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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\n", 1U << nbits);
85}
86
87#define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
88
89static const struct kernel_param_ops param_ops_hashtbl_sz = {
90 .set = param_set_hashtbl_sz,
91 .get = param_get_hashtbl_sz,
92};
93
94module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
95MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
96
97static unsigned long auth_max_cred_cachesize = ULONG_MAX;
98module_param(auth_max_cred_cachesize, ulong, 0644);
99MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
100
101static u32
102pseudoflavor_to_flavor(u32 flavor) {
103 if (flavor > RPC_AUTH_MAXFLAVOR)
104 return RPC_AUTH_GSS;
105 return flavor;
106}
107
108int
109rpcauth_register(const struct rpc_authops *ops)
110{
111 const struct rpc_authops *old;
112 rpc_authflavor_t flavor;
113
114 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
115 return -EINVAL;
116 old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], NULL, ops);
117 if (old == NULL || old == ops)
118 return 0;
119 return -EPERM;
120}
121EXPORT_SYMBOL_GPL(rpcauth_register);
122
123int
124rpcauth_unregister(const struct rpc_authops *ops)
125{
126 const struct rpc_authops *old;
127 rpc_authflavor_t flavor;
128
129 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
130 return -EINVAL;
131
132 old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], ops, NULL);
133 if (old == ops || old == NULL)
134 return 0;
135 return -EPERM;
136}
137EXPORT_SYMBOL_GPL(rpcauth_unregister);
138
139static const struct rpc_authops *
140rpcauth_get_authops(rpc_authflavor_t flavor)
141{
142 const struct rpc_authops *ops;
143
144 if (flavor >= RPC_AUTH_MAXFLAVOR)
145 return NULL;
146
147 rcu_read_lock();
148 ops = rcu_dereference(auth_flavors[flavor]);
149 if (ops == NULL) {
150 rcu_read_unlock();
151 request_module("rpc-auth-%u", flavor);
152 rcu_read_lock();
153 ops = rcu_dereference(auth_flavors[flavor]);
154 if (ops == NULL)
155 goto out;
156 }
157 if (!try_module_get(ops->owner))
158 ops = NULL;
159out:
160 rcu_read_unlock();
161 return ops;
162}
163
164static void
165rpcauth_put_authops(const struct rpc_authops *ops)
166{
167 module_put(ops->owner);
168}
169
170/**
171 * rpcauth_get_pseudoflavor - check if security flavor is supported
172 * @flavor: a security flavor
173 * @info: a GSS mech OID, quality of protection, and service value
174 *
175 * Verifies that an appropriate kernel module is available or already loaded.
176 * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
177 * not supported locally.
178 */
179rpc_authflavor_t
180rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
181{
182 const struct rpc_authops *ops = rpcauth_get_authops(flavor);
183 rpc_authflavor_t pseudoflavor;
184
185 if (!ops)
186 return RPC_AUTH_MAXFLAVOR;
187 pseudoflavor = flavor;
188 if (ops->info2flavor != NULL)
189 pseudoflavor = ops->info2flavor(info);
190
191 rpcauth_put_authops(ops);
192 return pseudoflavor;
193}
194EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
195
196/**
197 * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
198 * @pseudoflavor: GSS pseudoflavor to match
199 * @info: rpcsec_gss_info structure to fill in
200 *
201 * Returns zero and fills in "info" if pseudoflavor matches a
202 * supported mechanism.
