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 <net/net_namespace.h>
  40 #include "idmap.h"
  41 #include "nfsd.h"
  42
  43 /*
  44  * Turn off idmapping when using AUTH_SYS.
  45  */
  46 static bool nfs4_disable_idmapping = true;
  47 module_param(nfs4_disable_idmapping, bool, 0644);
  48 MODULE_PARM_DESC(nfs4_disable_idmapping,
  49                 "Turn off server's NFSv4 idmapping when using 'sec=sys'");
  50
  51 /*
  52  * Cache entry
  53  */
  54
  55 /*
  56  * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
  57  * that.
  58  */
  59
  60 #define IDMAP_TYPE_USER  0
  61 #define IDMAP_TYPE_GROUP 1
  62
  63 struct ent {
  64         struct cache_head h;
  65         int               type;                /* User / Group */
  66         uid_t             id;
  67         char              name[IDMAP_NAMESZ];
  68         char              authname[IDMAP_NAMESZ];
  69 };
  70
  71 /* Common entry handling */
  72
  73 #define ENT_HASHBITS          8
  74 #define ENT_HASHMAX           (1 << ENT_HASHBITS)
  75
  76 static void
  77 ent_init(struct cache_head *cnew, struct cache_head *citm)
  78 {
  79         struct ent *new = container_of(cnew, struct ent, h);
  80         struct ent *itm = container_of(citm, struct ent, h);
  81
  82         new->id = itm->id;
  83         new->type = itm->type;
  84
  85         strlcpy(new->name, itm->name, sizeof(new->name));
  86         strlcpy(new->authname, itm->authname, sizeof(new->name));
  87 }
  88
  89 static void
  90 ent_put(struct kref *ref)
  91 {
  92         struct ent *map = container_of(ref, struct ent, h.ref);
  93         kfree(map);
  94 }
  95
  96 static struct cache_head *
  97 ent_alloc(void)
  98 {
  99         struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
 100         if (e)
 101                 return &e->h;
 102         else
 103                 return NULL;
 104 }
 105
 106 /*
 107  * ID -> Name cache
 108  */
 109
 110 static struct cache_head *idtoname_table[ENT_HASHMAX];
 111
 112 static uint32_t
 113 idtoname_hash(struct ent *ent)
 114 {
 115         uint32_t hash;
 116
 117         hash = hash_str(ent->authname, ENT_HASHBITS);
 118         hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
 119
 120         /* Flip LSB for user/group */
 121         if (ent->type == IDMAP_TYPE_GROUP)
 122                 hash ^= 1;
 123
 124         return hash;
 125 }
 126
 127 static void
 128 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 129     int *blen)
 130 {
 131         struct ent *ent = container_of(ch, struct ent, h);
 132         char idstr[11];
 133
 134         qword_add(bpp, blen, ent->authname);
 135         snprintf(idstr, sizeof(idstr), "%u", ent->id);
 136         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 137         qword_add(bpp, blen, idstr);
 138
 139         (*bpp)[-1] = '\n';
 140 }
 141
 142 static int
 143 idtoname_upcall(struct cache_detail *cd, struct cache_head *ch)
 144 {
 145         return sunrpc_cache_pipe_upcall(cd, ch, idtoname_request);
 146 }
 147
 148 static int
 149 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 150 {
 151         struct ent *a = container_of(ca, struct ent, h);
 152         struct ent *b = container_of(cb, struct ent, h);
 153
 154         return (a->id == b->id && a->type == b->type &&
 155             strcmp(a->authname, b->authname) == 0);
 156 }
 157
 158 static int
 159 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 160 {
 161         struct ent *ent;
 162
 163         if (h == NULL) {
 164                 seq_puts(m, "#domain type id [name]\n");
 165                 return 0;
 166         }
 167         ent = container_of(h, struct ent, h);
 168         seq_printf(m, "%s %s %u", ent->authname,
 169                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 170                         ent->id);
 171         if (test_bit(CACHE_VALID, &h->flags))
 172                 seq_printf(m, " %s", ent->name);
 173         seq_printf(m, "\n");
 174         return 0;
 175 }
 176
 177 static void
 178 warn_no_idmapd(struct cache_detail *detail, int has_died)
 179 {
 180         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 181                         has_died ? "died" : "not been started");
 182 }
 183
 184
 185 static int         idtoname_parse(struct cache_detail *, char *, int);
 186 static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
 187 static struct ent *idtoname_update(struct cache_detail *, struct ent *,
 188                                    struct ent *);
 189
 190 static struct cache_detail idtoname_cache = {
 191         .owner          = THIS_MODULE,
