fs/nfsd/nfs4idmap.c

   1 /*
   2  *  fs/nfsd/nfs4idmap.c
   3  *
   4  *  Mapping of UID/GIDs to name and vice versa.
   5  *
   6  *  Copyright (c) 2002, 2003 The Regents of the University of
   7  *  Michigan.  All rights reserved.
   8  *
   9  *  Marius Aamodt Eriksen <marius@umich.edu>
  10  *
  11  *  Redistribution and use in source and binary forms, with or without
  12  *  modification, are permitted provided that the following conditions
  13  *  are met:
  14  *
  15  *  1. Redistributions of source code must retain the above copyright
  16  *     notice, this list of conditions and the following disclaimer.
  17  *  2. Redistributions in binary form must reproduce the above copyright
  18  *     notice, this list of conditions and the following disclaimer in the
  19  *     documentation and/or other materials provided with the distribution.
  20  *  3. Neither the name of the University nor the names of its
  21  *     contributors may be used to endorse or promote products derived
  22  *     from this software without specific prior written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include <linux/module.h>
  38 #include <linux/init.h>
  39
  40 #include <linux/mm.h>
  41 #include <linux/utsname.h>
  42 #include <linux/errno.h>
  43 #include <linux/string.h>
  44 #include <linux/sunrpc/clnt.h>
  45 #include <linux/nfs.h>
  46 #include <linux/nfs4.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/nfs_page.h>
  49 #include <linux/sunrpc/cache.h>
  50 #include <linux/nfsd_idmap.h>
  51 #include <linux/list.h>
  52 #include <linux/time.h>
  53 #include <linux/seq_file.h>
  54 #include <linux/sunrpc/svcauth.h>
  55
  56 /*
  57  * Cache entry
  58  */
  59
  60 /*
  61  * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
  62  * that.
  63  */
  64
  65 #define IDMAP_TYPE_USER  0
  66 #define IDMAP_TYPE_GROUP 1
  67
  68 struct ent {
  69         struct cache_head h;
  70         int               type;                /* User / Group */
  71         uid_t             id;
  72         char              name[IDMAP_NAMESZ];
  73         char              authname[IDMAP_NAMESZ];
  74 };
  75
  76 /* Common entry handling */
  77
  78 #define ENT_HASHBITS          8
  79 #define ENT_HASHMAX           (1 << ENT_HASHBITS)
  80 #define ENT_HASHMASK          (ENT_HASHMAX - 1)
  81
  82 static void
  83 ent_init(struct cache_head *cnew, struct cache_head *citm)
  84 {
  85         struct ent *new = container_of(cnew, struct ent, h);
  86         struct ent *itm = container_of(citm, struct ent, h);
  87
  88         new->id = itm->id;
  89         new->type = itm->type;
  90
  91         strlcpy(new->name, itm->name, sizeof(new->name));
  92         strlcpy(new->authname, itm->authname, sizeof(new->name));
  93 }
  94
  95 static void
  96 ent_put(struct kref *ref)
  97 {
  98         struct ent *map = container_of(ref, struct ent, h.ref);
  99         kfree(map);
 100 }
 101
 102 static struct cache_head *
 103 ent_alloc(void)
 104 {
 105         struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
 106         if (e)
 107                 return &e->h;
 108         else
 109                 return NULL;
 110 }
 111
 112 /*
 113  * ID -> Name cache
 114  */
 115
 116 static struct cache_head *idtoname_table[ENT_HASHMAX];
 117
 118 static uint32_t
 119 idtoname_hash(struct ent *ent)
 120 {
 121         uint32_t hash;
 122
 123         hash = hash_str(ent->authname, ENT_HASHBITS);
 124         hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
 125
 126         /* Flip LSB for user/group */