203 */
204int
205rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
206{
207 rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
208 const struct rpc_authops *ops;
209 int result;
210
211 ops = rpcauth_get_authops(flavor);
212 if (ops == NULL)
213 return -ENOENT;
214
215 result = -ENOENT;
216 if (ops->flavor2info != NULL)
217 result = ops->flavor2info(pseudoflavor, info);
218
219 rpcauth_put_authops(ops);
220 return result;
221}
222EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
223
224struct rpc_auth *
225rpcauth_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
226{
227 struct rpc_auth *auth = ERR_PTR(-EINVAL);
228 const struct rpc_authops *ops;
229 u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
230
231 ops = rpcauth_get_authops(flavor);
232 if (ops == NULL)
233 goto out;
234
235 auth = ops->create(args, clnt);
236
237 rpcauth_put_authops(ops);
238 if (IS_ERR(auth))
239 return auth;
240 if (clnt->cl_auth)
241 rpcauth_release(clnt->cl_auth);
242 clnt->cl_auth = auth;
243
244out:
245 return auth;
246}
247EXPORT_SYMBOL_GPL(rpcauth_create);
248
249void
250rpcauth_release(struct rpc_auth *auth)
251{
252 if (!refcount_dec_and_test(&auth->au_count))
253 return;
254 auth->au_ops->destroy(auth);
255}
256
257static DEFINE_SPINLOCK(rpc_credcache_lock);
258
259/*
260 * On success, the caller is responsible for freeing the reference
261 * held by the hashtable
262 */
263static bool
264rpcauth_unhash_cred_locked(struct rpc_cred *cred)
265{
266 if (!test_and_clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
267 return false;
268 hlist_del_rcu(&cred->cr_hash);
269 return true;
270}
271
272static bool
273rpcauth_unhash_cred(struct rpc_cred *cred)
274{
275 spinlock_t *cache_lock;
276 bool ret;
277
278 if (!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
279 return false;
280 cache_lock = &cred->cr_auth->au_credcache->lock;
281 spin_lock(cache_lock);
282 ret = rpcauth_unhash_cred_locked(cred);
283 spin_unlock(cache_lock);
284 return ret;
285}
286
287/*
288 * Initialize RPC credential cache
289 */
290int
291rpcauth_init_credcache(struct rpc_auth *auth)
292{
293 struct rpc_cred_cache *new;
294 unsigned int hashsize;
295
296 new = kmalloc(sizeof(*new), GFP_KERNEL);
297 if (!new)
298 goto out_nocache;
299 new->hashbits = auth_hashbits;
300 hashsize = 1U << new->hashbits;
301 new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
302 if (!new->hashtable)
303 goto out_nohashtbl;
304 spin_lock_init(&new->lock);
305 auth->au_credcache = new;
306 return 0;
307out_nohashtbl:
308 kfree(new);
309out_nocache:
310 return -ENOMEM;
311}
312EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
313
314char *
315rpcauth_stringify_acceptor(struct rpc_cred *cred)
316{
317 if (!cred->cr_ops->crstringify_acceptor)
318 return NULL;
319 return cred->cr_ops->crstringify_acceptor(cred);
320}
321EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
322
323/*
324 * Destroy a list of credentials
325 */
326static inline
327void rpcauth_destroy_credlist(struct list_head *head)
328{
329 struct rpc_cred *cred;
330
331 while (!list_empty(head)) {
332 cred = list_entry(head->next, struct rpc_cred, cr_lru);
333 list_del_init(&cred->cr_lru);
334 put_rpccred(cred);
335 }
336}
337
338static void
339rpcauth_lru_add_locked(struct rpc_cred *cred)
340{
341 if (!list_empty(&cred->cr_lru))
342 return;
343 number_cred_unused++;
344 list_add_tail(&cred->cr_lru, &cred_unused);
345}
346
347static void
348rpcauth_lru_add(struct rpc_cred *cred)
349{
350 if (!list_empty(&cred->cr_lru))
351 return;
352 spin_lock(&rpc_credcache_lock);
353 rpcauth_lru_add_locked(cred);
354 spin_unlock(&rpc_credcache_lock);
355}
356
357static void
358rpcauth_lru_remove_locked(struct rpc_cred *cred)
359{
360 if (list_empty(&cred->cr_lru))
361 return;
362 number_cred_unused--;
363 list_del_init(&cred->cr_lru);
364}
365
366static void
367rpcauth_lru_remove(struct rpc_cred *cred)
368{
369 if (list_empty(&cred->cr_lru))
370 return;
371 spin_lock(&rpc_credcache_lock);
372 rpcauth_lru_remove_locked(cred);
373 spin_unlock(&rpc_credcache_lock);
374}
375
376/*
377 * Clear the RPC credential cache, and delete those credentials
378 * that are not referenced.
