xref: /linux/net/sunrpc/auth_gss/svcauth_gss.c (revision c5288cda69ee2d8607f5026bd599a5cebf0ee783)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Neil Brown <neilb@cse.unsw.edu.au>
4  * J. Bruce Fields <bfields@umich.edu>
5  * Andy Adamson <andros@umich.edu>
6  * Dug Song <dugsong@monkey.org>
7  *
8  * RPCSEC_GSS server authentication.
9  * This implements RPCSEC_GSS as defined in rfc2203 (rpcsec_gss) and rfc2078
10  * (gssapi)
11  *
12  * The RPCSEC_GSS involves three stages:
13  *  1/ context creation
14  *  2/ data exchange
15  *  3/ context destruction
16  *
17  * Context creation is handled largely by upcalls to user-space.
18  *  In particular, GSS_Accept_sec_context is handled by an upcall
19  * Data exchange is handled entirely within the kernel
20  *  In particular, GSS_GetMIC, GSS_VerifyMIC, GSS_Seal, GSS_Unseal are in-kernel.
21  * Context destruction is handled in-kernel
22  *  GSS_Delete_sec_context is in-kernel
23  *
24  * Context creation is initiated by a RPCSEC_GSS_INIT request arriving.
25  * The context handle and gss_token are used as a key into the rpcsec_init cache.
26  * The content of this cache includes some of the outputs of GSS_Accept_sec_context,
27  * being major_status, minor_status, context_handle, reply_token.
28  * These are sent back to the client.
29  * Sequence window management is handled by the kernel.  The window size if currently
30  * a compile time constant.
31  *
32  * When user-space is happy that a context is established, it places an entry
33  * in the rpcsec_context cache. The key for this cache is the context_handle.
34  * The content includes:
35  *   uid/gidlist - for determining access rights
36  *   mechanism type
37  *   mechanism specific information, such as a key
38  *
39  */
40 
41 #include <linux/slab.h>
42 #include <linux/types.h>
43 #include <linux/module.h>
44 #include <linux/pagemap.h>
45 #include <linux/user_namespace.h>
46 
47 #include <linux/sunrpc/auth_gss.h>
48 #include <linux/sunrpc/gss_err.h>
49 #include <linux/sunrpc/svcauth.h>
50 #include <linux/sunrpc/svcauth_gss.h>
51 #include <linux/sunrpc/cache.h>
52 #include <linux/sunrpc/gss_krb5.h>
53 
54 #include <trace/events/rpcgss.h>
55 
56 #include "gss_rpc_upcall.h"
57 
58 /*
59  * Unfortunately there isn't a maximum checksum size exported via the
60  * GSS API. Manufacture one based on GSS mechanisms supported by this
61  * implementation.
62  */
63 #define GSS_MAX_CKSUMSIZE (GSS_KRB5_TOK_HDR_LEN + GSS_KRB5_MAX_CKSUM_LEN)
64 
65 /*
66  * This value may be increased in the future to accommodate other
67  * usage of the scratch buffer.
68  */
69 #define GSS_SCRATCH_SIZE GSS_MAX_CKSUMSIZE
70 
71 struct gss_svc_data {
72 	/* decoded gss client cred: */
73 	struct rpc_gss_wire_cred	clcred;
74 	u32				gsd_databody_offset;
75 	struct rsc			*rsci;
76 
77 	/* for temporary results */
78 	__be32				gsd_seq_num;
79 	u8				gsd_scratch[GSS_SCRATCH_SIZE];
80 };
81 
82 /* The rpcsec_init cache is used for mapping RPCSEC_GSS_{,CONT_}INIT requests
83  * into replies.
84  *
85  * Key is context handle (\x if empty) and gss_token.
86  * Content is major_status minor_status (integers) context_handle, reply_token.
87  *
88  */
89 
90 static int netobj_equal(struct xdr_netobj *a, struct xdr_netobj *b)
91 {
92 	return a->len == b->len && 0 == memcmp(a->data, b->data, a->len);
93 }
94 
95 #define	RSI_HASHBITS	6
96 #define	RSI_HASHMAX	(1<<RSI_HASHBITS)
97 
98 struct rsi {
99 	struct cache_head	h;
100 	struct xdr_netobj	in_handle, in_token;
101 	struct xdr_netobj	out_handle, out_token;
102 	int			major_status, minor_status;
103 	struct rcu_head		rcu_head;
104 };
105 
106 static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old);
107 static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item);
108 
109 static void rsi_free(struct rsi *rsii)
110 {
111 	kfree(rsii->in_handle.data);
112 	kfree(rsii->in_token.data);
113 	kfree(rsii->out_handle.data);
114 	kfree(rsii->out_token.data);
115 }
116 
117 static void rsi_free_rcu(struct rcu_head *head)
118 {
119 	struct rsi *rsii = container_of(head, struct rsi, rcu_head);
120 
121 	rsi_free(rsii);
122 	kfree(rsii);
123 }
124 
125 static void rsi_put(struct kref *ref)
126 {
127 	struct rsi *rsii = container_of(ref, struct rsi, h.ref);
128 
129 	call_rcu(&rsii->rcu_head, rsi_free_rcu);
130 }
131 
132 static inline int rsi_hash(struct rsi *item)
133 {
134 	return hash_mem(item->in_handle.data, item->in_handle.len, RSI_HASHBITS)
135 	     ^ hash_mem(item->in_token.data, item->in_token.len, RSI_HASHBITS);
136 }
137 
138 static int rsi_match(struct cache_head *a, struct cache_head *b)
139 {
140 	struct rsi *item = container_of(a, struct rsi, h);
141 	struct rsi *tmp = container_of(b, struct rsi, h);
142 	return netobj_equal(&item->in_handle, &tmp->in_handle) &&
143 	       netobj_equal(&item->in_token, &tmp->in_token);
144 }
145 
146 static int dup_to_netobj(struct xdr_netobj *dst, char *src, int len)
147 {
148 	dst->len = len;
149 	dst->data = (len ? kmemdup(src, len, GFP_KERNEL) : NULL);
150 	if (len && !dst->data)
151 		return -ENOMEM;
152 	return 0;
153 }
154 
155 static inline int dup_netobj(struct xdr_netobj *dst, struct xdr_netobj *src)
156 {
157 	return dup_to_netobj(dst, src->data, src->len);
158 }
159 
160 static void rsi_init(struct cache_head *cnew, struct cache_head *citem)
161 {
162 	struct rsi *new = container_of(cnew, struct rsi, h);
163 	struct rsi *item = container_of(citem, struct rsi, h);
164 
165 	new->out_handle.data = NULL;
166 	new->out_handle.len = 0;
167 	new->out_token.data = NULL;
168 	new->out_token.len = 0;
169 	new->in_handle.len = item->in_handle.len;
170 	item->in_handle.len = 0;
171 	new->in_token.len = item->in_token.len;
172 	item->in_token.len = 0;
173 	new->in_handle.data = item->in_handle.data;
174 	item->in_handle.data = NULL;
175 	new->in_token.data = item->in_token.data;
176 	item->in_token.data = NULL;
177 }
178 
179 static void update_rsi(struct cache_head *cnew, struct cache_head *citem)
180 {
181 	struct rsi *new = container_of(cnew, struct rsi, h);
182 	struct rsi *item = container_of(citem, struct rsi, h);
183 
184 	BUG_ON(new->out_handle.data || new->out_token.data);
185 	new->out_handle.len = item->out_handle.len;
186 	item->out_handle.len = 0;
187 	new->out_token.len = item->out_token.len;
188 	item->out_token.len = 0;
189 	new->out_handle.data = item->out_handle.data;
190 	item->out_handle.data = NULL;
191 	new->out_token.data = item->out_token.data;
192 	item->out_token.data = NULL;
193 
194 	new->major_status = item->major_status;
195 	new->minor_status = item->minor_status;
196 }
197 
198 static struct cache_head *rsi_alloc(void)
199 {
200 	struct rsi *rsii = kmalloc(sizeof(*rsii), GFP_KERNEL);
201 	if (rsii)
202 		return &rsii->h;
203 	else
204 		return NULL;
205 }
206 
207 static int rsi_upcall(struct cache_detail *cd, struct cache_head *h)
208 {
209 	return sunrpc_cache_pipe_upcall_timeout(cd, h);
210 }
211 
212 static void rsi_request(struct cache_detail *cd,
213 		       struct cache_head *h,
214 		       char **bpp, int *blen)
215 {
216 	struct rsi *rsii = container_of(h, struct rsi, h);
217 
218 	qword_addhex(bpp, blen, rsii->in_handle.data, rsii->in_handle.len);
219 	qword_addhex(bpp, blen, rsii->in_token.data, rsii->in_token.len);
220 	(*bpp)[-1] = '\n';
221 	WARN_ONCE(*blen < 0,
222 		  "RPCSEC/GSS credential too large - please use gssproxy\n");
223 }
224 
225 static int rsi_parse(struct cache_detail *cd,
226 		    char *mesg, int mlen)
227 {
228 	/* context token expiry major minor context token */
229 	char *buf = mesg;
230 	char *ep;
231 	int len;
232 	struct rsi rsii, *rsip = NULL;
233 	time64_t expiry;
234 	int status = -EINVAL;
235 
236 	memset(&rsii, 0, sizeof(rsii));
237 	/* handle */
238 	len = qword_get(&mesg, buf, mlen);
239 	if (len < 0)
240 		goto out;
241 	status = -ENOMEM;
242 	if (dup_to_netobj(&rsii.in_handle, buf, len))
243 		goto out;
244 
245 	/* token */
246 	len = qword_get(&mesg, buf, mlen);
247 	status = -EINVAL;
248 	if (len < 0)
249 		goto out;
250 	status = -ENOMEM;
251 	if (dup_to_netobj(&rsii.in_token, buf, len))
252 		goto out;
253 
254 	rsip = rsi_lookup(cd, &rsii);
255 	if (!rsip)
256 		goto out;
257 
258 	rsii.h.flags = 0;
259 	/* expiry */
260 	status = get_expiry(&mesg, &expiry);
261 	if (status)
262 		goto out;
263 
264 	status = -EINVAL;
265 	/* major/minor */
266 	len = qword_get(&mesg, buf, mlen);
267 	if (len <= 0)
268 		goto out;
269 	rsii.major_status = simple_strtoul(buf, &ep, 10);
270 	if (*ep)
271 		goto out;
272 	len = qword_get(&mesg, buf, mlen);
273 	if (len <= 0)
274 		goto out;
275 	rsii.minor_status = simple_strtoul(buf, &ep, 10);
276 	if (*ep)
277 		goto out;
278 
279 	/* out_handle */
280 	len = qword_get(&mesg, buf, mlen);
281 	if (len < 0)
282 		goto out;
283 	status = -ENOMEM;
284 	if (dup_to_netobj(&rsii.out_handle, buf, len))
285 		goto out;
286 
287 	/* out_token */
288 	len = qword_get(&mesg, buf, mlen);
289 	status = -EINVAL;
290 	if (len < 0)
291 		goto out;
292 	status = -ENOMEM;
293 	if (dup_to_netobj(&rsii.out_token, buf, len))
294 		goto out;
295 	rsii.h.expiry_time = expiry;
296 	rsip = rsi_update(cd, &rsii, rsip);
297 	status = 0;
298 out:
299 	rsi_free(&rsii);
300 	if (rsip)
301 		cache_put(&rsip->h, cd);
302 	else
303 		status = -ENOMEM;
304 	return status;
305 }
306 
307 static const struct cache_detail rsi_cache_template = {
308 	.owner		= THIS_MODULE,
309 	.hash_size	= RSI_HASHMAX,
310 	.name           = "auth.rpcsec.init",
311 	.cache_put      = rsi_put,
312 	.cache_upcall	= rsi_upcall,
313 	.cache_request  = rsi_request,
314 	.cache_parse    = rsi_parse,
315 	.match		= rsi_match,
316 	.init		= rsi_init,
317 	.update		= update_rsi,
318 	.alloc		= rsi_alloc,
319 };
320 
321 static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item)
322 {
323 	struct cache_head *ch;
324 	int hash = rsi_hash(item);
325 
326 	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
327 	if (ch)
328 		return container_of(ch, struct rsi, h);
329 	else
330 		return NULL;
331 }
332 
333 static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old)
334 {
335 	struct cache_head *ch;
336 	int hash = rsi_hash(new);
337 
338 	ch = sunrpc_cache_update(cd, &new->h,
339 				 &old->h, hash);
340 	if (ch)
341 		return container_of(ch, struct rsi, h);
342 	else
343 		return NULL;
344 }
345 
346 
347 /*
348  * The rpcsec_context cache is used to store a context that is
349  * used in data exchange.
