remote: separate (Client|Server)Handshake(Input|Output) types

hnix-store-remote/src/System/Nix/Store/Remote/Client.hs

@@ -30,7 +30,7 @@ import System.Nix.Store.Remote.Logger (processOutput)
 import System.Nix.Store.Remote.MonadStore
 import System.Nix.Store.Remote.Socket (sockPutS, sockGetS)
 import System.Nix.Store.Remote.Serializer (bool, enum, int, mapErrorS, protoVersion, storeRequest, text, trustedFlag, workerMagic)
-import System.Nix.Store.Remote.Types.Handshake (Handshake(..))
+import System.Nix.Store.Remote.Types.Handshake (ClientHandshakeInput(..), ClientHandshakeOutput(..))
 import System.Nix.Store.Remote.Types.Logger (Logger)
 import System.Nix.Store.Remote.Types.ProtoVersion (ProtoVersion(..), ourProtoVersion)
 import System.Nix.Store.Remote.Types.StoreConfig (PreStoreConfig, StoreConfig, preStoreConfigToStoreConfig)
@@ -177,16 +177,23 @@ runStoreSocket
   -> Run m a
 runStoreSocket preStoreConfig code =
   runRemoteStoreT preStoreConfig $ do
-    Handshake{..} <- greet
+    ClientHandshakeOutput{..}
+      <- greet
+          ClientHandshakeInput
+          { clientHandshakeInputOurVersion = ourProtoVersion
+          }
+
     mapStoreConfig
-      (preStoreConfigToStoreConfig handshakeProtoVersion)
+      (preStoreConfigToStoreConfig
+        clientHandshakeOutputLeastCommonVerison)
       code
 
   where
     greet
       :: MonadIO m
-      => RemoteStoreT PreStoreConfig m Handshake
-    greet = do
+      => ClientHandshakeInput
+      -> RemoteStoreT PreStoreConfig m ClientHandshakeOutput
+    greet ClientHandshakeInput{..} = do
 
       sockPutS
         (mapErrorS
@@ -210,19 +217,19 @@ runStoreSocket preStoreConfig code =
       when (daemonVersion < ProtoVersion 1 10)
         $ throwError RemoteStoreError_ClientVersionTooOld
 
-      sockPutS protoVersion ourProtoVersion
+      sockPutS protoVersion clientHandshakeInputOurVersion
 
-      let minimumCommonVersion = min daemonVersion ourProtoVersion
+      let leastCommonVersion = min daemonVersion ourProtoVersion
 
-      when (minimumCommonVersion >= ProtoVersion 1 14)
+      when (leastCommonVersion >= ProtoVersion 1 14)
         $ sockPutS int (0 :: Int) -- affinity, obsolete
 
-      when (minimumCommonVersion >= ProtoVersion 1 11) $ do
+      when (leastCommonVersion >= ProtoVersion 1 11) $ do
         sockPutS
           (mapErrorS RemoteStoreError_SerializerPut bool)
           False -- reserveSpace, obsolete
 
-      daemonNixVersion <- if minimumCommonVersion >= ProtoVersion 1 33
+      daemonNixVersion <- if leastCommonVersion >= ProtoVersion 1 33
         then do
           -- If we were buffering I/O, we would flush the output here.
           txtVer <-
@@ -233,19 +240,19 @@ runStoreSocket preStoreConfig code =
           pure $ Just txtVer
         else pure Nothing
 
-      remoteTrustsUs <- if minimumCommonVersion >= ProtoVersion 1 35
+      remoteTrustsUs <- if leastCommonVersion >= ProtoVersion 1 35
         then do
           sockGetS
             $ mapErrorS RemoteStoreError_SerializerHandshake trustedFlag
         else pure Nothing
 
       mapStoreConfig
-        (preStoreConfigToStoreConfig minimumCommonVersion)
+        (preStoreConfigToStoreConfig leastCommonVersion)
         processOutput
 
