429 lines
14 KiB
Haskell
429 lines
14 KiB
Haskell
{- git-annex ssh interface, with connection caching
|
|
-
|
|
- Copyright 2012-2017 Joey Hess <id@joeyh.name>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
{-# LANGUAGE CPP #-}
|
|
|
|
module Annex.Ssh (
|
|
ConsumeStdin(..),
|
|
SshCommand,
|
|
sshCommand,
|
|
sshOptions,
|
|
sshCacheDir,
|
|
sshReadPort,
|
|
forceSshCleanup,
|
|
sshOptionsEnv,
|
|
sshOptionsTo,
|
|
inRepoWithSshOptionsTo,
|
|
runSshOptions,
|
|
sshAskPassEnv,
|
|
runSshAskPass
|
|
) where
|
|
|
|
import Annex.Common
|
|
import Annex.LockFile
|
|
import qualified BuildInfo
|
|
import qualified Annex
|
|
import qualified Git
|
|
import qualified Git.Url
|
|
import Config
|
|
import Annex.Path
|
|
import Utility.Env
|
|
import Utility.FileSystemEncoding
|
|
import Utility.Hash
|
|
import Types.CleanupActions
|
|
import Types.Concurrency
|
|
import Git.Env
|
|
import Git.Ssh
|
|
#ifndef mingw32_HOST_OS
|
|
import Annex.Perms
|
|
import Annex.LockPool
|
|
#endif
|
|
|
|
import Control.Concurrent.STM
|
|
|
|
{- Some ssh commands are fed stdin on a pipe and so should be allowed to
|
|
- consume it. But ssh commands that are not piped stdin should generally
|
|
- not be allowed to consume the process's stdin. -}
|
|
data ConsumeStdin = ConsumeStdin | NoConsumeStdin
|
|
|
|
{- Generates a command to ssh to a given host (or user@host) on a given
|
|
- port. This includes connection caching parameters, and any ssh-options.
|
|
- If GIT_SSH or GIT_SSH_COMMAND is enabled, they are used instead. -}
|
|
sshCommand :: ConsumeStdin -> (SshHost, Maybe SshPort) -> RemoteGitConfig -> SshCommand -> Annex (FilePath, [CommandParam])
|
|
sshCommand cs (host, port) gc remotecmd = ifM (liftIO safe_GIT_SSH)
|
|
( maybe go return
|
|
=<< liftIO (gitSsh' host port remotecmd (consumeStdinParams cs))
|
|
, go
|
|
)
|
|
where
|
|
go = do
|
|
ps <- sshOptions cs (host, port) gc []
|
|
return ("ssh", Param (fromSshHost host):ps++[Param remotecmd])
|
|
|
|
{- Generates parameters to ssh to a given host (or user@host) on a given
|
|
- port. This includes connection caching parameters, and any
|
|
- ssh-options. Note that the host to ssh to and the command to run
|
|
- are not included in the returned options. -}
|
|
sshOptions :: ConsumeStdin -> (SshHost, Maybe Integer) -> RemoteGitConfig -> [CommandParam] -> Annex [CommandParam]
|
|
sshOptions cs (host, port) gc opts = go =<< sshCachingInfo (host, port)
|
|
where
|
|
go (Nothing, params) = return $ mkparams cs params
|
|
go (Just socketfile, params) = do
|
|
prepSocket socketfile host (mkparams NoConsumeStdin params)
|
|
|
|
return $ mkparams cs params
|
|
mkparams cs' ps = concat
|
|
[ ps
|
|
, map Param (remoteAnnexSshOptions gc)
|
|
, opts
|
|
, portParams port
|
|
, consumeStdinParams cs'
|
|
, [Param "-T"]
|
|
]
|
|
|
|
{- Due to passing -n to GIT_SSH and GIT_SSH_COMMAND, some settings
|
|
- of those that expect exactly git's parameters will break. So only
|
|
- use those if the user set GIT_ANNEX_USE_GIT_SSH to say it's ok. -}
|
|
safe_GIT_SSH :: IO Bool
|
|
safe_GIT_SSH = (== Just "1") <$> getEnv "GIT_ANNEX_USE_GIT_SSH"
|
|
|
|
consumeStdinParams :: ConsumeStdin -> [CommandParam]
|
|
consumeStdinParams ConsumeStdin = []
|
|
consumeStdinParams NoConsumeStdin = [Param "-n"]
|
|
|
|
{- Returns a filename to use for a ssh connection caching socket, and
|
|
- parameters to enable ssh connection caching. -}
|
|
sshCachingInfo :: (SshHost, Maybe Integer) -> Annex (Maybe FilePath, [CommandParam])
|
|
sshCachingInfo (host, port) = go =<< sshCacheDir
|
|
where
|
|
go Nothing = return (Nothing, [])
|
|
go (Just dir) =
|
|
liftIO (bestSocketPath $ dir </> hostport2socket host port) >>= return . \case
|
|
Nothing -> (Nothing, [])
|
|
Just socketfile -> (Just socketfile, sshConnectionCachingParams socketfile)
|
|
|
|
{- Given an absolute path to use for a socket file,
|
|
- returns whichever is shorter of that or the relative path to the same
|
|
- file.
