I bought some weeks ago a Ethernet-controllable 2-relay board. While my Chinese Top Seller could not provide any documentation for the item I had to find things myself.

The default IP for the device is 192.168.1.100. To control the device with my Linux device I found a nice Python script sr-201-relay. Since we know the IP of the board we can get rest of the configuration:

$ python sr-201-relay.py 192.168.1.100 config
ip=192.168.1.100
netmask=255.255.255.0
gateway=192.168.1.1
(unknown)=
power_persist=0
version=931
serial=XXXXX50E35000000
dns=192.168.1.1
cloud_server=connect.tutuuu.com
cloud_enabled=0
cloud_password=(not-sent)

Excellent! Now we can change the network settings to suit with my LAN:

$ python sr-201-relay.py 192.168.1.100 gateway=0.0.0.0
$ python sr-201-relay.py 192.168.1.100 dns=0.0.0.0
$ python sr-201-relay.py 192.168.1.100 ip=192.168.2.11
$ python sr-201-relay.py 192.168.1.100 reset

First I tried to make sure the device does not reach Internet and finally I set a static IP from the correct LAN.

The script offers methods to turn relays on (closed) and off (open):

$ python sr-201-relay.py 192.168.2.11 close:1
$ python sr-201-relay.py 192.168.2.11 status
relay status: 1-closed 2-open 3-open 4-open 5-open 6-open 7-open 8-open
$ python sr-201-relay.py 192.168.2.11 open:1
$ python sr-201-relay.py 192.168.2.11 status
relay status: 1-open 2-open 3-open 4-open 5-open 6-open 7-open 8-open

Tässä ohjeessa kerrotaan miten HST kortti otetaan käyttöön niin, että sillä voi kirjautua Firefoxilla viranomaisten sähköisiin verkkopalveluihin.

1. sudo apt-get install opensc
2. Käynnistä Firefox (esimerkissä 40.0.3)
3. Edit > Preferences > Advanced > Certificates > Security Devices > Load > Module Filename
   • 32-bittisessä anna: /usr/lib/i386-linux-gnu/opensc-pkcs11.so
   • 64-bittisessä anna: /usr/lib/x86_64-linux-gnu/opensc-pkcs11.so
4. OK

Lähde: http://www.linux.fi/wiki/HST

Paketista asennettuna opensc kysyy kirjautumisen yhteydessä molemmat PIN-koodit. OpenSC sisältää kirjaston onepin-opensc-pkcs11, joka kysyy vain PIN1:n. Tämän saa vain kääntämällä OpenSC:n uudelleen. Onneksi homma on helppo ja ohjeet ovat hyvät. OpenSC on asennettava ohjeiden mukaisesti /usr -haaraan. /usr/local ei toimi.

This post explains how to revert the GRUB after your Linux (Ubuntu 14.10)/Windows (7) dual-boot workstation boots directly to Windows the Windows update. This procedure is valid for non-EFI (legacy) workstations. For EFI workstations see another post.

1. Get a sysresccd boot image and boot the workstation from it.
   • Note that you cannot make an bootable USB stick using dd but executing an installation script as explained in the documentation.
   • This recipe was tested on 4.5.3.
2. Find your Linux root partiton using fdisk:
   1. fdisk /dev/sda (sdb, sdc…)
   2. p (prints the partiton table)
3. In this example we found the suspected root partition from /dev/sdb2. It has the boot flag on and the partition type is “Linux”.
4. mkdir /tmp/root
5. mount /dev/sdb2 /tmp/root
6. ls /tmp/root (make sure that this contains the root partition)
7. grub2-install –root-directory=/mnt /dev/sda
8. reboot
9. As soon as you get your Ubuntu up and running re-instal grub:
10. sudo grub-install /dev/sda

Some days ago I was in desperate need to run Raspberry Pi on my Ubuntu. As you might expect, there has been several others with similar need and i quickly ran to a number of blog posts explaining how to do this with QEMU. Maybe the best I could find is at http://paulscott.co.za/blog/full-raspberry-pi-raspbian-emulation-with-qemu/.

