OpenSS7 Linux Native SCTP

OpenSS7 Linux Native SCTP Installation and Reference Manual

About This Manual

This is Edition 26, last updated 2007-06-24, of The OpenSS7 Linux Native SCTP Installation and Reference Manual, for Version 0.2 release 26 of the OpenSS7 Linux Native SCTP package.

Preface

Notice

This package is released and distributed under the GNU General Public License (see GNU License). Please note, however, that there are different licensing terms for the manual pages and some of the documentation (derived from OpenGroup¹ publications and other sources). Consult the permission notices contained in the documentation for more information.

This manual, is released under the GNU Free Documentation License (see GNU Free Documentation License) with all sections invariant.

Abstract

This manual provides a Installation and Reference Manual for OpenSS7 Linux Native SCTP.

Objective

The objective of this manual is to provide a guide for the STREAMS programmer when developing STREAMS modules, drivers and application programs for OpenSS7 Linux Native SCTP.

This guide provides information to developers on the use of the STREAMS mechanism at user and kernel levels.

STREAMS was incorporated in UNIX System V Release 3 to augment the character input/output (I/O) mechanism and to support development of communication services.

STREAMS provides developers with integral functions, a set of utility routines, and facilities that expedite software design and implementation.

Intent

The intent of this manual is to act as an introductory guide to the STREAMS programmer. It is intended to be read alone and is not intended to replace or supplement the OpenSS7 Linux Native SCTP manual pages. For a reference for writing code, the manual pages (see STREAMS(9)) provide a better reference to the programmer. Although this describes the features of the OpenSS7 Linux Native SCTP package, OpenSS7 Corporation is under no obligation to provide any software, system or feature listed herein.

Audience

This manual is intended for a highly technical audience. The reader should already be familiar with Linux kernel programming, the Linux file system, character devices, driver input and output, interrupts, software interrupt handling, scheduling, process contexts, multiprocessor locks, etc.

The guide is intended for network and systems programmers, who use the STREAMS mechanism at user and kernel levels for Linux and UNIX system communication services.

Readers of the guide are expected to possess prior knowledge of the Linux and UNIX system, programming, networking, and data communication.

Revisions

Take care that you are working with a current version of this manual: you will not be notified of updates. To ensure that you are working with a current version, contact the Author, or check The OpenSS7 Project website for a current version.

A current version of this manual is normally distributed with the OpenSS7 Linux Native SCTP package.

Version Control

     
     sctp.texi,v
     Revision 0.9.2.22  2007/02/28 06:30:29  brian
     - updates and corrections, #ifdef instead of #if
     
     Revision 0.9.2.21  2006/09/18 01:06:21  brian
     - updated manuals and release texi docs
     
     Revision 0.9.2.20  2006/08/28 10:46:54  brian
     - correction
     
     Revision 0.9.2.19  2006/08/28 10:32:45  brian
     - updated references
     
     Revision 0.9.2.18  2006/08/27 12:26:34  brian
     - finalizing auto release files
     
     Revision 0.9.2.17  2006/08/26 09:16:38  brian
     - better release file generation
     
     Revision 0.9.2.16  2006/08/23 11:00:26  brian
     - added preface, corrections and updates for release
     
     Revision 0.9.2.14  2006-03-29 04:27:45 -0700  brian
     - corrections for rerelease, see ChangeLog
     
     Revision 0.9.2.13  2006-03-22 03:01:59 -0700  brian
     - added makefile target index
     
     Revision 0.9.2.12  2006-03-04 22:51:50 -0700  brian
     - minor updates of some release info for next release
     
     Revision 0.9.2.11  2005-07-08 07:15:51 -0600  brian
     - updates to documentation
     
     Revision 0.9.2.10  2005-06-24 07:38:58 -0600  brian
     - added troubleshooting section to manuals
     
     Revision 0.9.2.9  2005-05-14 02:29:32 -0600  brian
     - copyright header correction
     
     Revision 0.9.2.8  2005-04-12 17:01:41 -0600  brian
     - correct docs
     
     Revision 0.9.2.7  2005-04-12 03:28:55 -0600  brian
     - corrections
     
     Revision 0.9.2.6  2005-03-14 17:56:58 -0700  brian
     - Updated version numbering in texinfo files.
     
     Revision 0.9.2.5  2005-03-14 17:51:55 -0700  brian
     - Updated version numbering in texinfo files.
     
     Revision 0.9.2.4  2005-02-17 13:00:07 -0700  brian
     - Fixes for texi documentation.
     
     Revision 0.9.2.3  2005-01-24 04:57:59 -0700  brian
     - Updated texinfo headers.
     
     Revision 0.9.2.2  2004-12-21 15:20:24 -0700  brian
     - Some corrections.
     
     Revision 0.9.2.1  2004-12-20 03:18:19 -0700  brian
     - Big start on autoconf release of Linux Native SCTP.
     
     Revision 0.9  1996-12-31 17:00:00 -0700  brian
     *** empty log message ***
     

ISO 9000 Compliance

Only the TeX, texinfo, or roff source for this manual is controlled. An opaque (printed, postscript or portable document format) version of this manual is an UNCONTROLLED VERSION.

