Re: namespace support requires network modules to say "GPL"

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Eric W. Biederman wrote:
Ben Greear <[email protected]> writes:

Eric W. Biederman wrote:
However there also seem to be simpler cases like Ben's bridge module,
that don't appear to have any global state.

Well, my module has some global state, but I don't think it needs to care about
namespaces.  My first impression is that my module should be able to bridge
namespaces...not be contained within one.  I can have user-space make sure that
I don't bridge between
devices in different name-spaces, or perhaps bridging between namespaces
wouldn't be a problem anyway.

Bridging between namespaces should not be a problem, but it could be
a bit of a challenge to setup (in finding the network devices).
Probably the easy way is to setup the bridging and then move one of the
network devices to the other network namespace.

Essentially bridging between two network devices in two network
namespaces looks like bridging between two network devices on two
separate network stacks.   Although internally things look a little
better.

Ok, that sounds fine.

Currently I use procfs and ioctls bound to a procfs file descriptor.

Which is where it gets tricky   You are defining new userspace ABIs.
I can see where they occasionally make sense during development
and prototyping but long term out of tree userspace interfaces appear
to me to be a real maintenance problem.

They are completely contained within my module, and no one is going
to change my module w/out me knowing, so actually I have very little
problem here :)

For namespaces in general, will there be a way to just do a dev_get_by_* and
find the
device in *any* namespace and query the device to see what namespace it is in?
Then my module or some other more clever piece of code can determine the
namespaces
(by comparing pointers if nothing else) and make proper decision.  For instance,
maybe
we want to bridge two namespaces, or maybe we want to forbid that ever
happening...

The issue is that fundamentally all userspace device identifiers can
be duped between namespaces.  So since there is no unique identifier
we can not implement a function to do that.

Ok, but can a netdev at least know what namespace it is in?  I don't
need this for my module, but it seems very useful knowledge...

Thanks,
Ben


--
Ben Greear <[email protected]>
Candela Technologies Inc  http://www.candelatech.com

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux