*
*/
+#include <linux/netfilter.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_nat.h>
#include <linux/module.h>
#include <net/sock.h>
+#include <linux/if_arp.h>
+#include <net/arp.h>
-static int ebt_target_snat(struct sk_buff **pskb, unsigned int hooknr,
+static int ebt_target_snat(struct sk_buff *skb, unsigned int hooknr,
const struct net_device *in, const struct net_device *out,
const void *data, unsigned int datalen)
{
struct ebt_nat_info *info = (struct ebt_nat_info *) data;
- if (skb_shared(*pskb) || skb_cloned(*pskb)) {
- struct sk_buff *nskb;
+ if (skb_make_writable(skb, 0))
+ return NF_DROP;
- nskb = skb_copy(*pskb, GFP_ATOMIC);
- if (!nskb)
- return NF_DROP;
- if ((*pskb)->sk)
- skb_set_owner_w(nskb, (*pskb)->sk);
- kfree_skb(*pskb);
- *pskb = nskb;
+ memcpy(eth_hdr(skb)->h_source, info->mac, ETH_ALEN);
+ if (!(info->target & NAT_ARP_BIT) &&
+ eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) {
+ struct arphdr _ah, *ap;
+
+ ap = skb_header_pointer(skb, 0, sizeof(_ah), &_ah);
+ if (ap == NULL)
+ return EBT_DROP;
+ if (ap->ar_hln != ETH_ALEN)
+ goto out;
+ if (skb_store_bits(skb, sizeof(_ah), info->mac,ETH_ALEN))
+ return EBT_DROP;
}
- memcpy(eth_hdr(*pskb)->h_source, info->mac, ETH_ALEN);
- return info->target;
+out:
+ return info->target | ~EBT_VERDICT_BITS;
}
static int ebt_target_snat_check(const char *tablename, unsigned int hookmask,
const struct ebt_entry *e, void *data, unsigned int datalen)
{
struct ebt_nat_info *info = (struct ebt_nat_info *) data;
+ int tmp;
if (datalen != EBT_ALIGN(sizeof(struct ebt_nat_info)))
return -EINVAL;
- if (BASE_CHAIN && info->target == EBT_RETURN)
+ tmp = info->target | ~EBT_VERDICT_BITS;
+ if (BASE_CHAIN && tmp == EBT_RETURN)
return -EINVAL;
CLEAR_BASE_CHAIN_BIT;
if (strcmp(tablename, "nat"))
return -EINVAL;
if (hookmask & ~(1 << NF_BR_POST_ROUTING))
return -EINVAL;
- if (INVALID_TARGET)
+
+ if (tmp < -NUM_STANDARD_TARGETS || tmp >= 0)
+ return -EINVAL;
+ tmp = info->target | EBT_VERDICT_BITS;
+ if ((tmp & ~NAT_ARP_BIT) != ~NAT_ARP_BIT)
return -EINVAL;
return 0;
}