kernel/syscall/groups.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T
  23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27
  28 #include <sys/param.h>
  29 #include <sys/types.h>
  30 #include <sys/sysmacros.h>
  31 #include <sys/systm.h>
  32 #include <sys/cred.h>
  33 #include <sys/sid.h>
  34 #include <sys/errno.h>
  35 #include <sys/proc.h>
  36 #include <sys/debug.h>
  37 #include <sys/kmem.h>
  38 #include <sys/policy.h>
  39
  40 int
  41 setgroups(int gidsetsize, gid_t *gidset)
  42 {
  43         proc_t  *p;
  44         cred_t  *cr, *newcr;
  45         int     i;
  46         int     n = gidsetsize;
  47         int     error;
  48         int     scnt = 0;
  49         ksidlist_t *ksl = NULL;
  50         zone_t  *zone;
  51         struct credgrp *grps = NULL;
  52
  53         /* Perform the cheapest tests before grabbing p_crlock  */
  54         if (n > ngroups_max || n < 0)
  55                 return (set_errno(EINVAL));
  56
  57         zone = crgetzone(CRED());
  58         if (n != 0) {
  59                 const gid_t *groups;
  60
  61                 grps = crgrpcopyin(n, gidset);
  62
  63                 if (grps == NULL)
  64                         return (set_errno(EFAULT));
  65
  66                 groups = crgetggroups(grps);
  67
  68                 for (i = 0; i < n; i++) {
  69                         if (!VALID_GID(groups[i], zone)) {
  70                                 crgrprele(grps);
  71                                 return (set_errno(EINVAL));
  72                         }
  73                         if (groups[i] > MAXUID)
  74                                 scnt++;
  75                 }
  76                 if (scnt > 0) {
  77                         ksl = kcrsid_gidstosids(zone, n, (gid_t *)groups);
  78                         if (ksl == NULL) {
  79                                 crgrprele(grps);
  80                                 return (set_errno(EINVAL));
  81                         }
  82                 }
  83         }
  84
  85
  86         /*
  87          * Need to pre-allocate the new cred structure before acquiring
  88          * the p_crlock mutex.
  89          */
  90         newcr = cralloc_ksid();
  91         p = ttoproc(curthread);
  92         mutex_enter(&p->p_crlock);
  93 retry:
  94         cr = p->p_cred;
  95         crhold(cr);
  96         mutex_exit(&p->p_crlock);
  97
  98         if ((error = secpolicy_allow_setid(cr, -1, B_FALSE)) != 0) {
  99                 if (grps != NULL)
 100                         crgrprele(grps);
 101                 if (ksl != NULL)
 102                         ksidlist_rele(ksl);
 103                 crfree(newcr);
 104                 crfree(cr);
 105                 return (set_errno(error));
 106         }
 107         mutex_enter(&p->p_crlock);
 108         crfree(cr);
 109         if (cr != p->p_cred)
 110                 goto retry;
 111
 112         crdup_to(cr, newcr);
 113         crsetsidlist(newcr, ksl);
 114         crsetcredgrp(newcr, grps);
 115
 116         p->p_cred = newcr;
 117         crhold(newcr);                  /* hold for the current thread */
 118         crfree(cr);                     /* free the old one */
 119         mutex_exit(&p->p_crlock);
 120
 121         /*
 122          * Broadcast new cred to process threads (including the current one).
 123          */
 124         crset(p, newcr);
 125
 126         return (0);
 127 }
 128
 129 int
 130 getgroups(int gidsetsize, gid_t *gidset)
 131 {
 132         struct cred *cr;
 133         int n;
 134
 135         cr = curthread->t_cred;
 136         n = crgetngroups(cr);
 137
 138         if (gidsetsize != 0) {
 139                 if (gidsetsize < n)
 140                         return (set_errno(EINVAL));
 141                 if (copyout(crgetgroups(cr), gidset, n * sizeof (gid_t)))
 142                         return (set_errno(EFAULT));
 143         }
 144
 145         return (n);
 146 }