1 /*
2  * Neil Brown <neilb@cse.unsw.edu.au>
3  * J. Bruce Fields <bfields@umich.edu>
4  * Andy Adamson <andros@umich.edu>
5  * Dug Song <dugsong@monkey.org>
6  *
7  * RPCSEC_GSS server authentication.
8  * This implements RPCSEC_GSS as defined in rfc2203 (rpcsec_gss) and rfc2078
9  * (gssapi)
10  *
11  * The RPCSEC_GSS involves three stages:
12  *  1/ context creation
13  *  2/ data exchange
14  *  3/ context destruction
15  *
16  * Context creation is handled largely by upcalls to user-space.
17  *  In particular, GSS_Accept_sec_context is handled by an upcall
18  * Data exchange is handled entirely within the kernel
19  *  In particular, GSS_GetMIC, GSS_VerifyMIC, GSS_Seal, GSS_Unseal are in-kernel.
20  * Context destruction is handled in-kernel
21  *  GSS_Delete_sec_context is in-kernel
22  *
23  * Context creation is initiated by a RPCSEC_GSS_INIT request arriving.
24  * The context handle and gss_token are used as a key into the rpcsec_init cache.
25  * The content of this cache includes some of the outputs of GSS_Accept_sec_context,
26  * being major_status, minor_status, context_handle, reply_token.
27  * These are sent back to the client.
28  * Sequence window management is handled by the kernel.  The window size if currently
29  * a compile time constant.
30  *
31  * When user-space is happy that a context is established, it places an entry
32  * in the rpcsec_context cache. The key for this cache is the context_handle.
33  * The content includes:
34  *   uid/gidlist - for determining access rights
35  *   mechanism type
36  *   mechanism specific information, such as a key
37  *
38  */
39 
40 #include <linux/slab.h>
41 #include <linux/types.h>
42 #include <linux/module.h>
43 #include <linux/pagemap.h>
44 #include <linux/user_namespace.h>
45 
46 #include <linux/sunrpc/auth_gss.h>
47 #include <linux/sunrpc/gss_err.h>
48 #include <linux/sunrpc/svcauth.h>
49 #include <linux/sunrpc/svcauth_gss.h>
50 #include <linux/sunrpc/cache.h>
51 #include "gss_rpc_upcall.h"
52 
53 
54 #ifdef RPC_DEBUG
55 # define RPCDBG_FACILITY	RPCDBG_AUTH
56 #endif
57 
58 /* The rpcsec_init cache is used for mapping RPCSEC_GSS_{,CONT_}INIT requests
59  * into replies.
60  *
61  * Key is context handle (\x if empty) and gss_token.
62  * Content is major_status minor_status (integers) context_handle, reply_token.
63  *
64  */
65 
66 static int netobj_equal(struct xdr_netobj *a, struct xdr_netobj *b)
67 {
68 	return a->len == b->len && 0 == memcmp(a->data, b->data, a->len);
69 }
70 
71 #define	RSI_HASHBITS	6
72 #define	RSI_HASHMAX	(1<<RSI_HASHBITS)
73 
74 struct rsi {
75 	struct cache_head	h;
76 	struct xdr_netobj	in_handle, in_token;
77 	struct xdr_netobj	out_handle, out_token;
78 	int			major_status, minor_status;
79 };
80 
81 static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old);
82 static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item);
83 
84 static void rsi_free(struct rsi *rsii)
85 {
86 	kfree(rsii->in_handle.data);
87 	kfree(rsii->in_token.data);
88 	kfree(rsii->out_handle.data);
89 	kfree(rsii->out_token.data);
90 }
91 
92 static void rsi_put(struct kref *ref)
93 {
94 	struct rsi *rsii = container_of(ref, struct rsi, h.ref);
95 	rsi_free(rsii);
96 	kfree(rsii);
97 }
98 
99 static inline int rsi_hash(struct rsi *item)
100 {
101 	return hash_mem(item->in_handle.data, item->in_handle.len, RSI_HASHBITS)
102 	     ^ hash_mem(item->in_token.data, item->in_token.len, RSI_HASHBITS);
103 }
104 
105 static int rsi_match(struct cache_head *a, struct cache_head *b)
106 {
107 	struct rsi *item = container_of(a, struct rsi, h);
108 	struct rsi *tmp = container_of(b, struct rsi, h);
109 	return netobj_equal(&item->in_handle, &tmp->in_handle) &&
110 	       netobj_equal(&item->in_token, &tmp->in_token);
111 }
112 
113 static int dup_to_netobj(struct xdr_netobj *dst, char *src, int len)
114 {
115 	dst->len = len;
116 	dst->data = (len ? kmemdup(src, len, GFP_KERNEL) : NULL);
117 	if (len && !dst->data)
118 		return -ENOMEM;
119 	return 0;
120 }
121 
122 static inline int dup_netobj(struct xdr_netobj *dst, struct xdr_netobj *src)
123 {
124 	return dup_to_netobj(dst, src->data, src->len);
125 }
126 
127 static void rsi_init(struct cache_head *cnew, struct cache_head *citem)
128 {
129 	struct rsi *new = container_of(cnew, struct rsi, h);
130 	struct rsi *item = container_of(citem, struct rsi, h);
131 
132 	new->out_handle.data = NULL;
133 	new->out_handle.len = 0;
134 	new->out_token.data = NULL;
135 	new->out_token.len = 0;
136 	new->in_handle.len = item->in_handle.len;
137 	item->in_handle.len = 0;
138 	new->in_token.len = item->in_token.len;
139 	item->in_token.len = 0;
140 	new->in_handle.data = item->in_handle.data;
141 	item->in_handle.data = NULL;
142 	new->in_token.data = item->in_token.data;
143 	item->in_token.data = NULL;
144 }
145 
146 static void update_rsi(struct cache_head *cnew, struct cache_head *citem)
147 {
148 	struct rsi *new = container_of(cnew, struct rsi, h);
149 	struct rsi *item = container_of(citem, struct rsi, h);
150 
151 	BUG_ON(new->out_handle.data || new->out_token.data);
152 	new->out_handle.len = item->out_handle.len;
153 	item->out_handle.len = 0;
154 	new->out_token.len = item->out_token.len;
155 	item->out_token.len = 0;
156 	new->out_handle.data = item->out_handle.data;
157 	item->out_handle.data = NULL;
158 	new->out_token.data = item->out_token.data;
159 	item->out_token.data = NULL;
160 
161 	new->major_status = item->major_status;
162 	new->minor_status = item->minor_status;
163 }
164 
165 static struct cache_head *rsi_alloc(void)
166 {
167 	struct rsi *rsii = kmalloc(sizeof(*rsii), GFP_KERNEL);
168 	if (rsii)
169 		return &rsii->h;
170 	else
171 		return NULL;
172 }
173 
174 static void rsi_request(struct cache_detail *cd,
175 		       struct cache_head *h,
176 		       char **bpp, int *blen)
177 {
178 	struct rsi *rsii = container_of(h, struct rsi, h);
179 
180 	qword_addhex(bpp, blen, rsii->in_handle.data, rsii->in_handle.len);
181 	qword_addhex(bpp, blen, rsii->in_token.data, rsii->in_token.len);
182 	(*bpp)[-1] = '\n';
183 }
184 
185 static int rsi_parse(struct cache_detail *cd,
186 		    char *mesg, int mlen)
187 {
188 	/* context token expiry major minor context token */
189 	char *buf = mesg;
190 	char *ep;
191 	int len;
192 	struct rsi rsii, *rsip = NULL;
193 	time_t expiry;
194 	int status = -EINVAL;
195 
196 	memset(&rsii, 0, sizeof(rsii));
197 	/* handle */
198 	len = qword_get(&mesg, buf, mlen);
199 	if (len < 0)
200 		goto out;
201 	status = -ENOMEM;
