Loading...
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 [RPC_AUTH_TLS] = (const struct rpc_authops __force __rcu *)&authtls_ops,
36};
37
38static LIST_HEAD(cred_unused);
39static unsigned long number_cred_unused;
40
41static struct cred machine_cred = {
42 .usage = ATOMIC_INIT(1),
43};
44
45/*
46 * Return the machine_cred pointer to be used whenever
47 * the a generic machine credential is needed.
48 */
49const struct cred *rpc_machine_cred(void)
50{
51 return &machine_cred;
52}
53EXPORT_SYMBOL_GPL(rpc_machine_cred);
54
55#define MAX_HASHTABLE_BITS (14)
56static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
57{
58 unsigned long num;
59 unsigned int nbits;
60 int ret;
61
62 if (!val)
63 goto out_inval;
64 ret = kstrtoul(val, 0, &num);
65 if (ret)
66 goto out_inval;
67 nbits = fls(num - 1);
68 if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
69 goto out_inval;
70 *(unsigned int *)kp->arg = nbits;
71 return 0;
72out_inval:
73 return -EINVAL;
74}
75
76static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
77{
78 unsigned int nbits;
79
80 nbits = *(unsigned int *)kp->arg;
81 return sprintf(buffer, "%u\n", 1U << nbits);
82}
83
84#define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
85
86static const struct kernel_param_ops param_ops_hashtbl_sz = {
87 .set = param_set_hashtbl_sz,
88 .get = param_get_hashtbl_sz,
89};
90
91module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
92MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
93
94static unsigned long auth_max_cred_cachesize = ULONG_MAX;
95module_param(auth_max_cred_cachesize, ulong, 0644);
96MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
97
98static u32
99pseudoflavor_to_flavor(u32 flavor) {
100 if (flavor > RPC_AUTH_MAXFLAVOR)
101 return RPC_AUTH_GSS;
102 return flavor;
103}
104
105int
106rpcauth_register(const struct rpc_authops *ops)
107{
108 const struct rpc_authops *old;
109 rpc_authflavor_t flavor;
110
111 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
112 return -EINVAL;
113 old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], NULL, ops);
114 if (old == NULL || old == ops)
115 return 0;
116 return -EPERM;
117}
118EXPORT_SYMBOL_GPL(rpcauth_register);
119
120int
121rpcauth_unregister(const struct rpc_authops *ops)
122{
123 const struct rpc_authops *old;
124 rpc_authflavor_t flavor;
125
126 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
127 return -EINVAL;
128
129 old = cmpxchg((const struct rpc_authops ** __force)&auth_flavors[flavor], ops, NULL);
130 if (old == ops || old == NULL)
131 return 0;
132 return -EPERM;
133}
134EXPORT_SYMBOL_GPL(rpcauth_unregister);
135
136static const struct rpc_authops *
137rpcauth_get_authops(rpc_authflavor_t flavor)
138{
139 const struct rpc_authops *ops;
140
141 if (flavor >= RPC_AUTH_MAXFLAVOR)
142 return NULL;
143
144 rcu_read_lock();
145 ops = rcu_dereference(auth_flavors[flavor]);
146 if (ops == NULL) {
147 rcu_read_unlock();
148 request_module("rpc-auth-%u", flavor);
149 rcu_read_lock();
150 ops = rcu_dereference(auth_flavors[flavor]);
151 if (ops == NULL)
152 goto out;
153 }
154 if (!try_module_get(ops->owner))
155 ops = NULL;
156out:
157 rcu_read_unlock();
158 return ops;
159}
160
161static void
162rpcauth_put_authops(const struct rpc_authops *ops)
163{
164 module_put(ops->owner);
165}
166
167/**
168 * rpcauth_get_pseudoflavor - check if security flavor is supported
169 * @flavor: a security flavor
170 * @info: a GSS mech OID, quality of protection, and service value
171 *
172 * Verifies that an appropriate kernel module is available or already loaded.
173 * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
174 * not supported locally.
