1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * GSS Proxy upcall module
4 *
5 * Copyright (C) 2012 Simo Sorce <simo@redhat.com>
6 */
7
8 #include <linux/sunrpc/svcauth.h>
9 #include "gss_rpc_xdr.h"
10
11 static int gssx_enc_bool(struct xdr_stream *xdr, int v)
12 {
13 __be32 *p;
14
15 p = xdr_reserve_space(xdr, 4);
16 if (unlikely(p == NULL))
17 return -ENOSPC;
18 *p = v ? xdr_one : xdr_zero;
19 return 0;
20 }
21
22 static int gssx_dec_bool(struct xdr_stream *xdr, u32 *v)
23 {
24 __be32 *p;
25
26 p = xdr_inline_decode(xdr, 4);
27 if (unlikely(p == NULL))
28 return -ENOSPC;
29 *v = be32_to_cpu(*p);
30 return 0;
31 }
32
33 static int gssx_enc_buffer(struct xdr_stream *xdr,
34 const gssx_buffer *buf)
35 {
36 __be32 *p;
37
38 p = xdr_reserve_space(xdr, sizeof(u32) + buf->len);
39 if (!p)
40 return -ENOSPC;
41 xdr_encode_opaque(p, buf->data, buf->len);
42 return 0;
43 }
44
45 static int gssx_enc_in_token(struct xdr_stream *xdr,
46 const struct gssp_in_token *in)
47 {
48 __be32 *p;
49
50 p = xdr_reserve_space(xdr, 4);
51 if (!p)
52 return -ENOSPC;
53 *p = cpu_to_be32(in->page_len);
54
55 /* all we need to do is to write pages */
56 xdr_write_pages(xdr, in->pages, in->page_base, in->page_len);
57
58 return 0;
59 }
60
61
62 static int gssx_dec_buffer(struct xdr_stream *xdr,
63 gssx_buffer *buf)
64 {
65 u32 length;
66 __be32 *p;
67
68 p = xdr_inline_decode(xdr, 4);
69 if (unlikely(p == NULL))
70 return -ENOSPC;
71
72 length = be32_to_cpup(p);
73 p = xdr_inline_decode(xdr, length);
74 if (unlikely(p == NULL))
75 return -ENOSPC;
76
77 if (buf->len == 0) {
78 /* we intentionally are not interested in this buffer */
79 return 0;
80 }
81 if (length > buf->len)
82 return -ENOSPC;
83
84 if (!buf->data) {
85 buf->data = kmemdup(p, length, GFP_KERNEL);
86 if (!buf->data)
87 return -ENOMEM;
88 } else {
89 memcpy(buf->data, p, length);
90 }
91 buf->len = length;
92 return 0;
93 }
94
95 static int gssx_enc_option(struct xdr_stream *xdr,
96 struct gssx_option *opt)
97 {
98 int err;
99
100 err = gssx_enc_buffer(xdr, &opt->option);
101 if (err)
102 return err;
103 err = gssx_enc_buffer(xdr, &opt->value);
104 return err;
105 }
106
107 static int gssx_dec_option(struct xdr_stream *xdr,
108 struct gssx_option *opt)
109 {
110 int err;
111
112 err = gssx_dec_buffer(xdr, &opt->option);
113 if (err)
114 return err;
115 err = gssx_dec_buffer(xdr, &opt->value);
116 return err;
117 }
118
119 static int dummy_enc_opt_array(struct xdr_stream *xdr,
120 const struct gssx_option_array *oa)
121 {
122 __be32 *p;
123
124 if (oa->count != 0)
125 return -EINVAL;
126
127 p = xdr_reserve_space(xdr, 4);
128 if (!p)
129 return -ENOSPC;
130 *p = 0;
131
132 return 0;
133 }
134
135 static int dummy_dec_opt_array(struct xdr_stream *xdr,
136 struct gssx_option_array *oa)
137 {
138 struct gssx_option dummy;
139 u32 count, i;
140 __be32 *p;
141
142 p = xdr_inline_decode(xdr, 4);
143 if (unlikely(p == NULL))
144 return -ENOSPC;
145 count = be32_to_cpup(p++);
146 memset(&dummy, 0, sizeof(dummy));
147 for (i = 0; i < count; i++) {
148 gssx_dec_option(xdr, &dummy);
149 }
150
151 oa->count = 0;
152 oa->data = NULL;
153 return 0;
154 }
155
156 static int get_host_u32(struct xdr_stream *xdr, u32 *res)
157 {
158 __be32 *p;
