[PATCH] RPC: [PATCH] improve rpcauthauth_create error returns
[linux-2.6.git] / net / sunrpc / auth.c
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/socket.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/spinlock.h>
17
18 #ifdef RPC_DEBUG
19 # define RPCDBG_FACILITY        RPCDBG_AUTH
20 #endif
21
22 static 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 u32
29 pseudoflavor_to_flavor(u32 flavor) {
30         if (flavor >= RPC_AUTH_MAXFLAVOR)
31                 return RPC_AUTH_GSS;
32         return flavor;
33 }
34
35 int
36 rpcauth_register(struct rpc_authops *ops)
37 {
38         rpc_authflavor_t flavor;
39
40         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
41                 return -EINVAL;
42         if (auth_flavors[flavor] != NULL)
43                 return -EPERM;          /* what else? */
44         auth_flavors[flavor] = ops;
45         return 0;
46 }
47
48 int
49 rpcauth_unregister(struct rpc_authops *ops)
50 {
51         rpc_authflavor_t flavor;
52
53         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
54                 return -EINVAL;
55         if (auth_flavors[flavor] != ops)
56                 return -EPERM;          /* what else? */
57         auth_flavors[flavor] = NULL;
58         return 0;
59 }
60
61 struct rpc_auth *
62 rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
63 {
64         struct rpc_auth         *auth;
65         struct rpc_authops      *ops;
66         u32                     flavor = pseudoflavor_to_flavor(pseudoflavor);
67
68         if (flavor >= RPC_AUTH_MAXFLAVOR || !(ops = auth_flavors[flavor]))
69                 return ERR_PTR(-EINVAL);
70         auth = ops->create(clnt, pseudoflavor);
71         if (IS_ERR(auth))
72                 return auth;
73         if (clnt->cl_auth)
74                 rpcauth_destroy(clnt->cl_auth);
75         clnt->cl_auth = auth;
76         return auth;
77 }
78
79 void
80 rpcauth_destroy(struct rpc_auth *auth)
81 {
82         if (!atomic_dec_and_test(&auth->au_count))
83                 return;
84         auth->au_ops->destroy(auth);
85 }
86
87 static DEFINE_SPINLOCK(rpc_credcache_lock);
88
89 /*
90  * Initialize RPC credential cache
91  */
92 int
93 rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
94 {
95         struct rpc_cred_cache *new;
96         int i;
97
98         new = (struct rpc_cred_cache *)kmalloc(sizeof(*new), GFP_KERNEL);
99         if (!new)
100                 return -ENOMEM;
101         for (i = 0; i < RPC_CREDCACHE_NR; i++)
102                 INIT_HLIST_HEAD(&new->hashtable[i]);
103         new->expire = expire;
104         new->nextgc = jiffies + (expire >> 1);
105         auth->au_credcache = new;
106         return 0;
107 }
108
109 /*
110  * Destroy a list of credentials
111  */
112 static inline
113 void rpcauth_destroy_credlist(struct hlist_head *head)
114 {
115         struct rpc_cred *cred;
116
117         while (!hlist_empty(head)) {
118                 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
119                 hlist_del_init(&cred->cr_hash);
120                 put_rpccred(cred);
121         }
122 }
123
124 /*
125  * Clear the RPC credential cache, and delete those credentials
126  * that are not referenced.
127  */
128 void
129 rpcauth_free_credcache(struct rpc_auth *auth)
130 {
131         struct rpc_cred_cache *cache = auth->au_credcache;
132         HLIST_HEAD(free);
133         struct hlist_node *pos, *next;
134         struct rpc_cred *cred;
135         int             i;
136
137         spin_lock(&rpc_credcache_lock);
138         for (i = 0; i < RPC_CREDCACHE_NR; i++) {
139                 hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
140                         cred = hlist_entry(pos, struct rpc_cred, cr_hash);
141                         __hlist_del(&cred->cr_hash);
142                         hlist_add_head(&cred->cr_hash, &free);
143                 }
144         }
145         spin_unlock(&rpc_credcache_lock);
146         rpcauth_destroy_credlist(&free);
147 }
148
149 static void
150 rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist_head *free)
151 {
152         if (atomic_read(&cred->cr_count) != 1)
153                return;
154         if (time_after(jiffies, cred->cr_expire + auth->au_credcache->expire))
155                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
156         if (!(cred->cr_flags & RPCAUTH_CRED_UPTODATE)) {
157                 __hlist_del(&cred->cr_hash);
158                 hlist_add_head(&cred->cr_hash, free);
159         }
160 }
161
162 /*
163  * Remove stale credentials. Avoid sleeping inside the loop.