175 */
176rpc_authflavor_t
177rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
178{
179 const struct rpc_authops *ops = rpcauth_get_authops(flavor);
180 rpc_authflavor_t pseudoflavor;
181
182 if (!ops)
183 return RPC_AUTH_MAXFLAVOR;
184 pseudoflavor = flavor;
185 if (ops->info2flavor != NULL)
186 pseudoflavor = ops->info2flavor(info);
187
188 rpcauth_put_authops(ops);
189 return pseudoflavor;
190}
191EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
192
193/**
194 * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
195 * @pseudoflavor: GSS pseudoflavor to match
196 * @info: rpcsec_gss_info structure to fill in
197 *
198 * Returns zero and fills in "info" if pseudoflavor matches a
199 * supported mechanism.
200 */
201int
202rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
203{
204 rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
205 const struct rpc_authops *ops;
206 int result;
207
208 ops = rpcauth_get_authops(flavor);
209 if (ops == NULL)
210 return -ENOENT;
211
212 result = -ENOENT;
213 if (ops->flavor2info != NULL)
214 result = ops->flavor2info(pseudoflavor, info);
215
216 rpcauth_put_authops(ops);
217 return result;
218}
219EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
220
221struct rpc_auth *
222rpcauth_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
223{
224 struct rpc_auth *auth = ERR_PTR(-EINVAL);
225 const struct rpc_authops *ops;
226 u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
227
228 ops = rpcauth_get_authops(flavor);
229 if (ops == NULL)
230 goto out;
231
232 auth = ops->create(args, clnt);
233
234 rpcauth_put_authops(ops);
235 if (IS_ERR(auth))
236 return auth;
237 if (clnt->cl_auth)
238 rpcauth_release(clnt->cl_auth);
239 clnt->cl_auth = auth;
240
241out:
242 return auth;
243}
244EXPORT_SYMBOL_GPL(rpcauth_create);
245
246void
247rpcauth_release(struct rpc_auth *auth)
248{
249 if (!refcount_dec_and_test(&auth->au_count))
250 return;
251 auth->au_ops->destroy(auth);
252}
253
254static DEFINE_SPINLOCK(rpc_credcache_lock);
255
256/*
257 * On success, the caller is responsible for freeing the reference
258 * held by the hashtable
259 */
260static bool
261rpcauth_unhash_cred_locked(struct rpc_cred *cred)
262{
263 if (!test_and_clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
264 return false;
265 hlist_del_rcu(&cred->cr_hash);
266 return true;
267}
268
269static bool
270rpcauth_unhash_cred(struct rpc_cred *cred)
271{
272 spinlock_t *cache_lock;
273 bool ret;
274
275 if (!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
276 return false;
277 cache_lock = &cred->cr_auth->au_credcache->lock;
278 spin_lock(cache_lock);
279 ret = rpcauth_unhash_cred_locked(cred);
280 spin_unlock(cache_lock);
281 return ret;
282}
283
284/*
285 * Initialize RPC credential cache
286 */
287int
288rpcauth_init_credcache(struct rpc_auth *auth)
289{
290 struct rpc_cred_cache *new;
291 unsigned int hashsize;
292
293 new = kmalloc(sizeof(*new), GFP_KERNEL);
294 if (!new)
295 goto out_nocache;
296 new->hashbits = auth_hashbits;
297 hashsize = 1U << new->hashbits;
298 new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
299 if (!new->hashtable)
300 goto out_nohashtbl;
301 spin_lock_init(&new->lock);
302 auth->au_credcache = new;
303 return 0;
304out_nohashtbl:
305 kfree(new);
306out_nocache:
307 return -ENOMEM;
308}
309EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
310
311char *
312rpcauth_stringify_acceptor(struct rpc_cred *cred)
313{
314 if (!cred->cr_ops->crstringify_acceptor)
315 return NULL;
316 return cred->cr_ops->crstringify_acceptor(cred);
317}
318EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
319
320/*
321 * Destroy a list of credentials
322 */
323static inline
324void rpcauth_destroy_credlist(struct list_head *head)
325{
326 struct rpc_cred *cred;
327
328 while (!list_empty(head)) {
329 cred = list_entry(head->next, struct rpc_cred, cr_lru);
330 list_del_init(&cred->cr_lru);
331 put_rpccred(cred);
332 }
333}
334
335static void
336rpcauth_lru_add_locked(struct rpc_cred *cred)
337{
338 if (!list_empty(&cred->cr_lru))
339 return;
340 number_cred_unused++;
341 list_add_tail(&cred->cr_lru, &cred_unused);
342}
343
344static void
345rpcauth_lru_add(struct rpc_cred *cred)
346{
347 if (!list_empty(&cred->cr_lru))
348 return;
349 spin_lock(&rpc_credcache_lock);
350 rpcauth_lru_add_locked(cred);
351 spin_unlock(&rpc_credcache_lock);
352}
353
354static void
355rpcauth_lru_remove_locked(struct rpc_cred *cred)
356{
357 if (list_empty(&cred->cr_lru))
358 return;
359 number_cred_unused--;
360 list_del_init(&cred->cr_lru);
361}
362
363static void
364rpcauth_lru_remove(struct rpc_cred *cred)
365{
366 if (list_empty(&cred->cr_lru))
367 return;
368 spin_lock(&rpc_credcache_lock);
369 rpcauth_lru_remove_locked(cred);
370 spin_unlock(&rpc_credcache_lock);
371}
372
373/*
374 * Clear the RPC credential cache, and delete those credentials
375 * that are not referenced.
