X-Git-Url: https://git.octo.it/?p=collectd.git;a=blobdiff_plain;f=src%2Fcurl_xml.c;h=19ae5f462de8a4cd64c263ddf7c62a56436909a7;hp=1c2822771a0928a26e9124bf4800f744037319d4;hb=77ca1a45bab2f6adf9301723d0db68e5813a6d98;hpb=c3d354c58d56c4b2bb4138a227f3546928bd84f2

diff --git a/src/curl_xml.c b/src/curl_xml.c
index 1c282277..19ae5f46 100644
--- a/src/curl_xml.c
+++ b/src/curl_xml.c
@@ -54,6 +54,7 @@ struct cx_xpath_s /* {{{ */
   size_t values_len;
   char *instance_prefix;
   char *instance;
+  char *plugin_instance_from;
   int is_table;
   unsigned long magic;
 };
@@ -71,6 +72,7 @@ typedef struct cx_namespace_s cx_namespace_t;
 struct cx_s /* {{{ */
 {
   char *instance;
+  char *plugin_name;
   char *host;
 
   char *url;
@@ -95,7 +97,7 @@ struct cx_s /* {{{ */
   size_t buffer_size;
   size_t buffer_fill;
 
-  llist_t *list; /* list of xpath blocks */
+  llist_t *xpath_list; /* list of xpath blocks */
 };
 typedef struct cx_s cx_t; /* }}} */
 
@@ -105,25 +107,22 @@ typedef struct cx_s cx_t; /* }}} */
 static size_t cx_curl_callback(void *buf, /* {{{ */
                                size_t size, size_t nmemb, void *user_data) {
   size_t len = size * nmemb;
-  cx_t *db;
 
-  db = user_data;
+  cx_t *db = user_data;
   if (db == NULL) {
     ERROR("curl_xml plugin: cx_curl_callback: "
           "user_data pointer is NULL.");
-    return (0);
+    return 0;
   }
 
   if (len == 0)
-    return (len);
+    return len;
 
   if ((db->buffer_fill + len) >= db->buffer_size) {
-    char *temp;
-
-    temp = realloc(db->buffer, db->buffer_fill + len + 1);
+    char *temp = realloc(db->buffer, db->buffer_fill + len + 1);
     if (temp == NULL) {
       ERROR("curl_xml plugin: realloc failed.");
-      return (0);
+      return 0;
     }
     db->buffer = temp;
     db->buffer_size = db->buffer_fill + len + 1;
@@ -133,7 +132,7 @@ static size_t cx_curl_callback(void *buf, /* {{{ */
   db->buffer_fill += len;
   db->buffer[db->buffer_fill] = 0;
 
-  return (len);
+  return len;
 } /* }}} size_t cx_curl_callback */
 
 static void cx_xpath_free(cx_xpath_t *xpath) /* {{{ */
@@ -144,29 +143,28 @@ static void cx_xpath_free(cx_xpath_t *xpath) /* {{{ */
   sfree(xpath->path);
   sfree(xpath->type);
   sfree(xpath->instance_prefix);
+  sfree(xpath->plugin_instance_from);
   sfree(xpath->instance);
   sfree(xpath->values);
   sfree(xpath);
 } /* }}} void cx_xpath_free */
 
-static void cx_list_free(llist_t *list) /* {{{ */
+static void cx_xpath_list_free(llist_t *list) /* {{{ */
 {
   llentry_t *le;
 
   le = llist_head(list);
   while (le != NULL) {
-    llentry_t *le_next;
-
-    le_next = le->next;
+    llentry_t *le_next = le->next;
 
-    sfree(le->key);
+    /* this also frees xpath->path used for le->key */
     cx_xpath_free(le->value);
 
     le = le_next;
   }
 
   llist_destroy(list);
-} /* }}} void cx_list_free */
+} /* }}} void cx_xpath_list_free */
 
 static void cx_free(void *arg) /* {{{ */
 {
@@ -183,11 +181,12 @@ static void cx_free(void *arg) /* {{{ */
     curl_easy_cleanup(db->curl);
   db->curl = NULL;
 
-  if (db->list != NULL)
-    cx_list_free(db->list);
+  if (db->xpath_list != NULL)
+    cx_xpath_list_free(db->xpath_list);
 
   sfree(db->buffer);
   sfree(db->instance);
+  sfree(db->plugin_name);
   sfree(db->host);
 
   sfree(db->url);
@@ -208,7 +207,7 @@ static void cx_free(void *arg) /* {{{ */
   sfree(db);
 } /* }}} void cx_free */
 
-static const char *cx_host(cx_t *db) /* {{{ */
+static const char *cx_host(const cx_t *db) /* {{{ */
 {
   if (db->host == NULL)
     return hostname_g;
@@ -221,42 +220,40 @@ static int cx_config_append_string(const char *name,
   struct curl_slist *temp = NULL;
   if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING)) {
     WARNING("curl_xml plugin: `%s' needs exactly one string argument.", name);
-    return (-1);
+    return -1;
   }
 
   temp = curl_slist_append(*dest, ci->values[0].value.string);
   if (temp == NULL)
-    return (-1);
+    return -1;
 