159
160 p = xdr_inline_decode(xdr, 4);
161 if (!p)
162 return -EINVAL;
163 /* Contents of linux creds are all host-endian: */
164 memcpy(res, p, sizeof(u32));
165 return 0;
166 }
167
168 static int gssx_dec_linux_creds(struct xdr_stream *xdr,
169 struct svc_cred *creds)
170 {
171 u32 length;
172 __be32 *p;
173 u32 tmp;
174 u32 N;
175 int i, err;
176
177 p = xdr_inline_decode(xdr, 4);
178 if (unlikely(p == NULL))
179 return -ENOSPC;
180
181 length = be32_to_cpup(p);
182
183 if (length > (3 + NGROUPS_MAX) * sizeof(u32))
184 return -ENOSPC;
185
186 /* uid */
187 err = get_host_u32(xdr, &tmp);
188 if (err)
189 return err;
190 creds->cr_uid = make_kuid(&init_user_ns, tmp);
191
192 /* gid */
193 err = get_host_u32(xdr, &tmp);
194 if (err)
195 return err;
196 creds->cr_gid = make_kgid(&init_user_ns, tmp);
197
198 /* number of additional gid's */
199 err = get_host_u32(xdr, &tmp);
200 if (err)
201 return err;
202 N = tmp;
203 if ((3 + N) * sizeof(u32) != length)
204 return -EINVAL;
205 creds->cr_group_info = groups_alloc(N);
206 if (creds->cr_group_info == NULL)
207 return -ENOMEM;
208
209 /* gid's */
210 for (i = 0; i < N; i++) {
211 kgid_t kgid;
212 err = get_host_u32(xdr, &tmp);
213 if (err)
214 goto out_free_groups;
215 err = -EINVAL;
216 kgid = make_kgid(&init_user_ns, tmp);
217 if (!gid_valid(kgid))
218 goto out_free_groups;
219 creds->cr_group_info->gid[i] = kgid;
220 }
221 groups_sort(creds->cr_group_info);
222
223 return 0;
224 out_free_groups:
225 groups_free(creds->cr_group_info);
226 return err;
227 }
228
229 static int gssx_dec_option_array(struct xdr_stream *xdr,
230 struct gssx_option_array *oa)
231 {
232 struct svc_cred *creds;
233 u32 count, i;
234 __be32 *p;
235 int err;
236
237 p = xdr_inline_decode(xdr, 4);
238 if (unlikely(p == NULL))
239 return -ENOSPC;
240 count = be32_to_cpup(p++);
241 if (!count)
242 return 0;
243
244 /* we recognize only 1 currently: CREDS_VALUE */
245 oa->count = 1;
246
247 oa->data = kmalloc(sizeof(struct gssx_option), GFP_KERNEL);
248 if (!oa->data)
249 return -ENOMEM;
250
251 creds = kzalloc(sizeof(struct svc_cred), GFP_KERNEL);
252 if (!creds) {
253 err = -ENOMEM;
254 goto free_oa;
255 }
256
257 oa->data[0].option.data = CREDS_VALUE;
258 oa->data[0].option.len = sizeof(CREDS_VALUE);
259 oa->data[0].value.data = (void *)creds;
260 oa->data[0].value.len = 0;
261
262 for (i = 0; i < count; i++) {
263 gssx_buffer dummy = { 0, NULL };
264 u32 length;
265
266 /* option buffer */
267 p = xdr_inline_decode(xdr, 4);
268 if (unlikely(p == NULL)) {
269 err = -ENOSPC;
270 goto free_creds;
271 }
272
273 length = be32_to_cpup(p);
274 p = xdr_inline_decode(xdr, length);
275 if (unlikely(p == NULL)) {
276 err = -ENOSPC;
277 goto free_creds;
278 }
279
280 if (length == sizeof(CREDS_VALUE) &&
281 memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) {
282 /* We have creds here. parse them */
283 err = gssx_dec_linux_creds(xdr, creds);
284 if (err)
285 goto free_creds;
286 oa->data[0].value.len = 1; /* presence */
287 } else {
288 /* consume uninteresting buffer */
289 err = gssx_dec_buffer(xdr, &dummy);
290 if (err)
291 goto free_creds;
292 }
293 }
294 return 0;
295
296 free_creds:
297 kfree(creds);
298 free_oa:
299 kfree(oa->data);
