1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/nfs/callback_xdr.c
4 *
5 * Copyright (C) 2004 Trond Myklebust
6 *
7 * NFSv4 callback encode/decode procedures
8 */
9#include <linux/kernel.h>
10#include <linux/sunrpc/svc.h>
11#include <linux/nfs4.h>
12#include <linux/nfs_fs.h>
13#include <linux/ratelimit.h>
14#include <linux/printk.h>
15#include <linux/slab.h>
16#include <linux/sunrpc/bc_xprt.h>
17#include "nfs4_fs.h"
18#include "callback.h"
19#include "internal.h"
20#include "nfs4session.h"
21#include "nfs4trace.h"
22
23#define CB_OP_TAGLEN_MAXSZ		(512)
24#define CB_OP_HDR_RES_MAXSZ		(2 * 4) // opcode, status
25#define CB_OP_GETATTR_BITMAP_MAXSZ	(4 * 4) // bitmap length, 3 bitmaps
26#define CB_OP_GETATTR_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ + \
27					 CB_OP_GETATTR_BITMAP_MAXSZ + \
28					 /* change, size, ctime, mtime */\
29					 (2 + 2 + 3 + 3) * 4)
30#define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
31
32#if defined(CONFIG_NFS_V4_1)
33#define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
34#define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
35#define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
36					 NFS4_MAX_SESSIONID_LEN + \
37					 (1 + 3) * 4) // seqid, 3 slotids
38#define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
39#define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
40#define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
41#endif /* CONFIG_NFS_V4_1 */
42#ifdef CONFIG_NFS_V4_2
43#define CB_OP_OFFLOAD_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
44#endif /* CONFIG_NFS_V4_2 */
45
46#define NFSDBG_FACILITY NFSDBG_CALLBACK
47
48/* Internal error code */
49#define NFS4ERR_RESOURCE_HDR	11050
50
51struct callback_op {
52	__be32 (*process_op)(void *, void *, struct cb_process_state *);
53	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
54	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
55			const void *);
56	long res_maxsize;
57};
58
59static struct callback_op callback_ops[];
60
61static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
62{
63	return htonl(NFS4_OK);
64}
65
66/*
67 * svc_process_common() looks for an XDR encoder to know when
68 * not to drop a Reply.
69 */
70static bool nfs4_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
71{
72	return true;
73}
74
75static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
76		const char **str, size_t maxlen)
77{
78	ssize_t err;
79
80	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
81	if (err < 0)
82		return cpu_to_be32(NFS4ERR_RESOURCE);
83	*len = err;
84	return 0;
85}
86
87static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
88{
89	__be32 *p;
90
91	p = xdr_inline_decode(xdr, 4);
92	if (unlikely(p == NULL))
93		return htonl(NFS4ERR_RESOURCE);
94	fh->size = ntohl(*p);
95	if (fh->size > NFS4_FHSIZE)
96		return htonl(NFS4ERR_BADHANDLE);
97	p = xdr_inline_decode(xdr, fh->size);
98	if (unlikely(p == NULL))
99		return htonl(NFS4ERR_RESOURCE);
100	memcpy(&fh->data[0], p, fh->size);
101	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
102	return 0;
103}
104
105static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
106{
107	__be32 *p;
108	unsigned int attrlen;
109
110	p = xdr_inline_decode(xdr, 4);
111	if (unlikely(p == NULL))
112		return htonl(NFS4ERR_RESOURCE);
113	attrlen = ntohl(*p);
114	p = xdr_inline_decode(xdr, attrlen << 2);
115	if (unlikely(p == NULL))
116		return htonl(NFS4ERR_RESOURCE);
117	if (likely(attrlen > 0))
118		bitmap[0] = ntohl(*p++);
119	if (attrlen > 1)
120		bitmap[1] = ntohl(*p);
121	return 0;
122}
123
124static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
125{
126	__be32 *p;
127
128	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
129	if (unlikely(p == NULL))
130		return htonl(NFS4ERR_RESOURCE);
131	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
132	return 0;
133}
134
135static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
136{
137	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
138	return decode_stateid(xdr, stateid);
139}
140
141static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
