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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/spinlock.h>
17
18#ifdef RPC_DEBUG
19# define RPCDBG_FACILITY RPCDBG_AUTH
20#endif
21
22#define RPC_CREDCACHE_DEFAULT_HASHBITS (4)
23struct rpc_cred_cache {
24 struct hlist_head *hashtable;
25 unsigned int hashbits;
26 spinlock_t lock;
27};
28
29static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
30
31static DEFINE_SPINLOCK(rpc_authflavor_lock);
32static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
33 &authnull_ops,
34 &authunix_ops,
35 NULL,
36};
37
38static LIST_HEAD(cred_unused);
39static unsigned long number_cred_unused;
40
41#define MAX_HASHTABLE_BITS (14)
42static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
43{
44 unsigned long num;
45 unsigned int nbits;
46 int ret;
47
48 if (!val)
49 goto out_inval;
50 ret = strict_strtoul(val, 0, &num);
51 if (ret == -EINVAL)
52 goto out_inval;
53 nbits = fls(num);
54 if (num > (1U << nbits))
55 nbits++;
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 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 u32
83pseudoflavor_to_flavor(u32 flavor) {
84 if (flavor >= RPC_AUTH_MAXFLAVOR)
85 return RPC_AUTH_GSS;
86 return flavor;
87}
88
89int
90rpcauth_register(const struct rpc_authops *ops)
91{
92 rpc_authflavor_t flavor;
93 int ret = -EPERM;
94
95 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
96 return -EINVAL;
97 spin_lock(&rpc_authflavor_lock);
98 if (auth_flavors[flavor] == NULL) {
99 auth_flavors[flavor] = ops;
100 ret = 0;
101 }
102 spin_unlock(&rpc_authflavor_lock);
103 return ret;
104}
105EXPORT_SYMBOL_GPL(rpcauth_register);
106
107int
108rpcauth_unregister(const struct rpc_authops *ops)
109{
110 rpc_authflavor_t flavor;
111 int ret = -EPERM;
112
113 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
114 return -EINVAL;
115 spin_lock(&rpc_authflavor_lock);
116 if (auth_flavors[flavor] == ops) {
117 auth_flavors[flavor] = NULL;
118 ret = 0;
119 }
120 spin_unlock(&rpc_authflavor_lock);
121 return ret;
122}
123EXPORT_SYMBOL_GPL(rpcauth_unregister);
124
125struct rpc_auth *
126rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
127{
128 struct rpc_auth *auth;
129 const struct rpc_authops *ops;
130 u32 flavor = pseudoflavor_to_flavor(pseudoflavor);
131
132 auth = ERR_PTR(-EINVAL);
133 if (flavor >= RPC_AUTH_MAXFLAVOR)
134 goto out;
135
136 if ((ops = auth_flavors[flavor]) == NULL)
137 request_module("rpc-auth-%u", flavor);
138 spin_lock(&rpc_authflavor_lock);
139 ops = auth_flavors[flavor];
140 if (ops == NULL || !try_module_get(ops->owner)) {
141 spin_unlock(&rpc_authflavor_lock);
142 goto out;
143 }
144 spin_unlock(&rpc_authflavor_lock);
145 auth = ops->create(clnt, pseudoflavor);
146 module_put(ops->owner);
147 if (IS_ERR(auth))
148 return auth;
149 if (clnt->cl_auth)
150 rpcauth_release(clnt->cl_auth);
151 clnt->cl_auth = auth;
152
153out:
154 return auth;
155}
156EXPORT_SYMBOL_GPL(rpcauth_create);
157
158void
159rpcauth_release(struct rpc_auth *auth)
160{
161 if (!atomic_dec_and_test(&auth->au_count))
162 return;
163 auth->au_ops->destroy(auth);
164}
165
166static DEFINE_SPINLOCK(rpc_credcache_lock);
167
168static void
169rpcauth_unhash_cred_locked(struct rpc_cred *cred)
170{
171 hlist_del_rcu(&cred->cr_hash);
172 smp_mb__before_clear_bit();
173 clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
174}
175
176static int
177rpcauth_unhash_cred(struct rpc_cred *cred)
178{
179 spinlock_t *cache_lock;
180 int ret;
181
182 cache_lock = &cred->cr_auth->au_credcache->lock;
183 spin_lock(cache_lock);
184 ret = atomic_read(&cred->cr_count) == 0;
185 if (ret)
186 rpcauth_unhash_cred_locked(cred);
187 spin_unlock(cache_lock);
188 return ret;
189}
190
191
192
193
194int
195rpcauth_init_credcache(struct rpc_auth *auth)
196{
197 struct rpc_cred_cache *new;
198 unsigned int hashsize;
199
200 new = kmalloc(sizeof(*new), GFP_KERNEL);
201 if (!new)
202 goto out_nocache;
203 new->hashbits = auth_hashbits;
204 hashsize = 1U << new->hashbits;
