improve vboxwrapper network setup

[computezrmle]

VirtualBox manual suggests virtio network driver to be the best choice for (recent) Linux guests.
Nonetheless, when a Linux VM is created without a driver is explicitly set, it configures an Intel Pro emulation, most likely for maximum compatibility.

Further information can be found here:
https://www.virtualbox.org/manual/topics/networkingdetails.html

This PR sets virtio as default driver if a Linux guest can be assumed.
Otherwise it keeps the default Intel Pro.

In addition it allows to manually overrride the selection using <vm_network_driver>custom_name</vm_network_driver> in vbox_job.xml.

Also added to vbox_job.xml:
An option enable_nat_dns_host_resolver which specifies whether the VirtualBox NAT engine uses the host system's resolver mechanisms to handle DNS requests.

[Copilot]

Copilot wasn't able to review any files in this pull request.

Files not reviewed (3)

• samples/vboxwrapper/vbox_vboxmanage.cpp: Language not supported
• samples/vboxwrapper/vboxjob.cpp: Language not supported
• samples/vboxwrapper/vboxjob.h: Language not supported

[computezrmle]

I already tested the modifications on Linux with CMS Tasks from LHC@home.

@Crystal-Pellet
Please test on Windows using the PR related vboxwrapper artifact.

@NenTech
Please test on MacOS using the PR related vboxwrapper artifact.

[AenBleidd]

I'll review the code in a couple of hours and merge if it's good.
Thank you for the fix.

[NenTech]

This PR is working on MacOS. This changes are not fixing the weird DNS issue I have.

[Crystal-Pellet]

This PR is working on Windows.
My remarks regarding VirtualBox default location for the log- and xml-files (PR6018) still matters.
The new BOINC VirtualBox location on the same level as projects now, conflicts with Oracle VirtualBox default location c:/users/user.
There are possiblilities that Boinc's VMs are not seen by VirtualBox Manager.
BOINC's user can avoid this by setting the default location for VirtualBox files to the BOINC datadirectory in my situation to D:\Boinc1\projects\VirtualBox

[davidpanderson]

The comments in #6018 say that it works.
If not, please create a new issue.

[NenTech]

This PR is working on Windows.

My remarks regarding VirtualBox default location for the log- and xml-files (PR6018) still matters.

The new BOINC VirtualBox location on the same level as projects now, conflicts with Oracle VirtualBox default location c:/users/user.

There are possiblilities that Boinc's VMs are not seen by VirtualBox Manager.

BOINC's user can avoid this by setting the default location for VirtualBox files to the BOINC datadirectory in my situation to D:\Boinc1\projects\VirtualBox

@Crystal-Pellet

On Mac, the BOINC VM's are never shown in the VBox manager. If this causes crashes for you, there should be a difference in handling different processes on Windows. On Mac a seperate proces is created for every VM instance and the home location is linked to the instance.
Did you test it with a pull from the main branch? If yes, can you supply me the VBoxManager for Windows? Then I can compare between my Windows and Mac.