agent: known host, smp protocol: parse empty messages (#1953)

Co-authored-by: Evgeny @ SimpleX Chat <259188159+evgeny-simplex@users.noreply.github.com>

src/Simplex/Messaging/Agent/Client.hs

@@ -1194,10 +1194,10 @@ sendOrProxySMPCommand c nm userId destSrv@ProtocolServer {host = destHosts} conn
       cfg <- getNetworkConfig c
       case smpProxyMode cfg of
         SPMAlways -> pure True
-        SPMUnknown -> unknownServer
+        SPMUnknown -> unknownServer cfg
         SPMUnprotected
           | ipAddressProtected cfg destSrv -> pure False
-          | otherwise -> unknownServer
+          | otherwise -> unknownServer cfg
         SPMNever -> pure False
     directAllowed = do
       cfg <- getNetworkConfig c
@@ -1205,7 +1205,7 @@ sendOrProxySMPCommand c nm userId destSrv@ProtocolServer {host = destHosts} conn
         SPFAllow -> True
         SPFAllowProtected -> ipAddressProtected cfg destSrv
         SPFProhibit -> False
-    unknownServer = liftIO $ maybe True (\srvs -> all (`S.notMember` knownHosts srvs) destHosts) <$> TM.lookupIO userId (smpServers c)
+    unknownServer cfg = liftIO $ maybe True (\srvs -> either (const True) (`S.notMember` knownHosts srvs) $ chooseTransportHost cfg destHosts) <$> TM.lookupIO userId (smpServers c)
     sendViaProxy :: Maybe SMPServerWithAuth -> SMPTransportSession -> AM (Maybe SMPServer, a)
     sendViaProxy proxySrv_ destSess@(_, _, connId_) = do
       r <- tryAllErrors . withProxySession c nm proxySrv_ destSess entId ("PFWD " <> cmdStr) $ \(SMPConnectedClient smp _, proxySess@ProxiedRelay {prBasicAuth}) -> do

src/Simplex/Messaging/Protocol.hs

@@ -884,7 +884,7 @@ instance StrEncoding Message where
       msgQuotaP msgId msgTs = "quota" $> MessageQuota {msgId, msgTs}
       msgP msgId msgTs = do
         msgFlags <- ("flags=" *> strP_) <|> pure noMsgFlags
-        msgBody <- strP
+        msgBody <- strP <|> (C.unsafeMaxLenBS "" <$ A.endOfInput)
         pure Message {msgId, msgTs, msgFlags, msgBody}
 
 type EncNMsgMeta = ByteString

tests/SMPProxyTests.hs

@@ -142,6 +142,10 @@ smpProxyTests = do
           agentDeliverMessageViaProxy ([srv1], SPMNever, False) ([srv2], SPMNever, False) C.SEd448 "hello 1" "hello 2" 1
         it "first via proxy for unknown" $ twoServers $
           agentDeliverMessageViaProxy ([srv1], SPMUnknown, True) ([srv1, srv2], SPMUnknown, False) C.SEd448 "hello 1" "hello 2" 1
+        it "first via proxy for unknown chosen host" $ twoServers $
+          agentDeliverMessageViaProxy ([srv1], SPMUnknown, True) ([SMPServer (testHost2 <> testHost) testPort2 testKeyHash], SPMUnknown, False) C.SEd448 "hello 1" "hello 2" 1
+        it "first without proxy for known chosen host" $ twoServers $
+          agentDeliverMessageViaProxy ([srv1], SPMUnknown, False) ([SMPServer (testHost <> testHost2) testPort2 testKeyHash], SPMUnknown, False) C.SEd448 "hello 1" "hello 2" 1
         it "retries sending when destination or proxy relay is offline" $ \_ ->
           agentViaProxyRetryOffline
         it "retries sending when destination relay session disconnects in proxy" $ \_ ->

tests/ServerTests.hs

@@ -1091,7 +1091,7 @@ testRestoreMessages =
       -- messages below are delivered after server restart
       sId <- readTVarIO senderId
       Resp "2" _ OK <- signSendRecv h sKey ("2", sId, _SEND "hello 2")
-      Resp "3" _ OK <- signSendRecv h sKey ("3", sId, _SEND "hello 3")
+      Resp "3" _ OK <- signSendRecv h sKey ("3", sId, _SEND "")
       Resp "4" _ OK <- signSendRecv h sKey ("4", sId, _SEND "hello 4")
       Resp "5" _ OK <- signSendRecv h sKey ("5", sId, _SEND "hello 5")
       Resp "6" _ (ERR QUOTA) <- signSendRecv h sKey ("6", sId, _SEND "hello 6")
@@ -1108,7 +1108,7 @@ testRestoreMessages =
       (Resp "2" _ (SOK Nothing), Resp "" _ (Msg mId2 msg2)) <- signSendRecv2 h rKey ("2", rId, SUB)
       (dec mId2 msg2, Right "hello 2") #== "restored message delivered"
       Resp "3" _ (Msg mId3 msg3) <- signSendRecv h rKey ("3", rId, ACK mId2)
-      (dec mId3 msg3, Right "hello 3") #== "restored message delivered"
+      (dec mId3 msg3, Right "") #== "restored message delivered"
       Resp "4" _ (Msg mId4 msg4) <- signSendRecv h rKey ("4", rId, ACK mId3)
       (dec mId4 msg4, Right "hello 4") #== "restored message delivered"
     logSize testStoreLogFile `shouldReturn` (if compacting then 1 else 2)