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v6.8
  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	[RPC_AUTH_TLS]  = (const struct rpc_authops __force __rcu *)&authtls_ops,
 
 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};
 44
 45/*
 46 * Return the machine_cred pointer to be used whenever
 47 * the a generic machine credential is needed.
 48 */
 49const struct cred *rpc_machine_cred(void)
 50{
 51	return &machine_cred;
 52}
 53EXPORT_SYMBOL_GPL(rpc_machine_cred);
 54
 55#define MAX_HASHTABLE_BITS (14)
 56static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
 57{
 58	unsigned long num;
 59	unsigned int nbits;
 60	int ret;
 61
 62	if (!val)
 63		goto out_inval;
 64	ret = kstrtoul(val, 0, &num);
 65	if (ret)
 66		goto out_inval;
 67	nbits = fls(num - 1);
 
 
 68	if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
 69		goto out_inval;
 70	*(unsigned int *)kp->arg = nbits;
 71	return 0;
 72out_inval:
 73	return -EINVAL;
 74}
 75
 76static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
 77{
 78	unsigned int nbits;
 79
 80	nbits = *(unsigned int *)kp->arg;
 81	return sprintf(buffer, "%u\n", 1U << nbits);
 82}
 83
 84#define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
 85
 86static const struct kernel_param_ops param_ops_hashtbl_sz = {
 87	.set = param_set_hashtbl_sz,
 88	.get = param_get_hashtbl_sz,
 89};
 90
 91module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
 92MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
 93
 94static unsigned long auth_max_cred_cachesize = ULONG_MAX;
 95module_param(auth_max_cred_cachesize, ulong, 0644);
 96MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
 97
 98static u32
 99pseudoflavor_to_flavor(u32 flavor) {
100	if (flavor > RPC_AUTH_MAXFLAVOR)
101		return RPC_AUTH_GSS;
102	return flavor;
103}
104
105int
106rpcauth_register(const struct rpc_authops *ops)
107{
108	const struct rpc_authops *old;
109	rpc_authflavor_t flavor;
 
110
111	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
112		return -EINVAL;
113	old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], NULL, ops);
114	if (old == NULL || old == ops)
115		return 0;
116	return -EPERM;
 
 
 
117}
118EXPORT_SYMBOL_GPL(rpcauth_register);
119
120int
121rpcauth_unregister(const struct rpc_authops *ops)
122{
123	const struct rpc_authops *old;
124	rpc_authflavor_t flavor;
 
125
126	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
127		return -EINVAL;
128
129	old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], ops, NULL);
130	if (old == ops || old == NULL)
131		return 0;
132	return -EPERM;
 
 
133}
134EXPORT_SYMBOL_GPL(rpcauth_unregister);
135
136static const struct rpc_authops *
137rpcauth_get_authops(rpc_authflavor_t flavor)
138{
 
139	const struct rpc_authops *ops;
 
140
 
141	if (flavor >= RPC_AUTH_MAXFLAVOR)
142		return NULL;
143
144	rcu_read_lock();
145	ops = rcu_dereference(auth_flavors[flavor]);
146	if (ops == NULL) {
147		rcu_read_unlock();
148		request_module("rpc-auth-%u", flavor);
149		rcu_read_lock();
150		ops = rcu_dereference(auth_flavors[flavor]);
151		if (ops == NULL)
152			goto out;
 
153	}
154	if (!try_module_get(ops->owner))
155		ops = NULL;
156out:
157	rcu_read_unlock();
158	return ops;
159}
160
161static void
162rpcauth_put_authops(const struct rpc_authops *ops)
163{
164	module_put(ops->owner);
165}
166
167/**
168 * rpcauth_get_pseudoflavor - check if security flavor is supported
169 * @flavor: a security flavor
170 * @info: a GSS mech OID, quality of protection, and service value
171 *
172 * Verifies that an appropriate kernel module is available or already loaded.
173 * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
174 * not supported locally.
175 */
176rpc_authflavor_t
177rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
178{
179	const struct rpc_authops *ops = rpcauth_get_authops(flavor);
180	rpc_authflavor_t pseudoflavor;
181
182	if (!ops)
183		return RPC_AUTH_MAXFLAVOR;
184	pseudoflavor = flavor;
185	if (ops->info2flavor != NULL)
186		pseudoflavor = ops->info2flavor(info);
187
188	rpcauth_put_authops(ops);
189	return pseudoflavor;
190}
191EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
192
193/**
194 * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
195 * @pseudoflavor: GSS pseudoflavor to match
196 * @info: rpcsec_gss_info structure to fill in
197 *
198 * Returns zero and fills in "info" if pseudoflavor matches a
199 * supported mechanism.
200 */
201int
202rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
203{
204	rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
205	const struct rpc_authops *ops;
206	int result;
207
208	ops = rpcauth_get_authops(flavor);
209	if (ops == NULL)
210		return -ENOENT;
211
212	result = -ENOENT;
213	if (ops->flavor2info != NULL)
214		result = ops->flavor2info(pseudoflavor, info);
215
216	rpcauth_put_authops(ops);
217	return result;
218}
219EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
220
221struct rpc_auth *
222rpcauth_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
223{
224	struct rpc_auth	*auth = ERR_PTR(-EINVAL);
225	const struct rpc_authops *ops;
226	u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
227
228	ops = rpcauth_get_authops(flavor);
229	if (ops == NULL)
230		goto out;
231
232	auth = ops->create(args, clnt);
233
234	rpcauth_put_authops(ops);
235	if (IS_ERR(auth))
236		return auth;
237	if (clnt->cl_auth)
238		rpcauth_release(clnt->cl_auth);
239	clnt->cl_auth = auth;
240
241out:
242	return auth;
243}
244EXPORT_SYMBOL_GPL(rpcauth_create);
245
246void
247rpcauth_release(struct rpc_auth *auth)
248{
249	if (!refcount_dec_and_test(&auth->au_count))
250		return;
251	auth->au_ops->destroy(auth);
252}
253
254static DEFINE_SPINLOCK(rpc_credcache_lock);
255
256/*
257 * On success, the caller is responsible for freeing the reference
258 * held by the hashtable
259 */
260static bool
261rpcauth_unhash_cred_locked(struct rpc_cred *cred)
262{
263	if (!test_and_clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
264		return false;
265	hlist_del_rcu(&cred->cr_hash);
266	return true;
 