Disclaimer

OpenSS7 Corporation disclaims all warranties with regard to this documentation including all implied warranties of merchantability, fitness for a particular purpose, non-infringement, or title; that the contents of the manual are suitable for any purpose, or that the implementation of such contents will not infringe on any third party patents, copyrights, trademarks or other rights. In no event shall OpenSS7 Corporation be liable for any direct, indirect, special or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with any use of this manual or the performance or implementation of the contents thereof.

OpenSS7 Corporation reserves the right to revise this software and documentation for any reason, including but not limited to, conformity with standards promulgated by various agencies, utilization of advances in the state of the technical arts, or the reflection of changes in the design of any techniques, or procedures embodied, described, or referred to herein. OpenSS7 Corporation is under no obligation to provide any feature listed herein.

U.S. Government Restricted Rights

If you are licensing this Software on behalf of the U.S. Government ("Government"), the following provisions apply to you. If the Software is supplied by the Department of Defense ("DoD"), it is classified as "Commercial Computer Software" under paragraph 252.227-7014 of the DoD Supplement to the Federal Acquisition Regulations ("DFARS") (or any successor regulations) and the Government is acquiring only the license rights granted herein (the license rights customarily provided to non-Government users). If the Software is supplied to any unit or agency of the Government other than DoD, it is classified as "Restricted Computer Software" and the Government's rights in the Software are defined in paragraph 52.227-19 of the Federal Acquisition Regulations ("FAR") (or any successor regulations) or, in the cases of NASA, in paragraph 18.52.227-86 of the NASA Supplement to the FAR (or any successor regulations).

Acknowledgements

As with most open source projects, this project would not have been possible without the valiant efforts and productive software of the Free Software Foundation and the Linux Kernel Community.

Sponsors

Funding for completion of the OpenSS7 OpenSS7 Linux Native SCTP package was provided in part by:

Additional funding for The OpenSS7 Project was provided by:

Contributors

The primary contributor to the OpenSS7 OpenSS7 Linux Native SCTP package is Brian F. G. Bidulock. The following is a list of significant contributors to The OpenSS7 Project:

Authors

The authors of the OpenSS7 OpenSS7 Linux Native SCTP package include:

See Author Index, for a complete listing and cross-index of authors to sections of this manual.

Maintainer

The maintainer of the OpenSS7 OpenSS7 Linux Native SCTP package is:

Please send bug reports to bugs@openss7.org using the send-pr script included in the package, only after reading the BUGS file in the release, or See Problem Reports.

Web Resources

The OpenSS7 Project provides a website dedicated to the software packages released by the OpenSS7 Project.

Bug Reports

Please send bug reports to bugs@openss7.org using the send-pr script included in the OpenSS7 Linux Native SCTP package, only after reading the BUGS file in the release, or See Problem Reports. You can access the OpenSS7 GNATS database directly via the web, however, the preferred method for sending new bug reports is via mail with the send-pr script.

Mailing Lists

The OpenSS7 Project provides a number of general discussion Mailing Lists for discussion concerning the OpenSS7 OpenSS7 Linux Native SCTP package as well as other packages released by The OpenSS7 Project.

These are mailman mailing lists and so have convenient web interfaces for subscribers to control their settings. See http://www.openss7.org/mailinglist.html.

The mailing lists are as follows:

openss7

The openss7 mailing list is for general enquiries, information exchange and announcements regarding the OpenSS7 Project. This is our original mailing list and takes the highest amount of traffic.

openss7-announce

The openss7-announce mailing list is for announcements related to the OpenSS7 Project. This list will accept announcements posted by subscribers. Subscribe to this list if you are interested in announcements from the OpenSS7 Project, subscribers and sponsors, related to the OpenSS7 Project or STREAMS, SS7, SIGTRAN or SCTP in general.

openss7-cvs

The openss7-cvs mailing list is for automatic CVS log reporting. You must get permission of the owner to subscribe to this list. Subscribers are not allowed to post to this list, this is merely for distributing notification of changes to the CVS repository.h

openss7-develop

The openss7-develop mailing list is for email exchange related to the development projects under the OpenSS7 Project. This includes development requests, proposals, requests for comment or proposal. Subscribe to this list if you are interested in ongoing development details regarding the OpenSS7 Project.

openss7-test

The openss7-test mailing list is for email exchange related to the testing of code under the OpenSS7 Project. This specifically relates to conformance testing, verification testing, interoperability testing and beta testing. Subscribe to this list if you are interested in participating in and receiving ongoing details of test activities under the OpenSS7 Project.

openss7-bugs

The openss7-bugs mailing list is specifically tailored to bug tracking. The mailing list takes a feed from the OpenSS7 GNATS bug tracking system and accepts posting of responses to bug reports, tracking and resolution. Subscribe to this list if you are interested in receiving detailed OpenSS7 release code bug tracking information. This list is not archived; for historical information on problem reports, see our GNATS databases.

openss7-updates

The openss7-updates mailing list provides updates on OpenSS7 Project code releases and ongoing activities. Subscribers are not allowed to post to this list; this list is for official OpenSS7 Project announcements only. Subscribe to this list if you are interested in receiving updates concerning official releases and activities of the OpenSS7 Project.

openss7-streams

The openss7-streams mailing list is for email exchange related to the STREAMS development projects under the OpenSS7 Project. This includes development requests, proposals, requests for comment or proposal. Subscribe to this list if you are interested in ongoing development details regarding the OpenSS7 Project STREAMS components.

linux-streams

The linux-streams mailing list is for mail exchange related to Linux Fast-STREAMS or Linux STREAMS. This includes patches, development requests, proposals, requests for comment or proposal. Subscribe to this list if you are interested in ongoing development details regarding the STREAMS for Linux components. This is the the new (September 2006) home of the linux-streams list formerly of <gsyc.escet.urjc.es>.

