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 - 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         rpc_authflavor_t flavor;
  96         int ret = -EPERM;
  97
  98         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
  99                 return -EINVAL;
 100         spin_lock(&rpc_authflavor_lock);
 101         if (auth_flavors[flavor] == NULL) {
 102                 auth_flavors[flavor] = ops;
 103                 ret = 0;
 104         }
 105         spin_unlock(&rpc_authflavor_lock);
 106         return ret;
 107 }
 108 EXPORT_SYMBOL_GPL(rpcauth_register);
 109
 110 int
 111 rpcauth_unregister(const struct rpc_authops *ops)
 112 {
 113         rpc_authflavor_t flavor;
 114         int ret = -EPERM;
 115
 116         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 117                 return -EINVAL;
 118         spin_lock(&rpc_authflavor_lock);
 119         if (auth_flavors[flavor] == ops) {
 120                 auth_flavors[flavor] = NULL;
 121                 ret = 0;
 122         }
 123         spin_unlock(&rpc_authflavor_lock);
 124         return ret;
 125 }
 126 EXPORT_SYMBOL_GPL(rpcauth_unregister);
 127
 128 /**
 129  * rpcauth_get_pseudoflavor - check if security flavor is supported
 130  * @flavor: a security flavor
 131  * @info: a GSS mech OID, quality of protection, and service value
 132  *
 133  * Verifies that an appropriate kernel module is available or already loaded.
 134  * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
 135  * not supported locally.
 136  */
 137 rpc_authflavor_t
 138 rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
 139 {
 140         const struct rpc_authops *ops;
 141         rpc_authflavor_t pseudoflavor;
 142
 143         ops = auth_flavors[flavor];
 144         if (ops == NULL)
 145                 request_module("rpc-auth-%u", flavor);
 146         spin_lock(&rpc_authflavor_lock);
 147         ops = auth_flavors[flavor];
 148         if (ops == NULL || !try_module_get(ops->owner)) {
 149                 spin_unlock(&rpc_authflavor_lock);
 150                 return RPC_AUTH_MAXFLAVOR;
 151         }
 152         spin_unlock(&rpc_authflavor_lock);
 153
 154         pseudoflavor = flavor;
 155         if (ops->info2flavor != NULL)
 156                 pseudoflavor = ops->info2flavor(info);
 157
 158         module_put(ops->owner);
 159         return pseudoflavor;
 160 }
 161 EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
 162
 163 /**
 164  * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
 165  * @pseudoflavor: GSS pseudoflavor to match
 166  * @info: rpcsec_gss_info structure to fill in
 167  *
 168  * Returns zero and fills in "info" if pseudoflavor matches a
 169  * supported mechanism.
 170  */
 171 int
 172 rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
 173 {
 174         rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
 175         const struct rpc_authops *ops;
 176         int result;
 177
 178         if (flavor >= RPC_AUTH_MAXFLAVOR)
 179                 return -EINVAL;
 180
 181         ops = auth_flavors[flavor];
 182         if (ops == NULL)
 183                 request_module("rpc-auth-%u", flavor);
 184         spin_lock(&rpc_authflavor_lock);
 185         ops = auth_flavors[flavor];
 186         if (ops == NULL || !try_module_get(ops->owner)) {
 187                 spin_unlock(&rpc_authflavor_lock);
 188                 return -ENOENT;
 189         }
 190         spin_unlock(&rpc_authflavor_lock);
 191
 192         result = -ENOENT;
 193         if (ops->flavor2info != NULL)
 194                 result = ops->flavor2info(pseudoflavor, info);
 195
 196         module_put(ops->owner);
 197         return result;
 198 }
 199 EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
 200
 201 /**
 202  * rpcauth_list_flavors - discover registered flavors and pseudoflavors
 203  * @array: array to fill in
 204  * @size: size of "array"
 205  *
 206  * Returns the number of array items filled in, or a negative errno.
 207  *
 208  * The returned array is not sorted by any policy.  Callers should not
 209  * rely on the order of the items in the returned array.
