aboutsummaryrefslogtreecommitdiff
path: root/net/sunrpc/auth.c
blob: 1ca89c36da7abaa629e5485b0b04ca25afe42a69 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
/*
 * linux/net/sunrpc/auth.c
 *
 * Generic RPC client authentication API.
 *
 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/sunrpc/clnt.h>
#include <linux/spinlock.h>

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_AUTH
#endif

static struct rpc_authops *	auth_flavors[RPC_AUTH_MAXFLAVOR] = {
	&authnull_ops,		/* AUTH_NULL */
	&authunix_ops,		/* AUTH_UNIX */
	NULL,			/* others can be loadable modules */
};

static u32
pseudoflavor_to_flavor(u32 flavor) {
	if (flavor >= RPC_AUTH_MAXFLAVOR)
		return RPC_AUTH_GSS;
	return flavor;
}

int
rpcauth_register(struct rpc_authops *ops)
{
	rpc_authflavor_t flavor;

	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
		return -EINVAL;
	if (auth_flavors[flavor] != NULL)
		return -EPERM;		/* what else? */
	auth_flavors[flavor] = ops;
	return 0;
}

int
rpcauth_unregister(struct rpc_authops *ops)
{
	rpc_authflavor_t flavor;

	if ((flavor = ops->au_flavor) >= RPC_AUTH_MAXFLAVOR)
		return -EINVAL;
	if (auth_flavors[flavor] != ops)
		return -EPERM;		/* what else? */
	auth_flavors[flavor] = NULL;
	return 0;
}

struct rpc_auth *
rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
{
	struct rpc_auth		*auth;
	struct rpc_authops	*ops;
	u32			flavor = pseudoflavor_to_flavor(pseudoflavor);

	if (flavor >= RPC_AUTH_MAXFLAVOR || !(ops = auth_flavors[flavor]))
		return ERR_PTR(-EINVAL);
	auth = ops->create(clnt, pseudoflavor);
	if (IS_ERR(auth))
		return auth;
	if (clnt->cl_auth)
		rpcauth_destroy(clnt->cl_auth);
	clnt->cl_auth = auth;
	return auth;
}

void
rpcauth_destroy(struct rpc_auth *auth)
{
	if (!atomic_dec_and_test(&auth->au_count))
		return;
	auth->au_ops->destroy(auth);
}

static DEFINE_SPINLOCK(rpc_credcache_lock);

/*
 * Initialize RPC credential cache
 */
int
rpcauth_init_credcache(struct rpc_auth *auth, unsigned long expire)
{
	struct rpc_cred_cache *new;
	int i;

	new = kmalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		return -ENOMEM;
	for (i = 0; i < RPC_CREDCACHE_NR; i++)
		INIT_HLIST_HEAD(&new->hashtable[i]);
	new->expire = expire;
	new->nextgc = jiffies + (expire >> 1);
	auth->au_credcache = new;
	return 0;
}

/*
 * Destroy a list of credentials
 */
static inline
void rpcauth_destroy_credlist(struct hlist_head *head)
{
	struct rpc_cred *cred;

	while (!hlist_empty(head)) {
		cred = hlist_entry(head->first, struct rpc_cred, cr_hash);
		hlist_del_init(&cred->cr_hash);
		put_rpccred(cred);
	}
}

/*
 * Clear the RPC credential cache, and delete those credentials
 * that are not referenced.
 */
void
rpcauth_free_credcache(struct rpc_auth *auth)
{
	struct rpc_cred_cache *cache = auth->au_credcache;
	HLIST_HEAD(free);
	struct hlist_node *pos, *next;
	struct rpc_cred	*cred;
	int		i;

	spin_lock(&rpc_credcache_lock);
	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
		hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
			cred = hlist_entry(pos, struct rpc_cred, cr_hash);
			__hlist_del(&cred->cr_hash);
			hlist_add_head(&cred->cr_hash, &free);
		}
	}
	spin_unlock(&rpc_credcache_lock);
	rpcauth_destroy_credlist(&free);
}

static void
rpcauth_prune_expired(struct rpc_auth *auth, struct rpc_cred *cred, struct hlist_head *free)
{
	if (atomic_read(&cred->cr_count) != 1)
	       return;
	if (time_after(jiffies, cred->cr_expire + auth->au_credcache->expire))
		cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
	if (!(cred->cr_flags & RPCAUTH_CRED_UPTODATE)) {
		__hlist_del(&cred->cr_hash);
		hlist_add_head(&cred->cr_hash, free);
	}
}

