[IPV4]: Safer reassembly

Another spin of Herbert Xu's "safer ip reassembly" patch
for 2.6.16.

(The original patch is here:
http://marc.theaimsgroup.com/?l=linux-netdev&m=112281936522415&w=2
and my only contribution is to have tested it.)

This patch (optionally) does additional checks before accepting IP
fragments, which can greatly reduce the possibility of reassembling
fragments which originated from different IP datagrams.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arthur Kepner <akepner@sgi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index e4563bbee6ea..4d6294ba038e 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -45,6 +45,7 @@ struct inet_skb_parm
 #define IPSKB_TRANSLATED        2
 #define IPSKB_FORWARDED         4
 #define IPSKB_XFRM_TUNNEL_SIZE  8
+#define IPSKB_FRAG_COMPLETE     16
 };
 
 struct ipcm_cookie
@@ -168,6 +169,7 @@ extern int sysctl_ipfrag_high_thresh;
 extern int sysctl_ipfrag_low_thresh;
 extern int sysctl_ipfrag_time;
 extern int sysctl_ipfrag_secret_interval;
+extern int sysctl_ipfrag_max_dist;
 
 /* From inetpeer.c */
 extern int inet_peer_threshold;