bce(4) and lagg(4) fix [was: bce(4) sees all incoming frames as 2026 bytes in length]

[Nikolay Denev]

On Apr 30, 2009, at 2:56 PM, Nikolay Denev wrote:

> On Apr 29, 2009, at 7:04 PM, pluknet wrote:
>
>> 2009/4/29 Niki Denev <ndenev at gmail.com>:
>>
>>> bce1: <Broadcom NetXtreme II BCM5708 1000Base-T (B2)> mem
>>> 0xf8000000-0xf9ffffff irq 16 at device 0.0 on pci3
>>> bce1: Ethernet address: 00:22:19:xx:xx:xx
>>> bce1: [ITHREAD]
>>> bce1: ASIC (0x57081020); Rev (B2); Bus (PCI-X, 64-bit, 133MHz); B/C
>>> (0x04040105); Flags( MFW MSI )
>>>
>>> bce1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0  
>>> mtu 1500
>>>        
>>> options 
>>> = 
>>> 1bb 
>>> <RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4>
>>>       ether 00:22:19:xx:xx:xx
>>>       inet 10.18.2.1 netmask 0xffffff00 broadcast 10.18.2.255
>>>       media: Ethernet autoselect (1000baseTX <full-duplex>)
>>>       status: active
>>>
>>> And here is a tcpdump that shows the problem :
>>>
>>> 16:27:32.593808 00:22:19:yy:yy:yy > 00:22:19:xx:xx:xx, ethertype  
>>> IPv4
>>> (0x0800), length 2026: (tos 0x0, ttl 64, id 45347, offset 0, flags
>>> [none], proto ICMP (1), length 84) 10.18.2.2 > 10.18.2.1: ICMP echo
>>> request, id 13578, seq 36, length 64
>>> 16:27:32.593817 00:22:19:xx:xx:xx > 00:22:19:yy:yy:yy, ethertype  
>>> IPv4
>>> (0x0800), length 98: (tos 0x0, ttl 64, id 18415, offset 0, flags
>>> [none], proto ICMP (1), length 84) 10.18.2.1 > 10.18.2.2: ICMP echo
>>> reply, id 13578, seq 36, length 64
>>
>> Ok, now I see. A link level length is 2026 for me too for some sort  
>> of packets
>> (in opposite to proto's len where all is ok).
>>
>> Mine nic is <Broadcom NetXtreme II BCM5708 1000Base-T (B2)>
>> (same as yours).
>>
>> Looks like a regression.
>> I just also tested 7.1-R and it shows expected LL-length.
>>
>>
>> -- 
>> wbr,
>> pluknet
>
>
> I think I got it.
>
> It seems that the mbuf fields m_pkthdr.len and m_len are not updated  
> to the real packet size pkt_len.
> Well, actually they are updated, but only if we have  
> ZERO_COPY_SOCKETS defined.
>
> After I added this :
>
>    m0->m_pkthdr.len = m0->m_len = pkt_len;
>
> at about line 5930 in if_bce.c, the frame length reported by tcpdump  
> seems correct.
>
> P.S.: I guess this could be the cause for the lagg(4) over bce(4)  
> problems too?
>
> P.S.2: This fix will probably break the ZERO_COPY_SOCKETS case, but  
> should be fairly easy to make it a "proper" fix.
>
> Regards,
> Niki Denev
>

I can confirm that with this fix I was able to create lagg(4)  
interface in "failover" mode with only one member, a  bce(4)  
interface, and it seems to work OK.

Regards,
Niki Denev

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