inetpeer: Move ICMP rate limiting state into inet_peer entries.

Like metrics, the ICMP rate limiting bits are cached state about
a destination.  So move it into the inet_peer entries.

If an inet_peer cannot be bound (the reason is memory allocation
failure or similar), the policy is to allow.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 38 insertions, 18 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 0ba6a382b2b4..2e225dafc4f8 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1563,6 +1563,7 @@ void ip_rt_send_redirect(struct sk_buff *skb)
 {
         struct rtable *rt = skb_rtable(skb);
         struct in_device *in_dev;
+        struct inet_peer *peer;
         int log_martians;
 
         rcu_read_lock();
@@ -1574,33 +1575,41 @@ void ip_rt_send_redirect(struct sk_buff *skb)
         log_martians = IN_DEV_LOG_MARTIANS(in_dev);
         rcu_read_unlock();
 
+        if (!rt->peer)
+                rt_bind_peer(rt, 1);
+        peer = rt->peer;
+        if (!peer) {
+                icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
+                return;
+        }
+
         /* No redirected packets during ip_rt_redirect_silence;
          * reset the algorithm.
          */
-        if (time_after(jiffies, rt->dst.rate_last + ip_rt_redirect_silence))
-                rt->dst.rate_tokens = 0;
+        if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
+                peer->rate_tokens = 0;
 
         /* Too many ignored redirects; do not send anything
          * set dst.rate_last to the last seen redirected packet.
          */
-        if (rt->dst.rate_tokens >= ip_rt_redirect_number) {
-                rt->dst.rate_last = jiffies;
+        if (peer->rate_tokens >= ip_rt_redirect_number) {
+                peer->rate_last = jiffies;
                 return;
         }
 
         /* Check for load limit; set rate_last to the latest sent
          * redirect.
          */
-        if (rt->dst.rate_tokens == 0 ||
+        if (peer->rate_tokens == 0 ||
             time_after(jiffies,
-                       (rt->dst.rate_last +
-                        (ip_rt_redirect_load << rt->dst.rate_tokens)))) {
+                       (peer->rate_last +
+                        (ip_rt_redirect_load << peer->rate_tokens)))) {
                 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
-                rt->dst.rate_last = jiffies;
-                ++rt->dst.rate_tokens;
+                peer->rate_last = jiffies;
+                ++peer->rate_tokens;
 #ifdef CONFIG_IP_ROUTE_VERBOSE
                 if (log_martians &&
-                    rt->dst.rate_tokens == ip_rt_redirect_number &&
+                    peer->rate_tokens == ip_rt_redirect_number &&
                     net_ratelimit())
                         printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
                                 &rt->rt_src, rt->rt_iif,
@@ -1612,7 +1621,9 @@ void ip_rt_send_redirect(struct sk_buff *skb)
 static int ip_error(struct sk_buff *skb)
 {
         struct rtable *rt = skb_rtable(skb);
+        struct inet_peer *peer;
         unsigned long now;
+        bool send;
         int code;
 
         switch (rt->dst.error) {
@@ -1632,15 +1643,24 @@ static int ip_error(struct sk_buff *skb)
                         break;
         }
 
-        now = jiffies;
-        rt->dst.rate_tokens += now - rt->dst.rate_last;
-        if (rt->dst.rate_tokens > ip_rt_error_burst)
-                rt->dst.rate_tokens = ip_rt_error_burst;
-        rt->dst.rate_last = now;
-        if (rt->dst.rate_tokens >= ip_rt_error_cost) {
-                rt->dst.rate_tokens -= ip_rt_error_cost;
-                icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
+        if (!rt->peer)
+                rt_bind_peer(rt, 1);
+        peer = rt->peer;
+
+        send = true;
+        if (peer) {
+                now = jiffies;
+                peer->rate_tokens += now - peer->rate_last;
+                if (peer->rate_tokens > ip_rt_error_burst)
+                        peer->rate_tokens = ip_rt_error_burst;
+                peer->rate_last = now;
+                if (peer->rate_tokens >= ip_rt_error_cost)
+                        peer->rate_tokens -= ip_rt_error_cost;
+                else
+                        send = false;
         }
+        if (send)
+                icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
 
 out:    kfree_skb(skb);
         return 0;