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_upcall(struct cache_detail *cd, struct cache_head *ch)
 150 {
 151         return sunrpc_cache_pipe_upcall(cd, ch, idtoname_request);
 152 }
 153
 154 static int
 155 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 156 {
 157         struct ent *a = container_of(ca, struct ent, h);
 158         struct ent *b = container_of(cb, struct ent, h);
 159
 160         return (a->id == b->id && a->type == b->type &&
 161             strcmp(a->authname, b->authname) == 0);
 162 }
 163
 164 static int
 165 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 166 {
 167         struct ent *ent;
 168
 169         if (h == NULL) {
 170                 seq_puts(m, "#domain type id [name]\n");
 171                 return 0;
 172         }
 173         ent = container_of(h, struct ent, h);
 174         seq_printf(m, "%s %s %u", ent->authname,
 175                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 176                         ent->id);
 177         if (test_bit(CACHE_VALID, &h->flags))
 178                 seq_printf(m, " %s", ent->name);
 179         seq_printf(m, "\n");
 180         return 0;
 181 }
 182
 183 static void
 184 warn_no_idmapd(struct cache_detail *detail, int has_died)
 185 {
 186         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 187                         has_died ? "died" : "not been started");
 188 }
 189
 190
 191 static int         idtoname_parse(struct cache_detail *, char *, int);
 192 static struct ent *idtoname_lookup(struct ent *);
 193 static struct ent *idtoname_update(struct ent *, struct ent *);
 194
 195 static struct cache_detail idtoname_cache = {
 196         .owner          = THIS_MODULE,
 197         .hash_size      = ENT_HASHMAX,
 198         .hash_table     = idtoname_table,
 199         .name           = "nfs4.idtoname",
 200         .cache_put      = ent_put,
 201         .cache_upcall   = idtoname_upcall,
 202         .cache_parse    = idtoname_parse,
 203         .cache_show     = idtoname_show,
 204         .warn_no_listener = warn_no_idmapd,
 205         .match          = idtoname_match,
 206         .init           = ent_init,
 207         .update         = ent_init,
 208         .alloc          = ent_alloc,
 209 };
 210
 211 static int
 212 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 213 {
 214         struct ent ent, *res;
 215         char *buf1, *bp;
 216         int len;
 217         int error = -EINVAL;
 218
 219         if (buf[buflen - 1] != '\n')
 220                 return (-EINVAL);
 221         buf[buflen - 1]= '\0';
 222
 223         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 224         if (buf1 == NULL)
 225                 return (-ENOMEM);
 226
 227         memset(&ent, 0, sizeof(ent));
 228
 229         /* Authentication name */
 230         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 231                 goto out;
 232         memcpy(ent.authname, buf1, sizeof(ent.authname));
 233
 234         /* Type */
 235         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 236                 goto out;
 237         ent.type = strcmp(buf1, "user") == 0 ?
