module Ssh (
copySSH, SSHCmd(..), runSSH, getSSH,
environmentHelpSsh, environmentHelpScp, environmentHelpSshPort,
remoteDarcs
) where
import Prelude hiding ( lookup, catch )
import qualified Ratified( hGetContents )
import System.Exit ( ExitCode(..) )
import System.Environment ( getEnv )
#ifndef WIN32
import System.Posix.Process ( getProcessID )
#else
import Darcs.Utils ( showHexLen )
import Data.Bits ( (.&.) )
import System.Random ( randomIO )
#endif
import System.IO ( Handle, hSetBinaryMode, hPutStrLn, hGetLine, hFlush )
import System.IO.Unsafe ( unsafePerformIO )
import System.Directory ( doesFileExist, createDirectoryIfMissing )
import Control.Monad ( when )
import System.Process ( runInteractiveProcess )
import Data.Map ( Map, empty, insert, lookup )
import Data.IORef ( IORef, newIORef, readIORef, modifyIORef )
import Darcs.SignalHandler ( catchNonSignal )
import Darcs.Utils ( breakCommand, prettyException, catchall )
import Darcs.Global ( atexit, sshControlMasterDisabled, withDebugMode )
import Darcs.Lock ( tempdirLoc, removeFileMayNotExist )
import Darcs.URL (SshFilePath(..), urlOf)
import Exec ( exec, Redirects, Redirect(..), )
import Progress ( withoutProgress, debugMessage, debugFail )
import Darcs.Flags( RemoteDarcs(..) )
import qualified Data.ByteString as B (ByteString, hGet, writeFile )
sshConnections :: IORef (Map String (Maybe Connection))
sshConnections = unsafePerformIO $ newIORef empty
data Connection = C { inp :: !Handle, out :: !Handle, err :: !Handle, deb :: String -> IO () }
withSSHConnection :: String -> SshFilePath -> (Connection -> IO a) -> IO a -> IO a
withSSHConnection rdarcs repoid withconnection withoutconnection =
withoutProgress $
do cs <- readIORef sshConnections
case lookup (urlOf repoid) (cs :: Map String (Maybe Connection)) of
Just Nothing -> withoutconnection
Just (Just c) -> withconnection c
Nothing ->
do mc <- do (ssh,sshargs_) <- getSSHOnly SSH
let sshargs = sshargs_ ++ [sshUhost repoid, rdarcs,
"transfer-mode","--repodir",sshRepo repoid]
debugMessage $ "ssh "++unwords sshargs
(i,o,e,_) <- runInteractiveProcess ssh sshargs Nothing Nothing
hSetBinaryMode i True
hSetBinaryMode o True
l <- hGetLine o
if l == "Hello user, I am darcs transfer mode"
then return ()
else debugFail "Couldn't start darcs transfer-mode on server"
let c = C { inp = i, out = o, err = e,
deb = \s -> debugMessage ("with ssh (transfer-mode) "++sshUhost repoid++s) }
modifyIORef sshConnections (insert (urlOf repoid) (Just c))
return $ Just c
`catchNonSignal`
\e -> do debugMessage $ "Failed to start ssh connection:\n "++
prettyException e
severSSHConnection repoid
debugMessage $ unlines $
[ "NOTE: the server may be running a version of darcs prior to 2.0.0."
, ""
, "Installing darcs 2 on the server will speed up ssh-based commands."
]
return Nothing
maybe withoutconnection withconnection mc
severSSHConnection :: SshFilePath -> IO ()
severSSHConnection x = do debugMessage $ "Severing ssh failed connection to "++(sshUhost x)
modifyIORef sshConnections (insert (urlOf x) Nothing)
grabSSH :: SshFilePath -> Connection -> IO B.ByteString
grabSSH dest c = do
debugMessage $ "grabSSH dest=" ++ urlOf dest
let failwith e = do severSSHConnection dest
eee <- Ratified.hGetContents (err c)
debugFail $ e ++ " grabbing ssh file "++
urlOf dest++"/"++ file ++"\n"++eee
file = sshFile dest
deb c $ "get "++ file
hPutStrLn (inp c) $ "get " ++ file
hFlush (inp c)
l2 <- hGetLine (out c)
if l2 == "got "++file
then do showlen <- hGetLine (out c)
case reads showlen of
[(len,"")] -> B.hGet (out c) len
_ -> failwith "Couldn't get length"
else if l2 == "error "++file
then do e <- hGetLine (out c)
case reads e of
(msg,_):_ -> debugFail $ "Error reading file remotely:\n"++msg
[] -> failwith "An error occurred"
else failwith "Error"
sshStdErrMode :: IO Redirect
sshStdErrMode = withDebugMode $ \amdebugging ->
return $ if amdebugging then AsIs else Null
remoteDarcs :: RemoteDarcs -> String
remoteDarcs DefaultRemoteDarcs = "darcs"
remoteDarcs (RemoteDarcs x) = x
copySSH :: RemoteDarcs -> SshFilePath -> FilePath -> IO ()
copySSH remote dest to | rdarcs <- remoteDarcs remote = do
debugMessage $ "copySSH file: " ++ urlOf dest
withSSHConnection rdarcs dest (\c -> grabSSH dest c >>= B.writeFile to) $
do let u = escape_dollar $ urlOf dest
stderr_behavior <- sshStdErrMode
r <- runSSH SCP dest [u,to] (AsIs,AsIs,stderr_behavior)
when (r /= ExitSuccess) $
