Category Archives: sysadmin

How to fix Huawei E620 USB 3G Modem in Ubuntu 9.10 Karmic Koala

December 1, 2009 – 11:30 pm

I recently upgraded my laptop to Ubuntu 9.10 (Karmic Koala) and among a few other niggles (mostly related to intel video support, or lack thereof) it completely broke support for my Huawei 3G (E620) modem. Fortunately the fix is fairly straightforward: install a new kernel. I went with the latest (v2.6.32 release candidate available over here at kernel.ubuntu.org ) and the problem is solved.

If you want the gory details, check the thread over at bugs.launchpad.net. I’ll distil the useful bits below.

After the upgrade, my huawei 3G modem stopped being detected by NetworkManager. I’d see the fake ‘ZeroCD’ drive try to map itself and occasionally a gnome message box would be thrown up about a failed mount attempt, but no modem.

A look in the logs revealed /var/log/messages filling up with lines like this:

kernel: option 3-1:1.2: GSM modem (1-port) converter detected
kernel: usb 3-1: GSM modem (1-port) converter now attached to ttyUSB0
kernel: option 3-1:1.1: GSM modem (1-port) converter detected
kernel: usb 3-1: GSM modem (1-port) converter now attached to ttyUSB1
kernel: option 3-1:1.0: GSM modem (1-port) converter detected
kernel: usb 3-1: GSM modem (1-port) converter now attached to ttyUSB2
kernel: option1 ttyUSB2: GSM modem (1-port) converter now disconnected from ttyUSB2
kernel: option 3-1:1.0: device disconnected
kernel: option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
kernel: option 3-1:1.1: device disconnected
kernel: option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
kernel: option 3-1:1.2: device disconnected

So the modem was being disconnected and reconnected at least a couple of times a second for some reason, and the storage device was not appearing at all.

I tried the usb_modeswitch tool which is supposed to jolt misbehaving HUAWEI (and other brand) devices out of their stupor with some undocumented SCSI/USB commands, but no success this time.

After a bit of googling, it turns out this is (was) a known bug in the way the more recent linux kernel handles the combination USB Modem/Storage device hardware (and was allowed to remain in a major release of Ubuntu which is a bit unfortunate as it seems these types of USB modems are pretty common).

There are a couple of fixes pending an official update: either install a patched version of the kernel, or temporarily disable the USB Storage kernel module which looks pretty easy and apparently worked for a few people:

# rmmod usb-storage

Untested by me: Your mileage may vary.Â Be warned that even if this works, by unloading the usb-storage kernel module you will lose support for any USB based storage devices, so this is strictly a temporary workaround. I thought I’d try the more permanent and possibly dangerous (?) kernel solution first, which worked.

Steps to upgrade your kernel to a compatible version:

Check your current version with the uname -a command. My post-9.10-Karmic upgrade version was: 2.6.31-14-generic #48-Ubuntu SMPÂ x86_64 GNU/Linux
Go to http://kernel.ubuntu.com/~kernel-ppa/mainline/ and download the .deb files for the kernel headers (“all”) and the kernel for your architecture (“amd64” or “i386”). If you don’t have any kind of internet on the affected ubuntu box, grab them via another connected machine and copy them via removable media (windows or mac should be fine for just getting the files). You want the “linux-header” and “linux-image” files from within the folder with the latest (hopefully stable) version number. You can ignore the source file for now.
Go to a command prompt, change to the folder where the downloaded .deb files are located, and execute the following, substituting the .deb file names for the versions you have (make sure you install the headers first).

sudo dpkg -i ./linux-headers-2.6.32-020632rc8_2.6.32-020632rc8_all.deb

sudo dpkg -i ./linux-image-2.6.32-020632rc8-generic_2.6.32-020632rc8_amd64.deb

After this, provided everything worked, you’re a reboot away from your modem working again. After the boot, uname -a should reveal the newly installed kernel version. Mine is: 2.6.32-020632rc8-generic #020632rc8 SMP

Once plugged in, the modem worked instantly and my mobile broadband account connected fine. Hooray!

