Patch "netfilter: ipvs: Fix reuse connection if RS weight is 0" has been added to the 4.14-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    netfilter: ipvs: Fix reuse connection if RS weight is 0

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netfilter-ipvs-fix-reuse-connection-if-rs-weight-is-.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 53302ccd6dd926f8325c802218a754c28a8f620d
Author: yangxingwu <xingwu.yang@xxxxxxxxx>
Date:   Thu Nov 4 03:10:29 2021 +0100

    netfilter: ipvs: Fix reuse connection if RS weight is 0
    
    [ Upstream commit c95c07836fa4c1767ed11d8eca0769c652760e32 ]
    
    We are changing expire_nodest_conn to work even for reused connections when
    conn_reuse_mode=0, just as what was done with commit dc7b3eb900aa ("ipvs:
    Fix reuse connection if real server is dead").
    
    For controlled and persistent connections, the new connection will get the
    needed real server depending on the rules in ip_vs_check_template().
    
    Fixes: d752c3645717 ("ipvs: allow rescheduling of new connections when port reuse is detected")
    Co-developed-by: Chuanqi Liu <legend050709@xxxxxx>
    Signed-off-by: Chuanqi Liu <legend050709@xxxxxx>
    Signed-off-by: yangxingwu <xingwu.yang@xxxxxxxxx>
    Acked-by: Simon Horman <horms@xxxxxxxxxxxx>
    Acked-by: Julian Anastasov <ja@xxxxxx>
    Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/Documentation/networking/ipvs-sysctl.txt b/Documentation/networking/ipvs-sysctl.txt
index 056898685d408..fc531c29a2e83 100644
--- a/Documentation/networking/ipvs-sysctl.txt
+++ b/Documentation/networking/ipvs-sysctl.txt
@@ -30,8 +30,7 @@ conn_reuse_mode - INTEGER
 
 	0: disable any special handling on port reuse. The new
 	connection will be delivered to the same real server that was
-	servicing the previous connection. This will effectively
-	disable expire_nodest_conn.
+	servicing the previous connection.
 
 	bit 1: enable rescheduling of new connections when it is safe.
 	That is, whenever expire_nodest_conn and for TCP sockets, when
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index a95fe5fe9f046..4b9cd1c1c9987 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -1838,7 +1838,6 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int
 	struct ip_vs_proto_data *pd;
 	struct ip_vs_conn *cp;
 	int ret, pkts;
-	int conn_reuse_mode;
 	struct sock *sk;
 
 	/* Already marked as IPVS request or reply? */
@@ -1914,15 +1913,16 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int
 	 */
 	cp = pp->conn_in_get(ipvs, af, skb, &iph);
 
-	conn_reuse_mode = sysctl_conn_reuse_mode(ipvs);
-	if (conn_reuse_mode && !iph.fragoffs && is_new_conn(skb, &iph) && cp) {
+	if (!iph.fragoffs && is_new_conn(skb, &iph) && cp) {
+		int conn_reuse_mode = sysctl_conn_reuse_mode(ipvs);
 		bool old_ct = false, resched = false;
 
 		if (unlikely(sysctl_expire_nodest_conn(ipvs)) && cp->dest &&
 		    unlikely(!atomic_read(&cp->dest->weight))) {
 			resched = true;
 			old_ct = ip_vs_conn_uses_old_conntrack(cp, skb);
-		} else if (is_new_conn_expected(cp, conn_reuse_mode)) {
+		} else if (conn_reuse_mode &&
+			   is_new_conn_expected(cp, conn_reuse_mode)) {
 			old_ct = ip_vs_conn_uses_old_conntrack(cp, skb);
 			if (!atomic_read(&cp->n_control)) {
 				resched = true;