1/*
2 * linux/net/sunrpc/auth.c
3 *
4 * Generic RPC client authentication API.
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
8
9#include <linux/types.h>
10#include <linux/sched.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/errno.h>
14#include <linux/hash.h>
15#include <linux/sunrpc/clnt.h>
16#include <linux/sunrpc/gss_api.h>
17#include <linux/spinlock.h>
18
19#ifdef RPC_DEBUG
20# define RPCDBG_FACILITY	RPCDBG_AUTH
21#endif
22
23#define RPC_CREDCACHE_DEFAULT_HASHBITS	(4)
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 DEFINE_SPINLOCK(rpc_authflavor_lock);
33static 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
39static LIST_HEAD(cred_unused);
40static unsigned long number_cred_unused;
41
42#define MAX_HASHTABLE_BITS (14)
43static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
44{
45	unsigned long num;
46	unsigned int nbits;
47	int ret;
48
49	if (!val)
50		goto out_inval;
51	ret = kstrtoul(val, 0, &num);
52	if (ret == -EINVAL)
53		goto out_inval;
54	nbits = fls(num);
55	if (num > (1U << nbits))
56		nbits++;
57	if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
58		goto out_inval;
59	*(unsigned int *)kp->arg = nbits;
60	return 0;
61out_inval:
62	return -EINVAL;
63}
64
65static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
66{
67	unsigned int nbits;
68
69	nbits = *(unsigned int *)kp->arg;
70	return sprintf(buffer, "%u", 1U << nbits);
71}
72
73#define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
74
75static struct kernel_param_ops param_ops_hashtbl_sz = {
76	.set = param_set_hashtbl_sz,
77	.get = param_get_hashtbl_sz,
78};
79
80module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
81MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
82
83static unsigned long auth_max_cred_cachesize = ULONG_MAX;
84module_param(auth_max_cred_cachesize, ulong, 0644);
85MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
86
87static u32
88pseudoflavor_to_flavor(u32 flavor) {
89	if (flavor > RPC_AUTH_MAXFLAVOR)
90		return RPC_AUTH_GSS;
91	return flavor;
92}
93
94int
95rpcauth_register(const struct rpc_authops *ops)
96{
97	rpc_authflavor_t flavor;
98	int ret = -EPERM;
99
100	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
101		return -EINVAL;
102	spin_lock(&rpc_authflavor_lock);
103	if (auth_flavors[flavor] == NULL) {
104		auth_flavors[flavor] = ops;
105		ret = 0;
106	}
107	spin_unlock(&rpc_authflavor_lock);
108	return ret;
109}
110EXPORT_SYMBOL_GPL(rpcauth_register);
111
112int
113rpcauth_unregister(const struct rpc_authops *ops)
114{
115	rpc_authflavor_t flavor;
116	int ret = -EPERM;
117
118	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
119		return -EINVAL;
120	spin_lock(&rpc_authflavor_lock);
121	if (auth_flavors[flavor] == ops) {
122		auth_flavors[flavor] = NULL;
123		ret = 0;
124	}
125	spin_unlock(&rpc_authflavor_lock);
126	return ret;
127}
128EXPORT_SYMBOL_GPL(rpcauth_unregister);
129
130/**
131 * rpcauth_get_pseudoflavor - check if security flavor is supported
132 * @flavor: a security flavor
133 * @info: a GSS mech OID, quality of protection, and service value
134 *
135 * Verifies that an appropriate kernel module is available or already loaded.
136 * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
137 * not supported locally.
138 */
139rpc_authflavor_t
140rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
141{
142	const struct rpc_authops *ops;
143	rpc_authflavor_t pseudoflavor;
144
145	ops = auth_flavors[flavor];
146	if (ops == NULL)
147		request_module("rpc-auth-%u", flavor);
148	spin_lock(&rpc_authflavor_lock);
149	ops = auth_flavors[flavor];
150	if (ops == NULL || !try_module_get(ops->owner)) {
151		spin_unlock(&rpc_authflavor_lock);
152		return RPC_AUTH_MAXFLAVOR;
153	}
154	spin_unlock(&rpc_authflavor_lock);
155
156	pseudoflavor = flavor;
157	if (ops->info2flavor != NULL)
158		pseudoflavor = ops->info2flavor(info);
159
160	module_put(ops->owner);
161	return pseudoflavor;
162}
163EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
164
165/**
166 * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
167 * @pseudoflavor: GSS pseudoflavor to match
168 * @info: rpcsec_gss_info structure to fill in
169 *
170 * Returns zero and fills in "info" if pseudoflavor matches a
171 * supported mechanism.
