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