[net-next,1/3] netfilter: allow exp not to be removed in nf_ct_find_expectation

Commit Message

Xin Long July 16, 2023, 9:09 p.m. UTC

Currently nf_conntrack_in() calling nf_ct_find_expectation() will
remove the exp from the hash table. However, in some scenario, we
expect the exp not to be removed when the created ct will not be
confirmed, like in OVS and TC conntrack in the following patches.

This patch allows exp not to be removed by setting IPS_CONFIRMED
in the status of the tmpl.

Signed-off-by: Xin Long <[e-mail]>
---
 include/net/netfilter/nf_conntrack_expect.h | 2 +-
 net/netfilter/nf_conntrack_core.c           | 2 +-
 net/netfilter/nf_conntrack_expect.c         | 4 ++--
 net/netfilter/nft_ct.c                      | 2 ++
 4 files changed, 6 insertions(+), 4 deletions(-)

Comments

Aaron Conole July 19, 2023, 4:07 p.m. UTC | #1

Xin Long <[e-mail]> writes:

> Currently nf_conntrack_in() calling nf_ct_find_expectation() will
> remove the exp from the hash table. However, in some scenario, we
> expect the exp not to be removed when the created ct will not be
> confirmed, like in OVS and TC conntrack in the following patches.
>
> This patch allows exp not to be removed by setting IPS_CONFIRMED
> in the status of the tmpl.
>
> Signed-off-by: Xin Long <[e-mail]>
> ---

LGTM

Acked-by: Aaron Conole <[e-mail]>

Patch

diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index cf0d81be5a96..165e7a03b8e9 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -100,7 +100,7 @@  nf_ct_expect_find_get(struct net *net,
 struct nf_conntrack_expect *
 nf_ct_find_expectation(struct net *net,
 		       const struct nf_conntrack_zone *zone,
-		       const struct nf_conntrack_tuple *tuple);
+		       const struct nf_conntrack_tuple *tuple, bool unlink);
 
 void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
 				u32 portid, int report);
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 992393102d5f..9f6f2e643575 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1756,7 +1756,7 @@  init_conntrack(struct net *net, struct nf_conn *tmpl,
 	cnet = nf_ct_pernet(net);
 	if (cnet->expect_count) {
 		spin_lock_bh(&nf_conntrack_expect_lock);
-		exp = nf_ct_find_expectation(net, zone, tuple);
+		exp = nf_ct_find_expectation(net, zone, tuple, !tmpl || nf_ct_is_confirmed(tmpl));
 		if (exp) {
 			/* Welcome, Mr. Bond.  We've been expecting you... */
 			__set_bit(IPS_EXPECTED_BIT, &ct->status);
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 96948e98ec53..81ca348915c9 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -171,7 +171,7 @@  EXPORT_SYMBOL_GPL(nf_ct_expect_find_get);
 struct nf_conntrack_expect *
 nf_ct_find_expectation(struct net *net,
 		       const struct nf_conntrack_zone *zone,
-		       const struct nf_conntrack_tuple *tuple)
+		       const struct nf_conntrack_tuple *tuple, bool unlink)
 {
 	struct nf_conntrack_net *cnet = nf_ct_pernet(net);
 	struct nf_conntrack_expect *i, *exp = NULL;
@@ -211,7 +211,7 @@  nf_ct_find_expectation(struct net *net,
 		     !refcount_inc_not_zero(&exp->master->ct_general.use)))
 		return NULL;
 
-	if (exp->flags & NF_CT_EXPECT_PERMANENT) {
+	if (exp->flags & NF_CT_EXPECT_PERMANENT || !unlink) {
 		refcount_inc(&exp->use);
 		return exp;
 	} else if (del_timer(&exp->timeout)) {
diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index 38958e067aa8..e87fd4314c68 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -262,6 +262,7 @@  static void nft_ct_set_zone_eval(const struct nft_expr *expr,
 			regs->verdict.code = NF_DROP;
 			return;
 		}
+		__set_bit(IPS_CONFIRMED_BIT, &ct->status);
 	}
 
 	nf_ct_set(skb, ct, IP_CT_NEW);
@@ -368,6 +369,7 @@  static bool nft_ct_tmpl_alloc_pcpu(void)
 			return false;
 		}
 
+		__set_bit(IPS_CONFIRMED_BIT, &tmp->status);
 		per_cpu(nft_ct_pcpu_template, cpu) = tmp;
 	}