tcp bblog: use correct length

The length of tldl_reason is TCP_LOG_REASON_LEN, not TCP_LOG_ID_LEN.
No functional change intended.
Reported by: Coverity Scan
CID: 1418074
CID: 1418276
Reviewed by: glebius, rscheff
MFC after: 3 days
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D44510

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Update various sys/netinet source files to conform with the style(9)
guide on how to label FALLTHOUGH in switch statements.

No functional chance.

Reviewed By: tuexen, cc, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D40622

tcp: request tracking is not http specific.

This change is a name change only. TCP Request tracking can track sendfile and even non-sendfile requests. The
names however in the current code use http, and they should not. The feature is not http specific. Lets change the
name so they more properly reflect whats going on. This also fixes conflicts with http_req which caused application pain.

Reviewed by: tuexen
Sponsored by: Netflix Inc
Differential Revision:https://reviews.freebsd.org/D40229

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

We have a TCP_LOG_CONNEND log that should come out at the very last log of every connection. This
holds some nice stats about why/how the connection ended. Though with the current code it does not
come out without accounting due to the placement of the ifdefs. Also we need to make sure the stacks
fini has ran before calling in from tcp_subr so we get all logs the stack may make at its ending.

Reviewed by: rscheff
Sponsored by: Netflix Inc
Differential Revision:https://reviews.freebsd.org/D39693

tcp: Blackbox logging and tcp accounting together can cause a crash.

If you currently turn BB logging on and in combination have TCP Accounting on we can get a
crash where we have no NULL check and we run out of memory. Also lets make sure we
don't do a divide by 0 in calculating any BB ratios.

Reviewed by: tuexen
Sponsored by: Netflix Inc
Differential Revision:https://reviews.freebsd.org/D39622

Fixes in the tcp infrastructure with respect to stack changes as well as other infrastructure updates for incoming rack features.

So stack switching as always been a bit of a issue. We currently use a break before make setup which means that
if something goes wrong you have to try to get back to a stack. This patch among a lot of other things changes that so
that it is a make before break. We also expand some of the function blocks in prep for new features in rack that will allow
more controlled pacing. We also add other abilities such as the pathway for a stack to query a previous stack to acquire from
it critical state information so things in flight don't get dropped or mis-handled when switching stacks. We also add the
concept of a timer granularity. This allows an alternate stack to change from the old ticks granularity to microseconds and
of course this even gives us a pathway to go to nanosecond timekeeping if we need to (something for the data center to consider
for sure).

Once all this lands I will then update rack to begin using all these new features.

Reviewed by: tuexen
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D39210

Move access to tcp's t_logstate into inline functions and provide new tracepoint and bbpoint capabilities.

The TCP stacks have long accessed t_logstate directly, but in order to do tracepoints and the new bbpoints
we need to move to using the new inline functions. This adds them and moves rack to now use
the tcp_tracepoints.

Reviewed by: tuexen, gallatin
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D38831

BBLog: improve sysctl variables

Correct the format in sysctl net.inet.tcp.bb.disable_all and
sysctl net.inet.tcp.bb.log_auto_all.
Correct the format and the description in
net.inet.tcp.bb.log_auto_mode.

Reviewed by: rscheff, tuexen
MFC after: 1 week
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D37776

tcp: provide macros to access inpcb and socket from a tcpcb

There should be no functional changes with this commit.

Reviewed by: rscheff
Differential revision: https://reviews.freebsd.org/D37123

tcp: remove INP_TIMEWAIT flag

Mechanically cleanup INP_TIMEWAIT from the kernel sources. After
0d7445193ab, this commit shall not cause any functional changes.

Note: this flag was very often checked together with INP_DROPPED.
If we modify in_pcblookup*() not to return INP_DROPPED pcbs, we
will be able to remove most of this checks and turn them to
assertions. Some of them can be turned into assertions right now,
but that should be carefully done on a case by case basis.

