lustre/obdclass/idmap.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  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 #ifndef EXPORT_SYMTAB
  44 # define EXPORT_SYMTAB
  45 #endif
  46
  47 #define DEBUG_SUBSYSTEM S_SEC
  48
  49 #include <lustre_idmap.h>
  50 #include <obd_support.h>
  51
  52 #define lustre_get_group_info(group_info) do {             \
  53         atomic_inc(&(group_info)->usage);                  \
  54 } while (0)
  55
  56 #define lustre_put_group_info(group_info) do {             \
  57         if (atomic_dec_and_test(&(group_info)->usage))     \
  58                 groups_free(group_info);                   \
  59 } while (0)
  60
  61 /*
  62  * groups_search() is copied from linux kernel!
  63  * A simple bsearch.
  64  */
  65 static int lustre_groups_search(struct group_info *group_info, gid_t grp)
  66 {
  67         int left, right;
  68
  69         if (!group_info)
  70                 return 0;
  71
  72         left = 0;
  73         right = group_info->ngroups;
  74         while (left < right) {
  75                 int mid = (left + right) / 2;
  76                 int cmp = grp - 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 = CFS_GROUP_AT(group_info, right);
 122
 123                         while (left >= 0 &&
 124                                CFS_GROUP_AT(group_info, left) > tmp) {
 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) = tmp;
 131                 }
 132                 stride /= 3;
 133         }
 134 }
 135 EXPORT_SYMBOL(lustre_groups_sort);
 136
 137 int lustre_in_group_p(struct md_ucred *mu, gid_t grp)
 138 {
 139         int rc = 1;
 140
 141         if (grp != mu->mu_fsgid) {
 142                 struct group_info *group_info = NULL;
 143
 144                 if (mu->mu_ginfo || !mu->mu_identity ||
 145                     mu->mu_valid == UCRED_OLD)
 146                         if (grp == mu->mu_suppgids[0] ||
 147                             grp == mu->mu_suppgids[1])
 148                                 return 1;
 149
 150                 if (mu->mu_ginfo)
 151                         group_info = mu->mu_ginfo;
 152                 else if (mu->mu_identity)
 153                         group_info = mu->mu_identity->mi_ginfo;
 154
 155                 if (!group_info)
 156                         return 0;
 157
 158                 lustre_get_group_info(group_info);
 159                 rc = lustre_groups_search(group_info, grp);
 160                 lustre_put_group_info(group_info);
 161         }
 162         return rc;
 163 }
 164 EXPORT_SYMBOL(lustre_in_group_p);
 165
 166 struct lustre_idmap_entry {
 167         struct list_head lie_rmt_uid_hash; /* hashed as lie_rmt_uid; */
 168         struct list_head lie_lcl_uid_hash; /* hashed as lie_lcl_uid; */
 169         struct list_head lie_rmt_gid_hash; /* hashed as lie_rmt_gid; */
 170         struct list_head lie_lcl_gid_hash; /* hashed as lie_lcl_gid; */
 171         uid_t            lie_rmt_uid;      /* remote uid */
 172         uid_t            lie_lcl_uid;      /* local uid */
 173         gid_t            lie_rmt_gid;      /* remote gid */
 174         gid_t            lie_lcl_gid;      /* local gid */
 175 };
 176
 177 static inline __u32 lustre_idmap_hashfunc(__u32 id)
 178 {
 179         return id & (CFS_IDMAP_HASHSIZE - 1);
 180 }
 181
 182 static
 183 struct lustre_idmap_entry *idmap_entry_alloc(uid_t rmt_uid, uid_t lcl_uid,
 184                                              gid_t rmt_gid, gid_t lcl_gid)
 185 {
 186         struct lustre_idmap_entry *e;
 187
 188         OBD_ALLOC_PTR(e);
 189         if (e == NULL)
 190                 return NULL;
 191
 192         CFS_INIT_LIST_HEAD(&e->lie_rmt_uid_hash);
 193         CFS_INIT_LIST_HEAD(&e->lie_lcl_uid_hash);