 192         .hash_size      = ENT_HASHMAX,
 193         .hash_table     = idtoname_table,
 194         .name           = "nfs4.idtoname",
 195         .cache_put      = ent_put,
 196         .cache_upcall   = idtoname_upcall,
 197         .cache_parse    = idtoname_parse,
 198         .cache_show     = idtoname_show,
 199         .warn_no_listener = warn_no_idmapd,
 200         .match          = idtoname_match,
 201         .init           = ent_init,
 202         .update         = ent_init,
 203         .alloc          = ent_alloc,
 204 };
 205
 206 static int
 207 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 208 {
 209         struct ent ent, *res;
 210         char *buf1, *bp;
 211         int len;
 212         int error = -EINVAL;
 213
 214         if (buf[buflen - 1] != '\n')
 215                 return (-EINVAL);
 216         buf[buflen - 1]= '\0';
 217
 218         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 219         if (buf1 == NULL)
 220                 return (-ENOMEM);
 221
 222         memset(&ent, 0, sizeof(ent));
 223
 224         /* Authentication name */
 225         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 226                 goto out;
 227         memcpy(ent.authname, buf1, sizeof(ent.authname));
 228
 229         /* Type */
 230         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 231                 goto out;
 232         ent.type = strcmp(buf1, "user") == 0 ?
 233                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 234
 235         /* ID */
 236         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 237                 goto out;
 238         ent.id = simple_strtoul(buf1, &bp, 10);
 239         if (bp == buf1)
 240                 goto out;
 241
 242         /* expiry */
 243         ent.h.expiry_time = get_expiry(&buf);
 244         if (ent.h.expiry_time == 0)
 245                 goto out;
 246
 247         error = -ENOMEM;
 248         res = idtoname_lookup(cd, &ent);
 249         if (!res)
 250                 goto out;
 251
 252         /* Name */
 253         error = -EINVAL;
 254         len = qword_get(&buf, buf1, PAGE_SIZE);
 255         if (len < 0)
 256                 goto out;
 257         if (len == 0)
 258                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 259         else if (len >= IDMAP_NAMESZ)
 260                 goto out;
 261         else
 262                 memcpy(ent.name, buf1, sizeof(ent.name));
 263         error = -ENOMEM;
 264         res = idtoname_update(cd, &ent, res);
 265         if (res == NULL)
 266                 goto out;
 267
 268         cache_put(&res->h, cd);
 269
 270         error = 0;
 271 out:
 272         kfree(buf1);
 273
 274         return error;
 275 }
 276
 277
 278 static struct ent *
 279 idtoname_lookup(struct cache_detail *cd, struct ent *item)
 280 {
 281         struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
 282                                                     idtoname_hash(item));
 283         if (ch)
 284                 return container_of(ch, struct ent, h);
 285         else
 286                 return NULL;
 287 }
 288
 289 static struct ent *
 290 idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 291 {
 292         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 293                                                     idtoname_hash(new));
 294         if (ch)
 295                 return container_of(ch, struct ent, h);
 296         else
 297                 return NULL;
 298 }
 299
 300
 301 /*
 302  * Name -> ID cache
 303  */
 304
 305 static struct cache_head *nametoid_table[ENT_HASHMAX];
 306
 307 static inline int
 308 nametoid_hash(struct ent *ent)
 309 {
 310         return hash_str(ent->name, ENT_HASHBITS);
 311 }
 312
 313 static void
 314 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 315     int *blen)
 316 {
 317         struct ent *ent = container_of(ch, struct ent, h);
 318
 319         qword_add(bpp, blen, ent->authname);
 320         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 321         qword_add(bpp, blen, ent->name);
 322
 323         (*bpp)[-1] = '\n';
 324 }
 325
 326 static int
 327 nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
 328 {
 329         return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
 330 }
 331
 332 static int
 333 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 334 {
 335         struct ent *a = container_of(ca, struct ent, h);
 336         struct ent *b = container_of(cb, struct ent, h);
 337
 338         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 339             strcmp(a->authname, b->authname) == 0);
