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 error = -EINVAL;
 211
 212         if (buf[buflen - 1] != '\n')
 213                 return (-EINVAL);
 214         buf[buflen - 1]= '\0';
 215
 216         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 217         if (buf1 == NULL)
 218                 return (-ENOMEM);
 219
 220         memset(&ent, 0, sizeof(ent));
 221
 222         /* Authentication name */
 223         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 224                 goto out;
 225         memcpy(ent.authname, buf1, sizeof(ent.authname));
 226
 227         /* Type */
 228         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 229                 goto out;
 230         ent.type = strcmp(buf1, "user") == 0 ?
 231                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 232
 233         /* ID */
 234         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 235                 goto out;
 236         ent.id = simple_strtoul(buf1, &bp, 10);
 237         if (bp == buf1)
 238                 goto out;
 239
 240         /* expiry */
 241         ent.h.expiry_time = get_expiry(&buf);
 242         if (ent.h.expiry_time == 0)
 243                 goto out;
 244
 245         error = -ENOMEM;
 246         res = idtoname_lookup(&ent);
 247         if (!res)
 248                 goto out;
 249
 250         /* Name */
 251         error = qword_get(&buf, buf1, PAGE_SIZE);
 252         if (error == -EINVAL)
 253                 goto out;
 254         if (error == -ENOENT)
 255                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 256         else {
 257                 if (error >= IDMAP_NAMESZ) {
 258                         error = -EINVAL;
 259                         goto out;
 260                 }
 261                 memcpy(ent.name, buf1, sizeof(ent.name));
 262         }
 263         error = -ENOMEM;
 264         res = idtoname_update(&ent, res);
 265         if (res == NULL)
 266                 goto out;
 267
 268         cache_put(&res->h, &idtoname_cache);
 269
 270         error = 0;
 271 out:
 272         kfree(buf1);
 273
 274         return error;
 275 }
 276
 277
 278 static struct ent *
 279 idtoname_lookup(struct ent *item)
 280 {
 281         struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
 282                                                     &item->h,
 283                                                     idtoname_hash(item));
 284         if (ch)
 285                 return container_of(ch, struct ent, h);
 286         else
 287                 return NULL;
 288 }
 289
 290 static struct ent *
 291 idtoname_update(struct ent *new, struct ent *old)
 292 {
 293         struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
 294                                                     &new->h, &old->h,
 295                                                     idtoname_hash(new));
 296         if (ch)
 297                 return container_of(ch, struct ent, h);
 298         else
 299                 return NULL;
 300 }
 301
 302
 303 /*
 304  * Name -> ID cache
 305  */
 306
 307 static struct cache_head *nametoid_table[ENT_HASHMAX];
 308
 309 static inline int
 310 nametoid_hash(struct ent *ent)
 311 {
 312         return hash_str(ent->name, ENT_HASHBITS);
 313 }
 314
 315 static void
 316 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 317     int *blen)
 318 {
 319         struct ent *ent = container_of(ch, struct ent, h);
 320
 321         qword_add(bpp, blen, ent->authname);
 322         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 323         qword_add(bpp, blen, ent->name);
 324
 325         (*bpp)[-1] = '\n';
 326 }
 327
 328 static int
 329 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 330 {
 331         struct ent *a = container_of(ca, struct ent, h);
 332         struct ent *b = container_of(cb, struct ent, h);
 333
 334         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 335             strcmp(a->authname, b->authname) == 0);
 336 }
 337
 338 static int
 339 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 340 {
 341         struct ent *ent;
 342
 343         if (h == NULL) {
 344                 seq_puts(m, "#domain type name [id]\n");
 345                 return 0;
 346         }
 347         ent = container_of(h, struct ent, h);
 348         seq_printf(m, "%s %s %s", ent->authname,
 349                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 350                         ent->name);
