9b81be8d9946460f2576b8b9c8d6926ac7d456fe
[linux-3.10.git] / net / sunrpc / auth.c
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 #ifdef RPC_DEBUG
20 # define RPCDBG_FACILITY        RPCDBG_AUTH
21 #endif
22
23 #define RPC_CREDCACHE_DEFAULT_HASHBITS  (4)
24 struct rpc_cred_cache {
25         struct hlist_head       *hashtable;
26         unsigned int            hashbits;
27         spinlock_t              lock;
28 };
29
30 static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
31
32 static DEFINE_SPINLOCK(rpc_authflavor_lock);
33 static 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
39 static LIST_HEAD(cred_unused);
40 static unsigned long number_cred_unused;
41
42 #define MAX_HASHTABLE_BITS (14)
43 static 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 = strict_strtoul(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;
61 out_inval:
62         return -EINVAL;
63 }
64
65 static 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
75 static struct kernel_param_ops param_ops_hashtbl_sz = {
76         .set = param_set_hashtbl_sz,
77         .get = param_get_hashtbl_sz,
78 };
79
80 module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
81 MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
82
83 static u32
84 pseudoflavor_to_flavor(u32 flavor) {
85         if (flavor >= RPC_AUTH_MAXFLAVOR)
86                 return RPC_AUTH_GSS;
87         return flavor;
88 }
89
90 int
91 rpcauth_register(const struct rpc_authops *ops)
92 {
93         rpc_authflavor_t flavor;
94         int ret = -EPERM;
95
96         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
97                 return -EINVAL;
98         spin_lock(&rpc_authflavor_lock);
99         if (auth_flavors[flavor] == NULL) {
100                 auth_flavors[flavor] = ops;
101                 ret = 0;
102         }
103         spin_unlock(&rpc_authflavor_lock);
104         return ret;
105 }
106 EXPORT_SYMBOL_GPL(rpcauth_register);
107
108 int
109 rpcauth_unregister(const struct rpc_authops *ops)
110 {
111         rpc_authflavor_t flavor;
112         int ret = -EPERM;
113
114         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
115                 return -EINVAL;
116         spin_lock(&rpc_authflavor_lock);
117         if (auth_flavors[flavor] == ops) {
118                 auth_flavors[flavor] = NULL;
119                 ret = 0;
120         }
121         spin_unlock(&rpc_authflavor_lock);
122         return ret;
123 }
124 EXPORT_SYMBOL_GPL(rpcauth_unregister);
125
126 /**
127  * rpcauth_get_pseudoflavor - check if security flavor is supported
128  * @flavor: a security flavor
129  * @info: a GSS mech OID, quality of protection, and service value
130  *
131  * Verifies that an appropriate kernel module is available or already loaded.
132  * Returns an equivalent pseudoflavor, or RPC_AUTH_MAXFLAVOR if "flavor" is
133  * not supported locally.
134  */
135 rpc_authflavor_t
136 rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
137 {
138         const struct rpc_authops *ops;
139         rpc_authflavor_t pseudoflavor;
140
141         ops = auth_flavors[flavor];
142         if (ops == NULL)
143                 request_module("rpc-auth-%u", flavor);
144         spin_lock(&rpc_authflavor_lock);
145         ops = auth_flavors[flavor];
146         if (ops == NULL || !try_module_get(ops->owner)) {
147                 spin_unlock(&rpc_authflavor_lock);
148                 return RPC_AUTH_MAXFLAVOR;
149         }
150         spin_unlock(&rpc_authflavor_lock);
151
152         pseudoflavor = flavor;
153         if (ops->info2flavor != NULL)
154                 pseudoflavor = ops->info2flavor(info);
155
156         module_put(ops->owner);
157         return pseudoflavor;
158 }
159 EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
160
161 /**
162  * rpcauth_list_flavors - discover registered flavors and pseudoflavors
163  * @array: array to fill in
164  * @size: size of "array"
165  *
166  * Returns the number of array items filled in, or a negative errno.
167  *
168  * The returned array is not sorted by any policy.  Callers should not
169  * rely on the order of the items in the returned array.
