conf: add trustGuestRxFilters attribute to network and domain interface

This new attribute will control whether or not libvirt will pay
attention to guest notifications about changes to network device mac
addresses and receive filters. The default for this is 'no' (for
security reasons). If it is set to 'yes' *and* the specified device
model and connection support it (currently only macvtap+virtio) then
libvirt will watch for NIC_RX_FILTER_CHANGED events, and when it
receives one, it will issue a query-rx-filter command, retrieve the
result, and modify the host-side macvtap interface's mac address and
unicast/multicast filters accordingly.

The functionality behind this attribute will be in a later patch. This
patch merely adds the attribute to the top-level of a domain's
<interface> as well as to <network> and <portgroup>, and adds
documentation and schema/xml2xml tests. Rather than adding even more
test files, I've just added the net attribute in various applicable
places of existing test files.

docs/formatdomain.html.in

@@ -3343,10 +3343,9 @@
 <pre>
   ...
   &lt;devices&gt;
-    &lt;interface type='bridge'&gt;
+    &lt;interface type='direct' trustGuestRxFilters='yes'&gt;
-      &lt;source bridge='xenbr0'/&gt;
+      &lt;source dev='eth0'/&gt;
-      &lt;mac address='00:16:3e:5d:c7:9e'/&gt;
+      &lt;mac address='52:54:00:5d:c7:9e'/&gt;
-      &lt;script path='vif-bridge'/&gt;
       &lt;boot order='1'/&gt;
       &lt;rom bar='off'/&gt;
     &lt;/interface&gt;
@@ -3356,8 +3355,23 @@
     <p>
       There are several possibilities for specifying a network
       interface visible to the guest.  Each subsection below provides
-      more details about common setup options.  Additionally,
+      more details about common setup options.
-      each <code>&lt;interface&gt;</code> element has an
+    </p>
+    <p>
+      <span class="since">Since 1.2.10</span>),
+      the <code>interface</code> element
+      property <code>trustGuestRxFilters</code> provides the
+      capability for the host to detect and trust reports from the
+      guest regarding changes to the interface mac address and receive
+      filters by setting the attribute to <code>yes</code>. The default
+      setting for the attribute is <code>no</code> for security
+      reasons and support depends on the guest network device model as
+      well as the type of connection on the host - currently it is
+      only supported for the virtio ddevice model and for macvtap
+      connections on the host.
+    </p>
+    <p>
+      Each <code>&lt;interface&gt;</code> element has an
       optional <code>&lt;address&gt;</code> sub-element that can tie
       the interface to a particular pci slot, with
       attribute <code>type='pci'</code>
@@ -3589,6 +3603,18 @@
       being the default mode. The individual modes cause the delivery of
       packets to behave as follows:
     </p>
+    <p>
+      If the model type is set to <code>virtio</code> and
+      interface's <code>trustGuestRxFilters</code> attribute is set
+      to <code>yes</code>, changes made to the interface mac address,
+      unicast/multicast receive filters, and vlan settings in the
+      guest will be monitored and propagated to the associated macvtap
+      device on the host (<span class="since">Since
+      1.2.10</span>). If <code>trustGuestRxFilters</code> is not set,
+      or is not supported for the device model in use, an attempted
+      change to the mac address originating from the guest side will
+      result in a non-working network connection.
+    </p>
 
     <dl>
       <dt><code>vepa</code></dt>
@@ -3621,7 +3647,7 @@
   ...
   &lt;devices&gt;
     ...
-    &lt;interface type='direct'&gt;
+    &lt;interface type='direct' trustGuestRxFilters='no'&gt;
       &lt;source dev='eth0' mode='vepa'/&gt;
     &lt;/interface&gt;
   &lt;/devices&gt;

