lustre/obdclass/idmap.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2016, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/obdclass/idmap.c
  33  *
  34  * Lustre user identity mapping.
  35  *
  36  * Author: Fan Yong <fanyong@clusterfs.com>
  37  */
  38
  39 #define DEBUG_SUBSYSTEM S_SEC
  40
  41 #include <linux/user_namespace.h>
  42 #ifdef HAVE_UIDGID_HEADER
  43 # include <linux/uidgid.h>
  44 #endif
  45 #include <lustre_idmap.h>
  46 #include <upcall_cache.h>
  47 #include <md_object.h>
  48 #include <obd_support.h>
  49
  50 #define lustre_get_group_info(group_info) do {          \
  51         atomic_inc(&(group_info)->usage);               \
  52 } while (0)
  53
  54 #define lustre_put_group_info(group_info) do {          \
  55         if (atomic_dec_and_test(&(group_info)->usage))  \
  56                 groups_free(group_info);                \
  57 } while (0)
  58
  59 /*
  60  * groups_search() is copied from linux kernel!
  61  * A simple bsearch.
  62  */
  63 static int lustre_groups_search(struct group_info *group_info,
  64                                 gid_t grp)
  65 {
  66         int left, right;
  67
  68         if (!group_info)
  69                 return 0;
  70
  71         left = 0;
  72         right = group_info->ngroups;
  73         while (left < right) {
  74                 int mid = (left + right) / 2;
  75                 int cmp = grp -
  76                         from_kgid(&init_user_ns, CFS_GROUP_AT(group_info, mid));
  77
  78                 if (cmp > 0)
  79                         left = mid + 1;
  80                 else if (cmp < 0)
  81                         right = mid;
  82                 else
  83                         return 1;
  84         }
  85         return 0;
  86 }
  87
  88 void lustre_groups_from_list(struct group_info *ginfo, gid_t *glist)
  89 {
  90         int i;
  91         int count = ginfo->ngroups;
  92
  93         /* fill group_info from gid array */
  94         for (i = 0; i < ginfo->nblocks && count > 0; i++) {
  95                 int cp_count = min(CFS_NGROUPS_PER_BLOCK, count);
  96                 int off = i * CFS_NGROUPS_PER_BLOCK;
  97                 int len = cp_count * sizeof(*glist);
  98
  99                 memcpy(ginfo->blocks[i], glist + off, len);
 100                 count -= cp_count;
 101         }
 102 }
 103 EXPORT_SYMBOL(lustre_groups_from_list);
 104
 105 /* groups_sort() is copied from linux kernel! */
 106 /* a simple shell-metzner sort */
 107 void lustre_groups_sort(struct group_info *group_info)
 108 {
 109         int base, max, stride;
 110         int gidsetsize = group_info->ngroups;
 111
 112         for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
 113                 ; /* nothing */
 114         stride /= 3;
 115
 116         while (stride) {
 117                 max = gidsetsize - stride;
 118                 for (base = 0; base < max; base++) {
 119                         int left = base;
 120                         int right = left + stride;
 121                         gid_t tmp = from_kgid(&init_user_ns,
 122                                               CFS_GROUP_AT(group_info, right));
 123
 124                         while (left >= 0 &&
 125                                tmp < from_kgid(&init_user_ns,
 126                                                CFS_GROUP_AT(group_info, left))) {
 127                                 CFS_GROUP_AT(group_info, right) =
 128                                         CFS_GROUP_AT(group_info, left);
 129                                 right = left;
 130                                 left -= stride;
 131                         }
 132                         CFS_GROUP_AT(group_info, right) =
 133                                                 make_kgid(&init_user_ns, tmp);
 134                 }
 135                 stride /= 3;
 136         }
 137 }
 138 EXPORT_SYMBOL(lustre_groups_sort);
 139
 140 int lustre_in_group_p(struct lu_ucred *mu, gid_t grp)
 141 {
 142         int rc = 1;
 143
 144         if (grp != mu->uc_fsgid) {
 145                 struct group_info *group_info = NULL;
 146
 147                 if (mu->uc_ginfo || !mu->uc_identity ||
 148                     mu->uc_valid == UCRED_OLD)
 149                         if (grp == mu->uc_suppgids[0] ||
 150                             grp == mu->uc_suppgids[1])
 151                                 return 1;
 152
 153                 if (mu->uc_ginfo)
 154                         group_info = mu->uc_ginfo;
 155                 else if (mu->uc_identity)
 156                         group_info = mu->uc_identity->mi_ginfo;
 157
 158                 if (!group_info)
 159                         return 0;
 160
 161                 lustre_get_group_info(group_info);
 162                 rc = lustre_groups_search(group_info, grp);
 163                 lustre_put_group_info(group_info);
 164         }
 165         return rc;
 166 }
 167 EXPORT_SYMBOL(lustre_in_group_p);