267}
268
269static bool
270rpcauth_unhash_cred(struct rpc_cred *cred)
271{
272	spinlock_t *cache_lock;
273	bool ret;
274
275	if (!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
276		return false;
277	cache_lock = &cred->cr_auth->au_credcache->lock;
278	spin_lock(cache_lock);
279	ret = rpcauth_unhash_cred_locked(cred);
 
 
280	spin_unlock(cache_lock);
281	return ret;
282}
283
284/*
285 * Initialize RPC credential cache
286 */
287int
288rpcauth_init_credcache(struct rpc_auth *auth)
289{
290	struct rpc_cred_cache *new;
291	unsigned int hashsize;
292
293	new = kmalloc(sizeof(*new), GFP_KERNEL);
294	if (!new)
295		goto out_nocache;
296	new->hashbits = auth_hashbits;
297	hashsize = 1U << new->hashbits;
298	new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
299	if (!new->hashtable)
300		goto out_nohashtbl;
301	spin_lock_init(&new->lock);
302	auth->au_credcache = new;
303	return 0;
304out_nohashtbl:
305	kfree(new);
306out_nocache:
307	return -ENOMEM;
308}
309EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
310
311char *
312rpcauth_stringify_acceptor(struct rpc_cred *cred)
313{
314	if (!cred->cr_ops->crstringify_acceptor)
315		return NULL;
316	return cred->cr_ops->crstringify_acceptor(cred);
317}
318EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
319
320/*
321 * Destroy a list of credentials
322 */
323static inline
324void rpcauth_destroy_credlist(struct list_head *head)
325{
326	struct rpc_cred *cred;
327
328	while (!list_empty(head)) {
329		cred = list_entry(head->next, struct rpc_cred, cr_lru);
330		list_del_init(&cred->cr_lru);
331		put_rpccred(cred);
332	}
333}
334
335static void
336rpcauth_lru_add_locked(struct rpc_cred *cred)
337{
338	if (!list_empty(&cred->cr_lru))
339		return;
340	number_cred_unused++;
341	list_add_tail(&cred->cr_lru, &cred_unused);
342}
343
344static void
345rpcauth_lru_add(struct rpc_cred *cred)
346{
347	if (!list_empty(&cred->cr_lru))
348		return;
349	spin_lock(&rpc_credcache_lock);
350	rpcauth_lru_add_locked(cred);
351	spin_unlock(&rpc_credcache_lock);
352}
353
354static void
355rpcauth_lru_remove_locked(struct rpc_cred *cred)
356{
357	if (list_empty(&cred->cr_lru))
358		return;
359	number_cred_unused--;
360	list_del_init(&cred->cr_lru);
361}
362
363static void
364rpcauth_lru_remove(struct rpc_cred *cred)
365{
366	if (list_empty(&cred->cr_lru))
367		return;
368	spin_lock(&rpc_credcache_lock);
369	rpcauth_lru_remove_locked(cred);
370	spin_unlock(&rpc_credcache_lock);
371}
372
373/*
374 * Clear the RPC credential cache, and delete those credentials
375 * that are not referenced.
376 */
377void
378rpcauth_clear_credcache(struct rpc_cred_cache *cache)
379{
380	LIST_HEAD(free);
381	struct hlist_head *head;
382	struct rpc_cred	*cred;
383	unsigned int hashsize = 1U << cache->hashbits;
384	int		i;
385
386	spin_lock(&rpc_credcache_lock);
387	spin_lock(&cache->lock);
388	for (i = 0; i < hashsize; i++) {
389		head = &cache->hashtable[i];
390		while (!hlist_empty(head)) {
391			cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
392			rpcauth_unhash_cred_locked(cred);
393			/* Note: We now hold a reference to cred */
394			rpcauth_lru_remove_locked(cred);
 
 
395			list_add_tail(&cred->cr_lru, &free);
 
396		}
397	}
398	spin_unlock(&cache->lock);
399	spin_unlock(&rpc_credcache_lock);
400	rpcauth_destroy_credlist(&free);
401}
402
403/*
404 * Destroy the RPC credential cache
405 */
406void
407rpcauth_destroy_credcache(struct rpc_auth *auth)
408{
409	struct rpc_cred_cache *cache = auth->au_credcache;
410
411	if (cache) {
412		auth->au_credcache = NULL;
413		rpcauth_clear_credcache(cache);
414		kfree(cache->hashtable);
415		kfree(cache);
416	}
417}
418EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
419
420
421#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
422
423/*
424 * Remove stale credentials. Avoid sleeping inside the loop.
425 */
426static long
427rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
428{
 
