+static int lv_domain_get_tag(xmlXPathContextPtr xpath_ctx, const char *dom_name,
+ char *dom_tag) {
+ char xpath_str[BUFFER_MAX_LEN] = {'\0'};
+ xmlXPathObjectPtr xpath_obj = NULL;
+ xmlNodePtr xml_node = NULL;
+ int err = -1;
+
+ err = xmlXPathRegisterNs(xpath_ctx,
+ (const xmlChar *)METADATA_VM_PARTITION_PREFIX,
+ (const xmlChar *)METADATA_VM_PARTITION_URI);
+ if (err) {
+ ERROR(PLUGIN_NAME " plugin: xmlXpathRegisterNs(%s, %s) failed on domain %s",
+ METADATA_VM_PARTITION_PREFIX, METADATA_VM_PARTITION_URI, dom_name);
+ goto done;
+ }
+
+ ssnprintf(xpath_str, sizeof(xpath_str), "/domain/metadata/%s:%s/text()",
+ METADATA_VM_PARTITION_PREFIX, METADATA_VM_PARTITION_ELEMENT);
+ xpath_obj = xmlXPathEvalExpression((xmlChar *)xpath_str, xpath_ctx);
+ if (xpath_obj == NULL) {
+ ERROR(PLUGIN_NAME " plugin: xmlXPathEval(%s) failed on domain %s",
+ xpath_str, dom_name);
+ goto done;
+ }
+
+ if (xpath_obj->type != XPATH_NODESET) {
+ ERROR(PLUGIN_NAME " plugin: xmlXPathEval(%s) unexpected return type %d "
+ "(wanted %d) on domain %s",
+ xpath_str, xpath_obj->type, XPATH_NODESET, dom_name);
+ goto done;
+ }
+
+ /*
+ * from now on there is no real error, it's ok if a domain
+ * doesn't have the metadata partition tag.
+ */
+ err = 0;
+
+ if (xpath_obj->nodesetval == NULL || xpath_obj->nodesetval->nodeNr != 1) {
+ DEBUG(PLUGIN_NAME " plugin: xmlXPathEval(%s) return nodeset size=%i "
+ "expected=1 on domain %s",
+ xpath_str,
+ (xpath_obj->nodesetval == NULL) ? 0 : xpath_obj->nodesetval->nodeNr,
+ dom_name);
+ } else {
+ xml_node = xpath_obj->nodesetval->nodeTab[0];
+ sstrncpy(dom_tag, (const char *)xml_node->content, PARTITION_TAG_MAX_LEN);
+ }
+
+done:
+ if (xpath_obj)
+ xmlXPathFreeObject(xpath_obj);
+
+ return err;
+}
+
+static int is_known_tag(const char *dom_tag) {
+ for (size_t i = 0; i < nr_instances; ++i)
+ if (!strcmp(dom_tag, lv_read_user_data[i].inst.tag))
+ return 1;
+ return 0;
+}
+
+static int lv_instance_include_domain(struct lv_read_instance *inst,
+ const char *dom_name,
+ const char *dom_tag) {
+ if ((dom_tag[0] != '\0') && (strcmp(dom_tag, inst->tag) == 0))
+ return 1;
+
+ /* instance#0 will always be there, so it is in charge of extra duties */
+ if (inst->id == 0) {
+ if (dom_tag[0] == '\0' || !is_known_tag(dom_tag)) {
+ DEBUG(PLUGIN_NAME " plugin#%s: adopted domain %s "
+ "with unknown tag '%s'",
+ inst->tag, dom_name, dom_tag);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+static int refresh_lists(struct lv_read_instance *inst) {