170  */
171 int
172 rpcauth_list_flavors(rpc_authflavor_t *array, int size)
173 {
174         rpc_authflavor_t flavor;
175         int result = 0;
176
177         spin_lock(&rpc_authflavor_lock);
178         for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
179                 const struct rpc_authops *ops = auth_flavors[flavor];
180                 rpc_authflavor_t pseudos[4];
181                 int i, len;
182
183                 if (result >= size) {
184                         result = -ENOMEM;
185                         break;
186                 }
187
188                 if (ops == NULL)
189                         continue;
190                 if (ops->list_pseudoflavors == NULL) {
191                         array[result++] = ops->au_flavor;
192                         continue;
193                 }
194                 len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
195                 if (len < 0) {
196                         result = len;
197                         break;
198                 }
199                 for (i = 0; i < len; i++) {
200                         if (result >= size) {
201                                 result = -ENOMEM;
202                                 break;
203                         }
204                         array[result++] = pseudos[i];
205                 }
206         }
207         spin_unlock(&rpc_authflavor_lock);
208
209         dprintk("RPC:       %s returns %d\n", __func__, result);
210         return result;
211 }
212 EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
213
214 struct rpc_auth *
215 rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
216 {
217         struct rpc_auth         *auth;
218         const struct rpc_authops *ops;
219         u32                     flavor = pseudoflavor_to_flavor(pseudoflavor);
220
221         auth = ERR_PTR(-EINVAL);
222         if (flavor >= RPC_AUTH_MAXFLAVOR)
223                 goto out;
224
225         if ((ops = auth_flavors[flavor]) == NULL)
226                 request_module("rpc-auth-%u", flavor);
227         spin_lock(&rpc_authflavor_lock);
228         ops = auth_flavors[flavor];
229         if (ops == NULL || !try_module_get(ops->owner)) {
230                 spin_unlock(&rpc_authflavor_lock);
231                 goto out;
232         }
233         spin_unlock(&rpc_authflavor_lock);
234         auth = ops->create(clnt, pseudoflavor);
235         module_put(ops->owner);
236         if (IS_ERR(auth))
237                 return auth;
238         if (clnt->cl_auth)
239                 rpcauth_release(clnt->cl_auth);
240         clnt->cl_auth = auth;
241
242 out:
243         return auth;
244 }
245 EXPORT_SYMBOL_GPL(rpcauth_create);
246
247 void
248 rpcauth_release(struct rpc_auth *auth)
249 {
250         if (!atomic_dec_and_test(&auth->au_count))
251                 return;
252         auth->au_ops->destroy(auth);
253 }
254
255 static DEFINE_SPINLOCK(rpc_credcache_lock);
256
257 static void
258 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
259 {
260         hlist_del_rcu(&cred->cr_hash);
261         smp_mb__before_clear_bit();
262         clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
263 }
264
265 static int
266 rpcauth_unhash_cred(struct rpc_cred *cred)
267 {
268         spinlock_t *cache_lock;
269         int ret;
270
271         cache_lock = &cred->cr_auth->au_credcache->lock;
272         spin_lock(cache_lock);
273         ret = atomic_read(&cred->cr_count) == 0;
274         if (ret)
275                 rpcauth_unhash_cred_locked(cred);
276         spin_unlock(cache_lock);
277         return ret;
278 }
279
280 /*
281  * Initialize RPC credential cache
282  */
283 int
284 rpcauth_init_credcache(struct rpc_auth *auth)
285 {
286         struct rpc_cred_cache *new;
287         unsigned int hashsize;
288
289         new = kmalloc(sizeof(*new), GFP_KERNEL);
290         if (!new)
291                 goto out_nocache;
292         new->hashbits = auth_hashbits;
293         hashsize = 1U << new->hashbits;
294         new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
295         if (!new->hashtable)
296                 goto out_nohashtbl;
297         spin_lock_init(&new->lock);
298         auth->au_credcache = new;
299         return 0;
300 out_nohashtbl:
301         kfree(new);
302 out_nocache:
303         return -ENOMEM;
304 }
305 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
306
307 /*
308  * Destroy a list of credentials
309  */
310 static inline
311 void rpcauth_destroy_credlist(struct list_head *head)
312 {
313         struct rpc_cred *cred;
314
315         while (!list_empty(head)) {
316                 cred = list_entry(head->next, struct rpc_cred, cr_lru);
317                 list_del_init(&cred->cr_lru);
318                 put_rpccred(cred);
319         }
320 }
321
322 /*
323  * Clear the RPC credential cache, and delete those credentials
324  * that are not referenced.
