On Tue, Oct 20, 2015 at 06:01:37PM +0100, Peter Maydell wrote:
> On 20 October 2015 at 14:39, Daniel P. Berrange <berra...@redhat.com> wrote:
> > On Mon, Oct 19, 2015 at 04:20:09PM -0600, Eric Blake wrote:
> >> On 10/12/2015 05:14 AM, Daniel P. Berrange wrote:
> >> > The VNC code is currently using QemuOpts to configure the
> >> > sockets connections / listeners it needs. Convert it to
> >> > use SocketAddress to bring it in line with modern QAPI
> >> > based code elsewhere in QEMU.
>
> >>
> >> > + if (to) {
> >> > + saddr->inet->has_to = true;
> >> > + saddr->inet->to = to;
> >> > + }
> >> > + saddr->inet->ipv4 = saddr->inet->has_ipv4 = has_ipv4;
> >> > + saddr->inet->ipv6 = saddr->inet->has_ipv6 = has_ipv6;
> >>
> >> Do we want to specify has_ipvX as true even when setting inet->ipvX to
> >> false?
> >
> > This saddr instance is passed into 'socket_connect' which then
> > converts it back into a QemuOpts object using
> >
> > bool ipv4 = addr->has_ipv4 && addr->ipv4;
> >
> > So, we don't need to set has_ipvX to true, when ipvX is false.
>
> That is not the *only* thing that inet_addr_to_opts does with
> the has_* flags... this kind of thing can be the difference
> between "force ipv4" and "use ipv4 or ipv6".
The original code which used QemuOpts directly had this logic:
inet_listen_opts / inet_connect_opts use this logic:
ai.ai_family = PF_UNSPEC;
....
if (qemu_opt_get_bool(opts, "ipv4", 0))
ai.ai_family = PF_INET;
if (qemu_opt_get_bool(opts, "ipv6", 0))
ai.ai_family = PF_INET6;
IOW, these methods treat ipv4 being omitted, as equivalent to ipv4=off.
Thus the existing VNC -> qemu-sockets code has this logic:
VNC | qemu-sockets
QemuOpts | ai_family
----------------------------
ipv4 ipv6 |
----------------------------
- - | PF_UNSPEC
- off | PF_UNSPEC
- on | PF_INET6
off - | PF_UNSPEC
off off | PF_UNSPEC
off on | PF_INET6
on - | PF_INET
on off | PF_INET
on on | PF_INET6
My patch, which also does not distinguish ipv4=off from ipv4 omitted
has the following logic, at various stages of conversion between
QemuOpts & QAPI SocketAddress:
VNC | VNC | qemu-sockets | qemu-sockets
QemuOpts | QAPI SocketAddress | QemuOpts | ai_family
-------------------------------------------------------------------------
ipv4 ipv6 | has_ipv4 ipv4 has_ipv6 ipv6 | ipv4 ipv6 |
-------------------------------------------------------------------------
- - | f f f f | - - | PF_UNSPEC
- off | f f f f | - - | PF_UNSPEC
- on | f f t t | off on | PF_INET6
off - | f f f f | - - | PF_UNSPEC
off off | f f f f | - - | PF_UNSPEC
off on | f f t t | off on | PF_INET6
on - | t t f f | on off | PF_INET
on off | t t f f | on off | PF_INET
on on | t t t t | on on | PF_INET6
So, unless I've missed something, the final ai_family is set the same
way before & after my patch, for all combinations of VNC ipv4/ipv6
CLI options.
Regards,
Daniel
--
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