#include <libxml/valid.h>
#include <libxml/xmlschemas.h>
#include <libxml/tree.h>
+#include <libxml/xpath.h>
#include <lttng/lttng.h>
#include <lttng/snapshot.h>
return ret;
}
+static
+int load_session_from_document(struct config_document *document, const char *session_name,
+ struct session_config_validation_ctx *validation_ctx, int override)
+{
+ int ret, session_found = !session_name;
+ xmlNodePtr sessions_node;
+ xmlNodePtr session_node;
+
+ assert(validation_ctx);
+
+ ret = xmlSchemaValidateDoc(validation_ctx->schema_validation_ctx, document->document);
+ if (ret) {
+ ERR("Session configuration file validation failed");
+ ret = -LTTNG_ERR_LOAD_INVALID_CONFIG;
+ goto end;
+ }
+
+ sessions_node = xmlDocGetRootElement(document->document);
+ if (!sessions_node) {
+ goto end;
+ }
+
+ for (session_node = xmlFirstElementChild(sessions_node);
+ session_node; session_node =
+ xmlNextElementSibling(session_node)) {
+ ret = process_session_node(session_node,
+ session_name, override);
+ if (session_name && ret == 0) {
+ /* Target session found and loaded */
+ session_found = 1;
+ break;
+ }
+ }
+end:
+ if (!ret) {
+ ret = session_found ? 0 : -LTTNG_ERR_LOAD_SESSION_NOENT;
+ }
+ return ret;
+}
+
/* Allocate dirent as recommended by READDIR(3), NOTES on readdir_r */
static
struct dirent *alloc_dirent(const char *path)
{
xmlCleanupParser();
}
+
+LTTNG_HIDDEN
+struct config_document *config_document_get(const char *path)
+{
+ int ret;
+ struct config_document *document = NULL;
+ struct session_config_validation_ctx validation_ctx = { 0 };
+
+ assert(path);
+
+ ret = access(path, F_OK);
+ if (ret < 0) {
+ PERROR("access");
+ switch (errno) {
+ case ENOENT:
+ ERR("Configuration document path does not exist.");
+ break;
+ case EACCES:
+ ERR("Configuration document permission denied.");
+ break;
+ default:
+ ERR("Configuration document unknown error.");
+ break;
+ }
+ goto end;
+ }
+
+ ret = init_session_config_validation_ctx(&validation_ctx);
+ if (ret) {
+ goto end;
+ }
+
+ ret = validate_file_read_creds(path);
+ if (ret != 1) {
+ if (ret == -1) {
+ ERR("Configuration document permission denied.");
+ } else {
+ ERR("Configuration document does not exist.");
+ }
+ goto end;
+ }
+
+ document = zmalloc(sizeof(struct config_document));
+ if (!document) {
+ PERROR("zmalloc");
+ goto end;
+ }
+
+ document->document = xmlParseFile(path);
+ if (!document->document) {
+ ERR("Configuration document parsing failed.");
+ goto error;
+ }
+
+ ret = xmlSchemaValidateDoc(validation_ctx.schema_validation_ctx,
+ document->document);
+ if (ret) {
+ ERR("Session configuration file validation failed");
+ goto error;
+ }
+
+end:
+ return document;
+error:
+ xmlFreeDoc(document->document);
+ free(document);
+ return NULL;
+}
+
+LTTNG_HIDDEN
+void config_document_free(struct config_document *document)
+{
+ if (document) {
+ xmlFreeDoc(document->document);
+ document->document = NULL;
+ }
+}
+
+LTTNG_HIDDEN
+int config_document_replace_element_value(struct config_document *document,
+ const char *xpath, const char *value)
+{
+ int ret;
+ int xpath_result_size;
+
+ xmlXPathContextPtr xpath_context = NULL;
+ xmlXPathObjectPtr xpath_object = NULL;
+ xmlNodeSetPtr xpath_result_set = NULL;
+ xmlChar *internal_xpath = NULL;
+ xmlChar *internal_value = NULL;
+
+ assert(document);
+ assert(xpath);
+ assert(value);
+
+ internal_xpath = encode_string(xpath);
+ if (!internal_xpath) {
+ ret = -LTTNG_ERR_NOMEM;
+ ERR("Unable to encode xpath string");
+ goto end;
+ }
+
+ internal_value = encode_string(value);
+ if (!internal_value) {
+ ret = -LTTNG_ERR_NOMEM;
+ ERR("Unable to encode xpath replace value string");
+ goto end;
+ }
+
+ /* Initialize xpath context */
+ xpath_context = xmlXPathNewContext(document->document);
+ if (!xpath_context) {
+ ret = -LTTNG_ERR_NOMEM;
+ ERR("Unable to create xpath context");
+ goto end;
+ }
+
+ /* Evaluate de xpath expression */
+ xpath_object = xmlXPathEvalExpression(internal_xpath, xpath_context);
+ if (!xpath_object) {
+ ret = -LTTNG_ERR_CONFIG_INVALID_QUERY;
+ goto end;
+ }
+
+ /* TODO: from here could be extracted and previopus could be a step in
+ * subsequent operation, modify/substitute/delete node.
