?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
[PATCH] sunrpc: cache_register can use wrong module reference
[linux-2.6.git] / net / sunrpc / auth_gss / svcauth_gss.c
blobe3308195374e635b2ea617d64fc48684c24d1241
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/types.h>
41 #include <linux/module.h>
42 #include <linux/pagemap.h>
43
44 #include <linux/sunrpc/auth_gss.h>
45 #include <linux/sunrpc/svcauth.h>
46 #include <linux/sunrpc/gss_err.h>
47 #include <linux/sunrpc/svcauth.h>
48 #include <linux/sunrpc/svcauth_gss.h>
49 #include <linux/sunrpc/cache.h>
50
51 #ifdef RPC_DEBUG
52 # define RPCDBG_FACILITY RPCDBG_AUTH
53 #endif
54
55 /* The rpcsec_init cache is used for mapping RPCSEC_GSS_{,CONT_}INIT requests
56 * into replies.
57 *
58 * Key is context handle (\x if empty) and gss_token.
59 * Content is major_status minor_status (integers) context_handle, reply_token.
60 *
61 */
62
63 static int netobj_equal(struct xdr_netobj *a, struct xdr_netobj *b)
64 {
65 return a->len == b->len && 0 == memcmp(a->data, b->data, a->len);
66 }
67
68 #define RSI_HASHBITS 6
69 #define RSI_HASHMAX (1<<RSI_HASHBITS)
70 #define RSI_HASHMASK (RSI_HASHMAX-1)
71
72 struct rsi {
73 struct cache_head h;
74 struct xdr_netobj in_handle, in_token;
75 struct xdr_netobj out_handle, out_token;
76 int major_status, minor_status;
77 };
78
79 static struct cache_head *rsi_table[RSI_HASHMAX];
80 static struct cache_detail rsi_cache;
81 static struct rsi *rsi_lookup(struct rsi *item, int set);
82
83 static void rsi_free(struct rsi *rsii)
84 {
85 kfree(rsii->in_handle.data);
86 kfree(rsii->in_token.data);
87 kfree(rsii->out_handle.data);
88 kfree(rsii->out_token.data);
89 }
90
91 static void rsi_put(struct cache_head *item, struct cache_detail *cd)
92 {
93 struct rsi *rsii = container_of(item, struct rsi, h);
94 if (cache_put(item, cd)) {
95 rsi_free(rsii);
96 kfree(rsii);
97 }
98 }
99
100 static inline int rsi_hash(struct rsi *item)
101 {
102 return hash_mem(item->in_handle.data, item->in_handle.len, RSI_HASHBITS)
103 ^ hash_mem(item->in_token.data, item->in_token.len, RSI_HASHBITS);
104 }
105
106 static inline int rsi_match(struct rsi *item, struct rsi *tmp)
107 {
108 return netobj_equal(&item->in_handle, &tmp->in_handle)
109 && netobj_equal(&item->in_token, &tmp->in_token);
110 }
111
112 static int dup_to_netobj(struct xdr_netobj *dst, char *src, int len)
113 {
114 dst->len = len;
115 dst->data = (len ? kmalloc(len, GFP_KERNEL) : NULL);
116 if (dst->data)
117 memcpy(dst->data, src, len);
118 if (len && !dst->data)
119 return -ENOMEM;
120 return 0;
121 }
122
123 static inline int dup_netobj(struct xdr_netobj *dst, struct xdr_netobj *src)
124 {
125 return dup_to_netobj(dst, src->data, src->len);
126 }
127
128 static inline void rsi_init(struct rsi *new, struct rsi *item)
129 {
130 new->out_handle.data = NULL;
131 new->out_handle.len = 0;
132 new->out_token.data = NULL;
133 new->out_token.len = 0;
134 new->in_handle.len = item->in_handle.len;
135 item->in_handle.len = 0;
136 new->in_token.len = item->in_token.len;
137 item->in_token.len = 0;
138 new->in_handle.data = item->in_handle.data;
139 item->in_handle.data = NULL;