205 new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
206 if (!new->hashtable)
207 goto out_nohashtbl;
208 spin_lock_init(&new->lock);
209 auth->au_credcache = new;
210 return 0;
211out_nohashtbl:
212 kfree(new);
213out_nocache:
214 return -ENOMEM;
215}
216EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
217
218
219
220
221static inline
222void rpcauth_destroy_credlist(struct list_head *head)
223{
224 struct rpc_cred *cred;
225
226 while (!list_empty(head)) {
227 cred = list_entry(head->next, struct rpc_cred, cr_lru);
228 list_del_init(&cred->cr_lru);
229 put_rpccred(cred);
230 }
231}
232
233
234
235
236
237void
238rpcauth_clear_credcache(struct rpc_cred_cache *cache)
239{
240 LIST_HEAD(free);
241 struct hlist_head *head;
242 struct rpc_cred *cred;
243 unsigned int hashsize = 1U << cache->hashbits;
244 int i;
245
246 spin_lock(&rpc_credcache_lock);
247 spin_lock(&cache->lock);
248 for (i = 0; i < hashsize; i++) {
249 head = &cache->hashtable[i];
250 while (!hlist_empty(head)) {
251 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
252 get_rpccred(cred);
253 if (!list_empty(&cred->cr_lru)) {
254 list_del(&cred->cr_lru);
255 number_cred_unused--;
256 }
257 list_add_tail(&cred->cr_lru, &free);
258 rpcauth_unhash_cred_locked(cred);
259 }
260 }
261 spin_unlock(&cache->lock);
262 spin_unlock(&rpc_credcache_lock);
263 rpcauth_destroy_credlist(&free);
264}
265
266
267
268
269void
270rpcauth_destroy_credcache(struct rpc_auth *auth)
271{
272 struct rpc_cred_cache *cache = auth->au_credcache;
273
274 if (cache) {
275 auth->au_credcache = NULL;
276 rpcauth_clear_credcache(cache);
277 kfree(cache->hashtable);
278 kfree(cache);
279 }
280}
281EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
282
283
284#define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
285
286
287
288
289static int
290rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
291{
292 spinlock_t *cache_lock;
293 struct rpc_cred *cred, *next;
294 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
295
296 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
297
298 if (nr_to_scan-- == 0)
299 break;
300
301
302
303
304 if (time_in_range(cred->cr_expire, expired, jiffies) &&
305 test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
306 return 0;
307
308 list_del_init(&cred->cr_lru);
309 number_cred_unused--;
310 if (atomic_read(&cred->cr_count) != 0)
311 continue;
312
313 cache_lock = &cred->cr_auth->au_credcache->lock;
314 spin_lock(cache_lock);
315 if (atomic_read(&cred->cr_count) == 0) {
316 get_rpccred(cred);
317 list_add_tail(&cred->cr_lru, free);
318 rpcauth_unhash_cred_locked(cred);
319 }
320 spin_unlock(cache_lock);
321 }
322 return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
323}
324
325
326
327
328static int
329rpcauth_cache_shrinker(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
330{
331 LIST_HEAD(free);
332 int res;
333
334 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
335 return (nr_to_scan == 0) ? 0 : -1;
336 if (list_empty(&cred_unused))
337 return 0;
338 spin_lock(&rpc_credcache_lock);
339 res = rpcauth_prune_expired(&free, nr_to_scan);
340 spin_unlock(&rpc_credcache_lock);
341 rpcauth_destroy_credlist(&free);
342 return res;
343}
344
345
346
347
348struct rpc_cred *
349rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
350 int flags)
351{
352 LIST_HEAD(free);
353 struct rpc_cred_cache *cache = auth->au_credcache;
354 struct hlist_node *pos;
355 struct rpc_cred *cred = NULL,
356 *entry, *new;
357 unsigned int nr;
358
359 nr = hash_long(acred->uid, cache->hashbits);
360
361 rcu_read_lock();
362 hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
363 if (!entry->cr_ops->crmatch(acred, entry, flags))
364 continue;
365 spin_lock(&cache->lock);
366 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
367 spin_unlock(&cache->lock);
368 continue;
369 }
370 cred = get_rpccred(entry);
371 spin_unlock(&cache->lock);
372 break;
373 }
374 rcu_read_unlock();
375
376 if (cred != NULL)
377 goto found;
378
379 new = auth->au_ops->crcreate(auth, acred, flags);
