Commit Graph

61 Commits

Author SHA1 Message Date
Michael Tuexen
c6dcb64b18 Use exponential backoff for retransmitting SYN segments as specified
in the TCP RFCs.

Reviewed by:		rrs@, Richard Scheffenegger
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D18974
2019-02-20 17:56:38 +00:00
Warner Losh
52467047aa Regularize the Netflix copyright
Use recent best practices for Copyright form at the top of
the license:
1. Remove all the All Rights Reserved clauses on our stuff. Where we
   piggybacked others, use a separate line to make things clear.
2. Use "Netflix, Inc." everywhere.
3. Use a single line for the copyright for grep friendliness.
4. Use date ranges in all places for our stuff.

Approved by: Netflix Legal (who gave me the form), adrian@ (pmc files)
2019-02-04 21:28:25 +00:00
Michael Tuexen
116ef4d6e7 When handling SYN-ACK segments in the SYN-RCVD state, set tp->snd_wnd
consistently.

This inconsistency was observed when working on the bug reported in
PR 235256, although it does not fix the reported issue. The fix for
the PR will be a separate commit.

PR:			235256
Reviewed by:		rrs@, Richard Scheffenegger
MFC after:		3 days
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D19033
2019-02-01 12:33:00 +00:00
Michael Tuexen
bf7fcdb18a Fix the detection of ECN-setup SYN-ACK packets.
RFC 3168 defines an ECN-setup SYN-ACK packet as on with the ECE flags
set and the CWR flags not set. The code was only checking if ECE flag
is set. This patch adds the check to verify that the CWR flags is not
set.

Submitted by:		Richard Scheffenegger
Reviewed by:		tuexen@
MFC after:		1 week
Differential Revision:	https://reviews.freebsd.org/D18996
2019-01-28 12:45:31 +00:00
Michael Tuexen
7dc90a1de0 Fix a bug in the restart window computation of TCP New Reno
When implementing support for IW10, an update in the computation
of the restart window used after an idle phase was missed. To
minimize code duplication, implement the logic in tcp_compute_initwnd()
and call it. This fixes a bug in NewReno, which was not aware of
IW10.

Submitted by:		Richard Scheffenegger
Reviewed by:		tuexen@
MFC after:		1 week
Differential Revision:	https://reviews.freebsd.org/D18940
2019-01-25 13:57:09 +00:00
Michael Tuexen
ad2be38941 A TCP stack is required to check SEG.ACK first, when processing a
segment in the SYN-SENT state as stated in Section 3.9 of RFC 793,
page 66. Ensure this is also done by the TCP RACK stack.

Reviewed by:		rrs@
MFC after:		1 week
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D18034
2018-11-22 20:05:57 +00:00
Michael Tuexen
fef56019e9 Ensure that the TCP RACK stack honours the setting of the
net.inet.tcp.drop_synfin sysctl-variable.

Reviewed by:		rrs@
MFC after:		1 week
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D18033
2018-11-22 20:02:39 +00:00
Michael Tuexen
7e729f0787 Ensure that the default RTT stack can make an RTT measurement if
the TCP connection was initiated using the RACK stack, but the
peer does not support the TCP RACK extension.

This ensures that the TCP behaviour on the wire is the same if
the TCP connection is initated using the RACK stack or the default
stack.

Reviewed by:		rrs@
MFC after:		1 week
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D18032
2018-11-22 19:56:52 +00:00
Michael Tuexen
794107181a Ensure that TCP RST-segments announce consistently a receiver window of
zero. This was already done when sending them via tcp_respond().

Reviewed by:		rrs@
MFC after:		1 week
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D17949
2018-11-22 19:49:52 +00:00
Michael Tuexen
3bea9a2664 Improve two KASSERTs in the TCP RACK stack.
There are two locations where an always true comparison was made in
a KASSERT. Replace this by an appropriate check and use a consistent
panic message. Also use this code when checking a similar condition.

