regfio.c

samba-3.0.22.tar.gz 编译smb服务器的源码

/*
 * Unix SMB/CIFS implementation.
 * Windows NT registry I/O library
 * Copyright (c) Gerald (Jerry) Carter               2005
 *
 * 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; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  
 */

#include "includes.h"
#include "regfio.h"

/*******************************************************************
 *
 * TODO : Right now this code basically ignores classnames.
 *
 ******************************************************************/


/*******************************************************************
*******************************************************************/

static int write_block( REGF_FILE *file, prs_struct *ps, uint32 offset )
{
	int bytes_written, returned;
	char *buffer = prs_data_p( ps );
	uint32 buffer_size = prs_data_size( ps );
	SMB_STRUCT_STAT sbuf;

	if ( file->fd == -1 )
		return -1;

	/* check for end of file */

	if ( sys_fstat( file->fd, &sbuf ) ) {
		DEBUG(0,("write_block: stat() failed! (%s)\n", strerror(errno)));
		return -1;
	}

	if ( lseek( file->fd, offset, SEEK_SET ) == -1 ) {
		DEBUG(0,("write_block: lseek() failed! (%s)\n", strerror(errno) ));
		return -1;
	}
	
	bytes_written = returned = 0;
	while ( bytes_written < buffer_size ) {
		if ( (returned = write( file->fd, buffer+bytes_written, buffer_size-bytes_written )) == -1 ) {
			DEBUG(0,("write_block: write() failed! (%s)\n", strerror(errno) ));
			return False;
		}
				
		bytes_written += returned;
	}
	
	return bytes_written;
}

/*******************************************************************
*******************************************************************/

static int read_block( REGF_FILE *file, prs_struct *ps, uint32 file_offset, uint32 block_size )
{
	int bytes_read, returned;
	char *buffer;
	SMB_STRUCT_STAT sbuf;

	/* check for end of file */

	if ( sys_fstat( file->fd, &sbuf ) ) {
		DEBUG(0,("read_block: stat() failed! (%s)\n", strerror(errno)));
		return -1;
	}

	if ( (size_t)file_offset >= sbuf.st_size )
		return -1;
	
	/* if block_size == 0, we are parsing HBIN records and need 
	   to read some of the header to get the block_size from there */
	   
	if ( block_size == 0 ) {
		char hdr[0x20];

		if ( lseek( file->fd, file_offset, SEEK_SET ) == -1 ) {
			DEBUG(0,("read_block: lseek() failed! (%s)\n", strerror(errno) ));
			return -1;
		}

		returned = read( file->fd, hdr, 0x20 );
		if ( (returned == -1) || (returned < 0x20) ) {
			DEBUG(0,("read_block: failed to read in HBIN header. Is the file corrupt?\n"));
			return -1;
		}

		/* make sure this is an hbin header */

		if ( strncmp( hdr, "hbin", HBIN_HDR_SIZE ) != 0 ) {
			DEBUG(0,("read_block: invalid block header!\n"));
			return -1;
		}

		block_size = IVAL( hdr, 0x08 );
	}

	DEBUG(10,("read_block: block_size == 0x%x\n", block_size ));

	/* set the offset, initialize the buffer, and read the block from disk */

	if ( lseek( file->fd, file_offset, SEEK_SET ) == -1 ) {
		DEBUG(0,("read_block: lseek() failed! (%s)\n", strerror(errno) ));
		return -1;
	}
	
	prs_init( ps, block_size, file->mem_ctx, UNMARSHALL );
	buffer = prs_data_p( ps );
	bytes_read = returned = 0;

	while ( bytes_read < block_size ) {
		if ( (returned = read( file->fd, buffer+bytes_read, block_size-bytes_read )) == -1 ) {
			DEBUG(0,("read_block: read() failed (%s)\n", strerror(errno) ));
			return False;
		}
		if ( (returned == 0) && (bytes_read < block_size) ) {
			DEBUG(0,("read_block: not a vald registry file ?\n" ));
			return False;
		}	
		
		bytes_read += returned;
	}
	
	return bytes_read;
}

/*******************************************************************
*******************************************************************/

static BOOL write_hbin_block( REGF_FILE *file, REGF_HBIN *hbin )
{
	if ( !hbin->dirty )
		return True;

	/* write free space record if any is available */

	if ( hbin->free_off != REGF_OFFSET_NONE ) {
		uint32 header = 0xffffffff;

		if ( !prs_set_offset( &hbin->ps, hbin->free_off-sizeof(uint32) ) )
			return False;
		if ( !prs_uint32( "free_size", &hbin->ps, 0, &hbin->free_size ) )
			return False;
		if ( !prs_uint32( "free_header", &hbin->ps, 0, &header ) )
			return False;
	}

	hbin->dirty = (write_block( file, &hbin->ps, hbin->file_off ) != -1);

	return hbin->dirty;
}

/*******************************************************************
*******************************************************************/

static BOOL hbin_block_close( REGF_FILE *file, REGF_HBIN *hbin )
{
	REGF_HBIN *p;