   *dest = temp;
 
-  return (0);
+  return 0;
 } /* }}} int cx_config_append_string */
 
 static int cx_check_type(const data_set_t *ds, cx_xpath_t *xpath) /* {{{ */
 {
   if (!ds) {
     WARNING("curl_xml plugin: DataSet `%s' not defined.", xpath->type);
-    return (-1);
+    return -1;
   }
 
   if (ds->ds_num != xpath->values_len) {
-    WARNING("curl_xml plugin: DataSet `%s' requires %zu values, but config "
-            "talks about %zu",
+    WARNING("curl_xml plugin: DataSet `%s' requires %" PRIsz
+            " values, but config talks about %" PRIsz,
             xpath->type, ds->ds_num, xpath->values_len);
-    return (-1);
+    return -1;
   }
 
-  return (0);
+  return 0;
 } /* }}} cx_check_type */
 
-static xmlXPathObjectPtr
-cx_evaluate_xpath(xmlXPathContextPtr xpath_ctx, /* {{{ */
-                  xmlChar *expr) {
-  xmlXPathObjectPtr xpath_obj;
-
-  /* XXX: When to free this? */
-  xpath_obj = xmlXPathEvalExpression(BAD_CAST expr, xpath_ctx);
+static xmlXPathObjectPtr cx_evaluate_xpath(xmlXPathContextPtr xpath_ctx,
+                                           char *expr) /* {{{ */
+{
+  xmlXPathObjectPtr xpath_obj =
+      xmlXPathEvalExpression(BAD_CAST expr, xpath_ctx);
   if (xpath_obj == NULL) {
     WARNING("curl_xml plugin: "
             "Error unable to evaluate xpath expression \"%s\". Skipping...",
@@ -271,7 +268,7 @@ static int cx_if_not_text_node(xmlNodePtr node) /* {{{ */
 {
   if (node->type == XML_TEXT_NODE || node->type == XML_ATTRIBUTE_NODE ||
       node->type == XML_ELEMENT_NODE)
-    return (0);
+    return 0;
 
   WARNING("curl_xml plugin: "
           "Node \"%s\" doesn't seem to be a text node. Skipping...",
@@ -279,51 +276,65 @@ static int cx_if_not_text_node(xmlNodePtr node) /* {{{ */
   return -1;
 } /* }}} cx_if_not_text_node */
 
-static int cx_handle_single_value_xpath(xmlXPathContextPtr xpath_ctx, /* {{{ */
-                                        cx_xpath_t *xpath, const data_set_t *ds,
-                                        value_list_t *vl, int index) {
-  xmlXPathObjectPtr values_node_obj;
-  xmlNodeSetPtr values_node;
-  int tmp_size;
-  char *node_value;
-
-  values_node_obj =
-      cx_evaluate_xpath(xpath_ctx, BAD_CAST xpath->values[index].path);
+/*
+ * Returned value should be freed with xmlFree().
+ */
+static char *cx_get_text_node_value(xmlXPathContextPtr xpath_ctx, /* {{{ */
+                                    char *expr, const char *from_option) {
+  xmlXPathObjectPtr values_node_obj = cx_evaluate_xpath(xpath_ctx, expr);
   if (values_node_obj == NULL)
-    return (-1); /* Error already logged. */
+    return NULL; /* Error already logged. */
 
-  values_node = values_node_obj->nodesetval;
-  tmp_size = (values_node) ? values_node->nodeNr : 0;
+  xmlNodeSetPtr values_node = values_node_obj->nodesetval;
+  size_t tmp_size = (values_node) ? values_node->nodeNr : 0;
 
   if (tmp_size == 0) {
     WARNING("curl_xml plugin: "
-            "relative xpath expression \"%s\" doesn't match any of the nodes. "
-            "Skipping...",
-            xpath->values[index].path);
+            "relative xpath expression \"%s\" from '%s' doesn't match "
+            "any of the nodes.",
+            expr, from_option);
     xmlXPathFreeObject(values_node_obj);
-    return (-1);
+    return NULL;
   }
 
   if (tmp_size > 1) {
     WARNING("curl_xml plugin: "
-            "relative xpath expression \"%s\" is expected to return "
-            "only one node. Skipping...",
-            xpath->values[index].path);
+            "relative xpath expression \"%s\" from '%s' is expected to return "
+            "only one text node. Skipping the node.",
+            expr, from_option);
     xmlXPathFreeObject(values_node_obj);
-    return (-1);
+    return NULL;
   }
 
   /* ignoring the element if other than textnode/attribute*/
   if (cx_if_not_text_node(values_node->nodeTab[0])) {
     WARNING("curl_xml plugin: "
-            "relative xpath expression \"%s\" is expected to return "
-            "only text/attribute node which is not the case. Skipping...",
-            xpath->values[index].path);
+            "relative xpath expression \"%s\" from '%s' is expected to return "
+            "only text/attribute node which is not the case. "
+            "Skipping the node.",
+            expr, from_option);
     xmlXPathFreeObject(values_node_obj);
-    return (-1);
+    return NULL;
   }
 