/*
 * Remove stale credentials. Avoid sleeping inside the loop.
 */
static void
rpcauth_gc_credcache(struct rpc_auth *auth, struct hlist_head *free)
{
	struct rpc_cred_cache *cache = auth->au_credcache;
	struct hlist_node *pos, *next;
	struct rpc_cred	*cred;
	int		i;

	dprintk("RPC: gc'ing RPC credentials for auth %p\n", auth);
	for (i = 0; i < RPC_CREDCACHE_NR; i++) {
		hlist_for_each_safe(pos, next, &cache->hashtable[i]) {
			cred = hlist_entry(pos, struct rpc_cred, cr_hash);
			rpcauth_prune_expired(auth, cred, free);
		}
	}
	cache->nextgc = jiffies + cache->expire;
}

/*
 * Look up a process' credentials in the authentication cache
 */
struct rpc_cred *
rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
		int flags)
{
	struct rpc_cred_cache *cache = auth->au_credcache;
	HLIST_HEAD(free);
	struct hlist_node *pos, *next;
	struct rpc_cred	*new = NULL,
			*cred = NULL;
	int		nr = 0;

	if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
		nr = acred->uid & RPC_CREDCACHE_MASK;
retry:
	spin_lock(&rpc_credcache_lock);
	if (time_before(cache->nextgc, jiffies))
		rpcauth_gc_credcache(auth, &free);
	hlist_for_each_safe(pos, next, &cache->hashtable[nr]) {
		struct rpc_cred *entry;
	       	entry = hlist_entry(pos, struct rpc_cred, cr_hash);
		if (entry->cr_ops->crmatch(acred, entry, flags)) {
			hlist_del(&entry->cr_hash);
			cred = entry;
			break;
		}
		rpcauth_prune_expired(auth, entry, &free);
	}
	if (new) {
		if (cred)
			hlist_add_head(&new->cr_hash, &free);
		else
			cred = new;
	}
	if (cred) {
		hlist_add_head(&cred->cr_hash, &cache->hashtable[nr]);
		get_rpccred(cred);
	}
	spin_unlock(&rpc_credcache_lock);

	rpcauth_destroy_credlist(&free);

	if (!cred) {
		new = auth->au_ops->crcreate(auth, acred, flags);
		if (!IS_ERR(new)) {
#ifdef RPC_DEBUG
			new->cr_magic = RPCAUTH_CRED_MAGIC;
#endif
			goto retry;
		} else
			cred = new;
	}

	return (struct rpc_cred *) cred;
}

struct rpc_cred *
rpcauth_lookupcred(struct rpc_auth *auth, int flags)
{
	struct auth_cred acred = {
		.uid = current->fsuid,
		.gid = current->fsgid,
		.group_info = current->group_info,
	};
	struct rpc_cred *ret;

	dprintk("RPC:     looking up %s cred\n",
		auth->au_ops->au_name);
	get_group_info(acred.group_info);
	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
	put_group_info(acred.group_info);
	return ret;
}

struct rpc_cred *
rpcauth_bindcred(struct rpc_task *task)
{
	struct rpc_auth *auth = task->tk_auth;
	struct auth_cred acred = {
		.uid = current->fsuid,
		.gid = current->fsgid,
		.group_info = current->group_info,
	};
	struct rpc_cred *ret;
	int flags = 0;

