git-annex/RemoteDaemon/Transport/Ssh.hs
Joey Hess f07af03018
Run ssh with -n whenever input is not being piped into it
... to avoid it consuming stdin that it shouldn't.

This fixes git-annex-checkpresentkey --batch remote, which didn't output
results for all keys passed into it.

Other git-annex commands that communicate with a remote over ssh may also
have been consuming stdin that they shouldn't have, which could have
impacted using them in eg, shell scripts. For example, a shell script
reading files from stdin and passing them to git annex drop would be
impacted by this bug, whenever git annex drop ran git-annex-shell
checkpresent, it would consume part/all of the stdin that the shell script
was supposed to consume.

Fixed by adding a ConsumeStdin parameter to Annex.Ssh.sshOptions, which
is used throughout git-annex to run ssh (in order for ssh connection
caching to work). Every call site was checked to see if it used
CreatePipe for stdin, and if not was marked NoConsumeStdin.
2017-02-15 15:08:46 -04:00

106 lines
3.2 KiB
Haskell

{- git-remote-daemon, git-annex-shell over ssh transport
-
- Copyright 2014 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module RemoteDaemon.Transport.Ssh (transport, transportUsingCmd) where
import Annex.Common
import Annex.Ssh
import RemoteDaemon.Types
import RemoteDaemon.Common
import Remote.Helper.Ssh
import qualified RemoteDaemon.Transport.Ssh.Types as SshRemote
import Utility.SimpleProtocol
import qualified Git
import Git.Command
import Annex.ChangedRefs
import Control.Concurrent.STM
import Control.Concurrent.Async
transport :: Transport
transport rr@(RemoteRepo r _) url h ichan ochan = do
v <- liftAnnex h $ git_annex_shell ConsumeStdin r "notifychanges" [] []
case v of
Nothing -> noop
Just (cmd, params) -> transportUsingCmd cmd params rr url h ichan ochan
transportUsingCmd :: FilePath -> [CommandParam] -> Transport
transportUsingCmd cmd params rr@(RemoteRepo r gc) url h@(TransportHandle (LocalRepo g) s) ichan ochan = do
-- enable ssh connection caching wherever inLocalRepo is called
g' <- liftAnnex h $ sshOptionsTo r gc g
let transporthandle = TransportHandle (LocalRepo g') s
transportUsingCmd' cmd params rr url transporthandle ichan ochan
transportUsingCmd' :: FilePath -> [CommandParam] -> Transport
transportUsingCmd' cmd params (RemoteRepo r _) url transporthandle ichan ochan =
robustConnection 1 $ do
(Just toh, Just fromh, Just errh, pid) <-
createProcess (proc cmd (toCommand params))
{ std_in = CreatePipe
, std_out = CreatePipe
, std_err = CreatePipe
}
-- Run all threads until one finishes and get the status
-- of the first to finish. Cancel the rest.
status <- catchDefaultIO (Right ConnectionClosed) $
handlestderr errh
`race` handlestdout fromh
`race` handlecontrol
send (DISCONNECTED url)
hClose toh
hClose fromh
void $ waitForProcess pid
return $ either (either id id) id status
where
send msg = atomically $ writeTChan ochan msg
fetch = do
send (SYNCING url)
ok <- inLocalRepo transporthandle $
runBool [Param "fetch", Param $ Git.repoDescribe r]
send (DONESYNCING url ok)
handlestdout fromh = do
ml <- getProtocolLine fromh
case parseMessage =<< ml of
Just SshRemote.READY -> do
send (CONNECTED url)
handlestdout fromh
Just (SshRemote.CHANGED (ChangedRefs shas)) -> do
whenM (checkNewShas transporthandle shas) $
fetch
handlestdout fromh
-- avoid reconnect on protocol error
Nothing -> return ConnectionStopping
handlecontrol = do
msg <- atomically $ readTChan ichan
case msg of
STOP -> return ConnectionStopping
LOSTNET -> return ConnectionStopping
_ -> handlecontrol
-- Old versions of git-annex-shell that do not support
-- the notifychanges command will exit with a not very useful
-- error message. Detect that error, and avoid reconnecting.
-- Propigate all stderr.
handlestderr errh = do
s <- hGetSomeString errh 1024
hPutStr stderr s
hFlush stderr
if "git-annex-shell: git-shell failed" `isInfixOf` s
then do
send $ WARNING url $ unwords
[ "Remote", Git.repoDescribe r
, "needs its git-annex upgraded"
, "to 5.20140405 or newer"
]
return ConnectionStopping
else handlestderr errh