1	// SPDX-License-Identifier: BSD-3-Clause
2	/*
3	* linux/net/sunrpc/auth_gss/auth_gss.c
4	*
5	* RPCSEC_GSS client authentication.
6	*
7	* Copyright (c) 2000 The Regents of the University of Michigan.
8	* All rights reserved.
9	*
10	* Dug Song <dugsong@monkey.org>
11	* Andy Adamson <andros@umich.edu>
12	*/
13
14	#include <linux/module.h>
15	#include <linux/init.h>
16	#include <linux/types.h>
17	#include <linux/slab.h>
18	#include <linux/sched.h>
19	#include <linux/pagemap.h>
20	#include <linux/sunrpc/clnt.h>
21	#include <linux/sunrpc/auth.h>
22	#include <linux/sunrpc/auth_gss.h>
23	#include <linux/sunrpc/gss_krb5.h>
24	#include <linux/sunrpc/svcauth_gss.h>
25	#include <linux/sunrpc/gss_err.h>
26	#include <linux/workqueue.h>
27	#include <linux/sunrpc/rpc_pipe_fs.h>
28	#include <linux/sunrpc/gss_api.h>
29	#include <linux/uaccess.h>
30	#include <linux/hashtable.h>
31
32	#include "auth_gss_internal.h"
33	#include "../netns.h"
34
35	#include <trace/events/rpcgss.h>
36
37	static const struct rpc_authops authgss_ops;
38
39	static const struct rpc_credops gss_credops;
40	static const struct rpc_credops gss_nullops;
41
42	#define GSS_RETRY_EXPIRED 5
43	static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
44
45	#define GSS_KEY_EXPIRE_TIMEO 240
46	static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO;
47
48	#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
49	# define RPCDBG_FACILITY RPCDBG_AUTH
50	#endif
51
52	/*
53	* This compile-time check verifies that we will not exceed the
54	* slack space allotted by the client and server auth_gss code
55	* before they call gss_wrap().
56	*/
57	#define GSS_KRB5_MAX_SLACK_NEEDED \
58	(GSS_KRB5_TOK_HDR_LEN /* gss token header */ \
59	+ GSS_KRB5_MAX_CKSUM_LEN /* gss token checksum */ \
60	+ GSS_KRB5_MAX_BLOCKSIZE /* confounder */ \
61	+ GSS_KRB5_MAX_BLOCKSIZE /* possible padding */ \
62	+ GSS_KRB5_TOK_HDR_LEN /* encrypted hdr in v2 token */ \
63	+ GSS_KRB5_MAX_CKSUM_LEN /* encryption hmac */ \
64	+ XDR_UNIT * 2 /* RPC verifier */ \
65	+ GSS_KRB5_TOK_HDR_LEN \
66	+ GSS_KRB5_MAX_CKSUM_LEN)
67
68	#define GSS_CRED_SLACK (RPC_MAX_AUTH_SIZE * 2)
69	/* length of a krb5 verifier (48), plus data added before arguments when
70	* using integrity (two 4-byte integers): */
71	#define GSS_VERF_SLACK 100
72
73	static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
74	static DEFINE_SPINLOCK(gss_auth_hash_lock);
75
76	struct gss_pipe {
77	struct rpc_pipe_dir_object pdo;
78	struct rpc_pipe *pipe;
79	struct rpc_clnt *clnt;
80	const char *name;
81	struct kref kref;
82	};
83
84	struct gss_auth {
85	struct kref kref;
86	struct hlist_node hash;
87	struct rpc_auth rpc_auth;
88	struct gss_api_mech *mech;
89	enum rpc_gss_svc service;
90	struct rpc_clnt *client;
91	struct net *net;
92	netns_tracker ns_tracker;
93	/*
94	* There are two upcall pipes; dentry[1], named "gssd", is used
95	* for the new text-based upcall; dentry[0] is named after the
96	* mechanism (for example, "krb5") and exists for
97	* backwards-compatibility with older gssd's.
98	*/
99	struct gss_pipe *gss_pipe[2];
100	const char *target_name;
101	};
102
103	/* pipe_version >= 0 if and only if someone has a pipe open. */
104	static DEFINE_SPINLOCK(pipe_version_lock);
105	static struct rpc_wait_queue pipe_version_rpc_waitqueue;
106	static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
107	static void gss_put_auth(struct gss_auth *gss_auth);
108
109	static void gss_free_ctx(struct gss_cl_ctx *);
110	static const struct rpc_pipe_ops gss_upcall_ops_v0;
111	static const struct rpc_pipe_ops gss_upcall_ops_v1;
112
113	static inline struct gss_cl_ctx *
114	gss_get_ctx(struct gss_cl_ctx *ctx)
115	{
116	refcount_inc(r: &ctx->count);
117	return ctx;
118	}
119
120	static inline void
121	gss_put_ctx(struct gss_cl_ctx *ctx)
122	{
123	if (refcount_dec_and_test(r: &ctx->count))
124	gss_free_ctx(ctx);
125	}
126
127	/* gss_cred_set_ctx:
128	* called by gss_upcall_callback and gss_create_upcall in order
129	* to set the gss context. The actual exchange of an old context
130	* and a new one is protected by the pipe->lock.
131	*/
132	static void
133	gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
134	{
135	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
136
137	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
138	return;
139	gss_get_ctx(ctx);
140	rcu_assign_pointer(gss_cred->gc_ctx, ctx);
141	set_bit(RPCAUTH_CRED_UPTODATE, addr: &cred->cr_flags);
142	smp_mb__before_atomic();
143	clear_bit(RPCAUTH_CRED_NEW, addr: &cred->cr_flags);
144	}
145
146	static struct gss_cl_ctx *
147	gss_cred_get_ctx(struct rpc_cred *cred)
148	{
149	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
150	struct gss_cl_ctx *ctx = NULL;
151
152	rcu_read_lock();
153	ctx = rcu_dereference(gss_cred->gc_ctx);
154	if (ctx)
155	gss_get_ctx(ctx);
156	rcu_read_unlock();
157	return ctx;
158	}
159
160	static struct gss_cl_ctx *
161	gss_alloc_context(void)
162	{
163	struct gss_cl_ctx *ctx;
164
165	ctx = kzalloc(size: sizeof(*ctx), GFP_KERNEL);
166	if (ctx != NULL) {
167	ctx->gc_proc = RPC_GSS_PROC_DATA;
168	ctx->gc_seq = 1; /* NetApp 6.4R1 doesn't accept seq. no. 0 */
169	spin_lock_init(&ctx->gc_seq_lock);
170	refcount_set(r: &ctx->count,n: 1);
171	}
172	return ctx;
173	}
174
175	#define GSSD_MIN_TIMEOUT (60 * 60)
176	static const void *
177	gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
178	{
179	const void *q;
180	unsigned int seclen;
181	unsigned int timeout;
182	unsigned long now = jiffies;
183	u32 window_size;
184	int ret;
185
186	/* First unsigned int gives the remaining lifetime in seconds of the
187	* credential - e.g. the remaining TGT lifetime for Kerberos or
188	* the -t value passed to GSSD.
189	*/
190	p = simple_get_bytes(p, end, res: &timeout, len: sizeof(timeout));
191	if (IS_ERR(ptr: p))
192	goto err;
193	if (timeout == 0)
194	timeout = GSSD_MIN_TIMEOUT;
195	ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
196	/* Sequence number window. Determines the maximum number of
197	* simultaneous requests
198	*/
199	p = simple_get_bytes(p, end, res: &window_size, len: sizeof(window_size));
200	if (IS_ERR(ptr: p))
201	goto err;
202	ctx->gc_win = window_size;
203	/* gssd signals an error by passing ctx->gc_win = 0: */
204	if (ctx->gc_win == 0) {
205	/*
206	* in which case, p points to an error code. Anything other
207	* than -EKEYEXPIRED gets converted to -EACCES.
208	*/
209	p = simple_get_bytes(p, end, res: &ret, len: sizeof(ret));
210	if (!IS_ERR(ptr: p))
211	p = (ret == -EKEYEXPIRED) ? ERR_PTR(error: -EKEYEXPIRED) :
212	ERR_PTR(error: -EACCES);
213	goto err;
214	}
215	/* copy the opaque wire context */
216	p = simple_get_netobj(p, end, dest: &ctx->gc_wire_ctx);
217	if (IS_ERR(ptr: p))
218	goto err;
219	/* import the opaque security context */
220	p = simple_get_bytes(p, end, res: &seclen, len: sizeof(seclen));
221	if (IS_ERR(ptr: p))
222	goto err;
223	q = (const void *)((const char *)p + seclen);
224	if (unlikely(q > end || q < p)) {
225	p = ERR_PTR(error: -EFAULT);
226	goto err;
227	}
228	ret = gss_import_sec_context(input_token: p, bufsize: seclen, mech: gm, ctx_id: &ctx->gc_gss_ctx, NULL, GFP_KERNEL);
229	if (ret < 0) {
230	trace_rpcgss_import_ctx(status: ret);
231	p = ERR_PTR(error: ret);
232	goto err;
233	}
234
235	/* is there any trailing data? */
236	if (q == end) {
237	p = q;
238	goto done;
239	}
240
241	/* pull in acceptor name (if there is one) */
242	p = simple_get_netobj(p: q, end, dest: &ctx->gc_acceptor);
243	if (IS_ERR(ptr: p))
244	goto err;
245	done:
246	trace_rpcgss_context(window_size, expiry: ctx->gc_expiry, now, timeout,
247	len: ctx->gc_acceptor.len, data: ctx->gc_acceptor.data);
248	err:
249	return p;
250	}
251
252	/* XXX: Need some documentation about why UPCALL_BUF_LEN is so small.
253	* Is user space expecting no more than UPCALL_BUF_LEN bytes?
254	* Note that there are now _two_ NI_MAXHOST sized data items
255	* being passed in this string.
