entities.c

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/*
 * entities.c : implementation for the XML entities handling
 *
 * See Copyright for the status of this software.
 *
 * [e-mail]
 */

#define IN_LIBXML
#include "libxml.h"

#include <string.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <libxml/xmlmemory.h>
#include <libxml/hash.h>
#include <libxml/entities.h>
#include <libxml/parser.h>
#include <libxml/parserInternals.h>
#include <libxml/xmlerror.h>
#include <libxml/globals.h>
#include <libxml/dict.h>

/*
 * The XML predefined entities.
 */

static xmlEntity xmlEntityLt = {
    NULL, XML_ENTITY_DECL, BAD_CAST "lt",
    NULL, NULL, NULL, NULL, NULL, NULL, 
    BAD_CAST "<", BAD_CAST "<", 1,
    XML_INTERNAL_PREDEFINED_ENTITY,
    NULL, NULL, NULL, NULL, 0
};
static xmlEntity xmlEntityGt = {
    NULL, XML_ENTITY_DECL, BAD_CAST "gt",
    NULL, NULL, NULL, NULL, NULL, NULL, 
    BAD_CAST ">", BAD_CAST ">", 1,
    XML_INTERNAL_PREDEFINED_ENTITY,
    NULL, NULL, NULL, NULL, 0
};
static xmlEntity xmlEntityAmp = {
    NULL, XML_ENTITY_DECL, BAD_CAST "amp",
    NULL, NULL, NULL, NULL, NULL, NULL, 
    BAD_CAST "&", BAD_CAST "&", 1,
    XML_INTERNAL_PREDEFINED_ENTITY,
    NULL, NULL, NULL, NULL, 0
};
static xmlEntity xmlEntityQuot = {
    NULL, XML_ENTITY_DECL, BAD_CAST "quot",
    NULL, NULL, NULL, NULL, NULL, NULL, 
    BAD_CAST "\"", BAD_CAST "\"", 1,
    XML_INTERNAL_PREDEFINED_ENTITY,
    NULL, NULL, NULL, NULL, 0
};
static xmlEntity xmlEntityApos = {
    NULL, XML_ENTITY_DECL, BAD_CAST "apos",
    NULL, NULL, NULL, NULL, NULL, NULL, 
    BAD_CAST "'", BAD_CAST "'", 1,
    XML_INTERNAL_PREDEFINED_ENTITY,
    NULL, NULL, NULL, NULL, 0
};

/**
 * xmlEntitiesErrMemory:
 * @extra:  extra informations
 *
 * Handle an out of memory condition
 */
static void
xmlEntitiesErrMemory(const char *extra)
{
    __xmlSimpleError(XML_FROM_TREE, XML_ERR_NO_MEMORY, NULL, NULL, extra);
}

/**
 * xmlEntitiesErr:
 * @code:  the error code
 * @msg:  the message
 *
 * Handle an out of memory condition
 */
static void
xmlEntitiesErr(xmlParserErrors code, const char *msg)
{
    __xmlSimpleError(XML_FROM_TREE, code, NULL, msg, NULL);
}

/*
 * xmlFreeEntity : clean-up an entity record.
 */
static void
xmlFreeEntity(xmlEntityPtr entity)
{
    xmlDictPtr dict = NULL;

    if (entity == NULL)
        return;

    if (entity->doc != NULL)
        dict = entity->doc->dict;