Differential revision: https://reviews.freebsd.org/D36400

prometheus_sysctl_exporter: fix metric aliasing

When exporting sysctls to Prometheus, the exporter replaces "." with
"_". This caused several metrics to alias, confusing the Prometheus
server. Fix it by:

* Renaming the "tcp_log_bucket" UMA zone to "tcp_log_id_bucket". Also,
rename "tcp_log_node" to "tcp_log_id_node" for consistency.

* Not exporting sysctls with "(LEGACY)" in the description. That is
used by ZFS sysctls that have been replaced by others, many of which
alias to the same Prometheus metric name (like "vfs.zfs.arc_max" and
"vfs.zfs.arc.max").

PR: 259607
Reported by: delphij
MFC after: 2 weeks
Sponsored by: Axcient
Reviewed by: delphij,rew,thj
Differential Revision: https://reviews.freebsd.org/D34952

netinet: Use __diagused for variables only used in KASSERT().

net: clean up empty lines in .c and .h files

An important statistic in determining if a server process (or client) is being delayed
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

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

sack_newdata and snd_recover hold the same value. Therefore, use only
a single instance: use snd_recover also where sack_newdata was used.

Submitted by: Richard Scheffenegger
Differential Revision: https://reviews.freebsd.org/D18811

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

Sponsored by: Netflix Inc.

This change adds a small feature to the tcp logging code. Basically
a connection can now have a separate tag added to the id.

Obtained from: Lawrence Stewart
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D22866

Make use of the stats(3) framework in the TCP stack.

This makes it possible to retrieve per-connection statistical
information such as the receive window size, RTT, or goodput,
using a newly added TCP_STATS getsockopt(3) option, and extract
them using the stats_voistat_fetch(3) API.

See the net/tcprtt port for an example consumer of this API.

Compared to the existing TCP_INFO system, the main differences
are that this mechanism is easy to extend without breaking ABI,
and provides statistical information instead of raw "snapshots"
of values at a given point in time. stats(3) is more generic
and can be used in both userland and the kernel.

Reviewed by: thj
Tested by: thj
Obtained from: Netflix
Relnotes: yes
Sponsored by: Klara Inc, Netflix
Differential Revision: https://reviews.freebsd.org/D20655

Fix a small bug in the tcp_log_id where the bucket
was unlocked and yet the bucket-unlock flag was not
changed to false. This can cause a panic if INVARIANTS
is on and we go through the right path (though rare).
This fixes the correct bug :)

Reported by: syzbot+179a1ad49f3c4c215fa2@syzkaller.appspotmail.com
Reviewed by: tuexen@

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)

Clean up some debugging code left in tcp_log_buf.c from r331347.

Sponsored by: Netflix, Inc.

Fix compilation for platforms that don't support atomic_fetchadd_64()
after r331347.

Reported by: avg, br, jhibbits
Sponsored by: Netflix, Inc.

Add the "TCP Blackbox Recorder" which we discussed at the developer
summits at BSDCan and BSDCam in 2017.

The TCP Blackbox Recorder allows you to capture events on a TCP connection
in a ring buffer. It stores metadata with the event. It optionally stores
the TCP header associated with an event (if the event is associated with a
packet) and also optionally stores information on the sockets.

It supports setting a log ID on a TCP connection and using this to correlate
multiple connections that share a common log ID.

You can log connections in different modes. If you are doing a coordinated
test with a particular connection, you may tell the system to put it in
mode 4 (continuous dump). Or, if you just want to monitor for errors, you
can put it in mode 1 (ring buffer) and dump all the ring buffers associated
with the connection ID when we receive an error signal for that connection
ID. You can set a default mode that will be applied to a particular ratio
of incoming connections. You can also manually set a mode using a socket
option.

This commit includes only basic probes. rrs@ has added quite an abundance
of probes in his TCP development work. He plans to commit those soon.

There are user-space programs which we plan to commit as ports. These read
the data from the log device and output pcapng files, and then let you
analyze the data (and metadata) in the pcapng files.

Reviewed by: gnn (previous version)
Obtained from: Netflix, Inc.
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D11085