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