// =================================================================================================
// Copyright 2005-2008 Adobe Systems Incorporated
// All Rights Reserved.
//
// NOTICE: Adobe permits you to use, modify, and distribute this file in accordance with the terms
// of the Adobe license agreement accompanying it.
// =================================================================================================
#include "XMP_Environment.h" // ! Must be the first #include!
#include "XMPCore_Impl.hpp"
#include "ExpatAdapter.hpp"
#include "XMPMeta.hpp"
#include "expat.h"
#include <string.h>
using namespace std;
#if XMP_WinBuild
# ifdef _MSC_VER
#pragma warning ( disable : 4996 ) // '...' was declared deprecated
# endif
#endif
// *** Set memory handlers.
#ifndef DumpXMLParseEvents
#define DumpXMLParseEvents 0
#endif
#define FullNameSeparator '@'
// =================================================================================================
static void StartNamespaceDeclHandler ( void * userData, XMP_StringPtr prefix, XMP_StringPtr uri );
static void EndNamespaceDeclHandler ( void * userData, XMP_StringPtr prefix );
static void StartElementHandler ( void * userData, XMP_StringPtr name, XMP_StringPtr* attrs );
static void EndElementHandler ( void * userData, XMP_StringPtr name );
static void CharacterDataHandler ( void * userData, XMP_StringPtr cData, int len );
static void StartCdataSectionHandler ( void * userData );
static void EndCdataSectionHandler ( void * userData );
static void ProcessingInstructionHandler ( void * userData, XMP_StringPtr target, XMP_StringPtr data );
static void CommentHandler ( void * userData, XMP_StringPtr comment );
#if BanAllEntityUsage
// For now we do this by banning DOCTYPE entirely. This is easy and consistent with what is
// available in recent Java XML parsers. Another, somewhat less drastic, approach would be to
// ban all entity declarations. We can't allow declarations and ban references, Expat does not
// call the SkippedEntityHandler for references in attribute values.
// ! Standard entities (&, <, >, ", ', and numeric character references) are
// ! not banned. Expat handles them transparently no matter what.
static void StartDoctypeDeclHandler ( void * userData, XMP_StringPtr doctypeName,
XMP_StringPtr sysid, XMP_StringPtr pubid, int has_internal_subset );
#endif
// =================================================================================================
extern "C" ExpatAdapter * XMP_NewExpatAdapter()
{
return new ExpatAdapter;
} // XMP_NewExpatAdapter
// =================================================================================================
ExpatAdapter::ExpatAdapter() : parser(0)
{
#if XMP_DebugBuild
this->elemNesting = 0;
#if DumpXMLParseEvents
if ( this->parseLog == 0 ) this->parseLog = stdout;
#endif
#endif
this->parser = XML_ParserCreateNS ( 0, FullNameSeparator );
if ( this->parser == 0 ) XMP_Throw ( "Failure creating Expat parser", kXMPErr_ExternalFailure );
XML_SetUserData ( this->parser, this );
XML_SetNamespaceDeclHandler ( this->parser, StartNamespaceDeclHandler, EndNamespaceDeclHandler );
XML_SetElementHandler ( this->parser, StartElementHandler, EndElementHandler );
XML_SetCharacterDataHandler ( this->parser, CharacterDataHandler );
XML_SetCdataSectionHandler ( this->parser, StartCdataSectionHandler, EndCdataSectionHandler );
XML_SetProcessingInstructionHandler ( this->parser, ProcessingInstructionHandler );
XML_SetCommentHandler ( this->parser, CommentHandler );
#if BanAllEntityUsage
XML_SetStartDoctypeDeclHandler ( this->parser, StartDoctypeDeclHandler );
isAborted = false;
#endif
this->parseStack.push_back ( &this->tree ); // Push the XML root node.