376 */
377void
378rpcauth_clear_credcache(struct rpc_cred_cache *cache)
379{
380 LIST_HEAD(free);
381 struct hlist_head *head;
382 struct rpc_cred *cred;
383 unsigned int hashsize = 1U << cache->hashbits;
384 int i;
385
386 spin_lock(&rpc_credcache_lock);
387 spin_lock(&cache->lock);
388 for (i = 0; i < hashsize; i++) {
389 head = &cache->hashtable[i];
390 while (!hlist_empty(head)) {
391 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
392 rpcauth_unhash_cred_locked(cred);
393 /* Note: We now hold a reference to cred */
394 rpcauth_lru_remove_locked(cred);
395 list_add_tail(&cred->cr_lru, &free);
396 }
397 }
398 spin_unlock(&cache->lock);
399 spin_unlock(&rpc_credcache_lock);
400 rpcauth_destroy_credlist(&free);
401}
402
403/*
404 * Destroy the RPC credential cache
405 */
406void
407rpcauth_destroy_credcache(struct rpc_auth *auth)
408{
409 struct rpc_cred_cache *cache = auth->au_credcache;
410
411 if (cache) {
412 auth->au_credcache = NULL;
413 rpcauth_clear_credcache(cache);
414 kfree(cache->hashtable);
415 kfree(cache);
416 }
417}
418EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
419
420
421#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
422
423/*
424 * Remove stale credentials. Avoid sleeping inside the loop.
425 */
426static long
427rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
428{
429 struct rpc_cred *cred, *next;
430 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
431 long freed = 0;
432
433 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
434
435 if (nr_to_scan-- == 0)
436 break;
437 if (refcount_read(&cred->cr_count) > 1) {
438 rpcauth_lru_remove_locked(cred);
439 continue;
440 }
441 /*
442 * Enforce a 60 second garbage collection moratorium
443 * Note that the cred_unused list must be time-ordered.
444 */
445 if (time_in_range(cred->cr_expire, expired, jiffies))
446 continue;
447 if (!rpcauth_unhash_cred(cred))
448 continue;
449
450 rpcauth_lru_remove_locked(cred);
451 freed++;
452 list_add_tail(&cred->cr_lru, free);
453 }
454 return freed ? freed : SHRINK_STOP;
455}
456
457static unsigned long
458rpcauth_cache_do_shrink(int nr_to_scan)
459{
460 LIST_HEAD(free);
461 unsigned long freed;
462
463 spin_lock(&rpc_credcache_lock);
464 freed = rpcauth_prune_expired(&free, nr_to_scan);
465 spin_unlock(&rpc_credcache_lock);
466 rpcauth_destroy_credlist(&free);
467
468 return freed;
469}
470
471/*
472 * Run memory cache shrinker.
