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 #include "vfs.h"
  45
  46 /*
  47  * Turn off idmapping when using AUTH_SYS.
  48  */
  49 static bool nfs4_disable_idmapping = true;
  50 module_param(nfs4_disable_idmapping, bool, 0644);
  51 MODULE_PARM_DESC(nfs4_disable_idmapping,
  52                 "Turn off server's NFSv4 idmapping when using 'sec=sys'");
  53
  54 /*
  55  * Cache entry
  56  */
  57
  58 /*
  59  * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
  60  * that.
  61  */
  62
  63 struct ent {
  64         struct cache_head h;
  65         int               type;                /* User / Group */
  66         u32               id;
  67         char              name[IDMAP_NAMESZ];
  68         char              authname[IDMAP_NAMESZ];
  69         struct rcu_head   rcu_head;
  70 };
  71
  72 /* Common entry handling */
  73
  74 #define ENT_HASHBITS          8
  75 #define ENT_HASHMAX           (1 << ENT_HASHBITS)
  76
  77 static void
  78 ent_init(struct cache_head *cnew, struct cache_head *citm)
  79 {
  80         struct ent *new = container_of(cnew, struct ent, h);
  81         struct ent *itm = container_of(citm, struct ent, h);
  82
  83         new->id = itm->id;
  84         new->type = itm->type;
  85
  86         strscpy(new->name, itm->name, sizeof(new->name));
  87         strscpy(new->authname, itm->authname, sizeof(new->authname));
  88 }
  89
  90 static void
  91 ent_put(struct kref *ref)
  92 {
  93         struct ent *map = container_of(ref, struct ent, h.ref);
  94         kfree_rcu(map, rcu_head);
  95 }
  96
  97 static struct cache_head *
  98 ent_alloc(void)
  99 {
 100         struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
 101         if (e)
 102                 return &e->h;
 103         else
 104                 return NULL;
 105 }
 106
 107 /*
 108  * ID -> Name cache
 109  */
 110
 111 static uint32_t
 112 idtoname_hash(struct ent *ent)
 113 {
 114         uint32_t hash;
 115
 116         hash = hash_str(ent->authname, ENT_HASHBITS);
 117         hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
 118
 119         /* Flip LSB for user/group */
 120         if (ent->type == IDMAP_TYPE_GROUP)
 121                 hash ^= 1;
 122
 123         return hash;
 124 }
 125
 126 static int
 127 idtoname_upcall(struct cache_detail *cd, struct cache_head *h)
 128 {
 129         return sunrpc_cache_pipe_upcall_timeout(cd, h);
 130 }
 131
 132 static void
 133 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 134     int *blen)
 135 {
 136         struct ent *ent = container_of(ch, struct ent, h);
 137         char idstr[11];
 138
 139         qword_add(bpp, blen, ent->authname);
 140         snprintf(idstr, sizeof(idstr), "%u", ent->id);
 141         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 142         qword_add(bpp, blen, idstr);
 143
 144         (*bpp)[-1] = '\n';
 145 }
 146
 147 static int
 148 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 149 {
 150         struct ent *a = container_of(ca, struct ent, h);
 151         struct ent *b = container_of(cb, struct ent, h);
 152
 153         return (a->id == b->id && a->type == b->type &&
 154             strcmp(a->authname, b->authname) == 0);
 155 }
 156
 157 static int
 158 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 159 {
 160         struct ent *ent;
 161
 162         if (h == NULL) {
 163                 seq_puts(m, "#domain type id [name]\n");
 164                 return 0;
 165         }
 166         ent = container_of(h, struct ent, h);
 167         seq_printf(m, "%s %s %u", ent->authname,
 168                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 169                         ent->id);
 170         if (test_bit(CACHE_VALID, &h->flags))
 171                 seq_printf(m, " %s", ent->name);
 172         seq_putc(m, '\n');
 173         return 0;
 174 }
 175
 176 static void
 177 warn_no_idmapd(struct cache_detail *detail, int has_died)
 178 {
 179         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 180                         has_died ? "died" : "not been started");
 181 }
 182
 183
 184 static int         idtoname_parse(struct cache_detail *, char *, int);
 185 static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
 186 static struct ent *idtoname_update(struct cache_detail *, struct ent *,
 187                                    struct ent *);
 188
 189 static const struct cache_detail idtoname_cache_template = {
 190         .owner          = THIS_MODULE,