PR:			229664
Reviewed by:		rrs@
MFC after:		1 week
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D18021
2018-11-21 18:19:15 +00:00
Michael Tuexen
a8a8a8a808 Fix TCP Fast Open for the TCP RACK stack.
* Fix a bug where the SYN handling during established state was
  applied to a front state.
* Move a check for retransmission after the timer handling.
  This was suppressing timer based retransmissions.
* Fix an off-by one byte in the sequence number of retransmissions.
* Apply fixes corresponding to
  https://svnweb.freebsd.org/changeset/base/336934

Reviewed by:		rrs@
Approved by:		re (kib@)
MFC after:		1 month
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D16912
2018-09-12 10:27:58 +00:00
Randall Stewart
c28440db29 This change represents a substantial restructure of the way we
reassembly inbound tcp segments. The old algorithm just blindly
dropped in segments without coalescing. This meant that every
segment could take up greater and greater room on the linked list
of segments. This of course is now subject to a tighter limit (100)
of segments which in a high BDP situation will cause us to be a
lot more in-efficent as we drop segments beyond 100 entries that
we receive. What this restructure does is cause the reassembly
buffer to coalesce segments putting an emphasis on the two
common cases (which avoid walking the list of segments) i.e.
where we add to the back of the queue of segments and where we
add to the front. We also have the reassembly buffer supporting
a couple of debug options (black box logging as well as counters
for code coverage). These are compiled out by default but can
be added by uncommenting the defines.

Sponsored by:	Netflix Inc.
Differential Revision:	https://reviews.freebsd.org/D16626
2018-08-20 12:43:18 +00:00
Randall Stewart
d18ea344e6 Fix a small bug in rack where it will
end up sending the FIN twice.
Sponsored by:	Netflix Inc.
Differential Revision:	https://reviews.freebsd.org/D16604
2018-08-08 13:36:49 +00:00
Randall Stewart
936b2b64ae This fixes a bug in Rack where we were
not properly using the correct value for
Delayed Ack.

Sponsored by:	Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D16579
2018-08-06 09:22:07 +00:00
Randall Stewart
4ad5b7a0ac This fixes a hole where rack could end up
sending an invalid segment into the reassembly
queue. This would happen if you enabled the
data after close option.

Sponsored by:	Netflix
Differential Revision: https://reviews.freebsd.org/D16453
2018-07-30 10:23:29 +00:00
Randall Stewart
399973c33d Delete the example tcp stack "fastpath" which
was only put in has an example.

Sponsored by:	Netflix inc.
Differential Revision:	https://reviews.freebsd.org/D16420
2018-07-24 14:55:47 +00:00
Randall Stewart
8de9ac5eec Bump the ICMP echo limits to match the RFC
Reviewed by:	tuexen
Sponsored by: Netflix Inc.
Differential Revision:		https://reviews.freebsd.org/D16333
2018-07-18 22:49:53 +00:00
Michael Tuexen
a026a53a76 Use appropriate MSS value when populating the TCP FO client cookie cache
When a client receives a SYN-ACK segment with a TFP fast open cookie,
but without an MSS option, an MSS value from uninitialised stack memory is used.
This patch ensures that in case no MSS option is included in the SYN-ACK,
the appropriate value as given in RFC 7413 is used.

Reviewed by:		kbowling@
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D16175
2018-07-10 10:42:48 +00:00
Michael Tuexen
5f1347d7c9 Allow alternate TCP stack to populate the TCP FO client cookie
cache.

Without this patch, TCP FO could be used when using alternate
TCP stack, but only existing entires in the TCP client cookie
cache could be used. This cache was not populated by connections
using alternate TCP stacks.

Sponsored by:		Netflix, Inc.
2018-07-07 12:28:16 +00:00
Matt Macy
6573d7580b epoch(9): allow preemptible epochs to compose
- Add tracker argument to preemptible epochs
- Inline epoch read path in kernel and tied modules
- Change in_epoch to take an epoch as argument
- Simplify tfb_tcp_do_segment to not take a ti_locked argument,
  there's no longer any benefit to dropping the pcbinfo lock
  and trying to do so just adds an error prone branchfest to
  these functions
- Remove cases of same function recursion on the epoch as
  recursing is no longer free.
- Remove the the TAILQ_ENTRY and epoch_section from struct
  thread as the tracker field is now stack or heap allocated
  as appropriate.