140 new->in_token.data = item->in_token.data;
141 item->in_token.data = NULL;
142 }
143
144 static inline void rsi_update(struct rsi *new, struct rsi *item)
145 {
146 BUG_ON(new->out_handle.data || new->out_token.data);
147 new->out_handle.len = item->out_handle.len;
148 item->out_handle.len = 0;
149 new->out_token.len = item->out_token.len;
150 item->out_token.len = 0;
151 new->out_handle.data = item->out_handle.data;
152 item->out_handle.data = NULL;
153 new->out_token.data = item->out_token.data;
154 item->out_token.data = NULL;
155
156 new->major_status = item->major_status;
157 new->minor_status = item->minor_status;
158 }
159
160 static void rsi_request(struct cache_detail *cd,
161 struct cache_head *h,
162 char **bpp, int *blen)
163 {
164 struct rsi *rsii = container_of(h, struct rsi, h);
165
166 qword_addhex(bpp, blen, rsii->in_handle.data, rsii->in_handle.len);
167 qword_addhex(bpp, blen, rsii->in_token.data, rsii->in_token.len);
168 (*bpp)[-1] = '\n';
169 }
170
171
172 static int rsi_parse(struct cache_detail *cd,
173 char *mesg, int mlen)
174 {
175 /* context token expiry major minor context token */
176 char *buf = mesg;
177 char *ep;
178 int len;
179 struct rsi rsii, *rsip = NULL;
180 time_t expiry;
181 int status = -EINVAL;
182
183 memset(&rsii, 0, sizeof(rsii));
184 /* handle */
185 len = qword_get(&mesg, buf, mlen);
186 if (len < 0)
187 goto out;
188 status = -ENOMEM;
189 if (dup_to_netobj(&rsii.in_handle, buf, len))
190 goto out;
191
192 /* token */
193 len = qword_get(&mesg, buf, mlen);
194 status = -EINVAL;
195 if (len < 0)
196 goto out;
197 status = -ENOMEM;
198 if (dup_to_netobj(&rsii.in_token, buf, len))
199 goto out;
200
201 rsii.h.flags = 0;
202 /* expiry */
203 expiry = get_expiry(&mesg);
204 status = -EINVAL;
205 if (expiry == 0)
206 goto out;
207
208 /* major/minor */
209 len = qword_get(&mesg, buf, mlen);
210 if (len < 0)
211 goto out;
212 if (len == 0) {
213 goto out;
214 } else {
215 rsii.major_status = simple_strtoul(buf, &ep, 10);
216 if (*ep)
217 goto out;
218 len = qword_get(&mesg, buf, mlen);
219 if (len <= 0)
220 goto out;
221 rsii.minor_status = simple_strtoul(buf, &ep, 10);
222 if (*ep)
223 goto out;
224
225 /* out_handle */
226 len = qword_get(&mesg, buf, mlen);
227 if (len < 0)
228 goto out;
229 status = -ENOMEM;
230 if (dup_to_netobj(&rsii.out_handle, buf, len))
231 goto out;
232
233 /* out_token */
234 len = qword_get(&mesg, buf, mlen);
235 status = -EINVAL;
236 if (len < 0)
237 goto out;
238 status = -ENOMEM;
239 if (dup_to_netobj(&rsii.out_token, buf, len))
240 goto out;
241 }
242 rsii.h.expiry_time = expiry;
243 rsip = rsi_lookup(&rsii, 1);
244 status = 0;
245 out:
246 rsi_free(&rsii);
247 if (rsip)
248 rsi_put(&rsip->h, &rsi_cache);
249 return status;
250 }
251
252 static struct cache_detail rsi_cache = {
253 .owner = THIS_MODULE,
254 .hash_size = RSI_HASHMAX,
255 .hash_table = rsi_table,
256 .name = "auth.rpcsec.init",
257 .cache_put = rsi_put,
258 .cache_request = rsi_request,
259 .cache_parse = rsi_parse,
260 };
261
262 static DefineSimpleCacheLookup(rsi, 0)
263
264 /*
265 * The rpcsec_context cache is used to store a context that is
266 * used in data exchange.