 351         if (test_bit(CACHE_VALID, &h->flags))
 352                 seq_printf(m, " %u", ent->id);
 353         seq_printf(m, "\n");
 354         return 0;
 355 }
 356
 357 static struct ent *nametoid_lookup(struct ent *);
 358 static struct ent *nametoid_update(struct ent *, struct ent *);
 359 static int         nametoid_parse(struct cache_detail *, char *, int);
 360
 361 static struct cache_detail nametoid_cache = {
 362         .owner          = THIS_MODULE,
 363         .hash_size      = ENT_HASHMAX,
 364         .hash_table     = nametoid_table,
 365         .name           = "nfs4.nametoid",
 366         .cache_put      = ent_put,
 367         .cache_request  = nametoid_request,
 368         .cache_parse    = nametoid_parse,
 369         .cache_show     = nametoid_show,
 370         .warn_no_listener = warn_no_idmapd,
 371         .match          = nametoid_match,
 372         .init           = ent_init,
 373         .update         = ent_init,
 374         .alloc          = ent_alloc,
 375 };
 376
 377 static int
 378 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 379 {
 380         struct ent ent, *res;
 381         char *buf1;
 382         int error = -EINVAL;
 383
 384         if (buf[buflen - 1] != '\n')
 385                 return (-EINVAL);
 386         buf[buflen - 1]= '\0';
 387
 388         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 389         if (buf1 == NULL)
 390                 return (-ENOMEM);
 391
 392         memset(&ent, 0, sizeof(ent));
 393
 394         /* Authentication name */
 395         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 396                 goto out;
 397         memcpy(ent.authname, buf1, sizeof(ent.authname));
 398
 399         /* Type */
 400         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 401                 goto out;
 402         ent.type = strcmp(buf1, "user") == 0 ?
 403                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 404
 405         /* Name */
 406         error = qword_get(&buf, buf1, PAGE_SIZE);
 407         if (error <= 0 || error >= IDMAP_NAMESZ)
 408                 goto out;
 409         memcpy(ent.name, buf1, sizeof(ent.name));
 410
 411         /* expiry */
 412         ent.h.expiry_time = get_expiry(&buf);
 413         if (ent.h.expiry_time == 0)
 414                 goto out;
 415
 416         /* ID */
 417         error = get_int(&buf, &ent.id);
 418         if (error == -EINVAL)
 419                 goto out;
 420         if (error == -ENOENT)
 421                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 422
 423         error = -ENOMEM;
 424         res = nametoid_lookup(&ent);
 425         if (res == NULL)
 426                 goto out;
 427         res = nametoid_update(&ent, res);
 428         if (res == NULL)
 429                 goto out;
 430
 431         cache_put(&res->h, &nametoid_cache);
 432         error = 0;
 433 out:
 434         kfree(buf1);
 435
 436         return (error);
 437 }
 438
 439
 440 static struct ent *
 441 nametoid_lookup(struct ent *item)
 442 {
 443         struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
 444                                                     &item->h,
 445                                                     nametoid_hash(item));
 446         if (ch)
 447                 return container_of(ch, struct ent, h);
 448         else
 449                 return NULL;
 450 }
 451
 452 static struct ent *
 453 nametoid_update(struct ent *new, struct ent *old)
 454 {
 455         struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
 456                                                     &new->h, &old->h,
 457                                                     nametoid_hash(new));
 458         if (ch)
 459                 return container_of(ch, struct ent, h);
 460         else
 461                 return NULL;
 462 }
 463
 464 /*
 465  * Exported API
 466  */
 467
 468 void
 469 nfsd_idmap_init(void)
 470 {
 471         cache_register(&idtoname_cache);
 472         cache_register(&nametoid_cache);
 473 }
 474
 475 void
 476 nfsd_idmap_shutdown(void)
 477 {
 478         if (cache_unregister(&idtoname_cache))
 479                 printk(KERN_ERR "nfsd: failed to unregister idtoname cache\n");
 480         if (cache_unregister(&nametoid_cache))
 481                 printk(KERN_ERR "nfsd: failed to unregister nametoid cache\n");
 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 }