xinclude.c

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/*
 * xinclude.c : Code to implement XInclude processing
 *
 * World Wide Web Consortium W3C Last Call Working Draft 10 November 2003
 * http://www.w3.org/TR/2003/WD-xinclude-20031110
 *
 * See Copyright for the status of this software.
 *
 * [e-mail]
 */

#define IN_LIBXML
#include "libxml.h"

#include <string.h>
#include <libxml/xmlmemory.h>
#include <libxml/tree.h>
#include <libxml/parser.h>
#include <libxml/uri.h>
#include <libxml/xpointer.h>
#include <libxml/parserInternals.h>
#include <libxml/xmlerror.h>
#include <libxml/encoding.h>
#include <libxml/globals.h>

#ifdef LIBXML_XINCLUDE_ENABLED
#include <libxml/xinclude.h>


#define XINCLUDE_MAX_DEPTH 40

/* #define DEBUG_XINCLUDE */
#ifdef DEBUG_XINCLUDE
#ifdef LIBXML_DEBUG_ENABLED
#include <libxml/debugXML.h>
#endif
#endif

/************************************************************************
 *									*
 *			XInclude context handling			*
 *									*
 ************************************************************************/

/*
 * An XInclude context
 */
typedef xmlChar *xmlURL;

typedef struct _xmlXIncludeRef xmlXIncludeRef;
typedef xmlXIncludeRef *xmlXIncludeRefPtr;
struct _xmlXIncludeRef {
    xmlChar              *URI; /* the fully resolved resource URL */
    xmlChar         *fragment; /* the fragment in the URI */
    xmlDocPtr		  doc; /* the parsed document */
    xmlNodePtr            ref; /* the node making the reference in the source */
    xmlNodePtr            inc; /* the included copy */
    int                   xml; /* xml or txt */
    int                 count; /* how many refs use that specific doc */
    xmlXPathObjectPtr    xptr; /* the xpointer if needed */
    int		      emptyFb; /* flag to show fallback empty */
};

struct _xmlXIncludeCtxt {
    xmlDocPtr             doc; /* the source document */
    int               incBase; /* the first include for this document */
    int                 incNr; /* number of includes */
    int                incMax; /* size of includes tab */
    xmlXIncludeRefPtr *incTab; /* array of included references */

    int                 txtNr; /* number of unparsed documents */
    int                txtMax; /* size of unparsed documents tab */
    xmlNodePtr        *txtTab; /* array of unparsed text nodes */
    xmlURL         *txturlTab; /* array of unparsed text URLs */

    xmlChar *             url; /* the current URL processed */
    int                 urlNr; /* number of URLs stacked */
    int                urlMax; /* size of URL stack */
    xmlChar *         *urlTab; /* URL stack */

    int              nbErrors; /* the number of errors detected */
    int                legacy; /* using XINCLUDE_OLD_NS */
    int            parseFlags; /* the flags used for parsing XML documents */
    xmlChar *		 base; /* the current xml:base */
};

static int
xmlXIncludeDoProcess(xmlXIncludeCtxtPtr ctxt, xmlDocPtr doc, xmlNodePtr tree);


/************************************************************************
 *									*
 * 			XInclude error handler				*
 *									*
 ************************************************************************/

/**
 * xmlXIncludeErrMemory:
 * @extra:  extra information
 *
 * Handle an out of memory condition
 */
static void
xmlXIncludeErrMemory(xmlXIncludeCtxtPtr ctxt, xmlNodePtr node,
                     const char *extra)
{
    if (ctxt != NULL)
	ctxt->nbErrors++;
    __xmlRaiseError(NULL, NULL, NULL, ctxt, node, XML_FROM_XINCLUDE,
                    XML_ERR_NO_MEMORY, XML_ERR_ERROR, NULL, 0,
		    extra, NULL, NULL, 0, 0,
		    "Memory allocation failed : %s\n", extra);
}