While lsusb output looked the same as before:

Bus 006 Device 004: ID 12d1:1001 Huawei Technologies Co., Ltd. E620 USB Modem

My /var/log/messages also looked a lot healthier:

kernel: USB Serial support registered for GSM modem (1-port)
kernel: option 6-2:1.0: GSM modem (1-port) converter detected
kernel: usb 6-2: GSM modem (1-port) converter now attached to ttyUSB0
kernel: option 6-2:1.1: GSM modem (1-port) converter detected
kernel: usb 6-2: GSM modem (1-port) converter now attached to ttyUSB1
kernel: option 6-2:1.2: GSM modem (1-port) converter detected
kernel: usb 6-2: GSM modem (1-port) converter now attached to ttyUSB2
kernel: usbcore: registered new interface driver option
kernel: option: v0.7.2:USB Driver for GSM modems
kernel: scsi 8:0:0:0: CD-ROMÂ Â Â Â Â Â Â Â Â Â Â  HUAWEIÂ Â  Mass StorageÂ Â Â Â  2.31 PQ: 0 ANSI: 2
kernel: scsi 8:0:0:1: Direct-AccessÂ Â Â Â  HUAWEIÂ Â  SD StorageÂ Â Â Â Â Â  2.31 PQ: 0 ANSI: 2
kernel: sr0: scsi-1 drive
kernel: Uniform CD-ROM driver Revision: 3.20
kernel: sr 8:0:0:0: Attached scsi generic sg1 type 5
kernel: sd 8:0:0:1: Attached scsi generic sg2 type 0
kernel: sd 8:0:0:1: [sdb] Attached SCSI removable disk

Additionally, with the new kernel, both the pseudo cdrom, the 3G modem, and presumably the SD storage (though I don’t use it) are working at the same time. So, problem solved.

(Another improvement I noticed with the new version of ubuntu/kernel is I can disconnect the wireless broadband account via networkmanager without nasty gnome freeze-ups. Not sure what the culprit was for this: I worked around by disconnecting the hardware to avoid freezes, but looks like this too is now solved).

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mobile devices sysadmin technical

Windows Mobile 5/6 Networking Profiles, Proxy and VPN setup

November 4, 2008 – 11:53 pm

After the last rant on Windows Mobile networking, I’ll go over a few actual solutions to the issues I encountered: hopefully a few people may find this more helpful.

Note that the following explanations, definitions of features and so on are the product of my own observation and experimentation with various WM5 and WM6 mobile devices. I have found some documentation on their functions but the majority of information I have discovered through trial and error. If there is some official documentation somewhere which contradicts what I say here (and I wouldn’t be at all surprised) then so be it: what I can say for sure is mine works.

That said, Windows Mobile networking is in my experience notoriously flaky and even though the stuff here works for my device, your mileage may vary considerably.

Ok, lets get into it.

Golden rule: Anytime you change anything at all in the networking profiles, after you have saved the changes, disable and re-enable the wireless network/adapter. I have a control utility for this on my device – (HTC Hermes) – but this will vary between devices. Following this stepÂ every time I change anything has reduced my frustrations considerably – not doing this means settings often just don’t take effect, and after doing this sometimes things just start working.

A quick explanation of terms I’ve used:

“Config Profiles” refer to the named settings you can create and assign to different networks in “Network Management” (Start -> Settings -> Connections -> Connections -> Advanced -> Select Networks) – Some of the existing config profiles are ‘My ISP” and “My Workplace” (and you will have others automatically created for your ISP if you have mobile internet access on your SIM card via a 3G or GPRS network).

Explanation of how WM decides which network to use (And hence which attached config profile is used to decide how to connect)

Windows mobile networking is whack (but you knew that already, right?). Here’s how it breaks down: It decides how to handle a http network request based on whether there are any decimals (periods) in the dns name.

By its logic, anything with a decimal/period is ‘internet’ and anything without a decimal/period is ‘work’.

So:

“http://bogus.internal” is handled with the config profile attached to the“Internet” network
“http://bogus” is handled with the config profile attached to the“Private Network” network

You can create multiple different named config profiles and assign any of them to either “Internet” or “Private Network”.

