Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 alpha 4/15/85; site ucbvax.ARPA
Path: utzoo!watmath!clyde!burl!ulysses!ucbvax!tcp-ip
From: tcp-ip@ucbvax.ARPA
Newsgroups: fa.tcp-ip
Subject: Re:  Sun Gateway problems
Message-ID: <7185@ucbvax.ARPA>
Date: Thu, 16-May-85 20:46:19 EDT
Article-I.D.: ucbvax.7185
Posted: Thu May 16 20:46:19 1985
Date-Received: Fri, 17-May-85 05:21:46 EDT
Sender: daemon@ucbvax.ARPA
Organization: University of California at Berkeley
Lines: 26

From: Chris Torek <chris@gyre>

If it's the ICMP bug Jim and I found, and you have Sun source, you can
fix it by finding modules that call "m_pullup" but have already used
"mtod" on the argument to m_pullup.  Whatever was mtod'ed needs to be
mtod'ed again.

Example:

icmp_xyzzy(m)
	struct mbuf *m;
{
	struct icmp_hdr *ic = mtod(m, struct icmp_hdr *);
	... <code> ...
	if (m->m_len < sizeof (struct icmp_hdr)) {
		if ((m = m_pullup(m, sizeof (struct icmp_hdr))) == NULL) {
			/* forget it */
		}
+-->		ic = mtod(m, struct icmp_hdr *);
|	}
|	... <code using ic->icmp_fields> ...
|
+---ADD THIS LINE

(We've reported the bug to Sun; I don't know when they'll get around to
fixing it.)