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 struct ent {
  63         struct cache_head h;
  64         int               type;                /* User / Group */
  65         u32               id;
  66         char              name[IDMAP_NAMESZ];
  67         char              authname[IDMAP_NAMESZ];
  68         struct rcu_head   rcu_head;
  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->authname));
  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_rcu(map, rcu_head);
  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 uint32_t
 111 idtoname_hash(struct ent *ent)
 112 {
 113         uint32_t hash;
 114
 115         hash = hash_str(ent->authname, ENT_HASHBITS);
 116         hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
 117
 118         /* Flip LSB for user/group */
 119         if (ent->type == IDMAP_TYPE_GROUP)
 120                 hash ^= 1;
 121
 122         return hash;
 123 }
 124
 125 static int
 126 idtoname_upcall(struct cache_detail *cd, struct cache_head *h)
 127 {
 128         return sunrpc_cache_pipe_upcall_timeout(cd, h);
 129 }
 130
 131 static void
 132 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 133     int *blen)
 134 {
 135         struct ent *ent = container_of(ch, struct ent, h);
 136         char idstr[11];
 137
 138         qword_add(bpp, blen, ent->authname);
 139         snprintf(idstr, sizeof(idstr), "%u", ent->id);
 140         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 141         qword_add(bpp, blen, idstr);
 142
 143         (*bpp)[-1] = '\n';
 144 }
 145
 146 static int
 147 idtoname_match(struct cache_head *ca, struct cache_head *cb)
 148 {
 149         struct ent *a = container_of(ca, struct ent, h);
 150         struct ent *b = container_of(cb, struct ent, h);
 151
 152         return (a->id == b->id && a->type == b->type &&
 153             strcmp(a->authname, b->authname) == 0);
 154 }
 155
 156 static int
 157 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 158 {
 159         struct ent *ent;
 160
 161         if (h == NULL) {
 162                 seq_puts(m, "#domain type id [name]\n");
 163                 return 0;
 164         }
 165         ent = container_of(h, struct ent, h);
 166         seq_printf(m, "%s %s %u", ent->authname,
 167                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 168                         ent->id);
 169         if (test_bit(CACHE_VALID, &h->flags))
 170                 seq_printf(m, " %s", ent->name);
 171         seq_putc(m, '\n');
 172         return 0;
 173 }
 174
 175 static void
 176 warn_no_idmapd(struct cache_detail *detail, int has_died)
 177 {
 178         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 179                         has_died ? "died" : "not been started");
 180 }
 181
 182
 183 static int         idtoname_parse(struct cache_detail *, char *, int);
 184 static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
 185 static struct ent *idtoname_update(struct cache_detail *, struct ent *,
 186                                    struct ent *);
 187
 188 static const struct cache_detail idtoname_cache_template = {
 189         .owner          = THIS_MODULE,
 190         .hash_size      = ENT_HASHMAX,
 191         .name           = "nfs4.idtoname",
 192         .cache_put      = ent_put,
 193         .cache_upcall   = idtoname_upcall,
 194         .cache_request  = idtoname_request,
 195         .cache_parse    = idtoname_parse,
 196         .cache_show     = idtoname_show,
 197         .warn_no_listener = warn_no_idmapd,
 198         .match          = idtoname_match,
 199         .init           = ent_init,
 200         .update         = ent_init,
 201         .alloc          = ent_alloc,
 202 };
 203
 204 static int
 205 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 206 {
 207         struct ent ent, *res;
 208         char *buf1, *bp;
 209         int len;
 210         int error = -EINVAL;
 211
 212         if (buf[buflen - 1] != '\n')
 213                 return (-EINVAL);
 214         buf[buflen - 1]= '\0';
 215
 216         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 217         if (buf1 == NULL)
 218                 return (-ENOMEM);
 219
 220         memset(&ent, 0, sizeof(ent));
 221
 222         /* Authentication name */
 223         len = qword_get(&buf, buf1, PAGE_SIZE);
 224         if (len <= 0 || len >= IDMAP_NAMESZ)
 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 || len >= IDMAP_NAMESZ)
 255                 goto out;
 256         if (len == 0)
 257                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 258         else
 259                 memcpy(ent.name, buf1, sizeof(ent.name));
 260         error = -ENOMEM;
 261         res = idtoname_update(cd, &ent, res);
 262         if (res == NULL)
 263                 goto out;
 264
 265         cache_put(&res->h, cd);
 266         error = 0;
 267 out:
 268         kfree(buf1);
 269         return error;
 270 }
 271
 272 static struct ent *
 273 idtoname_lookup(struct cache_detail *cd, struct ent *item)
 274 {
 275         struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
 276                                                         idtoname_hash(item));
 277         if (ch)
 278                 return container_of(ch, struct ent, h);
 279         else
 280                 return NULL;
 281 }
 282
 283 static struct ent *
 284 idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 285 {
 286         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 287                                                     idtoname_hash(new));
 288         if (ch)
 289                 return container_of(ch, struct ent, h);
 290         else
 291                 return NULL;
 292 }
 293
 294
 295 /*
 296  * Name -> ID cache
 297  */
 298
 299 static inline int
 300 nametoid_hash(struct ent *ent)
 301 {
 302         return hash_str(ent->name, ENT_HASHBITS);
 303 }
 304
 305 static int
 306 nametoid_upcall(struct cache_detail *cd, struct cache_head *h)
 307 {
 308         return sunrpc_cache_pipe_upcall_timeout(cd, h);
 309 }
 310
 311 static void
 312 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 313     int *blen)
 314 {
 315         struct ent *ent = container_of(ch, struct ent, h);
 316
 317         qword_add(bpp, blen, ent->authname);
 318         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 319         qword_add(bpp, blen, ent->name);
 320
 321         (*bpp)[-1] = '\n';
 322 }
 323
 324 static int
 325 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 326 {
 327         struct ent *a = container_of(ca, struct ent, h);
 328         struct ent *b = container_of(cb, struct ent, h);
 329
 330         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 331             strcmp(a->authname, b->authname) == 0);
 332 }
 333
 334 static int
 335 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 336 {
 337         struct ent *ent;
 338
 339         if (h == NULL) {
 340                 seq_puts(m, "#domain type name [id]\n");
 341                 return 0;
 342         }
 343         ent = container_of(h, struct ent, h);
 344         seq_printf(m, "%s %s %s", ent->authname,
 345                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 346                         ent->name);
 347         if (test_bit(CACHE_VALID, &h->flags))
 348                 seq_printf(m, " %u", ent->id);
 349         seq_putc(m, '\n');
 350         return 0;
 351 }
 352
 353 static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
 354 static struct ent *nametoid_update(struct cache_detail *, struct ent *,
 355                                    struct ent *);
 356 static int         nametoid_parse(struct cache_detail *, char *, int);
 357
 358 static const struct cache_detail nametoid_cache_template = {
 359         .owner          = THIS_MODULE,
 360         .hash_size      = ENT_HASHMAX,
 361         .name           = "nfs4.nametoid",
 362         .cache_put      = ent_put,
 363         .cache_upcall   = nametoid_upcall,
 364         .cache_request  = nametoid_request,
 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 len, 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         len = qword_get(&buf, buf1, PAGE_SIZE);
 393         if (len <= 0 || len >= IDMAP_NAMESZ)
 394                 goto out;
 395         memcpy(ent.authname, buf1, sizeof(ent.authname));
 396
 397         /* Type */
 398         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 399                 goto out;
 400         ent.type = strcmp(buf1, "user") == 0 ?
 401                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 402
 403         /* Name */
 404         len = qword_get(&buf, buf1, PAGE_SIZE);
 405         if (len <= 0 || len >= IDMAP_NAMESZ)
 406                 goto out;
 407         memcpy(ent.name, buf1, sizeof(ent.name));
 408
 409         /* expiry */
 410         ent.h.expiry_time = get_expiry(&buf);
 411         if (ent.h.expiry_time == 0)
 412                 goto out;
 413
 414         /* ID */
 415         error = get_int(&buf, &ent.id);
 416         if (error == -EINVAL)
 417                 goto out;
 418         if (error == -ENOENT)
 419                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 420
 421         error = -ENOMEM;
 422         res = nametoid_lookup(cd, &ent);
 423         if (res == NULL)
 424                 goto out;
 425         res = nametoid_update(cd, &ent, res);
 426         if (res == NULL)
 427                 goto out;
 428
 429         cache_put(&res->h, cd);
 430         error = 0;
 431 out:
 432         kfree(buf1);
 433         return (error);
 434 }
 435
 436
 437 static struct ent *
 438 nametoid_lookup(struct cache_detail *cd, struct ent *item)
 439 {
 440         struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
 441                                                         nametoid_hash(item));
 442         if (ch)
 443                 return container_of(ch, struct ent, h);
 444         else
 445                 return NULL;
 446 }
 447
 448 static struct ent *
 449 nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 450 {
 451         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 452                                                     nametoid_hash(new));
 453         if (ch)
 454                 return container_of(ch, struct ent, h);
 455         else
 456                 return NULL;
 457 }
 458
 459 /*
 460  * Exported API
 461  */
 462
 463 int
 464 nfsd_idmap_init(struct net *net)
 465 {
 466         int rv;
 467         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 468
 469         nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
 470         if (IS_ERR(nn->idtoname_cache))
 471                 return PTR_ERR(nn->idtoname_cache);
 472         rv = cache_register_net(nn->idtoname_cache, net);
 473         if (rv)
 474                 goto destroy_idtoname_cache;
 475         nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
 476         if (IS_ERR(nn->nametoid_cache)) {
 477                 rv = PTR_ERR(nn->nametoid_cache);
 478                 goto unregister_idtoname_cache;
 479         }
 480         rv = cache_register_net(nn->nametoid_cache, net);
 481         if (rv)
 482                 goto destroy_nametoid_cache;
 483         return 0;
 484
 485 destroy_nametoid_cache:
 486         cache_destroy_net(nn->nametoid_cache, net);
 487 unregister_idtoname_cache:
 488         cache_unregister_net(nn->idtoname_cache, net);
 489 destroy_idtoname_cache:
 490         cache_destroy_net(nn->idtoname_cache, net);
 491         return rv;
 492 }
 493
 494 void
 495 nfsd_idmap_shutdown(struct net *net)
 496 {
 497         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 498
 499         cache_unregister_net(nn->idtoname_cache, net);
 500         cache_unregister_net(nn->nametoid_cache, net);
 501         cache_destroy_net(nn->idtoname_cache, net);
 502         cache_destroy_net(nn->nametoid_cache, net);
 503 }
 504
 505 static int
 506 idmap_lookup(struct svc_rqst *rqstp,
 507                 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
 508                 struct ent *key, struct cache_detail *detail, struct ent **item)
 509 {
 510         int ret;
 511
 512         *item = lookup_fn(detail, key);
 513         if (!*item)
 514                 return -ENOMEM;
 515  retry:
 516         ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
 517
 518         if (ret == -ETIMEDOUT) {
 519                 struct ent *prev_item = *item;
 520                 *item = lookup_fn(detail, key);
 521                 if (*item != prev_item)
 522                         goto retry;
 523                 cache_put(&(*item)->h, detail);
 524         }
 525         return ret;
 526 }
 527
 528 static char *
 529 rqst_authname(struct svc_rqst *rqstp)
 530 {
 531         struct auth_domain *clp;
 532
 533         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 534         return clp->name;
 535 }
 536
 537 static __be32
 538 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 539                 u32 *id)
 540 {
 541         struct ent *item, key = {
 542                 .type = type,
 543         };
 544         int ret;
 545         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 546
 547         if (namelen + 1 > sizeof(key.name))
 548                 return nfserr_badowner;
 549         memcpy(key.name, name, namelen);
