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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 [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}
1/*
2 * linux/net/sunrpc/auth.c
3 *
4 * Generic RPC client authentication API.
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
8
9#include <linux/types.h>
10#include <linux/sched.h>
11#include <linux/cred.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/errno.h>
15#include <linux/hash.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/sunrpc/gss_api.h>
18#include <linux/spinlock.h>
19
20#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
21# define RPCDBG_FACILITY RPCDBG_AUTH
22#endif
23
24#define RPC_CREDCACHE_DEFAULT_HASHBITS (4)
25struct rpc_cred_cache {
26 struct hlist_head *hashtable;
27 unsigned int hashbits;
28 spinlock_t lock;
29};
30
31static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
32
33static DEFINE_SPINLOCK(rpc_authflavor_lock);
34static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
35 &authnull_ops, /* AUTH_NULL */
36 &authunix_ops, /* AUTH_UNIX */
37 NULL, /* others can be loadable modules */
38};
39
40static LIST_HEAD(cred_unused);
41static unsigned long number_cred_unused;
42
43#define MAX_HASHTABLE_BITS (14)
44static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
45{
46 unsigned long num;
47 unsigned int nbits;
48 int ret;
49
50 if (!val)
51 goto out_inval;
52 ret = kstrtoul(val, 0, &num);
53 if (ret == -EINVAL)
54 goto out_inval;
55 nbits = fls(num - 1);
56 if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
57 goto out_inval;
58 *(unsigned int *)kp->arg = nbits;
59 return 0;
60out_inval:
61 return -EINVAL;
62}
63
64static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
65{
66 unsigned int nbits;
67
68 nbits = *(unsigned int *)kp->arg;
69 return sprintf(buffer, "%u", 1U << nbits);
70}
71
72#define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
73
74static const struct kernel_param_ops param_ops_hashtbl_sz = {
75 .set = param_set_hashtbl_sz,
76 .get = param_get_hashtbl_sz,
77};
78
79module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
80MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
81
82static unsigned long auth_max_cred_cachesize = ULONG_MAX;
83module_param(auth_max_cred_cachesize, ulong, 0644);
84MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
85
86static u32
87pseudoflavor_to_flavor(u32 flavor) {
88 if (flavor > RPC_AUTH_MAXFLAVOR)
89 return RPC_AUTH_GSS;
90 return flavor;
91}
92
93int
94rpcauth_register(const struct rpc_authops *ops)
95{
96 rpc_authflavor_t flavor;
97 int ret = -EPERM;
98
99 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
100 return -EINVAL;
101 spin_lock(&rpc_authflavor_lock);
102 if (auth_flavors[flavor] == NULL) {
103 auth_flavors[flavor] = ops;
104 ret = 0;
105 }
106 spin_unlock(&rpc_authflavor_lock);
107 return ret;
108}
109EXPORT_SYMBOL_GPL(rpcauth_register);
110
111int
112rpcauth_unregister(const struct rpc_authops *ops)
113{
114 rpc_authflavor_t flavor;
115 int ret = -EPERM;
116
117 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
118 return -EINVAL;
119 spin_lock(&rpc_authflavor_lock);
120 if (auth_flavors[flavor] == ops) {
121 auth_flavors[flavor] = NULL;
122 ret = 0;
123 }
124 spin_unlock(&rpc_authflavor_lock);
125 return ret;
126}
127EXPORT_SYMBOL_GPL(rpcauth_unregister);
128
129/**
130 * rpcauth_get_pseudoflavor - check if security flavor is supported
131 * @flavor: a security flavor
132 * @info: a GSS mech OID, quality of protection, and service value
133 *
134 * Verifies that an appropriate kernel module is available or already loaded.
135 * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
136 * not supported locally.
