Details

Reviewers

tuexen
rrs
bcr
siderop1_netapp.com
allanjude

Group Reviewers

transport
manpages

Commits

rS367015: MFC r366566;r366567: Extend netstat to display TCP stack and detailed…
rS366567: Extend netstat to display TCP stack and detailed congestion state (2)
rS366566: Extend netstat to display TCP stack and detailed congestion state

Summary

Upstreaming the "-c" option used to show detailed per-connection
congestion control state for TCP sessions.

This is one summary patch, which adds the relevant variables into
xtcpcb. As previous "spare" space is used, these changes are ABI
compatible (an older version of netstat will simply not show
the newly available data from newer kernels, and a newer version
of netstat will only show zeroed data querying older kernels.

Test Plan

Verify that "netstat -c" shows cwnd, ssthresh, maxseg and ecn/ace,
while "netstat -C" shows the CC-algo (e.g. newreno, reno,...) and
the TCP stack in use (e.g. FreeBSD, RACK, BBR).

Diff Detail

Lint

Lint Passed

Unit

No Test Coverage

Build Status

Buildable 33755
Build 30978: arc lint + arc unit

Event Timeline

rscheff created this revision.Sep 21 2020, 9:03 PM

Herald added a reviewer: transport. · View Herald TranscriptSep 21 2020, 9:03 PM

Herald added a subscriber: melifaro. · View Herald Transcript

rscheff requested review of this revision.Sep 21 2020, 9:03 PM

Harbormaster completed remote builds in B33704: Diff 77322.Sep 21 2020, 9:03 PM

tuexen added inline comments.Sep 21 2020, 9:21 PM

usr.bin/netstat/main.c
208–209	Other lines use show instead of Show. Change for consistency?

address uppercase oversight in comment

Harbormaster completed remote builds in B33728: Diff 77356.Sep 22 2020, 12:05 PM

rscheff marked an inline comment as done.Sep 22 2020, 12:06 PM

Not sure about showing the TCP stack name and the TCP congestion under the same flag. The TCP congestion control name scales to other transports, the TCP stack name doesn't.

Wouldn't the numbers fit also under -x?

allanjude added a subscriber: NetApp.Sep 22 2020, 4:32 PM

allanjude added a subscriber: thj.

move stack name output to -c option

Harbormaster completed remote builds in B33755: Diff 77409.Sep 23 2020, 10:21 AM

In D26518#590315, @tuexen wrote:

Not sure about showing the TCP stack name and the TCP congestion under the same flag. The TCP congestion control name scales to other transports, the TCP stack name doesn't.

Wouldn't the numbers fit also under -x?

Move the stack name to "-c".

-x is cluttered as it is;

I'm even thinking about limiting the column width for Stack and cc_algo, based on the maximum name length currently in use? If all you have is "rack", no need to reserve 16 character-wide columns, or?

adjust column width to maximum string length

Harbormaster completed remote builds in B33757: Diff 77411.Sep 23 2020, 10:48 AM

rscheff added inline comments.Sep 24 2020, 2:39 PM

usr.bin/netstat/inet.c
351	Discussed with @tuexen; will move the output of session-specific info to the -C flag below after the algo, and -c will only show the TCP specific Stack, when needed.