error_t
iohelp_restrict_iouser (struct iouser **new_user,
			const struct iouser *old_user,
			const uid_t *uids, int nuids,
			const gid_t *gids, int ngids)
{
  if (idvec_contains (old_user->uids, 0))
    /* OLD_USER has root access, and so may use any ids.  */
    return iohelp_create_complex_iouser (new_user, uids, nuids, gids, ngids);
  else
    {
      struct idvec *uvec, *gvec;
      int i;
      error_t err;

      uvec = make_idvec ();
      if (! uvec)
        return ENOMEM;

      gvec = make_idvec ();
      if (! gvec)
        {
	  idvec_free (uvec);
	  return ENOMEM;
	}

      /* Otherwise, use any of the requested ids that OLD_USER already has.  */
      for (i = 0; i < old_user->uids->num; i++)
	if (listmember (uids, old_user->uids->ids[i], nuids))
	  {
	    err = idvec_add (uvec, old_user->uids->ids[i]);
	    if (err)
	      goto out;
	  }
      for (i = 0; i < old_user->gids->num; i++)
	if (listmember (gids, old_user->gids->ids[i], ngids))
	  {
	    err = idvec_add (gvec, old_user->gids->ids[i]);
	    if (err)
	      goto out;
	  }

      err = iohelp_create_iouser (new_user, uvec, gvec);

      if (err)
        {
        out:
	  idvec_free (uvec);
	  idvec_free (gvec);
	}
      return err;
    }
}
kern_return_t
trivfs_S_io_restrict_auth (struct trivfs_protid *cred,
			   mach_port_t reply,
			   mach_msg_type_name_t replytype,
			   mach_port_t *newport,
			   mach_msg_type_name_t *newporttype,
			   uid_t *uids, size_t nuids,
			   uid_t *gids, size_t ngids)
{
  int i;
  error_t err;
  struct trivfs_protid *newcred;
  struct idvec *uvec, *gvec;
  struct iouser *user;

  if (!cred)
    return EOPNOTSUPP;

  if (cred->isroot)
    /* CRED has root access, and so may use any ids.  */
    {
      err = iohelp_create_complex_iouser (&user, uids, nuids, gids, ngids);
      if (err)
        return err;
    }
  else
    {
      uvec = make_idvec ();
      if (! uvec)
        return ENOMEM;

      gvec = make_idvec ();
      if (! gvec)
        {
	  idvec_free (uvec);
	  return ENOMEM;
	}

      /* Otherwise, use any of the requested ids that CRED already has.  */
      for (i = 0; i < cred->user->uids->num; i++)
	if (listmember (uids, cred->user->uids->ids[i], nuids))
	  {
	    err = idvec_add (uvec, cred->user->uids->ids[i]);
	    if (err)
	      goto out;
	  }

      for (i = 0; i < cred->user->gids->num; i++)
	if (listmember (gids, cred->user->gids->ids[i], ngids))
	  {
	    err = idvec_add (gvec, cred->user->gids->ids[i]);
	    if (err)
	      goto out;
	  }

      err = iohelp_create_iouser (&user, uvec, gvec);
      if (err)
        {
	out:
	  idvec_free (uvec);
	  idvec_free (gvec);
	  return err;
	}
    }

  err = ports_create_port (cred->po->cntl->protid_class,
			   cred->po->cntl->protid_bucket,
			   sizeof (struct trivfs_protid),
			   &newcred);
  if (err)
    {
      iohelp_free_iouser (user);
      return err;
    }

  newcred->isroot = 0;
  mutex_lock (&cred->po->cntl->lock);
  newcred->po = cred->po;
  newcred->po->refcnt++;
  mutex_unlock (&cred->po->cntl->lock);
  if (cred->isroot && idvec_contains (user->uids, 0))
    newcred->isroot = 1;
  newcred->user = user;
  newcred->hook = cred->hook;

  err = io_restrict_auth (cred->realnode, &newcred->realnode,
			  user->uids->ids, user->uids->num,
			  user->gids->ids, user->gids->num);
  if (!err && trivfs_protid_create_hook)
    {
      err = (*trivfs_protid_create_hook) (newcred);
      if (err)
	mach_port_deallocate (mach_task_self (), newcred->realnode);
    }

  if (err)
    /* Signal that the user destroy hook shouldn't be called on NEWCRED.  */
    newcred->realnode = MACH_PORT_NULL;
  else
    {
      *newport = ports_get_right (newcred);
      *newporttype = MACH_MSG_TYPE_MAKE_SEND;
    }

  /* This will destroy NEWCRED if we got an error and didn't do the
     ports_get_right above.  */
  ports_port_deref (newcred);

  return 0;
}
/* Return in FILE & FILE_TYPE the file in FSYS corresponding to the NFS file
   handle HANDLE & HANDLE_LEN.  */
error_t
diskfs_S_fsys_getfile (mach_port_t fsys,
		       mach_port_t reply, mach_msg_type_name_t reply_type,
		       uid_t *uids, mach_msg_type_number_t nuids,
		       gid_t *gids, mach_msg_type_number_t ngids,
		       char *handle, mach_msg_type_number_t handle_len,
		       mach_port_t *file, mach_msg_type_name_t *file_type)
{
  int flags;
  error_t err;
  struct node *node;
  const union diskfs_fhandle *f;
  struct protid *new_cred;
  struct peropen *new_po;
  struct iouser *user;
  struct port_info *pt =
    ports_lookup_port (diskfs_port_bucket, fsys, diskfs_control_class);

