ipv6: drop fragmented ndisc packets by default (RFC 6980)
This patch implements RFC6980: Drop fragmented ndisc packets by
default. If a fragmented ndisc packet is received the user is informed
that it is possible to disable the check.
Cc: Fernando Gont <fernando@gont.com.ar>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 04d31c2..41720fe 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1519,10 +1519,27 @@
kfree_skb(skb);
}
+static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
+{
+ struct inet6_dev *idev = __in6_dev_get(skb->dev);
+
+ if (!idev)
+ return true;
+ if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
+ idev->cnf.suppress_frag_ndisc) {
+ net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
+ return true;
+ }
+ return false;
+}
+
int ndisc_rcv(struct sk_buff *skb)
{
struct nd_msg *msg;
+ if (ndisc_suppress_frag_ndisc(skb))
+ return 0;
+
if (skb_linearize(skb))
return 0;