git-annex/Command/P2PStdIO.hs
Joey Hess 58d8ba5a4f
implement simple proxy actions (untested)
Still need to implement GET and PUT, and will implement CONNECT and
NOTIFYCHANGE for completeness.

All ServerMode checking is implemented for the proxy.

There are two possible approaches for how the proxy sends back messages
from the remote to the client. One would be to have a background thread
that reads messages and sends them back as they come in. The other,
which is being implemented so far, is to read messages from the remote
at points where it is expected to send them, and relay back to the
client before reading the next message from the client. At this point,
I'm unsure which approach would be better.

The need for proxynoresponse to be used by UNLOCKCONTENT, for example,
builds protocol knowledge into the proxy which it would not need with
the other method.
2024-06-11 12:56:20 -04:00

89 lines
2.9 KiB
Haskell

{- git-annex command
-
- Copyright 2018-2024 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Command.P2PStdIO where
import Command
import P2P.IO
import P2P.Annex
import P2P.Proxy
import qualified P2P.Protocol as P2P
import qualified Annex
import Annex.UUID
import qualified CmdLine.GitAnnexShell.Checks as Checks
import Remote.Helper.Ssh (openP2PSshConnection', closeP2PSshConnection)
import System.IO.Error
cmd :: Command
cmd = noMessages $ command "p2pstdio" SectionPlumbing
"communicate in P2P protocol over stdio"
paramUUID (withParams seek)
seek :: CmdParams -> CommandSeek
seek [u] = commandAction $ start $ toUUID u
seek _ = giveup "missing UUID parameter"
start :: UUID -> CommandStart
start theiruuid = startingCustomOutput (ActionItemOther Nothing) $ do
servermode <- liftIO $ do
ro <- Checks.checkEnvSet Checks.readOnlyEnv
ao <- Checks.checkEnvSet Checks.appendOnlyEnv
return $ case (ro, ao) of
(True, _) -> P2P.ServeReadOnly
(False, True) -> P2P.ServeAppendOnly
(False, False) -> P2P.ServeReadWrite
Annex.getState Annex.proxyremote >>= \case
Nothing -> performLocal theiruuid servermode
Just r -> performProxy theiruuid servermode r
performLocal :: UUID -> P2P.ServerMode -> CommandPerform
performLocal theiruuid servermode = do
myuuid <- getUUID
let conn = stdioP2PConnection Nothing
let server = do
P2P.net $ P2P.sendMessage (P2P.AUTH_SUCCESS myuuid)
P2P.serveAuthed servermode myuuid
runst <- liftIO $ mkRunState $ Serving theiruuid Nothing
runFullProto runst conn server >>= \case
Right () -> done
-- Avoid displaying an error when the client hung up on us.
Left (ProtoFailureIOError e) | isEOFError e -> done
Left e -> giveup (describeProtoFailure e)
where
done = next $ return True
performProxy :: UUID -> P2P.ServerMode -> Remote -> CommandPerform
performProxy clientuuid servermode remote = do
clientside <- ClientSide
<$> liftIO (mkRunState $ Serving clientuuid Nothing)
<*> pure (stdioP2PConnection Nothing)
getClientProtocolVersion remote clientside
(withclientversion clientside)
protoerrhandler
where
withclientversion clientside (Just (clientmaxversion, othermsg)) =
connectremote clientmaxversion $ \remoteside ->
proxy done servermode clientside remoteside
othermsg protoerrhandler
withclientversion _ Nothing = done
-- FIXME: Support special remotes and non-ssh git remotes.
connectremote clientmaxversion cont =
openP2PSshConnection' remote clientmaxversion >>= \case
Just conn@(P2P.IO.OpenConnection (remoterunst, remoteconn, _)) ->
cont (RemoteSide remoterunst remoteconn)
`finally` liftIO (closeP2PSshConnection conn)
_ -> giveup "Unable to connect to remote."
protoerrhandler cont a = a >>= \case
-- Avoid displaying an error when the client hung up on us.
Left (ProtoFailureIOError e) | isEOFError e -> done
Left e -> giveup (describeProtoFailure e)
Right v -> cont v
done = next $ return True