[PATCH nf] netfilter: ctnetlink: remove expired entries first

[Florian Westphal <fw@strlen.de>]

When dumping conntrack table to userspace via ctnetlink, check if the ct has
already expired before doing any of the 'skip' checks.

This expires dead entries faster.
/proc handler also removes outdated entries first.

Reported-by: Vitaly Zuevsky <vzuevsky@ns1.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 Vitaly, I suspect this might be related to the issue you reported,
 I suspect we skip the NAT-clash entries instead of evicting them from
 ctnetlink path too.

 net/netfilter/nf_conntrack_netlink.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 81d03acf68d4..ec4164c32d27 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1195,8 +1195,6 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 		}
 		hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[cb->args[0]],
 					   hnnode) {
-			if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
-				continue;
 			ct = nf_ct_tuplehash_to_ctrack(h);
 			if (nf_ct_is_expired(ct)) {
 				if (i < ARRAY_SIZE(nf_ct_evict) &&
@@ -1208,6 +1206,9 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
 			if (!net_eq(net, nf_ct_net(ct)))
 				continue;
 
+			if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
+				continue;
+
 			if (cb->args[1]) {
 				if (ct != last)
 					continue;
-- 
2.32.0