 191         .hash_size      = ENT_HASHMAX,
 192         .name           = "nfs4.idtoname",
 193         .cache_put      = ent_put,
 194         .cache_upcall   = idtoname_upcall,
 195         .cache_request  = idtoname_request,
 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         len = qword_get(&buf, buf1, PAGE_SIZE);
 225         if (len <= 0 || len >= IDMAP_NAMESZ)
 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         error = get_expiry(&buf, &ent.h.expiry_time);
 244         if (error)
 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 || len >= IDMAP_NAMESZ)
 256                 goto out;
 257         if (len == 0)
 258                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 259         else
 260                 memcpy(ent.name, buf1, sizeof(ent.name));
 261         error = -ENOMEM;
 262         res = idtoname_update(cd, &ent, res);
 263         if (res == NULL)
 264                 goto out;
 265
 266         cache_put(&res->h, cd);
 267         error = 0;
 268 out:
 269         kfree(buf1);
 270         return error;
 271 }
 272
 273 static struct ent *
 274 idtoname_lookup(struct cache_detail *cd, struct ent *item)
 275 {
 276         struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
 277                                                         idtoname_hash(item));
 278         if (ch)
 279                 return container_of(ch, struct ent, h);
 280         else
 281                 return NULL;
 282 }
 283
 284 static struct ent *
 285 idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 286 {
 287         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 288                                                     idtoname_hash(new));
 289         if (ch)
 290                 return container_of(ch, struct ent, h);
 291         else
 292                 return NULL;
 293 }
 294
 295
 296 /*
 297  * Name -> ID cache
 298  */
 299
 300 static inline int
 301 nametoid_hash(struct ent *ent)
 302 {
 303         return hash_str(ent->name, ENT_HASHBITS);
 304 }
 305
 306 static int
 307 nametoid_upcall(struct cache_detail *cd, struct cache_head *h)
 308 {
 309         return sunrpc_cache_pipe_upcall_timeout(cd, h);
 310 }
 311
 312 static void
 313 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 314     int *blen)
 315 {
 316         struct ent *ent = container_of(ch, struct ent, h);
 317
 318         qword_add(bpp, blen, ent->authname);
 319         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 320         qword_add(bpp, blen, ent->name);
 321
 322         (*bpp)[-1] = '\n';
 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_putc(m, '\n');
 351         return 0;
 352 }
 353
 354 static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
 355 static struct ent *nametoid_update(struct cache_detail *, struct ent *,
 356                                    struct ent *);
 357 static int         nametoid_parse(struct cache_detail *, char *, int);
 358
 359 static const struct cache_detail nametoid_cache_template = {
 360         .owner          = THIS_MODULE,
 361         .hash_size      = ENT_HASHMAX,
 362         .name           = "nfs4.nametoid",
 363         .cache_put      = ent_put,
 364         .cache_upcall   = nametoid_upcall,
 365         .cache_request  = nametoid_request,
 366         .cache_parse    = nametoid_parse,
 367         .cache_show     = nametoid_show,
 368         .warn_no_listener = warn_no_idmapd,
 369         .match          = nametoid_match,
 370         .init           = ent_init,
 371         .update         = ent_init,
 372         .alloc          = ent_alloc,
 373 };
 374
 375 static int
 376 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 377 {
 378         struct ent ent, *res;
 379         char *buf1;
 380         int len, error = -EINVAL;
 381
 382         if (buf[buflen - 1] != '\n')
 383                 return (-EINVAL);
 384         buf[buflen - 1]= '\0';
 385
 386         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 387         if (buf1 == NULL)
 388                 return (-ENOMEM);
 389
 390         memset(&ent, 0, sizeof(ent));
 391
 392         /* Authentication name */
 393         len = qword_get(&buf, buf1, PAGE_SIZE);
 394         if (len <= 0 || len >= IDMAP_NAMESZ)
 395                 goto out;
 396         memcpy(ent.authname, buf1, sizeof(ent.authname));
 397
 398         /* Type */
 399         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 400                 goto out;
 401         ent.type = strcmp(buf1, "user") == 0 ?
