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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/net/sunrpc/auth.c
4 *
5 * Generic RPC client authentication API.
6 *
7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
8 */
9
10#include <linux/types.h>
11#include <linux/sched.h>
12#include <linux/cred.h>
13#include <linux/module.h>
14#include <linux/slab.h>
15#include <linux/errno.h>
16#include <linux/hash.h>
17#include <linux/sunrpc/clnt.h>
18#include <linux/sunrpc/gss_api.h>
19#include <linux/spinlock.h>
20
21#include <trace/events/sunrpc.h>
22
23#define RPC_CREDCACHE_DEFAULT_HASHBITS (4)
24struct rpc_cred_cache {
25 struct hlist_head *hashtable;
26 unsigned int hashbits;
27 spinlock_t lock;
28};
29
30static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
31
32static const struct rpc_authops __rcu *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
33 [RPC_AUTH_NULL] = (const struct rpc_authops __force __rcu *)&authnull_ops,
34 [RPC_AUTH_UNIX] = (const struct rpc_authops __force __rcu *)&authunix_ops,
35 NULL, /* others can be loadable modules */
36};
37
38static LIST_HEAD(cred_unused);
39static unsigned long number_cred_unused;
40
41static struct cred machine_cred = {
42 .usage = ATOMIC_INIT(1),
43#ifdef CONFIG_DEBUG_CREDENTIALS
44 .magic = CRED_MAGIC,
45#endif
46};
47
48/*
49 * Return the machine_cred pointer to be used whenever
50 * the a generic machine credential is needed.
51 */
52const struct cred *rpc_machine_cred(void)
53{
54 return &machine_cred;
55}
56EXPORT_SYMBOL_GPL(rpc_machine_cred);
57
58#define MAX_HASHTABLE_BITS (14)
59static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
60{
61 unsigned long num;
62 unsigned int nbits;
63 int ret;
64
65 if (!val)
66 goto out_inval;
67 ret = kstrtoul(val, 0, &num);
68 if (ret)
69 goto out_inval;
70 nbits = fls(num - 1);
71 if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
72 goto out_inval;
73 *(unsigned int *)kp->arg = nbits;
74 return 0;
75out_inval:
76 return -EINVAL;
77}
78
79static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
80{
81 unsigned int nbits;
82
83 nbits = *(unsigned int *)kp->arg;
84 return sprintf(buffer, "%u", 1U << nbits);
85}
86
87#define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
88
89static const struct kernel_param_ops param_ops_hashtbl_sz = {
90 .set = param_set_hashtbl_sz,
91 .get = param_get_hashtbl_sz,
92};
93
94module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
95MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
96
97static unsigned long auth_max_cred_cachesize = ULONG_MAX;
98module_param(auth_max_cred_cachesize, ulong, 0644);
99MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
100
101static u32
102pseudoflavor_to_flavor(u32 flavor) {
103 if (flavor > RPC_AUTH_MAXFLAVOR)
104 return RPC_AUTH_GSS;
105 return flavor;
106}
107
108int
109rpcauth_register(const struct rpc_authops *ops)
110{
111 const struct rpc_authops *old;
112 rpc_authflavor_t flavor;
113
114 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
115 return -EINVAL;
116 old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], NULL, ops);
117 if (old == NULL || old == ops)
118 return 0;
119 return -EPERM;
120}
121EXPORT_SYMBOL_GPL(rpcauth_register);
122
123int
124rpcauth_unregister(const struct rpc_authops *ops)
125{
126 const struct rpc_authops *old;
127 rpc_authflavor_t flavor;
128
129 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
130 return -EINVAL;
131
132 old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], ops, NULL);
133 if (old == ops || old == NULL)
134 return 0;
135 return -EPERM;
136}
137EXPORT_SYMBOL_GPL(rpcauth_unregister);
138
139static const struct rpc_authops *
140rpcauth_get_authops(rpc_authflavor_t flavor)
141{
142 const struct rpc_authops *ops;
143
144 if (flavor >= RPC_AUTH_MAXFLAVOR)
145 return NULL;
146
147 rcu_read_lock();
148 ops = rcu_dereference(auth_flavors[flavor]);
149 if (ops == NULL) {
150 rcu_read_unlock();
151 request_module("rpc-auth-%u", flavor);
152 rcu_read_lock();
153 ops = rcu_dereference(auth_flavors[flavor]);
154 if (ops == NULL)
155 goto out;
156 }
157 if (!try_module_get(ops->owner))
158 ops = NULL;
159out:
160 rcu_read_unlock();
161 return ops;
162}
163
164static void
165rpcauth_put_authops(const struct rpc_authops *ops)
166{
167 module_put(ops->owner);
168}
169
170/**
171 * rpcauth_get_pseudoflavor - check if security flavor is supported
172 * @flavor: a security flavor
173 * @info: a GSS mech OID, quality of protection, and service value
174 *
175 * Verifies that an appropriate kernel module is available or already loaded.
176 * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
177 * not supported locally.
178 */
179rpc_authflavor_t
180rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
181{
182 const struct rpc_authops *ops = rpcauth_get_authops(flavor);
183 rpc_authflavor_t pseudoflavor;
184
185 if (!ops)
186 return RPC_AUTH_MAXFLAVOR;
187 pseudoflavor = flavor;
188 if (ops->info2flavor != NULL)
189 pseudoflavor = ops->info2flavor(info);
190
191 rpcauth_put_authops(ops);
192 return pseudoflavor;
193}
194EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
195
196/**
197 * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
198 * @pseudoflavor: GSS pseudoflavor to match
199 * @info: rpcsec_gss_info structure to fill in
200 *
201 * Returns zero and fills in "info" if pseudoflavor matches a
202 * supported mechanism.
