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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#if IS_ENABLED(CONFIG_SUNRPC_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 const 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#if IS_ENABLED(CONFIG_SUNRPC_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}