267 * The key is a context handle. The content is:
268 * uid, gidlist, mechanism, service-set, mech-specific-data
269 */
270
271 #define RSC_HASHBITS 10
272 #define RSC_HASHMAX (1<<RSC_HASHBITS)
273 #define RSC_HASHMASK (RSC_HASHMAX-1)
274
275 #define GSS_SEQ_WIN 128
276
277 struct gss_svc_seq_data {
278 /* highest seq number seen so far: */
279 int sd_max;
280 /* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of
281 * sd_win is nonzero iff sequence number i has been seen already: */
282 unsigned long sd_win[GSS_SEQ_WIN/BITS_PER_LONG];
283 spinlock_t sd_lock;
284 };
285
286 struct rsc {
287 struct cache_head h;
288 struct xdr_netobj handle;
289 struct svc_cred cred;
290 struct gss_svc_seq_data seqdata;
291 struct gss_ctx *mechctx;
292 };
293
294 static struct cache_head *rsc_table[RSC_HASHMAX];
295 static struct cache_detail rsc_cache;
296 static struct rsc *rsc_lookup(struct rsc *item, int set);
297
298 static void rsc_free(struct rsc *rsci)
299 {
300 kfree(rsci->handle.data);
301 if (rsci->mechctx)
302 gss_delete_sec_context(&rsci->mechctx);
303 if (rsci->cred.cr_group_info)
304 put_group_info(rsci->cred.cr_group_info);
305 }
306
307 static void rsc_put(struct cache_head *item, struct cache_detail *cd)
308 {
309 struct rsc *rsci = container_of(item, struct rsc, h);
310
311 if (cache_put(item, cd)) {
312 rsc_free(rsci);
313 kfree(rsci);
314 }
315 }
316
317 static inline int
318 rsc_hash(struct rsc *rsci)
319 {
320 return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS);
321 }
322
323 static inline int
324 rsc_match(struct rsc *new, struct rsc *tmp)
325 {
326 return netobj_equal(&new->handle, &tmp->handle);
327 }
328
329 static inline void
330 rsc_init(struct rsc *new, struct rsc *tmp)
331 {
332 new->handle.len = tmp->handle.len;
333 tmp->handle.len = 0;
334 new->handle.data = tmp->handle.data;
335 tmp->handle.data = NULL;
336 new->mechctx = NULL;
337 new->cred.cr_group_info = NULL;
338 }
339
340 static inline void
341 rsc_update(struct rsc *new, struct rsc *tmp)
342 {
343 new->mechctx = tmp->mechctx;
344 tmp->mechctx = NULL;
345 memset(&new->seqdata, 0, sizeof(new->seqdata));
346 spin_lock_init(&new->seqdata.sd_lock);
347 new->cred = tmp->cred;
348 tmp->cred.cr_group_info = NULL;
349 }
350
351 static int rsc_parse(struct cache_detail *cd,
352 char *mesg, int mlen)
353 {
354 /* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] */
355 char *buf = mesg;
356 int len, rv;
357 struct rsc rsci, *rscp = NULL;
358 time_t expiry;
359 int status = -EINVAL;
360
361 memset(&rsci, 0, sizeof(rsci));
362 /* context handle */
363 len = qword_get(&mesg, buf, mlen);
364 if (len < 0) goto out;
365 status = -ENOMEM;
366 if (dup_to_netobj(&rsci.handle, buf, len))
367 goto out;
368
369 rsci.h.flags = 0;
370 /* expiry */
371 expiry = get_expiry(&mesg);
372 status = -EINVAL;
373 if (expiry == 0)
374 goto out;
375
376 /* uid, or NEGATIVE */
377 rv = get_int(&mesg, &rsci.cred.cr_uid);
378 if (rv == -EINVAL)
379 goto out;
380 if (rv == -ENOENT)
381 set_bit(CACHE_NEGATIVE, &rsci.h.flags);
382 else {
383 int N, i;
384 struct gss_api_mech *gm;
385
386 /* gid */
387 if (get_int(&mesg, &rsci.cred.cr_gid))
388 goto out;
389
390 /* number of additional gid's */
391 if (get_int(&mesg, &N))
392 goto out;
393 status = -ENOMEM;
394 rsci.cred.cr_group_info = groups_alloc(N);
395 if (rsci.cred.cr_group_info == NULL)
396 goto out;
397
398 /* gid's */
399 status = -EINVAL;
400 for (i=0; i<N; i++) {
401 gid_t gid;
402 if (get_int(&mesg, &gid))
403 goto out;
404 GROUP_AT(rsci.cred.cr_group_info, i) = gid;
405 }
406
407 /* mech name */
408 len = qword_get(&mesg, buf, mlen);
409 if (len < 0)
410 goto out;
411 gm = gss_mech_get_by_name(buf);
412 status = -EOPNOTSUPP;
413 if (!gm)
414 goto out;
415
416 status = -EINVAL;
417 /* mech-specific data: */
418 len = qword_get(&mesg, buf, mlen);
419 if (len < 0) {
420 gss_mech_put(gm);
421 goto out;
422 }
423 if (gss_import_sec_context(buf, len, gm, &rsci.mechctx)) {
424 gss_mech_put(gm);
425 goto out;
426 }
427 gss_mech_put(gm);
428 }
429 rsci.h.expiry_time = expiry;
430 rscp = rsc_lookup(&rsci, 1);
431 status = 0;
432 out:
433 rsc_free(&rsci);
434 if (rscp)
435 rsc_put(&rscp->h, &rsc_cache);
436 return status;
