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 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 struct cache_detail idtoname_cache = {
 190         .hash_size      = ENT_HASHMAX,
 191         .hash_table     = idtoname_table,
 192         .name           = "nfs4.idtoname",
 193         .cache_put      = ent_put,
 194         .cache_request  = idtoname_request,
 195         .cache_parse    = idtoname_parse,
 196         .cache_show     = idtoname_show,
 197         .warn_no_listener = warn_no_idmapd,
 198 };
 199
 200 int
 201 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 202 {
 203         struct ent ent, *res;
 204         char *buf1, *bp;
 205         int error = -EINVAL;
 206
 207         if (buf[buflen - 1] != '\n')
 208                 return (-EINVAL);
 209         buf[buflen - 1]= '\0';
 210
 211         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 212         if (buf1 == NULL)
 213                 return (-ENOMEM);
 214
 215         memset(&ent, 0, sizeof(ent));
 216
 217         /* Authentication name */
 218         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 219                 goto out;
 220         memcpy(ent.authname, buf1, sizeof(ent.authname));
 221
 222         /* Type */
 223         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 224                 goto out;
 225         ent.type = strcmp(buf1, "user") == 0 ?
 226                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 227
 228         /* ID */
 229         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 230                 goto out;
 231         ent.id = simple_strtoul(buf1, &bp, 10);
 232         if (bp == buf1)
 233                 goto out;
 234
 235         /* expiry */
 236         ent.h.expiry_time = get_expiry(&buf);
 237         if (ent.h.expiry_time == 0)
 238                 goto out;
 239
 240         /* Name */
 241         error = qword_get(&buf, buf1, PAGE_SIZE);
 242         if (error == -EINVAL)
 243                 goto out;
 244         if (error == -ENOENT)
 245                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 246         else {
 247                 if (error >= IDMAP_NAMESZ) {
 248                         error = -EINVAL;
 249                         goto out;
 250                 }
 251                 memcpy(ent.name, buf1, sizeof(ent.name));
 252         }
 253         error = -ENOMEM;
 254         if ((res = idtoname_lookup(&ent, 1)) == NULL)
 255                 goto out;
 256
 257         ent_put(&res->h, &idtoname_cache);
 258
 259         error = 0;
 260 out:
 261         kfree(buf1);
 262
 263         return error;
 264 }
 265
 266 static DefineSimpleCacheLookupMap(ent, idtoname);
 267
 268 /*
 269  * Name -> ID cache
 270  */
 271
 272 static struct cache_head *nametoid_table[ENT_HASHMAX];
 273
 274 static inline int
 275 nametoid_hash(struct ent *ent)
 276 {
 277         return hash_str(ent->name, ENT_HASHBITS);
 278 }
 279
 280 void
 281 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 282     int *blen)
 283 {
 284         struct ent *ent = container_of(ch, struct ent, h);
 285
 286         qword_add(bpp, blen, ent->authname);
 287         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 288         qword_add(bpp, blen, ent->name);
 289
 290         (*bpp)[-1] = '\n';
 291 }
 292
 293 static inline int
 294 nametoid_match(struct ent *a, struct ent *b)
 295 {
 296         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 297             strcmp(a->authname, b->authname) == 0);
 298 }
 299
 300 static int
 301 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 302 {
 303         struct ent *ent;
 304
 305         if (h == NULL) {
 306                 seq_puts(m, "#domain type name [id]\n");
 307                 return 0;
 308         }
 309         ent = container_of(h, struct ent, h);
 310         seq_printf(m, "%s %s %s", ent->authname,
 311                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 312                         ent->name);
 313         if (test_bit(CACHE_VALID, &h->flags))
 314                 seq_printf(m, " %d", ent->id);
 315         seq_printf(m, "\n");
 316         return 0;
 317 }
 318
 319 static struct ent *nametoid_lookup(struct ent *, int);
 320 int                nametoid_parse(struct cache_detail *, char *, int);
 321
 322 struct cache_detail nametoid_cache = {
 323         .hash_size      = ENT_HASHMAX,
 324         .hash_table     = nametoid_table,
 325         .name           = "nfs4.nametoid",
 326         .cache_put      = ent_put,
 327         .cache_request  = nametoid_request,
 328         .cache_parse    = nametoid_parse,
 329         .cache_show     = nametoid_show,
 330         .warn_no_listener = warn_no_idmapd,
 331 };
 332
 333 int
 334 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 335 {
 336         struct ent ent, *res;
 337         char *buf1;
 338         int error = -EINVAL;
 339
 340         if (buf[buflen - 1] != '\n')
 341                 return (-EINVAL);
 342         buf[buflen - 1]= '\0';
 343
 344         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 345         if (buf1 == NULL)
 346                 return (-ENOMEM);
 347
 348         memset(&ent, 0, sizeof(ent));
 349
 350         /* Authentication name */
 351         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 352                 goto out;
 353         memcpy(ent.authname, buf1, sizeof(ent.authname));
 354
 355         /* Type */
 356         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 357                 goto out;
 358         ent.type = strcmp(buf1, "user") == 0 ?