172 */
173int
174rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
175{
176	rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
177	const struct rpc_authops *ops;
178	int result;
179
180	if (flavor >= RPC_AUTH_MAXFLAVOR)
181		return -EINVAL;
182
183	ops = auth_flavors[flavor];
184	if (ops == NULL)
185		request_module("rpc-auth-%u", flavor);
186	spin_lock(&rpc_authflavor_lock);
187	ops = auth_flavors[flavor];
188	if (ops == NULL || !try_module_get(ops->owner)) {
189		spin_unlock(&rpc_authflavor_lock);
190		return -ENOENT;
191	}
192	spin_unlock(&rpc_authflavor_lock);
193
194	result = -ENOENT;
195	if (ops->flavor2info != NULL)
196		result = ops->flavor2info(pseudoflavor, info);
197
198	module_put(ops->owner);
199	return result;
200}
201EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
202
203/**
204 * rpcauth_list_flavors - discover registered flavors and pseudoflavors
205 * @array: array to fill in
206 * @size: size of "array"
207 *
208 * Returns the number of array items filled in, or a negative errno.
209 *
210 * The returned array is not sorted by any policy.  Callers should not
211 * rely on the order of the items in the returned array.
212 */
213int
214rpcauth_list_flavors(rpc_authflavor_t *array, int size)
215{
216	rpc_authflavor_t flavor;
217	int result = 0;
218
219	spin_lock(&rpc_authflavor_lock);
220	for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
221		const struct rpc_authops *ops = auth_flavors[flavor];
222		rpc_authflavor_t pseudos[4];
223		int i, len;
224
225		if (result >= size) {
226			result = -ENOMEM;
227			break;
228		}
229
230		if (ops == NULL)
231			continue;
232		if (ops->list_pseudoflavors == NULL) {
233			array[result++] = ops->au_flavor;
234			continue;
235		}
236		len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
237		if (len < 0) {
238			result = len;
239			break;
240		}
241		for (i = 0; i < len; i++) {
242			if (result >= size) {
243				result = -ENOMEM;
244				break;
245			}
246			array[result++] = pseudos[i];
247		}
248	}
249	spin_unlock(&rpc_authflavor_lock);
250
251	dprintk("RPC:       %s returns %d\n", __func__, result);
252	return result;
253}
254EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
255
256struct rpc_auth *
257rpcauth_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
258{
259	struct rpc_auth		*auth;
260	const struct rpc_authops *ops;
261	u32			flavor = pseudoflavor_to_flavor(args->pseudoflavor);
262
263	auth = ERR_PTR(-EINVAL);
264	if (flavor >= RPC_AUTH_MAXFLAVOR)
265		goto out;
266
267	if ((ops = auth_flavors[flavor]) == NULL)
268		request_module("rpc-auth-%u", flavor);
269	spin_lock(&rpc_authflavor_lock);
270	ops = auth_flavors[flavor];
271	if (ops == NULL || !try_module_get(ops->owner)) {
272		spin_unlock(&rpc_authflavor_lock);
273		goto out;
274	}
275	spin_unlock(&rpc_authflavor_lock);
276	auth = ops->create(args, clnt);
277	module_put(ops->owner);
278	if (IS_ERR(auth))
279		return auth;
280	if (clnt->cl_auth)
281		rpcauth_release(clnt->cl_auth);
282	clnt->cl_auth = auth;
283
284out:
285	return auth;
286}
287EXPORT_SYMBOL_GPL(rpcauth_create);
288
289void
290rpcauth_release(struct rpc_auth *auth)
291{
292	if (!atomic_dec_and_test(&auth->au_count))
293		return;
294	auth->au_ops->destroy(auth);
295}
296
297static DEFINE_SPINLOCK(rpc_credcache_lock);
298
299static void
300rpcauth_unhash_cred_locked(struct rpc_cred *cred)
301{
302	hlist_del_rcu(&cred->cr_hash);
303	smp_mb__before_atomic();
304	clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
305}
306
307static int
308rpcauth_unhash_cred(struct rpc_cred *cred)
309{
310	spinlock_t *cache_lock;
311	int ret;
312
313	cache_lock = &cred->cr_auth->au_credcache->lock;
314	spin_lock(cache_lock);
315	ret = atomic_read(&cred->cr_count) == 0;
316	if (ret)
317		rpcauth_unhash_cred_locked(cred);
318	spin_unlock(cache_lock);
319	return ret;
320}
321
322/*
323 * Initialize RPC credential cache
324 */
325int
326rpcauth_init_credcache(struct rpc_auth *auth)
327{
328	struct rpc_cred_cache *new;
329	unsigned int hashsize;
330
331	new = kmalloc(sizeof(*new), GFP_KERNEL);
332	if (!new)
333		goto out_nocache;
334	new->hashbits = auth_hashbits;
335	hashsize = 1U << new->hashbits;
336	new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
337	if (!new->hashtable)
338		goto out_nohashtbl;
339	spin_lock_init(&new->lock);
340	auth->au_credcache = new;
