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/smp_lock.h>
  50 #include <linux/sunrpc/cache.h>
  51 #include <linux/nfsd_idmap.h>
  52 #include <linux/list.h>
  53 #include <linux/time.h>
  54 #include <linux/seq_file.h>
  55 #include <linux/sunrpc/svcauth.h>
  56
  57 /*
  58  * Cache entry
  59  */
  60
  61 /*
  62  * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
  63  * that.
  64  */
  65
  66 #define IDMAP_TYPE_USER  0
  67 #define IDMAP_TYPE_GROUP 1
  68
  69 struct ent {
  70         struct cache_head h;
  71         int               type;                /* User / Group */
  72         uid_t             id;
  73         char              name[IDMAP_NAMESZ];
  74         char              authname[IDMAP_NAMESZ];
  75 };
  76
  77 /* Common entry handling */
  78
  79 #define ENT_HASHBITS          8
  80 #define ENT_HASHMAX           (1 << ENT_HASHBITS)
  81 #define ENT_HASHMASK          (ENT_HASHMAX - 1)
  82
  83 static void
  84 ent_init(struct cache_head *cnew, struct cache_head *citm)
  85 {
  86         struct ent *new = container_of(cnew, struct ent, h);
  87         struct ent *itm = container_of(citm, struct ent, h);
  88
  89         new->id = itm->id;
  90         new->type = itm->type;
  91
  92         strlcpy(new->name, itm->name, sizeof(new->name));
  93         strlcpy(new->authname, itm->authname, sizeof(new->name));
  94 }
  95
  96 static void
  97 ent_put(struct kref *ref)
  98 {
  99         struct ent *map = container_of(ref, struct ent, h.ref);
 100         kfree(map);
 101 }
 102
 103 static struct cache_head *
 104 ent_alloc(void)
 105 {
 106         struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
 107         if (e)
 108                 return &e->h;
 109         else
 110                 return NULL;
 111 }
 112
 113 /*
 114  * ID -> Name cache
 115  */
 116
 117 static struct cache_head *idtoname_table[ENT_HASHMAX];
 118
 119 static uint32_t
 120 idtoname_hash(struct ent *ent)
 121 {
 122         uint32_t hash;
 123
 124         hash = hash_str(ent->authname, ENT_HASHBITS);
 125         hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
 126
 127         /* Flip LSB for user/group */
 128         if (ent->type == IDMAP_TYPE_GROUP)
 129                 hash ^= 1;
 130
 131         return hash;
 132 }
 133
 134 static void
 135 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 136     int *blen)
 137 {
 138         struct ent *ent = container_of(ch, struct ent, h);
 139         char idstr[11];
 140
 141         qword_add(bpp, blen, ent->authname);
 142         snprintf(idstr, sizeof(idstr), "%d", ent->id);
 143         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 144         qword_add(bpp, blen, idstr);
 145
 146         (*bpp)[-1] = '\n';
 147 }
 148
 149 static int
 150 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 151 {
 152         struct ent *a = container_of(ca, struct ent, h);
 153         struct ent *b = container_of(cb, struct ent, h);
 154
 155         return (a->id == b->id && a->type == b->type &&
 156             strcmp(a->authname, b->authname) == 0);
 157 }
 158
 159 static int
 160 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 161 {
 162         struct ent *ent;
 163
 164         if (h == NULL) {
 165                 seq_puts(m, "#domain type id [name]\n");
 166                 return 0;
 167         }
 168         ent = container_of(h, struct ent, h);
 169         seq_printf(m, "%s %s %d", ent->authname,
 170                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 171                         ent->id);
 172         if (test_bit(CACHE_VALID, &h->flags))
 173                 seq_printf(m, " %s", ent->name);
 174         seq_printf(m, "\n");
 175         return 0;
 176 }
 177
 178 static void
 179 warn_no_idmapd(struct cache_detail *detail)
 180 {
 181         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 182                         detail->last_close? "died" : "not been started");
 183 }
 184
 185
 186 static int         idtoname_parse(struct cache_detail *, char *, int);
 187 static struct ent *idtoname_lookup(struct ent *);
 188 static struct ent *idtoname_update(struct ent *, struct ent *);
 189
 190 static struct cache_detail idtoname_cache = {
 191         .owner          = THIS_MODULE,
 192         .hash_size      = ENT_HASHMAX,
 193         .hash_table     = idtoname_table,
 194         .name           = "nfs4.idtoname",
 195         .cache_put      = ent_put,
 196         .cache_request  = idtoname_request,
 197         .cache_parse    = idtoname_parse,
 198         .cache_show     = idtoname_show,
 199         .warn_no_listener = warn_no_idmapd,
 200         .match          = idtoname_match,
 201         .init           = ent_init,
 202         .update         = ent_init,
 203         .alloc          = ent_alloc,
 204 };
 205
 206 int
 207 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 208 {
 209         struct ent ent, *res;
 210         char *buf1, *bp;
