From 05d224468a273a9ee773a0e9d34227ee7f2c0840 Mon Sep 17 00:00:00 2001
From: Patrick McHardy <kaber@trash.net>
Date: Mon, 23 Apr 2007 22:39:02 -0700
Subject: [PATCH] [XFRM]: beet: fix pseudo header length value

draft-nikander-esp-beet-mode-07.txt is not entirely clear on how the length
value of the pseudo header should be calculated, it states "The Header Length
field contains the length of the pseudo header, IPv4 options, and padding in
8 octets units.", but also states "Length in octets (Header Len + 1) * 8".
draft-nikander-esp-beet-mode-08-pre1.txt [1] clarifies this, the header length
should not include the first 8 byte.

This change affects backwards compatibility, but option encapsulation didn't
work until very recently anyway.

[1] http://users.piuha.net/jmelen/BEET/draft-nikander-esp-beet-mode-08-pre1.txt

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/xfrm4_mode_beet.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/xfrm4_mode_beet.c b/net/ipv4/xfrm4_mode_beet.c
index f68dfd8a0f5c..d419e15d9803 100644
--- a/net/ipv4/xfrm4_mode_beet.c
+++ b/net/ipv4/xfrm4_mode_beet.c
@@ -52,7 +52,7 @@ static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb)
 
 		ph = (struct ip_beet_phdr *)skb->h.raw;
 		ph->padlen = 4 - (optlen & 4);
-		ph->hdrlen = (optlen + ph->padlen + sizeof(*ph)) / 8;
+		ph->hdrlen = optlen / 8;
 		ph->nexthdr = top_iph->protocol;
 		if (ph->padlen)
 			memset(ph + 1, IPOPT_NOP, ph->padlen);
@@ -85,7 +85,7 @@ static int xfrm4_beet_input(struct xfrm_state *x, struct sk_buff *skb)
 		ph = (struct ip_beet_phdr *)(skb->h.ipiph + 1);
 
 		phlen = sizeof(*ph) + ph->padlen;
-		optlen = ph->hdrlen * 8 - phlen;
+		optlen = ph->hdrlen * 8 + (IPV4_BEET_PHMAXLEN - phlen);
 		if (optlen < 0 || optlen & 3 || optlen > 250)
 			goto out;