From d69cefc4b2290fe69ef2505612ba3d70e692fb17 Mon Sep 17 00:00:00 2001
From: Andrei Tarassov <andrei.tarassov@thetradedesk.com>
Date: Tue, 29 Oct 2024 18:03:13 +1100
Subject: [PATCH] Turn off Nagle

---
 vsock-bridge/include/listener.h | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/vsock-bridge/include/listener.h b/vsock-bridge/include/listener.h
index 635ab19..676f17a 100644
--- a/vsock-bridge/include/listener.h
+++ b/vsock-bridge/include/listener.h
@@ -12,6 +12,7 @@
 #include <errno.h>
 #include <linux/vm_sockets.h>
 #include <netinet/in.h>
+#include <netinet/tcp.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/epoll.h>
@@ -51,6 +52,17 @@ namespace vsockio
 			}
 			return true;
 		}
+
+        static bool setTcpNoDelay(int fd) {
+            int enable = 1;
+            if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &enable, sizeof(enable)) < 0)
+            {
+                const int err = errno;
+                Logger::instance->Log(Logger::ERROR, "setsockopt error: ", strerror(err));
+                return false;
+            }
+            return true;
+        }
 	};
 
     struct Listener
@@ -156,7 +168,13 @@ namespace vsockio
 				return;
 			}
 
-			auto outPeer = connectToPeer();
+            if (_listenEp->getAddress().first->sa_family == AF_INET && !IOControl::setTcpNoDelay(clientFd))
+            {
+                Logger::instance->Log(Logger::ERROR, "failed to turn off Nagle algorithm (fd=", clientFd, ")");
+                return;
+            }
+
+            auto outPeer = connectToPeer();
 			if (!outPeer)
 			{
 				return;
@@ -183,6 +201,12 @@ namespace vsockio
 				return nullptr;
 			}
 
+            if (_connectEp->getAddress().first->sa_family == AF_INET && !IOControl::setTcpNoDelay(fd))
+            {
+                Logger::instance->Log(Logger::ERROR, "failed to turn off Nagle algorithm (fd=", fd, ")");
+                return nullptr;
+            }
+
             auto addrAndLen = _connectEp->getAddress();
             int status = connect(fd, addrAndLen.first, addrAndLen.second);
             if (status == 0 || (status = errno) == EINPROGRESS)