/*      $NetBSD: umap_subr.c,v 1.29 2014/11/09 18:08:07 maxv Exp $      */

/*
* Copyright (c) 1999 National Aeronautics & Space Administration
* All rights reserved.
*
* This software was written by William Studenmund of the
* Numerical Aerospace Simulation Facility, NASA Ames Research Center.
*
* 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 National Aeronautics & Space Administration
*    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 NATIONAL AERONAUTICS & SPACE ADMINISTRATION
* ``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 ADMINISTRATION OR CONTRIB-
* UTORS 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.
*/
/*
* Copyright (c) 1992, 1993, 1995
*      The Regents of the University of California.  All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* 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.
*
*      from: Id: lofs_subr.c, v 1.11 1992/05/30 10:05:43 jsp Exp
*      @(#)umap_subr.c 8.9 (Berkeley) 5/14/95
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: umap_subr.c,v 1.29 2014/11/09 18:08:07 maxv Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/kauth.h>

#include <miscfs/specfs/specdev.h>
#include <miscfs/umapfs/umap.h>

u_long umap_findid(u_long, u_long [][2], int);
int umap_node_alloc(struct mount *, struct vnode *,
                               struct vnode **);

/*
* umap_findid is called by various routines in umap_vnodeops.c to
* find a user or group id in a map.
*/
u_long
umap_findid(u_long id, u_long map[][2], int nentries)
{
       int i;

       /* Find uid entry in map */
       i = 0;
       while ((i<nentries) && ((map[i][0]) != id))
               i++;

       if (i < nentries)
               return (map[i][1]);
       else
               return (-1);

}

/*
* umap_reverse_findid is called by umap_getattr() in umap_vnodeops.c to
* find a user or group id in a map, in reverse.
*/
u_long
umap_reverse_findid(u_long id, u_long map[][2], int nentries)
{
       int i;

       /* Find uid entry in map */
       i = 0;
       while ((i<nentries) && ((map[i][1]) != id))
               i++;

       if (i < nentries)
               return (map[i][0]);
       else
               return (-1);

}

/* umap_mapids maps all of the ids in a credential, both user and group. */

void
umap_mapids(struct mount *v_mount, kauth_cred_t credp)
{
       int i, unentries, gnentries;
       uid_t uid;
       gid_t gid;
       u_long (*usermap)[2], (*groupmap)[2];
       gid_t groups[NGROUPS];
       uint16_t ngroups;

       if (credp == NOCRED || credp == FSCRED)
               return;

       unentries =  MOUNTTOUMAPMOUNT(v_mount)->info_nentries;
       usermap =  MOUNTTOUMAPMOUNT(v_mount)->info_mapdata;
       gnentries =  MOUNTTOUMAPMOUNT(v_mount)->info_gnentries;
       groupmap =  MOUNTTOUMAPMOUNT(v_mount)->info_gmapdata;

       /* Find uid entry in map */

       uid = (uid_t) umap_findid(kauth_cred_geteuid(credp), usermap, unentries);

       if (uid != -1)
               kauth_cred_seteuid(credp, uid);
       else
               kauth_cred_seteuid(credp, (uid_t)NOBODY);

#if 1
       /* cr_gid is the same as cr_groups[0] in 4BSD, but not in NetBSD */

       /* Find gid entry in map */

       gid = (gid_t) umap_findid(kauth_cred_getegid(credp), groupmap, gnentries);

       if (gid != -1)
               kauth_cred_setegid(credp, gid);
       else
               kauth_cred_setegid(credp, NULLGROUP);
#endif

       /* Now we must map each of the set of groups in the cr_groups
               structure. */

       ngroups = kauth_cred_ngroups(credp);
       for (i = 0; i < ngroups; i++) {
               /* XXX elad: can't we just skip cases where gid == -1? */
               groups[i] = kauth_cred_group(credp, i);
               gid = (gid_t) umap_findid(groups[i],
                                         groupmap, gnentries);
               if (gid != -1)
                       groups[i] = gid;
               else
                       groups[i] = NULLGROUP;
       }

       kauth_cred_setgroups(credp, groups, ngroups, -1, UIO_SYSSPACE);
}