1 /*
2 * linux/net/sunrpc/auth.c
3 *
4 * Generic RPC client authentication API.
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
8
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/sunrpc/clnt.h>
15 #include <linux/spinlock.h>
16
17 #ifdef RPC_DEBUG
18 # define RPCDBG_FACILITY RPCDBG_AUTH
19 #endif
20
21 static DEFINE_SPINLOCK(rpc_authflavor_lock);
22 static const struct rpc_authops *auth_flavors[RPC_AUTH_MAXFLAVOR] = {
23 &authnull_ops, /* AUTH_NULL */
24 &authunix_ops, /* AUTH_UNIX */
25 NULL, /* others can be loadable modules */
26 };
27
28 static LIST_HEAD(cred_unused);
29 static unsigned long number_cred_unused;
30
31 static u32
32 pseudoflavor_to_flavor(u32 flavor) {
33 if (flavor >= RPC_AUTH_MAXFLAVOR)
34 return RPC_AUTH_GSS;
35 return flavor;
36 }
37
38 int
39 rpcauth_register(const struct rpc_authops *ops)
40 {
41 rpc_authflavor_t flavor;
42 int ret = -EPERM;
43
44 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
45 return -EINVAL;
46 spin_lock(&rpc_authflavor_lock);
47 if (auth_flavors[flavor] == NULL) {
48 auth_flavors[flavor] = ops;
49 ret = 0;
50 }
51 spin_unlock(&rpc_authflavor_lock);
52 return ret;
53 }
54 EXPORT_SYMBOL_GPL(rpcauth_register);
55
56 int
57 rpcauth_unregister(const struct rpc_authops *ops)
58 {
59 rpc_authflavor_t flavor;
60 int ret = -EPERM;
61
62 if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
63 return -EINVAL;
64 spin_lock(&rpc_authflavor_lock);
65 if (auth_flavors[flavor] == ops) {
66 auth_flavors[flavor] = NULL;
67 ret = 0;
68 }
69 spin_unlock(&rpc_authflavor_lock);
70 return ret;
71 }
72 EXPORT_SYMBOL_GPL(rpcauth_unregister);
73
74 struct rpc_auth *
75 rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
76 {
77 struct rpc_auth *auth;
78 const struct rpc_authops *ops;
79 u32 flavor = pseudoflavor_to_flavor(pseudoflavor);
80
81 auth = ERR_PTR(-EINVAL);
82 if (flavor >= RPC_AUTH_MAXFLAVOR)
83 goto out;
84
85 #ifdef CONFIG_KMOD
86 if ((ops = auth_flavors[flavor]) == NULL)
87 request_module("rpc-auth-%u", flavor);
88 #endif
89 spin_lock(&rpc_authflavor_lock);
90 ops = auth_flavors[flavor];
91 if (ops == NULL || !try_module_get(ops->owner)) {
92 spin_unlock(&rpc_authflavor_lock);
93 goto out;
94 }
95 spin_unlock(&rpc_authflavor_lock);
96 auth = ops->create(clnt, pseudoflavor);
97 module_put(ops->owner);
98 if (IS_ERR(auth))
99 return auth;
100 if (clnt->cl_auth)
101 rpcauth_release(clnt->cl_auth);
102 clnt->cl_auth = auth;
103
104 out:
105 return auth;
106 }
107 EXPORT_SYMBOL_GPL(rpcauth_create);
108
109 void
110 rpcauth_release(struct rpc_auth *auth)
111 {
112 if (!atomic_dec_and_test(&auth->au_count))
113 return;
114 auth->au_ops->destroy(auth);
115 }
116
117 static DEFINE_SPINLOCK(rpc_credcache_lock);
118
119 static void
120 rpcauth_unhash_cred_locked(struct rpc_cred *cred)
121 {
122 hlist_del_rcu(&cred->cr_hash);
123 smp_mb__before_clear_bit();
124 clear_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
125 }
126
127 static void
128 rpcauth_unhash_cred(struct rpc_cred *cred)
129 {
130 spinlock_t *cache_lock;
131
132 cache_lock = &cred->cr_auth->au_credcache->lock;
133 spin_lock(cache_lock);
134 if (atomic_read(&cred->cr_count) == 0)
135 rpcauth_unhash_cred_locked(cred);
136 spin_unlock(cache_lock);
137 }
138
139 /*
140 * Initialize RPC credential cache
141 */
142 int
143 rpcauth_init_credcache(struct rpc_auth *auth)
144 {
145 struct rpc_cred_cache *new;
146 int i;
147
148 new = kmalloc(sizeof(*new), GFP_KERNEL);
149 if (!new)
150 return -ENOMEM;
151 for (i = 0; i < RPC_CREDCACHE_NR; i++)
152 INIT_HLIST_HEAD(&new->hashtable[i]);
153 spin_lock_init(&new->lock);
154 auth->au_credcache = new;
155 return 0;
156 }
157 EXPORT_SYMBOL_GPL(rpcauth_init_credcache);
158
159 /*
160 * Destroy a list of credentials
161 */
162 static inline
163 void rpcauth_destroy_credlist(struct list_head *head)
164 {
165 struct rpc_cred *cred;
166
167 while (!list_empty(head)) {
168 cred = list_entry(head->next, struct rpc_cred, cr_lru);
169 list_del_init(&cred->cr_lru);
170 put_rpccred(cred);
171 }
172 }
173
174 /*
175 * Clear the RPC credential cache, and delete those credentials
176 * that are not referenced.