An important thing to note is, a config cannot have a VPN server added to it (or use an already setup VPN) when applied to the ‘Internet’ network. If you want to use a VPN you’ll have to do it through the ‘Work’ network (see exceptions hint below).

Explanation of the ‘Exceptions’ settings.

Now – anything in the ‘Exceptions’ list goes through the “My Work” profile regardless of whether the dns name has decimals in it to not. The good news is you can use wildcards here to force a wide range of sites through the ‘My Work’ profile if you want – hint: http:/*.* and https://*.* . I didn’t end up using this for my solution, but you might find it useful.

I’m sure this flavor of networking makes sense to some software engineer in Microsoft land, but to me it just spells confusion. Once I worked out what was actually going on, I figured out some shortcuts/config hacks which can be used to railroad the networking into doing more or less what you tell it to.

So here’s what I’ve done to make mine work:

First, I access everything using its FQDN – no dotless machinename shortcuts. This makes sure everything is using the profile assigned to “Internet” (regardless of whether I’m on a work network or not).

Make sure the ‘Exceptions’ section has no entries.

Next, tell windows mobile that every wireless network you connect to is “The Internet”. Forget about the “Work” option . As far as my usage goes, that option is useless. All the wireless networks I connect to are set to “Internet”. If you have already added a wireless network and don’t know if its tagged to “Work” or “Internet, you can go into settings -> wireless networks, find existing networks, and change which network it connects to.

Next, create a couple of new custom network configs, as follows:

‘Direct Connection’ – this does as it says, and contains no settings for proxy or vpn.
‘Proxy Connection’ – this has my work proxy server entered

You do this via Settings –> connections (tab) –> connections (icon) –> Advanced (tab), Select Networks (button). Here you can edit existing or create new config profiles.

Incidentally, my workplace uses VPNs to grant authenticated access to the wireless network – so not allowing a VPN connection to a host on a “private network” just breaks everything.

Once you’ve done that and entered your proxy authentication credentials in the appropriate places, you’re ready to go. Whenever you want to change how you’re connecting to the net go to network settings, and change “internet” to one of your created profiles. Remember to start/stop the wireless to force the change, and your next network access should be using either direct, proxy, (or VPN – see below), whichever you’ve chosen.

By doing this you lose any pretense of windows Mobile networking transparently working from whichever location / network you are connected to, but it never worked properly for me anyway, and at least this way you have some control back.

Connecting to a VPN

The above covered getting web access only, either direct or via a proxy. To get a VPN connection active (eg for skype and the like) heres what you have to do instead:

Assign a config profile to the ‘work’ network
Add a VPN connection to the config profile you used. You can add VPN connections to a config profile by assigning it to to the “Internet” connection, hitting OK, going back to the ‘Tasks’ tab and clicking the ‘Add a new VPN server connection’.
Add the appropriate wildcard exceptions (to the ‘exceptions’ section) to trigger the VPN connection for every hostname.

Once I get a VPN up at my work from inside the wireless I can make direct connections to outside hosts, for example using PocketPutty. Be warned though that even if it does connect, Windows Mobile likes to shut down the VPN connection once it decides it is no longer in use, eg after you haven’t looked at web pages for a while, regardless of whatever else you are doing on the network, (say in a live SSH session). Parking pocket IE on a web page with an auto-refresh might possibly fool it into keeping the VPN alive, but I haven’t experimented with that yet.

Hopefully there is some useful info in here and it eases the pain of getting your mobile device networking in a saner fashion.

This is a fairly quick covering of networking with WM5/6 and its highly likely there are holes, inaccuracies and/or bits left out:Â If anyone has queries, corrections or extra to add, go ahead and comment or hit up the contact form for direct email.

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linux sysadmin technical

Simple quick and dirty linux to smb copy backup script using smbfs

May 10, 2008 – 10:39 pm

I recently wrote this bash script for the purpose of a simple selective backup on one of our linux servers. It tars up a bunch of files and copies them to a windows / SMB server elsewhere on the network (where it is then backed up to tape as per everything else on that server). I know there are many different examples of this type of script on the interweb already, but someone might find this version helpful as well.

