TCP complete end status work.

The ending of a connection can tell us a lot about what happened i.e. did
it fail to setup, did it timeout, was it a normal close. Often times this is
useful informatio

TCP complete end status work.

The ending of a connection can tell us a lot about what happened i.e. did
it fail to setup, did it timeout, was it a normal close. Often times this is
useful information to help analyze and debug issues. Rack has had
end status for some time but the base stack as not. Lets go a ahead
and add in the missing bits to populate the end status.

Reviewed by: tuexen, rscheff
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D36712

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protosw: retire PRU_ flags and their char names

For many years only TCP debugging used them, but relatively recently
TCP DTrace probes also start to use them. Move their declarations
into tcp_debug

protosw: retire PRU_ flags and their char names

For many years only TCP debugging used them, but relatively recently
TCP DTrace probes also start to use them. Move their declarations
into tcp_debug.h, but start including tcp_debug.h unconditionally,
so that compilation with DTrace and without TCPDEBUG is possible.

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tcp: use callout(9) directly instead of pr_slowtimo

Modern TCP stacks uses multiple callouts per tcpcb, and a global
callout is ancient artifact. However it is still used to garbage
collect compres

tcp: use callout(9) directly instead of pr_slowtimo

Modern TCP stacks uses multiple callouts per tcpcb, and a global
callout is ancient artifact. However it is still used to garbage
collect compressed timewait entries.

Reviewed by: melifaro, tuexen
Differential revision: https://reviews.freebsd.org/D36159

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netinet: simplify RSS ifdef statements

Approved by: transport (rrs)
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D31583

tcp: TCP output method can request tcp_drop

The advanced TCP stacks (bbr, rack) may decide to drop a TCP connection
when they do output on it. The default stack never does this, thus
existing frame

tcp: TCP output method can request tcp_drop

The advanced TCP stacks (bbr, rack) may decide to drop a TCP connection
when they do output on it. The default stack never does this, thus
existing framework expects tcp_output() always to return locked and
valid tcpcb.

Provide KPI extension to satisfy demands of advanced stacks. If the
output method returns negative error code, it means that caller must
call tcp_drop().

In tcp_var() provide three inline methods to call tcp_output():
- tcp_output() is a drop-in replacement for the default stack, so that
default stack can continue using it internally without modifications.
For advanced stacks it would perform tcp_drop() and unlock and report
that with negative error code.
- tcp_output_unlock() handles the negative code and always converts
it to positive and always unlocks.
- tcp_output_nodrop() just calls the method and leaves the responsibility
to drop on the caller.

Sweep over the advanced stacks and use new KPI instead of using HPTS
delayed drop queue for that.

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D33370

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tcp: mechanically substitute call to tfb_tcp_output to new method.

Made with sed(1) execution:

sed -Ef sed -i "" $(grep --exclude tcp_var.h -lr tcp_output sys/)

sed:
s/tp->t_fb->tfb_tcp_output\(tp

tcp: mechanically substitute call to tfb_tcp_output to new method.

Made with sed(1) execution:

sed -Ef sed -i "" $(grep --exclude tcp_var.h -lr tcp_output sys/)

sed:
s/tp->t_fb->tfb_tcp_output\(tp\)/tcp_output(tp)/
s/to tfb_tcp_output\(\)/to tcp_output()/

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D33366

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tcp: virtualise net.inet.tcp.msl sysctl.

VNET teardown waits 2*MSL (60 seconds by default) before expiring
tcp PCBs. These PCBs holds references to nexthops, which, in turn,
reference ifnets. This

tcp: virtualise net.inet.tcp.msl sysctl.

VNET teardown waits 2*MSL (60 seconds by default) before expiring
tcp PCBs. These PCBs holds references to nexthops, which, in turn,
reference ifnets. This chain results in VNET interfaces being destroyed
and moved to default VNET only after 60 seconds.
Allow tcp_msl to be set in jail by virtualising net.inet.tcp.msl sysctl,
permitting more predictable VNET tests outcomes.

