grub/grub-core/fs/romfs.c
Colin Watson 4eb8b75659 Remove nested functions from disk and file read hooks.
* include/grub/disk.h (grub_disk_read_hook_t): New type.
	(struct grub_disk): Add read_hook_data member.
	* include/grub/file.h (struct grub_file): Likewise.
	* include/grub/fshelp.h (grub_fshelp_read_file): Add read_hook_data
	argument.

	Update all callers.
2013-02-27 17:19:15 +01:00

484 lines
12 KiB
C

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2010 Free Software Foundation, Inc.
*
* GRUB 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 3 of the License, or
* (at your option) any later version.
*
* GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/file.h>
#include <grub/types.h>
#include <grub/dl.h>
#include <grub/mm.h>
#include <grub/disk.h>
#include <grub/fs.h>
#include <grub/fshelp.h>
GRUB_MOD_LICENSE ("GPLv3+");
struct grub_romfs_superblock
{
char magic[8];
#define GRUB_ROMFS_MAGIC "-rom1fs-"
grub_uint32_t total_size;
grub_uint32_t chksum;
char label[0];
};
struct grub_romfs_file_header
{
grub_uint32_t next_file;
grub_uint32_t spec;
grub_uint32_t size;
grub_uint32_t chksum;
char name[0];
};
struct grub_romfs_data
{
grub_disk_addr_t first_file;
grub_disk_t disk;
};
struct grub_fshelp_node
{
grub_disk_addr_t addr;
struct grub_romfs_data *data;
grub_disk_addr_t data_addr;
/* Not filled for root. */
struct grub_romfs_file_header file;
};
#define GRUB_ROMFS_ALIGN 16
#define GRUB_ROMFS_TYPE_MASK 7
#define GRUB_ROMFS_TYPE_HARDLINK 0
#define GRUB_ROMFS_TYPE_DIRECTORY 1
#define GRUB_ROMFS_TYPE_REGULAR 2
#define GRUB_ROMFS_TYPE_SYMLINK 3
static grub_err_t
do_checksum (void *in, grub_size_t insize)
{
grub_uint32_t *a = in;
grub_size_t sz = insize / 4;
grub_uint32_t *b = a + sz;
grub_uint32_t csum = 0;
while (a < b)
csum += grub_be_to_cpu32 (*a++);
if (csum)
return grub_error (GRUB_ERR_BAD_FS, "invalid checksum");
return GRUB_ERR_NONE;
}
static struct grub_romfs_data *
grub_romfs_mount (grub_device_t dev)
{
union {
struct grub_romfs_superblock sb;
char d[512];
} sb;
grub_err_t err;
char *ptr;
grub_disk_addr_t sec = 0;
struct grub_romfs_data *data;
if (!dev->disk)
{
grub_error (GRUB_ERR_BAD_FS, "not a disk");
return NULL;
}
err = grub_disk_read (dev->disk, 0, 0, sizeof (sb), &sb);
if (err == GRUB_ERR_OUT_OF_RANGE)
err = grub_errno = GRUB_ERR_BAD_FS;
if (err)
return NULL;
if (grub_be_to_cpu32 (sb.sb.total_size) < sizeof (sb))
{
grub_error (GRUB_ERR_BAD_FS, "too short filesystem");
return NULL;
}
if (grub_memcmp (sb.sb.magic, GRUB_ROMFS_MAGIC,
sizeof (sb.sb.magic)) != 0)
{
grub_error (GRUB_ERR_BAD_FS, "not romfs");
return NULL;
}
err = do_checksum (&sb, sizeof (sb) < grub_be_to_cpu32 (sb.sb.total_size) ?