256	*/
257	#define UPCALL_BUF_LEN 256
258
259	struct gss_upcall_msg {
260	refcount_t count;
261	kuid_t uid;
262	const char *service_name;
263	struct rpc_pipe_msg msg;
264	struct list_head list;
265	struct gss_auth *auth;
266	struct rpc_pipe *pipe;
267	struct rpc_wait_queue rpc_waitqueue;
268	wait_queue_head_t waitqueue;
269	struct gss_cl_ctx *ctx;
270	char databuf[UPCALL_BUF_LEN];
271	};
272
273	static int get_pipe_version(struct net *net)
274	{
275	struct sunrpc_net *sn = net_generic(net, id: sunrpc_net_id);
276	int ret;
277
278	spin_lock(lock: &pipe_version_lock);
279	if (sn->pipe_version >= 0) {
280	atomic_inc(v: &sn->pipe_users);
281	ret = sn->pipe_version;
282	} else
283	ret = -EAGAIN;
284	spin_unlock(lock: &pipe_version_lock);
285	return ret;
286	}
287
288	static void put_pipe_version(struct net *net)
289	{
290	struct sunrpc_net *sn = net_generic(net, id: sunrpc_net_id);
291
292	if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
293	sn->pipe_version = -1;
294	spin_unlock(lock: &pipe_version_lock);
295	}
296	}
297
298	static void
299	gss_release_msg(struct gss_upcall_msg *gss_msg)
300	{
301	struct net *net = gss_msg->auth->net;
302	if (!refcount_dec_and_test(r: &gss_msg->count))
303	return;
304	put_pipe_version(net);
305	BUG_ON(!list_empty(&gss_msg->list));
306	if (gss_msg->ctx != NULL)
307	gss_put_ctx(ctx: gss_msg->ctx);
308	rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
309	gss_put_auth(gss_auth: gss_msg->auth);
310	kfree_const(x: gss_msg->service_name);
311	kfree(objp: gss_msg);
312	}
313
314	static struct gss_upcall_msg *
315	__gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth)
316	{
317	struct gss_upcall_msg *pos;
318	list_for_each_entry(pos, &pipe->in_downcall, list) {
319	if (!uid_eq(left: pos->uid, right: uid))
320	continue;
321	if (pos->auth->service != auth->service)
322	continue;
323	refcount_inc(r: &pos->count);
324	return pos;
325	}
326	return NULL;
327	}
328
329	/* Try to add an upcall to the pipefs queue.
330	* If an upcall owned by our uid already exists, then we return a reference
331	* to that upcall instead of adding the new upcall.
332	*/
333	static inline struct gss_upcall_msg *
334	gss_add_msg(struct gss_upcall_msg *gss_msg)
335	{
336	struct rpc_pipe *pipe = gss_msg->pipe;
337	struct gss_upcall_msg *old;
338
339	spin_lock(lock: &pipe->lock);
340	old = __gss_find_upcall(pipe, uid: gss_msg->uid, auth: gss_msg->auth);
341	if (old == NULL) {
342	refcount_inc(r: &gss_msg->count);
343	list_add(new: &gss_msg->list, head: &pipe->in_downcall);
344	} else
345	gss_msg = old;
346	spin_unlock(lock: &pipe->lock);
347	return gss_msg;
348	}
349
350	static void
351	__gss_unhash_msg(struct gss_upcall_msg *gss_msg)
352	{
353	list_del_init(entry: &gss_msg->list);
354	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
355	wake_up_all(&gss_msg->waitqueue);
356	refcount_dec(r: &gss_msg->count);
357	}
358
359	static void
360	gss_unhash_msg(struct gss_upcall_msg *gss_msg)
361	{
362	struct rpc_pipe *pipe = gss_msg->pipe;
363
364	if (list_empty(head: &gss_msg->list))
365	return;
366	spin_lock(lock: &pipe->lock);
367	if (!list_empty(head: &gss_msg->list))
368	__gss_unhash_msg(gss_msg);
369	spin_unlock(lock: &pipe->lock);
370	}
371
372	static void
373	gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
374	{
375	switch (gss_msg->msg.errno) {
376	case 0:
377	if (gss_msg->ctx == NULL)
378	break;
379	clear_bit(RPCAUTH_CRED_NEGATIVE, addr: &gss_cred->gc_base.cr_flags);
380	gss_cred_set_ctx(cred: &gss_cred->gc_base, ctx: gss_msg->ctx);
381	break;
382	case -EKEYEXPIRED:
383	set_bit(RPCAUTH_CRED_NEGATIVE, addr: &gss_cred->gc_base.cr_flags);
384	}
385	gss_cred->gc_upcall_timestamp = jiffies;
386	gss_cred->gc_upcall = NULL;
387	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
388	}
389
390	static void
391	gss_upcall_callback(struct rpc_task *task)
392	{
393	struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
394	struct gss_cred, gc_base);
395	struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
396	struct rpc_pipe *pipe = gss_msg->pipe;
397
398	spin_lock(lock: &pipe->lock);
399	gss_handle_downcall_result(gss_cred, gss_msg);
400	spin_unlock(lock: &pipe->lock);
401	task->tk_status = gss_msg->msg.errno;
402	gss_release_msg(gss_msg);
403	}
404
405	static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg,
406	const struct cred *cred)
407	{
408	struct user_namespace *userns = cred->user_ns;
409
410	uid_t uid = from_kuid_munged(to: userns, uid: gss_msg->uid);
411	memcpy(gss_msg->databuf, &uid, sizeof(uid));
412	gss_msg->msg.data = gss_msg->databuf;
413	gss_msg->msg.len = sizeof(uid);
414
415	BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
416	}
417
418	static ssize_t
419	gss_v0_upcall(struct file *file, struct rpc_pipe_msg *msg,
420	char __user *buf, size_t buflen)
421	{
422	struct gss_upcall_msg *gss_msg = container_of(msg,
423	struct gss_upcall_msg,
424	msg);
425	if (msg->copied == 0)
426	gss_encode_v0_msg(gss_msg, cred: file->f_cred);
427	return rpc_pipe_generic_upcall(file, msg, buf, buflen);
428	}
429
430	static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
431	const char *service_name,
432	const char *target_name,
433	const struct cred *cred)
434	{
435	struct user_namespace *userns = cred->user_ns;
436	struct gss_api_mech *mech = gss_msg->auth->mech;
437	char *p = gss_msg->databuf;
438	size_t buflen = sizeof(gss_msg->databuf);
439	int len;
440
441	len = scnprintf(buf: p, size: buflen, fmt: "mech=%s uid=%d", mech->gm_name,
442	from_kuid_munged(to: userns, uid: gss_msg->uid));
443	buflen -= len;
444	p += len;
445	gss_msg->msg.len = len;
446
447	/*
448	* target= is a full service principal that names the remote
449	* identity that we are authenticating to.
450	*/
451	if (target_name) {
452	len = scnprintf(buf: p, size: buflen, fmt: " target=%s", target_name);
453	buflen -= len;
454	p += len;
455	gss_msg->msg.len += len;
456	}
457
458	/*
459	* gssd uses service= and srchost= to select a matching key from
460	* the system's keytab to use as the source principal.
461	*
462	* service= is the service name part of the source principal,
463	* or "*" (meaning choose any).
464	*
465	* srchost= is the hostname part of the source principal. When
466	* not provided, gssd uses the local hostname.
467	*/
468	if (service_name) {
469	char *c = strchr(service_name, '@');
470
471	if (!c)
472	len = scnprintf(buf: p, size: buflen, fmt: " service=%s",
473	service_name);
474	else
475	len = scnprintf(buf: p, size: buflen,
476	fmt: " service=%.*s srchost=%s",
477	(int)(c - service_name),
478	service_name, c + 1);
479	buflen -= len;
480	p += len;
481	gss_msg->msg.len += len;
482	}
483
484	if (mech->gm_upcall_enctypes) {
485	len = scnprintf(buf: p, size: buflen, fmt: " enctypes=%s",
486	mech->gm_upcall_enctypes);
487	buflen -= len;
488	p += len;
489	gss_msg->msg.len += len;
490	}
491	trace_rpcgss_upcall_msg(buf: gss_msg->databuf);
492	len = scnprintf(buf: p, size: buflen, fmt: "\n");
493	if (len == 0)
494	goto out_overflow;
495	gss_msg->msg.len += len;
496	gss_msg->msg.data = gss_msg->databuf;
497	return 0;
498	out_overflow:
499	WARN_ON_ONCE(1);
500	return -ENOMEM;
501	}
502
503	static ssize_t
504	gss_v1_upcall(struct file *file, struct rpc_pipe_msg *msg,
505	char __user *buf, size_t buflen)
506	{
507	struct gss_upcall_msg *gss_msg = container_of(msg,
508	struct gss_upcall_msg,
509	msg);
510	int err;
511	if (msg->copied == 0) {
512	err = gss_encode_v1_msg(gss_msg,
513	service_name: gss_msg->service_name,
514	target_name: gss_msg->auth->target_name,
515	cred: file->f_cred);
516	if (err)
517	return err;
518	}
519	return rpc_pipe_generic_upcall(file, msg, buf, buflen);
520	}
521
522	static struct gss_upcall_msg *
523	gss_alloc_msg(struct gss_auth *gss_auth,
524	kuid_t uid, const char *service_name)
525	{
526	struct gss_upcall_msg *gss_msg;
527	int vers;
528	int err = -ENOMEM;
529
530	gss_msg = kzalloc(size: sizeof(*gss_msg), GFP_KERNEL);
531	if (gss_msg == NULL)
532	goto err;
533	vers = get_pipe_version(net: gss_auth->net);
534	err = vers;
535	if (err < 0)
536	goto err_free_msg;
537	gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
538	INIT_LIST_HEAD(list: &gss_msg->list);
539	rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
540	init_waitqueue_head(&gss_msg->waitqueue);
541	refcount_set(r: &gss_msg->count, n: 1);
542	gss_msg->uid = uid;
543	gss_msg->auth = gss_auth;
544	kref_get(kref: &gss_auth->kref);
545	if (service_name) {
546	gss_msg->service_name = kstrdup_const(s: service_name, GFP_KERNEL);
547	if (!gss_msg->service_name) {
548	err = -ENOMEM;
549	goto err_put_pipe_version;
550	}
551	}
552	return gss_msg;
553	err_put_pipe_version:
554	put_pipe_version(net: gss_auth->net);
