xref: /openbmc/linux/net/sunrpc/auth_gss/auth_gss.c (revision d2999e1b)
1 /*
2  * linux/net/sunrpc/auth_gss/auth_gss.c
3  *
4  * RPCSEC_GSS client authentication.
5  *
6  *  Copyright (c) 2000 The Regents of the University of Michigan.
7  *  All rights reserved.
8  *
9  *  Dug Song       <dugsong@monkey.org>
10  *  Andy Adamson   <andros@umich.edu>
11  *
12  *  Redistribution and use in source and binary forms, with or without
13  *  modification, are permitted provided that the following conditions
14  *  are met:
15  *
16  *  1. Redistributions of source code must retain the above copyright
17  *     notice, this list of conditions and the following disclaimer.
18  *  2. Redistributions in binary form must reproduce the above copyright
19  *     notice, this list of conditions and the following disclaimer in the
20  *     documentation and/or other materials provided with the distribution.
21  *  3. Neither the name of the University nor the names of its
22  *     contributors may be used to endorse or promote products derived
23  *     from this software without specific prior written permission.
24  *
25  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
26  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
27  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
28  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
32  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
33  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
34  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
35  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 
39 #include <linux/module.h>
40 #include <linux/init.h>
41 #include <linux/types.h>
42 #include <linux/slab.h>
43 #include <linux/sched.h>
44 #include <linux/pagemap.h>
45 #include <linux/sunrpc/clnt.h>
46 #include <linux/sunrpc/auth.h>
47 #include <linux/sunrpc/auth_gss.h>
48 #include <linux/sunrpc/svcauth_gss.h>
49 #include <linux/sunrpc/gss_err.h>
50 #include <linux/workqueue.h>
51 #include <linux/sunrpc/rpc_pipe_fs.h>
52 #include <linux/sunrpc/gss_api.h>
53 #include <asm/uaccess.h>
54 #include <linux/hashtable.h>
55 
56 #include "../netns.h"
57 
58 static const struct rpc_authops authgss_ops;
59 
60 static const struct rpc_credops gss_credops;
61 static const struct rpc_credops gss_nullops;
62 
63 #define GSS_RETRY_EXPIRED 5
64 static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
65 
66 #define GSS_KEY_EXPIRE_TIMEO 240
67 static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO;
68 
69 #ifdef RPC_DEBUG
70 # define RPCDBG_FACILITY	RPCDBG_AUTH
71 #endif
72 
73 #define GSS_CRED_SLACK		(RPC_MAX_AUTH_SIZE * 2)
74 /* length of a krb5 verifier (48), plus data added before arguments when
75  * using integrity (two 4-byte integers): */
76 #define GSS_VERF_SLACK		100
77 
78 static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
79 static DEFINE_SPINLOCK(gss_auth_hash_lock);
80 
81 struct gss_pipe {
82 	struct rpc_pipe_dir_object pdo;
83 	struct rpc_pipe *pipe;
84 	struct rpc_clnt *clnt;
85 	const char *name;
86 	struct kref kref;
87 };
88 
89 struct gss_auth {
90 	struct kref kref;
91 	struct hlist_node hash;
92 	struct rpc_auth rpc_auth;
93 	struct gss_api_mech *mech;
94 	enum rpc_gss_svc service;
95 	struct rpc_clnt *client;
96 	struct net *net;
97 	/*
98 	 * There are two upcall pipes; dentry[1], named "gssd", is used
99 	 * for the new text-based upcall; dentry[0] is named after the
100 	 * mechanism (for example, "krb5") and exists for
101 	 * backwards-compatibility with older gssd's.
102 	 */
103 	struct gss_pipe *gss_pipe[2];
104 	const char *target_name;
105 };
106 
107 /* pipe_version >= 0 if and only if someone has a pipe open. */
108 static DEFINE_SPINLOCK(pipe_version_lock);
109 static struct rpc_wait_queue pipe_version_rpc_waitqueue;
110 static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
111 static void gss_put_auth(struct gss_auth *gss_auth);
112 
113 static void gss_free_ctx(struct gss_cl_ctx *);
114 static const struct rpc_pipe_ops gss_upcall_ops_v0;
115 static const struct rpc_pipe_ops gss_upcall_ops_v1;
116 
117 static inline struct gss_cl_ctx *
118 gss_get_ctx(struct gss_cl_ctx *ctx)
119 {
120 	atomic_inc(&ctx->count);
121 	return ctx;
122 }
123 
124 static inline void
125 gss_put_ctx(struct gss_cl_ctx *ctx)
126 {
127 	if (atomic_dec_and_test(&ctx->count))
128 		gss_free_ctx(ctx);
129 }
130 
131 /* gss_cred_set_ctx:
132  * called by gss_upcall_callback and gss_create_upcall in order
133  * to set the gss context. The actual exchange of an old context
134  * and a new one is protected by the pipe->lock.
135  */
136 static void
137 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
138 {
139 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
140 
141 	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
142 		return;
143 	gss_get_ctx(ctx);
144 	rcu_assign_pointer(gss_cred->gc_ctx, ctx);
145 	set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
146 	smp_mb__before_atomic();
147 	clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
148 }
149 
150 static const void *
151 simple_get_bytes(const void *p, const void *end, void *res, size_t len)
152 {
153 	const void *q = (const void *)((const char *)p + len);
154 	if (unlikely(q > end || q < p))
155 		return ERR_PTR(-EFAULT);
156 	memcpy(res, p, len);
157 	return q;
158 }
159 
160 static inline const void *
161 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
162 {
163 	const void *q;
164 	unsigned int len;
165 
166 	p = simple_get_bytes(p, end, &len, sizeof(len));
167 	if (IS_ERR(p))
168 		return p;
169 	q = (const void *)((const char *)p + len);
170 	if (unlikely(q > end || q < p))
171 		return ERR_PTR(-EFAULT);
172 	dest->data = kmemdup(p, len, GFP_NOFS);
173 	if (unlikely(dest->data == NULL))
174 		return ERR_PTR(-ENOMEM);
175 	dest->len = len;
176 	return q;
177 }
178 
179 static struct gss_cl_ctx *
180 gss_cred_get_ctx(struct rpc_cred *cred)
181 {
182 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
183 	struct gss_cl_ctx *ctx = NULL;
184 
185 	rcu_read_lock();
186 	if (gss_cred->gc_ctx)
187 		ctx = gss_get_ctx(gss_cred->gc_ctx);
188 	rcu_read_unlock();
189 	return ctx;
190 }
191 
192 static struct gss_cl_ctx *
193 gss_alloc_context(void)
194 {
195 	struct gss_cl_ctx *ctx;
196 
197 	ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
198 	if (ctx != NULL) {
199 		ctx->gc_proc = RPC_GSS_PROC_DATA;
200 		ctx->gc_seq = 1;	/* NetApp 6.4R1 doesn't accept seq. no. 0 */
201 		spin_lock_init(&ctx->gc_seq_lock);
202 		atomic_set(&ctx->count,1);
203 	}
204 	return ctx;
205 }
206 
207 #define GSSD_MIN_TIMEOUT (60 * 60)
208 static const void *
209 gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
210 {
211 	const void *q;
212 	unsigned int seclen;
213 	unsigned int timeout;
214 	unsigned long now = jiffies;
215 	u32 window_size;
216 	int ret;
217 
218 	/* First unsigned int gives the remaining lifetime in seconds of the
219 	 * credential - e.g. the remaining TGT lifetime for Kerberos or
220 	 * the -t value passed to GSSD.
221 	 */
222 	p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
223 	if (IS_ERR(p))
224 		goto err;
225 	if (timeout == 0)
226 		timeout = GSSD_MIN_TIMEOUT;
227 	ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
228 	/* Sequence number window. Determines the maximum number of
229 	 * simultaneous requests
230 	 */
231 	p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
232 	if (IS_ERR(p))
233 		goto err;
234 	ctx->gc_win = window_size;
235 	/* gssd signals an error by passing ctx->gc_win = 0: */
236 	if (ctx->gc_win == 0) {
237 		/*
238 		 * in which case, p points to an error code. Anything other
239 		 * than -EKEYEXPIRED gets converted to -EACCES.
