1 files changed, 87 insertions, 10 deletions

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 1927fc296f95..7c503b4751c4 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1517,9 +1517,9 @@ __nf_conntrack_alloc(struct net *net,
 	ct->status = 0;
 	ct->timeout = 0;
 	write_pnet(&ct->ct_net, net);
-	memset(&ct->__nfct_init_offset[0], 0,
+	memset(&ct->__nfct_init_offset, 0,
 	       offsetof(struct nf_conn, proto) -
-	       offsetof(struct nf_conn, __nfct_init_offset[0]));
+	       offsetof(struct nf_conn, __nfct_init_offset));
 
 	nf_ct_zone_add(ct, zone);
 
@@ -2014,22 +2014,18 @@ static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb)
 	nf_conntrack_get(skb_nfct(nskb));
 }
 
-static int nf_conntrack_update(struct net *net, struct sk_buff *skb)
+static int __nf_conntrack_update(struct net *net, struct sk_buff *skb,
+				 struct nf_conn *ct,
+				 enum ip_conntrack_info ctinfo)
 {
 	struct nf_conntrack_tuple_hash *h;
 	struct nf_conntrack_tuple tuple;
-	enum ip_conntrack_info ctinfo;
 	struct nf_nat_hook *nat_hook;
 	unsigned int status;
-	struct nf_conn *ct;
 	int dataoff;
 	u16 l3num;
 	u8 l4num;
 
-	ct = nf_ct_get(skb, &ctinfo);
-	if (!ct || nf_ct_is_confirmed(ct))
-		return 0;
-
 	l3num = nf_ct_l3num(ct);
 
 	dataoff = get_l4proto(skb, skb_network_offset(skb), l3num, &l4num);
@@ -2086,6 +2082,76 @@ static int nf_conntrack_update(struct net *net, struct sk_buff *skb)
 	return 0;
 }
 
+/* This packet is coming from userspace via nf_queue, complete the packet
+ * processing after the helper invocation in nf_confirm().
+ */
+static int nf_confirm_cthelper(struct sk_buff *skb, struct nf_conn *ct,
+			       enum ip_conntrack_info ctinfo)
+{
+	const struct nf_conntrack_helper *helper;
+	const struct nf_conn_help *help;
+	int protoff;
+
+	help = nfct_help(ct);
+	if (!help)
+		return 0;
+
+	helper = rcu_dereference(help->helper);
+	if (!(helper->flags & NF_CT_HELPER_F_USERSPACE))
+		return 0;
+
+	switch (nf_ct_l3num(ct)) {
+	case NFPROTO_IPV4:
+		protoff = skb_network_offset(skb) + ip_hdrlen(skb);
+		break;
+#if IS_ENABLED(CONFIG_IPV6)
+	case NFPROTO_IPV6: {
+		__be16 frag_off;
+		u8 pnum;
+
+		pnum = ipv6_hdr(skb)->nexthdr;
+		protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum,
+					   &frag_off);
+		if (protoff < 0 || (frag_off & htons(~0x7)) != 0)
+			return 0;
+		break;
+	}
+#endif
+	default:
+		return 0;
+	}
+
+	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
+	    !nf_is_loopback_packet(skb)) {
+		if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) {
+			NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
+			return -1;
+		}
+	}
+
+	/* We've seen it coming out the other side: confirm it */
+	return nf_conntrack_confirm(skb) == NF_DROP ? - 1 : 0;
+}
+
+static int nf_conntrack_update(struct net *net, struct sk_buff *skb)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct;
+	int err;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct)
+		return 0;
+
+	if (!nf_ct_is_confirmed(ct)) {
+		err = __nf_conntrack_update(net, skb, ct, ctinfo);
+		if (err < 0)
+			return err;
+	}
+
+	return nf_confirm_cthelper(skb, ct, ctinfo);
+}
+
 static bool nf_conntrack_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
 				       const struct sk_buff *skb)
 {
@@ -2137,8 +2203,19 @@ get_next_corpse(int (*iter)(struct nf_conn *i, void *data),
 		nf_conntrack_lock(lockp);
 		if (*bucket < nf_conntrack_htable_size) {
 			hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[*bucket], hnnode) {
-				if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
+				if (NF_CT_DIRECTION(h) != IP_CT_DIR_REPLY)
 					continue;
+				/* All nf_conn objects are added to hash table twice, one
+				 * for original direction tuple, once for the reply tuple.
+				 *
+				 * Exception: In the IPS_NAT_CLASH case, only the reply
+				 * tuple is added (the original tuple already existed for
+				 * a different object).
+				 *
+				 * We only need to call the iterator once for each
+				 * conntrack, so we just use the 'reply' direction
+				 * tuple while iterating.
+				 */
 				ct = nf_ct_tuplehash_to_ctrack(h);
 				if (iter(ct, data))
 					goto found;