Re: [PATCH] * grub-core/fs/udf.c: Add support for UUID

["Pali Rohár" <pali.rohar@gmail.com>]

Hi! I would like to remind this patch. It allows to use UUID of UDF
partition in grub2. Linux tool blkid is already able to handle it, so it
is possible to specify UUID of UDF partition in /etc/fstab.

UDF is filesystem used on optical disks (DVD), but also on hard disks as
it is natively supported by Windows, Linux and Mac OS X kernels. Which
is a good benefit for multi-boot environment.

On Monday 10 April 2017 20:35:30 Pali Rohár wrote:
> Use same algorithm as in libblkid from util-linux.
> ---
>  grub-core/fs/udf.c |  136 ++++++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 131 insertions(+), 5 deletions(-)
> 
> diff --git a/grub-core/fs/udf.c b/grub-core/fs/udf.c
> index 839bff8..a4baa4c 100644
> --- a/grub-core/fs/udf.c
> +++ b/grub-core/fs/udf.c
> @@ -321,6 +321,32 @@ struct grub_udf_partmap
>    };
>  } GRUB_PACKED;
>  
> +struct grub_udf_pvd
> +{
> +  struct grub_udf_tag tag;
> +  grub_uint32_t seq_num;
> +  grub_uint32_t pvd_num;
> +  grub_uint8_t ident[32];
> +  grub_uint16_t vol_seq_num;
> +  grub_uint16_t max_vol_seq_num;
> +  grub_uint16_t interchange_level;
> +  grub_uint16_t max_interchange_level;
> +  grub_uint32_t charset_list;
> +  grub_uint32_t max_charset_list;
> +  grub_uint8_t volset_ident[128];
> +  struct grub_udf_charspec desc_charset;
> +  struct grub_udf_charspec expl_charset;
> +  struct grub_udf_extent_ad vol_abstract;
> +  struct grub_udf_extent_ad vol_copyright;
> +  struct grub_udf_regid app_ident;
> +  struct grub_udf_timestamp recording_time;
> +  struct grub_udf_regid imp_ident;
> +  grub_uint8_t imp_use[64];
> +  grub_uint32_t pred_vds_loc;
> +  grub_uint16_t flags;
> +  grub_uint8_t reserved[22];
> +} GRUB_PACKED;
> +
>  struct grub_udf_lvd
>  {
>    struct grub_udf_tag tag;
> @@ -348,6 +374,7 @@ struct grub_udf_aed
>  struct grub_udf_data
>  {
>    grub_disk_t disk;
> +  struct grub_udf_pvd pvd;
>    struct grub_udf_lvd lvd;
>    struct grub_udf_pd pds[GRUB_UDF_MAX_PDS];
>    struct grub_udf_partmap *pms[GRUB_UDF_MAX_PMS];
> @@ -692,7 +719,17 @@ grub_udf_mount (grub_disk_t disk)
>  	}
>  
>        tag.tag_ident = U16 (tag.tag_ident);
> -      if (tag.tag_ident == GRUB_UDF_TAG_IDENT_PD)
> +      if (tag.tag_ident == GRUB_UDF_TAG_IDENT_PVD)
> +	{
> +	  if (grub_disk_read (disk, block << lbshift, 0,
> +			      sizeof (struct grub_udf_pvd),
> +			      &data->pvd))
> +	    {
> +	      grub_error (GRUB_ERR_BAD_FS, "not an UDF filesystem");
> +	      goto fail;
> +	    }
> +	}
> +      else if (tag.tag_ident == GRUB_UDF_TAG_IDENT_PD)
>  	{
>  	  if (data->npd >= GRUB_UDF_MAX_PDS)
>  	    {
> @@ -821,7 +858,7 @@ grub_udf_get_cluster_sector (grub_disk_t disk, grub_uint64_t *sec_per_lcn)
>  #endif
>  
>  static char *
> -read_string (const grub_uint8_t *raw, grub_size_t sz, char *outbuf)
> +read_string (const grub_uint8_t *raw, grub_size_t sz, char *outbuf, int normalize_utf8)
>  {
>    grub_uint16_t *utf16 = NULL;
>    grub_size_t utf16len = 0;
> @@ -832,6 +869,15 @@ read_string (const grub_uint8_t *raw, grub_size_t sz, char *outbuf)
>    if (raw[0] != 8 && raw[0] != 16)
>      return NULL;
>  
> +  if (raw[0] == 8 && !normalize_utf8)
> +    {
> +      if (!outbuf)
> +        outbuf = grub_strndup ((char *)raw + 1, sz - 1);
> +      else
