Commit Graph

31 Commits

Author SHA1 Message Date
Jonathan T. Looney
4b9dc36454 r330675 introduced an extra window check in the LRO code to ensure it
captured and reported the highest window advertisement with the same
SEQ/ACK.  However, the window comparison uses modulo 2**16 math, rather
than directly comparing the absolute values.  Because windows use
absolute values and not modulo 2**16 math (i.e. they don't wrap), we
need to compare the absolute values.

Reviewed by:	gallatin
MFC after:	3 days
Sponsored by:	Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D14937
2018-04-03 13:54:38 +00:00
Sean Bruno
d7fb35d13a Update tcp_lro with tested bugfixes from Netflix and LLNW:
rrs - Lets make the LRO code look for true dup-acks and window update acks
          fly on through and combine.
    rrs - Make the LRO engine a bit more aware of ack-only seq space. Lets not
          have it incorrectly wipe out newer acks for older acks when we have
          out-of-order acks (common in wifi environments).
    jeggleston - LRO eating window updates

Based on all of the above I think we are RFC compliant doing it this way:

https://tools.ietf.org/html/rfc1122

section 4.2.2.16

"Note that TCP has a heuristic to select the latest window update despite
possible datagram reordering; as a result, it may ignore a window update with
a smaller window than previously offered if neither the sequence number nor the
acknowledgment number is increased."

Submitted by:	Kevin Bowling <kevin.bowling@kev009.com>
Reviewed by:	rstone gallatin
Sponsored by:	NetFlix and Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D14540
2018-03-09 00:08:43 +00:00
Pedro F. Giffuni
51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00
Warner Losh
fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00
Jonathan T. Looney
3ac125068a Remove "long" variables from the TCP stack (not including the modular
congestion control framework).

Reviewed by:	gnn, lstewart (partial)
Sponsored by:	Juniper Networks, Netflix
Differential Revision:	(multiple)
Tested by:	Limelight, Netflix
2016-10-06 16:28:34 +00:00
Bjoern A. Zeeb
d8951c8a2f Fix PAWS (Protect Against Wrapped Sequence numbers) in cases when
hz >> 1000 and thus getting outside the timestamp clock frequenceny of
1ms < x < 1s per tick as mandated by RFC1323, leading to connection
resets on idle connections.

Always use a granularity of 1ms using getmicrouptime() making all but
relevant callouts independent of hz.

Use getmicrouptime(), not getmicrotime() as the latter may make a jump
possibly breaking TCP nfsroot mounts having our timestamps move forward
for more than 24.8 days in a second without having been idle for that
long.

PR:		kern/61404
Reviewed by:	jhb, mav, rrs
Discussed with:	silby, lstewart
Sponsored by:	Sandvine Incorporated (originally in 2011)
MFC after:	6 weeks
2012-02-15 16:09:56 +00:00
Andre Oppermann
6593a94979 Remove T/TCP RFC1644 Connection Count comparison macros. They are no longer
used and needed.

Sponsored by:   TCP/IP Optimization Fundraise 2005
2006-06-18 14:24:12 +00:00
Paul Saab
cf09195ba5 - Tighten up the Timestamp checks to prevent a spoofed segment from
setting ts_recent to an arbitrary value, stopping further
  communication between the two hosts.
- If the Echoed Timestamp is greater than the current time,
  fall back to the non RFC 1323 RTT calculation.

Submitted by:	Raja Mukerji (raja at moselle dot com)
Reviewed by:	Noritoshi Demizu, Mohan Srinivasan
2005-04-10 05:24:59 +00:00
Warner Losh
c398230b64 /* -> /*- for license, minor formatting changes 2005-01-07 01:45:51 +00:00
Andre Oppermann
c94c54e4df Remove RFC1644 T/TCP support from the TCP side of the network stack.
A complete rationale and discussion is given in this message
and the resulting discussion:

 http://docs.freebsd.org/cgi/mid.cgi?4177C8AD.6060706

Note that this commit removes only the functional part of T/TCP
from the tcp_* related functions in the kernel.  Other features
introduced with RFC1644 are left intact (socket layer changes,
sendmsg(2) on connection oriented protocols)  and are meant to
be reused by a simpler and less intrusive reimplemention of the
previous T/TCP functionality.

Discussed on:	-arch
2004-11-02 22:22:22 +00:00
Paul Saab
6d90faf3d8 Add support for TCP Selective Acknowledgements. The work for this
originated on RELENG_4 and was ported to -CURRENT.

The scoreboarding code was obtained from OpenBSD, and many
of the remaining changes were inspired by OpenBSD, but not
taken directly from there.

You can enable/disable sack using net.inet.tcp.do_sack. You can
also limit the number of sack holes that all senders can have in
the scoreboard with net.inet.tcp.sackhole_limit.

