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To: hackers@FreeBSD.org
Subject: Debugging networking code
Date: Thu, 02 Feb 1995 10:36:43 +0100
Message-Id: <849.791717803@utis156.cs.utwente.nl>
From: Andras Olah <olah@cs.utwente.nl>
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Currently, the only way to get debugging info from TCP is through
the tcp_debug routine which generates volumnious output on the
console.  I've got two problems with this: (1) I can't select what I
want to see (2) it slows down things considerably, so it's difficult
to test dynamic behavior.

I'd like to improve this situation and I'm asking for comments.  I
thought of the following scheme:
- during debugging I can compile in some probes which save
	state information to an internal structure; these probes
	should generate the minimal possible overhead
- there would an interface (probably a la bpf?) to get and
	save the info generated by the probes if someone is
	interested; and then this data could be post processed.

I'd appreciate comments on how this can be done (if it makes sense
at all).  I'd like to have this facility and there's a student here
who is willing to work on it.

Andras