From: Florian Westphal <fw@strlen.de>
To: netdev@vger.kernel.org
Subject: [PATCH 0/2] net: ip: push gso skb forwarding handling down the stack
Date: Mon, 5 May 2014 15:00:42 +0200 [thread overview]
Message-ID: <1399294844-7231-1-git-send-email-fw@strlen.de> (raw)
Turns out doing the segmentation in forwarding was not a bright idea,
there are corner-cases where this has unintended side-effects.
This patch pushes the segmentation downwards.
After this, netif_skb_dev_features() function can be removed
again, it was only added to fetch the features of the output device,
we can just use skb->dev after the pushdown.
Tested with following setup:
host -> kvm_router -> kvm_host
mtu 1500 mtu1280
- 'host' has route to kvm_host with locked mtu of 1500
- gso/gro enabled on all interfaces
Did tests with all of following combinations:
- netfilter conntrack off and on on kvm_router
- virtio-net and e1000 driver on kvm_router
- tcp and udp bulk xmit from host to kvm_host
for tcp, I added TCPMSS mangling on kvm_host to make it lie about tcp mss.
Also added a dummy '-t mangle -A POSTROUTING -p udp -f'
rule to make sure no udp fragments are seen in the 'conntrack on'
and 'virtio-net' case.
Also checked (with ping -M do -s 1400)' that it still sends the wanted
icmp error message when size exceeds 1280.
next reply other threads:[~2014-05-05 13:06 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-05 13:00 Florian Westphal [this message]
2014-05-05 13:00 ` [PATCH 1/2] net: ip: push gso skb forwarding handling down the stack Florian Westphal
2014-05-05 13:00 ` [PATCH 2/2] Revert "net: core: introduce netif_skb_dev_features" Florian Westphal
2014-05-07 19:49 ` [PATCH 0/2] net: ip: push gso skb forwarding handling down the stack David Miller
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