555	err_free_msg:
556	kfree(objp: gss_msg);
557	err:
558	return ERR_PTR(error: err);
559	}
560
561	static struct gss_upcall_msg *
562	gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
563	{
564	struct gss_cred *gss_cred = container_of(cred,
565	struct gss_cred, gc_base);
566	struct gss_upcall_msg *gss_new, *gss_msg;
567	kuid_t uid = cred->cr_cred->fsuid;
568
569	gss_new = gss_alloc_msg(gss_auth, uid, service_name: gss_cred->gc_principal);
570	if (IS_ERR(ptr: gss_new))
571	return gss_new;
572	gss_msg = gss_add_msg(gss_msg: gss_new);
573	if (gss_msg == gss_new) {
574	int res;
575	refcount_inc(r: &gss_msg->count);
576	res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
577	if (res) {
578	gss_unhash_msg(gss_msg: gss_new);
579	refcount_dec(r: &gss_msg->count);
580	gss_release_msg(gss_msg: gss_new);
581	gss_msg = ERR_PTR(error: res);
582	}
583	} else
584	gss_release_msg(gss_msg: gss_new);
585	return gss_msg;
586	}
587
588	static void warn_gssd(void)
589	{
590	dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
591	}
592
593	static inline int
594	gss_refresh_upcall(struct rpc_task *task)
595	{
596	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
597	struct gss_auth *gss_auth = container_of(cred->cr_auth,
598	struct gss_auth, rpc_auth);
599	struct gss_cred *gss_cred = container_of(cred,
600	struct gss_cred, gc_base);
601	struct gss_upcall_msg *gss_msg;
602	struct rpc_pipe *pipe;
603	int err = 0;
604
605	gss_msg = gss_setup_upcall(gss_auth, cred);
606	if (PTR_ERR(ptr: gss_msg) == -EAGAIN) {
607	/* XXX: warning on the first, under the assumption we
608	* shouldn't normally hit this case on a refresh. */
609	warn_gssd();
610	rpc_sleep_on_timeout(queue: &pipe_version_rpc_waitqueue,
611	task, NULL, timeout: jiffies + (15 * HZ));
612	err = -EAGAIN;
613	goto out;
614	}
615	if (IS_ERR(ptr: gss_msg)) {
616	err = PTR_ERR(ptr: gss_msg);
617	goto out;
618	}
619	pipe = gss_msg->pipe;
620	spin_lock(lock: &pipe->lock);
621	if (gss_cred->gc_upcall != NULL)
622	rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
623	else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
624	gss_cred->gc_upcall = gss_msg;
625	/* gss_upcall_callback will release the reference to gss_upcall_msg */
626	refcount_inc(r: &gss_msg->count);
627	rpc_sleep_on(&gss_msg->rpc_waitqueue, task, action: gss_upcall_callback);
628	} else {
629	gss_handle_downcall_result(gss_cred, gss_msg);
630	err = gss_msg->msg.errno;
631	}
632	spin_unlock(lock: &pipe->lock);
633	gss_release_msg(gss_msg);
634	out:
635	trace_rpcgss_upcall_result(uid: from_kuid(to: &init_user_ns,
636	uid: cred->cr_cred->fsuid), result: err);
637	return err;
638	}
639
640	static inline int
641	gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
642	{
643	struct net *net = gss_auth->net;
644	struct sunrpc_net *sn = net_generic(net, id: sunrpc_net_id);
645	struct rpc_pipe *pipe;
646	struct rpc_cred *cred = &gss_cred->gc_base;
647	struct gss_upcall_msg *gss_msg;
648	DEFINE_WAIT(wait);
649	int err;
650
651	retry:
652	err = 0;
653	/* if gssd is down, just skip upcalling altogether */
654	if (!gssd_running(net)) {
655	warn_gssd();
656	err = -EACCES;
657	goto out;
658	}
659	gss_msg = gss_setup_upcall(gss_auth, cred);
660	if (PTR_ERR(ptr: gss_msg) == -EAGAIN) {
661	err = wait_event_interruptible_timeout(pipe_version_waitqueue,
662	sn->pipe_version >= 0, 15 * HZ);
663	if (sn->pipe_version < 0) {
664	warn_gssd();
665	err = -EACCES;
666	}
667	if (err < 0)
668	goto out;
669	goto retry;
670	}
671	if (IS_ERR(ptr: gss_msg)) {
672	err = PTR_ERR(ptr: gss_msg);
673	goto out;
674	}
675	pipe = gss_msg->pipe;
676	for (;;) {
677	prepare_to_wait(wq_head: &gss_msg->waitqueue, wq_entry: &wait, TASK_KILLABLE);
678	spin_lock(lock: &pipe->lock);
679	if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
680	break;
681	}
682	spin_unlock(lock: &pipe->lock);
683	if (fatal_signal_pending(current)) {
684	err = -ERESTARTSYS;
685	goto out_intr;
686	}
687	schedule();
688	}
689	if (gss_msg->ctx) {
690	trace_rpcgss_ctx_init(gc: gss_cred);
691	gss_cred_set_ctx(cred, ctx: gss_msg->ctx);
692	} else {
693	err = gss_msg->msg.errno;
694	}
695	spin_unlock(lock: &pipe->lock);
696	out_intr:
697	finish_wait(wq_head: &gss_msg->waitqueue, wq_entry: &wait);
698	gss_release_msg(gss_msg);
699	out:
700	trace_rpcgss_upcall_result(uid: from_kuid(to: &init_user_ns,
701	uid: cred->cr_cred->fsuid), result: err);
702	return err;
703	}
704
705	static struct gss_upcall_msg *
706	gss_find_downcall(struct rpc_pipe *pipe, kuid_t uid)
707	{
708	struct gss_upcall_msg *pos;
709	list_for_each_entry(pos, &pipe->in_downcall, list) {
710	if (!uid_eq(left: pos->uid, right: uid))
711	continue;
712	if (!rpc_msg_is_inflight(msg: &pos->msg))
713	continue;
714	refcount_inc(r: &pos->count);
715	return pos;
716	}
717	return NULL;
718	}
719
720	#define MSG_BUF_MAXSIZE 1024
721
722	static ssize_t
723	gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
724	{
725	const void *p, *end;
726	void *buf;
727	struct gss_upcall_msg *gss_msg;
728	struct rpc_pipe *pipe = RPC_I(inode: file_inode(f: filp))->pipe;
729	struct gss_cl_ctx *ctx;
730	uid_t id;
731	kuid_t uid;
732	ssize_t err = -EFBIG;
733
734	if (mlen > MSG_BUF_MAXSIZE)
735	goto out;
736	err = -ENOMEM;
737	buf = kmalloc(size: mlen, GFP_KERNEL);
738	if (!buf)
739	goto out;
740
741	err = -EFAULT;
742	if (copy_from_user(to: buf, from: src, n: mlen))
743	goto err;
744
745	end = (const void *)((char *)buf + mlen);
746	p = simple_get_bytes(p: buf, end, res: &id, len: sizeof(id));
747	if (IS_ERR(ptr: p)) {
748	err = PTR_ERR(ptr: p);
749	goto err;
750	}
751
752	uid = make_kuid(current_user_ns(), uid: id);
753	if (!uid_valid(uid)) {
754	err = -EINVAL;
755	goto err;
756	}
757
758	err = -ENOMEM;
759	ctx = gss_alloc_context();
760	if (ctx == NULL)
761	goto err;
762
763	err = -ENOENT;
764	/* Find a matching upcall */
765	spin_lock(lock: &pipe->lock);
766	gss_msg = gss_find_downcall(pipe, uid);
767	if (gss_msg == NULL) {
768	spin_unlock(lock: &pipe->lock);
769	goto err_put_ctx;
770	}
771	list_del_init(entry: &gss_msg->list);
772	spin_unlock(lock: &pipe->lock);
773
774	p = gss_fill_context(p, end, ctx, gm: gss_msg->auth->mech);
775	if (IS_ERR(ptr: p)) {
776	err = PTR_ERR(ptr: p);
777	switch (err) {
778	case -EACCES:
779	case -EKEYEXPIRED:
780	gss_msg->msg.errno = err;
781	err = mlen;
782	break;
783	case -EFAULT:
784	case -ENOMEM:
785	case -EINVAL:
786	case -ENOSYS:
787	gss_msg->msg.errno = -EAGAIN;
788	break;
789	default:
790	printk(KERN_CRIT "%s: bad return from "
791	"gss_fill_context: %zd\n", __func__, err);
792	gss_msg->msg.errno = -EIO;
793	}
794	goto err_release_msg;
795	}
796	gss_msg->ctx = gss_get_ctx(ctx);
797	err = mlen;
798
799	err_release_msg:
800	spin_lock(lock: &pipe->lock);
801	__gss_unhash_msg(gss_msg);
802	spin_unlock(lock: &pipe->lock);
803	gss_release_msg(gss_msg);
804	err_put_ctx:
805	gss_put_ctx(ctx);
806	err:
807	kfree(objp: buf);
808	out:
809	return err;
810	}
811
812	static int gss_pipe_open(struct inode *inode, int new_version)
813	{
814	struct net *net = inode->i_sb->s_fs_info;
815	struct sunrpc_net *sn = net_generic(net, id: sunrpc_net_id);
816	int ret = 0;
817
818	spin_lock(lock: &pipe_version_lock);
819	if (sn->pipe_version < 0) {
820	/* First open of any gss pipe determines the version: */
821	sn->pipe_version = new_version;
822	rpc_wake_up(&pipe_version_rpc_waitqueue);
823	wake_up(&pipe_version_waitqueue);
824	} else if (sn->pipe_version != new_version) {
825	/* Trying to open a pipe of a different version */
826	ret = -EBUSY;
827	goto out;
828	}
829	atomic_inc(v: &sn->pipe_users);
830	out:
831	spin_unlock(lock: &pipe_version_lock);
832	return ret;
833
834	}
835
836	static int gss_pipe_open_v0(struct inode *inode)
837	{
838	return gss_pipe_open(inode, new_version: 0);
839	}
840
841	static int gss_pipe_open_v1(struct inode *inode)
842	{
843	return gss_pipe_open(inode, new_version: 1);
844	}
845
846	static void
847	gss_pipe_release(struct inode *inode)
848	{
849	struct net *net = inode->i_sb->s_fs_info;
850	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
851	struct gss_upcall_msg *gss_msg;
852
853	restart:
854	spin_lock(lock: &pipe->lock);
855	list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
856
857	if (!list_empty(head: &gss_msg->msg.list))
858	continue;
859	gss_msg->msg.errno = -EPIPE;
860	refcount_inc(r: &gss_msg->count);
861	__gss_unhash_msg(gss_msg);
862	spin_unlock(lock: &pipe->lock);
863	gss_release_msg(gss_msg);
864	goto restart;
865	}
866	spin_unlock(lock: &pipe->lock);
867
868	put_pipe_version(net);
869	}
870
871	static void
872	gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
873	{
874	struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
