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 <linux/sunrpc/svc_xprt.h>
  40 #include <net/net_namespace.h>
  41 #include "idmap.h"
  42 #include "nfsd.h"
  43 #include "netns.h"
  44
  45 /*
  46  * Turn off idmapping when using AUTH_SYS.
  47  */
  48 static bool nfs4_disable_idmapping = true;
  49 module_param(nfs4_disable_idmapping, bool, 0644);
  50 MODULE_PARM_DESC(nfs4_disable_idmapping,
  51                 "Turn off server's NFSv4 idmapping when using 'sec=sys'");
  52
  53 /*
  54  * Cache entry
  55  */
  56
  57 /*
  58  * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
  59  * that.
  60  */
  61
  62 #define IDMAP_TYPE_USER  0
  63 #define IDMAP_TYPE_GROUP 1
  64
  65 struct ent {
  66         struct cache_head h;
  67         int               type;                /* User / Group */
  68         uid_t             id;
  69         char              name[IDMAP_NAMESZ];
  70         char              authname[IDMAP_NAMESZ];
  71 };
  72
  73 /* Common entry handling */
  74
  75 #define ENT_HASHBITS          8
  76 #define ENT_HASHMAX           (1 << ENT_HASHBITS)
  77
  78 static void
  79 ent_init(struct cache_head *cnew, struct cache_head *citm)
  80 {
  81         struct ent *new = container_of(cnew, struct ent, h);
  82         struct ent *itm = container_of(citm, struct ent, h);
  83
  84         new->id = itm->id;
  85         new->type = itm->type;
  86
  87         strlcpy(new->name, itm->name, sizeof(new->name));
  88         strlcpy(new->authname, itm->authname, sizeof(new->name));
  89 }
  90
  91 static void
  92 ent_put(struct kref *ref)
  93 {
  94         struct ent *map = container_of(ref, struct ent, h.ref);
  95         kfree(map);
  96 }
  97
  98 static struct cache_head *
  99 ent_alloc(void)
 100 {
 101         struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
 102         if (e)
 103                 return &e->h;
 104         else
 105                 return NULL;
 106 }
 107
 108 /*
 109  * ID -> Name cache
 110  */
 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_template = {
 191         .owner          = THIS_MODULE,
 192         .hash_size      = ENT_HASHMAX,
 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(cd, &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(cd, &ent, res);
 264         if (res == NULL)
 265                 goto out;
 266
 267         cache_put(&res->h, cd);
 268
 269         error = 0;
 270 out:
 271         kfree(buf1);
 272
 273         return error;
 274 }
 275
 276
 277 static struct ent *
 278 idtoname_lookup(struct cache_detail *cd, struct ent *item)
 279 {
 280         struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
 281                                                     idtoname_hash(item));
 282         if (ch)
 283                 return container_of(ch, struct ent, h);
 284         else
 285                 return NULL;
 286 }
 287
 288 static struct ent *
 289 idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 290 {
 291         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 292                                                     idtoname_hash(new));
 293         if (ch)
 294                 return container_of(ch, struct ent, h);
 295         else
 296                 return NULL;
 297 }
 298
 299
 300 /*
 301  * Name -> ID cache
 302  */
 303
 304 static inline int
 305 nametoid_hash(struct ent *ent)
 306 {
 307         return hash_str(ent->name, ENT_HASHBITS);
 308 }
 309
 310 static void
 311 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 312     int *blen)
 313 {
 314         struct ent *ent = container_of(ch, struct ent, h);
 315
 316         qword_add(bpp, blen, ent->authname);
 317         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 318         qword_add(bpp, blen, ent->name);
 319
 320         (*bpp)[-1] = '\n';
 321 }
 322
 323 static int
 324 nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
 325 {
 326         return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
 327 }
 328
 329 static int
 330 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 331 {
 332         struct ent *a = container_of(ca, struct ent, h);
 333         struct ent *b = container_of(cb, struct ent, h);
 334
 335         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 336             strcmp(a->authname, b->authname) == 0);
 337 }
 338
 339 static int
 340 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 341 {
 342         struct ent *ent;
 343
 344         if (h == NULL) {
 345                 seq_puts(m, "#domain type name [id]\n");
 346                 return 0;
 347         }
 348         ent = container_of(h, struct ent, h);
 349         seq_printf(m, "%s %s %s", ent->authname,
 350                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 351                         ent->name);
 352         if (test_bit(CACHE_VALID, &h->flags))
 353                 seq_printf(m, " %u", ent->id);
 354         seq_printf(m, "\n");
