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From: "Timo Teräs" <timo.teras@iki.fi>
To: netdev@vger.kernel.org
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
	Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
	David Miller <davem@davemloft.net>
Subject: ip_gre headroom allocation
Date: Thu, 11 Jun 2009 11:22:34 +0300	[thread overview]
Message-ID: <4A30BECA.8030205@iki.fi> (raw)

I'm not entirely sure about this, but shouldn't we do something like
the below to make ip_gre allocation enough headroom for paths where
e.g. xfrm transformations take place (as a speed optimization)?

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index e62510d..eb78dd9 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -812,7 +812,7 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
                        tunnel->err_count = 0;
        }
 
-       max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen;
+       max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->u.dst.header_len;
 
        if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
            (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {

             reply	other threads:[~2009-06-11  8:22 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-11  8:22 Timo Teräs [this message]
2009-06-11 10:09 ` ip_gre headroom allocation David Miller
2009-06-11 10:17   ` Timo Teräs
2009-06-11 10:56     ` Herbert Xu
2009-06-11 11:29       ` Timo Teräs
2009-06-11 11:37         ` Herbert Xu
2009-06-11 11:51           ` Timo Teräs
2009-06-11 12:12             ` Herbert Xu

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