203 */
204int
205rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
206{
207 rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
208 const struct rpc_authops *ops;
209 int result;
210
211 ops = rpcauth_get_authops(flavor);
212 if (ops == NULL)
213 return -ENOENT;
214
215 result = -ENOENT;
216 if (ops->flavor2info != NULL)
217 result = ops->flavor2info(pseudoflavor, info);
218
219 rpcauth_put_authops(ops);
220 return result;
221}
222EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
223
224/**
225 * rpcauth_list_flavors - discover registered flavors and pseudoflavors
226 * @array: array to fill in
227 * @size: size of "array"
228 *
229 * Returns the number of array items filled in, or a negative errno.
230 *
231 * The returned array is not sorted by any policy. Callers should not
232 * rely on the order of the items in the returned array.
233 */
234int
235rpcauth_list_flavors(rpc_authflavor_t *array, int size)
236{
237 const struct rpc_authops *ops;
238 rpc_authflavor_t flavor, pseudos[4];
239 int i, len, result = 0;
240
241 rcu_read_lock();
242 for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
243 ops = rcu_dereference(auth_flavors[flavor]);
244 if (result >= size) {
245 result = -ENOMEM;
246 break;
247 }
248
249 if (ops == NULL)
250 continue;
251 if (ops->list_pseudoflavors == NULL) {
252 array[result++] = ops->au_flavor;
253 continue;
254 }
255 len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
256 if (len < 0) {
257 result = len;
258 break;
259 }
260 for (i = 0; i < len; i++) {
261 if (result >= size) {
262 result = -ENOMEM;
263 break;
264 }
265 array[result++] = pseudos[i];
266 }
267 }
268 rcu_read_unlock();
269 return result;
270}
271EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
272
273struct rpc_auth *
274rpcauth_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
275{
276 struct rpc_auth *auth = ERR_PTR(-EINVAL);
277 const struct rpc_authops *ops;
278 u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
279
280 ops = rpcauth_get_authops(flavor);
281 if (ops == NULL)
282 goto out;
283
284 auth = ops->create(args, clnt);
285
286 rpcauth_put_authops(ops);
287 if (IS_ERR(auth))
288 return auth;
289 if (clnt->cl_auth)
290 rpcauth_release(clnt->cl_auth);
291 clnt->cl_auth = auth;
292
293out:
294 return auth;
295}
296EXPORT_SYMBOL_GPL(rpcauth_create);
297
298void
299rpcauth_release(struct rpc_auth *auth)
300{
301 if (!refcount_dec_and_test(&auth->au_count))
302 return;
303 auth->au_ops->destroy(auth);
304}
305
306static DEFINE_SPINLOCK(rpc_credcache_lock);
307
308/*
309 * On success, the caller is responsible for freeing the reference
310 * held by the hashtable
311 */
312static bool
313rpcauth_unhash_cred_locked(struct rpc_cred *cred)
314{
315 if (!test_and_clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
316 return false;
317 hlist_del_rcu(&cred->cr_hash);
318 return true;
319}
320
321static bool
322rpcauth_unhash_cred(struct rpc_cred *cred)
323{
324 spinlock_t *cache_lock;
325 bool ret;
326
327 if (!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
328 return false;
329 cache_lock = &cred->cr_auth->au_credcache->lock;
330 spin_lock(cache_lock);
331 ret = rpcauth_unhash_cred_locked(cred);
332 spin_unlock(cache_lock);
333 return ret;
334}
335
336/*
337 * Initialize RPC credential cache
338 */
339int
340rpcauth_init_credcache(struct rpc_auth *auth)
341{
342 struct rpc_cred_cache *new;
343 unsigned int hashsize;
344
345 new = kmalloc(sizeof(*new), GFP_KERNEL);
346 if (!new)
347 goto out_nocache;
348 new->hashbits = auth_hashbits;
349 hashsize = 1U << new->hashbits;
350 new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
351 if (!new->hashtable)
352 goto out_nohashtbl;
353 spin_lock_init(&new->lock);
354 auth->au_credcache = new;
355 return 0;
356out_nohashtbl:
357 kfree(new);
358out_nocache:
359 return -ENOMEM;
360}
361EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
362
363char *
364rpcauth_stringify_acceptor(struct rpc_cred *cred)
365{
366 if (!cred->cr_ops->crstringify_acceptor)
367 return NULL;
368 return cred->cr_ops->crstringify_acceptor(cred);
369}
370EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
371
372/*
373 * Destroy a list of credentials
374 */
375static inline
376void rpcauth_destroy_credlist(struct list_head *head)
377{
378 struct rpc_cred *cred;
379
380 while (!list_empty(head)) {
381 cred = list_entry(head->next, struct rpc_cred, cr_lru);
382 list_del_init(&cred->cr_lru);
383 put_rpccred(cred);
384 }
385}
386
387static void
388rpcauth_lru_add_locked(struct rpc_cred *cred)
389{
390 if (!list_empty(&cred->cr_lru))
391 return;
392 number_cred_unused++;
393 list_add_tail(&cred->cr_lru, &cred_unused);
394}
395
396static void
397rpcauth_lru_add(struct rpc_cred *cred)
398{
399 if (!list_empty(&cred->cr_lru))
400 return;
401 spin_lock(&rpc_credcache_lock);
402 rpcauth_lru_add_locked(cred);
403 spin_unlock(&rpc_credcache_lock);
404}
405
406static void
407rpcauth_lru_remove_locked(struct rpc_cred *cred)
408{
409 if (list_empty(&cred->cr_lru))
410 return;
411 number_cred_unused--;
412 list_del_init(&cred->cr_lru);
413}
414
415static void
416rpcauth_lru_remove(struct rpc_cred *cred)
417{
418 if (list_empty(&cred->cr_lru))
419 return;
420 spin_lock(&rpc_credcache_lock);
421 rpcauth_lru_remove_locked(cred);
422 spin_unlock(&rpc_credcache_lock);
423}
424
425/*
426 * Clear the RPC credential cache, and delete those credentials
427 * that are not referenced.
