ipv6: Drop packets for loopback address from outside of the box.
[ Based upon original report and patch by Karsten Keil. Karsten
has verified that this fixes the TAHI test case "ICMPv6 test
v6LC.5.1.2 Part F". -DaveM ]
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index e0a612b..f422f72 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -367,6 +367,12 @@
a->s6_addr32[2] | a->s6_addr32[3] ) == 0);
}
+static inline int ipv6_addr_loopback(const struct in6_addr *a)
+{
+ return ((a->s6_addr32[0] | a->s6_addr32[1] |
+ a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0);
+}
+
static inline int ipv6_addr_v4mapped(const struct in6_addr *a)
{
return ((a->s6_addr32[0] | a->s6_addr32[1] |
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 4e5c861..17eb48b 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -102,6 +102,15 @@
if (hdr->version != 6)
goto err;
+ /*
+ * RFC4291 2.5.3
+ * A packet received on an interface with a destination address
+ * of loopback must be dropped.
+ */
+ if (!(dev->flags & IFF_LOOPBACK) &&
+ ipv6_addr_loopback(&hdr->daddr))
+ goto err;
+
skb->transport_header = skb->network_header + sizeof(*hdr);
IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