 238                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 239
 240         /* ID */
 241         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 242                 goto out;
 243         ent.id = simple_strtoul(buf1, &bp, 10);
 244         if (bp == buf1)
 245                 goto out;
 246
 247         /* expiry */
 248         ent.h.expiry_time = get_expiry(&buf);
 249         if (ent.h.expiry_time == 0)
 250                 goto out;
 251
 252         error = -ENOMEM;
 253         res = idtoname_lookup(&ent);
 254         if (!res)
 255                 goto out;
 256
 257         /* Name */
 258         error = -EINVAL;
 259         len = qword_get(&buf, buf1, PAGE_SIZE);
 260         if (len < 0)
 261                 goto out;
 262         if (len == 0)
 263                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 264         else if (len >= IDMAP_NAMESZ)
 265                 goto out;
 266         else
 267                 memcpy(ent.name, buf1, sizeof(ent.name));
 268         error = -ENOMEM;
 269         res = idtoname_update(&ent, res);
 270         if (res == NULL)
 271                 goto out;
 272
 273         cache_put(&res->h, &idtoname_cache);
 274
 275         error = 0;
 276 out:
 277         kfree(buf1);
 278
 279         return error;
 280 }
 281
 282
 283 static struct ent *
 284 idtoname_lookup(struct ent *item)
 285 {
 286         struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
 287                                                     &item->h,
 288                                                     idtoname_hash(item));
 289         if (ch)
 290                 return container_of(ch, struct ent, h);
 291         else
 292                 return NULL;
 293 }
 294
 295 static struct ent *
 296 idtoname_update(struct ent *new, struct ent *old)
 297 {
 298         struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
 299                                                     &new->h, &old->h,
 300                                                     idtoname_hash(new));
 301         if (ch)
 302                 return container_of(ch, struct ent, h);
 303         else
 304                 return NULL;
 305 }
 306
 307
 308 /*
 309  * Name -> ID cache
 310  */
 311
 312 static struct cache_head *nametoid_table[ENT_HASHMAX];
 313
 314 static inline int
 315 nametoid_hash(struct ent *ent)
 316 {
 317         return hash_str(ent->name, ENT_HASHBITS);
 318 }
 319
 320 static void
 321 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 322     int *blen)
 323 {
 324         struct ent *ent = container_of(ch, struct ent, h);
 325
 326         qword_add(bpp, blen, ent->authname);
 327         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 328         qword_add(bpp, blen, ent->name);
 329
 330         (*bpp)[-1] = '\n';
 331 }
 332
 333 static int
 334 nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
 335 {
 336         return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
 337 }
 338
 339 static int
 340 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 341 {
 342         struct ent *a = container_of(ca, struct ent, h);
 343         struct ent *b = container_of(cb, struct ent, h);
 344
 345         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 346             strcmp(a->authname, b->authname) == 0);
 347 }
 348
 349 static int
 350 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 351 {
 352         struct ent *ent;
 353
 354         if (h == NULL) {
 355                 seq_puts(m, "#domain type name [id]\n");
 356                 return 0;
 357         }
 358         ent = container_of(h, struct ent, h);
 359         seq_printf(m, "%s %s %s", ent->authname,
 360                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 361                         ent->name);
 362         if (test_bit(CACHE_VALID, &h->flags))
 363                 seq_printf(m, " %u", ent->id);
 364         seq_printf(m, "\n");
 365         return 0;
 366 }
 367
 368 static struct ent *nametoid_lookup(struct ent *);
 369 static struct ent *nametoid_update(struct ent *, struct ent *);
 370 static int         nametoid_parse(struct cache_detail *, char *, int);
 371
 372 static struct cache_detail nametoid_cache = {
 373         .owner          = THIS_MODULE,
 374         .hash_size      = ENT_HASHMAX,
 375         .hash_table     = nametoid_table,
 376         .name           = "nfs4.nametoid",
 377         .cache_put      = ent_put,
 378         .cache_upcall   = nametoid_upcall,
 379         .cache_parse    = nametoid_parse,
 380         .cache_show     = nametoid_show,
 381         .warn_no_listener = warn_no_idmapd,
 382         .match          = nametoid_match,
 383         .init           = ent_init,
 384         .update         = ent_init,
 385         .alloc          = ent_alloc,
 386 };
 387
 388 static int
 389 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 390 {
 391         struct ent ent, *res;
 392         char *buf1;
 393         int error = -EINVAL;
 394
 395         if (buf[buflen - 1] != '\n')
 396                 return (-EINVAL);
 397         buf[buflen - 1]= '\0';
 398
 399         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 400         if (buf1 == NULL)
 401                 return (-ENOMEM);
 402
 403         memset(&ent, 0, sizeof(ent));
 404
 405         /* Authentication name */
 406         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 407                 goto out;
 408         memcpy(ent.authname, buf1, sizeof(ent.authname));
 409
 410         /* Type */
 411         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 412                 goto out;
 413         ent.type = strcmp(buf1, "user") == 0 ?
