2 * linux/net/sunrpc/auth.c
4 * Generic RPC client authentication API.
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
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>
19 # define RPCDBG_FACILITY RPCDBG_AUTH
22 static DEFINE_SPINLOCK(rpc_authflavor_lock);
23 static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
24 &authnull_ops, /* AUTH_NULL */
25 &authunix_ops, /* AUTH_UNIX */
26 NULL, /* others can be loadable modules */
29 static LIST_HEAD(cred_unused);
30 static unsigned long number_cred_unused;
33 pseudoflavor_to_flavor(u32 flavor) {
34 if (flavor >= RPC_AUTH_MAXFLAVOR)
40 rpcauth_register(const struct rpc_authops *ops)
42 rpc_authflavor_t flavor;
45 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
47 spin_lock(&rpc_authflavor_lock);
48 if (auth_flavors[flavor] == NULL) {
49 auth_flavors[flavor] = ops;
52 spin_unlock(&rpc_authflavor_lock);
55 EXPORT_SYMBOL_GPL(rpcauth_register);
58 rpcauth_unregister(const struct rpc_authops *ops)
60 rpc_authflavor_t flavor;
63 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
65 spin_lock(&rpc_authflavor_lock);
66 if (auth_flavors[flavor] == ops) {
67 auth_flavors[flavor] = NULL;
70 spin_unlock(&rpc_authflavor_lock);
73 EXPORT_SYMBOL_GPL(rpcauth_unregister);
76 rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
78 struct rpc_auth *auth;
79 const struct rpc_authops *ops;
80 u32 flavor = pseudoflavor_to_flavor(pseudoflavor);
82 auth = ERR_PTR(-EINVAL);
83 if (flavor >= RPC_AUTH_MAXFLAVOR)
86 if ((ops = auth_flavors[flavor]) == NULL)
87 request_module("rpc-auth-%u", flavor);
88 spin_lock(&rpc_authflavor_lock);
89 ops = auth_flavors[flavor];
90 if (ops == NULL || !try_module_get(ops->owner)) {
91 spin_unlock(&rpc_authflavor_lock);
94 spin_unlock(&rpc_authflavor_lock);
95 auth = ops->create(clnt, pseudoflavor);
96 module_put(ops->owner);
100 rpcauth_release(clnt->cl_auth);
101 clnt->cl_auth = auth;
106 EXPORT_SYMBOL_GPL(rpcauth_create);
109 rpcauth_release(struct rpc_auth *auth)
111 if (!atomic_dec_and_test(&auth->au_count))
113 auth->au_ops->destroy(auth);
116 static DEFINE_SPINLOCK(rpc_credcache_lock);
119 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
121 hlist_del_rcu(&cred->cr_hash);
122 smp_mb__before_clear_bit();
123 clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
127 rpcauth_unhash_cred(struct rpc_cred *cred)
129 spinlock_t *cache_lock;
132 cache_lock = &cred->cr_auth->au_credcache->lock;
133 spin_lock(cache_lock);
134 ret = atomic_read(&cred->cr_count) == 0;
136 rpcauth_unhash_cred_locked(cred);
137 spin_unlock(cache_lock);
142 * Initialize RPC credential cache
145 rpcauth_init_credcache(struct rpc_auth *auth)
147 struct rpc_cred_cache *new;
150 new = kmalloc(sizeof(*new), GFP_KERNEL);
153 for (i = 0; i < RPC_CREDCACHE_NR; i++)
154 INIT_HLIST_HEAD(&new->hashtable[i]);
155 spin_lock_init(&new->lock);
156 auth->au_credcache = new;
159 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
162 * Destroy a list of credentials
165 void rpcauth_destroy_credlist(struct list_head *head)
167 struct rpc_cred *cred;
169 while (!list_empty(head)) {
170 cred = list_entry(head->next, struct rpc_cred, cr_lru);
171 list_del_init(&cred->cr_lru);
177 * Clear the RPC credential cache, and delete those credentials
178 * that are not referenced.
