[libvirt] Socket files in virt-aa-helper
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. Regards, Michal
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@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.
Regards, Michal
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@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. -- Jamie Strandboge http://www.ubuntu.com/
Thanks Jamie for the explanation. Regards, Michal On 16 June 2015 at 17:15, Jamie Strandboge <jamie@canonical.com> 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@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'
On 06/16/2015 08:40 AM, Michał Dubiel wrote: 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.
-- Jamie Strandboge http://www.ubuntu.com/
-- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Quoting Jamie Strandboge (jamie@canonical.com):
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@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.
So something like diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 35423b5..bb5e449 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -592,18 +592,8 @@ valid_path(const char *path, const bool readonly) if (!virFileExists(path)) { vah_warning(_("path does not exist, skipping file type checks")); - } else { - if (stat(path, &sb) == -1) - return -1; - - switch (sb.st_mode & S_IFMT) { - case S_IFSOCK: - return 1; - break; - default: - break; - } - } + } else if (stat(path, &sb) == -1) + return -1; opaths = sizeof(override)/sizeof(*(override)); should be ok?
Hi Serge, This is exactly what I had done locally when I solved the permission issues for my project, however removal of S_IFSOCK restriction is not enough to make vhost-user work correctly. You need also the changes to get_files() I wrote in the first e-mail about. I'll send a patch for review (in separate thread) that adds these changes. Regards, Michal On 18 June 2015 at 17:11, Serge Hallyn <serge.hallyn@ubuntu.com> wrote:
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@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'
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
Quoting Jamie Strandboge (jamie@canonical.com): path='/var/run/vrouter/uvh_vif_tapa8396c51-2a' 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.
So something like
diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 35423b5..bb5e449 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -592,18 +592,8 @@ valid_path(const char *path, const bool readonly)
if (!virFileExists(path)) { vah_warning(_("path does not exist, skipping file type checks")); - } else { - if (stat(path, &sb) == -1) - return -1; - - switch (sb.st_mode & S_IFMT) { - case S_IFSOCK: - return 1; - break; - default: - break; - } - } + } else if (stat(path, &sb) == -1) + return -1;
opaths = sizeof(override)/sizeof(*(override));
should be ok?
-- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
participants (3)
-
Jamie Strandboge -
Michał Dubiel -
Serge Hallyn