|
|
-
|
|
- If no path can be constructed that is a valid socket, returns Nothing. -}
|
|
bestSocketPath :: FilePath -> IO (Maybe FilePath)
|
|
bestSocketPath abssocketfile = do
|
|
relsocketfile <- liftIO $ relPathCwdToFile abssocketfile
|
|
let socketfile = if length abssocketfile <= length relsocketfile
|
|
then abssocketfile
|
|
else relsocketfile
|
|
return $ if valid_unix_socket_path (socketfile ++ sshgarbage)
|
|
then Just socketfile
|
|
else Nothing
|
|
where
|
|
-- ssh appends a 16 char extension to the socket when setting it
|
|
-- up, which needs to be taken into account when checking
|
|
-- that a valid socket was constructed.
|
|
sshgarbage = replicate (1+16) 'X'
|
|
|
|
sshConnectionCachingParams :: FilePath -> [CommandParam]
|
|
sshConnectionCachingParams socketfile =
|
|
[ Param "-S", Param socketfile
|
|
, Param "-o", Param "ControlMaster=auto"
|
|
, Param "-o", Param "ControlPersist=yes"
|
|
]
|
|
|
|
{- ssh connection caching creates sockets, so will not work on a
|
|
- crippled filesystem. A GIT_ANNEX_TMP_DIR can be provided to use
|
|
- a different filesystem. -}
|
|
sshCacheDir :: Annex (Maybe FilePath)
|
|
sshCacheDir
|
|
| BuildInfo.sshconnectioncaching =
|
|
ifM (fromMaybe True . annexSshCaching <$> Annex.getGitConfig)
|
|
( ifM crippledFileSystem
|
|
( maybe (return Nothing) usetmpdir =<< gettmpdir
|
|
, Just <$> fromRepo gitAnnexSshDir
|
|
)
|
|
, return Nothing
|
|
)
|
|
| otherwise = return Nothing
|
|
where
|
|
gettmpdir = liftIO $ getEnv "GIT_ANNEX_TMP_DIR"
|
|
usetmpdir tmpdir = liftIO $ catchMaybeIO $ do
|
|
let socktmp = tmpdir </> "ssh"
|
|
createDirectoryIfMissing True socktmp
|
|
return socktmp
|
|
|
|
portParams :: Maybe Integer -> [CommandParam]
|
|
portParams Nothing = []
|
|
portParams (Just port) = [Param "-p", Param $ show port]
|
|
|
|
{- Prepare to use a socket file for ssh connection caching.
|
|
-
|
|
- When concurrency is enabled, this blocks until a ssh connection
|
|
- has been made to the host. So, any password prompting by ssh will
|
|
- happen in this call, and only one ssh process will prompt at a time.
|
|
-
|
|
- Locks the socket lock file to prevent other git-annex processes from
|
|
- stopping the ssh multiplexer on this socket.
|
|
-}
|
|
prepSocket :: FilePath -> SshHost -> [CommandParam] -> Annex ()
|
|
prepSocket socketfile sshhost sshparams = do
|
|
-- There could be stale ssh connections hanging around
|
|
-- from a previous git-annex run that was interrupted.
