Posts Tagged ‘Source’

Frogatto & Friends – One of the TOP 10 Arcade Free Software & Open Source Games for GNU / Linux and FreeBSD

Friday, December 16th, 2011

Frogatto old-school 2d jump and run free software game for GNU / Linux and FreeBSD
1. Frogatto & Friends – Is an Indian Free Software (Open Source) game in the spirit of old-school jump’en runs like Commander Keen, Prehistoric, Jazz Jack Rabbit

The game is really entertaining, the graphics looks approximately nice, the music is awesome, the gamelplay is good even though after some point in the game the moment with “where should I go now, I can’t find exit” comes through and it gets boring.

Generally if you compare with all the existing jump and run arcade games free software games available for Linux and FreeBSD the game will definetely arrange itself in the list of TOP 10 free software Arcade Games
and therefore its my own believe that Frogatto is a game that every GNU / Linux and FreeBSD desktop should have in Application -> Games GNOME menu.

Frogatto is rich of levels, enemies obstacles objects, places to visit (which puts it ahead of many of the linux arcade games which often miss enough game levels, has a too short game plots, or simply miss overall game diversity).

Frogatto linux freebsd game bombing airplaine

The game’s general look & feel is like a professional game and not just some tiny free software arcade, made by its authors for the sake to learn some programming, graphics or music creation.
Frogatto door leading to Grotto

Frogatto Free Software game wood screenshot

Besides that Frogatto & Friends is multi-platform supporting all the major operating systems.
Game supports:
 

  • Windows
  • Mac
  • iPhone
  • Debian GNU / Linux
  • FreeBSD

The game source code is also available on Frogatto.com – The Game’s Official website

The game is available as a deb package in Debian and Ubuntu GNU / Linuxes so to install on those deb based distributions, simply use apt:

debian:~# apt-get install frogatto
...

The above command will install two packages frogatto (containing the game’s main executable binary) and frogatto-data containinng all the game textures, levels, graphics, music etc.

BTW the package saparation on a gamename and gamename-data in Debian (for all those who have not still noticed), can be seen on most of the games with a game data that takes more disk space.

After the game is installed the only way to start the game is to run it manually through pressing ALT+F2 in GNOME or running the progrtam through gnome-terminal with cmd:

debian:~$ frogatto

Here are few more Frogatto gameplay screenshots:

Frogatto free open source game screenshot a game bad guy

Frogatto different level screenshot

I’ve noticed Frogatto is also available as an RPM package for Fedora Linux, as well as has a FreeBSD port in the /usr/ports/games/frogatto and this makes it easy to install on most free software OSes in the wild.

While checking frogatto.com , I found an interesting link to a website offering free graphics (pictures), textures and sounds for free and open source games for all those who hold interest into the development of Free Software & Open Source Games make sure you check OpenGameArt.org

OpenGameArt.org looks like a great initiative and will definitely be highly beneficial to the development of more and better FSOS Games so I wish them God speed with this noble initiative.

Frogatto is very suitable for growing kids since it doesn’t contain no violence and every now and then the main game actor the Frogatto Frog leads few lines English dialogues with some of the characters found in the quest.
For none speaking English countries, the game can help the kids to learn some basic english words and thus can help develop kids intellect and knowledge
And oh yeah one more criticism towards the game is the Enlish structure, it seems people who wrote the plot can work this out in the time to come. Many of the English sentences during dialogues the frog leads with the cranks he met does not sound like a common and sometimes even correct english / phrases.

Besides those little game “defect”, the game is pretty awesome and worthy to kill some time and relax from a long stressy day.

How to harden Linux Security and imprpove network efficiency on Kernel sysctl Level to Stop SYN flood

Friday, July 8th, 2011

Power up Linux and protect against DDoS with sysctl var optimization

Some long time ago I’ve written an article Optimizing Linux tcp/ip networking

In the article I’ve examined a number of Linux kernel sysctl variables, which significantly improve the way TCP/IP networking is handled by a non router Linux based servers.

As the time progresses I’ve been continuing to read materials on blogs and internet sites on various tips and anti Denial of Service rules which one could apply on newly installed hosting (Apache/MySql/Qmail/Proxy) server to improve webserver responce times and tighten the overall security level.

In my quest for sysctl 😉 I found a few more handy sysctl variables apart from the old ones I incorporate on every Linux server I adminstrate.
The sysctl variables improves the overall network handling efficiency and protects about common SYN/ACK Denial of service attacks.

