dummy ethernet devices and sysfs

3 messages, 2 authors, 2016-01-13 · open the first message on its own page

dummy ethernet devices and sysfs

From: Warren Turkal <hidden>
Date: 2016-01-13 19:58:22

Hi,

I was looking through sysfs today, and something interesting jumped
out at me after I loaded the dummy module.

This directory exists: /sys/class/net/wlp2s0/device/

This directory does not: /sys/class/net/dummy0/device/

I can find the module that is providing the wlp2s0 device with the following:
$ ls /sys/class/net/wlp2s0/device/driver/module/drivers/
pci:iwlwifi

Shouldn't dummy have something similar so that one can figure out
which module is providing the dummy0 device?

FWIW, I am running the latest Ubuntu 15.10 kernel (4.2.0-23-generic).

Thanks,
wt

Re: dummy ethernet devices and sysfs

From: Stephen Hemminger <stephen@networkplumber.org>
Date: 2016-01-13 20:16:00

On Wed, 13 Jan 2016 11:58:01 -0800
Warren Turkal [off-list ref] wrote:
Hi,

I was looking through sysfs today, and something interesting jumped
out at me after I loaded the dummy module.

This directory exists: /sys/class/net/wlp2s0/device/

This directory does not: /sys/class/net/dummy0/device/

I can find the module that is providing the wlp2s0 device with the following:
$ ls /sys/class/net/wlp2s0/device/driver/module/drivers/
pci:iwlwifi

Shouldn't dummy have something similar so that one can figure out
which module is providing the dummy0 device?

FWIW, I am running the latest Ubuntu 15.10 kernel (4.2.0-23-generic).

Thanks,
wt
If you look carefully at the /sys/class/net/wlp2s0/device/ you will
see it is a symlink to the underlying /sys directory for the hardware (PCI)
device.  Since dummy (and other virtual interfaces) have no hardware,
there is no symlink.

Re: dummy ethernet devices and sysfs

From: Warren Turkal <hidden>
Date: 2016-01-13 22:54:35

On Wed, Jan 13, 2016 at 12:16 PM, Stephen Hemminger
[off-list ref] wrote:
If you look carefully at the /sys/class/net/wlp2s0/device/ you will
see it is a symlink to the underlying /sys directory for the hardware (PCI)
device.  Since dummy (and other virtual interfaces) have no hardware,
there is no symlink.
What's the right way for one find the module that caused dummy0 to exist?

wt

On Wed, Jan 13, 2016 at 12:16 PM, Stephen Hemminger
[off-list ref] wrote:
On Wed, 13 Jan 2016 11:58:01 -0800
Warren Turkal [off-list ref] wrote:
quoted
Hi,

I was looking through sysfs today, and something interesting jumped
out at me after I loaded the dummy module.

This directory exists: /sys/class/net/wlp2s0/device/

This directory does not: /sys/class/net/dummy0/device/

I can find the module that is providing the wlp2s0 device with the following:
$ ls /sys/class/net/wlp2s0/device/driver/module/drivers/
pci:iwlwifi

Shouldn't dummy have something similar so that one can figure out
which module is providing the dummy0 device?

FWIW, I am running the latest Ubuntu 15.10 kernel (4.2.0-23-generic).

Thanks,
wt
If you look carefully at the /sys/class/net/wlp2s0/device/ you will
see it is a symlink to the underlying /sys directory for the hardware (PCI)
device.  Since dummy (and other virtual interfaces) have no hardware,
there is no symlink.
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help