-      pure Handshake
-        { handshakeNixVersion = daemonNixVersion
-        , handshakeTrust = remoteTrustsUs
-        , handshakeProtoVersion = minimumCommonVersion
-        , handshakeRemoteProtoVersion = daemonVersion
+      pure ClientHandshakeOutput
+        { clientHandshakeOutputNixVersion = daemonNixVersion
+        , clientHandshakeOutputTrust = remoteTrustsUs
+        , clientHandshakeOutputLeastCommonVerison = leastCommonVersion
+        , clientHandshakeOutputServerVersion = daemonVersion
         }

hnix-store-remote/src/System/Nix/Store/Remote/Server.hs

@@ -27,7 +27,7 @@ import System.Nix.Store.Remote.Types.ProtoVersion (HasProtoVersion(..), ProtoVer
 import System.Nix.Store.Remote.Types.Logger (BasicError(..), ErrorInfo, Logger(..))
 
 import System.Nix.Store.Remote.MonadStore (WorkerError(..), WorkerException(..), RemoteStoreError(..), RemoteStoreT, runRemoteStoreT, mapStoreConfig)
-import System.Nix.Store.Remote.Types.Handshake (Handshake(..))
+import System.Nix.Store.Remote.Types.Handshake (ServerHandshakeInput(..), ServerHandshakeOutput(..))
 import System.Nix.Store.Remote.Types.ProtoVersion (ourProtoVersion)
 import System.Nix.Store.Remote.Types.WorkerMagic (WorkerMagic(..))
 
@@ -79,28 +79,26 @@ processConnection
   -> PreStoreConfig
   -> m ()
 processConnection workerHelper preStoreConfig = do
-  let handshake = Handshake
-        { handshakeNixVersion = Just "nixVersion (hnix-store-remote)"
-        , handshakeTrust = Nothing
-        -- TODO: doesn't make sense for server
-        , handshakeProtoVersion = ourProtoVersion
-        -- TODO: doesn't make sense for server
-        , handshakeRemoteProtoVersion = ourProtoVersion
-        }
-
   ~() <- void $ runRemoteStoreT preStoreConfig $ do
 
-    minimumCommonVersion <- greet handshake
+    ServerHandshakeOutput{..}
+      <- greet
+          ServerHandshakeInput
+          { serverHandshakeInputNixVersion = "nixVersion (hnix-store-remote)"
+          , serverHandshakeInputOurVersion= ourProtoVersion
+          , serverHandshakeInputTrust = Nothing
+          }
 
     mapStoreConfig
-      (preStoreConfigToStoreConfig minimumCommonVersion)
+      (preStoreConfigToStoreConfig
+        serverHandshakeOutputLeastCommonVersion)
       $ do
 
         tunnelLogger <- liftIO $ newTunnelLogger
         -- Send startup error messages to the client.
         startWork tunnelLogger
 
-        -- TODO: do we need auth at all?  probably?
+        -- TODO: do we need auth at all? probably?
         -- If we can't accept clientVersion, then throw an error *here* (not above).
         --authHook(*store);
         stopWork tunnelLogger
@@ -124,9 +122,9 @@ processConnection workerHelper preStoreConfig = do
     -- Exchange the greeting.
     greet
       :: MonadIO m
-      => Handshake
-      -> RemoteStoreT PreStoreConfig m ProtoVersion
-    greet Handshake{..} = do
+      => ServerHandshakeInput
+      -> RemoteStoreT PreStoreConfig m ServerHandshakeOutput
+    greet ServerHandshakeInput{..} = do
       magic <-
         sockGetS
         $ mapErrorS
@@ -135,7 +133,9 @@ processConnection workerHelper preStoreConfig = do
 
       liftIO $ print ("magic" :: Text, magic)
       when (magic /= WorkerMagic_One)
-        $ throwError $ RemoteStoreError_WorkerException WorkerException_ProtocolMismatch
+        $ throwError
+        $ RemoteStoreError_WorkerException
+            WorkerException_ProtocolMismatch
 
       sockPutS
         (mapErrorS
@@ -144,13 +144,13 @@ processConnection workerHelper preStoreConfig = do
         )
         WorkerMagic_Two
 
-      sockPutS protoVersion ourProtoVersion
+      sockPutS protoVersion serverHandshakeInputOurVersion
 
       clientVersion <- sockGetS protoVersion
 
-      let minimumCommonVersion = min clientVersion ourProtoVersion
+      let leastCommonVersion = min clientVersion ourProtoVersion
 