380 if (IS_ERR(new)) {
381 cred = new;
382 goto out;
383 }
384
385 spin_lock(&cache->lock);
386 hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
387 if (!entry->cr_ops->crmatch(acred, entry, flags))
388 continue;
389 cred = get_rpccred(entry);
390 break;
391 }
392 if (cred == NULL) {
393 cred = new;
394 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
395 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
396 } else
397 list_add_tail(&new->cr_lru, &free);
398 spin_unlock(&cache->lock);
399found:
400 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
401 cred->cr_ops->cr_init != NULL &&
402 !(flags & RPCAUTH_LOOKUP_NEW)) {
403 int res = cred->cr_ops->cr_init(auth, cred);
404 if (res < 0) {
405 put_rpccred(cred);
406 cred = ERR_PTR(res);
407 }
408 }
409 rpcauth_destroy_credlist(&free);
410out:
411 return cred;
412}
413EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
414
415struct rpc_cred *
416rpcauth_lookupcred(struct rpc_auth *auth, int flags)
417{
418 struct auth_cred acred;
419 struct rpc_cred *ret;
420 const struct cred *cred = current_cred();
421
422 dprintk("RPC: looking up %s cred\n",
423 auth->au_ops->au_name);
424
425 memset(&acred, 0, sizeof(acred));
426 acred.uid = cred->fsuid;
427 acred.gid = cred->fsgid;
428 acred.group_info = get_group_info(((struct cred *)cred)->group_info);
429
430 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
431 put_group_info(acred.group_info);
432 return ret;
433}
434
435void
436rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
437 struct rpc_auth *auth, const struct rpc_credops *ops)
438{
439 INIT_HLIST_NODE(&cred->cr_hash);
440 INIT_LIST_HEAD(&cred->cr_lru);
441 atomic_set(&cred->cr_count, 1);
442 cred->cr_auth = auth;
443 cred->cr_ops = ops;
444 cred->cr_expire = jiffies;
445#ifdef RPC_DEBUG
446 cred->cr_magic = RPCAUTH_CRED_MAGIC;
447#endif
448 cred->cr_uid = acred->uid;
449}
450EXPORT_SYMBOL_GPL(rpcauth_init_cred);
451
452struct rpc_cred *
453rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
454{
455 dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
456 cred->cr_auth->au_ops->au_name, cred);
457 return get_rpccred(cred);
458}
459EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
460
461static struct rpc_cred *
462rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
463{
464 struct rpc_auth *auth = task->tk_client->cl_auth;
465 struct auth_cred acred = {
466 .uid = 0,
467 .gid = 0,
468 };
469
470 dprintk("RPC: %5u looking up %s cred\n",
471 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
472 return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
473}
474
475static struct rpc_cred *
476rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
477{
478 struct rpc_auth *auth = task->tk_client->cl_auth;
479
480 dprintk("RPC: %5u looking up %s cred\n",
481 task->tk_pid, auth->au_ops->au_name);
482 return rpcauth_lookupcred(auth, lookupflags);
483}
484
485static int
486rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
487{
488 struct rpc_rqst *req = task->tk_rqstp;
489 struct rpc_cred *new;
490 int lookupflags = 0;
491
492 if (flags & RPC_TASK_ASYNC)
493 lookupflags |= RPCAUTH_LOOKUP_NEW;
494 if (cred != NULL)
495 new = cred->cr_ops->crbind(task, cred, lookupflags);
496 else if (flags & RPC_TASK_ROOTCREDS)
497 new = rpcauth_bind_root_cred(task, lookupflags);
498 else
499 new = rpcauth_bind_new_cred(task, lookupflags);
500 if (IS_ERR(new))
501 return PTR_ERR(new);
502 if (req->rq_cred != NULL)
503 put_rpccred(req->rq_cred);
504 req->rq_cred = new;
505 return 0;
506}
507
508void
509put_rpccred(struct rpc_cred *cred)
510{
511
512 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
513 if (atomic_dec_and_test(&cred->cr_count))
514 cred->cr_ops->crdestroy(cred);
515 return;
516 }
517
518 if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
519 return;
520 if (!list_empty(&cred->cr_lru)) {
521 number_cred_unused--;
522 list_del_init(&cred->cr_lru);
523 }
524 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
525 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