428 */
429void
430rpcauth_clear_credcache(struct rpc_cred_cache *cache)
431{
432 LIST_HEAD(free);
433 struct hlist_head *head;
434 struct rpc_cred *cred;
435 unsigned int hashsize = 1U << cache->hashbits;
436 int i;
437
438 spin_lock(&rpc_credcache_lock);
439 spin_lock(&cache->lock);
440 for (i = 0; i < hashsize; i++) {
441 head = &cache->hashtable[i];
442 while (!hlist_empty(head)) {
443 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
444 rpcauth_unhash_cred_locked(cred);
445 /* Note: We now hold a reference to cred */
446 rpcauth_lru_remove_locked(cred);
447 list_add_tail(&cred->cr_lru, &free);
448 }
449 }
450 spin_unlock(&cache->lock);
451 spin_unlock(&rpc_credcache_lock);
452 rpcauth_destroy_credlist(&free);
453}
454
455/*
456 * Destroy the RPC credential cache
457 */
458void
459rpcauth_destroy_credcache(struct rpc_auth *auth)
460{
461 struct rpc_cred_cache *cache = auth->au_credcache;
462
463 if (cache) {
464 auth->au_credcache = NULL;
465 rpcauth_clear_credcache(cache);
466 kfree(cache->hashtable);
467 kfree(cache);
468 }
469}
470EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
471
472
473#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
474
475/*
476 * Remove stale credentials. Avoid sleeping inside the loop.
477 */
478static long
479rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
480{
481 struct rpc_cred *cred, *next;
482 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
483 long freed = 0;
484
485 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
486
487 if (nr_to_scan-- == 0)
488 break;
489 if (refcount_read(&cred->cr_count) > 1) {
490 rpcauth_lru_remove_locked(cred);
491 continue;
492 }
493 /*
494 * Enforce a 60 second garbage collection moratorium
495 * Note that the cred_unused list must be time-ordered.
496 */
497 if (!time_in_range(cred->cr_expire, expired, jiffies))
498 continue;
499 if (!rpcauth_unhash_cred(cred))
500 continue;
501
502 rpcauth_lru_remove_locked(cred);
503 freed++;
504 list_add_tail(&cred->cr_lru, free);
505 }
506 return freed ? freed : SHRINK_STOP;
507}
508
509static unsigned long
510rpcauth_cache_do_shrink(int nr_to_scan)
511{
512 LIST_HEAD(free);
513 unsigned long freed;
514
515 spin_lock(&rpc_credcache_lock);
516 freed = rpcauth_prune_expired(&free, nr_to_scan);
517 spin_unlock(&rpc_credcache_lock);
518 rpcauth_destroy_credlist(&free);
519
520 return freed;
521}
522
523/*
524 * Run memory cache shrinker.
525 */
526static unsigned long
527rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
528
529{
530 if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
531 return SHRINK_STOP;
532
533 /* nothing left, don't come back */
534 if (list_empty(&cred_unused))
535 return SHRINK_STOP;
536
537 return rpcauth_cache_do_shrink(sc->nr_to_scan);
538}
539
540static unsigned long
541rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
542
543{
544 return number_cred_unused * sysctl_vfs_cache_pressure / 100;
545}
546
547static void
548rpcauth_cache_enforce_limit(void)
549{
550 unsigned long diff;
551 unsigned int nr_to_scan;
552
553 if (number_cred_unused <= auth_max_cred_cachesize)
554 return;
555 diff = number_cred_unused - auth_max_cred_cachesize;
556 nr_to_scan = 100;
557 if (diff < nr_to_scan)
558 nr_to_scan = diff;
559 rpcauth_cache_do_shrink(nr_to_scan);
560}
561
562/*
563 * Look up a process' credentials in the authentication cache
564 */
565struct rpc_cred *
566rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
567 int flags, gfp_t gfp)
568{
569 LIST_HEAD(free);
570 struct rpc_cred_cache *cache = auth->au_credcache;
571 struct rpc_cred *cred = NULL,
572 *entry, *new;
573 unsigned int nr;
574
575 nr = auth->au_ops->hash_cred(acred, cache->hashbits);
576
577 rcu_read_lock();
578 hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
579 if (!entry->cr_ops->crmatch(acred, entry, flags))
580 continue;
581 cred = get_rpccred(entry);
582 if (cred)
583 break;
584 }
585 rcu_read_unlock();
586
587 if (cred != NULL)
588 goto found;
589
590 new = auth->au_ops->crcreate(auth, acred, flags, gfp);
591 if (IS_ERR(new)) {
592 cred = new;
593 goto out;
594 }
595
596 spin_lock(&cache->lock);
597 hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
598 if (!entry->cr_ops->crmatch(acred, entry, flags))
599 continue;
600 cred = get_rpccred(entry);
601 if (cred)
602 break;
603 }
604 if (cred == NULL) {
605 cred = new;
606 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
607 refcount_inc(&cred->cr_count);
608 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
609 } else
610 list_add_tail(&new->cr_lru, &free);
611 spin_unlock(&cache->lock);
612 rpcauth_cache_enforce_limit();
613found:
614 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
615 cred->cr_ops->cr_init != NULL &&
616 !(flags & RPCAUTH_LOOKUP_NEW)) {
617 int res = cred->cr_ops->cr_init(auth, cred);
618 if (res < 0) {
619 put_rpccred(cred);
620 cred = ERR_PTR(res);
621 }
622 }
623 rpcauth_destroy_credlist(&free);
624out:
625 return cred;
626}
627EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
628
629struct rpc_cred *
630rpcauth_lookupcred(struct rpc_auth *auth, int flags)
631{
632 struct auth_cred acred;
633 struct rpc_cred *ret;
