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
netobj_equal(struct xdr_netobj * a,struct xdr_netobj * b)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
rsi_free(struct rsi * rsii)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
rsi_free_rcu(struct rcu_head * head)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
rsi_put(struct kref * ref)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
rsi_hash(struct rsi * item)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
rsi_match(struct cache_head * a,struct cache_head * b)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
dup_to_netobj(struct xdr_netobj * dst,char * src,int len)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
dup_netobj(struct xdr_netobj * dst,struct xdr_netobj * src)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
rsi_init(struct cache_head * cnew,struct cache_head * citem)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
update_rsi(struct cache_head * cnew,struct cache_head * citem)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
rsi_alloc(void)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
rsi_upcall(struct cache_detail * cd,struct cache_head * h)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
rsi_request(struct cache_detail * cd,struct cache_head * h,char ** bpp,int * blen)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
rsi_parse(struct cache_detail * cd,char * mesg,int mlen)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
rsi_lookup(struct cache_detail * cd,struct rsi * item)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
rsi_update(struct cache_detail * cd,struct rsi * new,struct rsi * old)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
rsc_free(struct rsc * rsci)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
rsc_free_rcu(struct rcu_head * head)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
rsc_put(struct kref * ref)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
rsc_hash(struct rsc * rsci)407 rsc_hash(struct rsc *rsci)
408 {
409 return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS);
410 }
411
412 static int
rsc_match(struct cache_head * a,struct cache_head * b)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
rsc_init(struct cache_head * cnew,struct cache_head * ctmp)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
update_rsc(struct cache_head * cnew,struct cache_head * ctmp)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 *
rsc_alloc(void)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
rsc_upcall(struct cache_detail * cd,struct cache_head * h)459 static int rsc_upcall(struct cache_detail *cd, struct cache_head *h)
460 {
461 return -EINVAL;
462 }
463
rsc_parse(struct cache_detail * cd,char * mesg,int mlen)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
rsc_lookup(struct cache_detail * cd,struct rsc * item)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
rsc_update(struct cache_detail * cd,struct rsc * new,struct rsc * old)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 *
gss_svc_searchbyctx(struct cache_detail * cd,struct xdr_netobj * handle)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 */
gss_check_seq_num(const struct svc_rqst * rqstp,struct rsc * rsci,u32 seq_num)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
svcauth_gss_verify_header(struct svc_rqst * rqstp,struct rsc * rsci,__be32 * rpcstart,struct rpc_gss_wire_cred * gc)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
svcauth_gss_encode_verf(struct svc_rqst * rqstp,struct gss_ctx * ctx_id,u32 seq)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 *
find_gss_auth_domain(struct gss_ctx * ctx,u32 svc)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
svcauth_gss_flavor(struct auth_domain * dom)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 *
svcauth_gss_register_pseudoflavor(u32 pseudoflavor,char * name)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
svcauth_gss_unwrap_integ(struct svc_rqst * rqstp,u32 seq,struct gss_ctx * ctx)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
svcauth_gss_unwrap_priv(struct svc_rqst * rqstp,u32 seq,struct gss_ctx * ctx)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
svcauth_gss_set_client(struct svc_rqst * rqstp)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
svcauth_gss_proc_init_verf(struct cache_detail * cd,struct svc_rqst * rqstp,struct xdr_netobj * out_handle,int * major_status,u32 seq_num)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
gss_free_in_token_pages(struct gssp_in_token * in_token)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
gss_read_proxy_verf(struct svc_rqst * rqstp,struct rpc_gss_wire_cred * gc,struct xdr_netobj * in_handle,struct gssp_in_token * in_token)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 + 1, 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
svcxdr_encode_gss_init_res(struct xdr_stream * xdr,struct xdr_netobj * handle,struct xdr_netobj * gss_token,unsigned int major_status,unsigned int minor_status,u32 seq_num)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
svcauth_gss_legacy_init(struct svc_rqst * rqstp,struct rpc_gss_wire_cred * gc)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
gss_proxy_save_rsc(struct cache_detail * cd,struct gssp_upcall_data * ud,uint64_t * handle)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
svcauth_gss_proxy_init(struct svc_rqst * rqstp,struct rpc_gss_wire_cred * gc)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 */
set_gss_proxy(struct net * net,int type)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
use_gss_proxy(struct net * net)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
svcauth_gss_proc_init(struct svc_rqst * rqstp,struct rpc_gss_wire_cred * gc)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
write_gssp(struct file * file,const char __user * buf,size_t count,loff_t * ppos)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
read_gssp(struct file * file,char __user * buf,size_t count,loff_t * ppos)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
create_use_gss_proxy_proc_entry(struct net * net)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
destroy_use_gss_proxy_proc_entry(struct net * net)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
read_gss_krb5_enctypes(struct file * file,char __user * buf,size_t count,loff_t * ppos)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
create_krb5_enctypes_proc_entry(struct net * net)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
destroy_krb5_enctypes_proc_entry(struct net * net)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
create_use_gss_proxy_proc_entry(struct net * net)1533 static int create_use_gss_proxy_proc_entry(struct net *net)
1534 {
1535 return 0;
1536 }
1537
destroy_use_gss_proxy_proc_entry(struct net * net)1538 static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
1539
create_krb5_enctypes_proc_entry(struct net * net)1540 static int create_krb5_enctypes_proc_entry(struct net *net)
1541 {
1542 return 0;
1543 }
1544
destroy_krb5_enctypes_proc_entry(struct net * net)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
svcauth_gss_decode_credbody(struct xdr_stream * xdr,struct rpc_gss_wire_cred * gc,__be32 ** rpcstart)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
svcauth_gss_accept(struct svc_rqst * rqstp)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
svcauth_gss_prepare_to_wrap(struct svc_rqst * rqstp,struct gss_svc_data * gsd)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 */
svcauth_gss_wrap_integ(struct svc_rqst * rqstp)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 */
svcauth_gss_wrap_priv(struct svc_rqst * rqstp)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
svcauth_gss_release(struct svc_rqst * rqstp)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
svcauth_gss_domain_release_rcu(struct rcu_head * head)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
svcauth_gss_domain_release(struct auth_domain * dom)1996 svcauth_gss_domain_release(struct auth_domain *dom)
1997 {
1998 call_rcu(&dom->rcu_head, svcauth_gss_domain_release_rcu);
1999 }
2000
svcauth_gss_pseudoflavor(struct svc_rqst * rqstp)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
rsi_cache_create_net(struct net * net)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
rsi_cache_destroy_net(struct net * net)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
rsc_cache_create_net(struct net * net)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
rsc_cache_destroy_net(struct net * net)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
gss_svc_init_net(struct net * net)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
gss_svc_shutdown_net(struct net * net)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
gss_svc_init(void)2115 gss_svc_init(void)
2116 {
2117 return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
2118 }
2119
2120 void
gss_svc_shutdown(void)2121 gss_svc_shutdown(void)
2122 {
2123 svc_auth_unregister(RPC_AUTH_GSS);
2124 }
2125