-      liftIO $ print ("Versions client, min" :: Text, clientVersion, minimumCommonVersion)
+      liftIO $ print ("Versions client, min" :: Text, clientVersion, leastCommonVersion)
 
       when (clientVersion < ProtoVersion 1 10)
         $ throwError
@@ -174,8 +174,7 @@ processConnection workerHelper preStoreConfig = do
              RemoteStoreError_SerializerPut
              text
           )
-          -- TODO
-          (maybe undefined id handshakeNixVersion)
+          serverHandshakeInputNixVersion
 
       when (clientVersion >= ProtoVersion 1 35) $ do
         sockPutS
@@ -183,9 +182,12 @@ processConnection workerHelper preStoreConfig = do
              RemoteStoreError_SerializerHandshake
              trustedFlag
           )
-          handshakeTrust
+          serverHandshakeInputTrust
 
-      pure minimumCommonVersion
+      pure ServerHandshakeOutput
+        { serverHandshakeOutputLeastCommonVersion = leastCommonVersion
+        , serverHandshakeOutputClientVersion = clientVersion
+        }
 
 simpleOp
   :: ( MonadIO m

hnix-store-remote/src/System/Nix/Store/Remote/Types/Handshake.hs

@@ -1,5 +1,8 @@
 module System.Nix.Store.Remote.Types.Handshake
-  ( Handshake(..)
+  ( ClientHandshakeInput(..)
+  , ClientHandshakeOutput(..)
+  , ServerHandshakeInput(..)
+  , ServerHandshakeOutput(..)
   ) where
 
 import Data.Text (Text)
@@ -7,11 +10,28 @@ import GHC.Generics (Generic)
 import System.Nix.Store.Remote.Types.ProtoVersion (ProtoVersion)
 import System.Nix.Store.Remote.Types.TrustedFlag (TrustedFlag)
 
--- | Data for initial protocol handshake
-data Handshake = Handshake
-  { handshakeNixVersion :: Maybe Text -- ^ Textual version, since 1.33
-  , handshakeTrust :: Maybe TrustedFlag -- ^ Whether remote side trusts us
-  , handshakeProtoVersion :: ProtoVersion -- ^ Minimum protocol supported by both sides
-  , handshakeRemoteProtoVersion :: ProtoVersion -- ^ Protocol supported by remote side
-  }
-  deriving (Eq, Generic, Ord, Show)
+-- | Data sent by the client during initial protocol handshake
+data ClientHandshakeInput = ClientHandshakeInput
+  { clientHandshakeInputOurVersion :: ProtoVersion -- ^ Our protocol version (that we advertise to the server)
+  } deriving (Eq, Generic, Ord, Show)
+
+-- | Data received by the client via initial protocol handshake
+data ClientHandshakeOutput = ClientHandshakeOutput
+  { clientHandshakeOutputNixVersion :: Maybe Text -- ^ Textual version, since 1.33
+  , clientHandshakeOutputTrust :: Maybe TrustedFlag -- ^ Whether remote side trusts us
+  , clientHandshakeOutputLeastCommonVerison :: ProtoVersion -- ^ Minimum protocol version supported by both sides
+  , clientHandshakeOutputServerVersion :: ProtoVersion -- ^ Protocol version supported by the server
+  } deriving (Eq, Generic, Ord, Show)
+
+-- | Data sent by the server during initial protocol handshake
+data ServerHandshakeInput = ServerHandshakeInput
+  { serverHandshakeInputNixVersion :: Text -- ^ Textual version, since 1.33
+  , serverHandshakeInputOurVersion :: ProtoVersion -- ^ Our protocol version (that we advertise to the client)
+  , serverHandshakeInputTrust :: Maybe TrustedFlag -- ^ Whether client should trusts us
+  } deriving (Eq, Generic, Ord, Show)
+
+-- | Data received by the server during initial protocol handshake
+data ServerHandshakeOutput = ServerHandshakeOutput
+  { serverHandshakeOutputLeastCommonVersion :: ProtoVersion -- ^ Minimum protocol version supported by both sides
+  , serverHandshakeOutputClientVersion :: ProtoVersion -- ^ Protocol version supported by the client
+  } deriving (Eq, Generic, Ord, Show)