137 */
138rpc_authflavor_t
139rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
140{
141 const struct rpc_authops *ops;
142 rpc_authflavor_t pseudoflavor;
143
144 ops = auth_flavors[flavor];
145 if (ops == NULL)
146 request_module("rpc-auth-%u", flavor);
147 spin_lock(&rpc_authflavor_lock);
148 ops = auth_flavors[flavor];
149 if (ops == NULL || !try_module_get(ops->owner)) {
150 spin_unlock(&rpc_authflavor_lock);
151 return RPC_AUTH_MAXFLAVOR;
152 }
153 spin_unlock(&rpc_authflavor_lock);
154
155 pseudoflavor = flavor;
156 if (ops->info2flavor != NULL)
157 pseudoflavor = ops->info2flavor(info);
158
159 module_put(ops->owner);
160 return pseudoflavor;
161}
162EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
163
164/**
165 * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
166 * @pseudoflavor: GSS pseudoflavor to match
167 * @info: rpcsec_gss_info structure to fill in
168 *
169 * Returns zero and fills in "info" if pseudoflavor matches a
170 * supported mechanism.
171 */
172int
173rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
174{
175 rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
176 const struct rpc_authops *ops;
177 int result;
178
179 if (flavor >= RPC_AUTH_MAXFLAVOR)
180 return -EINVAL;
181
182 ops = auth_flavors[flavor];
183 if (ops == NULL)
184 request_module("rpc-auth-%u", flavor);
185 spin_lock(&rpc_authflavor_lock);
186 ops = auth_flavors[flavor];
187 if (ops == NULL || !try_module_get(ops->owner)) {
188 spin_unlock(&rpc_authflavor_lock);
189 return -ENOENT;
190 }
191 spin_unlock(&rpc_authflavor_lock);
192
193 result = -ENOENT;
194 if (ops->flavor2info != NULL)
195 result = ops->flavor2info(pseudoflavor, info);
196
197 module_put(ops->owner);
198 return result;
199}
200EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
201
202/**
203 * rpcauth_list_flavors - discover registered flavors and pseudoflavors
204 * @array: array to fill in
205 * @size: size of "array"
206 *
207 * Returns the number of array items filled in, or a negative errno.
208 *
209 * The returned array is not sorted by any policy. Callers should not
210 * rely on the order of the items in the returned array.
211 */
212int
213rpcauth_list_flavors(rpc_authflavor_t *array, int size)
214{
215 rpc_authflavor_t flavor;
216 int result = 0;
217
218 spin_lock(&rpc_authflavor_lock);
219 for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
220 const struct rpc_authops *ops = auth_flavors[flavor];
221 rpc_authflavor_t pseudos[4];
222 int i, len;
223
224 if (result >= size) {
225 result = -ENOMEM;
226 break;
227 }
228
229 if (ops == NULL)
230 continue;
231 if (ops->list_pseudoflavors == NULL) {
232 array[result++] = ops->au_flavor;
233 continue;
234 }
235 len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
236 if (len < 0) {
237 result = len;
238 break;
239 }
240 for (i = 0; i < len; i++) {
241 if (result >= size) {
242 result = -ENOMEM;
243 break;
244 }
245 array[result++] = pseudos[i];
246 }
247 }
248 spin_unlock(&rpc_authflavor_lock);
249
250 dprintk("RPC: %s returns %d\n", __func__, result);
251 return result;
252}
253EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
254
255struct rpc_auth *
256rpcauth_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
257{
258 struct rpc_auth *auth;
259 const struct rpc_authops *ops;
260 u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
261
262 auth = ERR_PTR(-EINVAL);
263 if (flavor >= RPC_AUTH_MAXFLAVOR)
264 goto out;
265
266 if ((ops = auth_flavors[flavor]) == NULL)
267 request_module("rpc-auth-%u", flavor);
268 spin_lock(&rpc_authflavor_lock);
269 ops = auth_flavors[flavor];
270 if (ops == NULL || !try_module_get(ops->owner)) {
271 spin_unlock(&rpc_authflavor_lock);
272 goto out;
273 }
274 spin_unlock(&rpc_authflavor_lock);
275 auth = ops->create(args, clnt);
276 module_put(ops->owner);
277 if (IS_ERR(auth))
278 return auth;
279 if (clnt->cl_auth)
280 rpcauth_release(clnt->cl_auth);
281 clnt->cl_auth = auth;
282
283out:
284 return auth;
285}
286EXPORT_SYMBOL_GPL(rpcauth_create);
287
288void