634 const struct cred *cred = current_cred();
635
636 memset(&acred, 0, sizeof(acred));
637 acred.cred = cred;
638 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
639 return ret;
640}
641EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
642
643void
644rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
645 struct rpc_auth *auth, const struct rpc_credops *ops)
646{
647 INIT_HLIST_NODE(&cred->cr_hash);
648 INIT_LIST_HEAD(&cred->cr_lru);
649 refcount_set(&cred->cr_count, 1);
650 cred->cr_auth = auth;
651 cred->cr_flags = 0;
652 cred->cr_ops = ops;
653 cred->cr_expire = jiffies;
654 cred->cr_cred = get_cred(acred->cred);
655}
656EXPORT_SYMBOL_GPL(rpcauth_init_cred);
657
658static struct rpc_cred *
659rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
660{
661 struct rpc_auth *auth = task->tk_client->cl_auth;
662 struct auth_cred acred = {
663 .cred = get_task_cred(&init_task),
664 };
665 struct rpc_cred *ret;
666
667 ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
668 put_cred(acred.cred);
669 return ret;
670}
671
672static struct rpc_cred *
673rpcauth_bind_machine_cred(struct rpc_task *task, int lookupflags)
674{
675 struct rpc_auth *auth = task->tk_client->cl_auth;
676 struct auth_cred acred = {
677 .principal = task->tk_client->cl_principal,
678 .cred = init_task.cred,
679 };
680
681 if (!acred.principal)
682 return NULL;
683 return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
684}
685
686static struct rpc_cred *
687rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
688{
689 struct rpc_auth *auth = task->tk_client->cl_auth;
690
691 return rpcauth_lookupcred(auth, lookupflags);
692}
693
694static int
695rpcauth_bindcred(struct rpc_task *task, const struct cred *cred, int flags)
696{
697 struct rpc_rqst *req = task->tk_rqstp;
698 struct rpc_cred *new = NULL;
699 int lookupflags = 0;
700 struct rpc_auth *auth = task->tk_client->cl_auth;
701 struct auth_cred acred = {
702 .cred = cred,
703 };
704
705 if (flags & RPC_TASK_ASYNC)
706 lookupflags |= RPCAUTH_LOOKUP_NEW;
707 if (task->tk_op_cred)
708 /* Task must use exactly this rpc_cred */
709 new = get_rpccred(task->tk_op_cred);
710 else if (cred != NULL && cred != &machine_cred)
711 new = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
712 else if (cred == &machine_cred)
713 new = rpcauth_bind_machine_cred(task, lookupflags);
714
715 /* If machine cred couldn't be bound, try a root cred */
716 if (new)
717 ;
718 else if (cred == &machine_cred || (flags & RPC_TASK_ROOTCREDS))
719 new = rpcauth_bind_root_cred(task, lookupflags);
720 else if (flags & RPC_TASK_NULLCREDS)
721 new = authnull_ops.lookup_cred(NULL, NULL, 0);
722 else
723 new = rpcauth_bind_new_cred(task, lookupflags);
724 if (IS_ERR(new))
725 return PTR_ERR(new);
726 put_rpccred(req->rq_cred);
727 req->rq_cred = new;
728 return 0;
729}
730
731void
732put_rpccred(struct rpc_cred *cred)
733{
734 if (cred == NULL)
735 return;
736 rcu_read_lock();
737 if (refcount_dec_and_test(&cred->cr_count))
738 goto destroy;
739 if (refcount_read(&cred->cr_count) != 1 ||
740 !test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
741 goto out;
742 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
743 cred->cr_expire = jiffies;
744 rpcauth_lru_add(cred);
745 /* Race breaker */
746 if (unlikely(!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags)))
747 rpcauth_lru_remove(cred);
748 } else if (rpcauth_unhash_cred(cred)) {
749 rpcauth_lru_remove(cred);
750 if (refcount_dec_and_test(&cred->cr_count))
751 goto destroy;
752 }
753out:
754 rcu_read_unlock();
755 return;
756destroy:
757 rcu_read_unlock();
758 cred->cr_ops->crdestroy(cred);
759}
760EXPORT_SYMBOL_GPL(put_rpccred);
761
762/**
763 * rpcauth_marshcred - Append RPC credential to end of @xdr
764 * @task: controlling RPC task
765 * @xdr: xdr_stream containing initial portion of RPC Call header
766 *
767 * On success, an appropriate verifier is added to @xdr, @xdr is
768 * updated to point past the verifier, and zero is returned.
769 * Otherwise, @xdr is in an undefined state and a negative errno
770 * is returned.
771 */
772int rpcauth_marshcred(struct rpc_task *task, struct xdr_stream *xdr)
773{
774 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
775
776 return ops->crmarshal(task, xdr);
777}
778
779/**
780 * rpcauth_wrap_req_encode - XDR encode the RPC procedure
781 * @task: controlling RPC task
782 * @xdr: stream where on-the-wire bytes are to be marshalled
783 *
784 * On success, @xdr contains the encoded and wrapped message.
785 * Otherwise, @xdr is in an undefined state.
786 */
787int rpcauth_wrap_req_encode(struct rpc_task *task, struct xdr_stream *xdr)
788{
789 kxdreproc_t encode = task->tk_msg.rpc_proc->p_encode;
790
791 encode(task->tk_rqstp, xdr, task->tk_msg.rpc_argp);
792 return 0;
793}
794EXPORT_SYMBOL_GPL(rpcauth_wrap_req_encode);
795
796/**
797 * rpcauth_wrap_req - XDR encode and wrap the RPC procedure
798 * @task: controlling RPC task
799 * @xdr: stream where on-the-wire bytes are to be marshalled
800 *
801 * On success, @xdr contains the encoded and wrapped message,
802 * and zero is returned. Otherwise, @xdr is in an undefined
803 * state and a negative errno is returned.