240 		 */
241 		p = simple_get_bytes(p, end, &ret, sizeof(ret));
242 		if (!IS_ERR(p))
243 			p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
244 						    ERR_PTR(-EACCES);
245 		goto err;
246 	}
247 	/* copy the opaque wire context */
248 	p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
249 	if (IS_ERR(p))
250 		goto err;
251 	/* import the opaque security context */
252 	p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
253 	if (IS_ERR(p))
254 		goto err;
255 	q = (const void *)((const char *)p + seclen);
256 	if (unlikely(q > end || q < p)) {
257 		p = ERR_PTR(-EFAULT);
258 		goto err;
259 	}
260 	ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
261 	if (ret < 0) {
262 		p = ERR_PTR(ret);
263 		goto err;
264 	}
265 	dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u\n",
266 		__func__, ctx->gc_expiry, now, timeout);
267 	return q;
268 err:
269 	dprintk("RPC:       %s returns error %ld\n", __func__, -PTR_ERR(p));
270 	return p;
271 }
272 
273 #define UPCALL_BUF_LEN 128
274 
275 struct gss_upcall_msg {
276 	atomic_t count;
277 	kuid_t	uid;
278 	struct rpc_pipe_msg msg;
279 	struct list_head list;
280 	struct gss_auth *auth;
281 	struct rpc_pipe *pipe;
282 	struct rpc_wait_queue rpc_waitqueue;
283 	wait_queue_head_t waitqueue;
284 	struct gss_cl_ctx *ctx;
285 	char databuf[UPCALL_BUF_LEN];
286 };
287 
288 static int get_pipe_version(struct net *net)
289 {
290 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
291 	int ret;
292 
293 	spin_lock(&pipe_version_lock);
294 	if (sn->pipe_version >= 0) {
295 		atomic_inc(&sn->pipe_users);
296 		ret = sn->pipe_version;
297 	} else
298 		ret = -EAGAIN;
299 	spin_unlock(&pipe_version_lock);
300 	return ret;
301 }
302 
303 static void put_pipe_version(struct net *net)
304 {
305 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
306 
307 	if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
308 		sn->pipe_version = -1;
309 		spin_unlock(&pipe_version_lock);
310 	}
311 }
312 
313 static void
314 gss_release_msg(struct gss_upcall_msg *gss_msg)
315 {
316 	struct net *net = gss_msg->auth->net;
317 	if (!atomic_dec_and_test(&gss_msg->count))
318 		return;
319 	put_pipe_version(net);
320 	BUG_ON(!list_empty(&gss_msg->list));
321 	if (gss_msg->ctx != NULL)
322 		gss_put_ctx(gss_msg->ctx);
323 	rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
324 	gss_put_auth(gss_msg->auth);
325 	kfree(gss_msg);
326 }
327 
328 static struct gss_upcall_msg *
329 __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid)
330 {
331 	struct gss_upcall_msg *pos;
332 	list_for_each_entry(pos, &pipe->in_downcall, list) {
333 		if (!uid_eq(pos->uid, uid))
334 			continue;
335 		atomic_inc(&pos->count);
336 		dprintk("RPC:       %s found msg %p\n", __func__, pos);
337 		return pos;
338 	}
339 	dprintk("RPC:       %s found nothing\n", __func__);
340 	return NULL;
341 }
342 
343 /* Try to add an upcall to the pipefs queue.
344  * If an upcall owned by our uid already exists, then we return a reference
345  * to that upcall instead of adding the new upcall.
346  */
347 static inline struct gss_upcall_msg *
348 gss_add_msg(struct gss_upcall_msg *gss_msg)
349 {
350 	struct rpc_pipe *pipe = gss_msg->pipe;
351 	struct gss_upcall_msg *old;
352 
353 	spin_lock(&pipe->lock);
354 	old = __gss_find_upcall(pipe, gss_msg->uid);
355 	if (old == NULL) {
356 		atomic_inc(&gss_msg->count);
357 		list_add(&gss_msg->list, &pipe->in_downcall);
358 	} else
359 		gss_msg = old;
360 	spin_unlock(&pipe->lock);
361 	return gss_msg;
362 }
363 
364 static void
365 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
366 {
367 	list_del_init(&gss_msg->list);
368 	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
369 	wake_up_all(&gss_msg->waitqueue);
370 	atomic_dec(&gss_msg->count);
371 }
372 
373 static void
374 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
375 {
376 	struct rpc_pipe *pipe = gss_msg->pipe;
377 
378 	if (list_empty(&gss_msg->list))
379 		return;
380 	spin_lock(&pipe->lock);
381 	if (!list_empty(&gss_msg->list))
382 		__gss_unhash_msg(gss_msg);
383 	spin_unlock(&pipe->lock);
384 }
385 
386 static void
387 gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
388 {
389 	switch (gss_msg->msg.errno) {
390 	case 0:
391 		if (gss_msg->ctx == NULL)
392 			break;
393 		clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
394 		gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
395 		break;
396 	case -EKEYEXPIRED:
397 		set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
398 	}
399 	gss_cred->gc_upcall_timestamp = jiffies;
400 	gss_cred->gc_upcall = NULL;
401 	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
402 }
403 
404 static void
405 gss_upcall_callback(struct rpc_task *task)
406 {
407 	struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
408 			struct gss_cred, gc_base);
409 	struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
410 	struct rpc_pipe *pipe = gss_msg->pipe;
411 
412 	spin_lock(&pipe->lock);
413 	gss_handle_downcall_result(gss_cred, gss_msg);
414 	spin_unlock(&pipe->lock);
415 	task->tk_status = gss_msg->msg.errno;
416 	gss_release_msg(gss_msg);
417 }
418 
419 static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg)
420 {
421 	uid_t uid = from_kuid(&init_user_ns, gss_msg->uid);
422 	memcpy(gss_msg->databuf, &uid, sizeof(uid));
423 	gss_msg->msg.data = gss_msg->databuf;
424 	gss_msg->msg.len = sizeof(uid);
425 
426 	BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
427 }
428 
429 static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
430 				const char *service_name,
431 				const char *target_name)
432 {
433 	struct gss_api_mech *mech = gss_msg->auth->mech;
434 	char *p = gss_msg->databuf;
435 	size_t buflen = sizeof(gss_msg->databuf);
436 	int len;
437 
438 	len = scnprintf(p, buflen, "mech=%s uid=%d ", mech->gm_name,
439 			from_kuid(&init_user_ns, gss_msg->uid));
440 	buflen -= len;
441 	p += len;
442 	gss_msg->msg.len = len;
443 	if (target_name) {
444 		len = scnprintf(p, buflen, "target=%s ", target_name);
445 		buflen -= len;
446 		p += len;
447 		gss_msg->msg.len += len;
448 	}
449 	if (service_name != NULL) {
450 		len = scnprintf(p, buflen, "service=%s ", service_name);
451 		buflen -= len;
452 		p += len;
453 		gss_msg->msg.len += len;
454 	}
455 	if (mech->gm_upcall_enctypes) {
456 		len = scnprintf(p, buflen, "enctypes=%s ",
457 				mech->gm_upcall_enctypes);
458 		buflen -= len;
459 		p += len;
460 		gss_msg->msg.len += len;
461 	}
462 	len = scnprintf(p, buflen, "\n");
463 	if (len == 0)
464 		goto out_overflow;
465 	gss_msg->msg.len += len;
466 
467 	gss_msg->msg.data = gss_msg->databuf;
468 	return 0;
469 out_overflow:
470 	WARN_ON_ONCE(1);
471 	return -ENOMEM;
472 }
473 
474 static struct gss_upcall_msg *
475 gss_alloc_msg(struct gss_auth *gss_auth,
476 		kuid_t uid, const char *service_name)
477 {
478 	struct gss_upcall_msg *gss_msg;
479 	int vers;
480 	int err = -ENOMEM;
481 
482 	gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
483 	if (gss_msg == NULL)
484 		goto err;
485 	vers = get_pipe_version(gss_auth->net);
486 	err = vers;
487 	if (err < 0)
488 		goto err_free_msg;
489 	gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
490 	INIT_LIST_HEAD(&gss_msg->list);
491 	rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