341	return 0;
342out_nohashtbl:
343	kfree(new);
344out_nocache:
345	return -ENOMEM;
346}
347EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
348
349/*
350 * Setup a credential key lifetime timeout notification
351 */
352int
353rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
354{
355	if (!cred->cr_auth->au_ops->key_timeout)
356		return 0;
357	return cred->cr_auth->au_ops->key_timeout(auth, cred);
358}
359EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
360
361bool
362rpcauth_cred_key_to_expire(struct rpc_cred *cred)
363{
364	if (!cred->cr_ops->crkey_to_expire)
365		return false;
366	return cred->cr_ops->crkey_to_expire(cred);
367}
368EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
369
370char *
371rpcauth_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}
377EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
378
379/*
380 * Destroy a list of credentials
381 */
382static inline
383void 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 */
398void
399rpcauth_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 */
430void
431rpcauth_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}
442EXPORT_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 */
450static long
451rpcauth_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
488static unsigned long
489rpcauth_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 */
505static unsigned long
506rpcauth_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
519static unsigned long
520rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
521
522{
523	return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
524}
525
526static void
527rpcauth_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 */
544struct rpc_cred *
545rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
546		int flags)
547{
548	LIST_HEAD(free);
549	struct rpc_cred_cache *cache = auth->au_credcache;
550	struct rpc_cred	*cred = NULL,
551			*entry, *new;
552	unsigned int nr;
553
554	nr = hash_long(from_kuid(&init_user_ns, acred->uid), cache->hashbits);
555
556	rcu_read_lock();
557	hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
558		if (!entry->cr_ops->crmatch(acred, entry, flags))
559			continue;
560		if (flags & RPCAUTH_LOOKUP_RCU) {
561			if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) &&
562			    !test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags))
563				cred = entry;
564			break;
565		}
566		spin_lock(&cache->lock);
567		if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
568			spin_unlock(&cache->lock);
569			continue;
570		}
571		cred = get_rpccred(entry);
572		spin_unlock(&cache->lock);
573		break;
574	}
575	rcu_read_unlock();
576
577	if (cred != NULL)
578		goto found;
579
580	if (flags & RPCAUTH_LOOKUP_RCU)
581		return ERR_PTR(-ECHILD);
582
583	new = auth->au_ops->crcreate(auth, acred, flags);
584	if (IS_ERR(new)) {
585		cred = new;
586		goto out;
587	}
588
589	spin_lock(&cache->lock);
590	hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
591		if (!entry->cr_ops->crmatch(acred, entry, flags))
592			continue;
593		cred = get_rpccred(entry);
594		break;
595	}
596	if (cred == NULL) {
597		cred = new;
598		set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
599		hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
600	} else
601		list_add_tail(&new->cr_lru, &free);
602	spin_unlock(&cache->lock);
603	rpcauth_cache_enforce_limit();
604found:
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);
615out:
616	return cred;
617}
618EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
619
620struct rpc_cred *
621rpcauth_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}
637EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
638
639void
640rpcauth_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#ifdef RPC_DEBUG
650	cred->cr_magic = RPCAUTH_CRED_MAGIC;
651#endif
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	if (req->rq_cred != NULL)
707		put_rpccred(req->rq_cred);
708	req->rq_cred = new;
709	return 0;
710}
711
712void
713put_rpccred(struct rpc_cred *cred)
714{
715	/* Fast path for unhashed credentials */
716	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
717		if (atomic_dec_and_test(&cred->cr_count))
718			cred->cr_ops->crdestroy(cred);
719		return;
720	}
721
722	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
723		return;