 359                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 360
 361         /* Name */
 362         error = qword_get(&buf, buf1, PAGE_SIZE);
 363         if (error <= 0 || error >= IDMAP_NAMESZ)
 364                 goto out;
 365         memcpy(ent.name, buf1, sizeof(ent.name));
 366
 367         /* expiry */
 368         ent.h.expiry_time = get_expiry(&buf);
 369         if (ent.h.expiry_time == 0)
 370                 goto out;
 371
 372         /* ID */
 373         error = get_int(&buf, &ent.id);
 374         if (error == -EINVAL)
 375                 goto out;
 376         if (error == -ENOENT)
 377                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 378
 379         error = -ENOMEM;
 380         if ((res = nametoid_lookup(&ent, 1)) == NULL)
 381                 goto out;
 382
 383         ent_put(&res->h, &nametoid_cache);
 384         error = 0;
 385 out:
 386         kfree(buf1);
 387
 388         return (error);
 389 }
 390
 391 static DefineSimpleCacheLookupMap(ent, nametoid);
 392
 393 /*
 394  * Exported API
 395  */
 396
 397 void
 398 nfsd_idmap_init(void)
 399 {
 400         cache_register(&idtoname_cache);
 401         cache_register(&nametoid_cache);
 402 }
 403
 404 void
 405 nfsd_idmap_shutdown(void)
 406 {
 407         cache_unregister(&idtoname_cache);
 408         cache_unregister(&nametoid_cache);
 409 }
 410
 411 /*
 412  * Deferred request handling
 413  */
 414
 415 struct idmap_defer_req {
 416        struct cache_req         req;
 417        struct cache_deferred_req deferred_req;
 418        wait_queue_head_t        waitq;
 419        atomic_t                 count;
 420 };
 421
 422 static inline void
 423 put_mdr(struct idmap_defer_req *mdr)
 424 {
 425         if (atomic_dec_and_test(&mdr->count))
 426                 kfree(mdr);
 427 }
 428
 429 static inline void
 430 get_mdr(struct idmap_defer_req *mdr)
 431 {
 432         atomic_inc(&mdr->count);
 433 }
 434
 435 static void
 436 idmap_revisit(struct cache_deferred_req *dreq, int toomany)
 437 {
 438         struct idmap_defer_req *mdr =
 439                 container_of(dreq, struct idmap_defer_req, deferred_req);
 440
 441         wake_up(&mdr->waitq);
 442         put_mdr(mdr);
 443 }
 444
 445 static struct cache_deferred_req *
 446 idmap_defer(struct cache_req *req)
 447 {
 448         struct idmap_defer_req *mdr =
 449                 container_of(req, struct idmap_defer_req, req);
 450
 451         mdr->deferred_req.revisit = idmap_revisit;
 452         get_mdr(mdr);
 453         return (&mdr->deferred_req);
 454 }
 455
 456 static inline int
 457 do_idmap_lookup(struct ent *(*lookup_fn)(struct ent *, int), struct ent *key,
 458                 struct cache_detail *detail, struct ent **item,
 459                 struct idmap_defer_req *mdr)
 460 {
 461         *item = lookup_fn(key, 0);
 462         if (!*item)
 463                 return -ENOMEM;
 464         return cache_check(detail, &(*item)->h, &mdr->req);
 465 }
 466
 467 static inline int
 468 do_idmap_lookup_nowait(struct ent *(*lookup_fn)(struct ent *, int),
 469                         struct ent *key, struct cache_detail *detail,
 470                         struct ent **item)
 471 {
 472         int ret = -ENOMEM;
 473
 474         *item = lookup_fn(key, 0);
 475         if (!*item)
 476                 goto out_err;
 477         ret = -ETIMEDOUT;
 478         if (!test_bit(CACHE_VALID, &(*item)->h.flags)
 479                         || (*item)->h.expiry_time < get_seconds()
 480                         || detail->flush_time > (*item)->h.last_refresh)
