From 1274bc4fa8637380a82159c44dd9f3f0b42e8e32 Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Wed, 15 Jul 2009 07:16:31 +0200
Subject: [PATCH] [MINOR] apply tcp-smart-connect option for the checks too

We should respect tcp-smart-connect for checks too. First it reduces
the traffic, and second it ensures that the checks see the same thing
as the production traffic, which is better for debugging.
---
 src/checks.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/checks.c b/src/checks.c
index 4022cad58..40fb698ef 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -21,6 +21,7 @@
 #include <unistd.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <netinet/tcp.h>
 #include <arpa/inet.h>
 
 #include <common/compat.h>
@@ -677,6 +678,14 @@ struct task *process_chk(struct task *t)
 				}
 
 				if (s->result == SRV_CHK_UNKNOWN) {
+#ifdef TCP_QUICKACK
+					/* disabling tcp quick ack now allows
+					 * the request to leave the machine with
+					 * the first ACK.
+					 */
+					if (s->proxy->options2 & PR_O2_SMARTCON)
+						setsockopt(fd, SOL_TCP, TCP_QUICKACK, (char *) &zero, sizeof(zero));
+#endif
 					if ((connect(fd, (struct sockaddr *)&sa, sizeof(sa)) != -1) || (errno == EINPROGRESS)) {
 						/* OK, connection in progress or established */