429	struct rpc_cred *cred, *next;
430	unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
431	long freed = 0;
432
433	list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
434
435		if (nr_to_scan-- == 0)
436			break;
437		if (refcount_read(&cred->cr_count) > 1) {
438			rpcauth_lru_remove_locked(cred);
439			continue;
440		}
441		/*
442		 * Enforce a 60 second garbage collection moratorium
443		 * Note that the cred_unused list must be time-ordered.
444		 */
445		if (time_in_range(cred->cr_expire, expired, jiffies))
446			continue;
447		if (!rpcauth_unhash_cred(cred))
 
 
 
 
448			continue;
449
450		rpcauth_lru_remove_locked(cred);
451		freed++;
452		list_add_tail(&cred->cr_lru, free);
 
 
 
 
 
453	}
454	return freed ? freed : SHRINK_STOP;
455}
456
457static unsigned long
458rpcauth_cache_do_shrink(int nr_to_scan)
459{
460	LIST_HEAD(free);
461	unsigned long freed;
462
463	spin_lock(&rpc_credcache_lock);
464	freed = rpcauth_prune_expired(&free, nr_to_scan);
465	spin_unlock(&rpc_credcache_lock);
466	rpcauth_destroy_credlist(&free);
467
468	return freed;
469}
470
471/*
472 * Run memory cache shrinker.
473 */
474static unsigned long
475rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
476
477{
478	if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
479		return SHRINK_STOP;
 
 
480
481	/* nothing left, don't come back */
 
482	if (list_empty(&cred_unused))
483		return SHRINK_STOP;
484
485	return rpcauth_cache_do_shrink(sc->nr_to_scan);
486}
487
488static unsigned long
489rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
490
491{
492	return number_cred_unused * sysctl_vfs_cache_pressure / 100;
493}
494
495static void
496rpcauth_cache_enforce_limit(void)
497{
498	unsigned long diff;
499	unsigned int nr_to_scan;
500
501	if (number_cred_unused <= auth_max_cred_cachesize)
502		return;
503	diff = number_cred_unused - auth_max_cred_cachesize;
504	nr_to_scan = 100;
505	if (diff < nr_to_scan)
506		nr_to_scan = diff;
507	rpcauth_cache_do_shrink(nr_to_scan);
508}
509
510/*
511 * Look up a process' credentials in the authentication cache
512 */
513struct rpc_cred *
514rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
515		int flags, gfp_t gfp)
516{
517	LIST_HEAD(free);
518	struct rpc_cred_cache *cache = auth->au_credcache;
 
519	struct rpc_cred	*cred = NULL,
520			*entry, *new;
521	unsigned int nr;
522
523	nr = auth->au_ops->hash_cred(acred, cache->hashbits);
524
525	rcu_read_lock();
526	hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
527		if (!entry->cr_ops->crmatch(acred, entry, flags))
528			continue;
 
 
 
 
 
529		cred = get_rpccred(entry);
530		if (cred)
531			break;
532	}
533	rcu_read_unlock();
534
535	if (cred != NULL)
536		goto found;
537
538	new = auth->au_ops->crcreate(auth, acred, flags, gfp);
539	if (IS_ERR(new)) {
540		cred = new;
541		goto out;
542	}
543
544	spin_lock(&cache->lock);
545	hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
546		if (!entry->cr_ops->crmatch(acred, entry, flags))
547			continue;
548		cred = get_rpccred(entry);
549		if (cred)
550			break;
551	}
552	if (cred == NULL) {
553		cred = new;
554		set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
555		refcount_inc(&cred->cr_count);
556		hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
557	} else
558		list_add_tail(&new->cr_lru, &free);
559	spin_unlock(&cache->lock);
560	rpcauth_cache_enforce_limit();
561found:
562	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
563	    cred->cr_ops->cr_init != NULL &&
564	    !(flags & RPCAUTH_LOOKUP_NEW)) {
565		int res = cred->cr_ops->cr_init(auth, cred);
566		if (res < 0) {
567			put_rpccred(cred);
568			cred = ERR_PTR(res);
569		}
570	}
571	rpcauth_destroy_credlist(&free);
572out:
573	return cred;
574}
575EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
576
577struct rpc_cred *
578rpcauth_lookupcred(struct rpc_auth *auth, int flags)
579{
580	struct auth_cred acred;
581	struct rpc_cred *ret;
582	const struct cred *cred = current_cred();
583
 
 
 
584	memset(&acred, 0, sizeof(acred));
585	acred.cred = cred;
 
 
 
586	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
 
587	return ret;
588}
589EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
590
591void
592rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
593		  struct rpc_auth *auth, const struct rpc_credops *ops)
594{
595	INIT_HLIST_NODE(&cred->cr_hash);
596	INIT_LIST_HEAD(&cred->cr_lru);
597	refcount_set(&cred->cr_count, 1);
598	cred->cr_auth = auth;
599	cred->cr_flags = 0;
600	cred->cr_ops = ops;
601	cred->cr_expire = jiffies;
602	cred->cr_cred = get_cred(acred->cred);
 
 
 
603}
604EXPORT_SYMBOL_GPL(rpcauth_init_cred);
605
606static struct rpc_cred *
607rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
608{
609	struct rpc_auth *auth = task->tk_client->cl_auth;
610	struct auth_cred acred = {
611		.cred = get_task_cred(&init_task),
612	};
613	struct rpc_cred *ret;
614
615	if (RPC_IS_ASYNC(task))
616		lookupflags |= RPCAUTH_LOOKUP_ASYNC;
617	ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
618	put_cred(acred.cred);
619	return ret;
620}
 