	/* remove the block from the open list and flush it to disk */

	for ( p=file->block_list; p && p!=hbin; p=p->next )
		;;

	if ( p == hbin ) {
		DLIST_REMOVE( file->block_list, hbin );
	}
	else
		DEBUG(0,("hbin_block_close: block not in open list!\n"));

	if ( !write_hbin_block( file, hbin ) )
		return False;

	return True;
}

/*******************************************************************
*******************************************************************/

static BOOL prs_regf_block( const char *desc, prs_struct *ps, int depth, REGF_FILE *file )
{
	prs_debug(ps, depth, desc, "prs_regf_block");
	depth++;
	
	if ( !prs_uint8s( True, "header", ps, depth, (uint8*)file->header, sizeof( file->header )) )
		return False;
	
	/* yes, these values are always identical so store them only once */
	
	if ( !prs_uint32( "unknown1", ps, depth, &file->unknown1 ))
		return False;
	if ( !prs_uint32( "unknown1 (again)", ps, depth, &file->unknown1 ))
		return False;

	/* get the modtime */
	
	if ( !prs_set_offset( ps, 0x0c ) )
		return False;
	if ( !smb_io_time( "modtime", &file->mtime, ps, depth ) )
		return False;

	/* constants */
	
	if ( !prs_uint32( "unknown2", ps, depth, &file->unknown2 ))
		return False;
	if ( !prs_uint32( "unknown3", ps, depth, &file->unknown3 ))
		return False;
	if ( !prs_uint32( "unknown4", ps, depth, &file->unknown4 ))
		return False;
	if ( !prs_uint32( "unknown5", ps, depth, &file->unknown5 ))
		return False;

	/* get file offsets */
	
	if ( !prs_set_offset( ps, 0x24 ) )
		return False;
	if ( !prs_uint32( "data_offset", ps, depth, &file->data_offset ))
		return False;
	if ( !prs_uint32( "last_block", ps, depth, &file->last_block ))
		return False;
		
	/* one more constant */
	
	if ( !prs_uint32( "unknown6", ps, depth, &file->unknown6 ))
		return False;
		
	/* get the checksum */
	
	if ( !prs_set_offset( ps, 0x01fc ) )
		return False;
	if ( !prs_uint32( "checksum", ps, depth, &file->checksum ))
		return False;
	
	return True;
}

/*******************************************************************
*******************************************************************/

static BOOL prs_hbin_block( const char *desc, prs_struct *ps, int depth, REGF_HBIN *hbin )
{
	uint32 block_size2;

	prs_debug(ps, depth, desc, "prs_regf_block");
	depth++;
	
	if ( !prs_uint8s( True, "header", ps, depth, (uint8*)hbin->header, sizeof( hbin->header )) )
		return False;

	if ( !prs_uint32( "first_hbin_off", ps, depth, &hbin->first_hbin_off ))
		return False;

	/* The dosreg.cpp comments say that the block size is at 0x1c.
	   According to a WINXP NTUSER.dat file, this is wrong.  The block_size
	   is at 0x08 */

	if ( !prs_uint32( "block_size", ps, depth, &hbin->block_size ))
		return False;

	block_size2 = hbin->block_size;
	prs_set_offset( ps, 0x1c );
	if ( !prs_uint32( "block_size2", ps, depth, &block_size2 ))
		return False;

	if ( MARSHALLING(ps) )
		hbin->dirty = True;
	

	return True;
}

/*******************************************************************
*******************************************************************/

static BOOL prs_nk_rec( const char *desc, prs_struct *ps, int depth, REGF_NK_REC *nk )
{
	uint16 class_length, name_length;
	uint32 start;
	uint32 data_size, start_off, end_off;
	uint32 unknown_off = REGF_OFFSET_NONE;

	nk->hbin_off = prs_offset( ps );
	start = nk->hbin_off;
	
	prs_debug(ps, depth, desc, "prs_nk_rec");
	depth++;
	
	/* back up and get the data_size */
	
	if ( !prs_set_offset( ps, prs_offset(ps)-sizeof(uint32)) )
		return False;
	start_off = prs_offset( ps );
	if ( !prs_uint32( "rec_size", ps, depth, &nk->rec_size ))
		return False;
	
	if ( !prs_uint8s( True, "header", ps, depth, (uint8*)nk->header, sizeof( nk->header )) )
		return False;
		
	if ( !prs_uint16( "key_type", ps, depth, &nk->key_type ))
		return False;
	if ( !smb_io_time( "mtime", &nk->mtime, ps, depth ))
		return False;
		
