2 * collectd - src/curl_xml.c
3 * Copyright (C) 2009,2010 Amit Gupta
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 * Amit Gupta <amit.gupta221 at gmail.com>
25 #include "configfile.h"
26 #include "utils_llist.h"
28 #include <libxml/parser.h>
29 #include <libxml/tree.h>
30 #include <libxml/xpath.h>
32 #include <curl/curl.h>
34 #define CX_DEFAULT_HOST "localhost"
37 * Private data structures
39 struct cx_values_s /* {{{ */
41 char path[DATA_MAX_NAME_LEN];
44 typedef struct cx_values_s cx_values_t;
47 struct cx_xpath_s /* {{{ */
53 char *instance_prefix;
58 typedef struct cx_xpath_s cx_xpath_t;
75 char curl_errbuf[CURL_ERROR_SIZE];
80 llist_t *list; /* list of xpath blocks */
82 typedef struct cx_s cx_t; /* }}} */
87 static size_t cx_curl_callback (void *buf, /* {{{ */
88 size_t size, size_t nmemb, void *user_data)
90 size_t len = size * nmemb;
96 ERROR ("curl_xml plugin: cx_curl_callback: "
97 "user_data pointer is NULL.");
104 if ((db->buffer_fill + len) >= db->buffer_size)
108 temp = (char *) realloc (db->buffer,
109 db->buffer_fill + len + 1);
112 ERROR ("curl_xml plugin: realloc failed.");
116 db->buffer_size = db->buffer_fill + len + 1;
119 memcpy (db->buffer + db->buffer_fill, (char *) buf, len);
120 db->buffer_fill += len;
121 db->buffer[db->buffer_fill] = 0;
124 } /* }}} size_t cx_curl_callback */
126 static void cx_xpath_free (cx_xpath_t *xpath) /* {{{ */
133 sfree (xpath->instance_prefix);
134 sfree (xpath->instance);
135 sfree (xpath->values);
137 } /* }}} void cx_xpath_free */
139 static void cx_list_free (llist_t *list) /* {{{ */
143 le = llist_head (list);
151 cx_xpath_free (le->value);
156 llist_destroy (list);
158 } /* }}} void cx_list_free */
160 static void cx_free (void *arg) /* {{{ */
164 DEBUG ("curl_xml plugin: cx_free (arg = %p);", arg);
171 if (db->curl != NULL)
172 curl_easy_cleanup (db->curl);
175 if (db->list != NULL)
176 cx_list_free (db->list);
179 sfree (db->instance);
185 sfree (db->credentials);
189 } /* }}} void cx_free */
191 static int cx_check_type (const data_set_t *ds, cx_xpath_t *xpath) /* {{{ */
195 WARNING ("curl_xml plugin: DataSet `%s' not defined.", xpath->type);
199 if (ds->ds_num != xpath->values_len)
201 WARNING ("curl_xml plugin: DataSet `%s' requires %i values, but config talks about %i",
202 xpath->type, ds->ds_num, xpath->values_len);
207 } /* }}} cx_check_type */
209 static xmlXPathObjectPtr cx_evaluate_xpath (xmlXPathContextPtr xpath_ctx, /* {{{ */
212 xmlXPathObjectPtr xpath_obj;
214 /* XXX: When to free this? */
215 xpath_obj = xmlXPathEvalExpression(BAD_CAST expr, xpath_ctx);
216 if (xpath_obj == NULL)
218 WARNING ("curl_xml plugin: "
219 "Error unable to evaluate xpath expression \"%s\". Skipping...", expr);
224 } /* }}} cx_evaluate_xpath */
226 static int cx_if_not_text_node (xmlNodePtr node) /* {{{ */
228 if (node->type == XML_TEXT_NODE || node->type == XML_ATTRIBUTE_NODE)
231 WARNING ("curl_xml plugin: "
232 "Node \"%s\" doesn't seem to be a text node. Skipping...", node->name);
234 } /* }}} cx_if_not_text_node */
236 static int cx_handle_single_value_xpath (xmlXPathContextPtr xpath_ctx, /* {{{ */