 210  */
 211 int
 212 rpcauth_list_flavors(rpc_authflavor_t *array, int size)
 213 {
 214         rpc_authflavor_t flavor;
 215         int result = 0;
 216
 217         spin_lock(&rpc_authflavor_lock);
 218         for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
 219                 const struct rpc_authops *ops = auth_flavors[flavor];
 220                 rpc_authflavor_t pseudos[4];
 221                 int i, len;
 222
 223                 if (result >= size) {
 224                         result = -ENOMEM;
 225                         break;
 226                 }
 227
 228                 if (ops == NULL)
 229                         continue;
 230                 if (ops->list_pseudoflavors == NULL) {
 231                         array[result++] = ops->au_flavor;
 232                         continue;
 233                 }
 234                 len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
 235                 if (len < 0) {
 236                         result = len;
 237                         break;
 238                 }
 239                 for (i = 0; i < len; i++) {
 240                         if (result >= size) {
 241                                 result = -ENOMEM;
 242                                 break;
 243                         }
 244                         array[result++] = pseudos[i];
 245                 }
 246         }
 247         spin_unlock(&rpc_authflavor_lock);
 248
 249         dprintk("RPC:       %s returns %d\n", __func__, result);
 250         return result;
 251 }
 252 EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
 253
 254 struct rpc_auth *
 255 rpcauth_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 256 {
 257         struct rpc_auth         *auth;
 258         const struct rpc_authops *ops;
 259         u32                     flavor = pseudoflavor_to_flavor(args->pseudoflavor);
 260
 261         auth = ERR_PTR(-EINVAL);
 262         if (flavor >= RPC_AUTH_MAXFLAVOR)
 263                 goto out;
 264
 265         if ((ops = auth_flavors[flavor]) == NULL)
 266                 request_module("rpc-auth-%u", flavor);
 267         spin_lock(&rpc_authflavor_lock);
 268         ops = auth_flavors[flavor];
 269         if (ops == NULL || !try_module_get(ops->owner)) {
 270                 spin_unlock(&rpc_authflavor_lock);
 271                 goto out;
 272         }
 273         spin_unlock(&rpc_authflavor_lock);
 274         auth = ops->create(args, clnt);
 275         module_put(ops->owner);
 276         if (IS_ERR(auth))
 277                 return auth;
 278         if (clnt->cl_auth)
 279                 rpcauth_release(clnt->cl_auth);
 280         clnt->cl_auth = auth;
 281
 282 out:
 283         return auth;
 284 }
 285 EXPORT_SYMBOL_GPL(rpcauth_create);
 286
 287 void
 288 rpcauth_release(struct rpc_auth *auth)
 289 {
 290         if (!atomic_dec_and_test(&auth->au_count))
 291                 return;
 292         auth->au_ops->destroy(auth);
 293 }
 294
 295 static DEFINE_SPINLOCK(rpc_credcache_lock);
 296
 297 static void
 298 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
 299 {
 300         hlist_del_rcu(&cred->cr_hash);
 301         smp_mb__before_atomic();
 302         clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 303 }
 304
 305 static int
 306 rpcauth_unhash_cred(struct rpc_cred *cred)
 307 {
 308         spinlock_t *cache_lock;
 309         int ret;
 310
 311         cache_lock = &cred->cr_auth->au_credcache->lock;
 312         spin_lock(cache_lock);
 313         ret = atomic_read(&cred->cr_count) == 0;
 314         if (ret)
 315                 rpcauth_unhash_cred_locked(cred);
 316         spin_unlock(cache_lock);
 317         return ret;
 318 }
 319
 320 /*
 321  * Initialize RPC credential cache
 322  */
 323 int
 324 rpcauth_init_credcache(struct rpc_auth *auth)
 325 {
 326         struct rpc_cred_cache *new;
 327         unsigned int hashsize;
 328
 329         new = kmalloc(sizeof(*new), GFP_KERNEL);
 330         if (!new)
 331                 goto out_nocache;
 332         new->hashbits = auth_hashbits;
 333         hashsize = 1U << new->hashbits;
 334         new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
 335         if (!new->hashtable)
 336                 goto out_nohashtbl;
 337         spin_lock_init(&new->lock);
 338         auth->au_credcache = new;
 339         return 0;
 340 out_nohashtbl:
 341         kfree(new);
 342 out_nocache:
 343         return -ENOMEM;
 344 }
 345 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
 346
 347 /*
 348  * Setup a credential key lifetime timeout notification
 349  */
 350 int
 351 rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
 352 {
 353         if (!cred->cr_auth->au_ops->key_timeout)
 354                 return 0;
 355         return cred->cr_auth->au_ops->key_timeout(auth, cred);
 356 }
 357 EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
 358
 359 bool
 360 rpcauth_cred_key_to_expire(struct rpc_auth *auth, struct rpc_cred *cred)
 361 {
 362         if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
 363                 return false;
 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, gfp_t gfp)
 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, gfp);
 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         put_rpccred(req->rq_cred);
 707         req->rq_cred = new;
 708         return 0;
 709 }
 710
 711 void
 712 put_rpccred(struct rpc_cred *cred)
 713 {
 714         if (cred == NULL)
 715                 return;
 716         /* Fast path for unhashed credentials */
 717         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
 718                 if (atomic_dec_and_test(&cred->cr_count))
 719                         cred->cr_ops->crdestroy(cred);
 720                 return;
 721         }
 722