Tested by: pho and Limelight Networks
Reviewed by: kbowling at llnw dot com
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D16066
2018-07-04 02:47:16 +00:00
Gleb Smirnoff
a00f4ac22f Revert r334843, and partially revert r335180.
tcp_outflags[] were defined since 4BSD and are defined nowadays in
all its descendants. Removing them breaks third party application.
2018-06-23 06:53:53 +00:00
Randall Stewart
c6f76759ca Make sure that the t_peakrate_thr is not compiled in
by default until NF can upstream it.

Reviewed by:	and suggested lstewart
Sponsored by:	Netflix Inc.
2018-06-19 11:20:28 +00:00
Matt Macy
9e58ff6ff9 convert inpcbinfo hash and info rwlocks to epoch + mutex
- Convert inpcbinfo info & hash locks to epoch for read and mutex for write
- Garbage collect code that handled INP_INFO_TRY_RLOCK failures as
  INP_INFO_RLOCK which can no longer fail

When running 64 netperfs sending minimal sized packets on a 2x8x2 reduces
unhalted core cycles samples in rwlock rlock/runlock in udp_send from 51% to
3%.

Overall packet throughput rate limited by CPU affinity and NIC driver design
choices.

On the receiver unhalted core cycles samples in in_pcblookup_hash went from
13% to to 1.6%

Tested by LLNW and pho@

Reviewed by: jtl
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15686
2018-06-19 01:54:00 +00:00
Gleb Smirnoff
9293873e83 TCPOUTFLAGS no longer exists since r334843. 2018-06-14 22:25:10 +00:00
Randall Stewart
4aec110f70 This fixes several bugs that Larry Rosenman helped me find in
Rack with respect to its handling of TCP Fast Open. Several
fixes all related to TFO are included in this commit:
1) Handling of non-TFO retransmissions
2) Building the proper send-map when we are doing TFO
3) Dealing with the ack that comes back that includes the
   SYN and data.

It appears that with this commit TFO now works :-)

Thanks Larry for all your help!!

Sponsored by:	Netflix Inc.
Differential Revision:	https://reviews.freebsd.org/D15758
2018-06-14 03:27:42 +00:00
Jonathan T. Looney
cff21e484b Change RACK dependency on TCPHPTS from a build-time dependency to a load-
time dependency.

At present, RACK requires the TCPHPTS option to run. However, because
modules can be moved from machine to machine, this dependency is really
best assessed at load time rather than at build time.

Reviewed by:	rrs
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D15756
2018-06-11 14:27:19 +00:00
Randall Stewart
89e560f441 This commit brings in a new refactored TCP stack called Rack.
Rack includes the following features:
 - A different SACK processing scheme (the old sack structures are not used).
 - RACK (Recent acknowledgment) where counting dup-acks is no longer done
        instead time is used to knwo when to retransmit. (see the I-D)
 - TLP (Tail Loss Probe) where we will probe for tail-losses to attempt
        to try not to take a retransmit time-out. (see the I-D)
 - Burst mitigation using TCPHTPS
 - PRR (partial rate reduction) see the RFC.

Once built into your kernel, you can select this stack by either
socket option with the name of the stack is "rack" or by setting
the global sysctl so the default is rack.

Note that any connection that does not support SACK will be kicked
back to the "default" base  FreeBSD stack (currently known as "default").

