grub/fs/cpio.c
2009-06-10 21:04:23 +00:00

371 lines
7 KiB
C

/* cpio.c - cpio and tar filesystem. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2007,2008 Free Software Foundation, Inc.
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include <grub/file.h>
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/disk.h>
#include <grub/dl.h>
#ifndef MODE_USTAR
/* cpio support */
#define MAGIC_BCPIO 070707
struct head
{
grub_uint16_t magic;
grub_uint16_t dev;
grub_uint16_t ino;
grub_uint16_t mode;
grub_uint16_t uid;
grub_uint16_t gid;
grub_uint16_t nlink;
grub_uint16_t rdev;
grub_uint16_t mtime_1;
grub_uint16_t mtime_2;
grub_uint16_t namesize;
grub_uint16_t filesize_1;
grub_uint16_t filesize_2;
} __attribute__ ((packed));
#else
/* tar support */
#define MAGIC_USTAR "ustar"
struct head
{
char name[100];
char mode[8];
char uid[8];
char gid[8];
char size[12];
char mtime[12];
char chksum[8];
char typeflag;
char linkname[100];
char magic[6];
char version[2];
char uname[32];
char gname[32];
char devmajor[8];
char devminor[8];
char prefix[155];
} __attribute__ ((packed));
#endif
struct grub_cpio_data
{
grub_disk_t disk;
grub_uint32_t hofs;
grub_uint32_t dofs;
grub_uint32_t size;
};
static grub_dl_t my_mod;
static grub_err_t
grub_cpio_find_file (struct grub_cpio_data *data, char **name,
grub_uint32_t * ofs)
{
#ifndef MODE_USTAR
struct head hd;
if (grub_disk_read
(data->disk, 0, data->hofs, sizeof (hd), &hd))
return grub_errno;
if (hd.magic != MAGIC_BCPIO)
return grub_error (GRUB_ERR_BAD_FS, "Invalid cpio archive");
data->size = (((grub_uint32_t) hd.filesize_1) << 16) + hd.filesize_2;
if (hd.namesize & 1)
hd.namesize++;
if ((*name = grub_malloc (hd.namesize)) == NULL)
return grub_errno;
if (grub_disk_read (data->disk, 0, data->hofs + sizeof (hd),
hd.namesize, *name))
{
grub_free (*name);
return grub_errno;
}
if (data->size == 0 && hd.mode == 0 && hd.namesize == 11 + 1
&& ! grub_memcmp(*name, "TRAILER!!!", 11))
{
*ofs = 0;
return GRUB_ERR_NONE;
}
data->dofs = data->hofs + sizeof (hd) + hd.namesize;
*ofs = data->dofs + data->size;
if (data->size & 1)
(*ofs)++;
#else
struct head hd;
if (grub_disk_read
(data->disk, 0, data->hofs, sizeof (hd), &hd))
return grub_errno;
if (!hd.name[0])
{
*ofs = 0;
return GRUB_ERR_NONE;
}
if (grub_memcmp (hd.magic, MAGIC_USTAR, sizeof (MAGIC_USTAR) - 1))
return grub_error (GRUB_ERR_BAD_FS, "Invalid tar archive");
if ((*name = grub_strdup (hd.name)) == NULL)
return grub_errno;
data->size = grub_strtoul (hd.size, NULL, 8);
data->dofs = data->hofs + GRUB_DISK_SECTOR_SIZE;
*ofs = data->dofs + ((data->size + GRUB_DISK_SECTOR_SIZE - 1) &
~(GRUB_DISK_SECTOR_SIZE - 1));
#endif
return GRUB_ERR_NONE;
}
static struct grub_cpio_data *
grub_cpio_mount (grub_disk_t disk)
{
struct head hd;
struct grub_cpio_data *data;
if (grub_disk_read (disk, 0, 0, sizeof (hd), &hd))
goto fail;
#ifndef MODE_USTAR
if (hd.magic != MAGIC_BCPIO)
#else
