sys/sys/ucred.h

   1 /*
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)ucred.h     8.4 (Berkeley) 1/9/95
  30  * $FreeBSD: src/sys/sys/ucred.h,v 1.14.2.5 2002/03/09 05:20:25 dd Exp $
  31  * $DragonFly: src/sys/sys/ucred.h,v 1.9 2007/01/08 21:32:57 corecode Exp $
  32  */
  33
  34 #ifndef _SYS_UCRED_H_
  35 #define _SYS_UCRED_H_
  36
  37 #ifndef _SYS_TYPES_H_
  38 #include <sys/types.h>
  39 #endif
  40 #ifndef _SYS_PARAM_H_
  41 #include <sys/param.h>
  42 #endif
  43 #ifndef _SYS_SPINLOCK_H_
  44 #include <sys/spinlock.h>
  45 #endif
  46
  47 struct prison;
  48
  49 /*
  50  * Credentials.
  51  *
  52  * Please do not inspect cr_uid directly to determine superuserness.
  53  * Only the priv(9) functions should be used for this.
  54  *
  55  * NOTE: Creds are accessed a lot, and cr_ref is also adjusted a lot.
  56  *       This can ping-pong fields in its cache line that are otherwise
  57  *       read-only.  To solve this problem we note that even in really
  58  *       busy systems, ucred isn't replicated a whole lot.  So put
  59  *       the blasted cr_ref in its own cache line.
  60  */
  61 struct ucred {
  62         struct {
  63                 long    cr_ref;         /* reference count */
  64         } __cachealign;
  65         uid_t   cr_uid;                 /* effective user id */
  66         short   cr_ngroups;             /* number of groups */
  67         gid_t   cr_groups[NGROUPS];     /* groups */
  68         struct  uidinfo *cr_uidinfo;    /* per uid resource consumption */
  69         struct  uidinfo *cr_ruidinfo;   /* per ruid resource consumption */
  70         struct  prison *cr_prison;      /* prison info */
  71         uid_t   cr_ruid;                /* Real user id. */
  72         uid_t   cr_svuid;               /* Saved effective user id. */
  73         gid_t   cr_rgid;                /* Real group id. */
  74         gid_t   cr_svgid;               /* Saved effective group id. */
  75 } __cachealign;
  76
  77 #define cr_gid cr_groups[0]
  78 #define NOCRED ((struct ucred *)0)      /* no credential available */
  79 #define FSCRED ((struct ucred *)-1)     /* filesystem credential */
  80
  81 /*
  82  * This is the external representation of struct ucred, based upon the
  83  * size of a 4.2-RELEASE struct ucred.  There will probably never be
  84  * any need to change the size of this or layout of its used fields.
  85  */
  86 struct xucred {
  87         u_int   cr_version;             /* structure layout version */
  88         uid_t   cr_uid;                 /* effective user id */
  89         short   cr_ngroups;             /* number of groups */
  90         gid_t   cr_groups[NGROUPS];     /* groups */
  91         void    *_cr_unused1;           /* compatibility with old ucred */
  92 };
  93 #define XUCRED_VERSION  0
  94
  95 #ifdef _KERNEL
  96
  97 struct proc;
  98
  99 struct ucred    *change_euid (uid_t euid);
 100 struct ucred    *change_ruid (uid_t ruid);
 101 struct ucred    *cratom (struct ucred **pcr);
 102 struct ucred    *cratom_proc (struct proc *p);
 103 struct ucred    *crcopy (struct ucred *cr);
 104 struct ucred    *crdup (struct ucred *cr);
 105 void            crfree (struct ucred *cr);
 106 void            crinit (struct ucred *cr);
 107 struct ucred    *crget (void);
 108 struct ucred    *crhold (struct ucred *cr);
 109 void            cru2x (struct ucred *cr, struct xucred *xcr);
 110 int             groupmember (gid_t gid, struct ucred *cred);
 111 #endif /* _KERNEL */
 112
 113 #endif /* !_SYS_UCRED_H_ */