177 */
178 void
179 rpcauth_clear_credcache(struct rpc_cred_cache *cache)
180 {
181 LIST_HEAD(free);
182 struct hlist_head *head;
183 struct rpc_cred *cred;
184 int i;
185
186 spin_lock(&rpc_credcache_lock);
187 spin_lock(&cache->lock);
188 for (i = 0; i < RPC_CREDCACHE_NR; i++) {
189 head = &cache->hashtable[i];
190 while (!hlist_empty(head)) {
191 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
192 get_rpccred(cred);
193 if (!list_empty(&cred->cr_lru)) {
194 list_del(&cred->cr_lru);
195 number_cred_unused--;
196 }
197 list_add_tail(&cred->cr_lru, &free);
198 rpcauth_unhash_cred_locked(cred);
199 }
200 }
201 spin_unlock(&cache->lock);
202 spin_unlock(&rpc_credcache_lock);
203 rpcauth_destroy_credlist(&free);
204 }
205
206 /*
207 * Destroy the RPC credential cache
208 */
209 void
210 rpcauth_destroy_credcache(struct rpc_auth *auth)
211 {
212 struct rpc_cred_cache *cache = auth->au_credcache;
213
214 if (cache) {
215 auth->au_credcache = NULL;
216 rpcauth_clear_credcache(cache);
217 kfree(cache);
218 }
219 }
220 EXPORT_SYMBOL_GPL(rpcauth_destroy_credcache);
221
222 /*
223 * Remove stale credentials. Avoid sleeping inside the loop.
224 */
225 static int
226 rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
227 {
228 spinlock_t *cache_lock;
229 struct rpc_cred *cred;
230
231 while (!list_empty(&cred_unused)) {
232 cred = list_entry(cred_unused.next, struct rpc_cred, cr_lru);
233 list_del_init(&cred->cr_lru);
234 number_cred_unused--;
235 if (atomic_read(&cred->cr_count) != 0)
236 continue;
237 cache_lock = &cred->cr_auth->au_credcache->lock;
238 spin_lock(cache_lock);
239 if (atomic_read(&cred->cr_count) == 0) {
240 get_rpccred(cred);
241 list_add_tail(&cred->cr_lru, free);
242 rpcauth_unhash_cred_locked(cred);
243 nr_to_scan--;
244 }
245 spin_unlock(cache_lock);
246 if (nr_to_scan == 0)
247 break;
248 }
249 return nr_to_scan;
250 }
251
252 /*
253 * Run memory cache shrinker.