 723         if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
 724                 return;
 725         if (!list_empty(&cred->cr_lru)) {
 726                 number_cred_unused--;
 727                 list_del_init(&cred->cr_lru);
 728         }
 729         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
 730                 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
 731                         cred->cr_expire = jiffies;
 732                         list_add_tail(&cred->cr_lru, &cred_unused);
 733                         number_cred_unused++;
 734                         goto out_nodestroy;
 735                 }
 736                 if (!rpcauth_unhash_cred(cred)) {
 737                         /* We were hashed and someone looked us up... */
 738                         goto out_nodestroy;
 739                 }
 740         }
 741         spin_unlock(&rpc_credcache_lock);
 742         cred->cr_ops->crdestroy(cred);
 743         return;
 744 out_nodestroy:
 745         spin_unlock(&rpc_credcache_lock);
 746 }
 747 EXPORT_SYMBOL_GPL(put_rpccred);
 748
 749 __be32 *
 750 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
 751 {
 752         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 753
 754         dprintk("RPC: %5u marshaling %s cred %p\n",
 755                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 756
 757         return cred->cr_ops->crmarshal(task, p);
 758 }
 759
 760 __be32 *
 761 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
 762 {
 763         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 764
 765         dprintk("RPC: %5u validating %s cred %p\n",
 766                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 767
 768         return cred->cr_ops->crvalidate(task, p);
 769 }
 770
 771 static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
 772                                    __be32 *data, void *obj)
 773 {
 774         struct xdr_stream xdr;
 775
 776         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
 777         encode(rqstp, &xdr, obj);
 778 }
 779
 780 int
 781 rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
 782                 __be32 *data, void *obj)
 783 {
 784         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 785
 786         dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
 787                         task->tk_pid, cred->cr_ops->cr_name, cred);
 788         if (cred->cr_ops->crwrap_req)
 789                 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
 790         /* By default, we encode the arguments normally. */
 791         rpcauth_wrap_req_encode(encode, rqstp, data, obj);
 792         return 0;
 793 }
 794
 795 static int
 796 rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
 797                           __be32 *data, void *obj)
 798 {
 799         struct xdr_stream xdr;
 800
 801         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
 802         return decode(rqstp, &xdr, obj);
 803 }
 804
 805 int
 806 rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
 807                 __be32 *data, void *obj)
 808 {
 809         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 810
 811         dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
 812                         task->tk_pid, cred->cr_ops->cr_name, cred);
 813         if (cred->cr_ops->crunwrap_resp)
 814                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
 815                                                    data, obj);
 816         /* By default, we decode the arguments normally. */
 817         return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
 818 }
 819
 820 int
 821 rpcauth_refreshcred(struct rpc_task *task)
 822 {
 823         struct rpc_cred *cred;
 824         int err;
 825
 826         cred = task->tk_rqstp->rq_cred;
 827         if (cred == NULL) {
 828                 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
 829                 if (err < 0)
 830                         goto out;
 831                 cred = task->tk_rqstp->rq_cred;
 832         }
 833         dprintk("RPC: %5u refreshing %s cred %p\n",
 834                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 835
 836         err = cred->cr_ops->crrefresh(task);
 837 out:
 838         if (err < 0)
 839                 task->tk_status = err;
 840         return err;
 841 }
 842
 843 void
 844 rpcauth_invalcred(struct rpc_task *task)
 845 {
 846         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 847
 848         dprintk("RPC: %5u invalidating %s cred %p\n",
 849                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 850         if (cred)
 851                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 852 }
 853
 854 int
 855 rpcauth_uptodatecred(struct rpc_task *task)
 856 {
 857         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 858
 859         return cred == NULL ||
 860                 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
 861 }
 862
 863 static struct shrinker rpc_cred_shrinker = {
 864         .count_objects = rpcauth_cache_shrink_count,
 865         .scan_objects = rpcauth_cache_shrink_scan,
 866         .seeks = DEFAULT_SEEKS,
 867 };
 868
 869 int __init rpcauth_init_module(void)
 870 {
 871         int err;
 872
 873         err = rpc_init_authunix();
 874         if (err < 0)
 875                 goto out1;
 876         err = rpc_init_generic_auth();
 877         if (err < 0)
 878                 goto out2;
 879         register_shrinker(&rpc_cred_shrinker);
 880         return 0;
 881 out2:
 882         rpc_destroy_authunix();
 883 out1:
 884         return err;
 885 }
 886
 887 void rpcauth_remove_module(void)
 888 {
 889         rpc_destroy_authunix();
 890         rpc_destroy_generic_auth();
 891         unregister_shrinker(&rpc_cred_shrinker);
 892 }