804 */
805int rpcauth_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
806{
807 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
808
809 return ops->crwrap_req(task, xdr);
810}
811
812/**
813 * rpcauth_checkverf - Validate verifier in RPC Reply header
814 * @task: controlling RPC task
815 * @xdr: xdr_stream containing RPC Reply header
816 *
817 * On success, @xdr is updated to point past the verifier and
818 * zero is returned. Otherwise, @xdr is in an undefined state
819 * and a negative errno is returned.
820 */
821int
822rpcauth_checkverf(struct rpc_task *task, struct xdr_stream *xdr)
823{
824 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
825
826 return ops->crvalidate(task, xdr);
827}
828
829/**
830 * rpcauth_unwrap_resp_decode - Invoke XDR decode function
831 * @task: controlling RPC task
832 * @xdr: stream where the Reply message resides
833 *
834 * Returns zero on success; otherwise a negative errno is returned.
835 */
836int
837rpcauth_unwrap_resp_decode(struct rpc_task *task, struct xdr_stream *xdr)
838{
839 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
840
841 return decode(task->tk_rqstp, xdr, task->tk_msg.rpc_resp);
842}
843EXPORT_SYMBOL_GPL(rpcauth_unwrap_resp_decode);
844
845/**
846 * rpcauth_unwrap_resp - Invoke unwrap and decode function for the cred
847 * @task: controlling RPC task
848 * @xdr: stream where the Reply message resides
849 *
850 * Returns zero on success; otherwise a negative errno is returned.
851 */
852int
853rpcauth_unwrap_resp(struct rpc_task *task, struct xdr_stream *xdr)
854{
855 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
856
857 return ops->crunwrap_resp(task, xdr);
858}
859
860bool
861rpcauth_xmit_need_reencode(struct rpc_task *task)
862{
863 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
864
865 if (!cred || !cred->cr_ops->crneed_reencode)
866 return false;
867 return cred->cr_ops->crneed_reencode(task);
868}
869
870int
871rpcauth_refreshcred(struct rpc_task *task)
872{
873 struct rpc_cred *cred;
874 int err;
875
876 cred = task->tk_rqstp->rq_cred;
877 if (cred == NULL) {
878 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
879 if (err < 0)
880 goto out;
881 cred = task->tk_rqstp->rq_cred;
882 }
883
884 err = cred->cr_ops->crrefresh(task);
885out:
886 if (err < 0)
887 task->tk_status = err;
888 return err;
889}
890
891void
892rpcauth_invalcred(struct rpc_task *task)
893{
894 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
895
896 if (cred)
897 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
898}
899
900int
901rpcauth_uptodatecred(struct rpc_task *task)
902{
903 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
904
905 return cred == NULL ||
906 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
907}
908
909static struct shrinker rpc_cred_shrinker = {
910 .count_objects = rpcauth_cache_shrink_count,
911 .scan_objects = rpcauth_cache_shrink_scan,
912 .seeks = DEFAULT_SEEKS,
913};
914
915int __init rpcauth_init_module(void)
916{
917 int err;
918
919 err = rpc_init_authunix();
920 if (err < 0)
921 goto out1;
922 err = register_shrinker(&rpc_cred_shrinker);
923 if (err < 0)
924 goto out2;
925 return 0;
926out2:
927 rpc_destroy_authunix();
928out1:
929 return err;
930}
931
932void rpcauth_remove_module(void)
933{
934 rpc_destroy_authunix();
935 unregister_shrinker(&rpc_cred_shrinker);
936}
1/*
2 * linux/net/sunrpc/auth.c
3 *
4 * Generic RPC client authentication API.
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
8
9#include <linux/types.h>
10#include <linux/sched.h>
11#include <linux/cred.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/errno.h>
15#include <linux/hash.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/sunrpc/gss_api.h>
18#include <linux/spinlock.h>
19
20#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
21# define RPCDBG_FACILITY RPCDBG_AUTH
22#endif
23
24#define RPC_CREDCACHE_DEFAULT_HASHBITS (4)
25struct rpc_cred_cache {
26 struct hlist_head *hashtable;
27 unsigned int hashbits;
28 spinlock_t lock;
29};
30
31static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
32
33static DEFINE_SPINLOCK(rpc_authflavor_lock);
34static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
35 &authnull_ops, /* AUTH_NULL */
36 &authunix_ops, /* AUTH_UNIX */
37 NULL, /* others can be loadable modules */
38};
39
40static LIST_HEAD(cred_unused);
41static unsigned long number_cred_unused;
42
43#define MAX_HASHTABLE_BITS (14)
44static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
45{
46 unsigned long num;
47 unsigned int nbits;
48 int ret;
49
50 if (!val)
51 goto out_inval;
52 ret = kstrtoul(val, 0, &num);
53 if (ret == -EINVAL)
54 goto out_inval;
55 nbits = fls(num - 1);
56 if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
57 goto out_inval;
58 *(unsigned int *)kp->arg = nbits;
59 return 0;
60out_inval:
61 return -EINVAL;
62}
63
64static int param_get_hashtbl_sz(char *buffer, const 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
74static const struct kernel_param_ops param_ops_hashtbl_sz = {
75 .set = param_set_hashtbl_sz,
76 .get = param_get_hashtbl_sz,
77};
78
79module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
80MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
81
82static unsigned long auth_max_cred_cachesize = ULONG_MAX;
83module_param(auth_max_cred_cachesize, ulong, 0644);
84MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
85
86static u32
87pseudoflavor_to_flavor(u32 flavor) {
88 if (flavor > RPC_AUTH_MAXFLAVOR)
89 return RPC_AUTH_GSS;
90 return flavor;
91}
92
93int
94rpcauth_register(const struct rpc_authops *ops)
95{
96 rpc_authflavor_t flavor;
97 int ret = -EPERM;
98
99 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
100 return -EINVAL;
101 spin_lock(&rpc_authflavor_lock);
102 if (auth_flavors[flavor] == NULL) {
103 auth_flavors[flavor] = ops;
104 ret = 0;
105 }
106 spin_unlock(&rpc_authflavor_lock);
107 return ret;
108}
109EXPORT_SYMBOL_GPL(rpcauth_register);
110
111int
112rpcauth_unregister(const struct rpc_authops *ops)
113{
114 rpc_authflavor_t flavor;
115 int ret = -EPERM;
116
117 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
118 return -EINVAL;
119 spin_lock(&rpc_authflavor_lock);
120 if (auth_flavors[flavor] == ops) {
121 auth_flavors[flavor] = NULL;
122 ret = 0;
123 }
124 spin_unlock(&rpc_authflavor_lock);
125 return ret;
126}
127EXPORT_SYMBOL_GPL(rpcauth_unregister);
128
129/**
130 * rpcauth_get_pseudoflavor - check if security flavor is supported
131 * @flavor: a security flavor
132 * @info: a GSS mech OID, quality of protection, and service value
133 *
134 * Verifies that an appropriate kernel module is available or already loaded.