492 	init_waitqueue_head(&gss_msg->waitqueue);
493 	atomic_set(&gss_msg->count, 1);
494 	gss_msg->uid = uid;
495 	gss_msg->auth = gss_auth;
496 	switch (vers) {
497 	case 0:
498 		gss_encode_v0_msg(gss_msg);
499 		break;
500 	default:
501 		err = gss_encode_v1_msg(gss_msg, service_name, gss_auth->target_name);
502 		if (err)
503 			goto err_put_pipe_version;
504 	};
505 	kref_get(&gss_auth->kref);
506 	return gss_msg;
507 err_put_pipe_version:
508 	put_pipe_version(gss_auth->net);
509 err_free_msg:
510 	kfree(gss_msg);
511 err:
512 	return ERR_PTR(err);
513 }
514 
515 static struct gss_upcall_msg *
516 gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
517 {
518 	struct gss_cred *gss_cred = container_of(cred,
519 			struct gss_cred, gc_base);
520 	struct gss_upcall_msg *gss_new, *gss_msg;
521 	kuid_t uid = cred->cr_uid;
522 
523 	gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
524 	if (IS_ERR(gss_new))
525 		return gss_new;
526 	gss_msg = gss_add_msg(gss_new);
527 	if (gss_msg == gss_new) {
528 		int res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
529 		if (res) {
530 			gss_unhash_msg(gss_new);
531 			gss_msg = ERR_PTR(res);
532 		}
533 	} else
534 		gss_release_msg(gss_new);
535 	return gss_msg;
536 }
537 
538 static void warn_gssd(void)
539 {
540 	dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
541 }
542 
543 static inline int
544 gss_refresh_upcall(struct rpc_task *task)
545 {
546 	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
547 	struct gss_auth *gss_auth = container_of(cred->cr_auth,
548 			struct gss_auth, rpc_auth);
549 	struct gss_cred *gss_cred = container_of(cred,
550 			struct gss_cred, gc_base);
551 	struct gss_upcall_msg *gss_msg;
552 	struct rpc_pipe *pipe;
553 	int err = 0;
554 
555 	dprintk("RPC: %5u %s for uid %u\n",
556 		task->tk_pid, __func__, from_kuid(&init_user_ns, cred->cr_uid));
557 	gss_msg = gss_setup_upcall(gss_auth, cred);
558 	if (PTR_ERR(gss_msg) == -EAGAIN) {
559 		/* XXX: warning on the first, under the assumption we
560 		 * shouldn't normally hit this case on a refresh. */
561 		warn_gssd();
562 		task->tk_timeout = 15*HZ;
563 		rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
564 		return -EAGAIN;
565 	}
566 	if (IS_ERR(gss_msg)) {
567 		err = PTR_ERR(gss_msg);
568 		goto out;
569 	}
570 	pipe = gss_msg->pipe;
571 	spin_lock(&pipe->lock);
572 	if (gss_cred->gc_upcall != NULL)
573 		rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
574 	else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
575 		task->tk_timeout = 0;
576 		gss_cred->gc_upcall = gss_msg;
577 		/* gss_upcall_callback will release the reference to gss_upcall_msg */
578 		atomic_inc(&gss_msg->count);
579 		rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
580 	} else {
581 		gss_handle_downcall_result(gss_cred, gss_msg);
582 		err = gss_msg->msg.errno;
583 	}
584 	spin_unlock(&pipe->lock);
585 	gss_release_msg(gss_msg);
586 out:
587 	dprintk("RPC: %5u %s for uid %u result %d\n",
588 		task->tk_pid, __func__,
589 		from_kuid(&init_user_ns, cred->cr_uid),	err);
590 	return err;
591 }
592 
593 static inline int
594 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
595 {
596 	struct net *net = gss_auth->net;
597 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
598 	struct rpc_pipe *pipe;
599 	struct rpc_cred *cred = &gss_cred->gc_base;
600 	struct gss_upcall_msg *gss_msg;
601 	DEFINE_WAIT(wait);
602 	int err;
603 
604 	dprintk("RPC:       %s for uid %u\n",
605 		__func__, from_kuid(&init_user_ns, cred->cr_uid));
606 retry:
607 	err = 0;
608 	/* if gssd is down, just skip upcalling altogether */
609 	if (!gssd_running(net)) {
610 		warn_gssd();
611 		return -EACCES;
612 	}
613 	gss_msg = gss_setup_upcall(gss_auth, cred);
614 	if (PTR_ERR(gss_msg) == -EAGAIN) {
615 		err = wait_event_interruptible_timeout(pipe_version_waitqueue,
616 				sn->pipe_version >= 0, 15 * HZ);
617 		if (sn->pipe_version < 0) {
618 			warn_gssd();
619 			err = -EACCES;
620 		}
621 		if (err < 0)
622 			goto out;
623 		goto retry;
624 	}
625 	if (IS_ERR(gss_msg)) {
626 		err = PTR_ERR(gss_msg);
627 		goto out;
628 	}
629 	pipe = gss_msg->pipe;
630 	for (;;) {
631 		prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
632 		spin_lock(&pipe->lock);
633 		if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
634 			break;
635 		}
636 		spin_unlock(&pipe->lock);
637 		if (fatal_signal_pending(current)) {
638 			err = -ERESTARTSYS;
639 			goto out_intr;
640 		}
641 		schedule();
642 	}
643 	if (gss_msg->ctx)
644 		gss_cred_set_ctx(cred, gss_msg->ctx);
645 	else
646 		err = gss_msg->msg.errno;
647 	spin_unlock(&pipe->lock);
648 out_intr:
649 	finish_wait(&gss_msg->waitqueue, &wait);
650 	gss_release_msg(gss_msg);
651 out:
652 	dprintk("RPC:       %s for uid %u result %d\n",
653 		__func__, from_kuid(&init_user_ns, cred->cr_uid), err);
654 	return err;
655 }
656 
657 #define MSG_BUF_MAXSIZE 1024
658 
659 static ssize_t
660 gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
661 {
662 	const void *p, *end;
663 	void *buf;
664 	struct gss_upcall_msg *gss_msg;
665 	struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
666 	struct gss_cl_ctx *ctx;
667 	uid_t id;
668 	kuid_t uid;
669 	ssize_t err = -EFBIG;
670 
671 	if (mlen > MSG_BUF_MAXSIZE)
672 		goto out;
673 	err = -ENOMEM;
674 	buf = kmalloc(mlen, GFP_NOFS);
675 	if (!buf)
676 		goto out;
677 
678 	err = -EFAULT;
679 	if (copy_from_user(buf, src, mlen))
680 		goto err;
681 
682 	end = (const void *)((char *)buf + mlen);
683 	p = simple_get_bytes(buf, end, &id, sizeof(id));
684 	if (IS_ERR(p)) {
685 		err = PTR_ERR(p);
686 		goto err;
687 	}
688 
689 	uid = make_kuid(&init_user_ns, id);
690 	if (!uid_valid(uid)) {
691 		err = -EINVAL;
692 		goto err;
693 	}
694 
695 	err = -ENOMEM;
696 	ctx = gss_alloc_context();
697 	if (ctx == NULL)
698 		goto err;
699 
700 	err = -ENOENT;
701 	/* Find a matching upcall */
702 	spin_lock(&pipe->lock);
703 	gss_msg = __gss_find_upcall(pipe, uid);
704 	if (gss_msg == NULL) {
705 		spin_unlock(&pipe->lock);
706 		goto err_put_ctx;
707 	}
708 	list_del_init(&gss_msg->list);
709 	spin_unlock(&pipe->lock);
710 
711 	p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
712 	if (IS_ERR(p)) {
713 		err = PTR_ERR(p);
714 		switch (err) {
715 		case -EACCES:
716 		case -EKEYEXPIRED:
717 			gss_msg->msg.errno = err;
718 			err = mlen;
719 			break;
720 		case -EFAULT:
721 		case -ENOMEM:
722 		case -EINVAL:
723 		case -ENOSYS:
724 			gss_msg->msg.errno = -EAGAIN;
725 			break;
726 		default:
727 			printk(KERN_CRIT "%s: bad return from "
728 				"gss_fill_context: %zd\n", __func__, err);
729 			BUG();
730 		}
731 		goto err_release_msg;
732 	}
733 	gss_msg->ctx = gss_get_ctx(ctx);
734 	err = mlen;
735 
736 err_release_msg:
737 	spin_lock(&pipe->lock);
738 	__gss_unhash_msg(gss_msg);
739 	spin_unlock(&pipe->lock);
740 	gss_release_msg(gss_msg);
741 err_put_ctx:
742 	gss_put_ctx(ctx);
743 err:
744 	kfree(buf);
745 out:
746 	dprintk("RPC:       %s returning %Zd\n", __func__, err);
747 	return err;
748 }
749 
750 static int gss_pipe_open(struct inode *inode, int new_version)
751 {
752 	struct net *net = inode->i_sb->s_fs_info;
753 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
754 	int ret = 0;
755 
756 	spin_lock(&pipe_version_lock);