300 oa->data = NULL;
301 return err;
302 }
303
304 static int gssx_dec_status(struct xdr_stream *xdr,
305 struct gssx_status *status)
306 {
307 __be32 *p;
308 int err;
309
310 /* status->major_status */
311 p = xdr_inline_decode(xdr, 8);
312 if (unlikely(p == NULL))
313 return -ENOSPC;
314 p = xdr_decode_hyper(p, &status->major_status);
315
316 /* status->mech */
317 err = gssx_dec_buffer(xdr, &status->mech);
318 if (err)
319 return err;
320
321 /* status->minor_status */
322 p = xdr_inline_decode(xdr, 8);
323 if (unlikely(p == NULL))
324 return -ENOSPC;
325 p = xdr_decode_hyper(p, &status->minor_status);
326
327 /* status->major_status_string */
328 err = gssx_dec_buffer(xdr, &status->major_status_string);
329 if (err)
330 return err;
331
332 /* status->minor_status_string */
333 err = gssx_dec_buffer(xdr, &status->minor_status_string);
334 if (err)
335 return err;
336
337 /* status->server_ctx */
338 err = gssx_dec_buffer(xdr, &status->server_ctx);
339 if (err)
340 return err;
341
342 /* we assume we have no options for now, so simply consume them */
343 /* status->options */
344 err = dummy_dec_opt_array(xdr, &status->options);
345
346 return err;
347 }
348
349 static int gssx_enc_call_ctx(struct xdr_stream *xdr,
350 const struct gssx_call_ctx *ctx)
351 {
352 struct gssx_option opt;
353 __be32 *p;
354 int err;
355
356 /* ctx->locale */
357 err = gssx_enc_buffer(xdr, &ctx->locale);
358 if (err)
359 return err;
360
361 /* ctx->server_ctx */
362 err = gssx_enc_buffer(xdr, &ctx->server_ctx);
363 if (err)
364 return err;
365
366 /* we always want to ask for lucid contexts */
367 /* ctx->options */
368 p = xdr_reserve_space(xdr, 4);
369 *p = cpu_to_be32(2);
370
371 /* we want a lucid_v1 context */
372 opt.option.data = LUCID_OPTION;
373 opt.option.len = sizeof(LUCID_OPTION);
374 opt.value.data = LUCID_VALUE;
375 opt.value.len = sizeof(LUCID_VALUE);
376 err = gssx_enc_option(xdr, &opt);
377
378 /* ..and user creds */
379 opt.option.data = CREDS_OPTION;
380 opt.option.len = sizeof(CREDS_OPTION);
381 opt.value.data = CREDS_VALUE;
382 opt.value.len = sizeof(CREDS_VALUE);
383 err = gssx_enc_option(xdr, &opt);
384
385 return err;
386 }
387
388 static int gssx_dec_name_attr(struct xdr_stream *xdr,
389 struct gssx_name_attr *attr)
390 {
391 int err;
392
393 /* attr->attr */
394 err = gssx_dec_buffer(xdr, &attr->attr);
395 if (err)
396 return err;
397
398 /* attr->value */
399 err = gssx_dec_buffer(xdr, &attr->value);
400 if (err)
401 return err;
402
403 /* attr->extensions */
404 err = dummy_dec_opt_array(xdr, &attr->extensions);
405
406 return err;
407 }
408
409 static int dummy_enc_nameattr_array(struct xdr_stream *xdr,
410 struct gssx_name_attr_array *naa)
411 {
412 __be32 *p;
413
414 if (naa->count != 0)
415 return -EINVAL;
416
417 p = xdr_reserve_space(xdr, 4);
418 if (!p)
419 return -ENOSPC;
420 *p = 0;
421
422 return 0;
423 }
424
425 static int dummy_dec_nameattr_array(struct xdr_stream *xdr,
426 struct gssx_name_attr_array *naa)
427 {
428 struct gssx_name_attr dummy = { .attr = {.len = 0} };
429 u32 count, i;
430 __be32 *p;
431
432 p = xdr_inline_decode(xdr, 4);
433 if (unlikely(p == NULL))
434 return -ENOSPC;
435 count = be32_to_cpup(p++);
436 for (i = 0; i < count; i++) {