437 }
438
439 static struct cache_detail rsc_cache = {
440 .owner = THIS_MODULE,
441 .hash_size = RSC_HASHMAX,
442 .hash_table = rsc_table,
443 .name = "auth.rpcsec.context",
444 .cache_put = rsc_put,
445 .cache_parse = rsc_parse,
446 };
447
448 static DefineSimpleCacheLookup(rsc, 0);
449
450 static struct rsc *
451 gss_svc_searchbyctx(struct xdr_netobj *handle)
452 {
453 struct rsc rsci;
454 struct rsc *found;
455
456 memset(&rsci, 0, sizeof(rsci));
457 if (dup_to_netobj(&rsci.handle, handle->data, handle->len))
458 return NULL;
459 found = rsc_lookup(&rsci, 0);
460 rsc_free(&rsci);
461 if (!found)
462 return NULL;
463 if (cache_check(&rsc_cache, &found->h, NULL))
464 return NULL;
465 return found;
466 }
467
468 /* Implements sequence number algorithm as specified in RFC 2203. */
469 static int
470 gss_check_seq_num(struct rsc *rsci, int seq_num)
471 {
472 struct gss_svc_seq_data *sd = &rsci->seqdata;
473
474 spin_lock(&sd->sd_lock);
475 if (seq_num > sd->sd_max) {
476 if (seq_num >= sd->sd_max + GSS_SEQ_WIN) {
477 memset(sd->sd_win,0,sizeof(sd->sd_win));
478 sd->sd_max = seq_num;
479 } else while (sd->sd_max < seq_num) {
480 sd->sd_max++;
481 __clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win);
482 }
483 __set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
484 goto ok;
485 } else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) {
486 goto drop;
487 }
488 /* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */
489 if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
490 goto drop;
491 ok:
492 spin_unlock(&sd->sd_lock);
493 return 1;
494 drop:
495 spin_unlock(&sd->sd_lock);
496 return 0;
497 }
498
499 static inline u32 round_up_to_quad(u32 i)
500 {
501 return (i + 3 ) & ~3;
502 }
503
504 static inline int
505 svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o)
506 {
507 int l;
508
509 if (argv->iov_len < 4)
510 return -1;
511 o->len = ntohl(svc_getu32(argv));
512 l = round_up_to_quad(o->len);
513 if (argv->iov_len < l)
514 return -1;
515 o->data = argv->iov_base;
516 argv->iov_base += l;
517 argv->iov_len -= l;
518 return 0;
519 }
520
521 static inline int
522 svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o)
523 {
524 u32 *p;
525
526 if (resv->iov_len + 4 > PAGE_SIZE)
527 return -1;
528 svc_putu32(resv, htonl(o->len));
529 p = resv->iov_base + resv->iov_len;
530 resv->iov_len += round_up_to_quad(o->len);
531 if (resv->iov_len > PAGE_SIZE)
532 return -1;
533 memcpy(p, o->data, o->len);
534 memset((u8 *)p + o->len, 0, round_up_to_quad(o->len) - o->len);
535 return 0;
536 }
537
538 /* Verify the checksum on the header and return SVC_OK on success.
539 * Otherwise, return SVC_DROP (in the case of a bad sequence number)
540 * or return SVC_DENIED and indicate error in authp.
541 */
542 static int
543 gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
544 u32 *rpcstart, struct rpc_gss_wire_cred *gc, u32 *authp)
545 {
546 struct gss_ctx *ctx_id = rsci->mechctx;
547 struct xdr_buf rpchdr;
548 struct xdr_netobj checksum;
549 u32 flavor = 0;
550 struct kvec *argv = &rqstp->rq_arg.head[0];
551 struct kvec iov;
552
553 /* data to compute the checksum over: */
554 iov.iov_base = rpcstart;
555 iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart;
556 xdr_buf_from_iov(&iov, &rpchdr);
557
558 *authp = rpc_autherr_badverf;
559 if (argv->iov_len < 4)
560 return SVC_DENIED;
561 flavor = ntohl(svc_getu32(argv));
562 if (flavor != RPC_AUTH_GSS)
563 return SVC_DENIED;
564 if (svc_safe_getnetobj(argv, &checksum))
565 return SVC_DENIED;
566
567 if (rqstp->rq_deferred) /* skip verification of revisited request */
568 return SVC_OK;
569 if (gss_verify_mic(ctx_id, &rpchdr, &checksum, NULL)
570 != GSS_S_COMPLETE) {
571 *authp = rpcsec_gsserr_credproblem;
572 return SVC_DENIED;
573 }
574
575 if (gc->gc_seq > MAXSEQ) {
576 dprintk("RPC: svcauth_gss: discarding request with large sequence number %d\n",
577 gc->gc_seq);
578 *authp = rpcsec_gsserr_ctxproblem;
579 return SVC_DENIED;
580 }
581 if (!gss_check_seq_num(rsci, gc->gc_seq)) {
582 dprintk("RPC: svcauth_gss: discarding request with old sequence number %d\n",
583 gc->gc_seq);
584 return SVC_DROP;
585 }
586 return SVC_OK;
587 }
588
589 static int
