libvirt/src/xml.c

515 lines
14 KiB
C

/*
* xml.c: XML based interfaces for the libvir library
*
* Copyright (C) 2005, 2007-2009 Red Hat, Inc.
*
* See COPYING.LIB for the License of this software
*
* Daniel Veillard <veillard@redhat.com>
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <limits.h>
#include <math.h> /* for isnan() */
#include "virterror_internal.h"
#include "xml.h"
#include "buf.h"
#include "util.h"
#include "memory.h"
#define VIR_FROM_THIS VIR_FROM_XML
#define virXMLError(conn, code, fmt...) \
virReportErrorHelper(conn, VIR_FROM_XML, code, __FILE__, \
__FUNCTION__, __LINE__, fmt)
/************************************************************************
* *
* Wrappers around libxml2 XPath specific functions *
* *
************************************************************************/
/**
* virXPathString:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
*
* Convenience function to evaluate an XPath string
*
* Returns a new string which must be deallocated by the caller or NULL
* if the evaluation failed.
*/
char *
virXPathString(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt)
{
xmlXPathObjectPtr obj;
xmlNodePtr relnode;
char *ret;
if ((ctxt == NULL) || (xpath == NULL)) {
virXMLError(conn, VIR_ERR_INTERNAL_ERROR,
"%s", _("Invalid parameter to virXPathString()"));
return (NULL);
}
relnode = ctxt->node;
obj = xmlXPathEval(BAD_CAST xpath, ctxt);
if ((obj == NULL) || (obj->type != XPATH_STRING) ||
(obj->stringval == NULL) || (obj->stringval[0] == 0)) {
xmlXPathFreeObject(obj);
return (NULL);
}
ret = strdup((char *) obj->stringval);
xmlXPathFreeObject(obj);
if (ret == NULL) {
virReportOOMError(conn);
}
ctxt->node = relnode;
return (ret);
}
/**
* virXPathStringLimit:
* @xpath: the XPath string to evaluate
* @maxlen: maximum length permittred string
* @ctxt: an XPath context
*
* Wrapper for virXPathString, which validates the length of the returned
* string.
*
* Returns a new string which must be deallocated by the caller or NULL if
* the evaluation failed.
*/
char *
virXPathStringLimit(virConnectPtr conn,
const char *xpath,
size_t maxlen,
xmlXPathContextPtr ctxt)
{
char *tmp = virXPathString(conn, xpath, ctxt);
if (tmp != NULL && strlen(tmp) >= maxlen) {
virXMLError(conn, VIR_ERR_INTERNAL_ERROR,
_("\'%s\' value longer than %Zd bytes in virXPathStringLimit()"),
xpath, maxlen);
return NULL;
}
return tmp;
}
/**
* virXPathNumber:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
* @value: the returned double value
*
* Convenience function to evaluate an XPath number
*
* Returns 0 in case of success in which case @value is set,
* or -1 if the evaluation failed.
*/
int
virXPathNumber(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt,
double *value)
{
xmlXPathObjectPtr obj;
xmlNodePtr relnode;
if ((ctxt == NULL) || (xpath == NULL) || (value == NULL)) {
virXMLError(conn, VIR_ERR_INTERNAL_ERROR,
"%s", _("Invalid parameter to virXPathNumber()"));
return (-1);
}
relnode = ctxt->node;
obj = xmlXPathEval(BAD_CAST xpath, ctxt);
if ((obj == NULL) || (obj->type != XPATH_NUMBER) ||
(isnan(obj->floatval))) {
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (-1);
}
*value = obj->floatval;
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (0);
}
static int
virXPathLongBase(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt,
int base,
long *value)
{
xmlXPathObjectPtr obj;
xmlNodePtr relnode;
int ret = 0;
if ((ctxt == NULL) || (xpath == NULL) || (value == NULL)) {
virXMLError(conn, VIR_ERR_INTERNAL_ERROR,
"%s", _("Invalid parameter to virXPathLong()"));
return (-1);
}
relnode = ctxt->node;
obj = xmlXPathEval(BAD_CAST xpath, ctxt);
if ((obj != NULL) && (obj->type == XPATH_STRING) &&
(obj->stringval != NULL) && (obj->stringval[0] != 0)) {
char *conv = NULL;
long val;
val = strtol((const char *) obj->stringval, &conv, base);
if (conv == (const char *) obj->stringval) {
ret = -2;
} else {
*value = val;
}
} else if ((obj != NULL) && (obj->type == XPATH_NUMBER) &&
(!(isnan(obj->floatval)))) {
*value = (long) obj->floatval;
if (*value != obj->floatval) {
ret = -2;
}
} else {
ret = -1;
}
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (ret);
}
/**
* virXPathLong:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
* @value: the returned long value
*
* Convenience function to evaluate an XPath number
*
* Returns 0 in case of success in which case @value is set,
* or -1 if the XPath evaluation failed or -2 if the
* value doesn't have a long format.