202 	if (dup_to_netobj(&rsii.in_handle, buf, len))
203 		goto out;
204 
205 	/* token */
206 	len = qword_get(&mesg, buf, mlen);
207 	status = -EINVAL;
208 	if (len < 0)
209 		goto out;
210 	status = -ENOMEM;
211 	if (dup_to_netobj(&rsii.in_token, buf, len))
212 		goto out;
213 
214 	rsip = rsi_lookup(cd, &rsii);
215 	if (!rsip)
216 		goto out;
217 
218 	rsii.h.flags = 0;
219 	/* expiry */
220 	expiry = get_expiry(&mesg);
221 	status = -EINVAL;
222 	if (expiry == 0)
223 		goto out;
224 
225 	/* major/minor */
226 	len = qword_get(&mesg, buf, mlen);
227 	if (len <= 0)
228 		goto out;
229 	rsii.major_status = simple_strtoul(buf, &ep, 10);
230 	if (*ep)
231 		goto out;
232 	len = qword_get(&mesg, buf, mlen);
233 	if (len <= 0)
234 		goto out;
235 	rsii.minor_status = simple_strtoul(buf, &ep, 10);
236 	if (*ep)
237 		goto out;
238 
239 	/* out_handle */
240 	len = qword_get(&mesg, buf, mlen);
241 	if (len < 0)
242 		goto out;
243 	status = -ENOMEM;
244 	if (dup_to_netobj(&rsii.out_handle, buf, len))
245 		goto out;
246 
247 	/* out_token */
248 	len = qword_get(&mesg, buf, mlen);
249 	status = -EINVAL;
250 	if (len < 0)
251 		goto out;
252 	status = -ENOMEM;
253 	if (dup_to_netobj(&rsii.out_token, buf, len))
254 		goto out;
255 	rsii.h.expiry_time = expiry;
256 	rsip = rsi_update(cd, &rsii, rsip);
257 	status = 0;
258 out:
259 	rsi_free(&rsii);
260 	if (rsip)
261 		cache_put(&rsip->h, cd);
262 	else
263 		status = -ENOMEM;
264 	return status;
265 }
266 
267 static struct cache_detail rsi_cache_template = {
268 	.owner		= THIS_MODULE,
269 	.hash_size	= RSI_HASHMAX,
270 	.name           = "auth.rpcsec.init",
271 	.cache_put      = rsi_put,
272 	.cache_request  = rsi_request,
273 	.cache_parse    = rsi_parse,
274 	.match		= rsi_match,
275 	.init		= rsi_init,
276 	.update		= update_rsi,
277 	.alloc		= rsi_alloc,
278 };
279 
280 static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item)
281 {
282 	struct cache_head *ch;
283 	int hash = rsi_hash(item);
284 
285 	ch = sunrpc_cache_lookup(cd, &item->h, hash);
286 	if (ch)
287 		return container_of(ch, struct rsi, h);
288 	else
289 		return NULL;
290 }
291 
292 static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old)
293 {
294 	struct cache_head *ch;
295 	int hash = rsi_hash(new);
296 
297 	ch = sunrpc_cache_update(cd, &new->h,
298 				 &old->h, hash);
299 	if (ch)
300 		return container_of(ch, struct rsi, h);
301 	else
302 		return NULL;
303 }
304 
305 
306 /*
307  * The rpcsec_context cache is used to store a context that is
308  * used in data exchange.
309  * The key is a context handle. The content is:
310  *  uid, gidlist, mechanism, service-set, mech-specific-data
311  */
312 
313 #define	RSC_HASHBITS	10
314 #define	RSC_HASHMAX	(1<<RSC_HASHBITS)
315 
316 #define GSS_SEQ_WIN	128
317 
318 struct gss_svc_seq_data {
319 	/* highest seq number seen so far: */
320 	int			sd_max;
321 	/* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of
322 	 * sd_win is nonzero iff sequence number i has been seen already: */
323 	unsigned long		sd_win[GSS_SEQ_WIN/BITS_PER_LONG];
324 	spinlock_t		sd_lock;
325 };
326 
327 struct rsc {
328 	struct cache_head	h;
329 	struct xdr_netobj	handle;
330 	struct svc_cred		cred;
331 	struct gss_svc_seq_data	seqdata;
332 	struct gss_ctx		*mechctx;
333 };
334 
335 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old);
336 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item);
337 
338 static void rsc_free(struct rsc *rsci)
339 {
340 	kfree(rsci->handle.data);
341 	if (rsci->mechctx)
342 		gss_delete_sec_context(&rsci->mechctx);
343 	free_svc_cred(&rsci->cred);
344 }
345 
346 static void rsc_put(struct kref *ref)
347 {
348 	struct rsc *rsci = container_of(ref, struct rsc, h.ref);
349 
350 	rsc_free(rsci);
351 	kfree(rsci);
352 }
353 
354 static inline int
355 rsc_hash(struct rsc *rsci)
356 {
357 	return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS);
358 }
359 
360 static int
361 rsc_match(struct cache_head *a, struct cache_head *b)
362 {
363 	struct rsc *new = container_of(a, struct rsc, h);
364 	struct rsc *tmp = container_of(b, struct rsc, h);
365 
366 	return netobj_equal(&new->handle, &tmp->handle);
367 }
368 
369 static void
370 rsc_init(struct cache_head *cnew, struct cache_head *ctmp)
371 {
372 	struct rsc *new = container_of(cnew, struct rsc, h);
373 	struct rsc *tmp = container_of(ctmp, struct rsc, h);
374 
375 	new->handle.len = tmp->handle.len;
376 	tmp->handle.len = 0;
377 	new->handle.data = tmp->handle.data;
378 	tmp->handle.data = NULL;
379 	new->mechctx = NULL;
380 	init_svc_cred(&new->cred);
381 }
382 
383 static void
384 update_rsc(struct cache_head *cnew, struct cache_head *ctmp)
385 {
386 	struct rsc *new = container_of(cnew, struct rsc, h);
387 	struct rsc *tmp = container_of(ctmp, struct rsc, h);
388 
389 	new->mechctx = tmp->mechctx;
390 	tmp->mechctx = NULL;
391 	memset(&new->seqdata, 0, sizeof(new->seqdata));
392 	spin_lock_init(&new->seqdata.sd_lock);
393 	new->cred = tmp->cred;
394 	init_svc_cred(&tmp->cred);
395 }
396 
397 static struct cache_head *
398 rsc_alloc(void)
399 {
400 	struct rsc *rsci = kmalloc(sizeof(*rsci), GFP_KERNEL);
401 	if (rsci)
402 		return &rsci->h;
403 	else
404 		return NULL;
405 }
406 
407 static int rsc_parse(struct cache_detail *cd,
408 		     char *mesg, int mlen)
409 {
410 	/* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] */
411 	char *buf = mesg;
412 	int id;
413 	int len, rv;
414 	struct rsc rsci, *rscp = NULL;
415 	time_t expiry;
416 	int status = -EINVAL;
417 	struct gss_api_mech *gm = NULL;
418 
419 	memset(&rsci, 0, sizeof(rsci));
420 	/* context handle */
421 	len = qword_get(&mesg, buf, mlen);
422 	if (len < 0) goto out;
423 	status = -ENOMEM;
424 	if (dup_to_netobj(&rsci.handle, buf, len))
425 		goto out;
426 
427 	rsci.h.flags = 0;
428 	/* expiry */
429 	expiry = get_expiry(&mesg);
430 	status = -EINVAL;
431 	if (expiry == 0)
432 		goto out;
433 
434 	rscp = rsc_lookup(cd, &rsci);
435 	if (!rscp)
436 		goto out;
437 
438 	/* uid, or NEGATIVE */
439 	rv = get_int(&mesg, &id);
440 	if (rv == -EINVAL)
441 		goto out;
442 	if (rv == -ENOENT)
443 		set_bit(CACHE_NEGATIVE, &rsci.h.flags);
444 	else {
445 		int N, i;
446 
447 		/*
448 		 * NOTE: we skip uid_valid()/gid_valid() checks here:
449 		 * instead, * -1 id's are later mapped to the
450 		 * (export-specific) anonymous id by nfsd_setuser.
451 		 *
452 		 * (But supplementary gid's get no such special
453 		 * treatment so are checked for validity here.)