+ */
+ xpath_result_set = xpath_object->nodesetval;
+ if (!xpath_result_set) {
+ ret = -LTTNG_ERR_CONFIG_EMPTY_SET;
+ goto end;
+ }
+
+ xpath_result_size = xpath_result_set->nodeNr;
+
+ /*
+ * Reverse traversal since last element could be nested under parent
+ * element present in the result set.
+ */
+ for (int i = xpath_result_size - 1; i >=0; i--) {
+ assert(xpath_result_set->nodeTab[i]);
+ xmlNodeSetContent(xpath_result_set->nodeTab[i], internal_value);
+
+ /*
+ * Libxml2 quirk regarding the freing and namesplace node see
+ * libxml2 example and documentation for more details.
+ */
+ if (xpath_result_set->nodeTab[i]->type != XML_NAMESPACE_DECL) {
+ xpath_result_set->nodeTab[i] = NULL;
+ }
+ }
+
+end:
+ xmlXPathFreeContext(xpath_context);
+ xmlXPathFreeObject(xpath_object);
+ xmlFree(internal_xpath);
+ xmlFree(internal_value);
+ return ret;
+}
+
+LTTNG_HIDDEN
+int config_load_configuration_sessions(struct config_document *document,
+ const char *session_name, int override)
+{
+ int ret;
+ struct session_config_validation_ctx validation_ctx = { 0 };
+
+ ret = init_session_config_validation_ctx(&validation_ctx);
+ if (ret) {
+ goto end;
+ }
+ ret = load_session_from_document(document, session_name,
+ &validation_ctx, override);
+end:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int config_document_replace_element(struct config_document *document,
+ const char *xpath, const struct config_element *element)
+{
+ int ret = 0;
+ int xpath_result_size;
+
+ xmlXPathContextPtr xpath_context = NULL;
+ xmlXPathObjectPtr xpath_object = NULL;
+ xmlNodeSetPtr xpath_result_set = NULL;
+ xmlChar *internal_xpath = NULL;
+ xmlNodePtr old_node = NULL;
+ xmlNodePtr copy = NULL;
+
+ assert(document);
+ assert(xpath);
+ assert(element);
+ assert(element->element);
+
+ internal_xpath = encode_string(xpath);
+ if (!internal_xpath) {
+ ret = -LTTNG_ERR_NOMEM;
+ ERR("Unable to encode xpath string");
+ goto end;
+ }
+
+ /* Initialize xpath context */
+ xpath_context = xmlXPathNewContext(document->document);
+ if (!xpath_context) {
+ ret = -LTTNG_ERR_NOMEM;
+ ERR("Unable to create xpath context");
+ goto end;
+ }
+
+ /* Evaluate the xpath expression */
+ xpath_object = xmlXPathEvalExpression(internal_xpath, xpath_context);
+ if (!xpath_object) {
+ ret = -LTTNG_ERR_CONFIG_INVALID_QUERY;
+ goto end;
+ }
+
+ xpath_result_set = xpath_object->nodesetval;
+ if (!xpath_result_set) {
+ ret = -LTTNG_ERR_CONFIG_EMPTY_SET;
+ goto end;
+ }
+
+ xpath_result_size = xpath_result_set->nodeNr;
+
+ if (xpath_result_size > 1) {
+ ret = -LTTNG_ERR_CONFIG_INVALID_COUNT;
+ goto end;
+ }
+
+ if (xpath_result_size == 0) {
+ ret = -LTTNG_ERR_CONFIG_REPLACEMENT;
+ goto end;
+ }
+
+ assert(xpath_result_set->nodeTab[0]);
+
+ /* Do a copy of the element to ease caller memory management */
+ copy = xmlCopyNode(element->element, 1);
+ if (!copy) {
+ ret = -LTTNG_ERR_NOMEM;
+ ERR("Copy failed for node replacement");
+ goto end;
+ }
+
+
+ old_node = xmlReplaceNode(xpath_result_set->nodeTab[0], copy);
+ if (!old_node) {
+ ret = -LTTNG_ERR_CONFIG_REPLACEMENT;
+ xmlFreeNode(copy);
+ goto end;
+ }
+ xmlFree(old_node);
+end:
+ xmlXPathFreeContext(xpath_context);
+ xmlXPathFreeObject(xpath_object);
+ xmlFree(internal_xpath);
+ return ret;
+}
+
+LTTNG_HIDDEN
+char *config_document_get_element_value(struct config_document *document,
+ const char *xpath)
+{
+ char *value = NULL;
+ int xpath_result_size;
+ int value_result_size;
