smbclient tar restore problem (linkflag) from tape-drive

[Peter Wood]

Greetings,

I am currently having a problem using smbclient (Samba v2.05a) 
running on Solaris 2.5.1 to restore a tar file from a tape drive
onto a Win NT share.

smbclient works successfully when using a tar file on disk, 
but is skipping the tar file (created by a third party) 
on the tape drive.

The command used is as follows:

smbclient //celeborn/test -U peter -T x /dev/rmt/0

The problem seems to be that the linkflag obtained from the 
tape drive is not handled and the file is skipped. The 
linkflag appears to be NULL - the code wonders whether it 
could be a "gnu tar archive?". 

>From reading the code in "clitar.c" the current linkflag 
values that are currently handled are: '0', '5', and 'L'.  
If the linkflag is any other value (eg NULL) the file is skipped.

I have exprimented with substituting the code for linkflag case '0'
for the default case and removing the "skip_file" - the restore then 
works, but as I do not know the details of what the tar linkflag is, 
I am unsure how safe this is to do.

Any hints or comments gratefully accepted.

Peter






The relevant debug messages, and code follow:
-----------------------------------------------


(1) DEBUG MESSAGES

...
Reading the next header ...
checksum totals chk=5786 fchk=5786 chksum= 13232
firstb=805D9, secondb=A3E80, len=40
Warning: NULL link flag (gnu tar archive ?) \a\508_c_rle.ps.gz
Skip = 0, cliplist=<NULL>, file=\a\508_c_rle.ps.gz
Skiping file. Size = 2231512
Advancing to next block: a3e80
...


(2) CODE SNIPPETS from "clitar.c"


In clitar.c the problem appears to be due to the linkflag:

  /* can't handle some links at present */
  if ((hb->dbuf.linkflag != '0') && (hb -> dbuf.linkflag != '5')) {
    if (hb->dbuf.linkflag == 0) {
      DEBUG(6, ("Warning: NULL link flag (gnu tar archive ?) %s\n",
		finfo->name));

...

In the following code, since linkflag is NULL, it switches to the "default" case, 
which is to skip the file.

  linkflag = ((union hblock *)buffer_p) -> dbuf.linkflag;

    switch (linkflag) {

    case '0':  /* Should use symbolic names--FIXME */

      /* 
       * Skip to the next block first, so we can get the file, FIXME, should
       * be in get_file ...
       * The 'finfo.size != 0' fix is from Bob Boehmer <boehmer at worldnet.att.net>
       * Fixes bug where file size in tarfile is zero.
       */

      if ((finfo.size != 0) && next_block(tarbuf, &buffer_p, tbufsiz) <=0) {
	DEBUG(0, ("Short file, bailing out...\n"));
	return;
      }
      if (!get_file(finfo)) {
	DEBUG(0, ("Abandoning restore\n"));
	return;

      }
      break;

    case '5':
      if (!get_dir(finfo)) {
	DEBUG(0, ("Abandoning restore \n"));
	return;
      }
      break;

    case 'L':
      longfilename = get_longfilename(finfo);
      if (!longfilename) {
	DEBUG(0, ("abandoning restore\n"));
	return;

      }
      DEBUG(5, ("Long file name: %s\n", longfilename));
      break;

    default:

      skip_file(finfo.size);  /* Don't handle these yet */
      break;

    }

  }