valid.c

Vovida 社区开源的 SIP 协议源码

/*
 * valid.c : part of the code use to do the DTD handling and the validity
 *           checking
 *
 * See Copyright for the status of this software.
 *
 * [e-mail]
 */

#include "global.h"
#ifdef WIN32
#include "win32config.h"
#else
#include "config.h"
#endif

#include <stdio.h>
#include <string.h>

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif

#include <libxml/xmlmemory.h>
#include <libxml/valid.h>
#include <libxml/parser.h>
#include <libxml/parserInternals.h>

/*
 * Generic function for accessing stacks in the Validity Context
 */

#define PUSH_AND_POP(scope, type, name)					\
scope int name##VPush(xmlValidCtxtPtr ctxt, type value) {		\
    if (ctxt->name##Nr >= ctxt->name##Max) {				\
	ctxt->name##Max *= 2;						\
        ctxt->name##Tab = (void *) xmlRealloc(ctxt->name##Tab,		\
	             ctxt->name##Max * sizeof(ctxt->name##Tab[0]));	\
        if (ctxt->name##Tab == NULL) {					\
	    fprintf(stderr, "realloc failed !\n");			\
	    return(0);							\
	}								\
    }									\
    ctxt->name##Tab[ctxt->name##Nr] = value;				\
    ctxt->name = value;							\
    return(ctxt->name##Nr++);						\
}									\
scope type name##VPop(xmlValidCtxtPtr ctxt) {				\
    type ret;								\
    if (ctxt->name##Nr <= 0) return(0);					\
    ctxt->name##Nr--;							\
    if (ctxt->name##Nr > 0)						\
	ctxt->name = ctxt->name##Tab[ctxt->name##Nr - 1];		\
    else								\
        ctxt->name = NULL;						\
    ret = ctxt->name##Tab[ctxt->name##Nr];				\
    ctxt->name##Tab[ctxt->name##Nr] = 0;				\
    return(ret);							\
}									\

PUSH_AND_POP(static, xmlNodePtr, node)

/* #define DEBUG_VALID_ALGO */

#ifdef DEBUG_VALID_ALGO
void xmlValidPrintNodeList(xmlNodePtr cur) {
    if (cur == NULL)
	fprintf(stderr, "null ");
    while (cur != NULL) {
	switch (cur->type) {
	    case XML_ELEMENT_NODE:
		fprintf(stderr, "%s ", cur->name);
		break;
	    case XML_TEXT_NODE:
		fprintf(stderr, "text ");
		break;
	    case XML_CDATA_SECTION_NODE:
		fprintf(stderr, "cdata ");
		break;
	    case XML_ENTITY_REF_NODE:
		fprintf(stderr, "&%s; ", cur->name);
		break;
	    case XML_PI_NODE:
		fprintf(stderr, "pi(%s) ", cur->name);
		break;
	    case XML_COMMENT_NODE:
		fprintf(stderr, "comment ");
		break;
	    case XML_ATTRIBUTE_NODE:
		fprintf(stderr, "?attr? ");
		break;
	    case XML_ENTITY_NODE:
		fprintf(stderr, "?ent? ");
		break;
	    case XML_DOCUMENT_NODE:
		fprintf(stderr, "?doc? ");
		break;
	    case XML_DOCUMENT_TYPE_NODE:
		fprintf(stderr, "?doctype? ");
		break;
	    case XML_DOCUMENT_FRAG_NODE:
		fprintf(stderr, "?frag? ");
		break;
	    case XML_NOTATION_NODE:
		fprintf(stderr, "?nota? ");
		break;
	    case XML_HTML_DOCUMENT_NODE:
		fprintf(stderr, "?html? ");
		break;
	    case XML_DTD_NODE:
		fprintf(stderr, "?dtd? ");
		break;
	    case XML_ELEMENT_DECL:
		fprintf(stderr, "?edecl? ");
		break;
	    case XML_ATTRIBUTE_DECL:
		fprintf(stderr, "?adecl? ");
		break;
	    case XML_ENTITY_DECL:
		fprintf(stderr, "?entdecl? ");
		break;
	}
	cur = cur->next;
    }
}

void xmlValidDebug(xmlNodePtr cur, xmlElementContentPtr cont) {
    char expr[1000];

    expr[0] = 0;
    fprintf(stderr, "valid: ");
    xmlValidPrintNodeList(cur);
    fprintf(stderr, "against ");
    xmlSprintfElementContent(expr, cont, 0);
    fprintf(stderr, "%s\n", expr);
}

