Wireless configuration and startup - The Gentoo way

woody77 · Posted: Wed Feb 18, 2004 9:35 pm Post subject:

ifplugd is used to bring interfaces up/down when they have a good link. this works great for wired interfaces, but doesn't work right for wireless, at least not right off the bat.

With my wireles interface, you don't get what qualifies as a good connection until the interface is actually up, and then that kinda defeats the purpose.

With a bit of work, however, you could probably create a set of scripts that continually scanned for networks, and brought up the interface whenever a "more preferred" network was found. This is essentially what my windows drivers use, but getting this to work under linux is a bit more "interesting". Ripping your hair out ahead of time might save you some effort...

I think that my problems stem from the fact that my card seems to need to be driven by another app to perform the scanning. Hmm. This actually wouldn't be a hard app to write in C. I just would need to learn how to write a daemon that receives signals.

Basically sit in a loop, and scan, until a network is found, and then connect. Then, when you lose the network, continue scanning again. The difficult bit would be scanning for other networks while still attached to a network (my card seems to bork at this).

Remillard · Posted: Wed Feb 18, 2004 10:54 pm Post subject:

Okay, I think things are working alright from a kernel module aspect. I get this from dmesg.

fjorderus · n00b Joined: 07 Feb 2004 Posts: 3

woody77 · Posted: Thu Feb 19, 2004 5:29 am Post subject:

However, if you have both wireless and wired, as I do, then you have two different interfaces:

eth0 <-- wired
ath0 <-- wireless

Now, you'll want to use the gentoo-supplied init-script for eth0, and you'll want to use the script at the start of this thread for ath0. Copy the script to "/etc/init.d/net.ath0".

Then do the above command for rc-update:

UberLord · Posted: Thu Feb 19, 2004 9:54 am Post subject:

waproamd is made by the same author who wrote ifupd.

waproamd is great - however it does have a few caveats

1) It can't associate with AP's which do not broadcast their ESSID
2) It has no easy way of changing from DHCP to static IP's and/or setting new nameservers
3) If you're in range of 2 or 3 networks which you have configured, there's no way of saying which one you would prefer.

I've decided to start work on a more simple daemon. It just looks at the link quality. When it drops to zero it will restart the interface. That's all it will do.

Besides, it's a good way to brush up on my C skills. And I've never written a process on Linux before

If waproamd ever gets the above functionality then I would recommend it over my own scripts any day.

woody77 · Posted: Thu Feb 19, 2004 7:07 pm Post subject:

See, what I was thinking was something very much like what you suggest, but which executes configurable commands instead of forcibly doing anything.

Sounds like waproamd could be a good starting point.

I've got plenty of C/C++ experience, the problem is writing daemons. Something I've not done.

UberLord · Posted: Thu Feb 19, 2004 8:43 pm Post subject:

woody77 · Posted: Thu Feb 19, 2004 9:28 pm Post subject:

excellent!

Where'd you find good (or passable) instructions on writing a daemon? and traping the signals sent to shut it down/restart?

Remillard · Posted: Fri Feb 20, 2004 7:01 am Post subject:

Okay, I'm trying to set up the /etc/conf.d/net file and having a bit of trouble mapping the things that are on the wireless router to the items in the file. The Router is the Netgear WGR614. The card is the Netgear WG311 PCI card.

The madwifi drivers emerged, compiled, and have insmodded successfully into the kernel.

So in /etc/conf.d/net I have the following bits:

milkypostman · n00b Joined: 10 Oct 2002 Posts: 45

I am using your script and i like it except in running it i found that it was getting called from the pcmcia. Well, basically, cardmgr calls /etc/pcmcia/network (as per the /etc/pcmcia/config file) and from there it calls the /etc/pcmcia/wireless script and then calls /etc/init.d/net.eth1 (from the network script. it appears that rather than using your script you can edit /etc/pcmcia/wireless.opt and put in the ESSID and other information there.

However, i decided not to do this, i edited /etc/pcmcia/config and instead of setting the class to "network" i set it to "shared" which doesn't call any other scripts.

