From d920a2504b6d4653748da7d297cb13cd0a0f1f48 Mon Sep 17 00:00:00 2001
From: spaced4ndy <8711996+spaced4ndy@users.noreply.github.com>
Date: Wed, 25 Oct 2023 09:48:54 +0400
Subject: [PATCH] agent: check confirmed snd queue doesn't exist before
 replacing (#871)

---
 src/Simplex/Messaging/Agent/Store.hs        |  2 ++
 src/Simplex/Messaging/Agent/Store/SQLite.hs | 21 +++++++++++++++++----
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/Simplex/Messaging/Agent/Store.hs b/src/Simplex/Messaging/Agent/Store.hs
index dda6c7c65..27b193693 100644
--- a/src/Simplex/Messaging/Agent/Store.hs
+++ b/src/Simplex/Messaging/Agent/Store.hs
@@ -576,6 +576,8 @@ data StoreError
     SEServerNotFound
   | -- | Connection already used.
     SEConnDuplicate
+  | -- | Confirmed snd queue already exists.
+    SESndQueueExists
   | -- | Wrong connection type, e.g. "send" connection when "receive" or "duplex" is expected, or vice versa.
     -- 'upgradeRcvConnToDuplex' and 'upgradeSndConnToDuplex' do not allow duplex connections - they would also return this error.
     SEBadConnType ConnType
diff --git a/src/Simplex/Messaging/Agent/Store/SQLite.hs b/src/Simplex/Messaging/Agent/Store/SQLite.hs
index 59d05df32..ab2c294d8 100644
--- a/src/Simplex/Messaging/Agent/Store/SQLite.hs
+++ b/src/Simplex/Messaging/Agent/Store/SQLite.hs
@@ -560,10 +560,23 @@ createRcvConn db gVar cData@ConnData {userId, connAgentVersion, enableNtfs, dupl
 
 createSndConn :: DB.Connection -> TVar ChaChaDRG -> ConnData -> SndQueue -> IO (Either StoreError ConnId)
 createSndConn db gVar cData@ConnData {userId, connAgentVersion, enableNtfs, duplexHandshake} q@SndQueue {server} =
-  createConn_ gVar cData $ \connId -> do
-    serverKeyHash_ <- createServer_ db server
-    DB.execute db "INSERT INTO connections (user_id, conn_id, conn_mode, smp_agent_version, enable_ntfs, duplex_handshake) VALUES (?,?,?,?,?,?)" (userId, connId, SCMInvitation, connAgentVersion, enableNtfs, duplexHandshake)
-    void $ insertSndQueue_ db connId q serverKeyHash_
+  -- check confirmed snd queue doesn't already exist, to prevent it being deleted by REPLACE in insertSndQueue_
+  ifM (liftIO $ checkConfirmedSndQueueExists_ db q) (pure $ Left SESndQueueExists) $
+    createConn_ gVar cData $ \connId -> do
+      serverKeyHash_ <- createServer_ db server
+      DB.execute db "INSERT INTO connections (user_id, conn_id, conn_mode, smp_agent_version, enable_ntfs, duplex_handshake) VALUES (?,?,?,?,?,?)" (userId, connId, SCMInvitation, connAgentVersion, enableNtfs, duplexHandshake)
+      void $ insertSndQueue_ db connId q serverKeyHash_
+
+checkConfirmedSndQueueExists_ :: DB.Connection -> SndQueue -> IO Bool
+checkConfirmedSndQueueExists_ db SndQueue {server, sndId} = do
+  fromMaybe False
+    <$> maybeFirstRow
+      fromOnly
+      ( DB.query
+          db
+          "SELECT 1 FROM snd_queues WHERE host = ? AND port = ? AND snd_id = ? AND status != ? LIMIT 1"
+          (host server, port server, sndId, New)
+      )
 
 getRcvConn :: DB.Connection -> SMPServer -> SMP.RecipientId -> IO (Either StoreError (RcvQueue, SomeConn))
 getRcvConn db ProtocolServer {host, port} rcvId = runExceptT $ do