454 		 */
455 		/* uid */
456 		rsci.cred.cr_uid = make_kuid(&init_user_ns, id);
457 
458 		/* gid */
459 		if (get_int(&mesg, &id))
460 			goto out;
461 		rsci.cred.cr_gid = make_kgid(&init_user_ns, id);
462 
463 		/* number of additional gid's */
464 		if (get_int(&mesg, &N))
465 			goto out;
466 		status = -ENOMEM;
467 		rsci.cred.cr_group_info = groups_alloc(N);
468 		if (rsci.cred.cr_group_info == NULL)
469 			goto out;
470 
471 		/* gid's */
472 		status = -EINVAL;
473 		for (i=0; i<N; i++) {
474 			kgid_t kgid;
475 			if (get_int(&mesg, &id))
476 				goto out;
477 			kgid = make_kgid(&init_user_ns, id);
478 			if (!gid_valid(kgid))
479 				goto out;
480 			GROUP_AT(rsci.cred.cr_group_info, i) = kgid;
481 		}
482 
483 		/* mech name */
484 		len = qword_get(&mesg, buf, mlen);
485 		if (len < 0)
486 			goto out;
487 		gm = rsci.cred.cr_gss_mech = gss_mech_get_by_name(buf);
488 		status = -EOPNOTSUPP;
489 		if (!gm)
490 			goto out;
491 
492 		status = -EINVAL;
493 		/* mech-specific data: */
494 		len = qword_get(&mesg, buf, mlen);
495 		if (len < 0)
496 			goto out;
497 		status = gss_import_sec_context(buf, len, gm, &rsci.mechctx,
498 						NULL, GFP_KERNEL);
499 		if (status)
500 			goto out;
501 
502 		/* get client name */
503 		len = qword_get(&mesg, buf, mlen);
504 		if (len > 0) {
505 			rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL);
506 			if (!rsci.cred.cr_principal) {
507 				status = -ENOMEM;
508 				goto out;
509 			}
510 		}
511 
512 	}
513 	rsci.h.expiry_time = expiry;
514 	rscp = rsc_update(cd, &rsci, rscp);
515 	status = 0;
516 out:
517 	rsc_free(&rsci);
518 	if (rscp)
519 		cache_put(&rscp->h, cd);
520 	else
521 		status = -ENOMEM;
522 	return status;
523 }
524 
525 static struct cache_detail rsc_cache_template = {
526 	.owner		= THIS_MODULE,
527 	.hash_size	= RSC_HASHMAX,
528 	.name		= "auth.rpcsec.context",
529 	.cache_put	= rsc_put,
530 	.cache_parse	= rsc_parse,
531 	.match		= rsc_match,
532 	.init		= rsc_init,
533 	.update		= update_rsc,
534 	.alloc		= rsc_alloc,
535 };
536 
537 static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item)
538 {
539 	struct cache_head *ch;
540 	int hash = rsc_hash(item);
541 
542 	ch = sunrpc_cache_lookup(cd, &item->h, hash);
543 	if (ch)
544 		return container_of(ch, struct rsc, h);
545 	else
546 		return NULL;
547 }
548 
549 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old)
550 {
551 	struct cache_head *ch;
552 	int hash = rsc_hash(new);
553 
554 	ch = sunrpc_cache_update(cd, &new->h,
555 				 &old->h, hash);
556 	if (ch)
557 		return container_of(ch, struct rsc, h);
558 	else
559 		return NULL;
560 }
561 
562 
563 static struct rsc *
564 gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle)
565 {
566 	struct rsc rsci;
567 	struct rsc *found;
568 
569 	memset(&rsci, 0, sizeof(rsci));
570 	if (dup_to_netobj(&rsci.handle, handle->data, handle->len))
571 		return NULL;
572 	found = rsc_lookup(cd, &rsci);
573 	rsc_free(&rsci);
574 	if (!found)
575 		return NULL;
576 	if (cache_check(cd, &found->h, NULL))
577 		return NULL;
578 	return found;
579 }
580 
581 /* Implements sequence number algorithm as specified in RFC 2203. */
582 static int
583 gss_check_seq_num(struct rsc *rsci, int seq_num)
584 {
585 	struct gss_svc_seq_data *sd = &rsci->seqdata;
586 
587 	spin_lock(&sd->sd_lock);
588 	if (seq_num > sd->sd_max) {
589 		if (seq_num >= sd->sd_max + GSS_SEQ_WIN) {
590 			memset(sd->sd_win,0,sizeof(sd->sd_win));
591 			sd->sd_max = seq_num;
592 		} else while (sd->sd_max < seq_num) {
593 			sd->sd_max++;
594 			__clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win);
595 		}
596 		__set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
597 		goto ok;
598 	} else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) {
599 		goto drop;
600 	}
601 	/* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */
602 	if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
603 		goto drop;
604 ok:
605 	spin_unlock(&sd->sd_lock);
606 	return 1;
607 drop:
608 	spin_unlock(&sd->sd_lock);
609 	return 0;
610 }
611 
612 static inline u32 round_up_to_quad(u32 i)
613 {
614 	return (i + 3 ) & ~3;
615 }
616 
617 static inline int
618 svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o)
619 {
620 	int l;
621 
622 	if (argv->iov_len < 4)
623 		return -1;
624 	o->len = svc_getnl(argv);
625 	l = round_up_to_quad(o->len);
626 	if (argv->iov_len < l)
627 		return -1;
628 	o->data = argv->iov_base;
629 	argv->iov_base += l;
630 	argv->iov_len -= l;
631 	return 0;
632 }
633 
634 static inline int
635 svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o)
636 {
637 	u8 *p;
638 
639 	if (resv->iov_len + 4 > PAGE_SIZE)
640 		return -1;
641 	svc_putnl(resv, o->len);
642 	p = resv->iov_base + resv->iov_len;
643 	resv->iov_len += round_up_to_quad(o->len);
644 	if (resv->iov_len > PAGE_SIZE)
645 		return -1;
646 	memcpy(p, o->data, o->len);
647 	memset(p + o->len, 0, round_up_to_quad(o->len) - o->len);
648 	return 0;
649 }
650 
651 /*
652  * Verify the checksum on the header and return SVC_OK on success.
653  * Otherwise, return SVC_DROP (in the case of a bad sequence number)
654  * or return SVC_DENIED and indicate error in authp.
655  */
656 static int
657 gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
658 		  __be32 *rpcstart, struct rpc_gss_wire_cred *gc, __be32 *authp)
659 {
660 	struct gss_ctx		*ctx_id = rsci->mechctx;
661 	struct xdr_buf		rpchdr;
662 	struct xdr_netobj	checksum;
663 	u32			flavor = 0;
664 	struct kvec		*argv = &rqstp->rq_arg.head[0];
665 	struct kvec		iov;
666 
667 	/* data to compute the checksum over: */
668 	iov.iov_base = rpcstart;
669 	iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart;
670 	xdr_buf_from_iov(&iov, &rpchdr);
671 
672 	*authp = rpc_autherr_badverf;
673 	if (argv->iov_len < 4)
674 		return SVC_DENIED;
675 	flavor = svc_getnl(argv);
676 	if (flavor != RPC_AUTH_GSS)
677 		return SVC_DENIED;
678 	if (svc_safe_getnetobj(argv, &checksum))
679 		return SVC_DENIED;
680 
681 	if (rqstp->rq_deferred) /* skip verification of revisited request */
682 		return SVC_OK;
683 	if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) {
684 		*authp = rpcsec_gsserr_credproblem;
685 		return SVC_DENIED;
686 	}
687 
688 	if (gc->gc_seq > MAXSEQ) {
689 		dprintk("RPC:       svcauth_gss: discarding request with "
690 				"large sequence number %d\n", gc->gc_seq);
691 		*authp = rpcsec_gsserr_ctxproblem;
692 		return SVC_DENIED;
693 	}
694 	if (!gss_check_seq_num(rsci, gc->gc_seq)) {
695 		dprintk("RPC:       svcauth_gss: discarding request with "
696 				"old sequence number %d\n", gc->gc_seq);
697 		return SVC_DROP;
698 	}
699 	return SVC_OK;
700 }
701 
702 static int
703 gss_write_null_verf(struct svc_rqst *rqstp)
704 {
705 	__be32     *p;
706 
707 	svc_putnl(rqstp->rq_res.head, RPC_AUTH_NULL);
708 	p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
709 	/* don't really need to check if head->iov_len > PAGE_SIZE ... */
710 	*p++ = 0;
711 	if (!xdr_ressize_check(rqstp, p))
712 		return -1;
713 	return 0;
714 }
715 
716 static int
717 gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
718 {
719 	__be32			xdr_seq;
720 	u32			maj_stat;
721 	struct xdr_buf		verf_data;
722 	struct xdr_netobj	mic;
723 	__be32			*p;
724 	struct kvec		iov;
725 
726 	svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS);
727 	xdr_seq = htonl(seq);
728 
729 	iov.iov_base = &xdr_seq;
730 	iov.iov_len = sizeof(xdr_seq);
731 	xdr_buf_from_iov(&iov, &verf_data);
732 	p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
733 	mic.data = (u8 *)(p + 1);
734 	maj_stat = gss_get_mic(ctx_id, &verf_data, &mic);
735 	if (maj_stat != GSS_S_COMPLETE)
736 		return -1;
737 	*p++ = htonl(mic.len);
738 	memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);
739 	p += XDR_QUADLEN(mic.len);
740 	if (!xdr_ressize_check(rqstp, p))
741 		return -1;
742 	return 0;
743 }
744 
745 struct gss_domain {
746 	struct auth_domain	h;
747 	u32			pseudoflavor;
748 };
749 
750 static struct auth_domain *
751 find_gss_auth_domain(struct gss_ctx *ctx, u32 svc)
752 {
753 	char *name;
754 
755 	name = gss_service_to_auth_domain_name(ctx->mech_type, svc);
756 	if (!name)
757 		return NULL;
758 	return auth_domain_find(name);
759 }
760 
761 static struct auth_ops svcauthops_gss;
762 
763 u32 svcauth_gss_flavor(struct auth_domain *dom)
764 {
765 	struct gss_domain *gd = container_of(dom, struct gss_domain, h);
766 
767 	return gd->pseudoflavor;
768 }
769 
770 EXPORT_SYMBOL_GPL(svcauth_gss_flavor);
771 
772 int
773 svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name)
774 {
775 	struct gss_domain	*new;
776 	struct auth_domain	*test;
777 	int			stat = -ENOMEM;
778 
779 	new = kmalloc(sizeof(*new), GFP_KERNEL);
780 	if (!new)
781 		goto out;
782 	kref_init(&new->h.ref);
783 	new->h.name = kstrdup(name, GFP_KERNEL);
784 	if (!new->h.name)
785 		goto out_free_dom;
786 	new->h.flavour = &svcauthops_gss;
787 	new->pseudoflavor = pseudoflavor;
788 
789 	stat = 0;
790 	test = auth_domain_lookup(name, &new->h);
791 	if (test != &new->h) { /* Duplicate registration */
792 		auth_domain_put(test);
793 		kfree(new->h.name);
794 		goto out_free_dom;
795 	}
796 	return 0;
797 
798 out_free_dom:
799 	kfree(new);
800 out:
801 	return stat;
802 }
803 
804 EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor);
805 
806 static inline int
807 read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
808 {
809 	__be32  raw;
810 	int     status;
811 
812 	status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
813 	if (status)
814 		return status;
815 	*obj = ntohl(raw);
816 	return 0;
817 }
818 
819 /* It would be nice if this bit of code could be shared with the client.
