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 const struct rpc_authops __rcu *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
  34         [RPC_AUTH_NULL] = (const struct rpc_authops __force __rcu *)&authnull_ops,
  35         [RPC_AUTH_UNIX] = (const struct rpc_authops __force __rcu *)&authunix_ops,
  36         NULL,                   /* others can be loadable modules */
  37 };
  38
  39 static LIST_HEAD(cred_unused);
  40 static unsigned long number_cred_unused;
  41
  42 #define MAX_HASHTABLE_BITS (14)
  43 static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
  44 {
  45         unsigned long num;
  46         unsigned int nbits;
  47         int ret;
  48
  49         if (!val)
  50                 goto out_inval;
  51         ret = kstrtoul(val, 0, &num);
  52         if (ret)
  53                 goto out_inval;
  54         nbits = fls(num - 1);
  55         if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
  56                 goto out_inval;
  57         *(unsigned int *)kp->arg = nbits;
  58         return 0;
  59 out_inval:
  60         return -EINVAL;
  61 }
  62
  63 static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
  64 {
  65         unsigned int nbits;
  66
  67         nbits = *(unsigned int *)kp->arg;
  68         return sprintf(buffer, "%u", 1U << nbits);
  69 }
  70
  71 #define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
  72
  73 static const struct kernel_param_ops param_ops_hashtbl_sz = {
  74         .set = param_set_hashtbl_sz,
  75         .get = param_get_hashtbl_sz,
  76 };
  77
  78 module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
  79 MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
  80
  81 static unsigned long auth_max_cred_cachesize = ULONG_MAX;
  82 module_param(auth_max_cred_cachesize, ulong, 0644);
  83 MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
  84
  85 static u32
  86 pseudoflavor_to_flavor(u32 flavor) {
  87         if (flavor > RPC_AUTH_MAXFLAVOR)
  88                 return RPC_AUTH_GSS;
  89         return flavor;
  90 }
  91
  92 int
  93 rpcauth_register(const struct rpc_authops *ops)
  94 {
  95         const struct rpc_authops *old;
  96         rpc_authflavor_t flavor;
  97
  98         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
  99                 return -EINVAL;
 100         old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], NULL, ops);
 101         if (old == NULL || old == ops)
 102                 return 0;
 103         return -EPERM;
 104 }
 105 EXPORT_SYMBOL_GPL(rpcauth_register);
 106
 107 int
 108 rpcauth_unregister(const struct rpc_authops *ops)
 109 {
 110         const struct rpc_authops *old;
 111         rpc_authflavor_t flavor;
 112
 113         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 114                 return -EINVAL;
 115
 116         old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], ops, NULL);
 117         if (old == ops || old == NULL)
 118                 return 0;
 119         return -EPERM;
 120 }
 121 EXPORT_SYMBOL_GPL(rpcauth_unregister);
 122
 123 static const struct rpc_authops *
 124 rpcauth_get_authops(rpc_authflavor_t flavor)
 125 {
 126         const struct rpc_authops *ops;
 127
 128         if (flavor >= RPC_AUTH_MAXFLAVOR)
 129                 return NULL;
 130
 131         rcu_read_lock();
 132         ops = rcu_dereference(auth_flavors[flavor]);
 133         if (ops == NULL) {
 134                 rcu_read_unlock();
 135                 request_module("rpc-auth-%u", flavor);
 136                 rcu_read_lock();
 137                 ops = rcu_dereference(auth_flavors[flavor]);
 138                 if (ops == NULL)
 139                         goto out;
 140         }
 141         if (!try_module_get(ops->owner))
 142                 ops = NULL;
 143 out:
 144         rcu_read_unlock();
 145         return ops;
 146 }
 147
 148 static void
 149 rpcauth_put_authops(const struct rpc_authops *ops)
 150 {
 151         module_put(ops->owner);
 152 }
 153
 154 /**
 155  * rpcauth_get_pseudoflavor - check if security flavor is supported
 156  * @flavor: a security flavor
 157  * @info: a GSS mech OID, quality of protection, and service value
 158  *
 159  * Verifies that an appropriate kernel module is available or already loaded.
