[Qemu-devel] IPv6 support for -net user?

[Qemu-devel] IPv6 support for -net user?

[Ivan Shmakov]

	I'm writing an iPXE mini-HOWTO (in Russian), using QEMU and
	-net user in examples (so that they're runnable by unprivileged
	users.)

	However, the QEMU documentation [1] seems to suggest that only
	IPv4 is implemented for -net user, which made me curious on
	whether the IPv6 support is planned to be added anytime soon?

	Personally, I'm interested mostly in QEMU sending router
	(prefix) advertisements to the “guest”, and forwarding TCP and
	UDP traffic, although support for recursive DNS discovery and
	DHCPv6 may also be nice to have.

	TIA.

PS.  I hope to announce the mini-HOWTO itself later this week, in both
	the iPXE [2] and planning-ru@ [3] mailing lists.

[1] http://qemu.weilnetz.de/qemu-doc.html
[2] http://dir.gmane.org/gmane.network.ipxe.devel/
[3] http://dir.gmane.org/gmane.user-groups.foss.sfd.planning.ru/

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Re: [Qemu-devel] IPv6 support for -net user?

[Stefan Hajnoczi]

On Wed, Aug 29, 2012 at 04:43:18PM +0700, Ivan Shmakov wrote:
> 	I'm writing an iPXE mini-HOWTO (in Russian), using QEMU and
> 	-net user in examples (so that they're runnable by unprivileged
> 	users.)
> 
> 	However, the QEMU documentation [1] seems to suggest that only
> 	IPv4 is implemented for -net user, which made me curious on
> 	whether the IPv6 support is planned to be added anytime soon?
> 
> 	Personally, I'm interested mostly in QEMU sending router
> 	(prefix) advertisements to the “guest”, and forwarding TCP and
> 	UDP traffic, although support for recursive DNS discovery and
> 	DHCPv6 may also be nice to have.

Jan Kiszka is the -net user maintainer, I have CCed him.

I'm not aware of work to add IPv6 support to slirp.  Someone would have
to step up and submit patches :).

You can still do unprivileged IPv6 networking with external DHCPv6, etc
software:

  $ qemu -netdev socket,id=socket0,listen=127.0.0.1:1234 \
         -device virtio-net-pci,netdev=socket0

The socket netdev tunnels traffic over a TCP or UDP socket.  For TCP it
prefixes each packet with the big-endian uint32_t length.  For UDP no
length header is necessary because packet boundaries are preserved.

You could write your own code or find something that can speak with
QEMU's -netdev socket.

Stefan

Re: [Qemu-devel] IPv6 support for -net user?

[Jan Kiszka]

On 2012-08-30 09:23, Stefan Hajnoczi wrote:
> On Wed, Aug 29, 2012 at 04:43:18PM +0700, Ivan Shmakov wrote:
>> 	I'm writing an iPXE mini-HOWTO (in Russian), using QEMU and
>> 	-net user in examples (so that they're runnable by unprivileged
>> 	users.)
>>
>> 	However, the QEMU documentation [1] seems to suggest that only
>> 	IPv4 is implemented for -net user, which made me curious on
>> 	whether the IPv6 support is planned to be added anytime soon?
>>
>> 	Personally, I'm interested mostly in QEMU sending router
>> 	(prefix) advertisements to the “guest”, and forwarding TCP and
>> 	UDP traffic, although support for recursive DNS discovery and
>> 	DHCPv6 may also be nice to have.
> 
> Jan Kiszka is the -net user maintainer, I have CCed him.
> 
> I'm not aware of work to add IPv6 support to slirp.  Someone would have
> to step up and submit patches :).

Yep, I'm also not aware of plans or even activities in this direction.
Some refactoring will likely be required to make the IPv4-oriented stack
ready for this.

Jan

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