820  * Obstacles:
821  *	The client shouldn't malloc(), would have to pass in own memory.
822  *	The server uses base of head iovec as read pointer, while the
823  *	client uses separate pointer. */
824 static int
825 unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
826 {
827 	int stat = -EINVAL;
828 	u32 integ_len, maj_stat;
829 	struct xdr_netobj mic;
830 	struct xdr_buf integ_buf;
831 
832 	/* Did we already verify the signature on the original pass through? */
833 	if (rqstp->rq_deferred)
834 		return 0;
835 
836 	integ_len = svc_getnl(&buf->head[0]);
837 	if (integ_len & 3)
838 		return stat;
839 	if (integ_len > buf->len)
840 		return stat;
841 	if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
842 		BUG();
843 	/* copy out mic... */
844 	if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
845 		BUG();
846 	if (mic.len > RPC_MAX_AUTH_SIZE)
847 		return stat;
848 	mic.data = kmalloc(mic.len, GFP_KERNEL);
849 	if (!mic.data)
850 		return stat;
851 	if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len))
852 		goto out;
853 	maj_stat = gss_verify_mic(ctx, &integ_buf, &mic);
854 	if (maj_stat != GSS_S_COMPLETE)
855 		goto out;
856 	if (svc_getnl(&buf->head[0]) != seq)
857 		goto out;
858 	/* trim off the mic at the end before returning */
859 	xdr_buf_trim(buf, mic.len + 4);
860 	stat = 0;
861 out:
862 	kfree(mic.data);
863 	return stat;
864 }
865 
866 static inline int
867 total_buf_len(struct xdr_buf *buf)
868 {
869 	return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len;
870 }
871 
872 static void
873 fix_priv_head(struct xdr_buf *buf, int pad)
874 {
875 	if (buf->page_len == 0) {
876 		/* We need to adjust head and buf->len in tandem in this
877 		 * case to make svc_defer() work--it finds the original
878 		 * buffer start using buf->len - buf->head[0].iov_len. */
879 		buf->head[0].iov_len -= pad;
880 	}
881 }
882 
883 static int
884 unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
885 {
886 	u32 priv_len, maj_stat;
887 	int pad, saved_len, remaining_len, offset;
888 
889 	rqstp->rq_splice_ok = 0;
890 
891 	priv_len = svc_getnl(&buf->head[0]);
892 	if (rqstp->rq_deferred) {
893 		/* Already decrypted last time through! The sequence number
894 		 * check at out_seq is unnecessary but harmless: */
895 		goto out_seq;
896 	}
897 	/* buf->len is the number of bytes from the original start of the
898 	 * request to the end, where head[0].iov_len is just the bytes
899 	 * not yet read from the head, so these two values are different: */
900 	remaining_len = total_buf_len(buf);
901 	if (priv_len > remaining_len)
902 		return -EINVAL;
903 	pad = remaining_len - priv_len;
904 	buf->len -= pad;
905 	fix_priv_head(buf, pad);
906 
907 	/* Maybe it would be better to give gss_unwrap a length parameter: */
908 	saved_len = buf->len;
909 	buf->len = priv_len;
910 	maj_stat = gss_unwrap(ctx, 0, buf);
911 	pad = priv_len - buf->len;
912 	buf->len = saved_len;
913 	buf->len -= pad;
914 	/* The upper layers assume the buffer is aligned on 4-byte boundaries.
915 	 * In the krb5p case, at least, the data ends up offset, so we need to
916 	 * move it around. */
917 	/* XXX: This is very inefficient.  It would be better to either do
918 	 * this while we encrypt, or maybe in the receive code, if we can peak
919 	 * ahead and work out the service and mechanism there. */
920 	offset = buf->head[0].iov_len % 4;
921 	if (offset) {
922 		buf->buflen = RPCSVC_MAXPAYLOAD;
923 		xdr_shift_buf(buf, offset);
924 		fix_priv_head(buf, pad);
925 	}
926 	if (maj_stat != GSS_S_COMPLETE)
927 		return -EINVAL;
928 out_seq:
929 	if (svc_getnl(&buf->head[0]) != seq)
930 		return -EINVAL;
931 	return 0;
932 }
933 
934 struct gss_svc_data {
935 	/* decoded gss client cred: */
936 	struct rpc_gss_wire_cred	clcred;
937 	/* save a pointer to the beginning of the encoded verifier,
938 	 * for use in encryption/checksumming in svcauth_gss_release: */
939 	__be32				*verf_start;
940 	struct rsc			*rsci;
941 };
942 
943 static int
944 svcauth_gss_set_client(struct svc_rqst *rqstp)
945 {
946 	struct gss_svc_data *svcdata = rqstp->rq_auth_data;
947 	struct rsc *rsci = svcdata->rsci;
948 	struct rpc_gss_wire_cred *gc = &svcdata->clcred;
949 	int stat;
950 
951 	/*
952 	 * A gss export can be specified either by:
953 	 * 	export	*(sec=krb5,rw)
954 	 * or by
955 	 * 	export gss/krb5(rw)
956 	 * The latter is deprecated; but for backwards compatibility reasons
957 	 * the nfsd code will still fall back on trying it if the former
958 	 * doesn't work; so we try to make both available to nfsd, below.
