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/sunrpc/gss_api.h>
17 #include <linux/spinlock.h>
20 # define RPCDBG_FACILITY RPCDBG_AUTH
23 #define RPC_CREDCACHE_DEFAULT_HASHBITS (4)
24 struct rpc_cred_cache {
25 struct hlist_head *hashtable;
26 unsigned int hashbits;
30 static unsigned int auth_hashbits = RPC_CREDCACHE_DEFAULT_HASHBITS;
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 */
39 static LIST_HEAD(cred_unused);
40 static unsigned long number_cred_unused;
42 #define MAX_HASHTABLE_BITS (14)
43 static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
51 ret = strict_strtoul(val, 0, &num);
55 if (num > (1U << nbits))
57 if (nbits > MAX_HASHTABLE_BITS || nbits < 2)
59 *(unsigned int *)kp->arg = nbits;
65 static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
69 nbits = *(unsigned int *)kp->arg;
70 return sprintf(buffer, "%u", 1U << nbits);
73 #define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
75 static struct kernel_param_ops param_ops_hashtbl_sz = {
76 .set = param_set_hashtbl_sz,
77 .get = param_get_hashtbl_sz,
80 module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
81 MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
84 pseudoflavor_to_flavor(u32 flavor) {
85 if (flavor > RPC_AUTH_MAXFLAVOR)
91 rpcauth_register(const struct rpc_authops *ops)
93 rpc_authflavor_t flavor;
96 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
98 spin_lock(&rpc_authflavor_lock);
99 if (auth_flavors[flavor] == NULL) {
100 auth_flavors[flavor] = ops;
103 spin_unlock(&rpc_authflavor_lock);
106 EXPORT_SYMBOL_GPL(rpcauth_register);
109 rpcauth_unregister(const struct rpc_authops *ops)
111 rpc_authflavor_t flavor;
114 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
116 spin_lock(&rpc_authflavor_lock);
117 if (auth_flavors[flavor] == ops) {
118 auth_flavors[flavor] = NULL;
121 spin_unlock(&rpc_authflavor_lock);
124 EXPORT_SYMBOL_GPL(rpcauth_unregister);
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
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.
136 rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
138 const struct rpc_authops *ops;
139 rpc_authflavor_t pseudoflavor;
141 ops = auth_flavors[flavor];
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;
150 spin_unlock(&rpc_authflavor_lock);
152 pseudoflavor = flavor;
153 if (ops->info2flavor != NULL)
154 pseudoflavor = ops->info2flavor(info);
156 module_put(ops->owner);
159 EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
162 * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
163 * @pseudoflavor: GSS pseudoflavor to match
164 * @info: rpcsec_gss_info structure to fill in
166 * Returns zero and fills in "info" if pseudoflavor matches a
167 * supported mechanism.
170 rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
172 rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
173 const struct rpc_authops *ops;
176 if (flavor >= RPC_AUTH_MAXFLAVOR)
179 ops = auth_flavors[flavor];
181 request_module("rpc-auth-%u", flavor);
182 spin_lock(&rpc_authflavor_lock);
183 ops = auth_flavors[flavor];
184 if (ops == NULL || !try_module_get(ops->owner)) {
185 spin_unlock(&rpc_authflavor_lock);
188 spin_unlock(&rpc_authflavor_lock);
191 if (ops->flavor2info != NULL)
192 result = ops->flavor2info(pseudoflavor, info);
194 module_put(ops->owner);
197 EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
200 * rpcauth_list_flavors - discover registered flavors and pseudoflavors
201 * @array: array to fill in
202 * @size: size of "array"
204 * Returns the number of array items filled in, or a negative errno.
206 * The returned array is not sorted by any policy. Callers should not
207 * rely on the order of the items in the returned array.
