Commit Graph

46 Commits

Author SHA1 Message Date
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
Mike Silbersack
08517d530e Eliminate the allocation of a tcp template structure for each
connection.  The information contained in a tcptemp can be
reconstructed from a tcpcb when needed.

Previously, tcp templates required the allocation of one
mbuf per connection.  On large systems, this change should
free up a large number of mbufs.

Reviewed by:	bmilekic, jlemon, ru
MFC after: 2 weeks
2001-06-23 03:21:46 +00:00
Jesper Skriver
7ceb778366 Disable rfc1323 and rfc1644 TCP extensions if we havn't got
any response to our third SYN to work-around some broken
terminal servers (most of which have hopefully been retired)
that have bad VJ header compression code which trashes TCP
segments containing unknown-to-them TCP options.

PR:		kern/1689
Submitted by:	jesper
Reviewed by:	wollman
MFC after:	2 weeks
2001-05-31 19:24:49 +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
Jonathan Lemon
7d42e30c2e Use more aggressive retransmit timeouts for the initial SYN packet.
As we currently drop the connection after 4 retransmits + 2 ICMP errors,
this allows initial connection attempts to be dropped much faster.
2001-02-26 21:33:55 +00:00
Jonathan Lemon
d17e895b5f If TCPDEBUG is defined, we could dereference a tp which was freed. 2000-10-02 15:00:13 +00:00
Jonathan Lemon
af1270f87f It is possible for a TCP callout to be removed from the timing wheel,
but have a network interrupt arrive and deactivate the timeout before
the callout routine runs.  Check for this case in the callout routine;
it should only run if the callout is active and not on the wheel.
2000-09-16 00:53:53 +00:00
Poul-Henning Kamp
77978ab8bc Previous commit changing SYSCTL_HANDLER_ARGS violated KNF.
Pointed out by:	bde
2000-07-04 11:25:35 +00:00
Poul-Henning Kamp
82d9ae4e32 Style police catches up with rev 1.26 of src/sys/sys/sysctl.h:
Sanitize SYSCTL_HANDLER_ARGS so that simplistic tools can grog our
sources:

        -sysctl_vm_zone SYSCTL_HANDLER_ARGS
        +sysctl_vm_zone (SYSCTL_HANDLER_ARGS)
2000-07-03 09:35:31 +00:00
Jonathan Lemon
46f5848237 Implement TCP NewReno, as documented in RFC 2582. This allows
better recovery for multiple packet losses in a single window.
The algorithm can be toggled via the sysctl net.inet.tcp.newreno,
which defaults to "on".

Submitted by:  Jayanth Vijayaraghavan <jayanth@yahoo-inc.com>
2000-05-06 03:31:09 +00:00
Yoshinobu Inoue
fb59c426ff tcp updates to support IPv6.
also a small patch to sys/nfs/nfs_socket.c, as max_hdr size change.

Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project
2000-01-09 19:17:30 +00:00
Jonathan Lemon
9fc2bcf662 Simplify, and return an error if the user attempts to set a TCP
time value which results in < 1 tick.

Suggested by: 	bde
1999-08-31 16:34:20 +00:00
Jonathan Lemon
ccb4d0c653 Add a SYSCTL_PROC so that TCP timer values are now expressed to
the user in ms, while they are stored internally as ticks. Note
that there probably are rounding bogons here, especially on the
alpha.
1999-08-31 03:40:24 +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
Bill Fumerola
3d177f465a Add sysctl descriptions to many SYSCTL_XXXs
PR:		kern/11197
Submitted by:	Adrian Chadd <adrian@FreeBSD.org>
Reviewed by:	billf(spelling/style/minor nits)
Looked at by:	bde(style)
1999-05-03 23:57:32 +00:00
David Greenman
552b7df4c1 Ensure that TCP_REXMTVAL doesn't return a value less than t_rttmin. This
is believed to have been broken with the Brakmo/Peterson srtt
calculation changes. The result of this bug is that TCP connections
could time out extremely quickly (in 12 seconds).
Also backed out jdp's partial fix for this problem in rev 1.17 of
tcp_timer.c as it is obsoleted by this commit.
Bug was pointed out by Kevin Lehey <kml@roller.nas.nasa.gov>.

PR:	6068
1998-04-24 09:25:39 +00:00
Poul-Henning Kamp
8e5db87cdb Remove the last traces of TUBA.
Inspired by:	PR kern/3317
1998-04-06 06:52:47 +00:00
David Greenman
f498eeeead Changes to support the addition of a new sysctl variable:
net.inet.tcp.delack_enabled
Which defaults to 1 and can be set to 0 to disable TCP delayed-ack
processing (i.e. all acks are immediate).
1998-02-26 05:25:39 +00:00
Eivind Eklund
92252381f3 Make TCP_COMPAT_42 a new style option. 1998-01-25 04:23:33 +00:00
Joerg Wunsch
0cc12cc57e Make TCPDEBUG a new-style option. 1997-09-16 18:36:06 +00:00
Bruce Evans
1fd0b0588f Removed unused #includes. 1997-08-02 14:33:27 +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
Paul Traina
7b40aa327d Make the misnamed tcp initial keepalive timer value (which is really the
time, in seconds, that state for non-established TCP sessions stays about)
a sysctl modifyable variable.