 340 }
 341
 342 static int
 343 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 344 {
 345         struct ent *ent;
 346
 347         if (h == NULL) {
 348                 seq_puts(m, "#domain type name [id]\n");
 349                 return 0;
 350         }
 351         ent = container_of(h, struct ent, h);
 352         seq_printf(m, "%s %s %s", ent->authname,
 353                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 354                         ent->name);
 355         if (test_bit(CACHE_VALID, &h->flags))
 356                 seq_printf(m, " %u", ent->id);
 357         seq_printf(m, "\n");
 358         return 0;
 359 }
 360
 361 static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
 362 static struct ent *nametoid_update(struct cache_detail *, struct ent *,
 363                                    struct ent *);
 364 static int         nametoid_parse(struct cache_detail *, char *, int);
 365
 366 static struct cache_detail nametoid_cache = {
 367         .owner          = THIS_MODULE,
 368         .hash_size      = ENT_HASHMAX,
 369         .hash_table     = nametoid_table,
 370         .name           = "nfs4.nametoid",
 371         .cache_put      = ent_put,
 372         .cache_upcall   = nametoid_upcall,
 373         .cache_parse    = nametoid_parse,
 374         .cache_show     = nametoid_show,
 375         .warn_no_listener = warn_no_idmapd,
 376         .match          = nametoid_match,
 377         .init           = ent_init,
 378         .update         = ent_init,
 379         .alloc          = ent_alloc,
 380 };
 381
 382 static int
 383 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 384 {
 385         struct ent ent, *res;
 386         char *buf1;
 387         int error = -EINVAL;
 388
 389         if (buf[buflen - 1] != '\n')
 390                 return (-EINVAL);
 391         buf[buflen - 1]= '\0';
 392
 393         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 394         if (buf1 == NULL)
 395                 return (-ENOMEM);
 396
 397         memset(&ent, 0, sizeof(ent));
 398
 399         /* Authentication name */
 400         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 401                 goto out;
 402         memcpy(ent.authname, buf1, sizeof(ent.authname));
 403
 404         /* Type */
 405         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 406                 goto out;
 407         ent.type = strcmp(buf1, "user") == 0 ?
 408                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 409
 410         /* Name */
 411         error = qword_get(&buf, buf1, PAGE_SIZE);
 412         if (error <= 0 || error >= IDMAP_NAMESZ)
 413                 goto out;
 414         memcpy(ent.name, buf1, sizeof(ent.name));
 415
 416         /* expiry */
 417         ent.h.expiry_time = get_expiry(&buf);
 418         if (ent.h.expiry_time == 0)
 419                 goto out;
 420
 421         /* ID */
 422         error = get_int(&buf, &ent.id);
 423         if (error == -EINVAL)
 424                 goto out;
 425         if (error == -ENOENT)
 426                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 427
 428         error = -ENOMEM;
 429         res = nametoid_lookup(cd, &ent);
 430         if (res == NULL)
 431                 goto out;
 432         res = nametoid_update(cd, &ent, res);
 433         if (res == NULL)
 434                 goto out;
 435
 436         cache_put(&res->h, cd);
 437         error = 0;
 438 out:
 439         kfree(buf1);
 440
 441         return (error);
 442 }
 443
 444
 445 static struct ent *
 446 nametoid_lookup(struct cache_detail *cd, struct ent *item)
 447 {
 448         struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
 449                                                     nametoid_hash(item));
 450         if (ch)
 451                 return container_of(ch, struct ent, h);
 452         else
 453                 return NULL;
 454 }
 455
 456 static struct ent *
 457 nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 458 {
 459         struct cache_head *ch = sunrpc_cache_update(cd, &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 int
 472 nfsd_idmap_init(void)
 473 {
 474         int rv;
 475
 476         rv = cache_register_net(&idtoname_cache, &init_net);
 477         if (rv)
 478                 return rv;
 479         rv = cache_register_net(&nametoid_cache, &init_net);
 480         if (rv)
 481                 cache_unregister_net(&idtoname_cache, &init_net);
 482         return rv;
 483 }
 484
 485 void
 486 nfsd_idmap_shutdown(void)
 487 {
 488         cache_unregister_net(&idtoname_cache, &init_net);
