From: Florian Obser <florian@openbsd.org>
Subject: Re: imsg_get_data Question
To: tech@openbsd.org
Date: Sun, 16 Aug 2026 19:29:53 +0200

imsg is usually used over a privilege boundary. The sender is supposed
to send exactly len bytes of data. If it fails to do that the receiver
has to assume the sender is compromised and terminate itself.
E.g. (dhcpleased/engine.c):

case IMSG_CTL_LOG_VERBOSE:
	if (imsg_get_data(&imsg, &verbose,
	    sizeof(verbose)) == -1)
		fatalx("%s: invalid %s", __func__, i2s(type));

-- 
In my defence, I have been left unsupervised.