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 #define RPC_CREDCACHE_DEFAULT_HASHBITS (4)
23 struct rpc_cred_cache
{
24 struct hlist_head
*hashtable
;
25 unsigned int hashbits
;
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 (14)
42 static int param_set_hashtbl_sz(const char *val
, const struct kernel_param
*kp
)
50 ret
= strict_strtoul(val
, 0, &num
);
54 if (num
> (1U << nbits
))
56 if (nbits
> MAX_HASHTABLE_BITS
|| nbits
< 2)
58 *(unsigned int *)kp
->arg
= nbits
;
64 static int param_get_hashtbl_sz(char *buffer
, const struct kernel_param
*kp
)
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");
83 pseudoflavor_to_flavor(u32 flavor
) {
84 if (flavor
>= RPC_AUTH_MAXFLAVOR
)
90 rpcauth_register(const struct rpc_authops
*ops
)
92 rpc_authflavor_t flavor
;
95 if ((flavor
= ops
->au_flavor
) >= RPC_AUTH_MAXFLAVOR
)
97 spin_lock(&rpc_authflavor_lock
);
98 if (auth_flavors
[flavor
] == NULL
) {
99 auth_flavors
[flavor
] = ops
;
102 spin_unlock(&rpc_authflavor_lock
);
105 EXPORT_SYMBOL_GPL(rpcauth_register
);
108 rpcauth_unregister(const struct rpc_authops
*ops
)
110 rpc_authflavor_t flavor
;
113 if ((flavor
= ops
->au_flavor
) >= RPC_AUTH_MAXFLAVOR
)
115 spin_lock(&rpc_authflavor_lock
);
116 if (auth_flavors
[flavor
] == ops
) {
117 auth_flavors
[flavor
] = NULL
;
120 spin_unlock(&rpc_authflavor_lock
);
123 EXPORT_SYMBOL_GPL(rpcauth_unregister
);
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
)
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
);
144 spin_unlock(&rpc_authflavor_lock
);
145 auth
= ops
->create(clnt
, pseudoflavor
);
146 module_put(ops
->owner
);
150 rpcauth_release(clnt
->cl_auth
);
151 clnt
->cl_auth
= auth
;
156 EXPORT_SYMBOL_GPL(rpcauth_create
);
159 rpcauth_release(struct rpc_auth
*auth
)
161 if (!atomic_dec_and_test(&auth
->au_count
))
163 auth
->au_ops
->destroy(auth
);
166 static DEFINE_SPINLOCK(rpc_credcache_lock
);
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
);
177 rpcauth_unhash_cred(struct rpc_cred
*cred
)
179 spinlock_t
*cache_lock
;
182 cache_lock
= &cred
->cr_auth
->au_credcache
->lock
;
183 spin_lock(cache_lock
);
184 ret
= atomic_read(&cred
->cr_count
) == 0;
186 rpcauth_unhash_cred_locked(cred
);
187 spin_unlock(cache_lock
);
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
);
203 new->hashbits
= auth_hashbits
;
204 hashsize
= 1U << new->hashbits
;
205 new->hashtable
= kcalloc(hashsize
, sizeof(new->hashtable
[0]), GFP_KERNEL
);
208 spin_lock_init(&new->lock
);
209 auth
->au_credcache
= new;
216 EXPORT_SYMBOL_GPL(rpcauth_init_credcache
);
219 * Destroy a list of credentials
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
);
234 * Clear the RPC credential cache, and delete those credentials
235 * that are not referenced.
238 rpcauth_clear_credcache(struct rpc_cred_cache
*cache
)
241 struct hlist_head
*head
;
242 struct rpc_cred
*cred
;
243 unsigned int hashsize
= 1U << cache
->hashbits
;
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
);
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
270 rpcauth_destroy_credcache(struct rpc_auth
*auth
)
272 struct rpc_cred_cache
*cache
= auth
->au_credcache
;
275 auth
->au_credcache
= NULL
;
276 rpcauth_clear_credcache(cache
);
277 kfree(cache
->hashtable
);
281 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache
);
284 #define RPC_AUTH_EXPIRY_MORATORIUM (60 * HZ)
287 * Remove stale credentials. Avoid sleeping inside the loop.
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)
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)
308 list_del_init(&cred
->cr_lru
);
309 number_cred_unused
--;
310 if (atomic_read(&cred
->cr_count
) != 0)
313 cache_lock
= &cred
->cr_auth
->au_credcache
->lock
;
314 spin_lock(cache_lock
);
315 if (atomic_read(&cred
->cr_count
) == 0) {
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.
