From 77734c3cb758efe19df3c7d53f574b827164c742 Mon Sep 17 00:00:00 2001
From: Matthieu Herrb <matthieu@herrb.eu>
Date: Tue, 29 Sep 2015 19:18:07 +0200
Subject: [PATCH] Not all systems have the IP_MTU_DISCOVER sockopt

---
 echoc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/echoc.c b/echoc.c
index 9ea5790..5319a41 100644
--- a/echoc.c
+++ b/echoc.c
@@ -167,6 +167,7 @@ main(int argc, char *argv[])
 	if (buf == NULL)
 		err(2, "malloc receive buffer");
 
+#ifdef IP_MTU_DISCOVER
 	/* set the DF flag ? */
 	if (nofragment)
 		ch = IP_PMTUDISC_DO;
@@ -174,7 +175,7 @@ main(int argc, char *argv[])
 		ch = IP_PMTUDISC_DONT;
 	if (setsockopt(sock, IPPROTO_IP, IP_MTU_DISCOVER, &ch, sizeof(ch)) < 0)
 		err(2, "setsockopt IP_MTU_DISCOVER");
-
+#endif
 	while (1) {
 		/* poll() loop to handle interruptions by SIGALRM */
 		while (1) {