ipvs: add pmtu_disc option to disable IP DF for TUN packets

	Disabling PMTU discovery can increase the output packet
rate but some users have enough resources and prefer to fragment
than to drop traffic. By default, we copy the DF bit but if
pmtu_disc is disabled we do not send FRAG_NEEDED messages anymore.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 4b8f18ff4789..ee75ccdf5188 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -888,6 +888,7 @@ struct netns_ipvs {
         unsigned int            sysctl_sync_refresh_period;
         int                     sysctl_sync_retries;
         int                     sysctl_nat_icmp_send;
+        int                     sysctl_pmtu_disc;
 
         /* ip_vs_lblc */
         int                     sysctl_lblc_expiration;
@@ -974,6 +975,11 @@ static inline int sysctl_sync_sock_size(struct netns_ipvs *ipvs)
         return ipvs->sysctl_sync_sock_size;
 }
 
+static inline int sysctl_pmtu_disc(struct netns_ipvs *ipvs)
+{
+        return ipvs->sysctl_pmtu_disc;
+}
+
 #else
 
 static inline int sysctl_sync_threshold(struct netns_ipvs *ipvs)
@@ -1016,6 +1022,11 @@ static inline int sysctl_sync_sock_size(struct netns_ipvs *ipvs)
         return 0;
 }
 
+static inline int sysctl_pmtu_disc(struct netns_ipvs *ipvs)
+{
+        return 1;
+}
+
 #endif
 
 /*