621
622static struct rpc_cred *
623rpcauth_bind_machine_cred(struct rpc_task *task, int lookupflags)
624{
625	struct rpc_auth *auth = task->tk_client->cl_auth;
626	struct auth_cred acred = {
627		.principal = task->tk_client->cl_principal,
628		.cred = init_task.cred,
629	};
630
631	if (!acred.principal)
632		return NULL;
633	if (RPC_IS_ASYNC(task))
634		lookupflags |= RPCAUTH_LOOKUP_ASYNC;
635	return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
636}
637
638static struct rpc_cred *
639rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
640{
641	struct rpc_auth *auth = task->tk_client->cl_auth;
642
 
 
643	return rpcauth_lookupcred(auth, lookupflags);
644}
645
646static int
647rpcauth_bindcred(struct rpc_task *task, const struct cred *cred, int flags)
648{
649	struct rpc_rqst *req = task->tk_rqstp;
650	struct rpc_cred *new = NULL;
651	int lookupflags = 0;
652	struct rpc_auth *auth = task->tk_client->cl_auth;
653	struct auth_cred acred = {
654		.cred = cred,
655	};
656
657	if (flags & RPC_TASK_ASYNC)
658		lookupflags |= RPCAUTH_LOOKUP_NEW | RPCAUTH_LOOKUP_ASYNC;
659	if (task->tk_op_cred)
660		/* Task must use exactly this rpc_cred */
661		new = get_rpccred(task->tk_op_cred);
662	else if (cred != NULL && cred != &machine_cred)
663		new = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
664	else if (cred == &machine_cred)
665		new = rpcauth_bind_machine_cred(task, lookupflags);
666
667	/* If machine cred couldn't be bound, try a root cred */
668	if (new)
669		;
670	else if (cred == &machine_cred)
671		new = rpcauth_bind_root_cred(task, lookupflags);
672	else if (flags & RPC_TASK_NULLCREDS)
673		new = authnull_ops.lookup_cred(NULL, NULL, 0);
674	else
675		new = rpcauth_bind_new_cred(task, lookupflags);
676	if (IS_ERR(new))
677		return PTR_ERR(new);
678	put_rpccred(req->rq_cred);
 
679	req->rq_cred = new;
680	return 0;
681}
682
683void
684put_rpccred(struct rpc_cred *cred)
685{
686	if (cred == NULL)
 
 
 
687		return;
688	rcu_read_lock();
689	if (refcount_dec_and_test(&cred->cr_count))
690		goto destroy;
691	if (refcount_read(&cred->cr_count) != 1 ||
692	    !test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
693		goto out;
694	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
695		cred->cr_expire = jiffies;
696		rpcauth_lru_add(cred);
697		/* Race breaker */
698		if (unlikely(!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags)))
699			rpcauth_lru_remove(cred);
700	} else if (rpcauth_unhash_cred(cred)) {
701		rpcauth_lru_remove(cred);
702		if (refcount_dec_and_test(&cred->cr_count))
703			goto destroy;
704	}
705out:
706	rcu_read_unlock();
707	return;
708destroy:
709	rcu_read_unlock();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
710	cred->cr_ops->crdestroy(cred);
 
 
 
711}
712EXPORT_SYMBOL_GPL(put_rpccred);
713
714/**
715 * rpcauth_marshcred - Append RPC credential to end of @xdr
716 * @task: controlling RPC task
717 * @xdr: xdr_stream containing initial portion of RPC Call header
718 *
719 * On success, an appropriate verifier is added to @xdr, @xdr is
720 * updated to point past the verifier, and zero is returned.
721 * Otherwise, @xdr is in an undefined state and a negative errno
722 * is returned.
723 */
724int rpcauth_marshcred(struct rpc_task *task, struct xdr_stream *xdr)
725{
726	const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
727
728	return ops->crmarshal(task, xdr);
729}
730
731/**
732 * rpcauth_wrap_req_encode - XDR encode the RPC procedure
733 * @task: controlling RPC task
734 * @xdr: stream where on-the-wire bytes are to be marshalled
735 *
736 * On success, @xdr contains the encoded and wrapped message.
737 * Otherwise, @xdr is in an undefined state.
738 */
739int rpcauth_wrap_req_encode(struct rpc_task *task, struct xdr_stream *xdr)
740{
741	kxdreproc_t encode = task->tk_msg.rpc_proc->p_encode;
742
743	encode(task->tk_rqstp, xdr, task->tk_msg.rpc_argp);
744	return 0;
745}
746EXPORT_SYMBOL_GPL(rpcauth_wrap_req_encode);
747
748/**
749 * rpcauth_wrap_req - XDR encode and wrap the RPC procedure
750 * @task: controlling RPC task
751 * @xdr: stream where on-the-wire bytes are to be marshalled
752 *
753 * On success, @xdr contains the encoded and wrapped message,
754 * and zero is returned. Otherwise, @xdr is in an undefined
755 * state and a negative errno is returned.
756 */
757int rpcauth_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
758{
759	const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
760
761	return ops->crwrap_req(task, xdr);
 
 
 
762}
763
764/**
765 * rpcauth_checkverf - Validate verifier in RPC Reply header
766 * @task: controlling RPC task
767 * @xdr: xdr_stream containing RPC Reply header
768 *
769 * Return values:
770 *   %0: Verifier is valid. @xdr now points past the verifier.
771 *   %-EIO: Verifier is corrupted or message ended early.
772 *   %-EACCES: Verifier is intact but not valid.
773 *   %-EPROTONOSUPPORT: Server does not support the requested auth type.
774 *
775 * When a negative errno is returned, @xdr is left in an undefined
776 * state.
777 */
778int
779rpcauth_checkverf(struct rpc_task *task, struct xdr_stream *xdr)
780{
781	const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
782
783	return ops->crvalidate(task, xdr);
 
