[openib-general] [PATCH] ib_addr: local/loopback address handling

[Michael S. Tsirkin]

Quoting r. Sean Hefty <mshefty at ichips.intel.com>:
> Subject: Re: [openib-general] [PATCH] ib_addr: local/loopback address handling
> 
> Michael S. Tsirkin wrote:
> >>I'm not as sure about this change; specifically the use of LOOPBACK().  
> >>If the user specifies 127.0.0.1 for their source address, this will end 
> >>up changing that address to whatever the destination address is.  Is this 
> >>really what we want?
> >
> >My testing shows that in sockets 127.0.0.1 is same as 0.
> 
> Maybe I wasn't being clear.  If the user tries to connect from 127.0.0.1 to 
> 192.168.0.101, this patch will change their source address from 127.0.0.1 
> to be 192.168.0.101.  The current code leaves the source address as 
> 127.0.0.1.

And then the connection will fail since 127.0.0.1 is not an IB device.
So why is this behaviour useful?

> What ib_addr is trying to allow is connecting to a remote IP address.
> If a source address is not specified, then one is assigned.

Right, so it has to have some routing logic. If this code is not in ib_addr then
the same logic will have to be placed in all ULPs. That's not too bad, but it
just seems a waste.

-- 
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies