This post has been saved as a draft for a long time, and unfortunately I can’t remember the exact specifics. I’m publishing just in case it (albeit in a very rough, unfinished form) may help someone!
For the past couple of days I’ve been trying to get the Netgear MA401 wireless card working with my WPA2 secured wireless network.
In order to do this, yo
Stop the PCMCIA card from using IRQ3 by putting the following line in /etc/pcmcia/config.opts
exclude irq 3
Install hostap-utils, which should automatically blacklist the orinoco drivers:
apt-get install hostap-utils
If after a lsmod | grep orinoco they’re still in use, blacklist the orinico modules within /etc/modprobe.d/blacklist:
blacklist orinoco
blacklist orinoco_cs
The hostap modules should be automatically loaded. If not, run:
modprobe hostap_cs
If you do a iwconfig, you should see a wlan1 and a wifi0. The fact that udev has renamed it from wlan0 to wlan1 will cause problems with the prism2_srec program we’ll use to flash the card later, so change the device name by editing /etc/udev/rules.d/70-persistent-net.rules
So as you can see, I’m using v1.0.7 of the Primary Firmware, and v1.3.6 of the Station Firmware. I intend to update mine to v1.1.1 and v1.8.4 as various places online report that they work with WPA2 (though I’m sure earlier/later firmwares do too).
So next we need to flash the Prism firmware on the MA401 to enable support for WPA/WPA2. You can download the firmware here (**zip file**). [1]
Now, if you try and flash the card using prism2_srec as shown below (and as detailed at Jun Sun’s blog), you’ll no doubt get an error as shown:
Downloading to non-volatile memory (flash).
Note! This can take about 30 seconds. Do _not_ remove card during download.
Odd.. Download request for the kernel driver failed.
Are you sure you have compiled (and loaded the correct version of)
hostap.o module with PRISM2_DOWNLOAD_SUPPORT definition in
driver/module/hostap_config.h?
In addition, non-volatile download requires PRISM2_NON_VOLATILE_DOWNLOAD
to be defined.
ioctl[PRISM2_IOCTL_DOWNLOAD]: Operation not supported
You’ll also get the following message in dmesg:
wifi0: non-volatile downloading not enabled
Once you’ve extracted the firmware, you will need to recompile your kernel to allow support for the firmware flashing. First off, install the necessary packages:
Download the appropriate kernel source from www.kernel.org – for my laptop I used 2.6.26.
cd /usr/src
wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.26.tar.bz2
Unpack the source and create a symlink:
tar xjf linux-2.6.18.1.tar.bz2
ln -s linux-2.6.18.1 linux
cd /usr/src/linux
Copy your current kernel config to the sources directory:
cp /boot/config-`uname -r` ./.config
Now, ensuring we’re within the /usr/src/linux folder, run:
make menuconfig
You’ll be presented with a ncurses GUI, select “Load an Alternate Configuration File”, and then specify .config (should already be specified).
Then within the ncurses GUI navigate to the following:
Device Drivers —>
Network device support —>
Wireless LAN (non-hamradio) —>
IEEE 802.11 for Host AP (Prism2/2.5/3 and WEP/TKIP/CCMP)
Support downloading firmware images with Host AP driver
Support for non-volatile firmware download
Host AP driver for Prism2.5 PCI adaptors
Ensure that the “Support for non-volatile firmware download” is marked with an asterisk (change it by using space bar). Once that’s selected, keep selecting ‘Exit’ to leave the GUI. You’ll be prompted to ask if you want to save the new kernel configuration, select Yes.
Now you can build the kernel using the following commands:
This can take a few hours (it’s advisable to do the kernerl build on your most powerful machine; once the kernel has been recompiled you can transfer it to any other system and install it there).
Once the kernel has compiled, you should be able to see the .deb packages within /usr/src.
Once they’re installed, reboot, and then check that the new kernel has loaded by running:
uname -r
This should display something like 2.6.26-2-486-hostap.
In Kernel:
Device Drivers —>
Network device support —>
Wireless LAN (non-hamradio) —>
IEEE 802.11 for Host AP (Prism2/2.5/3 and WEP/TKIP/CCMP)
Support downloading firmware images with Host AP driver
Support for non-volatile firmware download
Host AP driver for Prism2.5 PCI adaptors
I’ve also been spending quite a lot of time with a friend developing a Java Weather API, which is now almost nearing completion (85th revision and counting). I’ve been using the API as part of a larger system that monitors climate conditions in certain locations during the course of a year, collating the results which will later be used to generate graphs and other statistics.
The API is pretty simple, but certainly effective, and makes use of Google’s own weather API that’s provided as a SOAP service.
The API parses the XML feed given by Google, and constructs Weather objects that can then further be manipulated.
Here’s a simple example of how the API could be used:
try
{
Weather weather = WeatherStation.getWeather("wirral");
}
catch(WeatherStationException wse)
{} // Bad!
weather.getConditions(); //Returns a string, such as "Fog", "Partly Cloudy"
weather.getTemperature(); //Default is to return result in degree celsius
As with my last post, we do fully intend to make these APIs available publicly at some point in the near future.
