2008/688 Sun Cluster TCP/IP Hooks Update

[Huafeng Lu]

于 2008年11月12日 14:49, Erik Nordmark 写道:
> James Carlson wrote:
> 
>>   The situation for UDP is a bit different.  Since there is no real
>>   connection in UDP and the same socket can be used to send to
>>   multiple destinations, the major task is to register the five-tuple
>>   at the cluster level.  Such registration is performed at connect(),
>>   sendto() and sendmsg(), which call the cl_inet_connect() hook at
>>   proper time.  For performance reasons, sendto()/sendmsg() calls the
>>   hook only when the destination is new.  To facilitate this, two new
>>   fields are added to the udp_t struct to store the most recent
>>   destination address and port: in6_addr_t udp_cl_v6lastdst; in_port_t
>>   udp_cl_lastdstport; In a sendto() or sendmsg(), the
>>   cl_inet_connect() hook is called only when the destination is
>>   different from most recent one.

[ cc Honsing from the Cluster team.]


Hi Erik,

Thanks for reviewing it.

> Since UDP currently does not call cl_inet_connect, I assume the above 
> paragraph refers to the proposed new behavior.

Yes, for the new behavior.
> 
> Does the reference to sendmsg/sendto imply that this will be implemented 
> in sockfs? Or will it be implemented in TCP?

When sendmsg/sendto are called from an application, the registrations 
are finally implemented in udp_wput(). You can refer to the webrev at 
http://greatwall.prc/~hl157128/tmp.cluster/webrev.stonedog.1111/
> 
> I don't understand why a new udp_cl_v6lastdst is needed since udp 
> already has a udp_v6lastdst field.

The udp_v6lastdst field is used for Trusted Extension. To be safe, I 
don't want to reuse it, so the two new fields are introduced.
> 
> 
> Is the intent that Cluster be useful with exclusive-IP zones in the future?
> If so it might make sense to take this opportunity to introduce an 
> instance identifier to the function signatures.

The requirement for this project (RFE 6717519) comes from a customer 
(Siemens). Using Cluster with exclusive zones is not in the requirement. 
I don't know if this will happen in the future.

Honsing is from the Cluster team, so he may provide such information.

Thanks.
--
Huafeng


> 
>    Erik
>