fs/nfsd/nfs4idmap.c

   1 /*
   2  *  Mapping of UID/GIDs to name and vice versa.
   3  *
   4  *  Copyright (c) 2002, 2003 The Regents of the University of
   5  *  Michigan.  All rights reserved.
   6  *
   7  *  Marius Aamodt Eriksen <marius@umich.edu>
   8  *
   9  *  Redistribution and use in source and binary forms, with or without
  10  *  modification, are permitted provided that the following conditions
  11  *  are met:
  12  *
  13  *  1. Redistributions of source code must retain the above copyright
  14  *     notice, this list of conditions and the following disclaimer.
  15  *  2. Redistributions in binary form must reproduce the above copyright
  16  *     notice, this list of conditions and the following disclaimer in the
  17  *     documentation and/or other materials provided with the distribution.
  18  *  3. Neither the name of the University nor the names of its
  19  *     contributors may be used to endorse or promote products derived
  20  *     from this software without specific prior written permission.
  21  *
  22  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  29  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  31  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  32  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <linux/module.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/sched.h>
  38 #include <linux/slab.h>
  39 #include "idmap.h"
  40 #include "nfsd.h"
  41
  42 /*
  43  * Cache entry
  44  */
  45
  46 /*
  47  * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
  48  * that.
  49  */
  50
  51 #define IDMAP_TYPE_USER  0
  52 #define IDMAP_TYPE_GROUP 1
  53
  54 struct ent {
  55         struct cache_head h;
  56         int               type;                /* User / Group */
  57         uid_t             id;
  58         char              name[IDMAP_NAMESZ];
  59         char              authname[IDMAP_NAMESZ];
  60 };
  61
  62 /* Common entry handling */
  63
  64 #define ENT_HASHBITS          8
  65 #define ENT_HASHMAX           (1 << ENT_HASHBITS)
  66 #define ENT_HASHMASK          (ENT_HASHMAX - 1)
  67
  68 static void
  69 ent_init(struct cache_head *cnew, struct cache_head *citm)
  70 {
  71         struct ent *new = container_of(cnew, struct ent, h);
  72         struct ent *itm = container_of(citm, struct ent, h);
  73
  74         new->id = itm->id;
  75         new->type = itm->type;
  76
  77         strlcpy(new->name, itm->name, sizeof(new->name));
  78         strlcpy(new->authname, itm->authname, sizeof(new->name));
  79 }
  80
  81 static void
  82 ent_put(struct kref *ref)
  83 {
  84         struct ent *map = container_of(ref, struct ent, h.ref);
  85         kfree(map);
  86 }
  87
  88 static struct cache_head *
  89 ent_alloc(void)
  90 {
  91         struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
  92         if (e)
  93                 return &e->h;
  94         else
  95                 return NULL;
  96 }
  97
  98 /*
  99  * ID -> Name cache
 100  */
 101
 102 static struct cache_head *idtoname_table[ENT_HASHMAX];
 103
 104 static uint32_t
 105 idtoname_hash(struct ent *ent)
 106 {
 107         uint32_t hash;
 108
 109         hash = hash_str(ent->authname, ENT_HASHBITS);
 110         hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
 111
 112         /* Flip LSB for user/group */
 113         if (ent->type == IDMAP_TYPE_GROUP)
 114                 hash ^= 1;
 115
 116         return hash;
 117 }
 118
 119 static void
 120 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 121     int *blen)
 122 {
 123         struct ent *ent = container_of(ch, struct ent, h);
 124         char idstr[11];
 125
 126         qword_add(bpp, blen, ent->authname);
 127         snprintf(idstr, sizeof(idstr), "%u", ent->id);
 128         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 129         qword_add(bpp, blen, idstr);
 130
 131         (*bpp)[-1] = '\n';
 132 }
 133
 134 static int
 135 idtoname_upcall(struct cache_detail *cd, struct cache_head *ch)
 136 {
 137         return sunrpc_cache_pipe_upcall(cd, ch, idtoname_request);
 138 }
 139
 140 static int
 141 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 142 {
 143         struct ent *a = container_of(ca, struct ent, h);
 144         struct ent *b = container_of(cb, struct ent, h);
 145
 146         return (a->id == b->id && a->type == b->type &&
 147             strcmp(a->authname, b->authname) == 0);
 148 }
 149
 150 static int
 151 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 152 {
 153         struct ent *ent;
 154
 155         if (h == NULL) {
 156                 seq_puts(m, "#domain type id [name]\n");
 157                 return 0;
 158         }
 159         ent = container_of(h, struct ent, h);
 160         seq_printf(m, "%s %s %u", ent->authname,
 161                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 162                         ent->id);
 163         if (test_bit(CACHE_VALID, &h->flags))
 164                 seq_printf(m, " %s", ent->name);
 165         seq_printf(m, "\n");
 166         return 0;
 167 }
 168
 169 static void
 170 warn_no_idmapd(struct cache_detail *detail, int has_died)
 171 {
 172         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 173                         has_died ? "died" : "not been started");
 174 }
 175
 176
 177 static int         idtoname_parse(struct cache_detail *, char *, int);
 178 static struct ent *idtoname_lookup(struct ent *);
 179 static struct ent *idtoname_update(struct ent *, struct ent *);
 180
 181 static struct cache_detail idtoname_cache = {
 182         .owner          = THIS_MODULE,
 183         .hash_size      = ENT_HASHMAX,
 184         .hash_table     = idtoname_table,
 185         .name           = "nfs4.idtoname",
 186         .cache_put      = ent_put,
 187         .cache_upcall   = idtoname_upcall,
 188         .cache_parse    = idtoname_parse,
 189         .cache_show     = idtoname_show,
 190         .warn_no_listener = warn_no_idmapd,
 191         .match          = idtoname_match,
 192         .init           = ent_init,
 193         .update         = ent_init,
 194         .alloc          = ent_alloc,
 195 };
 196
 197 static int
 198 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 199 {
 200         struct ent ent, *res;
 201         char *buf1, *bp;
 202         int len;
 203         int error = -EINVAL;
 204