sizeof (sb) : grub_be_to_cpu32 (sb.sb.total_size));
if (err)
{
grub_error (GRUB_ERR_BAD_FS, "checksum incorrect");
return NULL;
}
for (ptr = sb.sb.label; (void *) ptr < (void *) (&sb + 1)
&& ptr - sb.d < (grub_ssize_t) grub_be_to_cpu32 (sb.sb.total_size); ptr++)
if (!*ptr)
break;
while ((void *) ptr == &sb + 1)
{
sec++;
err = grub_disk_read (dev->disk, sec, 0, sizeof (sb), &sb);
if (err == GRUB_ERR_OUT_OF_RANGE)
err = grub_errno = GRUB_ERR_BAD_FS;
if (err)
return NULL;
for (ptr = sb.d; (void *) ptr < (void *) (&sb + 1)
&& (ptr - sb.d + (sec << GRUB_DISK_SECTOR_BITS)
< grub_be_to_cpu32 (sb.sb.total_size));
ptr++)
if (!*ptr)
break;
}
data = grub_malloc (sizeof (*data));
if (!data)
return NULL;
data->first_file = ALIGN_UP (ptr + 1 - sb.d, GRUB_ROMFS_ALIGN)
+ (sec << GRUB_DISK_SECTOR_BITS);
data->disk = dev->disk;
return data;
}
static char *
grub_romfs_read_symlink (grub_fshelp_node_t node)
{
char *ret;
grub_err_t err;
ret = grub_malloc (grub_be_to_cpu32 (node->file.size) + 1);
if (!ret)
return NULL;
err = grub_disk_read (node->data->disk,
(node->data_addr) >> GRUB_DISK_SECTOR_BITS,
(node->data_addr) & (GRUB_DISK_SECTOR_SIZE - 1),
grub_be_to_cpu32 (node->file.size), ret);
if (err)
{
grub_free (ret);
return NULL;
}
ret[grub_be_to_cpu32 (node->file.size)] = 0;
return ret;
}
static int
grub_romfs_iterate_dir (grub_fshelp_node_t dir,
grub_fshelp_iterate_dir_hook_t hook, void *hook_data)
{
grub_disk_addr_t caddr;
struct grub_romfs_file_header hdr;
unsigned nptr;
unsigned i, j;
grub_size_t a = 0;
grub_properly_aligned_t *name = NULL;
for (caddr = dir->data_addr; caddr;
caddr = grub_be_to_cpu32 (hdr.next_file) & ~(GRUB_ROMFS_ALIGN - 1))
{
grub_disk_addr_t naddr = caddr + sizeof (hdr);
grub_uint32_t csum = 0;
enum grub_fshelp_filetype filetype = GRUB_FSHELP_UNKNOWN;
struct grub_fshelp_node *node = NULL;
grub_err_t err;
err = grub_disk_read (dir->data->disk, caddr >> GRUB_DISK_SECTOR_BITS,
caddr & (GRUB_DISK_SECTOR_SIZE - 1),
sizeof (hdr), &hdr);
if (err)
{
grub_free (name);
return 1;
}
for (nptr = 0; ; nptr++, naddr += 16)
{
if (a <= nptr)
{
grub_properly_aligned_t *on;
a = 2 * (nptr + 1);
on = name;
name = grub_realloc (name, a * 16);
if (!name)
{
grub_free (on);
return 1;
}
}
COMPILE_TIME_ASSERT (16 % sizeof (name[0]) == 0);
err = grub_disk_read (dir->data->disk, naddr >> GRUB_DISK_SECTOR_BITS,
naddr & (GRUB_DISK_SECTOR_SIZE - 1),
16, name + (16 / sizeof (name[0])) * nptr);
if (err)
return 1;
for (j = 0; j < 16; j++)
if (!((char *) name)[16 * nptr + j])
break;
if (j != 16)
break;
}
for (i = 0; i < sizeof (hdr) / sizeof (grub_uint32_t); i++)
csum += grub_be_to_cpu32 (((grub_uint32_t *) &hdr)[i]);
for (i = 0; i < (nptr + 1) * 4; i++)
csum += grub_be_to_cpu32 (((grub_uint32_t *) name)[i]);
if (csum != 0)
{
grub_error (GRUB_ERR_BAD_FS, "invalid checksum");
grub_free (name);
return 1;
}
node = grub_malloc (sizeof (*node));
if (!node)
return 1;
node->addr = caddr;
node->data_addr = caddr + (nptr + 1) * 16 + sizeof (hdr);
node->data = dir->data;
node->file = hdr;
switch (grub_be_to_cpu32 (hdr.next_file) & GRUB_ROMFS_TYPE_MASK)
{
case GRUB_ROMFS_TYPE_REGULAR:
filetype = GRUB_FSHELP_REG;
break;
case GRUB_ROMFS_TYPE_SYMLINK:
filetype = GRUB_FSHELP_SYMLINK;
break;
case GRUB_ROMFS_TYPE_DIRECTORY:
node->data_addr = grub_be_to_cpu32 (hdr.spec);
filetype = GRUB_FSHELP_DIR;
break;
case GRUB_ROMFS_TYPE_HARDLINK:
{
grub_disk_addr_t laddr;
node->addr = laddr = grub_be_to_cpu32 (hdr.spec);
err = grub_disk_read (dir->data->disk,
laddr >> GRUB_DISK_SECTOR_BITS,
laddr & (GRUB_DISK_SECTOR_SIZE - 1),
sizeof (node->file), &node->file);
if (err)
return 1;
if ((grub_be_to_cpu32 (node->file.next_file) & GRUB_ROMFS_TYPE_MASK)
== GRUB_ROMFS_TYPE_REGULAR
|| (grub_be_to_cpu32 (node->file.next_file)
& GRUB_ROMFS_TYPE_MASK) == GRUB_ROMFS_TYPE_SYMLINK)
{
laddr += sizeof (hdr);
while (1)
{
char buf[16];
err = grub_disk_read (dir->data->disk,
laddr >> GRUB_DISK_SECTOR_BITS,
laddr & (GRUB_DISK_SECTOR_SIZE - 1),
16, buf);
if (err)
return 1;
for (i = 0; i < 16; i++)
if (!buf[i])
break;
if (i != 16)
break;
laddr += 16;
}
node->data_addr = laddr + 16;
