[IPV4]: Snmpv2 Mib IP counter ipInAddrErrors support

I followed Thomas' proposal to see every martian destination as a case
where the ipInAddrErrors counter has to be incremented. There are
two advantages by doing so: (1) The relation between the ipInReceive
counter and all the other ipInXXX counters is more accurate in the
case the RTN_UNICAST code check fails and (2) it makes the code in
ip_route_input_slow easier.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 12 insertions, 3 deletions

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index af2ec88bbb2..c703528e0bc 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -283,14 +283,18 @@ static inline int ip_rcv_finish(struct sk_buff *skb)
 {
         struct net_device *dev = skb->dev;
         struct iphdr *iph = skb->nh.iph;
+        int err;
 
         /*
          *      Initialise the virtual path cache for the packet. It describes
          *      how the packet travels inside Linux networking.
          */ 
         if (skb->dst == NULL) {
-                if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))
+                if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
+                        if (err == -EHOSTUNREACH)
+                                IP_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
                         goto drop; 
+                }
         }
 
 #ifdef CONFIG_NET_CLS_ROUTE
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 80cf633d9f4..12a1cf306f6 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1909,7 +1909,7 @@ static int ip_route_input_slow(struct sk_buff *skb, u32 daddr, u32 saddr,
          */
         if ((err = fib_lookup(&fl, &res)) != 0) {
                 if (!IN_DEV_FORWARD(in_dev))
-                        goto e_inval;
+                        goto e_hostunreach;
                 goto no_route;
         }
         free_res = 1;
@@ -1933,7 +1933,7 @@ static int ip_route_input_slow(struct sk_buff *skb, u32 daddr, u32 saddr,
         }
 
         if (!IN_DEV_FORWARD(in_dev))
-                goto e_inval;
+                goto e_hostunreach;
         if (res.type != RTN_UNICAST)
                 goto martian_destination;
 
@@ -2025,6 +2025,11 @@ martian_destination:
                         "%u.%u.%u.%u, dev %s\n",
                         NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
 #endif
+
+e_hostunreach:
+        err = -EHOSTUNREACH;
+        goto done;
+
 e_inval:
         err = -EINVAL;
         goto done;