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/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* Copyright (C) 2001 by First Peer, Inc. All rights reserved.
** Copyright (C) 2002 Ximian, Inc.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
** derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
** ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE. */
#include "xmlrpc_config.h"
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <libxml/parser.h>
#include "xmlrpc.h"
#include "xmlrpc_xmlparser.h"
/* Define the contents of our internal structure. */
struct _xml_element {
struct _xml_element *_parent;
char *_name;
xmlrpc_mem_block _cdata; /* char */
xmlrpc_mem_block _children; /* xml_element* */
};
#define XMLRPC_ASSERT_ELEM_OK(elem) \
XMLRPC_ASSERT((elem) != NULL && (elem)->_name != XMLRPC_BAD_POINTER)
/*=========================================================================
** xml_element_new
**=========================================================================
** Create a new xml_element. This routine isn't exported, because the
** arguments are implementation-dependent.
*/
static xml_element *xml_element_new (xmlrpc_env *env, char *name)
{
xml_element *retval;
int name_valid, cdata_valid, children_valid;
XMLRPC_ASSERT_ENV_OK(env);
XMLRPC_ASSERT(name != NULL);
/* Set up our error-handling preconditions. */
retval = NULL;
name_valid = cdata_valid = children_valid = 0;
/* Allocate our xml_element structure. */
retval = (xml_element*) malloc(sizeof(xml_element));
XMLRPC_FAIL_IF_NULL(retval, env, XMLRPC_INTERNAL_ERROR,
"Couldn't allocate memory for XML element");
/* Set our parent field to NULL. */
retval->_parent = NULL;
/* Copy over the element name. */
retval->_name = (char*) malloc(strlen(name) + 1);
XMLRPC_FAIL_IF_NULL(retval->_name, env, XMLRPC_INTERNAL_ERROR,
"Couldn't allocate memory for XML element");
name_valid = 1;
strcpy(retval->_name, name);
/* Initialize a block to hold our CDATA. */
XMLRPC_TYPED_MEM_BLOCK_INIT(char, env, &retval->_cdata, 0);
XMLRPC_FAIL_IF_FAULT(env);
cdata_valid = 1;
/* Initialize a block to hold our child elements. */
XMLRPC_TYPED_MEM_BLOCK_INIT(xml_element*, env, &retval->_children, 0);
XMLRPC_FAIL_IF_FAULT(env);
children_valid = 1;
cleanup:
if (env->fault_occurred) {
if (retval) {
if (name_valid)
free(retval->_name);
if (cdata_valid)
xmlrpc_mem_block_clean(&retval->_cdata);
if (children_valid)
xmlrpc_mem_block_clean(&retval->_children);
free(retval);
}
return NULL;
} else {
return retval;
}
}
/*=========================================================================
** xml_element_free
**=========================================================================
** Blow away an existing element & all of its child elements.
*/
void xml_element_free (xml_element *elem)
{
xmlrpc_mem_block *children;
int size, i;
xml_element **contents;
XMLRPC_ASSERT_ELEM_OK(elem);
free(elem->_name);
elem->_name = XMLRPC_BAD_POINTER;
xmlrpc_mem_block_clean(&elem->_cdata);
/* Deallocate all of our children recursively. */
children = &elem->_children;
contents = XMLRPC_TYPED_MEM_BLOCK_CONTENTS(xml_element*, children);
size = XMLRPC_TYPED_MEM_BLOCK_SIZE(xml_element*, children);
for (i = 0; i < size; i++)
xml_element_free(contents[i]);
xmlrpc_mem_block_clean(&elem->_children);
free(elem);
}
/*=========================================================================
** Miscellaneous Accessors
**=========================================================================
** Return the fields of the xml_element. See the header for more
** documentation on each function works.
*/
char *xml_element_name (xml_element *elem)
{
XMLRPC_ASSERT_ELEM_OK(elem);
return elem->_name;
}
/* The result of this function is NOT VALID until the end_element handler
** has been called! */
size_t xml_element_cdata_size (xml_element *elem)
{
XMLRPC_ASSERT_ELEM_OK(elem);
return XMLRPC_TYPED_MEM_BLOCK_SIZE(char, &elem->_cdata) - 1;
}
char *xml_element_cdata (xml_element *elem)
{
XMLRPC_ASSERT_ELEM_OK(elem);
return XMLRPC_TYPED_MEM_BLOCK_CONTENTS(char, &elem->_cdata);
}
size_t xml_element_children_size (xml_element *elem)
{
XMLRPC_ASSERT_ELEM_OK(elem);
return XMLRPC_TYPED_MEM_BLOCK_SIZE(xml_element*, &elem->_children);
}
xml_element **xml_element_children (xml_element *elem)
{
XMLRPC_ASSERT_ELEM_OK(elem);
return XMLRPC_TYPED_MEM_BLOCK_CONTENTS(xml_element*, &elem->_children);
}
/*=========================================================================
** Internal xml_element Utility Functions
**=========================================================================
*/
static void xml_element_append_cdata (xmlrpc_env *env,
xml_element *elem,
char *cdata,
size_t size)
{
XMLRPC_ASSERT_ENV_OK(env);
XMLRPC_ASSERT_ELEM_OK(elem);
XMLRPC_TYPED_MEM_BLOCK_APPEND(char, env, &elem->_cdata, cdata, size);
}
/* Whether or not this function succeeds, it takes ownership of the 'child'
** argument.
** WARNING - This is the exact opposite of the usual memory ownership
** rules for xmlrpc_value! So please pay attention. */
static void xml_element_append_child (xmlrpc_env *env,
xml_element *elem,
xml_element *child)
{
XMLRPC_ASSERT_ENV_OK(env);
XMLRPC_ASSERT_ELEM_OK(elem);
XMLRPC_ASSERT_ELEM_OK(child);
XMLRPC_ASSERT(child->_parent == NULL);
XMLRPC_TYPED_MEM_BLOCK_APPEND(xml_element*, env, &elem->_children,
&child, 1);
if (!env->fault_occurred)
child->_parent = elem;
else
xml_element_free(child);
}
/*=========================================================================
** Our parse context. We pass this around as libxml user data.
**=========================================================================
*/
typedef struct {
xmlrpc_env *env;
xml_element *root;
xml_element *current;
} parse_context;
/*=========================================================================
** LibXML Event Handler Functions
**=========================================================================
*/
static void
start_element (void *user_data, const xmlChar *name, const xmlChar **attrs)
{
parse_context *context;
xml_element *elem, *new_current;
XMLRPC_ASSERT(user_data != NULL && name != NULL);
/* Get our context and see if an error has already occured. */
context = (parse_context*) user_data;
if (!context->env->fault_occurred) {
/* Set up our error-handling preconditions. */
elem = NULL;
/* Build a new element. */
elem = xml_element_new(context->env, (char *) name);
XMLRPC_FAIL_IF_FAULT(context->env);
/* Insert it in the appropriate place. */
if (!context->root) {
context->root = elem;
context->current = elem;
elem = NULL;
} else {
XMLRPC_ASSERT(context->current != NULL);
/* (We need to watch our error handling invariants very carefully
** here. Read the docs for xml_element_append_child. */
new_current = elem;
xml_element_append_child(context->env, context->current, elem);
elem = NULL;
XMLRPC_FAIL_IF_FAULT(context->env);
context->current = new_current;
}
cleanup:
if (elem)
xml_element_free(elem);
}
}
static void
end_element (void *user_data, const xmlChar *name)
{
parse_context *context;
XMLRPC_ASSERT(user_data != NULL && name != NULL);
/* Get our context and see if an error has already occured. */
context = (parse_context*) user_data;
if (!context->env->fault_occurred) {
/* XXX - I think expat enforces these facts, but I want to be sure.
** If one of these assertion ever fails, it should be replaced by a
** non-assertion runtime error check. */
XMLRPC_ASSERT(strcmp(name, context->current->_name) == 0);
XMLRPC_ASSERT(context->current->_parent != NULL ||
context->current == context->root);
/* Add a trailing '\0' to our cdata. */
xml_element_append_cdata(context->env, context->current, "\0", 1);
XMLRPC_FAIL_IF_FAULT(context->env);
/* Pop our "stack" of elements. */
context->current = context->current->_parent;
cleanup:
return;
}
}
static void character_data (void *user_data, const xmlChar *s, int len)
{
parse_context *context;
XMLRPC_ASSERT(user_data != NULL && s != NULL && len >= 0);
/* Get our context and see if an error has already occured. */
context = (parse_context*) user_data;
if (!context->env->fault_occurred) {
XMLRPC_ASSERT(context->current != NULL);
xml_element_append_cdata(context->env, context->current, (char *) s, len);
XMLRPC_FAIL_IF_FAULT(context->env);
cleanup:
return;
}
}
/*=========================================================================
** LibXML Driver
**=========================================================================
** XXX - We should allow the user to specify the encoding of our xml_data.
*/
static xmlSAXHandler sax_handler = {
NULL, /* internalSubset */
NULL, /* isStandalone */
NULL, /* hasInternalSubset */
NULL, /* hasExternalSubset */
NULL, /* resolveEntity */
NULL, /* getEntity */
NULL, /* entityDecl */
NULL, /* notationDecl */
NULL, /* attributeDecl */
NULL, /* elementDecl */
NULL, /* unparsedEntityDecl */
NULL, /* setDocumentLocator */
NULL, /* startDocument */
NULL, /* endDocument */
start_element, /* startElement */
end_element, /* endElement */
NULL, /* reference */
character_data, /* characters */
NULL, /* ignorableWhitespace */
NULL, /* processingInstruction */
NULL, /* comment */
NULL, /* warning */
NULL, /* error */
NULL, /* fatalError */
};
xml_element *xml_parse (xmlrpc_env *env, char *xml_data, int xml_len)
{
parse_context context;
xmlParserCtxt *parser;
int err;
XMLRPC_ASSERT_ENV_OK(env);
XMLRPC_ASSERT(xml_data != NULL && xml_len >= 0);
/* Set up our error-handling preconditions. */
parser = NULL;
context.root = NULL;
/* Set up the rest of our parse context. */
context.env = env;
context.current = NULL;
/* Set up our XML parser. */
parser = xmlCreatePushParserCtxt(&sax_handler, &context, NULL, 0, NULL);
XMLRPC_FAIL_IF_NULL(parser, env, XMLRPC_INTERNAL_ERROR,
"Could not create expat parser");
/* Parse our data. */
err = xmlParseChunk(parser, xml_data, xml_len, 1);
if (err)
XMLRPC_FAIL(env, XMLRPC_PARSE_ERROR, "XML parsing failed");
XMLRPC_FAIL_IF_FAULT(env);
/* Perform some sanity checks. */
XMLRPC_ASSERT(context.root != NULL);
XMLRPC_ASSERT(context.current == NULL);
cleanup:
if (parser)
xmlFreeParserCtxt(parser);
if (env->fault_occurred) {
if (context.root)
xml_element_free(context.root);
return NULL;
} else {
return context.root;
}
}