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 kref *ref)
 100 {
 101         struct ent *map = container_of(ref, struct ent, h.ref);
 102         kfree(map);
 103 }
 104
 105 static struct cache_head *
 106 ent_alloc(void)
 107 {
 108         struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
 109         if (e)
 110                 return &e->h;
 111         else
 112                 return NULL;
 113 }
 114
 115 /*
 116  * ID -> Name cache
 117  */
 118
 119 static struct cache_head *idtoname_table[ENT_HASHMAX];
 120
 121 static uint32_t
 122 idtoname_hash(struct ent *ent)
 123 {
 124         uint32_t hash;
 125
 126         hash = hash_str(ent->authname, ENT_HASHBITS);
 127         hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
 128
 129         /* Flip LSB for user/group */
 130         if (ent->type == IDMAP_TYPE_GROUP)
 131                 hash ^= 1;
 132
 133         return hash;
 134 }
 135
 136 static void
 137 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 138     int *blen)
 139 {
 140         struct ent *ent = container_of(ch, struct ent, h);
 141         char idstr[11];
 142
 143         qword_add(bpp, blen, ent->authname);
 144         snprintf(idstr, sizeof(idstr), "%d", ent->id);
 145         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 146         qword_add(bpp, blen, idstr);
 147
 148         (*bpp)[-1] = '\n';
 149 }
 150
 151 static int
 152 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 153 {
 154         struct ent *a = container_of(ca, struct ent, h);
 155         struct ent *b = container_of(cb, struct ent, h);
 156
 157         return (a->id == b->id && a->type == b->type &&
 158             strcmp(a->authname, b->authname) == 0);
 159 }
 160
 161 static int
 162 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 163 {
 164         struct ent *ent;
 165
 166         if (h == NULL) {
 167                 seq_puts(m, "#domain type id [name]\n");
 168                 return 0;
 169         }
 170         ent = container_of(h, struct ent, h);
 171         seq_printf(m, "%s %s %d", ent->authname,
 172                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 173                         ent->id);
 174         if (test_bit(CACHE_VALID, &h->flags))
 175                 seq_printf(m, " %s", ent->name);
 176         seq_printf(m, "\n");
 177         return 0;
 178 }
 179
 180 static void
 181 warn_no_idmapd(struct cache_detail *detail)
 182 {
 183         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 184                         detail->last_close? "died" : "not been started");
 185 }
 186
 187
 188 static int         idtoname_parse(struct cache_detail *, char *, int);
 189 static struct ent *idtoname_lookup(struct ent *);
 190 static struct ent *idtoname_update(struct ent *, struct ent *);
 191
 192 static struct cache_detail idtoname_cache = {
 193         .owner          = THIS_MODULE,
 194         .hash_size      = ENT_HASHMAX,
 195         .hash_table     = idtoname_table,
 196         .name           = "nfs4.idtoname",
 197         .cache_put      = ent_put,
 198         .cache_request  = idtoname_request,
 199         .cache_parse    = idtoname_parse,
 200         .cache_show     = idtoname_show,
 201         .warn_no_listener = warn_no_idmapd,
 202         .match          = idtoname_match,
 203         .init           = ent_init,
 204         .update         = ent_init,
 205         .alloc          = ent_alloc,
 206 };
 207
 208 int
 209 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 210 {
 211         struct ent ent, *res;
 212         char *buf1, *bp;
 213         int error = -EINVAL;
 214
 215         if (buf[buflen - 1] != '\n')
 216                 return (-EINVAL);
 217         buf[buflen - 1]= '\0';
 218
 219         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 220         if (buf1 == NULL)
 221                 return (-ENOMEM);
 222
 223         memset(&ent, 0, sizeof(ent));
 224
 225         /* Authentication name */
 226         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 227                 goto out;
 228         memcpy(ent.authname, buf1, sizeof(ent.authname));
 229
 230         /* Type */
 231         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 232                 goto out;
 233         ent.type = strcmp(buf1, "user") == 0 ?