254 */
255 static int
256 rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
257 {
258 LIST_HEAD(free);
259 int res;
260
261 if (list_empty(&cred_unused))
262 return 0;
263 spin_lock(&rpc_credcache_lock);
264 nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan);
265 res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
266 spin_unlock(&rpc_credcache_lock);
267 rpcauth_destroy_credlist(&free);
268 return res;
269 }
270
271 /*
272 * Look up a process' credentials in the authentication cache
273 */
274 struct rpc_cred *
275 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
276 int flags)
277 {
278 LIST_HEAD(free);
279 struct rpc_cred_cache *cache = auth->au_credcache;
280 struct hlist_node *pos;
281 struct rpc_cred *cred = NULL,
282 *entry, *new;
283 int nr = 0;
284
285 if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
286 nr = acred->uid & RPC_CREDCACHE_MASK;
287
288 rcu_read_lock();
289 hlist_for_each_entry_rcu(entry, pos, &cache->hashtable[nr], cr_hash) {
290 if (!entry->cr_ops->crmatch(acred, entry, flags))
291 continue;
292 spin_lock(&cache->lock);
293 if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
294 spin_unlock(&cache->lock);
295 continue;
296 }
297 cred = get_rpccred(entry);
298 spin_unlock(&cache->lock);
299 break;
300 }
301 rcu_read_unlock();
302
303 if (cred != NULL)
304 goto found;
305
306 new = auth->au_ops->crcreate(auth, acred, flags);
307 if (IS_ERR(new)) {
308 cred = new;
309 goto out;
310 }
311
312 spin_lock(&cache->lock);
313 hlist_for_each_entry(entry, pos, &cache->hashtable[nr], cr_hash) {
314 if (!entry->cr_ops->crmatch(acred, entry, flags))
315 continue;
316 cred = get_rpccred(entry);
317 break;
318 }
319 if (cred == NULL) {
320 cred = new;
321 set_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags);
322 hlist_add_head_rcu(&cred->cr_hash, &cache->hashtable[nr]);
323 } else
324 list_add_tail(&new->cr_lru, &free);
325 spin_unlock(&cache->lock);
326 found:
327 if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags)
328 && cred->cr_ops->cr_init != NULL
329 && !(flags & RPCAUTH_LOOKUP_NEW)) {
330 int res = cred->cr_ops->cr_init(auth, cred);
331 if (res < 0) {
332 put_rpccred(cred);
333 cred = ERR_PTR(res);
334 }
335 }
336 rpcauth_destroy_credlist(&free);
337 out:
338 return cred;
339 }
340 EXPORT_SYMBOL_GPL(rpcauth_lookup_credcache);
341
342 struct rpc_cred *
343 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
344 {
345 struct auth_cred acred = {
346 .uid = current->fsuid,
347 .gid = current->fsgid,
348 .group_info = current->group_info,
349 };
350 struct rpc_cred *ret;
351
352 dprintk("RPC: looking up %s cred\n",
353 auth->au_ops->au_name);
354 get_group_info(acred.group_info);
355 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
356 put_group_info(acred.group_info);
357 return ret;
358 }
359 EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
360
361 void
362 rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred,
363 struct rpc_auth *auth, const struct rpc_credops *ops)
364 {
365 INIT_HLIST_NODE(&cred->cr_hash);
366 INIT_LIST_HEAD(&cred->cr_lru);
367 atomic_set(&cred->cr_count, 1);
368 cred->cr_auth = auth;
369 cred->cr_ops = ops;
370 cred->cr_expire = jiffies;
371 #ifdef RPC_DEBUG
372 cred->cr_magic = RPCAUTH_CRED_MAGIC;
373 #endif
374 cred->cr_uid = acred->uid;
375 }
376 EXPORT_SYMBOL_GPL(rpcauth_init_cred);
377
378 struct rpc_cred *
379 rpcauth_bindcred(struct rpc_task *task)
380 {
381 struct rpc_auth *auth = task->tk_client->cl_auth;
382 struct auth_cred acred = {
383 .uid = current->fsuid,
384 .gid = current->fsgid,
385 .group_info = current->group_info,
386 };
387 struct rpc_cred *ret;
388 int flags = 0;
389
390 dprintk("RPC: %5u looking up %s cred\n",
391 task->tk_pid, task->tk_client->cl_auth->au_ops->au_name);
392 get_group_info(acred.group_info);
393 if (task->tk_flags & RPC_TASK_ROOTCREDS)
394 flags |= RPCAUTH_LOOKUP_ROOTCREDS;
395 ret = auth->au_ops->lookup_cred(auth, &acred, flags);
396 if (!IS_ERR(ret))
397 task->tk_msg.rpc_cred = ret;
398 else
399 task->tk_status = PTR_ERR(ret);
400 put_group_info(acred.group_info);
401 return ret;
402 }
403
404 void
405 rpcauth_holdcred(struct rpc_task *task)
406 {
407 struct rpc_cred *cred = task->tk_msg.rpc_cred;