 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 = qword_get(&buf, buf1, PAGE_SIZE);
 253         if (error == -EINVAL)
 254                 goto out;
 255         if (error == -ENOENT)
 256                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 257         else {
 258                 if (error >= IDMAP_NAMESZ) {
 259                         error = -EINVAL;
 260                         goto out;
 261                 }
 262                 memcpy(ent.name, buf1, sizeof(ent.name));
 263         }
 264         error = -ENOMEM;
 265         res = idtoname_update(&ent, res);
 266         if (res == NULL)
 267                 goto out;
 268
 269         cache_put(&res->h, &idtoname_cache);
 270
 271         error = 0;
 272 out:
 273         kfree(buf1);
 274
 275         return error;
 276 }
 277
 278
 279 static struct ent *
 280 idtoname_lookup(struct ent *item)
 281 {
 282         struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
 283                                                     &item->h,
 284                                                     idtoname_hash(item));
 285         if (ch)
 286                 return container_of(ch, struct ent, h);
 287         else
 288                 return NULL;
 289 }
 290
 291 static struct ent *
 292 idtoname_update(struct ent *new, struct ent *old)
 293 {
 294         struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
 295                                                     &new->h, &old->h,
 296                                                     idtoname_hash(new));
 297         if (ch)
 298                 return container_of(ch, struct ent, h);
 299         else
 300                 return NULL;
 301 }
 302
 303
 304 /*
 305  * Name -> ID cache
 306  */
 307
 308 static struct cache_head *nametoid_table[ENT_HASHMAX];
 309
 310 static inline int
 311 nametoid_hash(struct ent *ent)
 312 {
 313         return hash_str(ent->name, ENT_HASHBITS);
 314 }
 315
 316 static void
 317 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 318     int *blen)
 319 {
 320         struct ent *ent = container_of(ch, struct ent, h);
 321
 322         qword_add(bpp, blen, ent->authname);
 323         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 324         qword_add(bpp, blen, ent->name);
 325
 326         (*bpp)[-1] = '\n';
 327 }
 328
 329 static int
 330 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 331 {
 332         struct ent *a = container_of(ca, struct ent, h);
 333         struct ent *b = container_of(cb, struct ent, h);
 334
 335         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 336             strcmp(a->authname, b->authname) == 0);
 337 }
 338
 339 static int
 340 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 341 {
 342         struct ent *ent;
 343
 344         if (h == NULL) {
 345                 seq_puts(m, "#domain type name [id]\n");
 346                 return 0;
 347         }
 348         ent = container_of(h, struct ent, h);
 349         seq_printf(m, "%s %s %s", ent->authname,
 350                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 351                         ent->name);
 352         if (test_bit(CACHE_VALID, &h->flags))
 353                 seq_printf(m, " %d", ent->id);
 354         seq_printf(m, "\n");
 355         return 0;
 356 }
 357
 358 static struct ent *nametoid_lookup(struct ent *);
 359 static struct ent *nametoid_update(struct ent *, struct ent *);
 360 static int         nametoid_parse(struct cache_detail *, char *, int);
 361
 362 static struct cache_detail nametoid_cache = {
 363         .owner          = THIS_MODULE,
 364         .hash_size      = ENT_HASHMAX,
 365         .hash_table     = nametoid_table,
 366         .name           = "nfs4.nametoid",
 367         .cache_put      = ent_put,
 368         .cache_request  = nametoid_request,
 369         .cache_parse    = nametoid_parse,
 370         .cache_show     = nametoid_show,
 371         .warn_no_listener = warn_no_idmapd,
 372         .match          = nametoid_match,
 373         .init           = ent_init,
 374         .update         = ent_init,
 375         .alloc          = ent_alloc,
 376 };
 377
 378 static int
 379 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 380 {
 381         struct ent ent, *res;
 382         char *buf1;
 383         int error = -EINVAL;
 384
 385         if (buf[buflen - 1] != '\n')
 386                 return (-EINVAL);
 387         buf[buflen - 1]= '\0';
 388
 389         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 390         if (buf1 == NULL)
 391                 return (-ENOMEM);
 392
 393         memset(&ent, 0, sizeof(ent));
 394
 395         /* Authentication name */
 396         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 397                 goto out;
 398         memcpy(ent.authname, buf1, sizeof(ent.authname));
 399
 400         /* Type */
 401         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 402                 goto out;
 403         ent.type = strcmp(buf1, "user") == 0 ?
