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\n", 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
224struct rpc_auth *
225rpcauth_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
226{
227	struct rpc_auth	*auth = ERR_PTR(-EINVAL);
228	const struct rpc_authops *ops;
229	u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
230
231	ops = rpcauth_get_authops(flavor);
232	if (ops == NULL)
233		goto out;
234
235	auth = ops->create(args, clnt);
236
237	rpcauth_put_authops(ops);
238	if (IS_ERR(auth))
239		return auth;
240	if (clnt->cl_auth)
241		rpcauth_release(clnt->cl_auth);
242	clnt->cl_auth = auth;
243
244out:
245	return auth;
246}
247EXPORT_SYMBOL_GPL(rpcauth_create);
248
249void
250rpcauth_release(struct rpc_auth *auth)
251{
252	if (!refcount_dec_and_test(&auth->au_count))
253		return;
254	auth->au_ops->destroy(auth);
255}
256
257static DEFINE_SPINLOCK(rpc_credcache_lock);
258
259/*
260 * On success, the caller is responsible for freeing the reference
261 * held by the hashtable
262 */
263static bool
264rpcauth_unhash_cred_locked(struct rpc_cred *cred)
265{
266	if (!test_and_clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
267		return false;
268	hlist_del_rcu(&cred->cr_hash);
269	return true;
270}
271
272static bool
273rpcauth_unhash_cred(struct rpc_cred *cred)
274{
275	spinlock_t *cache_lock;
276	bool ret;
277
278	if (!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
279		return false;
280	cache_lock = &cred->cr_auth->au_credcache->lock;
281	spin_lock(cache_lock);
282	ret = rpcauth_unhash_cred_locked(cred);
283	spin_unlock(cache_lock);
284	return ret;
285}
286
287/*
288 * Initialize RPC credential cache
289 */
290int
291rpcauth_init_credcache(struct rpc_auth *auth)
292{
293	struct rpc_cred_cache *new;
294	unsigned int hashsize;
295
296	new = kmalloc(sizeof(*new), GFP_KERNEL);
297	if (!new)
298		goto out_nocache;
299	new->hashbits = auth_hashbits;
300	hashsize = 1U << new->hashbits;
301	new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
302	if (!new->hashtable)
303		goto out_nohashtbl;
304	spin_lock_init(&new->lock);
305	auth->au_credcache = new;
306	return 0;
307out_nohashtbl:
308	kfree(new);
309out_nocache:
310	return -ENOMEM;
311}
312EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
313
314char *
315rpcauth_stringify_acceptor(struct rpc_cred *cred)
316{
317	if (!cred->cr_ops->crstringify_acceptor)
318		return NULL;
319	return cred->cr_ops->crstringify_acceptor(cred);
320}
321EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
322
323/*
324 * Destroy a list of credentials
325 */
326static inline
327void rpcauth_destroy_credlist(struct list_head *head)
328{
329	struct rpc_cred *cred;
330
331	while (!list_empty(head)) {
332		cred = list_entry(head->next, struct rpc_cred, cr_lru);
333		list_del_init(&cred->cr_lru);
334		put_rpccred(cred);
335	}
336}
337
338static void
339rpcauth_lru_add_locked(struct rpc_cred *cred)
340{
341	if (!list_empty(&cred->cr_lru))
342		return;
343	number_cred_unused++;
344	list_add_tail(&cred->cr_lru, &cred_unused);
345}
346
347static void
348rpcauth_lru_add(struct rpc_cred *cred)
349{
350	if (!list_empty(&cred->cr_lru))
351		return;
352	spin_lock(&rpc_credcache_lock);
353	rpcauth_lru_add_locked(cred);
354	spin_unlock(&rpc_credcache_lock);
355}
356
357static void
358rpcauth_lru_remove_locked(struct rpc_cred *cred)
359{
360	if (list_empty(&cred->cr_lru))
361		return;
362	number_cred_unused--;
363	list_del_init(&cred->cr_lru);
364}
365
366static void
367rpcauth_lru_remove(struct rpc_cred *cred)
368{
369	if (list_empty(&cred->cr_lru))
370		return;
371	spin_lock(&rpc_credcache_lock);
372	rpcauth_lru_remove_locked(cred);
373	spin_unlock(&rpc_credcache_lock);
374}
375
376/*
377 * Clear the RPC credential cache, and delete those credentials
378 * that are not referenced.