 355         return 0;
 356 }
 357
 358 static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
 359 static struct ent *nametoid_update(struct cache_detail *, struct ent *,
 360                                    struct ent *);
 361 static int         nametoid_parse(struct cache_detail *, char *, int);
 362
 363 static struct cache_detail nametoid_cache_template = {
 364         .owner          = THIS_MODULE,
 365         .hash_size      = ENT_HASHMAX,
 366         .name           = "nfs4.nametoid",
 367         .cache_put      = ent_put,
 368         .cache_upcall   = nametoid_upcall,
 369         .cache_parse    = nametoid_parse,
 370         .cache_show     = nametoid_show,
 371         .warn_no_listener = warn_no_idmapd,
 372         .match          = nametoid_match,
 373         .init           = ent_init,
 374         .update         = ent_init,
 375         .alloc          = ent_alloc,
 376 };
 377
 378 static int
 379 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 380 {
 381         struct ent ent, *res;
 382         char *buf1;
 383         int error = -EINVAL;
 384
 385         if (buf[buflen - 1] != '\n')
 386                 return (-EINVAL);
 387         buf[buflen - 1]= '\0';
 388
 389         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 390         if (buf1 == NULL)
 391                 return (-ENOMEM);
 392
 393         memset(&ent, 0, sizeof(ent));
 394
 395         /* Authentication name */
 396         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 397                 goto out;
 398         memcpy(ent.authname, buf1, sizeof(ent.authname));
 399
 400         /* Type */
 401         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 402                 goto out;
 403         ent.type = strcmp(buf1, "user") == 0 ?
 404                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 405
 406         /* Name */
 407         error = qword_get(&buf, buf1, PAGE_SIZE);
 408         if (error <= 0 || error >= IDMAP_NAMESZ)
 409                 goto out;
 410         memcpy(ent.name, buf1, sizeof(ent.name));
 411
 412         /* expiry */
 413         ent.h.expiry_time = get_expiry(&buf);
 414         if (ent.h.expiry_time == 0)
 415                 goto out;
 416
 417         /* ID */
 418         error = get_int(&buf, &ent.id);
 419         if (error == -EINVAL)
 420                 goto out;
 421         if (error == -ENOENT)
 422                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 423
 424         error = -ENOMEM;
 425         res = nametoid_lookup(cd, &ent);
 426         if (res == NULL)
 427                 goto out;
 428         res = nametoid_update(cd, &ent, res);
 429         if (res == NULL)
 430                 goto out;
 431
 432         cache_put(&res->h, cd);
 433         error = 0;
 434 out:
 435         kfree(buf1);
 436
 437         return (error);
 438 }
 439
 440
 441 static struct ent *
 442 nametoid_lookup(struct cache_detail *cd, struct ent *item)
 443 {
 444         struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
 445                                                     nametoid_hash(item));
 446         if (ch)
 447                 return container_of(ch, struct ent, h);
 448         else
 449                 return NULL;
 450 }
 451
 452 static struct ent *
 453 nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 454 {
 455         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 456                                                     nametoid_hash(new));
 457         if (ch)
 458                 return container_of(ch, struct ent, h);
 459         else
 460                 return NULL;
 461 }
 462
 463 /*
 464  * Exported API
 465  */
 466
 467 int
 468 nfsd_idmap_init(struct net *net)
 469 {
 470         int rv;
 471         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 472
 473         nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
 474         if (IS_ERR(nn->idtoname_cache))
 475                 return PTR_ERR(nn->idtoname_cache);
 476         rv = cache_register_net(nn->idtoname_cache, net);
 477         if (rv)
 478                 goto destroy_idtoname_cache;
 479         nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
 480         if (IS_ERR(nn->nametoid_cache)) {
 481                 rv = PTR_ERR(nn->idtoname_cache);
 482                 goto unregister_idtoname_cache;
 483         }
 484         rv = cache_register_net(nn->nametoid_cache, net);
 485         if (rv)
 486                 goto destroy_nametoid_cache;
 487         return 0;
 488
 489 destroy_nametoid_cache:
 490         cache_destroy_net(nn->nametoid_cache, net);
 491 unregister_idtoname_cache:
 492         cache_unregister_net(nn->idtoname_cache, net);
 493 destroy_idtoname_cache:
 494         cache_destroy_net(nn->idtoname_cache, net);
 495         return rv;
 496 }
 497
 498 void
 499 nfsd_idmap_shutdown(struct net *net)
 500 {
 501         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 502