325  */
326 void
327 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
328 {
329         LIST_HEAD(free);
330         struct hlist_head *head;
331         struct rpc_cred *cred;
332         unsigned int hashsize = 1U << cache->hashbits;
333         int             i;
334
335         spin_lock(&rpc_credcache_lock);
336         spin_lock(&cache->lock);
337         for (i = 0; i < hashsize; i++) {
338                 head = &cache->hashtable[i];
339                 while (!hlist_empty(head)) {
340                         cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
341                         get_rpccred(cred);
342                         if (!list_empty(&cred->cr_lru)) {
343                                 list_del(&cred->cr_lru);
344                                 number_cred_unused--;
345                         }
346                         list_add_tail(&cred->cr_lru, &free);
347                         rpcauth_unhash_cred_locked(cred);
348                 }
349         }
350         spin_unlock(&cache->lock);
351         spin_unlock(&rpc_credcache_lock);
352         rpcauth_destroy_credlist(&free);
353 }
354
355 /*
356  * Destroy the RPC credential cache
357  */
358 void
359 rpcauth_destroy_credcache(struct rpc_auth *auth)
360 {
361         struct rpc_cred_cache *cache = auth->au_credcache;
362
363         if (cache) {
364                 auth->au_credcache = NULL;
365                 rpcauth_clear_credcache(cache);
366                 kfree(cache->hashtable);
367                 kfree(cache);
368         }
369 }
370 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
371
372
373 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
374
375 /*
376  * Remove stale credentials. Avoid sleeping inside the loop.
377  */
378 static int
379 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
380 {
381         spinlock_t *cache_lock;
382         struct rpc_cred *cred, *next;
383         unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
384
385         list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
386
387                 if (nr_to_scan-- == 0)
388                         break;
389                 /*
390                  * Enforce a 60 second garbage collection moratorium
391                  * Note that the cred_unused list must be time-ordered.
392                  */
393                 if (time_in_range(cred->cr_expire, expired, jiffies) &&
394                     test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
395                         return 0;
396
397                 list_del_init(&cred->cr_lru);
398                 number_cred_unused--;
399                 if (atomic_read(&cred->cr_count) != 0)
400                         continue;
401
402                 cache_lock = &cred->cr_auth->au_credcache->lock;
403                 spin_lock(cache_lock);
404                 if (atomic_read(&cred->cr_count) == 0) {
405                         get_rpccred(cred);
406                         list_add_tail(&cred->cr_lru, free);
407                         rpcauth_unhash_cred_locked(cred);
408                 }
409                 spin_unlock(cache_lock);
410         }
411         return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
412 }
413
414 /*
415  * Run memory cache shrinker.
416  */
417 static int
418 rpcauth_cache_shrinker(struct shrinker *shrink, struct shrink_control *sc)
419 {
420         LIST_HEAD(free);
421         int res;
422         int nr_to_scan = sc->nr_to_scan;
423         gfp_t gfp_mask = sc->gfp_mask;
424
425         if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
426                 return (nr_to_scan == 0) ? 0 : -1;
427         if (list_empty(&cred_unused))
428                 return 0;
429         spin_lock(&rpc_credcache_lock);
430         res = rpcauth_prune_expired(&free, nr_to_scan);
431         spin_unlock(&rpc_credcache_lock);
432         rpcauth_destroy_credlist(&free);
433         return res;
434 }
435
436 /*
437  * Look up a process' credentials in the authentication cache
438  */
439 struct rpc_cred *
440 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
441                 int flags)
442 {
443         LIST_HEAD(free);
444         struct rpc_cred_cache *cache = auth->au_credcache;
445         struct rpc_cred *cred = NULL,
446                         *entry, *new;
447         unsigned int nr;
448
449         nr = hash_long(from_kuid(&init_user_ns, acred->uid), cache->hashbits);
450
451         rcu_read_lock();
452         hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
453                 if (!entry->cr_ops->crmatch(acred, entry, flags))
454                         continue;
455                 spin_lock(&cache->lock);
456                 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
457                         spin_unlock(&cache->lock);
458                         continue;
459                 }
460                 cred = get_rpccred(entry);
461                 spin_unlock(&cache->lock);
462                 break;
463         }
464         rcu_read_unlock();
465
466         if (cred != NULL)
467                 goto found;
468
469         new = auth->au_ops->crcreate(auth, acred, flags);
470         if (IS_ERR(new)) {
471                 cred = new;