> +        grub_memcpy (outbuf, raw + 1, sz - 1);
> +      return outbuf;
> +    }
> +
>    if (raw[0] == 8)
>      {
>        unsigned i;
> @@ -923,7 +969,7 @@ grub_udf_iterate_dir (grub_fshelp_node_t dir,
>  		  != dirent.file_ident_length)
>  		return 0;
>  
> -	      filename = read_string (raw, dirent.file_ident_length, 0);
> +	      filename = read_string (raw, dirent.file_ident_length, 0, 1);
>  	      if (!filename)
>  		grub_print_error ();
>  
> @@ -1009,7 +1055,7 @@ grub_udf_read_symlink (grub_fshelp_node_t node)
>  	  /* in 4 + n bytes. out, at most: 1 + 2 * n bytes.  */
>  	  if (optr != out)
>  	    *optr++ = '/';
> -	  if (!read_string (ptr + 4, s - 4, optr))
> +	  if (!read_string (ptr + 4, s - 4, optr, 1))
>  	    goto fail;
>  	  optr += grub_strlen (optr);
>  	  break;
> @@ -1197,7 +1243,7 @@ grub_udf_label (grub_device_t device, char **label)
>  
>    if (data)
>      {
> -      *label = read_string (data->lvd.ident, sizeof (data->lvd.ident), 0);
> +      *label = read_string (data->lvd.ident, sizeof (data->lvd.ident), 0, 1);
>        grub_free (data);
>      }
>    else
> @@ -1206,6 +1252,85 @@ grub_udf_label (grub_device_t device, char **label)
>    return grub_errno;
>  }
>  
> +static char *
> +gen_uuid_from_volset (char *volset_ident)
> +{
> +  grub_size_t i;
> +  grub_size_t len;
> +  grub_size_t binpos;
> +  grub_uint8_t buf[17];
> +  char *uuid;
> +
> +  len = grub_strlen (volset_ident);
> +  if (len < 8)
> +    return NULL;
> +
> +  uuid = grub_malloc (17);
> +  if (!uuid)
> +    return NULL;
> +
> +  if (len > 16)
> +    len = 16;
> +
> +  grub_memset (buf, 0, sizeof (buf));
> +  grub_memcpy (buf, volset_ident, len);
> +
> +  binpos = 16;
> +  for (i = 0; i < len; ++i)
> +    {
> +      if (!grub_isalnum (buf[i]))
> +        {
> +          binpos = i;
> +          break;
> +        }
> +    }
> +
> +  if (binpos < 8)
> +    {
> +      grub_snprintf (uuid, 17, "%02x%02x%02x%02x%02x%02x%02x%02x",
> +                    buf[0], buf[1], buf[2], buf[3],
> +                    buf[4], buf[5], buf[6], buf[7]);
> +    }
> +  else if (binpos < 16)
> +    {
> +      grub_memcpy (uuid, buf, 8);
> +      grub_snprintf (uuid+8, 9, "%02x%02x%02x%02x",
> +                    buf[8], buf[9], buf[10], buf[11]);
> +    }
> +  else
> +    {
> +      grub_memcpy (uuid, buf, 16);
> +      uuid[16] = 0;
> +    }
> +
> +  return uuid;
> +}
> +
> +static grub_err_t
> +grub_udf_uuid (grub_device_t device, char **uuid)
> +{
> +  char *volset_ident;
> +  struct grub_udf_data *data;
> +  data = grub_udf_mount (device->disk);
> +
> +  if (data)
> +    {
> +      volset_ident = read_string (data->pvd.volset_ident, sizeof (data->pvd.volset_ident), 0, 0);
> +      if (volset_ident)
> +        {
> +          *uuid = gen_uuid_from_volset (volset_ident);
> +          grub_free (volset_ident);
> +        }
> +      else
> +        *uuid = 0;
> +      grub_free (data);
> +    }
> +  else
> +    *uuid = 0;
> +
> +  return grub_errno;
> +}
> +
>  static struct grub_fs grub_udf_fs = {
>    .name = "udf",
>    .dir = grub_udf_dir,
> @@ -1213,6 +1338,7 @@ static struct grub_fs grub_udf_fs = {
>    .read = grub_udf_read,
>    .close = grub_udf_close,
>    .label = grub_udf_label,
> +  .uuid = grub_udf_uuid,
>  #ifdef GRUB_UTIL
>    .reserved_first_sector = 1,
>    .blocklist_install = 1,

-- 
Pali Rohár
pali.rohar@gmail.com