[PATCH] netfilter: ctnetlink: support CTA_FILTER for flush

[Changliang Wu <changliang.wu@smartx.com>]

From cb8aa9a, we can use kernel side filtering for dump, but
this capability is not available for flush.

This Patch allows advanced filter with CTA_FILTER for flush

Performace
1048576 ct flows in total, delete 50,000 flows by origin src ip
3.06s -> dump all, compare and delete
584ms -> directly flush with filter

Signed-off-by: Changliang Wu <changliang.wu@smartx.com>
---
 net/netfilter/nf_conntrack_netlink.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 3b846cbdc..93afe57d9 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1579,9 +1579,6 @@ static int ctnetlink_flush_conntrack(struct net *net,
 	};
 
 	if (ctnetlink_needs_filter(family, cda)) {
-		if (cda[CTA_FILTER])
-			return -EOPNOTSUPP;
-
 		filter = ctnetlink_alloc_filter(cda, family);
 		if (IS_ERR(filter))
 			return PTR_ERR(filter);
@@ -1610,14 +1607,14 @@ static int ctnetlink_del_conntrack(struct sk_buff *skb,
 	if (err < 0)
 		return err;
 
-	if (cda[CTA_TUPLE_ORIG])
+	if (cda[CTA_TUPLE_ORIG] && !cda[CTA_FILTER])
 		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG,
 					    family, &zone);
-	else if (cda[CTA_TUPLE_REPLY])
+	else if (cda[CTA_TUPLE_REPLY] && !cda[CTA_FILTER])
 		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY,
 					    family, &zone);
 	else {
-		u_int8_t u3 = info->nfmsg->version ? family : AF_UNSPEC;
+		u8 u3 = info->nfmsg->version || cda[CTA_FILTER] ? family : AF_UNSPEC;
 
 		return ctnetlink_flush_conntrack(info->net, cda,
 						 NETLINK_CB(skb).portid,
-- 
2.43.0