164  */
165 static void
166 rpcauth_gc_credcache(struct rpc_auth *auth, struct hlist_head *free)
167 {
168         struct rpc_cred_cache *cache = auth->au_credcache;
169         struct hlist_node *pos, *next;
170         struct rpc_cred *cred;
171         int             i;
172
173         dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth);
174         for (i = 0; i < RPC_CREDCACHE_NR; i++) {
175                 hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
176                         cred = hlist_entry(pos, struct rpc_cred, cr_hash);
177                         rpcauth_prune_expired(auth, cred, free);
178                 }
179         }
180         cache->nextgc = jiffies + cache->expire;
181 }
182
183 /*
184  * Look up a process' credentials in the authentication cache
185  */
186 struct rpc_cred *
187 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
188                 int taskflags)
189 {
190         struct rpc_cred_cache *cache = auth->au_credcache;
191         HLIST_HEAD(free);
192         struct hlist_node *pos, *next;
193         struct rpc_cred *new = NULL,
194                         *cred = NULL;
195         int             nr = 0;
196
197         if (!(taskflags & RPC_TASK_ROOTCREDS))
198                 nr = acred->uid & RPC_CREDCACHE_MASK;
199 retry:
200         spin_lock(&rpc_credcache_lock);
201         if (time_before(cache->nextgc, jiffies))
202                 rpcauth_gc_credcache(auth, &free);
203         hlist_for_each_safe(pos, next, &cache->hashtable[nr]) {
204                 struct rpc_cred *entry;
205                 entry = hlist_entry(pos, struct rpc_cred, cr_hash);
206                 if (entry->cr_ops->crmatch(acred, entry, taskflags)) {
207                         hlist_del(&entry->cr_hash);
208                         cred = entry;
209                         break;
210                 }
211                 rpcauth_prune_expired(auth, entry, &free);
212         }
213         if (new) {
214                 if (cred)
215                         hlist_add_head(&new->cr_hash, &free);
216                 else
217                         cred = new;
218         }
219         if (cred) {
220                 hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
221                 get_rpccred(cred);
222         }
223         spin_unlock(&rpc_credcache_lock);
224
225         rpcauth_destroy_credlist(&free);
226
227         if (!cred) {
228                 new = auth->au_ops->crcreate(auth, acred, taskflags);
229                 if (!IS_ERR(new)) {
230 #ifdef RPC_DEBUG
231                         new->cr_magic = RPCAUTH_CRED_MAGIC;
232 #endif
233                         goto retry;
234                 } else
235                         cred = new;
236         }
237
238         return (struct rpc_cred *) cred;
239 }
240
241 struct rpc_cred *
242 rpcauth_lookupcred(struct rpc_auth *auth, int taskflags)
243 {
244         struct auth_cred acred = {
245                 .uid = current->fsuid,
246                 .gid = current->fsgid,
247                 .group_info = current->group_info,
248         };
249         struct rpc_cred *ret;
250
251         dprintk("RPC:     looking up %s cred\n",
252                 auth->au_ops->au_name);
253         get_group_info(acred.group_info);
254         ret = auth->au_ops->lookup_cred(auth, &acred, taskflags);
255         put_group_info(acred.group_info);
256         return ret;
257 }
258
259 struct rpc_cred *
260 rpcauth_bindcred(struct rpc_task *task)
261 {
262         struct rpc_auth *auth = task->tk_auth;
263         struct auth_cred acred = {
264                 .uid = current->fsuid,
265                 .gid = current->fsgid,
266                 .group_info = current->group_info,
267         };
268         struct rpc_cred *ret;
269
270         dprintk("RPC: %4d looking up %s cred\n",
271                 task->tk_pid, task->tk_auth->au_ops->au_name);
272         get_group_info(acred.group_info);
273         ret = auth->au_ops->lookup_cred(auth, &acred, task->tk_flags);
274         if (!IS_ERR(ret))