 160  * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
 161  * not supported locally.
 162  */
 163 rpc_authflavor_t
 164 rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
 165 {
 166         const struct rpc_authops *ops = rpcauth_get_authops(flavor);
 167         rpc_authflavor_t pseudoflavor;
 168
 169         if (!ops)
 170                 return RPC_AUTH_MAXFLAVOR;
 171         pseudoflavor = flavor;
 172         if (ops->info2flavor != NULL)
 173                 pseudoflavor = ops->info2flavor(info);
 174
 175         rpcauth_put_authops(ops);
 176         return pseudoflavor;
 177 }
 178 EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
 179
 180 /**
 181  * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
 182  * @pseudoflavor: GSS pseudoflavor to match
 183  * @info: rpcsec_gss_info structure to fill in
 184  *
 185  * Returns zero and fills in "info" if pseudoflavor matches a
 186  * supported mechanism.
 187  */
 188 int
 189 rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
 190 {
 191         rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
 192         const struct rpc_authops *ops;
 193         int result;
 194
 195         ops = rpcauth_get_authops(flavor);
 196         if (ops == NULL)
 197                 return -ENOENT;
 198
 199         result = -ENOENT;
 200         if (ops->flavor2info != NULL)
 201                 result = ops->flavor2info(pseudoflavor, info);
 202
 203         rpcauth_put_authops(ops);
 204         return result;
 205 }
 206 EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
 207
 208 /**
 209  * rpcauth_list_flavors - discover registered flavors and pseudoflavors
 210  * @array: array to fill in
 211  * @size: size of "array"
 212  *
 213  * Returns the number of array items filled in, or a negative errno.
 214  *
 215  * The returned array is not sorted by any policy.  Callers should not
 216  * rely on the order of the items in the returned array.
 217  */
 218 int
 219 rpcauth_list_flavors(rpc_authflavor_t *array, int size)
 220 {
 221         const struct rpc_authops *ops;
 222         rpc_authflavor_t flavor, pseudos[4];
 223         int i, len, result = 0;
 224
 225         rcu_read_lock();
 226         for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
 227                 ops = rcu_dereference(auth_flavors[flavor]);
 228                 if (result >= size) {
 229                         result = -ENOMEM;
 230                         break;
 231                 }
 232
 233                 if (ops == NULL)
 234                         continue;
 235                 if (ops->list_pseudoflavors == NULL) {
 236                         array[result++] = ops->au_flavor;
 237                         continue;
 238                 }
 239                 len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
 240                 if (len < 0) {
 241                         result = len;
 242                         break;
 243                 }
 244                 for (i = 0; i < len; i++) {
 245                         if (result >= size) {
 246                                 result = -ENOMEM;
 247                                 break;
 248                         }
 249                         array[result++] = pseudos[i];
 250                 }
 251         }
 252         rcu_read_unlock();
 253
 254         dprintk("RPC:       %s returns %d\n", __func__, result);
 255         return result;
 256 }
 257 EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
 258
 259 struct rpc_auth *
 260 rpcauth_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 261 {
 262         struct rpc_auth *auth = ERR_PTR(-EINVAL);
 263         const struct rpc_authops *ops;
 264         u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
 265
 266         ops = rpcauth_get_authops(flavor);
 267         if (ops == NULL)
 268                 goto out;
 269
 270         auth = ops->create(args, clnt);
 271
 272         rpcauth_put_authops(ops);
 273         if (IS_ERR(auth))
 274                 return auth;
 275         if (clnt->cl_auth)
 276                 rpcauth_release(clnt->cl_auth);
 277         clnt->cl_auth = auth;
 278
 279 out:
 280         return auth;
 281 }
 282 EXPORT_SYMBOL_GPL(rpcauth_create);
 283
 284 void
 285 rpcauth_release(struct rpc_auth *auth)
 286 {
 287         if (!refcount_dec_and_test(&auth->au_count))
 288                 return;
 289         auth->au_ops->destroy(auth);
