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 ent *);
 187 static struct ent *idtoname_update(struct ent *, struct ent *);
 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_upcall   = idtoname_upcall,
 196         .cache_parse    = idtoname_parse,
 197         .cache_show     = idtoname_show,
 198         .warn_no_listener = warn_no_idmapd,
 199         .match          = idtoname_match,
 200         .init           = ent_init,
 201         .update         = ent_init,
 202         .alloc          = ent_alloc,
 203 };
 204
 205 static int
 206 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 207 {
 208         struct ent ent, *res;
 209         char *buf1, *bp;
 210         int len;
 211         int error = -EINVAL;
 212
 213         if (buf[buflen - 1] != '\n')
 214                 return (-EINVAL);
 215         buf[buflen - 1]= '\0';
 216
 217         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 218         if (buf1 == NULL)
 219                 return (-ENOMEM);
 220
 221         memset(&ent, 0, sizeof(ent));
 222
 223         /* Authentication name */
 224         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 225                 goto out;
 226         memcpy(ent.authname, buf1, sizeof(ent.authname));
 227
 228         /* Type */
 229         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 230                 goto out;
 231         ent.type = strcmp(buf1, "user") == 0 ?
 232                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 233
 234         /* ID */
 235         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 236                 goto out;
 237         ent.id = simple_strtoul(buf1, &bp, 10);
 238         if (bp == buf1)
 239                 goto out;
 240
 241         /* expiry */
 242         ent.h.expiry_time = get_expiry(&buf);
 243         if (ent.h.expiry_time == 0)
 244                 goto out;
 245
 246         error = -ENOMEM;
 247         res = idtoname_lookup(&ent);
 248         if (!res)
 249                 goto out;
 250
 251         /* Name */
 252         error = -EINVAL;
 253         len = qword_get(&buf, buf1, PAGE_SIZE);
 254         if (len < 0)
 255                 goto out;
 256         if (len == 0)
 257                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 258         else if (len >= IDMAP_NAMESZ)
 259                 goto out;
 260         else
 261                 memcpy(ent.name, buf1, sizeof(ent.name));
 262         error = -ENOMEM;
 263         res = idtoname_update(&ent, res);
 264         if (res == NULL)
 265                 goto out;
 266
 267         cache_put(&res->h, &idtoname_cache);
 268
 269         error = 0;
 270 out:
 271         kfree(buf1);
 272
 273         return error;
 274 }
 275
 276
 277 static struct ent *
 278 idtoname_lookup(struct ent *item)
 279 {
 280         struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
 281                                                     &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 ent *new, struct ent *old)
 291 {
 292         struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
 293                                                     &new->h, &old->h,
 294                                                     idtoname_hash(new));
 295         if (ch)
 296                 return container_of(ch, struct ent, h);
 297         else
 298                 return NULL;
 299 }
 300
 301
 302 /*
 303  * Name -> ID cache
 304  */
 305
 306 static struct cache_head *nametoid_table[ENT_HASHMAX];
 307
 308 static inline int
 309 nametoid_hash(struct ent *ent)
 310 {
 311         return hash_str(ent->name, ENT_HASHBITS);
 312 }
 313
 314 static void
 315 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 316     int *blen)
 317 {
 318         struct ent *ent = container_of(ch, struct ent, h);
 319
 320         qword_add(bpp, blen, ent->authname);
 321         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 322         qword_add(bpp, blen, ent->name);
 323
 324         (*bpp)[-1] = '\n';
 325 }
 326
 327 static int
 328 nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
 329 {
 330         return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
 331 }
 332
 333 static int
 334 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 335 {
 336         struct ent *a = container_of(ca, struct ent, h);
 337         struct ent *b = container_of(cb, struct ent, h);
 338
 339         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 340             strcmp(a->authname, b->authname) == 0);
 341 }
 342
 343 static int
 344 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 345 {
 346         struct ent *ent;
 347
 348         if (h == NULL) {
 349                 seq_puts(m, "#domain type name [id]\n");
 350                 return 0;
 351         }
 352         ent = container_of(h, struct ent, h);
 353         seq_printf(m, "%s %s %s", ent->authname,
 354                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 355                         ent->name);
 356         if (test_bit(CACHE_VALID, &h->flags))
 357                 seq_printf(m, " %u", ent->id);
 358         seq_printf(m, "\n");
 359         return 0;
 360 }
 361
 362 static struct ent *nametoid_lookup(struct ent *);
 363 static struct ent *nametoid_update(struct ent *, 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(&ent);
 430         if (res == NULL)
 431                 goto out;
 432         res = nametoid_update(&ent, res);
 433         if (res == NULL)
 434                 goto out;
 435
 436         cache_put(&res->h, &nametoid_cache);
 437         error = 0;
 438 out:
 439         kfree(buf1);
 440
 441         return (error);
 442 }
 443
 444
 445 static struct ent *
 446 nametoid_lookup(struct ent *item)
 447 {
 448         struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
