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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/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 = strict_strtoul(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 u32
84pseudoflavor_to_flavor(u32 flavor) {
85 if (flavor > RPC_AUTH_MAXFLAVOR)
86 return RPC_AUTH_GSS;
87 return flavor;
88}
89
90int
91rpcauth_register(const struct rpc_authops *ops)
92{
93 rpc_authflavor_t flavor;
94 int ret = -EPERM;
95
96 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
97 return -EINVAL;
98 spin_lock(&rpc_authflavor_lock);
99 if (auth_flavors[flavor] == NULL) {
100 auth_flavors[flavor] = ops;
101 ret = 0;
102 }
103 spin_unlock(&rpc_authflavor_lock);
104 return ret;
105}
106EXPORT_SYMBOL_GPL(rpcauth_register);
107
108int
109rpcauth_unregister(const struct rpc_authops *ops)
110{
111 rpc_authflavor_t flavor;
112 int ret = -EPERM;
113
114 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
115 return -EINVAL;
116 spin_lock(&rpc_authflavor_lock);
117 if (auth_flavors[flavor] == ops) {
118 auth_flavors[flavor] = NULL;
119 ret = 0;
120 }
121 spin_unlock(&rpc_authflavor_lock);
122 return ret;
123}
124EXPORT_SYMBOL_GPL(rpcauth_unregister);
125
126/**
127 * rpcauth_get_pseudoflavor - check if security flavor is supported
128 * @flavor: a security flavor
129 * @info: a GSS mech OID, quality of protection, and service value
130 *
131 * Verifies that an appropriate kernel module is available or already loaded.
132 * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
133 * not supported locally.
134 */
135rpc_authflavor_t
136rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
137{
138 const struct rpc_authops *ops;
139 rpc_authflavor_t pseudoflavor;
140
141 ops = auth_flavors[flavor];
142 if (ops == NULL)
143 request_module("rpc-auth-%u", flavor);
144 spin_lock(&rpc_authflavor_lock);
145 ops = auth_flavors[flavor];
146 if (ops == NULL || !try_module_get(ops->owner)) {
147 spin_unlock(&rpc_authflavor_lock);
148 return RPC_AUTH_MAXFLAVOR;
149 }
150 spin_unlock(&rpc_authflavor_lock);
151
152 pseudoflavor = flavor;
153 if (ops->info2flavor != NULL)
154 pseudoflavor = ops->info2flavor(info);
155
156 module_put(ops->owner);
157 return pseudoflavor;
158}
159EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
160
161/**
162 * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
163 * @pseudoflavor: GSS pseudoflavor to match
164 * @info: rpcsec_gss_info structure to fill in
165 *
166 * Returns zero and fills in "info" if pseudoflavor matches a
167 * supported mechanism.
168 */
169int
170rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
171{
172 rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
173 const struct rpc_authops *ops;
174 int result;
175
176 if (flavor >= RPC_AUTH_MAXFLAVOR)
177 return -EINVAL;
178
179 ops = auth_flavors[flavor];
180 if (ops == NULL)
181 request_module("rpc-auth-%u", flavor);
182 spin_lock(&rpc_authflavor_lock);
183 ops = auth_flavors[flavor];
184 if (ops == NULL || !try_module_get(ops->owner)) {
185 spin_unlock(&rpc_authflavor_lock);
186 return -ENOENT;
187 }
188 spin_unlock(&rpc_authflavor_lock);
189
190 result = -ENOENT;
191 if (ops->flavor2info != NULL)
192 result = ops->flavor2info(pseudoflavor, info);
193
194 module_put(ops->owner);
195 return result;
196}
197EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
198
199/**
200 * rpcauth_list_flavors - discover registered flavors and pseudoflavors
201 * @array: array to fill in
202 * @size: size of "array"
203 *
204 * Returns the number of array items filled in, or a negative errno.
205 *
206 * The returned array is not sorted by any policy. Callers should not
207 * rely on the order of the items in the returned array.