959 	 */
960 	rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
961 	if (rqstp->rq_gssclient == NULL)
962 		return SVC_DENIED;
963 	stat = svcauth_unix_set_client(rqstp);
964 	if (stat == SVC_DROP || stat == SVC_CLOSE)
965 		return stat;
966 	return SVC_OK;
967 }
968 
969 static inline int
970 gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
971 		struct xdr_netobj *out_handle, int *major_status)
972 {
973 	struct rsc *rsci;
974 	int        rc;
975 
976 	if (*major_status != GSS_S_COMPLETE)
977 		return gss_write_null_verf(rqstp);
978 	rsci = gss_svc_searchbyctx(cd, out_handle);
979 	if (rsci == NULL) {
980 		*major_status = GSS_S_NO_CONTEXT;
981 		return gss_write_null_verf(rqstp);
982 	}
983 	rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN);
984 	cache_put(&rsci->h, cd);
985 	return rc;
986 }
987 
988 static inline int
989 gss_read_common_verf(struct rpc_gss_wire_cred *gc,
990 		     struct kvec *argv, __be32 *authp,
991 		     struct xdr_netobj *in_handle)
992 {
993 	/* Read the verifier; should be NULL: */
994 	*authp = rpc_autherr_badverf;
995 	if (argv->iov_len < 2 * 4)
996 		return SVC_DENIED;
997 	if (svc_getnl(argv) != RPC_AUTH_NULL)
998 		return SVC_DENIED;
999 	if (svc_getnl(argv) != 0)
1000 		return SVC_DENIED;
1001 	/* Martial context handle and token for upcall: */
1002 	*authp = rpc_autherr_badcred;
1003 	if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
1004 		return SVC_DENIED;
1005 	if (dup_netobj(in_handle, &gc->gc_ctx))
1006 		return SVC_CLOSE;
1007 	*authp = rpc_autherr_badverf;
1008 
1009 	return 0;
1010 }
1011 
1012 static inline int
1013 gss_read_verf(struct rpc_gss_wire_cred *gc,
1014 	      struct kvec *argv, __be32 *authp,
1015 	      struct xdr_netobj *in_handle,
1016 	      struct xdr_netobj *in_token)
1017 {
1018 	struct xdr_netobj tmpobj;
1019 	int res;
1020 
1021 	res = gss_read_common_verf(gc, argv, authp, in_handle);
1022 	if (res)
1023 		return res;
1024 
1025 	if (svc_safe_getnetobj(argv, &tmpobj)) {
1026 		kfree(in_handle->data);
1027 		return SVC_DENIED;
1028 	}
1029 	if (dup_netobj(in_token, &tmpobj)) {
1030 		kfree(in_handle->data);
1031 		return SVC_CLOSE;
1032 	}
1033 
1034 	return 0;
1035 }
1036 
1037 /* Ok this is really heavily depending on a set of semantics in
1038  * how rqstp is set up by svc_recv and pages laid down by the
1039  * server when reading a request. We are basically guaranteed that
1040  * the token lays all down linearly across a set of pages, starting
1041  * at iov_base in rq_arg.head[0] which happens to be the first of a
1042  * set of pages stored in rq_pages[].
1043  * rq_arg.head[0].iov_base will provide us the page_base to pass
1044  * to the upcall.
1045  */
1046 static inline int
1047 gss_read_proxy_verf(struct svc_rqst *rqstp,
1048 		    struct rpc_gss_wire_cred *gc, __be32 *authp,
1049 		    struct xdr_netobj *in_handle,
1050 		    struct gssp_in_token *in_token)
1051 {
1052 	struct kvec *argv = &rqstp->rq_arg.head[0];
1053 	u32 inlen;
1054 	int res;
1055 
1056 	res = gss_read_common_verf(gc, argv, authp, in_handle);
1057 	if (res)
1058 		return res;
1059 
1060 	inlen = svc_getnl(argv);
1061 	if (inlen > (argv->iov_len + rqstp->rq_arg.page_len))
1062 		return SVC_DENIED;
1063 
1064 	in_token->pages = rqstp->rq_pages;
1065 	in_token->page_base = (ulong)argv->iov_base & ~PAGE_MASK;
1066 	in_token->page_len = inlen;
1067 
1068 	return 0;
1069 }
1070 
1071 static inline int
1072 gss_write_resv(struct kvec *resv, size_t size_limit,
1073 	       struct xdr_netobj *out_handle, struct xdr_netobj *out_token,
1074 	       int major_status, int minor_status)
1075 {
1076 	if (resv->iov_len + 4 > size_limit)
1077 		return -1;
1078 	svc_putnl(resv, RPC_SUCCESS);
1079 	if (svc_safe_putnetobj(resv, out_handle))
1080 		return -1;
1081 	if (resv->iov_len + 3 * 4 > size_limit)
1082 		return -1;
1083 	svc_putnl(resv, major_status);
1084 	svc_putnl(resv, minor_status);
1085 	svc_putnl(resv, GSS_SEQ_WIN);
1086 	if (svc_safe_putnetobj(resv, out_token))
1087 		return -1;
1088 	return 0;
1089 }
1090 
1091 /*
1092  * Having read the cred already and found we're in the context
1093  * initiation case, read the verifier and initiate (or check the results
1094  * of) upcalls to userspace for help with context initiation.  If
1095  * the upcall results are available, write the verifier and result.
1096  * Otherwise, drop the request pending an answer to the upcall.
1097  */
1098 static int svcauth_gss_legacy_init(struct svc_rqst *rqstp,
1099 			struct rpc_gss_wire_cred *gc, __be32 *authp)
1100 {
1101 	struct kvec *argv = &rqstp->rq_arg.head[0];
1102 	struct kvec *resv = &rqstp->rq_res.head[0];
1103 	struct rsi *rsip, rsikey;
1104 	int ret;
1105 	struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1106 
1107 	memset(&rsikey, 0, sizeof(rsikey));
1108 	ret = gss_read_verf(gc, argv, authp,
1109 			    &rsikey.in_handle, &rsikey.in_token);
1110 	if (ret)
1111 		return ret;
1112 
1113 	/* Perform upcall, or find upcall result: */
1114 	rsip = rsi_lookup(sn->rsi_cache, &rsikey);
1115 	rsi_free(&rsikey);
1116 	if (!rsip)
1117 		return SVC_CLOSE;
1118 	if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0)
1119 		/* No upcall result: */
1120 		return SVC_CLOSE;
1121 
1122 	ret = SVC_CLOSE;
1123 	/* Got an answer to the upcall; use it: */
1124 	if (gss_write_init_verf(sn->rsc_cache, rqstp,
1125 				&rsip->out_handle, &rsip->major_status))
1126 		goto out;
1127 	if (gss_write_resv(resv, PAGE_SIZE,
1128 			   &rsip->out_handle, &rsip->out_token,
1129 			   rsip->major_status, rsip->minor_status))
1130 		goto out;
1131 
1132 	ret = SVC_COMPLETE;
1133 out:
1134 	cache_put(&rsip->h, sn->rsi_cache);
1135 	return ret;
1136 }
1137 
1138 static int gss_proxy_save_rsc(struct cache_detail *cd,
1139 				struct gssp_upcall_data *ud,
1140 				uint64_t *handle)
1141 {
1142 	struct rsc rsci, *rscp = NULL;
1143 	static atomic64_t ctxhctr;
1144 	long long ctxh;
1145 	struct gss_api_mech *gm = NULL;
1146 	time_t expiry;
1147 	int status = -EINVAL;
1148 
1149 	memset(&rsci, 0, sizeof(rsci));
1150 	/* context handle */
1151 	status = -ENOMEM;
1152 	/* the handle needs to be just a unique id,
1153 	 * use a static counter */
1154 	ctxh = atomic64_inc_return(&ctxhctr);
1155 
1156 	/* make a copy for the caller */
1157 	*handle = ctxh;
1158 
1159 	/* make a copy for the rsc cache */
1160 	if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t)))
1161 		goto out;
1162 	rscp = rsc_lookup(cd, &rsci);
1163 	if (!rscp)
1164 		goto out;
1165 
1166 	/* creds */
1167 	if (!ud->found_creds) {
1168 		/* userspace seem buggy, we should always get at least a
1169 		 * mapping to nobody */
1170 		dprintk("RPC:       No creds found, marking Negative!\n");
1171 		set_bit(CACHE_NEGATIVE, &rsci.h.flags);
1172 	} else {
1173 