379 */
380void
381rpcauth_clear_credcache(struct rpc_cred_cache *cache)
382{
383	LIST_HEAD(free);
384	struct hlist_head *head;
385	struct rpc_cred	*cred;
386	unsigned int hashsize = 1U << cache->hashbits;
387	int		i;
388
389	spin_lock(&rpc_credcache_lock);
390	spin_lock(&cache->lock);
391	for (i = 0; i < hashsize; i++) {
392		head = &cache->hashtable[i];
393		while (!hlist_empty(head)) {
394			cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
395			rpcauth_unhash_cred_locked(cred);
396			/* Note: We now hold a reference to cred */
397			rpcauth_lru_remove_locked(cred);
398			list_add_tail(&cred->cr_lru, &free);
399		}
400	}
401	spin_unlock(&cache->lock);
402	spin_unlock(&rpc_credcache_lock);
403	rpcauth_destroy_credlist(&free);
404}
405
406/*
407 * Destroy the RPC credential cache
408 */
409void
410rpcauth_destroy_credcache(struct rpc_auth *auth)
411{
412	struct rpc_cred_cache *cache = auth->au_credcache;
413
414	if (cache) {
415		auth->au_credcache = NULL;
416		rpcauth_clear_credcache(cache);
417		kfree(cache->hashtable);
418		kfree(cache);
419	}
420}
421EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
422
423
424#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
425
426/*
427 * Remove stale credentials. Avoid sleeping inside the loop.
428 */
429static long
430rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
431{
432	struct rpc_cred *cred, *next;
433	unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
434	long freed = 0;
435
436	list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
437
438		if (nr_to_scan-- == 0)
439			break;
440		if (refcount_read(&cred->cr_count) > 1) {
441			rpcauth_lru_remove_locked(cred);
442			continue;
443		}
444		/*
445		 * Enforce a 60 second garbage collection moratorium
446		 * Note that the cred_unused list must be time-ordered.
447		 */
448		if (!time_in_range(cred->cr_expire, expired, jiffies))
449			continue;
450		if (!rpcauth_unhash_cred(cred))
451			continue;
452
453		rpcauth_lru_remove_locked(cred);
454		freed++;
455		list_add_tail(&cred->cr_lru, free);
456	}
457	return freed ? freed : SHRINK_STOP;
458}
459
460static unsigned long
461rpcauth_cache_do_shrink(int nr_to_scan)
462{
463	LIST_HEAD(free);
464	unsigned long freed;
465
466	spin_lock(&rpc_credcache_lock);
467	freed = rpcauth_prune_expired(&free, nr_to_scan);
468	spin_unlock(&rpc_credcache_lock);
469	rpcauth_destroy_credlist(&free);
470
471	return freed;
472}
473
474/*
475 * Run memory cache shrinker.
