[PATCH] netfilter/ipvs: expire no destination UDP connections when expire_nodest_conn=1

From: Andrew Sy Kim <kim.andrewsy@gmail.com>
To: unlisted-recipients:; (no To-header on input)
Cc: kim.andrewsy@gmail.com, Wensong Zhang <wensong@linux-vs.org>,
	Simon Horman <horms@verge.net.au>, Julian Anastasov <ja@ssi.bg>,
	Pablo Neira Ayuso <pablo@netfilter.org>,
	Jozsef Kadlecsik <kadlec@netfilter.org>,
	Florian Westphal <fw@strlen.de>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	netdev@vger.kernel.org (open list:IPVS),
	lvs-devel@vger.kernel.org (open list:IPVS),
	netfilter-devel@vger.kernel.org (open list:NETFILTER),
	coreteam@netfilter.org (open list:NETFILTER),
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] netfilter/ipvs: expire no destination UDP connections when expire_nodest_conn=1
Date: Thu, 14 May 2020 21:35:56 -0400	[thread overview]
Message-ID: <20200515013556.5582-1-kim.andrewsy@gmail.com> (raw)

When expire_nodest_conn=1 and an IPVS destination is deleted, IPVS
doesn't expire connections with the IP_VS_CONN_F_ONE_PACKET flag set (any
UDP connection). If there are many UDP packets to a virtual server from a
single client and a destination is deleted, many packets are silently
dropped whenever an existing connection entry with the same source port
exists. This patch ensures IPVS also expires UDP connections when a
packet matches an existing connection with no destinations.

Signed-off-by: Andrew Sy Kim <kim.andrewsy@gmail.com>
---
 net/netfilter/ipvs/ip_vs_core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index aa6a603a2425..f0535586fe75 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -2116,8 +2116,7 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int
 		else
 			ip_vs_conn_put(cp);
 
-		if (sysctl_expire_nodest_conn(ipvs) &&
-		    !(flags & IP_VS_CONN_F_ONE_PACKET)) {
+		if (sysctl_expire_nodest_conn(ipvs)) {
 			/* try to expire the connection immediately */
 			ip_vs_conn_expire_now(cp);
 		}
-- 
2.20.1