238 const data_set_t *ds, value_list_t *vl, int index)
240 xmlXPathObjectPtr values_node_obj;
241 xmlNodeSetPtr values_node;
245 values_node_obj = cx_evaluate_xpath (xpath_ctx, BAD_CAST xpath->values[index].path);
246 if (values_node_obj == NULL)
247 return (-1); /* Error already logged. */
249 values_node = values_node_obj->nodesetval;
250 tmp_size = (values_node) ? values_node->nodeNr : 0;
254 WARNING ("curl_xml plugin: "
255 "relative xpath expression \"%s\" doesn't match any of the nodes. "
256 "Skipping...", xpath->values[index].path);
257 xmlXPathFreeObject (values_node_obj);
263 WARNING ("curl_xml plugin: "
264 "relative xpath expression \"%s\" is expected to return "
265 "only one node. Skipping...", xpath->values[index].path);
266 xmlXPathFreeObject (values_node_obj);
270 /* ignoring the element if other than textnode/attribute*/
271 if (cx_if_not_text_node(values_node->nodeTab[0]))
273 WARNING ("curl_xml plugin: "
274 "relative xpath expression \"%s\" is expected to return "
275 "only text/attribute node which is not the case. Skipping...",
276 xpath->values[index].path);
277 xmlXPathFreeObject (values_node_obj);
281 node_value = (char *) xmlNodeGetContent(values_node->nodeTab[0]);
282 switch (ds->ds[index].type)
284 case DS_TYPE_COUNTER:
285 vl->values[index].counter = (counter_t) strtoull (node_value,
286 /* endptr = */ NULL, /* base = */ 0);
289 vl->values[index].derive = (derive_t) strtoll (node_value,
290 /* endptr = */ NULL, /* base = */ 0);
292 case DS_TYPE_ABSOLUTE:
293 vl->values[index].absolute = (absolute_t) strtoull (node_value,
294 /* endptr = */ NULL, /* base = */ 0);
297 vl->values[index].gauge = (gauge_t) strtod (node_value,
298 /* endptr = */ NULL);
302 xmlXPathFreeObject (values_node_obj);
304 /* We have reached here which means that
305 * we have got something to work */
307 } /* }}} int cx_handle_single_value_xpath */
309 static int cx_handle_all_value_xpaths (xmlXPathContextPtr xpath_ctx, /* {{{ */
311 const data_set_t *ds, value_list_t *vl)
313 value_t values[xpath->values_len];
317 assert (xpath->values_len > 0);
318 assert (xpath->values_len == vl->values_len);
319 assert (xpath->values_len == ds->ds_num);
322 for (i = 0; i < xpath->values_len; i++)
324 status = cx_handle_single_value_xpath (xpath_ctx, xpath, ds, vl, i);
326 return (-1); /* An error has been printed. */
327 } /* for (i = 0; i < xpath->values_len; i++) */
329 plugin_dispatch_values (vl);
333 } /* }}} int cx_handle_all_value_xpaths */
335 static int cx_handle_instance_xpath (xmlXPathContextPtr xpath_ctx, /* {{{ */
336 cx_xpath_t *xpath, value_list_t *vl,
339 xmlXPathObjectPtr instance_node_obj = NULL;
340 xmlNodeSetPtr instance_node = NULL;
342 memset (vl->type_instance, 0, sizeof (vl->type_instance));
344 /* If the base xpath returns more than one block, the result is assumed to be
345 * a table. The `Instnce' option is not optional in this case. Check for the
346 * condition and inform the user. */
347 if (is_table && (vl->type_instance == NULL))
349 WARNING ("curl_xml plugin: "
350 "Base-XPath %s is a table (more than one result was returned), "
351 "but no instance-XPath has been defined.",