To build this into your kernel you will need to enable in your
kernel:
   makeoptions WITH_EXTRA_TCP_STACKS=1
   options TCPHPTS

Sponsored by:	Netflix Inc.
Differential Revision:		https://reviews.freebsd.org/D15525
2018-06-07 18:18:13 +00:00
Randall Stewart
3ee9c3c4eb This commit brings in the TCP high precision timer system (tcp_hpts).
It is the forerunner/foundational work of bringing in both Rack and BBR
which use hpts for pacing out packets. The feature is optional and requires
the TCPHPTS option to be enabled before the feature will be active. TCP
modules that use it must assure that the base component is compile in
the kernel in which they are loaded.

MFC after:	Never
Sponsored by:	Netflix Inc.
Differential Revision:	https://reviews.freebsd.org/D15020
2018-04-19 13:37:59 +00:00
Gleb Smirnoff
3bdf4c4274 Declare more TCP globals in tcp_var.h, so that alternative TCP stacks
can use them.  Gather all TCP tunables in tcp_var.h in one place and
alphabetically sort them, to ease maintainance of the list.

Don't copy and paste declarations in tcp_stacks/fastpath.c.
2017-10-11 20:36:09 +00:00
Michael Tuexen
e8aba2eb21 Avoid TCP log messages which are false positives.
This is https://svnweb.freebsd.org/changeset/base/322812, just for
alternate TCP stacks.

XMFC with: 	322812
2017-08-23 15:08:51 +00:00
Sean Bruno
43053c125a Revert r307901 - Inform CC modules about loss events.
This was discussed between various transport@ members and it was
requested to be reverted and discussed.

Submitted by:	Kevin Bowling <kevin.bowling@kev009.com>
Reported by:	lawrence
Reviewed by:	hiren
Sponsored by:	Limelight Networks
2017-07-25 15:08:52 +00:00
Michael Tuexen
98732609d5 Improve comments to describe what the code does.
Reported by:		jtl
Sponsored by:		Netflix, Inc.
2017-06-01 15:11:18 +00:00
Michael Tuexen
ebfd753408 When a SYN-ACK is received in SYN-SENT state, RFC 793 requires the
validation of SEG.ACK as the first step. If the ACK is not acceptable,
a RST segment should be sent and the segment should be dropped.
Up to now, the segment was partially processed.
This patch moves the check for the SEG.ACK validation up to the front
as required.
Reviewed by:		hiren, gnn
MFC after:		1 week
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D10424
2017-04-26 06:20:58 +00:00
Michael Tuexen
013f4df643 The sysctl variable net.inet.tcp.drop_synfin is not honored in all states,
for example not in SYN-SENT.
This patch adds code to check the sysctl variable in other states than
LISTEN.
Thanks to ae and gnn for providing comments.
Reviewed by:		gnn
MFC after:		1 week
Sponsored by:		Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D9894
2017-04-12 20:27:15 +00:00
Steven Hartland
e44c1887fd Use estimated RTT for receive buffer auto resizing instead of timestamps
Switched from using timestamps to RTT estimates when performing TCP receive
buffer auto resizing, as not all hosts support / enable TCP timestamps.

Disabled reset of receive buffer auto scaling when not in bulk receive mode,
which gives an extra 20% performance increase.

Also extracted auto resizing to a common method shared between standard and
fastpath modules.

With this AWS S3 downloads at ~17ms latency on a 1Gbps connection jump from
~3MB/s to ~100MB/s using the default settings.

Reviewed by:    lstewart, gnn
MFC after:      2 weeks
Relnotes:       Yes
Sponsored by:   Multiplay
Differential Revision:  https://reviews.freebsd.org/D9668
2017-04-10 08:19:35 +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
Andrey V. Elsukov
fcf596178b Merge projects/ipsec into head/.
Small summary
 -------------