 205         if (buf[buflen - 1] != '\n')
 206                 return (-EINVAL);
 207         buf[buflen - 1]= '\0';
 208
 209         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 210         if (buf1 == NULL)
 211                 return (-ENOMEM);
 212
 213         memset(&ent, 0, sizeof(ent));
 214
 215         /* Authentication name */
 216         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 217                 goto out;
 218         memcpy(ent.authname, buf1, sizeof(ent.authname));
 219
 220         /* Type */
 221         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 222                 goto out;
 223         ent.type = strcmp(buf1, "user") == 0 ?
 224                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 225
 226         /* ID */
 227         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 228                 goto out;
 229         ent.id = simple_strtoul(buf1, &bp, 10);
 230         if (bp == buf1)
 231                 goto out;
 232
 233         /* expiry */
 234         ent.h.expiry_time = get_expiry(&buf);
 235         if (ent.h.expiry_time == 0)
 236                 goto out;
 237
 238         error = -ENOMEM;
 239         res = idtoname_lookup(&ent);
 240         if (!res)
 241                 goto out;
 242
 243         /* Name */
 244         error = -EINVAL;
 245         len = qword_get(&buf, buf1, PAGE_SIZE);
 246         if (len < 0)
 247                 goto out;
 248         if (len == 0)
 249                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 250         else if (len >= IDMAP_NAMESZ)
 251                 goto out;
 252         else
 253                 memcpy(ent.name, buf1, sizeof(ent.name));
 254         error = -ENOMEM;
 255         res = idtoname_update(&ent, res);
 256         if (res == NULL)
 257                 goto out;
 258
 259         cache_put(&res->h, &idtoname_cache);
 260
 261         error = 0;
 262 out:
 263         kfree(buf1);
 264
 265         return error;
 266 }
 267
 268
 269 static struct ent *
 270 idtoname_lookup(struct ent *item)
 271 {
 272         struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
 273                                                     &item->h,
 274                                                     idtoname_hash(item));
 275         if (ch)
 276                 return container_of(ch, struct ent, h);
 277         else
 278                 return NULL;
 279 }
 280
 281 static struct ent *
 282 idtoname_update(struct ent *new, struct ent *old)
 283 {
 284         struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
 285                                                     &new->h, &old->h,
 286                                                     idtoname_hash(new));
 287         if (ch)
 288                 return container_of(ch, struct ent, h);
 289         else
 290                 return NULL;
 291 }
 292
 293
 294 /*
 295  * Name -> ID cache
 296  */
 297
 298 static struct cache_head *nametoid_table[ENT_HASHMAX];
 299
 300 static inline int
 301 nametoid_hash(struct ent *ent)
 302 {
 303         return hash_str(ent->name, ENT_HASHBITS);
 304 }
 305
 306 static void
 307 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 308     int *blen)
 309 {
 310         struct ent *ent = container_of(ch, struct ent, h);
 311
 312         qword_add(bpp, blen, ent->authname);
 313         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 314         qword_add(bpp, blen, ent->name);
 315
 316         (*bpp)[-1] = '\n';
 317 }
 318
 319 static int
 320 nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
 321 {
 322         return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
 323 }
 324
 325 static int
 326 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 327 {
 328         struct ent *a = container_of(ca, struct ent, h);
 329         struct ent *b = container_of(cb, struct ent, h);
 330
 331         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 332             strcmp(a->authname, b->authname) == 0);
 333 }
 334
 335 static int
 336 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 337 {
 338         struct ent *ent;
 339
 340         if (h == NULL) {
 341                 seq_puts(m, "#domain type name [id]\n");
 342                 return 0;
 343         }
 344         ent = container_of(h, struct ent, h);
 345         seq_printf(m, "%s %s %s", ent->authname,
 346                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 347                         ent->name);
 348         if (test_bit(CACHE_VALID, &h->flags))
 349                 seq_printf(m, " %u", ent->id);
 350         seq_printf(m, "\n");
 351         return 0;
 352 }
 353
 354 static struct ent *nametoid_lookup(struct ent *);
 355 static struct ent *nametoid_update(struct ent *, struct ent *);
 356 static int         nametoid_parse(struct cache_detail *, char *, int);
 357
 358 static struct cache_detail nametoid_cache = {
 359         .owner          = THIS_MODULE,
 360         .hash_size      = ENT_HASHMAX,
 361         .hash_table     = nametoid_table,
 362         .name           = "nfs4.nametoid",
 363         .cache_put      = ent_put,
 364         .cache_upcall   = nametoid_upcall,
 365         .cache_parse    = nametoid_parse,
 366         .cache_show     = nametoid_show,
 367         .warn_no_listener = warn_no_idmapd,
 368         .match          = nametoid_match,
 369         .init           = ent_init,
 370         .update         = ent_init,
 371         .alloc          = ent_alloc,
 372 };
 373
 374 static int
 375 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 376 {
 377         struct ent ent, *res;
 378         char *buf1;
 379         int error = -EINVAL;
 380
 381         if (buf[buflen - 1] != '\n')
 382                 return (-EINVAL);
 383         buf[buflen - 1]= '\0';
 384
 385         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 386         if (buf1 == NULL)
 387                 return (-ENOMEM);
 388
 389         memset(&ent, 0, sizeof(ent));
 390
 391         /* Authentication name */
 392         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 393                 goto out;
 394         memcpy(ent.authname, buf1, sizeof(ent.authname));
 395
 396         /* Type */
 397         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 398                 goto out;
 399         ent.type = strcmp(buf1, "user") == 0 ?
