Path: utzoo!utgpu!watserv1!watmath!att!rutgers!mit-eddie!uw-beaver!milton!hubert@cac.washington.edu
From: hubert@cac.washington.edu (Steve Hubert)
Newsgroups: comp.mail.sendmail
Subject: temporarily broken nameserver breaks sendmail daemon
Message-ID: <9455@milton.u.washington.edu>
Date: 18 Oct 90 01:16:09 GMT
Sender: hubert@milton.u.washington.edu
Organization: University of Washington, Seattle
Lines: 45

DESCRIPTION:
If the nameserver is inaccessible when the sendmail daemon is
started it can come up with the wrong idea of its hostname.  This
will happen if the hostname is defined to be the short, unqualified
name instead of the FQ name.  In that case it will have an incorrect
idea of its hostname and will bounce mail with a configuration error
when the nameserver does come up.

FIX:
If you use the FQ name in your sethostname() call you don't have to
worry about it.  But, it can be fixed anyway in daemon.c by causing
sendmail to loop waiting for its nameserver to come up.

myhostname(hostbuf, size)
	char hostbuf[];
	int size;
{
	extern struct hostent *gethostbyname();
	struct hostent *hp;

	if (gethostname(hostbuf, size) < 0)
	{
		(void) strcpy(hostbuf, "localhost");
	}
#ifdef KEEPTRYING
	/*
	 * If the gethostbyname() call to the nameserver fails we should
	 * keep trying it instead of plowing ahead with the wrong
	 * information.  Hubert, Nov 89.
	 */
	while ((hp = gethostbyname(hostbuf)) == NULL) {
		setproctitle("gethostbyname(%s) unsuccessful, trying again", hostbuf);
		sleep(30);
	}
#else /* KEEPTRYING */
	hp = gethostbyname(hostbuf);
#endif /* KEEPTRYING */
	if (hp != NULL)
	{
		(void) strcpy(hostbuf, hp->h_name);
		return (hp->h_aliases);
	}
	else
		return (NULL);
}