 127         if (ent->type == IDMAP_TYPE_GROUP)
 128                 hash ^= 1;
 129
 130         return hash;
 131 }
 132
 133 static void
 134 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 135     int *blen)
 136 {
 137         struct ent *ent = container_of(ch, struct ent, h);
 138         char idstr[11];
 139
 140         qword_add(bpp, blen, ent->authname);
 141         snprintf(idstr, sizeof(idstr), "%u", ent->id);
 142         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 143         qword_add(bpp, blen, idstr);
 144
 145         (*bpp)[-1] = '\n';
 146 }
 147
 148 static int
 149 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 150 {
 151         struct ent *a = container_of(ca, struct ent, h);
 152         struct ent *b = container_of(cb, struct ent, h);
 153
 154         return (a->id == b->id && a->type == b->type &&
 155             strcmp(a->authname, b->authname) == 0);
 156 }
 157
 158 static int
 159 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 160 {
 161         struct ent *ent;
 162
 163         if (h == NULL) {
 164                 seq_puts(m, "#domain type id [name]\n");
 165                 return 0;
 166         }
 167         ent = container_of(h, struct ent, h);
 168         seq_printf(m, "%s %s %u", ent->authname,
 169                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 170                         ent->id);
 171         if (test_bit(CACHE_VALID, &h->flags))
 172                 seq_printf(m, " %s", ent->name);
 173         seq_printf(m, "\n");
 174         return 0;
 175 }
 176
 177 static void
 178 warn_no_idmapd(struct cache_detail *detail)
 179 {
 180         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 181                         detail->last_close? "died" : "not been started");
 182 }
 183
 184
 185 static int         idtoname_parse(struct cache_detail *, char *, int);
 186 static struct ent *idtoname_lookup(struct ent *);
 187 static struct ent *idtoname_update(struct ent *, struct ent *);
 188
 189 static struct cache_detail idtoname_cache = {
 190         .owner          = THIS_MODULE,
 191         .hash_size      = ENT_HASHMAX,
 192         .hash_table     = idtoname_table,
 193         .name           = "nfs4.idtoname",
 194         .cache_put      = ent_put,
 195         .cache_request  = idtoname_request,
 196         .cache_parse    = idtoname_parse,
 197         .cache_show     = idtoname_show,
 198         .warn_no_listener = warn_no_idmapd,
 199         .match          = idtoname_match,
 200         .init           = ent_init,
 201         .update         = ent_init,
 202         .alloc          = ent_alloc,
 203 };
 204
 205 int
 206 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 207 {
 208         struct ent ent, *res;
 209         char *buf1, *bp;
 210         int len;
 211         int error = -EINVAL;
 212
 213         if (buf[buflen - 1] != '\n')
 214                 return (-EINVAL);
 215         buf[buflen - 1]= '\0';
 216
 217         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 218         if (buf1 == NULL)
 219                 return (-ENOMEM);
 220
 221         memset(&ent, 0, sizeof(ent));
 222
 223         /* Authentication name */
 224         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 225                 goto out;
 226         memcpy(ent.authname, buf1, sizeof(ent.authname));
 227
 228         /* Type */
 229         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 230                 goto out;
 231         ent.type = strcmp(buf1, "user") == 0 ?
