Re: SCTP related issue with recent ARP changes?

Hi Qing,

I have tested your patch and it works!

Thanks you very much for your help.

Best regards
Michael

On Jan 2, 2009, at 11:15 PM, Li, Qing wrote:

> Hi Michael,
>
> The SCTP problem you were having was attributed to the arp-v2 changes.
> The reason TCP and UDP works well is because the TCP and UDP
> modules does not supply a route entry when calling ip_output().
> Consequently in ip_output() the destination (sockaddr) was  
> reinitialized
> and the sin_port field is 0.
>
> The destination sockaddr supplied in the route entry from the SCTP
> module has the actual port value in it.
>
> The new L2 search was (initially) written as a generic function.
> So the L3 address comparison was performed using bcmp() of  
> sockaddr_len
> bytes. The L2 entry was created with a sockaddr object that includes
> the port value, however, on ARP input the port value does not
> apply. The mismatch in port value causes the ARP lookup to fail
> and the SCTP connection never complete its negotiation.
>
> Please apply the patch for IPv4 in my home directory at
> http://people.freebsd.org/~qingli/in.c.diff
>
> I did the basic testing using the programs you gave me and now
> the client connects successful and completes the transfer. I also
> verified the packets in wireshark trace.
>
> Please let me know if this patch fixes your SCTP problems.
>
> Thank you for your help.
>
> -- Qing
>
>
>> -----Original Message-----
>> From: owner-freebsd-current_at_freebsd.org [mailto:owner-freebsd-
>> current_at_freebsd.org] On Behalf Of Li, Qing
>> Sent: Thursday, January 01, 2009 12:17 PM
>> To: Michael Tüxen; FreeBSD Net
>> Cc: qingli_at_freebsd.org; current_at_freebsd.org
>> Subject: RE: SCTP related issue with recent ARP changes?
>>
>>
>> Hi Michael,
>>
>> Your problem could be related to the recent ARP changes.
>> I will investigate further to confirm.
>>
>> Thanks,
>>
>> -- Qing
>>
>>
>> -----Original Message-----
>> From: owner-freebsd-net_at_freebsd.org on behalf of Michael Tüxen
>> Sent: Thu 1/1/2009 8:59 AM
>> To: FreeBSD Net
>> Subject: SCTP related issue with recent ARP changes?
>>
>> Dear all,
>>
>> I'm running the current CVS version of FreeBSD 8 in a virtual
>> machine using VMWare 2.0.1 on a Mac (not sure if this is relevant)
>> and bridged networking having an em interface on the virtual machine.
>> I'm using a similar setup with older FreeBSD machines and they are
>> running fine.
>>
>> Loopback communication based on UDP, TCP, SCTP or ICMP works fine.
>>
>> Communicating with other hosts using UDP, TCP or ICMP works fine.
>>
>> Communicating with other hosts using SCTP does not work.
>> The SCTP stack calls ip_output() and an ARP request for the
>> correct destination IP address is send out. A corresponding
>> ARP reply is visible in Wireshark (running on the FreeBSD 8 box)
>> and looks good. However, the corresponding SCTP packet it never
>> sent out. I'm not sure, but this might be related to the
>> recent ARP changes. Is there anything required from the
>> transport layer to be done when calling ip_output() that
>> was not required before?
>>
>> Best regards
>> Michael
>>
>
>
>