/*
* ModSecurity for Apache 2.x, http://www.modsecurity.org/
* Copyright (c) 2004-2013 Trustwave Holdings, Inc. (http://www.trustwave.com/)
*
* You may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* If any of the files related to licensing are missing or if you have any
* other questions related to licensing please contact Trustwave Holdings, Inc.
* directly using the email address security@modsecurity.org.
*/
#include "msc_xml.h"
static xmlParserInputBufferPtr
xml_unload_external_entity(const char *URI, xmlCharEncoding enc) {
return NULL;
}
/**
* Initialise XML parser.
*/
int xml_init(modsec_rec *msr, char **error_msg) {
xmlParserInputBufferCreateFilenameFunc entity;
if (error_msg == NULL) return -1;
*error_msg = NULL;
msr->xml = apr_pcalloc(msr->mp, sizeof(xml_data));
if (msr->xml == NULL) return -1;
if(msr->txcfg->xml_external_entity == 0) {
entity = xmlParserInputBufferCreateFilenameDefault(xml_unload_external_entity);
}
return 1;
}
#if 0
static void xml_receive_sax_error(void *data, const char *msg, ...) {
modsec_rec *msr = (modsec_rec *)data;
char message[256];
if (msr == NULL) return;
apr_snprintf(message, sizeof(message), "%s (line %d offset %d)",
log_escape_nq(msr->mp, msr->xml->parsing_ctx->lastError.message),
msr->xml->parsing_ctx->lastError.line,
msr->xml->parsing_ctx->lastError.int2);
msr_log(msr, 5, "XML: Parsing error: %s", message);
}
#endif
/**
* Feed one chunk of data to the XML parser.
*/
int xml_process_chunk(modsec_rec *msr, const char *buf, unsigned int size, char **error_msg) {
if (error_msg == NULL) return -1;
*error_msg = NULL;
/* We want to initialise our parsing context here, to
* enable us to pass it the first chunk of data so that
* it can attempt to auto-detect the encoding.
*/
if (msr->xml->parsing_ctx == NULL) {
/* First invocation. */
msr_log(msr, 4, "XML: Initialising parser.");
/* NOTE When Sax interface is used libxml will not
* create the document object, but we need it.
msr->xml->sax_handler = (xmlSAXHandler *)apr_pcalloc(msr->mp, sizeof(xmlSAXHandler));
if (msr->xml->sax_handler == NULL) return -1;
msr->xml->sax_handler->error = xml_receive_sax_error;
msr->xml->sax_handler->warning = xml_receive_sax_error;
msr->xml->parsing_ctx = xmlCreatePushParserCtxt(msr->xml->sax_handler, msr,
buf, size, "body.xml");
*/
msr->xml->parsing_ctx = xmlCreatePushParserCtxt(NULL, NULL, buf, size, "body.xml");
if (msr->xml->parsing_ctx == NULL) {
*error_msg = apr_psprintf(msr->mp, "XML: Failed to create parsing context.");
return -1;
}
} else {
/* Not a first invocation. */
xmlParseChunk(msr->xml->parsing_ctx, buf, size, 0);
if (msr->xml->parsing_ctx->wellFormed != 1) {
*error_msg = apr_psprintf(msr->mp, "XML: Failed parsing document.");
return -1;
}
}
return 1;
}
/**
* Finalise XML parsing.
*/
int xml_complete(modsec_rec *msr, char **error_msg) {
if (error_msg == NULL) return -1;
*error_msg = NULL;
/* Only if we have a context, meaning we've done some work. */
if (msr->xml->parsing_ctx != NULL) {
/* This is how we signalise the end of parsing to libxml. */
xmlParseChunk(msr->xml->parsing_ctx, NULL, 0, 1);
/* Preserve the results for our reference. */
msr->xml->well_formed = msr->xml->parsing_ctx->wellFormed;
msr->xml->doc = msr->xml->parsing_ctx->myDoc;
/* Clean up everything else. */
xmlFreeParserCtxt(msr->xml->parsing_ctx);
msr->xml->parsing_ctx = NULL;
msr_log(msr, 4, "XML: Parsing complete (well_formed %u).", msr->xml->well_formed);
if (msr->xml->well_formed != 1) {
*error_msg = apr_psprintf(msr->mp, "XML: Failed parsing document.");
return -1;
}
}
return 1;
}
/**
* Frees the resources used for XML parsing.
*/
apr_status_t xml_cleanup(modsec_rec *msr) {
if (msr->xml->doc != NULL) {
xmlFreeDoc(msr->xml->doc);
msr->xml->doc = NULL;
}
return 1;
}