 400                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 401
 402         /* Name */
 403         error = qword_get(&buf, buf1, PAGE_SIZE);
 404         if (error <= 0 || error >= IDMAP_NAMESZ)
 405                 goto out;
 406         memcpy(ent.name, buf1, sizeof(ent.name));
 407
 408         /* expiry */
 409         ent.h.expiry_time = get_expiry(&buf);
 410         if (ent.h.expiry_time == 0)
 411                 goto out;
 412
 413         /* ID */
 414         error = get_int(&buf, &ent.id);
 415         if (error == -EINVAL)
 416                 goto out;
 417         if (error == -ENOENT)
 418                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 419
 420         error = -ENOMEM;
 421         res = nametoid_lookup(&ent);
 422         if (res == NULL)
 423                 goto out;
 424         res = nametoid_update(&ent, res);
 425         if (res == NULL)
 426                 goto out;
 427
 428         cache_put(&res->h, &nametoid_cache);
 429         error = 0;
 430 out:
 431         kfree(buf1);
 432
 433         return (error);
 434 }
 435
 436
 437 static struct ent *
 438 nametoid_lookup(struct ent *item)
 439 {
 440         struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
 441                                                     &item->h,
 442                                                     nametoid_hash(item));
 443         if (ch)
 444                 return container_of(ch, struct ent, h);
 445         else
 446                 return NULL;
 447 }
 448
 449 static struct ent *
 450 nametoid_update(struct ent *new, struct ent *old)
 451 {
 452         struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
 453                                                     &new->h, &old->h,
 454                                                     nametoid_hash(new));
 455         if (ch)
 456                 return container_of(ch, struct ent, h);
 457         else
 458                 return NULL;
 459 }
 460
 461 /*
 462  * Exported API
 463  */
 464
 465 int
 466 nfsd_idmap_init(void)
 467 {
 468         int rv;
 469
 470         rv = cache_register(&idtoname_cache);
 471         if (rv)
 472                 return rv;
 473         rv = cache_register(&nametoid_cache);
 474         if (rv)
 475                 cache_unregister(&idtoname_cache);
 476         return rv;
 477 }
 478
 479 void
 480 nfsd_idmap_shutdown(void)
 481 {
 482         cache_unregister(&idtoname_cache);
 483         cache_unregister(&nametoid_cache);
 484 }
 485
 486 static int
 487 idmap_lookup(struct svc_rqst *rqstp,
 488                 struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 489                 struct cache_detail *detail, struct ent **item)
 490 {
 491         int ret;
 492
 493         *item = lookup_fn(key);
 494         if (!*item)
 495                 return -ENOMEM;
 496  retry:
 497         ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
 498
 499         if (ret == -ETIMEDOUT) {
 500                 struct ent *prev_item = *item;
 501                 *item = lookup_fn(key);
 502                 if (*item != prev_item)
 503                         goto retry;
 504                 cache_put(&(*item)->h, detail);
 505         }
 506         return ret;
 507 }
 508
 509 static char *
 510 rqst_authname(struct svc_rqst *rqstp)
 511 {
 512         struct auth_domain *clp;
 513
 514         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 515         return clp->name;
 516 }
 517
 518 static __be32
 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 nfserr_badowner;
 529         memcpy(key.name, name, namelen);
 530         key.name[namelen] = '\0';
 531         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 532         ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 533         if (ret == -ENOENT)
 534                 return nfserr_badowner;
 535         if (ret)
 536                 return nfserrno(ret);
 537         *id = item->id;
 538         cache_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, rqst_authname(rqstp), 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         cache_put(&item->h, &idtoname_cache);
 561         return ret;
 562 }
 563
 564 __be32
 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 __be32
 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 }