#define DEBUG_VALID_STATE(n,c) xmlValidDebug(n,c);
#else
#define DEBUG_VALID_STATE(n,c)
#endif

/* TODO: use hash table for accesses to elem and attribute dedinitions */

#define VERROR							\
   if ((ctxt != NULL) && (ctxt->error != NULL)) ctxt->error

#define VWARNING						\
   if ((ctxt != NULL) && (ctxt->warning != NULL)) ctxt->warning

#define CHECK_DTD						\
   if (doc == NULL) return(0);					\
   else if (doc->intSubset == NULL) return(0)

xmlElementPtr xmlGetDtdElementDesc(xmlDtdPtr dtd, const xmlChar *name);
xmlAttributePtr xmlScanAttributeDecl(xmlDtdPtr dtd, const xmlChar *elem);

/****************************************************************
 *								*
 *	Util functions for data allocation/deallocation		*
 *								*
 ****************************************************************/

/**
 * xmlNewElementContent:
 * @name:  the subelement name or NULL
 * @type:  the type of element content decl
 *
 * Allocate an element content structure.
 *
 * Returns NULL if not, othervise the new element content structure
 */
xmlElementContentPtr
xmlNewElementContent(xmlChar *name, xmlElementContentType type) {
    xmlElementContentPtr ret;

    switch(type) {
	case XML_ELEMENT_CONTENT_ELEMENT:
	    if (name == NULL) {
	        fprintf(stderr, "xmlNewElementContent : name == NULL !\n");
	    }
	    break;
        case XML_ELEMENT_CONTENT_PCDATA:
	case XML_ELEMENT_CONTENT_SEQ:
	case XML_ELEMENT_CONTENT_OR:
	    if (name != NULL) {
	        fprintf(stderr, "xmlNewElementContent : name != NULL !\n");
	    }
	    break;
	default:
	    fprintf(stderr, "xmlNewElementContent: unknown type %d\n", type);
	    return(NULL);
    }
    ret = (xmlElementContentPtr) xmlMalloc(sizeof(xmlElementContent));
    if (ret == NULL) {
	fprintf(stderr, "xmlNewElementContent : out of memory!\n");
	return(NULL);
    }
    ret->type = type;
    ret->ocur = XML_ELEMENT_CONTENT_ONCE;
    if (name != NULL)
        ret->name = xmlStrdup(name);
    else
        ret->name = NULL;
    ret->c1 = ret->c2 = NULL;
    return(ret);
}

/**
 * xmlCopyElementContent:
 * @content:  An element content pointer.
 *
 * Build a copy of an element content description.
 * 
 * Returns the new xmlElementContentPtr or NULL in case of error.
 */
xmlElementContentPtr
xmlCopyElementContent(xmlElementContentPtr cur) {
    xmlElementContentPtr ret;

    if (cur == NULL) return(NULL);
    ret = xmlNewElementContent((xmlChar *) cur->name, cur->type);
    if (ret == NULL) {
        fprintf(stderr, "xmlCopyElementContent : out of memory\n");
	return(NULL);
    }
    ret->ocur = cur->ocur;
    if (cur->c1 != NULL) ret->c1 = xmlCopyElementContent(cur->c1);
    if (cur->c2 != NULL) ret->c2 = xmlCopyElementContent(cur->c2);
    return(ret);
}

/**
 * xmlFreeElementContent:
 * @cur:  the element content tree to free
 *
 * Free an element content structure. This is a recursive call !
 */
void
xmlFreeElementContent(xmlElementContentPtr cur) {
    if (cur == NULL) return;
    if (cur->c1 != NULL) xmlFreeElementContent(cur->c1);
    if (cur->c2 != NULL) xmlFreeElementContent(cur->c2);
    if (cur->name != NULL) xmlFree((xmlChar *) cur->name);
    memset(cur, -1, sizeof(xmlElementContent));
    xmlFree(cur);
}