757 	if (sn->pipe_version < 0) {
758 		/* First open of any gss pipe determines the version: */
759 		sn->pipe_version = new_version;
760 		rpc_wake_up(&pipe_version_rpc_waitqueue);
761 		wake_up(&pipe_version_waitqueue);
762 	} else if (sn->pipe_version != new_version) {
763 		/* Trying to open a pipe of a different version */
764 		ret = -EBUSY;
765 		goto out;
766 	}
767 	atomic_inc(&sn->pipe_users);
768 out:
769 	spin_unlock(&pipe_version_lock);
770 	return ret;
771 
772 }
773 
774 static int gss_pipe_open_v0(struct inode *inode)
775 {
776 	return gss_pipe_open(inode, 0);
777 }
778 
779 static int gss_pipe_open_v1(struct inode *inode)
780 {
781 	return gss_pipe_open(inode, 1);
782 }
783 
784 static void
785 gss_pipe_release(struct inode *inode)
786 {
787 	struct net *net = inode->i_sb->s_fs_info;
788 	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
789 	struct gss_upcall_msg *gss_msg;
790 
791 restart:
792 	spin_lock(&pipe->lock);
793 	list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
794 
795 		if (!list_empty(&gss_msg->msg.list))
796 			continue;
797 		gss_msg->msg.errno = -EPIPE;
798 		atomic_inc(&gss_msg->count);
799 		__gss_unhash_msg(gss_msg);
800 		spin_unlock(&pipe->lock);
801 		gss_release_msg(gss_msg);
802 		goto restart;
803 	}
804 	spin_unlock(&pipe->lock);
805 
806 	put_pipe_version(net);
807 }
808 
809 static void
810 gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
811 {
812 	struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
813 
814 	if (msg->errno < 0) {
815 		dprintk("RPC:       %s releasing msg %p\n",
816 			__func__, gss_msg);
817 		atomic_inc(&gss_msg->count);
818 		gss_unhash_msg(gss_msg);
819 		if (msg->errno == -ETIMEDOUT)
820 			warn_gssd();
821 		gss_release_msg(gss_msg);
822 	}
823 }
824 
825 static void gss_pipe_dentry_destroy(struct dentry *dir,
826 		struct rpc_pipe_dir_object *pdo)
827 {
828 	struct gss_pipe *gss_pipe = pdo->pdo_data;
829 	struct rpc_pipe *pipe = gss_pipe->pipe;
830 
831 	if (pipe->dentry != NULL) {
832 		rpc_unlink(pipe->dentry);
833 		pipe->dentry = NULL;
834 	}
835 }
836 
837 static int gss_pipe_dentry_create(struct dentry *dir,
838 		struct rpc_pipe_dir_object *pdo)
839 {
840 	struct gss_pipe *p = pdo->pdo_data;
841 	struct dentry *dentry;
842 
843 	dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
844 	if (IS_ERR(dentry))
845 		return PTR_ERR(dentry);
846 	p->pipe->dentry = dentry;
847 	return 0;
848 }
849 
850 static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
851 	.create = gss_pipe_dentry_create,
852 	.destroy = gss_pipe_dentry_destroy,
853 };
854 
855 static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
856 		const char *name,
857 		const struct rpc_pipe_ops *upcall_ops)
858 {
859 	struct gss_pipe *p;
860 	int err = -ENOMEM;
861 
862 	p = kmalloc(sizeof(*p), GFP_KERNEL);
863 	if (p == NULL)
864 		goto err;
865 	p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
866 	if (IS_ERR(p->pipe)) {
867 		err = PTR_ERR(p->pipe);
868 		goto err_free_gss_pipe;
869 	}
870 	p->name = name;
871 	p->clnt = clnt;
872 	kref_init(&p->kref);
873 	rpc_init_pipe_dir_object(&p->pdo,
874 			&gss_pipe_dir_object_ops,
875 			p);
876 	return p;
877 err_free_gss_pipe:
878 	kfree(p);
879 err:
880 	return ERR_PTR(err);
881 }
882 
883 struct gss_alloc_pdo {
884 	struct rpc_clnt *clnt;
885 	const char *name;
886 	const struct rpc_pipe_ops *upcall_ops;
887 };
888 
889 static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
890 {
891 	struct gss_pipe *gss_pipe;
892 	struct gss_alloc_pdo *args = data;
893 
894 	if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
895 		return 0;
896 	gss_pipe = container_of(pdo, struct gss_pipe, pdo);
897 	if (strcmp(gss_pipe->name, args->name) != 0)
898 		return 0;
899 	if (!kref_get_unless_zero(&gss_pipe->kref))
900 		return 0;
901 	return 1;
902 }
903 
904 static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
905 {
906 	struct gss_pipe *gss_pipe;
907 	struct gss_alloc_pdo *args = data;
908 
909 	gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
910 	if (!IS_ERR(gss_pipe))
911 		return &gss_pipe->pdo;
912 	return NULL;
913 }
914 
915 static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
916 		const char *name,
917 		const struct rpc_pipe_ops *upcall_ops)
918 {
919 	struct net *net = rpc_net_ns(clnt);
920 	struct rpc_pipe_dir_object *pdo;
921 	struct gss_alloc_pdo args = {
922 		.clnt = clnt,
923 		.name = name,
924 		.upcall_ops = upcall_ops,
925 	};
926 
927 	pdo = rpc_find_or_alloc_pipe_dir_object(net,
928 			&clnt->cl_pipedir_objects,
929 			gss_pipe_match_pdo,
930 			gss_pipe_alloc_pdo,
931 			&args);
932 	if (pdo != NULL)
933 		return container_of(pdo, struct gss_pipe, pdo);
934 	return ERR_PTR(-ENOMEM);
935 }
936 
937 static void __gss_pipe_free(struct gss_pipe *p)
938 {
939 	struct rpc_clnt *clnt = p->clnt;
940 	struct net *net = rpc_net_ns(clnt);
941 
942 	rpc_remove_pipe_dir_object(net,
943 			&clnt->cl_pipedir_objects,
944 			&p->pdo);
945 	rpc_destroy_pipe_data(p->pipe);
946 	kfree(p);
947 }
948 
949 static void __gss_pipe_release(struct kref *kref)
950 {
951 	struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
952 
953 	__gss_pipe_free(p);
954 }
955 
956 static void gss_pipe_free(struct gss_pipe *p)
957 {
958 	if (p != NULL)
959 		kref_put(&p->kref, __gss_pipe_release);
960 }
961 
962 /*
963  * NOTE: we have the opportunity to use different
964  * parameters based on the input flavor (which must be a pseudoflavor)
965  */
966 static struct gss_auth *
967 gss_create_new(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
968 {
969 	rpc_authflavor_t flavor = args->pseudoflavor;
970 	struct gss_auth *gss_auth;
971 	struct gss_pipe *gss_pipe;
972 	struct rpc_auth * auth;
973 	int err = -ENOMEM; /* XXX? */
974 
975 	dprintk("RPC:       creating GSS authenticator for client %p\n", clnt);
976 
977 	if (!try_module_get(THIS_MODULE))
978 		return ERR_PTR(err);
979 	if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
980 		goto out_dec;
981 	INIT_HLIST_NODE(&gss_auth->hash);
982 	gss_auth->target_name = NULL;
983 	if (args->target_name) {
984 		gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
985 		if (gss_auth->target_name == NULL)
986 			goto err_free;
987 	}
988 	gss_auth->client = clnt;
989 	gss_auth->net = get_net(rpc_net_ns(clnt));
990 	err = -EINVAL;
991 	gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
992 	if (!gss_auth->mech) {
993 		dprintk("RPC:       Pseudoflavor %d not found!\n", flavor);
994 		goto err_put_net;
995 	}
996 	gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
997 	if (gss_auth->service == 0)
998 		goto err_put_mech;
999 	if (!gssd_running(gss_auth->net))
1000 		goto err_put_mech;
1001 	auth = &gss_auth->rpc_auth;
1002 	auth->au_cslack = GSS_CRED_SLACK >> 2;
1003 	auth->au_rslack = GSS_VERF_SLACK >> 2;
1004 	auth->au_ops = &authgss_ops;
1005 	auth->au_flavor = flavor;
1006 	atomic_set(&auth->au_count, 1);
1007 	kref_init(&gss_auth->kref);
1008 
1009 	err = rpcauth_init_credcache(auth);
1010 	if (err)
1011 		goto err_put_mech;
1012 	/*
1013 	 * Note: if we created the old pipe first, then someone who
1014 	 * examined the directory at the right moment might conclude
1015 	 * that we supported only the old pipe.  So we instead create
1016 	 * the new pipe first.