590 gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
591 {
592 u32 xdr_seq;
593 u32 maj_stat;
594 struct xdr_buf verf_data;
595 struct xdr_netobj mic;
596 u32 *p;
597 struct kvec iov;
598
599 svc_putu32(rqstp->rq_res.head, htonl(RPC_AUTH_GSS));
600 xdr_seq = htonl(seq);
601
602 iov.iov_base = &xdr_seq;
603 iov.iov_len = sizeof(xdr_seq);
604 xdr_buf_from_iov(&iov, &verf_data);
605 p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
606 mic.data = (u8 *)(p + 1);
607 maj_stat = gss_get_mic(ctx_id, 0, &verf_data, &mic);
608 if (maj_stat != GSS_S_COMPLETE)
609 return -1;
610 *p++ = htonl(mic.len);
611 memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);
612 p += XDR_QUADLEN(mic.len);
613 if (!xdr_ressize_check(rqstp, p))
614 return -1;
615 return 0;
616 }
617
618 struct gss_domain {
619 struct auth_domain h;
620 u32 pseudoflavor;
621 };
622
623 static struct auth_domain *
624 find_gss_auth_domain(struct gss_ctx *ctx, u32 svc)
625 {
626 char *name;
627
628 name = gss_service_to_auth_domain_name(ctx->mech_type, svc);
629 if (!name)
630 return NULL;
631 return auth_domain_find(name);
632 }
633
634 int
635 svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name)
636 {
637 struct gss_domain *new;
638 struct auth_domain *test;
639 int stat = -ENOMEM;
640
641 new = kmalloc(sizeof(*new), GFP_KERNEL);
642 if (!new)
643 goto out;
644 cache_init(&new->h.h);
645 new->h.name = kmalloc(strlen(name) + 1, GFP_KERNEL);
646 if (!new->h.name)
647 goto out_free_dom;
648 strcpy(new->h.name, name);
649 new->h.flavour = RPC_AUTH_GSS;
650 new->pseudoflavor = pseudoflavor;
651 new->h.h.expiry_time = NEVER;
652
653 test = auth_domain_lookup(&new->h, 1);
654 if (test == &new->h) {
655 BUG_ON(atomic_dec_and_test(&new->h.h.refcnt));
656 } else { /* XXX Duplicate registration? */
657 auth_domain_put(&new->h);
658 goto out;
659 }
660 return 0;
661
662 out_free_dom:
663 kfree(new);
664 out:
665 return stat;
666 }
667
668 EXPORT_SYMBOL(svcauth_gss_register_pseudoflavor);
669
670 static inline int
671 read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
672 {
673 u32 raw;
674 int status;
675
676 status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
677 if (status)
678 return status;
679 *obj = ntohl(raw);
680 return 0;
681 }
682
683 /* It would be nice if this bit of code could be shared with the client.
684 * Obstacles:
685 * The client shouldn't malloc(), would have to pass in own memory.
686 * The server uses base of head iovec as read pointer, while the
687 * client uses separate pointer. */
688 static int
689 unwrap_integ_data(struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
690 {
691 int stat = -EINVAL;
692 u32 integ_len, maj_stat;
693 struct xdr_netobj mic;
694 struct xdr_buf integ_buf;
695
696 integ_len = ntohl(svc_getu32(&buf->head[0]));
697 if (integ_len & 3)
698 goto out;
699 if (integ_len > buf->len)
700 goto out;
701 if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
702 BUG();
703 /* copy out mic... */
704 if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
705 BUG();
706 if (mic.len > RPC_MAX_AUTH_SIZE)
707 goto out;
708 mic.data = kmalloc(mic.len, GFP_KERNEL);
709 if (!mic.data)
710 goto out;
711 if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len))
712 goto out;
713 maj_stat = gss_verify_mic(ctx, &integ_buf, &mic, NULL);
714 if (maj_stat != GSS_S_COMPLETE)
715 goto out;
716 if (ntohl(svc_getu32(&buf->head[0])) != seq)
717 goto out;
718 stat = 0;
719 out:
720 return stat;
721 }
722
723 struct gss_svc_data {
724 /* decoded gss client cred: */
725 struct rpc_gss_wire_cred clcred;
726 /* pointer to the beginning of the procedure-specific results,
727 * which may be encrypted/checksummed in svcauth_gss_release: */
728 u32 *body_start;
729 struct rsc *rsci;
730 };
731
732 static int
733 svcauth_gss_set_client(struct svc_rqst *rqstp)
734 {
735 struct gss_svc_data *svcdata = rqstp->rq_auth_data;
736 struct rsc *rsci = svcdata->rsci;
737 struct rpc_gss_wire_cred *gc = &svcdata->clcred;
738
739 rqstp->rq_client = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
740 if (rqstp->rq_client == NULL)
741 return SVC_DENIED;
742 return SVC_OK;
743 }
744
745 /*
746 * Accept an rpcsec packet.
