SUNRPC: Move upcall out of auth->au_ops->crcreate()
[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/sunrpc/clnt.h>
15 #include <linux/spinlock.h>
16
17 #ifdef RPC_DEBUG
18 # define RPCDBG_FACILITY        RPCDBG_AUTH
19 #endif
20
21 static struct rpc_authops *     auth_flavors[RPC_AUTH_MAXFLAVOR] = {
22         &authnull_ops,          /* AUTH_NULL */
23         &authunix_ops,          /* AUTH_UNIX */
24         NULL,                   /* others can be loadable modules */
25 };
26
27 static u32
28 pseudoflavor_to_flavor(u32 flavor) {
29         if (flavor >= RPC_AUTH_MAXFLAVOR)
30                 return RPC_AUTH_GSS;
31         return flavor;
32 }
33
34 int
35 rpcauth_register(struct rpc_authops *ops)
36 {
37         rpc_authflavor_t flavor;
38
39         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
40                 return -EINVAL;
41         if (auth_flavors[flavor] != NULL)
42                 return -EPERM;          /* what else? */
43         auth_flavors[flavor] = ops;
44         return 0;
45 }
46
47 int
48 rpcauth_unregister(struct rpc_authops *ops)
49 {
50         rpc_authflavor_t flavor;
51
52         if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
53                 return -EINVAL;
54         if (auth_flavors[flavor] != ops)
55                 return -EPERM;          /* what else? */
56         auth_flavors[flavor] = NULL;
57         return 0;
58 }
59
60 struct rpc_auth *
61 rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
62 {
63         struct rpc_auth         *auth;
64         struct rpc_authops      *ops;
65         u32                     flavor = pseudoflavor_to_flavor(pseudoflavor);
66
67         if (flavor >= RPC_AUTH_MAXFLAVOR || !(ops = auth_flavors[flavor]))
68                 return ERR_PTR(-EINVAL);
69         auth = ops->create(clnt, pseudoflavor);
70         if (IS_ERR(auth))
71                 return auth;
72         if (clnt->cl_auth)
73                 rpcauth_destroy(clnt->cl_auth);
74         clnt->cl_auth = auth;
75         return auth;
76 }
77
78 void
79 rpcauth_destroy(struct rpc_auth *auth)
80 {
81         if (!atomic_dec_and_test(&auth->au_count))
82                 return;
83         auth->au_ops->destroy(auth);
84 }
85
86 static DEFINE_SPINLOCK(rpc_credcache_lock);
87
88 /*
89  * Initialize RPC credential cache
90  */
91 int
92 rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
93 {
94         struct rpc_cred_cache *new;
95         int i;
96
97         new = kmalloc(sizeof(*new), GFP_KERNEL);
98         if (!new)
99                 return -ENOMEM;
100         for (i = 0; i < RPC_CREDCACHE_NR; i++)
101                 INIT_HLIST_HEAD(&new->hashtable[i]);
102         new->expire = expire;
103         new->nextgc = jiffies + (expire >> 1);
104         auth->au_credcache = new;
105         return 0;
106 }
107
108 /*
109  * Destroy a list of credentials
110  */
111 static inline
112 void rpcauth_destroy_credlist(struct hlist_head *head)
113 {
114         struct rpc_cred *cred;
115
116         while (!hlist_empty(head)) {
117                 cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
118                 hlist_del_init(&cred->cr_hash);
119                 put_rpccred(cred);
120         }
121 }
122
123 /*
124  * Clear the RPC credential cache, and delete those credentials
125  * that are not referenced.
126  */
127 void
128 rpcauth_free_credcache(struct rpc_auth *auth)
129 {
130         struct rpc_cred_cache *cache = auth->au_credcache;
131         HLIST_HEAD(free);
132         struct hlist_node *pos, *next;
133         struct rpc_cred *cred;
134         int             i;
135
136         spin_lock(&rpc_credcache_lock);
137         for (i = 0; i < RPC_CREDCACHE_NR; i++) {
138                 hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
139                         cred = hlist_entry(pos, struct rpc_cred, cr_hash);
140                         __hlist_del(&cred->cr_hash);
141                         hlist_add_head(&cred->cr_hash, &free);
142                 }
143         }
144         spin_unlock(&rpc_credcache_lock);
145         rpcauth_destroy_credlist(&free);
146 }
147
148 static void
149 rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist_head *free)
150 {
151         if (atomic_read(&cred->cr_count) != 1)
152                return;
153         if (time_after(jiffies, cred->cr_expire + auth->au_credcache->expire))
154                 cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
155         if (!(cred->cr_flags & RPCAUTH_CRED_UPTODATE)) {
156                 __hlist_del(&cred->cr_hash);
157                 hlist_add_head(&cred->cr_hash, free);
158         }
159 }
160
161 /*
162  * Remove stale credentials. Avoid sleeping inside the loop.
