xftp-server: add inactiveClientExpiration (#936)

* xftp-server: add inactiveClientExpiration

* fix test config

* add test

* add xftpPing

* switch to PCEUnexpectedResponse

* remove watchdog when server quits

* rename, loop

---------

Co-authored-by: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>

src/Simplex/FileTransfer/Client.hs

@@ -132,11 +132,15 @@ xftpClientError = \case
   HCIOError e -> PCEIOError e
 
 sendXFTPCommand :: forall p. FilePartyI p => XFTPClient -> C.APrivateSignKey -> XFTPFileId -> FileCommand p -> Maybe XFTPChunkSpec -> ExceptT XFTPClientError IO (FileResponse, HTTP2Body)
-sendXFTPCommand XFTPClient {config, http2Client = http2@HTTP2Client {sessionId}} pKey fId cmd chunkSpec_ = do
+sendXFTPCommand c@XFTPClient {http2Client = HTTP2Client {sessionId}} pKey fId cmd chunkSpec_ = do
   t <-
     liftEither . first PCETransportError $
       xftpEncodeTransmission sessionId (Just pKey) ("", fId, FileCmd (sFileParty @p) cmd)
-  let req = H.requestStreaming N.methodPost "/" [] $ streamBody t
+  sendXFTPTransmission c t chunkSpec_
+
+sendXFTPTransmission :: XFTPClient -> ByteString -> Maybe XFTPChunkSpec -> ExceptT XFTPClientError IO (FileResponse, HTTP2Body)
+sendXFTPTransmission XFTPClient {config, http2Client = http2@HTTP2Client {sessionId}} t chunkSpec_ = do
+  let req = H.requestStreaming N.methodPost "/" [] streamBody
       reqTimeout = (\XFTPChunkSpec {chunkSize} -> chunkTimeout config chunkSize) <$> chunkSpec_
   HTTP2Response {respBody = body@HTTP2Body {bodyHead}} <- liftEitherError xftpClientError $ sendRequest http2 req reqTimeout
   when (B.length bodyHead /= xftpBlockSize) $ throwError $ PCEResponseError BLOCK
@@ -148,8 +152,8 @@ sendXFTPCommand XFTPClient {config, http2Client = http2@HTTP2Client {sessionId}}
       _ -> pure (r, body)
     Left e -> throwError $ PCEResponseError e
   where
-    streamBody :: ByteString -> (Builder -> IO ()) -> IO () -> IO ()
-    streamBody t send done = do
+    streamBody :: (Builder -> IO ()) -> IO () -> IO ()
+    streamBody send done = do
       send $ byteString t
       forM_ chunkSpec_ $ \XFTPChunkSpec {filePath, chunkOffset, chunkSize} ->
         withFile filePath ReadMode $ \h -> do
@@ -207,6 +211,16 @@ deleteXFTPChunk c spKey sId = sendXFTPCommand c spKey sId FDEL Nothing >>= okRes
 ackXFTPChunk :: XFTPClient -> C.APrivateSignKey -> RecipientId -> ExceptT XFTPClientError IO ()
 ackXFTPChunk c rpKey rId = sendXFTPCommand c rpKey rId FACK Nothing >>= okResponse
 
+pingXFTP :: XFTPClient -> ExceptT XFTPClientError IO ()
+pingXFTP c@XFTPClient {http2Client = HTTP2Client {sessionId}} = do
+  t <-
+    liftEither . first PCETransportError $
+      xftpEncodeTransmission sessionId Nothing ("", "", FileCmd SFRecipient PING)
+  (r, _) <- sendXFTPTransmission c t Nothing
+  case r of
+    FRPong -> pure ()
+    _ -> throwError $ PCEUnexpectedResponse $ bshow r
+
 okResponse :: (FileResponse, HTTP2Body) -> ExceptT XFTPClientError IO ()
 okResponse = \case
   (FROk, body) -> noFile body ()

src/Simplex/FileTransfer/Server.hs

@@ -70,7 +70,7 @@ runXFTPServerBlocking :: TMVar Bool -> XFTPServerConfig -> IO ()
 runXFTPServerBlocking started cfg = newXFTPServerEnv cfg >>= runReaderT (xftpServer cfg started)
 
 xftpServer :: XFTPServerConfig -> TMVar Bool -> M ()
-xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig} started = do
+xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpiration} started = do
   restoreServerStats
   raceAny_ (runServer : expireFilesThread_ cfg <> serverStatsThread_ cfg) `finally` stopServer
   where
@@ -79,7 +79,7 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig} started = do
       serverParams <- asks tlsServerParams
       env <- ask
       liftIO $
-        runHTTP2Server started xftpPort defaultHTTP2BufferSize serverParams transportConfig $ \sessionId r sendResponse -> do
+        runHTTP2Server started xftpPort defaultHTTP2BufferSize serverParams transportConfig inactiveClientExpiration $ \sessionId r sendResponse -> do
           reqBody <- getHTTP2Body r xftpBlockSize
           processRequest HTTP2Request {sessionId, request = r, reqBody, sendResponse} `runReaderT` env
 

