netdev - Re: IPv6 unique local address flushes on up/down

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 25 Mar 2008 18:11:38 +0300
From:	"Denis V. Lunev" <den@...allels.com>
To:	Chr <chunkeey@....de>
Cc:	hostap@...ts.shmoo.com, netdev@...r.kernel.org
Subject: Re: IPv6 unique local address flushes on up/down

On Tue, 2008-03-25 at 15:57 +0100, Chr wrote:
> Hi,
> 
> I have a problem with hostapd & IPv6... 
> 
> as you might know, or not... hostapd needs to initialize 
> the interface (e.g it changes it to master/accesspoint mode,
> which can only be done if the interface is down)... 
> 
> However if the interface is brought down & up again (e.g whenever
> hostap starts or restarts)... the IPv6 logic flushes the unique-local ipv6 
> address that I gave it (by hand) with ip addr add fddb:xyz...::1//64 dev ath0 
> in /etc/network/interfaces ifup script (-probably debian specific-).
> 
> And that's bad, because bind9,ISC dhcp-server v4.1 and racoon(IPsec/VPN)
> needs a static address for their records/lease database and configuration...
> 
> This wasn't problem with the old IPv4... because there the 
> 10.x.y.z or 192.168.a.b addresses aren't deleted when the interface 
> was _reinitialized_ by the hostap...
> 
> Now my question, which _one_ should we fix the applications or the stack?!
> I think the network stack, but I don't know if there are RFC about this 
> issue... or is there already some flag/setting which I've missed so far?  

On interface down IPv6 stack unconditionally deletes all addresses from
the interface in the addrconf_ifdown routine.

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html