Free the territory ahead software for linux

Wolfenstein: Enemy Territory is a Multiplayer Online First Person Shooter. Wolfenstein: Enemy Territory is a team game; you will win or fall along with your comrades. The only way to complete the objectives that lead to victory is by cooperation, with each player covering their teammates and using their class special abilities in concert with the others.

Featuring multiplayer support for as many as 64 players, Wolfenstein: Enemy Territory challenges gamers to the ultimate test of teamwork and strategy. Each of the five character classes is critical to a teams ultimate victory or defeat on the battlefield. The Covert Operative class allows players to steal uniforms, perform reconnaissance and gain access to enemy positions. While, the Engineer allows the Axis and Allied teams to lay and diffuse mines as well as build battlefield bridges, towers, forward command bases and other improvements in the midst of combat to gain advantages for their team.

Wolfenstein: Enemy Territory further online players the option to slug it out in the intense Team Last-Man-Standing game mode, where squad-mates cooperate to ensure their team has the last surviving man on the battlefield. With new game modes, character classes, weaponry, and added tactical skills, Wolfenstein: Enemy Territory will keep gamers in the trenches for hours.

The Wonder Shaper is a very special network shaper script with a lot of features. Works on Linux 2.4 & higher.

Goals

I attempted to create the holy grail:

* Maintain low latency for interfactive traffic at all times.

This means that downloading or uploading files should not disturb SSH or even telnet. These are the most important things, even 200ms latency is sluggish to work over.

* Allow surfing at reasonable speeds while up or downloading

Even though http is bulk traffic, other traffic should not drown it out too much.

* Make sure uploads dont harm downloads, and the other way around

This is a much observed phenomenon where upstream traffic simply destroys download speed. It turns out that all this is possible, at the cost of a tiny bit of bandwidth. The reason that uploads, downloads and ssh hurt eachother is the presence of large queues in many domestic access devices like cable or DSL modems.

Why it doesnt work well by default

ISPs know that they are benchmarked solely on how fast people can download. Besides available bandwidth, download speed is influenced heavily by packet loss, which seriously hampers TCP/IP performance. Large queues can help prevent packetloss, and speed up downloads. So ISPs configure large queues.

These large queues however damage interactivity. A keystroke must first travel the upstream queue, which may be seconds (!) long and go to your remote host. It is then displayed, which leads to a packet coming back, which must then traverse the downstream queue, located at your ISP, before it appears on your screen.

This HOWTO teaches you how to mangle and process the queue in many ways, but sadly, not all queues are accessible to us. The queue over at the ISP is completely off-limits, whereas the upstream queue probably lives inside your cable modem or DSL device. You may or may not be able to configure it. Most probably not.

So, what next? As we cant control either of those queues, they must be eliminated, and moved to your Linux router. Luckily this is possible.

Limit upload speed somewhat

By limiting our upload speed to slightly less than the truly available rate, no queues are built up in our modem. The queue is now moved to Linux.

Limit download speed

This is slightly trickier as we cant really influence how fast the internet ships us data. We can however drop packets that are coming in too fast, which causes TCP/IP to slow down to just the rate we want. Because we dont want to drop traffic unnecessarily, we configure a burst size we allow at higher speed.

Now, once we have done this, we have eliminated the downstream queue totally (except for short bursts), and gain the ability to manage the upstream queue with all the power Linux offers.

Let interactive traffic skip the queue

What remains to be done is to make sure interactive traffic jumps to the front of the upstream queue. To make sure that uploads dont hurt downloads, we also move ACK packets to the front of the queue. This is what normally causes the huge slowdown observed when generating bulk traffic both ways. The ACKnowledgements for downstream traffic must compete with upstream traffic, and get delayed in the process.

We also move other small packets to the front of the queue - this helps operating systems which do not set TOS bits, like everything from Microsoft.

Allow the user to specify low priority traffic (new in 1.1!)

Sometimes you may notice low priority OUTGOING traffic slowing down important traffic. In that case, the following options may help you:

NOPRIOHOSTSRC
Set this to hosts or netmasks in your network that should have low priority

NOPRIOHOSTDST
Set this to hosts or netmasks on the internet that should have low priority

NOPRIOPORTSRC
Set this to source ports that should have low priority. If you have an unimportant webserver on your traffic, set this to 80

NOPRIOPORTDST
Set this to destination ports that should have low priority.