210 rpcauth_list_flavors(rpc_authflavor_t *array, int size)
212 rpc_authflavor_t flavor;
215 spin_lock(&rpc_authflavor_lock);
216 for (flavor = 0; flavor < RPC_AUTH_MAXFLAVOR; flavor++) {
217 const struct rpc_authops *ops = auth_flavors[flavor];
218 rpc_authflavor_t pseudos[4];
221 if (result >= size) {
228 if (ops->list_pseudoflavors == NULL) {
229 array[result++] = ops->au_flavor;
232 len = ops->list_pseudoflavors(pseudos, ARRAY_SIZE(pseudos));
237 for (i = 0; i < len; i++) {
238 if (result >= size) {
242 array[result++] = pseudos[i];
245 spin_unlock(&rpc_authflavor_lock);
247 dprintk("RPC: %s returns %d\n", __func__, result);
250 EXPORT_SYMBOL_GPL(rpcauth_list_flavors);
253 rpcauth_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
255 struct rpc_auth *auth;
256 const struct rpc_authops *ops;
257 u32 flavor = pseudoflavor_to_flavor(args->pseudoflavor);
259 auth = ERR_PTR(-EINVAL);
260 if (flavor >= RPC_AUTH_MAXFLAVOR)
263 if ((ops = auth_flavors[flavor]) == NULL)
264 request_module("rpc-auth-%u", flavor);
265 spin_lock(&rpc_authflavor_lock);
266 ops = auth_flavors[flavor];
267 if (ops == NULL || !try_module_get(ops->owner)) {
268 spin_unlock(&rpc_authflavor_lock);
271 spin_unlock(&rpc_authflavor_lock);
272 auth = ops->create(args, clnt);
273 module_put(ops->owner);
277 rpcauth_release(clnt->cl_auth);
278 clnt->cl_auth = auth;
283 EXPORT_SYMBOL_GPL(rpcauth_create);
286 rpcauth_release(struct rpc_auth *auth)
288 if (!atomic_dec_and_test(&auth->au_count))
290 auth->au_ops->destroy(auth);
293 static DEFINE_SPINLOCK(rpc_credcache_lock);
296 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
298 hlist_del_rcu(&cred->cr_hash);
299 smp_mb__before_clear_bit();
300 clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
304 rpcauth_unhash_cred(struct rpc_cred *cred)
306 spinlock_t *cache_lock;
309 cache_lock = &cred->cr_auth->au_credcache->lock;
310 spin_lock(cache_lock);
311 ret = atomic_read(&cred->cr_count) == 0;
313 rpcauth_unhash_cred_locked(cred);
314 spin_unlock(cache_lock);
319 * Initialize RPC credential cache
322 rpcauth_init_credcache(struct rpc_auth *auth)
324 struct rpc_cred_cache *new;
325 unsigned int hashsize;
327 new = kmalloc(sizeof(*new), GFP_KERNEL);
330 new->hashbits = auth_hashbits;
331 hashsize = 1U << new->hashbits;
332 new->hashtable = kcalloc(hashsize, sizeof(new->hashtable[0]), GFP_KERNEL);
335 spin_lock_init(&new->lock);
336 auth->au_credcache = new;
343 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
346 * Setup a credential key lifetime timeout notification
349 rpcauth_key_timeout_notify(struct rpc_auth *auth, struct rpc_cred *cred)
351 if (!cred->cr_auth->au_ops->key_timeout)
353 return cred->cr_auth->au_ops->key_timeout(auth, cred);
355 EXPORT_SYMBOL_GPL(rpcauth_key_timeout_notify);
358 rpcauth_cred_key_to_expire(struct rpc_cred *cred)
360 if (!cred->cr_ops->crkey_to_expire)
362 return cred->cr_ops->crkey_to_expire(cred);
364 EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
367 * Destroy a list of credentials
370 void rpcauth_destroy_credlist(struct list_head *head)
372 struct rpc_cred *cred;
374 while (!list_empty(head)) {
375 cred = list_entry(head->next, struct rpc_cred, cr_lru);
376 list_del_init(&cred->cr_lru);
382 * Clear the RPC credential cache, and delete those credentials
383 * that are not referenced.
386 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
389 struct hlist_head *head;
390 struct rpc_cred *cred;
391 unsigned int hashsize = 1U << cache->hashbits;
394 spin_lock(&rpc_credcache_lock);
395 spin_lock(&cache->lock);
396 for (i = 0; i < hashsize; i++) {
397 head = &cache->hashtable[i];
398 while (!hlist_empty(head)) {
399 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
401 if (!list_empty(&cred->cr_lru)) {
402 list_del(&cred->cr_lru);
403 number_cred_unused--;
405 list_add_tail(&cred->cr_lru, &free);
406 rpcauth_unhash_cred_locked(cred);
409 spin_unlock(&cache->lock);
410 spin_unlock(&rpc_credcache_lock);
411 rpcauth_destroy_credlist(&free);
415 * Destroy the RPC credential cache
418 rpcauth_destroy_credcache(struct rpc_auth *auth)
420 struct rpc_cred_cache *cache = auth->au_credcache;
423 auth->au_credcache = NULL;
424 rpcauth_clear_credcache(cache);
425 kfree(cache->hashtable);
429 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
432 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
435 * Remove stale credentials. Avoid sleeping inside the loop.
