[libvirt] [PATCH] 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> --- src/conf/domain_conf.c | 26 +++++++++++++------- .../qemuxml2argv-seclabel-dynamic-relabel.args | 6 +++++ .../qemuxml2argv-seclabel-dynamic-relabel.xml | 28 ++++++++++++++++++++++ tests/qemuxml2argvtest.c | 1 + tests/qemuxml2xmltest.c | 1 + 5 files changed, 54 insertions(+), 8 deletions(-) create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.args create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.xml diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index c1e0ea7..ffdbe95 100644 --- 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 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 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 0629e31..7ff74aa 100644 --- 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 ffff3b5..ceaaf6a 100644 --- 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"); -- 1.8.3.2
On Mon, Nov 11, 2013 at 10:49:44AM +0100, Michal Privoznik wrote:
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.
I'm not sure I understand your explanation here, but this label: <seclabel type='dynamic' relabel='yes'/> is not model='none'. This is intended to be associated with whatever model is currently activated. So it may be model=none or model=selinux or model=apparmour - none of this should matter for the parser though. When the guest is actually started an explicit model='XXXX' should be added to the XML - eg the live state XML should always have a model set. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On 11.11.2013 11:51, Daniel P. Berrange wrote:
On Mon, Nov 11, 2013 at 10:49:44AM +0100, Michal Privoznik wrote:
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.
I'm not sure I understand your explanation here, but this label:
<seclabel type='dynamic' relabel='yes'/>
is not model='none'. This is intended to be associated with whatever model is currently activated. So it may be model=none or model=selinux or model=apparmour - none of this should matter for the parser though. When the guest is actually started an explicit model='XXXX' should be added to the XML - eg the live state XML should always have a model set.
Daniel
That's what I'm doing in chunks 3-5. But since model='none' doesn't contain any labels, I'm doing some adjustments to reflect this fact in chunks 1-2. Michal
On Mon, Nov 11, 2013 at 10:49:44AM +0100, Michal Privoznik wrote:
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> --- src/conf/domain_conf.c | 26 +++++++++++++------- .../qemuxml2argv-seclabel-dynamic-relabel.args | 6 +++++ .../qemuxml2argv-seclabel-dynamic-relabel.xml | 28 ++++++++++++++++++++++ tests/qemuxml2argvtest.c | 1 + tests/qemuxml2xmltest.c | 1 + 5 files changed, 54 insertions(+), 8 deletions(-) create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.args create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.xml
ACK Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On 11.11.2013 14:21, Daniel P. Berrange wrote:
On Mon, Nov 11, 2013 at 10:49:44AM +0100, Michal Privoznik wrote:
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> --- src/conf/domain_conf.c | 26 +++++++++++++------- .../qemuxml2argv-seclabel-dynamic-relabel.args | 6 +++++ .../qemuxml2argv-seclabel-dynamic-relabel.xml | 28 ++++++++++++++++++++++ tests/qemuxml2argvtest.c | 1 + tests/qemuxml2xmltest.c | 1 + 5 files changed, 54 insertions(+), 8 deletions(-) create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.args create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-seclabel-dynamic-relabel.xml
ACK
Daniel
Thanks, pushed. BTW: this deserved to be backported to maint branches. While trying to bisect this (I recalled some work in this area which I suspected to cause regression) I couldn't find a single release that would just work. Michal
participants (2)
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Daniel P. Berrange -
Michal Privoznik