379 */
380void
381rpcauth_clear_credcache(struct rpc_cred_cache *cache)
382{
383 LIST_HEAD(free);
384 struct hlist_head *head;
385 struct rpc_cred *cred;
386 unsigned int hashsize = 1U << cache->hashbits;
387 int i;
388
389 spin_lock(&rpc_credcache_lock);
390 spin_lock(&cache->lock);
391 for (i = 0; i < hashsize; i++) {
392 head = &cache->hashtable[i];
393 while (!hlist_empty(head)) {
394 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
395 rpcauth_unhash_cred_locked(cred);
396 /* Note: We now hold a reference to cred */
397 rpcauth_lru_remove_locked(cred);
398 list_add_tail(&cred->cr_lru, &free);
399 }
400 }
401 spin_unlock(&cache->lock);
402 spin_unlock(&rpc_credcache_lock);
403 rpcauth_destroy_credlist(&free);
404}
405
406/*
407 * Destroy the RPC credential cache
408 */
409void
410rpcauth_destroy_credcache(struct rpc_auth *auth)
411{
412 struct rpc_cred_cache *cache = auth->au_credcache;
413
414 if (cache) {
415 auth->au_credcache = NULL;
416 rpcauth_clear_credcache(cache);
417 kfree(cache->hashtable);
418 kfree(cache);
419 }
420}
421EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
422
423
424#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
425
426/*
427 * Remove stale credentials. Avoid sleeping inside the loop.
428 */
429static long
430rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
431{
432 struct rpc_cred *cred, *next;
433 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
434 long freed = 0;
435
436 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
437
438 if (nr_to_scan-- == 0)
439 break;
440 if (refcount_read(&cred->cr_count) > 1) {
441 rpcauth_lru_remove_locked(cred);
442 continue;
443 }
444 /*
445 * Enforce a 60 second garbage collection moratorium
446 * Note that the cred_unused list must be time-ordered.
447 */
448 if (time_in_range(cred->cr_expire, expired, jiffies))
449 continue;
450 if (!rpcauth_unhash_cred(cred))
451 continue;
452
453 rpcauth_lru_remove_locked(cred);
454 freed++;
455 list_add_tail(&cred->cr_lru, free);
456 }
457 return freed ? freed : SHRINK_STOP;
458}
459
460static unsigned long
461rpcauth_cache_do_shrink(int nr_to_scan)
462{
463 LIST_HEAD(free);
464 unsigned long freed;
465
466 spin_lock(&rpc_credcache_lock);
467 freed = rpcauth_prune_expired(&free, nr_to_scan);
468 spin_unlock(&rpc_credcache_lock);
469 rpcauth_destroy_credlist(&free);
470
471 return freed;
472}
473
474/*
475 * Run memory cache shrinker.
