Page MenuHomeFreeBSD

rtsol/rtsold: Add option to skip random delay
ClosedPublic

Authored by cperciva on Nov 12 2021, 5:14 AM.
Tags
None
Referenced Files
Unknown Object (File)
Jan 20 2024, 12:02 PM
Unknown Object (File)
Jan 17 2024, 6:13 PM
Unknown Object (File)
Dec 22 2023, 11:53 PM
Unknown Object (File)
Dec 20 2023, 9:49 PM
Unknown Object (File)
Dec 12 2023, 5:28 PM
Unknown Object (File)
Dec 7 2023, 12:27 PM
Unknown Object (File)
Nov 30 2023, 5:11 PM
Unknown Object (File)
Sep 27 2023, 8:23 AM
Subscribers

Details

Summary

In accordance with a SHOULD in RFC 4861, rtsol and rtsold wait a random time between
zero and one (aka MAX_RTR_SOLICITATION_DELAY) seconds before sending a Router
Solicitation, in order to avoid network congestion if many hosts come online at once. (The
question of how many hosts would be required to cause congestion by each sending a
single packet on a Gbps+ network is left to the reader.)

The new option -i disables this wait and instructs rtsol and rtsold to send the Router
Solicitation immediately.

Diff Detail

Repository
rG FreeBSD src repository
Lint
Lint Not Applicable
Unit
Tests Not Applicable

Event Timeline

cperciva created this revision.
kp added a subscriber: kp.

LGTM. The man page date will want to be bumped up.

This revision is now accepted and ready to land.Nov 12 2021, 9:25 AM
allanjude added inline comments.
usr.sbin/rtsold/rtsold.c
724–727

This if makes a double negative, I feel like this if would read better the other way around...

		if (no_solicitation_delay == 1)
			interval = 0;
		else
			interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * MILLION);

Bumped man page date & adjusted if logic to avoid double-negative.

This revision now requires review to proceed.Nov 12 2021, 8:10 PM
usr.sbin/rtsold/rtsold.c
102

bool given we have that these days (as opposed to 25 years ago)?

bz added a reviewer: hrs.

Apart from that this seems fine to me.

This revision is now accepted and ready to land.Nov 12 2021, 8:49 PM
usr.sbin/rtsold/rtsold.c
102

I considered that, but figured that it made sense to keep style consistency with the surrounding code.

(For the same reason, I didn't wrap the interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * MILLION); -- it's a long line, but it was *already* >80 characters before this change...)