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