netfilter: ipset: Allow matching on destination MAC address for mac and ipmac sets

[ Upstream commit 8cc4ccf58379935f3ad456cc34e61c4e4c921d0e ]

There doesn't seem to be any reason to restrict MAC address
matching to source MAC addresses in set types bitmap:ipmac,
hash:ipmac and hash:mac. With this patch, and this setup:

  ip netns add A
  ip link add veth1 type veth peer name veth2 netns A
  ip addr add 192.0.2.1/24 dev veth1
  ip -net A addr add 192.0.2.2/24 dev veth2
  ip link set veth1 up
  ip -net A link set veth2 up

  ip netns exec A ipset create test hash:mac
  dst=$(ip netns exec A cat /sys/class/net/veth2/address)
  ip netns exec A ipset add test ${dst}
  ip netns exec A iptables -P INPUT DROP
  ip netns exec A iptables -I INPUT -m set --match-set test dst -j ACCEPT

ipset will match packets based on destination MAC address:

  # ping -c1 192.0.2.2 >/dev/null
  # echo $?
  0
Reported-by: NYi Chen <yiche@redhat.com>
Signed-off-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: NSasha Levin <sashal@kernel.org>

net/netfilter/ipset/ip_set_bitmap_ipmac.c

@@ -219,10 +219,6 @@ bitmap_ipmac_kadt(struct ip_set *set, const struct sk_buff *skb,
 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
 	u32 ip;
 
-	/* MAC can be src only */
-	if (!(opt->flags & IPSET_DIM_TWO_SRC))
-		return 0;
-
 	ip = ntohl(ip4addr(skb, opt->flags & IPSET_DIM_ONE_SRC));
 	if (ip < map->first_ip || ip > map->last_ip)
 		return -IPSET_ERR_BITMAP_RANGE;
@@ -233,7 +229,11 @@ bitmap_ipmac_kadt(struct ip_set *set, const struct sk_buff *skb,
 		return -EINVAL;
 
 	e.id = ip_to_id(map, ip);
-	memcpy(e.ether, eth_hdr(skb)->h_source, ETH_ALEN);
+
+	if (opt->flags & IPSET_DIM_ONE_SRC)
+		ether_addr_copy(e.ether, eth_hdr(skb)->h_source);
+	else
+		ether_addr_copy(e.ether, eth_hdr(skb)->h_dest);
 
 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
 }

net/netfilter/ipset/ip_set_hash_ipmac.c

@@ -103,7 +103,11 @@ hash_ipmac4_kadt(struct ip_set *set, const struct sk_buff *skb,
 	    (skb_mac_header(skb) + ETH_HLEN) > skb->data)
 		return -EINVAL;
 
-	memcpy(e.ether, eth_hdr(skb)->h_source, ETH_ALEN);
+	if (opt->flags & IPSET_DIM_ONE_SRC)
+		ether_addr_copy(e.ether, eth_hdr(skb)->h_source);
+	else
+		ether_addr_copy(e.ether, eth_hdr(skb)->h_dest);
+
 	if (ether_addr_equal(e.ether, invalid_ether))
 		return -EINVAL;
 
@@ -211,15 +215,15 @@ hash_ipmac6_kadt(struct ip_set *set, const struct sk_buff *skb,
 	};
 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
 
-	 /* MAC can be src only */
-	if (!(opt->flags & IPSET_DIM_TWO_SRC))
-		return 0;
-
 	if (skb_mac_header(skb) < skb->head ||
 	    (skb_mac_header(skb) + ETH_HLEN) > skb->data)
 		return -EINVAL;
 
-	memcpy(e.ether, eth_hdr(skb)->h_source, ETH_ALEN);
+	if (opt->flags & IPSET_DIM_ONE_SRC)
+		ether_addr_copy(e.ether, eth_hdr(skb)->h_source);
+	else
+		ether_addr_copy(e.ether, eth_hdr(skb)->h_dest);
+
 	if (ether_addr_equal(e.ether, invalid_ether))
 		return -EINVAL;
 

net/netfilter/ipset/ip_set_hash_mac.c

@@ -81,15 +81,15 @@ hash_mac4_kadt(struct ip_set *set, const struct sk_buff *skb,
 	struct hash_mac4_elem e = { { .foo[0] = 0, .foo[1] = 0 } };
 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
 
-	 /* MAC can be src only */
-	if (!(opt->flags & IPSET_DIM_ONE_SRC))
-		return 0;
-
 	if (skb_mac_header(skb) < skb->head ||
 	    (skb_mac_header(skb) + ETH_HLEN) > skb->data)
 		return -EINVAL;
 
-	ether_addr_copy(e.ether, eth_hdr(skb)->h_source);
+	if (opt->flags & IPSET_DIM_ONE_SRC)
+		ether_addr_copy(e.ether, eth_hdr(skb)->h_source);
+	else
+		ether_addr_copy(e.ether, eth_hdr(skb)->h_dest);
+
 	if (is_zero_ether_addr(e.ether))
 		return -EINVAL;
 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);