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