From: Jeremy Harris <jgh146exb@wizmail.org>
Date: Sat, 22 Oct 2016 21:40:39 +0000 (+0100)
Subject: TFO: Support compilation on systems which define TCP_FASTOPEN but not MSG_FASTOPEN
X-Git-Tag: exim-4_88_RC3~3
X-Git-Url: https://git.exim.org/users/jgh/exim.git/commitdiff_plain/18f1b2f3f8829931ac096942ff2d1ef85ab5f891

TFO: Support compilation on systems which define TCP_FASTOPEN but not MSG_FASTOPEN

RHEL 7.0 does that, oddly
---

diff --git a/src/OS/os.h-Linux b/src/OS/os.h-Linux
index 6400e798e..510865c66 100644
--- a/src/OS/os.h-Linux
+++ b/src/OS/os.h-Linux
@@ -69,5 +69,9 @@ then change the 0 to 1 in the next block. */
 # define EXIM_HAVE_OPENAT
 #endif
 
+#if defined(TCP_FASTOPEN) && !defined(MSG_FASTOPEN)
+# define MSG_FASTOPEN 0x20000000
+#endif
+
 
 /* End */
diff --git a/src/src/ip.c b/src/src/ip.c
index b744f5d4c..a8230a149 100644
--- a/src/src/ip.c
+++ b/src/src/ip.c
@@ -224,7 +224,7 @@ callout_address = string_sprintf("[%s]:%d", address, port);
 sigalrm_seen = FALSE;
 if (timeout > 0) alarm(timeout);
 
-#ifdef TCP_FASTOPEN
+#if defined(TCP_FASTOPEN) && defined(MSG_FASTOPEN)
 /* TCP Fast Open, if the system has a cookie from a previous call to
 this peer, can send data in the SYN packet.  The peer can send data
 before it gets our ACK of its SYN,ACK - the latter is useful for