875
876	if (msg->errno < 0) {
877	refcount_inc(r: &gss_msg->count);
878	gss_unhash_msg(gss_msg);
879	if (msg->errno == -ETIMEDOUT)
880	warn_gssd();
881	gss_release_msg(gss_msg);
882	}
883	gss_release_msg(gss_msg);
884	}
885
886	static void gss_pipe_dentry_destroy(struct dentry *dir,
887	struct rpc_pipe_dir_object *pdo)
888	{
889	struct gss_pipe *gss_pipe = pdo->pdo_data;
890	struct rpc_pipe *pipe = gss_pipe->pipe;
891
892	if (pipe->dentry != NULL) {
893	rpc_unlink(pipe->dentry);
894	pipe->dentry = NULL;
895	}
896	}
897
898	static int gss_pipe_dentry_create(struct dentry *dir,
899	struct rpc_pipe_dir_object *pdo)
900	{
901	struct gss_pipe *p = pdo->pdo_data;
902	struct dentry *dentry;
903
904	dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
905	if (IS_ERR(ptr: dentry))
906	return PTR_ERR(ptr: dentry);
907	p->pipe->dentry = dentry;
908	return 0;
909	}
910
911	static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
912	.create = gss_pipe_dentry_create,
913	.destroy = gss_pipe_dentry_destroy,
914	};
915
916	static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
917	const char *name,
918	const struct rpc_pipe_ops *upcall_ops)
919	{
920	struct gss_pipe *p;
921	int err = -ENOMEM;
922
923	p = kmalloc(size: sizeof(*p), GFP_KERNEL);
924	if (p == NULL)
925	goto err;
926	p->pipe = rpc_mkpipe_data(ops: upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
927	if (IS_ERR(ptr: p->pipe)) {
928	err = PTR_ERR(ptr: p->pipe);
929	goto err_free_gss_pipe;
930	}
931	p->name = name;
932	p->clnt = clnt;
933	kref_init(kref: &p->kref);
934	rpc_init_pipe_dir_object(pdo: &p->pdo,
935	pdo_ops: &gss_pipe_dir_object_ops,
936	pdo_data: p);
937	return p;
938	err_free_gss_pipe:
939	kfree(objp: p);
940	err:
941	return ERR_PTR(error: err);
942	}
943
944	struct gss_alloc_pdo {
945	struct rpc_clnt *clnt;
946	const char *name;
947	const struct rpc_pipe_ops *upcall_ops;
948	};
949
950	static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
951	{
952	struct gss_pipe *gss_pipe;
953	struct gss_alloc_pdo *args = data;
954
955	if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
956	return 0;
957	gss_pipe = container_of(pdo, struct gss_pipe, pdo);
958	if (strcmp(gss_pipe->name, args->name) != 0)
959	return 0;
960	if (!kref_get_unless_zero(kref: &gss_pipe->kref))
961	return 0;
962	return 1;
963	}
964
965	static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
966	{
967	struct gss_pipe *gss_pipe;
968	struct gss_alloc_pdo *args = data;
969
970	gss_pipe = gss_pipe_alloc(clnt: args->clnt, name: args->name, upcall_ops: args->upcall_ops);
971	if (!IS_ERR(ptr: gss_pipe))
972	return &gss_pipe->pdo;
973	return NULL;
974	}
975
976	static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
977	const char *name,
978	const struct rpc_pipe_ops *upcall_ops)
979	{
980	struct net *net = rpc_net_ns(clnt);
981	struct rpc_pipe_dir_object *pdo;
982	struct gss_alloc_pdo args = {
983	.clnt = clnt,
984	.name = name,
985	.upcall_ops = upcall_ops,
986	};
987
988	pdo = rpc_find_or_alloc_pipe_dir_object(net,
989	pdh: &clnt->cl_pipedir_objects,
990	match: gss_pipe_match_pdo,
991	alloc: gss_pipe_alloc_pdo,
992	data: &args);
993	if (pdo != NULL)
994	return container_of(pdo, struct gss_pipe, pdo);
995	return ERR_PTR(error: -ENOMEM);
996	}
997
998	static void __gss_pipe_free(struct gss_pipe *p)
999	{
1000	struct rpc_clnt *clnt = p->clnt;
1001	struct net *net = rpc_net_ns(clnt);
1002
1003	rpc_remove_pipe_dir_object(net,
1004	pdh: &clnt->cl_pipedir_objects,
1005	pdo: &p->pdo);
1006	rpc_destroy_pipe_data(pipe: p->pipe);
1007	kfree(objp: p);
1008	}
1009
1010	static void __gss_pipe_release(struct kref *kref)
1011	{
1012	struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
1013
1014	__gss_pipe_free(p);
1015	}
1016
1017	static void gss_pipe_free(struct gss_pipe *p)
1018	{
1019	if (p != NULL)
1020	kref_put(kref: &p->kref, release: __gss_pipe_release);
1021	}
1022
1023	/*
1024	* NOTE: we have the opportunity to use different
1025	* parameters based on the input flavor (which must be a pseudoflavor)
1026	*/
1027	static struct gss_auth *
1028	gss_create_new(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1029	{
1030	rpc_authflavor_t flavor = args->pseudoflavor;
1031	struct gss_auth *gss_auth;
1032	struct gss_pipe *gss_pipe;
1033	struct rpc_auth * auth;
1034	int err = -ENOMEM; /* XXX? */
1035
1036	if (!try_module_get(THIS_MODULE))
1037	return ERR_PTR(error: err);
1038	if (!(gss_auth = kmalloc(size: sizeof(*gss_auth), GFP_KERNEL)))
1039	goto out_dec;
1040	INIT_HLIST_NODE(h: &gss_auth->hash);
1041	gss_auth->target_name = NULL;
1042	if (args->target_name) {
1043	gss_auth->target_name = kstrdup(s: args->target_name, GFP_KERNEL);
1044	if (gss_auth->target_name == NULL)
1045	goto err_free;
1046	}
1047	gss_auth->client = clnt;
1048	gss_auth->net = get_net_track(net: rpc_net_ns(clnt), tracker: &gss_auth->ns_tracker,
1049	GFP_KERNEL);
1050	err = -EINVAL;
1051	gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1052	if (!gss_auth->mech)
1053	goto err_put_net;
1054	gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, pseudoflavor: flavor);
1055	if (gss_auth->service == 0)
1056	goto err_put_mech;
1057	if (!gssd_running(net: gss_auth->net))
1058	goto err_put_mech;
1059	auth = &gss_auth->rpc_auth;
1060	auth->au_cslack = GSS_CRED_SLACK >> 2;
1061	BUILD_BUG_ON(GSS_KRB5_MAX_SLACK_NEEDED > RPC_MAX_AUTH_SIZE);
1062	auth->au_rslack = GSS_KRB5_MAX_SLACK_NEEDED >> 2;
1063	auth->au_verfsize = GSS_VERF_SLACK >> 2;
1064	auth->au_ralign = GSS_VERF_SLACK >> 2;
1065	__set_bit(RPCAUTH_AUTH_UPDATE_SLACK, &auth->au_flags);
1066	auth->au_ops = &authgss_ops;
1067	auth->au_flavor = flavor;
1068	if (gss_pseudoflavor_to_datatouch(gss_auth->mech, pseudoflavor: flavor))
1069	__set_bit(RPCAUTH_AUTH_DATATOUCH, &auth->au_flags);
1070	refcount_set(r: &auth->au_count, n: 1);
1071	kref_init(kref: &gss_auth->kref);
1072
1073	err = rpcauth_init_credcache(auth);
1074	if (err)
1075	goto err_put_mech;
1076	/*
1077	* Note: if we created the old pipe first, then someone who
1078	* examined the directory at the right moment might conclude
1079	* that we supported only the old pipe. So we instead create
1080	* the new pipe first.
1081	*/
1082	gss_pipe = gss_pipe_get(clnt, name: "gssd", upcall_ops: &gss_upcall_ops_v1);
1083	if (IS_ERR(ptr: gss_pipe)) {
1084	err = PTR_ERR(ptr: gss_pipe);
1085	goto err_destroy_credcache;
1086	}
1087	gss_auth->gss_pipe[1] = gss_pipe;
1088
1089	gss_pipe = gss_pipe_get(clnt, name: gss_auth->mech->gm_name,
1090	upcall_ops: &gss_upcall_ops_v0);
1091	if (IS_ERR(ptr: gss_pipe)) {
1092	err = PTR_ERR(ptr: gss_pipe);
1093	goto err_destroy_pipe_1;
1094	}
1095	gss_auth->gss_pipe[0] = gss_pipe;
1096
1097	return gss_auth;
1098	err_destroy_pipe_1:
1099	gss_pipe_free(p: gss_auth->gss_pipe[1]);
1100	err_destroy_credcache:
1101	rpcauth_destroy_credcache(auth);
1102	err_put_mech:
1103	gss_mech_put(gss_auth->mech);
1104	err_put_net:
1105	put_net_track(net: gss_auth->net, tracker: &gss_auth->ns_tracker);
1106	err_free:
1107	kfree(objp: gss_auth->target_name);
1108	kfree(objp: gss_auth);
1109	out_dec:
1110	module_put(THIS_MODULE);
1111	trace_rpcgss_createauth(flavor, error: err);
1112	return ERR_PTR(error: err);
1113	}
1114
1115	static void
1116	gss_free(struct gss_auth *gss_auth)
1117	{
1118	gss_pipe_free(p: gss_auth->gss_pipe[0]);
1119	gss_pipe_free(p: gss_auth->gss_pipe[1]);
1120	gss_mech_put(gss_auth->mech);
1121	put_net_track(net: gss_auth->net, tracker: &gss_auth->ns_tracker);
1122	kfree(objp: gss_auth->target_name);
1123
1124	kfree(objp: gss_auth);
1125	module_put(THIS_MODULE);
1126	}
1127
1128	static void
1129	gss_free_callback(struct kref *kref)
1130	{
1131	struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1132
1133	gss_free(gss_auth);
1134	}
1135
1136	static void
1137	gss_put_auth(struct gss_auth *gss_auth)
1138	{
1139	kref_put(kref: &gss_auth->kref, release: gss_free_callback);
1140	}
1141
1142	static void
1143	gss_destroy(struct rpc_auth *auth)
1144	{
1145	struct gss_auth *gss_auth = container_of(auth,
1146	struct gss_auth, rpc_auth);
1147
1148	if (hash_hashed(node: &gss_auth->hash)) {
1149	spin_lock(lock: &gss_auth_hash_lock);
1150	hash_del(node: &gss_auth->hash);
1151	spin_unlock(lock: &gss_auth_hash_lock);
1152	}
1153
1154	gss_pipe_free(p: gss_auth->gss_pipe[0]);
1155	gss_auth->gss_pipe[0] = NULL;
1156	gss_pipe_free(p: gss_auth->gss_pipe[1]);
1157	gss_auth->gss_pipe[1] = NULL;
1158	rpcauth_destroy_credcache(auth);
1159
1160	gss_put_auth(gss_auth);
1161	}
1162
1163	/*
1164	* Auths may be shared between rpc clients that were cloned from a
1165	* common client with the same xprt, if they also share the flavor and
1166	* target_name.