 414                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 415
 416         /* Name */
 417         error = qword_get(&buf, buf1, PAGE_SIZE);
 418         if (error <= 0 || error >= IDMAP_NAMESZ)
 419                 goto out;
 420         memcpy(ent.name, buf1, sizeof(ent.name));
 421
 422         /* expiry */
 423         ent.h.expiry_time = get_expiry(&buf);
 424         if (ent.h.expiry_time == 0)
 425                 goto out;
 426
 427         /* ID */
 428         error = get_int(&buf, &ent.id);
 429         if (error == -EINVAL)
 430                 goto out;
 431         if (error == -ENOENT)
 432                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 433
 434         error = -ENOMEM;
 435         res = nametoid_lookup(&ent);
 436         if (res == NULL)
 437                 goto out;
 438         res = nametoid_update(&ent, res);
 439         if (res == NULL)
 440                 goto out;
 441
 442         cache_put(&res->h, &nametoid_cache);
 443         error = 0;
 444 out:
 445         kfree(buf1);
 446
 447         return (error);
 448 }
 449
 450
 451 static struct ent *
 452 nametoid_lookup(struct ent *item)
 453 {
 454         struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
 455                                                     &item->h,
 456                                                     nametoid_hash(item));
 457         if (ch)
 458                 return container_of(ch, struct ent, h);
 459         else
 460                 return NULL;
 461 }
 462
 463 static struct ent *
 464 nametoid_update(struct ent *new, struct ent *old)
 465 {
 466         struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
 467                                                     &new->h, &old->h,
 468                                                     nametoid_hash(new));
 469         if (ch)
 470                 return container_of(ch, struct ent, h);
 471         else
 472                 return NULL;
 473 }
 474
 475 /*
 476  * Exported API
 477  */
 478
 479 int
 480 nfsd_idmap_init(void)
 481 {
 482         int rv;
 483
 484         rv = cache_register(&idtoname_cache);
 485         if (rv)
 486                 return rv;
 487         rv = cache_register(&nametoid_cache);
 488         if (rv)
 489                 cache_unregister(&idtoname_cache);
 490         return rv;
 491 }
 492
 493 void
 494 nfsd_idmap_shutdown(void)
 495 {
 496         cache_unregister(&idtoname_cache);
 497         cache_unregister(&nametoid_cache);
 498 }
 499
 500 /*
 501  * Deferred request handling
 502  */
 503
 504 struct idmap_defer_req {
 505        struct cache_req         req;
 506        struct cache_deferred_req deferred_req;
 507        wait_queue_head_t        waitq;
 508        atomic_t                 count;
 509 };
 510
 511 static inline void
 512 put_mdr(struct idmap_defer_req *mdr)
 513 {
 514         if (atomic_dec_and_test(&mdr->count))
 515                 kfree(mdr);
 516 }
 517
 518 static inline void
 519 get_mdr(struct idmap_defer_req *mdr)
 520 {
 521         atomic_inc(&mdr->count);
 522 }
 523
 524 static void
 525 idmap_revisit(struct cache_deferred_req *dreq, int toomany)
 526 {
 527         struct idmap_defer_req *mdr =
 528                 container_of(dreq, struct idmap_defer_req, deferred_req);
 529
 530         wake_up(&mdr->waitq);
 531         put_mdr(mdr);
 532 }
 533
 534 static struct cache_deferred_req *
 535 idmap_defer(struct cache_req *req)
 536 {
 537         struct idmap_defer_req *mdr =
 538                 container_of(req, struct idmap_defer_req, req);
 539
 540         mdr->deferred_req.revisit = idmap_revisit;
 541         get_mdr(mdr);
 542         return (&mdr->deferred_req);
 543 }
 544
 545 static inline int
 546 do_idmap_lookup(struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 547                 struct cache_detail *detail, struct ent **item,
 548                 struct idmap_defer_req *mdr)
 549 {
 550         *item = lookup_fn(key);
 551         if (!*item)
 552                 return -ENOMEM;
 553         return cache_check(detail, &(*item)->h, &mdr->req);
 554 }
 555
 556 static inline int
 557 do_idmap_lookup_nowait(struct ent *(*lookup_fn)(struct ent *),