1017 	 */
1018 	gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1019 	if (IS_ERR(gss_pipe)) {
1020 		err = PTR_ERR(gss_pipe);
1021 		goto err_destroy_credcache;
1022 	}
1023 	gss_auth->gss_pipe[1] = gss_pipe;
1024 
1025 	gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1026 			&gss_upcall_ops_v0);
1027 	if (IS_ERR(gss_pipe)) {
1028 		err = PTR_ERR(gss_pipe);
1029 		goto err_destroy_pipe_1;
1030 	}
1031 	gss_auth->gss_pipe[0] = gss_pipe;
1032 
1033 	return gss_auth;
1034 err_destroy_pipe_1:
1035 	gss_pipe_free(gss_auth->gss_pipe[1]);
1036 err_destroy_credcache:
1037 	rpcauth_destroy_credcache(auth);
1038 err_put_mech:
1039 	gss_mech_put(gss_auth->mech);
1040 err_put_net:
1041 	put_net(gss_auth->net);
1042 err_free:
1043 	kfree(gss_auth->target_name);
1044 	kfree(gss_auth);
1045 out_dec:
1046 	module_put(THIS_MODULE);
1047 	return ERR_PTR(err);
1048 }
1049 
1050 static void
1051 gss_free(struct gss_auth *gss_auth)
1052 {
1053 	gss_pipe_free(gss_auth->gss_pipe[0]);
1054 	gss_pipe_free(gss_auth->gss_pipe[1]);
1055 	gss_mech_put(gss_auth->mech);
1056 	put_net(gss_auth->net);
1057 	kfree(gss_auth->target_name);
1058 
1059 	kfree(gss_auth);
1060 	module_put(THIS_MODULE);
1061 }
1062 
1063 static void
1064 gss_free_callback(struct kref *kref)
1065 {
1066 	struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1067 
1068 	gss_free(gss_auth);
1069 }
1070 
1071 static void
1072 gss_put_auth(struct gss_auth *gss_auth)
1073 {
1074 	kref_put(&gss_auth->kref, gss_free_callback);
1075 }
1076 
1077 static void
1078 gss_destroy(struct rpc_auth *auth)
1079 {
1080 	struct gss_auth *gss_auth = container_of(auth,
1081 			struct gss_auth, rpc_auth);
1082 
1083 	dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
1084 			auth, auth->au_flavor);
1085 
1086 	if (hash_hashed(&gss_auth->hash)) {
1087 		spin_lock(&gss_auth_hash_lock);
1088 		hash_del(&gss_auth->hash);
1089 		spin_unlock(&gss_auth_hash_lock);
1090 	}
1091 
1092 	gss_pipe_free(gss_auth->gss_pipe[0]);
1093 	gss_auth->gss_pipe[0] = NULL;
1094 	gss_pipe_free(gss_auth->gss_pipe[1]);
1095 	gss_auth->gss_pipe[1] = NULL;
1096 	rpcauth_destroy_credcache(auth);
1097 
1098 	gss_put_auth(gss_auth);
1099 }
1100 
1101 /*
1102  * Auths may be shared between rpc clients that were cloned from a
1103  * common client with the same xprt, if they also share the flavor and
1104  * target_name.
1105  *
1106  * The auth is looked up from the oldest parent sharing the same
1107  * cl_xprt, and the auth itself references only that common parent
1108  * (which is guaranteed to last as long as any of its descendants).
1109  */
1110 static struct gss_auth *
1111 gss_auth_find_or_add_hashed(struct rpc_auth_create_args *args,
1112 		struct rpc_clnt *clnt,
1113 		struct gss_auth *new)
1114 {
1115 	struct gss_auth *gss_auth;
1116 	unsigned long hashval = (unsigned long)clnt;
1117 
1118 	spin_lock(&gss_auth_hash_lock);
1119 	hash_for_each_possible(gss_auth_hash_table,
1120 			gss_auth,
1121 			hash,
1122 			hashval) {
1123 		if (gss_auth->client != clnt)
1124 			continue;
1125 		if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1126 			continue;
1127 		if (gss_auth->target_name != args->target_name) {
1128 			if (gss_auth->target_name == NULL)
1129 				continue;
1130 			if (args->target_name == NULL)
1131 				continue;
1132 			if (strcmp(gss_auth->target_name, args->target_name))
1133 				continue;
1134 		}
1135 		if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
1136 			continue;
1137 		goto out;
1138 	}
1139 	if (new)
1140 		hash_add(gss_auth_hash_table, &new->hash, hashval);
1141 	gss_auth = new;
1142 out:
1143 	spin_unlock(&gss_auth_hash_lock);
1144 	return gss_auth;
1145 }
1146 
1147 static struct gss_auth *
1148 gss_create_hashed(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1149 {
1150 	struct gss_auth *gss_auth;
1151 	struct gss_auth *new;
1152 
1153 	gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1154 	if (gss_auth != NULL)
1155 		goto out;
1156 	new = gss_create_new(args, clnt);
1157 	if (IS_ERR(new))
1158 		return new;
1159 	gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1160 	if (gss_auth != new)
1161 		gss_destroy(&new->rpc_auth);
1162 out:
1163 	return gss_auth;
1164 }
1165 
1166 static struct rpc_auth *
1167 gss_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1168 {
1169 	struct gss_auth *gss_auth;
1170 	struct rpc_xprt *xprt = rcu_access_pointer(clnt->cl_xprt);
1171 
1172 	while (clnt != clnt->cl_parent) {
1173 		struct rpc_clnt *parent = clnt->cl_parent;
1174 		/* Find the original parent for this transport */
1175 		if (rcu_access_pointer(parent->cl_xprt) != xprt)
1176 			break;
1177 		clnt = parent;
1178 	}
1179 
1180 	gss_auth = gss_create_hashed(args, clnt);
1181 	if (IS_ERR(gss_auth))
1182 		return ERR_CAST(gss_auth);
1183 	return &gss_auth->rpc_auth;
1184 }
1185 
1186 /*
1187  * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
1188  * to the server with the GSS control procedure field set to
1189  * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1190  * all RPCSEC_GSS state associated with that context.
1191  */
1192 static int
1193 gss_destroying_context(struct rpc_cred *cred)
1194 {
1195 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1196 	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1197 	struct rpc_task *task;
1198 
1199 	if (gss_cred->gc_ctx == NULL ||
1200 	    test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
1201 		return 0;
1202 
1203 	gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1204 	cred->cr_ops = &gss_nullops;
1205 
1206 	/* Take a reference to ensure the cred will be destroyed either
1207 	 * by the RPC call or by the put_rpccred() below */
1208 	get_rpccred(cred);
1209 
1210 	task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC|RPC_TASK_SOFT);
1211 	if (!IS_ERR(task))
1212 		rpc_put_task(task);
1213 
1214 	put_rpccred(cred);
1215 	return 1;
1216 }
1217 
1218 /* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1219  * to create a new cred or context, so they check that things have been
1220  * allocated before freeing them. */
1221 static void
1222 gss_do_free_ctx(struct gss_cl_ctx *ctx)
1223 {
1224 	dprintk("RPC:       %s\n", __func__);
1225 
1226 	gss_delete_sec_context(&ctx->gc_gss_ctx);
1227 	kfree(ctx->gc_wire_ctx.data);
1228 	kfree(ctx);
1229 }
1230 
1231 static void
1232 gss_free_ctx_callback(struct rcu_head *head)
1233 {
1234 	struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1235 	gss_do_free_ctx(ctx);
1236 }
1237 
1238 static void
1239 gss_free_ctx(struct gss_cl_ctx *ctx)
1240 {
1241 	call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1242 }
1243 
1244 static void
1245 gss_free_cred(struct gss_cred *gss_cred)
1246 {
1247 	dprintk("RPC:       %s cred=%p\n", __func__, gss_cred);
1248 	kfree(gss_cred);
1249 }
1250 
1251 static void
1252 gss_free_cred_callback(struct rcu_head *head)
1253 {
1254 	struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1255 	gss_free_cred(gss_cred);
1256 }
1257 
1258 static void
1259 gss_destroy_nullcred(struct rpc_cred *cred)
1260 {
1261 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1262 	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1263 	struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
1264 
1265 	RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1266 	call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1267 	if (ctx)
1268 		gss_put_ctx(ctx);
1269 	gss_put_auth(gss_auth);
1270 }
1271 
1272 static void
1273 gss_destroy_cred(struct rpc_cred *cred)
1274 {
1275 
1276 	if (gss_destroying_context(cred))
1277 		return;
1278 	gss_destroy_nullcred(cred);
1279 }
1280 
