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