/* Routines for vectors of uids/gids

   Copyright (C) 1995 Free Software Foundation, Inc.

   Written by Miles Bader <miles@gnu.ai.mit.edu>

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program 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
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

#ifndef __IDVEC_H__
#define __IDVEC_H__

#include <sys/types.h>
#include <errno.h>
#include <hurd/hurd_types.h>

struct idvec 
{
  uid_t *ids;
  unsigned num, alloced;
};

/* Return a new, empty, idvec, or NULL if there wasn't enough memory.  */
struct idvec * make_idvec ();

/* Free's IDVEC, but not the storage pointed to by the IDS field.  */
void idvec_free_wrapper (struct idvec *idvec);

/* Frees IDVEC and any storage associated with it.  */
void idvec_free (struct idvec *idvec);

/* Mark IDVEC as not containing any ids.  */
extern inline void
idvec_clear (struct idvec *idvec)
{
  idvec->num = 0;
}

/* Ensure that IDVEC has enough spaced allocated to hold NUM ids, thus
   ensuring that any subsequent ids added won't return a memory allocation
   error unless it would result in more ids that NUM.  ENOMEM is returned if
   a memory allocation error occurs.  */
error_t idvec_ensure (struct idvec *idvec, unsigned num);

/* Like idvec_ensure(), but takes INC, the increment of the number of ids
   already in IDVEC as an argument.  */
error_t idvec_grow (struct idvec *idvec, unsigned inc);

/* Returns true if IDVEC contains ID, at or after position POS.  */
int idvec_tail_contains (struct idvec *idvec, unsigned pos, uid_t id);

/* Returns true if IDVEC contains ID.  */
int idvec_contains (struct idvec *idvec, uid_t id);

/* Insert ID into IDVEC at position POS, returning ENOMEM if there wasn't
   enough memory, or 0.  */
error_t idvec_insert (struct idvec *idvec, unsigned pos, uid_t id);

/* Add ID onto the end of IDVEC, returning ENOMEM if there's not enough memory,
   or 0.  */
error_t idvec_add (struct idvec *idvec, uid_t id);

/* If IDVEC doesn't contain ID, add it onto the end, returning ENOMEM if
   there's not enough memory; otherwise, do nothing.  */
error_t idvec_add_new (struct idvec *idvec, uid_t id);

/* If IDVEC doesn't contain ID at position POS or after, insert it at POS,
   returning ENOMEM if there's not enough memory; otherwise, do nothing.  */
error_t idvec_insert_new (struct idvec *idvec, unsigned pos, uid_t id);

/* Adds each id in the vector IDS (NUM elements long) to IDVEC, as if with
   idvec_add_new().  */
error_t idvec_merge_ids (struct idvec *idvec, uid_t *ids, unsigned num);

/* EFF and AVAIL should be idvec's corresponding to a processes effective and
   available ids.  ID replaces the first id in EFF, and what it replaces is
   preserved by adding it to AVAIL (if not already present).  If SECURE is
   non-NULL, and ID was not previously present in either EFF or AVAIL, then
   *SECURE is set to true.  ENOMEM is returned if a malloc fails, otherwise
   0.  The return parameters are only touched if this call succeeds.  */
error_t idvec_setid (struct idvec *eff, struct idvec *avail, uid_t id,
		     int *secure);

/* Add to all of EFF_UIDS, AVAIL_UIDS, EFF_GIDS, AVAIL_GIDS (as if with
   idvec_merge) the ids associated with the auth port AUTH.  Any of these
   parameters may be NULL if that information isn't desired.  */
error_t idvec_merge_auth (struct idvec *eff_uids, struct idvec *avail_uids,
			  struct idvec *eff_gids, struct idvec *avail_gids,
			  auth_t auth);

#endif /* __IDVEC_H__ */