1281 /*
1282  * Lookup RPCSEC_GSS cred for the current process
1283  */
1284 static struct rpc_cred *
1285 gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1286 {
1287 	return rpcauth_lookup_credcache(auth, acred, flags);
1288 }
1289 
1290 static struct rpc_cred *
1291 gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1292 {
1293 	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1294 	struct gss_cred	*cred = NULL;
1295 	int err = -ENOMEM;
1296 
1297 	dprintk("RPC:       %s for uid %d, flavor %d\n",
1298 		__func__, from_kuid(&init_user_ns, acred->uid),
1299 		auth->au_flavor);
1300 
1301 	if (!(cred = kzalloc(sizeof(*cred), GFP_NOFS)))
1302 		goto out_err;
1303 
1304 	rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1305 	/*
1306 	 * Note: in order to force a call to call_refresh(), we deliberately
1307 	 * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1308 	 */
1309 	cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1310 	cred->gc_service = gss_auth->service;
1311 	cred->gc_principal = NULL;
1312 	if (acred->machine_cred)
1313 		cred->gc_principal = acred->principal;
1314 	kref_get(&gss_auth->kref);
1315 	return &cred->gc_base;
1316 
1317 out_err:
1318 	dprintk("RPC:       %s failed with error %d\n", __func__, err);
1319 	return ERR_PTR(err);
1320 }
1321 
1322 static int
1323 gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1324 {
1325 	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1326 	struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1327 	int err;
1328 
1329 	do {
1330 		err = gss_create_upcall(gss_auth, gss_cred);
1331 	} while (err == -EAGAIN);
1332 	return err;
1333 }
1334 
1335 /*
1336  * Returns -EACCES if GSS context is NULL or will expire within the
1337  * timeout (miliseconds)
1338  */
1339 static int
1340 gss_key_timeout(struct rpc_cred *rc)
1341 {
1342 	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1343 	unsigned long now = jiffies;
1344 	unsigned long expire;
1345 
1346 	if (gss_cred->gc_ctx == NULL)
1347 		return -EACCES;
1348 
1349 	expire = gss_cred->gc_ctx->gc_expiry - (gss_key_expire_timeo * HZ);
1350 
1351 	if (time_after(now, expire))
1352 		return -EACCES;
1353 	return 0;
1354 }
1355 
1356 static int
1357 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1358 {
1359 	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1360 	int ret;
1361 
1362 	if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1363 		goto out;
1364 	/* Don't match with creds that have expired. */
1365 	if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
1366 		return 0;
1367 	if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1368 		return 0;
1369 out:
1370 	if (acred->principal != NULL) {
1371 		if (gss_cred->gc_principal == NULL)
1372 			return 0;
1373 		ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1374 		goto check_expire;
1375 	}
1376 	if (gss_cred->gc_principal != NULL)
1377 		return 0;
1378 	ret = uid_eq(rc->cr_uid, acred->uid);
1379 
1380 check_expire:
1381 	if (ret == 0)
1382 		return ret;
1383 
1384 	/* Notify acred users of GSS context expiration timeout */
1385 	if (test_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags) &&
1386 	    (gss_key_timeout(rc) != 0)) {
1387 		/* test will now be done from generic cred */
1388 		test_and_clear_bit(RPC_CRED_NOTIFY_TIMEOUT, &acred->ac_flags);
1389 		/* tell NFS layer that key will expire soon */
1390 		set_bit(RPC_CRED_KEY_EXPIRE_SOON, &acred->ac_flags);
1391 	}
1392 	return ret;
1393 }
1394 
1395 /*
1396 * Marshal credentials.
1397 * Maybe we should keep a cached credential for performance reasons.
1398 */
1399 static __be32 *
1400 gss_marshal(struct rpc_task *task, __be32 *p)
1401 {
1402 	struct rpc_rqst *req = task->tk_rqstp;
1403 	struct rpc_cred *cred = req->rq_cred;
1404 	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
1405 						 gc_base);
1406 	struct gss_cl_ctx	*ctx = gss_cred_get_ctx(cred);
1407 	__be32		*cred_len;
1408 	u32             maj_stat = 0;
1409 	struct xdr_netobj mic;
1410 	struct kvec	iov;
1411 	struct xdr_buf	verf_buf;
1412 
1413 	dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1414 
1415 	*p++ = htonl(RPC_AUTH_GSS);
1416 	cred_len = p++;
1417 
1418 	spin_lock(&ctx->gc_seq_lock);
1419 	req->rq_seqno = ctx->gc_seq++;
1420 	spin_unlock(&ctx->gc_seq_lock);
1421 
1422 	*p++ = htonl((u32) RPC_GSS_VERSION);
1423 	*p++ = htonl((u32) ctx->gc_proc);
1424 	*p++ = htonl((u32) req->rq_seqno);
1425 	*p++ = htonl((u32) gss_cred->gc_service);
1426 	p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1427 	*cred_len = htonl((p - (cred_len + 1)) << 2);
1428 
1429 	/* We compute the checksum for the verifier over the xdr-encoded bytes
1430 	 * starting with the xid and ending at the end of the credential: */
1431 	iov.iov_base = xprt_skip_transport_header(req->rq_xprt,
1432 					req->rq_snd_buf.head[0].iov_base);
1433 	iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1434 	xdr_buf_from_iov(&iov, &verf_buf);
1435 
1436 	/* set verifier flavor*/
1437 	*p++ = htonl(RPC_AUTH_GSS);
1438 
1439 	mic.data = (u8 *)(p + 1);
1440 	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1441 	if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
1442 		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1443 	} else if (maj_stat != 0) {
1444 		printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
1445 		goto out_put_ctx;
1446 	}
1447 	p = xdr_encode_opaque(p, NULL, mic.len);
1448 	gss_put_ctx(ctx);
1449 	return p;
1450 out_put_ctx:
1451 	gss_put_ctx(ctx);
1452 	return NULL;
1453 }
1454 
1455 static int gss_renew_cred(struct rpc_task *task)
1456 {
1457 	struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1458 	struct gss_cred *gss_cred = container_of(oldcred,
1459 						 struct gss_cred,
1460 						 gc_base);
1461 	struct rpc_auth *auth = oldcred->cr_auth;
1462 	struct auth_cred acred = {
1463 		.uid = oldcred->cr_uid,
1464 		.principal = gss_cred->gc_principal,
1465 		.machine_cred = (gss_cred->gc_principal != NULL ? 1 : 0),
1466 	};
1467 	struct rpc_cred *new;
1468 
1469 	new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1470 	if (IS_ERR(new))
1471 		return PTR_ERR(new);
1472 	task->tk_rqstp->rq_cred = new;
1473 	put_rpccred(oldcred);
1474 	return 0;
1475 }
1476 
1477 static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1478 {
1479 	if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1480 		unsigned long now = jiffies;
1481 		unsigned long begin, expire;
1482 		struct gss_cred *gss_cred;
1483 
1484 		gss_cred = container_of(cred, struct gss_cred, gc_base);
1485 		begin = gss_cred->gc_upcall_timestamp;
1486 		expire = begin + gss_expired_cred_retry_delay * HZ;
1487 
1488 		if (time_in_range_open(now, begin, expire))
1489 			return 1;
1490 	}
1491 	return 0;
1492 }
1493 
1494 /*
1495 * Refresh credentials. XXX - finish
1496 */
1497 static int
1498 gss_refresh(struct rpc_task *task)
1499 {
1500 	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1501 	int ret = 0;
1502 
1503 	if (gss_cred_is_negative_entry(cred))
1504 		return -EKEYEXPIRED;
1505 
1506 	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1507 			!test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1508 		ret = gss_renew_cred(task);
1509 		if (ret < 0)
1510 			goto out;
1511 		cred = task->tk_rqstp->rq_cred;
1512 	}
1513 
1514 	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1515 		ret = gss_refresh_upcall(task);
1516 out:
1517 	return ret;
1518 }
1519 
1520 /* Dummy refresh routine: used only when destroying the context */
1521 static int
1522 gss_refresh_null(struct rpc_task *task)
1523 {
1524 	return 0;
1525 }
1526 
1527 static __be32 *
