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/*
* ldm - Part of the Linux-NTFS project.
*
* Copyright (C) 2001 Richard Russon <ldm@flatcap.org>
* Copyright (C) 2001 Anton Altaparmakov <antona@users.sf.net> (AIA)
*
* Documentation is available at http://linux-ntfs.sf.net/ldm
*
* 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 (in the main directory of the Linux-NTFS source
* in the file COPYING); if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* 28/10/2001 - Added sorting of ldm partitions. (AIA)
*/
#include <linux/types.h>
#include <asm/unaligned.h>
#include <asm/byteorder.h>
#include <linux/genhd.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include "check.h"
#include "ldm.h"
#include "msdos.h"
#if 0 /* Fool kernel-doc since it doesn't do macros yet. */
/**
* ldm_debug - output an error message if debugging was enabled at compile time
* @f: a printf format string containing the message
* @...: the variables to substitute into @f
*
* ldm_debug() writes a DEBUG level message to the syslog but only if the
* driver was compiled with debug enabled. Otherwise, the call turns into a NOP.
*/
static void ldm_debug(const char *f, ...);
#endif
#ifdef CONFIG_LDM_DEBUG
#define ldm_debug(f, a...) \
{ \
printk(LDM_DEBUG " DEBUG (%s, %d): %s: ", \
__FILE__, __LINE__, __FUNCTION__); \
printk(f, ##a); \
}
#else /* !CONFIG_LDM_DEBUG */
#define ldm_debug(f, a...) do {} while (0)
#endif /* !CONFIG_LDM_DEBUG */
/* Necessary forward declarations. */
static int create_partition(struct gendisk *, int, int, int);
static int parse_privhead(const u8 *, struct privhead *);
static u64 get_vnum(const u8 *, int *);
static int get_vstr(const u8 *, u8 *, const int);
/**
* parse_vblk_part - parse a LDM database vblk partition record
* @buffer: vblk partition record loaded from the LDM database
* @buf_size: size of @buffer in bytes
* @vb: in memory vblk structure to return parsed information in
*
* This parses the LDM database vblk record of type VBLK_PART, i.e. a partition
* record, supplied in @buffer and sets up the in memory vblk structure @vb
* with the obtained information.
*
* Return 1 on success and -1 on error, in which case @vb is undefined.
*/
static int parse_vblk_part(const u8 *buffer, const int buf_size,
struct vblk *vb)
{
int err, rel_objid, rel_name, rel_size, rel_parent;
if (0x34 >= buf_size)
return -1;
/* Calculate relative offsets. */
rel_objid = 1 + buffer[0x18];
if (0x18 + rel_objid >= buf_size)
return -1;
rel_name = 1 + buffer[0x18 + rel_objid] + rel_objid;
if (0x34 + rel_name >= buf_size)
return -1;
rel_size = 1 + buffer[0x34 + rel_name] + rel_name;
if (0x34 + rel_size >= buf_size)
return -1;
rel_parent = 1 + buffer[0x34 + rel_size] + rel_size;
if (0x34 + rel_parent >= buf_size)
return -1;
/* Setup @vb. */
vb->vblk_type = VBLK_PART;
vb->obj_id = get_vnum(buffer + 0x18, &err);
if (err || 0x34 + rel_parent + buffer[0x34 + rel_parent] >= buf_size)
return -1;
vb->disk_id = get_vnum(buffer + 0x34 + rel_parent, &err);
if (err || 0x24 + rel_name + 8 > buf_size)
return -1;
vb->start_sector = BE64(buffer + 0x24 + rel_name);
if (0x34 + rel_name + buffer[0x34 + rel_name] >= buf_size)
return -1;
vb->num_sectors = get_vnum(buffer + 0x34 + rel_name, &err);
if (err || 0x18 + rel_objid + buffer[0x18 + rel_objid] >= buf_size)
return -1;
err = get_vstr(buffer + 0x18 + rel_objid, vb->name, sizeof(vb->name));
if (err == -1)
return err;
ldm_debug("Parsed Partition VBLK successfully.\n");
return 1;
}
/**
* parse_vblk - parse a LDM database vblk record
* @buffer: vblk record loaded from the LDM database
* @buf_size: size of @buffer in bytes
* @vb: in memory vblk structure to return parsed information in
*
* This parses the LDM database vblk record supplied in @buffer and sets up
* the in memory vblk structure @vb with the obtained information.
*
* Return 1 on success, 0 if successful but record not in use, and -1 on error.
* If the return value is 0 or -1, @vb is undefined.
*
* NOTE: Currently the only record type we handle is VBLK_PART, i.e. records
* describing a partition. For all others, we just set @vb->vblk_type to 0 and
* return success. This of course means that if @vb->vblk_type is zero, all
* other fields in @vb are undefined.
*/
static int parse_vblk(const u8 *buffer, const int buf_size, struct vblk *vb)
{
int err = 1;
if (buf_size < 0x14)
return -1;
if (MAGIC_VBLK != BE32(buffer)) {
printk(LDM_CRIT "Cannot find VBLK, database may be corrupt.\n");
return -1;
}
if ((BE16(buffer + 0x0E) == 0) || /* Record is not in use. */
(BE16(buffer + 0x0C) != 0)) /* Part 2 of an ext. record */
return 0;
/* FIXME: What about extended VBLKs? */
switch (buffer[0x13]) {
case VBLK_PART:
err = parse_vblk_part(buffer, buf_size, vb);
break;
default:
vb->vblk_type = 0;
}
if (err != -1)
ldm_debug("Parsed VBLK successfully.\n");
return err;
}
/**
* add_partition_to_list - insert partition into a partition list
* @pl: sorted list of partitions
* @hd: gendisk structure to which the data partition belongs
* @disk_minor: minor number of the disk device
* @start: first sector within the disk device
* @size: number of sectors on the partition device
*
* This sanity checks the partition specified by @start and @size against the
* device specified by @hd and inserts the partition into the sorted partition
* list @pl if the checks pass.
*
* On success return 1, otherwise return -1.
*
* TODO: Add sanity check for overlapping partitions. (AIA)
*/
static int add_partition_to_list(struct list_head *pl, const struct gendisk *hd,
const int disk_minor, const unsigned long start,
const unsigned long size)
{
struct ldm_part *lp, *lptmp;
struct list_head *tmp;
if (!hd->part)
return -1;
if ((start < 1) || ((start + size) > hd->part[disk_minor].nr_sects)) {
printk(LDM_CRIT "LDM partition exceeds physical disk. "
"Skipping.\n");
return -1;
}
lp = (struct ldm_part*)kmalloc(sizeof(struct ldm_part), GFP_KERNEL);
if (!lp) {
printk(LDM_CRIT "Not enough memory! Aborting LDM partition "
"parsing.\n");
return -2;
}
INIT_LIST_HEAD(&lp->part_list);
lp->start = start;
lp->size = size;
list_for_each(tmp, pl) {
lptmp = list_entry(tmp, struct ldm_part, part_list);
if (start > lptmp->start)
continue;
if (start < lptmp->start)
break;
printk(LDM_CRIT "Duplicate LDM partition entry! Skipping.\n");
kfree(lp);
return -1;
}
list_add_tail(&lp->part_list, tmp);
ldm_debug("Added LDM partition successfully.\n");
return 1;
}
/**
* create_data_partitions - create the data partition devices
* @hd: gendisk structure in which to create the data partitions
* @first_sector: first sector within the disk device
* @first_part_minor: first minor number of data partition devices
* @dev: partition device holding the LDM database
* @vm: in memory vmdb structure of @dev
* @ph: in memory privhead structure of the disk device
* @dk: in memory ldmdisk structure of the disk device
*
* The database contains ALL the partitions for ALL the disks, so we need to
* filter out this specific disk. Using the disk's object id, we can find all
* the partitions in the database that belong to this disk.
*
* For each found partition, we create a corresponding partition device starting
* with minor number @first_part_minor. But we do this in such a way that we
* actually sort the partitions in order of on-disk position. Any invalid
* partitions are completely ignored/skipped (an error is output but that's
* all).
*
* Return 1 on success and -1 on error.
*/
static int create_data_partitions(struct gendisk *hd,
const unsigned long first_sector, int first_part_minor,
struct block_device *bdev, const struct vmdb *vm,
const struct privhead *ph, const struct ldmdisk *dk,
unsigned long base)
{
Sector sect;
unsigned char *data;
struct vblk *vb;
LIST_HEAD(pl); /* Sorted list of partitions. */
struct ldm_part *lp;
struct list_head *tmp;
int vblk;
int vsize; /* VBLK size. */
int perbuf; /* VBLKs per buffer. */
int buffer, lastbuf, lastofs, err, disk_minor;
vb = (struct vblk*)kmalloc(sizeof(struct vblk), GFP_KERNEL);
if (!vb)
goto no_mem;
vsize = vm->vblk_size;
if (vsize < 1 || vsize > 512)
goto err_out;
perbuf = 512 / vsize;
if (perbuf < 1 || 512 % vsize)
goto err_out;
/* 512 == VMDB size */
lastbuf = vm->last_vblk_seq / perbuf - 1;
lastofs = vm->last_vblk_seq % perbuf;
if (lastofs)
lastbuf++;
if (OFF_VBLK * LDM_BLOCKSIZE + vm->last_vblk_seq * vsize >
ph->config_size * 512)
goto err_out;
/*
* Get the minor number of the parent device so we can check we don't
* go beyond the end of the device.