/**
 * xmlDumpElementContent:
 * @buf:  An XML buffer
 * @content:  An element table
 * @glob: 1 if one must print the englobing parenthesis, 0 otherwise
 *
 * This will dump the content of the element table as an XML DTD definition
 */
void
xmlDumpElementContent(xmlBufferPtr buf, xmlElementContentPtr content, int glob) {
    if (content == NULL) return;

    if (glob) xmlBufferWriteChar(buf, "(");
    switch (content->type) {
        case XML_ELEMENT_CONTENT_PCDATA:
            xmlBufferWriteChar(buf, "#PCDATA");
	    break;
	case XML_ELEMENT_CONTENT_ELEMENT:
	    xmlBufferWriteCHAR(buf, content->name);
	    break;
	case XML_ELEMENT_CONTENT_SEQ:
	    if ((content->c1->type == XML_ELEMENT_CONTENT_OR) ||
	        (content->c1->type == XML_ELEMENT_CONTENT_SEQ))
		xmlDumpElementContent(buf, content->c1, 1);
	    else
		xmlDumpElementContent(buf, content->c1, 0);
            xmlBufferWriteChar(buf, " , ");
	    if (content->c2->type == XML_ELEMENT_CONTENT_OR)
		xmlDumpElementContent(buf, content->c2, 1);
	    else
		xmlDumpElementContent(buf, content->c2, 0);
	    break;
	case XML_ELEMENT_CONTENT_OR:
	    if ((content->c1->type == XML_ELEMENT_CONTENT_OR) ||
	        (content->c1->type == XML_ELEMENT_CONTENT_SEQ))
		xmlDumpElementContent(buf, content->c1, 1);
	    else
		xmlDumpElementContent(buf, content->c1, 0);
            xmlBufferWriteChar(buf, " | ");
	    if (content->c2->type == XML_ELEMENT_CONTENT_SEQ)
		xmlDumpElementContent(buf, content->c2, 1);
	    else
		xmlDumpElementContent(buf, content->c2, 0);
	    break;
	default:
	    fprintf(stderr, "xmlDumpElementContent: unknown type %d\n",
	            content->type);
    }
    if (glob)
        xmlBufferWriteChar(buf, ")");
    switch (content->ocur) {
        case XML_ELEMENT_CONTENT_ONCE:
	    break;
        case XML_ELEMENT_CONTENT_OPT:
	    xmlBufferWriteChar(buf, "?");
	    break;
        case XML_ELEMENT_CONTENT_MULT:
	    xmlBufferWriteChar(buf, "*");
	    break;
        case XML_ELEMENT_CONTENT_PLUS:
	    xmlBufferWriteChar(buf, "+");
	    break;
    }
}

/**
 * xmlSprintfElementContent:
 * @buf:  an output buffer
 * @content:  An element table
 * @glob: 1 if one must print the englobing parenthesis, 0 otherwise
 *
 * This will dump the content of the element content definition
 * Intended just for the debug routine
 */
void
xmlSprintfElementContent(char *buf, xmlElementContentPtr content, int glob) {
    if (content == NULL) return;
    if (glob) strcat(buf, "(");
    switch (content->type) {
        case XML_ELEMENT_CONTENT_PCDATA:
            strcat(buf, "#PCDATA");
	    break;
	case XML_ELEMENT_CONTENT_ELEMENT:
	    strcat(buf, (char *) content->name);
	    break;
	case XML_ELEMENT_CONTENT_SEQ:
	    if ((content->c1->type == XML_ELEMENT_CONTENT_OR) ||
	        (content->c1->type == XML_ELEMENT_CONTENT_SEQ))
		xmlSprintfElementContent(buf, content->c1, 1);
	    else
		xmlSprintfElementContent(buf, content->c1, 0);
            strcat(buf, " , ");
	    if (content->c2->type == XML_ELEMENT_CONTENT_OR)
		xmlSprintfElementContent(buf, content->c2, 1);
	    else
		xmlSprintfElementContent(buf, content->c2, 0);
	    break;
	case XML_ELEMENT_CONTENT_OR:
	    if ((content->c1->type == XML_ELEMENT_CONTENT_OR) ||
	        (content->c1->type == XML_ELEMENT_CONTENT_SEQ))
		xmlSprintfElementContent(buf, content->c1, 1);
	    else
		xmlSprintfElementContent(buf, content->c1, 0);
            strcat(buf, " | ");
	    if (content->c2->type == XML_ELEMENT_CONTENT_SEQ)
		xmlSprintfElementContent(buf, content->c2, 1);
	    else
		xmlSprintfElementContent(buf, content->c2, 0);
	    break;
    }
    if (glob)
        strcat(buf, ")");
    switch (content->ocur) {
        case XML_ELEMENT_CONTENT_ONCE:
	    break;
        case XML_ELEMENT_CONTENT_OPT:
	    strcat(buf, "?");
	    break;
        case XML_ELEMENT_CONTENT_MULT:
	    strcat(buf, "*");
	    break;
        case XML_ELEMENT_CONTENT_PLUS:
	    strcat(buf, "+");
	    break;
    }
}

