unzip.cpp

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	/* offset of start of central directory with respect to the 
	      starting disk number */
	if (unzlocal_getLong(fin,&us.offset_central_dir)!=UNZ_OK)
		err=UNZ_ERRNO;

	/* zipfile comment length */
	if (unzlocal_getShort(fin,&us.gi.size_comment)!=UNZ_OK)
		err=UNZ_ERRNO;

	if ((central_pos<us.offset_central_dir+us.size_central_dir) && 
		(err==UNZ_OK))
		err=UNZ_BADZIPFILE;

	if (err!=UNZ_OK)
	{
		fclose(fin);
		return NULL;
	}

	us.file=fin;
	us.byte_before_the_zipfile = central_pos -
		                    (us.offset_central_dir+us.size_central_dir);
	us.central_pos = central_pos;
    us.pfile_in_zip_read = NULL;
	

	s=(unz_s*)malloc(sizeof(unz_s));
	*s=us;
//	unzGoToFirstFile((unzFile)s);	
	return (unzFile)s;	
}


/*
  Close a ZipFile opened with unzipOpen.
  If there is files inside the .Zip opened with unzipOpenCurrentFile (see later),
    these files MUST be closed with unzipCloseCurrentFile before call unzipClose.
  return UNZ_OK if there is no problem. */
extern int unzClose (unzFile file)
{
	unz_s* s;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;

    if (s->pfile_in_zip_read!=NULL)
        unzCloseCurrentFile(file);

	fclose(s->file);
	free(s);
	return UNZ_OK;
}


/*
  Write info about the ZipFile in the *pglobal_info structure.
  No preparation of the structure is needed
  return UNZ_OK if there is no problem. */
extern int unzGetGlobalInfo (unzFile file,unz_global_info *pglobal_info)
{
	unz_s* s;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	*pglobal_info=s->gi;
	return UNZ_OK;
}


/*
   Translate date/time from Dos format to tm_unz (readable more easilty)
*/
static void unzlocal_DosDateToTmuDate (uLong ulDosDate, tm_unz* ptm)
{
    uLong uDate;
    uDate = (uLong)(ulDosDate>>16);
    ptm->tm_mday = (uInt)(uDate&0x1f) ;
    ptm->tm_mon =  (uInt)((((uDate)&0x1E0)/0x20)-1) ;
    ptm->tm_year = (uInt)(((uDate&0x0FE00)/0x0200)+1980) ;

    ptm->tm_hour = (uInt) ((ulDosDate &0xF800)/0x800);
    ptm->tm_min =  (uInt) ((ulDosDate&0x7E0)/0x20) ;
    ptm->tm_sec =  (uInt) (2*(ulDosDate&0x1f)) ;
}

/*
  Get Info about the current file in the zipfile, with internal only info
*/
static int unzlocal_GetCurrentFileInfoInternal (unzFile file,
                                                  unz_file_info *pfile_info,
                                                  unz_file_info_internal 
                                                  *pfile_info_internal,
                                                  char *szFileName,
												  uLong fileNameBufferSize,
                                                  void *extraField,
												  uLong extraFieldBufferSize,
                                                  char *szComment,
												  uLong commentBufferSize)
{
	unz_s* s;
	unz_file_info file_info;
	unz_file_info_internal file_info_internal;
	int err=UNZ_OK;
	uLong uMagic;
	long lSeek=0;

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	if (fseek(s->file,s->pos_in_central_dir+s->byte_before_the_zipfile,SEEK_SET)!=0)
		err=UNZ_ERRNO;


	/* we check the magic */
	if (err==UNZ_OK)
		if (unzlocal_getLong(s->file,&uMagic) != UNZ_OK)
			err=UNZ_ERRNO;
		else if (uMagic!=0x02014b50)
			err=UNZ_BADZIPFILE;

	if (unzlocal_getShort(s->file,&file_info.version) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.version_needed) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.flag) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.compression_method) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.dosDate) != UNZ_OK)
		err=UNZ_ERRNO;

    unzlocal_DosDateToTmuDate(file_info.dosDate,&file_info.tmu_date);

	if (unzlocal_getLong(s->file,&file_info.crc) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.compressed_size) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.uncompressed_size) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.size_filename) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.size_file_extra) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.size_file_comment) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.disk_num_start) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.internal_fa) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.external_fa) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info_internal.offset_curfile) != UNZ_OK)
		err=UNZ_ERRNO;

	lSeek+=file_info.size_filename;
	if ((err==UNZ_OK) && (szFileName!=NULL))
	{
		uLong uSizeRead ;
		if (file_info.size_filename<fileNameBufferSize)
		{
			*(szFileName+file_info.size_filename)='\0';
			uSizeRead = file_info.size_filename;
		}
		else
			uSizeRead = fileNameBufferSize;

		if ((file_info.size_filename>0) && (fileNameBufferSize>0))
			if (fread(szFileName,(uInt)uSizeRead,1,s->file)!=1)
				err=UNZ_ERRNO;
		lSeek -= uSizeRead;
	}

	
	if ((err==UNZ_OK) && (extraField!=NULL))
	{
		uLong uSizeRead ;
		if (file_info.size_file_extra<extraFieldBufferSize)
			uSizeRead = file_info.size_file_extra;
		else
			uSizeRead = extraFieldBufferSize;