356 /* instance has to be an xpath expression */
357 if (xpath->instance != NULL)
361 instance_node_obj = cx_evaluate_xpath (xpath_ctx, BAD_CAST xpath->instance);
362 if (instance_node_obj == NULL)
363 return (-1); /* error is logged already */
365 instance_node = instance_node_obj->nodesetval;
366 tmp_size = (instance_node) ? instance_node->nodeNr : 0;
368 if ( (tmp_size == 0) && (is_table) )
370 WARNING ("curl_xml plugin: "
371 "relative xpath expression for 'InstanceFrom' \"%s\" doesn't match "
372 "any of the nodes. Skipping the node.", xpath->instance);
373 xmlXPathFreeObject (instance_node_obj);
379 WARNING ("curl_xml plugin: "
380 "relative xpath expression for 'InstanceFrom' \"%s\" is expected "
381 "to return only one text node. Skipping the node.", xpath->instance);
382 xmlXPathFreeObject (instance_node_obj);
386 /* ignoring the element if other than textnode/attribute */
387 if (cx_if_not_text_node(instance_node->nodeTab[0]))
389 WARNING ("curl_xml plugin: "
390 "relative xpath expression \"%s\" is expected to return only text node "
391 "which is not the case. Skipping the node.", xpath->instance);
392 xmlXPathFreeObject (instance_node_obj);
395 } /* if (xpath->instance != NULL) */
397 if (xpath->instance_prefix != NULL)
399 if (instance_node != NULL)
400 ssnprintf (vl->type_instance, sizeof (vl->type_instance),"%s%s",
401 xpath->instance_prefix, (char *) xmlNodeGetContent(instance_node->nodeTab[0]));
403 sstrncpy (vl->type_instance, xpath->instance_prefix,
404 sizeof (vl->type_instance));
408 /* If instance_prefix and instance_node are NULL, then
409 * don't set the type_instance */
410 if (instance_node != NULL)
411 sstrncpy (vl->type_instance, (char *) xmlNodeGetContent(instance_node->nodeTab[0]),
412 sizeof (vl->type_instance));
415 /* Free `instance_node_obj' this late, because `instance_node' points to
416 * somewhere inside this structure. */
417 xmlXPathFreeObject (instance_node_obj);
420 } /* }}} int cx_handle_instance_xpath */
422 static int cx_handle_base_xpath (char *plugin_instance, /* {{{ */
423 xmlXPathContextPtr xpath_ctx, const data_set_t *ds,
424 char *base_xpath, cx_xpath_t *xpath)
429 xmlXPathObjectPtr base_node_obj = NULL;
430 xmlNodeSetPtr base_nodes = NULL;
432 value_list_t vl = VALUE_LIST_INIT;
434 base_node_obj = cx_evaluate_xpath (xpath_ctx, BAD_CAST base_xpath);
435 if (base_node_obj == NULL)
436 return -1; /* error is logged already */
438 base_nodes = base_node_obj->nodesetval;
439 total_nodes = (base_nodes) ? base_nodes->nodeNr : 0;
441 if (total_nodes == 0)
443 ERROR ("curl_xml plugin: "
444 "xpath expression \"%s\" doesn't match any of the nodes. "
445 "Skipping the xpath block...", base_xpath);
446 xmlXPathFreeObject (base_node_obj);
450 /* If base_xpath returned multiple results, then */
451 /* Instance in the xpath block is required */
452 if (total_nodes > 1 && xpath->instance == NULL)
454 ERROR ("curl_xml plugin: "
455 "InstanceFrom is must in xpath block since the base xpath expression \"%s\" "
456 "returned multiple results. Skipping the xpath block...", base_xpath);
460 /* set the values for the value_list */
461 vl.values_len = ds->ds_num;