/****************************************************************
 *								*
 *	Registration of DTD declarations			*
 *								*
 ****************************************************************/

/**
 * xmlCreateElementTable:
 *
 * create and initialize an empty element hash table.
 *
 * Returns the xmlElementTablePtr just created or NULL in case of error.
 */
xmlElementTablePtr
xmlCreateElementTable(void) {
    xmlElementTablePtr ret;

    ret = (xmlElementTablePtr) 
         xmlMalloc(sizeof(xmlElementTable));
    if (ret == NULL) {
        fprintf(stderr, "xmlCreateElementTable : xmlMalloc(%ld) failed\n",
	        (long)sizeof(xmlElementTable));
        return(NULL);
    }
    ret->max_elements = XML_MIN_ELEMENT_TABLE;
    ret->nb_elements = 0;
    ret->table = (xmlElementPtr *) 
         xmlMalloc(ret->max_elements * sizeof(xmlElementPtr));
    if (ret == NULL) {
        fprintf(stderr, "xmlCreateElementTable : xmlMalloc(%ld) failed\n",
	        ret->max_elements * (long)sizeof(xmlElement));
	xmlFree(ret);
        return(NULL);
    }
    return(ret);
}


/**
 * xmlAddElementDecl:
 * @ctxt:  the validation context
 * @dtd:  pointer to the DTD
 * @name:  the entity name
 * @type:  the element type
 * @content:  the element content tree or NULL
 *
 * Register a new element declaration
 *
 * Returns NULL if not, othervise the entity
 */
xmlElementPtr
xmlAddElementDecl(xmlValidCtxtPtr ctxt, xmlDtdPtr dtd, const xmlChar *name,
                  xmlElementTypeVal type,
		  xmlElementContentPtr content) {
    xmlElementPtr ret, cur;
    xmlElementTablePtr table;
    int i;

    if (dtd == NULL) {
        fprintf(stderr, "xmlAddElementDecl: dtd == NULL\n");
	return(NULL);
    }
    if (name == NULL) {
        fprintf(stderr, "xmlAddElementDecl: name == NULL\n");
	return(NULL);
    }
    switch (type) {
        case XML_ELEMENT_TYPE_EMPTY:
	    if (content != NULL) {
	        fprintf(stderr,
		        "xmlAddElementDecl: content != NULL for EMPTY\n");
		return(NULL);
	    }
	    break;
	case XML_ELEMENT_TYPE_ANY:
	    if (content != NULL) {
	        fprintf(stderr,
		        "xmlAddElementDecl: content != NULL for ANY\n");
		return(NULL);
	    }
	    break;
	case XML_ELEMENT_TYPE_MIXED:
	    if (content == NULL) {
	        fprintf(stderr,
		        "xmlAddElementDecl: content == NULL for MIXED\n");
		return(NULL);
	    }
	    break;
	case XML_ELEMENT_TYPE_ELEMENT:
	    if (content == NULL) {
	        fprintf(stderr,
		        "xmlAddElementDecl: content == NULL for ELEMENT\n");
		return(NULL);
	    }
	    break;
	default:
	    fprintf(stderr, "xmlAddElementDecl: unknown type %d\n", type);
	    return(NULL);
    }

    /*
     * Create the Element table if needed.
     */
    table = dtd->elements;
    if (table == NULL) 
        table = dtd->elements = xmlCreateElementTable();
    if (table == NULL) {
	fprintf(stderr, "xmlAddElementDecl: Table creation failed!\n");
        return(NULL);
    }

    /*
     * Validity Check:
     * Search the DTD for previous declarations of the ELEMENT
     */
    for (i = 0;i < table->nb_elements;i++) {
        cur = table->table[i];
	if (!xmlStrcmp(cur->name, name)) {
	    /*
	     * The element is already defined in this Dtd.
	     */
	    VERROR(ctxt->userData, "Redefinition of element %s\n", name);
	    return(NULL);
	}
    }

    /*
     * Grow the table, if needed.
     */
    if (table->nb_elements >= table->max_elements) {
        /*
	 * need more elements.
	 */
	table->max_elements *= 2;
	table->table = (xmlElementPtr *) 
	    xmlRealloc(table->table, table->max_elements * sizeof(xmlElementPtr));
	if (table->table == NULL) {
	    fprintf(stderr, "xmlAddElementDecl: out of memory\n");
	    return(NULL);
	}
    }