		if (lSeek!=0)
			if (fseek(s->file,lSeek,SEEK_CUR)==0)
				lSeek=0;
			else
				err=UNZ_ERRNO;
		if ((file_info.size_file_extra>0) && (extraFieldBufferSize>0))
			if (fread(extraField,(uInt)uSizeRead,1,s->file)!=1)
				err=UNZ_ERRNO;
		lSeek += file_info.size_file_extra - uSizeRead;
	}
	else
		lSeek+=file_info.size_file_extra; 

	
	if ((err==UNZ_OK) && (szComment!=NULL))
	{
		uLong uSizeRead ;
		if (file_info.size_file_comment<commentBufferSize)
		{
			*(szComment+file_info.size_file_comment)='\0';
			uSizeRead = file_info.size_file_comment;
		}
		else
			uSizeRead = commentBufferSize;

		if (lSeek!=0)
			if (fseek(s->file,lSeek,SEEK_CUR)==0)
				lSeek=0;
			else
				err=UNZ_ERRNO;
		if ((file_info.size_file_comment>0) && (commentBufferSize>0))
			if (fread(szComment,(uInt)uSizeRead,1,s->file)!=1)
				err=UNZ_ERRNO;
		lSeek+=file_info.size_file_comment - uSizeRead;
	}
	else
		lSeek+=file_info.size_file_comment;

	if ((err==UNZ_OK) && (pfile_info!=NULL))
		*pfile_info=file_info;

	if ((err==UNZ_OK) && (pfile_info_internal!=NULL))
		*pfile_info_internal=file_info_internal;

	return err;
}



/*
  Write info about the ZipFile in the *pglobal_info structure.
  No preparation of the structure is needed
  return UNZ_OK if there is no problem.
*/
extern int unzGetCurrentFileInfo (	unzFile file, unz_file_info *pfile_info,
									char *szFileName, uLong fileNameBufferSize,
									void *extraField, uLong extraFieldBufferSize,
									char *szComment, uLong commentBufferSize)
{
	return unzlocal_GetCurrentFileInfoInternal(file,pfile_info,NULL,
												szFileName,fileNameBufferSize,
												extraField,extraFieldBufferSize,
												szComment,commentBufferSize);
}

/*
  Set the current file of the zipfile to the first file.
  return UNZ_OK if there is no problem
*/
extern int unzGoToFirstFile (unzFile file)
{
	int err=UNZ_OK;
	unz_s* s;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	s->pos_in_central_dir=s->offset_central_dir;
	s->num_file=0;
	err=unzlocal_GetCurrentFileInfoInternal(file,&s->cur_file_info,
											 &s->cur_file_info_internal,
											 NULL,0,NULL,0,NULL,0);
	s->current_file_ok = (err == UNZ_OK);
	return err;
}


/*
  Set the current file of the zipfile to the next file.
  return UNZ_OK if there is no problem
  return UNZ_END_OF_LIST_OF_FILE if the actual file was the latest.
*/
extern int unzGoToNextFile (unzFile file)
{
	unz_s* s;	
	int err;

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	if (!s->current_file_ok)
		return UNZ_END_OF_LIST_OF_FILE;
	if (s->num_file+1==s->gi.number_entry)
		return UNZ_END_OF_LIST_OF_FILE;

	s->pos_in_central_dir += SIZECENTRALDIRITEM + s->cur_file_info.size_filename +
			s->cur_file_info.size_file_extra + s->cur_file_info.size_file_comment ;
	s->num_file++;
	err = unzlocal_GetCurrentFileInfoInternal(file,&s->cur_file_info,
											   &s->cur_file_info_internal,
											   NULL,0,NULL,0,NULL,0);
	s->current_file_ok = (err == UNZ_OK);
	return err;
}


/*
  Try locate the file szFileName in the zipfile.
  For the iCaseSensitivity signification, see unzipStringFileNameCompare

  return value :
  UNZ_OK if the file is found. It becomes the current file.
  UNZ_END_OF_LIST_OF_FILE if the file is not found
*/
extern int unzLocateFile (unzFile file, const char *szFileName, int iCaseSensitivity)
{
	unz_s* s;	
	int err;

	
	uLong num_fileSaved;
	uLong pos_in_central_dirSaved;


	if (file==NULL)
		return UNZ_PARAMERROR;

    if (strlen(szFileName)>=UNZ_MAXFILENAMEINZIP)
        return UNZ_PARAMERROR;

	s=(unz_s*)file;
	if (!s->current_file_ok)
		return UNZ_END_OF_LIST_OF_FILE;

	num_fileSaved = s->num_file;
	pos_in_central_dirSaved = s->pos_in_central_dir;

	err = unzGoToFirstFile(file);

	while (err == UNZ_OK)
	{
		char szCurrentFileName[UNZ_MAXFILENAMEINZIP+1];
		unzGetCurrentFileInfo(file,NULL,
								szCurrentFileName,sizeof(szCurrentFileName)-1,
								NULL,0,NULL,0);
		if (unzStringFileNameCompare(szCurrentFileName,
										szFileName,iCaseSensitivity)==0)
			return UNZ_OK;
		err = unzGoToNextFile(file);
	}

	s->num_file = num_fileSaved ;
	s->pos_in_central_dir = pos_in_central_dirSaved ;
	return err;
}


/*
  Read the static header of the current zipfile
  Check the coherency of the static header and info in the end of central
        directory about this file
  store in *piSizeVar the size of extra info in static header
        (filename and size of extra field data)
*/
static int unzlocal_CheckCurrentFileCoherencyHeader (unz_s* s, uInt* piSizeVar,
													uLong *poffset_local_extrafield,
													uInt *psize_local_extrafield)
{