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                                MDFP
                  Projet Hipercom, INRIA Rocquencourt
      Copyright 2004 Institut National de Recherche en Informatique et
  en Automatique.  All rights reserved.  Distributed only with permission.
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                    This software is available at
		    http://hipercom.inria.fr/SMOLSR-MOLSR/
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0- Introduction
---------------

This document describes how to compile and install the MDFP daemon
(MDFP: Multicast Data Forwarding Protocol)


1- License
------------
 
This code and files in this package are property of INRIA, project Hipercom.
It is distributed under the GPL license, version 2 or later:
see the file GPL-2.
 

2-  MDFP Description
---------------------
MDFP is a forwarding protocol that enables a point to multipoint data 
transfer. It is based on the MPR flooding of the OLSR protocol. Multicast
packets are captured and encapsulated in order to be forwarded to the entire
network in case of simple multicast (SMOLSR), and inside a multicast tree in case of 
multicast (MOLSR). Forwarding rules are specified by OLSR daemon. Those rules consist
of a set of information sent by OLSR to MDFP.
With SMOLSR scheme, it includes (i) the list of 
neighbor interfaces which belong to symmetric neighbors of the host, 
(ii) the list of interfaces which belong to host MPR selectors, (iii) the main
address of the host, and (iv) the interface list of the host. 


With MOLSR scheme, it includes (i) the list of
neighbor interfaces which belong to symmetric neighbors of the host,
(ii), the multicast tree table built by MOLSR daemon (iii) the main
address of the host, and (iv) the interface list of the host.

Received packet which  are  not duplicated,  are decapsulted and given to the 
upper layer.

The actual version of MDFP is user space daemon based on Netfilter ipq 
library. Basically, it listens to the captured packet sent by Netfilter to 
the user space. A set of rules must be installed within Netfilter in order
to capture the outgoing multicast packets and the incoming broadcast packets
sent to MDFP.

MDFP processes captured packets and send them back to the kernel
with the corresponding verdict (DROP, ACCEPT). A copy of the packet that must 
be forwarded or relayed, are encapsulated, and broadcasted using the UDP.

3- Requirements
---------------
In this section we describe the system and the software required to make
MDFP running.

3.1- Software
-------------
MDFP needs a set of information to make decision on the captured packets.
Those information are sent by a modified OLSR daemon runing in SMOLSR mode
or MOLSR mode.

3.2- System Requirements
------------------------
Linux 2.4 or 2.6 is required.

MDFP processes captured data packets. This is accomplished by Netfilter that 
enables packet filtering and mangling. Netfilter framework is included
inside Linux kernels 2.4 and 2.6. 
Netfilter can be either compiled with the kernel or loaded as a module.

4- Compilation
--------------
Notice that MDFP uses the ipq library. This library must be installed  
within reach of the compiler (right path) before compilling.

Run 'make all' command. The generated binary file is called 'mangle'.

5- Running
----------
The binary files must run with root previleges.
In order to capture packets by Netfilter, we must specify the rules to follow. 
This is specified in the script file 'netfilterConfigure.sh'.

- Start the modified OOLSR daemon with '--molsrmode 1' option for MOLSR mode
and  with '--molsrmode 0' option for SMOLSR mode (default mode).
- Install the netfilter rules by running the script file.
- Start mangle.