 194         CFS_INIT_LIST_HEAD(&e->lie_rmt_gid_hash);
 195         CFS_INIT_LIST_HEAD(&e->lie_lcl_gid_hash);
 196         e->lie_rmt_uid = rmt_uid;
 197         e->lie_lcl_uid = lcl_uid;
 198         e->lie_rmt_gid = rmt_gid;
 199         e->lie_lcl_gid = lcl_gid;
 200
 201         return e;
 202 }
 203
 204 static void idmap_entry_free(struct lustre_idmap_entry *e)
 205 {
 206         if (!list_empty(&e->lie_rmt_uid_hash))
 207                 list_del(&e->lie_rmt_uid_hash);
 208         if (!list_empty(&e->lie_lcl_uid_hash))
 209                 list_del(&e->lie_lcl_uid_hash);
 210         if (!list_empty(&e->lie_rmt_gid_hash))
 211                 list_del(&e->lie_rmt_gid_hash);
 212         if (!list_empty(&e->lie_lcl_gid_hash))
 213                 list_del(&e->lie_lcl_gid_hash);
 214         OBD_FREE_PTR(e);
 215 }
 216
 217 /*
 218  * return value
 219  * NULL: not found entry
 220  * ERR_PTR(-EACCES): found 1(remote):N(local) mapped entry
 221  * others: found normal entry
 222  */
 223 static
 224 struct lustre_idmap_entry *idmap_search_entry(struct lustre_idmap_table *t,
 225                                               uid_t rmt_uid, uid_t lcl_uid,
 226                                               gid_t rmt_gid, gid_t lcl_gid)
 227 {
 228         struct list_head *head;
 229         struct lustre_idmap_entry *e;
 230
 231         head = &t->lit_idmaps[RMT_UIDMAP_IDX][lustre_idmap_hashfunc(rmt_uid)];
 232         list_for_each_entry(e, head, lie_rmt_uid_hash)
 233                 if (e->lie_rmt_uid == rmt_uid) {
 234                         if (e->lie_lcl_uid == lcl_uid) {
 235                                 if (e->lie_rmt_gid == rmt_gid &&
 236                                     e->lie_lcl_gid == lcl_gid)
 237                                         /* must be quaternion match */
 238                                         return e;
 239                         } else {
 240                                 /* 1:N uid mapping */
 241                                 CERROR("rmt uid %u already be mapped to %u"
 242                                        " (new %u)\n", e->lie_rmt_uid,
 243                                        e->lie_lcl_uid, lcl_uid);
 244                                 return ERR_PTR(-EACCES);
 245                         }
 246                 }
 247
 248         head = &t->lit_idmaps[RMT_GIDMAP_IDX][lustre_idmap_hashfunc(rmt_gid)];
 249         list_for_each_entry(e, head, lie_rmt_gid_hash)
 250                 if (e->lie_rmt_gid == rmt_gid) {
 251                         if (e->lie_lcl_gid == lcl_gid) {
 252                                 if (unlikely(e->lie_rmt_uid == rmt_uid &&
 253                                     e->lie_lcl_uid == lcl_uid))
 254                                         /* after uid mapping search above,
 255                                          * we should never come here */
 256                                         LBUG();
 257                         } else {
 258                                 /* 1:N gid mapping */
 259                                 CERROR("rmt gid %u already be mapped to %u"
 260                                        " (new %u)\n", e->lie_rmt_gid,
 261                                        e->lie_lcl_gid, lcl_gid);
 262                                 return ERR_PTR(-EACCES);
 263                         }
 264                 }
 265
 266         return NULL;
 267 }
 268
 269 static __u32 idmap_lookup_uid(struct list_head *hash, int reverse, __u32 uid)
 270 {
 271         struct list_head *head = &hash[lustre_idmap_hashfunc(uid)];
 272         struct lustre_idmap_entry *e;
 273
 274         if (!reverse) {
 275                 list_for_each_entry(e, head, lie_rmt_uid_hash)