	dprintk("RPC: %4d looking up %s cred\n",
		task->tk_pid, task->tk_auth->au_ops->au_name);
	get_group_info(acred.group_info);
	if (task->tk_flags & RPC_TASK_ROOTCREDS)
		flags |= RPCAUTH_LOOKUP_ROOTCREDS;
	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
	if (!IS_ERR(ret))
		task->tk_msg.rpc_cred = ret;
	else
		task->tk_status = PTR_ERR(ret);
	put_group_info(acred.group_info);
	return ret;
}

void
rpcauth_holdcred(struct rpc_task *task)
{
	dprintk("RPC: %4d holding %s cred %p\n",
		task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
	if (task->tk_msg.rpc_cred)
		get_rpccred(task->tk_msg.rpc_cred);
}

void
put_rpccred(struct rpc_cred *cred)
{
	cred->cr_expire = jiffies;
	if (!atomic_dec_and_test(&cred->cr_count))
		return;
	cred->cr_ops->crdestroy(cred);
}

void
rpcauth_unbindcred(struct rpc_task *task)
{
	struct rpc_cred	*cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %4d releasing %s cred %p\n",
		task->tk_pid, task->tk_auth->au_ops->au_name, cred);

	put_rpccred(cred);
	task->tk_msg.rpc_cred = NULL;
}

u32 *
rpcauth_marshcred(struct rpc_task *task, u32 *p)
{
	struct rpc_cred	*cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %4d marshaling %s cred %p\n",
		task->tk_pid, task->tk_auth->au_ops->au_name, cred);

	return cred->cr_ops->crmarshal(task, p);
}

u32 *
rpcauth_checkverf(struct rpc_task *task, u32 *p)
{
	struct rpc_cred	*cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %4d validating %s cred %p\n",
		task->tk_pid, task->tk_auth->au_ops->au_name, cred);

	return cred->cr_ops->crvalidate(task, p);
}

int
rpcauth_wrap_req(struct rpc_task *task, kxdrproc_t encode, void *rqstp,
		u32 *data, void *obj)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %4d using %s cred %p to wrap rpc data\n",
			task->tk_pid, cred->cr_ops->cr_name, cred);
	if (cred->cr_ops->crwrap_req)
		return cred->cr_ops->crwrap_req(task, encode, rqstp, data, obj);
	/* By default, we encode the arguments normally. */
	return encode(rqstp, data, obj);
}

int
rpcauth_unwrap_resp(struct rpc_task *task, kxdrproc_t decode, void *rqstp,
		u32 *data, void *obj)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	dprintk("RPC: %4d using %s cred %p to unwrap rpc data\n",
			task->tk_pid, cred->cr_ops->cr_name, cred);
	if (cred->cr_ops->crunwrap_resp)
		return cred->cr_ops->crunwrap_resp(task, decode, rqstp,
						   data, obj);
	/* By default, we decode the arguments normally. */
	return decode(rqstp, data, obj);
}

int
rpcauth_refreshcred(struct rpc_task *task)
{
	struct rpc_cred	*cred = task->tk_msg.rpc_cred;
	int err;

	dprintk("RPC: %4d refreshing %s cred %p\n",
		task->tk_pid, task->tk_auth->au_ops->au_name, cred);

	err = cred->cr_ops->crrefresh(task);
	if (err < 0)
		task->tk_status = err;
	return err;
}

void
rpcauth_invalcred(struct rpc_task *task)
{
	dprintk("RPC: %4d invalidating %s cred %p\n",
		task->tk_pid, task->tk_auth->au_ops->au_name, task->tk_msg.rpc_cred);
	spin_lock(&rpc_credcache_lock);
	if (task->tk_msg.rpc_cred)
		task->tk_msg.rpc_cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
	spin_unlock(&rpc_credcache_lock);
}

int
rpcauth_uptodatecred(struct rpc_task *task)
{
	return !(task->tk_msg.rpc_cred) ||
		(task->tk_msg.rpc_cred->cr_flags & RPCAUTH_CRED_UPTODATE);
}