-  node_value = (char *)xmlNodeGetContent(values_node->nodeTab[0]);
+  char *node_value = (char *)xmlNodeGetContent(values_node->nodeTab[0]);
+
+  /* free up object */
+  xmlXPathFreeObject(values_node_obj);
+
+  return node_value;
+} /* }}} char * cx_get_text_node_value */
+
+static int cx_handle_single_value_xpath(xmlXPathContextPtr xpath_ctx, /* {{{ */
+                                        cx_xpath_t *xpath, const data_set_t *ds,
+                                        value_list_t *vl, int index) {
+
+  char *node_value = cx_get_text_node_value(
+      xpath_ctx, xpath->values[index].path, "ValuesFrom");
+
+  if (node_value == NULL)
+    return -1;
+
   switch (ds->ds[index].type) {
   case DS_TYPE_COUNTER:
     vl->values[index].counter =
@@ -345,20 +356,17 @@ static int cx_handle_single_value_xpath(xmlXPathContextPtr xpath_ctx, /* {{{ */
                                               /* endptr = */ NULL);
   }
 
-  /* free up object */
-  xmlXPathFreeObject(values_node_obj);
-  sfree(node_value);
+  xmlFree(node_value);
 
   /* We have reached here which means that
    * we have got something to work */
-  return (0);
+  return 0;
 } /* }}} int cx_handle_single_value_xpath */
 
 static int cx_handle_all_value_xpaths(xmlXPathContextPtr xpath_ctx, /* {{{ */
                                       cx_xpath_t *xpath, const data_set_t *ds,
                                       value_list_t *vl) {
   value_t values[xpath->values_len];
-  int status;
 
   assert(xpath->values_len > 0);
   assert(xpath->values_len == vl->values_len);
@@ -366,187 +374,125 @@ static int cx_handle_all_value_xpaths(xmlXPathContextPtr xpath_ctx, /* {{{ */
   vl->values = values;
 
   for (size_t i = 0; i < xpath->values_len; i++) {
-    status = cx_handle_single_value_xpath(xpath_ctx, xpath, ds, vl, i);
-    if (status != 0)
-      return (-1); /* An error has been printed. */
-  }                /* for (i = 0; i < xpath->values_len; i++) */
+    if (cx_handle_single_value_xpath(xpath_ctx, xpath, ds, vl, i) != 0)
+      return -1; /* An error has been printed. */
+  }              /* for (i = 0; i < xpath->values_len; i++) */
 
   plugin_dispatch_values(vl);
   vl->values = NULL;
 
-  return (0);
+  return 0;
 } /* }}} int cx_handle_all_value_xpaths */
 
 static int cx_handle_instance_xpath(xmlXPathContextPtr xpath_ctx, /* {{{ */
-                                    cx_xpath_t *xpath, value_list_t *vl,
-                                    _Bool is_table) {
-  xmlXPathObjectPtr instance_node_obj = NULL;
-  xmlNodeSetPtr instance_node = NULL;
+                                    cx_xpath_t *xpath, value_list_t *vl) {
 
-  memset(vl->type_instance, 0, sizeof(vl->type_instance));
+  /* Handle type instance */
+  if (xpath->instance != NULL) {
+    char *node_value =
+        cx_get_text_node_value(xpath_ctx, xpath->instance, "InstanceFrom");
+    if (node_value == NULL)
+      return -1;
+
+    if (xpath->instance_prefix != NULL)
+      snprintf(vl->type_instance, sizeof(vl->type_instance), "%s%s",
+               xpath->instance_prefix, node_value);
+    else
+      sstrncpy(vl->type_instance, node_value, sizeof(vl->type_instance));
 
-  /* If the base xpath returns more than one block, the result is assumed to be
-   * a table. The `Instance' option is not optional in this case. Check for the
-   * condition and inform the user. */
-  if (is_table && (xpath->instance == NULL)) {
-    WARNING("curl_xml plugin: "
-            "Base-XPath %s is a table (more than one result was returned), "
-            "but no instance-XPath has been defined.",
-            xpath->path);
-    return (-1);
-  }
+    xmlFree(node_value);
+  } else if (xpath->instance_prefix != NULL)
+    sstrncpy(vl->type_instance, xpath->instance_prefix,
+             sizeof(vl->type_instance));
 
-  /* instance has to be an xpath expression */
-  if (xpath->instance != NULL) {
-    int tmp_size;
-
-    instance_node_obj = cx_evaluate_xpath(xpath_ctx, BAD_CAST xpath->instance);
-    if (instance_node_obj == NULL)
-      return (-1); /* error is logged already */
-
-    instance_node = instance_node_obj->nodesetval;
-    tmp_size = (instance_node) ? instance_node->nodeNr : 0;
-
-    if (tmp_size <= 0) {
-      WARNING(
-          "curl_xml plugin: "
-          "relative xpath expression for 'InstanceFrom' \"%s\" doesn't match "
-          "any of the nodes. Skipping the node.",
-          xpath->instance);
-      xmlXPathFreeObject(instance_node_obj);
-      return (-1);
-    }
+  /* Handle plugin instance */
+  if (xpath->plugin_instance_from != NULL) {
+    char *node_value = cx_get_text_node_value(
+        xpath_ctx, xpath->plugin_instance_from, "PluginInstanceFrom");
 
