Commit Graph

53 Commits

Author SHA1 Message Date
mouse b95116821c Create tcp.keepidle, tcp.keepintvl, tcp.keepcnt, tcp.slowhz sysctls. 1998-09-10 10:46:03 +00:00
thorpej 4dbfe05f1f Use an algorithm similar to that in tcp_notify() to determine if
syn_cache_unreach() should remove the entry, or just continue on.

Algorithm is to only remove the entry if we've had more than one unreach
error and have retransmitted 3 or more times.  This prevents the following
scenario, as noted in PR #5909 (PR from Ty Sarna, scenario from
Charles Hannum):

	* Host A sends a SYN.
	* Host A retransmits the SYN.
	* Host B gets the first SYN and sends a SYN-ACK.
	* Host B gets the second SYN and sends a SYN-ACK.
	* One of the SYN-ACK bounces with an
	  ICMP unreachable, causing the `SYN cache' entry to be
	  removed with no notification.
	* Host A receives the other SYN-ACK, sends an ACK, and goes to
	  ESTABLISHED state.

Should fix PR #5909.
1998-09-09 01:32:27 +00:00
mycroft cca4e566a9 Implement a better fix for the `gratuitous FIN' problem, as
mentioned on tcp-impl but with a bit more commentary.
1998-07-21 10:46:00 +00:00
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 ce3d776874 Rework the syn cache code somewhat:
- Don't use home-grown queue manipulation.  Use <sys/queue.h> instead.  The
  data structures are a little larger, but we are otherwise wasting the
  memory chunk anyway (we're already a 64-byte malloc bucket).
- Fix a bug in the cache-is-full case: if the oldest element removed from
  the first non-empty bucket was the only element in the bucket, the
  bucket wouldn't be removed from the bucket cache, causing queue corruption
  later.
- Optimize the syn cache timers by using PRT timers rather than home-grown
  decrement-and-propagate timers.

This code is now a fair bit smaller, and significantly easier to read
and understand.
1998-05-07 01:37:27 +00:00
thorpej 34e34c985a Use the monotonically increasing slow timer timestamp provided by
the protocol dispatch layer for TCP timers.  This saves having to
modify a potentially large number of timer values (which were shorts,
and expanded to ... a lot of code on the Alpha).
1998-05-06 01:24:38 +00:00
thorpej b71e4ddf4c Reintroduce the immediate ACK-on-PUSH behavior removed in revision 1.47,
but make the decision to do this dependent on the sysctl variable
net.inet.tcp.ack_on_push, which is disabled by default.
1998-05-02 04:21:58 +00:00
thorpej be12c489b4 Garbage-collect. 1998-05-01 18:31:12 +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
thorpej e81920fa23 Make tcp_compat_42 a sysctl option. 1998-04-30 17:55:27 +00:00
matt 334f006538 New TCP reassembly code. The new code reduces the memory needed by
out-of-order packets and builds the infrastructure needed for sending
SACK blocks (to be added shortly).
1998-04-29 20:43:29 +00:00
thorpej 13f972a4d6 Make use of the work-arounds for ancient broken TCP peers run-time
conditional (tcp_compat_42).  The kernel config option TCP_COMPAT_42
will still enable this by default, or disable this by default if the
option is not included (i.e. current behavior).  This will be made a
sysctl soon.
1998-04-29 05:16:46 +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 47b4697587 Remember any source routes that may have accompanied a SYN. 1998-04-07 05:09:19 +00:00
thorpej 04d3f25df8 Now that we have a flags word in the syn cache entry, use a flag to indicate
"peer will do timestamps" rather than a bitfield, and give the now-unsed
bit to the hash, making it now 32 bits.
1998-04-03 08:02:45 +00:00
thorpej b7c562b21c Clean up some comments wrt. the syn cache code. 1998-04-03 07:54:01 +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 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
perry f73530ba55 add/cleanup multiple inclusion protection. 1998-02-10 01:26:19 +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 3c5ff3879d Keep stats on connections dropped due to excessive persist timeout. 1997-12-17 06:06:41 +00:00
thorpej ee84a26869 After further examination of traces of bulk transfers (with help from
Kevin Lahey), undo the "defer window update until next delayed ACK".
1997-12-13 21:02:38 +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 3026b32ab3 In the PRU_RCVD entry point, if TF_DELACK is set, don't send the window
update now, since it will be sent within 200ms when the delayed ACK is
sent.  Instrument how many hits we get on this optimization.
1997-12-11 06:53:06 +00:00
thorpej c40f4eb3cc Implement tcp_drain(). 1997-12-10 01:58:07 +00:00
kml 86275dc497 TCP MSS fixes to provide cleaner slow-start and recovery. 1997-11-08 02:35:22 +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
explorer 790e114732 Add hooks to use the kernel random system to generate TCP sequence numbers. 1997-10-10 01:51:07 +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
gwr c74236bfc9 Tweaks to allow operation with an interface address of 0.0.0.0
(needed for NFS mountroot using BOOTP to get boot parameters)
1997-08-29 16:02:41 +00:00
thorpej 758a104426 Make the following tunable via sysctl, inspired by BSD/OS:
- tcp_sendspace
- tcp_recvspace
- tcp_mssdflt
- tcp_syn_cache_limit
- tcp_syn_bucket_limit
- tcp_syn_cache_timer
1997-07-28 22:18:48 +00:00
thorpej efa8881dbe Pull SYN_cache_branch down into the main line. 1997-07-23 21:26:40 +00:00
mycroft 315bb1ab50 Fix RTT scaling problems introduced with Brakmo and Peterson changes. 1996-12-10 18:20:19 +00:00
mycroft 49d52c9b1c Pass a proc pointer down to the usrreq and pcbbind functions for PRU_ATTACH, PRU_BIND and
PRU_CONTROL.  The usrreq interface really needs to be split up, but this will have to wait.
Remove SS_PRIV completely.
1996-05-22 13:54:55 +00:00
christos 14d9cd33af netinet prototypes 1996-02-13 23:40:59 +00:00
mycroft 67e78477db Build a hash table of PCBs. Hash function needs tweaking. 1996-01-31 03:49:23 +00:00
cgd dfad729a16 make netinet work on systems where pointers and longs are 64 bits
(like the alpha).  Biggest problem: IP headers were overlayed with
structure which included pointers, and which therefore didn't overlay
properly on 64-bit machines.  Solution: instead of threading pointers
through IP header overlays, add a "queue element" structure to do
the threading, and point it at the ip headers.
1995-11-21 01:07:34 +00:00
thorpej 7884abf9e5 Implement tcp_sysctl(). Add a sysctl option to enable/disable RFC1323
extensions to TCP.  From John Kohl <jtk@kolvir.blrc.ma.us>.
1995-09-30 07:02:00 +00:00
mycroft 6897f39ae9 Various cleanup, including:
* Convert several data structures to use queue.h.
* Split in_pcbnotify() into two parts; one for notifying a specific PCB, and
one for notifying all PCBs for a particular foreign address.
1995-06-12 00:46:47 +00:00
mycroft 2be9b519ac As suggested by Brakmo and Peterson:
* Don't add the extra 1/8 of the mss when ramping up the congestion window.
* Scale the RTT values slightly to adjust for rounding errors.
* Set the lower bound of the RTO to RTT+2.
1995-06-11 20:39:22 +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
jtc 7c04233887 KERNEL -> _KERNEL 1995-03-26 20:23:52 +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 627b841797 Change the counters to be all the same type -- u_long. 1994-01-10 23:27:39 +00:00
mycroft 699565c826 Don't prototype this until it's safe. 1994-01-10 00:31:11 +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