|
|
-- This must run only once, before we have made any ssh connection,
|
|
-- and any other prepSocket calls must block while it's run.
|
|
tv <- Annex.getState Annex.sshstalecleaned
|
|
join $ liftIO $ atomically $ do
|
|
cleaned <- takeTMVar tv
|
|
if cleaned
|
|
then do
|
|
putTMVar tv cleaned
|
|
return noop
|
|
else return $ do
|
|
sshCleanup
|
|
liftIO $ atomically $ putTMVar tv True
|
|
-- Cleanup at shutdown.
|
|
Annex.addCleanup SshCachingCleanup sshCleanup
|
|
|
|
liftIO $ createDirectoryIfMissing True $ parentDir socketfile
|
|
let socketlock = socket2lock socketfile
|
|
|
|
Annex.getState Annex.concurrency >>= \case
|
|
Concurrent {} -> makeconnection socketlock
|
|
_ -> return ()
|
|
|
|
lockFileCached socketlock
|
|
where
|
|
-- When the LockCache already has the socketlock in it,
|
|
-- the connection has already been started. Otherwise,
|
|
-- get the connection started now.
|
|
makeconnection socketlock = debugLocks $
|
|
whenM (isNothing <$> fromLockCache socketlock) $
|
|
-- See if ssh can connect in batch mode,
|
|
-- if so there's no need to block for a password
|
|
-- prompt.
|
|
unlessM (tryssh ["-o", "BatchMode=true"]) $
|
|
-- ssh needs to prompt (probably)
|
|
-- If the user enters the wrong password,
|
|
-- ssh will tell them, so we can ignore
|
|
-- failure.
|
|
void $ prompt $ tryssh []
|
|
-- Try to ssh to the host quietly. Returns True if ssh apparently
|
|
-- connected to the host successfully. If ssh failed to connect,
|
|
-- returns False.
|
|
-- Even if ssh is forced to run some specific command, this will
|
|
-- return True.
|
|
-- (Except there's an unlikely false positive where a forced
|
|
-- ssh command exits 255.)
|
|
tryssh extraps = liftIO $ withNullHandle $ \nullh -> do
|
|
let p = proc "ssh" $ concat
|
|
[ extraps
|
|
, toCommand sshparams
|
|
, [fromSshHost sshhost, "true"]
|
|
]
|
|
(Nothing, Nothing, Nothing, pid) <- createProcess $ p
|
|
{ std_out = UseHandle nullh
|
|
, std_err = UseHandle nullh
|
|
}
|
|
exitcode <- waitForProcess pid
|
|
return $ case exitcode of
|
|
ExitFailure 255 -> False
|
|
_ -> True
|
|
|
|
{- Find ssh socket files.
|
|
-
|
|
- The check that the lock file exists makes only socket files
|
|
- that were set up by prepSocket be found. On some NFS systems,
|
|
- a deleted socket file may linger for a while under another filename;
|
|
- and this check makes such files be skipped since the corresponding lock
|
|
- file won't exist.
|
|
-}
|
|
enumSocketFiles :: Annex [FilePath]
|
|
enumSocketFiles = liftIO . go =<< sshCacheDir
|
|
where
|
|
go Nothing = return []
|
|
go (Just dir) = filterM (doesFileExist . socket2lock)
|
|
=<< filter (not . isLock)
|
|
<$> catchDefaultIO [] (dirContents dir)
|
|
|
|
{- Stop any unused ssh connection caching processes. -}
|
|
sshCleanup :: Annex ()
|
|
sshCleanup = mapM_ cleanup =<< enumSocketFiles
|
|
where
|
|
cleanup socketfile = do
|
|
#ifndef mingw32_HOST_OS
|
|
-- Drop any shared lock we have, and take an
|
|
-- exclusive lock, without blocking. If the lock
|
|
-- succeeds, nothing is using this ssh, and it can
|
|
-- be stopped.
|
|
--
|
|
-- After ssh is stopped cannot remove the lock file;
|
|
-- other processes may be waiting on our exclusive
|
|
-- lock to use it.