208 */
209int
210rpcauth_list_flavors(rpc_authflavor_t *array, int size)
211{
212 rpc_authflavor_t flavor;
213 int result = 0;
214
215 spin_lock(&rpc_authflavor_lock);
216 for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
217 const struct rpc_authops *ops = auth_flavors[flavor];
218 rpc_authflavor_t pseudos[4];
219 int i, len;
220
221 if (result >= size) {
222 result = -ENOMEM;
223 break;
224 }
225
226 if (ops == NULL)
227 continue;
228 if (ops->list_pseudoflavors == NULL) {
229 array[result++] = ops->au_flavor;
230 continue;
231 }
232 len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
233 if (len < 0) {
234 result = len;
235 break;
236 }
237 for (i = 0; i < len; i++) {
238 if (result >= size) {
239 result = -ENOMEM;
240 break;
241 }
242 array[result++] = pseudos[i];
243 }
244 }
245 spin_unlock(&rpc_authflavor_lock);
246
247 dprintk("RPC: %s returns %d\n", __func__, result);
248 return result;
249}
250EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
251
252struct rpc_auth *
253rpcauth_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
254{
255 struct rpc_auth *auth;
256 const struct rpc_authops *ops;
257 u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
258
259 auth = ERR_PTR(-EINVAL);
260 if (flavor >= RPC_AUTH_MAXFLAVOR)
261 goto out;
262
263 if ((ops = auth_flavors[flavor]) == NULL)
264 request_module("rpc-auth-%u", flavor);
265 spin_lock(&rpc_authflavor_lock);
266 ops = auth_flavors[flavor];
267 if (ops == NULL || !try_module_get(ops->owner)) {
268 spin_unlock(&rpc_authflavor_lock);
269 goto out;
270 }
271 spin_unlock(&rpc_authflavor_lock);
272 auth = ops->create(args, clnt);
273 module_put(ops->owner);
274 if (IS_ERR(auth))
275 return auth;
276 if (clnt->cl_auth)
277 rpcauth_release(clnt->cl_auth);
278 clnt->cl_auth = auth;
279
280out:
281 return auth;
282}
283EXPORT_SYMBOL_GPL(rpcauth_create);
284
285void
286rpcauth_release(struct rpc_auth *auth)
287{
288 if (!atomic_dec_and_test(&auth->au_count))
289 return;
290 auth->au_ops->destroy(auth);
291}
292
293static DEFINE_SPINLOCK(rpc_credcache_lock);
294
295static void
296rpcauth_unhash_cred_locked(struct rpc_cred *cred)
297{
298 hlist_del_rcu(&cred->cr_hash);
299 smp_mb__before_clear_bit();
300 clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
301}
302
303static int
304rpcauth_unhash_cred(struct rpc_cred *cred)
305{
306 spinlock_t *cache_lock;
307 int ret;
308
309 cache_lock = &cred->cr_auth->au_credcache->lock;
310 spin_lock(cache_lock);
311 ret = atomic_read(&cred->cr_count) == 0;
312 if (ret)
313 rpcauth_unhash_cred_locked(cred);
314 spin_unlock(cache_lock);
315 return ret;
316}
317
318/*
319 * Initialize RPC credential cache
320 */
321int
322rpcauth_init_credcache(struct rpc_auth *auth)
323{
324 struct rpc_cred_cache *new;
325 unsigned int hashsize;
326
327 new = kmalloc(sizeof(*new), GFP_KERNEL);
328 if (!new)
329 goto out_nocache;
330 new->hashbits = auth_hashbits;
331 hashsize = 1U << new->hashbits;
332 new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
333 if (!new->hashtable)
334 goto out_nohashtbl;
335 spin_lock_init(&new->lock);
336 auth->au_credcache = new;
337 return 0;
338out_nohashtbl:
339 kfree(new);
340out_nocache:
341 return -ENOMEM;
342}
343EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
344
345/*
346 * Setup a credential key lifetime timeout notification
347 */
348int
349rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
350{
351 if (!cred->cr_auth->au_ops->key_timeout)
352 return 0;
353 return cred->cr_auth->au_ops->key_timeout(auth, cred);
354}
355EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
356
357bool
358rpcauth_cred_key_to_expire(struct rpc_cred *cred)
359{
360 if (!cred->cr_ops->crkey_to_expire)
361 return false;
362 return cred->cr_ops->crkey_to_expire(cred);
363}
364EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
365
366/*
367 * Destroy a list of credentials
368 */
369static inline
370void rpcauth_destroy_credlist(struct list_head *head)
371{
372 struct rpc_cred *cred;
373
374 while (!list_empty(head)) {
375 cred = list_entry(head->next, struct rpc_cred, cr_lru);
376 list_del_init(&cred->cr_lru);
377 put_rpccred(cred);
378 }
379}
380
381/*
382 * Clear the RPC credential cache, and delete those credentials
383 * that are not referenced.