 234                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 235
 236         /* ID */
 237         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 238                 goto out;
 239         ent.id = simple_strtoul(buf1, &bp, 10);
 240         if (bp == buf1)
 241                 goto out;
 242
 243         /* expiry */
 244         ent.h.expiry_time = get_expiry(&buf);
 245         if (ent.h.expiry_time == 0)
 246                 goto out;
 247
 248         error = -ENOMEM;
 249         res = idtoname_lookup(&ent);
 250         if (!res)
 251                 goto out;
 252
 253         /* Name */
 254         error = qword_get(&buf, buf1, PAGE_SIZE);
 255         if (error == -EINVAL)
 256                 goto out;
 257         if (error == -ENOENT)
 258                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 259         else {
 260                 if (error >= IDMAP_NAMESZ) {
 261                         error = -EINVAL;
 262                         goto out;
 263                 }
 264                 memcpy(ent.name, buf1, sizeof(ent.name));
 265         }
 266         error = -ENOMEM;
 267         res = idtoname_update(&ent, res);
 268         if (res == NULL)
 269                 goto out;
 270
 271         cache_put(&res->h, &idtoname_cache);
 272
 273         error = 0;
 274 out:
 275         kfree(buf1);
 276
 277         return error;
 278 }
 279
 280
 281 static struct ent *
 282 idtoname_lookup(struct ent *item)
 283 {
 284         struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
 285                                                     &item->h,
 286                                                     idtoname_hash(item));
 287         if (ch)
 288                 return container_of(ch, struct ent, h);
 289         else
 290                 return NULL;
 291 }
 292
 293 static struct ent *
 294 idtoname_update(struct ent *new, struct ent *old)
 295 {
 296         struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
 297                                                     &new->h, &old->h,
 298                                                     idtoname_hash(new));
 299         if (ch)
 300                 return container_of(ch, struct ent, h);
 301         else
 302                 return NULL;
 303 }
 304
 305
 306 /*
 307  * Name -> ID cache
 308  */
 309
 310 static struct cache_head *nametoid_table[ENT_HASHMAX];
 311
 312 static inline int
 313 nametoid_hash(struct ent *ent)
 314 {
 315         return hash_str(ent->name, ENT_HASHBITS);
 316 }
 317
 318 static void
 319 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 320     int *blen)
 321 {
 322         struct ent *ent = container_of(ch, struct ent, h);
 323
 324         qword_add(bpp, blen, ent->authname);
 325         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 326         qword_add(bpp, blen, ent->name);
 327
 328         (*bpp)[-1] = '\n';
 329 }
 330
 331 static int
 332 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 333 {
 334         struct ent *a = container_of(ca, struct ent, h);
 335         struct ent *b = container_of(cb, struct ent, h);
 336
 337         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 338             strcmp(a->authname, b->authname) == 0);
 339 }
 340
 341 static int
 342 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 343 {
 344         struct ent *ent;
 345
 346         if (h == NULL) {
 347                 seq_puts(m, "#domain type name [id]\n");
 348                 return 0;
 349         }
 350         ent = container_of(h, struct ent, h);
 351         seq_printf(m, "%s %s %s", ent->authname,
 352                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 353                         ent->name);
 354         if (test_bit(CACHE_VALID, &h->flags))
 355                 seq_printf(m, " %d", ent->id);
 356         seq_printf(m, "\n");
 357         return 0;
 358 }
 359
 360 static struct ent *nametoid_lookup(struct ent *);
 361 static struct ent *nametoid_update(struct ent *, struct ent *);
 362 static int         nametoid_parse(struct cache_detail *, char *, int);
 363
 364 static struct cache_detail nametoid_cache = {
 365         .owner          = THIS_MODULE,
 366         .hash_size      = ENT_HASHMAX,
 367         .hash_table     = nametoid_table,
 368         .name           = "nfs4.nametoid",
 369         .cache_put      = ent_put,
 370         .cache_request  = nametoid_request,
 371         .cache_parse    = nametoid_parse,
 372         .cache_show     = nametoid_show,
 373         .warn_no_listener = warn_no_idmapd,
 374         .match          = nametoid_match,
 375         .init           = ent_init,
 376         .update         = ent_init,
 377         .alloc          = ent_alloc,
 378 };
 379
 380 static int
 381 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 382 {
 383         struct ent ent, *res;
 384         char *buf1;
 385         int error = -EINVAL;
 386
 387         if (buf[buflen - 1] != '\n')
 388                 return (-EINVAL);
 389         buf[buflen - 1]= '\0';
 390
 391         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 392         if (buf1 == NULL)
 393                 return (-ENOMEM);
 394
 395         memset(&ent, 0, sizeof(ent));
 396
 397         /* Authentication name */
 398         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 399                 goto out;
 400         memcpy(ent.authname, buf1, sizeof(ent.authname));
 401
 402         /* Type */
 403         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 404                 goto out;
 405         ent.type = strcmp(buf1, "user") == 0 ?