-    if (tmp_size > 1) {
-      WARNING("curl_xml plugin: "
-              "relative xpath expression for 'InstanceFrom' \"%s\" is expected "
-              "to return only one text node. Skipping the node.",
-              xpath->instance);
-      xmlXPathFreeObject(instance_node_obj);
-      return (-1);
-    }
+    if (node_value == NULL)
+      return -1;
 
-    /* ignoring the element if other than textnode/attribute */
-    if (cx_if_not_text_node(instance_node->nodeTab[0])) {
-      WARNING("curl_xml plugin: "
-              "relative xpath expression \"%s\" is expected to return only "
-              "text node "
-              "which is not the case. Skipping the node.",
-              xpath->instance);
-      xmlXPathFreeObject(instance_node_obj);
-      return (-1);
-    }
-  } /* if (xpath->instance != NULL) */
-
-  if (xpath->instance_prefix != NULL) {
-    if (instance_node != NULL) {
-      char *node_value = (char *)xmlNodeGetContent(instance_node->nodeTab[0]);
-      ssnprintf(vl->type_instance, sizeof(vl->type_instance), "%s%s",
-                xpath->instance_prefix, node_value);
-      sfree(node_value);
-    } else
-      sstrncpy(vl->type_instance, xpath->instance_prefix,
-               sizeof(vl->type_instance));
-  } else {
-    /* If instance_prefix and instance_node are NULL, then
-     * don't set the type_instance */
-    if (instance_node != NULL) {
-      char *node_value = (char *)xmlNodeGetContent(instance_node->nodeTab[0]);
-      sstrncpy(vl->type_instance, node_value, sizeof(vl->type_instance));
-      sfree(node_value);
-    }
+    sstrncpy(vl->plugin_instance, node_value, sizeof(vl->plugin_instance));
+    xmlFree(node_value);
   }
 
-  /* Free `instance_node_obj' this late, because `instance_node' points to
-   * somewhere inside this structure. */
-  xmlXPathFreeObject(instance_node_obj);
-
-  return (0);
+  return 0;
 } /* }}} int cx_handle_instance_xpath */
 
-static int cx_handle_base_xpath(char const *plugin_instance, /* {{{ */
-                                char const *host, xmlXPathContextPtr xpath_ctx,
-                                const data_set_t *ds, char *base_xpath,
-                                cx_xpath_t *xpath) {
-  int total_nodes;
-
-  xmlXPathObjectPtr base_node_obj = NULL;
-  xmlNodeSetPtr base_nodes = NULL;
+static int cx_handle_xpath(const cx_t *db, /* {{{ */
+                           xmlXPathContextPtr xpath_ctx, cx_xpath_t *xpath) {
 
-  value_list_t vl = VALUE_LIST_INIT;
+  const data_set_t *ds = plugin_get_ds(xpath->type);
+  if (cx_check_type(ds, xpath) != 0)
+    return -1;
 
-  base_node_obj = cx_evaluate_xpath(xpath_ctx, BAD_CAST base_xpath);
+  xmlXPathObjectPtr base_node_obj = cx_evaluate_xpath(xpath_ctx, xpath->path);
   if (base_node_obj == NULL)
     return -1; /* error is logged already */
 
-  base_nodes = base_node_obj->nodesetval;
-  total_nodes = (base_nodes) ? base_nodes->nodeNr : 0;
+  xmlNodeSetPtr base_nodes = base_node_obj->nodesetval;
+  int total_nodes = (base_nodes) ? base_nodes->nodeNr : 0;
 
   if (total_nodes == 0) {
     ERROR("curl_xml plugin: "
           "xpath expression \"%s\" doesn't match any of the nodes. "
           "Skipping the xpath block...",
-          base_xpath);
+          xpath->path);
     xmlXPathFreeObject(base_node_obj);
     return -1;
   }
 
   /* If base_xpath returned multiple results, then */
-  /* Instance in the xpath block is required */
-  if (total_nodes > 1 && xpath->instance == NULL) {
+  /* InstanceFrom or PluginInstanceFrom in the xpath block is required */
+  if (total_nodes > 1 && xpath->instance == NULL &&
+      xpath->plugin_instance_from == NULL) {
     ERROR("curl_xml plugin: "
-          "InstanceFrom is must in xpath block since the base xpath expression "
-          "\"%s\" "
+          "InstanceFrom or PluginInstanceFrom is must in xpath block "
+          "since the base xpath expression \"%s\" "
           "returned multiple results. Skipping the xpath block...",
-          base_xpath);
+          xpath->path);
+    xmlXPathFreeObject(base_node_obj);
     return -1;
   }
 
+  value_list_t vl = VALUE_LIST_INIT;
+
   /* set the values for the value_list */
   vl.values_len = ds->ds_num;
   sstrncpy(vl.type, xpath->type, sizeof(vl.type));
-  sstrncpy(vl.plugin, "curl_xml", sizeof(vl.plugin));
-  sstrncpy(vl.host, host, sizeof(vl.host));
-  if (plugin_instance != NULL)
-    sstrncpy(vl.plugin_instance, plugin_instance, sizeof(vl.plugin_instance));
+  sstrncpy(vl.plugin, (db->plugin_name != NULL) ? db->plugin_name : "curl_xml",
+           sizeof(vl.plugin));
+  sstrncpy(vl.host, cx_host(db), sizeof(vl.host));
 
   for (int i = 0; i < total_nodes; i++) {
-    int status;
-
     xpath_ctx->node = base_nodes->nodeTab[i];
 