docs/formatnetwork.html.in

@@ -35,7 +35,7 @@
     </p>
 
     <pre>
-      &lt;network ipv6='yes'&gt;
+      &lt;network ipv6='yes' trustGuestRxFilters='no'&gt;
         &lt;name&gt;default&lt;/name&gt;
         &lt;uuid&gt;3e3fce45-4f53-4fa7-bb32-11f34168b82b&lt;/uuid&gt;
         ...</pre>
@@ -60,6 +60,16 @@
         to have guest-to-guest communications.  For further information,
         see the example below for the example with no gateway addresses.
         <span class="since">Since 1.0.1</span></dd>
+      <dt><code>trustGuestRxFilters='yes'</code></dt>
+      <dd>The optional parameter <code>trustGuestRxFilters</code> can
+        be used to set that attribute of the same name for each domain
+        interface connected to this network (<span class="since">since
+        1.2.10</span>). See
+        the <a href="formatdomain.html#elementSNICS">Network
+        interfaces</a> section of the domain XML documentation for
+        more details. Note that an explicit setting of this attribute
+        in a portgroup or the individual domain interface will
+        override the setting in the network.</dd>
     </dl>
 
     <h3><a name="elementsConnect">Connectivity</a></h3>
@@ -606,7 +616,7 @@
       &lt;outbound average='1000' peak='5000' burst='5120'/&gt;
     &lt;/bandwidth&gt;
   &lt;/portgroup&gt;</b>
-  <b>&lt;portgroup name='sales'&gt;
+  <b>&lt;portgroup name='sales' trustGuestRxFilters='no'&gt;
     &lt;virtualport type='802.1Qbh'&gt;
       &lt;parameters profileid='salestest'/&gt;
     &lt;/virtualport&gt;
@@ -626,7 +636,7 @@
       network can have multiple portgroup elements (and one of those
       can optionally be designated as the 'default' portgroup for the
       network), and each portgroup has a name, as well as various
-      subelements associated with it. The currently supported
+      attributes and subelements associated with it. The currently supported
       subelements are <code>&lt;bandwidth&gt;</code>
       (described <a href="formatnetwork.html#elementQoS">here</a>)
       and <code>&lt;virtualport&gt;</code>
@@ -650,6 +660,19 @@
       considered an error, and will prevent the interface from
       starting.
     </p>
+    <p>
+      portgroups also support the optional
+      parameter <code>trustGuestRxFilters</code> which can be used to
+      set that attribute of the same name for each domain interface
+      using this portgroup (<span class="since">since
+      1.2.10</span>). See
+      the <a href="formatdomain.html#elementSNICS">Network
+      interfaces</a> section of the domain XML documentation for more
+      details. Note that an explicit setting of this attribute in the
+      portgroup overrides the network-wide setting, and an explicit
+      setting in the individual domain interface will override the
+      setting in the portgroup.
+    </p>
 
     <h5><a name="elementsStaticroute">Static Routes</a></h5>
     <p>

docs/schemas/domaincommon.rng

@@ -2240,6 +2240,11 @@
           </interleave>
         </group>
       </choice>
+      <optional>
+        <attribute name="trustGuestRxFilters">
+          <ref name="virYesNo"/>
+        </attribute>
+      </optional>
     </element>
   </define>
   <!--

docs/schemas/network.rng

@@ -24,6 +24,11 @@
           <ref name="virYesNo"/>
         </attribute>
       </optional>
+      <optional>
+        <attribute name="trustGuestRxFilters">
+          <ref name="virYesNo"/>
+        </attribute>
+      </optional>
       <interleave>
 
         <!-- The name of the network, used to refer to it through the API
@@ -197,6 +202,11 @@
                 <ref name="virYesNo"/>
               </attribute>
             </optional>
+            <optional>
+              <attribute name="trustGuestRxFilters">
+                <ref name="virYesNo"/>
+              </attribute>
+            </optional>
             <interleave>
               <optional>
                 <ref name="virtualPortProfile"/>

src/conf/domain_conf.c

@@ -6784,6 +6784,7 @@ virDomainActualNetDefParseXML(xmlNodePtr node,
     char *type = NULL;
     char *mode = NULL;
     char *addrtype = NULL;
+    char *trustGuestRxFilters = NULL;
 
     if (VIR_ALLOC(actual) < 0)
         return -1;
@@ -6811,6 +6812,16 @@ virDomainActualNetDefParseXML(xmlNodePtr node,
         goto error;
     }
 