163  */
164 static void
165 rpcauth_gc_credcache(struct rpc_auth *auth, struct hlist_head *free)
166 {
167         struct rpc_cred_cache *cache = auth->au_credcache;
168         struct hlist_node *pos, *next;
169         struct rpc_cred *cred;
170         int             i;
171
172         dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth);
173         for (i = 0; i < RPC_CREDCACHE_NR; i++) {
174                 hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
175                         cred = hlist_entry(pos, struct rpc_cred, cr_hash);
176                         rpcauth_prune_expired(auth, cred, free);
177                 }
178         }
179         cache->nextgc = jiffies + cache->expire;
180 }
181
182 /*
183  * Look up a process' credentials in the authentication cache
184  */
185 struct rpc_cred *
186 rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
187                 int flags)
188 {
189         struct rpc_cred_cache *cache = auth->au_credcache;
190         HLIST_HEAD(free);
191         struct hlist_node *pos, *next;
192         struct rpc_cred *new = NULL,
193                         *cred = NULL;
194         int             nr = 0;
195
196         if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
197                 nr = acred->uid & RPC_CREDCACHE_MASK;
198 retry:
199         spin_lock(&rpc_credcache_lock);
200         if (time_before(cache->nextgc, jiffies))
201                 rpcauth_gc_credcache(auth, &free);
202         hlist_for_each_safe(pos, next, &cache->hashtable[nr]) {
203                 struct rpc_cred *entry;
204                 entry = hlist_entry(pos, struct rpc_cred, cr_hash);
205                 if (entry->cr_ops->crmatch(acred, entry, flags)) {
206                         hlist_del(&entry->cr_hash);
207                         cred = entry;
208                         break;
209                 }
210                 rpcauth_prune_expired(auth, entry, &free);
211         }
212         if (new) {
213                 if (cred)
214                         hlist_add_head(&new->cr_hash, &free);
215                 else
216                         cred = new;
217         }
218         if (cred) {
219                 hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
220                 get_rpccred(cred);
221         }
222         spin_unlock(&rpc_credcache_lock);
223
224         rpcauth_destroy_credlist(&free);
225
226         if (!cred) {
227                 new = auth->au_ops->crcreate(auth, acred, flags);
228                 if (!IS_ERR(new)) {
229 #ifdef RPC_DEBUG
230                         new->cr_magic = RPCAUTH_CRED_MAGIC;
231 #endif
232                         goto retry;
233                 } else
234                         cred = new;
235         } else if ((cred->cr_flags & RPCAUTH_CRED_NEW)
236                         && cred->cr_ops->cr_init != NULL
237                         && !(flags & RPCAUTH_LOOKUP_NEW)) {
238                 int res = cred->cr_ops->cr_init(auth, cred);
239                 if (res < 0) {
240                         put_rpccred(cred);
241                         cred = ERR_PTR(res);
242                 }
243         }
244
245         return (struct rpc_cred *) cred;
246 }
247
248 struct rpc_cred *
249 rpcauth_lookupcred(struct rpc_auth *auth, int flags)
250 {
251         struct auth_cred acred = {
252                 .uid = current->fsuid,
253                 .gid = current->fsgid,
254                 .group_info = current->group_info,
255         };
256         struct rpc_cred *ret;
257
258         dprintk("RPC:     looking up %s cred\n",
259                 auth->au_ops->au_name);
260         get_group_info(acred.group_info);
261         ret = auth->au_ops->lookup_cred(auth, &acred, flags);
262         put_group_info(acred.group_info);
263         return ret;
264 }
265
266 struct rpc_cred *
267 rpcauth_bindcred(struct rpc_task *task)
268 {
269         struct rpc_auth *auth = task->tk_auth;
270         struct auth_cred acred = {
271                 .uid = current->fsuid,
272                 .gid = current->fsgid,
273                 .group_info = current->group_info,
274         };
275         struct rpc_cred *ret;
276         int flags = 0;
277
278         dprintk("RPC: %4d looking up %s cred\n",
