From 6c84eaf5a01046a0fa175d75e7027f686e00a6ee Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Sat, 2 Nov 2013 15:10:29 -0400 Subject: Improve local pairing behavior when two computers both try to start the pairing process separately. I was able to reproduce something very like this bug by starting pairing separately on both computers under poor network conditions (ie, weak wifi on my front porch). Neither computer showed an alert for the PairReq messages it was seeing (intermittently) from the other. So, I've made a new PairReq message that has not been seen before always make the alert pop up, even if the assistant thinks it is in the middle of its own pairing process (or even another pairing process with a different box on the LAN). (This shouldn't cause a rogue PairAck to disrupt a pairing process part way through.) --- Assistant/Pairing.hs | 2 +- Assistant/Threads/PairListener.hs | 28 +++++++++++++++------- debian/changelog | 7 ++++++ ...Local_pairing_fails:_received_PairMsg_loop.mdwn | 14 +++++++++++ 4 files changed, 42 insertions(+), 9 deletions(-) diff --git a/Assistant/Pairing.hs b/Assistant/Pairing.hs index 4736c4396..bb1384a15 100644 --- a/Assistant/Pairing.hs +++ b/Assistant/Pairing.hs @@ -28,7 +28,7 @@ data PairStage | PairAck {- "I saw your PairAck; you can stop sending them." -} | PairDone - deriving (Eq, Read, Show, Ord) + deriving (Eq, Read, Show, Ord, Enum) newtype PairMsg = PairMsg (Verifiable (PairStage, PairData, SomeAddr)) deriving (Eq, Read, Show) diff --git a/Assistant/Threads/PairListener.hs b/Assistant/Threads/PairListener.hs index 0d3be4660..cd95ab5a4 100644 --- a/Assistant/Threads/PairListener.hs +++ b/Assistant/Threads/PairListener.hs @@ -43,20 +43,32 @@ pairListenerThread urlrenderer = namedThread "PairListener" $ do (pip, verified) <- verificationCheck m =<< (pairingInProgress <$> getDaemonStatus) let wrongstage = maybe False (\p -> pairMsgStage m <= inProgressPairStage p) pip - case (wrongstage, sane, pairMsgStage m) of - -- ignore our own messages, and - -- out of order messages - (_, False, _) -> go reqs cache sock - (True, _, _) -> go reqs cache sock - (_, _, PairReq) -> if m `elem` reqs + let fromus = maybe False (\p -> remoteSshPubKey (pairMsgData m) == remoteSshPubKey (inProgressPairData p)) pip + case (wrongstage, fromus, sane, pairMsgStage m) of + (_, True, _, _) -> do + debug ["ignoring message that looped back"] + go reqs cache sock + (_, _, False, _) -> go reqs cache sock + -- PairReq starts a pairing process, so a + -- new one is always heeded, even if + -- some other pairing is in process. + (_, _, _, PairReq) -> if m `elem` reqs then go reqs (invalidateCache m cache) sock else do pairReqReceived verified urlrenderer m go (m:take 10 reqs) (invalidateCache m cache) sock - (_, _, PairAck) -> do + (True, _, _, _) -> do + debug + ["ignoring out of order message" + , show (pairMsgStage m) + , "expected" + , show (succ . inProgressPairStage <$> pip) + ] + go reqs cache sock + (_, _, _, PairAck) -> do cache' <- pairAckReceived verified pip m cache go reqs cache' sock - (_, _, PairDone) -> do + (_,_ , _, PairDone) -> do pairDoneReceived verified pip m go reqs cache sock diff --git a/debian/changelog b/debian/changelog index 193976ac9..6c743e19a 100644 --- a/debian/changelog +++ b/debian/changelog @@ -1,3 +1,10 @@ +git-annex (4.20131102) UNRELEASED; urgency=low + + * Improve local pairing behavior when two computers both try to start + the pairing process separately. + + -- Joey Hess Sat, 02 Nov 2013 14:54:36 -0400 + git-annex (4.20131101) unstable; urgency=low * The "git annex content" command is renamed to "git annex wanted". diff --git a/doc/bugs/Local_pairing_fails:_received_PairMsg_loop.mdwn b/doc/bugs/Local_pairing_fails:_received_PairMsg_loop.mdwn index 1751429be..63f423e2c 100644 --- a/doc/bugs/Local_pairing_fails:_received_PairMsg_loop.mdwn +++ b/doc/bugs/Local_pairing_fails:_received_PairMsg_loop.mdwn @@ -23,3 +23,17 @@ I'm on Ubuntu Raring 13.04. I installed git-annex 4.20131024 from the Precise P ...and so on and so on... # End of transcript or log. """]] + +> I was able to reproduce something very like this by starting +> pairing separately on both computers under poor network conditions (ie, +> weak wifi on my front porch). +> +> So, I've made a new PairReq message that has not been seen before +> always make the alert pop up, even if the assistant thinks it is +> in the middle of its own pairing process (or even another pairing process +> with a different box on the LAN). +> +> (This shouldn't cause a rogue PairAck to disrupt a pairing process part +> way through.) +> +> [[done]] --[[Joey]] -- cgit v1.2.3