diff options
Diffstat (limited to 'grub-core/fs/cpio_common.c')
| -rw-r--r-- | grub-core/fs/cpio_common.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/grub-core/fs/cpio_common.c b/grub-core/fs/cpio_common.c new file mode 100644 index 0000000..4e885d6 --- /dev/null +++ b/grub-core/fs/cpio_common.c @@ -0,0 +1,253 @@ +/* cpio.c - cpio and tar filesystem. */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2007,2008,2009,2013 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> +#include <grub/i18n.h> +#include <grub/archelp.h> + +GRUB_MOD_LICENSE ("GPLv3+"); + +struct grub_archelp_data +{ + grub_disk_t disk; + grub_off_t hofs; + grub_off_t next_hofs; + grub_off_t dofs; + grub_off_t size; +}; + +#if __GNUC__ >= 9 +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Waddress-of-packed-member" +#endif + +static grub_err_t +grub_cpio_find_file (struct grub_archelp_data *data, char **name, + grub_int32_t *mtime, grub_uint32_t *mode) +{ + struct head hd; + grub_size_t namesize; + grub_uint32_t modeval; + + data->hofs = data->next_hofs; + + if (grub_disk_read (data->disk, 0, data->hofs, sizeof (hd), &hd)) + return grub_errno; + + if (grub_memcmp (hd.magic, MAGIC, sizeof (hd.magic)) != 0 +#ifdef MAGIC2 + && grub_memcmp (hd.magic, MAGIC2, sizeof (hd.magic)) != 0 +#endif + ) + return grub_error (GRUB_ERR_BAD_FS, "invalid cpio archive"); + data->size = read_number (hd.filesize, ARRAY_SIZE (hd.filesize)); + if (mtime) + *mtime = read_number (hd.mtime, ARRAY_SIZE (hd.mtime)); + modeval = read_number (hd.mode, ARRAY_SIZE (hd.mode)); + namesize = read_number (hd.namesize, ARRAY_SIZE (hd.namesize)); + + /* Don't allow negative numbers. */ + if (namesize >= 0x80000000) + { + /* Probably a corruption, don't attempt to recover. */ + *mode = GRUB_ARCHELP_ATTR_END; + return GRUB_ERR_NONE; + } + + *mode = modeval; + + *name = grub_malloc (namesize + 1); + if (*name == NULL) + return grub_errno; + + if (grub_disk_read (data->disk, 0, data->hofs + sizeof (hd), + namesize, *name)) + { + grub_free (*name); + return grub_errno; + } + (*name)[namesize] = 0; + + if (data->size == 0 && modeval == 0 && namesize == 11 + && grub_memcmp(*name, "TRAILER!!!", 11) == 0) + { + *mode = GRUB_ARCHELP_ATTR_END; + grub_free (*name); + return GRUB_ERR_NONE; + } + + data->dofs = data->hofs + ALIGN_CPIO (sizeof (hd) + namesize); + data->next_hofs = data->dofs + ALIGN_CPIO (data->size); + return GRUB_ERR_NONE; +} + +#if __GNUC__ >= 9 +#pragma GCC diagnostic pop +#endif + +static char * +grub_cpio_get_link_target (struct grub_archelp_data *data) +{ + char *ret; + grub_err_t err; + + if (data->size == 0) + return grub_strdup (""); + ret = grub_malloc (data->size + 1); + if (!ret) + return NULL; + + err = grub_disk_read (data->disk, 0, data->dofs, data->size, + ret); + if (err) + { + grub_free (ret); + return NULL; + } + ret[data->size] = '\0'; + return ret; +} + +static void +grub_cpio_rewind (struct grub_archelp_data *data) +{ + data->next_hofs = 0; +} + +static struct grub_archelp_ops arcops = + { + .find_file = grub_cpio_find_file, + .get_link_target = grub_cpio_get_link_target, + .rewind = grub_cpio_rewind + }; + +static struct grub_archelp_data * +grub_cpio_mount (grub_disk_t disk) +{ + struct head hd; + struct grub_archelp_data *data; + + if (grub_disk_read (disk, 0, 0, sizeof (hd), &hd)) + goto fail; + + if (grub_memcmp (hd.magic, MAGIC, sizeof (MAGIC) - 1) +#ifdef MAGIC2 + && grub_memcmp (hd.magic, MAGIC2, sizeof (MAGIC2) - 1) +#endif + ) + goto fail; + + data = (struct grub_archelp_data *) grub_zalloc (sizeof (*data)); + if (!data) + goto fail; + + data->disk = disk; + + return data; + +fail: + grub_error (GRUB_ERR_BAD_FS, "not a " FSNAME " filesystem"); + return 0; +} + +static grub_err_t +grub_cpio_dir (grub_device_t device, const char *path_in, + grub_fs_dir_hook_t hook, void *hook_data) +{ + struct grub_archelp_data *data; + grub_err_t err; + + data = grub_cpio_mount (device->disk); + if (!data) + return grub_errno; + + err = grub_archelp_dir (data, &arcops, + path_in, hook, hook_data); + + grub_free (data); + + return err; +} + +static grub_err_t +grub_cpio_open (grub_file_t file, const char *name_in) +{ + struct grub_archelp_data *data; + grub_err_t err; + + data = grub_cpio_mount (file->device->disk); + if (!data) + return grub_errno; + + err = grub_archelp_open (data, &arcops, name_in); + if (err) + { + grub_free (data); + } + else + { + file->data = data; + file->size = data->size; + } + return err; +} + +static grub_ssize_t +grub_cpio_read (grub_file_t file, char *buf, grub_size_t len) +{ + struct grub_archelp_data *data; + grub_ssize_t ret; + + data = file->data; + data->disk->read_hook = file->read_hook; + data->disk->read_hook_data = file->read_hook_data; + + ret = (grub_disk_read (data->disk, 0, data->dofs + file->offset, + len, buf)) ? -1 : (grub_ssize_t) len; + data->disk->read_hook = 0; + + return ret; +} + +static grub_err_t +grub_cpio_close (grub_file_t file) +{ + struct grub_archelp_data *data; + + data = file->data; + grub_free (data); + + return grub_errno; +} + +static struct grub_fs grub_cpio_fs = { + .name = FSNAME, + .fs_dir = grub_cpio_dir, + .fs_open = grub_cpio_open, + .fs_read = grub_cpio_read, + .fs_close = grub_cpio_close, +#ifdef GRUB_UTIL + .reserved_first_sector = 0, + .blocklist_install = 0, +#endif +}; |