275                 task->tk_msg.rpc_cred = ret;
276         else
277                 task->tk_status = PTR_ERR(ret);
278         put_group_info(acred.group_info);
279         return ret;
280 }
281
282 void
283 rpcauth_holdcred(struct rpc_task *task)
284 {
285         dprintk("RPC: %4d holding %s cred %p\n",
286                 task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
287         if (task->tk_msg.rpc_cred)
288                 get_rpccred(task->tk_msg.rpc_cred);
289 }
290
291 void
292 put_rpccred(struct rpc_cred *cred)
293 {
294         cred->cr_expire = jiffies;
295         if (!atomic_dec_and_test(&cred->cr_count))
296                 return;
297         cred->cr_ops->crdestroy(cred);
298 }
299
300 void
301 rpcauth_unbindcred(struct rpc_task *task)
302 {
303         struct rpc_auth *auth = task->tk_auth;
304         struct rpc_cred *cred = task->tk_msg.rpc_cred;
305
306         dprintk("RPC: %4d releasing %s cred %p\n",
307                 task->tk_pid, auth->au_ops->au_name, cred);
308
309         put_rpccred(cred);
310         task->tk_msg.rpc_cred = NULL;
311 }
312
313 u32 *
314 rpcauth_marshcred(struct rpc_task *task, u32 *p)
315 {
316         struct rpc_auth *auth = task->tk_auth;
317         struct rpc_cred *cred = task->tk_msg.rpc_cred;
318
319         dprintk("RPC: %4d marshaling %s cred %p\n",
320                 task->tk_pid, auth->au_ops->au_name, cred);
321         return cred->cr_ops->crmarshal(task, p);
322 }
323
324 u32 *
325 rpcauth_checkverf(struct rpc_task *task, u32 *p)
326 {
327         struct rpc_auth *auth = task->tk_auth;
328         struct rpc_cred *cred = task->tk_msg.rpc_cred;
329
330         dprintk("RPC: %4d validating %s cred %p\n",
331                 task->tk_pid, auth->au_ops->au_name, cred);
332         return cred->cr_ops->crvalidate(task, p);
333 }
334
335 int
336 rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
337                 u32 *data, void *obj)
338 {
339         struct rpc_cred *cred = task->tk_msg.rpc_cred;
340
341         dprintk("RPC: %4d using %s cred %p to wrap rpc data\n",
342                         task->tk_pid, cred->cr_ops->cr_name, cred);
343         if (cred->cr_ops->crwrap_req)
344                 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
345         /* By default, we encode the arguments normally. */
346         return encode(rqstp, data, obj);
347 }
348
349 int
350 rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
351                 u32 *data, void *obj)
352 {
353         struct rpc_cred *cred = task->tk_msg.rpc_cred;
354
355         dprintk("RPC: %4d using %s cred %p to unwrap rpc data\n",
356                         task->tk_pid, cred->cr_ops->cr_name, cred);
357         if (cred->cr_ops->crunwrap_resp)
358                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
359                                                    data, obj);
360         /* By default, we decode the arguments normally. */
361         return decode(rqstp, data, obj);
362 }
363
364 int
365 rpcauth_refreshcred(struct rpc_task *task)
366 {
367         struct rpc_auth *auth = task->tk_auth;
368         struct rpc_cred *cred = task->tk_msg.rpc_cred;
369         int err;
370
371         dprintk("RPC: %4d refreshing %s cred %p\n",
372                 task->tk_pid, auth->au_ops->au_name, cred);
373         err = cred->cr_ops->crrefresh(task);
374         if (err < 0)
375                 task->tk_status = err;
376         return err;
377 }
378
379 void
380 rpcauth_invalcred(struct rpc_task *task)
381 {
382         dprintk("RPC: %4d invalidating %s cred %p\n",
383                 task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
384         spin_lock(&rpc_credcache_lock);
385         if (task->tk_msg.rpc_cred)
386                 task->tk_msg.rpc_cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
387         spin_unlock(&rpc_credcache_lock);
388 }
389
390 int
391 rpcauth_uptodatecred(struct rpc_task *task)
392 {
393         return !(task->tk_msg.rpc_cred) ||
394                 (task->tk_msg.rpc_cred->cr_flags & RPCAUTH_CRED_UPTODATE);
395 }