-    status = cx_handle_instance_xpath(xpath_ctx, xpath, &vl,
-                                      /* is_table = */ (total_nodes > 1));
-    if (status != 0)
+    if (db->instance != NULL)
+      sstrncpy(vl.plugin_instance, db->instance, sizeof(vl.plugin_instance));
+
+    if (cx_handle_instance_xpath(xpath_ctx, xpath, &vl) != 0)
       continue; /* An error has already been reported. */
 
-    status = cx_handle_all_value_xpaths(xpath_ctx, xpath, ds, &vl);
-    if (status != 0)
+    if (cx_handle_all_value_xpaths(xpath_ctx, xpath, ds, &vl) != 0)
       continue; /* An error has been logged. */
   }             /* for (i = 0; i < total_nodes; i++) */
 
   /* free up the allocated memory */
   xmlXPathFreeObject(base_node_obj);
 
-  return (0);
-} /* }}} cx_handle_base_xpath */
+  return 0;
+} /* }}} cx_handle_xpath */
 
-static int cx_handle_parsed_xml(xmlDocPtr doc, /* {{{ */
-                                xmlXPathContextPtr xpath_ctx, cx_t *db) {
-  llentry_t *le;
-  const data_set_t *ds;
-  cx_xpath_t *xpath;
+static int cx_handle_parsed_xml(cx_t *db, xmlDocPtr doc, /* {{{ */
+                                xmlXPathContextPtr xpath_ctx) {
   int status = -1;
 
-  le = llist_head(db->list);
+  llentry_t *le = llist_head(db->xpath_list);
   while (le != NULL) {
-    /* get the ds */
-    xpath = (cx_xpath_t *)le->value;
-    ds = plugin_get_ds(xpath->type);
+    cx_xpath_t *xpath = (cx_xpath_t *)le->value;
 
-    if ((cx_check_type(ds, xpath) == 0) &&
-        (cx_handle_base_xpath(db->instance, cx_host(db), xpath_ctx, ds, le->key,
-                              xpath) == 0))
+    if (cx_handle_xpath(db, xpath_ctx, xpath) == 0)
       status = 0; /* we got atleast one success */
 
     le = le->next;
@@ -555,29 +501,25 @@ static int cx_handle_parsed_xml(xmlDocPtr doc, /* {{{ */
   return status;
 } /* }}} cx_handle_parsed_xml */
 
-static int cx_parse_stats_xml(xmlChar *xml, cx_t *db) /* {{{ */
+static int cx_parse_xml(cx_t *db, char *xml) /* {{{ */
 {
-  int status;
-  xmlDocPtr doc;
-  xmlXPathContextPtr xpath_ctx;
-
   /* Load the XML */
-  doc = xmlParseDoc(xml);
+  xmlDocPtr doc = xmlParseDoc(BAD_CAST xml);
   if (doc == NULL) {
     ERROR("curl_xml plugin: Failed to parse the xml document  - %s", xml);
-    return (-1);
+    return -1;
   }
 
-  xpath_ctx = xmlXPathNewContext(doc);
+  xmlXPathContextPtr xpath_ctx = xmlXPathNewContext(doc);
   if (xpath_ctx == NULL) {
     ERROR("curl_xml plugin: Failed to create the xml context");
     xmlFreeDoc(doc);
-    return (-1);
+    return -1;
   }
 
   for (size_t i = 0; i < db->namespaces_num; i++) {
     cx_namespace_t const *ns = db->namespaces + i;
-    status =
+    int status =
         xmlXPathRegisterNs(xpath_ctx, BAD_CAST ns->prefix, BAD_CAST ns->url);
     if (status != 0) {
       ERROR("curl_xml plugin: "
@@ -585,67 +527,57 @@ static int cx_parse_stats_xml(xmlChar *xml, cx_t *db) /* {{{ */
             ns->prefix, ns->url);
       xmlXPathFreeContext(xpath_ctx);
       xmlFreeDoc(doc);
-      return (status);
+      return status;
     }
   }
 
-  status = cx_handle_parsed_xml(doc, xpath_ctx, db);
+  int status = cx_handle_parsed_xml(db, doc, xpath_ctx);
   /* Cleanup */
   xmlXPathFreeContext(xpath_ctx);
   xmlFreeDoc(doc);
   return status;
-} /* }}} cx_parse_stats_xml */
+} /* }}} cx_parse_xml */
 