1528 gss_validate(struct rpc_task *task, __be32 *p)
1529 {
1530 	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1531 	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1532 	__be32		seq;
1533 	struct kvec	iov;
1534 	struct xdr_buf	verf_buf;
1535 	struct xdr_netobj mic;
1536 	u32		flav,len;
1537 	u32		maj_stat;
1538 	__be32		*ret = ERR_PTR(-EIO);
1539 
1540 	dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1541 
1542 	flav = ntohl(*p++);
1543 	if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
1544 		goto out_bad;
1545 	if (flav != RPC_AUTH_GSS)
1546 		goto out_bad;
1547 	seq = htonl(task->tk_rqstp->rq_seqno);
1548 	iov.iov_base = &seq;
1549 	iov.iov_len = sizeof(seq);
1550 	xdr_buf_from_iov(&iov, &verf_buf);
1551 	mic.data = (u8 *)p;
1552 	mic.len = len;
1553 
1554 	ret = ERR_PTR(-EACCES);
1555 	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1556 	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1557 		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1558 	if (maj_stat) {
1559 		dprintk("RPC: %5u %s: gss_verify_mic returned error 0x%08x\n",
1560 			task->tk_pid, __func__, maj_stat);
1561 		goto out_bad;
1562 	}
1563 	/* We leave it to unwrap to calculate au_rslack. For now we just
1564 	 * calculate the length of the verifier: */
1565 	cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1566 	gss_put_ctx(ctx);
1567 	dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",
1568 			task->tk_pid, __func__);
1569 	return p + XDR_QUADLEN(len);
1570 out_bad:
1571 	gss_put_ctx(ctx);
1572 	dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,
1573 		PTR_ERR(ret));
1574 	return ret;
1575 }
1576 
1577 static void gss_wrap_req_encode(kxdreproc_t encode, struct rpc_rqst *rqstp,
1578 				__be32 *p, void *obj)
1579 {
1580 	struct xdr_stream xdr;
1581 
1582 	xdr_init_encode(&xdr, &rqstp->rq_snd_buf, p);
1583 	encode(rqstp, &xdr, obj);
1584 }
1585 
1586 static inline int
1587 gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1588 		   kxdreproc_t encode, struct rpc_rqst *rqstp,
1589 		   __be32 *p, void *obj)
1590 {
1591 	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
1592 	struct xdr_buf	integ_buf;
1593 	__be32          *integ_len = NULL;
1594 	struct xdr_netobj mic;
1595 	u32		offset;
1596 	__be32		*q;
1597 	struct kvec	*iov;
1598 	u32             maj_stat = 0;
1599 	int		status = -EIO;
1600 
1601 	integ_len = p++;
1602 	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1603 	*p++ = htonl(rqstp->rq_seqno);
1604 
1605 	gss_wrap_req_encode(encode, rqstp, p, obj);
1606 
1607 	if (xdr_buf_subsegment(snd_buf, &integ_buf,
1608 				offset, snd_buf->len - offset))
1609 		return status;
1610 	*integ_len = htonl(integ_buf.len);
1611 
1612 	/* guess whether we're in the head or the tail: */
1613 	if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1614 		iov = snd_buf->tail;
1615 	else
1616 		iov = snd_buf->head;
1617 	p = iov->iov_base + iov->iov_len;
1618 	mic.data = (u8 *)(p + 1);
1619 
1620 	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1621 	status = -EIO; /* XXX? */
1622 	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1623 		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1624 	else if (maj_stat)
1625 		return status;
1626 	q = xdr_encode_opaque(p, NULL, mic.len);
1627 
1628 	offset = (u8 *)q - (u8 *)p;
1629 	iov->iov_len += offset;
1630 	snd_buf->len += offset;
1631 	return 0;
1632 }
1633 
1634 static void
1635 priv_release_snd_buf(struct rpc_rqst *rqstp)
1636 {
1637 	int i;
1638 
1639 	for (i=0; i < rqstp->rq_enc_pages_num; i++)
1640 		__free_page(rqstp->rq_enc_pages[i]);
1641 	kfree(rqstp->rq_enc_pages);
1642 }
1643 
1644 static int
1645 alloc_enc_pages(struct rpc_rqst *rqstp)
1646 {
1647 	struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1648 	int first, last, i;
1649 
1650 	if (snd_buf->page_len == 0) {
1651 		rqstp->rq_enc_pages_num = 0;
1652 		return 0;
1653 	}
1654 
1655 	first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1656 	last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_CACHE_SHIFT;
1657 	rqstp->rq_enc_pages_num = last - first + 1 + 1;
1658 	rqstp->rq_enc_pages
1659 		= kmalloc(rqstp->rq_enc_pages_num * sizeof(struct page *),
1660 				GFP_NOFS);
1661 	if (!rqstp->rq_enc_pages)
1662 		goto out;
1663 	for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1664 		rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1665 		if (rqstp->rq_enc_pages[i] == NULL)
1666 			goto out_free;
1667 	}
1668 	rqstp->rq_release_snd_buf = priv_release_snd_buf;
1669 	return 0;
1670 out_free:
1671 	rqstp->rq_enc_pages_num = i;
1672 	priv_release_snd_buf(rqstp);
1673 out:
1674 	return -EAGAIN;
1675 }
1676 
1677 static inline int
1678 gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1679 		  kxdreproc_t encode, struct rpc_rqst *rqstp,
1680 		  __be32 *p, void *obj)
1681 {
1682 	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
1683 	u32		offset;
1684 	u32             maj_stat;
1685 	int		status;
1686 	__be32		*opaque_len;
1687 	struct page	**inpages;
1688 	int		first;
1689 	int		pad;
1690 	struct kvec	*iov;
1691 	char		*tmp;
1692 
1693 	opaque_len = p++;
1694 	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1695 	*p++ = htonl(rqstp->rq_seqno);
1696 
1697 	gss_wrap_req_encode(encode, rqstp, p, obj);
1698 
1699 	status = alloc_enc_pages(rqstp);
1700 	if (status)
1701 		return status;
1702 	first = snd_buf->page_base >> PAGE_CACHE_SHIFT;
1703 	inpages = snd_buf->pages + first;
1704 	snd_buf->pages = rqstp->rq_enc_pages;
1705 	snd_buf->page_base -= first << PAGE_CACHE_SHIFT;
1706 	/*
1707 	 * Give the tail its own page, in case we need extra space in the
1708 	 * head when wrapping:
1709 	 *
1710 	 * call_allocate() allocates twice the slack space required
1711 	 * by the authentication flavor to rq_callsize.
1712 	 * For GSS, slack is GSS_CRED_SLACK.
1713 	 */
1714 	if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1715 		tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1716 		memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1717 		snd_buf->tail[0].iov_base = tmp;
1718 	}
1719 	maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1720 	/* slack space should prevent this ever happening: */
1721 	BUG_ON(snd_buf->len > snd_buf->buflen);
1722 	status = -EIO;
1723 	/* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1724 	 * done anyway, so it's safe to put the request on the wire: */
1725 	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1726 		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1727 	else if (maj_stat)
1728 		return status;
1729 
1730 	*opaque_len = htonl(snd_buf->len - offset);
1731 	/* guess whether we're in the head or the tail: */
1732 	if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1733 		iov = snd_buf->tail;
1734 	else
1735 		iov = snd_buf->head;
1736 	p = iov->iov_base + iov->iov_len;
1737 	pad = 3 - ((snd_buf->len - offset - 1) & 3);
1738 	memset(p, 0, pad);
1739 	iov->iov_len += pad;
1740 	snd_buf->len += pad;
1741 
1742 	return 0;
1743 }
1744 
1745 static int
1746 gss_wrap_req(struct rpc_task *task,
1747 	     kxdreproc_t encode, void *rqstp, __be32 *p, void *obj)
1748 {
1749 	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1750 	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
1751 			gc_base);
1752 	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1753 	int             status = -EIO;
1754 
1755 	dprintk("RPC: %5u %s\n", task->tk_pid, __func__);
1756 	if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1757 		/* The spec seems a little ambiguous here, but I think that not
1758 		 * wrapping context destruction requests makes the most sense.