} // ExpatAdapter::ExpatAdapter
// =================================================================================================
ExpatAdapter::~ExpatAdapter()
{
if ( this->parser != 0 ) XML_ParserFree ( this->parser );
this->parser = 0;
} // ExpatAdapter::~ExpatAdapter
// =================================================================================================
#if XMP_DebugBuild
static XMP_VarString sExpatMessage;
#endif
static const char * kOneSpace = " ";
void ExpatAdapter::ParseBuffer ( const void * buffer, size_t length, bool last /* = true */ )
{
enum XML_Status status;
if ( length == 0 ) { // Expat does not like empty buffers.
if ( ! last ) return;
buffer = kOneSpace;
length = 1;
}
status = XML_Parse ( this->parser, (const char *)buffer, length, last );
#if BanAllEntityUsage
if ( this->isAborted ) XMP_Throw ( "DOCTYPE is not allowed", kXMPErr_BadXML );
#endif
if ( status != XML_STATUS_OK ) {
XMP_StringPtr errMsg = "XML parsing failure";
#if 0 // XMP_DebugBuild // Disable for now to make test output uniform. Restore later with thread safety.
// *** This is a good candidate for a callback error notification mechanism.
// *** This code is not thread safe, the sExpatMessage isn't locked. But that's OK for debug usage.
enum XML_Error expatErr = XML_GetErrorCode ( this->parser );
const char * expatMsg = XML_ErrorString ( expatErr );
int errLine = XML_GetCurrentLineNumber ( this->parser );
char msgBuffer[1000];
// AUDIT: Use of sizeof(msgBuffer) for snprintf length is safe.
snprintf ( msgBuffer, sizeof(msgBuffer), "# Expat error %d at line %d, \"%s\"", expatErr, errLine, expatMsg );
sExpatMessage = msgBuffer;
errMsg = sExpatMessage.c_str();
#if DumpXMLParseEvents
if ( this->parseLog != 0 ) fprintf ( this->parseLog, "%s\n", errMsg, expatErr, errLine, expatMsg );
#endif
#endif
XMP_Throw ( errMsg, kXMPErr_BadXML );
}
} // ExpatAdapter::ParseBuffer
// =================================================================================================
// =================================================================================================
#if XMP_DebugBuild & DumpXMLParseEvents
static inline void PrintIndent ( FILE * file, size_t count )
{
for ( ; count > 0; --count ) fprintf ( file, " " );
}
#endif
// =================================================================================================
static void SetQualName ( XMP_StringPtr fullName, XML_Node * node )
{
// Expat delivers the full name as a catenation of namespace URI, separator, and local name.
// As a compatibility hack, an "about" or "ID" attribute of an rdf:Description element is
// changed to "rdf:about" or rdf:ID. Easier done here than in the RDF recognizer.
// As a bug fix hack, change a URI of "http://purl.org/dc/1.1/" to ""http://purl.org/dc/elements/1.1/.
// Early versions of Flash that put XMP in SWF used a bad URI for the dc: namespace.
// ! This code presumes the RDF namespace prefix is "rdf".
size_t sepPos = strlen(fullName);
for ( --sepPos; sepPos > 0; --sepPos ) {
if ( fullName[sepPos] == FullNameSeparator ) break;
}
if ( fullName[sepPos] == FullNameSeparator ) {
XMP_StringPtr prefix;
XMP_StringLen prefixLen;
XMP_StringPtr localPart = fullName + sepPos + 1;
node->ns.assign ( fullName, sepPos );
if ( node->ns == "http://purl.org/dc/1.1/" ) node->ns = "http://purl.org/dc/elements/1.1/";
bool found = XMPMeta::GetNamespacePrefix ( node->ns.c_str(), &prefix, &prefixLen );
if ( ! found ) XMP_Throw ( "Unknown URI in Expat full name", kXMPErr_ExternalFailure );
node->nsPrefixLen = prefixLen; // ! Includes the ':'.
node->name = prefix;
node->name += localPart;
} else {
node->name = fullName; // The name is not in a namespace.
if ( node->parent->name == "rdf:Description" ) {
if ( node->name == "about" ) {
node->ns = kXMP_NS_RDF;
node->name = "rdf:about";
node->nsPrefixLen = 4; // ! Include the ':'.
} else if ( node->name == "ID" ) {
node->ns = kXMP_NS_RDF;
node->name = "rdf:ID";
node->nsPrefixLen = 4; // ! Include the ':'.