747 * If context establishment, punt to user space
748 * If data exchange, verify/decrypt
749 * If context destruction, handle here
750 * In the context establishment and destruction case we encode
751 * response here and return SVC_COMPLETE.
752 */
753 static int
754 svcauth_gss_accept(struct svc_rqst *rqstp, u32 *authp)
755 {
756 struct kvec *argv = &rqstp->rq_arg.head[0];
757 struct kvec *resv = &rqstp->rq_res.head[0];
758 u32 crlen;
759 struct xdr_netobj tmpobj;
760 struct gss_svc_data *svcdata = rqstp->rq_auth_data;
761 struct rpc_gss_wire_cred *gc;
762 struct rsc *rsci = NULL;
763 struct rsi *rsip, rsikey;
764 u32 *rpcstart;
765 u32 *reject_stat = resv->iov_base + resv->iov_len;
766 int ret;
767
768 dprintk("RPC: svcauth_gss: argv->iov_len = %zd\n",argv->iov_len);
769
770 *authp = rpc_autherr_badcred;
771 if (!svcdata)
772 svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
773 if (!svcdata)
774 goto auth_err;
775 rqstp->rq_auth_data = svcdata;
776 svcdata->body_start = NULL;
777 svcdata->rsci = NULL;
778 gc = &svcdata->clcred;
779
780 /* start of rpc packet is 7 u32's back from here:
781 * xid direction rpcversion prog vers proc flavour
782 */
783 rpcstart = argv->iov_base;
784 rpcstart -= 7;
785
786 /* credential is:
787 * version(==1), proc(0,1,2,3), seq, service (1,2,3), handle
788 * at least 5 u32s, and is preceeded by length, so that makes 6.
789 */
790
791 if (argv->iov_len < 5 * 4)
792 goto auth_err;
793 crlen = ntohl(svc_getu32(argv));
794 if (ntohl(svc_getu32(argv)) != RPC_GSS_VERSION)
795 goto auth_err;
796 gc->gc_proc = ntohl(svc_getu32(argv));
797 gc->gc_seq = ntohl(svc_getu32(argv));
798 gc->gc_svc = ntohl(svc_getu32(argv));
799 if (svc_safe_getnetobj(argv, &gc->gc_ctx))
800 goto auth_err;
801 if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4)
802 goto auth_err;
803
804 if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
805 goto auth_err;
806
807 /*
808 * We've successfully parsed the credential. Let's check out the
809 * verifier. An AUTH_NULL verifier is allowed (and required) for
810 * INIT and CONTINUE_INIT requests. AUTH_RPCSEC_GSS is required for
811 * PROC_DATA and PROC_DESTROY.
812 *
813 * AUTH_NULL verifier is 0 (AUTH_NULL), 0 (length).
814 * AUTH_RPCSEC_GSS verifier is:
815 * 6 (AUTH_RPCSEC_GSS), length, checksum.
816 * checksum is calculated over rpcheader from xid up to here.
