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/*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* cramfs_common - cramfs common code
*
* Copyright (c) 2008 Roy Peled, the.roy.peled -at- gmail.com
* Copyright (c) 2004-2006 by Juliane Holzt, kju -at- fqdn.org
*
* 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.
*
*/
#include <string.h>
#include "cramfs.h"
#include "../include/bitops.h"
uint32_t u32_toggle_endianness(int big_endian, uint32_t what)
{
return big_endian == HOST_IS_BIG_ENDIAN ? what : swab32(what);
}
void super_toggle_endianness(int big_endian, struct cramfs_super *super)
{
if (big_endian != HOST_IS_BIG_ENDIAN) {
super->magic = swab32(super->magic);
super->size = swab32(super->size);
super->flags = swab32(super->flags);
super->future = swab32(super->future);
super->fsid.crc = swab32(super->fsid.crc);
super->fsid.edition = swab32(super->fsid.edition);
super->fsid.blocks = swab32(super->fsid.blocks);
super->fsid.files = swab32(super->fsid.files);
}
}
static void inode_toggle_endianness(int input_big_endian, int output_big_endian,
struct cramfs_inode *inode_in,
struct cramfs_inode *inode_out)
{
if (input_big_endian == output_big_endian) {
memmove(inode_out, inode_in, sizeof(*inode_out));
} else {
unsigned char inode_out_buf[sizeof(*inode_in)];
unsigned char *inode_in_buf = (unsigned char*)inode_in;
inode_out_buf[0] = inode_in_buf[1]; /* 16 bit: mode */
inode_out_buf[1] = inode_in_buf[0];
inode_out_buf[2] = inode_in_buf[3]; /* 16 bit: uid */
inode_out_buf[3] = inode_in_buf[2];
inode_out_buf[4] = inode_in_buf[6]; /* 24 bit: size */
inode_out_buf[5] = inode_in_buf[5];
inode_out_buf[6] = inode_in_buf[4];
inode_out_buf[7] = inode_in_buf[7]; /* 8 bit: gid width */
/*
* Stop the madness! Outlaw C bitfields! They are unportable
* and nasty! See for yourself what a mess this is:
*/
if (output_big_endian) {
inode_out_buf[ 8] = ( (inode_in_buf[ 8]&0x3F) << 2 ) |
( (inode_in_buf[11]&0xC0) >> 6 );
inode_out_buf[ 9] = ( (inode_in_buf[11]&0x3F) << 2 ) |
( (inode_in_buf[10]&0xC0) >> 6 );
inode_out_buf[10] = ( (inode_in_buf[10]&0x3F) << 2 ) |
( (inode_in_buf[ 9]&0xC0) >> 6 );
inode_out_buf[11] = ( (inode_in_buf[ 9]&0x3F) << 2 ) |
( (inode_in_buf[ 8]&0xC0) >> 6 );
} else {
inode_out_buf[ 8] = ( (inode_in_buf[ 8]&0xFD) >> 2 ) |
( (inode_in_buf[11]&0x03) << 6 );
inode_out_buf[ 9] = ( (inode_in_buf[11]&0xFD) >> 2 ) |
( (inode_in_buf[10]&0x03) << 6 );
inode_out_buf[10] = ( (inode_in_buf[10]&0xFD) >> 2 ) |
( (inode_in_buf[ 9]&0x03) << 6 );
inode_out_buf[11] = ( (inode_in_buf[ 9]&0xFD) >> 2 ) |
( (inode_in_buf[ 8]&0x03) << 6 );
}
memmove(inode_out, inode_out_buf, sizeof(*inode_out));
}
}
void inode_to_host(int from_big_endian, struct cramfs_inode *inode_in,
struct cramfs_inode *inode_out)
{
inode_toggle_endianness(from_big_endian, HOST_IS_BIG_ENDIAN, inode_in,
inode_out);
}
void inode_from_host(int to_big_endian, struct cramfs_inode *inode_in,
struct cramfs_inode *inode_out)
{
inode_toggle_endianness(HOST_IS_BIG_ENDIAN, to_big_endian, inode_in,
inode_out);
}
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