 406                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 407
 408         /* Name */
 409         error = qword_get(&buf, buf1, PAGE_SIZE);
 410         if (error <= 0 || error >= IDMAP_NAMESZ)
 411                 goto out;
 412         memcpy(ent.name, buf1, sizeof(ent.name));
 413
 414         /* expiry */
 415         ent.h.expiry_time = get_expiry(&buf);
 416         if (ent.h.expiry_time == 0)
 417                 goto out;
 418
 419         /* ID */
 420         error = get_int(&buf, &ent.id);
 421         if (error == -EINVAL)
 422                 goto out;
 423         if (error == -ENOENT)
 424                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 425
 426         error = -ENOMEM;
 427         res = nametoid_lookup(&ent);
 428         if (res == NULL)
 429                 goto out;
 430         res = nametoid_update(&ent, res);
 431         if (res == NULL)
 432                 goto out;
 433
 434         cache_put(&res->h, &nametoid_cache);
 435         error = 0;
 436 out:
 437         kfree(buf1);
 438
 439         return (error);
 440 }
 441
 442
 443 static struct ent *
 444 nametoid_lookup(struct ent *item)
 445 {
 446         struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
 447                                                     &item->h,
 448                                                     nametoid_hash(item));
 449         if (ch)
 450                 return container_of(ch, struct ent, h);
 451         else
 452                 return NULL;
 453 }
 454
 455 static struct ent *
 456 nametoid_update(struct ent *new, struct ent *old)
 457 {
 458         struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
 459                                                     &new->h, &old->h,
 460                                                     nametoid_hash(new));
 461         if (ch)
 462                 return container_of(ch, struct ent, h);
 463         else
 464                 return NULL;
 465 }
 466
 467 /*
 468  * Exported API
 469  */
 470
 471 void
 472 nfsd_idmap_init(void)
 473 {
 474         cache_register(&idtoname_cache);
 475         cache_register(&nametoid_cache);
 476 }
 477
 478 void
 479 nfsd_idmap_shutdown(void)
 480 {
 481         if (cache_unregister(&idtoname_cache))
 482                 printk(KERN_ERR "nfsd: failed to unregister idtoname cache\n");
 483         if (cache_unregister(&nametoid_cache))
 484                 printk(KERN_ERR "nfsd: failed to unregister nametoid cache\n");
 485 }
 486
 487 /*
 488  * Deferred request handling
 489  */
 490
 491 struct idmap_defer_req {
 492        struct cache_req         req;
 493        struct cache_deferred_req deferred_req;
 494        wait_queue_head_t        waitq;
 495        atomic_t                 count;
 496 };
 497
 498 static inline void
 499 put_mdr(struct idmap_defer_req *mdr)
 500 {
 501         if (atomic_dec_and_test(&mdr->count))
 502                 kfree(mdr);
 503 }
 504
 505 static inline void
 506 get_mdr(struct idmap_defer_req *mdr)
 507 {
 508         atomic_inc(&mdr->count);
 509 }
 510
 511 static void
 512 idmap_revisit(struct cache_deferred_req *dreq, int toomany)
 513 {
 514         struct idmap_defer_req *mdr =
 515                 container_of(dreq, struct idmap_defer_req, deferred_req);
 516
 517         wake_up(&mdr->waitq);
 518         put_mdr(mdr);
 519 }
 520
 521 static struct cache_deferred_req *
 522 idmap_defer(struct cache_req *req)
 523 {
 524         struct idmap_defer_req *mdr =
 525                 container_of(req, struct idmap_defer_req, req);
 526
 527         mdr->deferred_req.revisit = idmap_revisit;
 528         get_mdr(mdr);
 529         return (&mdr->deferred_req);
 530 }
 531
 532 static inline int
 533 do_idmap_lookup(struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 534                 struct cache_detail *detail, struct ent **item,
 535                 struct idmap_defer_req *mdr)
 536 {
 537         *item = lookup_fn(key);
 538         if (!*item)
 539                 return -ENOMEM;
 540         return cache_check(detail, &(*item)->h, &mdr->req);
 541 }
 542
 543 static inline int
