git-annex/CmdLine/GitAnnexShell.hs
2024-06-11 13:07:04 -04:00

213 lines
7.1 KiB
Haskell

{- git-annex-shell main program
-
- Copyright 2010-2024 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module CmdLine.GitAnnexShell where
import Annex.Common
import qualified Annex
import qualified Git.Construct
import qualified Git.Config
import CmdLine
import CmdLine.AnnexSetter
import Command
import Annex.UUID
import CmdLine.GitAnnexShell.Checks
import CmdLine.GitAnnexShell.Fields
import Remote.GCrypt (getGCryptUUID)
import P2P.Protocol (ServerMode(..))
import Git.Types
import Logs.Proxy
import Logs.UUID
import Remote
import qualified Command.ConfigList
import qualified Command.NotifyChanges
import qualified Command.GCryptSetup
import qualified Command.P2PStdIO
import qualified Command.InAnnex
import qualified Command.RecvKey
import qualified Command.SendKey
import qualified Command.DropKey
import qualified Data.Map as M
import qualified Data.Set as S
cmdsMap :: M.Map ServerMode [Command]
cmdsMap = M.fromList $ map mk
[ (ServeReadOnly, readonlycmds)
, (ServeAppendOnly, appendcmds)
, (ServeReadWrite, allcmds)
]
where
readonlycmds = map addAnnexOptions
[ notProxyable Command.ConfigList.cmd
, gitAnnexShellCheck Command.NotifyChanges.cmd
-- p2pstdio checks the environment variables to
-- determine the security policy to use, so is safe to
-- include in the readonly list even though it is not
-- always readonly
, gitAnnexShellCheck Command.P2PStdIO.cmd
, notProxyable (gitAnnexShellCheck Command.InAnnex.cmd)
, notProxyable (gitAnnexShellCheck Command.SendKey.cmd)
]
appendcmds = readonlycmds ++ map addAnnexOptions
[ notProxyable (gitAnnexShellCheck Command.RecvKey.cmd)
]
allcmds = appendcmds ++ map addAnnexOptions
[ notProxyable (gitAnnexShellCheck Command.DropKey.cmd)
, notProxyable Command.GCryptSetup.cmd
]
mk (s, l) = (s, map (adddirparam . noMessages) l)
adddirparam c = c { cmdparamdesc = "DIRECTORY " ++ cmdparamdesc c }
cmdsFor :: ServerMode -> [Command]
cmdsFor = fromMaybe [] . flip M.lookup cmdsMap
cmdsList :: [Command]
cmdsList = nub $ concat $ M.elems cmdsMap
addAnnexOptions :: Command -> Command
addAnnexOptions c = c { cmdannexoptions = commonShellOptions ++ cmdannexoptions c }
commonShellOptions :: [AnnexOption]
commonShellOptions =
annexOption (setAnnexState . checkUUID) (strOption
( long "uuid" <> metavar paramUUID
<> help "local repository uuid"
))
: commonOptions
where
checkUUID expected = getUUID >>= check
where
check NoUUID = checkGCryptUUID expected
check u
| u == toUUID expected = noop
| otherwise =
unlessM (checkProxy (toUUID expected) 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 = giveup $
"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
failure :: IO ()
failure = giveup $ "bad parameters\n\n" ++ usage h cmdsList
where
h = "git-annex-shell [-c] command [parameters ...] [option ...]"
builtins :: [String]
builtins = map cmdname cmdsList
builtin :: String -> String -> [String] -> IO ()
builtin cmd dir params = do
unless (cmd `elem` map cmdname (cmdsFor ServeReadOnly))
checkNotReadOnly
unless (cmd `elem` map cmdname (cmdsFor ServeAppendOnly))
checkNotAppendOnly
checkDirectory $ Just dir
let (params', fieldparams, opts) = partitionParams params
rsyncopts = ("RsyncOptions", unwords opts)
fields = rsyncopts : filter checkField (parseFields fieldparams)
dispatch False False (cmd : params') cmdsList fields mkrepo
"git-annex-shell"
"Restricted login shell for git-annex only SSH access"
where
mkrepo = do
r <- Git.Construct.repoAbsPath (toRawFilePath dir)
>>= Git.Construct.fromAbsPath
let r' = r { repoPathSpecifiedExplicitly = True }
Git.Config.read r'
`catchIO` \_ -> do
hn <- fromMaybe "unknown" <$> getHostname
giveup $ "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') $
giveup "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 autoInit = fieldCheck autoInit val
| otherwise = False
{- Check if this repository can proxy for a specified remote uuid,
- and if so enable proxying for it. -}
checkProxy :: UUID -> UUID -> Annex Bool
checkProxy remoteuuid ouruuid = M.lookup ouruuid <$> getProxies >>= \case
Nothing -> return False
-- This repository has (or had) proxying enabled. So it's
-- ok to display error messages that talk about proxies.
Just proxies ->
case filter (\p -> proxyRemoteUUID p == remoteuuid) (S.toList proxies) of
[] -> notconfigured
ps -> do
-- This repository may have multiple
-- remotes that access the same repository.
-- Proxy for the lowest cost one that
-- is configured to be used as a proxy.
rs <- concat . byCost <$> remoteList
let sameuuid r = uuid r == remoteuuid
let samename r p = name r == proxyRemoteName p
case headMaybe (filter (\r -> sameuuid r && any (samename r) ps) rs) of
Nothing -> notconfigured
Just r -> do
Annex.changeState $ \st ->
st { Annex.proxyremote = Just r }
return True
where
notconfigured = M.lookup remoteuuid <$> uuidDescMap >>= \case
Just desc -> giveup $ "not configured to proxy for repository " ++ (fromUUIDDesc desc)
Nothing -> return False