784}
785
786/**
787 * rpcauth_unwrap_resp_decode - Invoke XDR decode function
788 * @task: controlling RPC task
789 * @xdr: stream where the Reply message resides
790 *
791 * Returns zero on success; otherwise a negative errno is returned.
792 */
793int
794rpcauth_unwrap_resp_decode(struct rpc_task *task, struct xdr_stream *xdr)
 
795{
796	kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
797
798	return decode(task->tk_rqstp, xdr, task->tk_msg.rpc_resp);
 
 
 
 
 
 
799}
800EXPORT_SYMBOL_GPL(rpcauth_unwrap_resp_decode);
801
802/**
803 * rpcauth_unwrap_resp - Invoke unwrap and decode function for the cred
804 * @task: controlling RPC task
805 * @xdr: stream where the Reply message resides
806 *
807 * Returns zero on success; otherwise a negative errno is returned.
808 */
809int
810rpcauth_unwrap_resp(struct rpc_task *task, struct xdr_stream *xdr)
811{
812	const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
813
814	return ops->crunwrap_resp(task, xdr);
 
815}
816
817bool
818rpcauth_xmit_need_reencode(struct rpc_task *task)
 
819{
820	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
821
822	if (!cred || !cred->cr_ops->crneed_reencode)
823		return false;
824	return cred->cr_ops->crneed_reencode(task);
 
 
 
 
825}
826
827int
828rpcauth_refreshcred(struct rpc_task *task)
829{
830	struct rpc_cred	*cred;
831	int err;
832
833	cred = task->tk_rqstp->rq_cred;
834	if (cred == NULL) {
835		err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
836		if (err < 0)
837			goto out;
838		cred = task->tk_rqstp->rq_cred;
839	}
 
 
840
841	err = cred->cr_ops->crrefresh(task);
842out:
843	if (err < 0)
844		task->tk_status = err;
845	return err;
846}
847
848void
849rpcauth_invalcred(struct rpc_task *task)
850{
851	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
852
 
 
853	if (cred)
854		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
855}
856
857int
858rpcauth_uptodatecred(struct rpc_task *task)
859{
860	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
861
862	return cred == NULL ||
863		test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
864}
865
866static struct shrinker *rpc_cred_shrinker;
 
 
 
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	rpc_cred_shrinker = shrinker_alloc(0, "sunrpc_cred");
876	if (!rpc_cred_shrinker) {
877		err = -ENOMEM;
878		goto out2;
879	}
880
881	rpc_cred_shrinker->count_objects = rpcauth_cache_shrink_count;
882	rpc_cred_shrinker->scan_objects = rpcauth_cache_shrink_scan;
883
884	shrinker_register(rpc_cred_shrinker);
885
886	return 0;
887out2:
888	rpc_destroy_authunix();
889out1:
890	return err;
891}
892
893void rpcauth_remove_module(void)
894{
895	rpc_destroy_authunix();
896	shrinker_free(rpc_cred_shrinker);
 
897}
v3.1
 
  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/spinlock.h>
 17
 18#ifdef RPC_DEBUG
 19# define RPCDBG_FACILITY	RPCDBG_AUTH
 20#endif
 21
 22#define RPC_CREDCACHE_DEFAULT_HASHBITS	(4)
 23struct rpc_cred_cache {
 24	struct hlist_head	*hashtable;
 25	unsigned int		hashbits;
 26	spinlock_t		lock;
 27};
 28
 29static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
 30
 31static DEFINE_SPINLOCK(rpc_authflavor_lock);
 32static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
 33	&authnull_ops,		/* AUTH_NULL */
 34	&authunix_ops,		/* AUTH_UNIX */
 35	NULL,			/* others can be loadable modules */
 36};
 37
 38static LIST_HEAD(cred_unused);
 39static unsigned long number_cred_unused;
 40
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 41#define MAX_HASHTABLE_BITS (14)
 42static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
 43{
 44	unsigned long num;
 45	unsigned int nbits;
 46	int ret;
 47
 48	if (!val)
 49		goto out_inval;
 50	ret = strict_strtoul(val, 0, &num);
 51	if (ret == -EINVAL)
 52		goto out_inval;
 53	nbits = fls(num);
 54	if (num > (1U << nbits))
 55		nbits++;
 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 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 u32
 83pseudoflavor_to_flavor(u32 flavor) {
 84	if (flavor >= RPC_AUTH_MAXFLAVOR)
 85		return RPC_AUTH_GSS;
 86	return flavor;
 87}
 88
 89int
 90rpcauth_register(const struct rpc_authops *ops)
 91{
 
 92	rpc_authflavor_t flavor;
 93	int ret = -EPERM;
 94
 95	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
 96		return -EINVAL;
 97	spin_lock(&rpc_authflavor_lock);
 98	if (auth_flavors[flavor] == NULL) {
 99		auth_flavors[flavor] = ops;
100		ret = 0;
101	}
102	spin_unlock(&rpc_authflavor_lock);
103	return ret;
104}
105EXPORT_SYMBOL_GPL(rpcauth_register);
106
107int
108rpcauth_unregister(const struct rpc_authops *ops)
109{
 
