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John Polstra 66e39adc7c Fix a bug (apparently very old) that can cause a TCP connection to
be dropped when it has an unusual traffic pattern.  For full details
as well as a test case that demonstrates the failure, see the
referenced PR.

Under certain circumstances involving the persist state, it is
possible for the receive side's tp->rcv_nxt to advance beyond its
tp->rcv_adv.  This causes (tp->rcv_adv - tp->rcv_nxt) to become
negative.  However, in the code affected by this fix, that difference
was interpreted as an unsigned number by max().  Since it was
negative, it was taken as a huge unsigned number.  The effect was
to cause the receiver to believe that its receive window had negative
size, thereby rejecting all received segments including ACKs.  As
the test case shows, this led to fruitless retransmissions and
eventually to a dropped connection.  Even connections using the
loopback interface could be dropped.  The fix substitutes the signed
imax() for the unsigned max() function.

PR:		closes kern/3998
Reviewed by:	davidg, fenner, wollman
1997-07-01 05:42:16 +00:00
bin Remove lines inside #ifdef 0/#endif. 1997-06-30 11:10:18 +00:00
contrib Removed most unused files (about 8M total). 1997-06-29 18:12:14 +00:00
crypto Bring in the Starter files for the contrib-crypto dir. 1997-05-03 09:16:07 +00:00
eBones Replace random() by arc4random() since random() can't be used 1997-06-14 04:05:01 +00:00
etc sysconfig -> rc.conf 1997-06-30 19:10:50 +00:00
games Show the real revision date and not the date that this 1997-06-23 04:03:49 +00:00
gnu Removed -I path to gdb's readline. This didn't do much in -current 1997-06-30 23:10:54 +00:00
include merge in bind-4.9.6 changes (only effect is __res_send #define reverted) 1997-06-27 08:32:38 +00:00
lib _err() -> err(). 1997-06-29 00:33:17 +00:00
libexec Zap register keyword usage and convert: bcopy -> memmove, bzero -> memset, 1997-06-29 19:50:26 +00:00
lkm Take the OS release string from the kernel variable `osrelease' 1997-06-24 12:43:18 +00:00
release Allow distSetByName() to process all the relevant entries. 1997-07-01 03:50:58 +00:00
sbin Remove lines inside #ifdef 0/#endif. 1997-06-30 11:10:18 +00:00
secure Revert $FreeBSD$ to $Id$ 1997-02-22 14:40:44 +00:00
share Removed temporary SMP header fix. 1997-06-30 23:37:54 +00:00
sys Fix a bug (apparently very old) that can cause a TCP connection to 1997-07-01 05:42:16 +00:00
tools Some helpful improvements : 1997-06-10 01:53:01 +00:00
usr.bin Use EX_USAGE in usage(). 1997-06-30 11:24:18 +00:00
usr.sbin Allow distSetByName() to process all the relevant entries. 1997-07-01 03:50:58 +00:00
COPYRIGHT This is the official 4.4 Lite copyright. 1994-09-11 07:53:28 +00:00
Makefile Remove sgml stuff from the build-tools target. It is no longer used 1997-06-08 15:04:06 +00:00
README Revert $FreeBSD$ to $Id$ 1997-02-23 09:21:14 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on: $Id$

For copyright information, please see the file COPYRIGHT in this
directory (additional copyright information also exists for some
sources in this tree - please see the specific source directories for
more information).

The Makefile in this directory supports a number of targets for
building components (or all) of the FreeBSD source tree, the most
commonly used one being ``world'', which rebuilds and installs
everything in the FreeBSD system from the source tree except the
kernel.  Please see the top of the Makefile for more information on
the standard build targets and compile-time flags.

Building a kernel with config(8) is a somewhat more involved process,
documentation for which can be found at:
   http://www.freebsd.org/handbook/kernelconfig.html
And in the config(8) man page.

The sample kernel configuration files reside in the sys/i386/conf
sub-directory (assuming that you've installed the kernel sources), the
file named GENERIC being the one used to build your initial installation
kernel.  The file LINT contains entries for all possible devices, not
just those commonly used, and is meant more as a general reference
than an actual kernel configuration file (a kernel built from it
wouldn't even run).


Source Roadmap:
---------------
bin		System/User commands.

contrib		Packages contributed by 3rd parties.

eBones		Kerberos package - NOT FOR EXPORT!

etc		Template files for /etc

games		Amusements.

gnu		Various commands and libraries under the GNU Public License.
		Please see gnu/COPYING* for more information.

include		System include files.

lib		System libraries.

libexec		System daemons.

lkm		Loadable Kernel Modules.

release		Release building Makefile & associated tools.

sbin		System commands.

secure		DES and DES-related utilities - NOT FOR EXPORT!

share		Shared resources.

sys		Kernel sources.

tools		Utilities for regression testing and miscellaneous tasks.

usr.bin		User commands.

usr.sbin	System administration commands.


For information on synchronizing your source tree with one or more of
the FreeBSD Project's development branches, please see:

  http://www.freebsd.org/handbook/synching.html