462 sstrncpy (vl.type, xpath->type, sizeof (vl.type));
463 sstrncpy (vl.plugin, "curl_xml", sizeof (vl.plugin));
464 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
465 if (plugin_instance != NULL)
466 sstrncpy (vl.plugin_instance, plugin_instance, sizeof (vl.plugin_instance));
468 for (i = 0; i < total_nodes; i++)
472 xpath_ctx->node = base_nodes->nodeTab[i];
474 status = cx_handle_instance_xpath (xpath_ctx, xpath, &vl,
475 /* is_table = */ (total_nodes > 1));
477 continue; /* An error has already been reported. */
479 status = cx_handle_all_value_xpaths (xpath_ctx, xpath, ds, &vl);
481 continue; /* An error has been logged. */
482 } /* for (i = 0; i < total_nodes; i++) */
484 /* free up the allocated memory */
485 xmlXPathFreeObject (base_node_obj);
488 } /* }}} cx_handle_base_xpath */
490 static int cx_handle_parsed_xml(xmlDocPtr doc, /* {{{ */
491 xmlXPathContextPtr xpath_ctx, cx_t *db)
494 const data_set_t *ds;
499 le = llist_head (db->list);
503 xpath = (cx_xpath_t *) le->value;
504 ds = plugin_get_ds (xpath->type);
506 if ( (cx_check_type(ds, xpath) == 0) &&
507 (cx_handle_base_xpath(db->instance, xpath_ctx, ds, le->key, xpath) == 0) )
508 status = 0; /* we got atleast one success */
511 } /* while (le != NULL) */
514 } /* }}} cx_handle_parsed_xml */
516 static int cx_parse_stats_xml(xmlChar* xml, cx_t *db) /* {{{ */
520 xmlXPathContextPtr xpath_ctx;
523 doc = xmlParseDoc(xml);
526 ERROR ("curl_xml plugin: Failed to parse the xml document - %s", xml);
530 xpath_ctx = xmlXPathNewContext(doc);
531 if(xpath_ctx == NULL)
533 ERROR ("curl_xml plugin: Failed to create the xml context");
538 status = cx_handle_parsed_xml (doc, xpath_ctx, db);
540 xmlXPathFreeContext(xpath_ctx);
543 } /* }}} cx_parse_stats_xml */
545 static int cx_curl_perform (cx_t *db, CURL *curl) /* {{{ */
553 status = curl_easy_perform (curl);
555 curl_easy_getinfo(curl, CURLINFO_EFFECTIVE_URL, &url);
556 curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &rc);
558 /* The response code is zero if a non-HTTP transport was used. */
559 if ((rc != 0) && (rc != 200))
561 ERROR ("curl_xml plugin: curl_easy_perform failed with response code %ld (%s)",
568 ERROR ("curl_xml plugin: curl_easy_perform failed with status %i: %s (%s)",
569 status, db->curl_errbuf, url);
575 status = cx_parse_stats_xml(BAD_CAST ptr, db);
579 } /* }}} int cx_curl_perform */
581 static int cx_read (user_data_t *ud) /* {{{ */
585 if ((ud == NULL) || (ud->data == NULL))
587 ERROR ("curl_xml plugin: cx_read: Invalid user data.");
591 db = (cx_t *) ud->data;
593 return cx_curl_perform (db, db->curl);
594 } /* }}} int cx_read */
596 /* Configuration handling functions {{{ */
598 static int cx_config_add_values (const char *name, cx_xpath_t *xpath, /* {{{ */
603 if (ci->values_num < 1)
605 WARNING ("curl_xml plugin: `ValuesFrom' needs at least one argument.");
609 for (i = 0; i < ci->values_num; i++)
610 if (ci->values[i].type != OCONFIG_TYPE_STRING)
612 WARNING ("curl_xml plugin: `ValuesFrom' needs only string argument.");
616 sfree (xpath->values);
618 xpath->values_len = 0;
619 xpath->values = (cx_values_t *) malloc (sizeof (cx_values_t) * ci->values_num);