 449                                                     &item->h,
 450                                                     nametoid_hash(item));
 451         if (ch)
 452                 return container_of(ch, struct ent, h);
 453         else
 454                 return NULL;
 455 }
 456
 457 static struct ent *
 458 nametoid_update(struct ent *new, struct ent *old)
 459 {
 460         struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
 461                                                     &new->h, &old->h,
 462                                                     nametoid_hash(new));
 463         if (ch)
 464                 return container_of(ch, struct ent, h);
 465         else
 466                 return NULL;
 467 }
 468
 469 /*
 470  * Exported API
 471  */
 472
 473 int
 474 nfsd_idmap_init(void)
 475 {
 476         int rv;
 477
 478         rv = cache_register_net(&idtoname_cache, &init_net);
 479         if (rv)
 480                 return rv;
 481         rv = cache_register_net(&nametoid_cache, &init_net);
 482         if (rv)
 483                 cache_unregister_net(&idtoname_cache, &init_net);
 484         return rv;
 485 }
 486
 487 void
 488 nfsd_idmap_shutdown(void)
 489 {
 490         cache_unregister_net(&idtoname_cache, &init_net);
 491         cache_unregister_net(&nametoid_cache, &init_net);
 492 }
 493
 494 static int
 495 idmap_lookup(struct svc_rqst *rqstp,
 496                 struct ent *(*lookup_fn)(struct ent *), struct ent *key,
 497                 struct cache_detail *detail, struct ent **item)
 498 {
 499         int ret;
 500
 501         *item = lookup_fn(key);
 502         if (!*item)
 503                 return -ENOMEM;
 504  retry:
 505         ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
 506
 507         if (ret == -ETIMEDOUT) {
 508                 struct ent *prev_item = *item;
 509                 *item = lookup_fn(key);
 510                 if (*item != prev_item)
 511                         goto retry;
 512                 cache_put(&(*item)->h, detail);
 513         }
 514         return ret;
 515 }
 516
 517 static char *
 518 rqst_authname(struct svc_rqst *rqstp)
 519 {
 520         struct auth_domain *clp;
 521
 522         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 523         return clp->name;
 524 }
 525
 526 static __be32
 527 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 528                 uid_t *id)
 529 {
 530         struct ent *item, key = {
 531                 .type = type,
 532         };
 533         int ret;
 534
 535         if (namelen + 1 > sizeof(key.name))
 536                 return nfserr_badowner;
 537         memcpy(key.name, name, namelen);
 538         key.name[namelen] = '\0';
 539         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 540         ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
 541         if (ret == -ENOENT)
 542                 return nfserr_badowner;
 543         if (ret)
 544                 return nfserrno(ret);
 545         *id = item->id;
 546         cache_put(&item->h, &nametoid_cache);
 547         return 0;
 548 }
 549
 550 static int
 551 idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 552 {
 553         struct ent *item, key = {
 554                 .id = id,
 555                 .type = type,
 556         };
 557         int ret;
 558
 559         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 560         ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
 561         if (ret == -ENOENT)
 562                 return sprintf(name, "%u", id);
 563         if (ret)
 564                 return ret;
 565         ret = strlen(item->name);
 566         BUG_ON(ret > IDMAP_NAMESZ);
 567         memcpy(name, item->name, ret);
 568         cache_put(&item->h, &idtoname_cache);
 569         return ret;
 570 }
 571
 572 static bool
 573 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
 574 {
 575         int ret;
 576         char buf[11];
 577
 578         if (namelen + 1 > sizeof(buf))
 579                 /* too long to represent a 32-bit id: */
 580                 return false;
 581         /* Just to make sure it's null-terminated: */
 582         memcpy(buf, name, namelen);
 583         buf[namelen] = '\0';
 584         ret = kstrtouint(name, 10, id);
 585         return ret == 0;
 586 }
 587
 588 static __be32
 589 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
 590 {
 591         if (nfs4_disable_idmapping && rqstp->rq_flavor < RPC_AUTH_GSS)
 592                 if (numeric_name_to_id(rqstp, type, name, namelen, id))
 593                         return 0;
 594                 /*
 595                  * otherwise, fall through and try idmapping, for
 596                  * backwards compatibility with clients sending names:
 597                  */
 598         return idmap_name_to_id(rqstp, type, name, namelen, id);
 599 }
 600
 601 static int
 602 do_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 603 {
 604         if (nfs4_disable_idmapping && rqstp->rq_flavor < RPC_AUTH_GSS)
 605                 return sprintf(name, "%u", id);
 606         return idmap_id_to_name(rqstp, type, id, name);
 607 }
 608
 609 __be32
 610 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 611                 __u32 *id)
 612 {
 613         return do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
 614 }
 615
 616 __be32
 617 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 618                 __u32 *id)
 619 {
 620         return do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
 621 }
 622
 623 int
 624 nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 625 {
 626         return do_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 627 }
 628
 629 int
 630 nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 631 {
 632         return do_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 633 }