476 */
477static unsigned long
478rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
479
480{
481 if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
482 return SHRINK_STOP;
483
484 /* nothing left, don't come back */
485 if (list_empty(&cred_unused))
486 return SHRINK_STOP;
487
488 return rpcauth_cache_do_shrink(sc->nr_to_scan);
489}
490
491static unsigned long
492rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
493
494{
495 return number_cred_unused * sysctl_vfs_cache_pressure / 100;
496}
497
498static void
499rpcauth_cache_enforce_limit(void)
500{
501 unsigned long diff;
502 unsigned int nr_to_scan;
503
504 if (number_cred_unused <= auth_max_cred_cachesize)
505 return;
506 diff = number_cred_unused - auth_max_cred_cachesize;
507 nr_to_scan = 100;
508 if (diff < nr_to_scan)
509 nr_to_scan = diff;
510 rpcauth_cache_do_shrink(nr_to_scan);
511}
512
513/*
514 * Look up a process' credentials in the authentication cache
515 */
516struct rpc_cred *
517rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
518 int flags, gfp_t gfp)
519{
520 LIST_HEAD(free);
521 struct rpc_cred_cache *cache = auth->au_credcache;
522 struct rpc_cred *cred = NULL,
523 *entry, *new;
524 unsigned int nr;
525
526 nr = auth->au_ops->hash_cred(acred, cache->hashbits);
527
528 rcu_read_lock();
529 hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
530 if (!entry->cr_ops->crmatch(acred, entry, flags))
531 continue;
532 cred = get_rpccred(entry);
533 if (cred)
534 break;
535 }
536 rcu_read_unlock();
537
538 if (cred != NULL)
539 goto found;
540
541 new = auth->au_ops->crcreate(auth, acred, flags, gfp);
542 if (IS_ERR(new)) {
543 cred = new;
544 goto out;
545 }
546
547 spin_lock(&cache->lock);
548 hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
549 if (!entry->cr_ops->crmatch(acred, entry, flags))
550 continue;
551 cred = get_rpccred(entry);
552 if (cred)
553 break;
554 }
555 if (cred == NULL) {
556 cred = new;
557 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
558 refcount_inc(&cred->cr_count);
559 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
560 } else
561 list_add_tail(&new->cr_lru, &free);
562 spin_unlock(&cache->lock);
563 rpcauth_cache_enforce_limit();
564found:
565 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
566 cred->cr_ops->cr_init != NULL &&
567 !(flags & RPCAUTH_LOOKUP_NEW)) {
568 int res = cred->cr_ops->cr_init(auth, cred);
569 if (res < 0) {
570 put_rpccred(cred);
571 cred = ERR_PTR(res);
572 }
573 }
574 rpcauth_destroy_credlist(&free);
575out:
576 return cred;
577}
578EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
579
580struct rpc_cred *
581rpcauth_lookupcred(struct rpc_auth *auth, int flags)
582{
583 struct auth_cred acred;
584 struct rpc_cred *ret;
585 const struct cred *cred = current_cred();
586
587 memset(&acred, 0, sizeof(acred));
588 acred.cred = cred;
589 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
590 return ret;
591}
592EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
593
594void
595rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
596 struct rpc_auth *auth, const struct rpc_credops *ops)
597{
598 INIT_HLIST_NODE(&cred->cr_hash);
599 INIT_LIST_HEAD(&cred->cr_lru);
600 refcount_set(&cred->cr_count, 1);
601 cred->cr_auth = auth;
602 cred->cr_flags = 0;
603 cred->cr_ops = ops;
604 cred->cr_expire = jiffies;
605 cred->cr_cred = get_cred(acred->cred);
606}
607EXPORT_SYMBOL_GPL(rpcauth_init_cred);
608
609static struct rpc_cred *
610rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
611{
612 struct rpc_auth *auth = task->tk_client->cl_auth;
613 struct auth_cred acred = {
614 .cred = get_task_cred(&init_task),
615 };
616 struct rpc_cred *ret;
617
618 if (RPC_IS_ASYNC(task))
