finish git-annex enable-tor

Make it stash the address away for git-annex p2p to use later, rather
than outputting it. And, look up the UUID itself.

P2P/Address.hs

@@ -0,0 +1,79 @@
+{- P2P protocol addresses
+ -
+ - Copyright 2016 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module P2P.Address where
+
+import qualified Annex
+import Annex.Common
+import Git
+import Creds
+import Utility.AuthToken
+import Utility.Tor
+
+import qualified Data.Text as T
+
+-- | A P2P address, without an AuthToken.
+--
+-- This is enough information to connect to the peer,
+-- but not enough to authenticate with it.
+data P2PAddress = TorAnnex OnionAddress OnionPort
+	deriving (Eq, Show)
+
+-- | A P2P address, with an AuthToken
+data P2PAddressAuth = P2PAddressAuth P2PAddress AuthToken
+	deriving (Eq, Show)
+
+class FormatP2PAddress a where
+	formatP2PAddress :: a -> String
+	unformatP2PAddress :: String -> Maybe a
+
+instance FormatP2PAddress P2PAddress where
+	formatP2PAddress (TorAnnex (OnionAddress onionaddr) onionport) =
+		"tor-annex::" ++ onionaddr ++ ":" ++ show onionport
+	unformatP2PAddress s
+		| "tor-annex::" `isPrefixOf` s = do
+			let s' = dropWhile (== ':') $ dropWhile (/= ':') s
+			let (onionaddr, ps) = separate (== ':') s'
+			onionport <- readish ps
+			return (TorAnnex (OnionAddress onionaddr) onionport)
+		| otherwise = Nothing
+
+instance FormatP2PAddress P2PAddressAuth where
+	formatP2PAddress (P2PAddressAuth addr authtoken) =
+		formatP2PAddress addr ++ ":" ++ T.unpack (fromAuthToken authtoken)
+	unformatP2PAddress s = do
+		let (ra, rs) = separate (== ':') (reverse s)
+		addr <- unformatP2PAddress (reverse rs)
+		authtoken <- toAuthToken (T.pack $ reverse ra)
+		return (P2PAddressAuth addr authtoken)
+
+loadP2PAddresses :: Annex [P2PAddress]
+loadP2PAddresses = mapMaybe unformatP2PAddress . maybe [] lines
+	<$> readCacheCreds p2pAddressCredsFile
+
+storeP2PAddress :: P2PAddress -> Annex ()
+storeP2PAddress addr = do
+	addrs <- loadP2PAddresses
+	unless (addr `elem` addrs) $ do
+		let s = unlines $ map formatP2PAddress (addr:addrs)
+		let tmpnam = p2pAddressCredsFile ++ ".new"
+		writeCacheCreds s tmpnam
+		tmpf <- cacheCredsFile tmpnam
+		destf <- cacheCredsFile p2pAddressCredsFile
+		-- This may be run by root, so make the creds file
+		-- and directory have the same owner and group as
+		-- the git repository directory has.
+		st <- liftIO . getFileStatus =<< Annex.fromRepo repoLocation
+		let fixowner f = setOwnerAndGroup f (fileOwner st) (fileGroup st)
+		liftIO $ do
+			fixowner tmpf
+			fixowner (takeDirectory tmpf)
+			fixowner (takeDirectory (takeDirectory tmpf))
+			renameFile tmpf destf
+
+p2pAddressCredsFile :: FilePath
+p2pAddressCredsFile = "p2paddrs"