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|
{- git-annex-shell main program
-
- Copyright 2010-2012 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module CmdLine.GitAnnexShell where
import System.Environment
import Common.Annex
import qualified Git.Construct
import qualified Git.Config
import CmdLine
import CmdLine.GlobalSetter
import Command
import Annex.UUID
import CmdLine.GitAnnexShell.Fields
import Utility.UserInfo
import Remote.GCrypt (getGCryptUUID)
import qualified Annex
import Annex.Init
import qualified Command.ConfigList
import qualified Command.InAnnex
import qualified Command.DropKey
import qualified Command.RecvKey
import qualified Command.SendKey
import qualified Command.TransferInfo
import qualified Command.Commit
import qualified Command.NotifyChanges
import qualified Command.GCryptSetup
cmds_readonly :: [Command]
cmds_readonly =
[ gitAnnexShellCheck Command.ConfigList.cmd
, gitAnnexShellCheck Command.InAnnex.cmd
, gitAnnexShellCheck Command.SendKey.cmd
, gitAnnexShellCheck Command.TransferInfo.cmd
, gitAnnexShellCheck Command.NotifyChanges.cmd
]
cmds_notreadonly :: [Command]
cmds_notreadonly =
[ gitAnnexShellCheck Command.RecvKey.cmd
, gitAnnexShellCheck Command.DropKey.cmd
, gitAnnexShellCheck Command.Commit.cmd
, Command.GCryptSetup.cmd
]
cmds :: [Command]
cmds = map adddirparam $ cmds_readonly ++ cmds_notreadonly
where
adddirparam c = c { cmdparamdesc = "DIRECTORY " ++ cmdparamdesc c }
globalOptions :: [GlobalOption]
globalOptions =
globalSetter checkUUID (strOption
( long "uuid" <> metavar paramUUID
<> help "local repository uuid"
))
: commonGlobalOptions
where
checkUUID expected = getUUID >>= check
where
check u | u == toUUID expected = noop
check NoUUID = checkGCryptUUID expected
check u = unexpectedUUID expected u
checkGCryptUUID expected = check =<< getGCryptUUID True =<< gitRepo
where
check (Just u) | u == toUUID expected = noop
check Nothing = unexpected expected "uninitialized repository"
check (Just u) = unexpectedUUID expected u
unexpectedUUID expected u = unexpected expected $ "UUID " ++ fromUUID u
unexpected expected s = error $
"expected repository UUID " ++ expected ++ " but found " ++ s
run :: [String] -> IO ()
run [] = failure
-- skip leading -c options, passed by eg, ssh
run ("-c":p) = run p
-- a command can be either a builtin or something to pass to git-shell
run c@(cmd:dir:params)
| cmd `elem` builtins = builtin cmd dir params
| otherwise = external c
run c@(cmd:_)
-- Handle the case of being the user's login shell. It will be passed
-- a single string containing all the real parameters.
| "git-annex-shell " `isPrefixOf` cmd = run $ drop 1 $ shellUnEscape cmd
| cmd `elem` builtins = failure
| otherwise = external c
builtins :: [String]
builtins = map cmdname cmds
builtin :: String -> String -> [String] -> IO ()
builtin cmd dir params = do
checkNotReadOnly cmd
checkDirectory $ Just dir
let (params', fieldparams, opts) = partitionParams params
rsyncopts = ("RsyncOptions", unwords opts)
fields = rsyncopts : filter checkField (parseFields fieldparams)
dispatch False (cmd : params') cmds globalOptions fields mkrepo
"git-annex-shell"
"Restricted login shell for git-annex only SSH access"
where
mkrepo = do
r <- Git.Construct.repoAbsPath dir >>= Git.Construct.fromAbsPath
Git.Config.read r
`catchIO` \_ -> do
hn <- fromMaybe "unknown" <$> getHostname
error $ "failed to read git config of git repository in " ++ hn ++ " on " ++ dir ++ "; perhaps this repository is not set up correctly or has moved"
external :: [String] -> IO ()
external params = do
{- Normal git-shell commands all have the directory as their last
- parameter. -}
let lastparam = lastMaybe =<< shellUnEscape <$> lastMaybe params
(params', _, _) = partitionParams params
checkDirectory lastparam
checkNotLimited
unlessM (boolSystem "git-shell" $ map Param $ "-c":params') $
error "git-shell failed"
{- Split the input list into 3 groups separated with a double dash --.
- Parameters between two -- markers are field settings, in the form:
- field=value field=value
-
- Parameters after the last -- are the command itself and its arguments e.g.,
- rsync --bandwidth=100.
-}
partitionParams :: [String] -> ([String], [String], [String])
partitionParams ps = case segment (== "--") ps of
params:fieldparams:rest -> ( params, fieldparams, intercalate ["--"] rest )
[params] -> (params, [], [])
_ -> ([], [], [])
parseFields :: [String] -> [(String, String)]
parseFields = map (separate (== '='))
{- Only allow known fields to be set, ignore others.
- Make sure that field values make sense. -}
checkField :: (String, String) -> Bool
checkField (field, val)
| field == fieldName remoteUUID = fieldCheck remoteUUID val
| field == fieldName associatedFile = fieldCheck associatedFile val
| field == fieldName direct = fieldCheck direct val
| otherwise = False
failure :: IO ()
failure = error $ "bad parameters\n\n" ++ usage h cmds
where
h = "git-annex-shell [-c] command [parameters ...] [option ...]"
checkNotLimited :: IO ()
checkNotLimited = checkEnv "GIT_ANNEX_SHELL_LIMITED"
checkNotReadOnly :: String -> IO ()
checkNotReadOnly cmd
| cmd `elem` map cmdname cmds_readonly = noop
| otherwise = checkEnv "GIT_ANNEX_SHELL_READONLY"
checkDirectory :: Maybe FilePath -> IO ()
checkDirectory mdir = do
v <- catchMaybeIO $ getEnv "GIT_ANNEX_SHELL_DIRECTORY"
case (v, mdir) of
(Nothing, _) -> noop
(Just d, Nothing) -> req d Nothing
(Just d, Just dir)
| d `equalFilePath` dir -> noop
| otherwise -> do
home <- myHomeDir
d' <- canondir home d
dir' <- canondir home dir
if d' `equalFilePath` dir'
then noop
else req d' (Just dir')
where
req d mdir' = error $ unwords
[ "Only allowed to access"
, d
, maybe "and could not determine directory from command line" ("not " ++) mdir'
]
{- A directory may start with ~/ or in some cases, even /~/,
- or could just be relative to home, or of course could
- be absolute. -}
canondir home d
| "~/" `isPrefixOf` d = return d
| "/~/" `isPrefixOf` d = return $ drop 1 d
| otherwise = relHome $ absPathFrom home d
checkEnv :: String -> IO ()
checkEnv var = do
v <- catchMaybeIO $ getEnv var
case v of
Nothing -> noop
Just "" -> noop
Just _ -> error $ "Action blocked by " ++ var
{- Modifies a Command to check that it is run in either a git-annex
- repository, or a repository with a gcrypt-id set. -}
gitAnnexShellCheck :: Command -> Command
gitAnnexShellCheck = addCheck okforshell . dontCheck repoExists
where
okforshell = unlessM (isInitialized <||> isJust . gcryptId <$> Annex.getGitConfig) $
error "Not a git-annex or gcrypt repository."
|
