[v1] Apparmor support for less common devices

[libvirt] [PATCH 3/4] virt-aa-helper: generate rules for passthrough input devices

Posted by Christian Ehrhardt 7 years, 10 months ago

Input devices can passthrough an event device. This currently works only via
hotplug where the AppArmor label is created via the domain label callbacks.

This adds the virt-aa-helper support for passthrough input devices to generate
rules for the needed paths from the initial guest definition as well.

Example in domain xml:
  <input type='passthrough' bus='virtio'>
          <source evdev='/dev/input/event0' />
  </input>
Works to start now and creates:
  "/dev/input/event0" rw,

Fixes: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1757085

Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
---
 src/security/virt-aa-helper.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c
index 456cfce..1fc482d 100644
--- a/src/security/virt-aa-helper.c
+++ b/src/security/virt-aa-helper.c
@@ -1157,6 +1157,13 @@ get_files(vahControl * ctl)
         }
     }
 
+    for (i = 0; i < ctl->def->ninputs; i++) {
+        if (ctl->def->inputs[i]->type == VIR_DOMAIN_INPUT_TYPE_PASSTHROUGH) {
+            if (vah_add_file(&buf, ctl->def->inputs[i]->source.evdev, "rw") != 0)
+                goto cleanup;
+        }
+    }
+
     for (i = 0; i < ctl->def->nnets; i++) {
         if (ctl->def->nets[i] &&
                 ctl->def->nets[i]->type == VIR_DOMAIN_NET_TYPE_VHOSTUSER &&
-- 
2.7.4

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Re: [libvirt] [PATCH 3/4] virt-aa-helper: generate rules for passthrough input devices

Posted by Jamie Strandboge 7 years, 10 months ago

On Tue, 2018-03-20 at 13:08 +0100, Christian Ehrhardt wrote:
> Input devices can passthrough an event device. This currently works
> only via
> hotplug where the AppArmor label is created via the domain label
> callbacks.
> 
> This adds the virt-aa-helper support for passthrough input devices to
> generate
> rules for the needed paths from the initial guest definition as well.
> 
> Example in domain xml:
>   <input type='passthrough' bus='virtio'>
>           <source evdev='/dev/input/event0' />
>   </input>
> Works to start now and creates:
>   "/dev/input/event0" rw,
> 
> Fixes: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1757085
> 
> Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> ---
>  src/security/virt-aa-helper.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-
> helper.c
> index 456cfce..1fc482d 100644
> --- a/src/security/virt-aa-helper.c
> +++ b/src/security/virt-aa-helper.c
> @@ -1157,6 +1157,13 @@ get_files(vahControl * ctl)
>          }
>      }
>  
> +    for (i = 0; i < ctl->def->ninputs; i++) {
> +        if (ctl->def->inputs[i]->type ==
> VIR_DOMAIN_INPUT_TYPE_PASSTHROUGH) {

'if (ctl->def->inputs[i] && ctl->def->inputs[i]->type ==
VIR_DOMAIN_INPUT_TYPE_PASSTHROUGH)', no?

> +            if (vah_add_file(&buf, ctl->def->inputs[i]-
> >source.evdev, "rw") != 0)
> +                goto cleanup;
> +        }
> +    }
> +
>      for (i = 0; i < ctl->def->nnets; i++) {
>          if (ctl->def->nets[i] &&
>                  ctl->def->nets[i]->type ==
> VIR_DOMAIN_NET_TYPE_VHOSTUSER &&

Adding test cases for this would be good.

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Re: [libvirt] [PATCH 3/4] virt-aa-helper: generate rules for passthrough input devices

Posted by Christian Ehrhardt 7 years, 10 months ago

On Tue, Mar 20, 2018 at 10:00 PM, Jamie Strandboge <jamie@canonical.com>
wrote:

> On Tue, 2018-03-20 at 13:08 +0100, Christian Ehrhardt wrote:
> > Input devices can passthrough an event device. This currently works
> > only via
> > hotplug where the AppArmor label is created via the domain label
> > callbacks.
> >
> > This adds the virt-aa-helper support for passthrough input devices to
> > generate
> > rules for the needed paths from the initial guest definition as well.
> >
> > Example in domain xml:
> >   <input type='passthrough' bus='virtio'>
> >           <source evdev='/dev/input/event0' />
> >   </input>
> > Works to start now and creates:
> >   "/dev/input/event0" rw,
> >
> > Fixes: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1757085
> >
> > Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> > ---
> >  src/security/virt-aa-helper.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-
> > helper.c
> > index 456cfce..1fc482d 100644
> > --- a/src/security/virt-aa-helper.c
> > +++ b/src/security/virt-aa-helper.c
> > @@ -1157,6 +1157,13 @@ get_files(vahControl * ctl)
> >          }
> >      }
> >
> > +    for (i = 0; i < ctl->def->ninputs; i++) {
> > +        if (ctl->def->inputs[i]->type ==
> > VIR_DOMAIN_INPUT_TYPE_PASSTHROUGH) {
>
> 'if (ctl->def->inputs[i] && ctl->def->inputs[i]->type ==
> VIR_DOMAIN_INPUT_TYPE_PASSTHROUGH)', no?
>

Yes, checking the pointer to be valid is certainly better
Will be in a V2 of the series.


> > +            if (vah_add_file(&buf, ctl->def->inputs[i]-
> > >source.evdev, "rw") != 0)
> > +                goto cleanup;
> > +        }
> > +    }
> > +
> >      for (i = 0; i < ctl->def->nnets; i++) {
> >          if (ctl->def->nets[i] &&
> >                  ctl->def->nets[i]->type ==
> > VIR_DOMAIN_NET_TYPE_VHOSTUSER &&
>
> Adding test cases for this would be good.
>

Yes, I agree - will be in a V2


> --
> Jamie Strandboge             | http://www.canonical.com




-- 
Christian Ehrhardt
Software Engineer, Ubuntu Server
Canonical Ltd
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