	if ( !prs_set_offset( ps, start+0x0010 ) )
		return False;
	if ( !prs_uint32( "parent_off", ps, depth, &nk->parent_off ))
		return False;
	if ( !prs_uint32( "num_subkeys", ps, depth, &nk->num_subkeys ))
		return False;
		
	if ( !prs_set_offset( ps, start+0x001c ) )
		return False;
	if ( !prs_uint32( "subkeys_off", ps, depth, &nk->subkeys_off ))
		return False;
	if ( !prs_uint32( "unknown_off", ps, depth, &unknown_off) )
		return False;
		
	if ( !prs_set_offset( ps, start+0x0024 ) )
		return False;
	if ( !prs_uint32( "num_values", ps, depth, &nk->num_values ))
		return False;
	if ( !prs_uint32( "values_off", ps, depth, &nk->values_off ))
		return False;
	if ( !prs_uint32( "sk_off", ps, depth, &nk->sk_off ))
		return False;
	if ( !prs_uint32( "classname_off", ps, depth, &nk->classname_off ))
		return False;

	if ( !prs_uint32( "max_bytes_subkeyname", ps, depth, &nk->max_bytes_subkeyname))
		return False;
	if ( !prs_uint32( "max_bytes_subkeyclassname", ps, depth, &nk->max_bytes_subkeyclassname))
		return False;
	if ( !prs_uint32( "max_bytes_valuename", ps, depth, &nk->max_bytes_valuename))
		return False;
	if ( !prs_uint32( "max_bytes_value", ps, depth, &nk->max_bytes_value))
		return False;
	if ( !prs_uint32( "unknown index", ps, depth, &nk->unk_index))
		return False;

	name_length = nk->keyname ? strlen(nk->keyname) : 0 ;
	class_length = nk->classname ? strlen(nk->classname) : 0 ;
	if ( !prs_uint16( "name_length", ps, depth, &name_length ))
		return False;
	if ( !prs_uint16( "class_length", ps, depth, &class_length ))
		return False;	
		
	if ( class_length ) {
		;;
	}
	
	if ( name_length ) {
		if ( UNMARSHALLING(ps) ) {
			if ( !(nk->keyname = PRS_ALLOC_MEM( ps, char, name_length+1 )) )
				return False;
		}

		if ( !prs_uint8s( True, "name", ps, depth, (uint8*)nk->keyname, name_length) )
			return False;

		if ( UNMARSHALLING(ps) ) 
			nk->keyname[name_length] = '\0';
	}

	end_off = prs_offset( ps );

	/* data_size must be divisible by 8 and large enough to hold the original record */

	data_size = ((start_off - end_off) & 0xfffffff8 );
	if ( data_size > nk->rec_size )
		DEBUG(10,("Encountered reused record (0x%x < 0x%x)\n", data_size, nk->rec_size));

	if ( MARSHALLING(ps) )
		nk->hbin->dirty = True;

	return True;
}

/*******************************************************************
*******************************************************************/

static uint32 regf_block_checksum( prs_struct *ps )
{
	char *buffer = prs_data_p( ps );
	uint32 checksum, x;
	int i;

	/* XOR of all bytes 0x0000 - 0x01FB */
		
	checksum = x = 0;
	
	for ( i=0; i<0x01FB; i+=4 ) {
		x = IVAL(buffer, i );
		checksum ^= x;
	}
	
	return checksum;
}

/*******************************************************************
*******************************************************************/

static BOOL read_regf_block( REGF_FILE *file )
{
	prs_struct ps;
	uint32 checksum;
	
	/* grab the first block from the file */
		
	if ( read_block( file, &ps, 0, REGF_BLOCKSIZE ) == -1 )
		return False;
	
	/* parse the block and verify the checksum */
	
	if ( !prs_regf_block( "regf_header", &ps, 0, file ) )
		return False;	
		
	checksum = regf_block_checksum( &ps );
	
	prs_mem_free( &ps );
	
	if ( file->checksum !=  checksum ) {
		DEBUG(0,("read_regf_block: invalid checksum\n" ));
		return False;
	}

	return True;
}

/*******************************************************************
*******************************************************************/

static REGF_HBIN* read_hbin_block( REGF_FILE *file, off_t offset )
{
	REGF_HBIN *hbin;
	uint32 record_size, curr_off, block_size, header;
	
	if ( !(hbin = TALLOC_ZERO_P(file->mem_ctx, REGF_HBIN)) ) 
		return NULL;
	hbin->file_off = offset;
	hbin->free_off = -1;
		
	if ( read_block( file, &hbin->ps, offset, 0 ) == -1 )
		return NULL;
	
	if ( !prs_hbin_block( "hbin", &hbin->ps, 0, hbin ) )
		return NULL;	

	/* this should be the same thing as hbin->block_size but just in case */

	block_size = prs_data_size( &hbin->ps );	

	/* Find the available free space offset.  Always at the end,
	   so walk the record list and stop when you get to the end.
	   The end is defined by a record header of 0xffffffff.  The