Staging: brcm80211: remove unneeded #ifdef checks
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / sunrpc / auth.c
blob36cb66022a279e96869de77c3c9cebbbe9824ff4
1 /*
2 * linux/net/sunrpc/auth.c
4 * Generic RPC client authentication API.
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
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>
18 #ifdef RPC_DEBUG
19 # define RPCDBG_FACILITY RPCDBG_AUTH
20 #endif
22 #define RPC_CREDCACHE_DEFAULT_HASHBITS (4)
23 struct rpc_cred_cache {
24 struct hlist_head *hashtable;
25 unsigned int hashbits;
26 spinlock_t lock;
29 static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
31 static DEFINE_SPINLOCK(rpc_authflavor_lock);
32 static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
33 &authnull_ops, /* AUTH_NULL */
34 &authunix_ops, /* AUTH_UNIX */
35 NULL, /* others can be loadable modules */
38 static LIST_HEAD(cred_unused);
39 static unsigned long number_cred_unused;
41 #define MAX_HASHTABLE_BITS (10)
42 static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
44 unsigned long num;
45 unsigned int nbits;
46 int ret;
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;
60 out_inval:
61 return -EINVAL;
64 static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
66 unsigned int nbits;
68 nbits = *(unsigned int *)kp->arg;
69 return sprintf(buffer, "%u", 1U << nbits);
72 #define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
74 static struct kernel_param_ops param_ops_hashtbl_sz = {
75 .set = param_set_hashtbl_sz,
76 .get = param_get_hashtbl_sz,
79 module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
80 MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
82 static u32
83 pseudoflavor_to_flavor(u32 flavor) {
84 if (flavor >= RPC_AUTH_MAXFLAVOR)
85 return RPC_AUTH_GSS;
86 return flavor;
89 int
90 rpcauth_register(const struct rpc_authops *ops)
92 rpc_authflavor_t flavor;
93 int ret = -EPERM;
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;
102 spin_unlock(&rpc_authflavor_lock);
103 return ret;
105 EXPORT_SYMBOL_GPL(rpcauth_register);
108 rpcauth_unregister(const struct rpc_authops *ops)
110 rpc_authflavor_t flavor;
111 int ret = -EPERM;
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;
120 spin_unlock(&rpc_authflavor_lock);
121 return ret;
123 EXPORT_SYMBOL_GPL(rpcauth_unregister);
125 struct rpc_auth *
126 rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
128 struct rpc_auth *auth;
129 const struct rpc_authops *ops;
130 u32 flavor = pseudoflavor_to_flavor(pseudoflavor);
132 auth = ERR_PTR(-EINVAL);
133 if (flavor >= RPC_AUTH_MAXFLAVOR)
134 goto out;
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;
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;
153 out:
154 return auth;
156 EXPORT_SYMBOL_GPL(rpcauth_create);
158 void
159 rpcauth_release(struct rpc_auth *auth)
161 if (!atomic_dec_and_test(&auth->au_count))
162 return;
163 auth->au_ops->destroy(auth);
166 static DEFINE_SPINLOCK(rpc_credcache_lock);
168 static void
169 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
171 hlist_del_rcu(&cred->cr_hash);
172 smp_mb__before_clear_bit();
173 clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
176 static int
177 rpcauth_unhash_cred(struct rpc_cred *cred)
179 spinlock_t *cache_lock;
180 int ret;
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;
192 * Initialize RPC credential cache
195 rpcauth_init_credcache(struct rpc_auth *auth)
197 struct rpc_cred_cache *new;
198 unsigned int hashsize;
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;
211 out_nohashtbl:
212 kfree(new);
213 out_nocache:
214 return -ENOMEM;
216 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
219 * Destroy a list of credentials
221 static inline
222 void rpcauth_destroy_credlist(struct list_head *head)
224 struct rpc_cred *cred;
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);
234 * Clear the RPC credential cache, and delete those credentials
235 * that are not referenced.
237 void
238 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
240 LIST_HEAD(free);
241 struct hlist_head *head;
242 struct rpc_cred *cred;
243 unsigned int hashsize = 1U << cache->hashbits;
244 int i;
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--;
257 list_add_tail(&cred->cr_lru, &free);
258 rpcauth_unhash_cred_locked(cred);
261 spin_unlock(&cache->lock);
262 spin_unlock(&rpc_credcache_lock);
263 rpcauth_destroy_credlist(&free);
267 * Destroy the RPC credential cache
269 void
270 rpcauth_destroy_credcache(struct rpc_auth *auth)
272 struct rpc_cred_cache *cache = auth->au_credcache;
274 if (cache) {
275 auth->au_credcache = NULL;
276 rpcauth_clear_credcache(cache);
277 kfree(cache->hashtable);
278 kfree(cache);
281 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
284 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
287 * Remove stale credentials. Avoid sleeping inside the loop.
289 static int
290 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
292 spinlock_t *cache_lock;
293 struct rpc_cred *cred, *next;
294 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
296 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
298 if (nr_to_scan-- == 0)
299 break;
301 * Enforce a 60 second garbage collection moratorium
302 * Note that the cred_unused list must be time-ordered.