}
}
}
} // SetQualName
// =================================================================================================
static void StartNamespaceDeclHandler ( void * userData, XMP_StringPtr prefix, XMP_StringPtr uri )
{
IgnoreParam(userData);
// As a bug fix hack, change a URI of "http://purl.org/dc/1.1/" to ""http://purl.org/dc/elements/1.1/.
// Early versions of Flash that put XMP in SWF used a bad URI for the dc: namespace.
#if XMP_DebugBuild & DumpXMLParseEvents // Avoid unused variable warning.
ExpatAdapter * thiz = (ExpatAdapter*)userData;
#endif
if ( prefix == 0 ) prefix = "_dflt_"; // Have default namespace.
if ( uri == 0 ) return; // Ignore, have xmlns:pre="", no URI to register.
#if XMP_DebugBuild & DumpXMLParseEvents
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "StartNamespace: %s - \"%s\"\n", prefix, uri );
}
#endif
if ( XMP_LitMatch ( uri, "http://purl.org/dc/1.1/" ) ) uri = "http://purl.org/dc/elements/1.1/";
XMPMeta::RegisterNamespace ( uri, prefix );
} // StartNamespaceDeclHandler
// =================================================================================================
static void EndNamespaceDeclHandler ( void * userData, XMP_StringPtr prefix )
{
IgnoreParam(userData);
#if XMP_DebugBuild & DumpXMLParseEvents // Avoid unused variable warning.
ExpatAdapter * thiz = (ExpatAdapter*)userData;
#endif
if ( prefix == 0 ) prefix = "_dflt_"; // Have default namespace.
#if XMP_DebugBuild & DumpXMLParseEvents
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "EndNamespace: %s\n", prefix );
}
#endif
// ! Nothing to do, Expat has done all of the XML processing.
} // EndNamespaceDeclHandler
// =================================================================================================
static void StartElementHandler ( void * userData, XMP_StringPtr name, XMP_StringPtr* attrs )
{
XMP_Assert ( attrs != 0 );
ExpatAdapter * thiz = (ExpatAdapter*)userData;
size_t attrCount = 0;
for ( XMP_StringPtr* a = attrs; *a != 0; ++a ) ++attrCount;
if ( (attrCount & 1) != 0 ) XMP_Throw ( "Expat attribute info has odd length", kXMPErr_ExternalFailure );
attrCount = attrCount/2; // They are name/value pairs.
#if XMP_DebugBuild & DumpXMLParseEvents
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "StartElement: %s, %d attrs", name, attrCount );
for ( XMP_StringPtr* attr = attrs; *attr != 0; attr += 2 ) {
XMP_StringPtr attrName = *attr;
XMP_StringPtr attrValue = *(attr+1);
fprintf ( thiz->parseLog, ", %s = \"%s\"", attrName, attrValue );
}
fprintf ( thiz->parseLog, "\n" );
}
#endif
XML_Node * parentNode = thiz->parseStack.back();
XML_Node * elemNode = new XML_Node ( parentNode, "", kElemNode );
SetQualName ( name, elemNode );
for ( XMP_StringPtr* attr = attrs; *attr != 0; attr += 2 ) {
XMP_StringPtr attrName = *attr;
XMP_StringPtr attrValue = *(attr+1);
XML_Node * attrNode = new XML_Node ( elemNode, "", kAttrNode );
SetQualName ( attrName, attrNode );
attrNode->value = attrValue;
if ( attrNode->name == "xml:lang" ) NormalizeLangValue ( &attrNode->value );
elemNode->attrs.push_back ( attrNode );
}
parentNode->content.push_back ( elemNode );
thiz->parseStack.push_back ( elemNode );
if ( elemNode->name == "rdf:RDF" ) {
thiz->rootNode = elemNode;
++thiz->rootCount;
}
#if XMP_DebugBuild
++thiz->elemNesting;
#endif
} // StartElementHandler
// =================================================================================================
static void EndElementHandler ( void * userData, XMP_StringPtr name )
{
IgnoreParam(name);
ExpatAdapter * thiz = (ExpatAdapter*)userData;
#if XMP_DebugBuild
--thiz->elemNesting;
#endif
(void) thiz->parseStack.pop_back();
#if XMP_DebugBuild & DumpXMLParseEvents
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "EndElement: %s\n", name );
}
#endif
} // EndElementHandler
// =================================================================================================
static void CharacterDataHandler ( void * userData, XMP_StringPtr cData, int len )
{
ExpatAdapter * thiz = (ExpatAdapter*)userData;
if ( (cData == 0) || (len == 0) ) { cData = ""; len = 0; }
#if XMP_DebugBuild & DumpXMLParseEvents
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "CharContent: \"" );
for ( int i = 0; i < len; ++i ) fprintf ( thiz->parseLog, "%c", cData[i] );
fprintf ( thiz->parseLog, "\"\n" );
}
#endif
XML_Node * parentNode = thiz->parseStack.back();
XML_Node * cDataNode = new XML_Node ( parentNode, "", kCDataNode );
cDataNode->value.assign ( cData, len );
parentNode->content.push_back ( cDataNode );
} // CharacterDataHandler
// =================================================================================================
static void StartCdataSectionHandler ( void * userData )
{
IgnoreParam(userData);
#if XMP_DebugBuild & DumpXMLParseEvents // Avoid unused variable warning.