[part 1 of two commits, I just realized I can't play with the indices as
 I was typing this commit message.]
1996-09-13 23:51:44 +00:00
David Greenman
af7a299930 Fixed two bugs in previous commit: be sure to include tcp_debug.h when
TCPDEBUG is defined, and fix typo in TCPDEBUG2() macro.
1996-07-12 17:28:47 +00:00
Garrett Wollman
2c37256e5a Modify the kernel to use the new pr_usrreqs interface rather than the old
pr_usrreq mechanism which was poorly designed and error-prone.  This
commit renames pr_usrreq to pr_ousrreq so that old code which depended on it
would break in an obvious manner.  This commit also implements the new
interface for TCP, although the old function is left as an example
(#ifdef'ed out).  This commit ALSO fixes a longstanding bug in the
TCP timer processing (introduced by davidg on 1995/04/12) which caused
timer processing on a TCB to always stop after a single timer had
expired (because it misinterpreted the return value from tcp_usrreq()
to indicate that the TCB had been deleted).  Finally, some code
related to polling has been deleted from if.c because it is not
relevant t -current and doesn't look at all like my current code.
1996-07-11 16:32:50 +00:00
John Polstra
588c92252f Fix a bug in the handling of the "persist" state which, under certain
circumstances, caused perfectly good connections to be dropped.  This
happened for connections over a LAN, where the retransmit timer
calculation TCP_REXMTVAL(tp) returned 0.  If sending was blocked by flow
control for long enough, the old code dropped the connection, even
though timely replies were being received for all window probes.

Reviewed by:	W. Richard Stevens <rstevens@noao.edu>
1996-06-03 15:37:52 +00:00
David Greenman
2d8266af5c Two fixes from Rich Stevens:
1) Set the persist timer to help time-out connections in the CLOSING state.
2) Honor the keep-alive timer in the CLOSING state.

   This fixes problems with connections getting "stuck" due to incompletion
of the final connection shutdown which can be a BIG problem on busy WWW
servers.
1996-04-15 03:46:33 +00:00
Poul-Henning Kamp
34be9bf3ce Add a sysctl (net.inet.tcp.always_keepalive: 0) that when set will force
keepalive on all tcp sessions.  Setsockopt(2) cannot override this setting.
Maybe another one is needed that just changes the default for SO_KEEPALIVE ?
Requested by: Joe Greco <jgreco@brasil.moneng.mei.com>
1996-04-04 11:17:04 +00:00
David Greenman
2ee45d7d28 Move or add #include <queue.h> in preparation for upcoming struct socket
changes.
1996-03-11 15:13:58 +00:00
Andras Olah
74b48c1de1 Reverse the modification which caused the annoying m_copydata crash: set
the TF_ACKNOW flag when the REXMT timer goes off to force a
retransmission.  In certain situations pulling snd_nxt back to snd_una
is not sufficient.
1996-01-04 21:34:21 +00:00
Poul-Henning Kamp
0312fbe97d New style sysctl & staticize alot of stuff. 1995-11-14 20:34:56 +00:00
Poul-Henning Kamp
98163b98dc Start adding new style sysctl here too. 1995-11-09 20:23:09 +00:00
Andras Olah
356ad1b0cb Setting the TF_ACKNOW flag was redundant in the REXMT timeout because
tcp_output() checks for the condition snd_nxt == snd_una.

Reviewed by:	davidg, wollman, olah
Suggested by:	Richard Stevens
1995-11-03 22:19:50 +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
David Greenman
cc0964fb2b Add connection drop capability for persist timeouts.
Reviewed by:	Andras Olah
Obtained from:	4.4BSD-lite2 via W. Richard Stevens
1995-07-29 18:48:44 +00:00
Rodney W. Grimes
9b2e535452 Remove trailing whitespace. 1995-05-30 08:16:23 +00:00
David Greenman
230620627b Fixed bug I introduced when changing PCB list to use 4.4BSD style queue
macros. Basically, detect 'tp' going away differently.
1995-04-12 06:49:56 +00:00
David Greenman
15bd2b4385 Implemented PCB hashing. Includes new functions in_pcbinshash, in_pcbrehash,
and in_pcblookuphash.
1995-04-09 01:29:31 +00:00
Garrett Wollman
41f82abe5a Transaction TCP support now standard. Hack away! 1995-02-16 00:55:44 +00:00
Garrett Wollman
a0292f2375 Merge Transaction TCP, courtesy of Andras Olah <olah@cs.utwente.nl> and
Bob Braden <braden@isi.edu>.

NB: This has not had David's TCP ACK hack re-integrated.  It is not clear
what the correct solution to this problem is, if any.  If a better solution
doesn't pop up in response to this message, I'll put David's code back in
(or he's welcome to do so himself).
1995-02-09 23:13:27 +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