docs/132260: dhcpd(8) pid not stored in documented location

[Josh Paetzel]

The following reply was made to PR docs/132260; it has been noted by GNATS.

From: Josh Paetzel <jpaetzel at FreeBSD.org>
To: Daniel Feenberg <feenberg at nber.org>
Cc: bug-followup at FreeBSD.org,
 Giorgos Keramidas <keramida at FreeBSD.org>
Subject: Re: docs/132260: dhcpd(8) pid not stored in documented location
Date: Thu, 22 Oct 2009 14:33:42 -0500

 On Oct 22, 2009, at 1:43 PM, Daniel Feenberg wrote:
 
 >
 >
 > On Thu, 22 Oct 2009, Josh Paetzel wrote:
 >
 >> The reason that it puts the pidfile in /var/run/dhcpd is that you  
 >> are running with either paranoia or chmodded as the dhcpd user.  In  
 >> either case it can't write to /var/run as it starts up as the dhcpd  
 >> user.
 >
 > If you say so.
 >
 >>
 >> If you look at the ownership of /var/run/dhcpd you'll see it is  
 >> owned by dhcpd:dhcpd
 >
 > Yes
 >
 >>
 >> If you run as root, or without paranoia it will in fact create the  
 >> pidfile in /var/run/
 >
 > I do run dhcpd as root and without paranoia, so I question this  
 > claim. If the daemon changes its uid for security purposes, I have  
 > no objection (although there is no mention of this on the man page)  
 > but why not fill in /var/run as documented before dropping  
 > priviledges?
 >
 
  >ls -lah /var/run/dhcpd.pid
 -rw-r--r--  1 root  wheel     6B Oct 22 12:18 /var/run/dhcpd.pid
 
 The FreeBSD version of ISC-DHCP is heavily patched.   The man page is  
 straight from ISC, so it doesn't cover a lot of things, for instance  
 the mangling that is done to run in a jail.  I haven't had a chance to  
 fully analyze the startup script (which is also FreeBSD specific of  
 course)  I suspect that the reason /var/run/dhcpd.pid isn't always  
 used is there is code being shared that concerns the chroot option.   
 It could be that the use case you are encountering is a bug, maybe it  
 should be writing to /var/run/dhcpd.pid and it isn't by mistake.
 
 
 >>
 >> I suppose we could patch the man pages depending on the compilation  
 >> options or something.
 >>
 >
 > No need for anything so elaborate. You could just add a fourth file  
 > path to the list of files used.
 >
 > Thanks for having a look. It isn't a big deal and I thought I was  
 > helping.
 >
 > Daniel Feenberg
 >
 >
 
 Getting the path correct depends on compile time options.  If you  
 select PARANOIA from the menu when you build this port (which is the  
 default) (or use the package) it will use /var/run/dhcpd/dhcpd.conf
 
 Could you provide me with the output of cat /var/db/ports/isc-dhcp30- 
 server/options please?  If you are using a package there won't be an  
 options file.  I'd also be interested in whatever settings you have  
 in /etc/rc.conf that are relevant to the dhcpd so I can try and  
 duplicate this locally.
 
 Clearly the documentation does not match actual behavior in some  
 instances.  I'd like to fix that, and I appreciate you pointing it out.
 
 Thanks,
 
 Josh Paetzel