+
+ xmlXPathContextPtr xpath_context = NULL;
+ xmlXPathObjectPtr xpath_object = NULL;
+ xmlNodeSetPtr xpath_result_set = NULL;
+ xmlChar *internal_xpath = NULL;
+ xmlChar *internal_value = NULL;
+
+ assert(document);
+ assert(xpath);
+
+ internal_xpath = encode_string(xpath);
+ if (!internal_xpath) {
+ value = NULL;
+ ERR("Unable to encode xpath string");
+ goto end;
+ }
+
+ /* Initialize xpath context */
+ xpath_context = xmlXPathNewContext(document->document);
+ if (!xpath_context) {
+ value = NULL;
+ ERR("Unable to create xpath context");
+ goto end;
+ }
+
+ /* Evaluate the xpath expression */
+ xpath_object = xmlXPathEvalExpression(internal_xpath, xpath_context);
+ if (!xpath_object) {
+ value = NULL;
+ ERR("Unable to evaluate xpath query (invalid query format)");
+ goto end;
+ }
+
+ xpath_result_set = xpath_object->nodesetval;
+ if (!xpath_result_set) {
+ value = NULL;
+ goto end;
+ }
+
+ xpath_result_size = xpath_result_set->nodeNr;
+
+ if (xpath_result_size > 1) {
+ ERR("To many result while fetching config element value");
+ value = NULL;
+ goto end;
+ }
+
+ if (xpath_result_size == 0) {
+ value = NULL;
+ goto end;
+ }
+
+ /*
+ * Reverse traversal since last element could be nested under parent
+ * element present in the result set.
+ */
+ assert(xpath_result_set->nodeTab[0]);
+ internal_value = xmlNodeGetContent(xpath_result_set->nodeTab[0]);
+ if (!internal_value) {
+ value = NULL;
+ goto end;
+ }
+
+ value_result_size = xmlStrlen(internal_value);
+ value = calloc(value_result_size + 1, sizeof(char));
+ strncpy(value, (char *) internal_value, value_result_size);
+
+end:
+ xmlXPathFreeContext(xpath_context);
+ xmlXPathFreeObject(xpath_object);
+ xmlFree(internal_xpath);
+ xmlFree(internal_value);
+ return value;
+}
+
+LTTNG_HIDDEN
+int config_document_element_exist(struct config_document *document,
+ const char *xpath)
+{
+ int exist = 0;
+ int xpath_result_size;
+
+ xmlXPathContextPtr xpath_context = NULL;
+ xmlXPathObjectPtr xpath_object = NULL;
+ xmlNodeSetPtr xpath_result_set = NULL;
+ xmlChar *internal_xpath = NULL;
+
+ assert(document);
+ assert(document->document);
+ assert(xpath);
+
+ internal_xpath = encode_string(xpath);
+ if (!internal_xpath) {
+ ERR("Unable to encode xpath string");
+ goto end;
+ }
+
+ /* Initialize xpath context */
+ xpath_context = xmlXPathNewContext(document->document);
+ if (!xpath_context) {
+ ERR("Unable to create xpath context");
+ goto end;
+ }
+
+ /* Evaluate the xpath expression */
+ xpath_object = xmlXPathEvalExpression(internal_xpath, xpath_context);
+ if (!xpath_object) {
+ ERR("Unable to evaluate xpath query (invalid query format)");
+ goto end;
+ }
+
+ xpath_result_set = xpath_object->nodesetval;
+ if (!xpath_result_set) {
+ goto end;
+ }
+
+ xpath_result_size = xpath_result_set->nodeNr;
+
+ if (xpath_result_size > 0) {
+ exist = 1;
+ }
+end:
+ xmlXPathFreeContext(xpath_context);
+ xmlXPathFreeObject(xpath_object);
+ xmlFree(internal_xpath);
+ return exist;
+
+}
+
+LTTNG_HIDDEN
+struct config_element *config_element_create(const char *name,
+ const char* value)
+{
+ struct config_element *element;
+
+ assert(name);
+
+ xmlChar *internal_name = NULL;
+ xmlChar *internal_value = NULL;
+
+ internal_name = encode_string(name);
+ if (!internal_name) {
+ ERR("Unable to encode config element name string");
+ element = NULL;
+ goto end;
+ }
+
+
+ if (value) {
+ internal_value = encode_string(value);
+ if (!internal_value) {
