[NETFILTER]: ebtables: Update modules' descriptions

[karo-tx-linux.git] / net / bridge / netfilter / ebt_snat.c

diff --git a/net/bridge/netfilter/ebt_snat.c b/net/bridge/netfilter/ebt_snat.c
index cbb33e24ca8a8a982ec881e33296860392e7ed4b..ed858580b07e01383bfe1761fe07e5ba4623269e 100644 (file)
--- a/net/bridge/netfilter/ebt_snat.c
+++ b/net/bridge/netfilter/ebt_snat.c
@@ -8,47 +8,62 @@
  *
  */
 
+#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;
+       const struct ebt_nat_info *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)) {
+               const struct arphdr *ap;
+               struct arphdr _ah;
+
+               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;
+       const struct ebt_nat_info *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;
 }
@@ -73,4 +88,5 @@ static void __exit ebt_snat_fini(void)
 
 module_init(ebt_snat_init);
 module_exit(ebt_snat_fini);
+MODULE_DESCRIPTION("Ebtables: Source MAC address translation");
 MODULE_LICENSE("GPL");