X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=net%2Fbridge%2Fnetfilter%2Febt_snat.c;h=ed858580b07e01383bfe1761fe07e5ba4623269e;hb=f776c4cda449bab463f5388eb07bd63dc52e2b13;hp=cbb33e24ca8a8a982ec881e33296860392e7ed4b;hpb=d42510a0f58c2583c37c8e9b7548e3a68545863a;p=karo-tx-linux.git

diff --git a/net/bridge/netfilter/ebt_snat.c b/net/bridge/netfilter/ebt_snat.c
index cbb33e24ca8a..ed858580b07e 100644
--- 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");