From 29ca6bbd3488aa8ffa574bd61dfeea412c970cbf Mon Sep 17 00:00:00 2001
From: Kelly Kinkade <kelly.lynn.martin@gmail.com>
Date: Sun, 19 Nov 2023 06:59:04 -0600
Subject: [PATCH 1/3] RemoteServer: reset fail counter after success

should close #4040
---
 library/RemoteServer.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/library/RemoteServer.cpp b/library/RemoteServer.cpp
index 72f2a29b5..58a6f52ba 100644
--- a/library/RemoteServer.cpp
+++ b/library/RemoteServer.cpp
@@ -80,7 +80,7 @@ namespace {
     struct BlockedException : std::exception {
         const char* what() const noexcept override
         {
-            return "Core has blocked all connection. This should have been catched.";
+            return "Core has blocked all connection. This should have been caught.";
         }
     };
 }
@@ -478,23 +478,26 @@ void ServerMainImpl::threadFn(std::promise<bool> promise, int port)
     CActiveSocket *client = nullptr;
 
     try {
-        for (int acceptFail = 0 ; server.socket.IsSocketValid() && acceptFail < 5 ; acceptFail++)
+        for (int acceptFail = 0; server.socket.IsSocketValid() && acceptFail < 5; acceptFail++)
         {
             if ((client = server.socket.Accept()) != NULL)
             {
                 BlockGuard lock;
                 ServerConnection::Accepted(client);
                 client = nullptr;
+                acceptFail = 0;
             }
             else
             {
                 WARN(socket).print("Connection failure: %s (%d of %d)\n", server.socket.DescribeError(), acceptFail + 1, 5);
             }
         }
-    } catch(BlockedException &) {
+    }
+    catch (BlockedException&) {
         if (client)
             client->Close();
         delete client;
+        WARN(socket).print("Connection failure: unexpectedly blocked");
     }
 
     if (server.socket.IsSocketValid())

From 77ce84ca0a6c4129f1c85f9bdff056c95da02cfb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Vuchener?= <clement.vuchener@gmail.com>
Date: Sun, 19 Nov 2023 14:46:14 +0100
Subject: [PATCH 2/3] Improve Accept error handling in RemoteServer

Also makes sure the socket is blocking to avoid EWOULDBLOCK errors.
---
 library/RemoteServer.cpp | 39 ++++++++++++++++-----------------------
 1 file changed, 16 insertions(+), 23 deletions(-)

diff --git a/library/RemoteServer.cpp b/library/RemoteServer.cpp
index 72f2a29b5..192ead947 100644
--- a/library/RemoteServer.cpp
+++ b/library/RemoteServer.cpp
@@ -475,35 +475,28 @@ void ServerMainImpl::threadFn(std::promise<bool> promise, int port)
 {
     ServerMainImpl server{std::move(promise), port};
 
-    CActiveSocket *client = nullptr;
-
+    server.socket.SetBlocking();
     try {
-        for (int acceptFail = 0 ; server.socket.IsSocketValid() && acceptFail < 5 ; acceptFail++)
-        {
-            if ((client = server.socket.Accept()) != NULL)
-            {
+        while (server.socket.IsSocketValid()) {
+            if (std::unique_ptr<CActiveSocket> client{server.socket.Accept()}) {
                 BlockGuard lock;
-                ServerConnection::Accepted(client);
-                client = nullptr;
+                ServerConnection::Accepted(client.release());
             }
-            else
-            {
-                WARN(socket).print("Connection failure: %s (%d of %d)\n", server.socket.DescribeError(), acceptFail + 1, 5);
+            else switch (server.socket.GetSocketError()) {
+            case CSimpleSocket::SocketInvalidSocket:
+                WARN(socket).print("Listening socket invalid, shutting down RemoteServer\n");
+                server.socket.Close();
+                break;
+            case CSimpleSocket::SocketFirewallError:
+            case CSimpleSocket::SocketProtocolError:
+                WARN(socket).print("Connection failed: %s\n", server.socket.DescribeError());
+                break;
+            default:
+                break;
             }
         }
-    } catch(BlockedException &) {
-        if (client)
-            client->Close();
-        delete client;
-    }
-
-    if (server.socket.IsSocketValid())
-    {
-        WARN(socket).print("Too many failed accepts, shutting down RemoteServer\n");
     }
-    else
-    {
-        WARN(socket).print("Listening socket invalid, shutting down RemoteServer\n");
+    catch(BlockedException &) {
     }
 }
 

From 9a62a63f89dae56045e2e9da67b8394d23846f19 Mon Sep 17 00:00:00 2001
From: Myk Taylor <myk002@yahoo.com>
Date: Mon, 20 Nov 2023 00:09:30 -0800
Subject: [PATCH 3/3] update changelog

---
 docs/changelog.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/changelog.txt b/docs/changelog.txt
index b3c73f3b7..1d19d3f74 100644
--- a/docs/changelog.txt
+++ b/docs/changelog.txt
@@ -57,6 +57,7 @@ Template for new versions:
 
 ## Fixes
 - `buildingplan`: fix choosing the wrong mechanism (or something that isn't a mechanism) when linking a lever and manually choosing a mechanism, but then canceling the selection
+- RemoteServer: don't shut down the socket prematurely, allowing continuing connections from, for example, dfhack-run
 
 ## Misc Improvements
 - `buildingplan`: save magma safe mechanisms for when magma safety is requested when linking levers and pressure plates to targets