1167	*
1168	* The auth is looked up from the oldest parent sharing the same
1169	* cl_xprt, and the auth itself references only that common parent
1170	* (which is guaranteed to last as long as any of its descendants).
1171	*/
1172	static struct gss_auth *
1173	gss_auth_find_or_add_hashed(const struct rpc_auth_create_args *args,
1174	struct rpc_clnt *clnt,
1175	struct gss_auth *new)
1176	{
1177	struct gss_auth *gss_auth;
1178	unsigned long hashval = (unsigned long)clnt;
1179
1180	spin_lock(lock: &gss_auth_hash_lock);
1181	hash_for_each_possible(gss_auth_hash_table,
1182	gss_auth,
1183	hash,
1184	hashval) {
1185	if (gss_auth->client != clnt)
1186	continue;
1187	if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1188	continue;
1189	if (gss_auth->target_name != args->target_name) {
1190	if (gss_auth->target_name == NULL)
1191	continue;
1192	if (args->target_name == NULL)
1193	continue;
1194	if (strcmp(gss_auth->target_name, args->target_name))
1195	continue;
1196	}
1197	if (!refcount_inc_not_zero(r: &gss_auth->rpc_auth.au_count))
1198	continue;
1199	goto out;
1200	}
1201	if (new)
1202	hash_add(gss_auth_hash_table, &new->hash, hashval);
1203	gss_auth = new;
1204	out:
1205	spin_unlock(lock: &gss_auth_hash_lock);
1206	return gss_auth;
1207	}
1208
1209	static struct gss_auth *
1210	gss_create_hashed(const struct rpc_auth_create_args *args,
1211	struct rpc_clnt *clnt)
1212	{
1213	struct gss_auth *gss_auth;
1214	struct gss_auth *new;
1215
1216	gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1217	if (gss_auth != NULL)
1218	goto out;
1219	new = gss_create_new(args, clnt);
1220	if (IS_ERR(ptr: new))
1221	return new;
1222	gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1223	if (gss_auth != new)
1224	gss_destroy(auth: &new->rpc_auth);
1225	out:
1226	return gss_auth;
1227	}
1228
1229	static struct rpc_auth *
1230	gss_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1231	{
1232	struct gss_auth *gss_auth;
1233	struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1234
1235	while (clnt != clnt->cl_parent) {
1236	struct rpc_clnt *parent = clnt->cl_parent;
1237	/* Find the original parent for this transport */
1238	if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1239	break;
1240	clnt = parent;
1241	}
1242
1243	gss_auth = gss_create_hashed(args, clnt);
1244	if (IS_ERR(ptr: gss_auth))
1245	return ERR_CAST(ptr: gss_auth);
1246	return &gss_auth->rpc_auth;
1247	}
1248
1249	static struct gss_cred *
1250	gss_dup_cred(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
1251	{
1252	struct gss_cred *new;
1253
1254	/* Make a copy of the cred so that we can reference count it */
1255	new = kzalloc(size: sizeof(*gss_cred), GFP_KERNEL);
1256	if (new) {
1257	struct auth_cred acred = {
1258	.cred = gss_cred->gc_base.cr_cred,
1259	};
1260	struct gss_cl_ctx *ctx =
1261	rcu_dereference_protected(gss_cred->gc_ctx, 1);
1262
1263	rpcauth_init_cred(&new->gc_base, &acred,
1264	&gss_auth->rpc_auth,
1265	&gss_nullops);
1266	new->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
1267	new->gc_service = gss_cred->gc_service;
1268	new->gc_principal = gss_cred->gc_principal;
1269	kref_get(kref: &gss_auth->kref);
1270	rcu_assign_pointer(new->gc_ctx, ctx);
1271	gss_get_ctx(ctx);
1272	}
1273	return new;
1274	}
1275
1276	/*
1277	* gss_send_destroy_context will cause the RPCSEC_GSS to send a NULL RPC call
1278	* to the server with the GSS control procedure field set to
1279	* RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1280	* all RPCSEC_GSS state associated with that context.
1281	*/
1282	static void
1283	gss_send_destroy_context(struct rpc_cred *cred)
1284	{
1285	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1286	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1287	struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1288	struct gss_cred *new;
1289	struct rpc_task *task;
1290
1291	new = gss_dup_cred(gss_auth, gss_cred);
1292	if (new) {
1293	ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1294
1295	trace_rpcgss_ctx_destroy(gc: gss_cred);
1296	task = rpc_call_null(clnt: gss_auth->client, cred: &new->gc_base,
1297	RPC_TASK_ASYNC);
1298	if (!IS_ERR(ptr: task))
1299	rpc_put_task(task);
1300
1301	put_rpccred(&new->gc_base);
1302	}
1303	}
1304
1305	/* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1306	* to create a new cred or context, so they check that things have been
1307	* allocated before freeing them. */
1308	static void
1309	gss_do_free_ctx(struct gss_cl_ctx *ctx)
1310	{
1311	gss_delete_sec_context(ctx_id: &ctx->gc_gss_ctx);
1312	kfree(objp: ctx->gc_wire_ctx.data);
1313	kfree(objp: ctx->gc_acceptor.data);
1314	kfree(objp: ctx);
1315	}
1316
1317	static void
1318	gss_free_ctx_callback(struct rcu_head *head)
1319	{
1320	struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1321	gss_do_free_ctx(ctx);
1322	}
1323
1324	static void
1325	gss_free_ctx(struct gss_cl_ctx *ctx)
1326	{
1327	call_rcu(head: &ctx->gc_rcu, func: gss_free_ctx_callback);
1328	}
1329
1330	static void
1331	gss_free_cred(struct gss_cred *gss_cred)
1332	{
1333	kfree(objp: gss_cred);
1334	}
1335
1336	static void
1337	gss_free_cred_callback(struct rcu_head *head)
1338	{
1339	struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1340	gss_free_cred(gss_cred);
1341	}
1342
1343	static void
1344	gss_destroy_nullcred(struct rpc_cred *cred)
1345	{
1346	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1347	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1348	struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1349
1350	RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1351	put_cred(cred: cred->cr_cred);
1352	call_rcu(head: &cred->cr_rcu, func: gss_free_cred_callback);
1353	if (ctx)
1354	gss_put_ctx(ctx);
1355	gss_put_auth(gss_auth);
1356	}
1357
1358	static void
1359	gss_destroy_cred(struct rpc_cred *cred)
1360	{
1361	if (test_and_clear_bit(RPCAUTH_CRED_UPTODATE, addr: &cred->cr_flags) != 0)
1362	gss_send_destroy_context(cred);
1363	gss_destroy_nullcred(cred);
1364	}
1365
1366	static int
1367	gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1368	{
1369	return hash_64(val: from_kuid(to: &init_user_ns, uid: acred->cred->fsuid), bits: hashbits);
1370	}
1371
1372	/*
1373	* Lookup RPCSEC_GSS cred for the current process
1374	*/
1375	static struct rpc_cred *gss_lookup_cred(struct rpc_auth *auth,
1376	struct auth_cred *acred, int flags)
1377	{
1378	return rpcauth_lookup_credcache(auth, acred, flags,
1379	rpc_task_gfp_mask());
1380	}
1381
1382	static struct rpc_cred *
1383	gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1384	{
1385	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1386	struct gss_cred *cred = NULL;
1387	int err = -ENOMEM;
1388
1389	if (!(cred = kzalloc(size: sizeof(*cred), flags: gfp)))
1390	goto out_err;
1391
1392	rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1393	/*
1394	* Note: in order to force a call to call_refresh(), we deliberately
1395	* fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1396	*/
1397	cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1398	cred->gc_service = gss_auth->service;
1399	cred->gc_principal = acred->principal;
1400	kref_get(kref: &gss_auth->kref);
1401	return &cred->gc_base;
1402
1403	out_err:
1404	return ERR_PTR(error: err);
1405	}
1406
1407	static int
1408	gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1409	{
1410	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1411	struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1412	int err;
1413
1414	do {
1415	err = gss_create_upcall(gss_auth, gss_cred);
1416	} while (err == -EAGAIN);
1417	return err;
1418	}
1419
1420	static char *
1421	gss_stringify_acceptor(struct rpc_cred *cred)
1422	{
1423	char *string = NULL;
1424	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1425	struct gss_cl_ctx *ctx;
1426	unsigned int len;
1427	struct xdr_netobj *acceptor;
1428
1429	rcu_read_lock();
1430	ctx = rcu_dereference(gss_cred->gc_ctx);
1431	if (!ctx)
1432	goto out;
1433
1434	len = ctx->gc_acceptor.len;
1435	rcu_read_unlock();
1436
1437	/* no point if there's no string */
1438	if (!len)
1439	return NULL;
1440	realloc:
1441	string = kmalloc(size: len + 1, GFP_KERNEL);
1442	if (!string)
1443	return NULL;
1444
1445	rcu_read_lock();
1446	ctx = rcu_dereference(gss_cred->gc_ctx);
1447
1448	/* did the ctx disappear or was it replaced by one with no acceptor? */
1449	if (!ctx || !ctx->gc_acceptor.len) {
1450	kfree(objp: string);
1451	string = NULL;
1452	goto out;
1453	}
1454
1455	acceptor = &ctx->gc_acceptor;
1456
1457	/*
1458	* Did we find a new acceptor that's longer than the original? Allocate
1459	* a longer buffer and try again.
