Extend NWFilter parameter parser to cope with lists of values

This patch modifies the NWFilter parameter parser to support multiple
elements with the same name and to internally build a list of items.
An example of the XML looks like this:

        <parameter name='TEST' value='10.1.2.3'/>
        <parameter name='TEST' value='10.2.3.4'/>
        <parameter name='TEST' value='10.1.1.1'/>

The list of values is then stored in the newly introduced data type
virNWFilterVarValue.

The XML formatter is also adapted to print out all items in alphabetical
order sorted by 'name'.

This patch also fixes a bug in the XML schema on the way.
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>

docs/schemas/nwfilter.rng

@@ -312,7 +312,7 @@
     <attribute name="filter">
       <data type="NCName"/>
     </attribute>
-    <optional>
+    <zeroOrMore>
       <element name="parameter">
         <attribute name="name">
           <ref name="filter-param-name"/>
@@ -321,7 +321,7 @@
           <ref name="filter-param-value"/>
         </attribute>
       </element>
-    </optional>
+    </zeroOrMore>
   </define>
 
   <define name="rule-node-attributes">

src/conf/nwfilter_params.c

@@ -604,7 +604,7 @@ isValidVarName(const char *var)
 static bool
 isValidVarValue(const char *value)
 {
-    return value[strspn(value, VALID_VARVALUE)] == 0;
+    return (value[strspn(value, VALID_VARVALUE)] == 0) && (strlen(value) != 0);
 }
 
 static virNWFilterVarValuePtr
@@ -636,15 +636,22 @@ virNWFilterParseParamAttributes(xmlNodePtr cur)
                 if (nam != NULL && val != NULL) {
                     if (!isValidVarName(nam))
                         goto skip_entry;
+                    if (!isValidVarValue(val))
+                        goto skip_entry;
+                    value = virHashLookup(table->hashTable, nam);
+                    if (value) {
+                        /* add value to existing value -> list */
+                        if (virNWFilterVarValueAddValue(value, val) < 0) {
+                            value = NULL;
+                            goto err_exit;
+                        }
+                        val = NULL;
+                    } else {
                         value = virNWFilterParseVarValue(val);
                         if (!value)
                             goto skip_entry;
-                    if (virNWFilterHashTablePut(table, nam, value, 1)) {
-                        VIR_FREE(nam);
-                        VIR_FREE(val);
-                        virNWFilterVarValueFree(value);
-                        virNWFilterHashTableFree(table);
-                        return NULL;
+                        if (virNWFilterHashTablePut(table, nam, value, 1))
+                            goto err_exit;
                     }
                     value = NULL;
                 }
@@ -657,39 +664,66 @@ skip_entry:
         cur = cur->next;
     }
     return table;
+
+err_exit:
+    VIR_FREE(nam);
+    VIR_FREE(val);
+    virNWFilterVarValueFree(value);
+    virNWFilterHashTableFree(table);
+    return NULL;
 }
 
 
-static void
-_formatParameterAttrs(void *payload, const void *name, void *data)
+static int
+virNWFilterFormatParameterNameSorter(const virHashKeyValuePairPtr a,
+                                     const virHashKeyValuePairPtr b)
 {
-    virBufferPtr buf = data;
-
-    virBufferAsprintf(buf, "  <parameter name='%s' value='%s'/>\n",
-                      (const char *)name,
-                      (char *)payload);
+    return strcmp((const char *)a->key, (const char *)b->key);
 }
 
-
 int
 virNWFilterFormatParamAttributes(virBufferPtr buf,
                                  virNWFilterHashTablePtr table,
                                  const char *filterref)
 {
-    int count = virHashSize(table->hashTable);
+    virHashKeyValuePairPtr items;
+    int i, j, card, numKeys;
 
-    if (count < 0) {
+    numKeys = virHashSize(table->hashTable);
+
+    if (numKeys < 0) {
         virNWFilterReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                                _("missing filter parameter table"));
         return -1;
     }
+
+    items = virHashGetItems(table->hashTable,
+                            virNWFilterFormatParameterNameSorter);
+    if (!items)
+        return -1;
+
     virBufferAsprintf(buf, "<filterref filter='%s'", filterref);
-    if (count) {
+    if (numKeys) {
         virBufferAddLit(buf, ">\n");
-        virHashForEach(table->hashTable, _formatParameterAttrs, buf);
+        for (i = 0; i < numKeys; i++) {
+            const virNWFilterVarValuePtr value =
+                (const virNWFilterVarValuePtr)items[i].value;
+
+            card = virNWFilterVarValueGetCardinality(value);
+
+            for (j = 0; j < card; j++)
+                virBufferAsprintf(buf,
+                                  "  <parameter name='%s' value='%s'/>\n",
+                                  (const char *)items[i].key,
+                                  virNWFilterVarValueGetNthValue(value, j));
+
+        }
         virBufferAddLit(buf, "</filterref>\n");
     } else {
         virBufferAddLit(buf, "/>\n");
     }
+
+    VIR_FREE(items);
+
     return 0;
 }