[openib-general] mapping between IP address and device name

[James Lentini]

On Thu, 23 Jun 2005, Hal Rosenstock wrote:

> On Thu, 2005-06-23 at 11:47, Roland Dreier wrote:
>>     James> The IBAT API provides the two key services needed by kDAPL:
>>     James> the ability to obtain a route based on an IP address and
>>     James> the ability to map a GID to an IP address.
>>
>>     James> Is there agreement that an IB address translation service
>>     James> must provide these two services?
>>
>> I think the first service is reasonable, although one has to be
>> careful to design it so it works with things like IPv6 link-local
>> addresses.  The second service, mapping a GID to an IP address,
>> doesn't make sense to me: for a given GID, there may be no associated
>> IPoIB address, or there may be many IPoIB addresses -- in fact, it is
>> difficult to configure an IPoIB interface so that it doesn't have both
>> IPv4 and IPv6 addresses.
>
> In terms of mapping a GID to an IP address, the administrator can choose
> whether to run IPoIB or not and how it is configured.
>
> In the case of multiple addresses, the set of addresses is returned.
> In the case of no associated addresses, then an error is returned. I

Perhaps a bit of motivation of how the GID->IP service can be used is 
in order.

kDAPL uses this feature to provide the passive side of a connection 
with the IP address of the remote peer. kDAPL consumers can use this 
information as a weak authentication mechanism.

For example, an NFS server can be configured to export file systems to 
certain client systems. An NFS-RDMA server using kDAPL will use the 
GID-IP service to implement this feature.

Could SDP make use of this service to validate a connection 
request's source IP address?