1460	*/
1461	if (len < acceptor->len) {
1462	len = acceptor->len;
1463	rcu_read_unlock();
1464	kfree(objp: string);
1465	goto realloc;
1466	}
1467
1468	memcpy(string, acceptor->data, acceptor->len);
1469	string[acceptor->len] = '\0';
1470	out:
1471	rcu_read_unlock();
1472	return string;
1473	}
1474
1475	/*
1476	* Returns -EACCES if GSS context is NULL or will expire within the
1477	* timeout (miliseconds)
1478	*/
1479	static int
1480	gss_key_timeout(struct rpc_cred *rc)
1481	{
1482	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1483	struct gss_cl_ctx *ctx;
1484	unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1485	int ret = 0;
1486
1487	rcu_read_lock();
1488	ctx = rcu_dereference(gss_cred->gc_ctx);
1489	if (!ctx || time_after(timeout, ctx->gc_expiry))
1490	ret = -EACCES;
1491	rcu_read_unlock();
1492
1493	return ret;
1494	}
1495
1496	static int
1497	gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1498	{
1499	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1500	struct gss_cl_ctx *ctx;
1501	int ret;
1502
1503	if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1504	goto out;
1505	/* Don't match with creds that have expired. */
1506	rcu_read_lock();
1507	ctx = rcu_dereference(gss_cred->gc_ctx);
1508	if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1509	rcu_read_unlock();
1510	return 0;
1511	}
1512	rcu_read_unlock();
1513	if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1514	return 0;
1515	out:
1516	if (acred->principal != NULL) {
1517	if (gss_cred->gc_principal == NULL)
1518	return 0;
1519	ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1520	} else {
1521	if (gss_cred->gc_principal != NULL)
1522	return 0;
1523	ret = uid_eq(left: rc->cr_cred->fsuid, right: acred->cred->fsuid);
1524	}
1525	return ret;
1526	}
1527
1528	/*
1529	* Marshal credentials.
1530	*
1531	* The expensive part is computing the verifier. We can't cache a
1532	* pre-computed version of the verifier because the seqno, which
1533	* is different every time, is included in the MIC.
1534	*/
1535	static int gss_marshal(struct rpc_task *task, struct xdr_stream *xdr)
1536	{
1537	struct rpc_rqst *req = task->tk_rqstp;
1538	struct rpc_cred *cred = req->rq_cred;
1539	struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1540	gc_base);
1541	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1542	__be32 *p, *cred_len;
1543	u32 maj_stat = 0;
1544	struct xdr_netobj mic;
1545	struct kvec iov;
1546	struct xdr_buf verf_buf;
1547	int status;
1548
1549	/* Credential */
1550
1551	p = xdr_reserve_space(xdr, nbytes: 7 * sizeof(*p) +
1552	ctx->gc_wire_ctx.len);
1553	if (!p)
1554	goto marshal_failed;
1555	*p++ = rpc_auth_gss;
1556	cred_len = p++;
1557
1558	spin_lock(lock: &ctx->gc_seq_lock);
1559	req->rq_seqno = (ctx->gc_seq < MAXSEQ) ? ctx->gc_seq++ : MAXSEQ;
1560	spin_unlock(lock: &ctx->gc_seq_lock);
1561	if (req->rq_seqno == MAXSEQ)
1562	goto expired;
1563	trace_rpcgss_seqno(task);
1564
1565	*p++ = cpu_to_be32(RPC_GSS_VERSION);
1566	*p++ = cpu_to_be32(ctx->gc_proc);
1567	*p++ = cpu_to_be32(req->rq_seqno);
1568	*p++ = cpu_to_be32(gss_cred->gc_service);
1569	p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1570	*cred_len = cpu_to_be32((p - (cred_len + 1)) << 2);
1571
1572	/* Verifier */
1573
1574	/* We compute the checksum for the verifier over the xdr-encoded bytes
1575	* starting with the xid and ending at the end of the credential: */
1576	iov.iov_base = req->rq_snd_buf.head[0].iov_base;
1577	iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1578	xdr_buf_from_iov(&iov, &verf_buf);
1579
1580	p = xdr_reserve_space(xdr, nbytes: sizeof(*p));
1581	if (!p)
1582	goto marshal_failed;
1583	*p++ = rpc_auth_gss;
1584	mic.data = (u8 *)(p + 1);
1585	maj_stat = gss_get_mic(ctx_id: ctx->gc_gss_ctx, message: &verf_buf, mic_token: &mic);
1586	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1587	goto expired;
1588	else if (maj_stat != 0)
1589	goto bad_mic;
1590	if (xdr_stream_encode_opaque_inline(xdr, ptr: (void **)&p, len: mic.len) < 0)
1591	goto marshal_failed;
1592	status = 0;
1593	out:
1594	gss_put_ctx(ctx);
1595	return status;
1596	expired:
1597	clear_bit(RPCAUTH_CRED_UPTODATE, addr: &cred->cr_flags);
1598	status = -EKEYEXPIRED;
1599	goto out;
1600	marshal_failed:
1601	status = -EMSGSIZE;
1602	goto out;
1603	bad_mic:
1604	trace_rpcgss_get_mic(task, maj_stat);
1605	status = -EIO;
1606	goto out;
1607	}
1608
1609	static int gss_renew_cred(struct rpc_task *task)
1610	{
1611	struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1612	struct gss_cred *gss_cred = container_of(oldcred,
1613	struct gss_cred,
1614	gc_base);
1615	struct rpc_auth *auth = oldcred->cr_auth;
1616	struct auth_cred acred = {
1617	.cred = oldcred->cr_cred,
1618	.principal = gss_cred->gc_principal,
1619	};
1620	struct rpc_cred *new;
1621
1622	new = gss_lookup_cred(auth, acred: &acred, RPCAUTH_LOOKUP_NEW);
1623	if (IS_ERR(ptr: new))
1624	return PTR_ERR(ptr: new);
1625
1626	task->tk_rqstp->rq_cred = new;
1627	put_rpccred(oldcred);
1628	return 0;
1629	}
1630
1631	static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1632	{
1633	if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1634	unsigned long now = jiffies;
1635	unsigned long begin, expire;
1636	struct gss_cred *gss_cred;
1637
1638	gss_cred = container_of(cred, struct gss_cred, gc_base);
1639	begin = gss_cred->gc_upcall_timestamp;
1640	expire = begin + gss_expired_cred_retry_delay * HZ;
1641
1642	if (time_in_range_open(now, begin, expire))
1643	return 1;
1644	}
1645	return 0;
1646	}
1647
1648	/*
1649	* Refresh credentials. XXX - finish
1650	*/
1651	static int
1652	gss_refresh(struct rpc_task *task)
1653	{
1654	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1655	int ret = 0;
1656
1657	if (gss_cred_is_negative_entry(cred))
1658	return -EKEYEXPIRED;
1659
1660	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1661	!test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1662	ret = gss_renew_cred(task);
1663	if (ret < 0)
1664	goto out;
1665	cred = task->tk_rqstp->rq_cred;
1666	}
1667
1668	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1669	ret = gss_refresh_upcall(task);
1670	out:
1671	return ret;
1672	}
1673
1674	/* Dummy refresh routine: used only when destroying the context */
1675	static int
1676	gss_refresh_null(struct rpc_task *task)
1677	{
1678	return 0;
1679	}
1680
1681	static int
1682	gss_validate(struct rpc_task *task, struct xdr_stream *xdr)
1683	{
1684	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1685	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1686	__be32 *p, *seq = NULL;
1687	struct kvec iov;
1688	struct xdr_buf verf_buf;
1689	struct xdr_netobj mic;
1690	u32 len, maj_stat;
1691	int status;
1692
1693	p = xdr_inline_decode(xdr, nbytes: 2 * sizeof(*p));
1694	if (!p)
1695	goto validate_failed;
1696	if (*p++ != rpc_auth_gss)
1697	goto validate_failed;
1698	len = be32_to_cpup(p);
1699	if (len > RPC_MAX_AUTH_SIZE)
1700	goto validate_failed;
1701	p = xdr_inline_decode(xdr, nbytes: len);
1702	if (!p)
1703	goto validate_failed;
1704
1705	seq = kmalloc(size: 4, GFP_KERNEL);
1706	if (!seq)
1707	goto validate_failed;
1708	*seq = cpu_to_be32(task->tk_rqstp->rq_seqno);
1709	iov.iov_base = seq;
1710	iov.iov_len = 4;
1711	xdr_buf_from_iov(&iov, &verf_buf);
1712	mic.data = (u8 *)p;
1713	mic.len = len;
1714	maj_stat = gss_verify_mic(ctx_id: ctx->gc_gss_ctx, message: &verf_buf, mic_token: &mic);
1715	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1716	clear_bit(RPCAUTH_CRED_UPTODATE, addr: &cred->cr_flags);
1717	if (maj_stat)
1718	goto bad_mic;
1719
1720	/* We leave it to unwrap to calculate au_rslack. For now we just
1721	* calculate the length of the verifier: */
1722	if (test_bit(RPCAUTH_AUTH_UPDATE_SLACK, &cred->cr_auth->au_flags))
1723	cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
1724	status = 0;
1725	out:
1726	gss_put_ctx(ctx);
1727	kfree(objp: seq);
1728	return status;
1729
1730	validate_failed:
1731	status = -EIO;
1732	goto out;
1733	bad_mic:
1734	trace_rpcgss_verify_mic(task, maj_stat);
1735	status = -EACCES;
1736	goto out;
1737	}
1738
1739	static noinline_for_stack int
1740	gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1741	struct rpc_task *task, struct xdr_stream *xdr)
1742	{
1743	struct rpc_rqst *rqstp = task->tk_rqstp;
1744	struct xdr_buf integ_buf, *snd_buf = &rqstp->rq_snd_buf;
1745	struct xdr_netobj mic;