384 */
385void
386rpcauth_clear_credcache(struct rpc_cred_cache *cache)
387{
388 LIST_HEAD(free);
389 struct hlist_head *head;
390 struct rpc_cred *cred;
391 unsigned int hashsize = 1U << cache->hashbits;
392 int i;
393
394 spin_lock(&rpc_credcache_lock);
395 spin_lock(&cache->lock);
396 for (i = 0; i < hashsize; i++) {
397 head = &cache->hashtable[i];
398 while (!hlist_empty(head)) {
399 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
400 get_rpccred(cred);
401 if (!list_empty(&cred->cr_lru)) {
402 list_del(&cred->cr_lru);
403 number_cred_unused--;
404 }
405 list_add_tail(&cred->cr_lru, &free);
406 rpcauth_unhash_cred_locked(cred);
407 }
408 }
409 spin_unlock(&cache->lock);
410 spin_unlock(&rpc_credcache_lock);
411 rpcauth_destroy_credlist(&free);
412}
413
414/*
415 * Destroy the RPC credential cache
416 */
417void
418rpcauth_destroy_credcache(struct rpc_auth *auth)
419{
420 struct rpc_cred_cache *cache = auth->au_credcache;
421
422 if (cache) {
423 auth->au_credcache = NULL;
424 rpcauth_clear_credcache(cache);
425 kfree(cache->hashtable);
426 kfree(cache);
427 }
428}
429EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
430
431
432#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
433
434/*
435 * Remove stale credentials. Avoid sleeping inside the loop.
436 */
437static long
438rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
439{
440 spinlock_t *cache_lock;
441 struct rpc_cred *cred, *next;
442 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
443 long freed = 0;
444
445 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
446
447 if (nr_to_scan-- == 0)
448 break;
449 /*
450 * Enforce a 60 second garbage collection moratorium
451 * Note that the cred_unused list must be time-ordered.
452 */
453 if (time_in_range(cred->cr_expire, expired, jiffies) &&
454 test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
455 break;
456
457 list_del_init(&cred->cr_lru);
458 number_cred_unused--;
459 freed++;
460 if (atomic_read(&cred->cr_count) != 0)
461 continue;
462
463 cache_lock = &cred->cr_auth->au_credcache->lock;
464 spin_lock(cache_lock);
465 if (atomic_read(&cred->cr_count) == 0) {
466 get_rpccred(cred);
467 list_add_tail(&cred->cr_lru, free);
468 rpcauth_unhash_cred_locked(cred);
469 }
470 spin_unlock(cache_lock);
471 }
472 return freed;
473}
474
475/*
476 * Run memory cache shrinker.
477 */
478static unsigned long
479rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
480
481{
482 LIST_HEAD(free);
483 unsigned long freed;
484
485 if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
486 return SHRINK_STOP;
487
488 /* nothing left, don't come back */
489 if (list_empty(&cred_unused))
490 return SHRINK_STOP;
491
492 spin_lock(&rpc_credcache_lock);
493 freed = rpcauth_prune_expired(&free, sc->nr_to_scan);
494 spin_unlock(&rpc_credcache_lock);
495 rpcauth_destroy_credlist(&free);
496
497 return freed;
498}
499
500static unsigned long
501rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
502
503{
504 return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
505}
506
507/*
508 * Look up a process' credentials in the authentication cache
509 */
510struct rpc_cred *
511rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
512 int flags)
513{
514 LIST_HEAD(free);
515 struct rpc_cred_cache *cache = auth->au_credcache;
516 struct rpc_cred *cred = NULL,
517 *entry, *new;
518 unsigned int nr;
519
520 nr = hash_long(from_kuid(&init_user_ns, acred->uid), cache->hashbits);
521
522 rcu_read_lock();
523 hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
524 if (!entry->cr_ops->crmatch(acred, entry, flags))
525 continue;
526 spin_lock(&cache->lock);
527 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
528 spin_unlock(&cache->lock);
529 continue;
530 }
531 cred = get_rpccred(entry);
532 spin_unlock(&cache->lock);
533 break;
534 }
535 rcu_read_unlock();
536
537 if (cred != NULL)
538 goto found;
539
540 new = auth->au_ops->crcreate(auth, acred, flags);
541 if (IS_ERR(new)) {
542 cred = new;
543 goto out;
544 }
545
546 spin_lock(&cache->lock);