437 gssx_dec_name_attr(xdr, &dummy);
438 }
439
440 naa->count = 0;
441 naa->data = NULL;
442 return 0;
443 }
444
445 static struct xdr_netobj zero_netobj = {};
446
447 static struct gssx_name_attr_array zero_name_attr_array = {};
448
449 static struct gssx_option_array zero_option_array = {};
450
451 static int gssx_enc_name(struct xdr_stream *xdr,
452 struct gssx_name *name)
453 {
454 int err;
455
456 /* name->display_name */
457 err = gssx_enc_buffer(xdr, &name->display_name);
458 if (err)
459 return err;
460
461 /* name->name_type */
462 err = gssx_enc_buffer(xdr, &zero_netobj);
463 if (err)
464 return err;
465
466 /* name->exported_name */
467 err = gssx_enc_buffer(xdr, &zero_netobj);
468 if (err)
469 return err;
470
471 /* name->exported_composite_name */
472 err = gssx_enc_buffer(xdr, &zero_netobj);
473 if (err)
474 return err;
475
476 /* leave name_attributes empty for now, will add once we have any
477 * to pass up at all */
478 /* name->name_attributes */
479 err = dummy_enc_nameattr_array(xdr, &zero_name_attr_array);
480 if (err)
481 return err;
482
483 /* leave options empty for now, will add once we have any options
484 * to pass up at all */
485 /* name->extensions */
486 err = dummy_enc_opt_array(xdr, &zero_option_array);
487
488 return err;
489 }
490
491
492 static int gssx_dec_name(struct xdr_stream *xdr,
493 struct gssx_name *name)
494 {
495 struct xdr_netobj dummy_netobj = { .len = 0 };
496 struct gssx_name_attr_array dummy_name_attr_array = { .count = 0 };
497 struct gssx_option_array dummy_option_array = { .count = 0 };
498 int err;
499
500 /* name->display_name */
501 err = gssx_dec_buffer(xdr, &name->display_name);
502 if (err)
503 return err;
504
505 /* name->name_type */
506 err = gssx_dec_buffer(xdr, &dummy_netobj);
507 if (err)
508 return err;
509
510 /* name->exported_name */
511 err = gssx_dec_buffer(xdr, &dummy_netobj);
512 if (err)
513 return err;
514
515 /* name->exported_composite_name */
516 err = gssx_dec_buffer(xdr, &dummy_netobj);
517 if (err)
518 return err;
519
520 /* we assume we have no attributes for now, so simply consume them */
521 /* name->name_attributes */
522 err = dummy_dec_nameattr_array(xdr, &dummy_name_attr_array);
523 if (err)
524 return err;
525
526 /* we assume we have no options for now, so simply consume them */
527 /* name->extensions */
528 err = dummy_dec_opt_array(xdr, &dummy_option_array);
529
530 return err;
531 }
532
533 static int dummy_enc_credel_array(struct xdr_stream *xdr,
534 struct gssx_cred_element_array *cea)
535 {
536 __be32 *p;
537
538 if (cea->count != 0)
539 return -EINVAL;
540
541 p = xdr_reserve_space(xdr, 4);
542 if (!p)
543 return -ENOSPC;
544 *p = 0;
545
546 return 0;
547 }
548
549 static int gssx_enc_cred(struct xdr_stream *xdr,
550 struct gssx_cred *cred)
551 {
552 int err;
553
554 /* cred->desired_name */
555 err = gssx_enc_name(xdr, &cred->desired_name);
556 if (err)
557 return err;
558
559 /* cred->elements */
560 err = dummy_enc_credel_array(xdr, &cred->elements);
561 if (err)
562 return err;
563
564 /* cred->cred_handle_reference */
565 err = gssx_enc_buffer(xdr, &cred->cred_handle_reference);
566 if (err)
567 return err;
568
569 /* cred->needs_release */
570 err = gssx_enc_bool(xdr, cred->needs_release);