if (grub_memcmp (hd.magic, MAGIC_USTAR,
sizeof (MAGIC_USTAR) - 1))
#endif
goto fail;
data = (struct grub_cpio_data *) grub_malloc (sizeof (*data));
if (!data)
goto fail;
data->disk = disk;
return data;
fail:
grub_error (GRUB_ERR_BAD_FS, "not a "
#ifdef MODE_USTAR
"tar"
#else
"cpio"
#endif
" filesystem");
return 0;
}
static grub_err_t
grub_cpio_dir (grub_device_t device, const char *path,
int (*hook) (const char *filename,
const struct grub_dirhook_info *info))
{
struct grub_cpio_data *data;
grub_uint32_t ofs;
char *prev, *name;
const char *np;
int len;
grub_dl_ref (my_mod);
prev = 0;
data = grub_cpio_mount (device->disk);
if (!data)
goto fail;
np = path + 1;
len = grub_strlen (path) - 1;
data->hofs = 0;
while (1)
{
if (grub_cpio_find_file (data, &name, &ofs))
goto fail;
if (!ofs)
break;
if (grub_memcmp (np, name, len) == 0)
{
char *p, *n;
n = name + len;
if (*n == '/')
n++;
p = grub_strchr (name + len, '/');
if (p)
*p = 0;
if ((!prev) || (grub_strcmp (prev, name) != 0))
{
struct grub_dirhook_info info;
grub_memset (&info, 0, sizeof (info));
info.dir = (p != NULL);
hook (name + len, &info);
if (prev)
grub_free (prev);
prev = name;
}
else
grub_free (name);
}
data->hofs = ofs;
}
fail:
if (prev)
grub_free (prev);
if (data)
grub_free (data);
grub_dl_unref (my_mod);
return grub_errno;
}
static grub_err_t
grub_cpio_open (grub_file_t file, const char *name)
{
struct grub_cpio_data *data;
grub_uint32_t ofs;
char *fn;
int i, j;
grub_dl_ref (my_mod);
data = grub_cpio_mount (file->device->disk);
if (!data)
goto fail;
data->hofs = 0;
while (1)
{
if (grub_cpio_find_file (data, &fn, &ofs))
goto fail;
if (!ofs)
{
grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
break;
}
/* Compare NAME and FN by hand in order to cope with duplicate
slashes. */
i = 1;
j = 0;
while (1)
{
if (name[i] != fn[j])
goto no_match;
if (name[i] == '\0')
break;
if (name[i] == '/' && name[i+1] == '/')
i++;
i++;
j++;
}
file->data = data;
file->size = data->size;
grub_free (fn);
return GRUB_ERR_NONE;
no_match:
grub_free (fn);
data->hofs = ofs;
}
fail:
if (data)
grub_free (data);
grub_dl_unref (my_mod);
return grub_errno;
}
static grub_ssize_t
grub_cpio_read (grub_file_t file, char *buf, grub_size_t len)
{
struct grub_cpio_data *data;
data = file->data;
return (grub_disk_read (data->disk, 0, data->dofs + file->offset,
len, buf)) ? -1 : (grub_ssize_t) len;
}
static grub_err_t
grub_cpio_close (grub_file_t file)
{
grub_free (file->data);
grub_dl_unref (my_mod);
return grub_errno;
}
static struct grub_fs grub_cpio_fs = {
#ifdef MODE_USTAR
.name = "tarfs",
#else
.name = "cpiofs",
#endif
.dir = grub_cpio_dir,
.open = grub_cpio_open,
.read = grub_cpio_read,
.close = grub_cpio_close,
};
#ifdef MODE_USTAR
GRUB_MOD_INIT (cpio)
#else
GRUB_MOD_INIT (tar)
#endif
{
grub_fs_register (&grub_cpio_fs);
my_mod = mod;
}
#ifdef MODE_USTAR
GRUB_MOD_FINI (cpio)
#else
GRUB_MOD_FINI (tar)
#endif
{
grub_fs_unregister (&grub_cpio_fs);
}