usb4bsd patch review

[Poul-Henning Kamp]

In message <200808231034.54484.hselasky at c2i.net>, Hans Petter Selasky writes:


>The problem about "devfs.rules" with regard to USB is that you don't know what 
>you are giving permissions to. A rule that gives permission to "/dev/ulpt0" 
>will give permissions to the first printer you plug into the USB system. That 
>is not neccessarily what the user wants.

I think this might be a good time to consider the devd/devfs
distribution of work.

The reason devfs(8) works like "firewall rules" is that we did not want
some mandatory daemon to set the modes, in particular on embedded
systems.

The alternative solution is to always create device nodes "root:wheel r--"
and let the daemon set the mode as desired.

This model has the advantage of not needing the uid, gid and mode arguments
to make_dev, something that has always been acknowleded as a kludge.

The down side is that devd(8) becomes a mandatory daemon on most systems.

Given that devfs(8) has not exactly been a stellar success and that it
often and repeatedly bites people with it slightly pedantic semantics,
transitioning in that direction might be a good thing.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.