MFC after: 1 week
Reviewed by: glebius
Differential Revision: https://reviews.freebsd.org/D33270

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Add tcp_freecb() - single place to free tcpcb.

Until this change there were two places where we would free tcpcb -
tcp_discardcb() in case if all timers are drained and tcp_timer_discard()
otherwise

Add tcp_freecb() - single place to free tcpcb.

Until this change there were two places where we would free tcpcb -
tcp_discardcb() in case if all timers are drained and tcp_timer_discard()
otherwise. They were pretty much copy-n-paste, except that in the
default case we would run tcp_hc_update(). Merge this into single
function tcp_freecb() and move new short version of tcp_timer_discard()
to tcp_timer.c and make it static.

Reviewed by: rrs, hselasky
Differential revision: https://reviews.freebsd.org/D32965

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tcp_timers: check for (INP_TIMEWAIT | INP_DROPPED) only once

All timers keep inpcb locked through their execution. We need to
check these flags only once. Checking for INP_TIMEWAIT earlier is
is a

tcp_timers: check for (INP_TIMEWAIT | INP_DROPPED) only once

All timers keep inpcb locked through their execution. We need to
check these flags only once. Checking for INP_TIMEWAIT earlier is
is also safer, since such inpcbs point into tcptw rather than tcpcb,
and any dereferences of inp_ppcb as tcpcb are erroneous.

Reviewed by: rrs, hselasky
Differential revision: https://reviews.freebsd.org/D32967

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Improve the TCP blackhole detection. The principle is to reduce the
MSS in two steps and try each candidate two times. However, if two
candidates are the same (which is the case in TCP/IPv6), this ca

Improve the TCP blackhole detection. The principle is to reduce the
MSS in two steps and try each candidate two times. However, if two
candidates are the same (which is the case in TCP/IPv6), this candidate
was tested four times. This patch ensures that each candidate actually
reduced the MSS and is only tested 2 times. This reduces the time window
of missclassifying a temporary outage as an MTU issue.

Reviewed by: jtl
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D24308

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Allow the TCP backhole detection to be disabled at all, enabled only
for IPv4, enabled only for IPv6, and enabled for IPv4 and IPv6.
The current blackhole detection might classify a temporary outage

Allow the TCP backhole detection to be disabled at all, enabled only
for IPv4, enabled only for IPv6, and enabled for IPv4 and IPv6.
The current blackhole detection might classify a temporary outage as
an MTU issue and reduces permanently the MSS. Since the consequences of
such a reduction due to a misclassification are much more drastically
for IPv4 than for IPv6, allow the administrator to enable it for IPv6 only.

Reviewed by: bcr@ (man page), Richard Scheffenegger
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D24219

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Merge ^/head r358269 through r358399.

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly mark

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)

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

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Merge ^/head r357662 through r357854.

White space cleanup -- remove trailing tab's or spaces
from any line.

Sponsored by: Netflix Inc.

Merge ^/head r356931 through r357118.

Make tcp_output() require network epoch.

Enter the epoch before calling into tcp_output() from those
functions, that didn't do that before.

This eliminates a bunch of epoch recursions in TCP.

Make ip6_output() and ip_output() require network epoch.

All callers that before may called into these functions
without network epoch now must enter it.

vnet: virtualise more network stack sysctls.

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 we

vnet: virtualise more network stack sysctls.

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

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Use callout_func_t instead of the deprecated timeout_t.

Reviewed by: kib, imp
Differential Revision: https://reviews.freebsd.org/D22752

TCP timers are executed in callout context, so they need to enter network
epoch to look into PCB lists. Mechanically convert INP_INFO_RLOCK() to
NET_EPOCH_ENTER(). No functional change here.

MFHead@r345677

Add sysctl variable net.inet.tcp.rexmit_initial for setting RTO.Initial
used by TCP.

Reviewed by: rrs@, 0mp@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D19355

MFhead@r344527

Merge ^/head r344178 through r344512.