304 if (time_in_range(cred->cr_expire, expired, jiffies) &&
305 test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
306 return 0;
308 list_del_init(&cred->cr_lru);
309 number_cred_unused--;
310 if (atomic_read(&cred->cr_count) != 0)
311 continue;
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);
320 spin_unlock(cache_lock);
322 return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
326 * Run memory cache shrinker.
328 static int
329 rpcauth_cache_shrinker(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
331 LIST_HEAD(free);
332 int res;
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;
346 * Look up a process' credentials in the authentication cache
348 struct rpc_cred *
349 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
350 int flags)
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;
359 nr = hash_long(acred->uid, cache->hashbits);
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;
370 cred = get_rpccred(entry);
371 spin_unlock(&cache->lock);
372 break;
374 rcu_read_unlock();
376 if (cred != NULL)
377 goto found;
379 new = auth->au_ops->crcreate(auth, acred, flags);
380 if (IS_ERR(new)) {
381 cred = new;
382 goto out;
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;
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);
399 found:
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);
409 rpcauth_destroy_credlist(&free);
410 out:
411 return cred;
413 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
415 struct rpc_cred *
416 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
418 struct auth_cred acred;
419 struct rpc_cred *ret;
420 const struct cred *cred = current_cred();
422 dprintk("RPC: looking up %s cred\n",
423 auth->au_ops->au_name);
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);
430 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
431 put_group_info(acred.group_info);
432 return ret;
435 void
436 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
437 struct rpc_auth *auth, const struct rpc_credops *ops)
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;
450 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
452 struct rpc_cred *
453 rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
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);
459 EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
461 static struct rpc_cred *
462 rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
464 struct rpc_auth *auth = task->tk_client->cl_auth;
465 struct auth_cred acred = {
466 .uid = 0,
467 .gid = 0,
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);
475 static struct rpc_cred *
476 rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
478 struct rpc_auth *auth = task->tk_client->cl_auth;
480 dprintk("RPC: %5u looking up %s cred\n",
481 task->tk_pid, auth->au_ops->au_name);
482 return rpcauth_lookupcred(auth, lookupflags);
485 static int
486 rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
488 struct rpc_rqst *req = task->tk_rqstp;
489 struct rpc_cred *new;
490 int lookupflags = 0;
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;
508 void
509 put_rpccred(struct rpc_cred *cred)
511 /* Fast path for unhashed credentials */
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;
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);
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;
531 if (!rpcauth_unhash_cred(cred)) {
532 /* We were hashed and someone looked us up... */
533 goto out_nodestroy;
536 spin_unlock(&rpc_credcache_lock);
537 cred->cr_ops->crdestroy(cred);
538 return;
539 out_nodestroy:
540 spin_unlock(&rpc_credcache_lock);
542 EXPORT_SYMBOL_GPL(put_rpccred);
544 __be32 *
545 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
547 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
549 dprintk("RPC: %5u marshaling %s cred %p\n",
550 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
552 return cred->cr_ops->crmarshal(task, p);
555 __be32 *
556 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
558 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
560 dprintk("RPC: %5u validating %s cred %p\n",
561 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
563 return cred->cr_ops->crvalidate(task, p);
567 rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
568 __be32 *data, void *obj)
570 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
572 dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
573 task->tk_pid, cred->cr_ops->cr_name, cred);
574 if (cred->cr_ops->crwrap_req)
575 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
576 /* By default, we encode the arguments normally. */
577 return encode(rqstp, data, obj);
581 rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
582 __be32 *data, void *obj)
584 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
586 dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
587 task->tk_pid, cred->cr_ops->cr_name, cred);
588 if (cred->cr_ops->crunwrap_resp)
589 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
590 data, obj);
591 /* By default, we decode the arguments normally. */
592 return decode(rqstp, data, obj);
596 rpcauth_refreshcred(struct rpc_task *task)
598 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
599 int err;
601 cred = task->tk_rqstp->rq_cred;
602 if (cred == NULL) {
603 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
604 if (err < 0)
605 goto out;
606 cred = task->tk_rqstp->rq_cred;
608 dprintk("RPC: %5u refreshing %s cred %p\n",
609 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
611 err = cred->cr_ops->crrefresh(task);
612 out:
613 if (err < 0)
614 task->tk_status = err;
615 return err;
618 void
619 rpcauth_invalcred(struct rpc_task *task)
621 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
623 dprintk("RPC: %5u invalidating %s cred %p\n",
624 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
625 if (cred)
626 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
630 rpcauth_uptodatecred(struct rpc_task *task)
632 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
634 return cred == NULL ||
635 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
638 static struct shrinker rpc_cred_shrinker = {
639 .shrink = rpcauth_cache_shrinker,
640 .seeks = DEFAULT_SEEKS,
643 int __init rpcauth_init_module(void)
645 int err;
647 err = rpc_init_authunix();
648 if (err < 0)
649 goto out1;
650 err = rpc_init_generic_auth();
651 if (err < 0)
652 goto out2;
653 register_shrinker(&rpc_cred_shrinker);
654 return 0;
655 out2:
656 rpc_destroy_authunix();
657 out1:
658 return err;
661 void __exit rpcauth_remove_module(void)
663 rpc_destroy_authunix();
664 rpc_destroy_generic_auth();
665 unregister_shrinker(&rpc_cred_shrinker);