p2p --link now defaults to setting up a bi-directional link

Both the local and remote git repositories get remotes added
pointing at one-another.

Makes pairing twice as easy!

Security: The new LINK command in the protocol can be sent repeatedly,
but only by a peer who has authenticated with us. So, it's entirely safe to
add a link back to that peer, or to some other peer it knows about.
Anything we receive over such a link, the peer could send us over the
current connection.

There is some risk of being flooded with LINKs, and adding too many
remotes. To guard against that, there's a hard cap on the number of remotes
that can be set up this way. This will only be a problem if setting up
large p2p networks that have exceptional interconnectedness.

A new, dedicated authtoken is created when sending LINK.

This also allows, in theory, using a p2p network like tor, to learn about
links on other networks, like telehash.

This commit was sponsored by Bruno BEAUFILS on Patreon.

1 files changed, 8 insertions, 37 deletions

diff --git a/Command/P2P.hs b/Command/P2P.hs
index d59d774c4..323906f36 100644
--- a/Command/P2P.hs
+++ b/Command/P2P.hs
@@ -10,15 +10,10 @@ module Command.P2P where
 import Command
 import P2P.Address
 import P2P.Auth
-import P2P.IO
-import qualified P2P.Protocol as P2P
+import P2P.Annex
 import Utility.AuthToken
 import Git.Types
 import qualified Git.Remote
-import qualified Git.Command
-import qualified Annex
-import Annex.UUID
-import Config
 
 cmd :: Command
 cmd = command "p2p" SectionSetup
@@ -55,16 +50,6 @@ seek (LinkRemote, Just name) = commandAction $
 seek (LinkRemote, Nothing) = commandAction $
 	linkRemote =<< unusedPeerRemoteName
 
-unusedPeerRemoteName :: Annex RemoteName
-unusedPeerRemoteName = go (1 :: Integer) =<< usednames
-  where
-	usednames = mapMaybe remoteName . remotes <$> Annex.gitRepo
-	go n names = do
-		let name = "peer" ++ show n
-		if name `elem` names
-			then go (n+1) names
-			else return name
-
 -- Only addresses are output to stdout, to allow scripting.
 genAddresses :: [P2PAddress] -> Annex ()
 genAddresses [] = giveup "No P2P networks are currrently available."
@@ -95,24 +80,10 @@ linkRemote remotename = do
 				Nothing -> do
 					liftIO $ hPutStrLn stderr "Unable to parse that address, please check its format and try again."
 					prompt
-				Just addr -> setup addr
-	setup (P2PAddressAuth addr authtoken) = do
-		g <- Annex.gitRepo
-		conn <- liftIO $ connectPeer g addr
-			`catchNonAsync` connerror
-		u <- getUUID
-		v <- liftIO $ runNetProto conn $ P2P.auth u authtoken
-		case v of
-			Right (Just theiruuid) -> do
-				ok <- inRepo $ Git.Command.runBool
-					[ Param "remote", Param "add"
-					, Param remotename
-					, Param (formatP2PAddress addr)
-					]
-				when ok $ do
-					storeUUIDIn (remoteConfig remotename "uuid") theiruuid
-					storeP2PRemoteAuthToken addr authtoken
-				return ok
-			Right Nothing -> giveup "Unable to authenticate with peer. Please check the address and try again."
-			Left e -> giveup $ "Unable to authenticate with peer: " ++ e
-	connerror e = giveup $ "Unable to connect with peer. Please check that the peer is connected to the network, and try again. ("  ++ show e ++ ")"
+				Just addr -> do
+					myaddrs <- loadP2PAddresses
+					authtoken <- liftIO $ genAuthToken 128
+					storeP2PAuthToken authtoken
+					let linkbackto = map (`P2PAddressAuth` authtoken) myaddrs
+					linkAddress addr linkbackto remotename
+						>>= either giveup return