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>

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index c1e0ea736a0056d3c7f69d4b5f6bdfd4224ca535..ffdbe953d9f7016f6109e1dfc10d58ba0106bb9b 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -4370,6 +4370,17 @@ 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
      */
@@ -4408,11 +4419,6 @@ 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:
@@ -14177,7 +14183,9 @@ virDomainEventActionDefFormat(virBufferPtr buf,
 
 
 static void
-virSecurityLabelDefFormat(virBufferPtr buf, virSecurityLabelDefPtr def)
+virSecurityLabelDefFormat(virBufferPtr buf,
+                          virSecurityLabelDefPtr def,
+                          unsigned flags)
 {
     const char *sectype = virDomainSeclabelTypeToString(def->type);
 
@@ -14196,7 +14204,9 @@ 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) {
@@ -17107,7 +17117,7 @@ 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 0629e310efc9124926886b52ce51957f620ae2a0..7ff74aa6a66fb8fc3a93c5ca4f04f2bd957ed8d6 100644 (file)
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -963,6 +963,7 @@ 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 ffff3b556903d8f9dbf9fda26e084e45aec9d14f..ceaaf6a591dde3332ddb9378bc46478e7e06a2a4 100644 (file)
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -263,6 +263,7 @@ 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");