+ ERR("Unable to encode config_element value string");
+ element = NULL;
+ goto end;
+ }
+ }
+
+ element = zmalloc(sizeof(struct config_element));
+ if (!element) {
+ goto end;
+ }
+
+ element->element = xmlNewNode(NULL, internal_name);
+ if (!element->element) {
+ free(element);
+ element = NULL;
+ }
+
+ if (internal_value) {
+ xmlNodeAddContent(element->element, internal_value);
+ }
+end:
+ xmlFree(internal_name);
+ xmlFree(internal_value);
+ return element;
+}
+
+LTTNG_HIDDEN
+int config_element_add_child(struct config_element *parent,
+ const struct config_element *child)
+{
+ assert(parent);
+ assert(child);
+ assert(parent->element);
+ assert(child->element);
+
+ int ret = 0;
+ xmlNodePtr node = NULL;
+ xmlNodePtr copy = NULL;
+
+ /* Do a copy to ease the memory management for caller */
+ copy = xmlCopyNode(child->element, 1);
+ if (!copy) {
+ ret = -LTTNG_ERR_NOMEM;
+ goto error;
+ }
+ node = xmlAddChild(parent->element, copy);
+ if (!node) {
+ xmlFreeNode(copy);
+ ret = -LTTNG_ERR_CONFIG_ADD_CHILD;
+ goto error;
+ }
+error:
+ return ret;
+}
+
+
+LTTNG_HIDDEN
+int config_document_insert_element(struct config_document *document,
+ const char *xpath, const struct config_element *element)
+{
+ int ret = 0;
+ int xpath_result_size;
+
+ xmlXPathContextPtr xpath_context = NULL;
+ xmlXPathObjectPtr xpath_object = NULL;
+ xmlNodeSetPtr xpath_result_set = NULL;
+ xmlChar *internal_xpath = NULL;
+ xmlNodePtr child_node = NULL;
+ xmlNodePtr local_copy = NULL;
+
+ assert(document);
+ assert(xpath);
+ assert(element);
+ assert(element->element);
+
+ internal_xpath = encode_string(xpath);
+ if (!internal_xpath) {
+ ret = -LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /* Initialize xpath context */
+ xpath_context = xmlXPathNewContext(document->document);
+ if (!xpath_context) {
+ ret = -LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /* Evaluate the xpath expression */
+ xpath_object = xmlXPathEvalExpression(internal_xpath, xpath_context);
+ if (!xpath_object) {
+ ret = -LTTNG_ERR_CONFIG_INVALID_QUERY;
+ goto end;
+ }
+
+ xpath_result_set = xpath_object->nodesetval;
+ if (!xpath_result_set) {
+ ret = -LTTNG_ERR_CONFIG_EMPTY_SET;
+ goto end;
+ }
+
+ xpath_result_size = xpath_result_set->nodeNr;
+
+ if (xpath_result_size > 1) {
+ ret = -LTTNG_ERR_CONFIG_INVALID_COUNT;
+ goto end;
+ }
+
+ if (xpath_result_size == 0) {
+ ret = -LTTNG_ERR_CONFIG_INVALID_COUNT;
+ goto end;
+ }
+
+ assert(xpath_result_set->nodeTab[0]);
+ /* Do a copy to simply memory management */
+ local_copy = xmlCopyNode(element->element, 1);
+ if (!local_copy) {
+ ret = -LTTNG_ERR_NOMEM;
+ ERR("Duplication of node to be insert failed");
+ goto end;
+ }
+
+ child_node = xmlAddChild(xpath_result_set->nodeTab[0], local_copy);
+ if (!child_node) {
+ ret = -LTTNG_ERR_CONFIG_ADD_CHILD;
+ xmlFreeNode(local_copy);
+ goto end;
+ }
+end:
+ xmlXPathFreeContext(xpath_context);
+ xmlXPathFreeObject(xpath_object);
+ xmlFree(internal_xpath);
+ return ret;
+}
+
+LTTNG_HIDDEN
+void config_element_free(struct config_element *element) {
+ if (element->element) {
+ xmlFree(element->element);
+ }
+
+ free(element);
+}
/* Instance of a configuration writer. */
struct config_writer;
+/* Instance of a configuration document */
+struct config_document;
+
+struct config_element;
+
/*
* A config_entry_handler_cb receives config_entry structures belonging to the
* sections the handler has been registered to.
