Bug#499868: udev: multiple mac80211 interfaces created on the same

Bug#499868: udev: multiple mac80211 interfaces created on the same

[Marco d'Itri]

Does anybody have good ideas about how to fix this case?

Everything in the udevinfo output is identical except:

-    ATTR{link_mode}="1"
+    ATTR{link_mode}="0"

-    ATTR{carrier}="1"
-    ATTR{dormant}="0"

-    ATTR{flags}="0x1003"
+    ATTR{flags}="0x1002"

(The first one is the "real" interface.)

----- Forwarded message from Celejar <celejar@gmail.com> -----

From: Celejar <celejar@gmail.com>
To: Debian Bug Tracking System <submit@bugs.debian.org>
Subject: Bug#499868: udev: multiple mac80211 interfaces created on the same
	physical device are incorrectly renamed

Package: udev
Version: 0.125-6
Severity: normal

mac80211 drivers allow multiple interfaces to be created on the same physical
device, so the underlying wmaster0 device can have eth0, eth1 and eth2.  When
the driver is first loaded, a udev rule like this is written:

# PCI device 0x14e4:0x4318 (b43)
SUBSYSTEM="net", ACTION="add", DRIVERS="?*", ATTR{address}="xx:xx:xx:xx:xx:xx", ATTR{type}="1", KERNEL="wlan*", NAME="eth0"

(originally 'NAME="wlan0"', I changed it to eth0)

When I subsequently add an interface with

iw dev wmaster0 interface add eth1 type station

a udev rule like this is added:

# PCI device 0x14e4:0x4318 (b43)
SUBSYSTEM="net", ACTION="add", DRIVERS="?*", ATTR{address}="xx:xx:xx:xx:xx:xx", ATTR{type}="1", KERNEL="eth**", NAME="eth1"

Then, if I add another interface with

iw dev wmaster0 interface add eth2 type station

it gets caught by the existing rule and I get the infamous 'eth2_rename'
instead of 'eth2'.

I have seen this behavior with both b43 and ath5k.  Perhaps creating multiple
ethX interfaces is a corner case, but the documentation should at least warn
about it.


----- End forwarded message -----

-- 
ciao,
Marco

Bug#499868: udev: multiple mac80211 interfaces created on the same

[Marco d'Itri]

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Does anybody have good ideas about how to fix this case?

Everything in the udevinfo output is identical except:

-    ATTR{link_mode}=="1"
+    ATTR{link_mode}=="0"

-    ATTR{carrier}=="1"
-    ATTR{dormant}=="0"

-    ATTR{flags}=="0x1003"
+    ATTR{flags}=="0x1002"

(The first one is the "real" interface.)

----- Forwarded message from Celejar <celejar@gmail.com> -----

From: Celejar <celejar@gmail.com>
To: Debian Bug Tracking System <submit@bugs.debian.org>
Subject: Bug#499868: udev: multiple mac80211 interfaces created on the same
	physical device are incorrectly renamed

Package: udev
Version: 0.125-6
Severity: normal

mac80211 drivers allow multiple interfaces to be created on the same physical
device, so the underlying wmaster0 device can have eth0, eth1 and eth2.  When
the driver is first loaded, a udev rule like this is written:

# PCI device 0x14e4:0x4318 (b43)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="xx:xx:xx:xx:xx:xx", ATTR{type}=="1", KERNEL=="wlan*", NAME="eth0"

(originally 'NAME="wlan0"', I changed it to eth0)

When I subsequently add an interface with

iw dev wmaster0 interface add eth1 type station

a udev rule like this is added:

# PCI device 0x14e4:0x4318 (b43)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="xx:xx:xx:xx:xx:xx", ATTR{type}=="1", KERNEL=="eth**", NAME="eth1"

Then, if I add another interface with

iw dev wmaster0 interface add eth2 type station

it gets caught by the existing rule and I get the infamous 'eth2_rename'
instead of 'eth2'.

I have seen this behavior with both b43 and ath5k.  Perhaps creating multiple
ethX interfaces is a corner case, but the documentation should at least warn
about it.


----- End forwarded message -----

-- 
ciao,
Marco

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Re: Bug#499868: udev: multiple mac80211 interfaces created on the

[Kay Sievers]

On Wed, Apr 15, 2009 at 15:43, Marco d'Itri <md@linux.it> wrote:
> Does anybody have good ideas about how to fix this case?
>
> Everything in the udevinfo output is identical except:
>
> -    ATTR{link_mode}="1"
> +    ATTR{link_mode}="0"
>
> -    ATTR{carrier}="1"
> -    ATTR{dormant}="0"
>
> -    ATTR{flags}="0x1003"
> +    ATTR{flags}="0x1002"

> mac80211 drivers allow multiple interfaces to be created on the same physical
> device, so the underlying wmaster0 device can have eth0, eth1 and eth2.  When
> the driver is first loaded, a udev rule like this is written:

I don't think that can ever work in the default ethX namespace. The
userspace logic that requests these interfaces should be able to
supply a custom name along with the request for the new device.
Putting things like this by default under the ethX namespace can not
work with any current logic.

Alternatively, the persistent rules can be disabled by:
  echo "# disable persistent net rules" > \
    /etc/udev/rules.d/75-persistent-net-generator.rules
which will disable the rules file with the same name in /lib/udev/rules.d/.

But then nobody should be surprised by random names at booup, if
modules are not carfully loaded manually in a controlled order.

Kay