142{
143	__be32 *p;
144	__be32 status;
145
146	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
147	if (unlikely(status != 0))
148		return status;
149	p = xdr_inline_decode(xdr, 12);
150	if (unlikely(p == NULL))
151		return htonl(NFS4ERR_RESOURCE);
152	hdr->minorversion = ntohl(*p++);
153	/* Check for minor version support */
154	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
155		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
156	} else {
157		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
158			"illegal minor version %u!\n",
159			__func__, hdr->minorversion);
160		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
161	}
162	hdr->nops = ntohl(*p);
163	return 0;
164}
165
166static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
167{
168	__be32 *p;
169	p = xdr_inline_decode(xdr, 4);
170	if (unlikely(p == NULL))
171		return htonl(NFS4ERR_RESOURCE_HDR);
172	*op = ntohl(*p);
173	return 0;
174}
175
176static __be32 decode_getattr_args(struct svc_rqst *rqstp,
177		struct xdr_stream *xdr, void *argp)
178{
179	struct cb_getattrargs *args = argp;
180	__be32 status;
181
182	status = decode_fh(xdr, &args->fh);
183	if (unlikely(status != 0))
184		return status;
185	return decode_bitmap(xdr, args->bitmap);
186}
187
188static __be32 decode_recall_args(struct svc_rqst *rqstp,
189		struct xdr_stream *xdr, void *argp)
190{
191	struct cb_recallargs *args = argp;
192	__be32 *p;
193	__be32 status;
194
195	status = decode_delegation_stateid(xdr, &args->stateid);
196	if (unlikely(status != 0))
197		return status;
198	p = xdr_inline_decode(xdr, 4);
199	if (unlikely(p == NULL))
200		return htonl(NFS4ERR_RESOURCE);
201	args->truncate = ntohl(*p);
202	return decode_fh(xdr, &args->fh);
203}
204
205#if defined(CONFIG_NFS_V4_1)
206static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
207{
208	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
209	return decode_stateid(xdr, stateid);
210}
211
212static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
213				       struct xdr_stream *xdr, void *argp)
214{
215	struct cb_layoutrecallargs *args = argp;
216	__be32 *p;
217	__be32 status = 0;
218	uint32_t iomode;
219
220	p = xdr_inline_decode(xdr, 4 * sizeof(uint32_t));
221	if (unlikely(p == NULL))
222		return htonl(NFS4ERR_BADXDR);
223
224	args->cbl_layout_type = ntohl(*p++);
225	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
226	 * as it is unusable and ignored with the other types.
227	 */
228	iomode = ntohl(*p++);
229	args->cbl_layoutchanged = ntohl(*p++);
230	args->cbl_recall_type = ntohl(*p++);
231
232	if (args->cbl_recall_type == RETURN_FILE) {
233		args->cbl_range.iomode = iomode;
234		status = decode_fh(xdr, &args->cbl_fh);
235		if (unlikely(status != 0))
236			return status;
237
238		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
239		if (unlikely(p == NULL))
240			return htonl(NFS4ERR_BADXDR);
241		p = xdr_decode_hyper(p, &args->cbl_range.offset);
242		p = xdr_decode_hyper(p, &args->cbl_range.length);
243		return decode_layout_stateid(xdr, &args->cbl_stateid);
244	} else if (args->cbl_recall_type == RETURN_FSID) {
245		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
246		if (unlikely(p == NULL))
247			return htonl(NFS4ERR_BADXDR);
248		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
249		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
250	} else if (args->cbl_recall_type != RETURN_ALL)
251		return htonl(NFS4ERR_BADXDR);
252	return 0;
253}
254
255static
256__be32 decode_devicenotify_args(struct svc_rqst *rqstp,
257				struct xdr_stream *xdr,
258				void *argp)
259{
260	struct cb_devicenotifyargs *args = argp;
261	uint32_t tmp, n, i;
262	__be32 *p;
263	__be32 status = 0;
264
265	/* Num of device notifications */
266	p = xdr_inline_decode(xdr, sizeof(uint32_t));
267	if (unlikely(p == NULL)) {
268		status = htonl(NFS4ERR_BADXDR);
269		goto out;
270	}
271	n = ntohl(*p++);
272	if (n == 0)
273		goto out;
274
275	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
276	if (!args->devs) {
277		status = htonl(NFS4ERR_DELAY);
278		goto out;
279	}
280
281	/* Decode each dev notification */
