/* 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 . */ #include #include #include #include #include #include #include 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_malloc (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); }