110	rpc_authflavor_t flavor;
111	int ret = -EPERM;
112
113	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
114		return -EINVAL;
115	spin_lock(&rpc_authflavor_lock);
116	if (auth_flavors[flavor] == ops) {
117		auth_flavors[flavor] = NULL;
118		ret = 0;
119	}
120	spin_unlock(&rpc_authflavor_lock);
121	return ret;
122}
123EXPORT_SYMBOL_GPL(rpcauth_unregister);
124
125struct rpc_auth *
126rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
127{
128	struct rpc_auth		*auth;
129	const struct rpc_authops *ops;
130	u32			flavor = pseudoflavor_to_flavor(pseudoflavor);
131
132	auth = ERR_PTR(-EINVAL);
133	if (flavor >= RPC_AUTH_MAXFLAVOR)
134		goto out;
135
136	if ((ops = auth_flavors[flavor]) == NULL)
 
 
 
137		request_module("rpc-auth-%u", flavor);
138	spin_lock(&rpc_authflavor_lock);
139	ops = auth_flavors[flavor];
140	if (ops == NULL || !try_module_get(ops->owner)) {
141		spin_unlock(&rpc_authflavor_lock);
142		goto out;
143	}
144	spin_unlock(&rpc_authflavor_lock);
145	auth = ops->create(clnt, pseudoflavor);
 
 
 
 
 
 
 
 
146	module_put(ops->owner);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
147	if (IS_ERR(auth))
148		return auth;
149	if (clnt->cl_auth)
150		rpcauth_release(clnt->cl_auth);
151	clnt->cl_auth = auth;
152
153out:
154	return auth;
155}
156EXPORT_SYMBOL_GPL(rpcauth_create);
157
158void
159rpcauth_release(struct rpc_auth *auth)
160{
161	if (!atomic_dec_and_test(&auth->au_count))
162		return;
163	auth->au_ops->destroy(auth);
164}
165
166static DEFINE_SPINLOCK(rpc_credcache_lock);
167
168static void
 
 
 
 
169rpcauth_unhash_cred_locked(struct rpc_cred *cred)
170{
 
 
171	hlist_del_rcu(&cred->cr_hash);
172	smp_mb__before_clear_bit();
173	clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
174}
175
176static int
177rpcauth_unhash_cred(struct rpc_cred *cred)
178{
179	spinlock_t *cache_lock;
180	int ret;
181
 
 
182	cache_lock = &cred->cr_auth->au_credcache->lock;
183	spin_lock(cache_lock);
184	ret = atomic_read(&cred->cr_count) == 0;
185	if (ret)
186		rpcauth_unhash_cred_locked(cred);
187	spin_unlock(cache_lock);
188	return ret;
189}
190
191/*
192 * Initialize RPC credential cache
193 */
194int
195rpcauth_init_credcache(struct rpc_auth *auth)
196{
197	struct rpc_cred_cache *new;
198	unsigned int hashsize;
199
200	new = kmalloc(sizeof(*new), GFP_KERNEL);
201	if (!new)
202		goto out_nocache;
203	new->hashbits = auth_hashbits;
204	hashsize = 1U << new->hashbits;
205	new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
206	if (!new->hashtable)
207		goto out_nohashtbl;
208	spin_lock_init(&new->lock);
209	auth->au_credcache = new;
210	return 0;
211out_nohashtbl:
212	kfree(new);
213out_nocache:
214	return -ENOMEM;
215}
216EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
217
 
 
 
 
 
 
 
 
 
218/*
219 * Destroy a list of credentials
220 */
221static inline
222void rpcauth_destroy_credlist(struct list_head *head)
223{
224	struct rpc_cred *cred;
225
226	while (!list_empty(head)) {
227		cred = list_entry(head->next, struct rpc_cred, cr_lru);
228		list_del_init(&cred->cr_lru);
229		put_rpccred(cred);
230	}
231}
232
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
233/*
234 * Clear the RPC credential cache, and delete those credentials
235 * that are not referenced.
236 */
237void
238rpcauth_clear_credcache(struct rpc_cred_cache *cache)
239{
240	LIST_HEAD(free);
241	struct hlist_head *head;
242	struct rpc_cred	*cred;
243	unsigned int hashsize = 1U << cache->hashbits;
244	int		i;
245
246	spin_lock(&rpc_credcache_lock);
247	spin_lock(&cache->lock);
248	for (i = 0; i < hashsize; i++) {
249		head = &cache->hashtable[i];
250		while (!hlist_empty(head)) {
251			cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
252			get_rpccred(cred);
253			if (!list_empty(&cred->cr_lru)) {
254				list_del(&cred->cr_lru);
255				number_cred_unused--;
256			}
257			list_add_tail(&cred->cr_lru, &free);
258			rpcauth_unhash_cred_locked(cred);
259		}
260	}
261	spin_unlock(&cache->lock);
262	spin_unlock(&rpc_credcache_lock);
263	rpcauth_destroy_credlist(&free);
264}
265
266/*
267 * Destroy the RPC credential cache
268 */
269void
270rpcauth_destroy_credcache(struct rpc_auth *auth)
271{
272	struct rpc_cred_cache *cache = auth->au_credcache;
273
274	if (cache) {
275		auth->au_credcache = NULL;
276		rpcauth_clear_credcache(cache);
277		kfree(cache->hashtable);
278		kfree(cache);
279	}
280}
281EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
282
283
284#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
285
286/*
287 * Remove stale credentials. Avoid sleeping inside the loop.
288 */
289static int
290rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
291{
292	spinlock_t *cache_lock;
293	struct rpc_cred *cred, *next;
294	unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
 
295
296	list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
297
298		if (nr_to_scan-- == 0)
299			break;
 
 
 
