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