Function to validate a disk

Functions
static int	cbmimage_i_d1m_d2m_d4m_set_bam (cbmimage_image_settings *settings)
	occupy the blocks for the partition table of a CMD disk
static int	cbmimage_i_mark_global_and_local (cbmimage_fileimage *image, cbmimage_loop *loop_detector, cbmimage_blockaddress block_start, cbmimage_blockaddress block_current, cbmimage_blockaddress block_target)
static int	cbmimage_i_validate_follow_chain (cbmimage_fileimage *image, cbmimage_blockaddress block_start, size_t *count_blocks)
int	cbmimage_i_validate_1581_partition (cbmimage_fileimage *image, cbmimage_blockaddress block_start, int count)
static int	cbmimage_i_bam_check_equality (cbmimage_fileimage *image)
static int	cbmimage_i_validate_super_sidesector_plausibility (cbmimage_chain *chain)
static int	cbmimage_i_validate_super_sidesector_end (cbmimage_chain *chain, uint8_t offset)
static int	cbmimage_i_validate_sidesector_plausibility (cbmimage_chain *chain_sidesector, uint8_t *first_sidesector, uint8_t count_sidesector, int recordlength)
static int	cbmimage_i_validate_sidesector_chain (cbmimage_chain *chain_sidesector, cbmimage_chain *chain_file)
static int	cbmimage_i_validate_rel_file (cbmimage_fileimage *image, cbmimage_dir_entry *dir_entry, size_t *count_blocks)
static int	cbmimage_i_validate_geos_file (cbmimage_fileimage *image, cbmimage_dir_entry *dir_entry, size_t *count_blocks)
int	cbmimage_i_validate_process_file (cbmimage_fileimage *image, cbmimage_dir_entry *dir_entry)
	validate a specific file
int	cbmimage_validate (cbmimage_fileimage *image)
	validate the disk (and the bam)

Detailed Description

Function Documentation

cbmimage_i_bam_check_equality()

static int cbmimage_i_bam_check_equality ( cbmimage_fileimage * image )

static

check if the loop detector and the BAM are identical

Parameters

[in]

image

pointer to the image data

Returns

• 0 if the BAM and the loop detector are identical
• != 0 if not

Remarks

• this function goes through all blocks and tests if the BAM is free and not marked in the loop detector, or not free and marked in the loop detector. If there is an unequality, it reports an error.

cbmimage_i_d1m_d2m_d4m_set_bam()

static int cbmimage_i_d1m_d2m_d4m_set_bam ( cbmimage_image_settings * settings )

static

occupy the blocks for the partition table of a CMD disk

Parameters

[in]

settings

pointer to the image data

Returns

• 0 if no error occurred
• != 0 if an error occurred

Remarks

• special handling for validating D1M, D2M and D4M partition tables
• the blocks of a partition are treated as single file

cbmimage_i_mark_global_and_local()

static int cbmimage_i_mark_global_and_local ( cbmimage_fileimage * image, cbmimage_loop * loop_detector, cbmimage_blockaddress block_start, cbmimage_blockaddress block_current, cbmimage_blockaddress block_target )

static

mark blocks as used

This function marks a block in to loop detectors.

There is a first, global loop detector. It is used to find out if files (or other link chains) "overlap" each other, that is, one link chain and another link chain end in the same blocks. Thus, it is not really a loop, but some chain error that is detected.

The second, local loop detector, is used to find out if a link chain has an intertial loop. This loop detector has to be newly initialized for each link chain.

Parameters

[in]	image	pointer to the image data
[in]	loop_detector	pointer to the local loop detector
[in]	block_start	The starting block of this chain. This data is not used internally. It is helpful in the output, telling what went wrong and where a loop was detected.
[in]	block_current	The current block of this chain. This block is marked as used.
[in]	block_target	The next block/the target of the current block in this chain. This block is set as target for the current block

Returns

• 0 if there is no loop or sharing of links.
• != 0 if not

cbmimage_i_validate_1581_partition()

int cbmimage_i_validate_1581_partition	(	cbmimage_fileimage *	image,
		cbmimage_blockaddress	block_start,
		int	count )

check a 1581 partition

A 1581 partition is just a contiguous area of the disk, without any implied structure.
Thus, this function just marks all the blocks in the partition, nothing more.

Parameters

[in]	image	pointer to the image data
[in]	block_start	The starting block of this partion. From this block, the chain is followed and all blocks are marked as used.
[in]	count	The count of blocks that are occupied by this partition

Returns

• 0 if everything is ok
• != 0 if not

cbmimage_i_validate_follow_chain()

static int cbmimage_i_validate_follow_chain ( cbmimage_fileimage * image, cbmimage_blockaddress block_start, size_t * count_blocks )

static

follow a chain and check if it is consistent

This function follows a link chain. Doing this, it determines if there is a loop, or if this link chain shares blocks with another link chain. If any of this occurrs, this function reports an error.

