ipvs: add sync_maxlen parameter for the sync daemon

Allow setups with large MTU to send large sync packets by
adding sync_maxlen parameter. The default value is now based
on MTU but no more than 1500 for compatibility reasons.

To avoid problems if MTU changes allow fragmentation by
sending packets with DF=0. Problem reported by Dan Carpenter.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/uapi/linux/ip_vs.h b/include/uapi/linux/ip_vs.h
index 3199243f2028..68377d8c8870 100644
--- a/include/uapi/linux/ip_vs.h
+++ b/include/uapi/linux/ip_vs.h
@@ -406,6 +406,7 @@ enum {
         IPVS_DAEMON_ATTR_STATE,         /* sync daemon state (master/backup) */
         IPVS_DAEMON_ATTR_MCAST_IFN,     /* multicast interface name */
         IPVS_DAEMON_ATTR_SYNC_ID,       /* SyncID we belong to */
+        IPVS_DAEMON_ATTR_SYNC_MAXLEN,   /* UDP Payload Size */
         __IPVS_DAEMON_ATTR_MAX,
 };