drivers/staging/lustre/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, 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 <lustre_idmap.h>
  46 #include <md_object.h>
  47 #include <obd_support.h>
  48
  49 #define lustre_get_group_info(group_info) do {       \
  50         atomic_inc(&(group_info)->usage);             \
  51 } while (0)
  52
  53 #define lustre_put_group_info(group_info) do {       \
  54         if (atomic_dec_and_test(&(group_info)->usage)) \
  55                 groups_free(group_info);               \
  56 } while (0)
  57
  58 /*
  59  * groups_search() is copied from linux kernel!
  60  * A simple bsearch.
  61  */
  62 static int lustre_groups_search(group_info_t *group_info,
  63                                 gid_t grp)
  64 {
  65         int left, right;
  66
  67         if (!group_info)
  68                 return 0;
  69
  70         left = 0;
  71         right = group_info->ngroups;
  72         while (left < right) {
  73                 int mid = (left + right) / 2;
  74                 int cmp = grp -
  75                         from_kgid(&init_user_ns, CFS_GROUP_AT(group_info, mid));
  76
  77                 if (cmp > 0)
  78                         left = mid + 1;
  79                 else if (cmp < 0)
  80                         right = mid;
  81                 else
  82                         return 1;
  83         }
  84         return 0;
  85 }
  86
  87 void lustre_groups_from_list(group_info_t *ginfo, gid_t *glist)
  88 {
  89         int i;
  90         int count = ginfo->ngroups;
  91
  92         /* fill group_info from gid array */
  93         for (i = 0; i < ginfo->nblocks && count > 0; i++) {
  94                 int cp_count = min(CFS_NGROUPS_PER_BLOCK, count);
  95                 int off = i * CFS_NGROUPS_PER_BLOCK;
  96                 int len = cp_count * sizeof(*glist);
  97
  98                 memcpy(ginfo->blocks[i], glist + off, len);
  99                 count -= cp_count;
 100         }
 101 }
 102 EXPORT_SYMBOL(lustre_groups_from_list);
 103
 104 /* groups_sort() is copied from linux kernel! */
 105 /* a simple shell-metzner sort */
 106 void lustre_groups_sort(group_info_t *group_info)
 107 {
 108         int base, max, stride;
 109         int gidsetsize = group_info->ngroups;
 110
 111         for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
 112                 ; /* nothing */
 113         stride /= 3;
 114
 115         while (stride) {
 116                 max = gidsetsize - stride;
 117                 for (base = 0; base < max; base++) {
 118                         int left = base;
 119                         int right = left + stride;
 120                         gid_t tmp = from_kgid(&init_user_ns,
 121                                               CFS_GROUP_AT(group_info, right));
 122
 123                         while (left >= 0 &&
 124                                tmp < from_kgid(&init_user_ns,
 125                                                CFS_GROUP_AT(group_info, left))) {
 126                                 CFS_GROUP_AT(group_info, right) =
 127                                     CFS_GROUP_AT(group_info, left);
 128                                 right = left;
 129                                 left -= stride;
 130                         }
 131                         CFS_GROUP_AT(group_info, right) =
 132                                                 make_kgid(&init_user_ns, tmp);
 133                 }
 134                 stride /= 3;
 135         }
 136 }
 137 EXPORT_SYMBOL(lustre_groups_sort);
 138
 139 int lustre_in_group_p(struct lu_ucred *mu, gid_t grp)
 140 {
 141         int rc = 1;
 142
 143         if (grp != mu->uc_fsgid) {
 144                 group_info_t *group_info = NULL;
 145
 146                 if (mu->uc_ginfo || !mu->uc_identity ||
 147                     mu->uc_valid == UCRED_OLD)
 148                         if (grp == mu->uc_suppgids[0] ||
 149                             grp == mu->uc_suppgids[1])
 150                                 return 1;
 151
 152                 if (mu->uc_ginfo)
 153                         group_info = mu->uc_ginfo;
 154                 else if (mu->uc_identity)
 155                         group_info = mu->uc_identity->mi_ginfo;
 156
