TECHNICAL INFORMATION DOCUMENT

TITLE:  TF2090 - inet/tcp modules patch for fixing TC
DATE:  23AUG95
README FOR:  TF2090
PRODUCT and VERSION:

UnixWare 2.01

Installation Instructions:  

DATATYPE: datastream

1.  Download the tf2090.Z and tf2090.txt files to the /tmp directory
    on your machine.

2.  Read the release notes contained in file and follow the instuctions 
    to add the package to your system.

3.  Now become root, uncompress the file and add the package to your 
    system using the following commands:

        $ su
        # uncompress /tmp/tf2090.Z
        # pkgadd -d /tmp/tf2090

ENGINEERING REALEASE NOTES
--------------------------

Title
-----

PTF2090 - inet/tcp modules patch for fixing TCP flow control when 
setting SO_SNDBUF/SO_SNDLOWAT

Product And Version
--------------------

UnixWare 2.01, UnixWare 2.02

Abstract
--------

This patch installs the following updated files:

        /etc/conf/pack.d/inet/Driver_atup.o
        /etc/conf/pack.d/inet/Driver_mp.o
        /etc/conf/pack.d/tcp/Driver_atup.o
        /etc/conf/pack.d/tcp/Driver_mp.o

Symptom
-------
When a socket application sets SO_SNDBUF/SO_SNDLOWAT to tune 
the high/low water marks of the TCP stream queue, it can exhaust a 
system's memory (causing system panic usually) 
if enough data is transmitted quickly enough.

SOLUTION SPECIFICS
------------------

General Description.
-------------------

This patch modified the handling of SO_SNDBUF/SO_SNDLOWAT of the TCP
stream queue to eliminate the above symptom. 


New Features.
------------

None

Software Notes and Recommendations.

	This PTF can be installed on UnixWare 2.01 and UnixWare 2.02 
	systems which have the Internet Utilities (inet) package 
	installed.  

Testing of the modified software contained in this package has been
conducted only to the extent necessary to confirm that it resolves the
problem(s) stated above ("Symptom").  Such testing consists of
recreating the problem conditions test and verifying that the problem 
no longer occurs.  No other testing of this software has been done.

Hardware Notes and Recommendations.
----------------------------------

This PTF is targeted for the i386, i486 and Pentium CPU's.