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 (!atomic_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 static void
 295 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
 296 {
 297         hlist_del_rcu(&cred->cr_hash);
 298         smp_mb__before_atomic();
 299         clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 300 }
 301
 302 static int
 303 rpcauth_unhash_cred(struct rpc_cred *cred)
 304 {
 305         spinlock_t *cache_lock;
 306         int ret;
 307
 308         cache_lock = &cred->cr_auth->au_credcache->lock;
 309         spin_lock(cache_lock);
 310         ret = atomic_read(&cred->cr_count) == 0;
 311         if (ret)
 312                 rpcauth_unhash_cred_locked(cred);
 313         spin_unlock(cache_lock);
 314         return ret;
 315 }
 316
 317 /*
 318  * Initialize RPC credential cache
 319  */
 320 int
 321 rpcauth_init_credcache(struct rpc_auth *auth)
 322 {
 323         struct rpc_cred_cache *new;
 324         unsigned int hashsize;
 325
 326         new = kmalloc(sizeof(*new), GFP_KERNEL);
 327         if (!new)
 328                 goto out_nocache;
 329         new->hashbits = auth_hashbits;
 330         hashsize = 1U << new->hashbits;
 331         new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
 332         if (!new->hashtable)
 333                 goto out_nohashtbl;
 334         spin_lock_init(&new->lock);
 335         auth->au_credcache = new;
 336         return 0;
 337 out_nohashtbl:
 338         kfree(new);
 339 out_nocache:
 340         return -ENOMEM;
 341 }
 342 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
 343
 344 /*
 345  * Setup a credential key lifetime timeout notification
 346  */
 347 int
 348 rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
 349 {
 350         if (!cred->cr_auth->au_ops->key_timeout)
 351                 return 0;
 352         return cred->cr_auth->au_ops->key_timeout(auth, cred);
 353 }
 354 EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
 355
 356 bool
 357 rpcauth_cred_key_to_expire(struct rpc_auth *auth, struct rpc_cred *cred)
 358 {
 359         if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
 360                 return false;
 361         if (!cred->cr_ops->crkey_to_expire)
 362                 return false;
 363         return cred->cr_ops->crkey_to_expire(cred);
 364 }
 365 EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
 366
 367 char *
 368 rpcauth_stringify_acceptor(struct rpc_cred *cred)
 369 {
 370         if (!cred->cr_ops->crstringify_acceptor)
 371                 return NULL;
 372         return cred->cr_ops->crstringify_acceptor(cred);
 373 }
 374 EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
 375
 376 /*
 377  * Destroy a list of credentials
 378  */
 379 static inline
 380 void rpcauth_destroy_credlist(struct list_head *head)
 381 {
 382         struct rpc_cred *cred;
 383
 384         while (!list_empty(head)) {
 385                 cred = list_entry(head->next, struct rpc_cred, cr_lru);
 386                 list_del_init(&cred->cr_lru);
 387                 put_rpccred(cred);
 388         }
 389 }
 390
 391 /*
 392  * Clear the RPC credential cache, and delete those credentials
 393  * that are not referenced.
 394  */
 395 void
 396 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
 397 {
 398         LIST_HEAD(free);
 399         struct hlist_head *head;
 400         struct rpc_cred *cred;
 401         unsigned int hashsize = 1U << cache->hashbits;
 402         int             i;
 403
 404         spin_lock(&rpc_credcache_lock);
 405         spin_lock(&cache->lock);
 406         for (i = 0; i < hashsize; i++) {
 407                 head = &cache->hashtable[i];
 408                 while (!hlist_empty(head)) {
 409                         cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
 410                         get_rpccred(cred);
 411                         if (!list_empty(&cred->cr_lru)) {
 412                                 list_del(&cred->cr_lru);
 413                                 number_cred_unused--;
 414                         }
 415                         list_add_tail(&cred->cr_lru, &free);
 416                         rpcauth_unhash_cred_locked(cred);
 417                 }
 418         }
 419         spin_unlock(&cache->lock);
 420         spin_unlock(&rpc_credcache_lock);
 421         rpcauth_destroy_credlist(&free);
 422 }
 423
 424 /*
 425  * Destroy the RPC credential cache
 426  */
 427 void
 428 rpcauth_destroy_credcache(struct rpc_auth *auth)
 429 {
 430         struct rpc_cred_cache *cache = auth->au_credcache;
 431
 432         if (cache) {
 433                 auth->au_credcache = NULL;
 434                 rpcauth_clear_credcache(cache);
 435                 kfree(cache->hashtable);
 436                 kfree(cache);
 437         }
 438 }
 439 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
 440
 441
 442 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
 443
 444 /*
 445  * Remove stale credentials. Avoid sleeping inside the loop.
