Re: [Libvir] State of driver backend infrastructure

On Mon, Jun 12, 2006 at 06:52:57PM -0400, Daniel Veillard wrote: I'm attaching an initial patch which implements the driver backend calls for these five methods. I've tested that suspend & resume work, but my hardware died before I fully tested the other methods. I've got a couple questions before proceeding in any case: 1. In all of these methods I followed example from virDomainSetMemory and put in if (domain->conn->flags & VIR_CONNECT_RO) return (-1); This prevents these methods working with a 'read only' connection, however, this is a deviation from previous semantics. Even with a read only connection, XenD will let arbitrary unprivileged user shutdown/suspend/resume/etc a domain, so by putting this VIR_CONNECT_RO check in we'd be preventing an operation which used to work. However, IMHO this is a good thing, because it can be considered a *HUGE* security hole / denial of service attack, that unprivileged users can shutdown reboot, suspend, etc domains via XenD with no authentication. When this hole is eventually plugged, these methods would cease to work with a read only connection, so long term we'd end up in the same situation. Thus this patch could be considered a 'pre-emptive' solution. 2. The current implementation of shutdown & reboot methods calls the same code twice in a succession: /* * try first with the xend daemon */ ret = xenDaemonDomainShutdown(domain); if (ret == 0) { domain->flags |= DOMAIN_IS_SHUTDOWN; return (0); } /* * this is very hackish, the domU kernel probes for a special * node in the xenstore and launch the shutdown command if found. */ ret = xenDaemonDomainShutdown(domain); if (ret == 0) { domain->flags |= DOMAIN_IS_SHUTDOWN; } What was the reason to call xenDaemonDomainShutdown twice ? With my change to use the driver backends, it will only be called once. So I want to make sure I'm not missing an edge case here. Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|