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         u32               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_match(struct cache_head *ca, struct cache_head *cb)
 144 {
 145         struct ent *a = container_of(ca, struct ent, h);
 146         struct ent *b = container_of(cb, struct ent, h);
 147
 148         return (a->id == b->id && a->type == b->type &&
 149             strcmp(a->authname, b->authname) == 0);
 150 }
 151
 152 static int
 153 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 154 {
 155         struct ent *ent;
 156
 157         if (h == NULL) {
 158                 seq_puts(m, "#domain type id [name]\n");
 159                 return 0;
 160         }
 161         ent = container_of(h, struct ent, h);
 162         seq_printf(m, "%s %s %u", ent->authname,
 163                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 164                         ent->id);
 165         if (test_bit(CACHE_VALID, &h->flags))
 166                 seq_printf(m, " %s", ent->name);
 167         seq_printf(m, "\n");
 168         return 0;
 169 }
 170
 171 static void
 172 warn_no_idmapd(struct cache_detail *detail, int has_died)
 173 {
 174         printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
 175                         has_died ? "died" : "not been started");
 176 }
 177
 178
 179 static int         idtoname_parse(struct cache_detail *, char *, int);
 180 static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
 181 static struct ent *idtoname_update(struct cache_detail *, struct ent *,
 182                                    struct ent *);
 183
 184 static struct cache_detail idtoname_cache_template = {
 185         .owner          = THIS_MODULE,
 186         .hash_size      = ENT_HASHMAX,
 187         .name           = "nfs4.idtoname",
 188         .cache_put      = ent_put,
 189         .cache_request  = idtoname_request,
 190         .cache_parse    = idtoname_parse,
 191         .cache_show     = idtoname_show,
 192         .warn_no_listener = warn_no_idmapd,
 193         .match          = idtoname_match,
 194         .init           = ent_init,
 195         .update         = ent_init,
 196         .alloc          = ent_alloc,
 197 };
 198
 199 static int
 200 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 201 {
 202         struct ent ent, *res;
 203         char *buf1, *bp;
 204         int len;
 205         int error = -EINVAL;
 206
 207         if (buf[buflen - 1] != '\n')
 208                 return (-EINVAL);
 209         buf[buflen - 1]= '\0';
 210
 211         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 212         if (buf1 == NULL)
 213                 return (-ENOMEM);
 214
 215         memset(&ent, 0, sizeof(ent));
 216
 217         /* Authentication name */
 218         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 219                 goto out;
 220         memcpy(ent.authname, buf1, sizeof(ent.authname));
 221
 222         /* Type */
 223         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 224                 goto out;
 225         ent.type = strcmp(buf1, "user") == 0 ?
 226                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 227
 228         /* ID */
 229         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 230                 goto out;
 231         ent.id = simple_strtoul(buf1, &bp, 10);
 232         if (bp == buf1)
 233                 goto out;
 234
 235         /* expiry */
 236         ent.h.expiry_time = get_expiry(&buf);
 237         if (ent.h.expiry_time == 0)
 238                 goto out;
 239
 240         error = -ENOMEM;
 241         res = idtoname_lookup(cd, &ent);
 242         if (!res)
 243                 goto out;
 244
 245         /* Name */
 246         error = -EINVAL;
 247         len = qword_get(&buf, buf1, PAGE_SIZE);
 248         if (len < 0)
 249                 goto out;
 250         if (len == 0)
 251                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 252         else if (len >= IDMAP_NAMESZ)
 253                 goto out;
 254         else
 255                 memcpy(ent.name, buf1, sizeof(ent.name));
 256         error = -ENOMEM;
 257         res = idtoname_update(cd, &ent, res);
 258         if (res == NULL)
 259                 goto out;
 260
 261         cache_put(&res->h, cd);
 262
 263         error = 0;
 264 out:
 265         kfree(buf1);
 266
 267         return error;
 268 }
 269
 270
 271 static struct ent *
 272 idtoname_lookup(struct cache_detail *cd, struct ent *item)
 273 {
 274         struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
 275                                                     idtoname_hash(item));
 276         if (ch)
 277                 return container_of(ch, struct ent, h);
 278         else
 279                 return NULL;
 280 }
 281
 282 static struct ent *
 283 idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 284 {
 285         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 286                                                     idtoname_hash(new));
 287         if (ch)
 288                 return container_of(ch, struct ent, h);
 289         else
 290                 return NULL;
 291 }
 292
 293
 294 /*
 295  * Name -> ID cache
 296  */
 297
 298 static inline int
 299 nametoid_hash(struct ent *ent)
 300 {
 301         return hash_str(ent->name, ENT_HASHBITS);
 302 }
 303
 304 static void
 305 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
 306     int *blen)
 307 {
 308         struct ent *ent = container_of(ch, struct ent, h);
 309
 310         qword_add(bpp, blen, ent->authname);
 311         qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
 312         qword_add(bpp, blen, ent->name);
 313
 314         (*bpp)[-1] = '\n';
 315 }
 316
 317 static int
 318 nametoid_match(struct cache_head *ca, struct cache_head *cb)
 319 {
 320         struct ent *a = container_of(ca, struct ent, h);
 321         struct ent *b = container_of(cb, struct ent, h);
 322
 323         return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
 324             strcmp(a->authname, b->authname) == 0);
 325 }
 326
 327 static int
 328 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
 329 {
 330         struct ent *ent;
 331
 332         if (h == NULL) {
 333                 seq_puts(m, "#domain type name [id]\n");
 334                 return 0;
 335         }
 336         ent = container_of(h, struct ent, h);
 337         seq_printf(m, "%s %s %s", ent->authname,
 338                         ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
 339                         ent->name);
 340         if (test_bit(CACHE_VALID, &h->flags))
 341                 seq_printf(m, " %u", ent->id);
 342         seq_printf(m, "\n");
 343         return 0;
 344 }
 345
 346 static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
 347 static struct ent *nametoid_update(struct cache_detail *, struct ent *,
 348                                    struct ent *);
 349 static int         nametoid_parse(struct cache_detail *, char *, int);
 350
 351 static struct cache_detail nametoid_cache_template = {
 352         .owner          = THIS_MODULE,
 353         .hash_size      = ENT_HASHMAX,
 354         .name           = "nfs4.nametoid",
 355         .cache_put      = ent_put,
 356         .cache_request  = nametoid_request,
 357         .cache_parse    = nametoid_parse,
 358         .cache_show     = nametoid_show,
 359         .warn_no_listener = warn_no_idmapd,
 360         .match          = nametoid_match,
 361         .init           = ent_init,
 362         .update         = ent_init,
 363         .alloc          = ent_alloc,
 364 };
 365
 366 static int
 367 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 368 {
 369         struct ent ent, *res;
 370         char *buf1;
 371         int error = -EINVAL;
 372
 373         if (buf[buflen - 1] != '\n')
 374                 return (-EINVAL);
 375         buf[buflen - 1]= '\0';
 376
 377         buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
 378         if (buf1 == NULL)
 379                 return (-ENOMEM);
 380
 381         memset(&ent, 0, sizeof(ent));
 382
 383         /* Authentication name */
 384         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 385                 goto out;
 386         memcpy(ent.authname, buf1, sizeof(ent.authname));
 387
 388         /* Type */
 389         if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
 390                 goto out;
 391         ent.type = strcmp(buf1, "user") == 0 ?
 392                 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
 393
 394         /* Name */
 395         error = qword_get(&buf, buf1, PAGE_SIZE);
 396         if (error <= 0 || error >= IDMAP_NAMESZ)
 397                 goto out;
 398         memcpy(ent.name, buf1, sizeof(ent.name));
 399
 400         /* expiry */
 401         ent.h.expiry_time = get_expiry(&buf);
 402         if (ent.h.expiry_time == 0)
 403                 goto out;
 404
 405         /* ID */
 406         error = get_int(&buf, &ent.id);
 407         if (error == -EINVAL)
 408                 goto out;
 409         if (error == -ENOENT)
 410                 set_bit(CACHE_NEGATIVE, &ent.h.flags);
 411
 412         error = -ENOMEM;
 413         res = nametoid_lookup(cd, &ent);
 414         if (res == NULL)
 415                 goto out;
 416         res = nametoid_update(cd, &ent, res);
 417         if (res == NULL)
 418                 goto out;
 419
 420         cache_put(&res->h, cd);
 421         error = 0;
 422 out:
 423         kfree(buf1);
 424
 425         return (error);
 426 }
 427
 428
 429 static struct ent *
 430 nametoid_lookup(struct cache_detail *cd, struct ent *item)
 431 {
 432         struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
 433                                                     nametoid_hash(item));
 434         if (ch)
 435                 return container_of(ch, struct ent, h);
 436         else
 437                 return NULL;
 438 }
 439
 440 static struct ent *
 441 nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
 442 {
 443         struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
 444                                                     nametoid_hash(new));
 445         if (ch)
 446                 return container_of(ch, struct ent, h);
 447         else
 448                 return NULL;
 449 }
 450
 451 /*
 452  * Exported API
 453  */
 454
 455 int
 456 nfsd_idmap_init(struct net *net)
 457 {
 458         int rv;
 459         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 460
 461         nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
 462         if (IS_ERR(nn->idtoname_cache))
 463                 return PTR_ERR(nn->idtoname_cache);
 464         rv = cache_register_net(nn->idtoname_cache, net);
 465         if (rv)
 466                 goto destroy_idtoname_cache;
 467         nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
 468         if (IS_ERR(nn->nametoid_cache)) {
 469                 rv = PTR_ERR(nn->nametoid_cache);
 470                 goto unregister_idtoname_cache;
 471         }
 472         rv = cache_register_net(nn->nametoid_cache, net);
 473         if (rv)
 474                 goto destroy_nametoid_cache;
 475         return 0;
 476
 477 destroy_nametoid_cache:
 478         cache_destroy_net(nn->nametoid_cache, net);
 479 unregister_idtoname_cache:
 480         cache_unregister_net(nn->idtoname_cache, net);
 481 destroy_idtoname_cache:
 482         cache_destroy_net(nn->idtoname_cache, net);
 483         return rv;
 484 }
 485
 486 void
 487 nfsd_idmap_shutdown(struct net *net)
 488 {
 489         struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 490
 491         cache_unregister_net(nn->idtoname_cache, net);
 492         cache_unregister_net(nn->nametoid_cache, net);
 493         cache_destroy_net(nn->idtoname_cache, net);
 494         cache_destroy_net(nn->nametoid_cache, net);
 495 }
 496
 497 static int
 498 idmap_lookup(struct svc_rqst *rqstp,
 499                 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
 500                 struct ent *key, struct cache_detail *detail, struct ent **item)
 501 {
 502         int ret;
 503
 504         *item = lookup_fn(detail, key);
 505         if (!*item)
 506                 return -ENOMEM;
 507  retry:
 508         ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
 509
 510         if (ret == -ETIMEDOUT) {
 511                 struct ent *prev_item = *item;
 512                 *item = lookup_fn(detail, key);
 513                 if (*item != prev_item)
 514                         goto retry;
 515                 cache_put(&(*item)->h, detail);
 516         }
 517         return ret;
 518 }
 519
 520 static char *
 521 rqst_authname(struct svc_rqst *rqstp)
 522 {
 523         struct auth_domain *clp;
 524
 525         clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
 526         return clp->name;
 527 }
 528
 529 static __be32
 530 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
 531                 u32 *id)
 532 {
 533         struct ent *item, key = {
 534                 .type = type,
 535         };
 536         int ret;
 537         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 538
 539         if (namelen + 1 > sizeof(key.name))
 540                 return nfserr_badowner;
 541         memcpy(key.name, name, namelen);
 542         key.name[namelen] = '\0';
 543         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 544         ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
 545         if (ret == -ENOENT)
 546                 return nfserr_badowner;
 547         if (ret)
 548                 return nfserrno(ret);
 549         *id = item->id;
 550         cache_put(&item->h, nn->nametoid_cache);
 551         return 0;
 552 }
 553
 554 static int
 555 idmap_id_to_name(struct svc_rqst *rqstp, int type, u32 id, char *name)
 556 {
 557         struct ent *item, key = {
 558                 .id = id,
 559                 .type = type,
 560         };
 561         int ret;
 562         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 563
 564         strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
 565         ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
 566         if (ret == -ENOENT)
 567                 return sprintf(name, "%u", id);
 568         if (ret)
 569                 return ret;
 570         ret = strlen(item->name);
 571         BUG_ON(ret > IDMAP_NAMESZ);
 572         memcpy(name, item->name, ret);
 573         cache_put(&item->h, nn->idtoname_cache);
 574         return ret;
 575 }
 576
 577 static bool
 578 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 579 {
 580         int ret;
 581         char buf[11];
 582
 583         if (namelen + 1 > sizeof(buf))
 584                 /* too long to represent a 32-bit id: */
 585                 return false;
 586         /* Just to make sure it's null-terminated: */
 587         memcpy(buf, name, namelen);
 588         buf[namelen] = '\0';
 589         ret = kstrtouint(buf, 10, id);
 590         return ret == 0;
 591 }
 592
 593 static __be32
 594 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
 595 {
 596         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 597                 if (numeric_name_to_id(rqstp, type, name, namelen, id))
 598                         return 0;
 599                 /*
 600                  * otherwise, fall through and try idmapping, for
 601                  * backwards compatibility with clients sending names:
 602                  */
 603         return idmap_name_to_id(rqstp, type, name, namelen, id);
 604 }
 605
 606 static int
 607 do_id_to_name(struct svc_rqst *rqstp, int type, u32 id, char *name)
 608 {
 609         if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
 610                 return sprintf(name, "%u", id);
 611         return idmap_id_to_name(rqstp, type, id, name);
 612 }
 613
 614 __be32
 615 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 616                 kuid_t *uid)
 617 {
 618         __be32 status;
 619         u32 id = -1;
 620         status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
 621         *uid = make_kuid(&init_user_ns, id);
 622         if (!uid_valid(*uid))
 623                 status = nfserr_badowner;
 624         return status;
 625 }
 626
 627 __be32
 628 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 629                 kgid_t *gid)
 630 {
 631         __be32 status;
 632         u32 id = -1;
 633         status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
 634         *gid = make_kgid(&init_user_ns, id);
 635         if (!gid_valid(*gid))
 636                 status = nfserr_badowner;
 637         return status;
 638 }
 639
 640 int
 641 nfsd_map_uid_to_name(struct svc_rqst *rqstp, kuid_t uid, char *name)
 642 {
 643         u32 id = from_kuid(&init_user_ns, uid);
 644         return do_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
 645 }
 646
 647 int
 648 nfsd_map_gid_to_name(struct svc_rqst *rqstp, kgid_t gid, char *name)
 649 {
 650         u32 id = from_kgid(&init_user_ns, gid);
 651         return do_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
 652 }