1759 		 */
1760 		gss_wrap_req_encode(encode, rqstp, p, obj);
1761 		status = 0;
1762 		goto out;
1763 	}
1764 	switch (gss_cred->gc_service) {
1765 	case RPC_GSS_SVC_NONE:
1766 		gss_wrap_req_encode(encode, rqstp, p, obj);
1767 		status = 0;
1768 		break;
1769 	case RPC_GSS_SVC_INTEGRITY:
1770 		status = gss_wrap_req_integ(cred, ctx, encode, rqstp, p, obj);
1771 		break;
1772 	case RPC_GSS_SVC_PRIVACY:
1773 		status = gss_wrap_req_priv(cred, ctx, encode, rqstp, p, obj);
1774 		break;
1775 	}
1776 out:
1777 	gss_put_ctx(ctx);
1778 	dprintk("RPC: %5u %s returning %d\n", task->tk_pid, __func__, status);
1779 	return status;
1780 }
1781 
1782 static inline int
1783 gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1784 		struct rpc_rqst *rqstp, __be32 **p)
1785 {
1786 	struct xdr_buf	*rcv_buf = &rqstp->rq_rcv_buf;
1787 	struct xdr_buf integ_buf;
1788 	struct xdr_netobj mic;
1789 	u32 data_offset, mic_offset;
1790 	u32 integ_len;
1791 	u32 maj_stat;
1792 	int status = -EIO;
1793 
1794 	integ_len = ntohl(*(*p)++);
1795 	if (integ_len & 3)
1796 		return status;
1797 	data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1798 	mic_offset = integ_len + data_offset;
1799 	if (mic_offset > rcv_buf->len)
1800 		return status;
1801 	if (ntohl(*(*p)++) != rqstp->rq_seqno)
1802 		return status;
1803 
1804 	if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
1805 				mic_offset - data_offset))
1806 		return status;
1807 
1808 	if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
1809 		return status;
1810 
1811 	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1812 	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1813 		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1814 	if (maj_stat != GSS_S_COMPLETE)
1815 		return status;
1816 	return 0;
1817 }
1818 
1819 static inline int
1820 gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1821 		struct rpc_rqst *rqstp, __be32 **p)
1822 {
1823 	struct xdr_buf  *rcv_buf = &rqstp->rq_rcv_buf;
1824 	u32 offset;
1825 	u32 opaque_len;
1826 	u32 maj_stat;
1827 	int status = -EIO;
1828 
1829 	opaque_len = ntohl(*(*p)++);
1830 	offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
1831 	if (offset + opaque_len > rcv_buf->len)
1832 		return status;
1833 	/* remove padding: */
1834 	rcv_buf->len = offset + opaque_len;
1835 
1836 	maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
1837 	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1838 		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1839 	if (maj_stat != GSS_S_COMPLETE)
1840 		return status;
1841 	if (ntohl(*(*p)++) != rqstp->rq_seqno)
1842 		return status;
1843 
1844 	return 0;
1845 }
1846 
1847 static int
1848 gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
1849 		      __be32 *p, void *obj)
1850 {
1851 	struct xdr_stream xdr;
1852 
1853 	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
1854 	return decode(rqstp, &xdr, obj);
1855 }
1856 
1857 static int
1858 gss_unwrap_resp(struct rpc_task *task,
1859 		kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
1860 {
1861 	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1862 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1863 			gc_base);
1864 	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1865 	__be32		*savedp = p;
1866 	struct kvec	*head = ((struct rpc_rqst *)rqstp)->rq_rcv_buf.head;
1867 	int		savedlen = head->iov_len;
1868 	int             status = -EIO;
1869 
1870 	if (ctx->gc_proc != RPC_GSS_PROC_DATA)
1871 		goto out_decode;
1872 	switch (gss_cred->gc_service) {
1873 	case RPC_GSS_SVC_NONE:
1874 		break;
1875 	case RPC_GSS_SVC_INTEGRITY:
1876 		status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
1877 		if (status)
1878 			goto out;
1879 		break;
1880 	case RPC_GSS_SVC_PRIVACY:
1881 		status = gss_unwrap_resp_priv(cred, ctx, rqstp, &p);
1882 		if (status)
1883 			goto out;
1884 		break;
1885 	}
1886 	/* take into account extra slack for integrity and privacy cases: */
1887 	cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
1888 						+ (savedlen - head->iov_len);
1889 out_decode:
1890 	status = gss_unwrap_req_decode(decode, rqstp, p, obj);
1891 out:
1892 	gss_put_ctx(ctx);
1893 	dprintk("RPC: %5u %s returning %d\n",
1894 		task->tk_pid, __func__, status);
1895 	return status;
1896 }
1897 
1898 static const struct rpc_authops authgss_ops = {
1899 	.owner		= THIS_MODULE,
1900 	.au_flavor	= RPC_AUTH_GSS,
1901 	.au_name	= "RPCSEC_GSS",
1902 	.create		= gss_create,
1903 	.destroy	= gss_destroy,
1904 	.lookup_cred	= gss_lookup_cred,
1905 	.crcreate	= gss_create_cred,
1906 	.list_pseudoflavors = gss_mech_list_pseudoflavors,
1907 	.info2flavor	= gss_mech_info2flavor,
1908 	.flavor2info	= gss_mech_flavor2info,
1909 };
1910 
1911 static const struct rpc_credops gss_credops = {
1912 	.cr_name	= "AUTH_GSS",
1913 	.crdestroy	= gss_destroy_cred,
1914 	.cr_init	= gss_cred_init,
1915 	.crbind		= rpcauth_generic_bind_cred,
1916 	.crmatch	= gss_match,
1917 	.crmarshal	= gss_marshal,
1918 	.crrefresh	= gss_refresh,
1919 	.crvalidate	= gss_validate,
1920 	.crwrap_req	= gss_wrap_req,
1921 	.crunwrap_resp	= gss_unwrap_resp,
1922 	.crkey_timeout	= gss_key_timeout,
1923 };
1924 
1925 static const struct rpc_credops gss_nullops = {
1926 	.cr_name	= "AUTH_GSS",
1927 	.crdestroy	= gss_destroy_nullcred,
1928 	.crbind		= rpcauth_generic_bind_cred,
1929 	.crmatch	= gss_match,
1930 	.crmarshal	= gss_marshal,
1931 	.crrefresh	= gss_refresh_null,
1932 	.crvalidate	= gss_validate,
1933 	.crwrap_req	= gss_wrap_req,
1934 	.crunwrap_resp	= gss_unwrap_resp,
1935 };
1936 
1937 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
1938 	.upcall		= rpc_pipe_generic_upcall,
1939 	.downcall	= gss_pipe_downcall,
1940 	.destroy_msg	= gss_pipe_destroy_msg,
1941 	.open_pipe	= gss_pipe_open_v0,
1942 	.release_pipe	= gss_pipe_release,
1943 };
1944 
1945 static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
1946 	.upcall		= rpc_pipe_generic_upcall,
1947 	.downcall	= gss_pipe_downcall,
1948 	.destroy_msg	= gss_pipe_destroy_msg,
1949 	.open_pipe	= gss_pipe_open_v1,
1950 	.release_pipe	= gss_pipe_release,
1951 };
1952 
1953 static __net_init int rpcsec_gss_init_net(struct net *net)
1954 {
1955 	return gss_svc_init_net(net);
1956 }
1957 
1958 static __net_exit void rpcsec_gss_exit_net(struct net *net)
1959 {
1960 	gss_svc_shutdown_net(net);
1961 }
1962 
1963 static struct pernet_operations rpcsec_gss_net_ops = {
1964 	.init = rpcsec_gss_init_net,
1965 	.exit = rpcsec_gss_exit_net,
1966 };
1967 
1968 /*
1969  * Initialize RPCSEC_GSS module
1970  */
1971 static int __init init_rpcsec_gss(void)
1972 {
1973 	int err = 0;
1974 
1975 	err = rpcauth_register(&authgss_ops);
1976 	if (err)
1977 		goto out;
1978 	err = gss_svc_init();
1979 	if (err)
1980 		goto out_unregister;
1981 	err = register_pernet_subsys(&rpcsec_gss_net_ops);
1982 	if (err)
1983 		goto out_svc_exit;
1984 	rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
1985 	return 0;
1986 out_svc_exit:
1987 	gss_svc_shutdown();
1988 out_unregister:
1989 	rpcauth_unregister(&authgss_ops);
1990 out:
1991 	return err;
1992 }
1993 
1994 static void __exit exit_rpcsec_gss(void)
1995 {
1996 	unregister_pernet_subsys(&rpcsec_gss_net_ops);
1997 	gss_svc_shutdown();
1998 	rpcauth_unregister(&authgss_ops);
1999 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
2000 }
2001 
2002 MODULE_ALIAS("rpc-auth-6");
2003 MODULE_LICENSE("GPL");
2004 module_param_named(expired_cred_retry_delay,
2005 		   gss_expired_cred_retry_delay,
2006 		   uint, 0644);
2007 MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2008 		"the RPC engine retries an expired credential");
2009 
2010 module_param_named(key_expire_timeo,
2011 		   gss_key_expire_timeo,
2012 		   uint, 0644);
2013 MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2014 		"credential keys lifetime where the NFS layer cleans up "
2015 		"prior to key expiration");
2016 
2017 module_init(init_rpcsec_gss)
2018 module_exit(exit_rpcsec_gss)
2019