 446  */
 447 static long
 448 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
 449 {
 450         spinlock_t *cache_lock;
 451         struct rpc_cred *cred, *next;
 452         unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
 453         long freed = 0;
 454
 455         list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
 456
 457                 if (nr_to_scan-- == 0)
 458                         break;
 459                 /*
 460                  * Enforce a 60 second garbage collection moratorium
 461                  * Note that the cred_unused list must be time-ordered.
 462                  */
 463                 if (time_in_range(cred->cr_expire, expired, jiffies) &&
 464                     test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
 465                         freed = SHRINK_STOP;
 466                         break;
 467                 }
 468
 469                 list_del_init(&cred->cr_lru);
 470                 number_cred_unused--;
 471                 freed++;
 472                 if (atomic_read(&cred->cr_count) != 0)
 473                         continue;
 474
 475                 cache_lock = &cred->cr_auth->au_credcache->lock;
 476                 spin_lock(cache_lock);
 477                 if (atomic_read(&cred->cr_count) == 0) {
 478                         get_rpccred(cred);
 479                         list_add_tail(&cred->cr_lru, free);
 480                         rpcauth_unhash_cred_locked(cred);
 481                 }
 482                 spin_unlock(cache_lock);
 483         }
 484         return freed;
 485 }
 486
 487 static unsigned long
 488 rpcauth_cache_do_shrink(int nr_to_scan)
 489 {
 490         LIST_HEAD(free);
 491         unsigned long freed;
 492
 493         spin_lock(&rpc_credcache_lock);
 494         freed = rpcauth_prune_expired(&free, nr_to_scan);
 495         spin_unlock(&rpc_credcache_lock);
 496         rpcauth_destroy_credlist(&free);
 497
 498         return freed;
 499 }
 500
 501 /*
 502  * Run memory cache shrinker.
 503  */
 504 static unsigned long
 505 rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 506
 507 {
 508         if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
 509                 return SHRINK_STOP;
 510
 511         /* nothing left, don't come back */
 512         if (list_empty(&cred_unused))
 513                 return SHRINK_STOP;
 514
 515         return rpcauth_cache_do_shrink(sc->nr_to_scan);
 516 }
 517
 518 static unsigned long
 519 rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
 520
 521 {
 522         return number_cred_unused * sysctl_vfs_cache_pressure / 100;
 523 }
 524
 525 static void
 526 rpcauth_cache_enforce_limit(void)
 527 {
 528         unsigned long diff;
 529         unsigned int nr_to_scan;
 530
 531         if (number_cred_unused <= auth_max_cred_cachesize)
 532                 return;
 533         diff = number_cred_unused - auth_max_cred_cachesize;
 534         nr_to_scan = 100;
 535         if (diff < nr_to_scan)
 536                 nr_to_scan = diff;
 537         rpcauth_cache_do_shrink(nr_to_scan);
 538 }
 539
 540 /*
 541  * Look up a process' credentials in the authentication cache
 542  */
 543 struct rpc_cred *
 544 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 545                 int flags, gfp_t gfp)
 546 {
 547         LIST_HEAD(free);
 548         struct rpc_cred_cache *cache = auth->au_credcache;
 549         struct rpc_cred *cred = NULL,
 550                         *entry, *new;
 551         unsigned int nr;
 552
 553         nr = auth->au_ops->hash_cred(acred, cache->hashbits);
 554
 555         rcu_read_lock();
 556         hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
 557                 if (!entry->cr_ops->crmatch(acred, entry, flags))
 558                         continue;
 559                 if (flags & RPCAUTH_LOOKUP_RCU) {
 560                         if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) &&
 561                             !test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags))
 562                                 cred = entry;
 563                         break;
 564                 }
 565                 spin_lock(&cache->lock);
 566                 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
 567                         spin_unlock(&cache->lock);
 568                         continue;
 569                 }
 570                 cred = get_rpccred(entry);
 571                 spin_unlock(&cache->lock);
 572                 break;
 573         }
 574         rcu_read_unlock();
 575
 576         if (cred != NULL)
 577                 goto found;
 578
 579         if (flags & RPCAUTH_LOOKUP_RCU)
 580                 return ERR_PTR(-ECHILD);
 581
 582         new = auth->au_ops->crcreate(auth, acred, flags, gfp);
 583         if (IS_ERR(new)) {
 584                 cred = new;
 585                 goto out;
 586         }
 587
 588         spin_lock(&cache->lock);
 589         hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
 590                 if (!entry->cr_ops->crmatch(acred, entry, flags))
 591                         continue;
 592                 cred = get_rpccred(entry);
 593                 break;
 594         }
 595         if (cred == NULL) {
 596                 cred = new;
 597                 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 598                 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
 599         } else
 600                 list_add_tail(&new->cr_lru, &free);
 601         spin_unlock(&cache->lock);
 602         rpcauth_cache_enforce_limit();
 603 found:
 604         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 605             cred->cr_ops->cr_init != NULL &&
 606             !(flags & RPCAUTH_LOOKUP_NEW)) {
 607                 int res = cred->cr_ops->cr_init(auth, cred);
 608                 if (res < 0) {
 609                         put_rpccred(cred);
 610                         cred = ERR_PTR(res);
 611                 }
 612         }
 613         rpcauth_destroy_credlist(&free);
 614 out:
 615         return cred;
 616 }
 617 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
 618
 619 struct rpc_cred *
 620 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
 621 {
 622         struct auth_cred acred;
 623         struct rpc_cred *ret;
 624         const struct cred *cred = current_cred();
 625
 626         dprintk("RPC:       looking up %s cred\n",
 627                 auth->au_ops->au_name);
 628
 629         memset(&acred, 0, sizeof(acred));
 630         acred.uid = cred->fsuid;
 631         acred.gid = cred->fsgid;
 632         acred.group_info = cred->group_info;
 633         ret = auth->au_ops->lookup_cred(auth, &acred, flags);
 634         return ret;
 635 }
 636 EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
 637
 638 void
 639 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
 640                   struct rpc_auth *auth, const struct rpc_credops *ops)
 641 {
 642         INIT_HLIST_NODE(&cred->cr_hash);
 643         INIT_LIST_HEAD(&cred->cr_lru);
 644         atomic_set(&cred->cr_count, 1);
 645         cred->cr_auth = auth;
 646         cred->cr_ops = ops;
 647         cred->cr_expire = jiffies;
 648         cred->cr_uid = acred->uid;
 649 }
 650 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
 651
 652 struct rpc_cred *
 653 rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
 654 {
 655         dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
 656                         cred->cr_auth->au_ops->au_name, cred);
 657         return get_rpccred(cred);
 658 }
 659 EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
 660
 661 static struct rpc_cred *
 662 rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
 663 {
 664         struct rpc_auth *auth = task->tk_client->cl_auth;
 665         struct auth_cred acred = {
 666                 .uid = GLOBAL_ROOT_UID,
 667                 .gid = GLOBAL_ROOT_GID,
 668         };
 669
 670         dprintk("RPC: %5u looking up %s cred\n",
 671                 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
 672         return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
 673 }
 674
 675 static struct rpc_cred *
 676 rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
 677 {
 678         struct rpc_auth *auth = task->tk_client->cl_auth;
 679
 680         dprintk("RPC: %5u looking up %s cred\n",
 681                 task->tk_pid, auth->au_ops->au_name);
 682         return rpcauth_lookupcred(auth, lookupflags);
 683 }
 684
 685 static int
 686 rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
 687 {
 688         struct rpc_rqst *req = task->tk_rqstp;
 689         struct rpc_cred *new;
 690         int lookupflags = 0;
 691
 692         if (flags & RPC_TASK_ASYNC)
 693                 lookupflags |= RPCAUTH_LOOKUP_NEW;
 694         if (cred != NULL)
 695                 new = cred->cr_ops->crbind(task, cred, lookupflags);
 696         else if (flags & RPC_TASK_ROOTCREDS)
 697                 new = rpcauth_bind_root_cred(task, lookupflags);
 698         else
 699                 new = rpcauth_bind_new_cred(task, lookupflags);
 700         if (IS_ERR(new))
 701                 return PTR_ERR(new);
 702         put_rpccred(req->rq_cred);
 703         req->rq_cred = new;
 704         return 0;
 705 }
 706
 707 void
 708 put_rpccred(struct rpc_cred *cred)
 709 {
 710         if (cred == NULL)
 711                 return;
 712         /* Fast path for unhashed credentials */
 713         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
 714                 if (atomic_dec_and_test(&cred->cr_count))
 715                         cred->cr_ops->crdestroy(cred);
 716                 return;
 717         }
 718
 719         if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
 720                 return;
 721         if (!list_empty(&cred->cr_lru)) {
 722                 number_cred_unused--;
 723                 list_del_init(&cred->cr_lru);
 724         }
 725         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
 726                 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
 727                         cred->cr_expire = jiffies;
 728                         list_add_tail(&cred->cr_lru, &cred_unused);
 729                         number_cred_unused++;
 730                         goto out_nodestroy;
 731                 }
 732                 if (!rpcauth_unhash_cred(cred)) {
 733                         /* We were hashed and someone looked us up... */
 734                         goto out_nodestroy;
 735                 }
 736         }
 737         spin_unlock(&rpc_credcache_lock);
 738         cred->cr_ops->crdestroy(cred);
 739         return;
 740 out_nodestroy:
 741         spin_unlock(&rpc_credcache_lock);
 742 }
 743 EXPORT_SYMBOL_GPL(put_rpccred);
 744
 745 __be32 *
 746 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
 747 {
 748         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 749
 750         dprintk("RPC: %5u marshaling %s cred %p\n",
 751                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 752
 753         return cred->cr_ops->crmarshal(task, p);
 754 }
 755
 756 __be32 *
 757 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
 758 {
 759         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 760
 761         dprintk("RPC: %5u validating %s cred %p\n",
 762                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 763
 764         return cred->cr_ops->crvalidate(task, p);
 765 }
 766
 767 static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
 768                                    __be32 *data, void *obj)
 769 {
 770         struct xdr_stream xdr;
 771
 772         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
 773         encode(rqstp, &xdr, obj);
 774 }
 775
 776 int
 777 rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
 778                 __be32 *data, void *obj)
 779 {
 780         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 781
 782         dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
 783                         task->tk_pid, cred->cr_ops->cr_name, cred);
 784         if (cred->cr_ops->crwrap_req)
 785                 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
 786         /* By default, we encode the arguments normally. */
 787         rpcauth_wrap_req_encode(encode, rqstp, data, obj);
 788         return 0;
 789 }
 790
 791 static int
 792 rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
 793                           __be32 *data, void *obj)
 794 {
 795         struct xdr_stream xdr;
 796
 797         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
 798         return decode(rqstp, &xdr, obj);
 799 }
 800
 801 int
 802 rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
 803                 __be32 *data, void *obj)
 804 {
 805         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 806
 807         dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
 808                         task->tk_pid, cred->cr_ops->cr_name, cred);
 809         if (cred->cr_ops->crunwrap_resp)
 810                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
 811                                                    data, obj);
 812         /* By default, we decode the arguments normally. */
 813         return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
 814 }
 815
 816 bool
 817 rpcauth_xmit_need_reencode(struct rpc_task *task)
 818 {
 819         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 820
 821         if (!cred || !cred->cr_ops->crneed_reencode)
 822                 return false;
 823         return cred->cr_ops->crneed_reencode(task);
 824 }
 825
 826 int
 827 rpcauth_refreshcred(struct rpc_task *task)
 828 {
 829         struct rpc_cred *cred;
 830         int err;
 831
 832         cred = task->tk_rqstp->rq_cred;
 833         if (cred == NULL) {
 834                 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
 835                 if (err < 0)
 836                         goto out;
 837                 cred = task->tk_rqstp->rq_cred;
 838         }
 839         dprintk("RPC: %5u refreshing %s cred %p\n",
 840                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 841
 842         err = cred->cr_ops->crrefresh(task);
 843 out:
 844         if (err < 0)
 845                 task->tk_status = err;
 846         return err;
 847 }
 848
 849 void
 850 rpcauth_invalcred(struct rpc_task *task)
 851 {
 852         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 853
 854         dprintk("RPC: %5u invalidating %s cred %p\n",
 855                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 856         if (cred)
 857                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 858 }
 859
 860 int
 861 rpcauth_uptodatecred(struct rpc_task *task)
 862 {
 863         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 864
 865         return cred == NULL ||
 866                 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
 867 }
 868
 869 static struct shrinker rpc_cred_shrinker = {
 870         .count_objects = rpcauth_cache_shrink_count,
 871         .scan_objects = rpcauth_cache_shrink_scan,
 872         .seeks = DEFAULT_SEEKS,
 873 };
 874
 875 int __init rpcauth_init_module(void)
 876 {
 877         int err;
 878
 879         err = rpc_init_authunix();
 880         if (err < 0)
 881                 goto out1;
 882         err = rpc_init_generic_auth();
 883         if (err < 0)
 884                 goto out2;
 885         err = register_shrinker(&rpc_cred_shrinker);
 886         if (err < 0)
 887                 goto out3;
 888         return 0;
 889 out3:
 890         rpc_destroy_generic_auth();
 891 out2:
 892         rpc_destroy_authunix();
 893 out1:
 894         return err;
 895 }
 896
 897 void rpcauth_remove_module(void)
 898 {
 899         rpc_destroy_authunix();
 900         rpc_destroy_generic_auth();
 901         unregister_shrinker(&rpc_cred_shrinker);
 902 }