+    trustGuestRxFilters = virXMLPropString(node, "trustGuestRxFilters");
+    if (trustGuestRxFilters &&
+        ((actual->trustGuestRxFilters
+          = virTristateBoolTypeFromString(trustGuestRxFilters)) <= 0)) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("unknown trustGuestRxFilters value '%s'"),
+                       trustGuestRxFilters);
+        goto error;
+    }
+
     virtPortNode = virXPathNode("./virtualport", ctxt);
     if (virtPortNode) {
         if (actual->type == VIR_DOMAIN_NET_TYPE_BRIDGE ||
@@ -6906,6 +6917,7 @@ virDomainActualNetDefParseXML(xmlNodePtr node,
     VIR_FREE(type);
     VIR_FREE(mode);
     VIR_FREE(addrtype);
+    VIR_FREE(trustGuestRxFilters);
     virDomainActualNetDefFree(actual);
 
     ctxt->node = save_ctxt;
@@ -6957,6 +6969,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
     char *vhostuser_mode = NULL;
     char *vhostuser_path = NULL;
     char *vhostuser_type = NULL;
+    char *trustGuestRxFilters = NULL;
     virNWFilterHashTablePtr filterparams = NULL;
     virDomainActualNetDefPtr actual = NULL;
     xmlNodePtr oldnode = ctxt->node;
@@ -6978,6 +6991,16 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
         def->type = VIR_DOMAIN_NET_TYPE_USER;
     }
 
+    trustGuestRxFilters = virXMLPropString(node, "trustGuestRxFilters");
+    if (trustGuestRxFilters &&
+        ((def->trustGuestRxFilters
+          = virTristateBoolTypeFromString(trustGuestRxFilters)) <= 0)) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("unknown trustGuestRxFilters value '%s'"),
+                       trustGuestRxFilters);
+        goto error;
+    }
+
     cur = node->children;
     while (cur != NULL) {
         if (cur->type == XML_ELEMENT_NODE) {
@@ -7617,6 +7640,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
     VIR_FREE(mode);
     VIR_FREE(linkstate);
     VIR_FREE(addrtype);
+    VIR_FREE(trustGuestRxFilters);
     virNWFilterHashTableFree(filterparams);
 
     return def;
@@ -16740,6 +16764,9 @@ virDomainActualNetDefFormat(virBufferPtr buf,
         if  (hostdef && hostdef->managed)
             virBufferAddLit(buf, " managed='yes'");
     }
+    if (def->trustGuestRxFilters)
+        virBufferAsprintf(buf, " trustGuestRxFilters='%s'",
+                          virTristateBoolTypeToString(def->trustGuestRxFilters));
     virBufferAddLit(buf, ">\n");
 
     virBufferAdjustIndent(buf, 2);
@@ -16897,6 +16924,9 @@ virDomainNetDefFormat(virBufferPtr buf,
     virBufferAsprintf(buf, "<interface type='%s'", typeStr);
     if (hostdef && hostdef->managed)
         virBufferAddLit(buf, " managed='yes'");
+    if (def->trustGuestRxFilters)
+        virBufferAsprintf(buf, " trustGuestRxFilters='%s'",
+                          virTristateBoolTypeToString(def->trustGuestRxFilters));
     virBufferAddLit(buf, ">\n");
 
     virBufferAdjustIndent(buf, 2);
@@ -20371,6 +20401,18 @@ virDomainNetGetActualVlan(virDomainNetDefPtr iface)
     return NULL;
 }
 
+
+bool
+virDomainNetGetActualTrustGuestRxFilters(virDomainNetDefPtr iface)
+{
+    if (iface->type == VIR_DOMAIN_NET_TYPE_NETWORK &&
+        iface->data.network.actual)
+        return (iface->data.network.actual->trustGuestRxFilters
+                == VIR_TRISTATE_BOOL_YES);
+    return iface->trustGuestRxFilters == VIR_TRISTATE_BOOL_YES;
+}
+
+
 /* Return listens[i] from the appropriate union for the graphics
  * type, or NULL if this is an unsuitable type, or the index is out of
  * bounds. If force0 is TRUE, i == 0, and there is no listen array,

src/conf/domain_conf.h

@@ -885,6 +885,7 @@ struct _virDomainActualNetDef {
     virNetDevVPortProfilePtr virtPortProfile;
     virNetDevBandwidthPtr bandwidth;
     virNetDevVlan vlan;
+    int trustGuestRxFilters; /* enum virTristateBool */
     unsigned int class_id; /* class ID for bandwidth 'floor' */
 };
 
