module/os/linux/spl/spl-cred.c

   1 /*
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *
  10  *  The SPL is free software; you can redistribute it and/or modify it
  11  *  under the terms of the GNU General Public License as published by the
  12  *  Free Software Foundation; either version 2 of the License, or (at your
  13  *  option) any later version.
  14  *
  15  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  16  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18  *  for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  22  *
  23  *  Solaris Porting Layer (SPL) Credential Implementation.
  24  */
  25
  26 #include <sys/cred.h>
  27
  28 static int
  29 cr_groups_search(const struct group_info *group_info, kgid_t grp)
  30 {
  31         unsigned int left, right, mid;
  32         int cmp;
  33
  34         if (!group_info)
  35                 return (0);
  36
  37         left = 0;
  38         right = group_info->ngroups;
  39         while (left < right) {
  40                 mid = (left + right) / 2;
  41                 cmp = KGID_TO_SGID(grp) -
  42                     KGID_TO_SGID(GROUP_AT(group_info, mid));
  43
  44                 if (cmp > 0)
  45                         left = mid + 1;
  46                 else if (cmp < 0)
  47                         right = mid;
  48                 else
  49                         return (1);
  50         }
  51         return (0);
  52 }
  53
  54 /* Hold a reference on the credential */
  55 void
  56 crhold(cred_t *cr)
  57 {
  58         (void) get_cred((const cred_t *)cr);
  59 }
  60
  61 /* Free a reference on the credential */
  62 void
  63 crfree(cred_t *cr)
  64 {
  65         put_cred((const cred_t *)cr);
  66 }
  67
  68 /* Return the number of supplemental groups */
  69 int
  70 crgetngroups(const cred_t *cr)
  71 {
  72         struct group_info *gi;
  73         int rc;
  74
  75         gi = cr->group_info;
  76         rc = gi->ngroups;
  77
  78         return (rc);
  79 }
  80
  81 /*
  82  * Return an array of supplemental gids.  The returned address is safe
  83  * to use as long as the caller has taken a reference with crhold().
  84  */
  85 gid_t *
  86 crgetgroups(const cred_t *cr)
  87 {
  88         struct group_info *gi;
  89         gid_t *gids = NULL;
  90
  91         gi = cr->group_info;
  92         gids = KGIDP_TO_SGIDP(gi->gid);
  93
  94         return (gids);
  95 }
  96
  97 /* Check if the passed gid is available in supplied credential. */
  98 int
  99 groupmember(gid_t gid, const cred_t *cr)
 100 {
 101         struct group_info *gi;
 102         int rc;
 103
 104         gi = cr->group_info;
 105         rc = cr_groups_search(gi, SGID_TO_KGID(gid));
 106
 107         return (rc);
 108 }
 109
 110 /* Return the effective user id */
 111 uid_t
 112 crgetuid(const cred_t *cr)
 113 {
 114         return (KUID_TO_SUID(cr->fsuid));
 115 }
 116
 117 /* Return the real user id */
 118 uid_t
 119 crgetruid(const cred_t *cr)
 120 {
 121         return (KUID_TO_SUID(cr->uid));
 122 }
 123
 124 /* Return the effective group id */
 125 gid_t
 126 crgetgid(const cred_t *cr)
 127 {
 128         return (KGID_TO_SGID(cr->fsgid));
 129 }
 130
 131 /* Return the initial user ns or nop_mnt_idmap */
 132 zidmap_t *
 133 zfs_get_init_idmap(void)
 134 {
 135 #ifdef HAVE_IOPS_CREATE_IDMAP
 136         return ((zidmap_t *)&nop_mnt_idmap);
 137 #else
 138         return ((zidmap_t *)&init_user_ns);
 139 #endif
 140 }
 141
 142 EXPORT_SYMBOL(zfs_get_init_idmap);
 143 EXPORT_SYMBOL(crhold);
 144 EXPORT_SYMBOL(crfree);
 145 EXPORT_SYMBOL(crgetuid);
 146 EXPORT_SYMBOL(crgetruid);
 147 EXPORT_SYMBOL(crgetgid);
 148 EXPORT_SYMBOL(crgetngroups);
 149 EXPORT_SYMBOL(crgetgroups);
 150 EXPORT_SYMBOL(groupmember);