 232                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 233
 234         /* ID */
 235         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 236                 goto out;
 237         ent.id = simple_strtoul(buf1, &bp, 10);
 238         if (bp == buf1)
 239                 goto out;
 240
 241         /* expiry */
 242         ent.h.expiry_time = get_expiry(&buf);
 243         if (ent.h.expiry_time == 0)
 244                 goto out;
 245
 246         error = -ENOMEM;
 247         res = idtoname_lookup(&ent);
 248         if (!res)
 249                 goto out;
 250
 251         /* Name */
 252         error = -EINVAL;
 253         len = qword_get(&buf, buf1, PAGE_SIZE);
 254         if (len < 0)
 255                 goto out;
 256         if (len == 0)
 257                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 258         else if (len >= IDMAP_NAMESZ)
 259                 goto out;
 260         else
 261                 memcpy(ent.name, buf1, sizeof(ent.name));
 262         error = -ENOMEM;
 263         res = idtoname_update(&ent, res);
 264         if (res == NULL)
 265                 goto out;
 266
 267         cache_put(&res->h, &idtoname_cache);
 268
 269         error = 0;
 270 out:
 271         kfree(buf1);
 272
 273         return error;
 274 }
 275
 276
 277 static struct ent *
 278 idtoname_lookup(struct ent *item)
 279 {
 280         struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
 281                                                     &item->h,
 282                                                     idtoname_hash(item));
 283         if (ch)
 284                 return container_of(ch, struct ent, h);
 285         else
 286                 return NULL;
 287 }
 288
 289 static struct ent *
 290 idtoname_update(struct ent *new, struct ent *old)
 291 {
 292         struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
 293                                                     &new->h, &old->h,
 294                                                     idtoname_hash(new));
 295         if (ch)
 296                 return container_of(ch, struct ent, h);
 297         else
 298                 return NULL;
 299 }
 300
 301
 302 /*
 303  * Name -> ID cache
 304  */
 305
 306 static struct cache_head *nametoid_table[ENT_HASHMAX];
 307
 308 static inline int
 309 nametoid_hash(struct ent *ent)
 310 {
 311         return hash_str(ent->name, ENT_HASHBITS);
 312 }
 313
 314 static void
 315 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 316     int *blen)
 317 {
 318         struct ent *ent = container_of(ch, struct ent, h);
 319
 320         qword_add(bpp, blen, ent->authname);
 321         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 322         qword_add(bpp, blen, ent->name);
 323
 324         (*bpp)[-1] = '\n';
 325 }
 326
 327 static int
 328 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 329 {
 330         struct ent *a = container_of(ca, struct ent, h);
 331         struct ent *b = container_of(cb, struct ent, h);
 332
 333         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 334             strcmp(a->authname, b->authname) == 0);
 335 }
 336
 337 static int
 338 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 339 {
 340         struct ent *ent;
 341
 342         if (h == NULL) {
 343                 seq_puts(m, "#domain type name [id]\n");
 344                 return 0;
 345         }
 346         ent = container_of(h, struct ent, h);
 347         seq_printf(m, "%s %s %s", ent->authname,
 348                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 349                         ent->name);
 350         if (test_bit(CACHE_VALID, &h->flags))
 351                 seq_printf(m, " %u", ent->id);
 352         seq_printf(m, "\n");
 353         return 0;
 354 }
 355
 356 static struct ent *nametoid_lookup(struct ent *);
 357 static struct ent *nametoid_update(struct ent *, struct ent *);
 358 static int         nametoid_parse(struct cache_detail *, char *, int);
 359
 360 static struct cache_detail nametoid_cache = {
 361         .owner          = THIS_MODULE,
 362         .hash_size      = ENT_HASHMAX,
 363         .hash_table     = nametoid_table,
 364         .name           = "nfs4.nametoid",
 365         .cache_put      = ent_put,
 366         .cache_request  = nametoid_request,
 367         .cache_parse    = nametoid_parse,
 368         .cache_show     = nametoid_show,
 369         .warn_no_listener = warn_no_idmapd,
 370         .match          = nametoid_match,
 371         .init           = ent_init,
 372         .update         = ent_init,
 373         .alloc          = ent_alloc,
 374 };
 375
 376 static int
 377 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 378 {
 379         struct ent ent, *res;
 380         char *buf1;
 381         int error = -EINVAL;
 382
 383         if (buf[buflen - 1] != '\n')
 384                 return (-EINVAL);
 385         buf[buflen - 1]= '\0';
 386
 387         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 388         if (buf1 == NULL)
 389                 return (-ENOMEM);
 390
 391         memset(&ent, 0, sizeof(ent));
 392
 393         /* Authentication name */
 394         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 395                 goto out;
 396         memcpy(ent.authname, buf1, sizeof(ent.authname));
 397
 398         /* Type */
 399         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 400                 goto out;
 401         ent.type = strcmp(buf1, "user") == 0 ?
