Alternative MPPC compression/decompression library

MPPC stands for Microsoft Point-to-Point Compression. It is a protocol designed for transfering compressed datagrams over point-to-point links. The MPPC algorithm uses an LZ based algorithm with a sliding window history buffer. See RFC2118 for details.

Although the library's source code is completely free, MPPC itself is patented algorithm. Patents for *Microsoft* PPC is holded by the Hifn Inc. To avoid legal problems, US citizens shouldn't use this library. OK, you have been warned, now you can do whatever you want.

This library was written as replacement for Hifn's original MPPC library to work in conjuction with ng_mppc FreeBSD netgraph module. It was originally based on code from "MPPE/MPPC kernel module for Linux" by Jan Dubiec, http://mppe-mppc.alphacron.de/.

Download

mppc-1.0.tgz

This achive includes mppc.h (header file), mppcc.c (compressor part), mppcd.c (decompressor part)

FreeBSD install

Kernel Module

Download archive and put it's content to the /usr/src/sys/net.
Change directory to the /usr/src/sys/modules/netgraph/mppc

In Makefile change line

NETGRAPH_MPPC_COMPRESSION?=     0

NETGRAPH_MPPC_COMPRESSION?=     1

Make
```
make && make install && make clean
```
Stop all ng_mppc consumers and unload previous module with
```
kldunload ng_mppc
```
command.

Static

Download archive and put it's content to the /usr/src/sys/net.
Apply patch files.mppc.patch to /usr/src/sys/conf/files if it is not done in your sources (before 6-STABLE of 25.07.2007).

Add to the kernel configuration

options	NETGRAPH_MPPC_ENCRYPTION

options	NETGRAPH_MPPC_COMPRESSION

Build/install new kernel and reboot.