 
300		/*
301		 * Enforce a 60 second garbage collection moratorium
302		 * Note that the cred_unused list must be time-ordered.
303		 */
304		if (time_in_range(cred->cr_expire, expired, jiffies) &&
305		    test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
306			return 0;
307
308		list_del_init(&cred->cr_lru);
309		number_cred_unused--;
310		if (atomic_read(&cred->cr_count) != 0)
311			continue;
312
313		cache_lock = &cred->cr_auth->au_credcache->lock;
314		spin_lock(cache_lock);
315		if (atomic_read(&cred->cr_count) == 0) {
316			get_rpccred(cred);
317			list_add_tail(&cred->cr_lru, free);
318			rpcauth_unhash_cred_locked(cred);
319		}
320		spin_unlock(cache_lock);
321	}
322	return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
323}
324
325/*
326 * Run memory cache shrinker.
327 */
328static int
329rpcauth_cache_shrinker(struct shrinker *shrink, struct shrink_control *sc)
 
330{
331	LIST_HEAD(free);
332	int res;
333	int nr_to_scan = sc->nr_to_scan;
334	gfp_t gfp_mask = sc->gfp_mask;
335
336	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
337		return (nr_to_scan == 0) ? 0 : -1;
338	if (list_empty(&cred_unused))
339		return 0;
340	spin_lock(&rpc_credcache_lock);
341	res = rpcauth_prune_expired(&free, nr_to_scan);
342	spin_unlock(&rpc_credcache_lock);
343	rpcauth_destroy_credlist(&free);
344	return res;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
345}
346
347/*
348 * Look up a process' credentials in the authentication cache
349 */
350struct rpc_cred *
351rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
352		int flags)
353{
354	LIST_HEAD(free);
355	struct rpc_cred_cache *cache = auth->au_credcache;
356	struct hlist_node *pos;
357	struct rpc_cred	*cred = NULL,
358			*entry, *new;
359	unsigned int nr;
360
361	nr = hash_long(acred->uid, cache->hashbits);
362
363	rcu_read_lock();
364	hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
365		if (!entry->cr_ops->crmatch(acred, entry, flags))
366			continue;
367		spin_lock(&cache->lock);
368		if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
369			spin_unlock(&cache->lock);
370			continue;
371		}
372		cred = get_rpccred(entry);
373		spin_unlock(&cache->lock);
374		break;
375	}
376	rcu_read_unlock();
377
378	if (cred != NULL)
379		goto found;
380
381	new = auth->au_ops->crcreate(auth, acred, flags);
382	if (IS_ERR(new)) {
383		cred = new;
384		goto out;
385	}
386
387	spin_lock(&cache->lock);
388	hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
389		if (!entry->cr_ops->crmatch(acred, entry, flags))
390			continue;
391		cred = get_rpccred(entry);
392		break;
 
393	}
394	if (cred == NULL) {
395		cred = new;
396		set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
 
397		hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
398	} else
399		list_add_tail(&new->cr_lru, &free);
400	spin_unlock(&cache->lock);
 
401found:
402	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
403	    cred->cr_ops->cr_init != NULL &&
404	    !(flags & RPCAUTH_LOOKUP_NEW)) {
405		int res = cred->cr_ops->cr_init(auth, cred);
406		if (res < 0) {
407			put_rpccred(cred);
408			cred = ERR_PTR(res);
409		}
410	}
411	rpcauth_destroy_credlist(&free);
412out:
413	return cred;
414}
415EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
416
417struct rpc_cred *
418rpcauth_lookupcred(struct rpc_auth *auth, int flags)
419{
420	struct auth_cred acred;
421	struct rpc_cred *ret;
422	const struct cred *cred = current_cred();
423
424	dprintk("RPC:       looking up %s cred\n",
425		auth->au_ops->au_name);
426
427	memset(&acred, 0, sizeof(acred));
428	acred.uid = cred->fsuid;
429	acred.gid = cred->fsgid;
430	acred.group_info = get_group_info(((struct cred *)cred)->group_info);
431
432	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
433	put_group_info(acred.group_info);
434	return ret;
435}
 
436
437void
438rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
439		  struct rpc_auth *auth, const struct rpc_credops *ops)
440{
441	INIT_HLIST_NODE(&cred->cr_hash);
442	INIT_LIST_HEAD(&cred->cr_lru);
443	atomic_set(&cred->cr_count, 1);
444	cred->cr_auth = auth;
 
445	cred->cr_ops = ops;
446	cred->cr_expire = jiffies;
447#ifdef RPC_DEBUG
448	cred->cr_magic = RPCAUTH_CRED_MAGIC;
449#endif
450	cred->cr_uid = acred->uid;
451}
452EXPORT_SYMBOL_GPL(rpcauth_init_cred);
453
454struct rpc_cred *
455rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
456{
457	dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
458			cred->cr_auth->au_ops->au_name, cred);
459	return get_rpccred(cred);
 
 
 
 
 
 
 
 
460}
461EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
462
463static struct rpc_cred *
464rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
465{
466	struct rpc_auth *auth = task->tk_client->cl_auth;
467	struct auth_cred acred = {
468		.uid = 0,
469		.gid = 0,
470	};
471
472	dprintk("RPC: %5u looking up %s cred\n",
473		task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
 
 
474	return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
475}
476
477static struct rpc_cred *
478rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
479{
480	struct rpc_auth *auth = task->tk_client->cl_auth;
481
482	dprintk("RPC: %5u looking up %s cred\n",
483		task->tk_pid, auth->au_ops->au_name);
484	return rpcauth_lookupcred(auth, lookupflags);
485}
486
487static int
488rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
489{
490	struct rpc_rqst *req = task->tk_rqstp;
491	struct rpc_cred *new;
492	int lookupflags = 0;
 