Spam

To avoid spam being sent to the members of the OpenSS7 mailing list(s), we have blocked mail from non-subscribers. Please subscribe to the mailing list before attempting to post to them. (Attempts to post when not subscribed get bounced.)

As an additional measure against spam, subscriber lists for all OpenSS7 mailing lists are not accessible to non-subscribers; for most lists subscriber lists are only accessible to the list administrator. This keeps your mailing address from being picked off our website by bulk mailers.

Acceptable Use Policy

It is acceptable to post professional and courteous messages regarding the OpenSS7 package or any general information or questions concerning STREAMS, SS7, SIGTRAN, SCTP or telecommunications applications in general.

Large Attachments

The mailing list is blocked from messages of greater than 40k. If you have attachments (patches, test programs, etc.) and you mail them to the list, it will bounce to the list administrator. If you are interested in making your patches, test programs, test results or other large attachments available to the members of the mailing list, state in the message that you would like them posted and the list administrator will place them in the mail archives.

Quick Start Guide

OpenSS7 Linux Native SCTP

Package sctp-0.2.26 was released under GPLv2 2007-06-24.

The OpenSS7 Linux Native SCTP package is the OpenSS7 Linux Native (Sockets) Kernel implementation of Stream Control Transmission Protocol (SCTP).

sctp-0.2.26 is the 0.2.26 version of a Linux Kernel native implementation of RFC 2960 Stream Control Transmission Protocol. For information on using the implementation see the man/sctp.7 Linux manual page and look at the test programs in sctp-0.2.26/test/.

Warning: This is pre-release code. It is Beta but rather stable. Nevertheless, it is possible it will crash or lock your machine in some situations. Please remember that there is NO WARRANTY with this code and take appropriate precautions when attempting to run it.

This distribution is only currently applicable to Linux 2.4 kernels and was targeted at ix86, x86_64, ppc and ppc64 architectures, but should build and install for other architectures as well.

Release

This is the sctp-0.2.26 package, released 2007-06-24. This `0.2.26' release, and the latest version, can be obtained from the download area of The OpenSS7 Project website using a command such as:

     $> wget http://www.openss7.org/tarballs/sctp-0.2.26.tar.bz2

The release is available as an autoconf(1) tarball, src.rpm or dsc, or as a set of binary rpms or debs. See the download page for the autoconf(1) tarballs, src.rpms or dscs. See the sctp package page for tarballs, source and binary packages.

Please see the NEWS file for release notes and history of user visible changes for the current version, and the ChangeLog file for a more detailed history of implementation changes. The TODO file lists features not yet implemented and other outstanding items.

Please see the INSTALL, INSTALL-sctp and README-make, files (or see Installation) for installation instructions.

When working from cvs(1) or git(1), please see the README-cvs, file (or see Downloading from CVS). An abbreviated installation procedure that works for most applications appears below.

This release of the package is published strictly under Version 2 of the GNU Public License which can be found in the file COPYING. Package specific licensing terms (if any) can be found in the file LICENSES. Please respect these licensing arrangements. If you are interested in different licensing terms, please contact the copyright holder, or OpenSS7 Corporation <sales@openss7.com>.

See README-alpha (if it exists) for alpha release information.

Prerequisites

The quickest and easiest way to ensure that all prerequisites are met is to download and install this package from within the OpenSS7 Master Package, openss7-0.9.2.F, instead of separately.

Prerequisites for the OpenSS7 Linux Native SCTP package are as follows:

1. Linux distribution, somewhat Linux Standards Base compliant, with a 2.4 or 2.6 kernel and the appropriate tool chain for compiling out-of-tree kernel modules. Most recent Linux distributions are usable out of the box, but some development packages must be installed. For more information, see Compatibility.

   	− A fairly LSB compliant GNU/Linux distribution.2
   	− Linux 2.4 kernel (2.4.10 - 2.4.27).
   	− glibc2 or better.
   	− GNU info (for info files).
   	− GNU groff (for man pages).3

When configuring and building multiple OpenSS7 Project release packages, place all of the source packages (unpacked tarballs) at the same directory level and all build directories at the same directory level (e.g. all source packages under /usr/src).

