From e997d47bff5a467262ef224b4cf8cbba2d3eceea Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 3 Aug 2011 20:50:44 -0700
Subject: net: Compute protocol sequence numbers and fragment IDs using MD5.

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.

Reported-by: Dan Kaminsky <dan@doxpara.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 net/dccp/ipv4.c | 1 +
 net/dccp/ipv6.c | 9 ++-------
 2 files changed, 3 insertions(+), 7 deletions(-)

(limited to 'net/dccp')

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 8c36adfd1919..332639b56f4d 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -26,6 +26,7 @@
 #include <net/timewait_sock.h>
 #include <net/tcp_states.h>
 #include <net/xfrm.h>
+#include <net/secure_seq.h>
 
 #include "ackvec.h"
 #include "ccid.h"
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 8dc4348774a5..b74f76117dcf 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -29,6 +29,7 @@
 #include <net/transp_v6.h>
 #include <net/ip6_checksum.h>
 #include <net/xfrm.h>
+#include <net/secure_seq.h>
 
 #include "dccp.h"
 #include "ipv6.h"
@@ -69,13 +70,7 @@ static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
 	dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &np->daddr);
 }
 
-static inline __u32 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr,
-						  __be16 sport, __be16 dport   )
-{
-	return secure_tcpv6_sequence_number(saddr, daddr, sport, dport);
-}
-
-static inline __u32 dccp_v6_init_sequence(struct sk_buff *skb)
+static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
 {
 	return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
 					     ipv6_hdr(skb)->saddr.s6_addr32,
-- 
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