ExpatAdapter * thiz = (ExpatAdapter*)userData;
#endif
#if XMP_DebugBuild & DumpXMLParseEvents
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "StartCDATA\n" );
}
#endif
// *** Since markup isn't recognized inside CDATA, this affects XMP's double escaping.
} // StartCdataSectionHandler
// =================================================================================================
static void EndCdataSectionHandler ( void * userData )
{
IgnoreParam(userData);
#if XMP_DebugBuild & DumpXMLParseEvents // Avoid unused variable warning.
ExpatAdapter * thiz = (ExpatAdapter*)userData;
#endif
#if XMP_DebugBuild & DumpXMLParseEvents
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "EndCDATA\n" );
}
#endif
} // EndCdataSectionHandler
// =================================================================================================
static void ProcessingInstructionHandler ( void * userData, XMP_StringPtr target, XMP_StringPtr data )
{
XMP_Assert ( target != 0 );
ExpatAdapter * thiz = (ExpatAdapter*)userData;
if ( ! XMP_LitMatch ( target, "xpacket" ) ) return; // Ignore all PIs except the XMP packet wrapper.
if ( data == 0 ) data = "";
#if XMP_DebugBuild & DumpXMLParseEvents
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "PI: %s - \"%s\"\n", target, data );
}
#endif
XML_Node * parentNode = thiz->parseStack.back();
XML_Node * piNode = new XML_Node ( parentNode, target, kPINode );
piNode->value.assign ( data );
parentNode->content.push_back ( piNode );
} // ProcessingInstructionHandler
// =================================================================================================
static void CommentHandler ( void * userData, XMP_StringPtr comment )
{
IgnoreParam(userData);
#if XMP_DebugBuild & DumpXMLParseEvents // Avoid unused variable warning.
ExpatAdapter * thiz = (ExpatAdapter*)userData;
#endif
if ( comment == 0 ) comment = "";
#if XMP_DebugBuild & DumpXMLParseEvents
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "Comment: \"%s\"\n", comment );
}
#endif
// ! Comments are ignored.
} // CommentHandler
// =================================================================================================
#if BanAllEntityUsage
static void StartDoctypeDeclHandler ( void * userData, XMP_StringPtr doctypeName,
XMP_StringPtr sysid, XMP_StringPtr pubid, int has_internal_subset )
{
IgnoreParam(doctypeName);
IgnoreParam(sysid);
IgnoreParam(pubid);
IgnoreParam(has_internal_subset);
ExpatAdapter * thiz = (ExpatAdapter*)userData;
#if XMP_DebugBuild & DumpXMLParseEvents // Avoid unused variable warning.
if ( thiz->parseLog != 0 ) {
PrintIndent ( thiz->parseLog, thiz->elemNesting );
fprintf ( thiz->parseLog, "DocType: \"%s\"\n", doctypeName );
}
#endif
thiz->isAborted = true; // ! Can't throw an exception across the plain C Expat frames.
(void) XML_StopParser ( thiz->parser, XML_FALSE /* not resumable */ );
} // StartDoctypeDeclHandler
#endif
// =================================================================================================