350  * The key is a context handle. The content is:
351  *  uid, gidlist, mechanism, service-set, mech-specific-data
352  */
353 
354 #define	RSC_HASHBITS	10
355 #define	RSC_HASHMAX	(1<<RSC_HASHBITS)
356 
357 #define GSS_SEQ_WIN	128
358 
359 struct gss_svc_seq_data {
360 	/* highest seq number seen so far: */
361 	u32			sd_max;
362 	/* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of
363 	 * sd_win is nonzero iff sequence number i has been seen already: */
364 	unsigned long		sd_win[GSS_SEQ_WIN/BITS_PER_LONG];
365 	spinlock_t		sd_lock;
366 };
367 
368 struct rsc {
369 	struct cache_head	h;
370 	struct xdr_netobj	handle;
371 	struct svc_cred		cred;
372 	struct gss_svc_seq_data	seqdata;
373 	struct gss_ctx		*mechctx;
374 	struct rcu_head		rcu_head;
375 };
376 
377 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old);
378 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item);
379 
380 static void rsc_free(struct rsc *rsci)
381 {
382 	kfree(rsci->handle.data);
383 	if (rsci->mechctx)
384 		gss_delete_sec_context(&rsci->mechctx);
385 	free_svc_cred(&rsci->cred);
386 }
387 
388 static void rsc_free_rcu(struct rcu_head *head)
389 {
390 	struct rsc *rsci = container_of(head, struct rsc, rcu_head);
391 
392 	kfree(rsci->handle.data);
393 	kfree(rsci);
394 }
395 
396 static void rsc_put(struct kref *ref)
397 {
398 	struct rsc *rsci = container_of(ref, struct rsc, h.ref);
399 
400 	if (rsci->mechctx)
401 		gss_delete_sec_context(&rsci->mechctx);
402 	free_svc_cred(&rsci->cred);
403 	call_rcu(&rsci->rcu_head, rsc_free_rcu);
404 }
405 
406 static inline int
407 rsc_hash(struct rsc *rsci)
408 {
409 	return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS);
410 }
411 
412 static int
413 rsc_match(struct cache_head *a, struct cache_head *b)
414 {
415 	struct rsc *new = container_of(a, struct rsc, h);
416 	struct rsc *tmp = container_of(b, struct rsc, h);
417 
418 	return netobj_equal(&new->handle, &tmp->handle);
419 }
420 
421 static void
422 rsc_init(struct cache_head *cnew, struct cache_head *ctmp)
423 {
424 	struct rsc *new = container_of(cnew, struct rsc, h);
425 	struct rsc *tmp = container_of(ctmp, struct rsc, h);
426 
427 	new->handle.len = tmp->handle.len;
428 	tmp->handle.len = 0;
429 	new->handle.data = tmp->handle.data;
430 	tmp->handle.data = NULL;
431 	new->mechctx = NULL;
432 	init_svc_cred(&new->cred);
433 }
434 
435 static void
436 update_rsc(struct cache_head *cnew, struct cache_head *ctmp)
437 {
438 	struct rsc *new = container_of(cnew, struct rsc, h);
439 	struct rsc *tmp = container_of(ctmp, struct rsc, h);
440 
441 	new->mechctx = tmp->mechctx;
442 	tmp->mechctx = NULL;
443 	memset(&new->seqdata, 0, sizeof(new->seqdata));
444 	spin_lock_init(&new->seqdata.sd_lock);
445 	new->cred = tmp->cred;
446 	init_svc_cred(&tmp->cred);
447 }
448 
449 static struct cache_head *
450 rsc_alloc(void)
451 {
452 	struct rsc *rsci = kmalloc(sizeof(*rsci), GFP_KERNEL);
453 	if (rsci)
454 		return &rsci->h;
455 	else
456 		return NULL;
457 }
458 
459 static int rsc_upcall(struct cache_detail *cd, struct cache_head *h)
460 {
461 	return -EINVAL;
462 }
463 
464 static int rsc_parse(struct cache_detail *cd,
465 		     char *mesg, int mlen)
466 {
467 	/* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] */
468 	char *buf = mesg;
469 	int id;
470 	int len, rv;
471 	struct rsc rsci, *rscp = NULL;
472 	time64_t expiry;
473 	int status = -EINVAL;
474 	struct gss_api_mech *gm = NULL;
475 
476 	memset(&rsci, 0, sizeof(rsci));
477 	/* context handle */
478 	len = qword_get(&mesg, buf, mlen);
479 	if (len < 0) goto out;
480 	status = -ENOMEM;
481 	if (dup_to_netobj(&rsci.handle, buf, len))
482 		goto out;
483 
484 	rsci.h.flags = 0;
485 	/* expiry */
486 	status = get_expiry(&mesg, &expiry);
487 	if (status)
488 		goto out;
489 
490 	status = -EINVAL;
491 	rscp = rsc_lookup(cd, &rsci);
492 	if (!rscp)
493 		goto out;
494 
495 	/* uid, or NEGATIVE */
496 	rv = get_int(&mesg, &id);
497 	if (rv == -EINVAL)
498 		goto out;
499 	if (rv == -ENOENT)
500 		set_bit(CACHE_NEGATIVE, &rsci.h.flags);
501 	else {
502 		int N, i;
503 
504 		/*
505 		 * NOTE: we skip uid_valid()/gid_valid() checks here:
506 		 * instead, * -1 id's are later mapped to the
507 		 * (export-specific) anonymous id by nfsd_setuser.
508 		 *
509 		 * (But supplementary gid's get no such special
510 		 * treatment so are checked for validity here.)
