Re: [libvirt] [PATCH v2 3/5] Add two new security label types

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; Curently security labels can be of type 'dynamic' or 'static'.

If no security label is given, then 'dynamic' is assumed. The current code takes advantage of this default, and avoids even saving <seclabel> elements with type='dynamic' to disk. This means if you temporarily change security driver, the guests can all still start. With the introduction of sVirt to LXC though, there needs to be a new default of 'none' to allow unconfined LXC containers. This patch introduces two new security label types - default: the host configuration decides whether to run the guest with type 'none' or 'dynamic' at guest start - none: the guest will run unconfined by security policy The 'none' label type will obviously be undesirable for some deployments, so a new qemu.conf option allows a host admin to mandate confined guests. It is also possible to turn off default confinement security_default_confined = 1|0 (default == 1) security_require_confined = 1|0 (default == 0) * src/conf/domain_conf.c, src/conf/domain_conf.h: Add new seclabel types * src/security/security_manager.c, src/security/security_manager.h: Set default sec label types * src/security/security_selinux.c: Handle 'none' seclabel type * src/qemu/qemu.conf, src/qemu/qemu_conf.c, src/qemu/qemu_conf.h, src/qemu/libvirtd_qemu.aug: New security config options * src/qemu/qemu_driver.c: Tell security driver about default config --- docs/formatdomain.html.in | 24 +++++++++---- docs/schemas/domaincommon.rng | 5 +++ po/POTFILES.in | 1 + src/conf/domain_conf.c | 70 ++++++++++++++++++++++++-------------- src/conf/domain_conf.h | 2 + src/qemu/libvirtd_qemu.aug | 2 + src/qemu/qemu.conf | 8 ++++ src/qemu/qemu_conf.c | 11 ++++++ src/qemu/qemu_conf.h | 2 + src/qemu/qemu_driver.c | 7 +++- src/security/security_manager.c | 51 +++++++++++++++++++++++++--- src/security/security_manager.h | 8 ++++- src/security/security_selinux.c | 32 ++++++++++++++---- tests/seclabeltest.c | 2 +- 14 files changed, 177 insertions(+), 48 deletions(-)

@@ -3484,10 +3484,11 @@ qemu-kvm -net nic,model=? /dev/null <p> The <code>seclabel</code> element allows control over the - operation of the security drivers. There are two basic - modes of operation, dynamic where libvirt automatically - generates a unique security label, or static where the - application/administrator chooses the labels. With dynamic + operation of the security drivers. There are three basic + modes of operation, 'dynamic' where libvirt automatically + generates a unique security label, 'static' where the + application/administrator chooses the labels, or 'none' + where confinement is disabled. With dynamic label generation, libvirt will always automatically relabel any resources associated with the virtual machine. With static label assignment, by default, the administrator

@@ -3515,9 +3516,18 @@ qemu-kvm -net nic,model=? /dev/null &lt;seclabel type='static' model='selinux' relabel='yes'&gt; &lt;label&gt;system_u:system_r:svirt_t:s0:c392,c662&lt;/label&gt; &lt;/seclabel&gt; + + &lt;seclabel type='none'/&gt; </pre> <p> + If no 'type' attribute is provided in the input XML, then + the security driver default setting will be used, which + may be either 'none' or 'static'.

@@ -2591,12 +2602,15 @@ virSecurityLabelDefParseXML(virSecurityLabelDefPtr def, def->imagelabel = p; } - /* Only parse baselabel, for dynamic label */ - if (def->type == VIR_DOMAIN_SECLABEL_DYNAMIC) { + /* Only parse baselabel, for dynamic or none label types */ + if (def->type == VIR_DOMAIN_SECLABEL_DYNAMIC || + def->type == VIR_DOMAIN_SECLABEL_NONE) { p = virXPathStringLimit("string(./seclabel/baselabel[1])", VIR_SECURITY_LABEL_BUFLEN-1, ctxt); if (p != NULL) def->baselabel = p; + /* Forces none type to dynamic for back compat */ + def->type = VIR_DOMAIN_SECLABEL_DYNAMIC;