279                 task->tk_pid, task->tk_auth->au_ops->au_name);
280         get_group_info(acred.group_info);
281         if (task->tk_flags & RPC_TASK_ROOTCREDS)
282                 flags |= RPCAUTH_LOOKUP_ROOTCREDS;
283         ret = auth->au_ops->lookup_cred(auth, &acred, flags);
284         if (!IS_ERR(ret))
285                 task->tk_msg.rpc_cred = ret;
286         else
287                 task->tk_status = PTR_ERR(ret);
288         put_group_info(acred.group_info);
289         return ret;
290 }
291
292 void
293 rpcauth_holdcred(struct rpc_task *task)
294 {
295         dprintk("RPC: %4d holding %s cred %p\n",
296                 task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
297         if (task->tk_msg.rpc_cred)
298                 get_rpccred(task->tk_msg.rpc_cred);
299 }
300
301 void
302 put_rpccred(struct rpc_cred *cred)
303 {
304         cred->cr_expire = jiffies;
305         if (!atomic_dec_and_test(&cred->cr_count))
306                 return;
307         cred->cr_ops->crdestroy(cred);
308 }
309
310 void
311 rpcauth_unbindcred(struct rpc_task *task)
312 {
313         struct rpc_cred *cred = task->tk_msg.rpc_cred;
314
315         dprintk("RPC: %4d releasing %s cred %p\n",
316                 task->tk_pid, task->tk_auth->au_ops->au_name, cred);
317
318         put_rpccred(cred);
319         task->tk_msg.rpc_cred = NULL;
320 }
321
322 u32 *
323 rpcauth_marshcred(struct rpc_task *task, u32 *p)
324 {
325         struct rpc_cred *cred = task->tk_msg.rpc_cred;
326
327         dprintk("RPC: %4d marshaling %s cred %p\n",
328                 task->tk_pid, task->tk_auth->au_ops->au_name, cred);
329
330         return cred->cr_ops->crmarshal(task, p);
331 }
332
333 u32 *
334 rpcauth_checkverf(struct rpc_task *task, u32 *p)
335 {
336         struct rpc_cred *cred = task->tk_msg.rpc_cred;
337
338         dprintk("RPC: %4d validating %s cred %p\n",
339                 task->tk_pid, task->tk_auth->au_ops->au_name, cred);
340
341         return cred->cr_ops->crvalidate(task, p);
342 }
343
344 int
345 rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
346                 u32 *data, void *obj)
347 {
348         struct rpc_cred *cred = task->tk_msg.rpc_cred;
349
350         dprintk("RPC: %4d using %s cred %p to wrap rpc data\n",
351                         task->tk_pid, cred->cr_ops->cr_name, cred);
352         if (cred->cr_ops->crwrap_req)
353                 return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
354         /* By default, we encode the arguments normally. */
355         return encode(rqstp, data, obj);
356 }
357
358 int
359 rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
360                 u32 *data, void *obj)
361 {
362         struct rpc_cred *cred = task->tk_msg.rpc_cred;
363
364         dprintk("RPC: %4d using %s cred %p to unwrap rpc data\n",
365                         task->tk_pid, cred->cr_ops->cr_name, cred);
366         if (cred->cr_ops->crunwrap_resp)
367                 return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
368                                                    data, obj);
369         /* By default, we decode the arguments normally. */
370         return decode(rqstp, data, obj);
371 }
372
373 int
374 rpcauth_refreshcred(struct rpc_task *task)
375 {
376         struct rpc_cred *cred = task->tk_msg.rpc_cred;
377         int err;
378
379         dprintk("RPC: %4d refreshing %s cred %p\n",
380                 task->tk_pid, task->tk_auth->au_ops->au_name, cred);
381
382         err = cred->cr_ops->crrefresh(task);
383         if (err < 0)
384                 task->tk_status = err;
385         return err;
386 }
387
388 void
389 rpcauth_invalcred(struct rpc_task *task)
390 {
391         dprintk("RPC: %4d invalidating %s cred %p\n",
392                 task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
393         spin_lock(&rpc_credcache_lock);
394         if (task->tk_msg.rpc_cred)
395                 task->tk_msg.rpc_cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
396         spin_unlock(&rpc_credcache_lock);
397 }
398
399 int
400 rpcauth_uptodatecred(struct rpc_task *task)
401 {
402         return !(task->tk_msg.rpc_cred) ||
403                 (task->tk_msg.rpc_cred->cr_flags & RPCAUTH_CRED_UPTODATE);
404 }