 157                 if (!group_info)
 158                         return 0;
 159
 160                 lustre_get_group_info(group_info);
 161                 rc = lustre_groups_search(group_info, grp);
 162                 lustre_put_group_info(group_info);
 163         }
 164         return rc;
 165 }
 166 EXPORT_SYMBOL(lustre_in_group_p);
 167
 168 struct lustre_idmap_entry {
 169         struct list_head       lie_rmt_uid_hash; /* hashed as lie_rmt_uid; */
 170         struct list_head       lie_lcl_uid_hash; /* hashed as lie_lcl_uid; */
 171         struct list_head       lie_rmt_gid_hash; /* hashed as lie_rmt_gid; */
 172         struct list_head       lie_lcl_gid_hash; /* hashed as lie_lcl_gid; */
 173         uid_t       lie_rmt_uid;      /* remote uid */
 174         uid_t       lie_lcl_uid;      /* local uid */
 175         gid_t       lie_rmt_gid;      /* remote gid */
 176         gid_t       lie_lcl_gid;      /* local gid */
 177 };
 178
 179 static inline __u32 lustre_idmap_hashfunc(__u32 id)
 180 {
 181         return id & (CFS_IDMAP_HASHSIZE - 1);
 182 }
 183
 184 static
 185 struct lustre_idmap_entry *idmap_entry_alloc(uid_t rmt_uid, uid_t lcl_uid,
 186                                              gid_t rmt_gid, gid_t lcl_gid)
 187 {
 188         struct lustre_idmap_entry *e;
 189
 190         OBD_ALLOC_PTR(e);
 191         if (e == NULL)
 192                 return NULL;
 193
 194         INIT_LIST_HEAD(&e->lie_rmt_uid_hash);
 195         INIT_LIST_HEAD(&e->lie_lcl_uid_hash);
 196         INIT_LIST_HEAD(&e->lie_rmt_gid_hash);
 197         INIT_LIST_HEAD(&e->lie_lcl_gid_hash);
 198         e->lie_rmt_uid = rmt_uid;
 199         e->lie_lcl_uid = lcl_uid;
 200         e->lie_rmt_gid = rmt_gid;
 201         e->lie_lcl_gid = lcl_gid;
 202
 203         return e;
 204 }
 205
 206 static void idmap_entry_free(struct lustre_idmap_entry *e)
 207 {
 208         if (!list_empty(&e->lie_rmt_uid_hash))
 209                 list_del(&e->lie_rmt_uid_hash);
 210         if (!list_empty(&e->lie_lcl_uid_hash))
 211                 list_del(&e->lie_lcl_uid_hash);
 212         if (!list_empty(&e->lie_rmt_gid_hash))
 213                 list_del(&e->lie_rmt_gid_hash);
 214         if (!list_empty(&e->lie_lcl_gid_hash))
 215                 list_del(&e->lie_lcl_gid_hash);
 216         OBD_FREE_PTR(e);
 217 }
 218
 219 /*
 220  * return value
 221  * NULL: not found entry
 222  * ERR_PTR(-EACCES): found 1(remote):N(local) mapped entry
 223  * others: found normal entry
 224  */
 225 static
 226 struct lustre_idmap_entry *idmap_search_entry(struct lustre_idmap_table *t,
 227                                               uid_t rmt_uid, uid_t lcl_uid,
 228                                               gid_t rmt_gid, gid_t lcl_gid)
 229 {
 230         struct list_head *head;
 231         struct lustre_idmap_entry *e;
 232
 233         head = &t->lit_idmaps[RMT_UIDMAP_IDX][lustre_idmap_hashfunc(rmt_uid)];
 234         list_for_each_entry(e, head, lie_rmt_uid_hash)
 235                 if (e->lie_rmt_uid == rmt_uid) {
 236                         if (e->lie_lcl_uid == lcl_uid) {
 237                                 if (e->lie_rmt_gid == rmt_gid &&
 238                                     e->lie_lcl_gid == lcl_gid)
 239                                         /* must be quaternion match */
 240                                         return e;
 241                         } else {
 242                                 /* 1:N uid mapping */
 243                                 CERROR("rmt uid %u already be mapped to %u"
 244                                        " (new %u)\n", e->lie_rmt_uid,
 245                                        e->lie_lcl_uid, lcl_uid);
 246                                 return ERR_PTR(-EACCES);
 247                         }
 248                 }
 249
 250         head = &t->lit_idmaps[RMT_GIDMAP_IDX][lustre_idmap_hashfunc(rmt_gid)];
 251         list_for_each_entry(e, head, lie_rmt_gid_hash)
 252                 if (e->lie_rmt_gid == rmt_gid) {
 253                         if (e->lie_lcl_gid == lcl_gid) {
 254                                 if (unlikely(e->lie_rmt_uid == rmt_uid &&
 255                                     e->lie_lcl_uid == lcl_uid))
 256                                         /* after uid mapping search above,