620 if (xpath->values == NULL)
622 xpath->values_len = ci->values_num;
624 /* populate cx_values_t structure */
625 for (i = 0; i < ci->values_num; i++)
627 xpath->values[i].path_len = sizeof (ci->values[i].value.string);
628 sstrncpy (xpath->values[i].path, ci->values[i].value.string, sizeof (xpath->values[i].path));
632 } /* }}} cx_config_add_values */
634 static int cx_config_add_xpath (cx_t *db, /* {{{ */
641 xpath = (cx_xpath_t *) malloc (sizeof (*xpath));
644 ERROR ("curl_xml plugin: malloc failed.");
647 memset (xpath, 0, sizeof (*xpath));
649 status = cf_util_get_string (ci, &xpath->path);
656 /* error out if xpath->path is an empty string */
657 if (*xpath->path == 0)
659 ERROR ("curl_xml plugin: invalid xpath. "
660 "xpath value can't be an empty string");
665 for (i = 0; i < ci->children_num; i++)
667 oconfig_item_t *child = ci->children + i;
669 if (strcasecmp ("Type", child->key) == 0)
670 status = cf_util_get_string (child, &xpath->type);
671 else if (strcasecmp ("InstancePrefix", child->key) == 0)
672 status = cf_util_get_string (child, &xpath->instance_prefix);
673 else if (strcasecmp ("InstanceFrom", child->key) == 0)
674 status = cf_util_get_string (child, &xpath->instance);
675 else if (strcasecmp ("ValuesFrom", child->key) == 0)
676 status = cx_config_add_values ("ValuesFrom", xpath, child);
679 WARNING ("curl_xml plugin: Option `%s' not allowed here.", child->key);
685 } /* for (i = 0; i < ci->children_num; i++) */
687 if (status == 0 && xpath->type == NULL)
689 WARNING ("curl_xml plugin: `Type' missing in `xpath' block.");
698 if (db->list == NULL)
700 db->list = llist_create();
701 if (db->list == NULL)
703 ERROR ("curl_xml plugin: list creation failed.");
708 name = strdup(xpath->path);
711 ERROR ("curl_xml plugin: strdup failed.");
715 le = llentry_create (name, xpath);
718 ERROR ("curl_xml plugin: llentry_create failed.");
722 llist_append (db->list, le);
726 } /* }}} int cx_config_add_xpath */
728 /* Initialize db->curl */
729 static int cx_init_curl (cx_t *db) /* {{{ */
731 db->curl = curl_easy_init ();
732 if (db->curl == NULL)
734 ERROR ("curl_xml plugin: curl_easy_init failed.");
738 curl_easy_setopt (db->curl, CURLOPT_NOSIGNAL, 1);
739 curl_easy_setopt (db->curl, CURLOPT_WRITEFUNCTION, cx_curl_callback);
740 curl_easy_setopt (db->curl, CURLOPT_WRITEDATA, db);
741 curl_easy_setopt (db->curl, CURLOPT_USERAGENT,
742 PACKAGE_NAME"/"PACKAGE_VERSION);
743 curl_easy_setopt (db->curl, CURLOPT_ERRORBUFFER, db->curl_errbuf);
744 curl_easy_setopt (db->curl, CURLOPT_URL, db->url);
746 if (db->user != NULL)
748 size_t credentials_size;
750 credentials_size = strlen (db->user) + 2;
751 if (db->pass != NULL)
752 credentials_size += strlen (db->pass);
754 db->credentials = (char *) malloc (credentials_size);
755 if (db->credentials == NULL)
757 ERROR ("curl_xml plugin: malloc failed.");
761 ssnprintf (db->credentials, credentials_size, "%s:%s",
762 db->user, (db->pass == NULL) ? "" : db->pass);
763 curl_easy_setopt (db->curl, CURLOPT_USERPWD, db->credentials);
766 curl_easy_setopt (db->curl, CURLOPT_SSL_VERIFYPEER, db->verify_peer ? 1L : 0L);