  if (!pt)
    return EOPNOTSUPP;

  if (handle_len != sizeof *f)
    {
      ports_port_deref (pt);
      return EINVAL;
    }

  f = (const union diskfs_fhandle *) handle;

  err = diskfs_cached_lookup (f->data.cache_id, &node);
  if (err)
    {
      ports_port_deref (pt);
      return err;
    }

  if (node->dn_stat.st_gen != f->data.gen)
    {
      diskfs_nput (node);
      ports_port_deref (pt);
      return ESTALE;
    }

  err = iohelp_create_complex_iouser (&user, uids, nuids, gids, ngids);
  if (err)
    {
      diskfs_nput (node);
      ports_port_deref (pt);
      return err;
    }

  flags = 0;
  if (! fshelp_access (&node->dn_stat, S_IREAD, user))
    flags |= O_READ;
  if (! fshelp_access (&node->dn_stat, S_IEXEC, user))
    flags |= O_EXEC;
  if (! fshelp_access (&node->dn_stat, S_IWRITE, user)
      && ! S_ISDIR (node->dn_stat.st_mode)
      && ! diskfs_check_readonly ())
    flags |= O_WRITE;

  err = diskfs_make_peropen (node, flags, 0, &new_po);
  if (! err)
    {
      err = diskfs_create_protid (new_po, user, &new_cred);
      if (err)
	diskfs_release_peropen (new_po);
    }

  iohelp_free_iouser (user);

  diskfs_nput (node);
  ports_port_deref (pt);

  if (! err)
    {
      *file = ports_get_right (new_cred);
      *file_type = MACH_MSG_TYPE_MAKE_SEND;
    }

  return err;
}
Beispiel #4
0
kern_return_t
trivfs_S_fsys_getroot (struct trivfs_control *cntl,
		       mach_port_t reply_port,
		       mach_msg_type_name_t reply_port_type,
		       mach_port_t dotdot,
		       uid_t *uids, size_t nuids,
		       uid_t *gids, size_t ngids,
		       int flags,
		       retry_type *do_retry,
		       char *retry_name,
		       mach_port_t *newpt,
		       mach_msg_type_name_t *newpttype)
{
  int perms;
  error_t err = 0;
  mach_port_t new_realnode;
  struct trivfs_protid *cred;
  struct iouser *user;

  if (!cntl)
    return EOPNOTSUPP;

  if (trivfs_getroot_hook)
    {
      err = (*trivfs_getroot_hook) (cntl, reply_port, reply_port_type, dotdot,
				    uids, nuids, gids, ngids, flags,
				    do_retry, retry_name, newpt, newpttype);
      if (err != EAGAIN)
	return err;
    }

  if ((flags & O_WRITE & trivfs_allow_open) != (flags & O_WRITE))
    return EROFS;
  if ((flags & (O_READ|O_WRITE|O_EXEC) & trivfs_allow_open)
      != (flags & (O_READ|O_WRITE|O_EXEC)))
    return EACCES;

  /* O_CREAT and O_EXCL are not meaningful here; O_NOLINK and O_NOTRANS
     will only be useful when trivfs supports translators (which it doesn't
     now). */
  flags &= O_HURD;
  flags &= ~(O_CREAT|O_EXCL|O_NOLINK|O_NOTRANS);

  struct idvec idvec = {
    .ids = uids,
    .num = nuids,
    .alloced = nuids,
  };

  if (_is_privileged (&idvec))
    /* Privileged users should be given all our rights.  */
    err = io_duplicate (cntl->underlying, &new_realnode);
  else
    /* Non-privileged, restrict rights.  */
    err = io_restrict_auth (cntl->underlying,
			    &new_realnode, uids, nuids, gids, ngids);

  if (err)
    return err;

  err = iohelp_create_complex_iouser (&user, uids, nuids, gids, ngids);
  if (err)
    return err;

  /* Validate permissions.  */
  if (! trivfs_check_access_hook)
    file_check_access (new_realnode, &perms);
  else
    (*trivfs_check_access_hook) (cntl, user, new_realnode, &perms);
  if ((flags & (O_READ|O_WRITE|O_EXEC) & perms)
      != (flags & (O_READ|O_WRITE|O_EXEC)))
    err = EACCES;

  if (!err && trivfs_check_open_hook)
    err = (*trivfs_check_open_hook) (cntl, user, flags);
  if (!err)
    {
      if (! trivfs_open_hook)
	{
	  err = trivfs_open (cntl, user, flags, new_realnode, &cred);
	  if (!err)
	    mach_port_deallocate (mach_task_self (), dotdot);
	}
      else
	err = (*trivfs_open_hook) (cntl, user, dotdot, flags, new_realnode,
				   &cred);
    }

  if (err)
    {
      mach_port_deallocate (mach_task_self (), new_realnode);
      iohelp_free_iouser (user);
    }
  else
    {
      *do_retry = FS_RETRY_NORMAL;
      *retry_name = '\0';
      *newpt = ports_get_right (cred);
      *newpttype = MACH_MSG_TYPE_MAKE_SEND;
      ports_port_deref (cred);
    }

  return err;
}