SSH Tunneling

Last week I managed to configure OpenSSH(1) on my Arch server at home, hostname bluebeetle, to act as a SOCKS(2) tunnel so I could do a little more secure browsing when I'm at school, I used a Bash function(3) to launch the bound proxy in chromium on my laptop, hostname WhiskeyJack. This week I got a profile set up on my W7 box, hostname The-Mage, in PuTTY to connect through the SOCKS tunnel. While I was doing that I had the idea of seeing if I could use the tunnel to not only redirect my HTTP traffic through the tunnel but also if I could use the tunnel to connect low-level to the PostgreSQL server running on bluebeetle. After much tinkering around and a little goggling, plus a couple brain farts, I got the tunnel set up properly and I got the pgsql program I was writing to connect. Hint: it took longer than I care to admit that I should have changed bluebeetle's address in the source code from it's LAN address to 'localhost' since the tunnel was doing the routing not my router.

Boost

After class the other day a question had been raised about network programming, I've used Boost::asio in the past for my own network programming tasks. Boost is a third party library pack, designed for platform independence, that contains libraries for a large majority of common tasks. Boost ASIO is their (A)Synchronous In Out library that contains support for, among other tasks, TCP/UDP programming. In order to implement full duplex(asynchronous) communication you also need to implement threading to allow the reading and writing handles to run on separate threads to prevent them from blocking one another - synchronous communication. Boost provides thread management support in their Boost::thread library.

http://www.boost.org/

Week 3 To Do's

For the Xmover program, the solution I wrote is a total kludge. If I come up with something a little more elegant I'll post that code later.


case DOWN:
 if(row < console.getRows()-1){
 if(row == console.getRows()-2 && col == console.getCols()-1){
 console.alarm();
 }
 else{
 row++;
 }
      }
      else{
        console.alarm();
      }
      break;


case RIGHT:
      if(col < console.getCols()-1){
 if(col == console.getCols()-2 && row == console.getRows()-1){
 console.alarm();
 }
 else{
col++;
 }
      }
      else{
        console.alarm();
      }
      break;


For removing the 'if' from the ::display() function and reducing it to one line I once again wrote a total kludge, it is completely confusing to look at and it's ugly but dang it it works.


  void Console::display(const char* str, int row, int col, int fieldLen){
        setPos(row, col);
int i;
for(i=0,fieldLen==0?fieldLen=strlen(str):i=0;i<fieldLen;str[i]!=0?putChar(str[i]):putChar(' '),i++);
  }

This code also makes it possible to display any characters that you may insert past the first NULL char in the array when you are scrolling through str.

Chronic Misadventures

So I had decided to get an Arch server set up on an old tower to experiment with git, Apache, php, MySQL, among other things. I'm doing this on another Arch box so as not to clutter my Arch box installed on my laptop. It was also to re-familiarise myself with the Arch install process for when I start working on my Arch presentation for the Linux and Android Club.

I go ahead and get my old tower dusted off and plug everything back in but it doesn't want to boot. After an hour of fiddling around with parts and plugs and mix-and-matching components from two different towers I finally get the thing booting.

So after stumbling my way through it for an hour, I got Arch installed and configured. This was much much better then last time I installed Arch and I didn't use the guides. I get Arch installed and configured. I run the GRUB installer and get GRUB configured. I reboot and GRUB is now hanging... why?!?! I pop the installer back in, arch-chroot back into my fresh install and for some reason the linux.img and initramfs.img had gotten wiped by the GRUB install - mkinitcpio -p linux failing horribly was my clue >> . Reinstall Linux - too tired at this point to create the linux.img manually, rerun the GRUB config script - it finds the linux.img, success! and reboot. Huzzah! Its working.

Fast forward a couple hours later, OpenSSH is configured and I get my SSH key set up, everything is running smoothly. Reboot the server and switch back to Windows on my Laptop. SSH isn't working any more *scratch scratch*, 'Connection Refused' CentOS is telling me, 'Connection Terminated' PuTTY is telling me. Turns out systemd had forgotten to enable and start dhcpcd, ugh, took me twenty minutes to figure that out and only because I tried running pacman to install the internet utilities package.

It's now dinner time, I'm enjoying my meal and catching up on some TV on my laptop. I go to change the volume and knock over my tiny glass. SPLASH! it gets all over my keyboard, I turn my laptop off and upside down and let it drain. I check back a while later and I've short circuited my keyboard, yay! So now I sit here typing on a temporary rubber/soft-touch keyboard with a big hole in my laptop case where the keyboard goes.