I toyed with ideas like variadic macros (or functions), abusing some sort of global stack of void pointers to various types of structs, and a bunch of other ideas. Finally, I came up with the following code (an example of the technique):

#include <stdio.h>

struct threeint_args {
  int a;
  int b;
  int c;
};

void mult(void *args)
{
  struct threeint_args *ma = (struct threeint_args*)args;
  printf("%d * %d * %d = %d\n",
    ma->a, ma->b, ma->c,
    ma->a * ma->b * ma->c);
}

void add(void *args)
{
  struct threeint_args *aa = (struct threeint_args*)args;
  printf("%d + %d + %d = %d\n",
  aa->a, aa->b, aa->c,
  aa->a + aa->b + aa->c);
}

struct generic_func {
  void(*func)(void*);
  void *args;
};

void run_generics(struct generic_func gfs[])
{
  struct generic_func *gf = gfs;
  while(gf->func != NULL) {
    gf->func(gf->args);
    gf++;
  }
}

int main(int argc, char **argv)
{
  struct generic_func examples[] =
    {
      {mult, (void*)&(struct threeint_args){1, 2, 3}},
      {add, (void*)&(struct threeint_args){1, 2, 3}},

      {mult, (void*)&(struct threeint_args){4, 5, 6}},
      {add, (void*)&(struct threeint_args){4, 5, 6}},

      {mult, (void*)&(struct threeint_args){7, 8, 9}},
      {add, (void*)&(struct threeint_args){7, 8, 9}},

      {NULL}
    };

  run_generics(examples);
}

“Alright”, I thought to myself, “this little program probably will throw a fit if I try to compile it, but lets try anyway.”

$ gcc -ggdb -o test test.c
$

“Now wait a minute – no complaints? Certainly, if I try to run it, there will be some sort of segfault, or bug, or something. This can’t be right…”

$ valgrind ./test
==16546== Memcheck, a memory error detector
==16546== Copyright (C) 2002-2009, and GNU GPLd, by Julian Seward et al.
==16546== Using Valgrind-3.6.0.SVN-Debian and LibVEX; rerun with -h for copyright info
==16546== Command: ./test
==16546==
1 * 2 * 3 = 6
1 + 2 + 3 = 6
4 * 5 * 6 = 120
4 + 5 + 6 = 15
7 * 8 * 9 = 504
7 + 8 + 9 = 24
==16546==
==16546== HEAP SUMMARY:
==16546==     in use at exit: 0 bytes in 0 blocks
==16546==   total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==16546==
==16546== All heap blocks were freed -- no leaks are possible
==16546==
==16546== For counts of detected and suppressed errors, rerun with: -v
==16546== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 4)

Holy s**t. That just worked.

I don’t often get surprised by code that I write. After all, if I am writing it, it means I understand it (most of the time). This example; however, completely flabbergasted me. Being able to store the pointer to a function, and a pointer to the arguments to the function in an array means I can do all sorts of things. I could develop a signals and slots mechanism, I can pass table-local contexts to function pointers, hell, I could rule the world. I couldn’t find anything else like this on the web – so I thought I would share!

First, get this file: Cricket flip-flopper Compile it up (or use the precompiled 32 bit binaries), and install it. Keep the extracted files handy.

Drop in the A600, and wait for it to show up as a CDROM drive. In the previously extracted files, run “sudo ./flipflop.sh”. Let it finish.

Check dmesg to make sure you saw “ttyACM0″ go by at some point. Grep is good for this.

Lastly, install wvdial, and use the following in your /etc/wvdial.conf :

…
Modem = /dev/ttyACM0
Phone = #777
…

Exec sudo wvdial, and off you go!

Not to mention github is awesome.

git clone git://github.com/ajrisi/picodns.git

The purpose of the software is essentially to list the network interfaces, their IP address, and whatever their IP address resolves into. It’s just a single file of delicious C code, and it works like a charm. Check it out!

git clone git://github.com/ajrisi/lsif.git

The new code is called lsif, and it lists network interfaces on a computer, their IP address, and what that IP address resolves into.  You can download a copy from github by doing:

git clone git://github.com/ajrisi/lsif.git

Or, visit the page at github for more download options! As always, post here with any questions, and I will do my best to help you out! Of course, the benefit of using something like github is that if I need to do a revision, sending it out to all of you is easy. Enjoy!

Download: keylogger.tar.gz

View Source

Installation is simple:

tar xvf keylogger.tar.gz
cd keylogger
make
sudo make install

Documentation:

Look at keylogger’s man page: man keylogger

My code was based off of uberkey, and a few other key loggers available on the net.

Note: There may occasionally be discrepancies between the documentation for the program (man keylogger), and the program itself. If this happens, then the documentation will normally be updated within a day or two.

The bad news: It has a thirst for blood, and nobody can stop it!

Enough “hellos”, lets get down to business. Rachel got found (my missing friend). I made a RFID door unlocker. I am all ready to start another quarter at RIT. And this, this is a funny comic:

Cyanide & Happiness @ Explosm.net

I feel like its a delightful statement on the dangers of “feature creep”, oh, and funny. Yep, lots of funny. Anyway, just saying “Hi”, and that I hope to be posting more when I am back in the run of things at RIT. Yay school!

If only thunderstorms and daisy-chained extension cords went together just a little bit better…

Today, I have some unfortunate news to bring to you – One of my high school friends has gone missing. Her name is Rachel Lynn Martel.

She has been missing since 5/28/2009 (as of this post, 12 days).

If you see Rachel, please call the Essex Police Department at 802-879-4923. As I gather more information, it will be posted here.