udev /dev/net/tun bug

udev /dev/net/tun bug

[Alexander E. Patrakov]

To reproduce:

cd /etc/hotplug
modprobe tun
udevstart

Result:

The following synthetic "net" hotplug event is received:

=======
DEVPATH=/class/misc/tun
UDEV_NO_SLEEP=1
ACTION­d
PWD=/etc/hotplug
DEVNAME=/dev/net/tun
SHLVL=2
INTERFACE=/dev/net/tun
_=/usr/bin/env
=======

This event is bogus, because there is really no interface, but a 
character device /dev/net/tun is involved. You may be interested in the 
following information:

udevinfo -a -p /class/misc/tun

device '/sys/class/misc/tun' has major:minor 10:200
   looking at class device '/sys/class/misc/tun':
     SYSFS{dev}="10:200"

-- 
Alexander E. Patrakov


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Re: udev /dev/net/tun bug

[Greg KH]

On Tue, Jul 06, 2004 at 08:05:41AM +0600, Alexander E. Patrakov wrote:
> To reproduce:
> 
> cd /etc/hotplug
> modprobe tun
> udevstart
> 
> Result:
> 
> The following synthetic "net" hotplug event is received:

No, it's a real event.

> DEVPATH=/class/misc/tun
> UDEV_NO_SLEEP=1
> ACTION­d
> PWD=/etc/hotplug
> DEVNAME=/dev/net/tun
> SHLVL=2
> INTERFACE=/dev/net/tun
> _=/usr/bin/env
> =======
> 
> This event is bogus, because there is really no interface, but a 
> character device /dev/net/tun is involved.

Exactly, that's why this event is important.  Without it, udev would not
be able to create the character device.

What is the issue you are having with this?

thanks,

greg k-h


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Re: udev /dev/net/tun bug

[Kevin P. Fleming]

Greg KH wrote:

> Exactly, that's why this event is important.  Without it, udev would not
> be able to create the character device.
> 
> What is the issue you are having with this?

Agreed... I have 2.6.7 system here running udev-028 and OpenVPN, which 
uses /dev/net/tun to create tunnel interfaces, and it works just fine.


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Re: udev /dev/net/tun bug

[Alexander E. Patrakov]

Greg KH wrote:
> On Tue, Jul 06, 2004 at 08:05:41AM +0600, Alexander E. Patrakov wrote:
> 
>>To reproduce:
>>
>>cd /etc/hotplug
>>modprobe tun
>>udevstart
>>
>>Result:
>>
>>The following synthetic "net" hotplug event is received:
> 
> No, it's a real event.

Why do I re-receive that when I re-run udevstart? AFAIK just re-running 
udevstart doesn't produce any real hotplug events.

>>DEVPATH=/class/misc/tun
>>UDEV_NO_SLEEP=1
>>ACTION­d
>>PWD=/etc/hotplug
>>DEVNAME=/dev/net/tun
>>SHLVL=2
>>INTERFACE=/dev/net/tun
>>_=/usr/bin/env
>>=======
>>
>>This event is bogus, because there is really no interface, but a 
>>character device /dev/net/tun is involved.
> 
> Exactly, that's why this event is important.  Without it, udev would not
> be able to create the character device.
> 
> What is the issue you are having with this?

Yes, this is exactly the event due to which udev creates the 
/dev/net/tun character device :) However, it also gets dispatched to 
/etc/hotplug/net.agent for some reason.

-- 
Alexander E. Patrakov


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Re: udev /dev/net/tun bug

[Greg KH]

On Tue, Jul 06, 2004 at 03:26:44PM +0600, Alexander E. Patrakov wrote:
> Yes, this is exactly the event due to which udev creates the 
> /dev/net/tun character device :) However, it also gets dispatched to 
> /etc/hotplug/net.agent for some reason.

It does so because of the "net" in the class path.  No harm done.

thanks,

greg k-h


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