third_party/lksctp-tools/README

(C) Copyright 2007 Hewlett-Packard Development Company, L.P.
(C) Copyright IBM Corp. 2001, 2003
Copyright 2001 Motorola, Cisco, Intel, Nokia, La Monte Yarroll.
Copyright 2002 Nokia, La Monte Yarroll, Intel. 

This is the lksctp-tools package for Linux Kernel SCTP Reference 
Implementation.

This package is intended to supplement the Linux Kernel SCTP
Reference Implementation now available in the Linux kernel source
tree in versions  2.5.36 and following.  For more information on LKSCTP
see the below section titled "LKSCTP - Linux Kernel SCTP." 

lksctp-tools
____________

The lksctp-tools package is intended for two audiences.  
	1) SCTP application developers
	2) LKSCTP project developers

For SCTP application developers, this package provides the user-level
C language header files and a library for accessing SCTP specific
application programming interfaces not provided by the standard sockets.

For LKSCTP project developers, this package provides the API
regression and functional tests.  Developers should also check
lksctp_tests package that provides low level kernel tests.  These
are available from git.kernel.org.

For either role, this project provides sample code, utilities, and
tests that one may find useful.  


LKSCTP - Linux Kernel SCTP 
__________________________

The Linux Kernel SCTP Reference Implementation is free software; you
can redistribute it and/or modify it under the terms of the GNU
General Public License as published by the Free Software Foundation;
either version 2, or (at your option) any later version. For more
information on licensing terms, please see the file COPYING in this
directory.

SCTP (Stream Control Transmission Protocol) is a message oriented,
reliable transport protocol, with congestion control, support for
transparent multi-homing, and multiple ordered streams of messages.
RFC2960 defines the core protocol. The IETF SIGTRAN Working Group
developed SCTP.  The primary architects are Randy Stewart and Qiaobing
Xie.

The Kernel Reference is first and foremost an exposition of
RFC2960 and related documents. You will find that the comments and
variable names tie closely back to the RFC and Internet Drafts.

This work was started by a small team of developers at Motorola.
Throughout this document, "we" refers to that team.  We intend for the
meaning of "we" to expand to include the whole development community,
all 27 million programmers on the planet.

The Kernel Reference has loose origins in the SCTP User Space Reference
by Randy Stewart and Qiaobing Xie.

MANIFEST
--------
.
|-- bin
|-- doc
|-- man
|-- src
    |-- apps
    |-- func_tests
    |-- include
    |   `-- netinet
    |-- lib
    |-- testlib
    `-- withsctp

You may want to check the following files:

COPYING.lib	Licensing terms of libsctp
COPYING		Licensing terms of other pieces of the package
ROADMAP		A tour around the files in the distribution of SCTP-tools.
INSTALL       	How to install and run this beast.
ChangeLog	What has changed since the last release?

DESIGN GOALS
------------

- A primary design goal is to reflect RFC 2960 as closely as
practical.  We have changed many names from the user space reference to
follow the draft as closely as possible.  We have also included
extensive quotes from the draft adjacent to the code which implements
them.

- The other primary design goal is to integrate Linux kernel data
structures and idioms as much as possible.  The test framework (in
directory test/) provides many of the functions which would otherwise
come from the kernel.  The test frame does use libc features, but the
state machine code should be libc-free.

- A lesser design goal is to completely describe the actions for each
state transition in an sctp_command_t (see sctp_command.h).  This
means that the state functions (sctp_state_fn_t in sctp_sm.h) are NOT
allowed to modify their endpoint, association, or chunk arguments.
This is enforced by const modifiers--please respect the compiler
warnings.  All actions must be described in the last argument to the
state function.

- A byte order convention for dealing with the SCTP chunk headers: 
all SCTP chunks, regardless if the chunk is to be sent outbound
to the network or was received inbound from the network, the header portion
of the chunk is ALWAYS created and retained in the NETWORK BYTE ORDER.

- An error code handling convention is to return negative values internally.  
The sk->err field holds a positive valued errno values, so will need our 
internal values negated.   

- We are moving toward an XP development model.  So far we have
adopted pair-programming, coding-to-test (functional and unit), design
through refactoring, and story-based planning.

In order to make XP work, it is very important that we have a complete
set of tests for the code.  We can not safely refactor major parts of
the code without a way to find the things we break.  If you decide to
extend the SCTP Kernel Implementation we ask that you do the following:

	1) Pick an XP story.  Tell lksctp-developers@lists.sourceforge.net
	2) Write a functional test for that XP story.  The functional
	   test defines "DONE" for the story.
	3) Submit the functional test as a patch on SourceForge.
	4) Write unit tests for any new "objects" you define.
	5) Implement your feature.
	6) Submit the feature and the unit tests as a separate
	SourceForge patch.
	
Look in src/func_tests and in lksctp-tests package for examples of of tests.
Please do not submit code that fails its own tests or any of the unit tests.
If it fails a functional test, please document that with the submission.

Another XP requirement is to code only what is you need to make the
current test work.  Where this means omitting required features, we
have put in prominent BUG comments describing the omitted
functionality.

FEATURES
--------
This implementation uses a fairly compact cookie which is isolated in
its own substructure of SCTP_association.  We have been moving toward
aggregating data elements which need to travel together to minimize
copying of individual elements in favour of more efficient structure
copies.

You will find what we believe to be the smallest possible Internet
simulator in the middle of the function test_kernel.c:simulate_internet().
The simulator makes a few simplifying assumptions...

MAILING LISTS and WEB SITES
---------------------------
http://www.sourceforge.net/projects/lksctp

	This is the lksctp project webpage.  

linux-sctp@vger.kernel.org
	
	This is the discussion list for developers.  Join this list if	
	you are interested in following the day-to-day activities of
	the SCTP Kernel Reference Implementation development community. 
	See subscription directions at:  
		http://vger.kernel.org/vger-lists.html#linux-sctp

http://www.sctp.org

	This is Randy Stewart's SCTP web site.

http://sctp.de

	This is Michael Tuexen's SCTP web site.  Michael has collected
	dozens of documents related to SCTP.