I’ve spent the past couple of hours completing a first revision for a Java API that makes use of the excellent HtmlUnit libraries to enable monitoring of a web servers response time.
Here’s a simple example of how I’d implement the API:
String[] siteUrls = {"http://www.bingo.com",
"http://www.microsoft.com",
"http://www.google.com"};
for (String url : siteUrls)
{
Website test = new Website(url);
System.out.print("Site: ");
System.out.println(test.getSiteUrl());
for (int i = 0; i < 2; i++) {
System.out.println("\tTest " + i + ":");
System.out.println("\t\tCreated: " + test.getCreateDate());
System.out.println("\t\tResponse time: " + test.getResponseTime() + "ms");
System.out.println("\t\tTime of last refresh: " + test.getLastRefreshed());
}
System.out.println();
System.out.println("");
}
Which gives:
Site: http://www.bingo.com
Test 1:
Created: Tue Mar 02 20:29:29 GMT 2010
Response time: 149ms
Time of last refresh: Tue Mar 02 20:29:30 GMT 2010
Test 2:
Created: Tue Mar 02 20:29:29 GMT 2010
Response time: 100ms
Time of last refresh: Tue Mar 02 20:29:31 GMT 2010
Site: http://www.microsoft.com
Test 1:
Created: Tue Mar 02 20:29:31 GMT 2010
Response time: 507ms
Time of last refresh: Tue Mar 02 20:29:33 GMT 2010
Test 2:
Created: Tue Mar 02 20:29:31 GMT 2010
Response time: 361ms
Time of last refresh: Tue Mar 02 20:29:34 GMT 2010
Site: http://www.google.com
Test 1:
Created: Tue Mar 02 20:29:34 GMT 2010
Response time: 86ms
Time of last refresh: Tue Mar 02 20:29:35 GMT 2010
Test 2:
Created: Tue Mar 02 20:29:34 GMT 2010
Response time: 85ms
Time of last refresh: Tue Mar 02 20:29:35 GMT 2010
The idea is that I’ll use this API in a bigger project I’m working on, a simple OpenSource website monitoring/reporting suite.
Still a lot of work to do, leave a comment if you’d like to take a closer look at the API. I do intend to make a public SVN server at some point and start porting over some of these little projects.
I’ve only recently stumbled across this, but you can now (and probably have been able to since god knows what kernel ) use a swap file instead of having to create a swap partition. There’s no performance impact, and it’s easy to setup/configure.
Obviously you can put the file wherever you want. The real benefit of utilising a swap file rather than a swap partition may already be obvious: if you want to increase your swap size, simply swapoff, create a new, bigger file – and swapon again.
February 26, 2010 at 7:22 pm · Filed under BASH, Linux
If like me you use history extensively, then you’ve probably been annoyed at the fact that it forgets that complicated command from six months previous due to its size limitations.
Increasing the size of your history is an easy change, simply edit ~/.bashrc and insert the following line:
export HISTSIZE=10000
(Set HISTSIZE=0 if you want to disable the history all together).
As is already documented over at the ‘Linux Quick Tips‘ section, perhaps one of the most useful BASH shortcuts is the CTRL-R command, that allows you to search through the command history.
Also, it’s probably a good idea to stop duplicate lines from being entered one after another and taking needless space, so uncomment the following line to leave it as shown:
export HISTCONTROL=ignoredups
If you’re privacy conscious – you can change that line to read:
export HISTCONTROL=ignoreboth
That (and indeed having HISTCONTROL=ignorespace) will mean that any lines starting with a space will be ignored.
Whilst you’re in that file, you can also fix one of my pet hates when using BASH on other people’s servers – auto-completion features for programs that can use them, i.e. apt-get. If you’re logged in as a normal user, auto-completion for apt-get et al is already enabled. But for root, it isn’t.
To enable auto-completion, scroll to the bottom of the file and uncomment the appropriate section so it looks like the following:
if [ -f /etc/bash_completion ]; then
. /etc/bash_completion
fi
Finally, once you’ve saved and quitted vi/nano/vim/pico etc, to apply all the changes in your current shell, you can respawn bash by doing:
February 21, 2010 at 3:13 pm · Filed under Linux, Mailadmin
If you’re getting the following (non-)error in your log files (/var/log/mail.log), then there’s a quick way to fix it if you’re not interested in ignoring it:
Feb 21 13:57:53 zivi cyrus/imaps[4648]: SQUAT failed to open index file
Feb 21 13:57:53 zivi cyrus/imaps[4648]: SQUAT failed
The error is caused by a user doing a search within a mailbox, and a squatter file (aka a search index) is not available. Fix this by running the following as your cyrus user (typically ‘cyrus’):
#> squatter -r user.username
If you’re doing a tail -f of /var/log/mail.log you’ll see the indexes being created.