 404                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 405
 406         /* Name */
 407         error = qword_get(&buf, buf1, PAGE_SIZE);
 408         if (error <= 0 || error >= IDMAP_NAMESZ)
 409                 goto out;
 410         memcpy(ent.name, buf1, sizeof(ent.name));
 411
 412         /* expiry */
 413         ent.h.expiry_time = get_expiry(&buf);
 414         if (ent.h.expiry_time == 0)
 415                 goto out;
 416
 417         /* ID */
 418         error = get_int(&buf, &ent.id);
 419         if (error == -EINVAL)
 420                 goto out;
 421         if (error == -ENOENT)
 422                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 423
 424         error = -ENOMEM;
 425         res = nametoid_lookup(&ent);
 426         if (res == NULL)
 427                 goto out;
 428         res = nametoid_update(&ent, res);
 429         if (res == NULL)
 430                 goto out;
 431
 432         cache_put(&res->h, &nametoid_cache);
 433         error = 0;
 434 out:
 435         kfree(buf1);
 436
 437         return (error);
 438 }
 439
 440
 441 static struct ent *
 442 nametoid_lookup(struct ent *item)
 443 {
 444         struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
 445                                                     &item->h,
 446                                                     nametoid_hash(item));
 447         if (ch)
 448                 return container_of(ch, struct ent, h);
 449         else
 450                 return NULL;
 451 }
 452
 453 static struct ent *
 454 nametoid_update(struct ent *new, struct ent *old)
 455 {
 456         struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
 457                                                     &new->h, &old->h,
 458                                                     nametoid_hash(new));
 459         if (ch)
 460                 return container_of(ch, struct ent, h);
 461         else
 462                 return NULL;
 463 }
 464
 465 /*
 466  * Exported API
 467  */
 468
 469 void
 470 nfsd_idmap_init(void)
 471 {
 472         cache_register(&idtoname_cache);
 473         cache_register(&nametoid_cache);
 474 }
 475
 476 void
 477 nfsd_idmap_shutdown(void)
 478 {
 479         if (cache_unregister(&idtoname_cache))
 480                 printk(KERN_ERR "nfsd: failed to unregister idtoname cache\n");
 481         if (cache_unregister(&nametoid_cache))
 482                 printk(KERN_ERR "nfsd: failed to unregister nametoid cache\n");
 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 int
 592 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 593                 uid_t *id)
 594 {
 595         struct ent *item, key = {
 596                 .type = type,
 597         };
 598         int ret;
 599
 600         if (namelen + 1 > sizeof(key.name))
 601                 return -EINVAL;
 602         memcpy(key.name, name, namelen);
 603         key.name[namelen] = '\0';
 604         strlcpy(key.authname, rqstp->rq_client->name, sizeof(key.authname));
 605         ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 606         if (ret == -ENOENT)
 607                 ret = -ESRCH; /* nfserr_badname */
 608         if (ret)
 609                 return ret;
 610         *id = item->id;
 611         cache_put(&item->h, &nametoid_cache);
 612         return 0;
 613 }
 614
 615 static int
 616 idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 617 {
 618         struct ent *item, key = {
 619                 .id = id,
 620                 .type = type,
 621         };
 622         int ret;
 623
 624         strlcpy(key.authname, rqstp->rq_client->name, sizeof(key.authname));
 625         ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
 626         if (ret == -ENOENT)
 627                 return sprintf(name, "%u", id);
 628         if (ret)
 629                 return ret;
 630         ret = strlen(item->name);
 631         BUG_ON(ret > IDMAP_NAMESZ);
 632         memcpy(name, item->name, ret);
 633         cache_put(&item->h, &idtoname_cache);
 634         return ret;
 635 }
 636
 637 int
 638 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 639                 __u32 *id)
 640 {
 641         return idmap_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
 642 }
 643
 644 int
 645 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 646                 __u32 *id)
 647 {
 648         return idmap_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
 649 }
 650
 651 int
 652 nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 653 {
 654         return idmap_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 655 }
 656
 657 int
 658 nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 659 {
 660         return idmap_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 661 }