debugFail $ "(scp) failed to fetch: " ++ u
where
escape_dollar :: String -> String
escape_dollar = concatMap tr
where tr '$' = "\\$"
tr c = [c]
data SSHCmd = SSH | SCP | SFTP
instance Show SSHCmd where
show SSH = "ssh"
show SCP = "scp"
show SFTP = "sftp"
runSSH :: SSHCmd -> SshFilePath -> [String] -> Redirects -> IO ExitCode
runSSH cmd remoteAddr postArgs redirs =
do (ssh, args) <- getSSH cmd remoteAddr
exec ssh (args ++ [sshUhost remoteAddr] ++ postArgs) redirs
getSSH :: SSHCmd -> SshFilePath
-> IO (String, [String])
getSSH cmd remoteAddr =
do (ssh, ssh_args) <- getSSHOnly cmd
cm_args <- if sshControlMasterDisabled
then return []
else do
cmPath <- controlMasterPath remoteAddr
hasLaunchedCm <- doesFileExist cmPath
when (not hasLaunchedCm) $ launchSSHControlMaster remoteAddr
hasCmFeature <- doesFileExist cmPath
return $ if hasCmFeature then [ "-o ControlPath=" ++ cmPath ] else []
let verbosity = case cmd of
SCP -> ["-q"]
_ -> []
return (ssh, verbosity ++ ssh_args ++ cm_args)
getSSHOnly :: SSHCmd -> IO (String, [String])
getSSHOnly cmd =
do ssh_command <- getEnv (evar cmd) `catchall` return (show cmd)
port <- (portFlag cmd `fmap` getEnv "SSH_PORT") `catchall` return []
let (ssh, ssh_args) = breakCommand ssh_command
return (ssh, ssh_args ++ port)
where
evar SSH = "DARCS_SSH"
evar SCP = "DARCS_SCP"
evar SFTP = "DARCS_SFTP"
portFlag SSH x = ["-p", x]
portFlag SCP x = ["-P", x]
portFlag SFTP x = ["-oPort="++x]
environmentHelpSsh :: ([String], [String])
environmentHelpSsh = (["DARCS_SSH"], [
"Repositories of the form [user@]host:[dir] are taken to be remote",
"repositories, which Darcs accesses with the external program ssh(1).",
"",
"The environment variable $DARCS_SSH can be used to specify an",
"alternative SSH client. Arguments may be included, separated by",
"whitespace. The value is not interpreted by a shell, so shell",
"constructs cannot be used; in particular, it is not possible for the",
"program name to contain whitespace by using quoting or escaping."])
environmentHelpScp :: ([String], [String])
environmentHelpScp = (["DARCS_SCP", "DARCS_SFTP"], [
"When reading from a remote repository, Darcs will attempt to run",
"`darcs transfer-mode' on the remote host. This will fail if the",
"remote host only has Darcs 1 installed, doesn't have Darcs installed",
"at all, or only allows SFTP.",
"",
"If transfer-mode fails, Darcs will fall back on scp(1) and sftp(1).",
"The commands invoked can be customized with the environment variables",
"$DARCS_SCP and $DARCS_SFTP respectively, which behave like $DARCS_SSH.",
"If the remote end allows only sftp, try setting DARCS_SCP=sftp."])
environmentHelpSshPort :: ([String], [String])
environmentHelpSshPort = (["SSH_PORT"], [
"If this environment variable is set, it will be used as the port",
"number for all SSH calls made by Darcs (when accessing remote",
"repositories over SSH). This is useful if your SSH server does not",
"run on the default port, and your SSH client does not support",
"ssh_config(5). OpenSSH users will probably prefer to put something",
"like `Host *.example.net Port 443' into their ~/.ssh/config file."])
hasSSHControlMaster :: IO Bool
hasSSHControlMaster = do
(ssh, _) <- getSSHOnly SSH
sx <- exec ssh ["-O", "an_invalid_command"] (Null,Null,Null)
case sx of
ExitFailure 255 -> return True
_ -> return False
launchSSHControlMaster :: SshFilePath -> IO ()
launchSSHControlMaster dest = do
hasMaster <- hasSSHControlMaster
when hasMaster $ do
(ssh, ssh_args) <- getSSHOnly SSH
cmPath <- controlMasterPath dest
removeFileMayNotExist cmPath
_ <- exec ssh (ssh_args ++ [sshUhost dest, "-S", cmPath, "-N", "-f", "-M"]) (Null,Null,AsIs)
atexit $ exitSSHControlMaster dest
return ()
exitSSHControlMaster :: SshFilePath -> IO ()
exitSSHControlMaster addr = do
(ssh, ssh_args) <- getSSHOnly SSH
cmPath <- controlMasterPath addr
_ <- exec ssh (ssh_args ++ [sshUhost addr, "-S", cmPath, "-O", "exit"]) (Null,Null,Null)
return ()
controlMasterPath :: SshFilePath
-> IO FilePath
controlMasterPath dest = do
let addr = sshUhost dest
tmp <- (fmap (/// ".darcs") $ getEnv "HOME") `catchall` tempdirLoc
#ifdef WIN32
r <- randomIO
let suffix = (showHexLen 6 (r .&. 0xFFFFFF :: Int))
#else
suffix <- show `fmap` getProcessID
#endif
let tmpDarcsSsh = tmp /// "darcs-ssh"
createDirectoryIfMissing True tmpDarcsSsh
return $ tmpDarcsSsh /// addr ++ suffix
(///) :: FilePath -> FilePath -> FilePath
d /// f = d ++ "/" ++ f