*/
disk_minor = (first_part_minor >> hd->minor_shift) << hd->minor_shift;
for (buffer = 0; buffer < lastbuf; buffer++) {
data = read_dev_sector(bdev, base + 2*OFF_VBLK + buffer, §);
if (!data)
goto read_err;
for (vblk = 0; vblk < perbuf; vblk++) {
u8 *block;
if (lastofs && buffer == lastbuf - 1 && vblk >= lastofs)
break;
block = data + vsize * vblk;
if (block + vsize > data + 512)
goto brelse_out;
if (parse_vblk(block, vsize, vb) != 1)
continue;
if (vb->vblk_type != VBLK_PART)
continue;
if (dk->obj_id != vb->disk_id)
continue;
/* Ignore invalid partition errors. */
if (add_partition_to_list(&pl, hd, disk_minor,
first_sector + vb->start_sector +
ph->logical_disk_start,
vb->num_sectors) < -1)
goto brelse_out;
}
put_dev_sector(sect);
}
err = 1;
out:
/* Finally create the nicely sorted data partitions. */
printk(" <");
list_for_each(tmp, &pl) {
lp = list_entry(tmp, struct ldm_part, part_list);
add_gd_partition(hd, first_part_minor++, lp->start, lp->size);
}
printk(" >\n");
if (!list_empty(&pl)) {
struct list_head *tmp2;
/* Cleanup the partition list which is now superfluous. */
list_for_each_safe(tmp, tmp2, &pl) {
lp = list_entry(tmp, struct ldm_part, part_list);
list_del(tmp);
kfree(lp);
}
}
kfree(vb);
return err;
brelse_out:
put_dev_sector(sect);
goto err_out;
no_mem:
printk(LDM_CRIT "Not enough memory to allocate required buffers.\n");
goto err_out;
read_err:
printk(LDM_CRIT "Disk read failed in create_partitions.\n");
err_out:
err = -1;
goto out;
}
/**
* get_vnum - convert a variable-width, big endian number, to cpu u64 one
* @block: pointer to the variable-width number to convert
* @err: address of an integer into which to return the error code.
*
* This converts a variable-width, big endian number into a 64-bit, CPU format
* number and returns the result with err set to 0. If an error occurs return 0
* with err set to -1.
*
* The first byte of a variable-width number is the size of the number in bytes.
*/
static u64 get_vnum(const u8 *block, int *err)
{
u64 tmp = 0ULL;
u8 length = *block++;
if (length && length <= 8) {
while (length--)
tmp = (tmp << 8) | *block++;
*err = 0;
} else {
printk(LDM_ERR "Illegal length in get_vnum(): %d.\n", length);
*err = 1;
}
return tmp;
}
/**
* get_vstr - convert a counted, non-null-terminated ASCII string to C-style one
* @block: string to convert
* @buffer: output buffer
* @buflen: size of output buffer
*
* This converts @block, a counted, non-null-terminated ASCII string, into a
* C-style, null-terminated, ASCII string and returns this in @buffer. The
* maximum number of characters converted is given by @buflen.
*
* The first bytes of a counted string stores the length of the string in bytes.
*
* Return the number of characters written to @buffer, not including the
* terminating null character, on success, and -1 on error, in which case
* @buffer is not defined.
*/
static int get_vstr(const u8 *block, u8 *buffer, const int buflen)
{
int length = block[0];
if (length < 1)
return -1;
if (length >= buflen) {
printk(LDM_ERR "String too long for buffer in get_vstr(): "
"(%d/%d). Truncating.\n", length, buflen);
length = buflen - 1;
}
memcpy(buffer, block + 1, length);
buffer[length] = (u8)'\0';
return length;
}
/**
* get_disk_objid - obtain the object id for the device we are working on
* @dev: partition device holding the LDM database
* @vm: in memory vmdb structure of the LDM database
* @ph: in memory privhead structure of the device we are working on
* @dk: in memory ldmdisk structure to return information into
*
* This obtains the object id for the device we are working on as defined by
* the private header @ph. The obtained object id, together with the disk's
* GUID from @ph are returned in the ldmdisk structure pointed to by @dk.
*
* A Disk has two Ids. The main one is a GUID in string format. The second,
* used internally for cross-referencing, is a small, sequentially allocated,
* number. The PRIVHEAD, just after the partition table, tells us the disk's
* GUID. To find the disk's object id, we have to look through the database.
*
* Return 1 on success and -1 on error, in which case @dk is undefined.