472                 goto out;
473         }
474
475         spin_lock(&cache->lock);
476         hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
477                 if (!entry->cr_ops->crmatch(acred, entry, flags))
478                         continue;
479                 cred = get_rpccred(entry);
480                 break;
481         }
482         if (cred == NULL) {
483                 cred = new;
484                 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
485                 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
486         } else
487                 list_add_tail(&new->cr_lru, &free);
488         spin_unlock(&cache->lock);
489 found:
490         if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
491             cred->cr_ops->cr_init != NULL &&
492             !(flags & RPCAUTH_LOOKUP_NEW)) {
493                 int res = cred->cr_ops->cr_init(auth, cred);
494                 if (res < 0) {
495                         put_rpccred(cred);
496                         cred = ERR_PTR(res);
497                 }
498         }
499         rpcauth_destroy_credlist(&free);
500 out:
501         return cred;
502 }
503 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
504
505 struct rpc_cred *
506 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
507 {
508         struct auth_cred acred;
509         struct rpc_cred *ret;
510         const struct cred *cred = current_cred();
511
512         dprintk("RPC:       looking up %s cred\n",
513                 auth->au_ops->au_name);
514
515         memset(&acred, 0, sizeof(acred));
516         acred.uid = cred->fsuid;
517         acred.gid = cred->fsgid;
518         acred.group_info = get_group_info(((struct cred *)cred)->group_info);
519
520         ret = auth->au_ops->lookup_cred(auth, &acred, flags);
521         put_group_info(acred.group_info);
522         return ret;
523 }
524
525 void
526 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
527                   struct rpc_auth *auth, const struct rpc_credops *ops)
528 {
529         INIT_HLIST_NODE(&cred->cr_hash);
530         INIT_LIST_HEAD(&cred->cr_lru);
531         atomic_set(&cred->cr_count, 1);
532         cred->cr_auth = auth;
533         cred->cr_ops = ops;
534         cred->cr_expire = jiffies;
535 #ifdef RPC_DEBUG
536         cred->cr_magic = RPCAUTH_CRED_MAGIC;
537 #endif
538         cred->cr_uid = acred->uid;
539 }
540 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
541
542 struct rpc_cred *
543 rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
544 {
545         dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
546                         cred->cr_auth->au_ops->au_name, cred);
547         return get_rpccred(cred);
548 }
549 EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
550
551 static struct rpc_cred *
552 rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
553 {
554         struct rpc_auth *auth = task->tk_client->cl_auth;
555         struct auth_cred acred = {
556                 .uid = GLOBAL_ROOT_UID,
557                 .gid = GLOBAL_ROOT_GID,
558         };
559
560         dprintk("RPC: %5u looking up %s cred\n",
561                 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
562         return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
563 }
564
565 static struct rpc_cred *
566 rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
567 {
568         struct rpc_auth *auth = task->tk_client->cl_auth;
569
570         dprintk("RPC: %5u looking up %s cred\n",
571                 task->tk_pid, auth->au_ops->au_name);
572         return rpcauth_lookupcred(auth, lookupflags);
573 }
574
575 static int
576 rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
577 {
578         struct rpc_rqst *req = task->tk_rqstp;
579         struct rpc_cred *new;
580         int lookupflags = 0;
581
582         if (flags & RPC_TASK_ASYNC)
583                 lookupflags |= RPCAUTH_LOOKUP_NEW;
584         if (cred != NULL)
585                 new = cred->cr_ops->crbind(task, cred, lookupflags);
586         else if (flags & RPC_TASK_ROOTCREDS)
587                 new = rpcauth_bind_root_cred(task, lookupflags);
588         else
589                 new = rpcauth_bind_new_cred(task, lookupflags);
590         if (IS_ERR(new))
591                 return PTR_ERR(new);
592         if (req->rq_cred != NULL)
593                 put_rpccred(req->rq_cred);
594         req->rq_cred = new;
595         return 0;
596 }
597
598 void
599 put_rpccred(struct rpc_cred *cred)
600 {
601         /* Fast path for unhashed credentials */
602         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
603                 if (atomic_dec_and_test(&cred->cr_count))
604                         cred->cr_ops->crdestroy(cred);
605                 return;
606         }
607
608         if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
609                 return;
610         if (!list_empty(&cred->cr_lru)) {
611                 number_cred_unused--;
612                 list_del_init(&cred->cr_lru);
613         }
614         if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
615                 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
616                         cred->cr_expire = jiffies;