When installing packages that install as kernel modules, it is necessary to have the correct kernel development package installed. For the following distributions, use the following commands:

     Ubuntu:  $> apt-get install linux-headers
     Debian:  $> apt-get install kernel-headers
     Fedora:  $> yum install kernel-devel

You also need the same version of gcc(1) compiler with which the kernel was built. If it is not the default, add `CC=kgcc' on the line after `./configure', for example:

     $> ../sctp-0.2.26/configure CC='gcc-3.4'

Installation

The following commands will download, configure, build, check, install, validate, uninstall and remove the package:

     $> wget http://www.openss7.org/tarballs/sctp-0.2.26.tar.bz2
     $> tar -xjvf sctp-0.2.26.tar.bz2
     $> mkdir build
     $> pushd build
     $> ../sctp-0.2.26/configure --enable-autotest
     $> make
     $> make check
     $> sudo make install
     $> sudo make installcheck
     $> sudo make uninstall
     $> popd
     $> sudo rm -rf build
     $> rm -rf sctp-0.2.26
     $> rm -f sctp-0.2.26.tar.bz2

If you have problems, try building with the logging targets instead. If the make of a logging target fails, an automatic problem report will be generated that can be mailed to The OpenSS7 Project.⁴ Installation steps using the logging targets proceed as follows:

     $> wget http://www.openss7.org/tarballs/sctp-0.2.26.tar.bz2
     $> tar -xjvf sctp-0.2.26.tar.bz2
     $> mkdir build
     $> pushd build
     $> ../sctp-0.2.26/configure --enable-autotest
     $> make compile.log
     $> make check.log
     $> sudo make install.log
     $> sudo make installcheck.log
     $> sudo make uninstall.log
     $> popd
     $> sudo rm -rf build
     $> rm -rf sctp-0.2.26
     $> rm -f sctp-0.2.26.tar.bz2

See README-make for additional specialized make targets.

For custom applications, see the INSTALL and INSTALL-sctp files or the see Installation, as listed below. If you encounter troubles, see Troubleshooting, before issuing a bug report.

Brief Installation Instructions

The OpenSS7 Linux Native SCTP package is available from the downloads area of The OpenSS7 Project website using a command such as:

     $> wget http://www.openss7.org/tarballs/sctp-0.2.26.tar.bz2

Unpack the tarball using a command such as:

     $> tar -xjvf sctp-0.2.26.tar.bz2

The tarball will unpack into the relative subdirectory named after the package name: sctp-0.2.26.

The package builds using the GNU autoconf utilities and the configure script. To build the package, we recommend using a separate build directory as follows:

     $> mkdir build
     $> cd build
     $> ../sctp-0.2.26/configure

In general, the package configures and builds without adding any special options to the configure script. For general options to the configure script, see the GNU INSTALL file in the distribution:

     $> less ../sctp-0.2.26/INSTALL

For specific options to the configure script, see the INSTALL-sctp file in the distribution, or simply execute the configure script with the --help option like so:

     $> ../sctp-0.2.26/configure --help

After configuring the package, the package can be compiled simply by issuing the `make' command:

     $> make

Some specialized makefile targets exists, see the README-make file in the distribution or simply invoke the `help' target like so:

     $> make help | less

After successfully building the package, the package can be checked by invoking the `check' make target like so:

     $> make check

After successfully checking the package, the package can be installed by invoking the `install' make target (as root) like so:

     $> sudo make install

The test suites that ship with the package can be invoked after the package has been installed by invoking the `installcheck' target. This target can either be invoked as root, or as a normal user, like so:

     $> make installcheck

(Note: you must add the --enable-autotest flag to configure, above for the test suites to be invoked with `make installcheck'.)

The package can be cleanly removed by invoking the `uninstall' target (as root):

     $> sudo make uninstall

Then the build directory and tarball can be simply removed:

     $> cd ..
     $> rm -rf build
     $> rm -rf sctp-0.2.26
     $> rm -f sctp-0.2.26.tar.bz2

Detailed Installation Instructions

More detailed installation instructions can be found in the Installation, contained in the distribution in `text', `info', `html' and `pdf' formats:

     $> cd ../sctp-0.2.26
     $> less doc/manual/sctp.txt
     $> lynx doc/manual/sctp.html
     $> info doc/manual/sctp.info
     $> xpdf doc/manual/sctp.pdf

The `text' version of the manual is always available in the MANUAL file in the release.

The current manual is also always available online from The OpenSS7 Project website at:

     $> lynx http://www.openss7.org/sctp_manual.html

1 Introduction

This manual documents the design, implementation, installation, operation and future development schedule of the OpenSS7 Linux Native SCTP package.

1.1 Overview

This manual documents the design, implementation, installation, operation and future development of the OpenSS7 Linux Native SCTP package.

The OpenSS7 Linux Native SCTP package is an Open Linux SCTP package for Linux. It includes development tools, header files and manual pages for SCTP.

The OpenSS7 Linux Native SCTP package is essential to the development and support of SCTP networking modules and drivers and provides a fundamental set of header files and manual pages for such development.

1.2 Organization of this Manual

This manual is organized (loosely) into several sections as follows:

1.3 Conventions and Definitions

This manual uses texinfo typographic conventions.

2 Objective

3 Reference

3.1 Files

SCTP creates the following kernel modules files in the kernel modules directory, /lib/modules/2.4.20-28.7/:⁵

modules.sctp

SCTP installs the following kernel module files in the kernel modules directory, /lib/modules/2.4.20-28.7/kernel/net/ipv4/:⁶

sctp.o

This kernel module contains the SCTP protocol module.

SCTP installs the following header files in the system include directory, /usr/include/netinet/:

sctp.h

This file contains SCTP and socket option definitions.