619 lookupflags |= RPCAUTH_LOOKUP_ASYNC;
620 ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
621 put_cred(acred.cred);
622 return ret;
623}
624
625static struct rpc_cred *
626rpcauth_bind_machine_cred(struct rpc_task *task, int lookupflags)
627{
628 struct rpc_auth *auth = task->tk_client->cl_auth;
629 struct auth_cred acred = {
630 .principal = task->tk_client->cl_principal,
631 .cred = init_task.cred,
632 };
633
634 if (!acred.principal)
635 return NULL;
636 if (RPC_IS_ASYNC(task))
637 lookupflags |= RPCAUTH_LOOKUP_ASYNC;
638 return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
639}
640
641static struct rpc_cred *
642rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
643{
644 struct rpc_auth *auth = task->tk_client->cl_auth;
645
646 return rpcauth_lookupcred(auth, lookupflags);
647}
648
649static int
650rpcauth_bindcred(struct rpc_task *task, const struct cred *cred, int flags)
651{
652 struct rpc_rqst *req = task->tk_rqstp;
653 struct rpc_cred *new = NULL;
654 int lookupflags = 0;
655 struct rpc_auth *auth = task->tk_client->cl_auth;
656 struct auth_cred acred = {
657 .cred = cred,
658 };
659
660 if (flags & RPC_TASK_ASYNC)
661 lookupflags |= RPCAUTH_LOOKUP_NEW | RPCAUTH_LOOKUP_ASYNC;
662 if (task->tk_op_cred)
663 /* Task must use exactly this rpc_cred */
664 new = get_rpccred(task->tk_op_cred);
665 else if (cred != NULL && cred != &machine_cred)
666 new = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
667 else if (cred == &machine_cred)
668 new = rpcauth_bind_machine_cred(task, lookupflags);
669
670 /* If machine cred couldn't be bound, try a root cred */
671 if (new)
672 ;
673 else if (cred == &machine_cred)
674 new = rpcauth_bind_root_cred(task, lookupflags);
675 else if (flags & RPC_TASK_NULLCREDS)
676 new = authnull_ops.lookup_cred(NULL, NULL, 0);
677 else
678 new = rpcauth_bind_new_cred(task, lookupflags);
679 if (IS_ERR(new))
680 return PTR_ERR(new);
681 put_rpccred(req->rq_cred);
682 req->rq_cred = new;
683 return 0;
684}
685
686void
687put_rpccred(struct rpc_cred *cred)
688{
689 if (cred == NULL)
690 return;
691 rcu_read_lock();
692 if (refcount_dec_and_test(&cred->cr_count))
693 goto destroy;
694 if (refcount_read(&cred->cr_count) != 1 ||
695 !test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
696 goto out;
697 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
698 cred->cr_expire = jiffies;
699 rpcauth_lru_add(cred);
700 /* Race breaker */
701 if (unlikely(!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags)))
702 rpcauth_lru_remove(cred);
703 } else if (rpcauth_unhash_cred(cred)) {
704 rpcauth_lru_remove(cred);
705 if (refcount_dec_and_test(&cred->cr_count))
706 goto destroy;
707 }
708out:
709 rcu_read_unlock();
710 return;
711destroy:
712 rcu_read_unlock();
713 cred->cr_ops->crdestroy(cred);
714}
715EXPORT_SYMBOL_GPL(put_rpccred);
716
717/**
718 * rpcauth_marshcred - Append RPC credential to end of @xdr
719 * @task: controlling RPC task
720 * @xdr: xdr_stream containing initial portion of RPC Call header
721 *
722 * On success, an appropriate verifier is added to @xdr, @xdr is
723 * updated to point past the verifier, and zero is returned.
724 * Otherwise, @xdr is in an undefined state and a negative errno
725 * is returned.
726 */
727int rpcauth_marshcred(struct rpc_task *task, struct xdr_stream *xdr)
728{
729 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
730
731 return ops->crmarshal(task, xdr);
732}
733
734/**
735 * rpcauth_wrap_req_encode - XDR encode the RPC procedure
736 * @task: controlling RPC task
737 * @xdr: stream where on-the-wire bytes are to be marshalled
738 *
739 * On success, @xdr contains the encoded and wrapped message.
740 * Otherwise, @xdr is in an undefined state.
