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