767 curl_easy_setopt (db->curl, CURLOPT_SSL_VERIFYHOST,
768 db->verify_host ? 2L : 0L);
769 if (db->cacert != NULL)
770 curl_easy_setopt (db->curl, CURLOPT_CAINFO, db->cacert);
773 } /* }}} int cx_init_curl */
775 static int cx_config_add_url (oconfig_item_t *ci) /* {{{ */
781 if ((ci->values_num != 1)
782 || (ci->values[0].type != OCONFIG_TYPE_STRING))
784 WARNING ("curl_xml plugin: The `URL' block "
785 "needs exactly one string argument.");
789 db = (cx_t *) malloc (sizeof (*db));
792 ERROR ("curl_xml plugin: malloc failed.");
795 memset (db, 0, sizeof (*db));
797 if (strcasecmp ("URL", ci->key) == 0)
799 status = cf_util_get_string (ci, &db->url);
808 ERROR ("curl_xml plugin: cx_config: "
809 "Invalid key: %s", ci->key);
813 /* Fill the `cx_t' structure.. */
814 for (i = 0; i < ci->children_num; i++)
816 oconfig_item_t *child = ci->children + i;
818 if (strcasecmp ("Instance", child->key) == 0)
819 status = cf_util_get_string (child, &db->instance);
820 else if (strcasecmp ("Host", child->key) == 0)
821 status = cf_util_get_string (child, &db->host);
822 else if (strcasecmp ("User", child->key) == 0)
823 status = cf_util_get_string (child, &db->user);
824 else if (strcasecmp ("Password", child->key) == 0)
825 status = cf_util_get_string (child, &db->pass);
826 else if (strcasecmp ("VerifyPeer", child->key) == 0)
827 status = cf_util_get_boolean (child, &db->verify_peer);
828 else if (strcasecmp ("VerifyHost", child->key) == 0)
829 status = cf_util_get_boolean (child, &db->verify_host);
830 else if (strcasecmp ("CACert", child->key) == 0)
831 status = cf_util_get_string (child, &db->cacert);
832 else if (strcasecmp ("xpath", child->key) == 0)
833 status = cx_config_add_xpath (db, child);
836 WARNING ("curl_xml plugin: Option `%s' not allowed here.", child->key);
846 if (db->list == NULL)
848 WARNING ("curl_xml plugin: No (valid) `Key' block "
849 "within `URL' block `%s'.", db->url);
853 status = cx_init_curl (db);
856 /* If all went well, register this database for reading */
860 char cb_name[DATA_MAX_NAME_LEN];
862 if (db->instance == NULL)
863 db->instance = strdup("default");
865 DEBUG ("curl_xml plugin: Registering new read callback: %s",
868 memset (&ud, 0, sizeof (ud));
869 ud.data = (void *) db;
870 ud.free_func = cx_free;
872 ssnprintf (cb_name, sizeof (cb_name), "curl_xml-%s-%s",
873 db->instance, db->url);
875 plugin_register_complex_read (/* group = */ NULL, cb_name, cx_read,
876 /* interval = */ NULL, &ud);
885 } /* }}} int cx_config_add_url */
887 /* }}} End of configuration handling functions */
889 static int cx_config (oconfig_item_t *ci) /* {{{ */
899 for (i = 0; i < ci->children_num; i++)
901 oconfig_item_t *child = ci->children + i;
903 if (strcasecmp ("URL", child->key) == 0)
905 status = cx_config_add_url (child);
913 WARNING ("curl_xml plugin: Option `%s' not allowed here.", child->key);
918 if ((success == 0) && (errors > 0))
920 ERROR ("curl_xml plugin: All statements failed.");
925 } /* }}} int cx_config */
927 void module_register (void)
929 plugin_register_complex_config ("curl_xml", cx_config);
930 } /* void module_register */
932 /* vim: set sw=2 sts=2 et fdm=marker : */