511 		 */
512 		/* uid */
513 		rsci.cred.cr_uid = make_kuid(current_user_ns(), id);
514 
515 		/* gid */
516 		if (get_int(&mesg, &id))
517 			goto out;
518 		rsci.cred.cr_gid = make_kgid(current_user_ns(), id);
519 
520 		/* number of additional gid's */
521 		if (get_int(&mesg, &N))
522 			goto out;
523 		if (N < 0 || N > NGROUPS_MAX)
524 			goto out;
525 		status = -ENOMEM;
526 		rsci.cred.cr_group_info = groups_alloc(N);
527 		if (rsci.cred.cr_group_info == NULL)
528 			goto out;
529 
530 		/* gid's */
531 		status = -EINVAL;
532 		for (i=0; i<N; i++) {
533 			kgid_t kgid;
534 			if (get_int(&mesg, &id))
535 				goto out;
536 			kgid = make_kgid(current_user_ns(), id);
537 			if (!gid_valid(kgid))
538 				goto out;
539 			rsci.cred.cr_group_info->gid[i] = kgid;
540 		}
541 		groups_sort(rsci.cred.cr_group_info);
542 
543 		/* mech name */
544 		len = qword_get(&mesg, buf, mlen);
545 		if (len < 0)
546 			goto out;
547 		gm = rsci.cred.cr_gss_mech = gss_mech_get_by_name(buf);
548 		status = -EOPNOTSUPP;
549 		if (!gm)
550 			goto out;
551 
552 		status = -EINVAL;
553 		/* mech-specific data: */
554 		len = qword_get(&mesg, buf, mlen);
555 		if (len < 0)
556 			goto out;
557 		status = gss_import_sec_context(buf, len, gm, &rsci.mechctx,
558 						NULL, GFP_KERNEL);
559 		if (status)
560 			goto out;
561 
562 		/* get client name */
563 		len = qword_get(&mesg, buf, mlen);
564 		if (len > 0) {
565 			rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL);
566 			if (!rsci.cred.cr_principal) {
567 				status = -ENOMEM;
568 				goto out;
569 			}
570 		}
571 
572 	}
573 	rsci.h.expiry_time = expiry;
574 	rscp = rsc_update(cd, &rsci, rscp);
575 	status = 0;
576 out:
577 	rsc_free(&rsci);
578 	if (rscp)
579 		cache_put(&rscp->h, cd);
580 	else
581 		status = -ENOMEM;
582 	return status;
583 }
584 
585 static const struct cache_detail rsc_cache_template = {
586 	.owner		= THIS_MODULE,
587 	.hash_size	= RSC_HASHMAX,
588 	.name		= "auth.rpcsec.context",
589 	.cache_put	= rsc_put,
590 	.cache_upcall	= rsc_upcall,
591 	.cache_parse	= rsc_parse,
592 	.match		= rsc_match,
593 	.init		= rsc_init,
594 	.update		= update_rsc,
595 	.alloc		= rsc_alloc,
596 };
597 
598 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item)
599 {
600 	struct cache_head *ch;
601 	int hash = rsc_hash(item);
602 
603 	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
604 	if (ch)
605 		return container_of(ch, struct rsc, h);
606 	else
607 		return NULL;
608 }
609 
610 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old)
611 {
612 	struct cache_head *ch;
613 	int hash = rsc_hash(new);
614 
615 	ch = sunrpc_cache_update(cd, &new->h,
616 				 &old->h, hash);
617 	if (ch)
618 		return container_of(ch, struct rsc, h);
619 	else
620 		return NULL;
621 }
622 
623 
624 static struct rsc *
625 gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle)
626 {
627 	struct rsc rsci;
628 	struct rsc *found;
629 
630 	memset(&rsci, 0, sizeof(rsci));
631 	if (dup_to_netobj(&rsci.handle, handle->data, handle->len))
632 		return NULL;
633 	found = rsc_lookup(cd, &rsci);
634 	rsc_free(&rsci);
635 	if (!found)
636 		return NULL;
637 	if (cache_check(cd, &found->h, NULL))
638 		return NULL;
639 	return found;
640 }
641 
642 /**
643  * gss_check_seq_num - GSS sequence number window check
644  * @rqstp: RPC Call to use when reporting errors
645  * @rsci: cached GSS context state (updated on return)
646  * @seq_num: sequence number to check
647  *
648  * Implements sequence number algorithm as specified in
649  * RFC 2203, Section 5.3.3.1. "Context Management".
650  *
651  * Return values:
652  *   %true: @rqstp's GSS sequence number is inside the window
653  *   %false: @rqstp's GSS sequence number is outside the window
654  */
655 static bool gss_check_seq_num(const struct svc_rqst *rqstp, struct rsc *rsci,
656 			      u32 seq_num)
657 {
658 	struct gss_svc_seq_data *sd = &rsci->seqdata;
659 	bool result = false;
660 
661 	spin_lock(&sd->sd_lock);
662 	if (seq_num > sd->sd_max) {
663 		if (seq_num >= sd->sd_max + GSS_SEQ_WIN) {
664 			memset(sd->sd_win, 0, sizeof(sd->sd_win));
665 			sd->sd_max = seq_num;
666 		} else while (sd->sd_max < seq_num) {
667 			sd->sd_max++;
668 			__clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win);
669 		}
670 		__set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
671 		goto ok;
672 	} else if (seq_num + GSS_SEQ_WIN <= sd->sd_max) {
673 		goto toolow;
674 	}
675 	if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
676 		goto alreadyseen;
677 
678 ok:
679 	result = true;
680 out:
681 	spin_unlock(&sd->sd_lock);
682 	return result;
683 
684 toolow:
685 	trace_rpcgss_svc_seqno_low(rqstp, seq_num,
686 				   sd->sd_max - GSS_SEQ_WIN,
687 				   sd->sd_max);
688 	goto out;
689 alreadyseen:
690 	trace_rpcgss_svc_seqno_seen(rqstp, seq_num);
691 	goto out;
692 }
693 
694 /*
695  * Decode and verify a Call's verifier field. For RPC_AUTH_GSS Calls,
696  * the body of this field contains a variable length checksum.
697  *
698  * GSS-specific auth_stat values are mandated by RFC 2203 Section
699  * 5.3.3.3.
700  */
701 static int
702 svcauth_gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
703 			  __be32 *rpcstart, struct rpc_gss_wire_cred *gc)
704 {
705 	struct xdr_stream	*xdr = &rqstp->rq_arg_stream;
706 	struct gss_ctx		*ctx_id = rsci->mechctx;
707 	u32			flavor, maj_stat;
708 	struct xdr_buf		rpchdr;
709 	struct xdr_netobj	checksum;
710 	struct kvec		iov;
711 
712 	/*
713 	 * Compute the checksum of the incoming Call from the
714 	 * XID field to credential field:
715 	 */
716 	iov.iov_base = rpcstart;
717 	iov.iov_len = (u8 *)xdr->p - (u8 *)rpcstart;
718 	xdr_buf_from_iov(&iov, &rpchdr);
719 
720 	/* Call's verf field: */
721 	if (xdr_stream_decode_opaque_auth(xdr, &flavor,
722 					  (void **)&checksum.data,
723 					  &checksum.len) < 0) {
724 		rqstp->rq_auth_stat = rpc_autherr_badverf;
725 		return SVC_DENIED;
726 	}
727 	if (flavor != RPC_AUTH_GSS) {
728 		rqstp->rq_auth_stat = rpc_autherr_badverf;
729 		return SVC_DENIED;
730 	}
731 
732 	if (rqstp->rq_deferred)
733 		return SVC_OK;
734 	maj_stat = gss_verify_mic(ctx_id, &rpchdr, &checksum);
735 	if (maj_stat != GSS_S_COMPLETE) {
736 		trace_rpcgss_svc_mic(rqstp, maj_stat);
737 		rqstp->rq_auth_stat = rpcsec_gsserr_credproblem;
738 		return SVC_DENIED;
739 	}
740 
741 	if (gc->gc_seq > MAXSEQ) {
742 		trace_rpcgss_svc_seqno_large(rqstp, gc->gc_seq);
743 		rqstp->rq_auth_stat = rpcsec_gsserr_ctxproblem;
744 		return SVC_DENIED;
745 	}
746 	if (!gss_check_seq_num(rqstp, rsci, gc->gc_seq))
747 		return SVC_DROP;
748 	return SVC_OK;
749 }
750 
751 /*
752  * Construct and encode a Reply's verifier field. The verifier's body
753  * field contains a variable-length checksum of the GSS sequence
754  * number.
755  */
756 static bool
757 svcauth_gss_encode_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
758 {
759 	struct gss_svc_data	*gsd = rqstp->rq_auth_data;
760 	u32			maj_stat;
761 	struct xdr_buf		verf_data;
762 	struct xdr_netobj	checksum;
763 	struct kvec		iov;
764 
765 	gsd->gsd_seq_num = cpu_to_be32(seq);
766 	iov.iov_base = &gsd->gsd_seq_num;
767 	iov.iov_len = XDR_UNIT;
768 	xdr_buf_from_iov(&iov, &verf_data);
769 
770 	checksum.data = gsd->gsd_scratch;
771 	maj_stat = gss_get_mic(ctx_id, &verf_data, &checksum);
772 	if (maj_stat != GSS_S_COMPLETE)
773 		goto bad_mic;
774 
775 	return xdr_stream_encode_opaque_auth(&rqstp->rq_res_stream, RPC_AUTH_GSS,
776 					     checksum.data, checksum.len) > 0;
777 
778 bad_mic:
779 	trace_rpcgss_svc_get_mic(rqstp, maj_stat);
780 	return false;
781 }
782 
783 struct gss_domain {
784 	struct auth_domain	h;
785 	u32			pseudoflavor;
786 };
787 
788 static struct auth_domain *
789 find_gss_auth_domain(struct gss_ctx *ctx, u32 svc)
790 {
791 	char *name;
792 
793 	name = gss_service_to_auth_domain_name(ctx->mech_type, svc);
794 	if (!name)
795 		return NULL;
796 	return auth_domain_find(name);
797 }
798 
799 static struct auth_ops svcauthops_gss;
800 
801 u32 svcauth_gss_flavor(struct auth_domain *dom)
802 {
803 	struct gss_domain *gd = container_of(dom, struct gss_domain, h);
804 
805 	return gd->pseudoflavor;
806 }
807 
808 EXPORT_SYMBOL_GPL(svcauth_gss_flavor);
809 
810 struct auth_domain *
811 svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name)
812 {
813 	struct gss_domain	*new;
814 	struct auth_domain	*test;
815 	int			stat = -ENOMEM;
816 
817 	new = kmalloc(sizeof(*new), GFP_KERNEL);
818 	if (!new)
819 		goto out;
820 	kref_init(&new->h.ref);
821 	new->h.name = kstrdup(name, GFP_KERNEL);
822 	if (!new->h.name)
823 		goto out_free_dom;
824 	new->h.flavour = &svcauthops_gss;
825 	new->pseudoflavor = pseudoflavor;
826 
827 	test = auth_domain_lookup(name, &new->h);
828 	if (test != &new->h) {
829 		pr_warn("svc: duplicate registration of gss pseudo flavour %s.\n",
830 			name);
831 		stat = -EADDRINUSE;
832 		auth_domain_put(test);
833 		goto out_free_name;
834 	}
835 	return test;
836 
837 out_free_name:
838 	kfree(new->h.name);
839 out_free_dom:
840 	kfree(new);
841 out:
842 	return ERR_PTR(stat);
843 }
844 EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor);
845 
846 /*
847  * RFC 2203, Section 5.3.2.2
848  *
849  *	struct rpc_gss_integ_data {
850  *		opaque databody_integ<>;
851  *		opaque checksum<>;
852  *	};
853  *
854  *	struct rpc_gss_data_t {
855  *		unsigned int seq_num;
856  *		proc_req_arg_t arg;
857  *	};
858  */
859 static noinline_for_stack int
860 svcauth_gss_unwrap_integ(struct svc_rqst *rqstp, u32 seq, struct gss_ctx *ctx)
861 {
862 	struct gss_svc_data *gsd = rqstp->rq_auth_data;
863 	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
864 	u32 len, offset, seq_num, maj_stat;
865 	struct xdr_buf *buf = xdr->buf;
866 	struct xdr_buf databody_integ;
867 	struct xdr_netobj checksum;
868 
869 	/* Did we already verify the signature on the original pass through? */
870 	if (rqstp->rq_deferred)
871 		return 0;
872 
873 	if (xdr_stream_decode_u32(xdr, &len) < 0)
874 		goto unwrap_failed;
875 	if (len & 3)
876 		goto unwrap_failed;
877 	offset = xdr_stream_pos(xdr);
878 	if (xdr_buf_subsegment(buf, &databody_integ, offset, len))
879 		goto unwrap_failed;
880 
881 	/*
882 	 * The xdr_stream now points to the @seq_num field. The next
883 	 * XDR data item is the @arg field, which contains the clear
884 	 * text RPC program payload. The checksum, which follows the
885 	 * @arg field, is located and decoded without updating the
886 	 * xdr_stream.