741 */
742int rpcauth_wrap_req_encode(struct rpc_task *task, struct xdr_stream *xdr)
743{
744 kxdreproc_t encode = task->tk_msg.rpc_proc->p_encode;
745
746 encode(task->tk_rqstp, xdr, task->tk_msg.rpc_argp);
747 return 0;
748}
749EXPORT_SYMBOL_GPL(rpcauth_wrap_req_encode);
750
751/**
752 * rpcauth_wrap_req - XDR encode and wrap the RPC procedure
753 * @task: controlling RPC task
754 * @xdr: stream where on-the-wire bytes are to be marshalled
755 *
756 * On success, @xdr contains the encoded and wrapped message,
757 * and zero is returned. Otherwise, @xdr is in an undefined
758 * state and a negative errno is returned.
759 */
760int rpcauth_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
761{
762 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
763
764 return ops->crwrap_req(task, xdr);
765}
766
767/**
768 * rpcauth_checkverf - Validate verifier in RPC Reply header
769 * @task: controlling RPC task
770 * @xdr: xdr_stream containing RPC Reply header
771 *
772 * On success, @xdr is updated to point past the verifier and
773 * zero is returned. Otherwise, @xdr is in an undefined state
774 * and a negative errno is returned.
775 */
776int
777rpcauth_checkverf(struct rpc_task *task, struct xdr_stream *xdr)
778{
779 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
780
781 return ops->crvalidate(task, xdr);
782}
783
784/**
785 * rpcauth_unwrap_resp_decode - Invoke XDR decode function
786 * @task: controlling RPC task
787 * @xdr: stream where the Reply message resides
788 *
789 * Returns zero on success; otherwise a negative errno is returned.
790 */
791int
792rpcauth_unwrap_resp_decode(struct rpc_task *task, struct xdr_stream *xdr)
793{
794 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
795
796 return decode(task->tk_rqstp, xdr, task->tk_msg.rpc_resp);
797}
798EXPORT_SYMBOL_GPL(rpcauth_unwrap_resp_decode);
799
800/**
801 * rpcauth_unwrap_resp - Invoke unwrap and decode function for the cred
802 * @task: controlling RPC task
803 * @xdr: stream where the Reply message resides
804 *
805 * Returns zero on success; otherwise a negative errno is returned.
806 */
807int
808rpcauth_unwrap_resp(struct rpc_task *task, struct xdr_stream *xdr)
809{
810 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
811
812 return ops->crunwrap_resp(task, xdr);
813}
814
815bool
816rpcauth_xmit_need_reencode(struct rpc_task *task)
817{
818 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
819
820 if (!cred || !cred->cr_ops->crneed_reencode)
821 return false;
822 return cred->cr_ops->crneed_reencode(task);
823}
824
825int
826rpcauth_refreshcred(struct rpc_task *task)
827{
828 struct rpc_cred *cred;
829 int err;
830
831 cred = task->tk_rqstp->rq_cred;
832 if (cred == NULL) {
833 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
834 if (err < 0)
835 goto out;
836 cred = task->tk_rqstp->rq_cred;
837 }
838
839 err = cred->cr_ops->crrefresh(task);
840out:
841 if (err < 0)
842 task->tk_status = err;
843 return err;
844}
845
846void
847rpcauth_invalcred(struct rpc_task *task)
848{
849 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
850
851 if (cred)
852 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
853}
854
855int
856rpcauth_uptodatecred(struct rpc_task *task)
857{
858 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
859
860 return cred == NULL ||
861 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
862}
863
864static struct shrinker rpc_cred_shrinker = {
865 .count_objects = rpcauth_cache_shrink_count,
866 .scan_objects = rpcauth_cache_shrink_scan,
867 .seeks = DEFAULT_SEEKS,
868};
869
870int __init rpcauth_init_module(void)
871{
872 int err;
873
874 err = rpc_init_authunix();
875 if (err < 0)
876 goto out1;
877 err = register_shrinker(&rpc_cred_shrinker, "sunrpc_cred");
878 if (err < 0)
879 goto out2;
880 return 0;
881out2:
882 rpc_destroy_authunix();
883out1:
884 return err;
885}
886
887void rpcauth_remove_module(void)
888{
889 rpc_destroy_authunix();
890 unregister_shrinker(&rpc_cred_shrinker);
891}
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}