329 rpcauth_cache_shrinker(struct shrinker
*shrink
, int nr_to_scan
, gfp_t gfp_mask
)
334 if ((gfp_mask
& GFP_KERNEL
) != GFP_KERNEL
)
335 return (nr_to_scan
== 0) ? 0 : -1;
336 if (list_empty(&cred_unused
))
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
);
346 * Look up a process' credentials in the authentication cache
349 rpcauth_lookup_credcache(struct rpc_auth
*auth
, struct auth_cred
* acred
,
353 struct rpc_cred_cache
*cache
= auth
->au_credcache
;
354 struct hlist_node
*pos
;
355 struct rpc_cred
*cred
= NULL
,
359 nr
= hash_long(acred
->uid
, cache
->hashbits
);
362 hlist_for_each_entry_rcu(entry
, pos
, &cache
->hashtable
[nr
], cr_hash
) {
363 if (!entry
->cr_ops
->crmatch(acred
, entry
, flags
))
365 spin_lock(&cache
->lock
);
366 if (test_bit(RPCAUTH_CRED_HASHED
, &entry
->cr_flags
) == 0) {
367 spin_unlock(&cache
->lock
);
370 cred
= get_rpccred(entry
);
371 spin_unlock(&cache
->lock
);
379 new = auth
->au_ops
->crcreate(auth
, acred
, flags
);
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
))
389 cred
= get_rpccred(entry
);
394 set_bit(RPCAUTH_CRED_HASHED
, &cred
->cr_flags
);
395 hlist_add_head_rcu(&cred
->cr_hash
, &cache
->hashtable
[nr
]);
397 list_add_tail(&new->cr_lru
, &free
);
398 spin_unlock(&cache
->lock
);
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
);
409 rpcauth_destroy_credlist(&free
);
413 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache
);
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
);
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
;
444 cred
->cr_expire
= jiffies
;
446 cred
->cr_magic
= RPCAUTH_CRED_MAGIC
;
448 cred
->cr_uid
= acred
->uid
;
450 EXPORT_SYMBOL_GPL(rpcauth_init_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
= {
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
);
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;
492 if (flags
& RPC_TASK_ASYNC
)
493 lookupflags
|= RPCAUTH_LOOKUP_NEW
;
495 new = cred
->cr_ops
->crbind(task
, cred
, lookupflags
);
496 else if (flags
& RPC_TASK_ROOTCREDS
)
497 new = rpcauth_bind_root_cred(task
, lookupflags
);
499 new = rpcauth_bind_new_cred(task
, lookupflags
);
502 if (req
->rq_cred
!= NULL
)
503 put_rpccred(req
->rq_cred
);
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
);
518 if (!atomic_dec_and_lock(&cred
->cr_count
, &rpc_credcache_lock
))
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
++;
531 if (!rpcauth_unhash_cred(cred
)) {
532 /* We were hashed and someone looked us up... */
536 spin_unlock(&rpc_credcache_lock
);
537 cred
->cr_ops
->crdestroy(cred
);
540 spin_unlock(&rpc_credcache_lock
);
542 EXPORT_SYMBOL_GPL(put_rpccred
);
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
);
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
);
566 static void rpcauth_wrap_req_encode(kxdreproc_t encode
, struct rpc_rqst
*rqstp
,
567 __be32
*data
, void *obj
)
569 struct xdr_stream xdr
;
571 xdr_init_encode(&xdr
, &rqstp
->rq_snd_buf
, data
);
572 encode(rqstp
, &xdr
, obj
);
576 rpcauth_wrap_req(struct rpc_task
*task
, kxdreproc_t encode
, void *rqstp
,
577 __be32
*data
, void *obj
)
579 struct rpc_cred
*cred
= task
->tk_rqstp
->rq_cred
;
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 /* By default, we encode the arguments normally. */
586 rpcauth_wrap_req_encode(encode
, rqstp
, data
, obj
);
591 rpcauth_unwrap_req_decode(kxdrdproc_t decode
, struct rpc_rqst
*rqstp
,
592 __be32
*data
, void *obj
)
594 struct xdr_stream xdr
;
596 xdr_init_decode(&xdr
, &rqstp
->rq_rcv_buf
, data
);
597 return decode(rqstp
, &xdr
, obj
);
601 rpcauth_unwrap_resp(struct rpc_task
*task
, kxdrdproc_t decode
, void *rqstp
,
602 __be32
*data
, void *obj
)
604 struct rpc_cred
*cred
= task
->tk_rqstp
->rq_cred
;
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
,
611 /* By default, we decode the arguments normally. */
612 return rpcauth_unwrap_req_decode(decode
, rqstp
, data
, obj
);
616 rpcauth_refreshcred(struct rpc_task
*task
)
618 struct rpc_cred
*cred
;
621 cred
= task
->tk_rqstp
->rq_cred
;
623 err
= rpcauth_bindcred(task
, task
->tk_msg
.rpc_cred
, task
->tk_flags
);
626 cred
= task
->tk_rqstp
->rq_cred
;
628 dprintk("RPC: %5u refreshing %s cred %p\n",
629 task
->tk_pid
, cred
->cr_auth
->au_ops
->au_name
, cred
);
631 err
= cred
->cr_ops
->crrefresh(task
);
634 task
->tk_status
= err
;
639 rpcauth_invalcred(struct rpc_task
*task
)
641 struct rpc_cred
*cred
= task
->tk_rqstp
->rq_cred
;
643 dprintk("RPC: %5u invalidating %s cred %p\n",
644 task
->tk_pid
, cred
->cr_auth
->au_ops
->au_name
, cred
);
646 clear_bit(RPCAUTH_CRED_UPTODATE
, &cred
->cr_flags
);
650 rpcauth_uptodatecred(struct rpc_task
*task
)
652 struct rpc_cred
*cred
= task
->tk_rqstp
->rq_cred
;
654 return cred
== NULL
||
655 test_bit(RPCAUTH_CRED_UPTODATE
, &cred
->cr_flags
) != 0;
658 static struct shrinker rpc_cred_shrinker
= {
659 .shrink
= rpcauth_cache_shrinker
,
660 .seeks
= DEFAULT_SEEKS
,
663 int __init
rpcauth_init_module(void)
667 err
= rpc_init_authunix();
670 err
= rpc_init_generic_auth();
673 register_shrinker(&rpc_cred_shrinker
);
676 rpc_destroy_authunix();
681 void rpcauth_remove_module(void)
683 rpc_destroy_authunix();
684 rpc_destroy_generic_auth();
685 unregister_shrinker(&rpc_cred_shrinker
);