Reviewed by:	gnn
Obtained from:	Yahoo! (Mohan Srinivasan, Jayanth Vijayaraghavan)
2004-06-23 21:04:37 +00:00
Warner Losh
f36cfd49ad Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson
2004-04-07 20:46:16 +00:00
Jeffrey Hsu
9d11646de7 Unify the "send high" and "recover" variables as specified in the
lastest rev of the spec.  Use an explicit flag for Fast Recovery. [1]

Fix bug with exiting Fast Recovery on a retransmit timeout
diagnosed by Lu Guohan. [2]

Reviewed by:		Thomas Henderson <thomas.r.henderson@boeing.com>
Reported and tested by:	Lu Guohan <lguohan00@mails.tsinghua.edu.cn> [2]
Approved by:		Thomas Henderson <thomas.r.henderson@boeing.com>,
			Sally Floyd <floyd@acm.org> [1]
2003-07-15 21:49:53 +00:00
Jeffrey Hsu
cb942153c8 Fix NewReno.
Reviewed by: Tom Henderson <thomas.r.henderson@boeing.com>
2003-01-13 11:01:20 +00:00
Jonathan Lemon
d00fd2011d Move initialization of snd_recover into tcp_sendseqinit(). 2001-11-21 18:45:51 +00:00
Mike Silbersack
b0e3ad758b Much delayed but now present: RFC 1948 style sequence numbers
In order to ensure security and functionality, RFC 1948 style
initial sequence number generation has been implemented.  Barring
any major crypographic breakthroughs, this algorithm should be
unbreakable.  In addition, the problems with TIME_WAIT recycling
which affect our currently used algorithm are not present.

Reviewed by: jesper
2001-08-22 00:58:16 +00:00
Mike Silbersack
2d610a5028 Temporary feature: Runtime tuneable tcp initial sequence number
generation scheme.  Users may now select between the currently used
OpenBSD algorithm and the older random positive increment method.

While the OpenBSD algorithm is more secure, it also breaks TIME_WAIT
handling; this is causing trouble for an increasing number of folks.

To switch between generation schemes, one sets the sysctl
net.inet.tcp.tcp_seq_genscheme.  0 = random positive increments,
1 = the OpenBSD algorithm.  1 is still the default.

Once a secure _and_ compatible algorithm is implemented, this sysctl
will be removed.

Reviewed by: jlemon
Tested by: numerous subscribers of -net
2001-07-08 02:20:47 +00:00
Jesper Skriver
d1745f454d Say goodbye to TCP_COMPAT_42
Reviewed by:	wollman
Requested by:	wollman
2001-04-20 11:58:56 +00:00
Kris Kennaway
f0a04f3f51 Randomize the TCP initial sequence numbers more thoroughly.
Obtained from:	OpenBSD
Reviewed by:	jesper, peter, -developers
2001-04-17 18:08:01 +00:00
Kris Kennaway
be515d91ad Use stronger random number generation for TCP_ISSINCR and tcp_iss.
Reviewed by:	peter, jlemon
2000-09-29 01:37:19 +00:00
Peter Wemm
664a31e496 Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL"
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot).  This is consistant with the other
BSD's who made this change quite some time ago.  More commits to come.
1999-12-29 04:46:21 +00:00
Jonathan Lemon
9b8b58e033 Restructure TCP timeout handling:
- eliminate the fast/slow timeout lists for TCP and instead use a
    callout entry for each timer.
  - increase the TCP timer granularity to HZ
  - implement "bad retransmit" recovery, as presented in
    "On Estimating End-to-End Network Path Properties", by Allman and Paxson.

Submitted by:	jlemon, wollmann
1999-08-30 21:17:07 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Peter Wemm
6875d25465 Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.
1997-02-22 09:48:43 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
Garrett Wollman
e79adb8ed6 Finish 4.4-Lite-2 merge: randomize TCP initial sequence numbers
to make ISS-guessing spoofing attacks harder.
1995-10-03 16:54:17 +00:00
Garrett Wollman
2f96f1f446 Get rid of some unneeded #ifdef TTCP lines. Also, get rid of some
bogus commons declared in header files.
1995-02-14 02:35:19 +00:00
Garrett Wollman
eb6ad69646 Merge in T/TCP TCP header file changes. 1995-02-08 20:18:48 +00:00
Paul Richards
707f139edb Made idempotent.
Submitted by:	Paul
1994-08-21 05:27:42 +00:00
David Greenman
3c4dd3568f Added $Id$ 1994-08-02 07:55:43 +00:00
Rodney W. Grimes
df8bae1de4 BSD 4.4 Lite Kernel Sources 1994-05-24 10:09:53 +00:00