See the start of wshaper and wshaper.htb

Results

If we do all this we get the following measurements using an excellent ADSL connection from xs4all in the Netherlands:

Baseline latency:
round-trip min/avg/max = 14.4/17.1/21.7 ms

Without traffic conditioner, while downloading:
round-trip min/avg/max = 560.9/573.6/586.4 ms

Without traffic conditioner, while uploading:
round-trip min/avg/max = 2041.4/2332.1/2427.6 ms

With conditioner, during 220kbit/s upload:
round-trip min/avg/max = 15.7/51.8/79.9 ms

With conditioner, during 850kbit/s download:
round-trip min/avg/max = 20.4/46.9/74.0 ms

When uploading, downloads proceed at ~80% of the available speed. Uploads at around 90%. Latency then jumps to 850 ms, still figuring out why.

What you can expect from this script depends a lot on your actual uplink speed. When uploading at full speed, there will always be a single packet ahead of your keystroke. That is the lower limit to the latency you can achieve - divide your MTU by your upstream speed to calculate. Typical values will be somewhat higher than that. Lower your MTU for better effects!

A small table:

Uplink speed | Expected latency due to upload
--------------------------------------------------
32 | 234ms
64 | 117ms
128 | 58ms
256 | 29ms

So to calculate your effective latency, take a baseline measurement (ping on an unloaded link), and look up the number in the table, and add it. That is about the best you can expect. This number comes from a calculation that assumes that your upstream keystroke will have at most half a full sized packet ahead of it.

This boils down to:

mtu * 0.5 * 10
-------------- + baseline_latency
kbit

The factor 10 is not quite correct but works well in practice.

Your kernel

If you run a recent distribution, everything should be ok. You need 2.4 with QoS options turned on.

If you compile your own kernel, it must have some options enabled. Most notably, in the Networking Options menu, QoS and/or Fair Queueing, turn at least CBQ, PRIO, SFQ, Ingress, Traffic Policing, QoS support, Rate Estimator, QoS classifier, U32 classifier, fwmark classifier.

In practice, I (and most distributions) just turn on everything.

The scripts

The script comes in two versions, one which works on standard kernels and is implemented using CBQ. The other one uses the excellent HTB qdisc which is not in the default kernel. The CBQ version is more tested than the HTB one!

See wshaper and wshaper.htb.

Tuning

These scripts need to know the real rate of your ISP connection. This is hard to determine upfront as different ISPs use different kinds of bits it appears. People report success using the following technique:

Estimate both your upstream and downstream at half the rate your ISP specifies. Now verify if the script is functioning - check interactivity while uploading and while downloading. This should deliver the latency as calculated above. If not, check if the script executed without errors.

Now slowly increase the upstream & downstream numbers in the script until the latency comes back. This way you can find optimum values for your connection. If you are happy, please report to me so I can make a list of numbers that work well. Please let me know which ISP you use and the name of your subscription, and its reputed specifications, so I can list you here and save others the trouble.

Installation

If you dial in, you can copy the script to /etc/ppp/ip-up.d and it will be run at each connect.

If you want to remove the shaper from an interface, run wshaper stop. To see status information, run wshaper status.

KNOWN PROBLEMS

If you get errors, add an -x to the first line, as follows:

#!/bin/bash -x

And retry. This will show you which line gives an error. Before contacting me, make sure that you are running a recent version of iproute!