/**
 * xmlXIncludeErr:
 * @ctxt: the XInclude context
 * @node: the context node
 * @msg:  the error message
 * @extra:  extra information
 *
 * Handle an XInclude error
 */
static void
xmlXIncludeErr(xmlXIncludeCtxtPtr ctxt, xmlNodePtr node, int error,
               const char *msg, const xmlChar *extra)
{
    if (ctxt != NULL)
	ctxt->nbErrors++;
    __xmlRaiseError(NULL, NULL, NULL, ctxt, node, XML_FROM_XINCLUDE,
                    error, XML_ERR_ERROR, NULL, 0,
		    (const char *) extra, NULL, NULL, 0, 0,
		    msg, (const char *) extra);
}

#if 0
/**
 * xmlXIncludeWarn:
 * @ctxt: the XInclude context
 * @node: the context node
 * @msg:  the error message
 * @extra:  extra information
 *
 * Emit an XInclude warning.
 */
static void
xmlXIncludeWarn(xmlXIncludeCtxtPtr ctxt, xmlNodePtr node, int error,
               const char *msg, const xmlChar *extra)
{
    __xmlRaiseError(NULL, NULL, NULL, ctxt, node, XML_FROM_XINCLUDE,
                    error, XML_ERR_WARNING, NULL, 0,
		    (const char *) extra, NULL, NULL, 0, 0,
		    msg, (const char *) extra);
}
#endif

/**
 * xmlXIncludeGetProp:
 * @ctxt:  the XInclude context
 * @cur:  the node
 * @name:  the attribute name
 *
 * Get an XInclude attribute
 *
 * Returns the value (to be freed) or NULL if not found
 */
static xmlChar *
xmlXIncludeGetProp(xmlXIncludeCtxtPtr ctxt, xmlNodePtr cur,
                   const xmlChar *name) {
    xmlChar *ret;

    ret = xmlGetNsProp(cur, XINCLUDE_NS, name);
    if (ret != NULL)
        return(ret);
    if (ctxt->legacy != 0) {
	ret = xmlGetNsProp(cur, XINCLUDE_OLD_NS, name);
	if (ret != NULL)
	    return(ret);
    }
    ret = xmlGetProp(cur, name);
    return(ret);
}
/**
 * xmlXIncludeFreeRef:
 * @ref: the XInclude reference
 *
 * Free an XInclude reference
 */
static void
xmlXIncludeFreeRef(xmlXIncludeRefPtr ref) {
    if (ref == NULL)
	return;
#ifdef DEBUG_XINCLUDE
    xmlGenericError(xmlGenericErrorContext, "Freeing ref\n");
#endif
    if (ref->doc != NULL) {
#ifdef DEBUG_XINCLUDE
	xmlGenericError(xmlGenericErrorContext, "Freeing doc %s\n", ref->URI);
#endif
	xmlFreeDoc(ref->doc);
    }
    if (ref->URI != NULL)
	xmlFree(ref->URI);
    if (ref->fragment != NULL)
	xmlFree(ref->fragment);
    if (ref->xptr != NULL)
	xmlXPathFreeObject(ref->xptr);
    xmlFree(ref);
}

/**
 * xmlXIncludeNewRef:
 * @ctxt: the XInclude context
 * @URI:  the resource URI
 *
 * Creates a new reference within an XInclude context
 *
 * Returns the new set
 */
static xmlXIncludeRefPtr
xmlXIncludeNewRef(xmlXIncludeCtxtPtr ctxt, const xmlChar *URI,
	          xmlNodePtr ref) {
    xmlXIncludeRefPtr ret;