SCTP installs the following test programs in the system libexec directory, /usr/libexec/sctp/:⁷

send-pr

send-pr.config

The send-pr stand-alone shell script can be used for the automatic generation of problem reports for the OpenSS7 Linux Native SCTP package. The send-pr.config file provides localized definitions used by the send-pr program. For more information on problem reports, See Problem Reports, and, in particular, See Stand Alone Problem Reports.

test-sctp-dc

This binary contains a test program for delay test client for SCTP.

test-sctp-ds

This binary contains a test program for delay test server for SCTP.

test-sctp-sc

This binary contains a test program for socket test client for SCTP.

test-sctp-ss

This binary contains a test program for socket test server for SCTP.

test-sctp-tc

This binary contains a test program for throughput test client for SCTP.

test-sctp-ts

This binary contains a test program for throughput test server for SCTP.

test-sctpc

This binary contains a test program for a general testing test client for SCTP.

test-sctps

This binary contains a test program for a general testing test server for SCTP.

test-tcp-dc

This binary contains a test program for delay test client for TCP.

test-tcp-ds

This binary contains a test program for delay test server for TCP.

test-tcp-tc

This binary contains a test program for throughput test client for TCP.

test-tcp-ts

This binary contains a test program for throughput test server for TCP.

test-tcpc

This binary contains a test program for a general testing test client for TCP.

test-tcps

This binary contains a test program for a general testing test server for TCP.

test-udpc

This binary contains a test program for a general testing test client for UDP.

test-udps

This binary contains a test program for a general testing test server for UDP.

testsuite

atlocal

The testsuite stand-alone shell script invokes test cases in the test programs above as compiled into a comprehensive regression, troubleshooting and validation test suite for the OpenSS7 Linux Native SCTP drivers. The atlocal file provides localized definitions used by the testsuite program. For more information on test suites, See Test Suites, and, in particular, See Running Test Suites.

SCTP installs the following init scripts in the system init directory, /etc/rc.d/init.d/ (non-Debian) or /etc/init.d/ (Debian):

sctp

This is the name of the system init script on non-Debian based systems.

sctp.sh

This is the name of the system init script on Debian based systems.

SCTP installs the following system configuration files in the configuration directory, /etc/:

sctp.conf

This file provided configuration information for any system controls affected by the `SCTP' package.

modutils/sctp

This file provides module definitions and demand loading aliases for the sctp package. This file is really only applicable to older 2.4 kernels.

SCTP installs the following system configuration file in the system configuration directory, /etc/sysconfig/ (non-Debian) or /etc/default/ (Debian):

sctp

This file provides system configuration information used by init scripts for the `SCTP' package. Some options of init script execution can be controlled by this file.

SCTP installs the following info files in the system info directory, /usr/share/info/:

sctp.info

sctp.info-1

sctp.info-2

These files contain this manual in GNU info format.

SCTP installs the following manual page macros and reference database files in the system man directory, /usr/share/man/:⁸

sctp.macros

This file contains manual page macro definitions included by the manual pages included in the package.

sctp.refs

This file contains a reference database referenced by the manual pages included in the package.

SCTP installs the following manual pages in the system man directory, /usr/share/man/man7/:

sctp.7

This is the SCTP manual page.

SCTP installs the following manual pages in the system man directory, /usr/share/man/man8/:

test-sctp-dc.8

test-sctp-ds.8

test-sctp-sc.8

test-sctp-ss.8

test-sctp-tc.8

test-sctp-ts.8

test-sctpc.8

test-sctps.8

test-tcp-dc.8

test-tcp-ds.8

test-tcp-tc.8

test-tcp-ts.8

test-tcpc.8

test-tcps.8

test-udpc.8

test-udps.8

These are the test program manual pages.

3.2 Kernel Modules

3.2.1 Stream Control Transmission Protocol (SCTP) Module (sctp)

Licensing

The sctp module was originally written by Brian F. G. Bidulock and is licensed under the GNU General Public License Version 2 See GNU General Public License.

3.3 Libraries

3.4 Utilities

3.4.1 test-sctp-dc

Note that test-sctp-dc is maintained as a manual page, test-sctp-dc(8).

3.4.2 test-sctp-ds

Note that test-sctp-ds is maintained as a manual page, test-sctp-ds(8).

3.4.3 test-sctp-sc

Note that test-sctp-sc is maintained as a manual page, test-sctp-sc(8).

3.4.4 test-sctp-ss

Note that test-sctp-ss is maintained as a manual page, test-sctp-ss(8).

3.4.5 test-sctp-tc

Note that test-sctp-tc is maintained as a manual page, test-sctp-tc(8).

3.4.6 test-sctp-ts

Note that test-sctp-ts is maintained as a manual page, test-sctp-ts(8).

3.4.7 test-sctpc

Note that test-sctpc is maintained as a manual page, test-sctpc(8).

3.4.8 test-sctps

Note that test-sctps is maintained as a manual page, test-sctps(8).

3.4.9 test-tcp-dc

Note that test-tcp-dc is maintained as a manual page, test-tcp-dc(8).

3.4.10 test-tcp-ds

Note that test-tcp-ds is maintained as a manual page, test-tcp-ds(8).

3.4.11 test-tcp-tc

Note that test-tcp-tc is maintained as a manual page, test-tcp-tc(8).

3.4.12 test-tcp-ts

Note that test-tcp-ts is maintained as a manual page, test-tcp-ts(8).