 503         cache_unregister_net(nn->idtoname_cache, net);
 504         cache_unregister_net(nn->nametoid_cache, net);
 505         cache_destroy_net(nn->idtoname_cache, net);
 506         cache_destroy_net(nn->nametoid_cache, net);
 507 }
 508
 509 static int
 510 idmap_lookup(struct svc_rqst *rqstp,
 511                 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
 512                 struct ent *key, struct cache_detail *detail, struct ent **item)
 513 {
 514         int ret;
 515
 516         *item = lookup_fn(detail, key);
 517         if (!*item)
 518                 return -ENOMEM;
 519  retry:
 520         ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
 521
 522         if (ret == -ETIMEDOUT) {
 523                 struct ent *prev_item = *item;
 524                 *item = lookup_fn(detail, key);
 525                 if (*item != prev_item)
 526                         goto retry;
 527                 cache_put(&(*item)->h, detail);
 528         }
 529         return ret;
 530 }
 531
 532 static char *
 533 rqst_authname(struct svc_rqst *rqstp)
 534 {
 535         struct auth_domain *clp;
 536
 537         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 538         return clp->name;
 539 }
 540
 541 static __be32
 542 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 543                 uid_t *id)
 544 {
 545         struct ent *item, key = {
 546                 .type = type,
 547         };
 548         int ret;
 549         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 550
 551         if (namelen + 1 > sizeof(key.name))
 552                 return nfserr_badowner;
 553         memcpy(key.name, name, namelen);
 554         key.name[namelen] = '\0';
 555         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 556         ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
 557         if (ret == -ENOENT)
 558                 return nfserr_badowner;
 559         if (ret)
 560                 return nfserrno(ret);
 561         *id = item->id;
 562         cache_put(&item->h, nn->nametoid_cache);
 563         return 0;
 564 }
 565
 566 static int
 567 idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 568 {
 569         struct ent *item, key = {
 570                 .id = id,
 571                 .type = type,
 572         };
 573         int ret;
 574         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 575
 576         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 577         ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
 578         if (ret == -ENOENT)
 579                 return sprintf(name, "%u", id);
 580         if (ret)
 581                 return ret;
 582         ret = strlen(item->name);
 583         BUG_ON(ret > IDMAP_NAMESZ);
 584         memcpy(name, item->name, ret);
 585         cache_put(&item->h, nn->idtoname_cache);
 586         return ret;
 587 }
 588
 589 static bool
 590 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
 591 {
 592         int ret;
 593         char buf[11];
 594
 595         if (namelen + 1 > sizeof(buf))
 596                 /* too long to represent a 32-bit id: */
 597                 return false;
 598         /* Just to make sure it's null-terminated: */
 599         memcpy(buf, name, namelen);
 600         buf[namelen] = '\0';
 601         ret = kstrtouint(name, 10, id);
 602         return ret == 0;
 603 }
 604
 605 static __be32
 606 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
 607 {
 608         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 609                 if (numeric_name_to_id(rqstp, type, name, namelen, id))
 610                         return 0;
 611                 /*
 612                  * otherwise, fall through and try idmapping, for
 613                  * backwards compatibility with clients sending names:
 614                  */
 615         return idmap_name_to_id(rqstp, type, name, namelen, id);
 616 }
 617
 618 static int
 619 do_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
 620 {
 621         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 622                 return sprintf(name, "%u", id);
 623         return idmap_id_to_name(rqstp, type, id, name);
 624 }
 625
 626 __be32
 627 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 628                 __u32 *id)
 629 {
 630         return do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
 631 }
 632
 633 __be32
 634 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 635                 __u32 *id)
 636 {
 637         return do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
 638 }
 639
 640 int
 641 nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 642 {
 643         return do_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 644 }
 645
 646 int
 647 nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
 648 {
 649         return do_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 650 }