473 */
474static unsigned long
475rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
476
477{
478 if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
479 return SHRINK_STOP;
480
481 /* nothing left, don't come back */
482 if (list_empty(&cred_unused))
483 return SHRINK_STOP;
484
485 return rpcauth_cache_do_shrink(sc->nr_to_scan);
486}
487
488static unsigned long
489rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
490
491{
492 return number_cred_unused * sysctl_vfs_cache_pressure / 100;
493}
494
495static void
496rpcauth_cache_enforce_limit(void)
497{
498 unsigned long diff;
499 unsigned int nr_to_scan;
500
501 if (number_cred_unused <= auth_max_cred_cachesize)
502 return;
503 diff = number_cred_unused - auth_max_cred_cachesize;
504 nr_to_scan = 100;
505 if (diff < nr_to_scan)
506 nr_to_scan = diff;
507 rpcauth_cache_do_shrink(nr_to_scan);
508}
509
510/*
511 * Look up a process' credentials in the authentication cache
512 */
513struct rpc_cred *
514rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
515 int flags, gfp_t gfp)
516{
517 LIST_HEAD(free);
518 struct rpc_cred_cache *cache = auth->au_credcache;
519 struct rpc_cred *cred = NULL,
520 *entry, *new;
521 unsigned int nr;
522
523 nr = auth->au_ops->hash_cred(acred, cache->hashbits);
524
525 rcu_read_lock();
526 hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
527 if (!entry->cr_ops->crmatch(acred, entry, flags))
528 continue;
529 cred = get_rpccred(entry);
530 if (cred)
531 break;
532 }
533 rcu_read_unlock();
534
535 if (cred != NULL)
536 goto found;
537
538 new = auth->au_ops->crcreate(auth, acred, flags, gfp);
539 if (IS_ERR(new)) {
540 cred = new;
541 goto out;
542 }
543
544 spin_lock(&cache->lock);
545 hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
546 if (!entry->cr_ops->crmatch(acred, entry, flags))
547 continue;
548 cred = get_rpccred(entry);
549 if (cred)
550 break;
551 }
552 if (cred == NULL) {
553 cred = new;
554 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
555 refcount_inc(&cred->cr_count);
556 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
557 } else
558 list_add_tail(&new->cr_lru, &free);
559 spin_unlock(&cache->lock);
560 rpcauth_cache_enforce_limit();
561found:
562 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
563 cred->cr_ops->cr_init != NULL &&
564 !(flags & RPCAUTH_LOOKUP_NEW)) {
565 int res = cred->cr_ops->cr_init(auth, cred);
566 if (res < 0) {
567 put_rpccred(cred);
568 cred = ERR_PTR(res);
569 }
570 }
571 rpcauth_destroy_credlist(&free);
572out:
573 return cred;
574}
575EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
576
577struct rpc_cred *
578rpcauth_lookupcred(struct rpc_auth *auth, int flags)
579{
580 struct auth_cred acred;
581 struct rpc_cred *ret;
582 const struct cred *cred = current_cred();
583
584 memset(&acred, 0, sizeof(acred));
585 acred.cred = cred;
586 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
587 return ret;
588}
589EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
590
591void
592rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
593 struct rpc_auth *auth, const struct rpc_credops *ops)
594{
595 INIT_HLIST_NODE(&cred->cr_hash);
596 INIT_LIST_HEAD(&cred->cr_lru);
597 refcount_set(&cred->cr_count, 1);
598 cred->cr_auth = auth;
599 cred->cr_flags = 0;
600 cred->cr_ops = ops;
601 cred->cr_expire = jiffies;
602 cred->cr_cred = get_cred(acred->cred);
603}
604EXPORT_SYMBOL_GPL(rpcauth_init_cred);
605
606static struct rpc_cred *
607rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
608{
609 struct rpc_auth *auth = task->tk_client->cl_auth;
610 struct auth_cred acred = {
611 .cred = get_task_cred(&init_task),
612 };
613 struct rpc_cred *ret;
614
615 if (RPC_IS_ASYNC(task))
616 lookupflags |= RPCAUTH_LOOKUP_ASYNC;
617 ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
618 put_cred(acred.cred);
619 return ret;
620}
621
622static struct rpc_cred *
623rpcauth_bind_machine_cred(struct rpc_task *task, int lookupflags)
624{
625 struct rpc_auth *auth = task->tk_client->cl_auth;