 550         key.name[namelen] = '\0';
 551         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 552         ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
 553         if (ret == -ENOENT)
 554                 return nfserr_badowner;
 555         if (ret)
 556                 return nfserrno(ret);
 557         *id = item->id;
 558         cache_put(&item->h, nn->nametoid_cache);
 559         return 0;
 560 }
 561
 562 static __be32 encode_ascii_id(struct xdr_stream *xdr, u32 id)
 563 {
 564         char buf[11];
 565         int len;
 566         __be32 *p;
 567
 568         len = sprintf(buf, "%u", id);
 569         p = xdr_reserve_space(xdr, len + 4);
 570         if (!p)
 571                 return nfserr_resource;
 572         p = xdr_encode_opaque(p, buf, len);
 573         return 0;
 574 }
 575
 576 static __be32 idmap_id_to_name(struct xdr_stream *xdr,
 577                                struct svc_rqst *rqstp, int type, u32 id)
 578 {
 579         struct ent *item, key = {
 580                 .id = id,
 581                 .type = type,
 582         };
 583         __be32 *p;
 584         int ret;
 585         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 586
 587         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 588         ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
 589         if (ret == -ENOENT)
 590                 return encode_ascii_id(xdr, id);
 591         if (ret)
 592                 return nfserrno(ret);
 593         ret = strlen(item->name);
 594         WARN_ON_ONCE(ret > IDMAP_NAMESZ);
 595         p = xdr_reserve_space(xdr, ret + 4);
 596         if (!p)
 597                 return nfserr_resource;
 598         p = xdr_encode_opaque(p, item->name, ret);
 599         cache_put(&item->h, nn->idtoname_cache);
 600         return 0;
 601 }
 602
 603 static bool
 604 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 605 {
 606         int ret;
 607         char buf[11];
 608
 609         if (namelen + 1 > sizeof(buf))
 610                 /* too long to represent a 32-bit id: */
 611                 return false;
 612         /* Just to make sure it's null-terminated: */
 613         memcpy(buf, name, namelen);
 614         buf[namelen] = '\0';
 615         ret = kstrtouint(buf, 10, id);
 616         return ret == 0;
 617 }
 618
 619 static __be32
 620 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 621 {
 622         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 623                 if (numeric_name_to_id(rqstp, type, name, namelen, id))
 624                         return 0;
 625                 /*
 626                  * otherwise, fall through and try idmapping, for
 627                  * backwards compatibility with clients sending names:
 628                  */
 629         return idmap_name_to_id(rqstp, type, name, namelen, id);
 630 }
 631
 632 static __be32 encode_name_from_id(struct xdr_stream *xdr,
 633                                   struct svc_rqst *rqstp, int type, u32 id)
 634 {
 635         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 636                 return encode_ascii_id(xdr, id);
 637         return idmap_id_to_name(xdr, rqstp, type, id);
 638 }
 639
 640 __be32
 641 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 642                 kuid_t *uid)
 643 {
 644         __be32 status;
 645         u32 id = -1;
 646
 647         if (name == NULL || namelen == 0)
 648                 return nfserr_inval;
 649
 650         status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
 651         *uid = make_kuid(nfsd_user_namespace(rqstp), id);
 652         if (!uid_valid(*uid))
 653                 status = nfserr_badowner;
 654         return status;
 655 }
 656
 657 __be32
 658 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 659                 kgid_t *gid)
 660 {
 661         __be32 status;
 662         u32 id = -1;
 663
 664         if (name == NULL || namelen == 0)
 665                 return nfserr_inval;
 666
 667         status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
 668         *gid = make_kgid(nfsd_user_namespace(rqstp), id);
 669         if (!gid_valid(*gid))
 670                 status = nfserr_badowner;
 671         return status;
 672 }
 673
 674 __be32 nfsd4_encode_user(struct xdr_stream *xdr, struct svc_rqst *rqstp,
 675                          kuid_t uid)
 676 {
 677         u32 id = from_kuid_munged(nfsd_user_namespace(rqstp), uid);
 678         return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_USER, id);
 679 }
 680
 681 __be32 nfsd4_encode_group(struct xdr_stream *xdr, struct svc_rqst *rqstp,
 682                           kgid_t gid)
 683 {
 684         u32 id = from_kgid_munged(nfsd_user_namespace(rqstp), gid);
 685         return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_GROUP, id);
 686 }