|
|
let lockfile = socket2lock socketfile
|
|
unlockFile lockfile
|
|
mode <- annexFileMode
|
|
noUmask mode (tryLockExclusive (Just mode) lockfile) >>= \case
|
|
Nothing -> noop
|
|
Just lck -> do
|
|
forceStopSsh socketfile
|
|
liftIO $ dropLock lck
|
|
#else
|
|
forceStopSsh socketfile
|
|
#endif
|
|
|
|
{- Stop all ssh connection caching processes, even when they're in use. -}
|
|
forceSshCleanup :: Annex ()
|
|
forceSshCleanup = mapM_ forceStopSsh =<< enumSocketFiles
|
|
|
|
forceStopSsh :: FilePath -> Annex ()
|
|
forceStopSsh socketfile = do
|
|
let (dir, base) = splitFileName socketfile
|
|
let params = sshConnectionCachingParams base
|
|
-- "ssh -O stop" is noisy on stderr even with -q
|
|
void $ liftIO $ catchMaybeIO $
|
|
withQuietOutput createProcessSuccess $
|
|
(proc "ssh" $ toCommand $
|
|
[ Param "-O", Param "stop" ] ++
|
|
params ++ [Param "localhost"])
|
|
{ cwd = Just dir }
|
|
liftIO $ nukeFile socketfile
|
|
|
|
{- This needs to be as short as possible, due to limitations on the length
|
|
- of the path to a socket file. At the same time, it needs to be unique
|
|
- for each host.
|
|
-}
|
|
hostport2socket :: SshHost -> Maybe Integer -> FilePath
|
|
hostport2socket host Nothing = hostport2socket' $ fromSshHost host
|
|
hostport2socket host (Just port) = hostport2socket' $
|
|
fromSshHost host ++ "!" ++ show port
|
|
hostport2socket' :: String -> FilePath
|
|
hostport2socket' s
|
|
| length s > lengthofmd5s = show $ md5 $ encodeBS s
|
|
| otherwise = s
|
|
where
|
|
lengthofmd5s = 32
|
|
|
|
socket2lock :: FilePath -> FilePath
|
|
socket2lock socket = socket ++ lockExt
|
|
|
|
isLock :: FilePath -> Bool
|
|
isLock f = lockExt `isSuffixOf` f
|
|
|
|
lockExt :: String
|
|
lockExt = ".lock"
|
|
|
|
{- This is the size of the sun_path component of sockaddr_un, which
|
|
- is the limit to the total length of the filename of a unix socket.
|
|
-
|
|
- On Linux, this is 108. On OSX, 104. TODO: Probe
|
|
-}
|
|
sizeof_sockaddr_un_sun_path :: Int
|
|
sizeof_sockaddr_un_sun_path = 100
|
|
|
|
{- Note that this looks at the true length of the path in bytes, as it will
|
|
- appear on disk. -}
|
|
valid_unix_socket_path :: FilePath -> Bool
|
|
valid_unix_socket_path f = length (decodeW8 f) < sizeof_sockaddr_un_sun_path
|
|
|
|
{- Parses the SSH port, and returns the other OpenSSH options. If
|
|
- several ports are found, the last one takes precedence. -}
|
|
sshReadPort :: [String] -> (Maybe Integer, [String])
|
|
sshReadPort params = (port, reverse args)
|
|
where
|
|
(port,args) = aux (Nothing, []) params
|
|
aux (p,ps) [] = (p,ps)
|
|
aux (_,ps) ("-p":p:rest) = aux (readPort p, ps) rest
|
|
aux (p,ps) (q:rest) | "-p" `isPrefixOf` q = aux (readPort $ drop 2 q, ps) rest
|
|
| otherwise = aux (p,q:ps) rest
|
|
readPort p = fmap fst $ listToMaybe $ reads p
|
|
|
|
{- When this env var is set, git-annex runs ssh with the specified
|
|
- options. (The options are separated by newlines.)