571
572 return err;
573 }
574
575 static int gssx_enc_ctx(struct xdr_stream *xdr,
576 struct gssx_ctx *ctx)
577 {
578 __be32 *p;
579 int err;
580
581 /* ctx->exported_context_token */
582 err = gssx_enc_buffer(xdr, &ctx->exported_context_token);
583 if (err)
584 return err;
585
586 /* ctx->state */
587 err = gssx_enc_buffer(xdr, &ctx->state);
588 if (err)
589 return err;
590
591 /* ctx->need_release */
592 err = gssx_enc_bool(xdr, ctx->need_release);
593 if (err)
594 return err;
595
596 /* ctx->mech */
597 err = gssx_enc_buffer(xdr, &ctx->mech);
598 if (err)
599 return err;
600
601 /* ctx->src_name */
602 err = gssx_enc_name(xdr, &ctx->src_name);
603 if (err)
604 return err;
605
606 /* ctx->targ_name */
607 err = gssx_enc_name(xdr, &ctx->targ_name);
608 if (err)
609 return err;
610
611 /* ctx->lifetime */
612 p = xdr_reserve_space(xdr, 8+8);
613 if (!p)
614 return -ENOSPC;
615 p = xdr_encode_hyper(p, ctx->lifetime);
616
617 /* ctx->ctx_flags */
618 p = xdr_encode_hyper(p, ctx->ctx_flags);
619
620 /* ctx->locally_initiated */
621 err = gssx_enc_bool(xdr, ctx->locally_initiated);
622 if (err)
623 return err;
624
625 /* ctx->open */
626 err = gssx_enc_bool(xdr, ctx->open);
627 if (err)
628 return err;
629
630 /* leave options empty for now, will add once we have any options
631 * to pass up at all */
632 /* ctx->options */
633 err = dummy_enc_opt_array(xdr, &ctx->options);
634
635 return err;
636 }
637
638 static int gssx_dec_ctx(struct xdr_stream *xdr,
639 struct gssx_ctx *ctx)
640 {
641 __be32 *p;
642 int err;
643
644 /* ctx->exported_context_token */
645 err = gssx_dec_buffer(xdr, &ctx->exported_context_token);
646 if (err)
647 return err;
648
649 /* ctx->state */
650 err = gssx_dec_buffer(xdr, &ctx->state);
651 if (err)
652 return err;
653
654 /* ctx->need_release */
655 err = gssx_dec_bool(xdr, &ctx->need_release);
656 if (err)
657 return err;
658
659 /* ctx->mech */
660 err = gssx_dec_buffer(xdr, &ctx->mech);
661 if (err)
662 return err;
663
664 /* ctx->src_name */
665 err = gssx_dec_name(xdr, &ctx->src_name);
666 if (err)
667 return err;
668
669 /* ctx->targ_name */
670 err = gssx_dec_name(xdr, &ctx->targ_name);
671 if (err)
672 return err;
673
674 /* ctx->lifetime */
675 p = xdr_inline_decode(xdr, 8+8);
676 if (unlikely(p == NULL))
677 return -ENOSPC;
678 p = xdr_decode_hyper(p, &ctx->lifetime);
679
680 /* ctx->ctx_flags */
681 p = xdr_decode_hyper(p, &ctx->ctx_flags);
682
683 /* ctx->locally_initiated */
684 err = gssx_dec_bool(xdr, &ctx->locally_initiated);
685 if (err)
686 return err;
687
688 /* ctx->open */
689 err = gssx_dec_bool(xdr, &ctx->open);
690 if (err)
691 return err;
692
693 /* we assume we have no options for now, so simply consume them */
694 /* ctx->options */
695 err = dummy_dec_opt_array(xdr, &ctx->options);
696
697 return err;
698 }
699
700 static int gssx_enc_cb(struct xdr_stream *xdr, struct gssx_cb *cb)
701 {
702 __be32 *p;
703 int err;
704
705 /* cb->initiator_addrtype */
706 p = xdr_reserve_space(xdr, 8);
707 if (!p)
708 return -ENOSPC;
709 p = xdr_encode_hyper(p, cb->initiator_addrtype);
710
711 /* cb->initiator_address */
712 err = gssx_enc_buffer(xdr, &cb->initiator_address);
713 if (err)
714 return err;
715