 
 
 
493
494	if (flags & RPC_TASK_ASYNC)
495		lookupflags |= RPCAUTH_LOOKUP_NEW;
496	if (cred != NULL)
497		new = cred->cr_ops->crbind(task, cred, lookupflags);
498	else if (flags & RPC_TASK_ROOTCREDS)
 
 
 
 
 
 
 
 
 
499		new = rpcauth_bind_root_cred(task, lookupflags);
 
 
500	else
501		new = rpcauth_bind_new_cred(task, lookupflags);
502	if (IS_ERR(new))
503		return PTR_ERR(new);
504	if (req->rq_cred != NULL)
505		put_rpccred(req->rq_cred);
506	req->rq_cred = new;
507	return 0;
508}
509
510void
511put_rpccred(struct rpc_cred *cred)
512{
513	/* Fast path for unhashed credentials */
514	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
515		if (atomic_dec_and_test(&cred->cr_count))
516			cred->cr_ops->crdestroy(cred);
517		return;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
518	}
519
520	if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
521		return;
522	if (!list_empty(&cred->cr_lru)) {
523		number_cred_unused--;
524		list_del_init(&cred->cr_lru);
525	}
526	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
527		if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
528			cred->cr_expire = jiffies;
529			list_add_tail(&cred->cr_lru, &cred_unused);
530			number_cred_unused++;
531			goto out_nodestroy;
532		}
533		if (!rpcauth_unhash_cred(cred)) {
534			/* We were hashed and someone looked us up... */
535			goto out_nodestroy;
536		}
537	}
538	spin_unlock(&rpc_credcache_lock);
539	cred->cr_ops->crdestroy(cred);
540	return;
541out_nodestroy:
542	spin_unlock(&rpc_credcache_lock);
543}
544EXPORT_SYMBOL_GPL(put_rpccred);
545
546__be32 *
547rpcauth_marshcred(struct rpc_task *task, __be32 *p)
 
 
 
 
 
 
 
 
 
548{
549	struct rpc_cred	*cred = task->tk_rqstp->rq_cred;
 
 
 
550
551	dprintk("RPC: %5u marshaling %s cred %p\n",
552		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
 
 
 
 
 
 
 
 
 
553
554	return cred->cr_ops->crmarshal(task, p);
 
555}
 
556
557__be32 *
558rpcauth_checkverf(struct rpc_task *task, __be32 *p)
 
 
 
 
 
 
 
 
559{
560	struct rpc_cred	*cred = task->tk_rqstp->rq_cred;
561
562	dprintk("RPC: %5u validating %s cred %p\n",
563		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
564
565	return cred->cr_ops->crvalidate(task, p);
566}
567
568static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
569				   __be32 *data, void *obj)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
570{
571	struct xdr_stream xdr;
572
573	xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
574	encode(rqstp, &xdr, obj);
575}
576
 
 
 
 
 
 
 
577int
578rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
579		__be32 *data, void *obj)
580{
581	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
582
583	dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
584			task->tk_pid, cred->cr_ops->cr_name, cred);
585	if (cred->cr_ops->crwrap_req)
586		return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
587	/* By default, we encode the arguments normally. */
588	rpcauth_wrap_req_encode(encode, rqstp, data, obj);
589	return 0;
590}
 
591
592static int
593rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
594			  __be32 *data, void *obj)
 
 
 
 
 
 
595{
596	struct xdr_stream xdr;
597
598	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
599	return decode(rqstp, &xdr, obj);
600}
601
602int
603rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
604		__be32 *data, void *obj)
605{
606	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
607
608	dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
609			task->tk_pid, cred->cr_ops->cr_name, cred);
610	if (cred->cr_ops->crunwrap_resp)
611		return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
612						   data, obj);
613	/* By default, we decode the arguments normally. */
614	return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
615}
616
617int
618rpcauth_refreshcred(struct rpc_task *task)
619{
620	struct rpc_cred	*cred;
621	int err;
622
623	cred = task->tk_rqstp->rq_cred;
624	if (cred == NULL) {
625		err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
626		if (err < 0)
627			goto out;
628		cred = task->tk_rqstp->rq_cred;
629	}
630	dprintk("RPC: %5u refreshing %s cred %p\n",
631		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
632
633	err = cred->cr_ops->crrefresh(task);
634out:
635	if (err < 0)
636		task->tk_status = err;
637	return err;
638}
639
640void
641rpcauth_invalcred(struct rpc_task *task)
642{
643	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
644
645	dprintk("RPC: %5u invalidating %s cred %p\n",
646		task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
647	if (cred)
648		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
649}
650
651int
652rpcauth_uptodatecred(struct rpc_task *task)
653{
654	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
655
656	return cred == NULL ||
657		test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
658}
659
660static struct shrinker rpc_cred_shrinker = {
661	.shrink = rpcauth_cache_shrinker,
662	.seeks = DEFAULT_SEEKS,
663};
664
665int __init rpcauth_init_module(void)
666{
667	int err;
668
669	err = rpc_init_authunix();
670	if (err < 0)
671		goto out1;
672	err = rpc_init_generic_auth();
673	if (err < 0)
 
674		goto out2;
675	register_shrinker(&rpc_cred_shrinker);
 
 
 
 
 
 
676	return 0;
677out2:
678	rpc_destroy_authunix();
679out1:
680	return err;
681}
682
683void rpcauth_remove_module(void)
684{
685	rpc_destroy_authunix();
686	rpc_destroy_generic_auth();
687	unregister_shrinker(&rpc_cred_shrinker);
688}