From df453700e8d81b1bdafdf684365ee2b9431fb702 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 27 Mar 2019 12:40:33 -0700
Subject: inet: switch IP ID generator to siphash

According to Amit Klein and Benny Pinkas, IP ID generation is too weak
and might be used by attackers.

Even with recent net_hash_mix() fix (netns: provide pure entropy for net_hash_mix())
having 64bit key and Jenkins hash is risky.

It is time to switch to siphash and its 128bit keys.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/netns/ipv4.h | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'include/net/netns')

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 104a6669e344..7698460a3dd1 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -9,6 +9,7 @@
 #include <linux/uidgid.h>
 #include <net/inet_frag.h>
 #include <linux/rcupdate.h>
+#include <linux/siphash.h>
 
 struct tcpm_hash_bucket;
 struct ctl_table_header;
@@ -217,5 +218,6 @@ struct netns_ipv4 {
 	unsigned int	ipmr_seq;	/* protected by rtnl_mutex */
 
 	atomic_t	rt_genid;
+	siphash_key_t	ip_id_key;
 };
 #endif
-- 
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