887 	 */
888 
889 	offset += len;
890 	if (xdr_decode_word(buf, offset, &checksum.len))
891 		goto unwrap_failed;
892 	if (checksum.len > sizeof(gsd->gsd_scratch))
893 		goto unwrap_failed;
894 	checksum.data = gsd->gsd_scratch;
895 	if (read_bytes_from_xdr_buf(buf, offset + XDR_UNIT, checksum.data,
896 				    checksum.len))
897 		goto unwrap_failed;
898 
899 	maj_stat = gss_verify_mic(ctx, &databody_integ, &checksum);
900 	if (maj_stat != GSS_S_COMPLETE)
901 		goto bad_mic;
902 
903 	/* The received seqno is protected by the checksum. */
904 	if (xdr_stream_decode_u32(xdr, &seq_num) < 0)
905 		goto unwrap_failed;
906 	if (seq_num != seq)
907 		goto bad_seqno;
908 
909 	xdr_truncate_decode(xdr, XDR_UNIT + checksum.len);
910 	return 0;
911 
912 unwrap_failed:
913 	trace_rpcgss_svc_unwrap_failed(rqstp);
914 	return -EINVAL;
915 bad_seqno:
916 	trace_rpcgss_svc_seqno_bad(rqstp, seq, seq_num);
917 	return -EINVAL;
918 bad_mic:
919 	trace_rpcgss_svc_mic(rqstp, maj_stat);
920 	return -EINVAL;
921 }
922 
923 /*
924  * RFC 2203, Section 5.3.2.3
925  *
926  *	struct rpc_gss_priv_data {
927  *		opaque databody_priv<>
928  *	};
929  *
930  *	struct rpc_gss_data_t {
931  *		unsigned int seq_num;
932  *		proc_req_arg_t arg;
933  *	};
934  */
935 static noinline_for_stack int
936 svcauth_gss_unwrap_priv(struct svc_rqst *rqstp, u32 seq, struct gss_ctx *ctx)
937 {
938 	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
939 	u32 len, maj_stat, seq_num, offset;
940 	struct xdr_buf *buf = xdr->buf;
941 	unsigned int saved_len;
942 
943 	if (xdr_stream_decode_u32(xdr, &len) < 0)
944 		goto unwrap_failed;
945 	if (rqstp->rq_deferred) {
946 		/* Already decrypted last time through! The sequence number
947 		 * check at out_seq is unnecessary but harmless: */
948 		goto out_seq;
949 	}
950 	if (len > xdr_stream_remaining(xdr))
951 		goto unwrap_failed;
952 	offset = xdr_stream_pos(xdr);
953 
954 	saved_len = buf->len;
955 	maj_stat = gss_unwrap(ctx, offset, offset + len, buf);
956 	if (maj_stat != GSS_S_COMPLETE)
957 		goto bad_unwrap;
958 	xdr->nwords -= XDR_QUADLEN(saved_len - buf->len);
959 
960 out_seq:
961 	/* gss_unwrap() decrypted the sequence number. */
962 	if (xdr_stream_decode_u32(xdr, &seq_num) < 0)
963 		goto unwrap_failed;
964 	if (seq_num != seq)
965 		goto bad_seqno;
966 	return 0;
967 
968 unwrap_failed:
969 	trace_rpcgss_svc_unwrap_failed(rqstp);
970 	return -EINVAL;
971 bad_seqno:
972 	trace_rpcgss_svc_seqno_bad(rqstp, seq, seq_num);
973 	return -EINVAL;
974 bad_unwrap:
975 	trace_rpcgss_svc_unwrap(rqstp, maj_stat);
976 	return -EINVAL;
977 }
978 
979 static enum svc_auth_status
980 svcauth_gss_set_client(struct svc_rqst *rqstp)
981 {
982 	struct gss_svc_data *svcdata = rqstp->rq_auth_data;
983 	struct rsc *rsci = svcdata->rsci;
984 	struct rpc_gss_wire_cred *gc = &svcdata->clcred;
985 	int stat;
986 
987 	rqstp->rq_auth_stat = rpc_autherr_badcred;
988 
989 	/*
990 	 * A gss export can be specified either by:
991 	 * 	export	*(sec=krb5,rw)
992 	 * or by
993 	 * 	export gss/krb5(rw)
994 	 * The latter is deprecated; but for backwards compatibility reasons
995 	 * the nfsd code will still fall back on trying it if the former
996 	 * doesn't work; so we try to make both available to nfsd, below.
997 	 */
998 	rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
999 	if (rqstp->rq_gssclient == NULL)
1000 		return SVC_DENIED;
1001 	stat = svcauth_unix_set_client(rqstp);
1002 	if (stat == SVC_DROP || stat == SVC_CLOSE)
1003 		return stat;
1004 
1005 	rqstp->rq_auth_stat = rpc_auth_ok;
1006 	return SVC_OK;
1007 }
1008 
1009 static bool
1010 svcauth_gss_proc_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
1011 			   struct xdr_netobj *out_handle, int *major_status,
1012 			   u32 seq_num)
1013 {
1014 	struct xdr_stream *xdr = &rqstp->rq_res_stream;
1015 	struct rsc *rsci;
1016 	bool rc;
1017 
1018 	if (*major_status != GSS_S_COMPLETE)
1019 		goto null_verifier;
1020 	rsci = gss_svc_searchbyctx(cd, out_handle);
1021 	if (rsci == NULL) {
1022 		*major_status = GSS_S_NO_CONTEXT;
1023 		goto null_verifier;
1024 	}
1025 
1026 	rc = svcauth_gss_encode_verf(rqstp, rsci->mechctx, seq_num);
1027 	cache_put(&rsci->h, cd);
1028 	return rc;
1029 
1030 null_verifier:
1031 	return xdr_stream_encode_opaque_auth(xdr, RPC_AUTH_NULL, NULL, 0) > 0;
1032 }
1033 
1034 static void gss_free_in_token_pages(struct gssp_in_token *in_token)
1035 {
1036 	int i;
1037 
1038 	i = 0;
1039 	while (in_token->pages[i])
1040 		put_page(in_token->pages[i++]);
1041 	kfree(in_token->pages);
1042 	in_token->pages = NULL;
1043 }
1044 
1045 static int gss_read_proxy_verf(struct svc_rqst *rqstp,
1046 			       struct rpc_gss_wire_cred *gc,
1047 			       struct xdr_netobj *in_handle,
1048 			       struct gssp_in_token *in_token)
1049 {
1050 	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
1051 	unsigned int length, pgto_offs, pgfrom_offs;
1052 	int pages, i, pgto, pgfrom;
1053 	size_t to_offs, from_offs;
1054 	u32 inlen;
1055 
1056 	if (dup_netobj(in_handle, &gc->gc_ctx))
1057 		return SVC_CLOSE;
1058 
1059 	/*
1060 	 *  RFC 2203 Section 5.2.2
1061 	 *
1062 	 *	struct rpc_gss_init_arg {
1063 	 *		opaque gss_token<>;
1064 	 *	};
1065 	 */
1066 	if (xdr_stream_decode_u32(xdr, &inlen) < 0)
1067 		goto out_denied_free;
1068 	if (inlen > xdr_stream_remaining(xdr))
1069 		goto out_denied_free;
1070 
1071 	pages = DIV_ROUND_UP(inlen, PAGE_SIZE);
1072 	in_token->pages = kcalloc(pages, sizeof(struct page *), GFP_KERNEL);
1073 	if (!in_token->pages)
1074 		goto out_denied_free;
1075 	in_token->page_base = 0;
1076 	in_token->page_len = inlen;
1077 	for (i = 0; i < pages; i++) {
1078 		in_token->pages[i] = alloc_page(GFP_KERNEL);
1079 		if (!in_token->pages[i]) {
1080 			gss_free_in_token_pages(in_token);
1081 			goto out_denied_free;
1082 		}
1083 	}
1084 
1085 	length = min_t(unsigned int, inlen, (char *)xdr->end - (char *)xdr->p);
1086 	memcpy(page_address(in_token->pages[0]), xdr->p, length);
1087 	inlen -= length;
1088 
1089 	to_offs = length;
1090 	from_offs = rqstp->rq_arg.page_base;
1091 	while (inlen) {
1092 		pgto = to_offs >> PAGE_SHIFT;
1093 		pgfrom = from_offs >> PAGE_SHIFT;
1094 		pgto_offs = to_offs & ~PAGE_MASK;
1095 		pgfrom_offs = from_offs & ~PAGE_MASK;
1096 
1097 		length = min_t(unsigned int, inlen,
1098 			 min_t(unsigned int, PAGE_SIZE - pgto_offs,
1099 			       PAGE_SIZE - pgfrom_offs));
1100 		memcpy(page_address(in_token->pages[pgto]) + pgto_offs,
1101 		       page_address(rqstp->rq_arg.pages[pgfrom]) + pgfrom_offs,
1102 		       length);
1103 
1104 		to_offs += length;
1105 		from_offs += length;
1106 		inlen -= length;
1107 	}
1108 	return 0;
1109 
1110 out_denied_free:
1111 	kfree(in_handle->data);
1112 	return SVC_DENIED;
1113 }
1114 
1115 /*
1116  * RFC 2203, Section 5.2.3.1.