289rpcauth_release(struct rpc_auth *auth)
290{
291 if (!atomic_dec_and_test(&auth->au_count))
292 return;
293 auth->au_ops->destroy(auth);
294}
295
296static DEFINE_SPINLOCK(rpc_credcache_lock);
297
298static void
299rpcauth_unhash_cred_locked(struct rpc_cred *cred)
300{
301 hlist_del_rcu(&cred->cr_hash);
302 smp_mb__before_atomic();
303 clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
304}
305
306static int
307rpcauth_unhash_cred(struct rpc_cred *cred)
308{
309 spinlock_t *cache_lock;
310 int ret;
311
312 cache_lock = &cred->cr_auth->au_credcache->lock;
313 spin_lock(cache_lock);
314 ret = atomic_read(&cred->cr_count) == 0;
315 if (ret)
316 rpcauth_unhash_cred_locked(cred);
317 spin_unlock(cache_lock);
318 return ret;
319}
320
321/*
322 * Initialize RPC credential cache
323 */
324int
325rpcauth_init_credcache(struct rpc_auth *auth)
326{
327 struct rpc_cred_cache *new;
328 unsigned int hashsize;
329
330 new = kmalloc(sizeof(*new), GFP_KERNEL);
331 if (!new)
332 goto out_nocache;
333 new->hashbits = auth_hashbits;
334 hashsize = 1U << new->hashbits;
335 new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
336 if (!new->hashtable)
337 goto out_nohashtbl;
338 spin_lock_init(&new->lock);
339 auth->au_credcache = new;
340 return 0;
341out_nohashtbl:
342 kfree(new);
343out_nocache:
344 return -ENOMEM;
345}
346EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
347
348/*
349 * Setup a credential key lifetime timeout notification
350 */
351int
352rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
353{
354 if (!cred->cr_auth->au_ops->key_timeout)
355 return 0;
356 return cred->cr_auth->au_ops->key_timeout(auth, cred);
357}
358EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
359
360bool
361rpcauth_cred_key_to_expire(struct rpc_auth *auth, struct rpc_cred *cred)
362{
363 if (auth->au_flags & RPCAUTH_AUTH_NO_CRKEY_TIMEOUT)
364 return false;
365 if (!cred->cr_ops->crkey_to_expire)
366 return false;
367 return cred->cr_ops->crkey_to_expire(cred);
368}
369EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
370
371char *
372rpcauth_stringify_acceptor(struct rpc_cred *cred)
373{
374 if (!cred->cr_ops->crstringify_acceptor)
375 return NULL;
376 return cred->cr_ops->crstringify_acceptor(cred);
377}
378EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
379
380/*
381 * Destroy a list of credentials
382 */
383static inline
384void rpcauth_destroy_credlist(struct list_head *head)
385{
386 struct rpc_cred *cred;
387
388 while (!list_empty(head)) {
389 cred = list_entry(head->next, struct rpc_cred, cr_lru);
390 list_del_init(&cred->cr_lru);
391 put_rpccred(cred);
392 }
393}
394
395/*
396 * Clear the RPC credential cache, and delete those credentials
397 * that are not referenced.
398 */
399void
400rpcauth_clear_credcache(struct rpc_cred_cache *cache)
401{
402 LIST_HEAD(free);
403 struct hlist_head *head;
404 struct rpc_cred *cred;
405 unsigned int hashsize = 1U << cache->hashbits;
406 int i;
407
408 spin_lock(&rpc_credcache_lock);
409 spin_lock(&cache->lock);
410 for (i = 0; i < hashsize; i++) {
411 head = &cache->hashtable[i];
412 while (!hlist_empty(head)) {
413 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
414 get_rpccred(cred);
415 if (!list_empty(&cred->cr_lru)) {
416 list_del(&cred->cr_lru);
417 number_cred_unused--;
418 }
419 list_add_tail(&cred->cr_lru, &free);
420 rpcauth_unhash_cred_locked(cred);
421 }
422 }
423 spin_unlock(&cache->lock);
424 spin_unlock(&rpc_credcache_lock);
425 rpcauth_destroy_credlist(&free);
426}
427
428/*
429 * Destroy the RPC credential cache
430 */
431void
432rpcauth_destroy_credcache(struct rpc_auth *auth)
433{
434 struct rpc_cred_cache *cache = auth->au_credcache;
435
436 if (cache) {
437 auth->au_credcache = NULL;
438 rpcauth_clear_credcache(cache);
439 kfree(cache->hashtable);
440 kfree(cache);
441 }
442}
443EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
444
445
446#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
447
448/*
449 * Remove stale credentials. Avoid sleeping inside the loop.