-static int cx_curl_perform(cx_t *db, CURL *curl) /* {{{ */
+static int cx_read(user_data_t *ud) /* {{{ */
 {
-  int status;
+  if ((ud == NULL) || (ud->data == NULL)) {
+    ERROR("curl_xml plugin: cx_read: Invalid user data.");
+    return -1;
+  }
+
   long rc;
-  char *ptr;
   char *url;
-  url = db->url;
+  cx_t *db = (cx_t *)ud->data;
 
   db->buffer_fill = 0;
-  status = curl_easy_perform(curl);
+
+  curl_easy_setopt(db->curl, CURLOPT_URL, db->url);
+
+  int status = curl_easy_perform(db->curl);
   if (status != CURLE_OK) {
     ERROR("curl_xml plugin: curl_easy_perform failed with status %i: %s (%s)",
-          status, db->curl_errbuf, url);
-    return (-1);
+          status, db->curl_errbuf, db->url);
+    return -1;
   }
   if (db->stats != NULL)
     curl_stats_dispatch(db->stats, db->curl, cx_host(db), "curl_xml",
                         db->instance);
 
-  curl_easy_getinfo(curl, CURLINFO_EFFECTIVE_URL, &url);
-  curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &rc);
+  curl_easy_getinfo(db->curl, CURLINFO_EFFECTIVE_URL, &url);
+  curl_easy_getinfo(db->curl, CURLINFO_RESPONSE_CODE, &rc);
 
   /* The response code is zero if a non-HTTP transport was used. */
   if ((rc != 0) && (rc != 200)) {
     ERROR(
         "curl_xml plugin: curl_easy_perform failed with response code %ld (%s)",
         rc, url);
-    return (-1);
+    return -1;
   }
 
-  ptr = db->buffer;
-
-  status = cx_parse_stats_xml(BAD_CAST ptr, db);
+  status = cx_parse_xml(db, db->buffer);
   db->buffer_fill = 0;
 
   return status;
-} /* }}} int cx_curl_perform */
-
-static int cx_read(user_data_t *ud) /* {{{ */
-{
-  cx_t *db;
-
-  if ((ud == NULL) || (ud->data == NULL)) {
-    ERROR("curl_xml plugin: cx_read: Invalid user data.");
-    return (-1);
-  }
-
-  db = (cx_t *)ud->data;
-
-  return cx_curl_perform(db, db->curl);
 } /* }}} int cx_read */
 
 /* Configuration handling functions {{{ */
@@ -654,13 +586,13 @@ static int cx_config_add_values(const char *name, cx_xpath_t *xpath, /* {{{ */
                                 oconfig_item_t *ci) {
   if (ci->values_num < 1) {
     WARNING("curl_xml plugin: `ValuesFrom' needs at least one argument.");
-    return (-1);
+    return -1;
   }
 
   for (int i = 0; i < ci->values_num; i++)
     if (ci->values[i].type != OCONFIG_TYPE_STRING) {
       WARNING("curl_xml plugin: `ValuesFrom' needs only string argument.");
-      return (-1);
+      return -1;
     }
 
   sfree(xpath->values);
@@ -668,7 +600,7 @@ static int cx_config_add_values(const char *name, cx_xpath_t *xpath, /* {{{ */
   xpath->values_len = 0;
   xpath->values = malloc(sizeof(cx_values_t) * ci->values_num);
   if (xpath->values == NULL)
-    return (-1);
+    return -1;
   xpath->values_len = (size_t)ci->values_num;
 
   /* populate cx_values_t structure */
@@ -678,26 +610,21 @@ static int cx_config_add_values(const char *name, cx_xpath_t *xpath, /* {{{ */
              sizeof(xpath->values[i].path));
   }
 
-  return (0);
+  return 0;
 } /* }}} cx_config_add_values */
 
 static int cx_config_add_xpath(cx_t *db, oconfig_item_t *ci) /* {{{ */
 {
-  cx_xpath_t *xpath;
-  char *name;
-  llentry_t *le;
-  int status;
-
-  xpath = calloc(1, sizeof(*xpath));
+  cx_xpath_t *xpath = calloc(1, sizeof(*xpath));
   if (xpath == NULL) {
     ERROR("curl_xml plugin: calloc failed.");
-    return (-1);
+    return -1;
   }
 
-  status = cf_util_get_string(ci, &xpath->path);
+  int status = cf_util_get_string(ci, &xpath->path);
   if (status != 0) {
     cx_xpath_free(xpath);
-    return (status);
+    return status;
   }
 
   /* error out if xpath->path is an empty string */
@@ -705,7 +632,7 @@ static int cx_config_add_xpath(cx_t *db, oconfig_item_t *ci) /* {{{ */
     ERROR("curl_xml plugin: invalid xpath. "
           "xpath value can't be an empty string");
     cx_xpath_free(xpath);
-    return (-1);
+    return -1;
   }
 
   status = 0;
@@ -718,6 +645,8 @@ static int cx_config_add_xpath(cx_t *db, oconfig_item_t *ci) /* {{{ */
       status = cf_util_get_string(child, &xpath->instance_prefix);
     else if (strcasecmp("InstanceFrom", child->key) == 0)
       status = cf_util_get_string(child, &xpath->instance);
+    else if (strcasecmp("PluginInstanceFrom", child->key) == 0)
+      status = cf_util_get_string(child, &xpath->plugin_instance_from);
     else if (strcasecmp("ValuesFrom", child->key) == 0)
       status = cx_config_add_values("ValuesFrom", xpath, child);
     else {
@@ -740,50 +669,38 @@ static int cx_config_add_xpath(cx_t *db, oconfig_item_t *ci) /* {{{ */
     return -1;
   }
 