1117  *
1118  *	struct rpc_gss_init_res {
1119  *		opaque handle<>;
1120  *		unsigned int gss_major;
1121  *		unsigned int gss_minor;
1122  *		unsigned int seq_window;
1123  *		opaque gss_token<>;
1124  *	};
1125  */
1126 static bool
1127 svcxdr_encode_gss_init_res(struct xdr_stream *xdr,
1128 			   struct xdr_netobj *handle,
1129 			   struct xdr_netobj *gss_token,
1130 			   unsigned int major_status,
1131 			   unsigned int minor_status, u32 seq_num)
1132 {
1133 	if (xdr_stream_encode_opaque(xdr, handle->data, handle->len) < 0)
1134 		return false;
1135 	if (xdr_stream_encode_u32(xdr, major_status) < 0)
1136 		return false;
1137 	if (xdr_stream_encode_u32(xdr, minor_status) < 0)
1138 		return false;
1139 	if (xdr_stream_encode_u32(xdr, seq_num) < 0)
1140 		return false;
1141 	if (xdr_stream_encode_opaque(xdr, gss_token->data, gss_token->len) < 0)
1142 		return false;
1143 	return true;
1144 }
1145 
1146 /*
1147  * Having read the cred already and found we're in the context
1148  * initiation case, read the verifier and initiate (or check the results
1149  * of) upcalls to userspace for help with context initiation.  If
1150  * the upcall results are available, write the verifier and result.
1151  * Otherwise, drop the request pending an answer to the upcall.
1152  */
1153 static int
1154 svcauth_gss_legacy_init(struct svc_rqst *rqstp,
1155 			struct rpc_gss_wire_cred *gc)
1156 {
1157 	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
1158 	struct rsi *rsip, rsikey;
1159 	__be32 *p;
1160 	u32 len;
1161 	int ret;
1162 	struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
1163 
1164 	memset(&rsikey, 0, sizeof(rsikey));
1165 	if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx))
1166 		return SVC_CLOSE;
1167 
1168 	/*
1169 	 *  RFC 2203 Section 5.2.2
1170 	 *
1171 	 *	struct rpc_gss_init_arg {
1172 	 *		opaque gss_token<>;
1173 	 *	};
1174 	 */
1175 	if (xdr_stream_decode_u32(xdr, &len) < 0) {
1176 		kfree(rsikey.in_handle.data);
1177 		return SVC_DENIED;
1178 	}
1179 	p = xdr_inline_decode(xdr, len);
1180 	if (!p) {
1181 		kfree(rsikey.in_handle.data);
1182 		return SVC_DENIED;
1183 	}
1184 	rsikey.in_token.data = kmalloc(len, GFP_KERNEL);
1185 	if (ZERO_OR_NULL_PTR(rsikey.in_token.data)) {
1186 		kfree(rsikey.in_handle.data);
1187 		return SVC_CLOSE;
1188 	}
1189 	memcpy(rsikey.in_token.data, p, len);
1190 	rsikey.in_token.len = len;
1191 
1192 	/* Perform upcall, or find upcall result: */
1193 	rsip = rsi_lookup(sn->rsi_cache, &rsikey);
1194 	rsi_free(&rsikey);
1195 	if (!rsip)
1196 		return SVC_CLOSE;
1197 	if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0)
1198 		/* No upcall result: */
1199 		return SVC_CLOSE;
1200 
1201 	ret = SVC_CLOSE;
1202 	if (!svcauth_gss_proc_init_verf(sn->rsc_cache, rqstp, &rsip->out_handle,
1203 					&rsip->major_status, GSS_SEQ_WIN))
1204 		goto out;
1205 	if (!svcxdr_set_accept_stat(rqstp))
1206 		goto out;
1207 	if (!svcxdr_encode_gss_init_res(&rqstp->rq_res_stream, &rsip->out_handle,
1208 					&rsip->out_token, rsip->major_status,
1209 					rsip->minor_status, GSS_SEQ_WIN))
1210 		goto out;
1211 
1212 	ret = SVC_COMPLETE;
1213 out:
1214 	cache_put(&rsip->h, sn->rsi_cache);
1215 	return ret;
1216 }
1217 
1218 static int gss_proxy_save_rsc(struct cache_detail *cd,
1219 				struct gssp_upcall_data *ud,
1220 				uint64_t *handle)
1221 {
1222 	struct rsc rsci, *rscp = NULL;
1223 	static atomic64_t ctxhctr;
1224 	long long ctxh;
1225 	struct gss_api_mech *gm = NULL;
1226 	time64_t expiry;
1227 	int status;
1228 
1229 	memset(&rsci, 0, sizeof(rsci));
1230 	/* context handle */
1231 	status = -ENOMEM;
1232 	/* the handle needs to be just a unique id,
1233 	 * use a static counter */
1234 	ctxh = atomic64_inc_return(&ctxhctr);
1235 
1236 	/* make a copy for the caller */
1237 	*handle = ctxh;
1238 
1239 	/* make a copy for the rsc cache */
1240 	if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t)))
1241 		goto out;
1242 	rscp = rsc_lookup(cd, &rsci);
1243 	if (!rscp)
1244 		goto out;
1245 
1246 	/* creds */
1247 	if (!ud->found_creds) {
1248 		/* userspace seem buggy, we should always get at least a
1249 		 * mapping to nobody */
1250 		goto out;
1251 	} else {
1252 		struct timespec64 boot;
1253 
1254 		/* steal creds */
1255 		rsci.cred = ud->creds;
1256 		memset(&ud->creds, 0, sizeof(struct svc_cred));
1257 
1258 		status = -EOPNOTSUPP;
1259 		/* get mech handle from OID */
1260 		gm = gss_mech_get_by_OID(&ud->mech_oid);
1261 		if (!gm)
1262 			goto out;
1263 		rsci.cred.cr_gss_mech = gm;
1264 
1265 		status = -EINVAL;
1266 		/* mech-specific data: */
1267 		status = gss_import_sec_context(ud->out_handle.data,
1268 						ud->out_handle.len,
1269 						gm, &rsci.mechctx,
1270 						&expiry, GFP_KERNEL);
1271 		if (status)
1272 			goto out;
1273 
1274 		getboottime64(&boot);
1275 		expiry -= boot.tv_sec;
1276 	}
1277 
1278 	rsci.h.expiry_time = expiry;
1279 	rscp = rsc_update(cd, &rsci, rscp);
1280 	status = 0;
1281 out:
1282 	rsc_free(&rsci);
1283 	if (rscp)
1284 		cache_put(&rscp->h, cd);
1285 	else
1286 		status = -ENOMEM;
1287 	return status;
1288 }
1289 
1290 static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
1291 				  struct rpc_gss_wire_cred *gc)
1292 {
1293 	struct xdr_netobj cli_handle;
1294 	struct gssp_upcall_data ud;
1295 	uint64_t handle;
1296 	int status;
1297 	int ret;
1298 	struct net *net = SVC_NET(rqstp);
1299 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1300 
1301 	memset(&ud, 0, sizeof(ud));
1302 	ret = gss_read_proxy_verf(rqstp, gc, &ud.in_handle, &ud.in_token);
1303 	if (ret)
1304 		return ret;
1305 
1306 	ret = SVC_CLOSE;
1307 
1308 	/* Perform synchronous upcall to gss-proxy */
1309 	status = gssp_accept_sec_context_upcall(net, &ud);
1310 	if (status)
1311 		goto out;
1312 
1313 	trace_rpcgss_svc_accept_upcall(rqstp, ud.major_status, ud.minor_status);
1314 
1315 	switch (ud.major_status) {
1316 	case GSS_S_CONTINUE_NEEDED:
1317 		cli_handle = ud.out_handle;
1318 		break;
1319 	case GSS_S_COMPLETE:
1320 		status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle);
1321 		if (status)
1322 			goto out;
1323 		cli_handle.data = (u8 *)&handle;
1324 		cli_handle.len = sizeof(handle);
1325 		break;
1326 	default:
1327 		goto out;
1328 	}
1329 
1330 	if (!svcauth_gss_proc_init_verf(sn->rsc_cache, rqstp, &cli_handle,
1331 					&ud.major_status, GSS_SEQ_WIN))
1332 		goto out;
1333 	if (!svcxdr_set_accept_stat(rqstp))
1334 		goto out;
1335 	if (!svcxdr_encode_gss_init_res(&rqstp->rq_res_stream, &cli_handle,
1336 					&ud.out_token, ud.major_status,
1337 					ud.minor_status, GSS_SEQ_WIN))
1338 		goto out;
1339 
1340 	ret = SVC_COMPLETE;
1341 out:
1342 	gss_free_in_token_pages(&ud.in_token);
1343 	gssp_free_upcall_data(&ud);
1344 	return ret;
1345 }
1346 
1347 /*
1348  * Try to set the sn->use_gss_proxy variable to a new value. We only allow
1349  * it to be changed if it's currently undefined (-1). If it's any other value
1350  * then return -EBUSY unless the type wouldn't have changed anyway.