1746	__be32 *p, *integ_len;
1747	u32 offset, maj_stat;
1748
1749	p = xdr_reserve_space(xdr, nbytes: 2 * sizeof(*p));
1750	if (!p)
1751	goto wrap_failed;
1752	integ_len = p++;
1753	*p = cpu_to_be32(rqstp->rq_seqno);
1754
1755	if (rpcauth_wrap_req_encode(task, xdr))
1756	goto wrap_failed;
1757
1758	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1759	if (xdr_buf_subsegment(snd_buf, &integ_buf,
1760	offset, snd_buf->len - offset))
1761	goto wrap_failed;
1762	*integ_len = cpu_to_be32(integ_buf.len);
1763
1764	p = xdr_reserve_space(xdr, nbytes: 0);
1765	if (!p)
1766	goto wrap_failed;
1767	mic.data = (u8 *)(p + 1);
1768	maj_stat = gss_get_mic(ctx_id: ctx->gc_gss_ctx, message: &integ_buf, mic_token: &mic);
1769	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1770	clear_bit(RPCAUTH_CRED_UPTODATE, addr: &cred->cr_flags);
1771	else if (maj_stat)
1772	goto bad_mic;
1773	/* Check that the trailing MIC fit in the buffer, after the fact */
1774	if (xdr_stream_encode_opaque_inline(xdr, ptr: (void **)&p, len: mic.len) < 0)
1775	goto wrap_failed;
1776	return 0;
1777	wrap_failed:
1778	return -EMSGSIZE;
1779	bad_mic:
1780	trace_rpcgss_get_mic(task, maj_stat);
1781	return -EIO;
1782	}
1783
1784	static void
1785	priv_release_snd_buf(struct rpc_rqst *rqstp)
1786	{
1787	int i;
1788
1789	for (i=0; i < rqstp->rq_enc_pages_num; i++)
1790	__free_page(rqstp->rq_enc_pages[i]);
1791	kfree(objp: rqstp->rq_enc_pages);
1792	rqstp->rq_release_snd_buf = NULL;
1793	}
1794
1795	static int
1796	alloc_enc_pages(struct rpc_rqst *rqstp)
1797	{
1798	struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1799	int first, last, i;
1800
1801	if (rqstp->rq_release_snd_buf)
1802	rqstp->rq_release_snd_buf(rqstp);
1803
1804	if (snd_buf->page_len == 0) {
1805	rqstp->rq_enc_pages_num = 0;
1806	return 0;
1807	}
1808
1809	first = snd_buf->page_base >> PAGE_SHIFT;
1810	last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1811	rqstp->rq_enc_pages_num = last - first + 1 + 1;
1812	rqstp->rq_enc_pages
1813	= kmalloc_array(n: rqstp->rq_enc_pages_num,
1814	size: sizeof(struct page *),
1815	GFP_KERNEL);
1816	if (!rqstp->rq_enc_pages)
1817	goto out;
1818	for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1819	rqstp->rq_enc_pages[i] = alloc_page(GFP_KERNEL);
1820	if (rqstp->rq_enc_pages[i] == NULL)
1821	goto out_free;
1822	}
1823	rqstp->rq_release_snd_buf = priv_release_snd_buf;
1824	return 0;
1825	out_free:
1826	rqstp->rq_enc_pages_num = i;
1827	priv_release_snd_buf(rqstp);
1828	out:
1829	return -EAGAIN;
1830	}
1831
1832	static noinline_for_stack int
1833	gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1834	struct rpc_task *task, struct xdr_stream *xdr)
1835	{
1836	struct rpc_rqst *rqstp = task->tk_rqstp;
1837	struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1838	u32 pad, offset, maj_stat;
1839	int status;
1840	__be32 *p, *opaque_len;
1841	struct page **inpages;
1842	int first;
1843	struct kvec *iov;
1844
1845	status = -EIO;
1846	p = xdr_reserve_space(xdr, nbytes: 2 * sizeof(*p));
1847	if (!p)
1848	goto wrap_failed;
1849	opaque_len = p++;
1850	*p = cpu_to_be32(rqstp->rq_seqno);
1851
1852	if (rpcauth_wrap_req_encode(task, xdr))
1853	goto wrap_failed;
1854
1855	status = alloc_enc_pages(rqstp);
1856	if (unlikely(status))
1857	goto wrap_failed;
1858	first = snd_buf->page_base >> PAGE_SHIFT;
1859	inpages = snd_buf->pages + first;
1860	snd_buf->pages = rqstp->rq_enc_pages;
1861	snd_buf->page_base -= first << PAGE_SHIFT;
1862	/*
1863	* Move the tail into its own page, in case gss_wrap needs
1864	* more space in the head when wrapping.
1865	*
1866	* Still... Why can't gss_wrap just slide the tail down?
1867	*/
1868	if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1869	char *tmp;
1870
1871	tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1872	memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1873	snd_buf->tail[0].iov_base = tmp;
1874	}
1875	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1876	maj_stat = gss_wrap(ctx_id: ctx->gc_gss_ctx, offset, outbuf: snd_buf, inpages);
1877	/* slack space should prevent this ever happening: */
1878	if (unlikely(snd_buf->len > snd_buf->buflen))
1879	goto wrap_failed;
1880	/* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1881	* done anyway, so it's safe to put the request on the wire: */
1882	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1883	clear_bit(RPCAUTH_CRED_UPTODATE, addr: &cred->cr_flags);
1884	else if (maj_stat)
1885	goto bad_wrap;
1886
1887	*opaque_len = cpu_to_be32(snd_buf->len - offset);
1888	/* guess whether the pad goes into the head or the tail: */
1889	if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1890	iov = snd_buf->tail;
1891	else
1892	iov = snd_buf->head;
1893	p = iov->iov_base + iov->iov_len;
1894	pad = xdr_pad_size(n: snd_buf->len - offset);
1895	memset(p, 0, pad);
1896	iov->iov_len += pad;
1897	snd_buf->len += pad;
1898
1899	return 0;
1900	wrap_failed:
1901	return status;
1902	bad_wrap:
1903	trace_rpcgss_wrap(task, maj_stat);
1904	return -EIO;
1905	}
1906
1907	static int gss_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
1908	{
1909	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1910	struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
1911	gc_base);
1912	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1913	int status;
1914
1915	status = -EIO;
1916	if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1917	/* The spec seems a little ambiguous here, but I think that not
1918	* wrapping context destruction requests makes the most sense.
1919	*/
1920	status = rpcauth_wrap_req_encode(task, xdr);
1921	goto out;
1922	}
1923	switch (gss_cred->gc_service) {
1924	case RPC_GSS_SVC_NONE:
1925	status = rpcauth_wrap_req_encode(task, xdr);
1926	break;
1927	case RPC_GSS_SVC_INTEGRITY:
1928	status = gss_wrap_req_integ(cred, ctx, task, xdr);
1929	break;
1930	case RPC_GSS_SVC_PRIVACY:
1931	status = gss_wrap_req_priv(cred, ctx, task, xdr);
1932	break;
1933	default:
1934	status = -EIO;
1935	}
1936	out:
1937	gss_put_ctx(ctx);
1938	return status;
1939	}
1940
1941	/**
1942	* gss_update_rslack - Possibly update RPC receive buffer size estimates
1943	* @task: rpc_task for incoming RPC Reply being unwrapped
1944	* @cred: controlling rpc_cred for @task
1945	* @before: XDR words needed before each RPC Reply message
1946	* @after: XDR words needed following each RPC Reply message
1947	*
1948	*/
1949	static void gss_update_rslack(struct rpc_task *task, struct rpc_cred *cred,
1950	unsigned int before, unsigned int after)
1951	{
1952	struct rpc_auth *auth = cred->cr_auth;
1953
1954	if (test_and_clear_bit(RPCAUTH_AUTH_UPDATE_SLACK, addr: &auth->au_flags)) {
1955	auth->au_ralign = auth->au_verfsize + before;
1956	auth->au_rslack = auth->au_verfsize + after;
1957	trace_rpcgss_update_slack(task, auth);
1958	}
1959	}
1960
1961	static int
1962	gss_unwrap_resp_auth(struct rpc_task *task, struct rpc_cred *cred)
1963	{
1964	gss_update_rslack(task, cred, before: 0, after: 0);
1965	return 0;
1966	}
1967
1968	/*
1969	* RFC 2203, Section 5.3.2.2
1970	*
1971	* struct rpc_gss_integ_data {
1972	* opaque databody_integ<>;
1973	* opaque checksum<>;
1974	* };
1975	*
1976	* struct rpc_gss_data_t {
1977	* unsigned int seq_num;
1978	* proc_req_arg_t arg;
1979	* };
1980	*/
1981	static noinline_for_stack int
1982	gss_unwrap_resp_integ(struct rpc_task *task, struct rpc_cred *cred,
1983	struct gss_cl_ctx *ctx, struct rpc_rqst *rqstp,
1984	struct xdr_stream *xdr)
1985	{
1986	struct xdr_buf gss_data, *rcv_buf = &rqstp->rq_rcv_buf;
1987	u32 len, offset, seqno, maj_stat;
1988	struct xdr_netobj mic;
1989	int ret;
1990
1991	ret = -EIO;
1992	mic.data = NULL;
1993
1994	/* opaque databody_integ<>; */
1995	if (xdr_stream_decode_u32(xdr, ptr: &len))
1996	goto unwrap_failed;
1997	if (len & 3)
1998	goto unwrap_failed;
1999	offset = rcv_buf->len - xdr_stream_remaining(xdr);
2000	if (xdr_stream_decode_u32(xdr, ptr: &seqno))
2001	goto unwrap_failed;
2002	if (seqno != rqstp->rq_seqno)
2003	goto bad_seqno;
2004	if (xdr_buf_subsegment(rcv_buf, &gss_data, offset, len))
2005	goto unwrap_failed;
2006
2007	/*
2008	* The xdr_stream now points to the beginning of the
2009	* upper layer payload, to be passed below to
2010	* rpcauth_unwrap_resp_decode(). The checksum, which
2011	* follows the upper layer payload in @rcv_buf, is
2012	* located and parsed without updating the xdr_stream.