Parameters

[in]	image	pointer to the image data
[in]	block_start	The starting block of this chain. From this block, the chain is followed and all blocks are marked as used.
[in,out]	count_blocks	Pointer to a variable. On return, this function will add the number of blocks it followed in the chain. Can be NULL; in this case, nothing will be returned.

Returns

• 0 if there is no loop or sharing of links.
• != 0 if not

cbmimage_i_validate_geos_file()

static int cbmimage_i_validate_geos_file ( cbmimage_fileimage * image, cbmimage_dir_entry * dir_entry, size_t * count_blocks )

static

validate the specialities of a GEOS file

This functions checks that the info block and the chains from the VLIR table (if it is a VLIR file) do not share blocks with other files or structures.

Parameters

[in]	image	pointer to the image data
[in]	dir_entry	The directory entry of this file
[in,out]	count_blocks	Pointer to a variable. On return, this function will add the number of blocks it followed in the chain. Can be NULL; in this case, nothing will be returned.

Returns

• 0 if there is no loop or sharing of links.
• != 0 if not

cbmimage_i_validate_process_file()

int cbmimage_i_validate_process_file	(	cbmimage_fileimage *	image,
		cbmimage_dir_entry *	dir_entry )

validate a specific file

Parameters

[in]	image	pointer to the image data
[in]	dir_entry	pointer to the directory entry of the file to validate

Returns

• 0 if the file is consistent
• != 0 if not

Remarks

A file is consistent if the following applies:

• the file chain does not conflict with any other file chain that was processed before this file

Todo

implement GEOS support

Bug

GEOS is not supported yet!

Todo

implement CMD native partition

Todo

Bug

CMD native partition not yet implemented

cbmimage_i_validate_rel_file()

static int cbmimage_i_validate_rel_file ( cbmimage_fileimage * image, cbmimage_dir_entry * dir_entry, size_t * count_blocks )

static

validate the side sector block of a REL file

This function checks if the link chain of a REL file is represented correctly by the side-sector block(s) of it.

Additionally, it also checks if the side-sector blocks are consistent and do not share blocks with other files or structures.

Parameters

[in]	image	pointer to the image data
[in]	dir_entry	The directory entry of this file
[in,out]	count_blocks	Pointer to a variable. On return, this function will add the number of blocks it followed in the chain. Can be NULL; in this case, nothing will be returned.

Returns

• 0 if there is no loop or sharing of links.
• != 0 if not

cbmimage_i_validate_sidesector_chain()

static int cbmimage_i_validate_sidesector_chain ( cbmimage_chain * chain_sidesector, cbmimage_chain * chain_file )

static

validate the side-sector chain

Parameters

[in]	chain_sidesector	pointer to a link chain that points to the side-sector
[in]	chain_file	pointer to a link chain that points to the file contents

Returns

• 0 if the side-sector chain is correct
• != 0 if not

Remarks

This function goes through all the links in the side-sector block and checks that it matches the corresponding block in the file chain.

cbmimage_i_validate_sidesector_plausibility()

static int cbmimage_i_validate_sidesector_plausibility ( cbmimage_chain * chain_sidesector, uint8_t * first_sidesector, uint8_t count_sidesector, int recordlength )

static

check plausibility of a (non-super) side-sector

Parameters

[in]	chain_sidesector	pointer to a link chain that points to the side-sector
[in]	first_sidesector	pointer to a buffer that contains the data of the first side-sector in this side-sector group
[in]	count_sidesector	the number of this side-sector
[in]	recordlength

Returns

• 0 if the side-sector is plausible
• != 0 if not

Remarks

The side-sector is plausible if the following applies:

• the addresses of all side-sectors in this side-sector group are identical to the first side-sector of this group.
• the address of this side-sector is at the right place
• the recordlength is the same as the record-length in the directory

cbmimage_i_validate_super_sidesector_end()

static int cbmimage_i_validate_super_sidesector_end ( cbmimage_chain * chain, uint8_t offset )

static

check if the super side-sector does not contain extra data

Parameters

[in]	chain	pointer to a link chain that points to the super side-sector
[in]	offset	the offset from which to check if the super side-sector is empty

Returns

• 0 if the super side-sector is empty after the offset
• != 0 if not

cbmimage_i_validate_super_sidesector_plausibility()

static int cbmimage_i_validate_super_sidesector_plausibility ( cbmimage_chain * chain )

static

check plausibility of a super side-sector

Parameters

[in]

chain

pointer to a link chain that points to the super side-sector

Returns

• 0 if the super side-sector is plausible
• != 0 if not

Remarks

The super side-sector is plausible if the following applies:

• the link chain and the first side-sector group are identical
• the number of the side-sector block is 0xFE.

cbmimage_validate()

int cbmimage_validate

(

cbmimage_fileimage *

image

)

validate the disk (and the bam)

Parameters

[in]

image

pointer to the image data

Returns

• 0 if the BAM is consistent
• != 0 if not

Remarks

A BAM is consistent if the following applies:

• cbmimage_bam_check_consistency() reports success
• all reachable blocks from files are marked as used

Todo

How should details be given to the caller?

Todo

Implement GEOS support

Bug

GEOS is not supported yet!