*/
static int get_disk_objid(struct block_device *bdev, const struct vmdb *vm,
const struct privhead *ph, struct ldmdisk *dk,
unsigned long base)
{
Sector sect;
unsigned char *data;
u8 *disk_id;
int vblk;
int vsize; /* VBLK size. */
int perbuf; /* VBLKs per buffer. */
int buffer, lastbuf, lastofs, err;
disk_id = (u8*)kmalloc(DISK_ID_SIZE, GFP_KERNEL);
if (!disk_id)
goto no_mem;
vsize = vm->vblk_size;
if (vsize < 1 || vsize > 512)
goto err_out;
perbuf = 512 / vsize;
if (perbuf < 1 || 512 % vsize)
goto err_out;
/* 512 == VMDB size */
lastbuf = vm->last_vblk_seq / perbuf - 1;
lastofs = vm->last_vblk_seq % perbuf;
if (lastofs)
lastbuf++;
if (OFF_VBLK * LDM_BLOCKSIZE + vm->last_vblk_seq * vsize >
ph->config_size * 512)
goto err_out;
for (buffer = 0; buffer < lastbuf; buffer++) {
data = read_dev_sector(bdev, base + 2*OFF_VBLK + buffer, §);
if (!data)
goto read_err;
for (vblk = 0; vblk < perbuf; vblk++) {
int rel_objid, rel_name, delta;
u8 *block;
if (lastofs && buffer == lastbuf - 1 && vblk >= lastofs)
break;
block = data + vblk * vsize;
delta = vblk * vsize + 0x18;
if (delta >= 512)
goto brelse_out;
if (block[0x0D] != 0) /* Extended VBLK, ignore */
continue;
if ((block[0x13] != VBLK_DSK1) &&
(block[0x13] != VBLK_DSK2))
continue;
/* Calculate relative offsets. */
rel_objid = 1 + block[0x18];
if (delta + rel_objid >= 512)
goto brelse_out;
rel_name = 1 + block[0x18 + rel_objid] + rel_objid;
if (delta + rel_name >= 512 ||
delta + rel_name + block[0x18 + rel_name] >= 512)
goto brelse_out;
err = get_vstr(block + 0x18 + rel_name, disk_id,
DISK_ID_SIZE);
if (err == -1)
goto brelse_out;
if (!strncmp(disk_id, ph->disk_id, DISK_ID_SIZE)) {
dk->obj_id = get_vnum(block + 0x18, &err);
put_dev_sector(sect);
if (err)
goto out;
strncpy(dk->disk_id, ph->disk_id,
sizeof(dk->disk_id));
dk->disk_id[sizeof(dk->disk_id) - 1] = (u8)'\0';
err = 1;
goto out;
}
}
put_dev_sector(sect);
}
err = -1;
out:
kfree(disk_id);
return err;
brelse_out:
put_dev_sector(sect);
goto err_out;
no_mem:
printk(LDM_CRIT "Not enough memory to allocate required buffers.\n");
goto err_out;
read_err:
printk(LDM_CRIT "Disk read failed in get_disk_objid.\n");
err_out:
err = -1;
goto out;
}
/**
* parse_vmdb - parse the LDM database vmdb structure
* @buffer: LDM database vmdb structure loaded from the device
* @vm: in memory vmdb structure to return parsed information in
*
* This parses the LDM database vmdb structure supplied in @buffer and sets up
* the in memory vmdb structure @vm with the obtained information.
*
* Return 1 on success and -1 on error, in which case @vm is undefined.
*
* NOTE: The *_start, *_size and *_seq values returned in @vm have not been
* checked for validity, so make sure to check them when using them.
*/
static int parse_vmdb(const u8 *buffer, struct vmdb *vm)
{
if (MAGIC_VMDB != BE32(buffer)) {
printk(LDM_CRIT "Cannot find VMDB, database may be corrupt.\n");
return -1;
}
vm->ver_major = BE16(buffer + 0x12);
vm->ver_minor = BE16(buffer + 0x14);
if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
printk(LDM_ERR "Expected VMDB version %d.%d, got %d.%d. "
"Aborting.\n", 4, 10, vm->ver_major,
vm->ver_minor);
return -1;
}
vm->vblk_size = BE32(buffer + 0x08);
vm->vblk_offset = BE32(buffer + 0x0C);
vm->last_vblk_seq = BE32(buffer + 0x04);
ldm_debug("Parsed VMDB successfully.\n");
return 1;
}
/**
* validate_vmdb - validate the vmdb
* @dev: partition device holding the LDM database
* @vm: in memory vmdb in which to return information
*
* Find the vmdb of the LDM database stored on @dev and return the parsed
* information into @vm.
*
* Return 1 on success and -1 on error, in which case @vm is undefined.
