From mboxrd@z Thu Jan 1 00:00:00 1970 From: Timo Teras Subject: [PATCH] ip_gre: include route header_len in max_headroom calculation Date: Sat, 20 Mar 2010 14:27:58 +0200 Message-ID: <1269088078-7343-1-git-send-email-timo.teras@iki.fi> Cc: Timo Teras , Herbert Xu To: netdev@vger.kernel.org Return-path: Received: from ey-out-2122.google.com ([74.125.78.24]:53265 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751965Ab0CTM2E (ORCPT ); Sat, 20 Mar 2010 08:28:04 -0400 Received: by ey-out-2122.google.com with SMTP id d26so359442eyd.19 for ; Sat, 20 Mar 2010 05:28:03 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Taking route's header_len into account, and updating gre device needed_headroom will give better hints on upper bound of required headroom. This is useful if the gre traffic is xfrm'ed. Signed-off-by: Timo Teras Cc: Herbert Xu --- net/ipv4/ip_gre.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) This was earlier discussed in netdev thread: http://marc.info/?t=124470870200004&r=1&w=2 I just never got to writing the patch until now. diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index f47c9f7..f78402d 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -810,11 +810,13 @@ static netdev_tx_t 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))) { struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); + if (max_headroom > dev->needed_headroom) + dev->needed_headroom = max_headroom; if (!new_skb) { ip_rt_put(rt); txq->tx_dropped++; -- 1.6.3.3