[LEDE-DEV] [PATCH fstools] libblkid-tiny: add support for NTFS superblock

[John Crispin]

On 25/12/17 20:52, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal at milecki.pl>
>
> Its copied from the util-linux project and its libblkid. Call to the
> blkid_probe_set_utf8label was commented out due to libblkid-tiny not
> supporting it yet.
>
> Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
Acked-by: John Crispin <john at phrozen.org>
> ---
>   CMakeLists.txt                |   1 +
>   libblkid-tiny/libblkid-tiny.c |   1 +
>   libblkid-tiny/ntfs.c          | 228 ++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 230 insertions(+)
>   create mode 100644 libblkid-tiny/ntfs.c
>
> diff --git a/CMakeLists.txt b/CMakeLists.txt
> index 8752612..9e855bd 100644
> --- a/CMakeLists.txt
> +++ b/CMakeLists.txt
> @@ -24,6 +24,7 @@ ADD_LIBRARY(blkid-tiny SHARED
>   		libblkid-tiny/ext.c
>   		libblkid-tiny/jffs2.c
>   		libblkid-tiny/vfat.c
> +		libblkid-tiny/ntfs.c
>   		libblkid-tiny/hfs.c
>   		libblkid-tiny/swap.c
>   		libblkid-tiny/ubi.c
> diff --git a/libblkid-tiny/libblkid-tiny.c b/libblkid-tiny/libblkid-tiny.c
> index 352d1f6..f020e23 100644
> --- a/libblkid-tiny/libblkid-tiny.c
> +++ b/libblkid-tiny/libblkid-tiny.c
> @@ -162,6 +162,7 @@ static const struct blkid_idinfo *idinfos[] =
>   	&ext3_idinfo,
>   	&ext2_idinfo,
>   	&jbd_idinfo,
> +	&ntfs_idinfo,
>   	&squashfs_idinfo,
>   	&ubi_idinfo,
>   	&ubifs_idinfo,
> diff --git a/libblkid-tiny/ntfs.c b/libblkid-tiny/ntfs.c
> new file mode 100644
> index 0000000..93c1d88
> --- /dev/null
> +++ b/libblkid-tiny/ntfs.c
> @@ -0,0 +1,228 @@
> +/*
> + * Copyright (C) 2004 Kay Sievers <kay.sievers at vrfy.org>
> + * Copyright (C) 2008 Karel Zak <kzak at redhat.com>
> + *
> + * This file may be redistributed under the terms of the
> + * GNU Lesser General Public License.
> + */
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <unistd.h>
> +#include <string.h>
> +#include <inttypes.h>
> +
> +#include "superblocks.h"
> +
> +struct ntfs_bios_parameters {
> +	uint16_t	sector_size;	/* Size of a sector in bytes. */
> +	uint8_t		sectors_per_cluster;	/* Size of a cluster in sectors. */
> +	uint16_t	reserved_sectors;	/* zero */
> +	uint8_t		fats;			/* zero */
> +	uint16_t	root_entries;		/* zero */
> +	uint16_t	sectors;		/* zero */
> +	uint8_t		media_type;		/* 0xf8 = hard disk */
> +	uint16_t	sectors_per_fat;	/* zero */
> +	uint16_t	sectors_per_track;	/* irrelevant */
> +	uint16_t	heads;			/* irrelevant */
> +	uint32_t	hidden_sectors;		/* zero */
> +	uint32_t	large_sectors;		/* zero */
> +} __attribute__ ((__packed__));
> +
> +struct ntfs_super_block {
> +	uint8_t		jump[3];
> +	uint8_t		oem_id[8];	/* magic string */
> +
> +	struct ntfs_bios_parameters	bpb;
> +
> +	uint16_t	unused[2];
> +	uint64_t	number_of_sectors;
> +	uint64_t	mft_cluster_location;
> +	uint64_t	mft_mirror_cluster_location;
> +	int8_t		clusters_per_mft_record;
> +	uint8_t		reserved1[3];
> +	int8_t		cluster_per_index_record;
> +	uint8_t		reserved2[3];
> +	uint64_t	volume_serial;
> +	uint32_t	checksum;
> +} __attribute__((packed));
> +
> +struct master_file_table_record {
> +	uint32_t	magic;
> +	uint16_t	usa_ofs;
> +	uint16_t	usa_count;
> +	uint64_t	lsn;
> +	uint16_t	sequence_number;
> +	uint16_t	link_count;
> +	uint16_t	attrs_offset;
> +	uint16_t	flags;
> +	uint32_t	bytes_in_use;
> +	uint32_t	bytes_allocated;
> +} __attribute__((__packed__));
> +
> +struct file_attribute {
> +	uint32_t	type;
> +	uint32_t	len;
> +	uint8_t		non_resident;
> +	uint8_t		name_len;
> +	uint16_t	name_offset;
> +	uint16_t	flags;
> +	uint16_t	instance;
> +	uint32_t	value_len;
> +	uint16_t	value_offset;
> +} __attribute__((__packed__));
> +
> +#define MFT_RECORD_VOLUME	3
> +#define NTFS_MAX_CLUSTER_SIZE	(64 * 1024)
> +
> +enum {
> +	MFT_RECORD_ATTR_VOLUME_NAME		= 0x60,
> +	MFT_RECORD_ATTR_END			= 0xffffffff
> +};
> +
> +static int probe_ntfs(blkid_probe pr, const struct blkid_idmag *mag)
> +{
> +	struct ntfs_super_block *ns;
> +#if 0
> +	struct master_file_table_record *mft;