476 */
477static unsigned long
478rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
479
480{
481	if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
482		return SHRINK_STOP;
483
484	/* nothing left, don't come back */
485	if (list_empty(&cred_unused))
486		return SHRINK_STOP;
487
488	return rpcauth_cache_do_shrink(sc->nr_to_scan);
489}
490
491static unsigned long
492rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
493
494{
495	return number_cred_unused * sysctl_vfs_cache_pressure / 100;
496}
497
498static void
499rpcauth_cache_enforce_limit(void)
500{
501	unsigned long diff;
502	unsigned int nr_to_scan;
503
504	if (number_cred_unused <= auth_max_cred_cachesize)
505		return;
506	diff = number_cred_unused - auth_max_cred_cachesize;
507	nr_to_scan = 100;
508	if (diff < nr_to_scan)
509		nr_to_scan = diff;
510	rpcauth_cache_do_shrink(nr_to_scan);
511}
512
513/*
514 * Look up a process' credentials in the authentication cache
515 */
516struct rpc_cred *
517rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
518		int flags, gfp_t gfp)
519{
520	LIST_HEAD(free);
521	struct rpc_cred_cache *cache = auth->au_credcache;
522	struct rpc_cred	*cred = NULL,
523			*entry, *new;
524	unsigned int nr;
525
526	nr = auth->au_ops->hash_cred(acred, cache->hashbits);
527
528	rcu_read_lock();
529	hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
530		if (!entry->cr_ops->crmatch(acred, entry, flags))
531			continue;
532		cred = get_rpccred(entry);
533		if (cred)
534			break;
535	}
536	rcu_read_unlock();
537
538	if (cred != NULL)
539		goto found;
540
541	new = auth->au_ops->crcreate(auth, acred, flags, gfp);
542	if (IS_ERR(new)) {
543		cred = new;
544		goto out;
545	}
546
547	spin_lock(&cache->lock);
548	hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
549		if (!entry->cr_ops->crmatch(acred, entry, flags))
550			continue;
551		cred = get_rpccred(entry);
552		if (cred)
553			break;
554	}
555	if (cred == NULL) {
556		cred = new;
557		set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
558		refcount_inc(&cred->cr_count);
559		hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
560	} else
561		list_add_tail(&new->cr_lru, &free);
562	spin_unlock(&cache->lock);
563	rpcauth_cache_enforce_limit();
564found:
565	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
566	    cred->cr_ops->cr_init != NULL &&
567	    !(flags & RPCAUTH_LOOKUP_NEW)) {
568		int res = cred->cr_ops->cr_init(auth, cred);
569		if (res < 0) {
570			put_rpccred(cred);
571			cred = ERR_PTR(res);
572		}
573	}
574	rpcauth_destroy_credlist(&free);
575out:
576	return cred;
577}
578EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
579
580struct rpc_cred *
581rpcauth_lookupcred(struct rpc_auth *auth, int flags)
582{
583	struct auth_cred acred;
584	struct rpc_cred *ret;
585	const struct cred *cred = current_cred();
586
587	memset(&acred, 0, sizeof(acred));
588	acred.cred = cred;
589	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
590	return ret;
591}
592EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
593
594void
595rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
596		  struct rpc_auth *auth, const struct rpc_credops *ops)
597{
598	INIT_HLIST_NODE(&cred->cr_hash);
599	INIT_LIST_HEAD(&cred->cr_lru);
600	refcount_set(&cred->cr_count, 1);
601	cred->cr_auth = auth;
602	cred->cr_flags = 0;
603	cred->cr_ops = ops;
604	cred->cr_expire = jiffies;
605	cred->cr_cred = get_cred(acred->cred);
606}
607EXPORT_SYMBOL_GPL(rpcauth_init_cred);
608
609static struct rpc_cred *
610rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
611{
612	struct rpc_auth *auth = task->tk_client->cl_auth;
613	struct auth_cred acred = {
614		.cred = get_task_cred(&init_task),
