Forban is a p2p application for link-local and local area network.

Forban works independently from Internet and use only the local 

area capabilities to announce, discover, search or share files. 

Forban relies on HTTP and he is opportunistic.

The name took his origins from the old French word : 

http://fr.wiktionary.org/wiki/forban 

Forban name can be also a playword in English

for banning an unwanted software or services on Internet.

Forban is free software licensed under 

the GNU Affero General Public License version 3.

http://www.fsf.org/licensing/licenses/agpl-3.0.html

== message format used for announce/discovery ==

=== announce message ===

ASCII encoded message using UDP on port 12555 with

the following format: 

forban;name;<nameoftheforban>;uuid;<identityoftheforban>;hmac;<hmacvaluecofindex>

The messages are flooded in broadcast (IPv4) and using

ff02::1 (IPv6) at a regular interval.

Based on the source IP and the destination port used,

a HTTP URL is build to get to default forban service.

=== HTTP services for Forban ===

The UDP port 12555 is there for announcing forban services.

The TCP port 12555 is the HTTP server running for forban services.

base URL: [REQUIRED]

http://<ip>:<destport>/

index URL where Forban stored his index: [REQUIRED]

http://<ip>:<destport>/s/?g=forban/index

store URL where Forban stored his loot and how to get a file: [REQUIRED]

http://<ip>:<destport>/s/?g=base64_urlsafe(<filenamefromindex>)&f=b64e

search URL: [OPTIONAL]

http://<ip>:<destport>/q/?v=<yoursearch>&r=<refreshtimeinsec>

REQUIRED interfaces are required to have a full operational Forban

protocol in all the modes. The OPTIONAL interfaces are not required

for machine-to-machine interaction but used to ease the life of the users.

==== base64_urlsafe function (b64e) ====

'+' is replaced by '-'.

'/' is replaced by '_'(underscore).

'=' is replaced by '!'.

This is following the same approach of MIME::Base64::URLSafe

or the python base64.urlsafe_b64encode with an addition to

the equal sign being replaced by an exclamation mark.

=== Forban mode available ===

* Opportunistic mode

* Shared mode

The opportunistic mode and shared used all the REQUIRED components of

the protocol. The only difference is the lack of automatic file fetching

in the shared mode. The shared mode is usally used on fixed node content

where the opportunistic fetching is not desired (e.g. a fixed bookshelf).

The opportunistic mode is working as a simple gossip (or epidemic) protocol

to replicate the information from one local to another local Forban.

=== message format - notes about HMAC ===

The optional HMAC value has two purposes :

* To know if the index has been updated

* and to verify (if a PSK is set) if the index has been tampered.

When a PSK is not set, the default PSK value is 'Forban'.

The value is optional as other Forban can download any index when they

want.

=== software required ===

* Python (tested successfully with 2.5, 2.6 and 2.7) - 2.5 is required for the uuid library