724	if (!list_empty(&cred->cr_lru)) {
725		number_cred_unused--;
726		list_del_init(&cred->cr_lru);
727	}
728	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
729		if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
730			cred->cr_expire = jiffies;
731			list_add_tail(&cred->cr_lru, &cred_unused);
732			number_cred_unused++;
733			goto out_nodestroy;
734		}
735		if (!rpcauth_unhash_cred(cred)) {
736			/* We were hashed and someone looked us up... */
737			goto out_nodestroy;
738		}
739	}
740	spin_unlock(&rpc_credcache_lock);
741	cred->cr_ops->crdestroy(cred);
742	return;
743out_nodestroy:
744	spin_unlock(&rpc_credcache_lock);
745}
746EXPORT_SYMBOL_GPL(put_rpccred);
747
748__be32 *
749rpcauth_marshcred(struct rpc_task *task, __be32 *p)
750{
751	struct rpc_cred	*cred = task->tk_rqstp->rq_cred;
752
753	dprintk("RPC: %5u marshaling %s cred %p\n",
754		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
755
756	return cred->cr_ops->crmarshal(task, p);
757}
758
759__be32 *
760rpcauth_checkverf(struct rpc_task *task, __be32 *p)
761{
762	struct rpc_cred	*cred = task->tk_rqstp->rq_cred;
763
764	dprintk("RPC: %5u validating %s cred %p\n",
765		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
766
767	return cred->cr_ops->crvalidate(task, p);
768}
769
770static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
771				   __be32 *data, void *obj)
772{
773	struct xdr_stream xdr;
774
775	xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
776	encode(rqstp, &xdr, obj);
777}
778
779int
780rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
781		__be32 *data, void *obj)
782{
783	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
784
785	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
786			task->tk_pid, cred->cr_ops->cr_name, cred);
787	if (cred->cr_ops->crwrap_req)
788		return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
789	/* By default, we encode the arguments normally. */
790	rpcauth_wrap_req_encode(encode, rqstp, data, obj);
791	return 0;
792}
793
794static int
795rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
796			  __be32 *data, void *obj)
797{
798	struct xdr_stream xdr;
799
800	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
801	return decode(rqstp, &xdr, obj);
802}
803
804int
805rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
806		__be32 *data, void *obj)
807{
808	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
809
810	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
811			task->tk_pid, cred->cr_ops->cr_name, cred);
812	if (cred->cr_ops->crunwrap_resp)
813		return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
814						   data, obj);
815	/* By default, we decode the arguments normally. */
816	return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
817}
818
819int
820rpcauth_refreshcred(struct rpc_task *task)
821{
822	struct rpc_cred	*cred;
823	int err;
824
825	cred = task->tk_rqstp->rq_cred;
826	if (cred == NULL) {
827		err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
828		if (err < 0)
829			goto out;
830		cred = task->tk_rqstp->rq_cred;
831	}
832	dprintk("RPC: %5u refreshing %s cred %p\n",
833		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
834
835	err = cred->cr_ops->crrefresh(task);
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	dprintk("RPC: %5u invalidating %s cred %p\n",
848		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
849	if (cred)
850		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
851}
852
853int
854rpcauth_uptodatecred(struct rpc_task *task)
855{
856	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
857
858	return cred == NULL ||
859		test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
860}
861
862static struct shrinker rpc_cred_shrinker = {
863	.count_objects = rpcauth_cache_shrink_count,
864	.scan_objects = rpcauth_cache_shrink_scan,
865	.seeks = DEFAULT_SEEKS,
866};
867
868int __init rpcauth_init_module(void)
869{
870	int err;
871
872	err = rpc_init_authunix();
873	if (err < 0)
874		goto out1;
875	err = rpc_init_generic_auth();
876	if (err < 0)
877		goto out2;
878	register_shrinker(&rpc_cred_shrinker);
879	return 0;
880out2:
881	rpc_destroy_authunix();
882out1:
883	return err;
884}
885
886void rpcauth_remove_module(void)
887{
888	rpc_destroy_authunix();
889	rpc_destroy_generic_auth();
890	unregister_shrinker(&rpc_cred_shrinker);
891}
892