@@ -974,6 +975,7 @@ struct _virDomainNetDef {
     virNWFilterHashTablePtr filterparams;
     virNetDevBandwidthPtr bandwidth;
     virNetDevVlan vlan;
+    int trustGuestRxFilters; /* enum virTristateBool */
     int linkstate;
 };
 
@@ -2510,6 +2512,7 @@ virDomainNetGetActualVirtPortProfile(virDomainNetDefPtr iface);
 virNetDevBandwidthPtr
 virDomainNetGetActualBandwidth(virDomainNetDefPtr iface);
 virNetDevVlanPtr virDomainNetGetActualVlan(virDomainNetDefPtr iface);
+bool virDomainNetGetActualTrustGuestRxFilters(virDomainNetDefPtr iface);
 
 int virDomainControllerInsert(virDomainDefPtr def,
                               virDomainControllerDefPtr controller)

src/conf/network_conf.c

@@ -1615,6 +1615,7 @@ virNetworkPortGroupParseXML(virPortGroupDefPtr def,
     xmlNodePtr vlanNode;
     xmlNodePtr bandwidth_node;
     char *isDefault = NULL;
+    char *trustGuestRxFilters = NULL;
 
     int result = -1;
 
@@ -1632,6 +1633,18 @@ virNetworkPortGroupParseXML(virPortGroupDefPtr def,
     isDefault = virXPathString("string(./@default)", ctxt);
     def->isDefault = isDefault && STRCASEEQ(isDefault, "yes");
 
+    trustGuestRxFilters
+        = virXPathString("string(./@trustGuestRxFilters)", ctxt);
+    if (trustGuestRxFilters) {
+        if ((def->trustGuestRxFilters
+             = virTristateBoolTypeFromString(trustGuestRxFilters)) <= 0) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("Invalid trustGuestRxFilters setting '%s' "
+                             "in portgroup"), trustGuestRxFilters);
+            goto cleanup;
+        }
+    }
+
     virtPortNode = virXPathNode("./virtualport", ctxt);
     if (virtPortNode &&
         (!(def->virtPortProfile = virNetDevVPortProfileParse(virtPortNode, 0)))) {
@@ -1654,6 +1667,7 @@ virNetworkPortGroupParseXML(virPortGroupDefPtr def,
         virPortGroupDefClear(def);
     }
     VIR_FREE(isDefault);
+    VIR_FREE(trustGuestRxFilters);
 
     ctxt->node = save;
     return result;
@@ -2013,6 +2027,7 @@ virNetworkDefParseXML(xmlXPathContextPtr ctxt)
     xmlNodePtr virtPortNode = NULL;
     xmlNodePtr forwardNode = NULL;
     char *ipv6nogwStr = NULL;
+    char *trustGuestRxFilters = NULL;
     xmlNodePtr save = ctxt->node;
     xmlNodePtr bandwidthNode = NULL;
     xmlNodePtr vlanNode;
@@ -2061,6 +2076,20 @@ virNetworkDefParseXML(xmlXPathContextPtr ctxt)
         VIR_FREE(ipv6nogwStr);
     }
 
+    trustGuestRxFilters
+        = virXPathString("string(./@trustGuestRxFilters)", ctxt);
+    if (trustGuestRxFilters) {
+        if ((def->trustGuestRxFilters
+             = virTristateBoolTypeFromString(trustGuestRxFilters)) <= 0) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("Invalid trustGuestRxFilters setting '%s' "
+                             "in network '%s'"),
+                           trustGuestRxFilters, def->name);
+            goto error;
+        }
+        VIR_FREE(trustGuestRxFilters);
+    }
+
     /* Parse network domain information */
     def->domain = virXPathString("string(./domain[1]/@name)", ctxt);
 