Here are the extra sysctl variables I started incorporating just recently:

############ IPv4 Sysctl Settings ################
#Enable ExecShield protection (randomize virtual assigned space to protect against many exploits)
kernel.randomize_va_space = 1
#Increase the number of PIDs processes could assign this is very needed especially on more powerful servers
kernel.pid_max = 65536
# Prevent against the common 'syn flood attack'
net.ipv4.tcp_syncookies = 1
# Controls the use of TCP syncookies two is generally a better idea, though you might experiment
#net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_synack_retries = 2
##################################################
#
############## IPv6 Sysctl Settings ################
# Number of Router Solicitations to send until assuming no routers are present.
net.ipv6.conf.default.router_solicitations = 0
# Accept Router Preference in RA? Again not necessery if the server is not a router
net.ipv6.conf.default.accept_ra_rtr_pref = 0
# Learn Prefix Information in Router Advertisement (Unnecessery) for non-routers
net.ipv6.conf.default.accept_ra_pinfo = 0
# disable accept of hop limit settings from other routers (could be used for DoS)
net.ipv6.conf.default.accept_ra_defrtr = 0
# disable ipv6 global unicasts server assignments
net.ipv6.conf.default.autoconf = 0
# neighbor solicitations to send out per address (better if disabled)
net.ipv6.conf.default.dad_transmits = 0
# disable assigning more than 1 address per network interface
net.ipv6.conf.default.max_addresses = 1
#####################################################

 

To use this settings paste the above sysctl variables in /etc/sysctl.conf and ask sysctl command to read and apply the newly added conf settings:

server:~# sysctl -p
...

Hopefully you should not get errors while applying the sysctl settings, if you get some errors, it’s possible some of the variable is differently named (depending on the Linux kernel version) or the Linux distribution on which sysctl’s are implemented.

For some convenience I’ve created unified sysctl variables /etc/sysct.conf containing the newly variables I started implementing to servers with the ones I already exlpained in my previous post Optimizing Linux TCP/IP Networking

Here is the optimized / hardened sysctl.conf file for download

I use this exact sysctl.conf these days on both Linux hosting / VPS / Mail servers etc. as well as on my personal notebook 😉

Here is also the the complete content of above’s sysctl.conf file, just in case if somebody wants to directly copy/paste it in his /etc/sysctl.conf

# Sysctl kernel variables to improve network performance and protect against common Denial of Service attacks
# It's possible that not all of the variables are working on all Linux distributions, test to make sure
# Some of the variables might need a slight modification to match server hardware, however in most cases it should be fine
# variables list compiled by hip0
### https://www.pc-freak.net
#### date 08.07.2011
############ IPv4 Sysctl Kernel Settings ################
net.ipv4.ip_forward = 0
# ( Turn off IP Forwarding )
net.ipv4.conf.default.rp_filter = 1
# ( Control Source route verification )
net.ipv4.conf.default.accept_redirects = 0
# ( Disable ICMP redirects )
net.ipv4.conf.all.accept_redirects = 0
# ( same as above )
net.ipv4.conf.default.accept_source_route = 0
# ( Disable IP source routing )
net.ipv4.conf.all.accept_source_route = 0
# ( - || - )net.ipv4.tcp_fin_timeout = 40
# ( Decrease FIN timeout ) - Useful on busy/high load server
net.ipv4.tcp_keepalive_time = 4000
# ( keepalive tcp timeout )
net.core.rmem_default = 786426
# Receive memory stack size ( a good idea to increase it if your server receives big files )
##net.ipv4.tcp_rmem = "4096 87380 4194304"
net.core.wmem_default = 8388608
#( Reserved Memory per connection )
net.core.wmem_max = 8388608
net.core.optmem_max = 40960
# ( maximum amount of option memory buffers )
# tcp reordering, increase max buckets, increase the amount of backlost
net.ipv4.tcp_max_tw_buckets = 360000
net.ipv4.tcp_reordering = 5
##net.core.hot_list_length = 256
net.core.netdev_max_backlog = 1024
#Enable ExecShield protection (randomize virtual assigned space to protect against many exploits)
kernel.randomize_va_space = 1
#Increase the number of PIDs processes could assign this is very needed especially on more powerful servers
kernel.pid_max = 65536
# Prevent against the common 'syn flood attack'net.ipv4.tcp_syncookies = 1
# Controls the use of TCP syncookies two is generally a better idea, though you might experiment
#net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_synack_retries = 2
###################################################
############## IPv6 Sysctl Settings ################
# Number of Router Solicitations to send until assuming no routers are present.
net.ipv6.conf.default.router_solicitations = 0
# Accept Router Preference in RA? Again not necessery if the server is not a router
net.ipv6.conf.default.accept_ra_rtr_pref = 0
# Learn Prefix Information in Router Advertisement (Unnecessery) for non-routersnet.
ipv6.conf.default.accept_ra_pinfo = 0
# disable accept of hop limit settings from other routers (could be used for DoS)
net.ipv6.conf.default.accept_ra_defrtr = 0
# disable ipv6 global unicasts server assignmentsnet.
ipv6.conf.default.autoconf = 0
# neighbor solicitations to send out per address (better if disabled)
net.ipv6.conf.default.dad_transmits = 0
# disable assigning more than 1 address per network interfacenet.
ipv6.conf.default.max_addresses = 1
#####################################################
# Reboot if kernel panic
kernel.panic = 20

