fs/nfsd/nfs4idmap.c

   1 /*
   2  *  Mapping of UID/GIDs to name and vice versa.
   3  *
   4  *  Copyright (c) 2002, 2003 The Regents of the University of
   5  *  Michigan.  All rights reserved.
   6  *
   7  *  Marius Aamodt Eriksen <marius@umich.edu>
   8  *
   9  *  Redistribution and use in source and binary forms, with or without
  10  *  modification, are permitted provided that the following conditions
  11  *  are met:
  12  *
  13  *  1. Redistributions of source code must retain the above copyright
  14  *     notice, this list of conditions and the following disclaimer.
  15  *  2. Redistributions in binary form must reproduce the above copyright
  16  *     notice, this list of conditions and the following disclaimer in the
  17  *     documentation and/or other materials provided with the distribution.
  18  *  3. Neither the name of the University nor the names of its
  19  *     contributors may be used to endorse or promote products derived
  20  *     from this software without specific prior written permission.
  21  *
  22  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  29  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  31  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  32  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <linux/module.h>
  36 #include <linux/nfsd_idmap.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/sched.h>
  39
  40 /*
  41  * Cache entry
  42  */
  43
  44 /*
  45  * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
  46  * that.
  47  */
  48
  49 #define IDMAP_TYPE_USER  0
  50 #define IDMAP_TYPE_GROUP 1
  51
  52 struct ent {
  53         struct cache_head h;
  54         int               type;                /* User / Group */
  55         uid_t             id;
  56         char              name[IDMAP_NAMESZ];
  57         char              authname[IDMAP_NAMESZ];
  58 };
  59
  60 /* Common entry handling */
  61
  62 #define ENT_HASHBITS          8
  63 #define ENT_HASHMAX           (1 << ENT_HASHBITS)
  64 #define ENT_HASHMASK          (ENT_HASHMAX - 1)
  65
  66 static void
  67 ent_init(struct cache_head *cnew, struct cache_head *citm)
  68 {
  69         struct ent *new = container_of(cnew, struct ent, h);
  70         struct ent *itm = container_of(citm, struct ent, h);
  71
  72         new->id = itm->id;
  73         new->type = itm->type;
  74
  75         strlcpy(new->name, itm->name, sizeof(new->name));
  76         strlcpy(new->authname, itm->authname, sizeof(new->name));
  77 }
  78
  79 static void
  80 ent_put(struct kref *ref)
  81 {
  82         struct ent *map = container_of(ref, struct ent, h.ref);
  83         kfree(map);
  84 }
  85
  86 static struct cache_head *
  87 ent_alloc(void)
  88 {
  89         struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
  90         if (e)
  91                 return &e->h;
  92         else
  93                 return NULL;
  94 }
  95
  96 /*
  97  * ID -> Name cache
  98  */
  99
 100 static struct cache_head *idtoname_table[ENT_HASHMAX];
 101
 102 static uint32_t
 103 idtoname_hash(struct ent *ent)
 104 {
 105         uint32_t hash;
 106
 107         hash = hash_str(ent->authname, ENT_HASHBITS);
 108         hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
 109
 110         /* Flip LSB for user/group */
 111         if (ent->type == IDMAP_TYPE_GROUP)
 112                 hash ^= 1;
 113
 114         return hash;
 115 }
 116
 117 static void
 118 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 119     int *blen)