1351  */
1352 static int set_gss_proxy(struct net *net, int type)
1353 {
1354 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1355 	int ret;
1356 
1357 	WARN_ON_ONCE(type != 0 && type != 1);
1358 	ret = cmpxchg(&sn->use_gss_proxy, -1, type);
1359 	if (ret != -1 && ret != type)
1360 		return -EBUSY;
1361 	return 0;
1362 }
1363 
1364 static bool use_gss_proxy(struct net *net)
1365 {
1366 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1367 
1368 	/* If use_gss_proxy is still undefined, then try to disable it */
1369 	if (sn->use_gss_proxy == -1)
1370 		set_gss_proxy(net, 0);
1371 	return sn->use_gss_proxy;
1372 }
1373 
1374 static noinline_for_stack int
1375 svcauth_gss_proc_init(struct svc_rqst *rqstp, struct rpc_gss_wire_cred *gc)
1376 {
1377 	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
1378 	u32 flavor, len;
1379 	void *body;
1380 
1381 	/* Call's verf field: */
1382 	if (xdr_stream_decode_opaque_auth(xdr, &flavor, &body, &len) < 0)
1383 		return SVC_GARBAGE;
1384 	if (flavor != RPC_AUTH_NULL || len != 0) {
1385 		rqstp->rq_auth_stat = rpc_autherr_badverf;
1386 		return SVC_DENIED;
1387 	}
1388 
1389 	if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0) {
1390 		rqstp->rq_auth_stat = rpc_autherr_badcred;
1391 		return SVC_DENIED;
1392 	}
1393 
1394 	if (!use_gss_proxy(SVC_NET(rqstp)))
1395 		return svcauth_gss_legacy_init(rqstp, gc);
1396 	return svcauth_gss_proxy_init(rqstp, gc);
1397 }
1398 
1399 #ifdef CONFIG_PROC_FS
1400 
1401 static ssize_t write_gssp(struct file *file, const char __user *buf,
1402 			 size_t count, loff_t *ppos)
1403 {
1404 	struct net *net = pde_data(file_inode(file));
1405 	char tbuf[20];
1406 	unsigned long i;
1407 	int res;
1408 
1409 	if (*ppos || count > sizeof(tbuf)-1)
1410 		return -EINVAL;
1411 	if (copy_from_user(tbuf, buf, count))
1412 		return -EFAULT;
1413 
1414 	tbuf[count] = 0;
1415 	res = kstrtoul(tbuf, 0, &i);
1416 	if (res)
1417 		return res;
1418 	if (i != 1)
1419 		return -EINVAL;
1420 	res = set_gssp_clnt(net);
1421 	if (res)
1422 		return res;
1423 	res = set_gss_proxy(net, 1);
1424 	if (res)
1425 		return res;
1426 	return count;
1427 }
1428 
1429 static ssize_t read_gssp(struct file *file, char __user *buf,
1430 			 size_t count, loff_t *ppos)
1431 {
1432 	struct net *net = pde_data(file_inode(file));
1433 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1434 	unsigned long p = *ppos;
1435 	char tbuf[10];
1436 	size_t len;
1437 
1438 	snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy);
1439 	len = strlen(tbuf);
1440 	if (p >= len)
1441 		return 0;
1442 	len -= p;
1443 	if (len > count)
1444 		len = count;
1445 	if (copy_to_user(buf, (void *)(tbuf+p), len))
1446 		return -EFAULT;
1447 	*ppos += len;
1448 	return len;
1449 }
1450 
1451 static const struct proc_ops use_gss_proxy_proc_ops = {
1452 	.proc_open	= nonseekable_open,
1453 	.proc_write	= write_gssp,
1454 	.proc_read	= read_gssp,
1455 };
1456 
1457 static int create_use_gss_proxy_proc_entry(struct net *net)
1458 {
1459 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1460 	struct proc_dir_entry **p = &sn->use_gssp_proc;
1461 
1462 	sn->use_gss_proxy = -1;
1463 	*p = proc_create_data("use-gss-proxy", S_IFREG | 0600,
1464 			      sn->proc_net_rpc,
1465 			      &use_gss_proxy_proc_ops, net);
1466 	if (!*p)
1467 		return -ENOMEM;
1468 	init_gssp_clnt(sn);
1469 	return 0;
1470 }
1471 
1472 static void destroy_use_gss_proxy_proc_entry(struct net *net)
1473 {
1474 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1475 
1476 	if (sn->use_gssp_proc) {
1477 		remove_proc_entry("use-gss-proxy", sn->proc_net_rpc);
1478 		clear_gssp_clnt(sn);
1479 	}
1480 }
1481 
1482 static ssize_t read_gss_krb5_enctypes(struct file *file, char __user *buf,
1483 				      size_t count, loff_t *ppos)
1484 {
1485 	struct rpcsec_gss_oid oid = {
1486 		.len	= 9,
1487 		.data	= "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02",
1488 	};
1489 	struct gss_api_mech *mech;
1490 	ssize_t ret;
1491 
1492 	mech = gss_mech_get_by_OID(&oid);
1493 	if (!mech)
1494 		return 0;
1495 	if (!mech->gm_upcall_enctypes) {
1496 		gss_mech_put(mech);
1497 		return 0;
1498 	}
1499 
1500 	ret = simple_read_from_buffer(buf, count, ppos,
1501 				      mech->gm_upcall_enctypes,
1502 				      strlen(mech->gm_upcall_enctypes));
1503 	gss_mech_put(mech);
1504 	return ret;
1505 }
1506 
1507 static const struct proc_ops gss_krb5_enctypes_proc_ops = {
1508 	.proc_open	= nonseekable_open,
1509 	.proc_read	= read_gss_krb5_enctypes,
1510 };
1511 
1512 static int create_krb5_enctypes_proc_entry(struct net *net)
1513 {
1514 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1515 
1516 	sn->gss_krb5_enctypes =
1517 		proc_create_data("gss_krb5_enctypes", S_IFREG | 0444,
1518 				 sn->proc_net_rpc, &gss_krb5_enctypes_proc_ops,
1519 				 net);
1520 	return sn->gss_krb5_enctypes ? 0 : -ENOMEM;
1521 }
1522 
1523 static void destroy_krb5_enctypes_proc_entry(struct net *net)
1524 {
1525 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1526 
1527 	if (sn->gss_krb5_enctypes)
1528 		remove_proc_entry("gss_krb5_enctypes", sn->proc_net_rpc);
1529 }
1530 
1531 #else /* CONFIG_PROC_FS */
1532 
1533 static int create_use_gss_proxy_proc_entry(struct net *net)
1534 {
1535 	return 0;
1536 }
1537 
1538 static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
1539 
1540 static int create_krb5_enctypes_proc_entry(struct net *net)
1541 {
1542 	return 0;
1543 }
1544 
1545 static void destroy_krb5_enctypes_proc_entry(struct net *net) {}
1546 
1547 #endif /* CONFIG_PROC_FS */
1548 
1549 /*
1550  * The Call's credential body should contain a struct rpc_gss_cred_t.
1551  *
1552  * RFC 2203 Section 5
1553  *
1554  *	struct rpc_gss_cred_t {
1555  *		union switch (unsigned int version) {
1556  *		case RPCSEC_GSS_VERS_1:
1557  *			struct {
1558  *				rpc_gss_proc_t gss_proc;
1559  *				unsigned int seq_num;
1560  *				rpc_gss_service_t service;
1561  *				opaque handle<>;
1562  *			} rpc_gss_cred_vers_1_t;
1563  *		}
1564  *	};
1565  */
1566 static bool
1567 svcauth_gss_decode_credbody(struct xdr_stream *xdr,
1568 			    struct rpc_gss_wire_cred *gc,
1569 			    __be32 **rpcstart)
1570 {
1571 	ssize_t handle_len;
1572 	u32 body_len;
1573 	__be32 *p;
1574 
1575 	p = xdr_inline_decode(xdr, XDR_UNIT);
1576 	if (!p)
1577 		return false;
1578 	/*
1579 	 * start of rpc packet is 7 u32's back from here:
1580 	 * xid direction rpcversion prog vers proc flavour
1581 	 */
1582 	*rpcstart = p - 7;
1583 	body_len = be32_to_cpup(p);
1584 	if (body_len > RPC_MAX_AUTH_SIZE)
1585 		return false;
1586 
1587 	/* struct rpc_gss_cred_t */
1588 	if (xdr_stream_decode_u32(xdr, &gc->gc_v) < 0)
1589 		return false;
1590 	if (xdr_stream_decode_u32(xdr, &gc->gc_proc) < 0)
1591 		return false;
1592 	if (xdr_stream_decode_u32(xdr, &gc->gc_seq) < 0)
1593 		return false;
1594 	if (xdr_stream_decode_u32(xdr, &gc->gc_svc) < 0)
1595 		return false;
1596 	handle_len = xdr_stream_decode_opaque_inline(xdr,
1597 						     (void **)&gc->gc_ctx.data,
1598 						     body_len);
1599 	if (handle_len < 0)
1600 		return false;
1601 	if (body_len != XDR_UNIT * 5 + xdr_align_size(handle_len))
1602 		return false;
1603 
1604 	gc->gc_ctx.len = handle_len;
1605 	return true;
1606 }
1607 
1608 /**
1609  * svcauth_gss_accept - Decode and validate incoming RPC_AUTH_GSS credential
1610  * @rqstp: RPC transaction
1611  *
1612  * Return values:
1613  *   %SVC_OK: Success
1614  *   %SVC_COMPLETE: GSS context lifetime event
1615  *   %SVC_DENIED: Credential or verifier is not valid
1616  *   %SVC_GARBAGE: Failed to decode credential or verifier
1617  *   %SVC_CLOSE: Temporary failure
1618  *
1619  * The rqstp->rq_auth_stat field is also set (see RFCs 2203 and 5531).