181 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
184 struct hlist_head *head;
185 struct rpc_cred *cred;
188 spin_lock(&rpc_credcache_lock);
189 spin_lock(&cache->lock);
190 for (i = 0; i < RPC_CREDCACHE_NR; i++) {
191 head = &cache->hashtable[i];
192 while (!hlist_empty(head)) {
193 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
195 if (!list_empty(&cred->cr_lru)) {
196 list_del(&cred->cr_lru);
197 number_cred_unused--;
199 list_add_tail(&cred->cr_lru, &free);
200 rpcauth_unhash_cred_locked(cred);
203 spin_unlock(&cache->lock);
204 spin_unlock(&rpc_credcache_lock);
205 rpcauth_destroy_credlist(&free);
209 * Destroy the RPC credential cache
212 rpcauth_destroy_credcache(struct rpc_auth *auth)
214 struct rpc_cred_cache *cache = auth->au_credcache;
217 auth->au_credcache = NULL;
218 rpcauth_clear_credcache(cache);
222 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
225 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
228 * Remove stale credentials. Avoid sleeping inside the loop.
231 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
233 spinlock_t *cache_lock;
234 struct rpc_cred *cred, *next;
235 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
237 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
239 /* Enforce a 60 second garbage collection moratorium */
240 if (time_in_range(cred->cr_expire, expired, jiffies) &&
241 test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
244 list_del_init(&cred->cr_lru);
245 number_cred_unused--;
246 if (atomic_read(&cred->cr_count) != 0)
249 cache_lock = &cred->cr_auth->au_credcache->lock;
250 spin_lock(cache_lock);
251 if (atomic_read(&cred->cr_count) == 0) {
253 list_add_tail(&cred->cr_lru, free);
254 rpcauth_unhash_cred_locked(cred);
257 spin_unlock(cache_lock);
265 * Run memory cache shrinker.
268 rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
273 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
274 return (nr_to_scan == 0) ? 0 : -1;
275 if (list_empty(&cred_unused))
277 spin_lock(&rpc_credcache_lock);
278 nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
279 res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
280 spin_unlock(&rpc_credcache_lock);
281 rpcauth_destroy_credlist(&free);
286 * Look up a process' credentials in the authentication cache
289 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
293 struct rpc_cred_cache *cache = auth->au_credcache;
294 struct hlist_node *pos;
295 struct rpc_cred *cred = NULL,
299 nr = hash_long(acred->uid, RPC_CREDCACHE_HASHBITS);
302 hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
303 if (!entry->cr_ops->crmatch(acred, entry, flags))
305 spin_lock(&cache->lock);
306 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
307 spin_unlock(&cache->lock);
310 cred = get_rpccred(entry);
311 spin_unlock(&cache->lock);
319 new = auth->au_ops->crcreate(auth, acred, flags);
325 spin_lock(&cache->lock);
326 hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
327 if (!entry->cr_ops->crmatch(acred, entry, flags))
329 cred = get_rpccred(entry);
334 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
335 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
337 list_add_tail(&new->cr_lru, &free);
338 spin_unlock(&cache->lock);
340 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
341 cred->cr_ops->cr_init != NULL &&
342 !(flags & RPCAUTH_LOOKUP_NEW)) {
343 int res = cred->cr_ops->cr_init(auth, cred);
349 rpcauth_destroy_credlist(&free);
353 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
356 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
358 struct auth_cred acred;
359 struct rpc_cred *ret;
360 const struct cred *cred = current_cred();
362 dprintk("RPC: looking up %s cred\n",
363 auth->au_ops->au_name);
365 memset(&acred, 0, sizeof(acred));
366 acred.uid = cred->fsuid;
367 acred.gid = cred->fsgid;
368 acred.group_info = get_group_info(((struct cred *)cred)->group_info);
370 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
371 put_group_info(acred.group_info);
376 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
377 struct rpc_auth *auth, const struct rpc_credops *ops)
379 INIT_HLIST_NODE(&cred->cr_hash);
380 INIT_LIST_HEAD(&cred->cr_lru);
381 atomic_set(&cred->cr_count, 1);
382 cred->cr_auth = auth;
384 cred->cr_expire = jiffies;
386 cred->cr_magic = RPCAUTH_CRED_MAGIC;
388 cred->cr_uid = acred->uid;
390 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
393 rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
395 task->tk_msg.rpc_cred = get_rpccred(cred);
396 dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
397 cred->cr_auth->au_ops->au_name, cred);
