virSecurityLabelDefParseXML: Don't parse label on model='none'

https://bugzilla.redhat.com/show_bug.cgi?id=1027096

If there's the following snippet in the domain XML, the domain will be
lost upon the daemon restart (if the domain is started prior restart):

    <seclabel type='dynamic' relabel='yes'/>

The problem is, the 'label', 'imagelabel' and 'baselabel' are parsed
whenever the VIR_DOMAIN_XML_INACTIVE is *not* present or the label is
static. The latter is not our case, obviously. So, when libvirtd starts
up, it finds domain state xml and parse it. During parsing, many XML
flags are enabled but VIR_DOMAIN_XML_INACTIVE. Hence, our parser tries
to extract 'label', 'imagelabel' and 'baselabel' from the XML which
fails for model='none'. Err, this model - even though not specified in
XML - can be taken from qemu wide config file: /etc/libvirtd/qemu.conf.

However, in order to know we are dealing with model='none' the code in
question must be moved forward a bit. Then a new check must be
introduced. This is what the first two chunks are doing.

But this alone is not sufficient. The domain state XML won't contain the
model attribute without slight modification. The model should be
inserted into the XML even if equal to 'none' and the state XML is being
generated - what if the origin (the @security_driver variable in
qemu.conf) changes during libvirtd restarts?

At the end, a test to catch this scenario is introduced.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
(cherry picked from commit 9fb3f9571db4bd20b8287a160e9b2680f23dde45)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 53889e0e04a7b7c893e20542e3d7713506b9703c..184049567f40a63e42e0d602eebd22dc9a3dd7f8 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -4363,6 +4363,17 @@ virSecurityLabelDefParseXML(xmlXPathContextPtr ctxt,
             def->norelabel = false;
     }
 
+    /* Always parse model */
+    p = virXPathStringLimit("string(./@model)",
+                            VIR_SECURITY_MODEL_BUFLEN-1, ctxt);
+    def->model = p;
+
+    /* For the model 'none' none of the following labels is going to be
+     * present. Hence, return now. */
+
+    if (STREQ_NULLABLE(def->model, "none"))
+        return def;
+
     /* Only parse label, if using static labels, or
      * if the 'live' VM XML is requested
      */
@@ -4401,11 +4412,6 @@ virSecurityLabelDefParseXML(xmlXPathContextPtr ctxt,
         def->baselabel = p;
     }
 
-    /* Always parse model */
-    p = virXPathStringLimit("string(./@model)",
-                            VIR_SECURITY_MODEL_BUFLEN-1, ctxt);
-    def->model = p;
-
     return def;
 
 error:
@@ -14109,7 +14115,9 @@ virDomainEventActionDefFormat(virBufferPtr buf,
 
 
 static void
-virSecurityLabelDefFormat(virBufferPtr buf, virSecurityLabelDefPtr def)
+virSecurityLabelDefFormat(virBufferPtr buf,
+                          virSecurityLabelDefPtr def,
+                          unsigned flags)
 {
     const char *sectype = virDomainSeclabelTypeToString(def->type);
 
@@ -14128,7 +14136,9 @@ virSecurityLabelDefFormat(virBufferPtr buf, virSecurityLabelDefPtr def)
     virBufferAsprintf(buf, "<seclabel type='%s'",
                       sectype);
 
-    if (def->model && STRNEQ(def->model, "none"))
+    /* When generating state XML do include the model */
+    if (flags & VIR_DOMAIN_XML_INTERNAL_STATUS ||
+        STRNEQ_NULLABLE(def->model, "none"))
         virBufferEscapeString(buf, " model='%s'", def->model);
 
     if (def->type == VIR_DOMAIN_SECLABEL_NONE) {
@@ -16981,7 +16991,7 @@ virDomainDefFormatInternal(virDomainDefPtr def,
 
     virBufferAdjustIndent(buf, 2);
     for (n = 0; n < def->nseclabels; n++)
-        virSecurityLabelDefFormat(buf, def->seclabels[n]);
+        virSecurityLabelDefFormat(buf, def->seclabels[n], flags);
     virBufferAdjustIndent(buf, -2);
 
     if (def->namespaceData && def->ns.format) {

diff --git a/tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.args b/tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.args
new file mode 100644 (file)
index 0000000..8bef546
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.args
@@ -0,0 +1,6 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
+/usr/bin/qemu \
+-name QEMUGuest1 -S -M pc -m 214 -smp 1 -nographic -monitor \
+unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -usb \
+-hda /dev/HostVG/QEMUGuest1 -net none -serial \
+none -parallel none

diff --git a/tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.xml b/tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.xml
new file mode 100644 (file)
index 0000000..cb74239
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.xml
@@ -0,0 +1,28 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static' cpuset='1-4,8-20,525'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <memballoon model='virtio'/>
+  </devices>
+  <seclabel type='dynamic' relabel='yes'/>
+</domain>

diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 38319e5a70c9591a690837bbc7c1d9096cc2d24d..d23f54553ab63ee58abe1efaa22cc26c27dda4b7 100644 (file)
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -940,6 +940,7 @@ mymain(void)
     DO_TEST("seclabel-dynamic-baselabel", QEMU_CAPS_NAME);
     DO_TEST("seclabel-dynamic-override", QEMU_CAPS_NAME);
     DO_TEST("seclabel-dynamic-labelskip", QEMU_CAPS_NAME);
+    DO_TEST("seclabel-dynamic-relabel", QEMU_CAPS_NAME);
     DO_TEST("seclabel-static", QEMU_CAPS_NAME);
     DO_TEST("seclabel-static-relabel", QEMU_CAPS_NAME);
     DO_TEST("seclabel-static-labelskip", QEMU_CAPS_NAME);

diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index c6615739b47011c81f35f122bb66535a5ba2c5f9..6a32cc563744c66898c61d3208a9f4530d6f4e74 100644 (file)
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -258,6 +258,7 @@ mymain(void)
     DO_TEST_FULL("seclabel-dynamic-baselabel", false, WHEN_INACTIVE);
     DO_TEST_FULL("seclabel-dynamic-override", false, WHEN_INACTIVE);
     DO_TEST_FULL("seclabel-dynamic-labelskip", true, WHEN_INACTIVE);
+    DO_TEST_FULL("seclabel-dynamic-relabel", false, WHEN_INACTIVE);
     DO_TEST("seclabel-static");
     DO_TEST_FULL("seclabel-static-labelskip", false, WHEN_ACTIVE);
     DO_TEST("seclabel-none");