bin/51568: base dhcpd dmps core in a CARP setup

[Hauke Fath <hf%spg.tu-darmstadt.de@localhost>]

>Number:         51568
>Category:       bin
>Synopsis:       base dhcpd dmps core in a CARP setup
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Oct 21 15:20:00 +0000 2016
>Originator:     Hauke Fath
>Release:        NetBSD 7.0_STABLE
>Organization:
Technische Universitaet Darmstadt
>Environment:
	
	
System: NetBSD Zinnenwand 7.0_STABLE NetBSD 7.0_STABLE (FIFI-$Revision: 1.85 $) #1: Tue Oct 18 11:19:47 CEST 2016 hf@Hochstuhl:/var/obj/netbsd-builds/7/amd64/sys/arch/amd64/compile/FIFI amd64
Architecture: x86_64
Machine: amd64
>Description:

	On a pair of machines set up as redundant router with carp(4),
	the base dhcpd(8) [v4.3.0 on netbsd-7, configured for
	failover] frequently dumps core, probably in an attempt to
	sync leases, which according to the logs does not
	happen. Beyond a

Oct 19 13:22:01 Zinnenwand /netbsd: pid 467 (dhcpd), uid 0: exited on signal 6 (core dumped)

	there is nothing in the logs; 'gdb dhcpd dhcpd.core' shows an
	assertion failure.

	Unfortunately, make(1)ing binaries from the source tree is
	severely underdocumented compared to build.sh. I wanted to
	build dhcpd with -g3; went to build named's libisc, and punted
	when that wanted to build libthread, instead of using the
	installed library.

	A debug build of the pkgsrc net/isc-dhcpd turned out lots
	easier, as well as unnecessary: its v4.3.3 works just fine.

	
>How-To-Repeat:

	Set up a carp(4) based redundant router pair, run dhcpd(8) on
	it with failover configured. Watch the daemon dump core on
	both sides.

	
>Fix:

	Pull up -current dhcp 4.3.3 to (at least) netbsd-7, I guess.

	I can test this, if anybody can provide me with a reasonable
	way of building dhcpd from -current sources against a netbsd-7
	installation...
	

	

>Unformatted: