net/sunrpc/auth.c

   1 /*
   2  * linux/net/sunrpc/auth.c
   3  *
   4  * Generic RPC client authentication API.
   5  *
   6  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/sched.h>
  11 #include <linux/cred.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/errno.h>
  15 #include <linux/hash.h>
  16 #include <linux/sunrpc/clnt.h>
  17 #include <linux/sunrpc/gss_api.h>
  18 #include <linux/spinlock.h>
  19
  20 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  21 # define RPCDBG_FACILITY        RPCDBG_AUTH
  22 #endif
  23
  24 #define RPC_CREDCACHE_DEFAULT_HASHBITS  (4)
  25 struct rpc_cred_cache {
  26         struct hlist_head       *hashtable;
  27         unsigned int            hashbits;
  28         spinlock_t              lock;
  29 };
  30
  31 static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
  32
  33 static DEFINE_SPINLOCK(rpc_authflavor_lock);
  34 static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
  35         &authnull_ops,          /* AUTH_NULL */
  36         &authunix_ops,          /* AUTH_UNIX */
  37         NULL,                   /* others can be loadable modules */
  38 };
  39
  40 static LIST_HEAD(cred_unused);
  41 static unsigned long number_cred_unused;
  42
  43 #define MAX_HASHTABLE_BITS (14)
  44 static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
  45 {
  46         unsigned long num;
  47         unsigned int nbits;
  48         int ret;
  49
  50         if (!val)
  51                 goto out_inval;
  52         ret = kstrtoul(val, 0, &num);
  53         if (ret)
  54                 goto out_inval;
  55         nbits = fls(num - 1);
  56         if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
  57                 goto out_inval;
  58         *(unsigned int *)kp->arg = nbits;
  59         return 0;
  60 out_inval:
  61         return -EINVAL;
  62 }
  63
  64 static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
  65 {
  66         unsigned int nbits;
  67
  68         nbits = *(unsigned int *)kp->arg;
  69         return sprintf(buffer, "%u", 1U << nbits);
  70 }
  71
  72 #define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
  73
  74 static const struct kernel_param_ops param_ops_hashtbl_sz = {
  75         .set = param_set_hashtbl_sz,
  76         .get = param_get_hashtbl_sz,
  77 };
  78
  79 module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
  80 MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
  81
  82 static unsigned long auth_max_cred_cachesize = ULONG_MAX;
  83 module_param(auth_max_cred_cachesize, ulong, 0644);
  84 MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
  85
  86 static u32
  87 pseudoflavor_to_flavor(u32 flavor) {
  88         if (flavor > RPC_AUTH_MAXFLAVOR)
  89                 return RPC_AUTH_GSS;
  90         return flavor;
  91 }
  92
  93 int
  94 rpcauth_register(const struct rpc_authops *ops)
  95 {
  96         rpc_authflavor_t flavor;
  97         int ret = -EPERM;
  98
  99         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 100                 return -EINVAL;
 101         spin_lock(&rpc_authflavor_lock);
 102         if (auth_flavors[flavor] == NULL) {
 103                 auth_flavors[flavor] = ops;
 104                 ret = 0;
 105         }
 106         spin_unlock(&rpc_authflavor_lock);
 107         return ret;
 108 }
 109 EXPORT_SYMBOL_GPL(rpcauth_register);
 110
 111 int
 112 rpcauth_unregister(const struct rpc_authops *ops)
 113 {
 114         rpc_authflavor_t flavor;
 115         int ret = -EPERM;
 116
 117         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 118                 return -EINVAL;
 119         spin_lock(&rpc_authflavor_lock);
 120         if (auth_flavors[flavor] == ops) {
 121                 auth_flavors[flavor] = NULL;
 122                 ret = 0;
 123         }
 124         spin_unlock(&rpc_authflavor_lock);
 125         return ret;
 126 }
 127 EXPORT_SYMBOL_GPL(rpcauth_unregister);
 128
 129 /**
 130  * rpcauth_get_pseudoflavor - check if security flavor is supported
 131  * @flavor: a security flavor
 132  * @info: a GSS mech OID, quality of protection, and service value
 133  *
 134  * Verifies that an appropriate kernel module is available or already loaded.
 135  * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
 136  * not supported locally.
 137  */
 138 rpc_authflavor_t
 139 rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
 140 {
 141         const struct rpc_authops *ops;
 142         rpc_authflavor_t pseudoflavor;
 143
 144         ops = auth_flavors[flavor];
 145         if (ops == NULL)
 146                 request_module("rpc-auth-%u", flavor);
 147         spin_lock(&rpc_authflavor_lock);
 148         ops = auth_flavors[flavor];
 149         if (ops == NULL || !try_module_get(ops->owner)) {
 150                 spin_unlock(&rpc_authflavor_lock);
 151                 return RPC_AUTH_MAXFLAVOR;
 152         }
 153         spin_unlock(&rpc_authflavor_lock);
 154
 155         pseudoflavor = flavor;
 156         if (ops->info2flavor != NULL)
 157                 pseudoflavor = ops->info2flavor(info);
 158
 159         module_put(ops->owner);
 160         return pseudoflavor;
 161 }
 162 EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
 163
 164 /**
 165  * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
 166  * @pseudoflavor: GSS pseudoflavor to match
 167  * @info: rpcsec_gss_info structure to fill in
 168  *
 169  * Returns zero and fills in "info" if pseudoflavor matches a
 170  * supported mechanism.
 171  */
 172 int
 173 rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
 174 {
 175         rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
 176         const struct rpc_authops *ops;
 177         int result;
 178
 179         if (flavor >= RPC_AUTH_MAXFLAVOR)
 180                 return -EINVAL;
 181
 182         ops = auth_flavors[flavor];
 183         if (ops == NULL)
 184                 request_module("rpc-auth-%u", flavor);
 185         spin_lock(&rpc_authflavor_lock);
 186         ops = auth_flavors[flavor];
 187         if (ops == NULL || !try_module_get(ops->owner)) {
 188                 spin_unlock(&rpc_authflavor_lock);
 189                 return -ENOENT;
 190         }
 191         spin_unlock(&rpc_authflavor_lock);
 192
 193         result = -ENOENT;
 194         if (ops->flavor2info != NULL)
 195                 result = ops->flavor2info(pseudoflavor, info);
 196
 197         module_put(ops->owner);
 198         return result;
 199 }
 200 EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
 201
 202 /**
 203  * rpcauth_list_flavors - discover registered flavors and pseudoflavors
 204  * @array: array to fill in
 205  * @size: size of "array"
 206  *
 207  * Returns the number of array items filled in, or a negative errno.
 208  *
 209  * The returned array is not sorted by any policy.  Callers should not
 210  * rely on the order of the items in the returned array.
 211  */
 212 int
 213 rpcauth_list_flavors(rpc_authflavor_t *array, int size)
 214 {
 215         rpc_authflavor_t flavor;
 216         int result = 0;
 217
 218         spin_lock(&rpc_authflavor_lock);
 219         for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
 220                 const struct rpc_authops *ops = auth_flavors[flavor];
 221                 rpc_authflavor_t pseudos[4];
 222                 int i, len;
 223
 224                 if (result >= size) {
 225                         result = -ENOMEM;
 226                         break;
 227                 }
 228
 229                 if (ops == NULL)
 230                         continue;
 231                 if (ops->list_pseudoflavors == NULL) {
 232                         array[result++] = ops->au_flavor;
 233                         continue;
 234                 }
 235                 len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
 236                 if (len < 0) {
 237                         result = len;
 238                         break;
 239                 }
 240                 for (i = 0; i < len; i++) {
 241                         if (result >= size) {
 242                                 result = -ENOMEM;
 243                                 break;
 244                         }
 245                         array[result++] = pseudos[i];
 246                 }
 247         }
 248         spin_unlock(&rpc_authflavor_lock);
 249
 250         dprintk("RPC:       %s returns %d\n", __func__, result);
 251         return result;
 252 }
 253 EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
 254
 255 struct rpc_auth *
 256 rpcauth_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 257 {
 258         struct rpc_auth         *auth;
 259         const struct rpc_authops *ops;
 260         u32                     flavor = pseudoflavor_to_flavor(args->pseudoflavor);
 261
 262         auth = ERR_PTR(-EINVAL);
 263         if (flavor >= RPC_AUTH_MAXFLAVOR)
 264                 goto out;
 265
 266         if ((ops = auth_flavors[flavor]) == NULL)
 267                 request_module("rpc-auth-%u", flavor);
 268         spin_lock(&rpc_authflavor_lock);
 269         ops = auth_flavors[flavor];
 270         if (ops == NULL || !try_module_get(ops->owner)) {
 271                 spin_unlock(&rpc_authflavor_lock);
 272                 goto out;
 273         }
 274         spin_unlock(&rpc_authflavor_lock);
 275         auth = ops->create(args, clnt);
 276         module_put(ops->owner);
 277         if (IS_ERR(auth))
 278                 return auth;
 279         if (clnt->cl_auth)
 280                 rpcauth_release(clnt->cl_auth);
 281         clnt->cl_auth = auth;
 282
 283 out:
 284         return auth;
 285 }
 286 EXPORT_SYMBOL_GPL(rpcauth_create);
 287
 288 void
 289 rpcauth_release(struct rpc_auth *auth)
 290 {
 291         if (!atomic_dec_and_test(&auth->au_count))
 292                 return;
 293         auth->au_ops->destroy(auth);
 294 }
 295
 296 static DEFINE_SPINLOCK(rpc_credcache_lock);
 297
 298 static void
 299 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
 300 {
 301         hlist_del_rcu(&cred->cr_hash);
 302         smp_mb__before_atomic();
 303         clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 304 }
 305
 306 static int
 307 rpcauth_unhash_cred(struct rpc_cred *cred)
 308 {
 309         spinlock_t *cache_lock;
 310         int ret;
 311
 312         cache_lock = &cred->cr_auth->au_credcache->lock;
 313         spin_lock(cache_lock);
 314         ret = atomic_read(&cred->cr_count) == 0;
 315         if (ret)
 316                 rpcauth_unhash_cred_locked(cred);
 317         spin_unlock(cache_lock);
 318         return ret;
 319 }
 320
 321 /*
 322  * Initialize RPC credential cache
 323  */
 324 int
 325 rpcauth_init_credcache(struct rpc_auth *auth)
 326 {
 327         struct rpc_cred_cache *new;
 328         unsigned int hashsize;
 329
 330         new = kmalloc(sizeof(*new), GFP_KERNEL);
 331         if (!new)
 332                 goto out_nocache;
 333         new->hashbits = auth_hashbits;
 334         hashsize = 1U << new->hashbits;
 335         new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
 336         if (!new->hashtable)
 337                 goto out_nohashtbl;
 338         spin_lock_init(&new->lock);
 339         auth->au_credcache = new;
 340         return 0;
 341 out_nohashtbl:
 342         kfree(new);
 343 out_nocache:
 344         return -ENOMEM;
 345 }
 346 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
 347
 348 /*
 349  * Setup a credential key lifetime timeout notification
 350  */
 351 int
 352 rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
 353 {
 354         if (!cred->cr_auth->au_ops->key_timeout)
 355                 return 0;
 356         return cred->cr_auth->au_ops->key_timeout(auth, cred);
 357 }
 358 EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
 359
 360 bool
 361 rpcauth_cred_key_to_expire(struct rpc_auth *auth, struct rpc_cred *cred)
 362 {
 363         if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
 364                 return false;
 365         if (!cred->cr_ops->crkey_to_expire)
 366                 return false;
 367         return cred->cr_ops->crkey_to_expire(cred);
 368 }
 369 EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
 370
 371 char *
 372 rpcauth_stringify_acceptor(struct rpc_cred *cred)
 373 {
 374         if (!cred->cr_ops->crstringify_acceptor)
 375                 return NULL;
 376         return cred->cr_ops->crstringify_acceptor(cred);
 377 }
 378 EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
 379
 380 /*
 381  * Destroy a list of credentials
 382  */
 383 static inline
 384 void rpcauth_destroy_credlist(struct list_head *head)
 385 {
 386         struct rpc_cred *cred;
 387
 388         while (!list_empty(head)) {
 389                 cred = list_entry(head->next, struct rpc_cred, cr_lru);
 390                 list_del_init(&cred->cr_lru);
 391                 put_rpccred(cred);
 392         }
 393 }
 394
 395 /*
 396  * Clear the RPC credential cache, and delete those credentials
 397  * that are not referenced.