3.4.13 test-tcpc

Note that test-tcpc is maintained as a manual page, test-tcpc(8).

3.4.14 test-tcps

Note that test-tcps is maintained as a manual page, test-tcps(8).

3.4.15 test-udpc

Note that test-udpc is maintained as a manual page, test-udpc(8).

3.4.16 test-udps

Note that test-udps is maintained as a manual page, test-udps(8).

3.5 Development

OpenSS7 Linux Native SCTP does not currently install any libraries. The socket library normally available under Linux in libc are sufficient. OpenSS7 Linux Native SCTP does, however, install the /usr/include/netinet/sctp.h header file for development of applications programs that use the sctp kernel module.

3.6 SCTP Reference Page

NAME

sctp - Stream Control Transmission Protocol (SCTP).

SYNOPSIS

     #include <sys/socket.h>
     #include <netinet/in.h>
     #include <netinet/sctp.h>
     
     sctp_socket = socket(PF_INET, SOCK_SEQPACKET, 0);
     sctp_socket = socket(PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP);
     sctp_socket = socket(PF_INET, SOCK_STREAM, IPPROTO_SCTP);
     sctp_socket = socket(PF_INET, SOCK_RDM, 0IPPROTO_SCTP

DESCRIPTION

SCTP is an implementation of the SCTP (Stream Control Transmission Protocol) defined in RFC 2960. SCTP provides reliable delivery of ordered or unordered packets over a full duplex connection between two `SOCK_SEQPACKET' sockets on top of ip(7). SCTP can guarantee that the data arrives in order on a stream, if requested, and retransmits lost packets. It generates and checks a per packet checksum to catch transmission errors.

SCTP provides the following socket types:

`SOCK_SEQPACKET'

A standard `SOCK_SEQPACKET' socket that preserves message boundaries, Nagles at the association level, and provides ordered and unordered reliable and partial reliable, acknowledged and unacknowledged delivery on multiple streams.

`SOCK_STREAM'

A tcp(7) compatible `SOCK_STREAM' socket that does not preserve message boundaries, Nagles at the stream level, and provides ordered and out-of-band unacknowledged delivery on a single stream. This is an optional capability of SCTP which provides for maximum compatibility with applications written for tcp(7). This socket type is available when SCTP is compiled with the kernel configuration parameter `CONFIG_SCTP_TCP_COMPATIBLE' set.

`SOCK_RDM'

An udp(7) compatible `SOCK_RDM' socket that preserves message boundaries, does not Nagle, and provides only unordered but reliable or partially reliable delivery on multiple streams. This is an optional capability of SCTP which provides for maximum compatibility with applications written for udp(7). This socket type is available when SCTP is compiled with the kernel configuration parameter `CONFIG_SCTP_UDP_COMPATIBLE' set.

Connection Establishment

A fresh SCTP socket has no remote or local address and is not fully specified. To create an outgoing SCTP association use connect(2) to establish an association with another SCTP endpoint. To receive incoming associations bind(2) the socket first to a number of local addresses and a port and then call listen(2) to put the socket into listening state. Then a new socket for each incoming association can be accepted using accept(2). A socket that has had accept(2) or connect(2) successfully called on it is fully specified and may transmit data. Data cannot be transmitted on listening or not yet connected sockets.

SCTP supports large windows to support links with high latency or bandwidth. Large SCTP windows can be used by increasing the send and receive buffer sizes. They can be set globally with the `net.core.wmem_default' and `net.core.rmem_default' system controls, or on individual sockets by using the `SO_SNDBUF' and `SO_RCVBUF' socket options. The maximum sizes for socket buffers are limited by the `net.core.wmem_max' and `net.core.rmem_max' system controls. See socket(7) for more information.

Sending Data

When sending data, the specific destination address within the association to which to send the data can be specified by providing a valid destination address as an argument to sendto(2) or sendmsg(2). Data sent with send(2) or write(2) will use SCTP's destination transport address selection policies for transmission and retransmission to single- and multi-homed hosts. The stream upon which to send the data can also be set with the `SCTP_SID' socket option on a socket basis with setsockopt(2) or on a per-message basis with `SCTP_SID' control message to sendmsg(2). In addition, the ip(7) `IP_PKTINFO' option can be used with sendmsg(2) to specify the interface, first-hop destination address and source address to be used in the outbound packet on `SOCK_SEQPACKET' and `SOCK_RDM' sockets. IP options can also be specified for the outbound packet with the ip(7) `IP_OPTIONS' or `IP_RETOPTS' control messages to sendmsg(2).

For `SOCK_SEQPACKET' socket, send operations may also use the `MSG_MORE' flag when sending with send(2), sendto(2) or sendmsg(2) to indicate that the next write operation will provide additional data belonging to the same packet. `SOCK_STREAM' sockets do not support send options and do not return the `MSG_TRUNC' flag on send operations.

If a `SOCK_SEQPACKET' or `SOCK_STREAM' socket does not have sufficient room to buffer the sent data, it buffers what it can and returns the amount of user data buffered. `SOCK_RDM' sockets wait for sufficient room to buffer the entire sent packet before returning. `SOCK_SEQPACKET' and `SOCK_STREAM' sockets will segment large data writes in to smaller segments for delivery to the peer.