135 * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
136 * not supported locally.
137 */
138rpc_authflavor_t
139rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
140{
141 const struct rpc_authops *ops;
142 rpc_authflavor_t pseudoflavor;
143
144 ops = auth_flavors[flavor];
145 if (ops == NULL)
146 request_module("rpc-auth-%u", flavor);
147 spin_lock(&rpc_authflavor_lock);
148 ops = auth_flavors[flavor];
149 if (ops == NULL || !try_module_get(ops->owner)) {
150 spin_unlock(&rpc_authflavor_lock);
151 return RPC_AUTH_MAXFLAVOR;
152 }
153 spin_unlock(&rpc_authflavor_lock);
154
155 pseudoflavor = flavor;
156 if (ops->info2flavor != NULL)
157 pseudoflavor = ops->info2flavor(info);
158
159 module_put(ops->owner);
160 return pseudoflavor;
161}
162EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
163
164/**
165 * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
166 * @pseudoflavor: GSS pseudoflavor to match
167 * @info: rpcsec_gss_info structure to fill in
168 *
169 * Returns zero and fills in "info" if pseudoflavor matches a
170 * supported mechanism.
171 */
172int
173rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
174{
175 rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
176 const struct rpc_authops *ops;
177 int result;
178
179 if (flavor >= RPC_AUTH_MAXFLAVOR)
180 return -EINVAL;
181
182 ops = auth_flavors[flavor];
183 if (ops == NULL)
184 request_module("rpc-auth-%u", flavor);
185 spin_lock(&rpc_authflavor_lock);
186 ops = auth_flavors[flavor];
187 if (ops == NULL || !try_module_get(ops->owner)) {
188 spin_unlock(&rpc_authflavor_lock);
189 return -ENOENT;
190 }
191 spin_unlock(&rpc_authflavor_lock);
192
193 result = -ENOENT;
194 if (ops->flavor2info != NULL)
195 result = ops->flavor2info(pseudoflavor, info);
196
197 module_put(ops->owner);
198 return result;
199}
200EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
201
202/**
203 * rpcauth_list_flavors - discover registered flavors and pseudoflavors
204 * @array: array to fill in
205 * @size: size of "array"
206 *
207 * Returns the number of array items filled in, or a negative errno.
208 *
209 * The returned array is not sorted by any policy. Callers should not
210 * rely on the order of the items in the returned array.
211 */
212int
213rpcauth_list_flavors(rpc_authflavor_t *array, int size)
214{
215 rpc_authflavor_t flavor;
216 int result = 0;
217
218 spin_lock(&rpc_authflavor_lock);
219 for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
220 const struct rpc_authops *ops = auth_flavors[flavor];
221 rpc_authflavor_t pseudos[4];
222 int i, len;
223
224 if (result >= size) {
225 result = -ENOMEM;
226 break;
227 }
228
229 if (ops == NULL)
230 continue;
231 if (ops->list_pseudoflavors == NULL) {
232 array[result++] = ops->au_flavor;
233 continue;
234 }
235 len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
236 if (len < 0) {
237 result = len;
238 break;
239 }
240 for (i = 0; i < len; i++) {
241 if (result >= size) {
242 result = -ENOMEM;
243 break;
244 }
245 array[result++] = pseudos[i];
246 }
247 }
248 spin_unlock(&rpc_authflavor_lock);
249
250 dprintk("RPC: %s returns %d\n", __func__, result);
251 return result;
252}
253EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
254
255struct rpc_auth *
256rpcauth_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
257{
258 struct rpc_auth *auth;
259 const struct rpc_authops *ops;
260 u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
261
262 auth = ERR_PTR(-EINVAL);
263 if (flavor >= RPC_AUTH_MAXFLAVOR)
264 goto out;
265
266 if ((ops = auth_flavors[flavor]) == NULL)
267 request_module("rpc-auth-%u", flavor);
268 spin_lock(&rpc_authflavor_lock);
269 ops = auth_flavors[flavor];
270 if (ops == NULL || !try_module_get(ops->owner)) {
271 spin_unlock(&rpc_authflavor_lock);
272 goto out;
273 }
274 spin_unlock(&rpc_authflavor_lock);
275 auth = ops->create(args, clnt);
276 module_put(ops->owner);
277 if (IS_ERR(auth))
278 return auth;
279 if (clnt->cl_auth)
280 rpcauth_release(clnt->cl_auth);
281 clnt->cl_auth = auth;
282
283out:
284 return auth;
285}
286EXPORT_SYMBOL_GPL(rpcauth_create);
287
288void
289rpcauth_release(struct rpc_auth *auth)
290{
291 if (!atomic_dec_and_test(&auth->au_count))
292 return;
293 auth->au_ops->destroy(auth);
294}
295
296static DEFINE_SPINLOCK(rpc_credcache_lock);
297
298static void
299rpcauth_unhash_cred_locked(struct rpc_cred *cred)
300{
301 hlist_del_rcu(&cred->cr_hash);
302 smp_mb__before_atomic();
303 clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
304}
305
306static int
307rpcauth_unhash_cred(struct rpc_cred *cred)
308{
309 spinlock_t *cache_lock;
310 int ret;
311
312 cache_lock = &cred->cr_auth->au_credcache->lock;
313 spin_lock(cache_lock);
314 ret = atomic_read(&cred->cr_count) == 0;
315 if (ret)