-  if (db->list == NULL) {
-    db->list = llist_create();
-    if (db->list == NULL) {
-      ERROR("curl_xml plugin: list creation failed.");
-      cx_xpath_free(xpath);
-      return (-1);
-    }
-  }
-
-  name = strdup(xpath->path);
-  if (name == NULL) {
-    ERROR("curl_xml plugin: strdup failed.");
+  if (xpath->values_len == 0) {
+    WARNING("curl_xml plugin: `ValuesFrom' missing in `xpath' block.");
     cx_xpath_free(xpath);
-    return (-1);
+    return -1;
   }
 
-  le = llentry_create(name, xpath);
+  llentry_t *le = llentry_create(xpath->path, xpath);
   if (le == NULL) {
     ERROR("curl_xml plugin: llentry_create failed.");
     cx_xpath_free(xpath);
-    sfree(name);
-    return (-1);
+    return -1;
   }
 
-  llist_append(db->list, le);
-  return (0);
+  llist_append(db->xpath_list, le);
+  return 0;
 } /* }}} int cx_config_add_xpath */
 
 static int cx_config_add_namespace(cx_t *db, /* {{{ */
                                    oconfig_item_t *ci) {
-  cx_namespace_t *ns;
 
   if ((ci->values_num != 2) || (ci->values[0].type != OCONFIG_TYPE_STRING) ||
       (ci->values[1].type != OCONFIG_TYPE_STRING)) {
     WARNING("curl_xml plugin: The `Namespace' option "
             "needs exactly two string arguments.");
-    return (EINVAL);
+    return EINVAL;
   }
 
-  ns = realloc(db->namespaces,
-               sizeof(*db->namespaces) * (db->namespaces_num + 1));
+  cx_namespace_t *ns = realloc(
+      db->namespaces, sizeof(*db->namespaces) * (db->namespaces_num + 1));
   if (ns == NULL) {
     ERROR("curl_xml plugin: realloc failed.");
-    return (ENOMEM);
+    return ENOMEM;
   }
   db->namespaces = ns;
   ns = db->namespaces + db->namespaces_num;
@@ -796,11 +713,11 @@ static int cx_config_add_namespace(cx_t *db, /* {{{ */
     sfree(ns->prefix);
     sfree(ns->url);
     ERROR("curl_xml plugin: strdup failed.");
-    return (ENOMEM);
+    return ENOMEM;
   }
 
   db->namespaces_num++;
-  return (0);
+  return 0;
 } /* }}} int cx_config_add_namespace */
 
 /* Initialize db->curl */
@@ -809,7 +726,7 @@ static int cx_init_curl(cx_t *db) /* {{{ */
   db->curl = curl_easy_init();
   if (db->curl == NULL) {
     ERROR("curl_xml plugin: curl_easy_init failed.");
-    return (-1);
+    return -1;
   }
 
   curl_easy_setopt(db->curl, CURLOPT_NOSIGNAL, 1L);
@@ -817,7 +734,6 @@ static int cx_init_curl(cx_t *db) /* {{{ */
   curl_easy_setopt(db->curl, CURLOPT_WRITEDATA, db);
   curl_easy_setopt(db->curl, CURLOPT_USERAGENT, COLLECTD_USERAGENT);
   curl_easy_setopt(db->curl, CURLOPT_ERRORBUFFER, db->curl_errbuf);
-  curl_easy_setopt(db->curl, CURLOPT_URL, db->url);
   curl_easy_setopt(db->curl, CURLOPT_FOLLOWLOCATION, 1L);
   curl_easy_setopt(db->curl, CURLOPT_MAXREDIRS, 50L);
 
@@ -836,11 +752,11 @@ static int cx_init_curl(cx_t *db) /* {{{ */
     db->credentials = malloc(credentials_size);
     if (db->credentials == NULL) {
       ERROR("curl_xml plugin: malloc failed.");
-      return (-1);
+      return -1;
     }
 
-    ssnprintf(db->credentials, credentials_size, "%s:%s", db->user,
-              (db->pass == NULL) ? "" : db->pass);
+    snprintf(db->credentials, credentials_size, "%s:%s", db->user,
+             (db->pass == NULL) ? "" : db->pass);
     curl_easy_setopt(db->curl, CURLOPT_USERPWD, db->credentials);
 #endif
 
@@ -865,40 +781,46 @@ static int cx_init_curl(cx_t *db) /* {{{ */
                      (long)CDTIME_T_TO_MS(plugin_get_interval()));
 #endif
 
-  return (0);
+  return 0;
 } /* }}} int cx_init_curl */
 
 static int cx_config_add_url(oconfig_item_t *ci) /* {{{ */
 {
-  cx_t *db;
-  int status = 0;
-
   if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_STRING)) {
     WARNING("curl_xml plugin: The `URL' block "
             "needs exactly one string argument.");
-    return (-1);
+    return -1;
   }
 