@@ -2303,6 +2332,7 @@ virNetworkDefParseXML(xmlXPathContextPtr ctxt)
     VIR_FREE(ipNodes);
     VIR_FREE(portGroupNodes);
     VIR_FREE(ipv6nogwStr);
+    VIR_FREE(trustGuestRxFilters);
     ctxt->node = save;
     return NULL;
 }
@@ -2597,6 +2627,9 @@ virPortGroupDefFormat(virBufferPtr buf,
     if (def->isDefault) {
         virBufferAddLit(buf, " default='yes'");
     }
+    if (def->trustGuestRxFilters)
+        virBufferAsprintf(buf, " trustGuestRxFilters='%s'",
+                          virTristateBoolTypeToString(def->trustGuestRxFilters));
     virBufferAddLit(buf, ">\n");
     virBufferAdjustIndent(buf, 2);
     if (virNetDevVlanFormat(&def->vlan, buf) < 0)
@@ -2675,6 +2708,9 @@ virNetworkDefFormatBuf(virBufferPtr buf,
     }
     if (def->ipv6nogw)
         virBufferAddLit(buf, " ipv6='yes'");
+    if (def->trustGuestRxFilters)
+        virBufferAsprintf(buf, " trustGuestRxFilters='%s'",
+                          virTristateBoolTypeToString(def->trustGuestRxFilters));
     virBufferAddLit(buf, ">\n");
     virBufferAdjustIndent(buf, 2);
     virBufferEscapeString(buf, "<name>%s</name>\n", def->name);

src/conf/network_conf.h

@@ -219,6 +219,7 @@ struct _virPortGroupDef {
     virNetDevVPortProfilePtr virtPortProfile;
     virNetDevBandwidthPtr bandwidth;
     virNetDevVlan vlan;
+    int trustGuestRxFilters; /* enum virTristateBool */
 };
 
 typedef struct _virNetworkDef virNetworkDef;
@@ -256,6 +257,7 @@ struct _virNetworkDef {
     virPortGroupDefPtr portGroups;
     virNetDevBandwidthPtr bandwidth;
     virNetDevVlan vlan;
+    int trustGuestRxFilters; /* enum virTristateBool */
 };
 
 typedef struct _virNetworkObj virNetworkObj;

src/libvirt_private.syms

@@ -331,6 +331,7 @@ virDomainNetGetActualBridgeName;
 virDomainNetGetActualDirectDev;
 virDomainNetGetActualDirectMode;
 virDomainNetGetActualHostdev;
+virDomainNetGetActualTrustGuestRxFilters;
 virDomainNetGetActualType;
 virDomainNetGetActualVirtPortProfile;
 virDomainNetGetActualVlan;

tests/networkxml2xmlin/vepa-net.xml

@@ -1,4 +1,4 @@
-<network>
+<network trustGuestRxFilters="no">
   <name>vepa-net</name>
   <uuid>81ff0d90-c91e-6742-64da-4a736edb9a8b</uuid>
   <forward mode="vepa">
@@ -14,7 +14,7 @@
       <parameters typeid="2193047" typeidversion="3"/>
     </virtualport>
   </portgroup>
-  <portgroup name="alice">
+  <portgroup name="alice" trustGuestRxFilters="yes">
     <virtualport type="802.1Qbg">
       <parameters managerid="13"/>
     </virtualport>

tests/networkxml2xmlout/vepa-net.xml

@@ -1,4 +1,4 @@
-<network>
+<network trustGuestRxFilters='no'>
   <name>vepa-net</name>
   <uuid>81ff0d90-c91e-6742-64da-4a736edb9a8b</uuid>
   <forward dev='eth1' mode='vepa'>
@@ -14,7 +14,7 @@
       <parameters typeid='2193047' typeidversion='3'/>
     </virtualport>
   </portgroup>
-  <portgroup name='alice'>
+  <portgroup name='alice' trustGuestRxFilters='yes'>
     <virtualport type='802.1Qbg'>
       <parameters managerid='13'/>
     </virtualport>

tests/qemuxml2argvdata/qemuxml2argv-net-virtio-network-portgroup.xml

@@ -22,7 +22,7 @@
     <controller type='usb' index='0'/>
     <controller type='ide' index='0'/>
     <controller type='pci' index='0' model='pci-root'/>
-    <interface type='network'>
+    <interface type='network' trustGuestRxFilters='yes'>
       <mac address='00:11:22:33:44:55'/>
       <source network='rednet' portgroup='bob'/>
       <vlan>
@@ -33,7 +33,7 @@
       </virtualport>
       <model type='virtio'/>
     </interface>
-    <interface type='network'>
+    <interface type='network' trustGuestRxFilters='no'>
       <mac address='10:11:22:33:44:55'/>
       <source network='blue' portgroup='sam'/>
       <virtualport>