 489         cache_unregister_net(&nametoid_cache, &init_net);
 490 }
 491
 492 static int
 493 idmap_lookup(struct svc_rqst *rqstp,
 494                 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
 495                 struct ent *key, struct cache_detail *detail, struct ent **item)
 496 {
 497         int ret;
 498
 499         *item = lookup_fn(detail, key);
 500         if (!*item)
 501                 return -ENOMEM;
 502  retry:
 503         ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
 504
 505         if (ret == -ETIMEDOUT) {
 506                 struct ent *prev_item = *item;
 507                 *item = lookup_fn(detail, key);
 508                 if (*item != prev_item)
 509                         goto retry;
 510                 cache_put(&(*item)->h, detail);
 511         }
 512         return ret;
 513 }
 514
 515 static char *
 516 rqst_authname(struct svc_rqst *rqstp)
 517 {
 518         struct auth_domain *clp;
 519
 520         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 521         return clp->name;
 522 }
 523
 524 static __be32
 525 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 526                 uid_t *id)
 527 {
 528         struct ent *item, key = {
 529                 .type = type,
 530         };
 531         int ret;
 532
 533         if (namelen + 1 > sizeof(key.name))
 534                 return nfserr_badowner;
 535         memcpy(key.name, name, namelen);
 536         key.name[namelen] = '\0';
 537         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 538         ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 539         if (ret == -ENOENT)
 540                 return nfserr_badowner;
 541         if (ret)
 542                 return nfserrno(ret);
 543         *id = item->id;
 544         cache_put(&item->h, &nametoid_cache);
 545         return 0;
 546 }
 547
 548 static int
 549 idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 550 {
 551         struct ent *item, key = {
 552                 .id = id,
 553                 .type = type,
 554         };
 555         int ret;
 556
 557         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 558         ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
 559         if (ret == -ENOENT)
 560                 return sprintf(name, "%u", id);
 561         if (ret)
 562                 return ret;
 563         ret = strlen(item->name);
 564         BUG_ON(ret > IDMAP_NAMESZ);
 565         memcpy(name, item->name, ret);
 566         cache_put(&item->h, &idtoname_cache);
 567         return ret;
 568 }
 569
 570 static bool
 571 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
 572 {
 573         int ret;
 574         char buf[11];
 575
 576         if (namelen + 1 > sizeof(buf))
 577                 /* too long to represent a 32-bit id: */
 578                 return false;
 579         /* Just to make sure it's null-terminated: */
 580         memcpy(buf, name, namelen);
 581         buf[namelen] = '\0';
 582         ret = kstrtouint(name, 10, id);
 583         return ret == 0;
 584 }
 585
 586 static __be32
 587 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
 588 {
 589         if (nfs4_disable_idmapping && rqstp->rq_flavor < RPC_AUTH_GSS)
 590                 if (numeric_name_to_id(rqstp, type, name, namelen, id))
 591                         return 0;
 592                 /*
 593                  * otherwise, fall through and try idmapping, for
 594                  * backwards compatibility with clients sending names:
 595                  */
 596         return idmap_name_to_id(rqstp, type, name, namelen, id);
 597 }
 598
 599 static int
 600 do_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 601 {
 602         if (nfs4_disable_idmapping && rqstp->rq_flavor < RPC_AUTH_GSS)
 603                 return sprintf(name, "%u", id);
 604         return idmap_id_to_name(rqstp, type, id, name);
 605 }
 606
 607 __be32
 608 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 609                 __u32 *id)
 610 {
 611         return do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
 612 }
 613
 614 __be32
 615 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 616                 __u32 *id)
 617 {
 618         return do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
 619 }
 620
 621 int
 622 nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 623 {
 624         return do_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 625 }
 626
 627 int
 628 nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 629 {
 630         return do_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 631 }