Subject: Re: setbuf() in hostalias()
To: None <>
From: Paul A Vixie <>
List: tech-net
Date: 04/25/2000 21:30:23
this setbuf() is only needed on systems where setuid-root binaries
are willing to dump core when run by non-root euid's.  otherwise,
the stdio buffer could have data from normally-unreadable files.

(sendmail on sunos was the proximate cause of this pain, with a
"setenv HOSTALIAS /etc/shadow" as the disease vector.)

> 	There's
> 		setbuf(fp, NULL)
> 	in hostalias() (lib/libc/net/res_query.c).  I wonder why it is
> 	here, and why it is #if 0'ed in NetBSD (1.21 -> 1.22).
> 	Are there any reason for putting it in hostalias(), and is it safe
> 	to remove it?
> 	By doing some checking, current situation is like this.
> 		BSDI4 has it, and it is the origin of setbuf(fp, NULL)
> 		FreeBSD and OpenBSD has it enabled
> 		NetBSD #if 0'ed it
> 		(BSDI switched to BIND8 resolver already so I can't compare)