Introduce convenience macros to retrieve the DSCP, ECN or traffic class
bits from an IPv6 header.
Use them where appropriate.
Reviewed by: ae (previous version), rscheff, tuexen, rgrimes
Sponsored by: Rubicon Communications, LLC ("Netgate")
Differential Revision: https://reviews.freebsd.org/D29056
(cherry picked from commit bb4a7d94b9)
Add proper PRR vnet declarations for consistency.
Also add pointer to tcpopt struct to tcp_do_prr_ack, in preparation
for it to deal with non-SACK window reduction (after loss).
No functional change.
MFC after: 2 weeks
Reviewed By: tuexen, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D29440
(cherry picked from commit 90cca08e91)
Currently ip6_input() calls in6ifa_ifwithaddr() for
every local packet, in order to check if the target ip
belongs to the local ifa in proper state and increase
its counters.
in6ifa_ifwithaddr() references found ifa.
With epoch changes, both `ip6_input()` and all other current callers
of `in6ifa_ifwithaddr()` do not need this reference
anymore, as epoch provides stability guarantee.
Given that, update `in6ifa_ifwithaddr()` to allow
it to return ifa without referencing it, while preserving
option for getting referenced ifa if so desired.
Differential Revision: https://reviews.freebsd.org/D28648
(cherry picked from commit 8268d82cff)
- improved pipe calculation which does not degrade under heavy loss
- engaging in Loss Recovery earlier under adverse conditions
- Rescue Retransmission in case some of the trailing packets of a request got lost
All above changes are toggled with the sysctl "rfc6675_pipe" (disabled by default).
Reviewers: #transport, tuexen, lstewart, slavash, jtl, hselasky, kib, rgrimes, chengc_netapp.com, thj, #manpages, kbowling, #netapp, rscheff
Reviewed By: #transport
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D18985
(cherry picked from commit 3c40e1d52c)
has to take into consideration.
PR: 253576
Reviewed By: tuexen, #transport
MFC after: 3 days
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D28652
(cherry picked from commit 2593f858d7)
- address second instance of cwnd potentially becoming zero
- fix sublte bug due to implicit int to uint typecase in max()
- fix bug due to typo in hand-coded CEILING() function by using howmany() macro
- use int instead of long, and add a missing long typecast
- replace if conditionals with easier to read imax/imin (as in pseudocode)
Reviewed By: #transport, kbowling
MFC after: 3 days
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D28813
(cherry picked from commit 48396dc779)
Under some circumstances, PRR may end up with a fully
collapsed cwnd when finalizing the loss recovery.
Reviewed By: #transport, kbowling
Reported by: Liang Tian
MFC after: 5 days
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D28780
(cherry picked from commit 853fd7a2e3)
Adding a safety net prior to the division in tcp_prr_partialack
function, which was missed in D28114.
Reviewed-by: tuexen, mm, @transport
MFC: 3 days
Differential Revision: https://reviews.freebsd.org/D28326
(cherry picked from commit 6a376af0cd)
Summary:
When using the base stack in conjunction with RACK, it appears that
infrequently, ++tp->t_dupacks is instantly larger than tcprexmtthresh.
This leaves the recover flightsize (sackhint.recover_fs) uninitialized,
leading to a div/0 panic.
Address this by properly initializing the variable just prior to first
use, if it is not properly initialized.
In order to prevent stale information from a prior recovery to
negatively impact the PRR calculations in this event, also clear
recover_fs once loss recovery is finished.
Finally, improve the readability of the initialization of recover_fs
when t_dupacks == tcprexmtthresh by adjusting the indentation and
using the max(1, snd_nxt - snd_una) macro.
Reviewers: rrs, kbowling, tuexen, jtl, #transport, gnn!, jmg, manu, #manpages
Reviewed By: rrs, kbowling, #transport
Subscribers: bdrewery, andrew, rpokala, ae, emaste, bz, bcran, #linuxkpi, imp, melifaro
Differential Revision: https://reviews.freebsd.org/D28114
When timestamp support has been negotiated, TCP segements received
without a timestamp should be discarded. However, there are broken
TCP implementations (for example, stacks used by Omniswitch 63xx and
64xx models), which send TCP segments without timestamps although
they negotiated timestamp support.
