From a7f10103f94d2b4814dbd397208bf289490af40d Mon Sep 17 00:00:00 2001
From: Hasan Mahmood <hasan.mahmood@datadoghq.com>
Date: Fri, 1 Apr 2022 18:53:53 -0500
Subject: [PATCH] Ignore ENOPROTOOPT error when setting NETLINK_EXT_ACK to 0

---
 nl/nl_linux.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/nl/nl_linux.go b/nl/nl_linux.go
index 20ea144..9db1eca 100644
--- a/nl/nl_linux.go
+++ b/nl/nl_linux.go
@@ -798,7 +798,13 @@ func (s *NetlinkSocket) SetExtAck(enable bool) error {
 		enableN = 1
 	}
 
-	return unix.SetsockoptInt(int(s.fd), unix.SOL_NETLINK, unix.NETLINK_EXT_ACK, enableN)
+	var err error
+	if err = unix.SetsockoptInt(int(s.fd), unix.SOL_NETLINK, unix.NETLINK_EXT_ACK, enableN); err == unix.ENOPROTOOPT && !enable {
+		// older kernels may not support NETLINK_EXT_ACK
+		return nil
+	}
+
+	return err
 }
 
 func (s *NetlinkSocket) GetPid() (uint32, error) {