1174 		/* steal creds */
1175 		rsci.cred = ud->creds;
1176 		memset(&ud->creds, 0, sizeof(struct svc_cred));
1177 
1178 		status = -EOPNOTSUPP;
1179 		/* get mech handle from OID */
1180 		gm = gss_mech_get_by_OID(&ud->mech_oid);
1181 		if (!gm)
1182 			goto out;
1183 		rsci.cred.cr_gss_mech = gm;
1184 
1185 		status = -EINVAL;
1186 		/* mech-specific data: */
1187 		status = gss_import_sec_context(ud->out_handle.data,
1188 						ud->out_handle.len,
1189 						gm, &rsci.mechctx,
1190 						&expiry, GFP_KERNEL);
1191 		if (status)
1192 			goto out;
1193 	}
1194 
1195 	rsci.h.expiry_time = expiry;
1196 	rscp = rsc_update(cd, &rsci, rscp);
1197 	status = 0;
1198 out:
1199 	rsc_free(&rsci);
1200 	if (rscp)
1201 		cache_put(&rscp->h, cd);
1202 	else
1203 		status = -ENOMEM;
1204 	return status;
1205 }
1206 
1207 static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
1208 			struct rpc_gss_wire_cred *gc, __be32 *authp)
1209 {
1210 	struct kvec *resv = &rqstp->rq_res.head[0];
1211 	struct xdr_netobj cli_handle;
1212 	struct gssp_upcall_data ud;
1213 	uint64_t handle;
1214 	int status;
1215 	int ret;
1216 	struct net *net = rqstp->rq_xprt->xpt_net;
1217 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1218 
1219 	memset(&ud, 0, sizeof(ud));
1220 	ret = gss_read_proxy_verf(rqstp, gc, authp,
1221 				  &ud.in_handle, &ud.in_token);
1222 	if (ret)
1223 		return ret;
1224 
1225 	ret = SVC_CLOSE;
1226 
1227 	/* Perform synchronous upcall to gss-proxy */
1228 	status = gssp_accept_sec_context_upcall(net, &ud);
1229 	if (status)
1230 		goto out;
1231 
1232 	dprintk("RPC:       svcauth_gss: gss major status = %d\n",
1233 			ud.major_status);
1234 
1235 	switch (ud.major_status) {
1236 	case GSS_S_CONTINUE_NEEDED:
1237 		cli_handle = ud.out_handle;
1238 		break;
1239 	case GSS_S_COMPLETE:
1240 		status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle);
1241 		if (status)
1242 			goto out;
1243 		cli_handle.data = (u8 *)&handle;
1244 		cli_handle.len = sizeof(handle);
1245 		break;
1246 	default:
1247 		ret = SVC_CLOSE;
1248 		goto out;
1249 	}
1250 
1251 	/* Got an answer to the upcall; use it: */
1252 	if (gss_write_init_verf(sn->rsc_cache, rqstp,
1253 				&cli_handle, &ud.major_status))
1254 		goto out;
1255 	if (gss_write_resv(resv, PAGE_SIZE,
1256 			   &cli_handle, &ud.out_token,
1257 			   ud.major_status, ud.minor_status))
1258 		goto out;
1259 
1260 	ret = SVC_COMPLETE;
1261 out:
1262 	gssp_free_upcall_data(&ud);
1263 	return ret;
1264 }
1265 
1266 DEFINE_SPINLOCK(use_gssp_lock);
1267 
1268 static bool use_gss_proxy(struct net *net)
1269 {
1270 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1271 
1272 	if (sn->use_gss_proxy != -1)
1273 		return sn->use_gss_proxy;
1274 	spin_lock(&use_gssp_lock);
1275 	/*
1276 	 * If you wanted gss-proxy, you should have said so before
1277 	 * starting to accept requests:
1278 	 */
1279 	sn->use_gss_proxy = 0;
1280 	spin_unlock(&use_gssp_lock);
1281 	return 0;
1282 }
1283 
1284 #ifdef CONFIG_PROC_FS
1285 
1286 static int set_gss_proxy(struct net *net, int type)
1287 {
1288 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1289 	int ret = 0;
1290 
1291 	WARN_ON_ONCE(type != 0 && type != 1);
1292 	spin_lock(&use_gssp_lock);
1293 	if (sn->use_gss_proxy == -1 || sn->use_gss_proxy == type)
1294 		sn->use_gss_proxy = type;
1295 	else
1296 		ret = -EBUSY;
1297 	spin_unlock(&use_gssp_lock);
1298 	wake_up(&sn->gssp_wq);
1299 	return ret;
1300 }
1301 
1302 static inline bool gssp_ready(struct sunrpc_net *sn)
1303 {
1304 	switch (sn->use_gss_proxy) {
1305 		case -1:
1306 			return false;
1307 		case 0:
1308 			return true;
1309 		case 1:
1310 			return sn->gssp_clnt;
1311 	}
1312 	WARN_ON_ONCE(1);
1313 	return false;
1314 }
1315 
1316 static int wait_for_gss_proxy(struct net *net, struct file *file)
1317 {
1318 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1319 
1320 	if (file->f_flags & O_NONBLOCK && !gssp_ready(sn))
1321 		return -EAGAIN;
1322 	return wait_event_interruptible(sn->gssp_wq, gssp_ready(sn));
1323 }
1324 
1325 
1326 static ssize_t write_gssp(struct file *file, const char __user *buf,
1327 			 size_t count, loff_t *ppos)
1328 {
1329 	struct net *net = PDE_DATA(file_inode(file));
1330 	char tbuf[20];
1331 	unsigned long i;
1332 	int res;
1333 
1334 	if (*ppos || count > sizeof(tbuf)-1)
1335 		return -EINVAL;
1336 	if (copy_from_user(tbuf, buf, count))
1337 		return -EFAULT;
1338 
1339 	tbuf[count] = 0;
1340 	res = kstrtoul(tbuf, 0, &i);
1341 	if (res)
1342 		return res;
1343 	if (i != 1)
1344 		return -EINVAL;
1345 	res = set_gss_proxy(net, 1);
1346 	if (res)
1347 		return res;
1348 	res = set_gssp_clnt(net);
1349 	if (res)
1350 		return res;
1351 	return count;
1352 }
1353 
1354 static ssize_t read_gssp(struct file *file, char __user *buf,
1355 			 size_t count, loff_t *ppos)
1356 {
1357 	struct net *net = PDE_DATA(file_inode(file));
1358 	unsigned long p = *ppos;
1359 	char tbuf[10];
1360 	size_t len;
1361 	int ret;
1362 
1363 	ret = wait_for_gss_proxy(net, file);
1364 	if (ret)
1365 		return ret;
1366 
1367 	snprintf(tbuf, sizeof(tbuf), "%d\n", use_gss_proxy(net));
1368 	len = strlen(tbuf);
1369 	if (p >= len)
1370 		return 0;
1371 	len -= p;
1372 	if (len > count)
1373 		len = count;
1374 	if (copy_to_user(buf, (void *)(tbuf+p), len))
1375 		return -EFAULT;
1376 	*ppos += len;
1377 	return len;
1378 }
1379 
1380 static const struct file_operations use_gss_proxy_ops = {
1381 	.open = nonseekable_open,
1382 	.write = write_gssp,
1383 	.read = read_gssp,
1384 };
1385 
1386 static int create_use_gss_proxy_proc_entry(struct net *net)
1387 {
1388 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1389 	struct proc_dir_entry **p = &sn->use_gssp_proc;
1390 
1391 	sn->use_gss_proxy = -1;
1392 	*p = proc_create_data("use-gss-proxy", S_IFREG|S_IRUSR|S_IWUSR,
1393 			      sn->proc_net_rpc,
1394 			      &use_gss_proxy_ops, net);
1395 	if (!*p)
1396 		return -ENOMEM;
1397 	init_gssp_clnt(sn);
1398 	return 0;
1399 }
1400 
1401 static void destroy_use_gss_proxy_proc_entry(struct net *net)
1402 {
1403 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1404 
1405 	if (sn->use_gssp_proc) {
1406 		remove_proc_entry("use-gss-proxy", sn->proc_net_rpc);
1407 		clear_gssp_clnt(sn);
1408 	}
1409 }
1410 #else /* CONFIG_PROC_FS */
1411 
1412 static int create_use_gss_proxy_proc_entry(struct net *net)
1413 {
1414 	return 0;
1415 }
1416 
1417 static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
1418 
1419 #endif /* CONFIG_PROC_FS */
1420 
1421 /*
1422  * Accept an rpcsec packet.
1423  * If context establishment, punt to user space
1424  * If data exchange, verify/decrypt
1425  * If context destruction, handle here
1426  * In the context establishment and destruction case we encode
1427  * response here and return SVC_COMPLETE.