617                         list_add_tail(&cred->cr_lru, &cred_unused);
618                         number_cred_unused++;
619                         goto out_nodestroy;
620                 }
621                 if (!rpcauth_unhash_cred(cred)) {
622                         /* We were hashed and someone looked us up... */
623                         goto out_nodestroy;
624                 }
625         }
626         spin_unlock(&rpc_credcache_lock);
627         cred->cr_ops->crdestroy(cred);
628         return;
629 out_nodestroy:
630         spin_unlock(&rpc_credcache_lock);
631 }
632 EXPORT_SYMBOL_GPL(put_rpccred);
633
634 __be32 *
635 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
636 {
637         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
638
639         dprintk("RPC: %5u marshaling %s cred %p\n",
640                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
641
642         return cred->cr_ops->crmarshal(task, p);
643 }
644
645 __be32 *
646 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
647 {
648         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
649
650         dprintk("RPC: %5u validating %s cred %p\n",
651                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
652
653         return cred->cr_ops->crvalidate(task, p);
654 }
655
656 static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
657                                    __be32 *data, void *obj)
658 {
659         struct xdr_stream xdr;
660
661         xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
662         encode(rqstp, &xdr, obj);
663 }
664
665 int
666 rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
667                 __be32 *data, void *obj)
668 {
669         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
670
671         dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
672                         task->tk_pid, cred->cr_ops->cr_name, cred);
673         if (cred->cr_ops->crwrap_req)
674                 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
675         /* By default, we encode the arguments normally. */
676         rpcauth_wrap_req_encode(encode, rqstp, data, obj);
677         return 0;
678 }
679
680 static int
681 rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
682                           __be32 *data, void *obj)
683 {
684         struct xdr_stream xdr;
685
686         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
687         return decode(rqstp, &xdr, obj);
688 }
689
690 int
691 rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
692                 __be32 *data, void *obj)
693 {
694         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
695
696         dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
697                         task->tk_pid, cred->cr_ops->cr_name, cred);
698         if (cred->cr_ops->crunwrap_resp)
699                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
700                                                    data, obj);
701         /* By default, we decode the arguments normally. */
702         return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
703 }
704
705 int
706 rpcauth_refreshcred(struct rpc_task *task)
707 {
708         struct rpc_cred *cred;
709         int err;
710
711         cred = task->tk_rqstp->rq_cred;
712         if (cred == NULL) {
713                 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
714                 if (err < 0)
715                         goto out;
716                 cred = task->tk_rqstp->rq_cred;
717         }
718         dprintk("RPC: %5u refreshing %s cred %p\n",
719                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
720
721         err = cred->cr_ops->crrefresh(task);
722 out:
723         if (err < 0)
724                 task->tk_status = err;
725         return err;
726 }
727
728 void
729 rpcauth_invalcred(struct rpc_task *task)
730 {
731         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
732
733         dprintk("RPC: %5u invalidating %s cred %p\n",
734                 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
735         if (cred)
736                 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
737 }
738
739 int
740 rpcauth_uptodatecred(struct rpc_task *task)
741 {
742         struct rpc_cred *cred = task->tk_rqstp->rq_cred;
743
744         return cred == NULL ||
745                 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
746 }
747
748 static struct shrinker rpc_cred_shrinker = {
749         .shrink = rpcauth_cache_shrinker,
750         .seeks = DEFAULT_SEEKS,
751 };
752
753 int __init rpcauth_init_module(void)
754 {
755         int err;
756
757         err = rpc_init_authunix();
758         if (err < 0)
759                 goto out1;
760         err = rpc_init_generic_auth();
761         if (err < 0)
762                 goto out2;
763         register_shrinker(&rpc_cred_shrinker);
764         return 0;
765 out2:
766         rpc_destroy_authunix();
767 out1:
768         return err;
769 }
770
771 void rpcauth_remove_module(void)
772 {
773         rpc_destroy_authunix();
774         rpc_destroy_generic_auth();
775         unregister_shrinker(&rpc_cred_shrinker);
776 }