615	};
616	struct rpc_cred *ret;
617
 
 
618	ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
619	put_cred(acred.cred);
620	return ret;
621}
622
623static struct rpc_cred *
624rpcauth_bind_machine_cred(struct rpc_task *task, int lookupflags)
625{
626	struct rpc_auth *auth = task->tk_client->cl_auth;
627	struct auth_cred acred = {
628		.principal = task->tk_client->cl_principal,
629		.cred = init_task.cred,
630	};
631
632	if (!acred.principal)
633		return NULL;
 
 
634	return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
635}
636
637static struct rpc_cred *
638rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
639{
640	struct rpc_auth *auth = task->tk_client->cl_auth;
641
642	return rpcauth_lookupcred(auth, lookupflags);
643}
644
645static int
646rpcauth_bindcred(struct rpc_task *task, const struct cred *cred, int flags)
647{
648	struct rpc_rqst *req = task->tk_rqstp;
649	struct rpc_cred *new = NULL;
650	int lookupflags = 0;
651	struct rpc_auth *auth = task->tk_client->cl_auth;
652	struct auth_cred acred = {
653		.cred = cred,
654	};
655
656	if (flags & RPC_TASK_ASYNC)
657		lookupflags |= RPCAUTH_LOOKUP_NEW;
658	if (task->tk_op_cred)
659		/* Task must use exactly this rpc_cred */
660		new = get_rpccred(task->tk_op_cred);
661	else if (cred != NULL && cred != &machine_cred)
662		new = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
663	else if (cred == &machine_cred)
664		new = rpcauth_bind_machine_cred(task, lookupflags);
665
666	/* If machine cred couldn't be bound, try a root cred */
667	if (new)
668		;
669	else if (cred == &machine_cred || (flags & RPC_TASK_ROOTCREDS))
670		new = rpcauth_bind_root_cred(task, lookupflags);
671	else if (flags & RPC_TASK_NULLCREDS)
672		new = authnull_ops.lookup_cred(NULL, NULL, 0);
673	else
674		new = rpcauth_bind_new_cred(task, lookupflags);
675	if (IS_ERR(new))
676		return PTR_ERR(new);
677	put_rpccred(req->rq_cred);
678	req->rq_cred = new;
679	return 0;
680}
681
682void
683put_rpccred(struct rpc_cred *cred)
684{
685	if (cred == NULL)
686		return;
687	rcu_read_lock();
688	if (refcount_dec_and_test(&cred->cr_count))
689		goto destroy;
690	if (refcount_read(&cred->cr_count) != 1 ||
691	    !test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
692		goto out;
693	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
694		cred->cr_expire = jiffies;
695		rpcauth_lru_add(cred);
696		/* Race breaker */
697		if (unlikely(!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags)))
698			rpcauth_lru_remove(cred);
699	} else if (rpcauth_unhash_cred(cred)) {
700		rpcauth_lru_remove(cred);
701		if (refcount_dec_and_test(&cred->cr_count))
702			goto destroy;
703	}
704out:
705	rcu_read_unlock();
706	return;
707destroy:
708	rcu_read_unlock();
709	cred->cr_ops->crdestroy(cred);
710}
711EXPORT_SYMBOL_GPL(put_rpccred);
712
713/**
714 * rpcauth_marshcred - Append RPC credential to end of @xdr
715 * @task: controlling RPC task
716 * @xdr: xdr_stream containing initial portion of RPC Call header
717 *
718 * On success, an appropriate verifier is added to @xdr, @xdr is
719 * updated to point past the verifier, and zero is returned.
720 * Otherwise, @xdr is in an undefined state and a negative errno
721 * is returned.
722 */
723int rpcauth_marshcred(struct rpc_task *task, struct xdr_stream *xdr)
724{
725	const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
726
727	return ops->crmarshal(task, xdr);
728}
729
730/**
731 * rpcauth_wrap_req_encode - XDR encode the RPC procedure
732 * @task: controlling RPC task
733 * @xdr: stream where on-the-wire bytes are to be marshalled
734 *
735 * On success, @xdr contains the encoded and wrapped message.
736 * Otherwise, @xdr is in an undefined state.