These sysctl settings will tweaken the Linux kernel default network settings performance and you will notice the improvements in website responsiveness immediately in some cases implementing this kernel level goodies will make the server perform better and the system load might decrease even 😉

This optimizations on a kernel level are not only handy for servers, their implementation on Linux Desktop should also have a positive influence on the way the network behaves and could improve significantly the responce times of opening pages in Firefox/Opera/Epiphany Torrent downloads etc.

Hope this kernel tweakenings are helpful to someone.
Cheers 😉

BB – A must see ASCII Art Audio / Video portable demo for Linux, FreeBSD, UNIX and DOS

Thursday, May 24th, 2012

bb Audio Visual ASCII art Linux FreeBSD demonstration old school demo logo

I know and I have enjoyed BB – Portable Demo for already a decade.
I'm sure many newbies to the Free And Open Source (FOSS) realm don't know or heard of bb's existence as nowdays ASCII art is not so well known among youngsters. Hence this short post aims to raise some awareness of the existence of this already OLD but GOLD – awesome! text console / terminal demonstation BB 🙂

bb is pretty much in the spirit of Oldschool Assembly DOS demo scene dominating the geeks dome in the late 80's and yearly 90's.

Historically bb used to be one of the main stunning things one could show to a fellow GNU / Linux new comer.

For the year 2000, seeing all this awesome ASCII video demo running on free Operating System like GNU / Linux was a big think.
The fact that such an advanced ASCII art was distributed freely for an OS which used to exist since only (6 / 7 years) was really outstanding of its time.

BB text ascii art Linux demo entry screen characters matrix

I still remember how much I was amazed seeing a plain ascii video stream was possible only Linux. Moreover the minimal requirements of bb were quite low for its time – it worked on mostly all PCs one can find at the time.

BB's minimum requirements to work with no chops is just an old 486/66 DX2 CPU Mhz with few megas of memory (32MB of memory was more than enough to run it)

BB text sacii art Linux demo entry screen char matrix

A very unique feature of bb was it was the first Linux demo that succesfully run simultaneously playing on two monitor screens as one can read on the project website.
Unfortunately I didn't owned two monitors back in the day so never ever had the opportunity to see it running on two screens.
Anyhow I've seen it runnign somewhere on some of the Linux install fests visited some years ago…

The demo was developed by 4 man group ppl – the AA group the same digital artists are also the guys behind the AA Project.

AA Lib mascot logo :)

The main aim of AA-lib was to make possible (Doom, Second Reality, X windows) to run rendered in plain ASCII art text.

The project succeeded in a lot of his goals already as there is already existent such an ascii art ports of large games like QUAKE! Be sure to check this awesome project too AAquake ascii quake page is here
, as well as video and pictures could be viewed under a plain console Linux tty or in terminal (via SSH 🙂 )

Thanks to AA-Lib even text mode doom exists.

bb as well as aa-lib has ports for most modern Linux distros in that number one can easily get rpm or deb packages for most of distros.
On Slackware Linux you should compile it from source. Though compilation should be a straightfoward process, not that i tried it myself but I remember a close friend of mine (a great Slackware devotee) who was the one to show me the demo for a first time on his Slackware box.

1. Installing bb on Debian Linux

Debian Linux users like me are privileged as for already many years a Debian package of bb is maintaned thanks to Uwe Herman

Hence for anyone willing to enjoy bb install it by running:

debian:~# apt-get --yes install bb
....
ho@debian:~$ bb

If you're running a X server the aa-lib will immediately run with its X server compiled support:

Running BB Music Screesnhot

2. Installing BB demo on FreeBSD

On FreeBSD, bb demo has a port to install it run:

freebsd# cd /usr/ports/misc/bb freebsd# make install clean ...