*/
static int validate_vmdb(struct block_device *bdev, struct vmdb *vm, unsigned long base)
{
Sector sect;
unsigned char *data;
int ret;
data = read_dev_sector(bdev, base + OFF_VMDB * 2 + 1, §);
if (!data) {
printk(LDM_CRIT "Disk read failed in validate_vmdb.\n");
return -1;
}
ret = parse_vmdb(data, vm);
put_dev_sector(sect);
return ret;
}
/**
* compare_tocblocks - compare two tables of contents
* @toc1: first toc
* @toc2: second toc
*
* This compares the two tables of contents @toc1 and @toc2.
*
* Return 1 if @toc1 and @toc2 are equal and -1 otherwise.
*/
static int compare_tocblocks(const struct tocblock *toc1,
const struct tocblock *toc2)
{
if ((toc1->bitmap1_start == toc2->bitmap1_start) &&
(toc1->bitmap1_size == toc2->bitmap1_size) &&
(toc1->bitmap2_start == toc2->bitmap2_start) &&
(toc1->bitmap2_size == toc2->bitmap2_size) &&
!strncmp(toc1->bitmap1_name, toc2->bitmap1_name,
sizeof(toc1->bitmap1_name)) &&
!strncmp(toc1->bitmap2_name, toc2->bitmap2_name,
sizeof(toc1->bitmap2_name)))
return 1;
return -1;
}
/**
* parse_tocblock - parse the LDM database table of contents structure
* @buffer: LDM database toc structure loaded from the device
* @toc: in memory toc structure to return parsed information in
*
* This parses the LDM database table of contents structure supplied in @buffer
* and sets up the in memory table of contents structure @toc with the obtained
* information.
*
* Return 1 on success and -1 on error, in which case @toc is undefined.
*
* FIXME: The *_start and *_size values returned in @toc are not been checked
* for validity but as we don't use the actual values for anything other than
* comparing between the toc and its backups, the values are not important.
*/
static int parse_tocblock(const u8 *buffer, struct tocblock *toc)
{
if (MAGIC_TOCBLOCK != BE64(buffer)) {
printk(LDM_CRIT "Cannot find TOCBLOCK, database may be "
"corrupt.\n");
return -1;
}
strncpy(toc->bitmap1_name, buffer + 0x24, sizeof(toc->bitmap1_name));
toc->bitmap1_name[sizeof(toc->bitmap1_name) - 1] = (u8)'\0';
toc->bitmap1_start = BE64(buffer + 0x2E);
toc->bitmap1_size = BE64(buffer + 0x36);
/*toc->bitmap1_flags = BE64(buffer + 0x3E);*/
if (strncmp(toc->bitmap1_name, TOC_BITMAP1,
sizeof(toc->bitmap1_name)) != 0) {
printk(LDM_CRIT "TOCBLOCK's first bitmap should be %s, but is "
"%s.\n", TOC_BITMAP1, toc->bitmap1_name);
return -1;
}
strncpy(toc->bitmap2_name, buffer + 0x46, sizeof(toc->bitmap2_name));
toc->bitmap2_name[sizeof(toc->bitmap2_name) - 1] = (u8)'\0';
toc->bitmap2_start = BE64(buffer + 0x50);
toc->bitmap2_size = BE64(buffer + 0x58);
/*toc->bitmap2_flags = BE64(buffer + 0x60);*/
if (strncmp(toc->bitmap2_name, TOC_BITMAP2,
sizeof(toc->bitmap2_name)) != 0) {
printk(LDM_CRIT "TOCBLOCK's second bitmap should be %s, but is "
"%s.\n", TOC_BITMAP2, toc->bitmap2_name);
return -1;
}
ldm_debug("Parsed TOCBLOCK successfully.\n");
return 1;
}
/**
* validate_tocblocks - validate the table of contents and its backups
* @dev: partition device holding the LDM database
* @toc1: in memory table of contents in which to return information
*
* Find and compare the four tables of contents of the LDM database stored on
* @dev and return the parsed information into @toc1.
*
* Return 1 on success and -1 on error, in which case @toc1 is undefined.