450 */
451static long
452rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
453{
454 spinlock_t *cache_lock;
455 struct rpc_cred *cred, *next;
456 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
457 long freed = 0;
458
459 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
460
461 if (nr_to_scan-- == 0)
462 break;
463 /*
464 * Enforce a 60 second garbage collection moratorium
465 * Note that the cred_unused list must be time-ordered.
466 */
467 if (time_in_range(cred->cr_expire, expired, jiffies) &&
468 test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
469 freed = SHRINK_STOP;
470 break;
471 }
472
473 list_del_init(&cred->cr_lru);
474 number_cred_unused--;
475 freed++;
476 if (atomic_read(&cred->cr_count) != 0)
477 continue;
478
479 cache_lock = &cred->cr_auth->au_credcache->lock;
480 spin_lock(cache_lock);
481 if (atomic_read(&cred->cr_count) == 0) {
482 get_rpccred(cred);
483 list_add_tail(&cred->cr_lru, free);
484 rpcauth_unhash_cred_locked(cred);
485 }
486 spin_unlock(cache_lock);
487 }
488 return freed;
489}
490
491static unsigned long
492rpcauth_cache_do_shrink(int nr_to_scan)
493{
494 LIST_HEAD(free);
495 unsigned long freed;
496
497 spin_lock(&rpc_credcache_lock);
498 freed = rpcauth_prune_expired(&free, nr_to_scan);
499 spin_unlock(&rpc_credcache_lock);
500 rpcauth_destroy_credlist(&free);
501
502 return freed;
503}
504
505/*
506 * Run memory cache shrinker.
507 */
508static unsigned long
509rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
510
511{
512 if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
513 return SHRINK_STOP;
514
515 /* nothing left, don't come back */
516 if (list_empty(&cred_unused))
517 return SHRINK_STOP;
518
519 return rpcauth_cache_do_shrink(sc->nr_to_scan);
520}
521
522static unsigned long
523rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
524
525{
526 return number_cred_unused * sysctl_vfs_cache_pressure / 100;
527}
528
529static void
530rpcauth_cache_enforce_limit(void)
531{
532 unsigned long diff;
533 unsigned int nr_to_scan;
534
535 if (number_cred_unused <= auth_max_cred_cachesize)
536 return;
537 diff = number_cred_unused - auth_max_cred_cachesize;
538 nr_to_scan = 100;
539 if (diff < nr_to_scan)
540 nr_to_scan = diff;
541 rpcauth_cache_do_shrink(nr_to_scan);
542}
543
544/*
545 * Look up a process' credentials in the authentication cache
546 */
547struct rpc_cred *
548rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
549 int flags, gfp_t gfp)
550{
551 LIST_HEAD(free);
552 struct rpc_cred_cache *cache = auth->au_credcache;
553 struct rpc_cred *cred = NULL,
554 *entry, *new;
555 unsigned int nr;
556
557 nr = auth->au_ops->hash_cred(acred, cache->hashbits);
558
559 rcu_read_lock();
560 hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
561 if (!entry->cr_ops->crmatch(acred, entry, flags))
562 continue;
563 if (flags & RPCAUTH_LOOKUP_RCU) {
564 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) &&
565 !test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags))
566 cred = entry;
567 break;
568 }
569 spin_lock(&cache->lock);
570 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
571 spin_unlock(&cache->lock);
572 continue;
573 }
574 cred = get_rpccred(entry);
575 spin_unlock(&cache->lock);
576 break;
577 }
578 rcu_read_unlock();
579
580 if (cred != NULL)
581 goto found;
582
583 if (flags & RPCAUTH_LOOKUP_RCU)
584 return ERR_PTR(-ECHILD);
585
586 new = auth->au_ops->crcreate(auth, acred, flags, gfp);
587 if (IS_ERR(new)) {
588 cred = new;
589 goto out;
590 }
591
592 spin_lock(&cache->lock);
593 hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
594 if (!entry->cr_ops->crmatch(acred, entry, flags))
595 continue;
596 cred = get_rpccred(entry);
597 break;
598 }
599 if (cred == NULL) {
600 cred = new;
601 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
602 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
603 } else
604 list_add_tail(&new->cr_lru, &free);