SCTP provides a mechanism for receiving positive and negative acknowledgements of sent data on `SOCK_SEQPACKET' and `SOCK_RDM' sockets. When the socket option `SCTP_DISPOSITION' is set to `SCTP_DISPOSITION_ACKED', or when data is sent using the `MSG_CONFIRM' flag to send(2), sendto(2) or sendmsg(2), message confirmation or delivery failures can be received by passing the `MSG_CONFIRM' flag to recv(2), recvfrom(2) or recvmsg(2). This mechanism also provides for retrieval and disposition of undelivered messages after the association has aborted or shut down, but before a call to close(2).

Receiving Data

For `SOCK_SEQPACKET' and `SOCK_RDM' sockets, all receive operations return only one packet, or a portion of one packet. When the packet is smaller than the passed buffer only that much data is returned, when it is larger the packet is truncated and the `MSG_TRUNC' flag is set for `SOCK_RDM' sockets. Subsequent recv or read(2), or a subsequent recvfrom(2) or recvmsg(2) for the same stream will return the remainder of the packet for `SOCK_SEQPACKET' sockets. `SOCK_SEQPACKET' sockets also return the `MSG_EOR' flag when the end of the packet has been received successfully. For `SOCK_STREAM' sockets, all receive operations return only the amount of data available on the current stream. `MSG_TRUNC' and `MSG_EOR' are never set for `SOCK_STREAM' sockets.

IP options may be sent or received using the socket options described in ip(7). They are only processed by the kernel when the appropriate system control is enabled (but still passed to the user even when it is turned off). See ip(7).

When the `MSG_DONTROUTE' flag is set on sending, the destination address must refer to a local interface address and the packet is only sent to that interface.

SCTP fragments a packet when its total length exceeds the association MTU (Maximum Transmission Unit). A more network friendly alternative is to use path MTU discovery as described in the `IP_PMTU_DISCOVER' section of ip(7).

SCTP supports urgent data similar to tcp(7). Urgent data is used to signal the receiver that some important message is part of the data stream and that it should be processed as soon as possible. Urgent data is always sent out of order. To send urgent (or out of order) data specify the `MSG_OOB' option to send(2), sendto(2), or sendmsg(2). When urgent data is received, the kernel sends a `SIGURG' signal to the reading process or the process or process group that has been set for the socket using the `FIOCSPGRP' or `FIOCSETOWN' I/O controls. When the `SO_OOBINLINE' socket option is enabled, urgent data is put into the normal data stream (and can be tested for by the `SIOCATMARK' I/O control), otherwise it can only be received when the `MSG_OOB' flag is set for recvmsg(2).

ADDRESS FORMATS

SCTP is built on top of IP (see ip(7)). The address formats defined by ip(7) apply to SCTP. SCTP uses the IPv4 sockaddr_in address format described in ip(7).

SCTP supports multiple-stream point-to-point communication within multi-homed associations; broadcasting and multi-casting are not supported.

In addition to normal IP addressing, SCTP provides extensions on the bind(2), accept(2), connect(2), getsockname(2), and getpeername(2) system calls. These functions normally take or return a single sockaddr_in as an address argument. When used in conjunction with an SCTP socket on or to a multi-homed host, these calls will accept or return an array of sockaddr_in structures. The number of addresses in the structure is indicated by the length of the structure and the protocol family of the socket. SCTP will only support one port number being specified in the address list, and each sockaddr_in structure in the list must contain the same sin_port. (Note: Linux uses `MAX_SOCK_ADDR' as a maximum size of the socket address length. This is currently only 128 bytes or eight (8) sockaddr_in structures. Eight (8) addresses should be sufficient for most applications.)

Multiple addresses provided to the bind(2) system call will be interpreted as multiple local addresses to provide to the peer at connection time as well as the local address/port combinations upon which a listening socket will accept incoming associations. A call to accept(2) requesting the source address of the peer will return multiple transport addresses if the connecting peer is multi-homed. Multiple addresses provided to the connect(2) system call will be interpreted as multiple destination address/port combinations to which to attempt to form an association. The getpeername(2) system call returns the list of destination address/port combinations to which the socket is connected. The getsockname(2) system call returns the list of local address/port combinations to which the socket is bound.

getsockname(2)

A call to getsockname(2) can provide multiple bound transport addresses for a multi-homed host when the socket is bound to multiple addresses or `INADDR_ANY' using bind(2). The first address in the list is the primary address to which the socket is bound. This is the first address that will be attempted to be used as a source address when sending an INIT chunk to the SCTP peer as a result of a call to connect(2). Otherwise, the order of the addresses has no significance. When the socket is not bound to any address, the call to getsockname(2) returns a socket address with address family `AF_UNSPEC'.

As a result of binding to `INADDR_ANY' or the ADD-IP extension, subsequent calls to getsockname(2) may return different addresses depending on the state of the connection or resulting from the exchange of ASCONF control chunks. This list of transport addresses returned by getsockname(2) represents the current list of local transport addresses bound to the endpoint. When the connection is multi-homed or supports ADD-IP, this behaviour is different from tcp(7) and other connection-oriented protocols, whose bound address does not change during the lifespan of a connection.

getpeername(2)

A call to getpeername(2) can provide multiple peer transport addresses for a multi-homed peer when the socket is connecting or connected to multiple addresses using connect(2). The first address is always the current primary destination transport address. The current primary destination transport address is the address to which all messages will be sent in the absence of congestion or failure.

