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