1620  */
1621 static enum svc_auth_status
1622 svcauth_gss_accept(struct svc_rqst *rqstp)
1623 {
1624 	struct gss_svc_data *svcdata = rqstp->rq_auth_data;
1625 	__be32		*rpcstart;
1626 	struct rpc_gss_wire_cred *gc;
1627 	struct rsc	*rsci = NULL;
1628 	int		ret;
1629 	struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
1630 
1631 	rqstp->rq_auth_stat = rpc_autherr_badcred;
1632 	if (!svcdata)
1633 		svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
1634 	if (!svcdata)
1635 		goto auth_err;
1636 	rqstp->rq_auth_data = svcdata;
1637 	svcdata->gsd_databody_offset = 0;
1638 	svcdata->rsci = NULL;
1639 	gc = &svcdata->clcred;
1640 
1641 	if (!svcauth_gss_decode_credbody(&rqstp->rq_arg_stream, gc, &rpcstart))
1642 		goto auth_err;
1643 	if (gc->gc_v != RPC_GSS_VERSION)
1644 		goto auth_err;
1645 
1646 	switch (gc->gc_proc) {
1647 	case RPC_GSS_PROC_INIT:
1648 	case RPC_GSS_PROC_CONTINUE_INIT:
1649 		if (rqstp->rq_proc != 0)
1650 			goto auth_err;
1651 		return svcauth_gss_proc_init(rqstp, gc);
1652 	case RPC_GSS_PROC_DESTROY:
1653 		if (rqstp->rq_proc != 0)
1654 			goto auth_err;
1655 		fallthrough;
1656 	case RPC_GSS_PROC_DATA:
1657 		rqstp->rq_auth_stat = rpcsec_gsserr_credproblem;
1658 		rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
1659 		if (!rsci)
1660 			goto auth_err;
1661 		switch (svcauth_gss_verify_header(rqstp, rsci, rpcstart, gc)) {
1662 		case SVC_OK:
1663 			break;
1664 		case SVC_DENIED:
1665 			goto auth_err;
1666 		case SVC_DROP:
1667 			goto drop;
1668 		}
1669 		break;
1670 	default:
1671 		if (rqstp->rq_proc != 0)
1672 			goto auth_err;
1673 		rqstp->rq_auth_stat = rpc_autherr_rejectedcred;
1674 		goto auth_err;
1675 	}
1676 
1677 	/* now act upon the command: */
1678 	switch (gc->gc_proc) {
1679 	case RPC_GSS_PROC_DESTROY:
1680 		if (!svcauth_gss_encode_verf(rqstp, rsci->mechctx, gc->gc_seq))
1681 			goto auth_err;
1682 		if (!svcxdr_set_accept_stat(rqstp))
1683 			goto auth_err;
1684 		/* Delete the entry from the cache_list and call cache_put */
1685 		sunrpc_cache_unhash(sn->rsc_cache, &rsci->h);
1686 		goto complete;
1687 	case RPC_GSS_PROC_DATA:
1688 		rqstp->rq_auth_stat = rpcsec_gsserr_ctxproblem;
1689 		if (!svcauth_gss_encode_verf(rqstp, rsci->mechctx, gc->gc_seq))
1690 			goto auth_err;
1691 		if (!svcxdr_set_accept_stat(rqstp))
1692 			goto auth_err;
1693 		svcdata->gsd_databody_offset = xdr_stream_pos(&rqstp->rq_res_stream);
1694 		rqstp->rq_cred = rsci->cred;
1695 		get_group_info(rsci->cred.cr_group_info);
1696 		rqstp->rq_auth_stat = rpc_autherr_badcred;
1697 		switch (gc->gc_svc) {
1698 		case RPC_GSS_SVC_NONE:
1699 			break;
1700 		case RPC_GSS_SVC_INTEGRITY:
1701 			/* placeholders for body length and seq. number: */
1702 			xdr_reserve_space(&rqstp->rq_res_stream, XDR_UNIT * 2);
1703 			if (svcauth_gss_unwrap_integ(rqstp, gc->gc_seq,
1704 						     rsci->mechctx))
1705 				goto garbage_args;
1706 			svcxdr_set_auth_slack(rqstp, RPC_MAX_AUTH_SIZE);
1707 			break;
1708 		case RPC_GSS_SVC_PRIVACY:
1709 			/* placeholders for body length and seq. number: */
1710 			xdr_reserve_space(&rqstp->rq_res_stream, XDR_UNIT * 2);
1711 			if (svcauth_gss_unwrap_priv(rqstp, gc->gc_seq,
1712 						    rsci->mechctx))
1713 				goto garbage_args;
1714 			svcxdr_set_auth_slack(rqstp, RPC_MAX_AUTH_SIZE * 2);
1715 			break;
1716 		default:
1717 			goto auth_err;
1718 		}
1719 		svcdata->rsci = rsci;
1720 		cache_get(&rsci->h);
1721 		rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor(
1722 					rsci->mechctx->mech_type,
1723 					GSS_C_QOP_DEFAULT,
1724 					gc->gc_svc);
1725 		ret = SVC_OK;
1726 		trace_rpcgss_svc_authenticate(rqstp, gc);
1727 		goto out;
1728 	}
1729 garbage_args:
1730 	ret = SVC_GARBAGE;
1731 	goto out;
1732 auth_err:
1733 	xdr_truncate_encode(&rqstp->rq_res_stream, XDR_UNIT * 2);
1734 	ret = SVC_DENIED;
1735 	goto out;
1736 complete:
1737 	ret = SVC_COMPLETE;
1738 	goto out;
1739 drop:
1740 	ret = SVC_CLOSE;
1741 out:
1742 	if (rsci)
1743 		cache_put(&rsci->h, sn->rsc_cache);
1744 	return ret;
1745 }
1746 
1747 static u32
1748 svcauth_gss_prepare_to_wrap(struct svc_rqst *rqstp, struct gss_svc_data *gsd)
1749 {
1750 	u32 offset;
1751 
1752 	/* Release can be called twice, but we only wrap once. */
1753 	offset = gsd->gsd_databody_offset;
1754 	gsd->gsd_databody_offset = 0;
1755 
1756 	/* AUTH_ERROR replies are not wrapped. */
1757 	if (rqstp->rq_auth_stat != rpc_auth_ok)
1758 		return 0;
1759 
1760 	/* Also don't wrap if the accept_stat is nonzero: */
1761 	if (*rqstp->rq_accept_statp != rpc_success)
1762 		return 0;
1763 
1764 	return offset;
1765 }
1766 
1767 /*
1768  * RFC 2203, Section 5.3.2.2
1769  *
1770  *	struct rpc_gss_integ_data {
1771  *		opaque databody_integ<>;
1772  *		opaque checksum<>;
1773  *	};
1774  *
1775  *	struct rpc_gss_data_t {
1776  *		unsigned int seq_num;
1777  *		proc_req_arg_t arg;
1778  *	};
1779  *
1780  * The RPC Reply message has already been XDR-encoded. rq_res_stream
1781  * is now positioned so that the checksum can be written just past
1782  * the RPC Reply message.
1783  */
1784 static int svcauth_gss_wrap_integ(struct svc_rqst *rqstp)
1785 {
1786 	struct gss_svc_data *gsd = rqstp->rq_auth_data;
1787 	struct xdr_stream *xdr = &rqstp->rq_res_stream;
1788 	struct rpc_gss_wire_cred *gc = &gsd->clcred;
1789 	struct xdr_buf *buf = xdr->buf;
1790 	struct xdr_buf databody_integ;
1791 	struct xdr_netobj checksum;
1792 	u32 offset, maj_stat;
1793 
1794 	offset = svcauth_gss_prepare_to_wrap(rqstp, gsd);
1795 	if (!offset)
1796 		goto out;
1797 
1798 	if (xdr_buf_subsegment(buf, &databody_integ, offset + XDR_UNIT,
1799 			       buf->len - offset - XDR_UNIT))
1800 		goto wrap_failed;
1801 	/* Buffer space for these has already been reserved in
1802 	 * svcauth_gss_accept(). */
1803 	if (xdr_encode_word(buf, offset, databody_integ.len))
1804 		goto wrap_failed;
1805 	if (xdr_encode_word(buf, offset + XDR_UNIT, gc->gc_seq))
1806 		goto wrap_failed;
1807 
1808 	checksum.data = gsd->gsd_scratch;
1809 	maj_stat = gss_get_mic(gsd->rsci->mechctx, &databody_integ, &checksum);
1810 	if (maj_stat != GSS_S_COMPLETE)
1811 		goto bad_mic;
1812 
1813 	if (xdr_stream_encode_opaque(xdr, checksum.data, checksum.len) < 0)
1814 		goto wrap_failed;
1815 	xdr_commit_encode(xdr);
1816 
1817 out:
1818 	return 0;
1819 
1820 bad_mic:
1821 	trace_rpcgss_svc_get_mic(rqstp, maj_stat);
1822 	return -EINVAL;
1823 wrap_failed:
1824 	trace_rpcgss_svc_wrap_failed(rqstp);
1825 	return -EINVAL;
1826 }
1827 
1828 /*
1829  * RFC 2203, Section 5.3.2.3
1830  *
1831  *	struct rpc_gss_priv_data {
1832  *		opaque databody_priv<>
1833  *	};
1834  *
1835  *	struct rpc_gss_data_t {
1836  *		unsigned int seq_num;
1837  *		proc_req_arg_t arg;
1838  *	};
1839  *
1840  * gss_wrap() expands the size of the RPC message payload in the
1841  * response buffer. The main purpose of svcauth_gss_wrap_priv()
1842  * is to ensure there is adequate space in the response buffer to
1843  * avoid overflow during the wrap.