    if ((entity->children) && (entity->owner == 1) &&
        (entity == (xmlEntityPtr) entity->children->parent))
        xmlFreeNodeList(entity->children);
    if (dict != NULL) {
        if ((entity->name != NULL) && (!xmlDictOwns(dict, entity->name)))
            xmlFree((char *) entity->name);
        if ((entity->ExternalID != NULL) &&
	    (!xmlDictOwns(dict, entity->ExternalID)))
            xmlFree((char *) entity->ExternalID);
        if ((entity->SystemID != NULL) &&
	    (!xmlDictOwns(dict, entity->SystemID)))
            xmlFree((char *) entity->SystemID);
        if ((entity->URI != NULL) && (!xmlDictOwns(dict, entity->URI)))
            xmlFree((char *) entity->URI);
        if ((entity->content != NULL)
            && (!xmlDictOwns(dict, entity->content)))
            xmlFree((char *) entity->content);
        if ((entity->orig != NULL) && (!xmlDictOwns(dict, entity->orig)))
            xmlFree((char *) entity->orig);
    } else {
        if (entity->name != NULL)
            xmlFree((char *) entity->name);
        if (entity->ExternalID != NULL)
            xmlFree((char *) entity->ExternalID);
        if (entity->SystemID != NULL)
            xmlFree((char *) entity->SystemID);
        if (entity->URI != NULL)
            xmlFree((char *) entity->URI);
        if (entity->content != NULL)
            xmlFree((char *) entity->content);
        if (entity->orig != NULL)
            xmlFree((char *) entity->orig);
    }
    xmlFree(entity);
}

/*
 * xmlAddEntity : register a new entity for an entities table.
 */
static xmlEntityPtr
xmlAddEntity(xmlDtdPtr dtd, const xmlChar *name, int type,
	  const xmlChar *ExternalID, const xmlChar *SystemID,
	  const xmlChar *content) {
    xmlDictPtr dict = NULL;
    xmlEntitiesTablePtr table = NULL;
    xmlEntityPtr ret;

    if (name == NULL)
	return(NULL);
    if (dtd == NULL)
	return(NULL);
    if (dtd->doc != NULL)
        dict = dtd->doc->dict;

    switch (type) {
        case XML_INTERNAL_GENERAL_ENTITY:
        case XML_EXTERNAL_GENERAL_PARSED_ENTITY:
        case XML_EXTERNAL_GENERAL_UNPARSED_ENTITY:
	    if (dtd->entities == NULL)
		dtd->entities = xmlHashCreateDict(0, dict);
	    table = dtd->entities;
	    break;
        case XML_INTERNAL_PARAMETER_ENTITY:
        case XML_EXTERNAL_PARAMETER_ENTITY:
	    if (dtd->pentities == NULL)
		dtd->pentities = xmlHashCreateDict(0, dict);
	    table = dtd->pentities;
	    break;
        case XML_INTERNAL_PREDEFINED_ENTITY:
	    return(NULL);
    }
    if (table == NULL)
	return(NULL);
    ret = (xmlEntityPtr) xmlMalloc(sizeof(xmlEntity));
    if (ret == NULL) {
        xmlEntitiesErrMemory("xmlAddEntity:: malloc failed");
	return(NULL);
    }
    memset(ret, 0, sizeof(xmlEntity));
    ret->type = XML_ENTITY_DECL;

    /*
     * fill the structure.
     */
    ret->etype = (xmlEntityType) type;
    if (dict == NULL) {
	ret->name = xmlStrdup(name);
	if (ExternalID != NULL)
	    ret->ExternalID = xmlStrdup(ExternalID);
	if (SystemID != NULL)
	    ret->SystemID = xmlStrdup(SystemID);
    } else {
        ret->name = xmlDictLookup(dict, name, -1);
	if (ExternalID != NULL)
	    ret->ExternalID = xmlDictLookup(dict, ExternalID, -1);
	if (SystemID != NULL)
	    ret->SystemID = xmlDictLookup(dict, SystemID, -1);
    }
    if (content != NULL) {
        ret->length = xmlStrlen(content);
	if ((dict != NULL) && (ret->length < 5))
	    ret->content = (xmlChar *)
	                   xmlDictLookup(dict, content, ret->length);
	else
	    ret->content = xmlStrndup(content, ret->length);
     } else {
        ret->length = 0;
        ret->content = NULL;
    }
    ret->URI = NULL; /* to be computed by the layer knowing
			the defining entity */
    ret->orig = NULL;
    ret->owner = 0;
    ret->doc = dtd->doc;

    if (xmlHashAddEntry(table, name, ret)) {
	/*
	 * entity was already defined at another level.
	 */
        xmlFreeEntity(ret);
	return(NULL);
    }
    return(ret);
}