#ifdef DEBUG_XINCLUDE
    xmlGenericError(xmlGenericErrorContext, "New ref %s\n", URI);
#endif
    ret = (xmlXIncludeRefPtr) xmlMalloc(sizeof(xmlXIncludeRef));
    if (ret == NULL) {
        xmlXIncludeErrMemory(ctxt, ref, "growing XInclude context");
	return(NULL);
    }
    memset(ret, 0, sizeof(xmlXIncludeRef));
    if (URI == NULL)
	ret->URI = NULL;
    else
	ret->URI = xmlStrdup(URI);
    ret->fragment = NULL;
    ret->ref = ref;
    ret->doc = 0;
    ret->count = 0;
    ret->xml = 0;
    ret->inc = NULL;
    if (ctxt->incMax == 0) {
	ctxt->incMax = 4;
        ctxt->incTab = (xmlXIncludeRefPtr *) xmlMalloc(ctxt->incMax *
					      sizeof(ctxt->incTab[0]));
        if (ctxt->incTab == NULL) {
	    xmlXIncludeErrMemory(ctxt, ref, "growing XInclude context");
	    xmlXIncludeFreeRef(ret);
	    return(NULL);
	}
    }
    if (ctxt->incNr >= ctxt->incMax) {
	ctxt->incMax *= 2;
        ctxt->incTab = (xmlXIncludeRefPtr *) xmlRealloc(ctxt->incTab,
	             ctxt->incMax * sizeof(ctxt->incTab[0]));
        if (ctxt->incTab == NULL) {
	    xmlXIncludeErrMemory(ctxt, ref, "growing XInclude context");
	    xmlXIncludeFreeRef(ret);
	    return(NULL);
	}
    }
    ctxt->incTab[ctxt->incNr++] = ret;
    return(ret);
}

/**
 * xmlXIncludeNewContext:
 * @doc:  an XML Document
 *
 * Creates a new XInclude context
 *
 * Returns the new set
 */
xmlXIncludeCtxtPtr
xmlXIncludeNewContext(xmlDocPtr doc) {
    xmlXIncludeCtxtPtr ret;

#ifdef DEBUG_XINCLUDE
    xmlGenericError(xmlGenericErrorContext, "New context\n");
#endif
    if (doc == NULL)
	return(NULL);
    ret = (xmlXIncludeCtxtPtr) xmlMalloc(sizeof(xmlXIncludeCtxt));
    if (ret == NULL) {
	xmlXIncludeErrMemory(NULL, (xmlNodePtr) doc,
	                     "creating XInclude context");
	return(NULL);
    }
    memset(ret, 0, sizeof(xmlXIncludeCtxt));
    ret->doc = doc;
    ret->incNr = 0;
    ret->incBase = 0;
    ret->incMax = 0;
    ret->incTab = NULL;
    ret->nbErrors = 0;
    return(ret);
}

/**
 * xmlXIncludeURLPush:
 * @ctxt:  the parser context
 * @value:  the url
 *
 * Pushes a new url on top of the url stack
 *
 * Returns -1 in case of error, the index in the stack otherwise
 */
static int
xmlXIncludeURLPush(xmlXIncludeCtxtPtr ctxt,
	           const xmlChar *value)
{
    if (ctxt->urlNr > XINCLUDE_MAX_DEPTH) {
	xmlXIncludeErr(ctxt, NULL, XML_XINCLUDE_RECURSION,
	               "detected a recursion in %s\n", value);
	return(-1);
    }
    if (ctxt->urlTab == NULL) {
	ctxt->urlMax = 4;
	ctxt->urlNr = 0;
	ctxt->urlTab = (xmlChar * *) xmlMalloc(
		        ctxt->urlMax * sizeof(ctxt->urlTab[0]));
        if (ctxt->urlTab == NULL) {
	    xmlXIncludeErrMemory(ctxt, NULL, "adding URL");
            return (-1);
        }
    }
    if (ctxt->urlNr >= ctxt->urlMax) {
        ctxt->urlMax *= 2;
        ctxt->urlTab =
            (xmlChar * *) xmlRealloc(ctxt->urlTab,
                                      ctxt->urlMax *
                                      sizeof(ctxt->urlTab[0]));
        if (ctxt->urlTab == NULL) {
	    xmlXIncludeErrMemory(ctxt, NULL, "adding URL");
            return (-1);
        }
    }
    ctxt->url = ctxt->urlTab[ctxt->urlNr] = xmlStrdup(value);
    return (ctxt->urlNr++);
}

/**
 * xmlXIncludeURLPop:
 * @ctxt: the parser context
 *
 * Pops the top URL from the URL stack
 */
static void
xmlXIncludeURLPop(xmlXIncludeCtxtPtr ctxt)
{
    xmlChar * ret;

    if (ctxt->urlNr <= 0)
        return;
    ctxt->urlNr--;
    if (ctxt->urlNr > 0)
        ctxt->url = ctxt->urlTab[ctxt->urlNr - 1];
    else
        ctxt->url = NULL;
    ret = ctxt->urlTab[ctxt->urlNr];
    ctxt->urlTab[ctxt->urlNr] = 0;
    if (ret != NULL)
	xmlFree(ret);
}

