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marcmagus: Ten the hard way (ten the hard way)
Friday, July 2nd, 2010 12:18 pm

Apparently, and I'm not sure if this is a change and I haven't found any documentation for it anywhere, the "intel" X.Org driver will not permit access to hardware acceleration and the DRI unless the user is a member of the "video" group. That was a good hour of Googling to find.

So, if you use an Intel-based graphics controller such as the Intel 82945G/GZ (or any other 945G chipset controller), make sure to add your primary user to "video" if you want hardware acceleration.

I was wondering why it was using the software renderer; I thought I'd gotten this working last year. Oh, well...working now.

marcmagus: (regexp)
Sunday, April 11th, 2010 05:15 pm

I recently purchased a new wireless access point/router (Netgear WNDR3300 for $30 shipped from NewEgg; got $5 off a future purchase due to a minor defect [missing rubber foot], so final cost was $25), which arrived on Friday and I set about to set it up.

Part of the reason for the purchase is that, try as I might, my friends with Macintosh laptops have consistently had trouble connecting to my current Trendnet TEW-432BRP AP/router. In fact, at some point they went from an odd 10 minutes on/10 minutes off cycle to flat-out unable to connect. Weird.

So on Friday I asked [livejournal.com profile] kdsorceress to come over while I played with setting up the router. First I confirmed that she was able to connect to the default firmware, so I knew I had this as a fallback. Then I decided to play with installing DD-WRT, which is really cool. Confirmed that the Mac could still connect [though I've played with some settings since and will need to reconfirm].

So last night I got hit by one of those sporadic attacks against my main system that I get because I have ssh enabled, and decided to attempt to configure iptables on the router to rate-limit incoming ssh connections. This is a nice little trick to interrupt brute-force attacks on your password. For some reason, though, nothing I did seemed to work, or at least I couldn't trigger the dropping by attempting to connect from one of my computers to another of my computers.

Thinking the problem might be because all computers in question were inside the LAN, and might thus not be passing through the router even though I was telling them to [for some strange reason], I resolved to borrow a neighbor's wireless for a bit using my netbook so I could test an incoming connection that way. Unluckily, all the visible networks were protected with at least WEP.

Well, WEP is terrible security, I'm told, and there are plenty of packages out there to defeat it rapidly, so I thought maybe it was time to give one of those a try. The one I decide to try depends on another tool to log packets, and recommends kismet, so I go to install that.

Whereupon I discover the driver I'm using for the wireless card in the netbook [the proprietary Broadcom wl driver] doesn't support monitor mode, recommended to switch to the in-kernel driver. After some research, I discover that a very recent version of the b43 driver does support my card in the mode I want, but to make it work I both need to fetch a firmware update [fine], and update my kernel, because the version I'm using doesn't support my particular card even with the firmware update.

So now I'm recompiling the kernel on my netbook. To update the wireless driver. To sniff wireless network traffic. To break WEP encryption. To connect to my neighbor's wireless. To test that my router is properly protecting me from outside attacks.

But I don't know why she swallowed the fly.

[Note: Yes, this is probably technically computer trespass. In much the same way that cutting across the neighbor's lawn to get home is technically trespass. The amount of bandwidth I'll be using is completely negligible, and I won't be snooping around their network while I'm there.]

marcmagus: Me playing cribbage in regency attire (Default)
Thursday, March 13th, 2008 08:03 pm

I have finally succeeded in my quest, to get XKB to easily set up the keyboard in an arbitrary fashion, not limited to the options presented in the rules database, using the system database for everything I'm not explicitly overriding, without needing to edit any system files or have any special privileges!

This should allow me to map CapsLock to Super (or Esc, or something else, I'm still playing) on any computer I have an account on.

Most of you probably don't care about the details... )
marcmagus: (regexp)
Thursday, May 17th, 2007 10:30 pm

Now that I have the nifty new monitor, I have enough space on my desk to have my laptop next to the monitor without it being all cramped. Which reminded me of an especially nifty bit of software my coworker mentioned a few weeks ago called Synergy.

It's a software KM (no V, but they're talking about maybe putting that into a future version). You have a keyboard and mouse hooked up to a "primary" computer. When you mouse off the edge of the screen, the mouse teleports to the monitor of another computer, and keyboard events are also forwarded to that computer. So if all your computers have independent displays, you can use your one good quality keyboard and mouse to work on all of them. It handles clients dropping connection smoothly (your mouse just skips them). It can do some nifty stuff with connection the edges in interesting ways which make sense (only part of an edge connects to another computer, say because you have two small monitors side-by-side beneath a widescreen?). And, for bonus niftiness, it shares clipboard contents (at least text) and is supposed to be able to synchronize screen savers so the clients are slaved to the server.