-  db = calloc(1, sizeof(*db));
+  cx_t *db = calloc(1, sizeof(*db));
   if (db == NULL) {
     ERROR("curl_xml plugin: calloc failed.");
-    return (-1);
+    return -1;
+  }
+
+  db->instance = strdup("default");
+  if (db->instance == NULL) {
+    ERROR("curl_xml plugin: strdup failed.");
+    sfree(db);
+    return -1;
+  }
+
+  db->xpath_list = llist_create();
+  if (db->xpath_list == NULL) {
+    ERROR("curl_xml plugin: list creation failed.");
+    sfree(db->instance);
+    sfree(db);
+    return -1;
   }
 
   db->timeout = -1;
 
-  if (strcasecmp("URL", ci->key) == 0) {
-    status = cf_util_get_string(ci, &db->url);
-    if (status != 0) {
-      sfree(db);
-      return (status);
-    }
-  } else {
-    ERROR("curl_xml plugin: cx_config: "
-          "Invalid key: %s",
-          ci->key);
-    cx_free(db);
-    return (-1);
+  int status = cf_util_get_string(ci, &db->url);
+  if (status != 0) {
+    llist_destroy(db->xpath_list);
+    sfree(db->instance);
+    sfree(db);
+    return status;
   }
 
   /* Fill the `cx_t' structure.. */
@@ -907,6 +829,8 @@ static int cx_config_add_url(oconfig_item_t *ci) /* {{{ */
 
     if (strcasecmp("Instance", child->key) == 0)
       status = cf_util_get_string(child, &db->instance);
+    else if (strcasecmp("Plugin", child->key) == 0)
+      status = cf_util_get_string(child, &db->plugin_name);
     else if (strcasecmp("Host", child->key) == 0)
       status = cf_util_get_string(child, &db->host);
     else if (strcasecmp("User", child->key) == 0)
@@ -944,59 +868,49 @@ static int cx_config_add_url(oconfig_item_t *ci) /* {{{ */
       break;
   }
 
-  if (status == 0) {
-    if (db->list == NULL) {
-      WARNING("curl_xml plugin: No (valid) `Key' block "
-              "within `URL' block `%s'.",
-              db->url);
-      status = -1;
-    }
-    if (status == 0)
-      status = cx_init_curl(db);
+  if (status != 0) {
+    cx_free(db);
+    return status;
   }
 
-  /* If all went well, register this database for reading */
-  if (status == 0) {
-    char *cb_name;
-
-    if (db->instance == NULL)
-      db->instance = strdup("default");
-
-    DEBUG("curl_xml plugin: Registering new read callback: %s", db->instance);
-
-    cb_name = ssnprintf_alloc("curl_xml-%s-%s", db->instance, db->url);
+  if (llist_size(db->xpath_list) == 0) {
+    WARNING("curl_xml plugin: No `xpath' block within `URL' block `%s'.",
+            db->url);
+    cx_free(db);
+    return -1;
+  }
 
-    plugin_register_complex_read(/* group = */ "curl_xml", cb_name, cx_read,
-                                 /* interval = */ 0,
-                                 &(user_data_t){
-                                     .data = db, .free_func = cx_free,
-                                 });
-    sfree(cb_name);
-  } else {
+  if (cx_init_curl(db) != 0) {
     cx_free(db);
-    return (-1);
+    return -1;
   }
 
-  return (0);
+  /* If all went well, register this database for reading */
+  DEBUG("curl_xml plugin: Registering new read callback: %s", db->instance);
+
+  char *cb_name = ssnprintf_alloc("curl_xml-%s-%s", db->instance, db->url);
+
+  plugin_register_complex_read(/* group = */ "curl_xml", cb_name, cx_read,
+                               /* interval = */ 0,
+                               &(user_data_t){
+                                   .data = db, .free_func = cx_free,
+                               });
+  sfree(cb_name);
+  return 0;
 } /* }}} int cx_config_add_url */
 
 /* }}} End of configuration handling functions */
 
 static int cx_config(oconfig_item_t *ci) /* {{{ */
 {
-  int success;
-  int errors;
-  int status;
-
-  success = 0;
-  errors = 0;
+  int success = 0;
+  int errors = 0;
 
   for (int i = 0; i < ci->children_num; i++) {
     oconfig_item_t *child = ci->children + i;
 
     if (strcasecmp("URL", child->key) == 0) {
-      status = cx_config_add_url(child);
-      if (status == 0)
+      if (cx_config_add_url(child) == 0)
         success++;
       else
         errors++;
@@ -1008,10 +922,10 @@ static int cx_config(oconfig_item_t *ci) /* {{{ */
 
   if ((success == 0) && (errors > 0)) {
     ERROR("curl_xml plugin: All statements failed.");
-    return (-1);
+    return -1;
   }
 
-  return (0);
+  return 0;
 } /* }}} int cx_config */
 
 static int cx_init(void) /* {{{ */
@@ -1019,7 +933,7 @@ static int cx_init(void) /* {{{ */
   /* Call this while collectd is still single-threaded to avoid
    * initialization issues in libgcrypt. */
   curl_global_init(CURL_GLOBAL_SSL);
-  return (0);
+  return 0;
 } /* }}} int cx_init */
 
 void module_register(void) {