 120 {
 121         struct ent *ent = container_of(ch, struct ent, h);
 122         char idstr[11];
 123
 124         qword_add(bpp, blen, ent->authname);
 125         snprintf(idstr, sizeof(idstr), "%u", ent->id);
 126         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 127         qword_add(bpp, blen, idstr);
 128
 129         (*bpp)[-1] = '\n';
 130 }
 131
 132 static int
 133 idtoname_upcall(struct cache_detail *cd, struct cache_head *ch)
 134 {
 135         return sunrpc_cache_pipe_upcall(cd, ch, idtoname_request);
 136 }
 137
 138 static int
 139 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 140 {
 141         struct ent *a = container_of(ca, struct ent, h);
 142         struct ent *b = container_of(cb, struct ent, h);
 143
 144         return (a->id == b->id && a->type == b->type &&
 145             strcmp(a->authname, b->authname) == 0);
 146 }
 147
 148 static int
 149 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 150 {
 151         struct ent *ent;
 152
 153         if (h == NULL) {
 154                 seq_puts(m, "#domain type id [name]\n");
 155                 return 0;
 156         }
 157         ent = container_of(h, struct ent, h);
 158         seq_printf(m, "%s %s %u", ent->authname,
 159                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 160                         ent->id);
 161         if (test_bit(CACHE_VALID, &h->flags))
 162                 seq_printf(m, " %s", ent->name);
 163         seq_printf(m, "\n");
 164         return 0;
 165 }
 166
 167 static void
 168 warn_no_idmapd(struct cache_detail *detail, int has_died)
 169 {
 170         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 171                         has_died ? "died" : "not been started");
 172 }
 173
 174
 175 static int         idtoname_parse(struct cache_detail *, char *, int);
 176 static struct ent *idtoname_lookup(struct ent *);
 177 static struct ent *idtoname_update(struct ent *, struct ent *);
 178
 179 static struct cache_detail idtoname_cache = {
 180         .owner          = THIS_MODULE,
 181         .hash_size      = ENT_HASHMAX,
 182         .hash_table     = idtoname_table,
 183         .name           = "nfs4.idtoname",
 184         .cache_put      = ent_put,
 185         .cache_upcall   = idtoname_upcall,
 186         .cache_parse    = idtoname_parse,
 187         .cache_show     = idtoname_show,
 188         .warn_no_listener = warn_no_idmapd,
 189         .match          = idtoname_match,
 190         .init           = ent_init,
 191         .update         = ent_init,
 192         .alloc          = ent_alloc,
 193 };
 194
 195 static int
 196 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 197 {
 198         struct ent ent, *res;
 199         char *buf1, *bp;
 200         int len;
 201         int error = -EINVAL;
 202
 203         if (buf[buflen - 1] != '\n')
 204                 return (-EINVAL);
 205         buf[buflen - 1]= '\0';
 206
 207         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 208         if (buf1 == NULL)
 209                 return (-ENOMEM);
 210
 211         memset(&ent, 0, sizeof(ent));
 212
 213         /* Authentication name */
 214         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 215                 goto out;
 216         memcpy(ent.authname, buf1, sizeof(ent.authname));
 217
 218         /* Type */
 219         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 220                 goto out;
 221         ent.type = strcmp(buf1, "user") == 0 ?
