interface: clean up virInterfaceDefDevFormat

This modifies the formatting function of virInterface to be a proper
mirror of the parse function, including the addition of a
"parentIfType" arg so that we can decide whether or not it is
appropriate to emit the elements that are only in toplevel interfaces,
as well as the <link> element (which isn't allowed for bridge
interfaces).

Since the restructuring of the code necessarily changes the order of
some of the elements, some test case data had to be updated.

src/conf/interface_conf.c

@@ -41,7 +41,8 @@ VIR_ENUM_IMPL(virInterface,
 static virInterfaceDefPtr
 virInterfaceDefParseXML(xmlXPathContextPtr ctxt, int parentIfType);
 static int
-virInterfaceDefDevFormat(virBufferPtr buf, const virInterfaceDef *def);
+virInterfaceDefDevFormat(virBufferPtr buf, const virInterfaceDef *def,
+                         virInterfaceType parentIfType);
 
 static
 void virInterfaceIpDefFree(virInterfaceIpDefPtr def)
@@ -870,7 +871,8 @@ virInterfaceBridgeDefFormat(virBufferPtr buf, const virInterfaceDef *def)
     virBufferAdjustIndent(buf, 2);
 
     for (i = 0; i < def->data.bridge.nbItf; i++) {
-        if (virInterfaceDefDevFormat(buf, def->data.bridge.itf[i]) < 0)
+        if (virInterfaceDefDevFormat(buf, def->data.bridge.itf[i],
+                                     VIR_INTERFACE_TYPE_BRIDGE) < 0)
             ret = -1;
     }
 
@@ -932,7 +934,8 @@ virInterfaceBondDefFormat(virBufferPtr buf, const virInterfaceDef *def)
         virBufferAddLit(buf, "/>\n");
     }
     for (i = 0; i < def->data.bond.nbItf; i++) {
-        if (virInterfaceDefDevFormat(buf, def->data.bond.itf[i]) < 0)
+        if (virInterfaceDefDevFormat(buf, def->data.bond.itf[i],
+                                     VIR_INTERFACE_TYPE_BOND) < 0)
             ret = -1;
     }
 
@@ -1035,7 +1038,8 @@ virInterfaceStartmodeDefFormat(virBufferPtr buf,
 }
 
 static int
-virInterfaceDefDevFormat(virBufferPtr buf, const virInterfaceDef *def)
+virInterfaceDefDevFormat(virBufferPtr buf, const virInterfaceDef *def,
+                         virInterfaceType parentIfType)
 {
     const char *type = NULL;
 
@@ -1063,39 +1067,33 @@ virInterfaceDefDevFormat(virBufferPtr buf, const virInterfaceDef *def)
     virBufferAddLit(buf, ">\n");
     virBufferAdjustIndent(buf, 2);
 
