From: Timo Teras <timo.teras@iki.fi>
To: Pravin B Shelar <pshelar@nicira.com>
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH net v2] ip_tunnels: Use skb-len to PMTU check.
Date: Mon, 1 Jul 2013 09:41:32 +0300 [thread overview]
Message-ID: <20130701094132.3019afb4@vostro> (raw)
In-Reply-To: <1372660232-12174-1-git-send-email-pshelar@nicira.com>
On Sun, 30 Jun 2013 23:30:32 -0700
Pravin B Shelar <pshelar@nicira.com> wrote:
> In path mtu check, ip header total length works for gre device
> but not for gre-tap device. Use skb len which is consistent
> for all tunneling types. This is old bug in gre.
> This also fixes mtu calculation bug introduced by
> commit c54419321455631079c7d (GRE: Refactor GRE tunneling code).
>
> Reported-by: Timo Teras <timo.teras@iki.fi>
> Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
> ---
> v1-v2:
> - Fix pmtu set.
> - This patch also restructures code which help couple of
> improvements I have.
Looks good to me. One additional comment below.
> diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
> index 7fa8f08..ae5b78c 100644
> --- a/net/ipv4/ip_tunnel.c
> +++ b/net/ipv4/ip_tunnel.c
> @@ -486,6 +486,53 @@ drop:
> }
> EXPORT_SYMBOL_GPL(ip_tunnel_rcv);
>
> +static int tnl_update_pmtu(struct net_device *dev, struct sk_buff
> *skb,
> + struct rtable *rt, __be16 df)
> +{
> + struct ip_tunnel *tunnel = netdev_priv(dev);
> + int pkt_size = skb->len - tunnel->hlen;
> + int mtu;
> +
> + if (df)
> + mtu = dst_mtu(&rt->dst) - dev->hard_header_len
> + - sizeof(struct iphdr) -
> tunnel->hlen;
> + else
> + mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) :
> dev->mtu; +
> + if (skb_dst(skb))
> + skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL,
> skb, mtu); +
Since mtu can change for skb_dst() only if df is set, would it make
sense to move the whole update_pmtu call inside if (df) {} block?
- Timo
next prev parent reply other threads:[~2013-07-01 6:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-01 6:30 [PATCH net v2] ip_tunnels: Use skb-len to PMTU check Pravin B Shelar
2013-07-01 6:41 ` Timo Teras [this message]
2013-07-01 7:06 ` Pravin Shelar
2013-07-01 12:18 ` Timo Teras
2013-07-02 6:56 ` David Miller
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