 402                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 403
 404         /* Name */
 405         len = qword_get(&buf, buf1, PAGE_SIZE);
 406         if (len <= 0 || len >= IDMAP_NAMESZ)
 407                 goto out;
 408         memcpy(ent.name, buf1, sizeof(ent.name));
 409
 410         /* expiry */
 411         error = get_expiry(&buf, &ent.h.expiry_time);
 412         if (error)
 413                 goto out;
 414
 415         /* ID */
 416         error = get_int(&buf, &ent.id);
 417         if (error == -EINVAL)
 418                 goto out;
 419         if (error == -ENOENT)
 420                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 421
 422         error = -ENOMEM;
 423         res = nametoid_lookup(cd, &ent);
 424         if (res == NULL)
 425                 goto out;
 426         res = nametoid_update(cd, &ent, res);
 427         if (res == NULL)
 428                 goto out;
 429
 430         cache_put(&res->h, cd);
 431         error = 0;
 432 out:
 433         kfree(buf1);
 434         return (error);
 435 }
 436
 437
 438 static struct ent *
 439 nametoid_lookup(struct cache_detail *cd, struct ent *item)
 440 {
 441         struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &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 cache_detail *cd, struct ent *new, struct ent *old)
 451 {
 452         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 453                                                     nametoid_hash(new));
 454         if (ch)
 455                 return container_of(ch, struct ent, h);
 456         else
 457                 return NULL;
 458 }
 459
 460 /*
 461  * Exported API
 462  */
 463
 464 int
 465 nfsd_idmap_init(struct net *net)
 466 {
 467         int rv;
 468         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 469
 470         nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
 471         if (IS_ERR(nn->idtoname_cache))
 472                 return PTR_ERR(nn->idtoname_cache);
 473         rv = cache_register_net(nn->idtoname_cache, net);
 474         if (rv)
 475                 goto destroy_idtoname_cache;
 476         nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
 477         if (IS_ERR(nn->nametoid_cache)) {
 478                 rv = PTR_ERR(nn->nametoid_cache);
 479                 goto unregister_idtoname_cache;
 480         }
 481         rv = cache_register_net(nn->nametoid_cache, net);
 482         if (rv)
 483                 goto destroy_nametoid_cache;
 484         return 0;
 485
 486 destroy_nametoid_cache:
 487         cache_destroy_net(nn->nametoid_cache, net);
 488 unregister_idtoname_cache:
 489         cache_unregister_net(nn->idtoname_cache, net);
 490 destroy_idtoname_cache:
 491         cache_destroy_net(nn->idtoname_cache, net);
 492         return rv;
 493 }
 494
 495 void
 496 nfsd_idmap_shutdown(struct net *net)
 497 {
 498         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 499
 500         cache_unregister_net(nn->idtoname_cache, net);
 501         cache_unregister_net(nn->nametoid_cache, net);
 502         cache_destroy_net(nn->idtoname_cache, net);
 503         cache_destroy_net(nn->nametoid_cache, net);
 504 }
 505
 506 static int
 507 idmap_lookup(struct svc_rqst *rqstp,
 508                 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
 509                 struct ent *key, struct cache_detail *detail, struct ent **item)
 510 {
 511         int ret;
 512
 513         *item = lookup_fn(detail, key);
 514         if (!*item)
 515                 return -ENOMEM;
 516  retry:
 517         ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
 518
 519         if (ret == -ETIMEDOUT) {
 520                 struct ent *prev_item = *item;
 521                 *item = lookup_fn(detail, key);
 522                 if (*item != prev_item)
 523                         goto retry;
 524                 cache_put(&(*item)->h, detail);
 525         }
 526         return ret;
 527 }
 528
 529 static char *
 530 rqst_authname(struct svc_rqst *rqstp)
 531 {
 532         struct auth_domain *clp;
 533
 534         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 535         return clp->name;
 536 }
 537
 538 static __be32
 539 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 540                 u32 *id)
 541 {
 542         struct ent *item, key = {
 543                 .type = type,
 544         };
 545         int ret;
 546         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 547
 548         if (namelen + 1 > sizeof(key.name))
 549                 return nfserr_badowner;
 550         memcpy(key.name, name, namelen);
 551         key.name[namelen] = '\0';
 552         strscpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 553         ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
