#war walking

Earlier this year I got back into urban hiking by taking up war walking again around home.  Not too long after that, I started picking up buzz that upcoming versions of Android are specifically not going to make it easy (or probably possible) to wardrive or war walk by changing how the wifi drivers work.  By this, I mean they're making it possible to trigger a wireless scan once every two minutes instead of whenver you ask it to.  Unsurprisingly, if you read through that ticket's comments this is going to break a lot of other applications out there, but when you're the 500 pound gorilla you can pretty much dictate terms, and to hell with what your users actually ask for.

Yeah, I'm still bitter about that.  Moving on.

So, I decided that to futureproof my war walking fun, I was going to build myself a nice little dedicated unit that would run off of a USB power brick for a couple of hours, would be as automated as possible, and I could throw into my pocket on my way out the door, come home, and pull out a flash drive with the map data on it.  I bought myself a Raspberry Pi Zero W kit off of Amazon and scrounged up the rest of the stuff I needed around the house.  I already had a tiny GPS receiver that plugs into a USB port, a tiny USB hub from an earlier project to plug everything into (because the RasPi W has only one usable USB jack, and even then you need an OTG adapter cable to do so (though there's one in that kit I linked to)), and a wireless adapter that I knew would work for wireless mapping.  Scrounging up a microSD card to put the OS on didn't take nearly as long as it did to download the latest build of Raspbian.

Assembly was about as straightforward as you might think.  I just plugged everything together, booted Raspbian, and set to work getting everything working the way I wanted.  Due to the fact that development of Kismet has picked up again I thought I'd give the new version a try.  If nothing else there are always new features to play around with.  Logging into the new RasPi on my workbench, I went through the process of checking out the source code and compiling it.  I immediately ran into a couple of problems: For starters, the RasPi Zero just doesn't have a lot of horsepower to it.  Looking at the official specs it has only one CPU and half a gig of RAM.  The compilation process ran out of memory a few times (remedied by turning off a bunch of system services and expanding the size of the swapfile) and crashed the unit a couple of times despite the heatsink on the CPU and the fan in my office.

Second, and this is the most important bit... every time I fired up Kisemt it would run for a couple of seconds and then my RasPi Zero would crash.  Just locked up solid.  I tried a couple of different tricks and ways, but each one resulted in a hard-locked RasPi.  So, I am forced to conclude that the Zero W isn't a good option for this sort of thing.  The RasPi 3B (4 CPUs, 1 GB RAM) or 3B+ are probably better options for such a project.  Though, after some consideration I don't think it would be a good option for building an ultra-portable Kodi media server, either.  I'd briefly entertained re-using it as a portable media box that I could take on the road with me but I'm skeptical of the notion it'll be good for that, either.

It's been an interesting couple of weeks, to be sure.  While lots of different things have been going on lately, none of them are related in any particularly clear or straightforward fashion, so fitting all of this stuff together is going to be a bit of a struggle.  You may as well kick back with the beverage of your choice in a responsible fashion while I spin this yarn.

I suppose it all started with wardriving in northern Virginia many years ago.  In a nutshell, I had loaded Windbringer up with a rather small for the time USB GPS unit, installed Kismet, put the wifi NIC into monitor mode so it would pick up frames from every access point within range, and went driving around for a couple of hours.  The idea is that the software records the datestamp and GPS coordinates at which you picked up the strongest signal from a wireless access point.  Rinse, repeat for as long as your power cells hold out, or as long as you care to drive, bike, walk, ski, or employ any other means of personal transportation to move around.  At the time I was uploading my results to wigle.net to contribute to their crowdsourced global map of wireless coverage.  Then I moved, and I seem to have accidentally tripped Wigle's bot detector (probably because I was going out for many hours at a time to cover very large areas).  End result, I didn't go wardriving for a very long time.

A couple of months back I decided that I needed to get more exercise than I could get at home (which I'll probably ramble about in a later post) so I joined the local gym.  Doing so gave me access to a much more broad selection of equipment to work with, and a lot more space than my office at home.  There isn't much to say on that particular point other than it's been a great investment, and I spent a nontrivial amount of downtime there working out.  While I haven't lost weight per se, I do seem to be trading some amount of body fat for muscle mass.  I don't know how much adipose tissue I've actually lost but my clothes are getting tight against my body in different ways than before.  I guess that's something.

Then... and remember, I did warn you that this would be a bit of a ramble... I found myself at BSidesSF in May, where I spent much of my time completely forgetting that I'd signed up for some workshops (I didn't know they were hands-on, so I didn't bring my laptop... fail) and hanging out in the locksport village practicing.  I also spent a couple of hours geeking out with the guys who founded wigle.net and, after they were kind enough to unlock my account after so many years, I started kicking around some of the random ideas I'd been toying with to get back into the wardriving game.  Take a RaspberryPi, a USB power bank, and a USB GPS receiver, add a small touchscreen to control the device with, and I'd have a compact wardriving rig a little bigger than a Rubik's cube.  Or, depending on how I patched everything together, about the size of a paperback book.  No electrical engineering involved, just a neat wiring job.

If this was a certain television show from the very early 1990's, this is where the narrative freezes suddenly as the unseen narrator hits the pause button.  Now let's talk about hardware upgrades...

A week before BSidesSF, both Lyssa and I discovered that our phones were on their way out.  We got them at roughly the same time just after we settled in out here, which meant that they were wearing out at roughly the same rate.  Add to that the fact that even replacement power cells weren't helping, which caused a couple of minor emergencies while running errands, and we had to drop a chunk of change on new phones all in one night.  Aside from having working wifi and GPS (they'd both been getting dodgy on my old phone), my new phone has a not inconsiderable amount of onboard storage (64 gigabytes, up from.. wait for it... 4 gigabytes on my old phone).  Which meant that I suddenly had rather a lot more onboard storage to work with.

Unpause.

The Wigle folks informed me that they had a very useful Android application available for war-whatevering, and I might want to give it a try.  (Play store, F-Droid package repository, source code on Github)

So, I did.  And I must admit to being flat-out amazed, not only with a new smartphone that's reasonably up to date for the first time in a couple of years, but at how well the Wigle app works.  Many years ago (go ahead and laugh) a nontrivial amount of setup went into my average wardriving expedition.  Make sure Kismet was up to date, configure Windbringer to not go into hibernation when the lid was closed, fiddle with gpsd to make sure it would still work with the GPS I was using (because I had to patch it to work)... now I just turn on wifi and GPS on my phone and activate the Wigle app.  Into my pocket my phone goes, and by the time I get to where I'm going I've got a bunch of coordinates to upload to Wigle.

Now, let's back to my earlier mention of getting more exercise... I've noticed myself walking a lot more for the fun of it, rather than because I had to go someplace new.  I think that how easy warwalking has gotten for me has been a positive addition to getting regular exercise.  Sure, I can pick a direction and hit the bricks, and maybe listen to something along the way (lately, I've been listening to On Her Majesty's Secret Podcast both on the road and while exercising), but the added incentive of finding new wireless points and adding them to the map makes me want to get out more and walk to new places.