605 spin_unlock(&cache->lock);
606 rpcauth_cache_enforce_limit();
607found:
608 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
609 cred->cr_ops->cr_init != NULL &&
610 !(flags & RPCAUTH_LOOKUP_NEW)) {
611 int res = cred->cr_ops->cr_init(auth, cred);
612 if (res < 0) {
613 put_rpccred(cred);
614 cred = ERR_PTR(res);
615 }
616 }
617 rpcauth_destroy_credlist(&free);
618out:
619 return cred;
620}
621EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
622
623struct rpc_cred *
624rpcauth_lookupcred(struct rpc_auth *auth, int flags)
625{
626 struct auth_cred acred;
627 struct rpc_cred *ret;
628 const struct cred *cred = current_cred();
629
630 dprintk("RPC: looking up %s cred\n",
631 auth->au_ops->au_name);
632
633 memset(&acred, 0, sizeof(acred));
634 acred.uid = cred->fsuid;
635 acred.gid = cred->fsgid;
636 acred.group_info = cred->group_info;
637 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
638 return ret;
639}
640EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
641
642void
643rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
644 struct rpc_auth *auth, const struct rpc_credops *ops)
645{
646 INIT_HLIST_NODE(&cred->cr_hash);
647 INIT_LIST_HEAD(&cred->cr_lru);
648 atomic_set(&cred->cr_count, 1);
649 cred->cr_auth = auth;
650 cred->cr_ops = ops;
651 cred->cr_expire = jiffies;
652 cred->cr_uid = acred->uid;
653}
654EXPORT_SYMBOL_GPL(rpcauth_init_cred);
655
656struct rpc_cred *
657rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
658{
659 dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
660 cred->cr_auth->au_ops->au_name, cred);
661 return get_rpccred(cred);
662}
663EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
664
665static struct rpc_cred *
666rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
667{
668 struct rpc_auth *auth = task->tk_client->cl_auth;
669 struct auth_cred acred = {
670 .uid = GLOBAL_ROOT_UID,
671 .gid = GLOBAL_ROOT_GID,
672 };
673
674 dprintk("RPC: %5u looking up %s cred\n",
675 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
676 return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
677}
678
679static struct rpc_cred *
680rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
681{
682 struct rpc_auth *auth = task->tk_client->cl_auth;
683
684 dprintk("RPC: %5u looking up %s cred\n",
685 task->tk_pid, auth->au_ops->au_name);
686 return rpcauth_lookupcred(auth, lookupflags);
687}
688
689static int
690rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
691{
692 struct rpc_rqst *req = task->tk_rqstp;
693 struct rpc_cred *new;
694 int lookupflags = 0;
695
696 if (flags & RPC_TASK_ASYNC)
697 lookupflags |= RPCAUTH_LOOKUP_NEW;
698 if (cred != NULL)
699 new = cred->cr_ops->crbind(task, cred, lookupflags);
700 else if (flags & RPC_TASK_ROOTCREDS)
701 new = rpcauth_bind_root_cred(task, lookupflags);
702 else
703 new = rpcauth_bind_new_cred(task, lookupflags);
704 if (IS_ERR(new))
705 return PTR_ERR(new);
706 put_rpccred(req->rq_cred);
707 req->rq_cred = new;
708 return 0;
709}
710
711void
712put_rpccred(struct rpc_cred *cred)
713{
714 if (cred == NULL)
715 return;
716 /* Fast path for unhashed credentials */
717 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
718 if (atomic_dec_and_test(&cred->cr_count))
719 cred->cr_ops->crdestroy(cred);
720 return;
721 }
722
723 if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
724 return;
725 if (!list_empty(&cred->cr_lru)) {
726 number_cred_unused--;
727 list_del_init(&cred->cr_lru);
728 }
729 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
730 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
731 cred->cr_expire = jiffies;
732 list_add_tail(&cred->cr_lru, &cred_unused);
733 number_cred_unused++;
734 goto out_nodestroy;
735 }
736 if (!rpcauth_unhash_cred(cred)) {
737 /* We were hashed and someone looked us up... */
738 goto out_nodestroy;
739 }
740 }
741 spin_unlock(&rpc_credcache_lock);
742 cred->cr_ops->crdestroy(cred);
743 return;