 257                                          * we should never come here */
 258                                         LBUG();
 259                         } else {
 260                                 /* 1:N gid mapping */
 261                                 CERROR("rmt gid %u already be mapped to %u"
 262                                        " (new %u)\n", e->lie_rmt_gid,
 263                                        e->lie_lcl_gid, lcl_gid);
 264                                 return ERR_PTR(-EACCES);
 265                         }
 266                 }
 267
 268         return NULL;
 269 }
 270
 271 static __u32 idmap_lookup_uid(struct list_head *hash, int reverse,
 272                               __u32 uid)
 273 {
 274         struct list_head *head = &hash[lustre_idmap_hashfunc(uid)];
 275         struct lustre_idmap_entry *e;
 276
 277         if (!reverse) {
 278                 list_for_each_entry(e, head, lie_rmt_uid_hash)
 279                         if (e->lie_rmt_uid == uid)
 280                                 return e->lie_lcl_uid;
 281         } else {
 282                 list_for_each_entry(e, head, lie_lcl_uid_hash)
 283                         if (e->lie_lcl_uid == uid)
 284                                 return e->lie_rmt_uid;
 285         }
 286
 287         return CFS_IDMAP_NOTFOUND;
 288 }
 289
 290 static __u32 idmap_lookup_gid(struct list_head *hash, int reverse, __u32 gid)
 291 {
 292         struct list_head *head = &hash[lustre_idmap_hashfunc(gid)];
 293         struct lustre_idmap_entry *e;
 294
 295         if (!reverse) {
 296                 list_for_each_entry(e, head, lie_rmt_gid_hash)
 297                         if (e->lie_rmt_gid == gid)
 298                                 return e->lie_lcl_gid;
 299         } else {
 300                 list_for_each_entry(e, head, lie_lcl_gid_hash)
 301                         if (e->lie_lcl_gid == gid)
 302                                 return e->lie_rmt_gid;
 303         }
 304
 305         return CFS_IDMAP_NOTFOUND;
 306 }
 307
 308 int lustre_idmap_add(struct lustre_idmap_table *t,
 309                      uid_t ruid, uid_t luid,
 310                      gid_t rgid, gid_t lgid)
 311 {
 312         struct lustre_idmap_entry *e0, *e1;
 313
 314         LASSERT(t);
 315
 316         spin_lock(&t->lit_lock);
 317         e0 = idmap_search_entry(t, ruid, luid, rgid, lgid);
 318         spin_unlock(&t->lit_lock);
 319         if (!e0) {
 320                 e0 = idmap_entry_alloc(ruid, luid, rgid, lgid);
 321                 if (!e0)
 322                         return -ENOMEM;
 323
 324                 spin_lock(&t->lit_lock);
 325                 e1 = idmap_search_entry(t, ruid, luid, rgid, lgid);
 326                 if (e1 == NULL) {
 327                         list_add_tail(&e0->lie_rmt_uid_hash,
 328                                           &t->lit_idmaps[RMT_UIDMAP_IDX]
 329                                           [lustre_idmap_hashfunc(ruid)]);
 330                         list_add_tail(&e0->lie_lcl_uid_hash,
 331                                           &t->lit_idmaps[LCL_UIDMAP_IDX]
 332                                           [lustre_idmap_hashfunc(luid)]);
 333                         list_add_tail(&e0->lie_rmt_gid_hash,
 334                                           &t->lit_idmaps[RMT_GIDMAP_IDX]
 335                                           [lustre_idmap_hashfunc(rgid)]);
 336                         list_add_tail(&e0->lie_lcl_gid_hash,
 337                                           &t->lit_idmaps[LCL_GIDMAP_IDX]
 338                                           [lustre_idmap_hashfunc(lgid)]);
 339                 }
 340                 spin_unlock(&t->lit_lock);
 341                 if (e1 != NULL) {
 342                         idmap_entry_free(e0);
 343                         if (IS_ERR(e1))
 344                                 return PTR_ERR(e1);
 345                 }
 346         } else if (IS_ERR(e0)) {
 347                 return PTR_ERR(e0);
 348         }
 349
 350         return 0;
 351 }
 352 EXPORT_SYMBOL(lustre_idmap_add);
 353
 354 int lustre_idmap_del(struct lustre_idmap_table *t,
 355                     uid_t ruid, uid_t luid,
 356                     gid_t rgid, gid_t lgid)
 357 {