*/
int
virXPathLong(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt,
long *value)
{
return virXPathLongBase(conn, xpath, ctxt, 10, value);
}
/**
* virXPathLongHex:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
* @value: the returned long value
*
* Convenience function to evaluate an XPath number
* according to a base of 16
*
* Returns 0 in case of success in which case @value is set,
* or -1 if the XPath evaluation failed or -2 if the
* value doesn't have a long format.
*/
int
virXPathLongHex(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt,
long *value)
{
return virXPathLongBase(conn, xpath, ctxt, 16, value);
}
static int
virXPathULongBase(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt,
int base,
unsigned long *value)
{
xmlXPathObjectPtr obj;
xmlNodePtr relnode;
int ret = 0;
if ((ctxt == NULL) || (xpath == NULL) || (value == NULL)) {
virXMLError(conn, VIR_ERR_INTERNAL_ERROR,
"%s", _("Invalid parameter to virXPathULong()"));
return (-1);
}
relnode = ctxt->node;
obj = xmlXPathEval(BAD_CAST xpath, ctxt);
if ((obj != NULL) && (obj->type == XPATH_STRING) &&
(obj->stringval != NULL) && (obj->stringval[0] != 0)) {
char *conv = NULL;
long val;
val = strtoul((const char *) obj->stringval, &conv, base);
if (conv == (const char *) obj->stringval) {
ret = -2;
} else {
*value = val;
}
} else if ((obj != NULL) && (obj->type == XPATH_NUMBER) &&
(!(isnan(obj->floatval)))) {
*value = (unsigned long) obj->floatval;
if (*value != obj->floatval) {
ret = -2;
}
} else {
ret = -1;
}
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (ret);
}
/**
* virXPathULong:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
* @value: the returned long value
*
* Convenience function to evaluate an XPath number
*
* Returns 0 in case of success in which case @value is set,
* or -1 if the XPath evaluation failed or -2 if the
* value doesn't have a long format.
*/
int
virXPathULong(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt,
unsigned long *value)
{
return virXPathULongBase(conn, xpath, ctxt, 10, value);
}
/**
* virXPathUHex:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
* @value: the returned long value
*
* Convenience function to evaluate an XPath number
* according to base of 16
*
* Returns 0 in case of success in which case @value is set,
* or -1 if the XPath evaluation failed or -2 if the
* value doesn't have a long format.
*/
int
virXPathULongHex(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt,
unsigned long *value)
{
return virXPathULongBase(conn, xpath, ctxt, 16, value);
}
/**
* virXPathULongLong:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
* @value: the returned long long value
*
* Convenience function to evaluate an XPath number
*
* Returns 0 in case of success in which case @value is set,
* or -1 if the XPath evaluation failed or -2 if the
* value doesn't have a long format.