547 hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
548 if (!entry->cr_ops->crmatch(acred, entry, flags))
549 continue;
550 cred = get_rpccred(entry);
551 break;
552 }
553 if (cred == NULL) {
554 cred = new;
555 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
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);
560found:
561 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
562 cred->cr_ops->cr_init != NULL &&
563 !(flags & RPCAUTH_LOOKUP_NEW)) {
564 int res = cred->cr_ops->cr_init(auth, cred);
565 if (res < 0) {
566 put_rpccred(cred);
567 cred = ERR_PTR(res);
568 }
569 }
570 rpcauth_destroy_credlist(&free);
571out:
572 return cred;
573}
574EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
575
576struct rpc_cred *
577rpcauth_lookupcred(struct rpc_auth *auth, int flags)
578{
579 struct auth_cred acred;
580 struct rpc_cred *ret;
581 const struct cred *cred = current_cred();
582
583 dprintk("RPC: looking up %s cred\n",
584 auth->au_ops->au_name);
585
586 memset(&acred, 0, sizeof(acred));
587 acred.uid = cred->fsuid;
588 acred.gid = cred->fsgid;
589 acred.group_info = get_group_info(((struct cred *)cred)->group_info);
590
591 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
592 put_group_info(acred.group_info);
593 return ret;
594}
595
596void
597rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
598 struct rpc_auth *auth, const struct rpc_credops *ops)
599{
600 INIT_HLIST_NODE(&cred->cr_hash);
601 INIT_LIST_HEAD(&cred->cr_lru);
602 atomic_set(&cred->cr_count, 1);
603 cred->cr_auth = auth;
604 cred->cr_ops = ops;
605 cred->cr_expire = jiffies;
606#ifdef RPC_DEBUG
607 cred->cr_magic = RPCAUTH_CRED_MAGIC;
608#endif
609 cred->cr_uid = acred->uid;
610}
611EXPORT_SYMBOL_GPL(rpcauth_init_cred);
612
613struct rpc_cred *
614rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
615{
616 dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
617 cred->cr_auth->au_ops->au_name, cred);
618 return get_rpccred(cred);
619}
620EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
621
622static struct rpc_cred *
623rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
624{
625 struct rpc_auth *auth = task->tk_client->cl_auth;
626 struct auth_cred acred = {
627 .uid = GLOBAL_ROOT_UID,
628 .gid = GLOBAL_ROOT_GID,
629 };
630
631 dprintk("RPC: %5u looking up %s cred\n",
632 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
633 return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
634}
635
636static struct rpc_cred *
637rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
638{
639 struct rpc_auth *auth = task->tk_client->cl_auth;
640
641 dprintk("RPC: %5u looking up %s cred\n",
642 task->tk_pid, auth->au_ops->au_name);
643 return rpcauth_lookupcred(auth, lookupflags);
644}
645
646static int
647rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
648{
649 struct rpc_rqst *req = task->tk_rqstp;
650 struct rpc_cred *new;
651 int lookupflags = 0;
652
653 if (flags & RPC_TASK_ASYNC)
654 lookupflags |= RPCAUTH_LOOKUP_NEW;
655 if (cred != NULL)
656 new = cred->cr_ops->crbind(task, cred, lookupflags);
657 else if (flags & RPC_TASK_ROOTCREDS)
658 new = rpcauth_bind_root_cred(task, lookupflags);
659 else
660 new = rpcauth_bind_new_cred(task, lookupflags);
661 if (IS_ERR(new))
662 return PTR_ERR(new);
663 if (req->rq_cred != NULL)
664 put_rpccred(req->rq_cred);
665 req->rq_cred = new;
666 return 0;
667}
668
669void
670put_rpccred(struct rpc_cred *cred)
671{
672 /* Fast path for unhashed credentials */
673 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
674 if (atomic_dec_and_test(&cred->cr_count))
675 cred->cr_ops->crdestroy(cred);
676 return;
677 }
678
679 if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
680 return;
681 if (!list_empty(&cred->cr_lru)) {
682 number_cred_unused--;
683 list_del_init(&cred->cr_lru);
684 }
685 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
686 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
687 cred->cr_expire = jiffies;
688 list_add_tail(&cred->cr_lru, &cred_unused);
689 number_cred_unused++;
690 goto out_nodestroy;
691 }