438 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
440 spinlock_t *cache_lock;
441 struct rpc_cred *cred, *next;
442 unsigned long expired = jiffies - RPC_AUTH_EXPIRY_MORATORIUM;
444 list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) {
446 if (nr_to_scan-- == 0)
449 * Enforce a 60 second garbage collection moratorium
450 * Note that the cred_unused list must be time-ordered.
452 if (time_in_range(cred->cr_expire, expired, jiffies) &&
453 test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
456 list_del_init(&cred->cr_lru);
457 number_cred_unused--;
458 if (atomic_read(&cred->cr_count) != 0)
461 cache_lock = &cred->cr_auth->au_credcache->lock;
462 spin_lock(cache_lock);
463 if (atomic_read(&cred->cr_count) == 0) {
465 list_add_tail(&cred->cr_lru, free);
466 rpcauth_unhash_cred_locked(cred);
468 spin_unlock(cache_lock);
470 return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
474 * Run memory cache shrinker.
477 rpcauth_cache_shrinker(struct shrinker *shrink, struct shrink_control *sc)
481 int nr_to_scan = sc->nr_to_scan;
482 gfp_t gfp_mask = sc->gfp_mask;
484 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
485 return (nr_to_scan == 0) ? 0 : -1;
486 if (list_empty(&cred_unused))
488 spin_lock(&rpc_credcache_lock);
489 res = rpcauth_prune_expired(&free, nr_to_scan);
490 spin_unlock(&rpc_credcache_lock);
491 rpcauth_destroy_credlist(&free);
496 * Look up a process' credentials in the authentication cache
499 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
503 struct rpc_cred_cache *cache = auth->au_credcache;
504 struct rpc_cred *cred = NULL,
508 nr = hash_long(from_kuid(&init_user_ns, acred->uid), cache->hashbits);
511 hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
512 if (!entry->cr_ops->crmatch(acred, entry, flags))
514 spin_lock(&cache->lock);
515 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
516 spin_unlock(&cache->lock);
519 cred = get_rpccred(entry);
520 spin_unlock(&cache->lock);
528 new = auth->au_ops->crcreate(auth, acred, flags);
534 spin_lock(&cache->lock);
535 hlist_for_each_entry(entry, &cache->hashtable[nr], cr_hash) {
536 if (!entry->cr_ops->crmatch(acred, entry, flags))
538 cred = get_rpccred(entry);
543 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
544 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
546 list_add_tail(&new->cr_lru, &free);
547 spin_unlock(&cache->lock);
549 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
550 cred->cr_ops->cr_init != NULL &&
551 !(flags & RPCAUTH_LOOKUP_NEW)) {
552 int res = cred->cr_ops->cr_init(auth, cred);
558 rpcauth_destroy_credlist(&free);
562 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
565 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
567 struct auth_cred acred;
568 struct rpc_cred *ret;
569 const struct cred *cred = current_cred();
571 dprintk("RPC: looking up %s cred\n",
572 auth->au_ops->au_name);
574 memset(&acred, 0, sizeof(acred));
575 acred.uid = cred->fsuid;
576 acred.gid = cred->fsgid;
577 acred.group_info = get_group_info(((struct cred *)cred)->group_info);
579 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
580 put_group_info(acred.group_info);
585 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
586 struct rpc_auth *auth, const struct rpc_credops *ops)
588 INIT_HLIST_NODE(&cred->cr_hash);
589 INIT_LIST_HEAD(&cred->cr_lru);
590 atomic_set(&cred->cr_count, 1);
591 cred->cr_auth = auth;
593 cred->cr_expire = jiffies;
595 cred->cr_magic = RPCAUTH_CRED_MAGIC;
597 cred->cr_uid = acred->uid;
599 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
602 rpcauth_generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags)
604 dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
605 cred->cr_auth->au_ops->au_name, cred);
606 return get_rpccred(cred);
608 EXPORT_SYMBOL_GPL(rpcauth_generic_bind_cred);
610 static struct rpc_cred *
611 rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
613 struct rpc_auth *auth = task->tk_client->cl_auth;
614 struct auth_cred acred = {
615 .uid = GLOBAL_ROOT_UID,
616 .gid = GLOBAL_ROOT_GID,
619 dprintk("RPC: %5u looking up %s cred\n",
620 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
621 return auth->au_ops->lookup_cred(auth, &acred, lookupflags);
624 static struct rpc_cred *
625 rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags)
627 struct rpc_auth *auth = task->tk_client->cl_auth;
629 dprintk("RPC: %5u looking up %s cred\n",
630 task->tk_pid, auth->au_ops->au_name);
631 return rpcauth_lookupcred(auth, lookupflags);