 402                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 403
 404         /* Name */
 405         error = qword_get(&buf, buf1, PAGE_SIZE);
 406         if (error <= 0 || error >= IDMAP_NAMESZ)
 407                 goto out;
 408         memcpy(ent.name, buf1, sizeof(ent.name));
 409
 410         /* expiry */
 411         ent.h.expiry_time = get_expiry(&buf);
 412         if (ent.h.expiry_time == 0)
 413                 goto out;
 414
 415         /* ID */
 416         error = get_int(&buf, &ent.id);
 417         if (error == -EINVAL)
 418                 goto out;
 419         if (error == -ENOENT)
 420                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 421
 422         error = -ENOMEM;
 423         res = nametoid_lookup(&ent);
 424         if (res == NULL)
 425                 goto out;
 426         res = nametoid_update(&ent, res);
 427         if (res == NULL)
 428                 goto out;
 429
 430         cache_put(&res->h, &nametoid_cache);
 431         error = 0;
 432 out:
 433         kfree(buf1);
 434
 435         return (error);
 436 }
 437
 438
 439 static struct ent *
 440 nametoid_lookup(struct ent *item)
 441 {
 442         struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
 443                                                     &item->h,
 444                                                     nametoid_hash(item));
 445         if (ch)
 446                 return container_of(ch, struct ent, h);
 447         else
 448                 return NULL;
 449 }
 450
 451 static struct ent *
 452 nametoid_update(struct ent *new, struct ent *old)
 453 {
 454         struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
 455                                                     &new->h, &old->h,
 456                                                     nametoid_hash(new));
 457         if (ch)
 458                 return container_of(ch, struct ent, h);
 459         else
 460                 return NULL;
 461 }
 462
 463 /*
 464  * Exported API
 465  */
 466
 467 int
 468 nfsd_idmap_init(void)
 469 {
 470         int rv;
 471
 472         rv = cache_register(&idtoname_cache);
 473         if (rv)
 474                 return rv;
 475         rv = cache_register(&nametoid_cache);
 476         if (rv)
 477                 cache_unregister(&idtoname_cache);
 478         return rv;
 479 }
 480
 481 void
 482 nfsd_idmap_shutdown(void)
 483 {
 484         cache_unregister(&idtoname_cache);
 485         cache_unregister(&nametoid_cache);
 486 }
 487
 488 /*
 489  * Deferred request handling
 490  */
 491
 492 struct idmap_defer_req {
 493        struct cache_req         req;
 494        struct cache_deferred_req deferred_req;
 495        wait_queue_head_t        waitq;
 496        atomic_t                 count;
 497 };
 498
 499 static inline void
 500 put_mdr(struct idmap_defer_req *mdr)
 501 {
 502         if (atomic_dec_and_test(&mdr->count))
 503                 kfree(mdr);
 504 }
 505
 506 static inline void
 507 get_mdr(struct idmap_defer_req *mdr)
 508 {
 509         atomic_inc(&mdr->count);
 510 }
 511
 512 static void
 513 idmap_revisit(struct cache_deferred_req *dreq, int toomany)
 514 {
 515         struct idmap_defer_req *mdr =
 516                 container_of(dreq, struct idmap_defer_req, deferred_req);
 517
 518         wake_up(&mdr->waitq);
 519         put_mdr(mdr);
 520 }
 521
 522 static struct cache_deferred_req *
 523 idmap_defer(struct cache_req *req)
 524 {
 525         struct idmap_defer_req *mdr =
 526                 container_of(req, struct idmap_defer_req, req);
 527
 528         mdr->deferred_req.revisit = idmap_revisit;
 529         get_mdr(mdr);
 530         return (&mdr->deferred_req);
 531 }
 532
 533 static inline int
 534 do_idmap_lookup(struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 535                 struct cache_detail *detail, struct ent **item,
 536                 struct idmap_defer_req *mdr)
 537 {
 538         *item = lookup_fn(key);
 539         if (!*item)
 540                 return -ENOMEM;
 541         return cache_check(detail, &(*item)->h, &mdr->req);
 542 }
 543
 544 static inline int
 545 do_idmap_lookup_nowait(struct ent *(*lookup_fn)(struct ent *),