626 struct auth_cred acred = {
627 .principal = task->tk_client->cl_principal,
628 .cred = init_task.cred,
629 };
630
631 if (!acred.principal)
632 return NULL;
633 if (RPC_IS_ASYNC(task))
634 lookupflags |= RPCAUTH_LOOKUP_ASYNC;
635 return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
636}
637
638static struct rpc_cred *
639rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
640{
641 struct rpc_auth *auth = task->tk_client->cl_auth;
642
643 return rpcauth_lookupcred(auth, lookupflags);
644}
645
646static int
647rpcauth_bindcred(struct rpc_task *task, const struct cred *cred, int flags)
648{
649 struct rpc_rqst *req = task->tk_rqstp;
650 struct rpc_cred *new = NULL;
651 int lookupflags = 0;
652 struct rpc_auth *auth = task->tk_client->cl_auth;
653 struct auth_cred acred = {
654 .cred = cred,
655 };
656
657 if (flags & RPC_TASK_ASYNC)
658 lookupflags |= RPCAUTH_LOOKUP_NEW | RPCAUTH_LOOKUP_ASYNC;
659 if (task->tk_op_cred)
660 /* Task must use exactly this rpc_cred */
661 new = get_rpccred(task->tk_op_cred);
662 else if (cred != NULL && cred != &machine_cred)
663 new = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
664 else if (cred == &machine_cred)
665 new = rpcauth_bind_machine_cred(task, lookupflags);
666
667 /* If machine cred couldn't be bound, try a root cred */
668 if (new)
669 ;
670 else if (cred == &machine_cred)
671 new = rpcauth_bind_root_cred(task, lookupflags);
672 else if (flags & RPC_TASK_NULLCREDS)
673 new = authnull_ops.lookup_cred(NULL, NULL, 0);
674 else
675 new = rpcauth_bind_new_cred(task, lookupflags);
676 if (IS_ERR(new))
677 return PTR_ERR(new);
678 put_rpccred(req->rq_cred);
679 req->rq_cred = new;
680 return 0;
681}
682
683void
684put_rpccred(struct rpc_cred *cred)
685{
686 if (cred == NULL)
687 return;
688 rcu_read_lock();
689 if (refcount_dec_and_test(&cred->cr_count))
690 goto destroy;
691 if (refcount_read(&cred->cr_count) != 1 ||
692 !test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags))
693 goto out;
694 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
695 cred->cr_expire = jiffies;
696 rpcauth_lru_add(cred);
697 /* Race breaker */
698 if (unlikely(!test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags)))
699 rpcauth_lru_remove(cred);
700 } else if (rpcauth_unhash_cred(cred)) {
701 rpcauth_lru_remove(cred);
702 if (refcount_dec_and_test(&cred->cr_count))
703 goto destroy;
704 }
705out:
706 rcu_read_unlock();
707 return;
708destroy:
709 rcu_read_unlock();
710 cred->cr_ops->crdestroy(cred);
711}
712EXPORT_SYMBOL_GPL(put_rpccred);
713
714/**
715 * rpcauth_marshcred - Append RPC credential to end of @xdr
716 * @task: controlling RPC task
717 * @xdr: xdr_stream containing initial portion of RPC Call header
718 *
719 * On success, an appropriate verifier is added to @xdr, @xdr is
720 * updated to point past the verifier, and zero is returned.
721 * Otherwise, @xdr is in an undefined state and a negative errno
722 * is returned.
723 */
724int rpcauth_marshcred(struct rpc_task *task, struct xdr_stream *xdr)
725{
726 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
727
728 return ops->crmarshal(task, xdr);
729}
730
731/**
732 * rpcauth_wrap_req_encode - XDR encode the RPC procedure
733 * @task: controlling RPC task
734 * @xdr: stream where on-the-wire bytes are to be marshalled
735 *
736 * On success, @xdr contains the encoded and wrapped message.
737 * Otherwise, @xdr is in an undefined state.
738 */
739int rpcauth_wrap_req_encode(struct rpc_task *task, struct xdr_stream *xdr)
740{
741 kxdreproc_t encode = task->tk_msg.rpc_proc->p_encode;
742
743 encode(task->tk_rqstp, xdr, task->tk_msg.rpc_argp);
744 return 0;
745}
746EXPORT_SYMBOL_GPL(rpcauth_wrap_req_encode);
747
748/**
749 * rpcauth_wrap_req - XDR encode and wrap the RPC procedure
750 * @task: controlling RPC task
751 * @xdr: stream where on-the-wire bytes are to be marshalled
752 *
753 * On success, @xdr contains the encoded and wrapped message,
754 * and zero is returned. Otherwise, @xdr is in an undefined
755 * state and a negative errno is returned.
