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, 2017, 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 /*
  51  * groups_search() is copied from linux kernel!
  52  * A simple bsearch.
  53  */
  54 static int lustre_groups_search(struct group_info *group_info,
  55                                 gid_t grp)
  56 {
  57         int left, right;
  58
  59         if (!group_info)
  60                 return 0;
  61
  62         left = 0;
  63         right = group_info->ngroups;
  64         while (left < right) {
  65                 int mid = (left + right) / 2;
  66                 int cmp = grp -
  67                         from_kgid(&init_user_ns, CFS_GROUP_AT(group_info, mid));
  68
  69                 if (cmp > 0)
  70                         left = mid + 1;
  71                 else if (cmp < 0)
  72                         right = mid;
  73                 else
  74                         return 1;
  75         }
  76         return 0;
  77 }
  78
  79 void lustre_groups_from_list(struct group_info *ginfo, gid_t *glist)
  80 {
  81 #ifdef HAVE_GROUP_INFO_GID
  82         memcpy(ginfo->gid, glist, ginfo->ngroups * sizeof(__u32));
  83 #else
  84         int i;
  85         int count = ginfo->ngroups;
  86
  87         /* fill group_info from gid array */
  88         for (i = 0; i < ginfo->nblocks && count > 0; i++) {
  89                 int cp_count = min(CFS_NGROUPS_PER_BLOCK, count);
  90                 int off = i * CFS_NGROUPS_PER_BLOCK;
  91                 int len = cp_count * sizeof(*glist);
  92
  93                 memcpy(ginfo->blocks[i], glist + off, len);
  94                 count -= cp_count;
  95         }
  96 #endif
  97 }
  98 EXPORT_SYMBOL(lustre_groups_from_list);
  99
 100 /* groups_sort() is copied from linux kernel! */
 101 /* a simple shell-metzner sort */
 102 void lustre_groups_sort(struct group_info *group_info)
 103 {
 104         int base, max, stride;
 105         int gidsetsize = group_info->ngroups;
 106
 107         for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
 108                 ; /* nothing */
 109         stride /= 3;
 110
 111         while (stride) {
 112                 max = gidsetsize - stride;
 113                 for (base = 0; base < max; base++) {
 114                         int left = base;
 115                         int right = left + stride;
 116                         gid_t tmp = from_kgid(&init_user_ns,
 117                                               CFS_GROUP_AT(group_info, right));
 118
 119                         while (left >= 0 &&
 120                                tmp < from_kgid(&init_user_ns,
 121                                                CFS_GROUP_AT(group_info, left))) {
 122                                 CFS_GROUP_AT(group_info, right) =
 123                                         CFS_GROUP_AT(group_info, left);
 124                                 right = left;
 125                                 left -= stride;
 126                         }
 127                         CFS_GROUP_AT(group_info, right) =
 128                                                 make_kgid(&init_user_ns, tmp);
 129                 }
 130                 stride /= 3;
 131         }
 132 }
 133 EXPORT_SYMBOL(lustre_groups_sort);
 134
 135 int lustre_in_group_p(struct lu_ucred *mu, gid_t grp)
 136 {
 137         int rc = 1;
 138
 139         if (grp != mu->uc_fsgid) {
 140                 struct group_info *group_info = NULL;
 141
 142                 if (mu->uc_ginfo || !mu->uc_identity ||
 143                     mu->uc_valid == UCRED_OLD)
 144                         if (grp == mu->uc_suppgids[0] ||
 145                             grp == mu->uc_suppgids[1])
 146                                 return 1;
 147
 148                 if (mu->uc_ginfo)
 149                         group_info = mu->uc_ginfo;
 150                 else if (mu->uc_identity)
 151                         group_info = mu->uc_identity->mi_ginfo;
 152
 153                 if (!group_info)
 154                         return 0;
 155
 156                 atomic_inc(&group_info->usage);
 157                 rc = lustre_groups_search(group_info, grp);
 158                 if (atomic_dec_and_test(&group_info->usage))
 159                         groups_free(group_info);
 160         }
 161         return rc;
 162 }
 163 EXPORT_SYMBOL(lustre_in_group_p);