716 /* cb->acceptor_addrtype */
717 p = xdr_reserve_space(xdr, 8);
718 if (!p)
719 return -ENOSPC;
720 p = xdr_encode_hyper(p, cb->acceptor_addrtype);
721
722 /* cb->acceptor_address */
723 err = gssx_enc_buffer(xdr, &cb->acceptor_address);
724 if (err)
725 return err;
726
727 /* cb->application_data */
728 err = gssx_enc_buffer(xdr, &cb->application_data);
729
730 return err;
731 }
732
733 void gssx_enc_accept_sec_context(struct rpc_rqst *req,
734 struct xdr_stream *xdr,
735 const void *data)
736 {
737 const struct gssx_arg_accept_sec_context *arg = data;
738 int err;
739
740 err = gssx_enc_call_ctx(xdr, &arg->call_ctx);
741 if (err)
742 goto done;
743
744 /* arg->context_handle */
745 if (arg->context_handle)
746 err = gssx_enc_ctx(xdr, arg->context_handle);
747 else
748 err = gssx_enc_bool(xdr, 0);
749 if (err)
750 goto done;
751
752 /* arg->cred_handle */
753 if (arg->cred_handle)
754 err = gssx_enc_cred(xdr, arg->cred_handle);
755 else
756 err = gssx_enc_bool(xdr, 0);
757 if (err)
758 goto done;
759
760 /* arg->input_token */
761 err = gssx_enc_in_token(xdr, &arg->input_token);
762 if (err)
763 goto done;
764
765 /* arg->input_cb */
766 if (arg->input_cb)
767 err = gssx_enc_cb(xdr, arg->input_cb);
768 else
769 err = gssx_enc_bool(xdr, 0);
770 if (err)
771 goto done;
772
773 err = gssx_enc_bool(xdr, arg->ret_deleg_cred);
774 if (err)
775 goto done;
776
777 /* leave options empty for now, will add once we have any options
778 * to pass up at all */
779 /* arg->options */
780 err = dummy_enc_opt_array(xdr, &arg->options);
781
782 xdr_inline_pages(&req->rq_rcv_buf,
783 PAGE_SIZE/2 /* pretty arbitrary */,
784 arg->pages, 0 /* page base */, arg->npages * PAGE_SIZE);
785 done:
786 if (err)
787 dprintk("RPC: gssx_enc_accept_sec_context: %d\n", err);
788 }
789
790 int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
791 struct xdr_stream *xdr,
792 void *data)
793 {
794 struct gssx_res_accept_sec_context *res = data;
795 u32 value_follows;
796 int err;
797 struct page *scratch;
798
799 scratch = alloc_page(GFP_KERNEL);
800 if (!scratch)
801 return -ENOMEM;
802 xdr_set_scratch_page(xdr, scratch);
803
804 /* res->status */
805 err = gssx_dec_status(xdr, &res->status);
806 if (err)
807 goto out_free;
808
809 /* res->context_handle */
810 err = gssx_dec_bool(xdr, &value_follows);
811 if (err)
812 goto out_free;
813 if (value_follows) {
814 err = gssx_dec_ctx(xdr, res->context_handle);
815 if (err)
816 goto out_free;
817 } else {
818 res->context_handle = NULL;
819 }
820
821 /* res->output_token */
822 err = gssx_dec_bool(xdr, &value_follows);
823 if (err)
824 goto out_free;
825 if (value_follows) {
826 err = gssx_dec_buffer(xdr, res->output_token);
827 if (err)
828 goto out_free;
829 } else {
830 res->output_token = NULL;
831 }
832
833 /* res->delegated_cred_handle */
834 err = gssx_dec_bool(xdr, &value_follows);
835 if (err)
836 goto out_free;
837 if (value_follows) {
838 /* we do not support upcall servers sending this data. */
839 err = -EINVAL;
840 goto out_free;
841 }
842
843 /* res->options */
844 err = gssx_dec_option_array(xdr, &res->options);
845
846 out_free:
847 __free_page(scratch);
848 return err;
849 }
850
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