 222                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 223
 224         /* ID */
 225         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 226                 goto out;
 227         ent.id = simple_strtoul(buf1, &bp, 10);
 228         if (bp == buf1)
 229                 goto out;
 230
 231         /* expiry */
 232         ent.h.expiry_time = get_expiry(&buf);
 233         if (ent.h.expiry_time == 0)
 234                 goto out;
 235
 236         error = -ENOMEM;
 237         res = idtoname_lookup(&ent);
 238         if (!res)
 239                 goto out;
 240
 241         /* Name */
 242         error = -EINVAL;
 243         len = qword_get(&buf, buf1, PAGE_SIZE);
 244         if (len < 0)
 245                 goto out;
 246         if (len == 0)
 247                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 248         else if (len >= IDMAP_NAMESZ)
 249                 goto out;
 250         else
 251                 memcpy(ent.name, buf1, sizeof(ent.name));
 252         error = -ENOMEM;
 253         res = idtoname_update(&ent, res);
 254         if (res == NULL)
 255                 goto out;
 256
 257         cache_put(&res->h, &idtoname_cache);
 258
 259         error = 0;
 260 out:
 261         kfree(buf1);
 262
 263         return error;
 264 }
 265
 266
 267 static struct ent *
 268 idtoname_lookup(struct ent *item)
 269 {
 270         struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
 271                                                     &item->h,
 272                                                     idtoname_hash(item));
 273         if (ch)
 274                 return container_of(ch, struct ent, h);
 275         else
 276                 return NULL;
 277 }
 278
 279 static struct ent *
 280 idtoname_update(struct ent *new, struct ent *old)
 281 {
 282         struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
 283                                                     &new->h, &old->h,
 284                                                     idtoname_hash(new));
 285         if (ch)
 286                 return container_of(ch, struct ent, h);
 287         else
 288                 return NULL;
 289 }
 290
 291
 292 /*
 293  * Name -> ID cache
 294  */
 295
 296 static struct cache_head *nametoid_table[ENT_HASHMAX];
 297
 298 static inline int
 299 nametoid_hash(struct ent *ent)
 300 {
 301         return hash_str(ent->name, ENT_HASHBITS);
 302 }
 303
 304 static void
 305 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 306     int *blen)
 307 {
 308         struct ent *ent = container_of(ch, struct ent, h);
 309
 310         qword_add(bpp, blen, ent->authname);
 311         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 312         qword_add(bpp, blen, ent->name);
 313
 314         (*bpp)[-1] = '\n';
 315 }
 316
 317 static int
 318 nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
 319 {
 320         return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
 321 }
 322
 323 static int
 324 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 325 {
 326         struct ent *a = container_of(ca, struct ent, h);
 327         struct ent *b = container_of(cb, struct ent, h);
 328
 329         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 330             strcmp(a->authname, b->authname) == 0);
 331 }
 332
 333 static int
 334 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 335 {
 336         struct ent *ent;
 337
 338         if (h == NULL) {
 339                 seq_puts(m, "#domain type name [id]\n");
 340                 return 0;
 341         }
 342         ent = container_of(h, struct ent, h);
 343         seq_printf(m, "%s %s %s", ent->authname,
 344                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 345                         ent->name);
 346         if (test_bit(CACHE_VALID, &h->flags))
 347                 seq_printf(m, " %u", ent->id);
 348         seq_printf(m, "\n");
 349         return 0;
 350 }
 351
 352 static struct ent *nametoid_lookup(struct ent *);
 353 static struct ent *nametoid_update(struct ent *, struct ent *);
 354 static int         nametoid_parse(struct cache_detail *, char *, int);
 355
 356 static struct cache_detail nametoid_cache = {
 357         .owner          = THIS_MODULE,
 358         .hash_size      = ENT_HASHMAX,
 359         .hash_table     = nametoid_table,
 360         .name           = "nfs4.nametoid",
 361         .cache_put      = ent_put,
 362         .cache_upcall   = nametoid_upcall,
 363         .cache_parse    = nametoid_parse,
 364         .cache_show     = nametoid_show,
 365         .warn_no_listener = warn_no_idmapd,
 366         .match          = nametoid_match,
 367         .init           = ent_init,
 368         .update         = ent_init,
 369         .alloc          = ent_alloc,
 370 };
 371
 372 static int
 373 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 374 {
 375         struct ent ent, *res;
 376         char *buf1;
 377         int error = -EINVAL;
 378
 379         if (buf[buflen - 1] != '\n')
 380                 return (-EINVAL);
 381         buf[buflen - 1]= '\0';
 382
 383         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 384         if (buf1 == NULL)
 385                 return (-ENOMEM);
 386
 387         memset(&ent, 0, sizeof(ent));
 388
 389         /* Authentication name */
 390         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 391                 goto out;
 392         memcpy(ent.authname, buf1, sizeof(ent.authname));
 393
 394         /* Type */
 395         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 396                 goto out;
 397         ent.type = strcmp(buf1, "user") == 0 ?
