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.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2012, 2014, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/obdclass/idmap.c
  37  *
  38  * Lustre user identity mapping.
  39  *
  40  * Author: Fan Yong <fanyong@clusterfs.com>
  41  */
  42
  43 #define DEBUG_SUBSYSTEM S_SEC
  44
  45 #include <linux/user_namespace.h>
  46 #ifdef HAVE_UIDGID_HEADER
  47 # include <linux/uidgid.h>
  48 #endif
  49 #include <lustre_idmap.h>
  50 #include <upcall_cache.h>
  51 #include <md_object.h>
  52 #include <obd_support.h>
  53
  54 #define lustre_get_group_info(group_info) do {          \
  55         atomic_inc(&(group_info)->usage);               \
  56 } while (0)
  57
  58 #define lustre_put_group_info(group_info) do {          \
  59         if (atomic_dec_and_test(&(group_info)->usage))  \
  60                 groups_free(group_info);                \
  61 } while (0)
  62
  63 /*
  64  * groups_search() is copied from linux kernel!
  65  * A simple bsearch.
  66  */
  67 static int lustre_groups_search(struct group_info *group_info,
  68                                 gid_t grp)
  69 {
  70         int left, right;
  71
  72         if (!group_info)
  73                 return 0;
  74
  75         left = 0;
  76         right = group_info->ngroups;
  77         while (left < right) {
  78                 int mid = (left + right) / 2;
  79                 int cmp = grp -
  80                         from_kgid(&init_user_ns, CFS_GROUP_AT(group_info, mid));
  81
  82                 if (cmp > 0)
  83                         left = mid + 1;
  84                 else if (cmp < 0)
  85                         right = mid;
  86                 else
  87                         return 1;
  88         }
  89         return 0;
  90 }
  91
  92 void lustre_groups_from_list(struct group_info *ginfo, gid_t *glist)
  93 {
  94         int i;
  95         int count = ginfo->ngroups;
  96
  97         /* fill group_info from gid array */
  98         for (i = 0; i < ginfo->nblocks && count > 0; i++) {
  99                 int cp_count = min(CFS_NGROUPS_PER_BLOCK, count);
 100                 int off = i * CFS_NGROUPS_PER_BLOCK;
 101                 int len = cp_count * sizeof(*glist);
 102
 103                 memcpy(ginfo->blocks[i], glist + off, len);
 104                 count -= cp_count;
 105         }
 106 }
 107 EXPORT_SYMBOL(lustre_groups_from_list);
 108
 109 /* groups_sort() is copied from linux kernel! */
 110 /* a simple shell-metzner sort */
 111 void lustre_groups_sort(struct group_info *group_info)
 112 {
 113         int base, max, stride;
 114         int gidsetsize = group_info->ngroups;
 115
 116         for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
 117                 ; /* nothing */
 118         stride /= 3;
 119
 120         while (stride) {
 121                 max = gidsetsize - stride;
 122                 for (base = 0; base < max; base++) {
 123                         int left = base;
 124                         int right = left + stride;
 125                         gid_t tmp = from_kgid(&init_user_ns,
 126                                               CFS_GROUP_AT(group_info, right));
 127
 128                         while (left >= 0 &&
 129                                tmp < from_kgid(&init_user_ns,
 130                                                CFS_GROUP_AT(group_info, left))) {
 131                                 CFS_GROUP_AT(group_info, right) =
 132                                         CFS_GROUP_AT(group_info, left);
 133                                 right = left;
 134                                 left -= stride;
 135                         }
 136                         CFS_GROUP_AT(group_info, right) =
 137                                                 make_kgid(&init_user_ns, tmp);
 138                 }
 139                 stride /= 3;
 140         }
 141 }
 142 EXPORT_SYMBOL(lustre_groups_sort);
 143
 144 int lustre_in_group_p(struct lu_ucred *mu, gid_t grp)
 145 {
 146         int rc = 1;
 147
 148         if (grp != mu->uc_fsgid) {
 149                 struct group_info *group_info = NULL;
 150
 151                 if (mu->uc_ginfo || !mu->uc_identity ||
 152                     mu->uc_valid == UCRED_OLD)
 153                         if (grp == mu->uc_suppgids[0] ||
 154                             grp == mu->uc_suppgids[1])
 155                                 return 1;
 156
 157                 if (mu->uc_ginfo)
 158                         group_info = mu->uc_ginfo;
 159                 else if (mu->uc_identity)
 160                         group_info = mu->uc_identity->mi_ginfo;
 161
 162                 if (!group_info)
 163                         return 0;
 164
 165                 lustre_get_group_info(group_info);
 166                 rc = lustre_groups_search(group_info, grp);
 167                 lustre_put_group_info(group_info);
 168         }
 169         return rc;
 170 }
 171 EXPORT_SYMBOL(lustre_in_group_p);