|
|
-
|
|
- This is a workaround for GIT_SSH not being able to contain
|
|
- additional parameters to pass to ssh. (GIT_SSH_COMMAND can,
|
|
- but is not supported by older versions of git.) -}
|
|
sshOptionsEnv :: String
|
|
sshOptionsEnv = "GIT_ANNEX_SSHOPTION"
|
|
|
|
toSshOptionsEnv :: [CommandParam] -> String
|
|
toSshOptionsEnv = unlines . toCommand
|
|
|
|
fromSshOptionsEnv :: String -> [CommandParam]
|
|
fromSshOptionsEnv = map Param . lines
|
|
|
|
{- Enables ssh caching for git push/pull to a particular
|
|
- remote git repo. (Can safely be used on non-ssh remotes.)
|
|
-
|
|
- Also propigates any configured ssh-options.
|
|
-
|
|
- Like inRepo, the action is run with the local git repo.
|
|
- But here it's a modified version, with gitEnv to set GIT_SSH=git-annex,
|
|
- and sshOptionsEnv set so that git-annex will know what socket
|
|
- file to use. -}
|
|
inRepoWithSshOptionsTo :: Git.Repo -> RemoteGitConfig -> (Git.Repo -> IO a) -> Annex a
|
|
inRepoWithSshOptionsTo remote gc a =
|
|
liftIO . a =<< sshOptionsTo remote gc =<< gitRepo
|
|
|
|
{- To make any git commands be run with ssh caching enabled,
|
|
- and configured ssh-options alters the local Git.Repo's gitEnv
|
|
- to set GIT_SSH=git-annex, and set sshOptionsEnv when running git
|
|
- commands.
|
|
-
|
|
- If GIT_SSH or GIT_SSH_COMMAND are enabled, this has no effect. -}
|
|
sshOptionsTo :: Git.Repo -> RemoteGitConfig -> Git.Repo -> Annex Git.Repo
|
|
sshOptionsTo remote gc localr
|
|
| not (Git.repoIsUrl remote) || Git.repoIsHttp remote = unchanged
|
|
| otherwise = case Git.Url.hostuser remote of
|
|
Nothing -> unchanged
|
|
Just host -> ifM (liftIO $ safe_GIT_SSH <&&> gitSshEnvSet)
|
|
( unchanged
|
|
, do
|
|
let port = Git.Url.port remote
|
|
let sshhost = either error id (mkSshHost host)
|
|
(msockfile, cacheparams) <- sshCachingInfo (sshhost, port)
|
|
case msockfile of
|
|
Nothing -> use []
|
|
Just sockfile -> do
|
|
prepSocket sockfile sshhost $ concat
|
|
[ cacheparams
|
|
, map Param (remoteAnnexSshOptions gc)
|
|
, portParams port
|
|
, consumeStdinParams NoConsumeStdin
|
|
, [Param "-T"]
|
|
]
|
|
use cacheparams
|
|
)
|
|
where
|
|
unchanged = return localr
|
|
|
|
use opts = do
|
|
let sshopts = concat
|
|
[ opts
|
|
, map Param (remoteAnnexSshOptions gc)
|
|
]
|
|
if null sshopts
|
|
then unchanged
|
|
else do
|
|
command <- liftIO programPath
|
|
liftIO $ do
|
|
localr' <- addGitEnv localr sshOptionsEnv
|
|
(toSshOptionsEnv sshopts)
|
|
addGitEnv localr' gitSshEnv command
|
|
|
|
runSshOptions :: [String] -> String -> IO ()
|
|
runSshOptions args s = do
|
|
let args' = toCommand (fromSshOptionsEnv s) ++ args
|
|
let p = proc "ssh" args'
|
|
exitWith =<< waitForProcess . processHandle =<< createProcess p
|
|
|
|
{- When this env var is set, git-annex is being used as a ssh-askpass
|
|
- program, and should read the password from the specified location,
|
|
- and output it for ssh to read. -}
|
|
sshAskPassEnv :: String
|
|
sshAskPassEnv = "GIT_ANNEX_SSHASKPASS"
|
|
|
|
runSshAskPass :: FilePath -> IO ()
|
|
runSshAskPass passfile = putStrLn =<< readFile passfile
|