The setup guide is really good, so no comments here on how to get it working. I have two computers in loop, so it doesn't matter which side I stick the laptop on. When there's no laptop, I just end up with the right edge of my screen warping to the left, and vice versa. I suppose that could get annoying, I don't know. One caveat, it doesn't play nicely with window managers which use screen edges for virtual desktop switching; they recommend you turn that off and use keyboard for that. I already wasn't using those, so it wasn't an issue for me.

marcmagus: (regexp)
Thursday, May 17th, 2007 06:36 pm

I just got a new display for my desktop, an Acer AL2216W widescreen LCD. It has a native display resolution of 1680x1050. It's quite adequate, especially since it finally has me off of CRT, giving me a ton more desk space.

The problem is that the video card in my computer (that onboard Intel 950 described in the spec) doesn't have an internal mode for 1680x1050. But it can actually supoprt that resolution, it just needs to be convinced. Fortunately, someone clever has written a program which pokes the appropriate values into the appropriate places to convince this kind of video card that it supports resolutions it doesn't know it supports.

Unfortunately, I've already misplaced the link for the very nice walkthrough I used. But the little program is called 915resolution. It's as simple as running that with one line to overwrite a resolution you're not going to use (that's anything, with an LCD you want to be in native resolution anyway) with one you want to. This only affects RAM, so it has to be rerun every time you boot. That's good news, as it means you can't break anything permanently unless you try really hard.

Gentoo makes it even easier for you. The 915resolution package comes with a nice init.d script. Just drop an appropriate line into /etc/conf.d/915resolution, add it to whatever runlevels you need to, and you're good to go.

As for me, I'm enjoying my increased desk space (nearly 4 sq. ft.), my increased screen real-estate (453280 px), and not having to shove my face up to the screen and/or squint to read text in an XTerm at default resolution (a significant gain in effective screen space).

marcmagus: (regexp)
Thursday, April 19th, 2007 11:37 am

As you probably already know, I tend to prefer to do text-based things (email, chat, BBSing, etc.) using a program which resides in a terminal window rather than something with a lot of GUI around it. There are a few reasons for this, including that they tend to have better support for a keyboard-driven interface rather than requiring the mouse for some actions. The main reason these days has to do with my having (finally) discovered screen.

Screen is a beautiful program which lets you treat one terminal window as as many as you like, and also lets you detach from the real terminal and still keep all those applications running in their, errr, pseudo-pseudo-terminals. Which means I can have my im client (if it runs in the terminal) run on my home computer, and attach to it from anywhere with an internet connection, so I never have to log out. And I get the whole thing, the real UI for the chat program, because I'm really attached to it, not just some hacked-together command-line remote control interface.

It gets more technical from here... )
marcmagus: (regexp)
Monday, April 9th, 2007 01:07 pm

In the past I've had trouble configuring my computers both to send mail out to the internet and to deliver locally generated mail locally*. The problem is that I've been trying to use little lightweight MTAs like ssmtp and msmtp. This time I went ahead and did a Postfix installation.

I followed the guide at the Gentoo Wiki. It was easy and it works. It's possible that some ISPs will reject my mail because it comes from a dynamic IP (coming, as it does, from a computer sitting on our home network which gets its IP from our cable company). If this becomes a problem, they have nice directions for having Postfix route the mail via your ISP, which I figure I should be able to use to get it working.

A nice side benefit of this setup is that, being a full-blown MTA, I can theoretically ditch Gmail and give myself an email address at my domain (available thanks to dynamic DNS from DynDNS). I'm not sure I want to do that just yet...I'd be trading off not having to let Google snoop my mail for a downgrade in delivery reliability (if the network connection goes down, or the power goes out at home, or the IP changes and the DNS takes a while to propagate, or one of my housemates chokes the bandwidth on the connection, or something else interferes with my access). But my quick test did show that I can both send and receive mail directly. (If anybody wants to help me play with that a little, let me know.)

* (For those who don't know, a lot of *NIX system processes which run quietly in the background will send an email to the machine administrator when something goes wrong. If the thing which went wrong involves the network connection, it's useful for one of the places this mail gets delivered to be local to the machine.)

marcmagus: (regexp)
Thursday, April 5th, 2007 11:55 am

About a week ago I bought a new computer, and I've started setting it up with Gentoo. It occurred to me that it would be nice to keep a log of any tricky things I've had to do to get it functioning the way I want it to, that it might be good to put it somewhere not on the computer in case I need to refer to it again, and that it might be nice to put it somewhere public in case anybody else runs into the same difficulty. For now, I'm going to blog about these discoveries here. Some day I may compile it somewhere else for nicer reference.

Details will be lj-cut for people skimming.

Like this... )