Et voila – no more errors:
Feb 21 14:10:11 zivi cyrus/imaps[5073]: SQUAT returned 277 messages
If you want to take it a step further, you can automate this by creating a cronjob. Or if you’re using a standard Cyrus installation, the last few lines of your /etc/cyrus.conf will have some useful settings commented out that will allow Cyrus to schedule the SQUAT operations automatically:
# reindex changed mailboxes (fulltext) approximately every other hour
#squatter_1 cmd=”/usr/bin/nice -n 19 /usr/sbin/squatter -s” period=120
# reindex all mailboxes (fulltext) daily
#squatter_a cmd=”/usr/sbin/squatter” at=0517
As hinted at the beginning of this entry, this is a sort of non-error in as much as it can be safely ignored, and squat indexes need only be created if their is an advantage to doing so (that is, searches are often carried out).
February 7, 2010 at 5:11 pm · Filed under Uncategorized
I’ve been working on a website for the past few weeks, and as I’m reaching the final stages I’ve started to look at loading times and performance etc. The site uses quite a lot of jQuery and other AJAX libraries, but I was still shocked when I realised that over 500kB was being used just in Javascript!
Whilst the vast majority of the population are probably now on broadband, even I can’t forgive the homepage of this website totalling almost a 1MB download when images and the rafts of CSS are included.
So I’ve been making good use of YSlow, the excellent performance debugger produced by Yahoo, which runs within Firefox (as part of the excellent Firebug suite).
My initial score was as bad as I thought, with the index page receiving a ‘Grade E’. My first port of call was to fix the GZip compression on my Apache box, which involved putting the following in a .htaccess file in the root web directory (/var/www on my Ubuntu server).
# Below uses mod_deflate to compress text files. Never compress binary files.
AddOutputFilterByType DEFLATE text/html text/plain text/css text/javascript text/xml image/svg+xml application/javascript application/x-javascript application/atom_xml application/rss+xml application/xml ap$
# Properly handle old browsers that do not support compression
BrowserMatch ^Mozilla/4 gzip-only-text/html
BrowserMatch ^Mozilla/4\.0[678] no-gzip
BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
# Explicitly exclude binary files from compression just in case
SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.(?:exe|t?gz|zip|bz2|sit|rar)$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.pdf$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.avi$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.mov$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.mp3$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.mp4$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.rm$ no-gzip dont-vary
YSlow also complained that none of the page elements had expiry headers. Expiry headers are used by the browser in order know how long to cache an object for.
First of all, enable mod_expires:
#> a2enmod expires
And then put the following in your httpd.conf (/etc/apache2/httpd.conf):
ExpiresActive on
ExpiresDefault "access plus 1 year"
You should be able to see that the above sets the expiry headers for the most common file formats, and sets them for one year in the future. You can modify this value as per your requirements, but be warned that YSlow complains if it isn’t “too far in the future”.
Finally, YSlow was complaining about ETags. ETags are explained thoroughly here, which can be summarised with: the majority of browsers use the “Last modified” header tag to validate components, and as such, ETags are largely redundant and as such they’re best turned off.
To do so, first enable mod_headers:
#> a2enmod headers
And then place the following in your site config file (i.e. /etc/apache2/sites-enabled/sitename):
Finally, all that was left to do was follow the remaining tips offered by YSlow, namely merge all the JScripts into one file, the same for CSS. And then run all the images through the excellent Smush.It.
Et voila! Grade: A
Google now offers there own performance analysis tool: Google Page Speed. Like YSlow, it tags on to the Firebug backend. Initial reports are mixed, but there’s a helpful comparison of both tools here.
January 13, 2010 at 4:11 pm · Filed under Uncategorized
For anyone who uses Synergy as much as me, you’re probably sad to see that it is no longer maintained, which means bugs that have for long gone unanswered will never get fixed unless you start looking at the code.
Alas, a new fork has been created – synergy+, which can be found over at their Google code project page.
Anyway, if like me you’re still using Synergy2 to share your keyboard and mouse between your Windows and Linux systems, you’ve probably come across the bug whereby the @ symbol on your Linux system (presuming Windows is your ‘server’) is replaced by the Greek Omega letter (Ω). A bug report exists over at the Launchpad site for Synergy2 detailing this problem, and thankfully somebody has posted a quick fix/hack for it.
October 22, 2009 at 12:11 am · Filed under Windows, Wireless
I recently needed the MAC address for another AP in my house, and after downloading and installing NetStumbler, was dismayed to find that for some reason the Atheros 11n chipset in my MBP isn’t supported.
A quick scout around and I found this command, which makes use of the excellent netsh command within Windows (XP onwards only I think, and the syntax/parameters seem to change every release – this was tested in Windows 7 and is known working in Vista…):
netsh wlan show networks mode=bssid
Et voila! You should have a nicely detailed list of all the APs in your vicinity. Nice to not have to use a third party app for something simple within Windows!
) use a swap file instead of having to create a swap partition. There’s no performance impact, and it’s easy to setup/configure.