Commit Graph

39 Commits

Author SHA1 Message Date
thorpej 5596fe2614 Nuke TUBA per my note to tech-net; there's no reason to keep it around. 1998-05-11 19:57:23 +00:00
thorpej 1ffa60ac01 Use macros from tcp_timer.h to manipulate TCP timers, so that their
implementation can be changed easily.
1998-05-06 01:21:20 +00:00
thorpej e1934b4c36 Correct a comment related to Congestion Window Monitoring. 1998-05-02 01:00:24 +00:00
thorpej ce40806e29 In the CWM code, don't use the Floyd initial window computation as
the burst size allowed, but rather a fixed number of packets, as
described in the Internet Draft.  Default allowed burst is 4 packets,
per the Draft.

Make the use of CWM and the allowed burst size tunable via sysctl.
1998-04-30 18:27:20 +00:00
kml 1579dcec47 Add support for deletion of routes added by path MTU discovery;
uses new generic route timeout code.  Add sysctl for timeout period.
1998-04-29 03:44:11 +00:00
kml fcf0227962 Fix to ensure that the correct MSS is advertised for loopback
TCP connections by using the MTU of the interface.  Also added
a knob, mss_ifmtu, to force all connections to use the MTU of
the interface to calculate the advertised MSS.
1998-04-13 21:18:19 +00:00
thorpej f9463514bf Implement Congestion Window Monitoring as described in the TCPIMPL
meeting of IETF #41 by Amy Hughes <ahughes@isi.edu>, and in an upcoming
internet draft from Hughes, Touch, and Heidemann.

CWM eliminates line-rate bursts after idle periods by counting pending
(unacknowledged) packets and limiting the congestion window to the
initial congestion window plus the pending packet count.  This has the
effect of allowing us to use the window as long as we continue to transmit,
but as soon as we stop transmitting, we go back to a slow-start (also known
as `use it or lose it').

This is not enabled by default.  You can enable this behavior by patching
the "tcp_cwm" global (set it to non-zero) or by building a kernel with the
TCP_CWM option.
1998-04-01 22:15:52 +00:00
thorpej 2da6c91259 Fix a potential-congestion case in the larger initial congestion window
code, as clarified in the TCPIMPL WG meeting at IETF #41: If the SYN
(active open) or SYN,ACK (passive open) was retransmitted, the initial
congestion window for the first slow start of that connection must be
one segment.
1998-03-31 22:49:09 +00:00
kml 96954c2a53 Ensure that we take the IP option length into account when we calculate
the effective maximum send size for TCP.  ip_optlen() and tcp_optlen()
should probably be inlined for efficiency.
1998-03-24 03:10:02 +00:00
kml 123232e156 Fix a retransmission bug introduced by the Brakmo and Peterson
RTO estimation changes.  Under some circumstances it would return a value
of 0, while the old Van Jacobson RTO code would return a minimum of 3.
This would result in 12 retransmissions, each 1 second apart.
This takes care of those instances, and ensures that t_rttmin is
used everywhere as a lower bound.
1998-03-19 22:29:33 +00:00
kml ffb211fb9d Ensure that the TCP segment size reflects the size of TCP options
in the packet.  This fixes a bug that was resulting in extra packets
in retransmissions (the second packet would be 12 bytes long,
reflecting the RFC1323 timestamp option size).
1998-03-17 23:50:30 +00:00
thorpej 5837cc6b07 Update copyright (sigh, should have done this long ago). 1998-02-19 02:36:42 +00:00
thorpej e5e283e02d Finishing merging 4.4BSD-Lite2 netinet. At this point, the only changes
left were SCCS IDs and Copyright dates.
1998-01-05 10:31:44 +00:00
thorpej 673fb149c6 Implement a queue for delayed ACK processing. This queue is used in
tcp_fasttimo() in lieu of scanning all open TCP connections.
1997-12-31 03:31:23 +00:00
thorpej 82ce1f6a97 From 4.4BSD-Lite2:
- If we fail to allocate mbufs for the outgoing segment, free the header
  and abort.

From Stevens:
- Ensure the persist timer is running if the send window reaches zero.
  Part of the fix for kern/2335 (pete@daemon.net).
1997-12-17 05:59:32 +00:00
thorpej c02a72fcd0 Implement an infrastructure to allow larger initial congestion windows.
The sysctl'able variable "tcp_init_win", when set to 0, selects an
auto-tuning algorithm for selecting the initial window, based on transmit
segment size, per discussion in the IETF tcpimpl working group.