 276                         if (e->lie_rmt_uid == uid)
 277                                 return e->lie_lcl_uid;
 278         } else {
 279                 list_for_each_entry(e, head, lie_lcl_uid_hash)
 280                         if (e->lie_lcl_uid == uid)
 281                                 return e->lie_rmt_uid;
 282         }
 283
 284         return CFS_IDMAP_NOTFOUND;
 285 }
 286
 287 static __u32 idmap_lookup_gid(struct list_head *hash, int reverse, __u32 gid)
 288 {
 289         struct list_head *head = &hash[lustre_idmap_hashfunc(gid)];
 290         struct lustre_idmap_entry *e;
 291
 292         if (!reverse) {
 293                 list_for_each_entry(e, head, lie_rmt_gid_hash)
 294                         if (e->lie_rmt_gid == gid)
 295                                 return e->lie_lcl_gid;
 296         } else {
 297                 list_for_each_entry(e, head, lie_lcl_gid_hash)
 298                         if (e->lie_lcl_gid == gid)
 299                                 return e->lie_rmt_gid;
 300         }
 301
 302         return CFS_IDMAP_NOTFOUND;
 303 }
 304
 305 int lustre_idmap_add(struct lustre_idmap_table *t,
 306                      uid_t ruid, uid_t luid,
 307                      gid_t rgid, gid_t lgid)
 308 {
 309         struct lustre_idmap_entry *e0, *e1;
 310
 311         LASSERT(t);
 312
 313         spin_lock(&t->lit_lock);
 314         e0 = idmap_search_entry(t, ruid, luid, rgid, lgid);
 315         spin_unlock(&t->lit_lock);
 316         if (!e0) {
 317                 e0 = idmap_entry_alloc(ruid, luid, rgid, lgid);
 318                 if (!e0)
 319                         return -ENOMEM;
 320
 321                 spin_lock(&t->lit_lock);
 322                 e1 = idmap_search_entry(t, ruid, luid, rgid, lgid);
 323                 if (e1 == NULL) {
 324                         list_add_tail(&e0->lie_rmt_uid_hash,
 325                                       &t->lit_idmaps[RMT_UIDMAP_IDX]
 326                                         [lustre_idmap_hashfunc(ruid)]);
 327                         list_add_tail(&e0->lie_lcl_uid_hash,
 328                                       &t->lit_idmaps[LCL_UIDMAP_IDX]
 329                                         [lustre_idmap_hashfunc(luid)]);
 330                         list_add_tail(&e0->lie_rmt_gid_hash,
 331                                       &t->lit_idmaps[RMT_GIDMAP_IDX]
 332                                         [lustre_idmap_hashfunc(rgid)]);
 333                         list_add_tail(&e0->lie_lcl_gid_hash,
 334                                       &t->lit_idmaps[LCL_GIDMAP_IDX]
 335                                         [lustre_idmap_hashfunc(lgid)]);
 336                 }
 337                 spin_unlock(&t->lit_lock);
 338                 if (e1 != NULL) {
 339                         idmap_entry_free(e0);
 340                         if (IS_ERR(e1))
 341                                 return PTR_ERR(e1);
 342                 }
 343         } else if (IS_ERR(e0)) {
 344                 return PTR_ERR(e0);
 345         }
 346
 347         return 0;
 348 }
 349 EXPORT_SYMBOL(lustre_idmap_add);
 350
 351 int lustre_idmap_del(struct lustre_idmap_table *t,
 352                     uid_t ruid, uid_t luid,
 353                     gid_t rgid, gid_t lgid)
 354 {
 355         struct lustre_idmap_entry *e;
 356         int rc = 0;
 357
 358         LASSERT(t);
 359
 360         spin_lock(&t->lit_lock);
 361         e = idmap_search_entry(t, ruid, luid, rgid, lgid);
 362         if (IS_ERR(e))
 363                 rc = PTR_ERR(e);
 364         else if (e)
 365                 idmap_entry_free(e);
 366         spin_unlock(&t->lit_lock);
 367
 368         return rc;
 369 }
 370 EXPORT_SYMBOL(lustre_idmap_del);
 371
 372 int lustre_idmap_lookup_uid(struct md_ucred *mu,