316 rpcauth_unhash_cred_locked(cred);
317 spin_unlock(cache_lock);
318 return ret;
319}
320
321/*
322 * Initialize RPC credential cache
323 */
324int
325rpcauth_init_credcache(struct rpc_auth *auth)
326{
327 struct rpc_cred_cache *new;
328 unsigned int hashsize;
329
330 new = kmalloc(sizeof(*new), GFP_KERNEL);
331 if (!new)
332 goto out_nocache;
333 new->hashbits = auth_hashbits;
334 hashsize = 1U << new->hashbits;
335 new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
336 if (!new->hashtable)
337 goto out_nohashtbl;
338 spin_lock_init(&new->lock);
339 auth->au_credcache = new;
340 return 0;
341out_nohashtbl:
342 kfree(new);
343out_nocache:
344 return -ENOMEM;
345}
346EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
347
348/*
349 * Setup a credential key lifetime timeout notification
350 */
351int
352rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
353{
354 if (!cred->cr_auth->au_ops->key_timeout)
355 return 0;
356 return cred->cr_auth->au_ops->key_timeout(auth, cred);
357}
358EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
359
360bool
361rpcauth_cred_key_to_expire(struct rpc_auth *auth, struct rpc_cred *cred)
362{
363 if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
364 return false;
365 if (!cred->cr_ops->crkey_to_expire)
366 return false;
367 return cred->cr_ops->crkey_to_expire(cred);
368}
369EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
370
371char *
372rpcauth_stringify_acceptor(struct rpc_cred *cred)
373{
374 if (!cred->cr_ops->crstringify_acceptor)
375 return NULL;
376 return cred->cr_ops->crstringify_acceptor(cred);
377}
378EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
379
380/*
381 * Destroy a list of credentials
382 */
383static inline
384void rpcauth_destroy_credlist(struct list_head *head)
385{
386 struct rpc_cred *cred;
387
388 while (!list_empty(head)) {
389 cred = list_entry(head->next, struct rpc_cred, cr_lru);
390 list_del_init(&cred->cr_lru);
391 put_rpccred(cred);
392 }
393}
394
395/*
396 * Clear the RPC credential cache, and delete those credentials
397 * that are not referenced.
398 */
399void
400rpcauth_clear_credcache(struct rpc_cred_cache *cache)
401{
402 LIST_HEAD(free);
403 struct hlist_head *head;
404 struct rpc_cred *cred;
405 unsigned int hashsize = 1U << cache->hashbits;
406 int i;
407
408 spin_lock(&rpc_credcache_lock);
409 spin_lock(&cache->lock);
410 for (i = 0; i < hashsize; i++) {
411 head = &cache->hashtable[i];
412 while (!hlist_empty(head)) {
413 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
414 get_rpccred(cred);
415 if (!list_empty(&cred->cr_lru)) {
416 list_del(&cred->cr_lru);
417 number_cred_unused--;
418 }
419 list_add_tail(&cred->cr_lru, &free);
420 rpcauth_unhash_cred_locked(cred);
421 }
422 }
423 spin_unlock(&cache->lock);
424 spin_unlock(&rpc_credcache_lock);
425 rpcauth_destroy_credlist(&free);
426}
427
428/*
429 * Destroy the RPC credential cache
430 */
431void
432rpcauth_destroy_credcache(struct rpc_auth *auth)
433{
434 struct rpc_cred_cache *cache = auth->au_credcache;
435
436 if (cache) {
437 auth->au_credcache = NULL;
438 rpcauth_clear_credcache(cache);
439 kfree(cache->hashtable);
440 kfree(cache);
441 }
442}
443EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
444
445
446#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
447
448/*
449 * Remove stale credentials. Avoid sleeping inside the loop.
450 */
451static long
452rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
453{
454 spinlock_t *cache_lock;
455 struct rpc_cred *cred, *next;
456 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
457 long freed = 0;
458
459 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
460
461 if (nr_to_scan-- == 0)
462 break;
463 /*
464 * Enforce a 60 second garbage collection moratorium
465 * Note that the cred_unused list must be time-ordered.
466 */
467 if (time_in_range(cred->cr_expire, expired, jiffies) &&
468 test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
469 freed = SHRINK_STOP;
470 break;
471 }
472
473 list_del_init(&cred->cr_lru);
474 number_cred_unused--;
475 freed++;
476 if (atomic_read(&cred->cr_count) != 0)
477 continue;
478
479 cache_lock = &cred->cr_auth->au_credcache->lock;
480 spin_lock(cache_lock);
481 if (atomic_read(&cred->cr_count) == 0) {
482 get_rpccred(cred);
483 list_add_tail(&cred->cr_lru, free);
484 rpcauth_unhash_cred_locked(cred);
485 }
486 spin_unlock(cache_lock);
487 }
488 return freed;
489}
490
491static unsigned long
492rpcauth_cache_do_shrink(int nr_to_scan)
493{
494 LIST_HEAD(free);
495 unsigned long freed;
496
497 spin_lock(&rpc_credcache_lock);
498 freed = rpcauth_prune_expired(&free, nr_to_scan);
499 spin_unlock(&rpc_credcache_lock);
500 rpcauth_destroy_credlist(&free);
501
502 return freed;
503}
504
505/*
506 * Run memory cache shrinker.