 544 do_idmap_lookup_nowait(struct ent *(*lookup_fn)(struct ent *),
 545                         struct ent *key, struct cache_detail *detail,
 546                         struct ent **item)
 547 {
 548         int ret = -ENOMEM;
 549
 550         *item = lookup_fn(key);
 551         if (!*item)
 552                 goto out_err;
 553         ret = -ETIMEDOUT;
 554         if (!test_bit(CACHE_VALID, &(*item)->h.flags)
 555                         || (*item)->h.expiry_time < get_seconds()
 556                         || detail->flush_time > (*item)->h.last_refresh)
 557                 goto out_put;
 558         ret = -ENOENT;
 559         if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
 560                 goto out_put;
 561         return 0;
 562 out_put:
 563         cache_put(&(*item)->h, detail);
 564 out_err:
 565         *item = NULL;
 566         return ret;
 567 }
 568
 569 static int
 570 idmap_lookup(struct svc_rqst *rqstp,
 571                 struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 572                 struct cache_detail *detail, struct ent **item)
 573 {
 574         struct idmap_defer_req *mdr;
 575         int ret;
 576
 577         mdr = kmalloc(sizeof(*mdr), GFP_KERNEL);
 578         if (!mdr)
 579                 return -ENOMEM;
 580         memset(mdr, 0, sizeof(*mdr));
 581         atomic_set(&mdr->count, 1);
 582         init_waitqueue_head(&mdr->waitq);
 583         mdr->req.defer = idmap_defer;
 584         ret = do_idmap_lookup(lookup_fn, key, detail, item, mdr);
 585         if (ret == -EAGAIN) {
 586                 wait_event_interruptible_timeout(mdr->waitq,
 587                         test_bit(CACHE_VALID, &(*item)->h.flags), 1 * HZ);
 588                 ret = do_idmap_lookup_nowait(lookup_fn, key, detail, item);
 589         }
 590         put_mdr(mdr);
 591         return ret;
 592 }
 593
 594 static int
 595 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 596                 uid_t *id)
 597 {
 598         struct ent *item, key = {
 599                 .type = type,
 600         };
 601         int ret;
 602
 603         if (namelen + 1 > sizeof(key.name))
 604                 return -EINVAL;
 605         memcpy(key.name, name, namelen);
 606         key.name[namelen] = '\0';
 607         strlcpy(key.authname, rqstp->rq_client->name, sizeof(key.authname));
 608         ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 609         if (ret == -ENOENT)
 610                 ret = -ESRCH; /* nfserr_badname */
 611         if (ret)
 612                 return ret;
 613         *id = item->id;
 614         cache_put(&item->h, &nametoid_cache);
 615         return 0;
 616 }
 617
 618 static int
 619 idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 620 {
 621         struct ent *item, key = {
 622                 .id = id,
 623                 .type = type,
 624         };
 625         int ret;
 626
 627         strlcpy(key.authname, rqstp->rq_client->name, sizeof(key.authname));
 628         ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
 629         if (ret == -ENOENT)
 630                 return sprintf(name, "%u", id);
 631         if (ret)
 632                 return ret;
 633         ret = strlen(item->name);
 634         BUG_ON(ret > IDMAP_NAMESZ);
 635         memcpy(name, item->name, ret);
 636         cache_put(&item->h, &idtoname_cache);
 637         return ret;
 638 }
 639
 640 int
 641 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 642                 __u32 *id)
 643 {
 644         return idmap_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
 645 }
 646
 647 int
 648 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 649                 __u32 *id)
 650 {
 651         return idmap_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
 652 }
 653
 654 int
 655 nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 656 {
 657         return idmap_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 658 }
 659
 660 int
 661 nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 662 {
 663         return idmap_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 664 }