There seems to be a few different ways to get the SMB bit done but I ended up using smbfs: you’ll need this on your system for this script to work. If you don’t have it and you’re using a package manager it should be pretty simple to get, a bit of #apt-get install smbfs should do the trick.

Note: I am aware of various security issues with running scripts as root, storing passwords in scripts, and this sort of thing. Since this is a super simple backup script, I’m doing it anyway : Complaints department is /dev/null ;)

Script 1: this is a super simple version. It tars and copies some folders to the remote share and thats it.

#!/bin/bash

#simple backup script
#by Glen Scott, glenscott.net

# set smb server and auth vars
sharename="//ourserver/ourshare"
username="ourdomain\ourbackupuser"
password="passwordgoeshere"

backuplocation="/backups/*"
savepath="/root/"
filename=$(hostname).backup.$(date +%a).tar
mountpoint="/mnt/smb"

#tar up the backup folder
tar -cf $savepath$filename $backuplocation

#connect to the share
mount.smbfs $sharename $mountpoint -o username=$username,password=$password

# move the tar
mv -f $savepath$filename $mountpoint

# disconnect the share
umount $mountpoint

#all done!

Script 2: this is the second version I made for another box. It needed a mysql database backed up as well so I added a few lines in for that. I also took the chance to add a quick working folders checker / creator, tidy it up a bit and comment everything.

#!/bin/bash

# simple backup script
# by Glen Scott, glenscott.net

# this is a simple script to tar.gz certain folder locations and copy them to a SMB share
# this script should be run periodically from crontab
# you will need smbfs installed on your system or modify the samba mount method

# set smb server and auth vars
sharename="//ourserver/ourshare"
username="ourdomain\ourbackupuser"
password="passwordgoeshere"

#set mysql details
mysqlhost="localhost"
mysqlusername="root"
mysqlpasswd="mysqlpasswordhere"

#set which folder locations we want to backup, inc trailing slashes
#add more here and append to the appropriate tar line further down the script if needed

location1="/var/"
location2="/backup/"

#set temp files and folders
backuptemp="/backuptmp/"
savepath="/root/backup/"
filename=$(hostname).backup.$(date +%a).tar.gz
mountpoint="/mnt/smb"

# make sure our working folders are present and accounted for

if [ ! -d "${backuptemp}" ]
then
mkdir $backuptemp
fi

if [ ! -d "${savepath}" ]
then
mkdir $savepath
fi

if [ ! -d "${mountpoint}" ]
then
mkdir $mountpoint
fi

# tar up the files we want into the backup temp
tar -cf ${backuptemp}files.tar $location1 $location2

#dump the local mysql db into the backup temp
mysqldump "-h${mysqlhost}" "-u${mysqluser}" "-p${mysqlpasswd}" --all-databases --lock-tables > ${backuptemp}mysqldump.sql

#tar up the backup temp folder
tar -czf $savepath$filename $backuptemp

#connect the smb share to our mount point
mount.smbfs $sharename $mountpoint -o username=$username,password=$password

# copy the tar (could also move it but whatever you like)
cp -f $savepath$filename $mountpoint

# disconnect the share
umount $mountpoint

#all done

As long as you have smbfs installed, the above should work fine.

A word on smbfs: without it the above script will fail. You can probably install smbfs quite easily on your system with the command apt-get install smbfs (or yum if you’re using redhat/fedora, or whatever your flavor of package manager happens to be). I use debian, so apt-get works just fine for me.

A word on Crontab: You’ll need to add the script to your local cron to get regular backups.

I won’t go into hideous details about how crontab works, theres plenty of that on the net already. To keep it simple, if your distro supports it (most should) you can put a symlink to the script in /etc/cron.daily or /etc/cron.weekly which will give you a simple schedule.

If you want something a bit more complicated, you’ll have to mess with the crontab. I’m aware there are commands to get this done but I’ve always just edited the system crontab directly. Mine runs twice a week, on wednesdays and fridays, so my crontab line looks like this:

# m h dom mon dow user    command
0  2    * * 3,5 root    /root/backupscript

UPDATE: I notice a mutated version of this script has been posted in this forum thread over at linuxquestions.org – cool! Check it out over there if you want to see what someone else has done with it.

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