 358         struct lustre_idmap_entry *e;
 359         int rc = 0;
 360
 361         LASSERT(t);
 362
 363         spin_lock(&t->lit_lock);
 364         e = idmap_search_entry(t, ruid, luid, rgid, lgid);
 365         if (IS_ERR(e))
 366                 rc = PTR_ERR(e);
 367         else if (e)
 368                 idmap_entry_free(e);
 369         spin_unlock(&t->lit_lock);
 370
 371         return rc;
 372 }
 373 EXPORT_SYMBOL(lustre_idmap_del);
 374
 375 int lustre_idmap_lookup_uid(struct lu_ucred *mu,
 376                             struct lustre_idmap_table *t,
 377                             int reverse, uid_t uid)
 378 {
 379         struct list_head *hash;
 380
 381         if (mu && (mu->uc_valid == UCRED_OLD || mu->uc_valid == UCRED_NEW)) {
 382                 if (!reverse) {
 383                         if (uid == mu->uc_o_uid)
 384                                 return mu->uc_uid;
 385                         else if (uid == mu->uc_o_fsuid)
 386                                 return mu->uc_fsuid;
 387                 } else {
 388                         if (uid == mu->uc_uid)
 389                                 return mu->uc_o_uid;
 390                         else if (uid == mu->uc_fsuid)
 391                                 return mu->uc_o_fsuid;
 392                 }
 393         }
 394
 395         if (t == NULL)
 396                 return CFS_IDMAP_NOTFOUND;
 397
 398         hash = t->lit_idmaps[reverse ? LCL_UIDMAP_IDX : RMT_UIDMAP_IDX];
 399
 400         spin_lock(&t->lit_lock);
 401         uid = idmap_lookup_uid(hash, reverse, uid);
 402         spin_unlock(&t->lit_lock);
 403
 404         return uid;
 405 }
 406 EXPORT_SYMBOL(lustre_idmap_lookup_uid);
 407
 408 int lustre_idmap_lookup_gid(struct lu_ucred *mu, struct lustre_idmap_table *t,
 409                             int reverse, gid_t gid)
 410 {
 411         struct list_head *hash;
 412
 413         if (mu && (mu->uc_valid == UCRED_OLD || mu->uc_valid == UCRED_NEW)) {
 414                 if (!reverse) {
 415                         if (gid == mu->uc_o_gid)
 416                                 return mu->uc_gid;
 417                         else if (gid == mu->uc_o_fsgid)
 418                                 return mu->uc_fsgid;
 419                 } else {
 420                         if (gid == mu->uc_gid)
 421                                 return mu->uc_o_gid;
 422                         else if (gid == mu->uc_fsgid)
 423                                 return mu->uc_o_fsgid;
 424                 }
 425         }
 426
 427         if (t == NULL)
 428                 return CFS_IDMAP_NOTFOUND;
 429
 430         hash = t->lit_idmaps[reverse ? LCL_GIDMAP_IDX : RMT_GIDMAP_IDX];
 431
 432         spin_lock(&t->lit_lock);
 433         gid = idmap_lookup_gid(hash, reverse, gid);
 434         spin_unlock(&t->lit_lock);
 435
 436         return gid;
 437 }
 438 EXPORT_SYMBOL(lustre_idmap_lookup_gid);
 439
 440 struct lustre_idmap_table *lustre_idmap_init(void)
 441 {
 442         struct lustre_idmap_table *t;
 443         int i, j;
 444
 445         OBD_ALLOC_PTR(t);
 446         if(unlikely(t == NULL))
 447                 return (ERR_PTR(-ENOMEM));
 448
 449         spin_lock_init(&t->lit_lock);
 450         for (i = 0; i < ARRAY_SIZE(t->lit_idmaps); i++)
 451                 for (j = 0; j < ARRAY_SIZE(t->lit_idmaps[i]); j++)
 452                         INIT_LIST_HEAD(&t->lit_idmaps[i][j]);
 453
 454         return t;
 455 }
 456 EXPORT_SYMBOL(lustre_idmap_init);
 457
 458 void lustre_idmap_fini(struct lustre_idmap_table *t)
 459 {
 460         struct list_head *list;
 461         struct lustre_idmap_entry *e;
 462         int i;
 463         LASSERT(t);
 464
 465         list = t->lit_idmaps[RMT_UIDMAP_IDX];
 466         spin_lock(&t->lit_lock);
 467         for (i = 0; i < CFS_IDMAP_HASHSIZE; i++)
 468                 while (!list_empty(&list[i])) {
 469                         e = list_entry(list[i].next,
 470                                            struct lustre_idmap_entry,
 471                                            lie_rmt_uid_hash);
 472                         idmap_entry_free(e);
 473                 }
 474         spin_unlock(&t->lit_lock);
 475
 476         OBD_FREE_PTR(t);
 477 }
 478 EXPORT_SYMBOL(lustre_idmap_fini);