Bug 196429

Summary:	DHCPv6 server in rawhide returns malformed replies
Product:	[Fedora] Fedora	Reporter:	Tomas Mraz <tmraz>
Component:	dhcpv6	Assignee:	Dave Cantrell <dcantrell>
Status:	CLOSED RAWHIDE	QA Contact:
Severity:	high	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	pvrabec
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2006-11-22 17:40:52 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	150223

Description Tomas Mraz 2006-06-23 08:43:03 UTC

Server from dhcpv6-0.10-26 returns malformed replies to dhcpv6 client. The
client version is dhcpv6_client-0.10-16.1. When the server is downgraded to the
same version as client, it works fine.

The syslog on client machine contains:

Jun 23 09:56:48 ipv6srot dhcp6c[6736]:   malformed IA option: type 16384, len 33
28
Jun 23 09:56:48 ipv6srot dhcp6c[6736]: failed to parse options
Jun 23 09:56:48 ipv6srot dhcp6c[6736]: unexpected reply

Comment 1 Jason Vas Dias 2006-07-19 06:58:00 UTC

This is now fixed with dhcpv6-0.10-30 in rawhide / FC-6 .

The problem was that previous to dhcpv6-0.10-24? the only way to set the
client address prefix was by router advertisement; after adding the new
address, dhcpv6 expected the route dst_len to be set automatically by
router advertisement in the kernel ; this did not happen, (unless a radvd
was running on the network) so effectively, no client address prefixes could 
be set without radvd.

Then, with -24, I made the server explicitly send the prefix length configured
in the server configuration file to the client; but this broke the packet
parse for earlier clients.

Now, clients must send a new 'DH6OPT_REQUEST_PREFIX' nil-valued option (28),
which will cause the server to send the extra prefix length byte,  if
the 'address{ .. prefix ...}' option or 'range ::x ::x/NN' statements 
specify a non-zero prefix.

This can be disabled in dhcp6c.conf and dhcp6s.conf by use of the 
new 'use_ra_prefix' option, which specifies the default upstream
behaviour of relying on radvd for the address prefixes.