Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next

Pablo Neira Ayuso says:

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

1) Revert CHECKSUM_UNNECESSARY for UDP packet from conntrack.

2) Reject unsupported families when creating tables, from Phil Sutter.

3) GRE support for the flowtable, from Toshiaki Makita.

4) Add GRE offload support for act_ct, also from Toshiaki.

5) Update mlx5 driver to support for GRE flowtable offload,
   from Toshiaki Makita.

6) Oneliner to clean up incorrect indentation in nf_conntrack_bridge,
   from Jiapeng Chong.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: bridge: clean up some inconsistent indenting
  net/mlx5: Support GRE conntrack offload
  act_ct: Support GRE offload
  netfilter: flowtable: Support GRE
  netfilter: nf_tables: Reject tables of unsupported family
  Revert "netfilter: conntrack: mark UDP zero checksum as CHECKSUM_UNNECESSARY"
====================

Link: https://lore.kernel.org/r/20220315091513.66544-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 91 insertions, 24 deletions

diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index 89e46f66e3d9..6a34f7b80a6d 100644
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -420,6 +420,19 @@ static void tcf_ct_flow_table_process_conn(struct tcf_ct_flow_table *ct_ft,
 		break;
 	case IPPROTO_UDP:
 		break;
+#ifdef CONFIG_NF_CT_PROTO_GRE
+	case IPPROTO_GRE: {
+		struct nf_conntrack_tuple *tuple;
+
+		if (ct->status & IPS_NAT_MASK)
+			return;
+		tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+		/* No support for GRE v1 */
+		if (tuple->src.u.gre.key || tuple->dst.u.gre.key)
+			return;
+		break;
+	}
+#endif
 	default:
 		return;
 	}
@@ -439,6 +452,8 @@ tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb,
 	struct flow_ports *ports;
 	unsigned int thoff;
 	struct iphdr *iph;
+	size_t hdrsize;
+	u8 ipproto;
 
 	if (!pskb_network_may_pull(skb, sizeof(*iph)))
 		return false;
@@ -450,29 +465,54 @@ tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb,
 	    unlikely(thoff != sizeof(struct iphdr)))
 		return false;
 
-	if (iph->protocol != IPPROTO_TCP &&
-	    iph->protocol != IPPROTO_UDP)
+	ipproto = iph->protocol;
+	switch (ipproto) {
+	case IPPROTO_TCP:
+		hdrsize = sizeof(struct tcphdr);
+		break;
+	case IPPROTO_UDP:
+		hdrsize = sizeof(*ports);
+		break;
+#ifdef CONFIG_NF_CT_PROTO_GRE
+	case IPPROTO_GRE:
+		hdrsize = sizeof(struct gre_base_hdr);
+		break;
+#endif
+	default:
 		return false;
+	}
 
 	if (iph->ttl <= 1)
 		return false;
 
-	if (!pskb_network_may_pull(skb, iph->protocol == IPPROTO_TCP ?
-					thoff + sizeof(struct tcphdr) :
-					thoff + sizeof(*ports)))
+	if (!pskb_network_may_pull(skb, thoff + hdrsize))
 		return false;
 
-	iph = ip_hdr(skb);
-	if (iph->protocol == IPPROTO_TCP)
+	switch (ipproto) {
+	case IPPROTO_TCP:
 		*tcph = (void *)(skb_network_header(skb) + thoff);
+		fallthrough;
+	case IPPROTO_UDP:
+		ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
+		tuple->src_port = ports->source;
+		tuple->dst_port = ports->dest;
+		break;
+	case IPPROTO_GRE: {
+		struct gre_base_hdr *greh;
+
+		greh = (struct gre_base_hdr *)(skb_network_header(skb) + thoff);
+		if ((greh->flags & GRE_VERSION) != GRE_VERSION_0)
+			return false;
+		break;
+	}
+	}
+
+	iph = ip_hdr(skb);
 
-	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
 	tuple->src_v4.s_addr = iph->saddr;
 	tuple->dst_v4.s_addr = iph->daddr;
-	tuple->src_port = ports->source;
-	tuple->dst_port = ports->dest;
 	tuple->l3proto = AF_INET;
-	tuple->l4proto = iph->protocol;
+	tuple->l4proto = ipproto;
 
 	return true;
 }
@@ -485,36 +525,63 @@ tcf_ct_flow_table_fill_tuple_ipv6(struct sk_buff *skb,
 	struct flow_ports *ports;
 	struct ipv6hdr *ip6h;
 	unsigned int thoff;
+	size_t hdrsize;
+	u8 nexthdr;
 
 	if (!pskb_network_may_pull(skb, sizeof(*ip6h)))
 		return false;
 
 	ip6h = ipv6_hdr(skb);
+	thoff = sizeof(*ip6h);
 
-	if (ip6h->nexthdr != IPPROTO_TCP &&
-	    ip6h->nexthdr != IPPROTO_UDP)
-		return false;
+	nexthdr = ip6h->nexthdr;
+	switch (nexthdr) {
+	case IPPROTO_TCP:
+		hdrsize = sizeof(struct tcphdr);
+		break;
+	case IPPROTO_UDP:
+		hdrsize = sizeof(*ports);
+		break;
+#ifdef CONFIG_NF_CT_PROTO_GRE
+	case IPPROTO_GRE:
+		hdrsize = sizeof(struct gre_base_hdr);
+		break;
+#endif
+	default:
+		return -1;
+	}
 
 	if (ip6h->hop_limit <= 1)
 		return false;
 
-	thoff = sizeof(*ip6h);
-	if (!pskb_network_may_pull(skb, ip6h->nexthdr == IPPROTO_TCP ?
-					thoff + sizeof(struct tcphdr) :
-					thoff + sizeof(*ports)))
+	if (!pskb_network_may_pull(skb, thoff + hdrsize))
 		return false;
 
-	ip6h = ipv6_hdr(skb);
-	if (ip6h->nexthdr == IPPROTO_TCP)
+	switch (nexthdr) {
+	case IPPROTO_TCP:
 		*tcph = (void *)(skb_network_header(skb) + thoff);
+		fallthrough;
+	case IPPROTO_UDP:
+		ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
+		tuple->src_port = ports->source;
+		tuple->dst_port = ports->dest;
+		break;
+	case IPPROTO_GRE: {
+		struct gre_base_hdr *greh;
+
+		greh = (struct gre_base_hdr *)(skb_network_header(skb) + thoff);
+		if ((greh->flags & GRE_VERSION) != GRE_VERSION_0)
+			return false;
+		break;
+	}
+	}
+
+	ip6h = ipv6_hdr(skb);
 
-	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
 	tuple->src_v6 = ip6h->saddr;
 	tuple->dst_v6 = ip6h->daddr;
-	tuple->src_port = ports->source;
-	tuple->dst_port = ports->dest;
 	tuple->l3proto = AF_INET6;
-	tuple->l4proto = ip6h->nexthdr;
+	tuple->l4proto = nexthdr;
 
 	return true;
 }