*/
static int validate_tocblocks(struct block_device *bdev,
struct tocblock *toc1,
unsigned long base)
{
Sector sect;
unsigned char *data;
struct tocblock *toc2 = NULL, *toc3 = NULL, *toc4 = NULL;
int err;
toc2 = (struct tocblock*)kmalloc(sizeof(*toc2), GFP_KERNEL);
if (!toc2)
goto no_mem;
toc3 = (struct tocblock*)kmalloc(sizeof(*toc3), GFP_KERNEL);
if (!toc3)
goto no_mem;
toc4 = (struct tocblock*)kmalloc(sizeof(*toc4), GFP_KERNEL);
if (!toc4)
goto no_mem;
/* Read and parse first toc. */
data = read_dev_sector(bdev, base + OFF_TOCBLOCK1 * 2 + 1, §);
if (!data) {
printk(LDM_CRIT "Disk read 1 failed in validate_tocblocks.\n");
goto err_out;
}
err = parse_tocblock(data, toc1);
put_dev_sector(sect);
if (err != 1)
goto out;
/* Read and parse second toc. */
data = read_dev_sector(bdev, base + OFF_TOCBLOCK2 * 2, §);
if (!data) {
printk(LDM_CRIT "Disk read 2 failed in validate_tocblocks.\n");
goto err_out;
}
err = parse_tocblock(data, toc2);
put_dev_sector(sect);
if (err != 1)
goto out;
/* Read and parse third toc. */
data = read_dev_sector(bdev, base + OFF_TOCBLOCK3 * 2 + 1, §);
if (!data) {
printk(LDM_CRIT "Disk read 3 failed in validate_tocblocks.\n");
goto err_out;
}
err = parse_tocblock(data, toc3);
put_dev_sector(sect);
if (err != 1)
goto out;
/* Read and parse fourth toc. */
data = read_dev_sector(bdev, base + OFF_TOCBLOCK4 * 2, §);
if (!data) {
printk(LDM_CRIT "Disk read 4 failed in validate_tocblocks.\n");
goto err_out;
}
err = parse_tocblock(data, toc4);
put_dev_sector(sect);
if (err != 1)
goto out;
/* Compare all tocs. */
err = compare_tocblocks(toc1, toc2);
if (err != 1) {
printk(LDM_CRIT "First and second TOCBLOCKs don't match.\n");
goto out;
}
err = compare_tocblocks(toc3, toc4);
if (err != 1) {
printk(LDM_CRIT "Third and fourth TOCBLOCKs don't match.\n");
goto out;
}
err = compare_tocblocks(toc1, toc3);
if (err != 1)
printk(LDM_CRIT "First and third TOCBLOCKs don't match.\n");
else
ldm_debug("Validated TOCBLOCKs successfully.\n");
out:
kfree(toc2);
kfree(toc3);
kfree(toc4);
return err;
no_mem:
printk(LDM_CRIT "Not enough memory to allocate required buffers.\n");
err_out:
err = -1;
goto out;
}
/**
* compare_privheads - compare two privheads
* @ph1: first privhead
* @ph2: second privhead
*
* This compares the two privheads @ph1 and @ph2.
*
* Return 1 if @ph1 and @ph2 are equal and -1 otherwise.
*/
static int compare_privheads(const struct privhead *ph1,
const struct privhead *ph2)
{
if ((ph1->ver_major == ph2->ver_major) &&
(ph1->ver_minor == ph2->ver_minor) &&
(ph1->logical_disk_start == ph2->logical_disk_start) &&
(ph1->logical_disk_size == ph2->logical_disk_size) &&
(ph1->config_start == ph2->config_start) &&
(ph1->config_size == ph2->config_size) &&
!strncmp(ph1->disk_id, ph2->disk_id, sizeof(ph1->disk_id)))
return 1;
return -1;
}
/**
* validate_privheads - compare the privhead backups to the first one
* @dev: partition device holding the LDM database
* @ph1: first privhead which we have already validated before
*
* We already have one privhead from the beginning of the disk.
* Now we compare the two other copies for safety.
*
* Return 1 on succes and -1 on error.
*/
static int validate_privheads(struct block_device *bdev,
const struct privhead *ph1,
unsigned long base)
{
Sector sect;
unsigned char *data;
struct privhead *ph2 = NULL, *ph3 = NULL;
int err;
ph2 = (struct privhead*)kmalloc(sizeof(*ph2), GFP_KERNEL);
if (!ph2)
goto no_mem;
ph3 = (struct privhead*)kmalloc(sizeof(*ph3), GFP_KERNEL);
if (!ph3)
goto no_mem;
data = read_dev_sector(bdev, base + OFF_PRIVHEAD2 * 2, §);
if (!data) {
printk(LDM_CRIT "Disk read 1 failed in validate_privheads.\n");
goto err_out;
}
err = parse_privhead(data, ph2);
put_dev_sector(sect);
if (err != 1)
goto out;
data = read_dev_sector(bdev, base + OFF_PRIVHEAD3 * 2 + 1, §);
if (!data) {
printk(LDM_CRIT "Disk read 2 failed in validate_privheads.\n");
goto err_out;
}
err = parse_privhead(data, ph3);
put_dev_sector(sect);
if (err != 1)
goto out;
err = compare_privheads(ph1, ph2);
if (err != 1) {
printk(LDM_CRIT "First and second PRIVHEADs don't match.\n");
goto out;
}
err = compare_privheads(ph1, ph3);
if (err != 1)
printk(LDM_CRIT "First and third PRIVHEADs don't match.\n");
else
/* We _could_ have checked more. */
ldm_debug("Validated PRIVHEADs successfully.\n");
out:
kfree(ph2);
kfree(ph3);
return err;
no_mem:
printk(LDM_CRIT "Not enough memory to allocate required buffers.\n");
err_out:
err = -1;
goto out;
}
/**
* create_partition - validate input and create a kernel partition device
* @hd: gendisk structure in which to create partition
* @minor: minor number for device to create
* @start: starting offset of the partition into the parent device
* @size: size of the partition
*
* This validates the range, then puts an entry into the kernel's partition
* table.
