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

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: Yi Chen <yiche@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

3 files changed, 20 insertions, 16 deletions

diff --git a/net/netfilter/ipset/ip_set_bitmap_ipmac.c b/net/netfilter/ipset/ip_set_bitmap_ipmac.c
index c00b6a2e8e3c..13ade5782847 100644
--- a/net/netfilter/ipset/ip_set_bitmap_ipmac.c
+++ b/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);
 }
diff --git a/net/netfilter/ipset/ip_set_hash_ipmac.c b/net/netfilter/ipset/ip_set_hash_ipmac.c
index 1ab5ed2f6839..fd87de3ed55b 100644
--- a/net/netfilter/ipset/ip_set_hash_ipmac.c
+++ b/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;
 
diff --git a/net/netfilter/ipset/ip_set_hash_mac.c b/net/netfilter/ipset/ip_set_hash_mac.c
index f9d5a2a1e3d0..4fe5f243d0a3 100644
--- a/net/netfilter/ipset/ip_set_hash_mac.c
+++ b/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);