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-rw-r--r--grub-core/fs/tar.c345
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);
+}