This patch adds a sysctl variable which tolerates such TCP segments
and allows to interoperate with broken stacks.
Reviewed by: jtl@, rscheff@
Differential Revision: https://reviews.freebsd.org/D28142
Sponsored by: Netflix, Inc.
PR: 252449
MFC after: 1 week
A TCP RST segment should be processed even it is missing TCP
timestamps.
Reported by: dmgk@, kevans@
Reviewed by: rscheff@, dmgk@
Sponsored by: Netflix, Inc.
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D28143
PRR improves loss recovery and avoids RTOs in a wide range
of scenarios (ACK thinning) over regular SACK loss recovery.
PRR is disabled by default, enable by net.inet.tcp.do_prr = 1.
Performance may be impeded by token bucket rate policers at
the bottleneck, where net.inet.tcp.do_prr_conservate = 1
should be enabled in addition.
Submitted by: Aris Angelogiannopoulos
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D18892
* TCP segments without timestamps should be dropped when support for
the timestamp option has been negotiated.
* TCP segments with timestamps should be processed normally if support
for the timestamp option has not been negotiated.
This patch enforces the above.
PR: 250499
Reviewed by: gnn, rrs
MFC after: 1 week
Sponsored by: Netflix, Inc
Differential Revision: https://reviews.freebsd.org/D27148
Under specific conditions, a window update can be sent with
outdated SACK information. Some clients react to this by
subsequently delaying loss recovery, making TCP perform very
poorly.
Reported by: chengc_netapp.com
Reviewed by: rrs, jtl
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D24237
This will pave the way of setting ssthresh differently in TCP CUBIC, according
to RFC8312 section 4.7.
No functional change, only code movement.
Submitted by: chengc_netapp.com
Reviewed by: rrs, tuexen, rscheff
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D26807
of acked bytes as described in Section 2.2 of that document.
This patch ensures that this limit is not also applied in congestion
avoidance. Applying this limit also in congestion avoidance can result in
using less bandwidth than allowed.
Reported by: l.tian.email@gmail.com
Reviewed by: rrs, rscheff
MFC after: 3 days
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D26120
Adding proper accounting of sacked_bytes and (per-ACK)
delivered data to the SACK scoreboard. This will
allow more aspects of RFC6675 to be implemented as well
as Proportional Rate Reduction (RFC6937).
Prior to this change, the pipe calculation controlled with
net.inet.tcp.rfc6675_pipe was also susceptible to incorrect
results when more than 3 (or 4) holes in the sequence space
were present, which can no longer all fit into a single
ACK's SACK option.
Reviewed by: kbowling, rgrimes (mentor)
Approved by: rgrimes (mentor, blanket)
MFC after: 3 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D18624
is to know the time to first byte in and time to first byte out. Currently we
have no way to know these all we have is t_starttime. That (t_starttime) tells us
what time the 3 way handshake completed. We don't know when the first
request came in or how quickly we responded. Nor from a client perspective
do we know how long from when we sent out the first byte before the
server responded.
This small change adds the ability to track the TTFB's. This will show up in
BB logging which then can be pulled for later analysis. Note that currently
the tracking is via the ticks variable of all three variables. This provides
a very rough estimate (hz=1000 its 1ms). A follow-on set of work will be
to change all three of these values into something with a much finer resolution
(either microseconds or nanoseconds), though we may want to make the resolution
configurable so that on lower powered machines we could still use the much
cheaper ticks variable.
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D24902
of them have to do with TFO. Even the default stack
had one of the issues:
1) We need to make sure for rack that we don't advance
snd_nxt beyond iss when we are not doing fast open. We
otherwise can get a bunch of SYN's sent out incorrectly
with the seq number advancing.