The pcmcia script is required for operation of the network card (loads the modules) and while i haven't tried their configuration utility i'll try it and see how it goes. Basically what it looks like it will do is set the ESSID and all he other parameters and THEN call net.eth1 (gentoo version not yours) and handle the actual interface configuration there. Going to give it a shot tommorrow. Too tired from digging through the files to see what was going on.
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UberLord · Posted: Fri Feb 20, 2004 9:46 am Post subject:

UberLord · Posted: Fri Feb 20, 2004 9:48 am Post subject:

UberLord · Posted: Fri Feb 20, 2004 9:59 am Post subject:

milkypostman · n00b Joined: 10 Oct 2002 Posts: 45

I don't know much about the script you wrote... its full of fun lines but it doesn't appear to have any place in it for leap authentication. I wouldn't mind contributing and i know the procedure to get it going. Any chance you could throw something in there to handle it? Like extra parameters based off ESSID?
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funkmankey · Guru Joined: 06 Mar 2003 Posts: 304 Location: CH

UberLord: many thanks.

I am using a ralink 2460 based minipci card in my toshiba appliance server, and it is very picky about the order in which various ifconfig/iwconfig values are assigned. whether by luck or by design, this script works perfectly.
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giannifive · n00b Joined: 29 Jan 2004 Posts: 50 Location: Chicago, IL

Thanks UberLord. This wireless setup should be a standard part of Gentoo!

MrDooM · n00b Joined: 22 Oct 2003 Posts: 69

My wirless lan works now very fine. Thank you.

I've only one problem. After some hours of running (Filesharing for example) i come back to my computer and see this:

Link Quality:0/94

My net.ath0 is offline and i have no connection.
If i do a /etc/init.d/net.ath0 restart everything is ok for the next hours.
I use the scripts from uberlord, my card is a netgear 311 pci card.
Under win xp everything works fine mor than days, so the card is not defect.

Has anyone this problems too or can anyone help me?
I use the newest CVS madwifi drivers.

Thx

UberLord · Posted: Sun Feb 22, 2004 11:08 am Post subject:

Mr DOOM - I have the exact same problem with my 311 card as well. It has to be a madwifi-driver problem

UberLord · Posted: Sun Feb 22, 2004 11:10 am Post subject:

milkypostman · n00b Joined: 10 Oct 2002 Posts: 45

Procedure is as follows:

1) associate to the ESSID
2.a [optional]) run /opt/cisco/bin/bcard (this sets up saved cisco settings, i don't personally use it)
2.b) run /opt/cisco/bin/leapscript <user> <password> (yeah unfortunatly plain text)
3) run dhcpd or setup static ip settings.
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truth · n00b Joined: 20 Jun 2002 Posts: 31

For some reason my Wep key doesnt show in iwconfig after this script runs, And therefore does not connect to the AP. However I can get the wireless NIC running if i use: iwconfig eth1 essid truth; iwconfig eth1 enc 123456789; dhcpcd eth1. When running the script i get t he following:

UberLord · Posted: Sun Feb 22, 2004 11:18 pm Post subject:

WEP and ESSID are reset to nothing by my script if it cannot associate with an AP which explains your last point.

For WEP problems, I would recommend trying to associate without WEP. When that works - and you can use the wireless correctly - then apply the WEP settings.

A common problem with WEP is a typo - but most times you can associate with an invalid WEP key. Which is why I recommend trying without WEP first.

UberLord · Posted: Sun Feb 22, 2004 11:20 pm Post subject:

truth · n00b Joined: 20 Jun 2002 Posts: 31

As i suspected it connects fine with WEP disabled. However i would like WEP enabled, I have tried more than one key and triple checked the key to make sure it isnt a typo. Maybe my config is missing something? Guess im not particularly clear about the association process. Like i mentioned in my previous post WEP works fine when i use iwconfig to bring up the wireless NIC.
Any Suggestions anyone?
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truth
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Squirells..Natures little speed bumps.

truth · n00b Joined: 20 Jun 2002 Posts: 31

I went through the script and found key_iface so i changed /etc/conf.d/net to read wireless_key_<essid>="restricted 123456789ABCDEF" instead of wireless_iface_<essid>="restricted 123456789ABCDEF" and it worked. Not sure if this is correct but if it is then i misread your example conf. What would i need to do to have it scan for available AP's?

Thx for the response earlier Uber.
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truth
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Squirells..Natures little speed bumps.