Recent versions can be found at your Linux distributor, or if you prefer compiling, here:
ftp://ftp.inr.ac.ru/ip-routing/iproute2-current.tar.gz

Hanihani Operation Sanctuary project is an English adaptation of a Japanese visual novel game.
The girl that fell out of the blue.
And the protagonists life, which began to take a turn little by little into the realm of the extraordinary starting from that very day.
- Nao-kun, if you dont get up soon, youre going to be late.
The new school term started today. The protagonists childhood friend, Honami, has kept telling him that hes not a child anymore, and yet continues to come to wake him up. They proceed as they always have to "Hasumidai Academy", which stands atop a hill ... but this time around, as second-year students.
- Naoki, Im going on ahead of you!
And the protagonists cousin, Matsuri, zips past the two of them. After having lost both parents in a terrible accident 5 years ago, the protagonist Naoki Kuzumi was taken in by Matsuris parents. And now, Matsuri herself -- who had been so opposed to Naokis moving in back then -- has become a freshman at Hasumidai Academy.
These ordinary, ordinary days, stretching on forever.
... but then, one day, up on the roof of school ...
Enhancements:
- RTM, all platforms.
- Initial page release. Currently in QC. Expect RTM for all platforms this weekend.

ScatterChat is a HACKTIVIST WEAPON designed to allow non-technical human rights activists and political dissidents to communicate securely and anonymously while operating in hostile territory. ScatterChat is also useful in corporate settings, or in other situations where privacy is desired.

It is a secure instant messaging client (based upon the Gaim software) that provides end-to-end encryption, integrated onion-routing with Tor, secure file transfers, and easy-to-read documentation.

Its security features include resiliency against partial compromise through perfect forward secrecy, immunity from replay attacks, and limited resistance to traffic analysis... all reinforced through a pro-actively secure design.

Those Funny Funguloids project is actually a nice little piece of entertainment. You collect mushrooms, bring them back to your home base and profit! Thats the basic idea in a nutshell.

It has smooth, appealing 3d graphics and nice atmospheric sound effects. Go ahead and try it out - it has sounds too!

Those Funny Funguloids! is free, open source software. Were using Ogre graphics engine for visuals, Lua for scripting and FMOD Ex for audio output.

CacheTable is a C++ template library that implements a very fast hash map container.
Its particularity, compared with std::hash_map and google::sparse_hash_map, is that it has a fixed size (decided it when it is created) and a random item replacement policy: in case of an "hash collision" the older item is "discarded" and replaced with the new one.
This container is ideal for implementing a caching system, when you want very fast item insertion and retrieval and you know the memory amount you want to dedicate ahead of time.
Enhancements:
- This release fixes a bug with deletion of iterator range, and work continues on more complete documentation.
- The test case has been reorganized to not require external libraries.

String::Tokenizer is a simple string tokenizer.

SYNOPSIS

use String::Tokenizer;

# create the tokenizer and tokenize input
my $tokenizer = String::Tokenizer->new("((5+5) * 10)", +*());

# create tokenizer
my $tokenizer = String::Tokenizer->new();
# ... then tokenize the string
$tokenizer->tokenize("((5 + 5) - 10)", ());

# will print (, (, 5, +, 5, ), -, 10, )
print join ", " => $tokenizer->getTokens();

# create tokenizer which retains whitespace
my $st = String::Tokenizer->new(
this is a test with, (signifigant) whitespace,
,(),
String::Tokenizer->RETAIN_WHITESPACE
);

# this will print:
# this, , is, , a, , test, , with, , (, signifigant, ), , whitespace
print "" . (join ", " => $tokenizer->getTokens()) . "";

# get a token iterator
my $i = $tokenizer->iterator();
while ($i->hasNextToken()) {
my $next = $i->nextToken();
# peek ahead at the next token
my $look_ahead = $i->lookAheadToken();
# ...
# skip the next 2 tokens
$i->skipTokens(2);
# ...
# then backtrack 1 token
my $previous = $i->prevToken();
# ...
# get the current token
my $current = $i->currentToken();
# ...
}

A simple string tokenizer which takes a string and splits it on whitespace. It also optionally takes a string of characters to use as delimiters, and returns them with the token set as well. This allows for splitting the string in many different ways.

This is a very basic tokenizer, so more complex needs should be either addressed with a custom written tokenizer or post-processing of the output generated by this module. Basically, this will not fill everyones needs, but it spans a gap between simple split / /, $string and the other options that involve much larger and complex modules.

Also note that this is not a lexical analyser. Many people confuse tokenization with lexical analysis. A tokenizer mearly splits its input into specific chunks, a lexical analyzer classifies those chunks. Sometimes these two steps are combined, but not here.