mirror of
https://github.com/ventoy/Ventoy.git
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135 lines
3.1 KiB
C
135 lines
3.1 KiB
C
/*
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* Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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/**
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* @file
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*
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* CPIO archives
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*
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*/
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#include <stdint.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "wimboot.h"
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#include "cpio.h"
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/**
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* Align CPIO length to nearest dword
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*
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* @v len Length
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* @ret len Aligned length
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*/
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static size_t cpio_align ( size_t len ) {
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return ( ( len + 0x03 ) & ~0x03 );
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}
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/**
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* Parse CPIO field value
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*
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* @v field ASCII field
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* @ret value Field value
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*/
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static unsigned long cpio_value ( const char *field ) {
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char buf[9];
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memcpy ( buf, field, ( sizeof ( buf ) - 1 ) );
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buf[ sizeof ( buf ) - 1 ] = '\0';
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return strtoul ( buf, NULL, 16 );
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}
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/**
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* Extract files from CPIO archive
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*
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* @v data CPIO archive
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* @v len Maximum length of CPIO archive
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* @v file File handler
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* @ret rc Return status code
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*/
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int cpio_extract ( void *data, size_t len,
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int ( * file ) ( const char *name, void *data,
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size_t len ) ) {
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const struct cpio_header *cpio;
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const uint32_t *pad;
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const char *file_name;
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void *file_data;
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size_t file_name_len;
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size_t file_len;
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size_t cpio_len;
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int rc;
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while ( 1 ) {
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/* Skip over any padding */
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while ( len >= sizeof ( *pad ) ) {
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pad = data;
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if ( *pad )
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break;
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data += sizeof ( *pad );
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len -= sizeof ( *pad );
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}
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/* Stop if we have reached the end of the archive */
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if ( ! len )
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return 0;
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/* Sanity check */
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if ( len < sizeof ( *cpio ) ) {
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DBG ( "Truncated CPIO header\n" );
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return -1;
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}
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cpio = data;
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/* Check magic */
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if ( memcmp ( cpio->c_magic, CPIO_MAGIC,
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sizeof ( cpio->c_magic ) ) != 0 ) {
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DBG ( "Bad CPIO magic\n" );
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return -1;
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}
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/* Extract file parameters */
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file_name = ( ( void * ) ( cpio + 1 ) );
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file_name_len = cpio_value ( cpio->c_namesize );
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file_data = ( data + cpio_align ( sizeof ( *cpio ) +
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file_name_len ) );
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file_len = cpio_value ( cpio->c_filesize );
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cpio_len = ( file_data + file_len - data );
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if ( cpio_len < len )
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cpio_len = cpio_align ( cpio_len );
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if ( cpio_len > len ) {
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DBG ( "Truncated CPIO file\n" );
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return -1;
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}
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/* If we reach the trailer, we're done */
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if ( strcmp ( file_name, CPIO_TRAILER ) == 0 )
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return 0;
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/* Process file */
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if ( ( rc = file ( file_name, file_data, file_len ) ) != 0 )
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return rc;
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/* Move to next file */
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data += cpio_len;
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len -= cpio_len;
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}
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}
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