 290 }
 291
 292 static DEFINE_SPINLOCK(rpc_credcache_lock);
 293
 294 /*
 295  * On success, the caller is responsible for freeing the reference
 296  * held by the hashtable
 297  */
 298 static bool
 299 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
 300 {
 301         if (!test_and_clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
 302                 return false;
 303         hlist_del_rcu(&cred->cr_hash);
 304         return true;
 305 }
 306
 307 static bool
 308 rpcauth_unhash_cred(struct rpc_cred *cred)
 309 {
 310         spinlock_t *cache_lock;
 311         bool ret;
 312
 313         if (!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
 314                 return false;
 315         cache_lock = &cred->cr_auth->au_credcache->lock;
 316         spin_lock(cache_lock);
 317         ret = rpcauth_unhash_cred_locked(cred);
 318         spin_unlock(cache_lock);
 319         return ret;
 320 }
 321
 322 /*
 323  * Initialize RPC credential cache
 324  */
 325 int
 326 rpcauth_init_credcache(struct rpc_auth *auth)
 327 {
 328         struct rpc_cred_cache *new;
 329         unsigned int hashsize;
 330
 331         new = kmalloc(sizeof(*new), GFP_KERNEL);
 332         if (!new)
 333                 goto out_nocache;
 334         new->hashbits = auth_hashbits;
 335         hashsize = 1U << new->hashbits;
 336         new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
 337         if (!new->hashtable)
 338                 goto out_nohashtbl;
 339         spin_lock_init(&new->lock);
 340         auth->au_credcache = new;
 341         return 0;
 342 out_nohashtbl:
 343         kfree(new);
 344 out_nocache:
 345         return -ENOMEM;
 346 }
 347 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
 348
 349 /*
 350  * Setup a credential key lifetime timeout notification
 351  */
 352 int
 353 rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
 354 {
 355         if (!cred->cr_auth->au_ops->key_timeout)
 356                 return 0;
 357         return cred->cr_auth->au_ops->key_timeout(auth, cred);
 358 }
 359 EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
 360
 361 bool
 362 rpcauth_cred_key_to_expire(struct rpc_auth *auth, struct rpc_cred *cred)
 363 {
 364         if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
 365                 return false;
 366         if (!cred->cr_ops->crkey_to_expire)
 367                 return false;
 368         return cred->cr_ops->crkey_to_expire(cred);
 369 }
 370 EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
 371
 372 char *
 373 rpcauth_stringify_acceptor(struct rpc_cred *cred)
 374 {
 375         if (!cred->cr_ops->crstringify_acceptor)
 376                 return NULL;
 377         return cred->cr_ops->crstringify_acceptor(cred);
 378 }
 379 EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
 380
 381 /*
 382  * Destroy a list of credentials
 383  */
 384 static inline
 385 void rpcauth_destroy_credlist(struct list_head *head)
 386 {
 387         struct rpc_cred *cred;
 388
 389         while (!list_empty(head)) {
 390                 cred = list_entry(head->next, struct rpc_cred, cr_lru);
 391                 list_del_init(&cred->cr_lru);
 392                 put_rpccred(cred);
 393         }
 394 }
 395
 396 static void
 397 rpcauth_lru_add_locked(struct rpc_cred *cred)
 398 {
 399         if (!list_empty(&cred->cr_lru))
 400                 return;
 401         number_cred_unused++;
 402         list_add_tail(&cred->cr_lru, &cred_unused);
 403 }
 404
 405 static void
 406 rpcauth_lru_add(struct rpc_cred *cred)
 407 {
 408         if (!list_empty(&cred->cr_lru))
 409                 return;
 410         spin_lock(&rpc_credcache_lock);
 411         rpcauth_lru_add_locked(cred);
 412         spin_unlock(&rpc_credcache_lock);
 413 }
 414
 415 static void
 416 rpcauth_lru_remove_locked(struct rpc_cred *cred)
 417 {
 418         if (list_empty(&cred->cr_lru))
 419                 return;
 420         number_cred_unused--;
 421         list_del_init(&cred->cr_lru);
 422 }
 423
 424 static void
 425 rpcauth_lru_remove(struct rpc_cred *cred)
 426 {
 427         if (list_empty(&cred->cr_lru))
 428                 return;
 429         spin_lock(&rpc_credcache_lock);
 430         rpcauth_lru_remove_locked(cred);
 431         spin_unlock(&rpc_credcache_lock);
 432 }
 433
 434 /*
 435  * Clear the RPC credential cache, and delete those credentials
 436  * that are not referenced.