399 EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
402 rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
404 struct rpc_auth *auth = task->tk_client->cl_auth;
405 struct auth_cred acred = {
409 struct rpc_cred *ret;
411 dprintk("RPC: %5u looking up %s cred\n",
412 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
413 ret = auth->au_ops->lookup_cred(auth, &acred, lookupflags);
415 task->tk_msg.rpc_cred = ret;
417 task->tk_status = PTR_ERR(ret);
421 rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
423 struct rpc_auth *auth = task->tk_client->cl_auth;
424 struct rpc_cred *ret;
426 dprintk("RPC: %5u looking up %s cred\n",
427 task->tk_pid, auth->au_ops->au_name);
428 ret = rpcauth_lookupcred(auth, lookupflags);
430 task->tk_msg.rpc_cred = ret;
432 task->tk_status = PTR_ERR(ret);
436 rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
440 if (flags & RPC_TASK_ASYNC)
441 lookupflags |= RPCAUTH_LOOKUP_NEW;
443 cred->cr_ops->crbind(task, cred, lookupflags);
444 else if (flags & RPC_TASK_ROOTCREDS)
445 rpcauth_bind_root_cred(task, lookupflags);
447 rpcauth_bind_new_cred(task, lookupflags);
451 put_rpccred(struct rpc_cred *cred)
453 /* Fast path for unhashed credentials */
454 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
455 if (atomic_dec_and_test(&cred->cr_count))
456 cred->cr_ops->crdestroy(cred);
460 if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
462 if (!list_empty(&cred->cr_lru)) {
463 number_cred_unused--;
464 list_del_init(&cred->cr_lru);
466 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
467 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
468 cred->cr_expire = jiffies;
469 list_add_tail(&cred->cr_lru, &cred_unused);
470 number_cred_unused++;
473 if (!rpcauth_unhash_cred(cred)) {
474 /* We were hashed and someone looked us up... */
478 spin_unlock(&rpc_credcache_lock);
479 cred->cr_ops->crdestroy(cred);
482 spin_unlock(&rpc_credcache_lock);
484 EXPORT_SYMBOL_GPL(put_rpccred);
487 rpcauth_unbindcred(struct rpc_task *task)
489 struct rpc_cred *cred = task->tk_msg.rpc_cred;
491 dprintk("RPC: %5u releasing %s cred %p\n",
492 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
495 task->tk_msg.rpc_cred = NULL;
499 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
501 struct rpc_cred *cred = task->tk_msg.rpc_cred;
503 dprintk("RPC: %5u marshaling %s cred %p\n",
504 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
506 return cred->cr_ops->crmarshal(task, p);
510 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
512 struct rpc_cred *cred = task->tk_msg.rpc_cred;
514 dprintk("RPC: %5u validating %s cred %p\n",
515 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
517 return cred->cr_ops->crvalidate(task, p);
521 rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
522 __be32 *data, void *obj)
524 struct rpc_cred *cred = task->tk_msg.rpc_cred;
526 dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
527 task->tk_pid, cred->cr_ops->cr_name, cred);
528 if (cred->cr_ops->crwrap_req)
529 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
530 /* By default, we encode the arguments normally. */
531 return encode(rqstp, data, obj);
535 rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
536 __be32 *data, void *obj)
538 struct rpc_cred *cred = task->tk_msg.rpc_cred;
540 dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
541 task->tk_pid, cred->cr_ops->cr_name, cred);
542 if (cred->cr_ops->crunwrap_resp)
543 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
545 /* By default, we decode the arguments normally. */
546 return decode(rqstp, data, obj);
550 rpcauth_refreshcred(struct rpc_task *task)
552 struct rpc_cred *cred = task->tk_msg.rpc_cred;
555 dprintk("RPC: %5u refreshing %s cred %p\n",
556 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
558 err = cred->cr_ops->crrefresh(task);
560 task->tk_status = err;
565 rpcauth_invalcred(struct rpc_task *task)
567 struct rpc_cred *cred = task->tk_msg.rpc_cred;
569 dprintk("RPC: %5u invalidating %s cred %p\n",
570 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
572 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
576 rpcauth_uptodatecred(struct rpc_task *task)
578 struct rpc_cred *cred = task->tk_msg.rpc_cred;
580 return cred == NULL ||
581 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
584 static struct shrinker rpc_cred_shrinker = {
585 .shrink = rpcauth_cache_shrinker,
586 .seeks = DEFAULT_SEEKS,
589 void __init rpcauth_init_module(void)
592 rpc_init_generic_auth();
593 register_shrinker(&rpc_cred_shrinker);
596 void __exit rpcauth_remove_module(void)
598 unregister_shrinker(&rpc_cred_shrinker);