2) When we complete the 3-way handshake we should not ever
append to reassembly if the tlen is 0, if TFO is enabled
prior to this fix we could still call the reasemmbly. Note
this effects all three stacks.
3) Rack like its cousin BBR should track if a SYN is on a
send map entry.
4) Both bbr and rack need to only consider len incremented on a SYN
if the starting seq is iss, otherwise we don't increment len which
may mean we return without adding a sendmap entry.
This work was done in collaberation with Michael Tuexen, thanks for
all the testing!
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D25000
Overly conservative data receivers may ignore the CWR flag
on other packets, and keep ECE latched. This can result in
continous reduction of the congestion window, and very poor
performance when ECN is enabled.
Reviewed by: rgrimes (mentor), rrs
Approved by: rgrimes (mentor), tuexen (mentor)
MFC after: 3 days
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D23364
When receiving a parallel SYN in SYN-SENT state, remove all the
options only we supported locally before sending the SYN,ACK.
This addresses a consistency issue on parallel opens.
Also, on such a parallel open, the stack could be coaxed into
running with timestamps enabled, even if administratively disabled.
Reviewed by: tuexen (mentor)
Approved by: tuexen (mentor)
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D23371
While testing simultaneous open TCP with ECN, found that
negotiation fails to arrive at the expected final state.
Reviewed by: tuexen (mentor)
Approved by: tuexen (mentor), rgrimes (mentor)
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D23373
by not including the SYN bit sequence space in cwnd related calculations.
Snd_und is adjusted explicitly in all cases, outside the cwnd update, instead.
This fixes an off-by-one conformance issue with regular TCP sessions not
using Appropriate Byte Counting (RFC3465), sending one more packet during
the initial window than expected.
PR: 235256
Reviewed by: tuexen (mentor), rgrimes (mentor)
Approved by: tuexen (mentor), rgrimes (mentor)
MFC after: 3 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D19000
in all cases, by adjust snd_una right after the
connection initialization, to include the one byte
in sequence space occupied by the SYN bit.
This does not change the regular ACK processing,
while making the BYTES_THIS_ACK macro to work properly.
PR: 235256
Reviewed by: tuexen (mentor), rgrimes (mentor)
Approved by: tuexen (mentor), rgrimes (mentor)
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D19000
these are kernel modules. Also add a KMOD_TCPSTAT_ADD and use that
instead of TCPSTAT_ADD.
Reviewed by: jtl@, rrs@
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D23904
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
a single instance: use snd_recover also where sack_newdata was used.
Submitted by: Richard Scheffenegger
Differential Revision: https://reviews.freebsd.org/D18811
and not only for the DCTCP congestion control.
Submitted by: Richard Scheffenegger
Reviewed by: rgrimes, tuexen@, Cheng Cui
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23119
indicates that ECN should be negotiated for the client side.
Submitted by: Richard Scheffenegger
Reviewed by: rgrimes@, tuexen@
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23228
This allows the data sender to increase the CWND faster.
Submitted by: Richard Scheffenegger
Reviewed by: rgrimes@, tuexen@, Cheng Cui
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22670
including user data in the SYN-ACK. When DSACK support was added in
r347382, an immediate ACK was sent even for the received SYN with
user data. This patch fixes that and allows again to send user data with
the SYN-ACK.
Reported by: Jeremy Harris
Reviewed by: Richard Scheffenegger, rrs@
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D23212
Virtualise tcp_always_keepalive, TCP and UDP log_in_vain. All three are
set in the netoptions startup script, which we would love to run for VNETs
as well [1].
While virtualising the log_in_vain sysctls seems pointles at first for as
long as the kernel message buffer is not virtualised, it at least allows
an administrator to debug the base system or an individual jail if needed
without turning the logging on for all jails running on a system.
PR: 243193 [1]
MFC after: 2 weeks
also commonizes the functions that both the freebsd and
rack stack uses.
Sponsored by:Netflix Inc
Differential Revision: https://reviews.freebsd.org/D23052