1844  */
1845 static int svcauth_gss_wrap_priv(struct svc_rqst *rqstp)
1846 {
1847 	struct gss_svc_data *gsd = rqstp->rq_auth_data;
1848 	struct rpc_gss_wire_cred *gc = &gsd->clcred;
1849 	struct xdr_buf *buf = &rqstp->rq_res;
1850 	struct kvec *head = buf->head;
1851 	struct kvec *tail = buf->tail;
1852 	u32 offset, pad, maj_stat;
1853 	__be32 *p;
1854 
1855 	offset = svcauth_gss_prepare_to_wrap(rqstp, gsd);
1856 	if (!offset)
1857 		return 0;
1858 
1859 	/*
1860 	 * Buffer space for this field has already been reserved
1861 	 * in svcauth_gss_accept(). Note that the GSS sequence
1862 	 * number is encrypted along with the RPC reply payload.
1863 	 */
1864 	if (xdr_encode_word(buf, offset + XDR_UNIT, gc->gc_seq))
1865 		goto wrap_failed;
1866 
1867 	/*
1868 	 * If there is currently tail data, make sure there is
1869 	 * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in
1870 	 * the page, and move the current tail data such that
1871 	 * there is RPC_MAX_AUTH_SIZE slack space available in
1872 	 * both the head and tail.
1873 	 */
1874 	if (tail->iov_base) {
1875 		if (tail->iov_base >= head->iov_base + PAGE_SIZE)
1876 			goto wrap_failed;
1877 		if (tail->iov_base < head->iov_base)
1878 			goto wrap_failed;
1879 		if (tail->iov_len + head->iov_len
1880 				+ 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1881 			goto wrap_failed;
1882 		memmove(tail->iov_base + RPC_MAX_AUTH_SIZE, tail->iov_base,
1883 			tail->iov_len);
1884 		tail->iov_base += RPC_MAX_AUTH_SIZE;
1885 	}
1886 	/*
1887 	 * If there is no current tail data, make sure there is
1888 	 * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the
1889 	 * allotted page, and set up tail information such that there
1890 	 * is RPC_MAX_AUTH_SIZE slack space available in both the
1891 	 * head and tail.
1892 	 */
1893 	if (!tail->iov_base) {
1894 		if (head->iov_len + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1895 			goto wrap_failed;
1896 		tail->iov_base = head->iov_base
1897 			+ head->iov_len + RPC_MAX_AUTH_SIZE;
1898 		tail->iov_len = 0;
1899 	}
1900 
1901 	maj_stat = gss_wrap(gsd->rsci->mechctx, offset + XDR_UNIT, buf,
1902 			    buf->pages);
1903 	if (maj_stat != GSS_S_COMPLETE)
1904 		goto bad_wrap;
1905 
1906 	/* Wrapping can change the size of databody_priv. */
1907 	if (xdr_encode_word(buf, offset, buf->len - offset - XDR_UNIT))
1908 		goto wrap_failed;
1909 	pad = xdr_pad_size(buf->len - offset - XDR_UNIT);
1910 	p = (__be32 *)(tail->iov_base + tail->iov_len);
1911 	memset(p, 0, pad);
1912 	tail->iov_len += pad;
1913 	buf->len += pad;
1914 
1915 	return 0;
1916 wrap_failed:
1917 	trace_rpcgss_svc_wrap_failed(rqstp);
1918 	return -EINVAL;
1919 bad_wrap:
1920 	trace_rpcgss_svc_wrap(rqstp, maj_stat);
1921 	return -ENOMEM;
1922 }
1923 
1924 /**
1925  * svcauth_gss_release - Wrap payload and release resources
1926  * @rqstp: RPC transaction context
1927  *
1928  * Return values:
1929  *    %0: the Reply is ready to be sent
1930  *    %-ENOMEM: failed to allocate memory
1931  *    %-EINVAL: encoding error
1932  */
1933 static int
1934 svcauth_gss_release(struct svc_rqst *rqstp)
1935 {
1936 	struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
1937 	struct gss_svc_data *gsd = rqstp->rq_auth_data;
1938 	struct rpc_gss_wire_cred *gc;
1939 	int stat;
1940 
1941 	if (!gsd)
1942 		goto out;
1943 	gc = &gsd->clcred;
1944 	if (gc->gc_proc != RPC_GSS_PROC_DATA)
1945 		goto out;
1946 
1947 	switch (gc->gc_svc) {
1948 	case RPC_GSS_SVC_NONE:
1949 		break;
1950 	case RPC_GSS_SVC_INTEGRITY:
1951 		stat = svcauth_gss_wrap_integ(rqstp);
1952 		if (stat)
1953 			goto out_err;
1954 		break;
1955 	case RPC_GSS_SVC_PRIVACY:
1956 		stat = svcauth_gss_wrap_priv(rqstp);
1957 		if (stat)
1958 			goto out_err;
1959 		break;
1960 	/*
1961 	 * For any other gc_svc value, svcauth_gss_accept() already set
1962 	 * the auth_error appropriately; just fall through:
1963 	 */
1964 	}
1965 
1966 out:
1967 	stat = 0;
1968 out_err:
1969 	if (rqstp->rq_client)
1970 		auth_domain_put(rqstp->rq_client);
1971 	rqstp->rq_client = NULL;
1972 	if (rqstp->rq_gssclient)
1973 		auth_domain_put(rqstp->rq_gssclient);
1974 	rqstp->rq_gssclient = NULL;
1975 	if (rqstp->rq_cred.cr_group_info)
1976 		put_group_info(rqstp->rq_cred.cr_group_info);
1977 	rqstp->rq_cred.cr_group_info = NULL;
1978 	if (gsd && gsd->rsci) {
1979 		cache_put(&gsd->rsci->h, sn->rsc_cache);
1980 		gsd->rsci = NULL;
1981 	}
1982 	return stat;
1983 }
1984 
1985 static void
1986 svcauth_gss_domain_release_rcu(struct rcu_head *head)
1987 {
1988 	struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head);
1989 	struct gss_domain *gd = container_of(dom, struct gss_domain, h);
1990 
1991 	kfree(dom->name);
1992 	kfree(gd);
1993 }
1994 
1995 static void
1996 svcauth_gss_domain_release(struct auth_domain *dom)
1997 {
1998 	call_rcu(&dom->rcu_head, svcauth_gss_domain_release_rcu);
1999 }
2000 
2001 static rpc_authflavor_t svcauth_gss_pseudoflavor(struct svc_rqst *rqstp)
2002 {
2003 	return svcauth_gss_flavor(rqstp->rq_gssclient);
2004 }
2005 
2006 static struct auth_ops svcauthops_gss = {
2007 	.name		= "rpcsec_gss",
2008 	.owner		= THIS_MODULE,
2009 	.flavour	= RPC_AUTH_GSS,
2010 	.accept		= svcauth_gss_accept,
2011 	.release	= svcauth_gss_release,
2012 	.domain_release = svcauth_gss_domain_release,
2013 	.set_client	= svcauth_gss_set_client,
2014 	.pseudoflavor	= svcauth_gss_pseudoflavor,
2015 };
2016 
2017 static int rsi_cache_create_net(struct net *net)
2018 {
2019 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2020 	struct cache_detail *cd;
2021 	int err;
2022 
2023 	cd = cache_create_net(&rsi_cache_template, net);
2024 	if (IS_ERR(cd))
2025 		return PTR_ERR(cd);
2026 	err = cache_register_net(cd, net);
2027 	if (err) {
2028 		cache_destroy_net(cd, net);
2029 		return err;
2030 	}
2031 	sn->rsi_cache = cd;
2032 	return 0;
2033 }
2034 
2035 static void rsi_cache_destroy_net(struct net *net)
2036 {
2037 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2038 	struct cache_detail *cd = sn->rsi_cache;
2039 
2040 	sn->rsi_cache = NULL;
2041 	cache_purge(cd);
2042 	cache_unregister_net(cd, net);
2043 	cache_destroy_net(cd, net);
2044 }
2045 
2046 static int rsc_cache_create_net(struct net *net)
2047 {
2048 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2049 	struct cache_detail *cd;
2050 	int err;
2051 
2052 	cd = cache_create_net(&rsc_cache_template, net);
2053 	if (IS_ERR(cd))
2054 		return PTR_ERR(cd);
2055 	err = cache_register_net(cd, net);
2056 	if (err) {
2057 		cache_destroy_net(cd, net);
2058 		return err;
2059 	}
2060 	sn->rsc_cache = cd;
2061 	return 0;
2062 }
2063 
2064 static void rsc_cache_destroy_net(struct net *net)
2065 {
2066 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2067 	struct cache_detail *cd = sn->rsc_cache;
2068 
2069 	sn->rsc_cache = NULL;
2070 	cache_purge(cd);
2071 	cache_unregister_net(cd, net);
2072 	cache_destroy_net(cd, net);
2073 }
2074 
2075 int
2076 gss_svc_init_net(struct net *net)
2077 {
2078 	int rv;
2079 
2080 	rv = rsc_cache_create_net(net);
2081 	if (rv)
2082 		return rv;
2083 	rv = rsi_cache_create_net(net);
2084 	if (rv)
2085 		goto out1;
2086 	rv = create_use_gss_proxy_proc_entry(net);
2087 	if (rv)
2088 		goto out2;
2089 
2090 	rv = create_krb5_enctypes_proc_entry(net);
2091 	if (rv)
2092 		goto out3;
2093 
2094 	return 0;
2095 
2096 out3:
2097 	destroy_use_gss_proxy_proc_entry(net);
2098 out2:
2099 	rsi_cache_destroy_net(net);
2100 out1:
2101 	rsc_cache_destroy_net(net);
2102 	return rv;
2103 }
2104 
2105 void
2106 gss_svc_shutdown_net(struct net *net)
2107 {
2108 	destroy_krb5_enctypes_proc_entry(net);
2109 	destroy_use_gss_proxy_proc_entry(net);
2110 	rsi_cache_destroy_net(net);
2111 	rsc_cache_destroy_net(net);
2112 }
2113 
2114 int
2115 gss_svc_init(void)
2116 {
2117 	return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
2118 }
2119 
2120 void
2121 gss_svc_shutdown(void)
2122 {
2123 	svc_auth_unregister(RPC_AUTH_GSS);
2124 }
2125