}
if ((grub_be_to_cpu32 (node->file.next_file)
& GRUB_ROMFS_TYPE_MASK) == GRUB_ROMFS_TYPE_REGULAR)
filetype = GRUB_FSHELP_REG;
if ((grub_be_to_cpu32 (node->file.next_file)
& GRUB_ROMFS_TYPE_MASK) == GRUB_ROMFS_TYPE_SYMLINK)
filetype = GRUB_FSHELP_SYMLINK;
if ((grub_be_to_cpu32 (node->file.next_file) & GRUB_ROMFS_TYPE_MASK)
== GRUB_ROMFS_TYPE_DIRECTORY)
{
node->data_addr = grub_be_to_cpu32 (node->file.spec);
filetype = GRUB_FSHELP_DIR;
}
break;
}
}
if (hook ((char *) name, filetype, node, hook_data))
{
grub_free (name);
return 1;
}
}
grub_free (name);
return 0;
}
/* Context for grub_romfs_dir. */
struct grub_romfs_dir_ctx
{
grub_fs_dir_hook_t hook;
void *hook_data;
};
/* Helper for grub_romfs_dir. */
static int
grub_romfs_dir_iter (const char *filename, enum grub_fshelp_filetype filetype,
grub_fshelp_node_t node, void *data)
{
struct grub_romfs_dir_ctx *ctx = data;
struct grub_dirhook_info info;
grub_memset (&info, 0, sizeof (info));
info.dir = ((filetype & GRUB_FSHELP_TYPE_MASK) == GRUB_FSHELP_DIR);
grub_free (node);
return ctx->hook (filename, &info, ctx->hook_data);
}
static grub_err_t
grub_romfs_dir (grub_device_t device, const char *path,
grub_fs_dir_hook_t hook, void *hook_data)
{
struct grub_romfs_dir_ctx ctx = { hook, hook_data };
struct grub_romfs_data *data = 0;
struct grub_fshelp_node *fdiro = 0, start;
data = grub_romfs_mount (device);
if (! data)
goto fail;
start.addr = data->first_file;
start.data_addr = data->first_file;
start.data = data;
grub_fshelp_find_file (path, &start, &fdiro, grub_romfs_iterate_dir,
grub_romfs_read_symlink, GRUB_FSHELP_DIR);
if (grub_errno)
goto fail;
grub_romfs_iterate_dir (fdiro, grub_romfs_dir_iter, &ctx);
fail:
grub_free (data);
return grub_errno;
}
static grub_err_t
grub_romfs_open (struct grub_file *file, const char *name)
{
struct grub_romfs_data *data = 0;
struct grub_fshelp_node *fdiro = 0, start;
data = grub_romfs_mount (file->device);
if (! data)
goto fail;
start.addr = data->first_file;
start.data_addr = data->first_file;
start.data = data;
grub_fshelp_find_file (name, &start, &fdiro, grub_romfs_iterate_dir,
grub_romfs_read_symlink, GRUB_FSHELP_REG);
if (grub_errno)
goto fail;
file->size = grub_be_to_cpu32 (fdiro->file.size);
file->data = fdiro;
return GRUB_ERR_NONE;
fail:
grub_free (data);
return grub_errno;
}
static grub_ssize_t
grub_romfs_read (grub_file_t file, char *buf, grub_size_t len)
{
struct grub_fshelp_node *data = file->data;
/* XXX: The file is stored in as a single extent. */
data->data->disk->read_hook = file->read_hook;
data->data->disk->read_hook_data = file->read_hook_data;
grub_disk_read (data->data->disk,
(data->data_addr + file->offset) >> GRUB_DISK_SECTOR_BITS,
(data->data_addr + file->offset) & (GRUB_DISK_SECTOR_SIZE - 1),
len, buf);
data->data->disk->read_hook = NULL;
if (grub_errno)
return -1;
return len;
}
static grub_err_t
grub_romfs_close (grub_file_t file)
{
struct grub_fshelp_node *data = file->data;
grub_free (data->data);
grub_free (data);
return GRUB_ERR_NONE;
}
static grub_err_t
grub_romfs_label (grub_device_t device, char **label)
{
struct grub_romfs_data *data;
grub_err_t err;
*label = NULL;
data = grub_romfs_mount (device);
if (!data)
return grub_errno;
*label = grub_malloc (data->first_file + 1
- sizeof (struct grub_romfs_superblock));
if (!*label)
{
grub_free (data);
return grub_errno;
}
err = grub_disk_read (device->disk, 0, sizeof (struct grub_romfs_superblock),
data->first_file
- sizeof (struct grub_romfs_superblock),
*label);
if (err)
{
grub_free (data);
grub_free (*label);
*label = NULL;
return err;
}
(*label)[data->first_file - sizeof (struct grub_romfs_superblock)] = 0;
grub_free (data);
return GRUB_ERR_NONE;
}
static struct grub_fs grub_romfs_fs =
{
.name = "romfs",
.dir = grub_romfs_dir,
.open = grub_romfs_open,
.read = grub_romfs_read,
.close = grub_romfs_close,
.label = grub_romfs_label,
#ifdef GRUB_UTIL
.reserved_first_sector = 0,
.blocklist_install = 0,
#endif
.next = 0
};
GRUB_MOD_INIT(romfs)
{
grub_fs_register (&grub_romfs_fs);
}
GRUB_MOD_FINI(romfs)
{
grub_fs_unregister (&grub_romfs_fs);
}