However, all these documents had a similar drawback. For some reason you cannot just make QEMU to boot from the Raspbian image file but you need a kernel file (often referred as kernel-qemu) which is given with -kernel parameter to QEMU. All these blogs pointed at currently no-existing blog at xecdesign.com and did not explain where this magical kernel file came from.

It appears that you have to do apply a number of patches (armhf? qemu?) to stock kernel to make it boot in QEMU. Of yourse, you have to cross-compile the kernel to ARM.

Finally I found the kernel-qemu inside the pre-packaged QEMU+Raspbian Windows installation at sourceforge. If you just need the kernel-qemu, go ahead and download it. This is probably the one that origins from xecdesign.com. There is another alternative (http://elinux.org/File:ZImage.7z) which gives you 3.6.1 kernel (download).

However, both the two have same drawback. You don’t get modules and they lack some important modules. For example the USB stack does not work.

My son uses connects the Internet via our local WLAN network. To help him to just lag on the sofa and browse YouTube for hours we decided to block the video service from his mobile. It appears to be quite easy to block video services using squid but a bit harder to find the streaming server IPs. I have now found a solution which appears to work.

First we want to redirect the pass-through packages from the son’s mobile to the chain “funban”.

$IPTABLES -N funban
$IPTABLES -A FORWARD -m mac --mac-source 11:22:33:aa:bb:cc -j funban

Now we just have to build necessary rules to the chain.

#!/bin/bash

IPTABLES=/sbin/iptables

function block_ips {
 for THIS_IP in $1
 do
 # XXX.XXX.XXX.XXX/XX
 if [[ $THIS_IP =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+\/[0-9]+$ ]]; then
 $IPTABLES -A funban -d $THIS_IP -j DROP
 fi
 # XXX.XXX.XXX.XXX
 if [[ $THIS_IP =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
 $IPTABLES -A funban -d $THIS_IP -j DROP
 fi
 done
}

function accept_ips {
 for THIS_IP in $1
 do
 # XXX.XXX.XXX.XXX/XX
 if [[ $THIS_IP =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+\/[0-9]+$ ]]; then
 $IPTABLES -A funban -d $THIS_IP -j ACCEPT
 fi
 # XXX.XXX.XXX.XXX
 if [[ $THIS_IP =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
 $IPTABLES -A funban -d $THIS_IP -j ACCEPT
 fi
 done
}

function get_ips {
 echo "`dig ${1} A | grep -E '^[^;]' | grep -o -E '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+'`"
}

# Flush funban chain
$IPTABLES -F funban

# Block all Google-related IPs. The "AS15169" is taken from
# http://networktools.nl/asinfo/google.com
block_ips "`whois -h whois.radb.net -- '-i origin AS15169' | grep ^route\:`"
# Add these IPs to make google search to work (NOTE: This is not sufficient and blocks Google searches)
accept_ips `get_ips www.google.com`

My firewall server runs this script hourly to make sure the changes in the IPs don’t open unexpected possibilities to our YouTube addict. The blockade will surely affect other Google services as well. We possibly have to add more accept_ips commands to the script.

Do you have Linux/Windows dual boot workstation? Have you ever found your GRUB installation overwritten by another Windows Update? If your workstation supports EFI boot loader there is an easy way to reinstall the grub from your Linux distribution. In case your workstation is non-EFI (legacy, older way of booting) see another post.

1. Get yourself another workstation.
2. Get eEFInd USB image. You’ll find it from the download page. Look for “A USB flash drive image file”.
3. Unzip the image package and write it to the USB memory:
   • Linux: Give following command where /dev/sdX points to your USB memory.

     sudo dd if=refind-flashdrive-0.8.6.img of=/dev/sdX bs=1M

   • Windows: Use Win 32 Disk Imager to write the image to the USB memory.
4. Boot the target workstation from rEFInd USB. It creates a nice boot menu for you. Select the option which looks most promising and give it a try.
5. After the successful boot reinstall grub:

   sudo grub-install

6. Reboot. Don’t forget to remove the USB memory.