From 7f53878dc2618bf7c01e2135bd271ac01bd85dc9 Mon Sep 17 00:00:00 2001
From: Mitsuru Chinen <mitch@linux.vnet.ibm.com>
Date: Fri, 7 Dec 2007 01:07:24 -0800
Subject: [IPv4]: Reply net unreachable ICMP message

IPv4 stack doesn't reply any ICMP destination unreachable message
with net unreachable code when IP detagrams are being discarded
because of no route could be found in the forwarding path.
Incidentally, IPv6 stack replies such ICMPv6 message in the similar
situation.

Signed-off-by: Mitsuru Chinen <mitch@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c426dec..79c4b93 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1252,6 +1252,7 @@ static int ip_error(struct sk_buff *skb)
 			break;
 		case ENETUNREACH:
 			code = ICMP_NET_UNREACH;
+			IP_INC_STATS_BH(IPSTATS_MIB_INNOROUTES);
 			break;
 		case EACCES:
 			code = ICMP_PKT_FILTERED;
@@ -1881,6 +1882,8 @@ no_route:
 	RT_CACHE_STAT_INC(in_no_route);
 	spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
 	res.type = RTN_UNREACHABLE;
+	if (err == -ESRCH)
+		err = -ENETUNREACH;
 	goto local_input;
 
 	/*
-- 
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