+    if (parentIfType == VIR_INTERFACE_TYPE_LAST) {
+        /* these elements are only valid on top-level interfaces - IP
+         * address info ("protocol") only makes sense for the
+         * top-level, and subordinate interfaces inherit the toplevel
+         * setting for mtu and start mode, which cannot be overridden.
+         */
+        virInterfaceStartmodeDefFormat(buf, def->startmode);
+        if (def->mtu)
+            virBufferAsprintf(buf, "<mtu size='%d'/>\n", def->mtu);
+        virInterfaceProtocolDefFormat(buf, def);
+    }
+
+    if (def->type != VIR_INTERFACE_TYPE_BRIDGE) {
+        virInterfaceLinkFormat(buf, &def->lnk);
+    }
     switch (def->type) {
         case VIR_INTERFACE_TYPE_ETHERNET:
-            virInterfaceStartmodeDefFormat(buf, def->startmode);
-            if (def->mac != NULL)
+            if (def->mac)
                 virBufferAsprintf(buf, "<mac address='%s'/>\n", def->mac);
-            virInterfaceLinkFormat(buf, &def->lnk);
-            if (def->mtu != 0)
-                virBufferAsprintf(buf, "<mtu size='%d'/>\n", def->mtu);
-            virInterfaceProtocolDefFormat(buf, def);
             break;
         case VIR_INTERFACE_TYPE_BRIDGE:
-            virInterfaceStartmodeDefFormat(buf, def->startmode);
-            if (def->mtu != 0)
-                virBufferAsprintf(buf, "<mtu size='%d'/>\n", def->mtu);
-            virInterfaceProtocolDefFormat(buf, def);
             virInterfaceBridgeDefFormat(buf, def);
             break;
         case VIR_INTERFACE_TYPE_BOND:
-            virInterfaceStartmodeDefFormat(buf, def->startmode);
-            virInterfaceLinkFormat(buf, &def->lnk);
-            if (def->mtu != 0)
-                virBufferAsprintf(buf, "<mtu size='%d'/>\n", def->mtu);
-            virInterfaceProtocolDefFormat(buf, def);
             virInterfaceBondDefFormat(buf, def);
             break;
         case VIR_INTERFACE_TYPE_VLAN:
-            virInterfaceStartmodeDefFormat(buf, def->startmode);
-            if (def->mac != NULL)
-                virBufferAsprintf(buf, "<mac address='%s'/>\n", def->mac);
-            virInterfaceLinkFormat(buf, &def->lnk);
-            if (def->mtu != 0)
-                virBufferAsprintf(buf, "<mtu size='%d'/>\n", def->mtu);
-            virInterfaceProtocolDefFormat(buf, def);
             virInterfaceVlanDefFormat(buf, def);
             break;
     }
@@ -1116,7 +1114,7 @@ char *virInterfaceDefFormat(const virInterfaceDef *def)
 {
     virBuffer buf = VIR_BUFFER_INITIALIZER;
 
-    if (virInterfaceDefDevFormat(&buf, def) < 0) {
+    if (virInterfaceDefDevFormat(&buf, def, VIR_INTERFACE_TYPE_LAST) < 0) {
         virBufferFreeAndReset(&buf);
         return NULL;
     }

tests/interfaceschemadata/bond.xml

 <interface type='bond' name='bond0'>
   <start mode='none'/>
-  <link speed='1000' state='up'/>
   <protocol family='ipv4'>
     <ip address='192.168.50.7' prefix='24'/>
     <route gateway='192.168.50.1'/>
   </protocol>
+  <link speed='1000' state='up'/>
   <bond mode='active-backup'>
     <miimon freq='100' updelay='10' carrier='ioctl'/>
     <interface type='ethernet' name='eth1'>

tests/interfaceschemadata/bridge-no-address.xml

@@ -3,8 +3,8 @@
   <mtu size='1500'/>
   <bridge stp='off'>
     <interface type='ethernet' name='eth0'>
-      <mac address='ab:bb:cc:dd:ee:ff'/>
       <link speed='1000' state='up'/>
+      <mac address='ab:bb:cc:dd:ee:ff'/>
     </interface>
     <interface type='ethernet' name='eth1'>
     </interface>

tests/interfaceschemadata/bridge.xml

@@ -6,8 +6,8 @@
   </protocol>
   <bridge stp='off' delay='0.01'>
     <interface type='ethernet' name='eth0'>
-      <mac address='ab:bb:cc:dd:ee:ff'/>
       <link speed='10'/>
+      <mac address='ab:bb:cc:dd:ee:ff'/>
     </interface>
     <interface type='ethernet' name='eth1'>
     </interface>

tests/interfaceschemadata/ethernet-dhcp.xml

 <interface type='ethernet' name='eth0'>
   <start mode='none'/>
-  <mac address='aa:bb:cc:dd:ee:ff'/>
-  <link state='down'/>
   <mtu size='1492'/>
   <protocol family='ipv4'>
     <dhcp peerdns='no'/>
   </protocol>
+  <link state='down'/>
+  <mac address='aa:bb:cc:dd:ee:ff'/>
 </interface>

tests/interfaceschemadata/vlan.xml

 <interface type='vlan' name='eth0.42'>
   <start mode='onboot'/>
-  <link state='lowerlayerdown'/>
   <protocol family='ipv4'>
     <dhcp peerdns='no'/>
   </protocol>
+  <link state='lowerlayerdown'/>
   <vlan tag='42'>
     <interface name='eth0'/>
   </vlan>