635 rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags)
637 struct rpc_rqst *req = task->tk_rqstp;
638 struct rpc_cred *new;
641 if (flags & RPC_TASK_ASYNC)
642 lookupflags |= RPCAUTH_LOOKUP_NEW;
644 new = cred->cr_ops->crbind(task, cred, lookupflags);
645 else if (flags & RPC_TASK_ROOTCREDS)
646 new = rpcauth_bind_root_cred(task, lookupflags);
648 new = rpcauth_bind_new_cred(task, lookupflags);
651 if (req->rq_cred != NULL)
652 put_rpccred(req->rq_cred);
658 put_rpccred(struct rpc_cred *cred)
660 /* Fast path for unhashed credentials */
661 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) == 0) {
662 if (atomic_dec_and_test(&cred->cr_count))
663 cred->cr_ops->crdestroy(cred);
667 if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
669 if (!list_empty(&cred->cr_lru)) {
670 number_cred_unused--;
671 list_del_init(&cred->cr_lru);
673 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
674 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0) {
675 cred->cr_expire = jiffies;
676 list_add_tail(&cred->cr_lru, &cred_unused);
677 number_cred_unused++;
680 if (!rpcauth_unhash_cred(cred)) {
681 /* We were hashed and someone looked us up... */
685 spin_unlock(&rpc_credcache_lock);
686 cred->cr_ops->crdestroy(cred);
689 spin_unlock(&rpc_credcache_lock);
691 EXPORT_SYMBOL_GPL(put_rpccred);
694 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
696 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
698 dprintk("RPC: %5u marshaling %s cred %p\n",
699 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
701 return cred->cr_ops->crmarshal(task, p);
705 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
707 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
709 dprintk("RPC: %5u validating %s cred %p\n",
710 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
712 return cred->cr_ops->crvalidate(task, p);
715 static void rpcauth_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
716 __be32 *data, void *obj)
718 struct xdr_stream xdr;
720 xdr_init_encode(&xdr, &rqstp->rq_snd_buf, data);
721 encode(rqstp, &xdr, obj);
725 rpcauth_wrap_req(struct rpc_task *task, kxdreproc_t encode, void *rqstp,
726 __be32 *data, void *obj)
728 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
730 dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
731 task->tk_pid, cred->cr_ops->cr_name, cred);
732 if (cred->cr_ops->crwrap_req)
733 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
734 /* By default, we encode the arguments normally. */
735 rpcauth_wrap_req_encode(encode, rqstp, data, obj);
740 rpcauth_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
741 __be32 *data, void *obj)
743 struct xdr_stream xdr;
745 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, data);
746 return decode(rqstp, &xdr, obj);
750 rpcauth_unwrap_resp(struct rpc_task *task, kxdrdproc_t decode, void *rqstp,
751 __be32 *data, void *obj)
753 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
755 dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
756 task->tk_pid, cred->cr_ops->cr_name, cred);
757 if (cred->cr_ops->crunwrap_resp)
758 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
760 /* By default, we decode the arguments normally. */
761 return rpcauth_unwrap_req_decode(decode, rqstp, data, obj);
765 rpcauth_refreshcred(struct rpc_task *task)
767 struct rpc_cred *cred;
770 cred = task->tk_rqstp->rq_cred;
772 err = rpcauth_bindcred(task, task->tk_msg.rpc_cred, task->tk_flags);
775 cred = task->tk_rqstp->rq_cred;
777 dprintk("RPC: %5u refreshing %s cred %p\n",
778 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
780 err = cred->cr_ops->crrefresh(task);
783 task->tk_status = err;
788 rpcauth_invalcred(struct rpc_task *task)
790 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
792 dprintk("RPC: %5u invalidating %s cred %p\n",
793 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
795 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
799 rpcauth_uptodatecred(struct rpc_task *task)
801 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
803 return cred == NULL ||
804 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
807 static struct shrinker rpc_cred_shrinker = {
808 .shrink = rpcauth_cache_shrinker,
809 .seeks = DEFAULT_SEEKS,
812 int __init rpcauth_init_module(void)
816 err = rpc_init_authunix();
819 err = rpc_init_generic_auth();
822 register_shrinker(&rpc_cred_shrinker);
825 rpc_destroy_authunix();
830 void rpcauth_remove_module(void)
832 rpc_destroy_authunix();
833 rpc_destroy_generic_auth();
834 unregister_shrinker(&rpc_cred_shrinker);