756 */
757int rpcauth_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
758{
759 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
760
761 return ops->crwrap_req(task, xdr);
762}
763
764/**
765 * rpcauth_checkverf - Validate verifier in RPC Reply header
766 * @task: controlling RPC task
767 * @xdr: xdr_stream containing RPC Reply header
768 *
769 * Return values:
770 * %0: Verifier is valid. @xdr now points past the verifier.
771 * %-EIO: Verifier is corrupted or message ended early.
772 * %-EACCES: Verifier is intact but not valid.
773 * %-EPROTONOSUPPORT: Server does not support the requested auth type.
774 *
775 * When a negative errno is returned, @xdr is left in an undefined
776 * state.
777 */
778int
779rpcauth_checkverf(struct rpc_task *task, struct xdr_stream *xdr)
780{
781 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
782
783 return ops->crvalidate(task, xdr);
784}
785
786/**
787 * rpcauth_unwrap_resp_decode - Invoke XDR decode function
788 * @task: controlling RPC task
789 * @xdr: stream where the Reply message resides
790 *
791 * Returns zero on success; otherwise a negative errno is returned.
792 */
793int
794rpcauth_unwrap_resp_decode(struct rpc_task *task, struct xdr_stream *xdr)
795{
796 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
797
798 return decode(task->tk_rqstp, xdr, task->tk_msg.rpc_resp);
799}
800EXPORT_SYMBOL_GPL(rpcauth_unwrap_resp_decode);
801
802/**
803 * rpcauth_unwrap_resp - Invoke unwrap and decode function for the cred
804 * @task: controlling RPC task
805 * @xdr: stream where the Reply message resides
806 *
807 * Returns zero on success; otherwise a negative errno is returned.
808 */
809int
810rpcauth_unwrap_resp(struct rpc_task *task, struct xdr_stream *xdr)
811{
812 const struct rpc_credops *ops = task->tk_rqstp->rq_cred->cr_ops;
813
814 return ops->crunwrap_resp(task, xdr);
815}
816
817bool
818rpcauth_xmit_need_reencode(struct rpc_task *task)
819{
820 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
821
822 if (!cred || !cred->cr_ops->crneed_reencode)
823 return false;
824 return cred->cr_ops->crneed_reencode(task);
825}
826
827int
828rpcauth_refreshcred(struct rpc_task *task)
829{
830 struct rpc_cred *cred;
831 int err;
832
833 cred = task->tk_rqstp->rq_cred;
834 if (cred == NULL) {
835 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
836 if (err < 0)
837 goto out;
838 cred = task->tk_rqstp->rq_cred;
839 }
840
841 err = cred->cr_ops->crrefresh(task);
842out:
843 if (err < 0)
844 task->tk_status = err;
845 return err;
846}
847
848void
849rpcauth_invalcred(struct rpc_task *task)
850{
851 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
852
853 if (cred)
854 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
855}
856
857int
858rpcauth_uptodatecred(struct rpc_task *task)
859{
860 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
861
862 return cred == NULL ||
863 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
864}
865
866static struct shrinker *rpc_cred_shrinker;
867
868int __init rpcauth_init_module(void)
869{
870 int err;
871
872 err = rpc_init_authunix();
873 if (err < 0)
874 goto out1;
875 rpc_cred_shrinker = shrinker_alloc(0, "sunrpc_cred");
876 if (!rpc_cred_shrinker) {
877 err = -ENOMEM;
878 goto out2;
879 }
880
881 rpc_cred_shrinker->count_objects = rpcauth_cache_shrink_count;
882 rpc_cred_shrinker->scan_objects = rpcauth_cache_shrink_scan;
883
884 shrinker_register(rpc_cred_shrinker);
885
886 return 0;
887out2:
888 rpc_destroy_authunix();
889out1:
890 return err;
891}
892
893void rpcauth_remove_module(void)
894{
895 rpc_destroy_authunix();
896 shrinker_free(rpc_cred_shrinker);
897}