507 */
508static unsigned long
509rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
510
511{
512 if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
513 return SHRINK_STOP;
514
515 /* nothing left, don't come back */
516 if (list_empty(&cred_unused))
517 return SHRINK_STOP;
518
519 return rpcauth_cache_do_shrink(sc->nr_to_scan);
520}
521
522static unsigned long
523rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
524
525{
526 return number_cred_unused * sysctl_vfs_cache_pressure / 100;
527}
528
529static void
530rpcauth_cache_enforce_limit(void)
531{
532 unsigned long diff;
533 unsigned int nr_to_scan;
534
535 if (number_cred_unused <= auth_max_cred_cachesize)
536 return;
537 diff = number_cred_unused - auth_max_cred_cachesize;
538 nr_to_scan = 100;
539 if (diff < nr_to_scan)
540 nr_to_scan = diff;
541 rpcauth_cache_do_shrink(nr_to_scan);
542}
543
544/*
545 * Look up a process' credentials in the authentication cache
546 */
547struct rpc_cred *
548rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
549 int flags, gfp_t gfp)
550{
551 LIST_HEAD(free);
552 struct rpc_cred_cache *cache = auth->au_credcache;
553 struct rpc_cred *cred = NULL,
554 *entry, *new;
555 unsigned int nr;
556
557 nr = auth->au_ops->hash_cred(acred, cache->hashbits);
558
559 rcu_read_lock();
560 hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
561 if (!entry->cr_ops->crmatch(acred, entry, flags))
562 continue;
563 if (flags & RPCAUTH_LOOKUP_RCU) {
564 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) &&
565 !test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags))
566 cred = entry;
567 break;
568 }
569 spin_lock(&cache->lock);
570 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
571 spin_unlock(&cache->lock);
572 continue;
573 }
574 cred = get_rpccred(entry);
575 spin_unlock(&cache->lock);
576 break;
577 }
578 rcu_read_unlock();
579
580 if (cred != NULL)
581 goto found;
582
583 if (flags & RPCAUTH_LOOKUP_RCU)
584 return ERR_PTR(-ECHILD);
585
586 new = auth->au_ops->crcreate(auth, acred, flags, gfp);
587 if (IS_ERR(new)) {
588 cred = new;
589 goto out;
590 }
591
592 spin_lock(&cache->lock);
593 hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
594 if (!entry->cr_ops->crmatch(acred, entry, flags))
595 continue;
596 cred = get_rpccred(entry);
597 break;
598 }
599 if (cred == NULL) {
600 cred = new;
601 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
602 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
603 } else
604 list_add_tail(&new->cr_lru, &free);
605 spin_unlock(&cache->lock);
606 rpcauth_cache_enforce_limit();
607found:
608 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
609 cred->cr_ops->cr_init != NULL &&
610 !(flags & RPCAUTH_LOOKUP_NEW)) {
611 int res = cred->cr_ops->cr_init(auth, cred);
612 if (res < 0) {
613 put_rpccred(cred);
614 cred = ERR_PTR(res);
615 }
616 }
617 rpcauth_destroy_credlist(&free);
618out:
619 return cred;
620}
621EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
622
623struct rpc_cred *
624rpcauth_lookupcred(struct rpc_auth *auth, int flags)
625{
626 struct auth_cred acred;
627 struct rpc_cred *ret;
628 const struct cred *cred = current_cred();
629
630 dprintk("RPC: looking up %s cred\n",
631 auth->au_ops->au_name);
632
633 memset(&acred, 0, sizeof(acred));
634 acred.uid = cred->fsuid;
635 acred.gid = cred->fsgid;
636 acred.group_info = cred->group_info;
637 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
638 return ret;
639}
640EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
641
642void
643rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
644 struct rpc_auth *auth, const struct rpc_credops *ops)
645{
646 INIT_HLIST_NODE(&cred->cr_hash);
647 INIT_LIST_HEAD(&cred->cr_lru);
648 atomic_set(&cred->cr_count, 1);
649 cred->cr_auth = auth;
650 cred->cr_ops = ops;
651 cred->cr_expire = jiffies;
652 cred->cr_uid = acred->uid;
653}
654EXPORT_SYMBOL_GPL(rpcauth_init_cred);
655
656struct rpc_cred *
657rpcauth_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}
663EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
664
665static struct rpc_cred *
666rpcauth_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
679static struct rpc_cred *
680rpcauth_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
689static int
690rpcauth_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
711void
712put_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;
744out_nodestroy:
745 spin_unlock(&rpc_credcache_lock);
746}
747EXPORT_SYMBOL_GPL(put_rpccred);
748
749__be32 *
750rpcauth_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 *
761rpcauth_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
771static 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
780int
781rpcauth_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
795static int
796rpcauth_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
805int
806rpcauth_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
820int
821rpcauth_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);
837out:
838 if (err < 0)
839 task->tk_status = err;
840 return err;
841}
842
843void
844rpcauth_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
854int
855rpcauth_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
863static 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
869int __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 err = register_shrinker(&rpc_cred_shrinker);
880 if (err < 0)
881 goto out3;
882 return 0;
883out3:
884 rpc_destroy_generic_auth();
885out2:
886 rpc_destroy_authunix();
887out1:
888 return err;
889}
890
891void rpcauth_remove_module(void)
892{
893 rpc_destroy_authunix();
894 rpc_destroy_generic_auth();
895 unregister_shrinker(&rpc_cred_shrinker);
896}