Re: [libvirt] Socket files in virt-aa-helper

On 06/16/2015 08:40 AM, Michał Dubiel wrote: > Hi all, > > May I kindly ask someone for some advice on this topic? > > Regards, > Michal > > On 21 May 2015 at 20:23, Michał Dubiel <md(a)semihalf.com > <mailto:md@semihalf.com>> wrote: > > Hi guys, > > I have got a question. I need to add apparmor support for vhost-user socket > files used to communicate with the vhost-user server app. Those ones defined > with something like: > <interface type='vhostuser'> > <mac address='02:ed:f3:5d:de:f3'/> > <source type='unix' path='/var/run/vrouter/uvh_vif_tapa8396c51-2a' > mode='client'/> > <model type='virtio'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x03' > function='0x0'/> > </interface> > > I added something like this into get_files() function in virt-aa-helper.c: > for (i = 0; i < ctl->def->nnets; i++) { > if (ctl->def->nets[i] && > ctl->def->nets[i]->type == VIR_DOMAIN_NET_TYPE_VHOSTUSER && > ctl->def->nets[i]->data.vhostuser) { > virDomainChrSourceDefPtr vhu = ctl->def->nets[i]->data.vhostuser; > > if (vah_add_file_chardev(&buf, vhu->data.nix.path, "rw", > vhu->type) != 0) > goto cleanup; > } > } > > However, there is a restriction for the socket file types in valid_path() > function: > switch (sb.st_mode & S_IFMT) { > case S_IFSOCK: > return 1; > break; > default: > break; > } > That prevents this from working. > > May I ask why the socket file types are restricted? Vhost-user uses sockets > so if I want to use apparmor virt-aa-helper has to be able to add the line > for the socket file into /etc/apparmor.d/libvirt/libvirt-UUID.files. > They are restricted only because at the time virt-aa-helper.c was written there wasn't a valid use for them. There were more checks in this part of the code but over the years as more valid types were added to libvirt, they've been removed and now we are left with just this one. Since there is now a valid usecase for S_IFSOCK, it seems this can simply be removed.