 398  */
 399 void
 400 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
 401 {
 402         LIST_HEAD(free);
 403         struct hlist_head *head;
 404         struct rpc_cred *cred;
 405         unsigned int hashsize = 1U << cache->hashbits;
 406         int             i;
 407
 408         spin_lock(&rpc_credcache_lock);
 409         spin_lock(&cache->lock);
 410         for (i = 0; i < hashsize; i++) {
 411                 head = &cache->hashtable[i];
 412                 while (!hlist_empty(head)) {
 413                         cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
 414                         get_rpccred(cred);
 415                         if (!list_empty(&cred->cr_lru)) {
 416                                 list_del(&cred->cr_lru);
 417                                 number_cred_unused--;
 418                         }
 419                         list_add_tail(&cred->cr_lru, &free);
 420                         rpcauth_unhash_cred_locked(cred);
 421                 }
 422         }
 423         spin_unlock(&cache->lock);
 424         spin_unlock(&rpc_credcache_lock);
 425         rpcauth_destroy_credlist(&free);
 426 }
 427
 428 /*
 429  * Destroy the RPC credential cache
 430  */
 431 void
 432 rpcauth_destroy_credcache(struct rpc_auth *auth)
 433 {
 434         struct rpc_cred_cache *cache = auth->au_credcache;
 435
 436         if (cache) {
 437                 auth->au_credcache = NULL;
 438                 rpcauth_clear_credcache(cache);
 439                 kfree(cache->hashtable);
 440                 kfree(cache);
 441         }
 442 }
 443 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
 444
 445
 446 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
 447
 448 /*
 449  * Remove stale credentials. Avoid sleeping inside the loop.
 450  */
 451 static long
 452 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
 453 {
 454         spinlock_t *cache_lock;
 455         struct rpc_cred *cred, *next;
 456         unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
 457         long freed = 0;
 458
 459         list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
 460
 461                 if (nr_to_scan-- == 0)
 462                         break;
 463                 /*
 464                  * Enforce a 60 second garbage collection moratorium
 465                  * Note that the cred_unused list must be time-ordered.
 466                  */
 467                 if (time_in_range(cred->cr_expire, expired, jiffies) &&
 468                     test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
 469                         freed = SHRINK_STOP;
 470                         break;
 471                 }
 472
 473                 list_del_init(&cred->cr_lru);
 474                 number_cred_unused--;
 475                 freed++;
 476                 if (atomic_read(&cred->cr_count) != 0)
 477                         continue;
 478
 479                 cache_lock = &cred->cr_auth->au_credcache->lock;
 480                 spin_lock(cache_lock);
 481                 if (atomic_read(&cred->cr_count) == 0) {
 482                         get_rpccred(cred);
 483                         list_add_tail(&cred->cr_lru, free);
 484                         rpcauth_unhash_cred_locked(cred);
 485                 }
 486                 spin_unlock(cache_lock);
 487         }
 488         return freed;
 489 }
 490
 491 static unsigned long
 492 rpcauth_cache_do_shrink(int nr_to_scan)
 493 {
 494         LIST_HEAD(free);
 495         unsigned long freed;
 496
 497         spin_lock(&rpc_credcache_lock);
 498         freed = rpcauth_prune_expired(&free, nr_to_scan);
 499         spin_unlock(&rpc_credcache_lock);
 500         rpcauth_destroy_credlist(&free);
 501
 502         return freed;
 503 }
 504
 505 /*
 506  * Run memory cache shrinker.
 507  */
 508 static unsigned long
 509 rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 510
 511 {
 512         if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
 513                 return SHRINK_STOP;
 514
 515         /* nothing left, don't come back */
 516         if (list_empty(&cred_unused))
 517                 return SHRINK_STOP;
 518
 519         return rpcauth_cache_do_shrink(sc->nr_to_scan);
 520 }
 521
 522 static unsigned long
 523 rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
 524
 525 {
 526         return number_cred_unused * sysctl_vfs_cache_pressure / 100;
 527 }
 528
 529 static void
 530 rpcauth_cache_enforce_limit(void)
 531 {
 532         unsigned long diff;
 533         unsigned int nr_to_scan;
 534
 535         if (number_cred_unused <= auth_max_cred_cachesize)
 536                 return;
 537         diff = number_cred_unused - auth_max_cred_cachesize;
 538         nr_to_scan = 100;
 539         if (diff < nr_to_scan)
 540                 nr_to_scan = diff;
 541         rpcauth_cache_do_shrink(nr_to_scan);
 542 }
 543
 544 /*
 545  * Look up a process' credentials in the authentication cache
 546  */
 547 struct rpc_cred *
 548 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 549                 int flags, gfp_t gfp)
 550 {
 551         LIST_HEAD(free);
 552         struct rpc_cred_cache *cache = auth->au_credcache;
 553         struct rpc_cred *cred = NULL,
 554                         *entry, *new;
 555         unsigned int nr;
 556
 557         nr = auth->au_ops->hash_cred(acred, cache->hashbits);
 558
 559         rcu_read_lock();
 560         hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
 561                 if (!entry->cr_ops->crmatch(acred, entry, flags))
 562                         continue;
 563                 if (flags & RPCAUTH_LOOKUP_RCU) {
 564                         if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) &&
 565                             !test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags))
 566                                 cred = entry;
 567                         break;
 568                 }
 569                 spin_lock(&cache->lock);
 570                 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
 571                         spin_unlock(&cache->lock);
 572                         continue;
 573                 }
 574                 cred = get_rpccred(entry);
 575                 spin_unlock(&cache->lock);
 576                 break;
 577         }
 578         rcu_read_unlock();
 579
 580         if (cred != NULL)
 581                 goto found;
 582
 583         if (flags & RPCAUTH_LOOKUP_RCU)
 584                 return ERR_PTR(-ECHILD);
 585
 586         new = auth->au_ops->crcreate(auth, acred, flags, gfp);
 587         if (IS_ERR(new)) {
 588                 cred = new;
 589                 goto out;
 590         }
 591
 592         spin_lock(&cache->lock);
 593         hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
 594                 if (!entry->cr_ops->crmatch(acred, entry, flags))
 595                         continue;
 596                 cred = get_rpccred(entry);
 597                 break;
 598         }
 599         if (cred == NULL) {
 600                 cred = new;
 601                 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 602                 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
 603         } else
 604                 list_add_tail(&new->cr_lru, &free);
 605         spin_unlock(&cache->lock);
 606         rpcauth_cache_enforce_limit();
 607 found:
 608         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 609             cred->cr_ops->cr_init != NULL &&
 610             !(flags & RPCAUTH_LOOKUP_NEW)) {
 611                 int res = cred->cr_ops->cr_init(auth, cred);
 612                 if (res < 0) {
 613                         put_rpccred(cred);
 614                         cred = ERR_PTR(res);
 615                 }
 616         }
 617         rpcauth_destroy_credlist(&free);
 618 out:
 619         return cred;
 620 }
 621 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
 622
 623 struct rpc_cred *
 624 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
 625 {
 626         struct auth_cred acred;
 627         struct rpc_cred *ret;
 628         const struct cred *cred = current_cred();
 629
 630         dprintk("RPC:       looking up %s cred\n",
 631                 auth->au_ops->au_name);
 632
 633         memset(&acred, 0, sizeof(acred));
 634         acred.uid = cred->fsuid;
 635         acred.gid = cred->fsgid;
 636         acred.group_info = cred->group_info;
 637         ret = auth->au_ops->lookup_cred(auth, &acred, flags);
 638         return ret;
 639 }
 640 EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
 641
 642 void
 643 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
 644                   struct rpc_auth *auth, const struct rpc_credops *ops)
 645 {
 646         INIT_HLIST_NODE(&cred->cr_hash);
 647         INIT_LIST_HEAD(&cred->cr_lru);
 648         atomic_set(&cred->cr_count, 1);
 649         cred->cr_auth = auth;
 650         cred->cr_ops = ops;
 651         cred->cr_expire = jiffies;
 652         cred->cr_uid = acred->uid;
 653 }
 654 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
 655
 656 struct rpc_cred *
 657 rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
 658 {
 659         dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
 660                         cred->cr_auth->au_ops->au_name, cred);
 661         return get_rpccred(cred);
 662 }
 663 EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
 664
 665 static struct rpc_cred *
 666 rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
 667 {
 668         struct rpc_auth *auth = task->tk_client->cl_auth;
 669         struct auth_cred acred = {
 670                 .uid = GLOBAL_ROOT_UID,
 671                 .gid = GLOBAL_ROOT_GID,
 672         };
 673
 674         dprintk("RPC: %5u looking up %s cred\n",
 675                 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
 676         return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
 677 }
 678
 679 static struct rpc_cred *
 680 rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
 681 {
 682         struct rpc_auth *auth = task->tk_client->cl_auth;
 683
 684         dprintk("RPC: %5u looking up %s cred\n",
 685                 task->tk_pid, auth->au_ops->au_name);
 686         return rpcauth_lookupcred(auth, lookupflags);
 687 }
 688
 689 static int
 690 rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
 691 {
 692         struct rpc_rqst *req = task->tk_rqstp;
 693         struct rpc_cred *new;
 694         int lookupflags = 0;
 695
 696         if (flags & RPC_TASK_ASYNC)
 697                 lookupflags |= RPCAUTH_LOOKUP_NEW;
 698         if (cred != NULL)
 699                 new = cred->cr_ops->crbind(task, cred, lookupflags);
 700         else if (flags & RPC_TASK_ROOTCREDS)
 701                 new = rpcauth_bind_root_cred(task, lookupflags);
 702         else
 703                 new = rpcauth_bind_new_cred(task, lookupflags);
 704         if (IS_ERR(new))
 705                 return PTR_ERR(new);
 706         put_rpccred(req->rq_cred);
 707         req->rq_cred = new;
 708         return 0;
 709 }
 710
 711 void
 712 put_rpccred(struct rpc_cred *cred)
 713 {
 714         if (cred == NULL)
 715                 return;
 716         /* Fast path for unhashed credentials */
 717         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
 718                 if (atomic_dec_and_test(&cred->cr_count))
 719                         cred->cr_ops->crdestroy(cred);
 720                 return;
 721         }
 722
 723         if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
 724                 return;
 725         if (!list_empty(&cred->cr_lru)) {
 726                 number_cred_unused--;
 727                 list_del_init(&cred->cr_lru);
 728         }
 729         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
 730                 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
 731                         cred->cr_expire = jiffies;
 732                         list_add_tail(&cred->cr_lru, &cred_unused);
 733                         number_cred_unused++;
 734                         goto out_nodestroy;
 735                 }
 736                 if (!rpcauth_unhash_cred(cred)) {
 737                         /* We were hashed and someone looked us up... */
 738                         goto out_nodestroy;
 739                 }
 740         }
 741         spin_unlock(&rpc_credcache_lock);
 742         cred->cr_ops->crdestroy(cred);
 743         return;
 744 out_nodestroy:
 745         spin_unlock(&rpc_credcache_lock);
 746 }
 747 EXPORT_SYMBOL_GPL(put_rpccred);
 748
 749 __be32 *
 750 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
 751 {
 752         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 753
 754         dprintk("RPC: %5u marshaling %s cred %p\n",
 755                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 756
 757         return cred->cr_ops->crmarshal(task, p);
 758 }
 759
 760 __be32 *
 761 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
 762 {
 763         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 764
 765         dprintk("RPC: %5u validating %s cred %p\n",
 766                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 767
 768         return cred->cr_ops->crvalidate(task, p);
 769 }
 770
 771 static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
 772                                    __be32 *data, void *obj)
 773 {
 774         struct xdr_stream xdr;
 775
 776         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
 777         encode(rqstp, &xdr, obj);
 778 }
 779
 780 int
 781 rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
 782                 __be32 *data, void *obj)
 783 {
 784         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 785
 786         dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
 787                         task->tk_pid, cred->cr_ops->cr_name, cred);
 788         if (cred->cr_ops->crwrap_req)
 789                 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
 790         /* By default, we encode the arguments normally. */
 791         rpcauth_wrap_req_encode(encode, rqstp, data, obj);
 792         return 0;
 793 }
 794
 795 static int
 796 rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
 797                           __be32 *data, void *obj)
 798 {
 799         struct xdr_stream xdr;
 800
 801         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
 802         return decode(rqstp, &xdr, obj);
 803 }
 804
 805 int
 806 rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
 807                 __be32 *data, void *obj)
 808 {
 809         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 810
 811         dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
 812                         task->tk_pid, cred->cr_ops->cr_name, cred);
 813         if (cred->cr_ops->crunwrap_resp)
 814                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
 815                                                    data, obj);
 816         /* By default, we decode the arguments normally. */
 817         return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
 818 }
 819
 820 int
 821 rpcauth_refreshcred(struct rpc_task *task)
 822 {
 823         struct rpc_cred *cred;
 824         int err;
 825
 826         cred = task->tk_rqstp->rq_cred;
 827         if (cred == NULL) {
 828                 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
 829                 if (err < 0)
 830                         goto out;
 831                 cred = task->tk_rqstp->rq_cred;
 832         }
 833         dprintk("RPC: %5u refreshing %s cred %p\n",
 834                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 835
 836         err = cred->cr_ops->crrefresh(task);
 837 out:
 838         if (err < 0)
 839                 task->tk_status = err;
 840         return err;
 841 }
 842
 843 void
 844 rpcauth_invalcred(struct rpc_task *task)
 845 {
 846         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 847
 848         dprintk("RPC: %5u invalidating %s cred %p\n",
 849                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 850         if (cred)
 851                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 852 }
 853
 854 int
 855 rpcauth_uptodatecred(struct rpc_task *task)
 856 {
 857         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 858
 859         return cred == NULL ||
 860                 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
 861 }
 862
 863 static struct shrinker rpc_cred_shrinker = {
 864         .count_objects = rpcauth_cache_shrink_count,
 865         .scan_objects = rpcauth_cache_shrink_scan,
 866         .seeks = DEFAULT_SEEKS,
 867 };
 868
 869 int __init rpcauth_init_module(void)
 870 {
 871         int err;
 872
 873         err = rpc_init_authunix();
 874         if (err < 0)
 875                 goto out1;
 876         err = rpc_init_generic_auth();
 877         if (err < 0)
 878                 goto out2;
 879         err = register_shrinker(&rpc_cred_shrinker);
 880         if (err < 0)
 881                 goto out3;
 882         return 0;
 883 out3:
 884         rpc_destroy_generic_auth();
 885 out2:
 886         rpc_destroy_authunix();
 887 out1:
 888         return err;
 889 }
 890
 891 void rpcauth_remove_module(void)
 892 {
 893         rpc_destroy_authunix();
 894         rpc_destroy_generic_auth();
 895         unregister_shrinker(&rpc_cred_shrinker);
 896 }