additional ifupdown problems

Wed Sep 21 13:29:20 UTC 2016

Hi Dave,

On Wed, Sep 21, 2016 at 2:06 PM, David Henderson
<dhenderson at digital-pipe.com> wrote:
> Good morning everyone!  I'll add each question with the answer below:
>
> Q: maybe because something in if-pre-up.d fails?
> A: there is only that one test script in if-up.d, no others so nothing
> there to fail.  And judging by the output from 'ifup', it doesn't even
> appear that the parsing of the if-up.d directory is happening, only
> if-pre-up.d.
You misread the question, maybe something in if-pre-up.d fails which
means it doesn't even attempt if-up.d, I don't know the implementation
that well so I don't know if this would happen.
>
> Q: maybe something is overwriting it (do you have inotfiy-watch)?
> A: I do not have inotify-watch running.  Unless something in BB is
> happening I have nothing else regarding networking running (e.g.
> ifplugd, pppd, openvpn, etc).
inotify-watch is a utility that you could run to determine if the file
is being overwritten but maybe hard to use during boot anyway.
>
> Q: permissions?
> A: file has been adjusted during the boot process (before 'ifup -a' is
> called) to become: root:staff 664.  Additionally I have tried changing
> to my own user account with the 'staff' group and 777 - no difference.
>
I had a quick look through the code and as ifup is failing it is not
writing out the new interface to ifstate so you need to find out why
ifup is not working.

As a test you could move all scripts out of if-pre-up.d and see if
your test script gets called this will confirm whether something in
if-pre-up.d is the problem.  If so move them back in one at a time
until it breaks again.  Otherwise I'm out of ideas I'm afraid.

> Q: Out of interest what is your /etc/network/interfaces file if it can
> be shared?
> A: Shown below:
>
> auto eth0
> iface eth0 inet static
> address 192.168.0.23
> netmask 255.255.255.0
> gateway 192.168.0.1
> dns-nameservers 8.8.8.8 8.8.4.4
> dns-search whatever.local
>
Looks pretty good to me.

> Thanks,
> Dave
>
>
> On 9/20/16, Martin Townsend <mtownsend1973 at gmail.com> wrote:
>> Hi Dave,
>>
>> On Tue, Sep 20, 2016 at 4:40 PM, David Henderson
>> <dhenderson at digital-pipe.com> wrote:
>>> That's what my research has yielded as well, however, it doesn't
>>> appear that /var/run/ifstate is getting written to.  I check the
>>> ownership/permissions of the file:
>>>
>>> root:root 644
>>>
>>> I since changed it to mimic yours and attempted an 'ifup' again - no
>>> luck, same message.  I then tried adding the 'eth0=eth0' to the file
>>> and calling 'ifdown eth0' which worked like a charm.  So it appears
>>> that the problem lies with 'ifup'?  Also, the 'ifstate' file is
>>> dynamically being created during the boot cycle (most likely by the
>>> 'ifup -a' call during boot), so I'm assuming the file ownership and
>>> permissions are getting set there.
>>>
>>> Thanks,
>>> Dave
>>>
>>>
>>> On 9/20/16, Martin Townsend <mtownsend1973 at gmail.com> wrote:
>>>> Hi David,
>>>>
>>>> On Tue, Sep 20, 2016 at 4:03 PM, David Henderson
>>>> <dhenderson at digital-pipe.com> wrote:
>>>>> Good morning everyone!  During the boot of the OS, an 'ifup -a' is
>>>>> called to bring all the configured adapters online via the
>>>>> /etc/network/interfaces file.  Once the device is up and running, I
>>>>> can see the proper configurations via an 'ifconfig' call.  However,
>>>>> when I issue an 'ifdown eth0' call, I get the following error:
>>>>>
>>>>> ifdown: interface eth0 not configured
>>>>>
>>>>> Checking with the 'ifconfig' confirms that no action was taken and
>>>>> that the adapter is still up and running.  Running an 'ifdown -f eth0'
>>>>> achieves the desired goals, but why do I need to force this?  Checking
>>>>> the /var/run/ifstate file shows that it is 0 bytes at all times (e.g.
>>>>> right after a reboot, after tinkering with ifup/down, etc).  Also,
>>>>> once the configuration is removed and an 'ifup -v eth0' is called,
>>>>> here's what I get:
>>>>>
>>>>> run-parts /etc/network/if-pre-up.d
>>>>> ip addr add 192.168.0.25/22 dev eth0 label eth0
>>>>> ip link setup eth0 up
>>>>> ip route add default via 192.168.0.1 dev eth0
>>>>> ip: RTNETLINK answers: File exists
>>>>>
>>>>> I've tried calling a "ip addr flush dev eth0" to see if that would
>>>>> resolve the problem, but didn't work.  Also keep in mind that I can
>>>>> not run an 'strace' since the machine I'm working on (or more
>>>>> precisely developing on) does NOT have a current Internet connection.
>>>>>
>>>>> As a side note to one of my other posts, it doesn't appear that any
>>>>> other if-*.d directories are getting processed (which would explain
>>>>> why my test script isn't being called).  Is this due to the error
>>>>> preventing further processing, or are the other directories getting
>>>>> skipped for some other reason?
>>>>>
>>>>> Thanks,
>>>>> Dave
>>>>> _______________________________________________
>>>>> busybox mailing list
>>>>> busybox at busybox.net
>>>>> http://lists.busybox.net/mailman/listinfo/busybox
>>>>
>>>>
>>>> I'm sure that /var/run/ifstate must contain the name of the currently
>>>> configured network interfaces otherwise ifdown will not work so I
>>>> would start there.   On my system /var/run is in tmpfs and is a link
>>>> to /run as should have 777 permissions.
>>>>  df -h /var/run
>>>> Filesystem      Size  Used Avail Use% Mounted on
>>>> tmpfs           503M  8.5M  495M   2% /run
>>>> ls -al /var/run
>>>> lrwxrwxrwx 1 root root 6 Sep 19 17:28 /var/run -> ../run
>>>>
>>>> Is there anything in dmesg about ifstate?  can you write to ifstate
>>>>
>>>> echo "eth0=eth0" > /var/run/ifstate
>>>> if so does ifdown now work?
>>>>
>>>> -Martin
>>>>
>>
>> Hmm.  So ifup/down is not writing to the ifstate file like it should,
>> maybe because something in if-pre-up.d fails? or maybe something is
>> overwriting it (do you have inotfiy-watch) ? Permissions? Out of
>> interest what is your /etc/network/interfaces file if it can be
>> shared? errors in here can give " ip: RTNETLINK answers: File exists"
>>
>> - Martin.
>>