*
* @start and @size are numbers of sectors.
*
* Return 1 on succes and -1 on error.
*/
static int create_partition(struct gendisk *hd, const int minor,
const int start, const int size)
{
int disk_minor;
if (!hd->part)
return -1;
/*
* Get the minor number of the parent device so we can check we don't
* go beyond the end of the device.
*/
disk_minor = (minor >> hd->minor_shift) << hd->minor_shift;
if ((start < 1) || ((start + size) > hd->part[disk_minor].nr_sects)) {
printk(LDM_CRIT "LDM Partition exceeds physical disk. "
"Aborting.\n");
return -1;
}
add_gd_partition(hd, minor, start, size);
ldm_debug("Created partition successfully.\n");
return 1;
}
/**
* parse_privhead - parse the LDM database PRIVHEAD structure
* @buffer: LDM database privhead structure loaded from the device
* @ph: in memory privhead structure to return parsed information in
*
* This parses the LDM database PRIVHEAD structure supplied in @buffer and
* sets up the in memory privhead structure @ph with the obtained information.
*
* Return 1 on succes and -1 on error, in which case @ph is undefined.
*/
static int parse_privhead(const u8 *buffer, struct privhead *ph)
{
if (MAGIC_PRIVHEAD != BE64(buffer)) {
printk(LDM_ERR "Cannot find PRIVHEAD structure. LDM database "
"is corrupt. Aborting.\n");
return -1;
}
ph->ver_major = BE16(buffer + 0x000C);
ph->ver_minor = BE16(buffer + 0x000E);
if ((ph->ver_major != 2) || (ph->ver_minor != 11)) {
printk(LDM_ERR "Expected PRIVHEAD version %d.%d, got %d.%d. "
"Aborting.\n", 2, 11, ph->ver_major,
ph->ver_minor);
return -1;
}
ph->config_start = BE64(buffer + 0x012B);
ph->config_size = BE64(buffer + 0x0133);
if (ph->config_size != LDM_DB_SIZE) { /* 1 MiB in sectors. */
printk(LDM_ERR "Database should be %u bytes, claims to be %Lu "
"bytes. Aborting.\n", LDM_DB_SIZE,
ph->config_size);
return -1;
}
ph->logical_disk_start = BE64(buffer + 0x011B);
ph->logical_disk_size = BE64(buffer + 0x0123);
if (!ph->logical_disk_size ||
ph->logical_disk_start + ph->logical_disk_size > ph->config_start)
return -1;
memcpy(ph->disk_id, buffer + 0x0030, sizeof(ph->disk_id));
ldm_debug("Parsed PRIVHEAD successfully.\n");
return 1;
}
/**
* create_db_partition - create a dedicated partition for our database
* @hd: gendisk structure in which to create partition
* @dev: device of which to create partition
* @ph: @dev's LDM database private header
*
* Find the primary private header, locate the LDM database, then create a
* partition to wrap it.
*
* Return 1 on succes, 0 if device is not a dynamic disk and -1 on error.
*/
static int create_db_partition(struct gendisk *hd, struct block_device *bdev,
const unsigned long first_sector, const int first_part_minor,
struct privhead *ph)
{
Sector sect;
unsigned char *data;
int err;
data = read_dev_sector(bdev, OFF_PRIVHEAD1*2, §);
if (!data) {
printk(LDM_CRIT __FUNCTION__ "(): Device read failed.\n");
return -1;
}
if (BE64(data) != MAGIC_PRIVHEAD) {
ldm_debug("Cannot find PRIVHEAD structure. Not a dynamic disk "
"or corrupt LDM database.\n");
return 0;
}
err = parse_privhead(data, ph);
if (err == 1)
err = create_partition(hd, first_part_minor, first_sector +
ph->config_start, ph->config_size);
put_dev_sector(sect);
return err;
}
/**
* validate_patition_table - check whether @dev is a dynamic disk
* @dev: device to test
*
* Check whether @dev is a dynamic disk by looking for an MS-DOS-style partition
* table with one or more entries of type 0x42 (the former Secure File System
* (Landis) partition type, now recycled by Microsoft for dynamic disks) in it.