src/Simplex/FileTransfer/Server/Env.hs

@@ -46,6 +46,8 @@ data XFTPServerConfig = XFTPServerConfig
     newFileBasicAuth :: Maybe BasicAuth,
     -- | time after which the files can be removed and check interval, seconds
     fileExpiration :: Maybe ExpirationConfig,
+    -- | time after which inactive clients can be disconnected and check interval, seconds
+    inactiveClientExpiration :: Maybe ExpirationConfig,
     -- CA certificate private key is not needed for initialization
     caCertificateFile :: FilePath,
     privateKeyFile :: FilePath,
@@ -58,6 +60,13 @@ data XFTPServerConfig = XFTPServerConfig
     transportConfig :: TransportServerConfig
   }
 
+defaultInactiveClientExpiration :: ExpirationConfig
+defaultInactiveClientExpiration =
+  ExpirationConfig
+    { ttl = 43200, -- seconds, 12 hours
+      checkInterval = 3600 -- seconds, 1 hours
+    }
+
 data XFTPEnv = XFTPEnv
   { config :: XFTPServerConfig,
     store :: FileStore,

src/Simplex/FileTransfer/Server/Main.hs

@@ -19,7 +19,7 @@ import Options.Applicative
 import Simplex.FileTransfer.Chunks
 import Simplex.FileTransfer.Description (FileSize (..))
 import Simplex.FileTransfer.Server (runXFTPServer)
-import Simplex.FileTransfer.Server.Env (XFTPServerConfig (..), defFileExpirationHours, defaultFileExpiration)
+import Simplex.FileTransfer.Server.Env (XFTPServerConfig (..), defFileExpirationHours, defaultFileExpiration, defaultInactiveClientExpiration)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol (ProtoServerWithAuth (..), pattern XFTPServer)
@@ -104,6 +104,12 @@ xftpServerCLI cfgPath logPath = do
                \[FILES]\n"
             <> ("path: " <> filesPath <> "\n")
             <> ("storage_quota: " <> B.unpack (strEncode fileSizeQuota) <> "\n")
+            <> "\n\
+                \[INACTIVE_CLIENTS]\n\
+                \# TTL and interval to check inactive clients\n\
+                \disconnect: off\n"
+            <> ("# ttl: " <> show (ttl defaultInactiveClientExpiration) <> "\n")
+            <> ("# check_interval: " <> show (checkInterval defaultInactiveClientExpiration) <> "\n")
     runServer ini = do
       hSetBuffering stdout LineBuffering
       hSetBuffering stderr LineBuffering
@@ -118,13 +124,16 @@ xftpServerCLI cfgPath logPath = do
         enableStoreLog = settingIsOn "STORE_LOG" "enable" ini
         logStats = settingIsOn "STORE_LOG" "log_stats" ini
         c = combine cfgPath . ($ defaultX509Config)
-        printXFTPConfig XFTPServerConfig {allowNewFiles, newFileBasicAuth, xftpPort, storeLogFile, fileExpiration} = do
+        printXFTPConfig XFTPServerConfig {allowNewFiles, newFileBasicAuth, xftpPort, storeLogFile, fileExpiration, inactiveClientExpiration} = do
           putStrLn $ case storeLogFile of
             Just f -> "Store log: " <> f
             _ -> "Store log disabled."
           putStrLn $ case fileExpiration of
             Just ExpirationConfig {ttl} -> "expiring files after " <> showTTL ttl
             _ -> "not expiring files"
+          putStrLn $ case inactiveClientExpiration of
+            Just ExpirationConfig {ttl, checkInterval} -> "expiring clients inactive for " <> show ttl <> " seconds every " <> show checkInterval <> " seconds"
+            _ -> "not expiring inactive clients"
           putStrLn $
             "Uploading new files "
               <> if allowNewFiles
@@ -147,6 +156,12 @@ xftpServerCLI cfgPath logPath = do
                   defaultFileExpiration
                     { ttl = 3600 * readIniDefault defFileExpirationHours "STORE_LOG" "expire_files_hours" ini
                     },
+              inactiveClientExpiration =
+                settingIsOn "INACTIVE_CLIENTS" "disconnect" ini
+                  $> ExpirationConfig
+                    { ttl = readStrictIni "INACTIVE_CLIENTS" "ttl" ini,
+                      checkInterval = readStrictIni "INACTIVE_CLIENTS" "check_interval" ini
+                    },
               caCertificateFile = c caCrtFile,
               privateKeyFile = c serverKeyFile,
               certificateFile = c serverCrtFile,