kernel: in6_delayed_cksum: delayed m_pullup

[Dries Michiels]

> -----Original Message-----
> From: Tom Jones <thj at freebsd.org>
> Sent: donderdag 10 mei 2018 15:48
> To: Dries Michiels <driesm.michiels at gmail.com>
> Cc: freebsd-net at freebsd.org
> Subject: Re: kernel: in6_delayed_cksum: delayed m_pullup
> 
> On Mon, Apr 30, 2018 at 09:54:48AM +0200, Dries Michiels wrote:
> >
> > Tom,
> >
> > I’m using the igb (intel I210) driver for my LAN interface and the em
> > (intel I219-V) driver for the WAN interface.  I use this FreeBSD box
> > as my home server so I wouldn’t say that it has a heavy ipv6 workload.
> >
> 
> Hi Dries,
> 
> Does this bug persist on later snapshots? Or have you stayed with the same
> one from the original question?

I had updated the day after to see if it was just a regression but the error message was not gone:
May  1 22:19:51 vados kernel: in6_delayed_cksum: delayed m_pullup, m->len: 48 plen 68 off 56 csum_flags=400<CSUM_IP6_TCP>
May  1 22:27:57 vados last message repeated 29 times
May  1 22:36:53 vados last message repeated 17 times
May  1 22:49:41 vados last message repeated 6 times
May  1 23:00:09 vados last message repeated 8 times
May  1 23:01:06 vados last message repeated 7 times
May  1 23:18:05 vados last message repeated 12 times
For this reason I had disabled IPV6 for my LAN clients (disabled rtadvd).
My server was still ipv6 reachable and error messages where gone.

> Could you send me the ifconfig flags lines for igb0 and em0?
> 
> like this
> 
> $ ifconfig em0
> em0:
> flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST>
> metric 0 mtu 1500
> 	options=40098<VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,VL
> AN_HWTSO>
> 
> $ ifconfig igb0
> igb0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0
> mtu 1500
> 
> options=6403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMB
> O_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM
> _IPV6>

ifconfig flags of my interfaces shown below.
em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        description: WAN
        options=209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC>
igb0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        description: LAN
        options=6403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6>

> My em interfaces don't have flags for ipv6 checksum offload, I suspect the
> issue is from the em side of your network.
> 
> I have tried moving 100GB of v6 tcp through each interface with iperf3 to see
> if I could stimulate the bug, but no luck so far. I will leave the test box sitting
> exposed to my network for a while.
> 
> - [tj]