git-annex/Assistant/XMPP/Client.hs
Joey Hess 780efc775c When an XMPP server has SRV records, try them, but don't then fall back to the regular host if they all fail.
gmail.com has some XMPP SRV records, but does not itself respond to XMPP
traffic, although it does accept connections on port 5222. So if a user
entered the wrong password, it would try all the SRVs and fall back to
trying gmail, and hang at that point.

This seems the right thing to do, not just a workaround.
2013-07-20 21:18:55 -04:00

84 lines
2.3 KiB
Haskell

{- xmpp client support
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Assistant.XMPP.Client where
import Assistant.Common
import Utility.SRV
import Creds
import Network.Protocol.XMPP
import Network
import Control.Concurrent
import qualified Data.Text as T
import Control.Exception (SomeException)
{- Everything we need to know to connect to an XMPP server. -}
data XMPPCreds = XMPPCreds
{ xmppUsername :: T.Text
, xmppPassword :: T.Text
, xmppHostname :: HostName
, xmppPort :: Int
, xmppJID :: T.Text
}
deriving (Read, Show)
connectXMPP :: XMPPCreds -> (JID -> XMPP a) -> IO [(HostPort, Either SomeException ())]
connectXMPP c a = case parseJID (xmppJID c) of
Nothing -> error "bad JID"
Just jid -> connectXMPP' jid c a
{- Do a SRV lookup, but if it fails, fall back to the cached xmppHostname. -}
connectXMPP' :: JID -> XMPPCreds -> (JID -> XMPP a) -> IO [(HostPort, Either SomeException ())]
connectXMPP' jid c a = reverse <$> (handle =<< lookupSRV srvrecord)
where
srvrecord = mkSRVTcp "xmpp-client" $
T.unpack $ strDomain $ jidDomain jid
serverjid = JID Nothing (jidDomain jid) Nothing
handle [] = do
let h = xmppHostname c
let p = PortNumber $ fromIntegral $ xmppPort c
r <- run h p $ a jid
return [r]
handle srvs = go [] srvs
go l [] = return l
go l ((h,p):rest) = do
{- Try each SRV record in turn, until one connects,
- at which point the MVar will be full. -}
mv <- newEmptyMVar
r <- run h p $ do
liftIO $ putMVar mv ()
a jid
ifM (isEmptyMVar mv)
( go (r : l) rest
, return (r : l)
)
{- Async exceptions are let through so the XMPP thread can
- be killed. -}
run h p a' = do
r <- tryNonAsync $
runClientError (Server serverjid h p) jid
(xmppUsername c) (xmppPassword c) (void a')
return ((h, p), r)
{- XMPP runClient, that throws errors rather than returning an Either -}
runClientError :: Server -> JID -> T.Text -> T.Text -> XMPP a -> IO a
runClientError s j u p x = either (error . show) return =<< runClient s j u p x
getXMPPCreds :: Annex (Maybe XMPPCreds)
getXMPPCreds = parse <$> readCacheCreds xmppCredsFile
where
parse s = readish =<< s
setXMPPCreds :: XMPPCreds -> Annex ()
setXMPPCreds creds = writeCacheCreds (show creds) xmppCredsFile
xmppCredsFile :: FilePath
xmppCredsFile = "xmpp"