 398                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 399
 400         /* Name */
 401         error = qword_get(&buf, buf1, PAGE_SIZE);
 402         if (error <= 0 || error >= IDMAP_NAMESZ)
 403                 goto out;
 404         memcpy(ent.name, buf1, sizeof(ent.name));
 405
 406         /* expiry */
 407         ent.h.expiry_time = get_expiry(&buf);
 408         if (ent.h.expiry_time == 0)
 409                 goto out;
 410
 411         /* ID */
 412         error = get_int(&buf, &ent.id);
 413         if (error == -EINVAL)
 414                 goto out;
 415         if (error == -ENOENT)
 416                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 417
 418         error = -ENOMEM;
 419         res = nametoid_lookup(&ent);
 420         if (res == NULL)
 421                 goto out;
 422         res = nametoid_update(&ent, res);
 423         if (res == NULL)
 424                 goto out;
 425
 426         cache_put(&res->h, &nametoid_cache);
 427         error = 0;
 428 out:
 429         kfree(buf1);
 430
 431         return (error);
 432 }
 433
 434
 435 static struct ent *
 436 nametoid_lookup(struct ent *item)
 437 {
 438         struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
 439                                                     &item->h,
 440                                                     nametoid_hash(item));
 441         if (ch)
 442                 return container_of(ch, struct ent, h);
 443         else
 444                 return NULL;
 445 }
 446
 447 static struct ent *
 448 nametoid_update(struct ent *new, struct ent *old)
 449 {
 450         struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
 451                                                     &new->h, &old->h,
 452                                                     nametoid_hash(new));
 453         if (ch)
 454                 return container_of(ch, struct ent, h);
 455         else
 456                 return NULL;
 457 }
 458
 459 /*
 460  * Exported API
 461  */
 462
 463 int
 464 nfsd_idmap_init(void)
 465 {
 466         int rv;
 467
 468         rv = cache_register(&idtoname_cache);
 469         if (rv)
 470                 return rv;
 471         rv = cache_register(&nametoid_cache);
 472         if (rv)
 473                 cache_unregister(&idtoname_cache);
 474         return rv;
 475 }
 476
 477 void
 478 nfsd_idmap_shutdown(void)
 479 {
 480         cache_unregister(&idtoname_cache);
 481         cache_unregister(&nametoid_cache);
 482 }
 483
 484 /*
 485  * Deferred request handling
 486  */
 487
 488 struct idmap_defer_req {
 489        struct cache_req         req;
 490        struct cache_deferred_req deferred_req;
 491        wait_queue_head_t        waitq;
 492        atomic_t                 count;
 493 };
 494
 495 static inline void
 496 put_mdr(struct idmap_defer_req *mdr)
 497 {
 498         if (atomic_dec_and_test(&mdr->count))
 499                 kfree(mdr);
 500 }
 501
 502 static inline void
 503 get_mdr(struct idmap_defer_req *mdr)
 504 {
 505         atomic_inc(&mdr->count);
 506 }
 507
 508 static void
 509 idmap_revisit(struct cache_deferred_req *dreq, int toomany)
 510 {
 511         struct idmap_defer_req *mdr =
 512                 container_of(dreq, struct idmap_defer_req, deferred_req);
 513
 514         wake_up(&mdr->waitq);
 515         put_mdr(mdr);
 516 }
 517
 518 static struct cache_deferred_req *
 519 idmap_defer(struct cache_req *req)
 520 {
 521         struct idmap_defer_req *mdr =
 522                 container_of(req, struct idmap_defer_req, req);
 523
 524         mdr->deferred_req.revisit = idmap_revisit;
 525         get_mdr(mdr);
 526         return (&mdr->deferred_req);
 527 }
 528
 529 static inline int
 530 do_idmap_lookup(struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 531                 struct cache_detail *detail, struct ent **item,
 532                 struct idmap_defer_req *mdr)
 533 {
 534         *item = lookup_fn(key);
 535         if (!*item)
 536                 return -ENOMEM;
 537         return cache_check(detail, &(*item)->h, &mdr->req);
 538 }
 539
 540 static inline int
 541 do_idmap_lookup_nowait(struct ent *(*lookup_fn)(struct ent *),