1428  */
1429 static int
1430 svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
1431 {
1432 	struct kvec	*argv = &rqstp->rq_arg.head[0];
1433 	struct kvec	*resv = &rqstp->rq_res.head[0];
1434 	u32		crlen;
1435 	struct gss_svc_data *svcdata = rqstp->rq_auth_data;
1436 	struct rpc_gss_wire_cred *gc;
1437 	struct rsc	*rsci = NULL;
1438 	__be32		*rpcstart;
1439 	__be32		*reject_stat = resv->iov_base + resv->iov_len;
1440 	int		ret;
1441 	struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1442 
1443 	dprintk("RPC:       svcauth_gss: argv->iov_len = %zd\n",
1444 			argv->iov_len);
1445 
1446 	*authp = rpc_autherr_badcred;
1447 	if (!svcdata)
1448 		svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
1449 	if (!svcdata)
1450 		goto auth_err;
1451 	rqstp->rq_auth_data = svcdata;
1452 	svcdata->verf_start = NULL;
1453 	svcdata->rsci = NULL;
1454 	gc = &svcdata->clcred;
1455 
1456 	/* start of rpc packet is 7 u32's back from here:
1457 	 * xid direction rpcversion prog vers proc flavour
1458 	 */
1459 	rpcstart = argv->iov_base;
1460 	rpcstart -= 7;
1461 
1462 	/* credential is:
1463 	 *   version(==1), proc(0,1,2,3), seq, service (1,2,3), handle
1464 	 * at least 5 u32s, and is preceded by length, so that makes 6.
1465 	 */
1466 
1467 	if (argv->iov_len < 5 * 4)
1468 		goto auth_err;
1469 	crlen = svc_getnl(argv);
1470 	if (svc_getnl(argv) != RPC_GSS_VERSION)
1471 		goto auth_err;
1472 	gc->gc_proc = svc_getnl(argv);
1473 	gc->gc_seq = svc_getnl(argv);
1474 	gc->gc_svc = svc_getnl(argv);
1475 	if (svc_safe_getnetobj(argv, &gc->gc_ctx))
1476 		goto auth_err;
1477 	if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4)
1478 		goto auth_err;
1479 
1480 	if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
1481 		goto auth_err;
1482 
1483 	*authp = rpc_autherr_badverf;
1484 	switch (gc->gc_proc) {
1485 	case RPC_GSS_PROC_INIT:
1486 	case RPC_GSS_PROC_CONTINUE_INIT:
1487 		if (use_gss_proxy(SVC_NET(rqstp)))
1488 			return svcauth_gss_proxy_init(rqstp, gc, authp);
1489 		else
1490 			return svcauth_gss_legacy_init(rqstp, gc, authp);
1491 	case RPC_GSS_PROC_DATA:
1492 	case RPC_GSS_PROC_DESTROY:
1493 		/* Look up the context, and check the verifier: */
1494 		*authp = rpcsec_gsserr_credproblem;
1495 		rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
1496 		if (!rsci)
1497 			goto auth_err;
1498 		switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) {
1499 		case SVC_OK:
1500 			break;
1501 		case SVC_DENIED:
1502 			goto auth_err;
1503 		case SVC_DROP:
1504 			goto drop;
1505 		}
1506 		break;
1507 	default:
1508 		*authp = rpc_autherr_rejectedcred;
1509 		goto auth_err;
1510 	}
1511 
1512 	/* now act upon the command: */
1513 	switch (gc->gc_proc) {
1514 	case RPC_GSS_PROC_DESTROY:
1515 		if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1516 			goto auth_err;
1517 		rsci->h.expiry_time = get_seconds();
1518 		set_bit(CACHE_NEGATIVE, &rsci->h.flags);
1519 		if (resv->iov_len + 4 > PAGE_SIZE)
1520 			goto drop;
1521 		svc_putnl(resv, RPC_SUCCESS);
1522 		goto complete;
1523 	case RPC_GSS_PROC_DATA:
1524 		*authp = rpcsec_gsserr_ctxproblem;
1525 		svcdata->verf_start = resv->iov_base + resv->iov_len;
1526 		if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
1527 			goto auth_err;
1528 		rqstp->rq_cred = rsci->cred;
1529 		get_group_info(rsci->cred.cr_group_info);
1530 		*authp = rpc_autherr_badcred;
1531 		switch (gc->gc_svc) {
1532 		case RPC_GSS_SVC_NONE:
1533 			break;
1534 		case RPC_GSS_SVC_INTEGRITY:
1535 			/* placeholders for length and seq. number: */
1536 			svc_putnl(resv, 0);
1537 			svc_putnl(resv, 0);
1538 			if (unwrap_integ_data(rqstp, &rqstp->rq_arg,
1539 					gc->gc_seq, rsci->mechctx))
1540 				goto garbage_args;
1541 			break;
1542 		case RPC_GSS_SVC_PRIVACY:
1543 			/* placeholders for length and seq. number: */
1544 			svc_putnl(resv, 0);
1545 			svc_putnl(resv, 0);
1546 			if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
1547 					gc->gc_seq, rsci->mechctx))
1548 				goto garbage_args;
1549 			break;
1550 		default:
1551 			goto auth_err;
1552 		}
1553 		svcdata->rsci = rsci;
1554 		cache_get(&rsci->h);
1555 		rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor(
1556 					rsci->mechctx->mech_type,
1557 					GSS_C_QOP_DEFAULT,
1558 					gc->gc_svc);
1559 		ret = SVC_OK;
1560 		goto out;
1561 	}
1562 garbage_args:
1563 	ret = SVC_GARBAGE;
1564 	goto out;
1565 auth_err:
1566 	/* Restore write pointer to its original value: */
1567 	xdr_ressize_check(rqstp, reject_stat);
1568 	ret = SVC_DENIED;
1569 	goto out;
1570 complete:
1571 	ret = SVC_COMPLETE;
1572 	goto out;
1573 drop:
1574 	ret = SVC_DROP;
1575 out:
1576 	if (rsci)
1577 		cache_put(&rsci->h, sn->rsc_cache);
1578 	return ret;
1579 }
1580 
1581 static __be32 *
1582 svcauth_gss_prepare_to_wrap(struct xdr_buf *resbuf, struct gss_svc_data *gsd)
1583 {
1584 	__be32 *p;
1585 	u32 verf_len;
1586 
1587 	p = gsd->verf_start;
1588 	gsd->verf_start = NULL;
1589 
1590 	/* If the reply stat is nonzero, don't wrap: */
1591 	if (*(p-1) != rpc_success)
1592 		return NULL;
1593 	/* Skip the verifier: */
1594 	p += 1;
1595 	verf_len = ntohl(*p++);
1596 	p += XDR_QUADLEN(verf_len);
1597 	/* move accept_stat to right place: */
1598 	memcpy(p, p + 2, 4);
1599 	/* Also don't wrap if the accept stat is nonzero: */
1600 	if (*p != rpc_success) {
1601 		resbuf->head[0].iov_len -= 2 * 4;
1602 		return NULL;
1603 	}
1604 	p++;
1605 	return p;
1606 }
1607 
1608 static inline int
1609 svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
1610 {
1611 	struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1612 	struct rpc_gss_wire_cred *gc = &gsd->clcred;
1613 	struct xdr_buf *resbuf = &rqstp->rq_res;
1614 	struct xdr_buf integ_buf;
1615 	struct xdr_netobj mic;
1616 	struct kvec *resv;
1617 	__be32 *p;
1618 	int integ_offset, integ_len;
1619 	int stat = -EINVAL;
1620 
1621 	p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1622 	if (p == NULL)
1623 		goto out;
1624 	integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base;
1625 	integ_len = resbuf->len - integ_offset;
1626 	BUG_ON(integ_len % 4);
1627 	*p++ = htonl(integ_len);
1628 	*p++ = htonl(gc->gc_seq);
1629 	if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset,
1630 				integ_len))
1631 		BUG();
1632 	if (resbuf->tail[0].iov_base == NULL) {
1633 		if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1634 			goto out_err;
1635 		resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1636 						+ resbuf->head[0].iov_len;
1637 		resbuf->tail[0].iov_len = 0;
1638 		resv = &resbuf->tail[0];
1639 	} else {
1640 		resv = &resbuf->tail[0];
1641 	}
1642 	mic.data = (u8 *)resv->iov_base + resv->iov_len + 4;
1643 	if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic))
1644 		goto out_err;
1645 	svc_putnl(resv, mic.len);
1646 	memset(mic.data + mic.len, 0,
1647 			round_up_to_quad(mic.len) - mic.len);
1648 	resv->iov_len += XDR_QUADLEN(mic.len) << 2;
1649 	/* not strictly required: */
1650 	resbuf->len += XDR_QUADLEN(mic.len) << 2;
1651 	BUG_ON(resv->iov_len > PAGE_SIZE);
1652 out:
1653 	stat = 0;
1654 out_err:
1655 	return stat;
1656 }
1657 
1658 static inline int
1659 svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
1660 {
1661 	struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1662 	struct rpc_gss_wire_cred *gc = &gsd->clcred;
1663 	struct xdr_buf *resbuf = &rqstp->rq_res;
1664 	struct page **inpages = NULL;
1665 	__be32 *p, *len;
1666 	int offset;
1667 	int pad;
1668 
1669 	p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
1670 	if (p == NULL)
1671 		return 0;
1672 	len = p++;
1673 	offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base;
1674 	*p++ = htonl(gc->gc_seq);
1675 	inpages = resbuf->pages;
1676 	/* XXX: Would be better to write some xdr helper functions for
1677 	 * nfs{2,3,4}xdr.c that place the data right, instead of copying: */
1678 
1679 	/*
1680 	 * If there is currently tail data, make sure there is
1681 	 * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in
1682 	 * the page, and move the current tail data such that
1683 	 * there is RPC_MAX_AUTH_SIZE slack space available in
1684 	 * both the head and tail.