o Almost all IPsec releated code was moved into sys/netipsec.
o New kernel modules added: ipsec.ko and tcpmd5.ko. New kernel
  option IPSEC_SUPPORT added. It enables support for loading
  and unloading of ipsec.ko and tcpmd5.ko kernel modules.
o IPSEC_NAT_T option was removed. Now NAT-T support is enabled by
  default. The UDP_ENCAP_ESPINUDP_NON_IKE encapsulation type
  support was removed. Added TCP/UDP checksum handling for
  inbound packets that were decapsulated by transport mode SAs.
  setkey(8) modified to show run-time NAT-T configuration of SA.
o New network pseudo interface if_ipsec(4) added. For now it is
  build as part of ipsec.ko module (or with IPSEC kernel).
  It implements IPsec virtual tunnels to create route-based VPNs.
o The network stack now invokes IPsec functions using special
  methods. The only one header file <netipsec/ipsec_support.h>
  should be included to declare all the needed things to work
  with IPsec.
o All IPsec protocols handlers (ESP/AH/IPCOMP protosw) were removed.
  Now these protocols are handled directly via IPsec methods.
o TCP_SIGNATURE support was reworked to be more close to RFC.
o PF_KEY SADB was reworked:
  - now all security associations stored in the single SPI namespace,
    and all SAs MUST have unique SPI.
  - several hash tables added to speed up lookups in SADB.
  - SADB now uses rmlock to protect access, and concurrent threads
    can do SA lookups in the same time.
  - many PF_KEY message handlers were reworked to reflect changes
    in SADB.
  - SADB_UPDATE message was extended to support new PF_KEY headers:
    SADB_X_EXT_NEW_ADDRESS_SRC and SADB_X_EXT_NEW_ADDRESS_DST. They
    can be used by IKE daemon to change SA addresses.
o ipsecrequest and secpolicy structures were cardinally changed to
  avoid locking protection for ipsecrequest. Now we support
  only limited number (4) of bundled SAs, but they are supported
  for both INET and INET6.
o INPCB security policy cache was introduced. Each PCB now caches
  used security policies to avoid SP lookup for each packet.
o For inbound security policies added the mode, when the kernel does
  check for full history of applied IPsec transforms.
o References counting rules for security policies and security
  associations were changed. The proper SA locking added into xform
  code.
o xform code was also changed. Now it is possible to unregister xforms.
  tdb_xxx structures were changed and renamed to reflect changes in
  SADB/SPDB, and changed rules for locking and refcounting.

Reviewed by:	gnn, wblock
Obtained from:	Yandex LLC
Relnotes:	yes
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D9352
2017-02-06 08:49:57 +00:00
George V. Neville-Neil
fad073dd44 Followup to mtod removal in main stack (r311225). Continued removal
of mtod() calls from TCP_PROBE macros.

MFC after:	1 week
Sponsored by:	Limelight Networks
2017-01-04 04:00:28 +00:00
Michael Tuexen
35dfb8cb68 Ensure that TCP state changes to state-closing are reported via dtrace.
This does not cover state changes from TIME-WAIT.

Reviewed by:		gnn
MFC after:		3 weeks
Sponsored by:		Netflix
Differential Revision:	https://reviews.freebsd.org/D8443
2016-11-19 14:45:08 +00:00
Michael Tuexen
6779a1a101 Notify the use via setting errno when a TCP RST segment is received
either in the CLOSING or LAST-ACK state.

Reviewed by:		hiren
MFC after:		3 weeks
Sponsored by:		Netflix
Differential Revision:	https://reviews.freebsd.org/D8371
2016-11-17 08:15:02 +00:00
Hiren Panchasara
4e7f755377 FreeBSD tcp stack used to inform respective congestion control module about the
loss event but not use or obay the recommendations i.e. values set by it in some
cases.

Here is an attempt to solve that confusion by following relevant RFCs/drafts.
Stack only sets congestion window/slow start threshold values when there is no
CC module availalbe to take that action. All CC modules are inspected and
updated when needed to take appropriate action on loss.

tcp_stacks/fastpath module has been updated to adapt these changes.

Note: Probably, the most significant change would be to not bring congestion
window down to 1MSS on a loss signaled by 3-duplicate acks and letting
respective CC decide that value.

