Subject: Re: [PATCH] net: Add etun driver

From: Patrick McHardy <[email-masked]>
Date: Wed, 11 Apr 2007 18:15:41 +0200

Johannes Berg wrote:
> On Tue, 2007-04-10 at 02:06 +0200, Patrick McHardy wrote:
> 
> 
>>Same way as the current RTM_SETLINK message works, but with creating
>>a new link in advance. It works fine in other subsystems, so I don't
>>see why it would in this case as well. Some subsystems do it in an
>>atomic fashion (network schedulers for example), some first create
>>the object, then configure it (network classifiers in the non-compat
>>cases). In the network device case I suppose the later should work
>>fine since a device needs to be set UP in a second action before
>>it really does anything.
> 
> 
> Looking at br_netlink.c it seems that this sort of contradicts why
> generic netlink was done, now all the sudden everything that wants to
> create new links need its own netlink protocol number, no?

No, generic netlink avoids allocating netlink families. br_netlink
uses the same netlink family as the other network configuration stuff
(NETLINK_ROUTE), but a different rtgen_family (which matches the
address families). But you have a valid point, if we want to use
this for things like bonding or VLAN that aren't actually address
families, we should consider introducing "rtnetlink families" to
avoid adding AF_BONDING, AF_8021Q etc.