Here is good time to say that even though in most of the machines, I've tested the demo I had on some of the hosts problems with sound due to buggy sound drivers.
As of time of writting hopefully on most machines there will be no troubles as most of the Linux sb drivers are better supported by ALSA.

Everyone interested in both Free Software and ASCII art knows well how big in significance is the AA-lib project for the historical development and attraction for new hackers to the Linux dome.
In that sense AAlib head developer Jan HubickaBy the way Jan Hubicka is also the author of another Linux tool called xaos. Xaos is a tool to deal with some kind of advanced higher mathematics stuff called fractals.

XAOS Screenshot Debian Squeeze Linux

Unfortunately I don't know a bit for fractal maths and what the purpose of the tool is but as you can see on the shot it looks nice running 🙂

Here are also, lot of the major BB parts in shots:

Running bb music screen screenshot Linux Debian 6 Squeeze

BB AScii fire Linux shot

bb demo ascii art fractals

BB demo ascii art back head and description of the dev

bb demo ascii zebra Linux screenshot

bb demo cannon gun shot

BB demo ring screenshot

BB demo spots Debian shot

BB developer head shot 2

BB developer profile shot

bb game ascii invaders demo

Linux extremist BB demo

BB demo zoomed text ascii art text

BB Demo thanks for watching screen

For those on MS-Windows OS platform, here is the demo 🙂

BB ASCII Demo standard size running in Linux (With sound)

Enjoy ! 🙂

How to convert Postscript files to PDF on Debian GNU / Linux with ps2pdf

Saturday, December 3rd, 2011

convert ps to pdf linux,Free as in Freedom book cover - Richard Stallman GNU and Free Software Father

I’m currently reading Free as in Freedom (2.0) R. Stallman and the Free Software Revolution
The book includes a reference to Eric S. Raymond ‘s famous The Cathedral and the Bazaar which does makes a point about the important of Open Source . I’ve read the The Cathedral and the Bazaar paper some very long time ago (in my young days so to say) and hence I couldn’t resemble much of the document so I jumped in after the footnote in the FAIF book and decided to take a quick look on The Cathedral and the Bazaar once again to bring up some memories. I was stunned to find the paper is available in many formats but officially not included in PDF . Since i’m a GNU / Linux user I’ve never managed to get into the habit to read postscript documents which from modern day stand point are also already a bit of obsolete and therefore I found it as a wise idea to convert and mirror the POSTSCRIPT (PS) version of the document to PDF on www.pc-freak.net

Happily the ps2pdf command to convert the ps to pdf on my debian gnu / linux is really easy:

ps2pdf cathedral-and-the-bazaar-Eric_Raymond.ps Cathedral-and-the-bazaar-Eric_Raymond.pdf

ps2pdf is part of the ghostscript deb package, so if you can’t find the program you will need to have it installed with apt-get first.

By the way the Postscript file is easily readable using my default gnome PDF reader evince , but anyways I converted and mirrored the paper for all those windows users who might like to take a look at the document in PDF.
I’ve also made a mirror of the original Cathedral and the Bazaaar postscript document here , for all those who want to check out The PDF version of the Cathedral and the Bazaaar is for download here

Even though the “open source” movement is an interesting idea and it had some major impact on the development of some free software the idiology of open source which was very much influenced by this document is very weak compared to the philosophy Richard Stallman indcuded as of the great need of the software to be free.

To be honest looking back in time for a long time being a Linux user I did not make any distinguishment between “Free Software” concept and “Open Source”, even worser I considered to evangelize on Open Source not realizing that initially what attracted me to free software was the idiology of open source and not the real values on which ground free software is built.
This kind of miss understanding between perception of “open source” and “free software” I got and spread for years now I fully realize and I seem like when I red back then The Cathedral and the Bazaar document I didn’t looked any critical at the document but it had a major, I would say “bad” impact on my idiology on software for a long time. So for all those who had not checked it it’s worthy checking but only in case if one fully understands Richard Stallman’s concept of Free Software, without this understanding one can easily slip into the wrong believe (just like me back in thme) that open source is the same as free software. Even though open source can be free software it is not presumably that an open source is free software and that it guarantees that the published source will be free. But I’ll stop now as I slept away from my goal of the article to just log here how a convertion of postscript to pdf on gnu / linux is done.
Just to close up this article I warmly recommend on all people interested into hacking and the history of Free operating systems and Free software as FreeBSD and GNU / Linux the Free as in Freedom (2.0) book ! Its truly a remarkable and great inspirational reading for all people like me involved into free software realm of ICT.