 437  */
 438 void
 439 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
 440 {
 441         LIST_HEAD(free);
 442         struct hlist_head *head;
 443         struct rpc_cred *cred;
 444         unsigned int hashsize = 1U << cache->hashbits;
 445         int             i;
 446
 447         spin_lock(&rpc_credcache_lock);
 448         spin_lock(&cache->lock);
 449         for (i = 0; i < hashsize; i++) {
 450                 head = &cache->hashtable[i];
 451                 while (!hlist_empty(head)) {
 452                         cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
 453                         rpcauth_unhash_cred_locked(cred);
 454                         /* Note: We now hold a reference to cred */
 455                         rpcauth_lru_remove_locked(cred);
 456                         list_add_tail(&cred->cr_lru, &free);
 457                 }
 458         }
 459         spin_unlock(&cache->lock);
 460         spin_unlock(&rpc_credcache_lock);
 461         rpcauth_destroy_credlist(&free);
 462 }
 463
 464 /*
 465  * Destroy the RPC credential cache
 466  */
 467 void
 468 rpcauth_destroy_credcache(struct rpc_auth *auth)
 469 {
 470         struct rpc_cred_cache *cache = auth->au_credcache;
 471
 472         if (cache) {
 473                 auth->au_credcache = NULL;
 474                 rpcauth_clear_credcache(cache);
 475                 kfree(cache->hashtable);
 476                 kfree(cache);
 477         }
 478 }
 479 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
 480
 481
 482 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
 483
 484 /*
 485  * Remove stale credentials. Avoid sleeping inside the loop.
 486  */
 487 static long
 488 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
 489 {
 490         struct rpc_cred *cred, *next;
 491         unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
 492         long freed = 0;
 493
 494         list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
 495
 496                 if (nr_to_scan-- == 0)
 497                         break;
 498                 if (refcount_read(&cred->cr_count) > 1) {
 499                         rpcauth_lru_remove_locked(cred);
 500                         continue;
 501                 }
 502                 /*
 503                  * Enforce a 60 second garbage collection moratorium
 504                  * Note that the cred_unused list must be time-ordered.
 505                  */
 506                 if (!time_in_range(cred->cr_expire, expired, jiffies))
 507                         continue;
 508                 if (!rpcauth_unhash_cred(cred))
 509                         continue;
 510
 511                 rpcauth_lru_remove_locked(cred);
 512                 freed++;
 513                 list_add_tail(&cred->cr_lru, free);
 514         }
 515         return freed ? freed : SHRINK_STOP;
 516 }
 517
 518 static unsigned long
 519 rpcauth_cache_do_shrink(int nr_to_scan)
 520 {
 521         LIST_HEAD(free);
 522         unsigned long freed;
 523
 524         spin_lock(&rpc_credcache_lock);
 525         freed = rpcauth_prune_expired(&free, nr_to_scan);
 526         spin_unlock(&rpc_credcache_lock);
 527         rpcauth_destroy_credlist(&free);
 528
 529         return freed;
 530 }
 531
 532 /*
 533  * Run memory cache shrinker.
 534  */
 535 static unsigned long
 536 rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 537
 538 {
 539         if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
 540                 return SHRINK_STOP;
 541
 542         /* nothing left, don't come back */
 543         if (list_empty(&cred_unused))
 544                 return SHRINK_STOP;
 545
 546         return rpcauth_cache_do_shrink(sc->nr_to_scan);
 547 }
 548
 549 static unsigned long
 550 rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
 551
 552 {
 553         return number_cred_unused * sysctl_vfs_cache_pressure / 100;
 554 }
 555
 556 static void
 557 rpcauth_cache_enforce_limit(void)
 558 {
 559         unsigned long diff;
 560         unsigned int nr_to_scan;
 561
 562         if (number_cred_unused <= auth_max_cred_cachesize)
 563                 return;
 564         diff = number_cred_unused - auth_max_cred_cachesize;
 565         nr_to_scan = 100;
 566         if (diff < nr_to_scan)
 567                 nr_to_scan = diff;
 568         rpcauth_cache_do_shrink(nr_to_scan);
 569 }
 570
 571 /*
 572  * Look up a process' credentials in the authentication cache
 573  */
 574 struct rpc_cred *
 575 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 576                 int flags, gfp_t gfp)
 577 {
 578         LIST_HEAD(free);
 579         struct rpc_cred_cache *cache = auth->au_credcache;
 580         struct rpc_cred *cred = NULL,
 581                         *entry, *new;
 582         unsigned int nr;
 583
 584         nr = auth->au_ops->hash_cred(acred, cache->hashbits);
 585
 586         rcu_read_lock();
 587         hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
 588                 if (!entry->cr_ops->crmatch(acred, entry, flags))
 589                         continue;
 590                 if (flags & RPCAUTH_LOOKUP_RCU) {
 591                         if (test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags) ||
 592                             refcount_read(&entry->cr_count) == 0)
 593                                 continue;
 594                         cred = entry;
 595                         break;
 596                 }
 597                 cred = get_rpccred(entry);
 598                 if (cred)
 599                         break;
 600         }
 601         rcu_read_unlock();
 602
 603         if (cred != NULL)
 604                 goto found;
 605
 606         if (flags & RPCAUTH_LOOKUP_RCU)
 607                 return ERR_PTR(-ECHILD);
 608
 609         new = auth->au_ops->crcreate(auth, acred, flags, gfp);
 610         if (IS_ERR(new)) {
 611                 cred = new;
 612                 goto out;
 613         }
 614
 615         spin_lock(&cache->lock);
 616         hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
 617                 if (!entry->cr_ops->crmatch(acred, entry, flags))
 618                         continue;
 619                 cred = get_rpccred(entry);
 620                 if (cred)
 621                         break;
 622         }
 623         if (cred == NULL) {
 624                 cred = new;
 625                 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 626                 refcount_inc(&cred->cr_count);
 627                 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
 628         } else
 629                 list_add_tail(&new->cr_lru, &free);
 630         spin_unlock(&cache->lock);
 631         rpcauth_cache_enforce_limit();
 632 found:
 633         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 634             cred->cr_ops->cr_init != NULL &&
 635             !(flags & RPCAUTH_LOOKUP_NEW)) {
 636                 int res = cred->cr_ops->cr_init(auth, cred);
 637                 if (res < 0) {
 638                         put_rpccred(cred);
 639                         cred = ERR_PTR(res);
 640                 }
 641         }
 642         rpcauth_destroy_credlist(&free);
 643 out:
 644         return cred;
 645 }
 646 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
 647
 648 struct rpc_cred *
 649 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
 650 {
 651         struct auth_cred acred;
 652         struct rpc_cred *ret;
 653         const struct cred *cred = current_cred();
 654
 655         dprintk("RPC:       looking up %s cred\n",
 656                 auth->au_ops->au_name);
 657
 658         memset(&acred, 0, sizeof(acred));
 659         acred.uid = cred->fsuid;
 660         acred.gid = cred->fsgid;
 661         acred.group_info = cred->group_info;
 662         ret = auth->au_ops->lookup_cred(auth, &acred, flags);
 663         return ret;
 664 }
 665 EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
 666
 667 void
 668 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
 669                   struct rpc_auth *auth, const struct rpc_credops *ops)
 670 {
 671         INIT_HLIST_NODE(&cred->cr_hash);
 672         INIT_LIST_HEAD(&cred->cr_lru);
 673         refcount_set(&cred->cr_count, 1);
 674         cred->cr_auth = auth;
 675         cred->cr_ops = ops;
 676         cred->cr_expire = jiffies;
 677         cred->cr_uid = acred->uid;
 678 }
 679 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
 680
 681 struct rpc_cred *
 682 rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
 683 {
 684         dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
 685                         cred->cr_auth->au_ops->au_name, cred);
 686         return get_rpccred(cred);
 687 }
 688 EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
 689
 690 static struct rpc_cred *
 691 rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
 692 {
 693         struct rpc_auth *auth = task->tk_client->cl_auth;
 694         struct auth_cred acred = {
 695                 .uid = GLOBAL_ROOT_UID,
 696                 .gid = GLOBAL_ROOT_GID,
 697         };
 698
 699         dprintk("RPC: %5u looking up %s cred\n",
 700                 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
 701         return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
 702 }
 703
 704 static struct rpc_cred *
 705 rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
 706 {
 707         struct rpc_auth *auth = task->tk_client->cl_auth;
 708
 709         dprintk("RPC: %5u looking up %s cred\n",
 710                 task->tk_pid, auth->au_ops->au_name);
 711         return rpcauth_lookupcred(auth, lookupflags);
 712 }
 713
 714 static int
 715 rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
 716 {
 717         struct rpc_rqst *req = task->tk_rqstp;
 718         struct rpc_cred *new;
 719         int lookupflags = 0;
 720
 721         if (flags & RPC_TASK_ASYNC)
 722                 lookupflags |= RPCAUTH_LOOKUP_NEW;
 723         if (cred != NULL)
 724                 new = cred->cr_ops->crbind(task, cred, lookupflags);
 725         else if (flags & RPC_TASK_ROOTCREDS)
 726                 new = rpcauth_bind_root_cred(task, lookupflags);
 727         else
 728                 new = rpcauth_bind_new_cred(task, lookupflags);
 729         if (IS_ERR(new))
 730                 return PTR_ERR(new);
 731         put_rpccred(req->rq_cred);
 732         req->rq_cred = new;
 733         return 0;
 734 }
 735
 736 void
 737 put_rpccred(struct rpc_cred *cred)
 738 {
 739         if (cred == NULL)
 740                 return;
 741         rcu_read_lock();
 742         if (refcount_dec_and_test(&cred->cr_count))
 743                 goto destroy;
 744         if (refcount_read(&cred->cr_count) != 1 ||
 745             !test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
 746                 goto out;
 747         if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
 748                 cred->cr_expire = jiffies;
 749                 rpcauth_lru_add(cred);
 750                 /* Race breaker */
 751                 if (unlikely(!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags)))
 752                         rpcauth_lru_remove(cred);
 753         } else if (rpcauth_unhash_cred(cred)) {
 754                 rpcauth_lru_remove(cred);
 755                 if (refcount_dec_and_test(&cred->cr_count))
 756                         goto destroy;
 757         }
 758 out:
 759         rcu_read_unlock();
 760         return;
 761 destroy:
 762         rcu_read_unlock();
 763         cred->cr_ops->crdestroy(cred);
 764 }
 765 EXPORT_SYMBOL_GPL(put_rpccred);
 766
 767 __be32 *
 768 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
 769 {
 770         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 771
 772         dprintk("RPC: %5u marshaling %s cred %p\n",
 773                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 774
 775         return cred->cr_ops->crmarshal(task, p);
 776 }
 777
 778 __be32 *
 779 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
 780 {
 781         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 782
 783         dprintk("RPC: %5u validating %s cred %p\n",
 784                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 785
 786         return cred->cr_ops->crvalidate(task, p);
 787 }
 788
 789 static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
 790                                    __be32 *data, void *obj)
 791 {
 792         struct xdr_stream xdr;
 793
 794         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
 795         encode(rqstp, &xdr, obj);
 796 }
 797
 798 int
 799 rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
 800                 __be32 *data, void *obj)
 801 {
 802         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 803
 804         dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
 805                         task->tk_pid, cred->cr_ops->cr_name, cred);
 806         if (cred->cr_ops->crwrap_req)
 807                 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
 808         /* By default, we encode the arguments normally. */
 809         rpcauth_wrap_req_encode(encode, rqstp, data, obj);
 810         return 0;
 811 }
 812
 813 static int
 814 rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
 815                           __be32 *data, void *obj)
 816 {
 817         struct xdr_stream xdr;
 818
 819         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
 820         return decode(rqstp, &xdr, obj);
 821 }
 822
 823 int
 824 rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
 825                 __be32 *data, void *obj)
 826 {
 827         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 828
 829         dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
 830                         task->tk_pid, cred->cr_ops->cr_name, cred);
 831         if (cred->cr_ops->crunwrap_resp)
 832                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
 833                                                    data, obj);
 834         /* By default, we decode the arguments normally. */
 835         return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
 836 }
 837
 838 bool
 839 rpcauth_xmit_need_reencode(struct rpc_task *task)
 840 {
 841         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 842
 843         if (!cred || !cred->cr_ops->crneed_reencode)
 844                 return false;
 845         return cred->cr_ops->crneed_reencode(task);
 846 }
 847
 848 int
 849 rpcauth_refreshcred(struct rpc_task *task)
 850 {
 851         struct rpc_cred *cred;
 852         int err;
 853
 854         cred = task->tk_rqstp->rq_cred;
 855         if (cred == NULL) {
 856                 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
 857                 if (err < 0)
 858                         goto out;
 859                 cred = task->tk_rqstp->rq_cred;
 860         }
 861         dprintk("RPC: %5u refreshing %s cred %p\n",
 862                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 863
 864         err = cred->cr_ops->crrefresh(task);
 865 out:
 866         if (err < 0)
 867                 task->tk_status = err;
 868         return err;
 869 }
 870
 871 void
 872 rpcauth_invalcred(struct rpc_task *task)
 873 {
 874         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 875
 876         dprintk("RPC: %5u invalidating %s cred %p\n",
 877                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 878         if (cred)
 879                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 880 }
 881
 882 int
 883 rpcauth_uptodatecred(struct rpc_task *task)
 884 {
 885         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 886
 887         return cred == NULL ||
 888                 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
 889 }
 890
 891 static struct shrinker rpc_cred_shrinker = {
 892         .count_objects = rpcauth_cache_shrink_count,
 893         .scan_objects = rpcauth_cache_shrink_scan,
 894         .seeks = DEFAULT_SEEKS,
 895 };
 896
 897 int __init rpcauth_init_module(void)
 898 {
 899         int err;
 900
 901         err = rpc_init_authunix();
 902         if (err < 0)
 903                 goto out1;
 904         err = rpc_init_generic_auth();
 905         if (err < 0)
 906                 goto out2;
 907         err = register_shrinker(&rpc_cred_shrinker);
 908         if (err < 0)
 909                 goto out3;
 910         return 0;
 911 out3:
 912         rpc_destroy_generic_auth();
 913 out2:
 914         rpc_destroy_authunix();
 915 out1:
 916         return err;
 917 }
 918
 919 void rpcauth_remove_module(void)
 920 {
 921         rpc_destroy_authunix();
 922         rpc_destroy_generic_auth();
 923         unregister_shrinker(&rpc_cred_shrinker);
 924 }