408 if (cred != NULL) {
409 get_rpccred(cred);
410 dprintk("RPC: %5u holding %s cred %p\n", task->tk_pid,
411 cred->cr_auth->au_ops->au_name, cred);
412 }
413 }
414
415 void
416 put_rpccred(struct rpc_cred *cred)
417 {
418 /* Fast path for unhashed credentials */
419 if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0)
420 goto need_lock;
421
422 if (!atomic_dec_and_test(&cred->cr_count))
423 return;
424 goto out_destroy;
425 need_lock:
426 if (!atomic_dec_and_lock(&cred->cr_count, &rpc_credcache_lock))
427 return;
428 if (!list_empty(&cred->cr_lru)) {
429 number_cred_unused--;
430 list_del_init(&cred->cr_lru);
431 }
432 if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
433 rpcauth_unhash_cred(cred);
434 else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
435 cred->cr_expire = jiffies;
436 list_add_tail(&cred->cr_lru, &cred_unused);
437 number_cred_unused++;
438 spin_unlock(&rpc_credcache_lock);
439 return;
440 }
441 spin_unlock(&rpc_credcache_lock);
442 out_destroy:
443 cred->cr_ops->crdestroy(cred);
444 }
445 EXPORT_SYMBOL_GPL(put_rpccred);
446
447 void
448 rpcauth_unbindcred(struct rpc_task *task)
449 {
450 struct rpc_cred *cred = task->tk_msg.rpc_cred;
451
452 dprintk("RPC: %5u releasing %s cred %p\n",
453 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
454
455 put_rpccred(cred);
456 task->tk_msg.rpc_cred = NULL;
457 }
458
459 __be32 *
460 rpcauth_marshcred(struct rpc_task *task, __be32 *p)
461 {
462 struct rpc_cred *cred = task->tk_msg.rpc_cred;
463
464 dprintk("RPC: %5u marshaling %s cred %p\n",
465 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
466
467 return cred->cr_ops->crmarshal(task, p);
468 }
469
470 __be32 *
471 rpcauth_checkverf(struct rpc_task *task, __be32 *p)
472 {
473 struct rpc_cred *cred = task->tk_msg.rpc_cred;
474
475 dprintk("RPC: %5u validating %s cred %p\n",
476 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
477
478 return cred->cr_ops->crvalidate(task, p);
479 }
480
481 int
482 rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
483 __be32 *data, void *obj)
484 {
485 struct rpc_cred *cred = task->tk_msg.rpc_cred;
486
487 dprintk("RPC: %5u using %s cred %p to wrap rpc data\n",
488 task->tk_pid, cred->cr_ops->cr_name, cred);
489 if (cred->cr_ops->crwrap_req)
490 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
491 /* By default, we encode the arguments normally. */
492 return rpc_call_xdrproc(encode, rqstp, data, obj);
493 }
494
495 int
496 rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
497 __be32 *data, void *obj)
498 {
499 struct rpc_cred *cred = task->tk_msg.rpc_cred;
500
501 dprintk("RPC: %5u using %s cred %p to unwrap rpc data\n",
502 task->tk_pid, cred->cr_ops->cr_name, cred);
503 if (cred->cr_ops->crunwrap_resp)
504 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
505 data, obj);
506 /* By default, we decode the arguments normally. */
507 return rpc_call_xdrproc(decode, rqstp, data, obj);
508 }
509
510 int
511 rpcauth_refreshcred(struct rpc_task *task)
512 {
513 struct rpc_cred *cred = task->tk_msg.rpc_cred;
514 int err;
515
516 dprintk("RPC: %5u refreshing %s cred %p\n",
517 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
518
519 err = cred->cr_ops->crrefresh(task);
520 if (err < 0)
521 task->tk_status = err;
522 return err;
523 }
524
525 void
526 rpcauth_invalcred(struct rpc_task *task)
527 {
528 struct rpc_cred *cred = task->tk_msg.rpc_cred;
529
530 dprintk("RPC: %5u invalidating %s cred %p\n",
531 task->tk_pid, cred->cr_auth->au_ops->au_name, cred);
532 if (cred)
533 clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
534 }
535
536 int
537 rpcauth_uptodatecred(struct rpc_task *task)
538 {
539 struct rpc_cred *cred = task->tk_msg.rpc_cred;
540
541 return cred == NULL ||
542 test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0;
543 }
544
545 static struct shrinker rpc_cred_shrinker = {
546 .shrink = rpcauth_cache_shrinker,
547 .seeks = DEFAULT_SEEKS,
548 };
549
550 void __init rpcauth_init_module(void)
551 {
552 rpc_init_authunix();
553 register_shrinker(&rpc_cred_shrinker);
554 }
555
556 void __exit rpcauth_remove_module(void)
557 {
558 unregister_shrinker(&rpc_cred_shrinker);
559 }
560
|
This page was automatically generated by the
LXR engine.
|