In collaboration with:	Matt Macy <mmacy at nextbsd dot org>
Discussed on:		transport@ mailing list
Reviewed by:		jtl
MFC after:		1 month
Sponsored by:		Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D8225
2016-10-25 05:45:47 +00:00
Jonathan T. Looney
6d172f58a2 The code currently resets the keepalive timer each time a packet is
received on a TCP session that has entered the ESTABLISHED state. This
results in a lot of calls to reset the keepalive timer.

This patch changes the behavior so we set the keepalive timer for the
keepalive idle time (TP_KEEPIDLE). When the keepalive timer fires, it will
first check to see if the session has been idle for TP_KEEPIDLE ticks. If
not, it will reschedule the keepalive timer for the time the session will
have been idle for TP_KEEPIDLE ticks.

For a session with regular communication, the keepalive timer should fire
approximately once every TP_KEEPIDLE ticks. For sessions with irregular
communication, the keepalive timer might fire more often. But, the
disruption from a periodic keepalive timer should be less than the regular
cost of resetting the keepalive timer on every packet.

(FWIW, this change saved approximately 1.73% of the busy CPU cycles on a
particular test system with a heavy TCP output load. Of course, the
actual impact is very specific to the particular hardware and workload.)

Reviewed by:	gallatin, rrs
MFC after:	2 weeks
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D8243
2016-10-14 14:57:43 +00:00
Gleb Smirnoff
ec7bbf1f79 With build without TCP_HHOOK and with INVARIANTS. Before mutex.h came
via sys/hhook.h -> sys/rmlock.h -> sys/mutex.h.
2016-10-13 18:02:29 +00:00
Jonathan T. Looney
bd79708dbf In the TCP stack, the hhook(9) framework provides hooks for kernel modules
to add actions that run when a TCP frame is sent or received on a TCP
session in the ESTABLISHED state. In the base tree, this functionality is
only used for the h_ertt module, which is used by the cc_cdg, cc_chd, cc_hd,
and cc_vegas congestion control modules.

Presently, we incur overhead to check for hooks each time a TCP frame is
sent or received on an ESTABLISHED TCP session.

This change adds a new compile-time option (TCP_HHOOK) to determine whether
to include the hhook(9) framework for TCP. To retain backwards
compatibility, I added the TCP_HHOOK option to every configuration file that
already defined "options INET". (Therefore, this patch introduces no
functional change. In order to see a functional difference, you need to
compile a custom kernel without the TCP_HHOOK option.) This change will
allow users to easily exclude this functionality from their kernel, should
they wish to do so.

Note that any users who use a custom kernel configuration and use one of the
congestion control modules listed above will need to add the TCP_HHOOK
option to their kernel configuration.

Reviewed by:	rrs, lstewart, hiren (previous version), sjg (makefiles only)
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D8185
2016-10-12 02:16:42 +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
Hiren Panchasara
06b99bd826 Adjust TCP module fastpath after r304803's cc_ack_received() changes.
Reported by:		hiren, bz, np
Reviewed by:		rrs
Sponsored by:		Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D7664
2016-08-26 19:23:17 +00:00
Andrey V. Elsukov
4c10540274 Cleanup unneded include "opt_ipfw.h".
It was used for conditional build IPFIREWALL_FORWARD support.
But IPFIREWALL_FORWARD option was removed a long time ago.
2016-06-09 05:48:34 +00:00
Randall Stewart
5105a92c49 This small change adopts the excellent suggestion for using named
structures in the add of a new tcp-stack that came in late to me
via email after the last commit. It also makes it so that a new
stack may optionally get a callback during a retransmit
timeout. This allows the new stack to clear specific state (think
sack scoreboards or other such structures).

Sponsored by:	Netflix Inc.
Differential Revision:	http://reviews.freebsd.org/D6303
2016-05-17 09:53:22 +00:00
Mark Johnston
565e7fd3bc opt_kdtrace.h is not needed for SDT probes as of r258541. 2016-05-15 20:04:43 +00:00
Pedro F. Giffuni
a4641f4eaa sys/net*: minor spelling fixes.
No functional change.
2016-05-03 18:05:43 +00:00