 546                         struct ent *key, struct cache_detail *detail,
 547                         struct ent **item)
 548 {
 549         int ret = -ENOMEM;
 550
 551         *item = lookup_fn(key);
 552         if (!*item)
 553                 goto out_err;
 554         ret = -ETIMEDOUT;
 555         if (!test_bit(CACHE_VALID, &(*item)->h.flags)
 556                         || (*item)->h.expiry_time < get_seconds()
 557                         || detail->flush_time > (*item)->h.last_refresh)
 558                 goto out_put;
 559         ret = -ENOENT;
 560         if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
 561                 goto out_put;
 562         return 0;
 563 out_put:
 564         cache_put(&(*item)->h, detail);
 565 out_err:
 566         *item = NULL;
 567         return ret;
 568 }
 569
 570 static int
 571 idmap_lookup(struct svc_rqst *rqstp,
 572                 struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 573                 struct cache_detail *detail, struct ent **item)
 574 {
 575         struct idmap_defer_req *mdr;
 576         int ret;
 577
 578         mdr = kzalloc(sizeof(*mdr), GFP_KERNEL);
 579         if (!mdr)
 580                 return -ENOMEM;
 581         atomic_set(&mdr->count, 1);
 582         init_waitqueue_head(&mdr->waitq);
 583         mdr->req.defer = idmap_defer;
 584         ret = do_idmap_lookup(lookup_fn, key, detail, item, mdr);
 585         if (ret == -EAGAIN) {
 586                 wait_event_interruptible_timeout(mdr->waitq,
 587                         test_bit(CACHE_VALID, &(*item)->h.flags), 1 * HZ);
 588                 ret = do_idmap_lookup_nowait(lookup_fn, key, detail, item);
 589         }
 590         put_mdr(mdr);
 591         return ret;
 592 }
 593
 594 static char *
 595 rqst_authname(struct svc_rqst *rqstp)
 596 {
 597         struct auth_domain *clp;
 598
 599         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 600         return clp->name;
 601 }
 602
 603 static int
 604 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 605                 uid_t *id)
 606 {
 607         struct ent *item, key = {
 608                 .type = type,
 609         };
 610         int ret;
 611
 612         if (namelen + 1 > sizeof(key.name))
 613                 return -EINVAL;
 614         memcpy(key.name, name, namelen);
 615         key.name[namelen] = '\0';
 616         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 617         ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 618         if (ret == -ENOENT)
 619                 ret = -ESRCH; /* nfserr_badname */
 620         if (ret)
 621                 return ret;
 622         *id = item->id;
 623         cache_put(&item->h, &nametoid_cache);
 624         return 0;
 625 }
 626
 627 static int
 628 idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 629 {
 630         struct ent *item, key = {
 631                 .id = id,
 632                 .type = type,
 633         };
 634         int ret;
 635
 636         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 637         ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
 638         if (ret == -ENOENT)
 639                 return sprintf(name, "%u", id);
 640         if (ret)
 641                 return ret;
 642         ret = strlen(item->name);
 643         BUG_ON(ret > IDMAP_NAMESZ);
 644         memcpy(name, item->name, ret);
 645         cache_put(&item->h, &idtoname_cache);
 646         return ret;
 647 }
 648
 649 int
 650 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 651                 __u32 *id)
 652 {
 653         return idmap_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
 654 }
 655
 656 int
 657 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 658                 __u32 *id)
 659 {
 660         return idmap_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
 661 }
 662
 663 int
 664 nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 665 {
 666         return idmap_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 667 }
 668
 669 int
 670 nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 671 {
 672         return idmap_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 673 }