 554         if (ret == -ENOENT)
 555                 return nfserr_badowner;
 556         if (ret)
 557                 return nfserrno(ret);
 558         *id = item->id;
 559         cache_put(&item->h, nn->nametoid_cache);
 560         return 0;
 561 }
 562
 563 static __be32 encode_ascii_id(struct xdr_stream *xdr, u32 id)
 564 {
 565         char buf[11];
 566         int len;
 567         __be32 *p;
 568
 569         len = sprintf(buf, "%u", id);
 570         p = xdr_reserve_space(xdr, len + 4);
 571         if (!p)
 572                 return nfserr_resource;
 573         p = xdr_encode_opaque(p, buf, len);
 574         return 0;
 575 }
 576
 577 static __be32 idmap_id_to_name(struct xdr_stream *xdr,
 578                                struct svc_rqst *rqstp, int type, u32 id)
 579 {
 580         struct ent *item, key = {
 581                 .id = id,
 582                 .type = type,
 583         };
 584         __be32 status = nfs_ok;
 585         __be32 *p;
 586         int ret;
 587         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 588
 589         strscpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 590         ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
 591         if (ret == -ENOENT)
 592                 return encode_ascii_id(xdr, id);
 593         if (ret)
 594                 return nfserrno(ret);
 595         ret = strlen(item->name);
 596         WARN_ON_ONCE(ret > IDMAP_NAMESZ);
 597
 598         p = xdr_reserve_space(xdr, ret + 4);
 599         if (unlikely(!p)) {
 600                 status = nfserr_resource;
 601                 goto out_put;
 602         }
 603         xdr_encode_opaque(p, item->name, ret);
 604 out_put:
 605         cache_put(&item->h, nn->idtoname_cache);
 606         return status;
 607 }
 608
 609 static bool
 610 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 611 {
 612         int ret;
 613         char buf[11];
 614
 615         if (namelen + 1 > sizeof(buf))
 616                 /* too long to represent a 32-bit id: */
 617                 return false;
 618         /* Just to make sure it's null-terminated: */
 619         memcpy(buf, name, namelen);
 620         buf[namelen] = '\0';
 621         ret = kstrtouint(buf, 10, id);
 622         return ret == 0;
 623 }
 624
 625 static __be32
 626 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 627 {
 628         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 629                 if (numeric_name_to_id(rqstp, type, name, namelen, id))
 630                         return 0;
 631                 /*
 632                  * otherwise, fall through and try idmapping, for
 633                  * backwards compatibility with clients sending names:
 634                  */
 635         return idmap_name_to_id(rqstp, type, name, namelen, id);
 636 }
 637
 638 static __be32 encode_name_from_id(struct xdr_stream *xdr,
 639                                   struct svc_rqst *rqstp, int type, u32 id)
 640 {
 641         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 642                 return encode_ascii_id(xdr, id);
 643         return idmap_id_to_name(xdr, rqstp, type, id);
 644 }
 645
 646 __be32
 647 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 648                 kuid_t *uid)
 649 {
 650         __be32 status;
 651         u32 id = -1;
 652
 653         if (name == NULL || namelen == 0)
 654                 return nfserr_inval;
 655
 656         status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
 657         *uid = make_kuid(nfsd_user_namespace(rqstp), id);
 658         if (!uid_valid(*uid))
 659                 status = nfserr_badowner;
 660         return status;
 661 }
 662
 663 __be32
 664 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 665                 kgid_t *gid)
 666 {
 667         __be32 status;
 668         u32 id = -1;
 669
 670         if (name == NULL || namelen == 0)
 671                 return nfserr_inval;
 672
 673         status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
 674         *gid = make_kgid(nfsd_user_namespace(rqstp), id);
 675         if (!gid_valid(*gid))
 676                 status = nfserr_badowner;
 677         return status;
 678 }
 679
 680 __be32 nfsd4_encode_user(struct xdr_stream *xdr, struct svc_rqst *rqstp,
 681                          kuid_t uid)
 682 {
 683         u32 id = from_kuid_munged(nfsd_user_namespace(rqstp), uid);
 684         return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_USER, id);
 685 }
 686
 687 __be32 nfsd4_encode_group(struct xdr_stream *xdr, struct svc_rqst *rqstp,
 688                           kgid_t gid)
 689 {
 690         u32 id = from_kgid_munged(nfsd_user_namespace(rqstp), gid);
 691         return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_GROUP, id);
 692 }