Don't process packets in NAT that aren't destined for us.

This time for sure!

diff --git a/datapath/nx_act_snat.c b/datapath/nx_act_snat.c
index dddbf4b370121d5ea40d7e33922cfe09f76c1f25..819299e641412ae6e72c073e6987350c67f8d9dd 100644 (file)
--- a/datapath/nx_act_snat.c
+++ b/datapath/nx_act_snat.c
@@ -116,23 +116,13 @@ void snat_local_in(struct sk_buff *skb)
 static int
 dnat_mac(struct net_bridge_port *p, struct sk_buff *skb)
 {
-       struct snat_conf *sc;
+       struct snat_conf *sc = p->snat;
        struct iphdr *iph = ip_hdr(skb);
        struct ethhdr *eh = eth_hdr(skb);
        struct snat_mapping *m;
-       unsigned long flags;
-
-       spin_lock_irqsave(&p->lock, flags);
-       sc = p->snat;
-       if (!sc) {
-               spin_unlock_irqrestore(&p->lock, flags);
-               return -EINVAL;
-       }
 
-       if (skb->protocol != htons(ETH_P_IP)) {
-               spin_unlock_irqrestore(&p->lock, flags);
+       if (skb->protocol != htons(ETH_P_IP)) 
                return 0;
-       }
 
        list_for_each_entry (m, &sc->mappings, node) {
                if (m->ip_addr == iph->daddr){
@@ -140,7 +130,6 @@ dnat_mac(struct net_bridge_port *p, struct sk_buff *skb)
                        if (!make_writable(&skb)) {
                                if (net_ratelimit())
                                        printk("make_writable failed\n");
-                               spin_unlock_irqrestore(&p->lock, flags);
                                return -EINVAL;
                        }
                        m->used = jiffies;
@@ -149,7 +138,6 @@ dnat_mac(struct net_bridge_port *p, struct sk_buff *skb)
                }
        }
 
-       spin_unlock_irqrestore(&p->lock, flags);
        return 0;
 }
 
@@ -157,15 +145,31 @@ static int
 snat_pre_route_finish(struct sk_buff *skb)
 {
        struct net_bridge_port *p = skb->dev->br_port;
+       struct snat_conf *sc;
+       struct iphdr *iph = ip_hdr(skb);
+       uint32_t ip_addr;
+       unsigned long flags;
 
        skb->dst = (struct dst_entry *)&__fake_rtable;
        dst_hold(skb->dst);
 
+       /* Don't process packets that were not translated due to NAT */
+       spin_lock_irqsave(&p->lock, flags);
+       sc = p->snat;
+       ip_addr = ntohl(iph->daddr);
+       if (sc && (ip_addr >= sc->ip_addr_start) 
+                       && (ip_addr <= sc->ip_addr_end)) {
+               spin_unlock_irqrestore(&p->lock, flags);
+               return -1;
+       }
+
        /* If SNAT is configured for this input device, check the IP->MAC
         * mappings to see if we should update the destination MAC. */
-       if (p->snat)
+       if (sc)
                dnat_mac(skb->dev->br_port, skb);
 
+       spin_unlock_irqrestore(&p->lock, flags);
+
        return 0;
 }