[IPv4] ESP: Discard dummy packets introduced in rfc4303

RFC4303 introduces dummy packets with a nexthdr value of 59
to implement traffic confidentiality. Such packets need to
be dropped silently and the payload may not be attempted to
be parsed as it consists of random chunk.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index c31bccb9b526c99d539c1c13a94531f23c982318..1738113268bc12f1e1a23e4a1ca14bb82a637ffa 100644 (file)
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -9,6 +9,7 @@
 #include <linux/pfkeyv2.h>
 #include <linux/random.h>
 #include <linux/spinlock.h>
+#include <linux/in6.h>
 #include <net/icmp.h>
 #include <net/protocol.h>
 #include <net/udp.h>
@@ -224,6 +225,10 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 
        /* ... check padding bits here. Silly. :-) */
 
+       /* RFC4303: Drop dummy packets without any error */
+       if (nexthdr[1] == IPPROTO_NONE)
+               goto out;
+
        iph = ip_hdr(skb);
        ihl = iph->ihl * 4;