/* Copyright (C) 1991-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <hurd.h>

#include <hurd/msg_server.h>

#include <hurd/id.h>

#include <string.h>

int

_hurd_refport_secure_p (mach_port_t ref)

{

  if (ref == __mach_task_self ())

    return 1;

  if (__USEPORT (AUTH, ref == port))

    return 1;

  return 0;

}

kern_return_t

_S_msg_add_auth (mach_port_t me,

		 auth_t addauth)

{

  error_t err;

  auth_t newauth;

  uid_t *genuids, *gengids, *auxuids, *auxgids;

  mach_msg_type_number_t ngenuids, ngengids, nauxuids, nauxgids;

  uid_t *newgenuids, *newgengids, *newauxuids, *newauxgids;

  mach_msg_type_number_t nnewgenuids, nnewgengids, nnewauxuids, nnewauxgids;

  /* Create a list of ids and store it in NEWLISTP, length NEWLISTLEN.

     Keep all the ids in EXIST (len NEXIST), adding in those from NEW

     (len NNEW) which are not already there.  */

  error_t make_list (uid_t **newlistp, mach_msg_type_number_t *newlistlen,

		     uid_t *exist, mach_msg_type_number_t nexist,

		     uid_t *new, mach_msg_type_number_t nnew)

    {

      error_t urp;

      int i, j, k;

      vm_size_t offset;

      urp = __vm_allocate (mach_task_self (), (vm_address_t *) newlistp,

			   nexist + nnew * sizeof (uid_t), 1);

      if (urp)

	return urp;

      j = 0;

      for (i = 0; i < nexist; i++)

	(*newlistp)[j++] = exist[i];

      for (i = 0; i < nnew; i++)

	{

	  for (k = 0; k < nexist; k++)

	    if (exist[k] == new[i])

	      break;

	  if (k < nexist)

	    continue;

	  (*newlistp)[j++] = new[i];

	}

      offset = (round_page (nexist + nnew * sizeof (uid_t))

		- round_page (j * sizeof (uid_t)));

      if (offset)

	__vm_deallocate (mach_task_self (),

		         (vm_address_t) (*newlistp

				         + (nexist + nnew * sizeof (uid_t))),

		         offset);

      *newlistlen = j;

      return 0;

    }

  /* Find out what ids ADDAUTH refers to */

  genuids = gengids = auxuids = auxgids = 0;

  ngenuids = ngengids = nauxuids = nauxgids = 0;

  err = __auth_getids (addauth,

		       &genuids, &ngenuids,

		       &auxuids, &nauxuids,

		       &gengids, &ngengids,

		       &auxgids, &nauxgids);

  if (err)

    return err;

  /* OR in these ids to what we already have, creating a new list. */

  HURD_CRITICAL_BEGIN;

  __mutex_lock (&_hurd_id.lock);

  _hurd_check_ids ();

#define MAKE(genaux,uidgid) 						    \

  make_list (&new ## genaux ## uidgid ## s, 				    \

	     &nnew ## genaux ## uidgid ## s,				    \

	     _hurd_id.genaux.uidgid ## s,				    \

	     _hurd_id.genaux.n ## uidgid ## s,				    \

	     genaux ## uidgid ## s,					    \

	     n ## genaux ## uidgid ## s)

  err = MAKE (gen, uid);

  if (!err)

    MAKE (aux, uid);

  if (!err)

    MAKE (gen, gid);

  if (!err)

    MAKE (aux, gid);

#undef MAKE

  __mutex_unlock (&_hurd_id.lock);

  HURD_CRITICAL_END;

  /* Create the new auth port */

  if (!err)

    err = __USEPORT (AUTH,

		     __auth_makeauth (port,

				      &addauth, MACH_MSG_TYPE_MOVE_SEND, 1,

				      newgenuids, nnewgenuids,

				      newauxuids, nnewauxuids,

				      newgengids, nnewgengids,

				      newauxgids, nnewauxgids,

				      &newauth));

#define freeup(array, len) \

  if (array) \

    __vm_deallocate (mach_task_self (), (vm_address_t) array, \

		     len * sizeof (uid_t));

  freeup (genuids, ngenuids);

  freeup (auxuids, nauxuids);

  freeup (gengids, ngengids);

  freeup (auxgids, nauxgids);

  freeup (newgenuids, nnewgenuids);

  freeup (newauxuids, nnewauxuids);

  freeup (newgengids, nnewgengids);

  freeup (newauxgids, nnewauxgids);

#undef freeup

  if (err)

    return err;

  /* And install it. */

  err = __setauth (newauth);

  __mach_port_deallocate (__mach_task_self (), newauth);

  if (err)

    return errno;

  return 0;

}

kern_return_t

_S_msg_del_auth (mach_port_t me,

		 task_t task,

		 intarray_t uids, mach_msg_type_number_t nuids,

		 intarray_t gids, mach_msg_type_number_t ngids)

{

  error_t err;

  auth_t newauth;

  if (!_hurd_refport_secure_p (task))

    return EPERM;

  HURD_CRITICAL_BEGIN;

  __mutex_lock (&_hurd_id.lock);

  err = _hurd_check_ids ();

  if (!err)

    {

      size_t i, j;

      size_t nu = _hurd_id.gen.nuids, ng = _hurd_id.gen.ngids;

      uid_t newu[nu];

      gid_t newg[ng];

      memcpy (newu, _hurd_id.gen.uids, nu * sizeof (uid_t));

      memcpy (newg, _hurd_id.gen.gids, ng * sizeof (gid_t));

      for (j = 0; j < nuids; ++j)

	{

	  const uid_t uid = uids[j];

	  for (i = 0; i < nu; ++i)

	    if (newu[i] == uid)

	      /* Move the last uid into this slot, and decrease the

		 number of uids so the last slot is no longer used.  */

	      newu[i] = newu[--nu];

	}

      __vm_deallocate (__mach_task_self (),

		       (vm_address_t) uids, nuids * sizeof (uid_t));

      for (j = 0; j < ngids; ++j)

	{

	  const gid_t gid = gids[j];

	  for (i = 0; i < nu; ++i)

	    if (newu[i] == gid)

	      /* Move the last gid into this slot, and decrease the

		 number of gids so the last slot is no longer used.  */

	      newu[i] = newu[--nu];

	}

      __vm_deallocate (__mach_task_self (),

		       (vm_address_t) gids, ngids * sizeof (gid_t));

      err = __USEPORT (AUTH, __auth_makeauth

		       (port,

			NULL, MACH_MSG_TYPE_COPY_SEND, 0,

			newu, nu,

			_hurd_id.aux.uids, _hurd_id.aux.nuids,

			newg, ng,

			_hurd_id.aux.uids, _hurd_id.aux.ngids,

			&newauth));

    }

  __mutex_unlock (&_hurd_id.lock);

  HURD_CRITICAL_END;

  if (err)

    return err;

  err = __setauth (newauth);

  __mach_port_deallocate (__mach_task_self (), newauth);

  if (err)

    return errno;

  return 0;

}