737 */
738int rpcauth_wrap_req_encode(struct rpc_task *task, struct xdr_stream *xdr)
739{
740	kxdreproc_t encode = task->tk_msg.rpc_proc->p_encode;
741
742	encode(task->tk_rqstp, xdr, task->tk_msg.rpc_argp);
743	return 0;
744}
745EXPORT_SYMBOL_GPL(rpcauth_wrap_req_encode);
746
747/**
748 * rpcauth_wrap_req - XDR encode and wrap the RPC procedure
749 * @task: controlling RPC task
750 * @xdr: stream where on-the-wire bytes are to be marshalled
751 *
752 * On success, @xdr contains the encoded and wrapped message,
753 * and zero is returned. Otherwise, @xdr is in an undefined
754 * state and a negative errno is returned.
755 */
756int rpcauth_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
757{
758	const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
759
760	return ops->crwrap_req(task, xdr);
761}
762
763/**
764 * rpcauth_checkverf - Validate verifier in RPC Reply header
765 * @task: controlling RPC task
766 * @xdr: xdr_stream containing RPC Reply header
767 *
768 * On success, @xdr is updated to point past the verifier and
769 * zero is returned. Otherwise, @xdr is in an undefined state
770 * and a negative errno is returned.
771 */
772int
773rpcauth_checkverf(struct rpc_task *task, struct xdr_stream *xdr)
774{
775	const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
776
777	return ops->crvalidate(task, xdr);
778}
779
780/**
781 * rpcauth_unwrap_resp_decode - Invoke XDR decode function
782 * @task: controlling RPC task
783 * @xdr: stream where the Reply message resides
784 *
785 * Returns zero on success; otherwise a negative errno is returned.
786 */
787int
788rpcauth_unwrap_resp_decode(struct rpc_task *task, struct xdr_stream *xdr)
789{
790	kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
791
792	return decode(task->tk_rqstp, xdr, task->tk_msg.rpc_resp);
793}
794EXPORT_SYMBOL_GPL(rpcauth_unwrap_resp_decode);
795
796/**
797 * rpcauth_unwrap_resp - Invoke unwrap and decode function for the cred
798 * @task: controlling RPC task
799 * @xdr: stream where the Reply message resides
800 *
801 * Returns zero on success; otherwise a negative errno is returned.
802 */
803int
804rpcauth_unwrap_resp(struct rpc_task *task, struct xdr_stream *xdr)
805{
806	const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
807
808	return ops->crunwrap_resp(task, xdr);
809}
810
811bool
812rpcauth_xmit_need_reencode(struct rpc_task *task)
813{
814	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
815
816	if (!cred || !cred->cr_ops->crneed_reencode)
817		return false;
818	return cred->cr_ops->crneed_reencode(task);
819}
820
821int
822rpcauth_refreshcred(struct rpc_task *task)
823{
824	struct rpc_cred	*cred;
825	int err;
826
827	cred = task->tk_rqstp->rq_cred;
828	if (cred == NULL) {
829		err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
830		if (err < 0)
831			goto out;
832		cred = task->tk_rqstp->rq_cred;
833	}
834
835	err = cred->cr_ops->crrefresh(task);
836out:
837	if (err < 0)
838		task->tk_status = err;
839	return err;
840}
841
842void
843rpcauth_invalcred(struct rpc_task *task)
844{
845	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
846
847	if (cred)
848		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
849}
850
851int
852rpcauth_uptodatecred(struct rpc_task *task)
853{
854	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
855
856	return cred == NULL ||
857		test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
858}
859
860static struct shrinker rpc_cred_shrinker = {
861	.count_objects = rpcauth_cache_shrink_count,
862	.scan_objects = rpcauth_cache_shrink_scan,
863	.seeks = DEFAULT_SEEKS,
864};
865
866int __init rpcauth_init_module(void)
867{
868	int err;
869
870	err = rpc_init_authunix();
871	if (err < 0)
872		goto out1;
873	err = register_shrinker(&rpc_cred_shrinker);
874	if (err < 0)
875		goto out2;
876	return 0;
877out2:
878	rpc_destroy_authunix();
879out1:
880	return err;
881}
882
883void rpcauth_remove_module(void)
884{
885	rpc_destroy_authunix();
886	unregister_shrinker(&rpc_cred_shrinker);
887}