* If this succeeds we assume we have a dynamic disk, and not otherwise.
*
* Return 1 if @dev is a dynamic disk, 0 if not and -1 on error.
*/
static int validate_partition_table(struct block_device *bdev)
{
Sector sect;
unsigned char *data;
struct partition *p;
int i, nr_sfs;
data = read_dev_sector(bdev, 0, §);
if (!data)
return -1;
if (*(u16*)(data + 0x01FE) != cpu_to_le16(MSDOS_LABEL_MAGIC)) {
ldm_debug("No MS-DOS partition found.\n");
goto no_msdos_partition;
}
nr_sfs = 0;
p = (struct partition*)(data + 0x01BE);
for (i = 0; i < 4; i++) {
if (!SYS_IND(p+i) || SYS_IND(p+i) == WIN2K_EXTENDED_PARTITION)
continue;
if (SYS_IND(p+i) == WIN2K_DYNAMIC_PARTITION) {
nr_sfs++;
continue;
}
goto not_dynamic_disk;
}
if (!nr_sfs)
goto not_dynamic_disk;
ldm_debug("Parsed partition table successfully.\n");
put_dev_sector(sect);
return 1;
not_dynamic_disk:
// ldm_debug("Found basic MS-DOS partition, not a dynamic disk.\n");
no_msdos_partition:
put_dev_sector(sect);
return 0;
}
/**
* ldm_partition - find out whether a device is a dynamic disk and handle it
* @hd: gendisk structure in which to return the handled disk
* @dev: device we need to look at
* @first_sector: first sector within the device
* @first_part_minor: first minor number of partitions for the device
*
* Description:
*
* This determines whether the device @dev is a dynamic disk and if so creates
* the partitions necessary in the gendisk structure pointed to by @hd.
*
* We create a dummy device 1, which contains the LDM database, we skip
* devices 2-4 and then create each partition described by the LDM database
* in sequence as devices 5 and following. For example, if the device is hda,
* we would have: hda1: LDM database, hda2-4: nothing, hda5-following: the
* actual data containing partitions.
*
* Return values:
*
* 1 if @dev is a dynamic disk and we handled it,
* 0 if @dev is not a dynamic disk,
* -1 if an error occured.
*/
int ldm_partition(struct gendisk *hd, struct block_device *bdev,
unsigned long first_sector, int first_part_minor)
{
struct privhead *ph = NULL;
struct tocblock *toc = NULL;
struct vmdb *vm = NULL;
struct ldmdisk *dk = NULL;
unsigned long db_first;
int err;
if (!hd)
return 0;
/* Check the partition table. */
err = validate_partition_table(bdev);
if (err != 1)
return err;
if (!(ph = (struct privhead*)kmalloc(sizeof(*ph), GFP_KERNEL)))
goto no_mem;
/* Create the LDM database device. */
err = create_db_partition(hd, bdev, first_sector, first_part_minor, ph);
if (err != 1)
goto out;
db_first = hd->part[first_part_minor].start_sect;
/* Check the backup privheads. */
err = validate_privheads(bdev, ph, db_first);
if (err != 1)
goto out;
/* Check the table of contents and its backups. */
if (!(toc = (struct tocblock*)kmalloc(sizeof(*toc), GFP_KERNEL)))
goto no_mem;
err = validate_tocblocks(bdev, toc, db_first);
if (err != 1)
goto out;
/* Check the vmdb. */
if (!(vm = (struct vmdb*)kmalloc(sizeof(*vm), GFP_KERNEL)))
goto no_mem;
err = validate_vmdb(bdev, vm, db_first);
if (err != 1)
goto out;
/* Find the object id for @dev in the LDM database. */
if (!(dk = (struct ldmdisk*)kmalloc(sizeof(*dk), GFP_KERNEL)))
goto no_mem;
err = get_disk_objid(bdev, vm, ph, dk, db_first);
if (err != 1)
goto out;
/* Finally, create the data partition devices. */
err = create_data_partitions(hd, first_sector, first_part_minor +
LDM_FIRST_PART_OFFSET, bdev, vm, ph, dk, db_first);
if (err == 1)
ldm_debug("Parsed LDM database successfully.\n");
out:
kfree(ph);
kfree(toc);
kfree(vm);
kfree(dk);
return err;
no_mem:
printk(LDM_CRIT "Not enough memory to allocate required buffers.\n");
err = -1;
goto out;
}
|