Default initial window is still 1 segment, but will soon become 2 segments,
per discussion in tcpimpl.
1997-12-11 22:47:24 +00:00
thorpej 8346cea65d Count delayed ACKs after they have been sucessfully transmitted. 1997-12-11 06:37:48 +00:00
thorpej e2a99027d2 Add missing (implied) int to a variable declaration. 1997-11-20 19:12:41 +00:00
kml 86275dc497 TCP MSS fixes to provide cleaner slow-start and recovery. 1997-11-08 02:35:22 +00:00
kml 6b86b260cb change sysctl net.inet.icmp.mtudisc to net.inet.ip.mtudisc 1997-10-18 21:18:28 +00:00
kml 323c04642b Path MTU Discovery support. This is turned off by default.
Use sysctl -w net.inet.icmp.mtudisc=1 to turn on.
Still to come:  path removal after some period, black hole detection
1997-10-17 22:12:14 +00:00
thorpej 67a3811e05 Fix an oversight in my previous MSS-related changes:
Basically, in silly window avoidance, don't use the raw MSS we advertised
to the peer.  What we really want here is the _expected_ size of received
segments, so we need to account for the path MTU (eventually; right now,
the interface MTU for "local" addresses and loopback or tcp_mssdflt for
non-local addresses).  Without this, silly window avoidance would never
kick in if we advertised a very large (e.g. ~64k) MSS to the peer.
1997-10-08 16:32:48 +00:00
thorpej 4ed600dbd0 Fix several annoyances related to MSS handling in BSD TCP:
- Don't overload t_maxseg.  Previous behavior was to set it to the min
  of the peer's advertised MSS, our advertised MSS, and tcp_mssdflt
  (for non-local networks).  This breaks PMTU discovery running on
  either host.  Instead, remember the MSS we advertise, and use it
  as appropriate (in silly window avoidance).
- Per last bullet, split tcp_mss() into several functions for handling
  MSS (ours and peer's), and performing various tasks when a connection
  becomes ESTABLISHED.
- Introduce a new function, tcp_segsize(), which computes the max size
  for every segment transmitted in tcp_output().  This will eventually
  be used to hook in PMTU discovery.
1997-09-22 21:49:55 +00:00
kml 6a233e37f6 Fix urgent pointer overflow problems when used with large windows 1997-06-03 16:17:09 +00:00
mycroft 315bb1ab50 Fix RTT scaling problems introduced with Brakmo and Peterson changes. 1996-12-10 18:20:19 +00:00
christos 14d9cd33af netinet prototypes 1996-02-13 23:40:59 +00:00
cgd 1e2fe7fa41 oops; missed the chance to fix a cast, that then becamse a compiler warning. 1995-04-13 20:09:23 +00:00
cgd 80929f8527 be a bit more careful and explicit with types. (basically a large no-op.) 1995-04-13 06:35:38 +00:00
mycroft 153c5e083f Fix a condition where we sometimes sent a FIN too early. Also, a small
optimization.
1995-01-23 20:18:35 +00:00
cgd cf92afd66e New RCS ID's, take two. they're more aesthecially pleasant, and use 'NetBSD' 1994-06-29 06:29:24 +00:00
mycroft 07b4f2ab54 Update to 4.4-Lite networking code, with a few local changes. 1994-05-13 06:02:48 +00:00
mycroft 55a96d2a3f Acks with no data should have the highest sequence number sent. 1994-04-12 18:09:47 +00:00
mycroft b79490fcca Should compile now with or without `options MULTICAST'. 1994-01-10 20:14:14 +00:00
mycroft e43117185e Prototypes. 1994-01-08 23:07:16 +00:00
mycroft 4fe12e6e88 Fix some inconsistent spacing; spaces at the end of lines, etc. 1994-01-08 21:21:28 +00:00
mycroft 95b048b53a Canonicalize all #includes. 1993-12-18 00:40:47 +00:00
cgd fe1802950b add include of select.h if necessary for protos, or delete if extraneous 1993-05-22 11:40:42 +00:00
cgd 8d6c77881c make kernel select interface be one-stop shopping & clean it all up. 1993-05-18 18:18:40 +00:00
cgd 61f282557f initial import of 386bsd-0.1 sources 1993-03-21 09:45:37 +00:00