2013	*/
2014
2015	/* opaque checksum<>; */
2016	offset += len;
2017	if (xdr_decode_word(rcv_buf, offset, &len))
2018	goto unwrap_failed;
2019	offset += sizeof(__be32);
2020	if (offset + len > rcv_buf->len)
2021	goto unwrap_failed;
2022	mic.len = len;
2023	mic.data = kmalloc(size: len, GFP_KERNEL);
2024	if (ZERO_OR_NULL_PTR(mic.data))
2025	goto unwrap_failed;
2026	if (read_bytes_from_xdr_buf(rcv_buf, offset, mic.data, mic.len))
2027	goto unwrap_failed;
2028
2029	maj_stat = gss_verify_mic(ctx_id: ctx->gc_gss_ctx, message: &gss_data, mic_token: &mic);
2030	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
2031	clear_bit(RPCAUTH_CRED_UPTODATE, addr: &cred->cr_flags);
2032	if (maj_stat != GSS_S_COMPLETE)
2033	goto bad_mic;
2034
2035	gss_update_rslack(task, cred, before: 2, after: 2 + 1 + XDR_QUADLEN(mic.len));
2036	ret = 0;
2037
2038	out:
2039	kfree(objp: mic.data);
2040	return ret;
2041
2042	unwrap_failed:
2043	trace_rpcgss_unwrap_failed(task);
2044	goto out;
2045	bad_seqno:
2046	trace_rpcgss_bad_seqno(task, expected: rqstp->rq_seqno, received: seqno);
2047	goto out;
2048	bad_mic:
2049	trace_rpcgss_verify_mic(task, maj_stat);
2050	goto out;
2051	}
2052
2053	static noinline_for_stack int
2054	gss_unwrap_resp_priv(struct rpc_task *task, struct rpc_cred *cred,
2055	struct gss_cl_ctx *ctx, struct rpc_rqst *rqstp,
2056	struct xdr_stream *xdr)
2057	{
2058	struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf;
2059	struct kvec *head = rqstp->rq_rcv_buf.head;
2060	u32 offset, opaque_len, maj_stat;
2061	__be32 *p;
2062
2063	p = xdr_inline_decode(xdr, nbytes: 2 * sizeof(*p));
2064	if (unlikely(!p))
2065	goto unwrap_failed;
2066	opaque_len = be32_to_cpup(p: p++);
2067	offset = (u8 *)(p) - (u8 *)head->iov_base;
2068	if (offset + opaque_len > rcv_buf->len)
2069	goto unwrap_failed;
2070
2071	maj_stat = gss_unwrap(ctx_id: ctx->gc_gss_ctx, offset,
2072	len: offset + opaque_len, inbuf: rcv_buf);
2073	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
2074	clear_bit(RPCAUTH_CRED_UPTODATE, addr: &cred->cr_flags);
2075	if (maj_stat != GSS_S_COMPLETE)
2076	goto bad_unwrap;
2077	/* gss_unwrap decrypted the sequence number */
2078	if (be32_to_cpup(p: p++) != rqstp->rq_seqno)
2079	goto bad_seqno;
2080
2081	/* gss_unwrap redacts the opaque blob from the head iovec.
2082	* rcv_buf has changed, thus the stream needs to be reset.
2083	*/
2084	xdr_init_decode(xdr, buf: rcv_buf, p, rqst: rqstp);
2085
2086	gss_update_rslack(task, cred, before: 2 + ctx->gc_gss_ctx->align,
2087	after: 2 + ctx->gc_gss_ctx->slack);
2088
2089	return 0;
2090	unwrap_failed:
2091	trace_rpcgss_unwrap_failed(task);
2092	return -EIO;
2093	bad_seqno:
2094	trace_rpcgss_bad_seqno(task, expected: rqstp->rq_seqno, be32_to_cpup(p: --p));
2095	return -EIO;
2096	bad_unwrap:
2097	trace_rpcgss_unwrap(task, maj_stat);
2098	return -EIO;
2099	}
2100
2101	static bool
2102	gss_seq_is_newer(u32 new, u32 old)
2103	{
2104	return (s32)(new - old) > 0;
2105	}
2106
2107	static bool
2108	gss_xmit_need_reencode(struct rpc_task *task)
2109	{
2110	struct rpc_rqst *req = task->tk_rqstp;
2111	struct rpc_cred *cred = req->rq_cred;
2112	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
2113	u32 win, seq_xmit = 0;
2114	bool ret = true;
2115
2116	if (!ctx)
2117	goto out;
2118
2119	if (gss_seq_is_newer(new: req->rq_seqno, READ_ONCE(ctx->gc_seq)))
2120	goto out_ctx;
2121
2122	seq_xmit = READ_ONCE(ctx->gc_seq_xmit);
2123	while (gss_seq_is_newer(new: req->rq_seqno, old: seq_xmit)) {
2124	u32 tmp = seq_xmit;
2125
2126	seq_xmit = cmpxchg(&ctx->gc_seq_xmit, tmp, req->rq_seqno);
2127	if (seq_xmit == tmp) {
2128	ret = false;
2129	goto out_ctx;
2130	}
2131	}
2132
2133	win = ctx->gc_win;
2134	if (win > 0)
2135	ret = !gss_seq_is_newer(new: req->rq_seqno, old: seq_xmit - win);
2136
2137	out_ctx:
2138	gss_put_ctx(ctx);
2139	out:
2140	trace_rpcgss_need_reencode(task, seq_xmit, ret);
2141	return ret;
2142	}
2143
2144	static int
2145	gss_unwrap_resp(struct rpc_task *task, struct xdr_stream *xdr)
2146	{
2147	struct rpc_rqst *rqstp = task->tk_rqstp;
2148	struct rpc_cred *cred = rqstp->rq_cred;
2149	struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
2150	gc_base);
2151	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
2152	int status = -EIO;
2153
2154	if (ctx->gc_proc != RPC_GSS_PROC_DATA)
2155	goto out_decode;
2156	switch (gss_cred->gc_service) {
2157	case RPC_GSS_SVC_NONE:
2158	status = gss_unwrap_resp_auth(task, cred);
2159	break;
2160	case RPC_GSS_SVC_INTEGRITY:
2161	status = gss_unwrap_resp_integ(task, cred, ctx, rqstp, xdr);
2162	break;
2163	case RPC_GSS_SVC_PRIVACY:
2164	status = gss_unwrap_resp_priv(task, cred, ctx, rqstp, xdr);
2165	break;
2166	}
2167	if (status)
2168	goto out;
2169
2170	out_decode:
2171	status = rpcauth_unwrap_resp_decode(task, xdr);
2172	out:
2173	gss_put_ctx(ctx);
2174	return status;
2175	}
2176
2177	static const struct rpc_authops authgss_ops = {
2178	.owner = THIS_MODULE,
2179	.au_flavor = RPC_AUTH_GSS,
2180	.au_name = "RPCSEC_GSS",
2181	.create = gss_create,
2182	.destroy = gss_destroy,
2183	.hash_cred = gss_hash_cred,
2184	.lookup_cred = gss_lookup_cred,
2185	.crcreate = gss_create_cred,
2186	.info2flavor = gss_mech_info2flavor,
2187	.flavor2info = gss_mech_flavor2info,
2188	};
2189
2190	static const struct rpc_credops gss_credops = {
2191	.cr_name = "AUTH_GSS",
2192	.crdestroy = gss_destroy_cred,
2193	.cr_init = gss_cred_init,
2194	.crmatch = gss_match,
2195	.crmarshal = gss_marshal,
2196	.crrefresh = gss_refresh,
2197	.crvalidate = gss_validate,
2198	.crwrap_req = gss_wrap_req,
2199	.crunwrap_resp = gss_unwrap_resp,
2200	.crkey_timeout = gss_key_timeout,
2201	.crstringify_acceptor = gss_stringify_acceptor,
2202	.crneed_reencode = gss_xmit_need_reencode,
2203	};
2204
2205	static const struct rpc_credops gss_nullops = {
2206	.cr_name = "AUTH_GSS",
2207	.crdestroy = gss_destroy_nullcred,
2208	.crmatch = gss_match,
2209	.crmarshal = gss_marshal,
2210	.crrefresh = gss_refresh_null,
2211	.crvalidate = gss_validate,
2212	.crwrap_req = gss_wrap_req,
2213	.crunwrap_resp = gss_unwrap_resp,
2214	.crstringify_acceptor = gss_stringify_acceptor,
2215	};
2216
2217	static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2218	.upcall = gss_v0_upcall,
2219	.downcall = gss_pipe_downcall,
2220	.destroy_msg = gss_pipe_destroy_msg,
2221	.open_pipe = gss_pipe_open_v0,
2222	.release_pipe = gss_pipe_release,
2223	};
2224
2225	static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2226	.upcall = gss_v1_upcall,
2227	.downcall = gss_pipe_downcall,
2228	.destroy_msg = gss_pipe_destroy_msg,
2229	.open_pipe = gss_pipe_open_v1,
2230	.release_pipe = gss_pipe_release,
2231	};
2232
2233	static __net_init int rpcsec_gss_init_net(struct net *net)
2234	{
2235	return gss_svc_init_net(net);
2236	}
2237
2238	static __net_exit void rpcsec_gss_exit_net(struct net *net)
2239	{
2240	gss_svc_shutdown_net(net);
2241	}
2242
2243	static struct pernet_operations rpcsec_gss_net_ops = {
2244	.init = rpcsec_gss_init_net,
2245	.exit = rpcsec_gss_exit_net,
2246	};
2247
2248	/*
2249	* Initialize RPCSEC_GSS module
2250	*/
2251	static int __init init_rpcsec_gss(void)
2252	{
2253	int err = 0;
2254
2255	err = rpcauth_register(&authgss_ops);
2256	if (err)
2257	goto out;
2258	err = gss_svc_init();
2259	if (err)
2260	goto out_unregister;
2261	err = register_pernet_subsys(&rpcsec_gss_net_ops);
2262	if (err)
2263	goto out_svc_exit;
2264	rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2265	return 0;
2266	out_svc_exit:
2267	gss_svc_shutdown();
2268	out_unregister:
2269	rpcauth_unregister(&authgss_ops);
2270	out:
2271	return err;
2272	}
2273
2274	static void __exit exit_rpcsec_gss(void)
2275	{
2276	unregister_pernet_subsys(&rpcsec_gss_net_ops);
2277	gss_svc_shutdown();
2278	rpcauth_unregister(&authgss_ops);
2279	rcu_barrier(); /* Wait for completion of call_rcu()'s */
2280	}
2281
2282	MODULE_ALIAS("rpc-auth-6");
2283	MODULE_DESCRIPTION("Sun RPC Kerberos RPCSEC_GSS client authentication");
2284	MODULE_LICENSE("GPL");
2285	module_param_named(expired_cred_retry_delay,
2286	gss_expired_cred_retry_delay,
2287	uint, 0644);
2288	MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2289	"the RPC engine retries an expired credential");
2290
2291	module_param_named(key_expire_timeo,
2292	gss_key_expire_timeo,
2293	uint, 0644);
2294	MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2295	"credential keys lifetime where the NFS layer cleans up "
2296	"prior to key expiration");
2297
2298	module_init(init_rpcsec_gss)
2299	module_exit(exit_rpcsec_gss)
2300