744out_nodestroy:
745 spin_unlock(&rpc_credcache_lock);
746}
747EXPORT_SYMBOL_GPL(put_rpccred);
748
749__be32 *
750rpcauth_marshcred(struct rpc_task *task, __be32 *p)
751{
752 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
753
754 dprintk("RPC: %5u marshaling %s cred %p\n",
755 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
756
757 return cred->cr_ops->crmarshal(task, p);
758}
759
760__be32 *
761rpcauth_checkverf(struct rpc_task *task, __be32 *p)
762{
763 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
764
765 dprintk("RPC: %5u validating %s cred %p\n",
766 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
767
768 return cred->cr_ops->crvalidate(task, p);
769}
770
771static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
772 __be32 *data, void *obj)
773{
774 struct xdr_stream xdr;
775
776 xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
777 encode(rqstp, &xdr, obj);
778}
779
780int
781rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
782 __be32 *data, void *obj)
783{
784 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
785
786 dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
787 task->tk_pid, cred->cr_ops->cr_name, cred);
788 if (cred->cr_ops->crwrap_req)
789 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
790 /* By default, we encode the arguments normally. */
791 rpcauth_wrap_req_encode(encode, rqstp, data, obj);
792 return 0;
793}
794
795static int
796rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
797 __be32 *data, void *obj)
798{
799 struct xdr_stream xdr;
800
801 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
802 return decode(rqstp, &xdr, obj);
803}
804
805int
806rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
807 __be32 *data, void *obj)
808{
809 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
810
811 dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
812 task->tk_pid, cred->cr_ops->cr_name, cred);
813 if (cred->cr_ops->crunwrap_resp)
814 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
815 data, obj);
816 /* By default, we decode the arguments normally. */
817 return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
818}
819
820int
821rpcauth_refreshcred(struct rpc_task *task)
822{
823 struct rpc_cred *cred;
824 int err;
825
826 cred = task->tk_rqstp->rq_cred;
827 if (cred == NULL) {
828 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
829 if (err < 0)
830 goto out;
831 cred = task->tk_rqstp->rq_cred;
832 }
833 dprintk("RPC: %5u refreshing %s cred %p\n",
834 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
835
836 err = cred->cr_ops->crrefresh(task);
837out:
838 if (err < 0)
839 task->tk_status = err;
840 return err;
841}
842
843void
844rpcauth_invalcred(struct rpc_task *task)
845{
846 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
847
848 dprintk("RPC: %5u invalidating %s cred %p\n",
849 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
850 if (cred)
851 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
852}
853
854int
855rpcauth_uptodatecred(struct rpc_task *task)
856{
857 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
858
859 return cred == NULL ||
860 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
861}
862
863static struct shrinker rpc_cred_shrinker = {
864 .count_objects = rpcauth_cache_shrink_count,
865 .scan_objects = rpcauth_cache_shrink_scan,
866 .seeks = DEFAULT_SEEKS,
867};
868
869int __init rpcauth_init_module(void)
870{
871 int err;
872
873 err = rpc_init_authunix();
874 if (err < 0)
875 goto out1;
876 err = rpc_init_generic_auth();
877 if (err < 0)
878 goto out2;
879 err = register_shrinker(&rpc_cred_shrinker);
880 if (err < 0)
881 goto out3;
882 return 0;
883out3:
884 rpc_destroy_generic_auth();
885out2:
886 rpc_destroy_authunix();
887out1:
888 return err;
889}
890
891void rpcauth_remove_module(void)
892{
893 rpc_destroy_authunix();
894 rpc_destroy_generic_auth();
895 unregister_shrinker(&rpc_cred_shrinker);
896}