/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)ucred.h     8.4 (Berkeley) 1/9/95
 * $FreeBSD: src/sys/sys/ucred.h,v 1.14.2.5 2002/03/09 05:20:25 dd Exp $
 * $DragonFly: src/sys/sys/ucred.h,v 1.9 2007/01/08 21:32:57 corecode Exp $
 */

#ifndef _SYS_UCRED_H_
#define _SYS_UCRED_H_

#ifndef _SYS_TYPES_H_
#include <sys/types.h>
#endif
#ifndef _SYS_PARAM_H_
#include <sys/param.h>
#endif
#ifndef _SYS_CAPS_H_
#include <sys/caps.h>
#endif
#ifndef _SYS_SPINLOCK_H_
#include <sys/spinlock.h>
#endif

struct prison;

/*
 * Credentials.
 *
 * Please do not inspect cr_uid directly to determine superuserness.
 * Only the priv(9) functions should be used for this.
 *
 * NOTE: Creds are accessed a lot, and cr_ref is also adjusted a lot.
 *       This can ping-pong fields in its cache line that are otherwise
 *       read-only.  To solve this problem we note that even in really
 *       busy systems, ucred isn't replicated a whole lot.  So put
 *       the blasted cr_ref in its own cache line.
 */
struct ucred {
        struct {
                long    cr_ref;         /* reference count */
        } __cachealign;
        uid_t   cr_uid;                 /* effective user id */
        short   cr_ngroups;             /* number of groups */
        gid_t   cr_groups[NGROUPS];     /* groups */
        struct  uidinfo *cr_uidinfo;    /* per uid resource consumption */
        struct  uidinfo *cr_ruidinfo;   /* per ruid resource consumption */
        struct  prison *cr_prison;      /* prison info */
        uid_t   cr_ruid;                /* Real user id. */
        uid_t   cr_svuid;               /* Saved effective user id. */
        gid_t   cr_rgid;                /* Real group id. */
        gid_t   cr_svgid;               /* Saved effective group id. */
        __syscaps_t cr_caps;            /* System restrictions */
} __cachealign;

#define cr_gid cr_groups[0]
#define NOCRED ((struct ucred *)0)      /* no credential available */
#define FSCRED ((struct ucred *)-1)     /* filesystem credential */

/*
 * This is the external representation of struct ucred, based upon the
 * size of a 4.2-RELEASE struct ucred.  There will probably never be
 * any need to change the size of this or layout of its used fields.
 */
struct xucred {
        u_int   cr_version;             /* structure layout version */
        uid_t   cr_uid;                 /* effective user id */
        short   cr_ngroups;             /* number of groups */
        gid_t   cr_groups[NGROUPS];     /* groups */
        void    *_cr_unused1;           /* compatibility with old ucred */
};
#define XUCRED_VERSION  0

#ifdef _KERNEL

struct proc;

struct ucred    *change_euid (uid_t euid);
struct ucred    *change_ruid (uid_t ruid);
struct ucred    *cratom (struct ucred **pcr);
struct ucred    *cratom_proc (struct proc *p);
struct ucred    *crcopy (struct ucred *cr);
struct ucred    *crdup (struct ucred *cr);
struct ucred    *crdup_nocaps (struct ucred *cr);
void            crfree (struct ucred *cr);
struct ucred    *crget (void);
struct ucred    *crhold (struct ucred *cr);
void            cru2x (struct ucred *cr, struct xucred *xcr);
int             groupmember (gid_t gid, struct ucred *cred);
#endif /* _KERNEL */

#endif /* !_SYS_UCRED_H_ */