diff options
Diffstat (limited to 'grub-core/fs/tar.c')
| -rw-r--r-- | grub-core/fs/tar.c | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/grub-core/fs/tar.c b/grub-core/fs/tar.c new file mode 100644 index 0000000..c551ed6 --- /dev/null +++ b/grub-core/fs/tar.c @@ -0,0 +1,345 @@ +/* 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/misc.h> +#include <grub/disk.h> +#include <grub/archelp.h> + +#include <grub/file.h> +#include <grub/mm.h> +#include <grub/dl.h> +#include <grub/i18n.h> + +GRUB_MOD_LICENSE ("GPLv3+"); + +/* tar support */ +#define MAGIC "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]; +} GRUB_PACKED; + +static inline unsigned long long +read_number (const char *str, grub_size_t size) +{ + unsigned long long ret = 0; + while (size-- && *str >= '0' && *str <= '7') + ret = (ret << 3) | (*str++ & 0xf); + return ret; +} + +struct grub_archelp_data +{ + grub_disk_t disk; + grub_off_t hofs, next_hofs; + grub_off_t dofs; + grub_off_t size; + char *linkname; + grub_size_t linkname_alloc; +}; + +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; + int reread = 0, have_longname = 0, have_longlink = 0; + + data->hofs = data->next_hofs; + + for (reread = 0; reread < 3; reread++) + { + if (grub_disk_read (data->disk, 0, data->hofs, sizeof (hd), &hd)) + return grub_errno; + + if (!hd.name[0] && !hd.prefix[0]) + { + *mode = GRUB_ARCHELP_ATTR_END; + return GRUB_ERR_NONE; + } + + if (grub_memcmp (hd.magic, MAGIC, sizeof (MAGIC) - 1)) + return grub_error (GRUB_ERR_BAD_FS, "invalid tar archive"); + + if (hd.typeflag == 'L') + { + grub_err_t err; + grub_size_t namesize = read_number (hd.size, sizeof (hd.size)); + *name = grub_malloc (namesize + 1); + if (*name == NULL) + return grub_errno; + err = grub_disk_read (data->disk, 0, + data->hofs + GRUB_DISK_SECTOR_SIZE, namesize, + *name); + (*name)[namesize] = 0; + if (err) + return err; + data->hofs += GRUB_DISK_SECTOR_SIZE + + ((namesize + GRUB_DISK_SECTOR_SIZE - 1) & + ~(GRUB_DISK_SECTOR_SIZE - 1)); + have_longname = 1; + continue; + } + + if (hd.typeflag == 'K') + { + grub_err_t err; + grub_size_t linksize = read_number (hd.size, sizeof (hd.size)); + if (data->linkname_alloc < linksize + 1) + { + char *n; + n = grub_calloc (2, linksize + 1); + if (!n) + return grub_errno; + grub_free (data->linkname); + data->linkname = n; + data->linkname_alloc = 2 * (linksize + 1); + } + + err = grub_disk_read (data->disk, 0, + data->hofs + GRUB_DISK_SECTOR_SIZE, linksize, + data->linkname); + if (err) + return err; + data->linkname[linksize] = 0; + data->hofs += GRUB_DISK_SECTOR_SIZE + + ((linksize + GRUB_DISK_SECTOR_SIZE - 1) & + ~(GRUB_DISK_SECTOR_SIZE - 1)); + have_longlink = 1; + continue; + } + + if (!have_longname) + { + grub_size_t extra_size = 0; + + while (extra_size < sizeof (hd.prefix) + && hd.prefix[extra_size]) + extra_size++; + *name = grub_malloc (sizeof (hd.name) + extra_size + 2); + if (*name == NULL) + return grub_errno; + if (hd.prefix[0]) + { + grub_memcpy (*name, hd.prefix, extra_size); + (*name)[extra_size++] = '/'; + } + grub_memcpy (*name + extra_size, hd.name, sizeof (hd.name)); + (*name)[extra_size + sizeof (hd.name)] = 0; + } + + data->size = read_number (hd.size, sizeof (hd.size)); + data->dofs = data->hofs + GRUB_DISK_SECTOR_SIZE; + data->next_hofs = data->dofs + ((data->size + GRUB_DISK_SECTOR_SIZE - 1) & + ~(GRUB_DISK_SECTOR_SIZE - 1)); + if (mtime) + *mtime = read_number (hd.mtime, sizeof (hd.mtime)); + if (mode) + { + *mode = read_number (hd.mode, sizeof (hd.mode)); + switch (hd.typeflag) + { + /* Hardlink. */ + case '1': + /* Symlink. */ + case '2': + *mode |= GRUB_ARCHELP_ATTR_LNK; + break; + case '0': + *mode |= GRUB_ARCHELP_ATTR_FILE; + break; + case '5': + *mode |= GRUB_ARCHELP_ATTR_DIR; + break; + } + } + if (!have_longlink) + { + if (data->linkname_alloc < 101) + { + char *n; + n = grub_malloc (101); + if (!n) + return grub_errno; + grub_free (data->linkname); + data->linkname = n; + data->linkname_alloc = 101; + } + grub_memcpy (data->linkname, hd.linkname, sizeof (hd.linkname)); + data->linkname[100] = 0; + } + return GRUB_ERR_NONE; + } + return GRUB_ERR_NONE; +} + +static char * +grub_cpio_get_link_target (struct grub_archelp_data *data) +{ + return grub_strdup (data->linkname); +} + +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)) + 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 tarfs 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->linkname); + 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->linkname); + 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->linkname); + grub_free (data); + + return grub_errno; +} + +static struct grub_fs grub_cpio_fs = { + .name = "tarfs", + .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 +}; + +GRUB_MOD_INIT (tar) +{ + grub_fs_register (&grub_cpio_fs); +} + +GRUB_MOD_FINI (tar) +{ + grub_fs_unregister (&grub_cpio_fs); +} |