 373                             struct lustre_idmap_table *t,
 374                             int reverse, uid_t uid)
 375 {
 376         struct list_head *hash;
 377
 378         if (mu && (mu->mu_valid == UCRED_OLD || mu->mu_valid == UCRED_NEW)) {
 379                 if (!reverse) {
 380                         if (uid == mu->mu_o_uid)
 381                                 return mu->mu_uid;
 382                         else if (uid == mu->mu_o_fsuid)
 383                                 return mu->mu_fsuid;
 384                 } else {
 385                         if (uid == mu->mu_uid)
 386                                 return mu->mu_o_uid;
 387                         else if (uid == mu->mu_fsuid)
 388                                 return mu->mu_o_fsuid;
 389                 }
 390         }
 391
 392         if (t == NULL)
 393                 return CFS_IDMAP_NOTFOUND;
 394
 395         hash = t->lit_idmaps[reverse ? LCL_UIDMAP_IDX : RMT_UIDMAP_IDX];
 396
 397         spin_lock(&t->lit_lock);
 398         uid = idmap_lookup_uid(hash, reverse, uid);
 399         spin_unlock(&t->lit_lock);
 400
 401         return uid;
 402 }
 403 EXPORT_SYMBOL(lustre_idmap_lookup_uid);
 404
 405 int lustre_idmap_lookup_gid(struct md_ucred *mu, struct lustre_idmap_table *t,
 406                             int reverse, gid_t gid)
 407 {
 408         struct list_head *hash;
 409
 410         if (mu && (mu->mu_valid == UCRED_OLD || mu->mu_valid == UCRED_NEW)) {
 411                 if (!reverse) {
 412                         if (gid == mu->mu_o_gid)
 413                                 return mu->mu_gid;
 414                         else if (gid == mu->mu_o_fsgid)
 415                                 return mu->mu_fsgid;
 416                 } else {
 417                         if (gid == mu->mu_gid)
 418                                 return mu->mu_o_gid;
 419                         else if (gid == mu->mu_fsgid)
 420                                 return mu->mu_o_fsgid;
 421                 }
 422         }
 423
 424         if (t == NULL)
 425                 return CFS_IDMAP_NOTFOUND;
 426
 427         hash = t->lit_idmaps[reverse ? LCL_GIDMAP_IDX : RMT_GIDMAP_IDX];
 428
 429         spin_lock(&t->lit_lock);
 430         gid = idmap_lookup_gid(hash, reverse, gid);
 431         spin_unlock(&t->lit_lock);
 432
 433         return gid;
 434 }
 435 EXPORT_SYMBOL(lustre_idmap_lookup_gid);
 436
 437 struct lustre_idmap_table *lustre_idmap_init(void)
 438 {
 439         struct lustre_idmap_table *t;
 440         int i, j;
 441
 442         OBD_ALLOC_PTR(t);
 443         if(unlikely(t == NULL))
 444                 return (ERR_PTR(-ENOMEM));
 445
 446         spin_lock_init(&t->lit_lock);
 447         for (i = 0; i < ARRAY_SIZE(t->lit_idmaps); i++)
 448                 for (j = 0; j < ARRAY_SIZE(t->lit_idmaps[i]); j++)
 449                         INIT_LIST_HEAD(&t->lit_idmaps[i][j]);
 450
 451         return t;
 452 }
 453 EXPORT_SYMBOL(lustre_idmap_init);
 454
 455 void lustre_idmap_fini(struct lustre_idmap_table *t)
 456 {
 457         struct list_head *list;
 458         struct lustre_idmap_entry *e;
 459         int i;
 460         LASSERT(t);
 461
 462         list = t->lit_idmaps[RMT_UIDMAP_IDX];
 463         spin_lock(&t->lit_lock);
 464         for (i = 0; i < CFS_IDMAP_HASHSIZE; i++)
 465                 while (!list_empty(&list[i])) {
 466                         e = list_entry(list[i].next, struct lustre_idmap_entry,
 467                                        lie_rmt_uid_hash);
 468                         idmap_entry_free(e);
 469                 }
 470         spin_unlock(&t->lit_lock);
 471
 472         OBD_FREE_PTR(t);
 473 }
 474 EXPORT_SYMBOL(lustre_idmap_fini);