/**
 * xmlGetPredefinedEntity:
 * @name:  the entity name
 *
 * Check whether this name is an predefined entity.
 *
 * Returns NULL if not, otherwise the entity
 */
xmlEntityPtr
xmlGetPredefinedEntity(const xmlChar *name) {
    if (name == NULL) return(NULL);
    switch (name[0]) {
        case 'l':
	    if (xmlStrEqual(name, BAD_CAST "lt"))
	        return(&xmlEntityLt);
	    break;
        case 'g':
	    if (xmlStrEqual(name, BAD_CAST "gt"))
	        return(&xmlEntityGt);
	    break;
        case 'a':
	    if (xmlStrEqual(name, BAD_CAST "amp"))
	        return(&xmlEntityAmp);
	    if (xmlStrEqual(name, BAD_CAST "apos"))
	        return(&xmlEntityApos);
	    break;
        case 'q':
	    if (xmlStrEqual(name, BAD_CAST "quot"))
	        return(&xmlEntityQuot);
	    break;
	default:
	    break;
    }
    return(NULL);
}

/**
 * xmlAddDtdEntity:
 * @doc:  the document
 * @name:  the entity name
 * @type:  the entity type XML_xxx_yyy_ENTITY
 * @ExternalID:  the entity external ID if available
 * @SystemID:  the entity system ID if available
 * @content:  the entity content
 *
 * Register a new entity for this document DTD external subset.
 *
 * Returns a pointer to the entity or NULL in case of error
 */
xmlEntityPtr
xmlAddDtdEntity(xmlDocPtr doc, const xmlChar *name, int type,
	        const xmlChar *ExternalID, const xmlChar *SystemID,
		const xmlChar *content) {
    xmlEntityPtr ret;
    xmlDtdPtr dtd;

    if (doc == NULL) {
	xmlEntitiesErr(XML_DTD_NO_DOC,
	        "xmlAddDtdEntity: document is NULL");
	return(NULL);
    }
    if (doc->extSubset == NULL) {
	xmlEntitiesErr(XML_DTD_NO_DTD,
	        "xmlAddDtdEntity: document without external subset");
	return(NULL);
    }
    dtd = doc->extSubset;
    ret = xmlAddEntity(dtd, name, type, ExternalID, SystemID, content);
    if (ret == NULL) return(NULL);

    /*
     * Link it to the DTD
     */
    ret->parent = dtd;
    ret->doc = dtd->doc;
    if (dtd->last == NULL) {
	dtd->children = dtd->last = (xmlNodePtr) ret;
    } else {
        dtd->last->next = (xmlNodePtr) ret;
	ret->prev = dtd->last;
	dtd->last = (xmlNodePtr) ret;
    }
    return(ret);
}

/**
 * xmlAddDocEntity:
 * @doc:  the document
 * @name:  the entity name
 * @type:  the entity type XML_xxx_yyy_ENTITY
 * @ExternalID:  the entity external ID if available
 * @SystemID:  the entity system ID if available
 * @content:  the entity content
 *
 * Register a new entity for this document.
 *
 * Returns a pointer to the entity or NULL in case of error
 */
xmlEntityPtr
xmlAddDocEntity(xmlDocPtr doc, const xmlChar *name, int type,
	        const xmlChar *ExternalID, const xmlChar *SystemID,
	        const xmlChar *content) {
    xmlEntityPtr ret;
    xmlDtdPtr dtd;

    if (doc == NULL) {
	xmlEntitiesErr(XML_DTD_NO_DOC,
	        "xmlAddDocEntity: document is NULL");
	return(NULL);
    }
    if (doc->intSubset == NULL) {
	xmlEntitiesErr(XML_DTD_NO_DTD,
	        "xmlAddDocEntity: document without internal subset");
	return(NULL);
    }
    dtd = doc->intSubset;
    ret = xmlAddEntity(dtd, name, type, ExternalID, SystemID, content);
    if (ret == NULL) return(NULL);

    /*
     * Link it to the DTD
     */
    ret->parent = dtd;
    ret->doc = dtd->doc;
    if (dtd->last == NULL) {
	dtd->children = dtd->last = (xmlNodePtr) ret;
    } else {
	dtd->last->next = (xmlNodePtr) ret;
	ret->prev = dtd->last;
	dtd->last = (xmlNodePtr) ret;
    }
    return(ret);
}