> +#endif
> +
> +	uint32_t sectors_per_cluster, mft_record_size;
> +	uint16_t sector_size;
> +	uint64_t nr_clusters, off; //, attr_off;
> +	unsigned char *buf_mft;
> +
> +	ns = blkid_probe_get_sb(pr, mag, struct ntfs_super_block);
> +	if (!ns)
> +		return errno ? -errno : 1;
> +
> +	/*
> +	 * Check bios parameters block
> +	 */
> +	sector_size = le16_to_cpu(ns->bpb.sector_size);
> +	sectors_per_cluster = ns->bpb.sectors_per_cluster;
> +
> +	if (sector_size < 256 || sector_size > 4096)
> +		return 1;
> +
> +	switch (sectors_per_cluster) {
> +	case 1: case 2: case 4: case 8: case 16: case 32: case 64: case 128:
> +		break;
> +	default:
> +		return 1;
> +	}
> +
> +	if ((uint16_t) le16_to_cpu(ns->bpb.sector_size) *
> +			ns->bpb.sectors_per_cluster > NTFS_MAX_CLUSTER_SIZE)
> +		return 1;
> +
> +	/* Unused fields must be zero */
> +	if (le16_to_cpu(ns->bpb.reserved_sectors)
> +	    || le16_to_cpu(ns->bpb.root_entries)
> +	    || le16_to_cpu(ns->bpb.sectors)
> +	    || le16_to_cpu(ns->bpb.sectors_per_fat)
> +	    || le32_to_cpu(ns->bpb.large_sectors)
> +	    || ns->bpb.fats)
> +		return 1;
> +
> +	if ((uint8_t) ns->clusters_per_mft_record < 0xe1
> +	    || (uint8_t) ns->clusters_per_mft_record > 0xf7) {
> +
> +		switch (ns->clusters_per_mft_record) {
> +		case 1: case 2: case 4: case 8: case 16: case 32: case 64:
> +			break;
> +		default:
> +			return 1;
> +		}
> +	}
> +
> +	if (ns->clusters_per_mft_record > 0)
> +		mft_record_size = ns->clusters_per_mft_record *
> +				  sectors_per_cluster * sector_size;
> +	else
> +		mft_record_size = 1 << (0 - ns->clusters_per_mft_record);
> +
> +	nr_clusters = le64_to_cpu(ns->number_of_sectors) / sectors_per_cluster;
> +
> +	if ((le64_to_cpu(ns->mft_cluster_location) > nr_clusters) ||
> +	    (le64_to_cpu(ns->mft_mirror_cluster_location) > nr_clusters))
> +		return 1;
> +
> +
> +	off = le64_to_cpu(ns->mft_cluster_location) * sector_size *
> +		sectors_per_cluster;
> +
> +	DBG(LOWPROBE, ul_debug("NTFS: sector_size=%"PRIu16", mft_record_size=%"PRIu32", "
> +			"sectors_per_cluster=%"PRIu32", nr_clusters=%"PRIu64" "
> +			"cluster_offset=%"PRIu64"",
> +			sector_size, mft_record_size,
> +			sectors_per_cluster, nr_clusters,
> +			off));
> +
> +	buf_mft = blkid_probe_get_buffer(pr, off, mft_record_size);
> +	if (!buf_mft)
> +		return errno ? -errno : 1;
> +
> +	if (memcmp(buf_mft, "FILE", 4))
> +		return 1;
> +
> +	off += MFT_RECORD_VOLUME * mft_record_size;
> +
> +	buf_mft = blkid_probe_get_buffer(pr, off, mft_record_size);
> +	if (!buf_mft)
> +		return errno ? -errno : 1;
> +
> +	if (memcmp(buf_mft, "FILE", 4))
> +		return 1;
> +
> +#if 0
> +	mft = (struct master_file_table_record *) buf_mft;
> +	attr_off = le16_to_cpu(mft->attrs_offset);
> +
> +	while (attr_off + sizeof(struct file_attribute) <= mft_record_size &&
> +	       attr_off <= le32_to_cpu(mft->bytes_allocated)) {
> +
> +		uint32_t attr_len;
> +		struct file_attribute *attr;
> +
> +		attr = (struct file_attribute *) (buf_mft + attr_off);
> +		attr_len = le32_to_cpu(attr->len);
> +		if (!attr_len)
> +			break;
> +
> +		if (le32_to_cpu(attr->type) == MFT_RECORD_ATTR_END)
> +			break;
> +		if (le32_to_cpu(attr->type) == MFT_RECORD_ATTR_VOLUME_NAME) {
> +			unsigned int val_off = le16_to_cpu(attr->value_offset);
> +			unsigned int val_len = le32_to_cpu(attr->value_len);
> +			unsigned char *val = ((uint8_t *) attr) + val_off;
> +
> +			if (attr_off + val_off + val_len <= mft_record_size)
> +				blkid_probe_set_utf8label(pr, val, val_len,
> +							  BLKID_ENC_UTF16LE);
> +			break;
> +		}
> +
> +		attr_off += attr_len;
> +	}
> +#endif
> +
> +	blkid_probe_sprintf_uuid(pr,
> +			(unsigned char *) &ns->volume_serial,
> +			sizeof(ns->volume_serial),
> +			"%016" PRIX64, le64_to_cpu(ns->volume_serial));
> +	return 0;
> +}
> +
> +
> +const struct blkid_idinfo ntfs_idinfo =
> +{
> +	.name		= "ntfs",
> +	.usage		= BLKID_USAGE_FILESYSTEM,
> +	.probefunc	= probe_ntfs,
> +	.magics		=
> +	{
> +		{ .magic = "NTFS    ", .len = 8, .sboff = 3 },
> +		{ NULL }
> +	}
> +};
> +