817 */
818 *authp = rpc_autherr_badverf;
819 switch (gc->gc_proc) {
820 case RPC_GSS_PROC_INIT:
821 case RPC_GSS_PROC_CONTINUE_INIT:
822 if (argv->iov_len < 2 * 4)
823 goto auth_err;
824 if (ntohl(svc_getu32(argv)) != RPC_AUTH_NULL)
825 goto auth_err;
826 if (ntohl(svc_getu32(argv)) != 0)
827 goto auth_err;
828 break;
829 case RPC_GSS_PROC_DATA:
830 case RPC_GSS_PROC_DESTROY:
831 *authp = rpcsec_gsserr_credproblem;
832 rsci = gss_svc_searchbyctx(&gc->gc_ctx);
833 if (!rsci)
834 goto auth_err;
835 switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) {
836 case SVC_OK:
837 break;
838 case SVC_DENIED:
839 goto auth_err;
840 case SVC_DROP:
841 goto drop;
842 }
843 break;
844 default:
845 *authp = rpc_autherr_rejectedcred;
846 goto auth_err;
847 }
848
849 /* now act upon the command: */
850 switch (gc->gc_proc) {
851 case RPC_GSS_PROC_INIT:
852 case RPC_GSS_PROC_CONTINUE_INIT:
853 *authp = rpc_autherr_badcred;
854 if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
855 goto auth_err;
856 memset(&rsikey, 0, sizeof(rsikey));
857 if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx))
858 goto drop;
859 *authp = rpc_autherr_badverf;
860 if (svc_safe_getnetobj(argv, &tmpobj)) {
861 kfree(rsikey.in_handle.data);
862 goto auth_err;
863 }
864 if (dup_netobj(&rsikey.in_token, &tmpobj)) {
865 kfree(rsikey.in_handle.data);
866 goto drop;
867 }
868
869 rsip = rsi_lookup(&rsikey, 0);
870 rsi_free(&rsikey);
871 if (!rsip) {
872 goto drop;
873 }
874 switch(cache_check(&rsi_cache, &rsip->h, &rqstp->rq_chandle)) {
875 case -EAGAIN:
876 goto drop;
877 case -ENOENT:
878 goto drop;
879 case 0:
880 rsci = gss_svc_searchbyctx(&rsip->out_handle);
881 if (!rsci) {
882 goto drop;
883 }
884 if (gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN))
885 goto drop;
886 if (resv->iov_len + 4 > PAGE_SIZE)
887 goto drop;
888 svc_putu32(resv, rpc_success);
889 if (svc_safe_putnetobj(resv, &rsip->out_handle))
890 goto drop;
891 if (resv->iov_len + 3 * 4 > PAGE_SIZE)
892 goto drop;
893 svc_putu32(resv, htonl(rsip->major_status));
894 svc_putu32(resv, htonl(rsip->minor_status));
895 svc_putu32(resv, htonl(GSS_SEQ_WIN));
896 if (svc_safe_putnetobj(resv, &rsip->out_token))
897 goto drop;
898 rqstp->rq_client = NULL;
899 }
900 goto complete;
901 case RPC_GSS_PROC_DESTROY:
902 set_bit(CACHE_NEGATIVE, &rsci->h.flags);
903 if (resv->iov_len + 4 > PAGE_SIZE)
904 goto drop;
905 svc_putu32(resv, rpc_success);
906 goto complete;
907 case RPC_GSS_PROC_DATA:
908 *authp = rpcsec_gsserr_ctxproblem;
909 if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
910 goto auth_err;
911 rqstp->rq_cred = rsci->cred;
912 get_group_info(rsci->cred.cr_group_info);
913 *authp = rpc_autherr_badcred;
914 switch (gc->gc_svc) {
915 case RPC_GSS_SVC_NONE:
916 break;
917 case RPC_GSS_SVC_INTEGRITY:
918 if (unwrap_integ_data(&rqstp->rq_arg,
919 gc->gc_seq, rsci->mechctx))
920 goto auth_err;
921 /* placeholders for length and seq. number: */
922 svcdata->body_start = resv->iov_base + resv->iov_len;
923 svc_putu32(resv, 0);
924 svc_putu32(resv, 0);
925 break;
926 case RPC_GSS_SVC_PRIVACY:
927 /* currently unsupported */
928 default:
929 goto auth_err;
930 }
931 svcdata->rsci = rsci;
932 cache_get(&rsci->h);
933 ret = SVC_OK;
934 goto out;
935 }
936 auth_err:
937 /* Restore write pointer to original value: */
938 xdr_ressize_check(rqstp, reject_stat);
939 ret = SVC_DENIED;
940 goto out;
941 complete:
942 ret = SVC_COMPLETE;
943 goto out;
944 drop:
945 ret = SVC_DROP;
946 out:
947 if (rsci)
948 rsc_put(&rsci->h, &rsc_cache);
949 return ret;
950 }
951
952 static int
953 svcauth_gss_release(struct svc_rqst *rqstp)
954 {
955 struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
956 struct rpc_gss_wire_cred *gc = &gsd->clcred;
957 struct xdr_buf *resbuf = &rqstp->rq_res;