1685 	 */
1686 	if (resbuf->tail[0].iov_base) {
1687 		BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
1688 							+ PAGE_SIZE);
1689 		BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base);
1690 		if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len
1691 				+ 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1692 			return -ENOMEM;
1693 		memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE,
1694 			resbuf->tail[0].iov_base,
1695 			resbuf->tail[0].iov_len);
1696 		resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
1697 	}
1698 	/*
1699 	 * If there is no current tail data, make sure there is
1700 	 * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the
1701 	 * allotted page, and set up tail information such that there
1702 	 * is RPC_MAX_AUTH_SIZE slack space available in both the
1703 	 * head and tail.
1704 	 */
1705 	if (resbuf->tail[0].iov_base == NULL) {
1706 		if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
1707 			return -ENOMEM;
1708 		resbuf->tail[0].iov_base = resbuf->head[0].iov_base
1709 			+ resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE;
1710 		resbuf->tail[0].iov_len = 0;
1711 	}
1712 	if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages))
1713 		return -ENOMEM;
1714 	*len = htonl(resbuf->len - offset);
1715 	pad = 3 - ((resbuf->len - offset - 1)&3);
1716 	p = (__be32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len);
1717 	memset(p, 0, pad);
1718 	resbuf->tail[0].iov_len += pad;
1719 	resbuf->len += pad;
1720 	return 0;
1721 }
1722 
1723 static int
1724 svcauth_gss_release(struct svc_rqst *rqstp)
1725 {
1726 	struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
1727 	struct rpc_gss_wire_cred *gc = &gsd->clcred;
1728 	struct xdr_buf *resbuf = &rqstp->rq_res;
1729 	int stat = -EINVAL;
1730 	struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);
1731 
1732 	if (gc->gc_proc != RPC_GSS_PROC_DATA)
1733 		goto out;
1734 	/* Release can be called twice, but we only wrap once. */
1735 	if (gsd->verf_start == NULL)
1736 		goto out;
1737 	/* normally not set till svc_send, but we need it here: */
1738 	/* XXX: what for?  Do we mess it up the moment we call svc_putu32
1739 	 * or whatever? */
1740 	resbuf->len = total_buf_len(resbuf);
1741 	switch (gc->gc_svc) {
1742 	case RPC_GSS_SVC_NONE:
1743 		break;
1744 	case RPC_GSS_SVC_INTEGRITY:
1745 		stat = svcauth_gss_wrap_resp_integ(rqstp);
1746 		if (stat)
1747 			goto out_err;
1748 		break;
1749 	case RPC_GSS_SVC_PRIVACY:
1750 		stat = svcauth_gss_wrap_resp_priv(rqstp);
1751 		if (stat)
1752 			goto out_err;
1753 		break;
1754 	/*
1755 	 * For any other gc_svc value, svcauth_gss_accept() already set
1756 	 * the auth_error appropriately; just fall through:
1757 	 */
1758 	}
1759 
1760 out:
1761 	stat = 0;
1762 out_err:
1763 	if (rqstp->rq_client)
1764 		auth_domain_put(rqstp->rq_client);
1765 	rqstp->rq_client = NULL;
1766 	if (rqstp->rq_gssclient)
1767 		auth_domain_put(rqstp->rq_gssclient);
1768 	rqstp->rq_gssclient = NULL;
1769 	if (rqstp->rq_cred.cr_group_info)
1770 		put_group_info(rqstp->rq_cred.cr_group_info);
1771 	rqstp->rq_cred.cr_group_info = NULL;
1772 	if (gsd->rsci)
1773 		cache_put(&gsd->rsci->h, sn->rsc_cache);
1774 	gsd->rsci = NULL;
1775 
1776 	return stat;
1777 }
1778 
1779 static void
1780 svcauth_gss_domain_release(struct auth_domain *dom)
1781 {
1782 	struct gss_domain *gd = container_of(dom, struct gss_domain, h);
1783 
1784 	kfree(dom->name);
1785 	kfree(gd);
1786 }
1787 
1788 static struct auth_ops svcauthops_gss = {
1789 	.name		= "rpcsec_gss",
1790 	.owner		= THIS_MODULE,
1791 	.flavour	= RPC_AUTH_GSS,
1792 	.accept		= svcauth_gss_accept,
1793 	.release	= svcauth_gss_release,
1794 	.domain_release = svcauth_gss_domain_release,
1795 	.set_client	= svcauth_gss_set_client,
1796 };
1797 
1798 static int rsi_cache_create_net(struct net *net)
1799 {
1800 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1801 	struct cache_detail *cd;
1802 	int err;
1803 
1804 	cd = cache_create_net(&rsi_cache_template, net);
1805 	if (IS_ERR(cd))
1806 		return PTR_ERR(cd);
1807 	err = cache_register_net(cd, net);
1808 	if (err) {
1809 		cache_destroy_net(cd, net);
1810 		return err;
1811 	}
1812 	sn->rsi_cache = cd;
1813 	return 0;
1814 }
1815 
1816 static void rsi_cache_destroy_net(struct net *net)
1817 {
1818 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1819 	struct cache_detail *cd = sn->rsi_cache;
1820 
1821 	sn->rsi_cache = NULL;
1822 	cache_purge(cd);
1823 	cache_unregister_net(cd, net);
1824 	cache_destroy_net(cd, net);
1825 }
1826 
1827 static int rsc_cache_create_net(struct net *net)
1828 {
1829 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1830 	struct cache_detail *cd;
1831 	int err;
1832 
1833 	cd = cache_create_net(&rsc_cache_template, net);
1834 	if (IS_ERR(cd))
1835 		return PTR_ERR(cd);
1836 	err = cache_register_net(cd, net);
1837 	if (err) {
1838 		cache_destroy_net(cd, net);
1839 		return err;
1840 	}
1841 	sn->rsc_cache = cd;
1842 	return 0;
1843 }
1844 
1845 static void rsc_cache_destroy_net(struct net *net)
1846 {
1847 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1848 	struct cache_detail *cd = sn->rsc_cache;
1849 
1850 	sn->rsc_cache = NULL;
1851 	cache_purge(cd);
1852 	cache_unregister_net(cd, net);
1853 	cache_destroy_net(cd, net);
1854 }
1855 
1856 int
1857 gss_svc_init_net(struct net *net)
1858 {
1859 	int rv;
1860 
1861 	rv = rsc_cache_create_net(net);
1862 	if (rv)
1863 		return rv;
1864 	rv = rsi_cache_create_net(net);
1865 	if (rv)
1866 		goto out1;
1867 	rv = create_use_gss_proxy_proc_entry(net);
1868 	if (rv)
1869 		goto out2;
1870 	return 0;
1871 out2:
1872 	destroy_use_gss_proxy_proc_entry(net);
1873 out1:
1874 	rsc_cache_destroy_net(net);
1875 	return rv;
1876 }
1877 
1878 void
1879 gss_svc_shutdown_net(struct net *net)
1880 {
1881 	destroy_use_gss_proxy_proc_entry(net);
1882 	rsi_cache_destroy_net(net);
1883 	rsc_cache_destroy_net(net);
1884 }
1885 
1886 int
1887 gss_svc_init(void)
1888 {
1889 	return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
1890 }
1891 
1892 void
1893 gss_svc_shutdown(void)
1894 {
1895 	svc_auth_unregister(RPC_AUTH_GSS);
1896 }
1897