int config_load_session(const char *path, const char *session_name,
int override, unsigned int autoload);
+/*
+ * Load session configuration from a document
+ *
+ * document The document to be loaded as a configuration
+ * session_name Name of the session to load. Will load all sessions from the
+ * passed document if NULL
+ *
+ * override Override current session configuration if it exists.
+ *
+ * Returns zero if the session could be loaded successfully. Returns
+ * a negative LTTNG_ERR code on error.
+ */
+LTTNG_HIDDEN
+int config_load_configuration_sessions(struct config_document *document,
+ const char *session_name, int override);
+
+/*
+ * Get the document corresponding to the path.
+ *
+ * path Path to a configuration file.
+ * xsd_validation Whether or not to do a xsd validation
+ *
+ * Returns an new allocated config_document when successful.
+ * Returns NULL on error;
+ *
+ * The caller is responsible of freeing the document via config_document_free.
+ */
+LTTNG_HIDDEN
+struct config_document *config_document_get(const char *path);
+
+/*
+ * Free an allocated document.
+ *
+ * document The document to free.
+ */
+LTTNG_HIDDEN
+void config_document_free(struct config_document *document);
+
+/*
+ * Replace the value of a document element
+ *
+ * document The document containing the element to be modified.
+ * xpath The xpath string to the element.
+ * value The value to be placed inside the element.
+ *
+ * Returns zero if the session could be loaded successfully. Returns
+ * a negative LTTNG_ERR code on error.
+ * */
+LTTNG_HIDDEN
+int config_document_replace_element_value(struct config_document *document, const char *xpath, const char *value);
+
+/*
+ * Swap a document node by the passed element.
+ *
+ * document The document containing the element to be modified.
+ * xpath The xpath string to the element.
+ * element The replacement element.
+ *
+ * Returns zero if the session could be loaded successfully. Returns
+ * a negative LTTNG_ERR code on error.
+ */
+LTTNG_HIDDEN
+int config_document_replace_element(struct config_document *document, const char *xpath, const struct config_element *element);
+
+/*
+ * Get the value of a document element.
+ *
+ * document The document to be searched.
+ * xpath The xpath string to the element.
+ *
+ * Return null if multiple values exists or there is no
+ * value for the passed path.
+ */
+LTTNG_HIDDEN
+char *config_document_get_element_value(struct config_document *document, const char *xpath);
+
+/*
+ * Check if an element exists inside a document.
+ *
+ * document The document to be searched.
+ * xpath The xpath string to the element.
+ *
+ * Returns 1 on success and 0 on failure.
+ */
+LTTNG_HIDDEN
+int config_document_element_exist(struct config_document *document, const char *xpath);
+
+/*
+ *
+ */
+LTTNG_HIDDEN
+void config_element_free(struct config_element *element);
+
+LTTNG_HIDDEN
+struct config_element *config_element_create(const char *name, const char *value);
+
+/*
+ * Add a child element to an element.
+ *
+ * parent The parent element.
+ * child The element to add as a child.
+ *
+ * Returns zero if the session could be loaded successfully. Returns
+ * a negative LTTNG_ERR code on error.
+ */
+LTTNG_HIDDEN
+int config_element_add_child(struct config_element *parent, const struct config_element *child);
+
+/*
+ * Insert element to an existing document.
+ *
+ * document The document to be modified.
+ * xpath The xpath string to the insertion path.
+ * element The element to be inserted.
+ *
+ * Returns zero if the session could be loaded successfully. Returns
+ * a negative LTTNG_ERR code on error.
+ */
+LTTNG_HIDDEN
+int config_document_insert_element(struct config_document *document, const char *xpath, const struct config_element *element);
+
+
#endif /* _CONFIG_H */
projects / lttng-tools.git / commitdiff