958 struct xdr_buf integ_buf;
959 struct xdr_netobj mic;
960 struct kvec *resv;
961 u32 *p;
962 int integ_offset, integ_len;
963 int stat = -EINVAL;
964
965 if (gc->gc_proc != RPC_GSS_PROC_DATA)
966 goto out;
967 /* Release can be called twice, but we only wrap once. */
968 if (gsd->body_start == NULL)
969 goto out;
970 /* normally not set till svc_send, but we need it here: */
971 resbuf->len = resbuf->head[0].iov_len
972 + resbuf->page_len + resbuf->tail[0].iov_len;
973 switch (gc->gc_svc) {
974 case RPC_GSS_SVC_NONE:
975 break;
976 case RPC_GSS_SVC_INTEGRITY:
977 p = gsd->body_start;
978 gsd->body_start = NULL;
979 /* move accept_stat to right place: */
980 memcpy(p, p + 2, 4);
981 /* don't wrap in failure case: */
982 /* Note: counting on not getting here if call was not even
983 * accepted! */
984 if (*p != rpc_success) {
985 resbuf->head[0].iov_len -= 2 * 4;
986 goto out;
987 }
988 p++;
989 integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base;
990 integ_len = resbuf->len - integ_offset;
991 BUG_ON(integ_len % 4);
992 *p++ = htonl(integ_len);
993 *p++ = htonl(gc->gc_seq);
994 if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset,
995 integ_len))
996 BUG();
997 if (resbuf->page_len == 0
998 && resbuf->tail[0].iov_len + RPC_MAX_AUTH_SIZE
999 < PAGE_SIZE) {
1000 BUG_ON(resbuf->tail[0].iov_len);
1001 /* Use head for everything */
1002 resv = &resbuf->head[0];
1003 } else if (resbuf->tail[0].iov_base == NULL) {
1004 /* copied from nfsd4_encode_read */
1005 svc_take_page(rqstp);
1006 resbuf->tail[0].iov_base = page_address(rqstp
1007 ->rq_respages[rqstp->rq_resused-1]);
1008 rqstp->rq_restailpage = rqstp->rq_resused-1;
1009 resbuf->tail[0].iov_len = 0;
1010 resv = &resbuf->tail[0];
1011 } else {
1012 resv = &resbuf->tail[0];
1013 }
1014 mic.data = (u8 *)resv->iov_base + resv->iov_len + 4;
1015 if (gss_get_mic(gsd->rsci->mechctx, 0, &integ_buf, &mic))
1016 goto out_err;
1017 svc_putu32(resv, htonl(mic.len));
1018 memset(mic.data + mic.len, 0,
1019 round_up_to_quad(mic.len) - mic.len);
1020 resv->iov_len += XDR_QUADLEN(mic.len) << 2;
1021 /* not strictly required: */
1022 resbuf->len += XDR_QUADLEN(mic.len) << 2;
1023 BUG_ON(resv->iov_len > PAGE_SIZE);
1024 break;
1025 case RPC_GSS_SVC_PRIVACY:
1026 default:
1027 goto out_err;
1028 }
1029
1030 out:
1031 stat = 0;
1032 out_err:
1033 if (rqstp->rq_client)
1034 auth_domain_put(rqstp->rq_client);
1035 rqstp->rq_client = NULL;
1036 if (rqstp->rq_cred.cr_group_info)
1037 put_group_info(rqstp->rq_cred.cr_group_info);
1038 rqstp->rq_cred.cr_group_info = NULL;
1039 if (gsd->rsci)
1040 rsc_put(&gsd->rsci->h, &rsc_cache);
1041 gsd->rsci = NULL;
1042
1043 return stat;
1044 }
1045
1046 static void
1047 svcauth_gss_domain_release(struct auth_domain *dom)
1048 {
1049 struct gss_domain *gd = container_of(dom, struct gss_domain, h);
1050
1051 kfree(dom->name);
1052 kfree(gd);
1053 }
1054
1055 static struct auth_ops svcauthops_gss = {
1056 .name = "rpcsec_gss",
1057 .owner = THIS_MODULE,
1058 .flavour = RPC_AUTH_GSS,
1059 .accept = svcauth_gss_accept,
1060 .release = svcauth_gss_release,
1061 .domain_release = svcauth_gss_domain_release,
1062 .set_client = svcauth_gss_set_client,
1063 };
1064
1065 int
1066 gss_svc_init(void)
1067 {
1068 int rv = svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
1069 if (rv == 0) {
1070 cache_register(&rsc_cache);
1071 cache_register(&rsi_cache);
1072 }
1073 return rv;
1074 }
1075
1076 void
1077 gss_svc_shutdown(void)
1078 {
1079 if (cache_unregister(&rsc_cache))
1080 printk(KERN_ERR "auth_rpcgss: failed to unregister rsc cache\n");
1081 if (cache_unregister(&rsi_cache))
1082 printk(KERN_ERR "auth_rpcgss: failed to unregister rsi cache\n");
1083 svc_auth_unregister(RPC_AUTH_GSS);
1084 }
Linus' kernel tree