As a result of connecting to multiple transport addresses using connect(2) or the ADD-IP extension, the membership of the list of transport addresses returned by getpeername(2) may change due to the state of the socket or resulting from the exchange of ASCONF control chunks. When the SCTP connection is multi-homed or supports ADD-IP, this behaviour is different from tcp(7) and other connection-oriented protocol, whose peer address does not change during the lifespan of a connection.

SOCKET CALLS

Socket calls for `SOCK_STREAM', `SOCK_SEQPACKET' and `SOCK_RDM' sockets are different in some respects (addressing and options) than their tcp(7) or udp(7) counterparts. These differences are described here. For common behaviour, please see the indicated manual page in Section 2.

bind(2)

A call to bind(2) can provide multiple address if the host is multi-homed. Binds to `INADDR_ANY' will result in a binding to all of the local transport addresses belonging to the host that do not cause a conflict at the time that a connection is formed. As with other sockets, the local port number is assigned at the time that bind(2) is called.

As with other sockets, binding to a socket address with address family `AF_UNSPEC' will cause the socket to be unbound from all transport addresses.

Consistent with tcp(7), SCTP supports binding of multiple sockets to the same transport address providing that the socket option `SO_REUSEADDR' (see socket(7)) is set on the sockets and that no sockets have executed listen(2) bound to the same transport address.

accept(2)

A call to accept(2) requesting the peer address of the connection will return multiple transport addresses if the connecting peer is multi-homed. The first transport address in the list is the primary transport address of the connecting peer. The primary transport address is the address upon which the INIT message was received. Otherwise, the accept(2) operation is unchanged.

connect(2)

A call to connect(2) can provide multiple destination transport addresses if the peer host is multi-homed. If an INIT chunk sent to the first destination transport address is not acknowledged, the next INIT chunk will be sent to the next address in the list. This will occur until an acknowledgement is received from one of the addresses or the connection attempt times out. Each address will be retried sctp_max_init_retries times before the connection process is considered to have timed out. Broadcast and multicast addresses are permitted for the call to connect(2) but will not form an endpoint address in the association. This feature permits fast and reliable initialization of associations.

As with other connection-oriented sockets, connecting to a socket address with address family `AF_UNSPEC' will cause a socket engaged in active connections to be disconnected.

read(2)

recv(2)

recvfrom(2)

recvmsg(2)

SCTP preserves message boundaries on read for `SOCK_SEQPACKET' and `SOCK_RDM' sockets. Message boundaries are never preserved for `SOCK_STREAM' sockets.

The following message flags to, or returned from, recv(2), recvfrom(2) and recvmsg(2) have special interpretations for SCTP:

`MSG_OOB'

SCTP supports the return of the `MSG_OOB' flag from recv(2), recvfrom(2) and recvmsg(2). Data read with the `MSG_OOB' flag set indicates that the data was received on the specified SCTP stream with the Unordered bit set. Operation is similar to tcp(7).

`MSG_EOR'

For `SOCK_SEQPACKET' sockets, the `MSG_EOR' flag returned from recv(2), recvfrom(2) or recvmsg(2) indicates that the data read has been read to the end of a record. The `MSG_EOR' flag is not used for `SOCK_STREAM' or `SOCK_RDM' sockets.

`MSG_TRUNC'

SCTP supports the use of the `MSG_TRUNC' flag to recv(2), recvfrom(2) and recvmsg(2). Data read with the `MSG_TRUNC' flag set will return the number of bytes available in the packet rather than the number of bytes read.

When the `MSG_TRUNC' flag is returned from recv(2), recvfrom(2) and recvmsg(2), it indicates that the record was truncated. `MSG_TRUNC' will only be returned on `SOCK_RDM' sockets. `MSG_TRUNC' is never set on return for `SOCK_STREAM' and `SOCK_SEQPACKET' sockets.

`MSG_CONFIRM'

SCTP supports the use of the `MSG_CONFIRM' flag to recv(2), recvfrom(2) and recvmsg(2). Data read with the `MSG_CONFIRM' flag set will return messages receipt acknowledgements as well as messages which have exceeded their life-times, messages which have been dropped by PR-SCTP, and messages held for retrieval after abort or shutdown.

When the `MSG_CONFIRM' flag is returned from recv(2), recvfrom(2) and recvmsg(2), it indicates that the read data represents data that was confirmed as acknowledged by the peer. See also `SCTP_DISPOSITION' under SOCKET OPTIONS.

Other message flags have the same interpretation as described in recv(2), recvfrom(2) and recvmsg(2).

write(2)

send(2)

sendto(2)

sendmsg(2)

SCTP preserves message boundaries on write for `SOCK_SEQPACKET' and `SOCK_RDM' sockets. Message boundaries are never preserved for `SOCK_STREAM' sockets.

The following message flags to send(2), sendto(2) and sendmsg(2) have special interpretations for SCTP:

`MSG_OOB'

SCTP supports the use of the `MSG_OOB' flag to send(2), sendto(2) and sendmsg(2). Data writt