526 cred->cr_expire = jiffies;
527 list_add_tail(&cred->cr_lru, &cred_unused);
528 number_cred_unused++;
529 goto out_nodestroy;
530 }
531 if (!rpcauth_unhash_cred(cred)) {
532
533 goto out_nodestroy;
534 }
535 }
536 spin_unlock(&rpc_credcache_lock);
537 cred->cr_ops->crdestroy(cred);
538 return;
539out_nodestroy:
540 spin_unlock(&rpc_credcache_lock);
541}
542EXPORT_SYMBOL_GPL(put_rpccred);
543
544__be32 *
545rpcauth_marshcred(struct rpc_task *task, __be32 *p)
546{
547 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
548
549 dprintk("RPC: %5u marshaling %s cred %p\n",
550 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
551
552 return cred->cr_ops->crmarshal(task, p);
553}
554
555__be32 *
556rpcauth_checkverf(struct rpc_task *task, __be32 *p)
557{
558 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
559
560 dprintk("RPC: %5u validating %s cred %p\n",
561 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
562
563 return cred->cr_ops->crvalidate(task, p);
564}
565
566static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
567 __be32 *data, void *obj)
568{
569 struct xdr_stream xdr;
570
571 xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
572 encode(rqstp, &xdr, obj);
573}
574
575int
576rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
577 __be32 *data, void *obj)
578{
579 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
580
581 dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
582 task->tk_pid, cred->cr_ops->cr_name, cred);
583 if (cred->cr_ops->crwrap_req)
584 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
585
586 rpcauth_wrap_req_encode(encode, rqstp, data, obj);
587 return 0;
588}
589
590static int
591rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
592 __be32 *data, void *obj)
593{
594 struct xdr_stream xdr;
595
596 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
597 return decode(rqstp, &xdr, obj);
598}
599
600int
601rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
602 __be32 *data, void *obj)
603{
604 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
605
606 dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
607 task->tk_pid, cred->cr_ops->cr_name, cred);
608 if (cred->cr_ops->crunwrap_resp)
609 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
610 data, obj);
611
612 return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
613}
614
615int
616rpcauth_refreshcred(struct rpc_task *task)
617{
618 struct rpc_cred *cred;
619 int err;
620
621 cred = task->tk_rqstp->rq_cred;
622 if (cred == NULL) {
623 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
624 if (err < 0)
625 goto out;
626 cred = task->tk_rqstp->rq_cred;
627 };
628 dprintk("RPC: %5u refreshing %s cred %p\n",
629 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
630
631 err = cred->cr_ops->crrefresh(task);
632out:
633 if (err < 0)
634 task->tk_status = err;
635 return err;
636}
637
638void
639rpcauth_invalcred(struct rpc_task *task)
640{
641 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
642
643 dprintk("RPC: %5u invalidating %s cred %p\n",
644 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
645 if (cred)
646 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
647}
648
649int
650rpcauth_uptodatecred(struct rpc_task *task)
651{
652 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
653
654 return cred == NULL ||
655 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
656}
657
658static struct shrinker rpc_cred_shrinker = {
659 .shrink = rpcauth_cache_shrinker,
660 .seeks = DEFAULT_SEEKS,
661};
662
663int __init rpcauth_init_module(void)
664{
665 int err;
666
667 err = rpc_init_authunix();
668 if (err < 0)
669 goto out1;
670 err = rpc_init_generic_auth();
671 if (err < 0)
672 goto out2;
673 register_shrinker(&rpc_cred_shrinker);
674 return 0;
675out2:
676 rpc_destroy_authunix();
677out1:
678 return err;
679}
680
681void rpcauth_remove_module(void)
682{
683 rpc_destroy_authunix();
684 rpc_destroy_generic_auth();
685 unregister_shrinker(&rpc_cred_shrinker);
686}
687