 558                         struct ent *key, struct cache_detail *detail,
 559                         struct ent **item)
 560 {
 561         int ret = -ENOMEM;
 562
 563         *item = lookup_fn(key);
 564         if (!*item)
 565                 goto out_err;
 566         ret = -ETIMEDOUT;
 567         if (!test_bit(CACHE_VALID, &(*item)->h.flags)
 568                         || (*item)->h.expiry_time < get_seconds()
 569                         || detail->flush_time > (*item)->h.last_refresh)
 570                 goto out_put;
 571         ret = -ENOENT;
 572         if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
 573                 goto out_put;
 574         return 0;
 575 out_put:
 576         cache_put(&(*item)->h, detail);
 577 out_err:
 578         *item = NULL;
 579         return ret;
 580 }
 581
 582 static int
 583 idmap_lookup(struct svc_rqst *rqstp,
 584                 struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 585                 struct cache_detail *detail, struct ent **item)
 586 {
 587         struct idmap_defer_req *mdr;
 588         int ret;
 589
 590         mdr = kzalloc(sizeof(*mdr), GFP_KERNEL);
 591         if (!mdr)
 592                 return -ENOMEM;
 593         atomic_set(&mdr->count, 1);
 594         init_waitqueue_head(&mdr->waitq);
 595         mdr->req.defer = idmap_defer;
 596         ret = do_idmap_lookup(lookup_fn, key, detail, item, mdr);
 597         if (ret == -EAGAIN) {
 598                 wait_event_interruptible_timeout(mdr->waitq,
 599                         test_bit(CACHE_VALID, &(*item)->h.flags), 1 * HZ);
 600                 ret = do_idmap_lookup_nowait(lookup_fn, key, detail, item);
 601         }
 602         put_mdr(mdr);
 603         return ret;
 604 }
 605
 606 static char *
 607 rqst_authname(struct svc_rqst *rqstp)
 608 {
 609         struct auth_domain *clp;
 610
 611         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 612         return clp->name;
 613 }
 614
 615 static int
 616 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 617                 uid_t *id)
 618 {
 619         struct ent *item, key = {
 620                 .type = type,
 621         };
 622         int ret;
 623
 624         if (namelen + 1 > sizeof(key.name))
 625                 return -EINVAL;
 626         memcpy(key.name, name, namelen);
 627         key.name[namelen] = '\0';
 628         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 629         ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 630         if (ret == -ENOENT)
 631                 ret = -ESRCH; /* nfserr_badname */
 632         if (ret)
 633                 return ret;
 634         *id = item->id;
 635         cache_put(&item->h, &nametoid_cache);
 636         return 0;
 637 }
 638
 639 static int
 640 idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 641 {
 642         struct ent *item, key = {
 643                 .id = id,
 644                 .type = type,
 645         };
 646         int ret;
 647
 648         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 649         ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
 650         if (ret == -ENOENT)
 651                 return sprintf(name, "%u", id);
 652         if (ret)
 653                 return ret;
 654         ret = strlen(item->name);
 655         BUG_ON(ret > IDMAP_NAMESZ);
 656         memcpy(name, item->name, ret);
 657         cache_put(&item->h, &idtoname_cache);
 658         return ret;
 659 }
 660
 661 int
 662 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 663                 __u32 *id)
 664 {
 665         return idmap_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
 666 }
 667
 668 int
 669 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 670                 __u32 *id)
 671 {
 672         return idmap_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
 673 }
 674
 675 int
 676 nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 677 {
 678         return idmap_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 679 }
 680
 681 int
 682 nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 683 {
 684         return idmap_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 685 }