/* Support code for dealing with priorities in the Hurd.

   Copyright (C) 1994-2018 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/resource.h>

#include <sys/mman.h>

#include <unistd.h>

error_t

_hurd_priority_which_map (enum __priority_which which, int who,

			  error_t (*function) (pid_t, struct procinfo *),

			  int pi_flags)

{

  mach_msg_type_number_t npids = 64, i;

  pid_t pidbuf[npids], *pids = pidbuf;

  error_t err;

  struct procinfo *pip;

  int pibuf[sizeof *pip + 5 * sizeof (pip->threadinfos[0])], *pi = pibuf;

  mach_msg_type_number_t pisize = sizeof (pibuf) / sizeof (int);

  switch (which)

    {

    default:

      return EINVAL;

    case PRIO_PROCESS:

      err = (*function) (who ?: getpid (), 0); /* XXX special-case self? */

      break;

    case PRIO_PGRP:

      err = __USEPORT (PROC, __proc_getpgrppids (port, who, &pids, &npids));

      for (i = 0; !err && i < npids; ++i)

	err = (*function) (pids[i], 0);

      break;

    case PRIO_USER:

      if (who == 0)

	who = __geteuid ();

      err = __USEPORT (PROC, __proc_getallpids (port, &pids, &npids));

      for (i = 0; !err && i < npids; ++i)

	{

	  /* Get procinfo to check the owner.  */

	  int *oldpi = pi;

	  mach_msg_type_number_t oldpisize = pisize;

	  char *tw = 0;

	  size_t twsz = 0;

	  err = __USEPORT (PROC, __proc_getprocinfo (port, pids[i],

						     &pi_flags,

						     &pi, &pisize,

						     &tw, &twsz));

	  if (!err)

	    {

	      if (twsz)		/* Gratuitous.  */

		__munmap (tw, twsz);

	      if (pi != oldpi && oldpi != pibuf)

		/* Old buffer from last call was not reused; free it.  */

		__munmap (oldpi, oldpisize * sizeof pi[0]);

	      pip = (struct procinfo *) pi;

	      if (pip->owner == (uid_t) who)

		err = (*function) (pids[i], pip);

	    }

	}

      break;

    }

  if (pids != pidbuf)

    __munmap (pids, npids * sizeof pids[0]);

  if (pi != pibuf)

    __munmap (pi, pisize * sizeof pi[0]);

  return err;

}