 481                 goto out_put;
 482         ret = -ENOENT;
 483         if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
 484                 goto out_put;
 485         return 0;
 486 out_put:
 487         ent_put(&(*item)->h, detail);
 488 out_err:
 489         *item = NULL;
 490         return ret;
 491 }
 492
 493 static int
 494 idmap_lookup(struct svc_rqst *rqstp,
 495                 struct ent *(*lookup_fn)(struct ent *, int), struct ent *key,
 496                 struct cache_detail *detail, struct ent **item)
 497 {
 498         struct idmap_defer_req *mdr;
 499         int ret;
 500
 501         mdr = kmalloc(sizeof(*mdr), GFP_KERNEL);
 502         if (!mdr)
 503                 return -ENOMEM;
 504         memset(mdr, 0, sizeof(*mdr));
 505         atomic_set(&mdr->count, 1);
 506         init_waitqueue_head(&mdr->waitq);
 507         mdr->req.defer = idmap_defer;
 508         ret = do_idmap_lookup(lookup_fn, key, detail, item, mdr);
 509         if (ret == -EAGAIN) {
 510                 wait_event_interruptible_timeout(mdr->waitq,
 511                         test_bit(CACHE_VALID, &(*item)->h.flags), 1 * HZ);
 512                 ret = do_idmap_lookup_nowait(lookup_fn, key, detail, item);
 513         }
 514         put_mdr(mdr);
 515         return ret;
 516 }
 517
 518 static int
 519 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 520                 uid_t *id)
 521 {
 522         struct ent *item, key = {
 523                 .type = type,
 524         };
 525         int ret;
 526
 527         if (namelen + 1 > sizeof(key.name))
 528                 return -EINVAL;
 529         memcpy(key.name, name, namelen);
 530         key.name[namelen] = '\0';
 531         strlcpy(key.authname, rqstp->rq_client->name, sizeof(key.authname));
 532         ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 533         if (ret == -ENOENT)
 534                 ret = -ESRCH; /* nfserr_badname */
 535         if (ret)
 536                 return ret;
 537         *id = item->id;
 538         ent_put(&item->h, &nametoid_cache);
 539         return 0;
 540 }
 541
 542 static int
 543 idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 544 {
 545         struct ent *item, key = {
 546                 .id = id,
 547                 .type = type,
 548         };
 549         int ret;
 550
 551         strlcpy(key.authname, rqstp->rq_client->name, sizeof(key.authname));
 552         ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
 553         if (ret == -ENOENT)
 554                 return sprintf(name, "%u", id);
 555         if (ret)
 556                 return ret;
 557         ret = strlen(item->name);
 558         BUG_ON(ret > IDMAP_NAMESZ);
 559         memcpy(name, item->name, ret);
 560         ent_put(&item->h, &idtoname_cache);
 561         return ret;
 562 }
 563
 564 int
 565 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 566                 __u32 *id)
 567 {
 568         return idmap_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
 569 }
 570
 571 int
 572 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 573                 __u32 *id)
 574 {
 575         return idmap_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
 576 }
 577
 578 int
 579 nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 580 {
 581         return idmap_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 582 }
 583
 584 int
 585 nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 586 {
 587         return idmap_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 588 }