 542                         struct ent *key, struct cache_detail *detail,
 543                         struct ent **item)
 544 {
 545         int ret = -ENOMEM;
 546
 547         *item = lookup_fn(key);
 548         if (!*item)
 549                 goto out_err;
 550         ret = -ETIMEDOUT;
 551         if (!test_bit(CACHE_VALID, &(*item)->h.flags)
 552                         || (*item)->h.expiry_time < get_seconds()
 553                         || detail->flush_time > (*item)->h.last_refresh)
 554                 goto out_put;
 555         ret = -ENOENT;
 556         if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
 557                 goto out_put;
 558         return 0;
 559 out_put:
 560         cache_put(&(*item)->h, detail);
 561 out_err:
 562         *item = NULL;
 563         return ret;
 564 }
 565
 566 static int
 567 idmap_lookup(struct svc_rqst *rqstp,
 568                 struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 569                 struct cache_detail *detail, struct ent **item)
 570 {
 571         struct idmap_defer_req *mdr;
 572         int ret;
 573
 574         mdr = kzalloc(sizeof(*mdr), GFP_KERNEL);
 575         if (!mdr)
 576                 return -ENOMEM;
 577         atomic_set(&mdr->count, 1);
 578         init_waitqueue_head(&mdr->waitq);
 579         mdr->req.defer = idmap_defer;
 580         ret = do_idmap_lookup(lookup_fn, key, detail, item, mdr);
 581         if (ret == -EAGAIN) {
 582                 wait_event_interruptible_timeout(mdr->waitq,
 583                         test_bit(CACHE_VALID, &(*item)->h.flags), 1 * HZ);
 584                 ret = do_idmap_lookup_nowait(lookup_fn, key, detail, item);
 585         }
 586         put_mdr(mdr);
 587         return ret;
 588 }
 589
 590 static char *
 591 rqst_authname(struct svc_rqst *rqstp)
 592 {
 593         struct auth_domain *clp;
 594
 595         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 596         return clp->name;
 597 }
 598
 599 static int
 600 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 601                 uid_t *id)
 602 {
 603         struct ent *item, key = {
 604                 .type = type,
 605         };
 606         int ret;
 607
 608         if (namelen + 1 > sizeof(key.name))
 609                 return -EINVAL;
 610         memcpy(key.name, name, namelen);
 611         key.name[namelen] = '\0';
 612         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 613         ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 614         if (ret == -ENOENT)
 615                 ret = -ESRCH; /* nfserr_badname */
 616         if (ret)
 617                 return ret;
 618         *id = item->id;
 619         cache_put(&item->h, &nametoid_cache);
 620         return 0;
 621 }
 622
 623 static int
 624 idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 625 {
 626         struct ent *item, key = {
 627                 .id = id,
 628                 .type = type,
 629         };
 630         int ret;
 631
 632         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 633         ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
 634         if (ret == -ENOENT)
 635                 return sprintf(name, "%u", id);
 636         if (ret)
 637                 return ret;
 638         ret = strlen(item->name);
 639         BUG_ON(ret > IDMAP_NAMESZ);
 640         memcpy(name, item->name, ret);
 641         cache_put(&item->h, &idtoname_cache);
 642         return ret;
 643 }
 644
 645 int
 646 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 647                 __u32 *id)
 648 {
 649         return idmap_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
 650 }
 651
 652 int
 653 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 654                 __u32 *id)
 655 {
 656         return idmap_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
 657 }
 658
 659 int
 660 nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 661 {
 662         return idmap_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 663 }
 664
 665 int
 666 nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 667 {
 668         return idmap_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 669 }