/**
 * xmlGetEntityFromTable:
 * @table:  an entity table
 * @name:  the entity name
 * @parameter:  look for parameter entities
 *
 * Do an entity lookup in the table.
 * returns the corresponding parameter entity, if found.
 * 
 * Returns A pointer to the entity structure or NULL if not found.
 */
static xmlEntityPtr
xmlGetEntityFromTable(xmlEntitiesTablePtr table, const xmlChar *name) {
    return((xmlEntityPtr) xmlHashLookup(table, name));
}

/**
 * xmlGetParameterEntity:
 * @doc:  the document referencing the entity
 * @name:  the entity name
 *
 * Do an entity lookup in the internal and external subsets and
 * returns the corresponding parameter entity, if found.
 * 
 * Returns A pointer to the entity structure or NULL if not found.
 */
xmlEntityPtr
xmlGetParameterEntity(xmlDocPtr doc, const xmlChar *name) {
    xmlEntitiesTablePtr table;
    xmlEntityPtr ret;

    if (doc == NULL)
	return(NULL);
    if ((doc->intSubset != NULL) && (doc->intSubset->pentities != NULL)) {
	table = (xmlEntitiesTablePtr) doc->intSubset->pentities;
	ret = xmlGetEntityFromTable(table, name);
	if (ret != NULL)
	    return(ret);
    }
    if ((doc->extSubset != NULL) && (doc->extSubset->pentities != NULL)) {
	table = (xmlEntitiesTablePtr) doc->extSubset->pentities;
	return(xmlGetEntityFromTable(table, name));
    }
    return(NULL);
}

/**
 * xmlGetDtdEntity:
 * @doc:  the document referencing the entity
 * @name:  the entity name
 *
 * Do an entity lookup in the DTD entity hash table and
 * returns the corresponding entity, if found.
 * Note: the first argument is the document node, not the DTD node.
 * 
 * Returns A pointer to the entity structure or NULL if not found.
 */
xmlEntityPtr
xmlGetDtdEntity(xmlDocPtr doc, const xmlChar *name) {
    xmlEntitiesTablePtr table;

    if (doc == NULL)
	return(NULL);
    if ((doc->extSubset != NULL) && (doc->extSubset->entities != NULL)) {
	table = (xmlEntitiesTablePtr) doc->extSubset->entities;
	return(xmlGetEntityFromTable(table, name));
    }
    return(NULL);
}

/**
 * xmlGetDocEntity:
 * @doc:  the document referencing the entity
 * @name:  the entity name
 *
 * Do an entity lookup in the document entity hash table and
 * returns the corresponding entity, otherwise a lookup is done
 * in the predefined entities too.
 * 
 * Returns A pointer to the entity structure or NULL if not found.
 */
xmlEntityPtr
xmlGetDocEntity(xmlDocPtr doc, const xmlChar *name) {
    xmlEntityPtr cur;
    xmlEntitiesTablePtr table;

    if (doc != NULL) {
	if ((doc->intSubset != NULL) && (doc->intSubset->entities != NULL)) {
	    table = (xmlEntitiesTablePtr) doc->intSubset->entities;
	    cur = xmlGetEntityFromTable(table, name);
	    if (cur != NULL)
		return(cur);
	}
	if (doc->standalone != 1) {
	    if ((doc->extSubset != NULL) &&
		(doc->extSubset->entities != NULL)) {
		table = (xmlEntitiesTablePtr) doc->extSubset->entities;
		cur = xmlGetEntityFromTable(table, name);
		if (cur != NULL)
		    return(cur);
	    }
	}
    }
    return(xmlGetPredefinedEntity(name));
}

/*
 * Macro used to grow the current buffer.
 */
#define growBufferReentrant() {						\
    buffer_size *= 2;							\
    buffer = (xmlChar *)						\
    		xmlRealloc(buffer, buffer_size * sizeof(xmlChar));	\
    if (buffer == NULL) {						\
        xmlEntitiesErrMemory("xmlEncodeEntitiesReentrant: realloc failed");\
	return(NULL);							\
    }									\
}


/**
 * xmlEncodeEntitiesReentrant: