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/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/errno.h>
  14 #include <linux/hash.h>
  15 #include <linux/sunrpc/clnt.h>
  16 #include <linux/spinlock.h>
  17
  18 #ifdef RPC_DEBUG
  19 # define RPCDBG_FACILITY        RPCDBG_AUTH
  20 #endif
  21
  22 #define RPC_CREDCACHE_DEFAULT_HASHBITS  (4)
  23 struct rpc_cred_cache {
  24         struct hlist_head       *hashtable;
  25         unsigned int            hashbits;
  26         spinlock_t              lock;
  27 };
  28
  29 static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
  30
  31 static DEFINE_SPINLOCK(rpc_authflavor_lock);
  32 static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
  33         &authnull_ops,          /* AUTH_NULL */
  34         &authunix_ops,          /* AUTH_UNIX */
  35         NULL,                   /* others can be loadable modules */
  36 };
  37
  38 static LIST_HEAD(cred_unused);
  39 static unsigned long number_cred_unused;
  40
  41 #define MAX_HASHTABLE_BITS (10)
  42 static int param_set_hashtbl_sz(const char *val, struct kernel_param *kp)
  43 {
  44         unsigned long num;
  45         unsigned int nbits;
  46         int ret;
  47
  48         if (!val)
  49                 goto out_inval;
  50         ret = strict_strtoul(val, 0, &num);
  51         if (ret == -EINVAL)
  52                 goto out_inval;
  53         nbits = fls(num);
  54         if (num > (1U << nbits))
  55                 nbits++;
  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, 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 module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
  75 MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
  76
  77 static u32
  78 pseudoflavor_to_flavor(u32 flavor) {
  79         if (flavor >= RPC_AUTH_MAXFLAVOR)
  80                 return RPC_AUTH_GSS;
  81         return flavor;
  82 }
  83
  84 int
  85 rpcauth_register(const struct rpc_authops *ops)
  86 {
  87         rpc_authflavor_t flavor;
  88         int ret = -EPERM;
  89
  90         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
  91                 return -EINVAL;
  92         spin_lock(&rpc_authflavor_lock);
  93         if (auth_flavors[flavor] == NULL) {
  94                 auth_flavors[flavor] = ops;
  95                 ret = 0;
  96         }
  97         spin_unlock(&rpc_authflavor_lock);
  98         return ret;
  99 }
 100 EXPORT_SYMBOL_GPL(rpcauth_register);
 101
 102 int
 103 rpcauth_unregister(const struct rpc_authops *ops)
 104 {
 105         rpc_authflavor_t flavor;
 106         int ret = -EPERM;
 107
 108         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 109                 return -EINVAL;
 110         spin_lock(&rpc_authflavor_lock);
 111         if (auth_flavors[flavor] == ops) {
 112                 auth_flavors[flavor] = NULL;
 113                 ret = 0;
 114         }
 115         spin_unlock(&rpc_authflavor_lock);
 116         return ret;
 117 }
 118 EXPORT_SYMBOL_GPL(rpcauth_unregister);
 119
 120 struct rpc_auth *
 121 rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
 122 {
 123         struct rpc_auth         *auth;
 124         const struct rpc_authops *ops;
 125         u32                     flavor = pseudoflavor_to_flavor(pseudoflavor);
 126
 127         auth = ERR_PTR(-EINVAL);
 128         if (flavor >= RPC_AUTH_MAXFLAVOR)
 129                 goto out;
 130
 131         if ((ops = auth_flavors[flavor]) == NULL)
 132                 request_module("rpc-auth-%u", flavor);
 133         spin_lock(&rpc_authflavor_lock);
 134         ops = auth_flavors[flavor];
 135         if (ops == NULL || !try_module_get(ops->owner)) {
 136                 spin_unlock(&rpc_authflavor_lock);
 137                 goto out;
 138         }
 139         spin_unlock(&rpc_authflavor_lock);
 140         auth = ops->create(clnt, pseudoflavor);
 141         module_put(ops->owner);
 142         if (IS_ERR(auth))
 143                 return auth;
 144         if (clnt->cl_auth)
 145                 rpcauth_release(clnt->cl_auth);
 146         clnt->cl_auth = auth;
 147
 148 out:
 149         return auth;
 150 }
 151 EXPORT_SYMBOL_GPL(rpcauth_create);
 152
 153 void
 154 rpcauth_release(struct rpc_auth *auth)
 155 {
 156         if (!atomic_dec_and_test(&auth->au_count))
 157                 return;
 158         auth->au_ops->destroy(auth);
 159 }
 160
 161 static DEFINE_SPINLOCK(rpc_credcache_lock);
 162
 163 static void
 164 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
 165 {
 166         hlist_del_rcu(&cred->cr_hash);
 167         smp_mb__before_clear_bit();
 168         clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 169 }
 170
 171 static int
 172 rpcauth_unhash_cred(struct rpc_cred *cred)
 173 {
 174         spinlock_t *cache_lock;
 175         int ret;
 176
 177         cache_lock = &cred->cr_auth->au_credcache->lock;
 178         spin_lock(cache_lock);
 179         ret = atomic_read(&cred->cr_count) == 0;
 180         if (ret)
 181                 rpcauth_unhash_cred_locked(cred);
 182         spin_unlock(cache_lock);
 183         return ret;
 184 }
 185
 186 /*
 187  * Initialize RPC credential cache
 188  */
 189 int
 190 rpcauth_init_credcache(struct rpc_auth *auth)
 191 {
 192         struct rpc_cred_cache *new;
 193         unsigned int hashsize;
 194
 195         new = kmalloc(sizeof(*new), GFP_KERNEL);
 196         if (!new)
 197                 goto out_nocache;
 198         new->hashbits = auth_hashbits;
 199         hashsize = 1U << new->hashbits;
 200         new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
 201         if (!new->hashtable)
 202                 goto out_nohashtbl;
 203         spin_lock_init(&new->lock);
 204         auth->au_credcache = new;
 205         return 0;
 206 out_nohashtbl:
 207         kfree(new);
 208 out_nocache:
 209         return -ENOMEM;
 210 }
 211 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
 212
 213 /*
 214  * Destroy a list of credentials
 215  */
 216 static inline
 217 void rpcauth_destroy_credlist(struct list_head *head)
 218 {
 219         struct rpc_cred *cred;
 220
 221         while (!list_empty(head)) {
 222                 cred = list_entry(head->next, struct rpc_cred, cr_lru);
 223                 list_del_init(&cred->cr_lru);
 224                 put_rpccred(cred);
 225         }
 226 }
 227
 228 /*
 229  * Clear the RPC credential cache, and delete those credentials
 230  * that are not referenced.
 231  */
 232 void
 233 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
 234 {
 235         LIST_HEAD(free);
 236         struct hlist_head *head;
 237         struct rpc_cred *cred;
 238         unsigned int hashsize = 1U << cache->hashbits;
 239         int             i;
 240
 241         spin_lock(&rpc_credcache_lock);
 242         spin_lock(&cache->lock);
 243         for (i = 0; i < hashsize; i++) {
 244                 head = &cache->hashtable[i];
 245                 while (!hlist_empty(head)) {
 246                         cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
 247                         get_rpccred(cred);
 248                         if (!list_empty(&cred->cr_lru)) {
 249                                 list_del(&cred->cr_lru);
 250                                 number_cred_unused--;
 251                         }
 252                         list_add_tail(&cred->cr_lru, &free);
 253                         rpcauth_unhash_cred_locked(cred);
 254                 }
 255         }
 256         spin_unlock(&cache->lock);
 257         spin_unlock(&rpc_credcache_lock);
 258         rpcauth_destroy_credlist(&free);
 259 }
 260
 261 /*
 262  * Destroy the RPC credential cache
 263  */
 264 void
 265 rpcauth_destroy_credcache(struct rpc_auth *auth)
 266 {
 267         struct rpc_cred_cache *cache = auth->au_credcache;
 268
 269         if (cache) {
 270                 auth->au_credcache = NULL;
 271                 rpcauth_clear_credcache(cache);
 272                 kfree(cache->hashtable);
 273                 kfree(cache);
 274         }
 275 }
 276 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
 277
 278
 279 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
 280
 281 /*
 282  * Remove stale credentials. Avoid sleeping inside the loop.
 283  */
 284 static int
 285 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
 286 {
 287         spinlock_t *cache_lock;
 288         struct rpc_cred *cred, *next;
 289         unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
 290
 291         list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
 292
 293                 if (nr_to_scan-- == 0)
 294                         break;
 295                 /*
 296                  * Enforce a 60 second garbage collection moratorium
 297                  * Note that the cred_unused list must be time-ordered.
 298                  */
 299                 if (time_in_range(cred->cr_expire, expired, jiffies) &&
 300                     test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
 301                         return 0;
 302
 303                 list_del_init(&cred->cr_lru);
 304                 number_cred_unused--;
 305                 if (atomic_read(&cred->cr_count) != 0)
 306                         continue;
 307
 308                 cache_lock = &cred->cr_auth->au_credcache->lock;
 309                 spin_lock(cache_lock);
 310                 if (atomic_read(&cred->cr_count) == 0) {
 311                         get_rpccred(cred);
 312                         list_add_tail(&cred->cr_lru, free);
 313                         rpcauth_unhash_cred_locked(cred);
 314                 }
 315                 spin_unlock(cache_lock);
 316         }
 317         return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
 318 }
 319
 320 /*
 321  * Run memory cache shrinker.
 322  */
 323 static int
 324 rpcauth_cache_shrinker(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
 325 {
 326         LIST_HEAD(free);
 327         int res;
 328
 329         if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
 330                 return (nr_to_scan == 0) ? 0 : -1;
 331         if (list_empty(&cred_unused))
 332                 return 0;
 333         spin_lock(&rpc_credcache_lock);
 334         res = rpcauth_prune_expired(&free, nr_to_scan);
 335         spin_unlock(&rpc_credcache_lock);
 336         rpcauth_destroy_credlist(&free);
 337         return res;
 338 }
 339
 340 /*
 341  * Look up a process' credentials in the authentication cache
 342  */
 343 struct rpc_cred *
 344 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 345                 int flags)
 346 {
 347         LIST_HEAD(free);
 348         struct rpc_cred_cache *cache = auth->au_credcache;
 349         struct hlist_node *pos;
 350         struct rpc_cred *cred = NULL,
 351                         *entry, *new;
 352         unsigned int nr;
 353
 354         nr = hash_long(acred->uid, cache->hashbits);
 355
 356         rcu_read_lock();
 357         hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
 358                 if (!entry->cr_ops->crmatch(acred, entry, flags))
 359                         continue;
 360                 spin_lock(&cache->lock);
 361                 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
 362                         spin_unlock(&cache->lock);
 363                         continue;
 364                 }
 365                 cred = get_rpccred(entry);
 366                 spin_unlock(&cache->lock);
 367                 break;
 368         }
 369         rcu_read_unlock();
 370
 371         if (cred != NULL)
 372                 goto found;
 373
 374         new = auth->au_ops->crcreate(auth, acred, flags);
 375         if (IS_ERR(new)) {
 376                 cred = new;
 377                 goto out;
 378         }
 379
 380         spin_lock(&cache->lock);
 381         hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
 382                 if (!entry->cr_ops->crmatch(acred, entry, flags))
 383                         continue;
 384                 cred = get_rpccred(entry);
 385                 break;
 386         }
 387         if (cred == NULL) {
 388                 cred = new;
 389                 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 390                 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
 391         } else
 392                 list_add_tail(&new->cr_lru, &free);
 393         spin_unlock(&cache->lock);
 394 found:
 395         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 396             cred->cr_ops->cr_init != NULL &&
 397             !(flags & RPCAUTH_LOOKUP_NEW)) {
 398                 int res = cred->cr_ops->cr_init(auth, cred);
 399                 if (res < 0) {
 400                         put_rpccred(cred);
 401                         cred = ERR_PTR(res);
 402                 }
 403         }
 404         rpcauth_destroy_credlist(&free);
 405 out:
 406         return cred;
 407 }
 408 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
 409
 410 struct rpc_cred *
 411 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
 412 {
 413         struct auth_cred acred;
 414         struct rpc_cred *ret;
 415         const struct cred *cred = current_cred();
 416
 417         dprintk("RPC:       looking up %s cred\n",
 418                 auth->au_ops->au_name);
 419
 420         memset(&acred, 0, sizeof(acred));
 421         acred.uid = cred->fsuid;
 422         acred.gid = cred->fsgid;
 423         acred.group_info = get_group_info(((struct cred *)cred)->group_info);
 424
 425         ret = auth->au_ops->lookup_cred(auth, &acred, flags);
 426         put_group_info(acred.group_info);
 427         return ret;
 428 }
 429
 430 void
 431 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
 432                   struct rpc_auth *auth, const struct rpc_credops *ops)
 433 {
 434         INIT_HLIST_NODE(&cred->cr_hash);
 435         INIT_LIST_HEAD(&cred->cr_lru);
 436         atomic_set(&cred->cr_count, 1);
 437         cred->cr_auth = auth;
 438         cred->cr_ops = ops;
 439         cred->cr_expire = jiffies;
 440 #ifdef RPC_DEBUG
 441         cred->cr_magic = RPCAUTH_CRED_MAGIC;
 442 #endif
 443         cred->cr_uid = acred->uid;
 444 }
 445 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
 446
 447 struct rpc_cred *
 448 rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
 449 {
 450         dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
 451                         cred->cr_auth->au_ops->au_name, cred);
 452         return get_rpccred(cred);
 453 }
 454 EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
 455
 456 static struct rpc_cred *
 457 rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
 458 {
 459         struct rpc_auth *auth = task->tk_client->cl_auth;
 460         struct auth_cred acred = {
 461                 .uid = 0,
 462                 .gid = 0,
 463         };
 464
 465         dprintk("RPC: %5u looking up %s cred\n",
 466                 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
 467         return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
 468 }
 469
 470 static struct rpc_cred *
 471 rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
 472 {
 473         struct rpc_auth *auth = task->tk_client->cl_auth;
 474
 475         dprintk("RPC: %5u looking up %s cred\n",
 476                 task->tk_pid, auth->au_ops->au_name);
 477         return rpcauth_lookupcred(auth, lookupflags);
 478 }
 479
 480 static int
 481 rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
 482 {
 483         struct rpc_rqst *req = task->tk_rqstp;
 484         struct rpc_cred *new;
 485         int lookupflags = 0;
 486
 487         if (flags & RPC_TASK_ASYNC)
 488                 lookupflags |= RPCAUTH_LOOKUP_NEW;
 489         if (cred != NULL)
 490                 new = cred->cr_ops->crbind(task, cred, lookupflags);
 491         else if (flags & RPC_TASK_ROOTCREDS)
 492                 new = rpcauth_bind_root_cred(task, lookupflags);
 493         else
 494                 new = rpcauth_bind_new_cred(task, lookupflags);
 495         if (IS_ERR(new))
 496                 return PTR_ERR(new);
 497         if (req->rq_cred != NULL)
 498                 put_rpccred(req->rq_cred);
 499         req->rq_cred = new;
 500         return 0;
 501 }
 502
 503 void
 504 put_rpccred(struct rpc_cred *cred)
 505 {
 506         /* Fast path for unhashed credentials */
 507         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
 508                 if (atomic_dec_and_test(&cred->cr_count))
 509                         cred->cr_ops->crdestroy(cred);
 510                 return;
 511         }
 512
 513         if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
 514                 return;
 515         if (!list_empty(&cred->cr_lru)) {
 516                 number_cred_unused--;
 517                 list_del_init(&cred->cr_lru);
 518         }
 519         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
 520                 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
 521                         cred->cr_expire = jiffies;
 522                         list_add_tail(&cred->cr_lru, &cred_unused);
 523                         number_cred_unused++;
 524                         goto out_nodestroy;
 525                 }
 526                 if (!rpcauth_unhash_cred(cred)) {
 527                         /* We were hashed and someone looked us up... */
 528                         goto out_nodestroy;
 529                 }
 530         }
 531         spin_unlock(&rpc_credcache_lock);
 532         cred->cr_ops->crdestroy(cred);
 533         return;
 534 out_nodestroy:
 535         spin_unlock(&rpc_credcache_lock);
 536 }
 537 EXPORT_SYMBOL_GPL(put_rpccred);
 538
 539 __be32 *
 540 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
 541 {
 542         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 543
 544         dprintk("RPC: %5u marshaling %s cred %p\n",
 545                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 546
 547         return cred->cr_ops->crmarshal(task, p);
 548 }
 549
 550 __be32 *
 551 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
 552 {
 553         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 554
 555         dprintk("RPC: %5u validating %s cred %p\n",
 556                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 557
 558         return cred->cr_ops->crvalidate(task, p);
 559 }
 560
 561 int
 562 rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
 563                 __be32 *data, void *obj)
 564 {
 565         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 566
 567         dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
 568                         task->tk_pid, cred->cr_ops->cr_name, cred);
 569         if (cred->cr_ops->crwrap_req)
 570                 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
 571         /* By default, we encode the arguments normally. */
 572         return encode(rqstp, data, obj);
 573 }
 574
 575 int
 576 rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
 577                 __be32 *data, void *obj)
 578 {
 579         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 580
 581         dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
 582                         task->tk_pid, cred->cr_ops->cr_name, cred);
 583         if (cred->cr_ops->crunwrap_resp)
 584                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
 585                                                    data, obj);
 586         /* By default, we decode the arguments normally. */
 587         return decode(rqstp, data, obj);
 588 }
 589
 590 int
 591 rpcauth_refreshcred(struct rpc_task *task)
 592 {
 593         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 594         int err;
 595
 596         cred = task->tk_rqstp->rq_cred;
 597         if (cred == NULL) {
 598                 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
 599                 if (err < 0)
 600                         goto out;
 601                 cred = task->tk_rqstp->rq_cred;
 602         };
 603         dprintk("RPC: %5u refreshing %s cred %p\n",
 604                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 605
 606         err = cred->cr_ops->crrefresh(task);
 607 out:
 608         if (err < 0)
 609                 task->tk_status = err;
 610         return err;
 611 }
 612
 613 void
 614 rpcauth_invalcred(struct rpc_task *task)
 615 {
 616         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 617
 618         dprintk("RPC: %5u invalidating %s cred %p\n",
 619                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 620         if (cred)
 621                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 622 }
 623
 624 int
 625 rpcauth_uptodatecred(struct rpc_task *task)
 626 {
 627         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 628
 629         return cred == NULL ||
 630                 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
 631 }
 632
 633 static struct shrinker rpc_cred_shrinker = {
 634         .shrink = rpcauth_cache_shrinker,
 635         .seeks = DEFAULT_SEEKS,
 636 };
 637
 638 int __init rpcauth_init_module(void)
 639 {
 640         int err;
 641
 642         err = rpc_init_authunix();
 643         if (err < 0)
 644                 goto out1;
 645         err = rpc_init_generic_auth();
 646         if (err < 0)
 647                 goto out2;
 648         register_shrinker(&rpc_cred_shrinker);
 649         return 0;
 650 out2:
 651         rpc_destroy_authunix();
 652 out1:
 653         return err;
 654 }
 655
 656 void __exit rpcauth_remove_module(void)
 657 {
 658         rpc_destroy_authunix();
 659         rpc_destroy_generic_auth();
 660         unregister_shrinker(&rpc_cred_shrinker);
 661 }