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