*/
int
virXPathULongLong(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt,
unsigned long long *value)
{
xmlXPathObjectPtr obj;
xmlNodePtr relnode;
int ret = 0;
if ((ctxt == NULL) || (xpath == NULL) || (value == NULL)) {
virXMLError(conn, VIR_ERR_INTERNAL_ERROR,
"%s", _("Invalid parameter to virXPathULong()"));
return (-1);
}
relnode = ctxt->node;
obj = xmlXPathEval(BAD_CAST xpath, ctxt);
if ((obj != NULL) && (obj->type == XPATH_STRING) &&
(obj->stringval != NULL) && (obj->stringval[0] != 0)) {
char *conv = NULL;
unsigned long long val;
val = strtoull((const char *) obj->stringval, &conv, 10);
if (conv == (const char *) obj->stringval) {
ret = -2;
} else {
*value = val;
}
} else if ((obj != NULL) && (obj->type == XPATH_NUMBER) &&
(!(isnan(obj->floatval)))) {
*value = (unsigned long long) obj->floatval;
if (*value != obj->floatval) {
ret = -2;
}
} else {
ret = -1;
}
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (ret);
}
char *
virXMLPropString(xmlNodePtr node,
const char *name)
{
return (char *)xmlGetProp(node, BAD_CAST name);
}
/**
* virXPathBoolean:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
*
* Convenience function to evaluate an XPath boolean
*
* Returns 0 if false, 1 if true, or -1 if the evaluation failed.
*/
int
virXPathBoolean(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt)
{
xmlXPathObjectPtr obj;
xmlNodePtr relnode;
int ret;
if ((ctxt == NULL) || (xpath == NULL)) {
virXMLError(conn, VIR_ERR_INTERNAL_ERROR,
"%s", _("Invalid parameter to virXPathBoolean()"));
return (-1);
}
relnode = ctxt->node;
obj = xmlXPathEval(BAD_CAST xpath, ctxt);
if ((obj == NULL) || (obj->type != XPATH_BOOLEAN) ||
(obj->boolval < 0) || (obj->boolval > 1)) {
xmlXPathFreeObject(obj);
return (-1);
}
ret = obj->boolval;
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (ret);
}
/**
* virXPathNode:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
*
* Convenience function to evaluate an XPath node set and returning
* only one node, the first one in the set if any
*
* Returns a pointer to the node or NULL if the evaluation failed.
*/
xmlNodePtr
virXPathNode(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt)
{
xmlXPathObjectPtr obj;
xmlNodePtr relnode;
xmlNodePtr ret;
if ((ctxt == NULL) || (xpath == NULL)) {
virXMLError(conn, VIR_ERR_INTERNAL_ERROR,
"%s", _("Invalid parameter to virXPathNode()"));
return (NULL);
}
relnode = ctxt->node;
obj = xmlXPathEval(BAD_CAST xpath, ctxt);
if ((obj == NULL) || (obj->type != XPATH_NODESET) ||
(obj->nodesetval == NULL) || (obj->nodesetval->nodeNr <= 0) ||
(obj->nodesetval->nodeTab == NULL)) {
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (NULL);
}
ret = obj->nodesetval->nodeTab[0];
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (ret);
}
/**
* virXPathNodeSet:
* @xpath: the XPath string to evaluate
* @ctxt: an XPath context
* @list: the returned list of nodes (or NULL if only count matters)
*
* Convenience function to evaluate an XPath node set
*
* Returns the number of nodes found in which case @list is set (and
* must be freed) or -1 if the evaluation failed.
*/
int
virXPathNodeSet(virConnectPtr conn,
const char *xpath,
xmlXPathContextPtr ctxt,
xmlNodePtr **list)
{
xmlXPathObjectPtr obj;
xmlNodePtr relnode;
int ret;
if ((ctxt == NULL) || (xpath == NULL)) {
virXMLError(conn, VIR_ERR_INTERNAL_ERROR,
"%s", _("Invalid parameter to virXPathNodeSet()"));
return (-1);
}
if (list != NULL)
*list = NULL;
relnode = ctxt->node;
obj = xmlXPathEval(BAD_CAST xpath, ctxt);
if ((obj == NULL) || (obj->type != XPATH_NODESET) ||
(obj->nodesetval == NULL) || (obj->nodesetval->nodeNr < 0)) {
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (-1);
}
ret = obj->nodesetval->nodeNr;
if (list != NULL && ret) {
if (VIR_ALLOC_N(*list, ret) < 0) {
virReportOOMError(conn);
ret = -1;
} else {
memcpy(*list, obj->nodesetval->nodeTab,
ret * sizeof(xmlNodePtr));
}
}
xmlXPathFreeObject(obj);
ctxt->node = relnode;
return (ret);
}