/**
 * xmlXIncludeFreeContext:
 * @ctxt: the XInclude context
 *
 * Free an XInclude context
 */
void
xmlXIncludeFreeContext(xmlXIncludeCtxtPtr ctxt) {
    int i;

#ifdef DEBUG_XINCLUDE
    xmlGenericError(xmlGenericErrorContext, "Freeing context\n");
#endif
    if (ctxt == NULL)
	return;
    while (ctxt->urlNr > 0)
	xmlXIncludeURLPop(ctxt);
    if (ctxt->urlTab != NULL)
	xmlFree(ctxt->urlTab);
    for (i = 0;i < ctxt->incNr;i++) {
	if (ctxt->incTab[i] != NULL)
	    xmlXIncludeFreeRef(ctxt->incTab[i]);
    }
    for (i = 0;i < ctxt->txtNr;i++) {
	if (ctxt->txturlTab[i] != NULL)
	    xmlFree(ctxt->txturlTab[i]);
    }
    if (ctxt->incTab != NULL)
	xmlFree(ctxt->incTab);
    if (ctxt->txtTab != NULL)
	xmlFree(ctxt->txtTab);
    if (ctxt->txturlTab != NULL)
	xmlFree(ctxt->txturlTab);
    if (ctxt->base != NULL) {
        xmlFree(ctxt->base);
    }
    xmlFree(ctxt);
}

/**
 * xmlXIncludeParseFile:
 * @ctxt:  the XInclude context
 * @URL:  the URL or file path
 * 
 * parse a document for XInclude
 */
static xmlDocPtr
xmlXIncludeParseFile(xmlXIncludeCtxtPtr ctxt, const char *URL) {
    xmlDocPtr ret;
    xmlParserCtxtPtr pctxt;
    char *directory = NULL;
    xmlParserInputPtr inputStream;

    xmlInitParser();

    pctxt = xmlNewParserCtxt();
    if (pctxt == NULL) {
	xmlXIncludeErrMemory(ctxt, NULL, "cannot allocate parser context");
	return(NULL);
    }
    /*
     * try to ensure that new documents included are actually
     * built with the same dictionary as the including document.
     */
    if ((ctxt->doc != NULL) && (ctxt->doc->dict != NULL) &&
        (pctxt->dict != NULL)) {
	xmlDictFree(pctxt->dict);
	pctxt->dict = ctxt->doc->dict;
	xmlDictReference(pctxt->dict);
    }

    xmlCtxtUseOptions(pctxt, ctxt->parseFlags | XML_PARSE_DTDLOAD);
    
    inputStream = xmlLoadExternalEntity(URL, NULL, pctxt);
    if (inputStream == NULL) {
	xmlFreeParserCtxt(pctxt);
	return(NULL);
    }

    inputPush(pctxt, inputStream);

    if ((pctxt->directory == NULL) && (directory == NULL))
        directory = xmlParserGetDirectory(URL);
    if ((pctxt->directory == NULL) && (directory != NULL))
        pctxt->directory = (char *) xmlStrdup((xmlChar *) directory);

    pctxt->loadsubset |= XML_DETECT_IDS;

    xmlParseDocument(pctxt);

    if (pctxt->wellFormed) {
        ret = pctxt->myDoc;
    }
    else {
        ret = NULL;
	if (pctxt->myDoc != NULL)
	    xmlFreeDoc(pctxt->myDoc);
        pctxt->myDoc = NULL;
    }
    xmlFreeParserCtxt(pctxt);
    
    return(ret);
}

/**
 * xmlXIncludeAddNode:
 * @ctxt:  the XInclude context
 * @cur:  the new node
 * 
 * Add a new node to process to an XInclude context
 */
static int
xmlXIncludeAddNode(xmlXIncludeCtxtPtr ctxt, xmlNodePtr cur) {
    xmlXIncludeRefPtr ref;
    xmlURIPtr uri;
    xmlChar *URL;
    xmlChar *fragment = NULL;