692 if (!rpcauth_unhash_cred(cred)) {
693 /* We were hashed and someone looked us up... */
694 goto out_nodestroy;
695 }
696 }
697 spin_unlock(&rpc_credcache_lock);
698 cred->cr_ops->crdestroy(cred);
699 return;
700out_nodestroy:
701 spin_unlock(&rpc_credcache_lock);
702}
703EXPORT_SYMBOL_GPL(put_rpccred);
704
705__be32 *
706rpcauth_marshcred(struct rpc_task *task, __be32 *p)
707{
708 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
709
710 dprintk("RPC: %5u marshaling %s cred %p\n",
711 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
712
713 return cred->cr_ops->crmarshal(task, p);
714}
715
716__be32 *
717rpcauth_checkverf(struct rpc_task *task, __be32 *p)
718{
719 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
720
721 dprintk("RPC: %5u validating %s cred %p\n",
722 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
723
724 return cred->cr_ops->crvalidate(task, p);
725}
726
727static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
728 __be32 *data, void *obj)
729{
730 struct xdr_stream xdr;
731
732 xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
733 encode(rqstp, &xdr, obj);
734}
735
736int
737rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
738 __be32 *data, void *obj)
739{
740 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
741
742 dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
743 task->tk_pid, cred->cr_ops->cr_name, cred);
744 if (cred->cr_ops->crwrap_req)
745 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
746 /* By default, we encode the arguments normally. */
747 rpcauth_wrap_req_encode(encode, rqstp, data, obj);
748 return 0;
749}
750
751static int
752rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
753 __be32 *data, void *obj)
754{
755 struct xdr_stream xdr;
756
757 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
758 return decode(rqstp, &xdr, obj);
759}
760
761int
762rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
763 __be32 *data, void *obj)
764{
765 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
766
767 dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
768 task->tk_pid, cred->cr_ops->cr_name, cred);
769 if (cred->cr_ops->crunwrap_resp)
770 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
771 data, obj);
772 /* By default, we decode the arguments normally. */
773 return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
774}
775
776int
777rpcauth_refreshcred(struct rpc_task *task)
778{
779 struct rpc_cred *cred;
780 int err;
781
782 cred = task->tk_rqstp->rq_cred;
783 if (cred == NULL) {
784 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
785 if (err < 0)
786 goto out;
787 cred = task->tk_rqstp->rq_cred;
788 }
789 dprintk("RPC: %5u refreshing %s cred %p\n",
790 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
791
792 err = cred->cr_ops->crrefresh(task);
793out:
794 if (err < 0)
795 task->tk_status = err;
796 return err;
797}
798
799void
800rpcauth_invalcred(struct rpc_task *task)
801{
802 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
803
804 dprintk("RPC: %5u invalidating %s cred %p\n",
805 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
806 if (cred)
807 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
808}
809
810int
811rpcauth_uptodatecred(struct rpc_task *task)
812{
813 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
814
815 return cred == NULL ||
816 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
817}
818
819static struct shrinker rpc_cred_shrinker = {
820 .count_objects = rpcauth_cache_shrink_count,
821 .scan_objects = rpcauth_cache_shrink_scan,
822 .seeks = DEFAULT_SEEKS,
823};
824
825int __init rpcauth_init_module(void)
826{
827 int err;
828
829 err = rpc_init_authunix();
830 if (err < 0)
831 goto out1;
832 err = rpc_init_generic_auth();
833 if (err < 0)
834 goto out2;
835 register_shrinker(&rpc_cred_shrinker);
836 return 0;
837out2:
838 rpc_destroy_authunix();
839out1:
840 return err;
841}
842
843void rpcauth_remove_module(void)
844{
845 rpc_destroy_authunix();
846 rpc_destroy_generic_auth();
847 unregister_shrinker(&rpc_cred_shrinker);
848}