fsdelete.c

一个免费的SMART CARD OS系统。

/* ============================================================================
   Project Name : jayaCard
   Module Name  : proto/bios/fs/fsdelete.c
   Version : $Id: fsdelete.c,v 1.20 2004/04/24 12:07:31 dgil Exp $

	Description: Delete EF or DF

    The Original Code is jayaCard code.

    The Initial Developer of the Original Code is Gilles Dumortier.

	Portions created by the Initial Developer are Copyright (C) 2002-2004 the
    Initial Developer. All Rights Reserved.

    Contributor(s):

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; see http://www.gnu.org/licenses/gpl.html

   History Rev	Description
   040203 dgil	wrote it from scratch
   ============================================================================
*/

#include "precomp.h"

#ifdef JAYA_FILESYSTEM_DELETE
/* ============================================================================
	Import from fstools.c
   ========================================================================= */

void __fs_save_file_header(void);
void __fs_load_EF_header(jword link);
void __fs_save_EF_header(void);
jword __fs_header_bodysize(void);
void __fs_save_EF_header(void);
void __fs_erase_file(void);

/* ============================================================================
	__fs_delete_file()

	current_DF would be the parent of the deleted file
	current_EF is the file under deletion.

	Some error code in lasterr if any problem.
   ========================================================================= */

void __fs_delete_file(void)
{
	LOCAL(jword,addr);		/* address of some header file in EEPROM */
	LOCAL(jword,del_addr);	/* address of the header file in EEPROM to be deleted */
	LOCAL(jbool,bWrite);
    LOCAL(jbyte,res);

	LOG1("FS","__fs_delete_file(): fid=0x%.4X - enter",current_EF.fid);

    /* do not support deletion of DF in this version */
	if ( (current_EF.fdesc&FDESC_TYPE_MASK) == FDESC_TYPE_DF) {
		LOG1("FS","__fs_delete_file(): fid=0x%.4X - can't delete a DF !",current_EF.fid);
		BIOS_SETERR(ERR_INVALID_FILE_TYPE);
		return;
	}

    /* check that we are able to delete files in the DF */
    gGlobalSem = JSEC_FAIL;

    res = FS_CHECK_AC(ACC_CHECK_DF|ACC_DELETE_FILE);
    gGlobalSem++;

    if (res != JSEC_OK) {
        BIOS_SETERR(ERR_ACCESS_DENIED);
        return;
    }

    if (gGlobalSem!=JSEC_SEM) {
        LOG("ATTACK","__fs_delete_file() #1 - check security failure !");
        BIOS_SETERR(ERR_ACCESS_DENIED);
        HAL_HALT();
        return;
    }

    /* check that we are able to delete the file itself */
    gGlobalSem = JSEC_FAIL;

    res = FS_CHECK_AC(ACC_CHECK_EF|ACC_DELETE);
    gGlobalSem++;

    if (res != JSEC_OK) {
        BIOS_SETERR(ERR_ACCESS_DENIED);
        return;
    }

    if (gGlobalSem!=JSEC_SEM) {
        LOG("ATTACK","__fs_delete_file() #2 - check security failure !");
        BIOS_SETERR(ERR_ACCESS_DENIED);
        HAL_HALT();
        return;
    }

    /* save the current EF to header file */
	HAL_MEMCPY((jbyte xdata*)&header_file,(jbyte xdata*)&current_EF,SIZE_HEADER_FILE);
	del_addr = current_EF_addr;

	LOG2("FS","__fs_delete_file(): fid=0x%.4X addr=%.4X - cut the links",header_file.fid,del_addr);

	/* we need to cut the links - move through the headers and cut ! */
	header_file_addr = HAL_EEPROM_READ_WORD(FREE_HEADER_FILE_ADDR);

	/* begin the move at the base of headers */
	addr = ADDR_HEADER_MF;
	while (addr<header_file_addr) {
		__fs_load_EF_header(addr);
		if (lasterr!=SUCCESS) {
			LOG2("FS","__fs_delete_file() error code %d moving through the headers ! (adr==%x.4X)",lasterr,addr);
			return;
		}
		bWrite = jfalse;

		if (current_EF.fid != FID_RFU) {
			/* check if header_file is linked by this EF */
			if (current_EF.u2.next_file == del_addr) {
				/* cut the link */
                LOG3("FS","__fs_delete_file(): EF_addr=%.4X next was: %.4X - next will: %.4X ",current_EF_addr,del_addr,header_file.u2.next_file);
                current_EF.u2.next_file = header_file.u2.next_file;
				bWrite = jtrue;
			}

			#ifdef JAYACFG_FILESYSTEM_ALIAS
			if ((current_EF.fdesc&FDESC_ALIAS)==FDESC_ALIAS) {
				/* check if header_file is linked by this alias ! */
				/* if this is the case, we have to suppress also the alias ! */

				/* mark the alias has bogus / next time it will be removed ! */
				current_EF.fid = FID_BOGUS;
				bWrite = jtrue;

			} else
			#endif
			if ((current_EF.fdesc&FDESC_TYPE_MASK)==FDESC_TYPE_DF) {
				/* check if header_file is linked by this DF/MF */
				if (current_EF.u4.first_file == del_addr) {
					/* cut the link */
                    LOG3("FS","__fs_delete_file(): DF_addr=%.4X first was: %.4X - first will: %.4X ",current_EF_addr,del_addr,header_file.u2.next_file);
                    current_EF.u4.first_file = header_file.u2.next_file;
					bWrite = jtrue;
				}
           }
		}

		if (bWrite) {
			/* update this file */
			__fs_save_EF_header();
			if (lasterr != SUCCESS) {
				/* __x XXX big challenge here ! */
			}
		}

        /* special case : current_EF is the current_DF ! need also to update it ! */
        if (current_EF_addr == current_DF_addr) {
            HAL_MEMCPY((jbyte xdata*)&current_DF,(jbyte xdata*)&current_EF,SIZE_HEADER_FILE);
        }

		/* next header */
		addr += SIZE_HEADER_FILE;
	}

	/* then mark the header file deleted / should be re-usable by the next
	   CREATE FILE. Don't touch any other field so we should be able to
	   re-use also the body part.
	*/

	LOG2("FS","__fs_delete_file(): fid=0x%.4X - mark deleted header=%.4X",header_file.fid,del_addr);
	header_file.fid = FID_RFU;
	header_file_addr = del_addr;

	if ((header_file.fdesc&FDESC_TYPE_LINEAR)==FDESC_TYPE_LINEAR) {
		/* convert recorded body to transparent body => create will be able to
		   split more easily this chunk if required
		*/
		header_file.u4.sizefile = __fs_header_bodysize();
		header_file.fdesc = FDESC_TYPE_BINARY;
	}

	if ((header_file.fdesc&FDESC_TYPE_BINARY)==FDESC_TYPE_BINARY) {
		/* clear the body */
		FS_ERASE_FILE();

		/* compact the memory */
		#ifdef JAYA_FILESYSTEM_COMPACT
			/* __x IMPLEMENTME */
		#endif
	}

    /* no file after */
    header_file.u2.next_file = 0x0000;

	/* flush the header file to EEPROM */
	__fs_save_file_header();

	/* no more EF selected ! */
	FS_NEW_SESSION(jfalse,jfalse);
}

/* =========================================================================
	That's all folks !
   ========================================================================= */
#endif
/* JAYA_FILESYSTEM */