIO . go =<< fromRepo getSharedRepository
where
dir = parentDir file
go GroupShared = groupWriteRead dir
go AllShared = groupWriteRead dir
go _ = preventWrite dir
{- Makes the directory tree to store an annexed file's content,
- with appropriate permissions on each level. -}
createContentDir :: FilePath -> Annex ()
createContentDir dest = do
unlessM (liftIO $ doesDirectoryExist dir) $
createAnnexDirectory dir
-- might have already existed with restricted perms
unlessM crippledFileSystem $
liftIO $ allowWrite dir
where
dir = parentDir dest