Merge branch 'main' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next

Florian Westphal says:

====================
Netfilter updates for net-next

1. nf_tables 'brouting' support, from Sriram Yagnaraman.

2. Update bridge netfilter and ovs conntrack helpers to handle
   IPv6 Jumbo packets properly, i.e. fetch the packet length
   from hop-by-hop extension header, from Xin Long.

   This comes with a test BIG TCP test case, added to
   tools/testing/selftests/net/.

3. Fix spelling and indentation in conntrack, from Jeremy Sowden.

* 'main' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nat: fix indentation of function arguments
  netfilter: conntrack: fix typo
  selftests: add a selftest for big tcp
  netfilter: use nf_ip6_check_hbh_len in nf_ct_skb_network_trim
  netfilter: move br_nf_check_hbh_len to utils
  netfilter: bridge: move pskb_trim_rcsum out of br_nf_check_hbh_len
  netfilter: bridge: check len before accessing more nh data
  netfilter: bridge: call pskb_may_pull in br_nf_check_hbh_len
  netfilter: bridge: introduce broute meta statement
====================

Link: https://lore.kernel.org/r/20230308193033.13965-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 64 insertions, 5 deletions

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index c6a6a6099b4e..db1ea361f2da 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1294,7 +1294,7 @@ dying:
 }
 EXPORT_SYMBOL_GPL(__nf_conntrack_confirm);
 
-/* Returns true if a connection correspondings to the tuple (required
+/* Returns true if a connection corresponds to the tuple (required
    for NAT). */
 int
 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
diff --git a/net/netfilter/nf_conntrack_ovs.c b/net/netfilter/nf_conntrack_ovs.c
index 52b776bdf526..068e9489e1c2 100644
--- a/net/netfilter/nf_conntrack_ovs.c
+++ b/net/netfilter/nf_conntrack_ovs.c
@@ -6,6 +6,7 @@
 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
 #include <net/ipv6_frag.h>
 #include <net/ip.h>
+#include <linux/netfilter_ipv6.h>
 
 /* 'skb' should already be pulled to nh_ofs. */
 int nf_ct_helper(struct sk_buff *skb, struct nf_conn *ct,
@@ -120,8 +121,14 @@ int nf_ct_skb_network_trim(struct sk_buff *skb, int family)
 		len = skb_ip_totlen(skb);
 		break;
 	case NFPROTO_IPV6:
-		len = sizeof(struct ipv6hdr)
-			+ ntohs(ipv6_hdr(skb)->payload_len);
+		len = ntohs(ipv6_hdr(skb)->payload_len);
+		if (ipv6_hdr(skb)->nexthdr == NEXTHDR_HOP) {
+			int err = nf_ip6_check_hbh_len(skb, &len);
+
+			if (err)
+				return err;
+		}
+		len += sizeof(struct ipv6hdr);
 		break;
 	default:
 		len = skb->len;
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index e29e4ccb5c5a..ce829d434f13 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -549,8 +549,8 @@ get_unique_tuple(struct nf_conntrack_tuple *tuple,
 		if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
 			if (!(range->flags & NF_NAT_RANGE_PROTO_OFFSET) &&
 			    l4proto_in_range(tuple, maniptype,
-			          &range->min_proto,
-			          &range->max_proto) &&
+					     &range->min_proto,
+					     &range->max_proto) &&
 			    (range->min_proto.all == range->max_proto.all ||
 			     !nf_nat_used_tuple(tuple, ct)))
 				return;
diff --git a/net/netfilter/utils.c b/net/netfilter/utils.c
index 2182d361e273..acef4155f0da 100644
--- a/net/netfilter/utils.c
+++ b/net/netfilter/utils.c
@@ -215,3 +215,55 @@ int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry)
 	}
 	return ret;
 }
+
+/* Only get and check the lengths, not do any hop-by-hop stuff. */
+int nf_ip6_check_hbh_len(struct sk_buff *skb, u32 *plen)
+{
+	int len, off = sizeof(struct ipv6hdr);
+	unsigned char *nh;
+
+	if (!pskb_may_pull(skb, off + 8))
+		return -ENOMEM;
+	nh = (unsigned char *)(ipv6_hdr(skb) + 1);
+	len = (nh[1] + 1) << 3;
+
+	if (!pskb_may_pull(skb, off + len))
+		return -ENOMEM;
+	nh = skb_network_header(skb);
+
+	off += 2;
+	len -= 2;
+	while (len > 0) {
+		int optlen;
+
+		if (nh[off] == IPV6_TLV_PAD1) {
+			off++;
+			len--;
+			continue;
+		}
+		if (len < 2)
+			return -EBADMSG;
+		optlen = nh[off + 1] + 2;
+		if (optlen > len)
+			return -EBADMSG;
+
+		if (nh[off] == IPV6_TLV_JUMBO) {
+			u32 pkt_len;
+
+			if (nh[off + 1] != 4 || (off & 3) != 2)
+				return -EBADMSG;
+			pkt_len = ntohl(*(__be32 *)(nh + off + 2));
+			if (pkt_len <= IPV6_MAXPLEN ||
+			    ipv6_hdr(skb)->payload_len)
+				return -EBADMSG;
+			if (pkt_len > skb->len - sizeof(struct ipv6hdr))
+				return -EBADMSG;
+			*plen = pkt_len;
+		}
+		off += optlen;
+		len -= optlen;
+	}
+
+	return len ? -EBADMSG : 0;
+}
+EXPORT_SYMBOL_GPL(nf_ip6_check_hbh_len);