282	for (i = 0; i < n; i++) {
283		struct cb_devicenotifyitem *dev = &args->devs[i];
284
285		p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
286				      NFS4_DEVICEID4_SIZE);
287		if (unlikely(p == NULL)) {
288			status = htonl(NFS4ERR_BADXDR);
289			goto err;
290		}
291
292		tmp = ntohl(*p++);	/* bitmap size */
293		if (tmp != 1) {
294			status = htonl(NFS4ERR_INVAL);
295			goto err;
296		}
297		dev->cbd_notify_type = ntohl(*p++);
298		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
299		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
300			status = htonl(NFS4ERR_INVAL);
301			goto err;
302		}
303
304		tmp = ntohl(*p++);	/* opaque size */
305		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
306		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
307		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
308		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
309			status = htonl(NFS4ERR_INVAL);
310			goto err;
311		}
312		dev->cbd_layout_type = ntohl(*p++);
313		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
314		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
315
316		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
317			p = xdr_inline_decode(xdr, sizeof(uint32_t));
318			if (unlikely(p == NULL)) {
319				status = htonl(NFS4ERR_BADXDR);
320				goto err;
321			}
322			dev->cbd_immediate = ntohl(*p++);
323		} else {
324			dev->cbd_immediate = 0;
325		}
326
327		dprintk("%s: type %d layout 0x%x immediate %d\n",
328			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
329			dev->cbd_immediate);
330	}
331	args->ndevs = n;
332	dprintk("%s: ndevs %d\n", __func__, args->ndevs);
333	return 0;
334err:
335	kfree(args->devs);
336out:
337	args->devs = NULL;
338	args->ndevs = 0;
339	dprintk("%s: status %d ndevs %d\n",
340		__func__, ntohl(status), args->ndevs);
341	return status;
342}
343
344static __be32 decode_sessionid(struct xdr_stream *xdr,
345				 struct nfs4_sessionid *sid)
346{
347	__be32 *p;
348
349	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
350	if (unlikely(p == NULL))
351		return htonl(NFS4ERR_RESOURCE);
352
353	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
354	return 0;
355}
356
357static __be32 decode_rc_list(struct xdr_stream *xdr,
358			       struct referring_call_list *rc_list)
359{
360	__be32 *p;
361	int i;
362	__be32 status;
363
364	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
365	if (status)
366		goto out;
367
368	status = htonl(NFS4ERR_RESOURCE);
369	p = xdr_inline_decode(xdr, sizeof(uint32_t));
370	if (unlikely(p == NULL))
371		goto out;
372
373	rc_list->rcl_nrefcalls = ntohl(*p++);
374	if (rc_list->rcl_nrefcalls) {
375		p = xdr_inline_decode(xdr,
376			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
377		if (unlikely(p == NULL))
378			goto out;
379		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
380						sizeof(*rc_list->rcl_refcalls),
381						GFP_KERNEL);
382		if (unlikely(rc_list->rcl_refcalls == NULL))
383			goto out;
384		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
385			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
386			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
387		}
388	}
389	status = 0;
390
391out:
392	return status;
393}
394
395static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
396					struct xdr_stream *xdr,
397					void *argp)
398{
399	struct cb_sequenceargs *args = argp;
400	__be32 *p;
401	int i;
402	__be32 status;
403
404	status = decode_sessionid(xdr, &args->csa_sessionid);
405	if (status)
406		return status;
407
408	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
409	if (unlikely(p == NULL))
410		return htonl(NFS4ERR_RESOURCE);
411
412	args->csa_addr = svc_addr(rqstp);
413	args->csa_sequenceid = ntohl(*p++);
414	args->csa_slotid = ntohl(*p++);
415	args->csa_highestslotid = ntohl(*p++);
416	args->csa_cachethis = ntohl(*p++);
417	args->csa_nrclists = ntohl(*p++);
418	args->csa_rclists = NULL;
419	if (args->csa_nrclists) {
420		args->csa_rclists = kmalloc_array(args->csa_nrclists,
421						  sizeof(*args->csa_rclists),
422						  GFP_KERNEL);
423		if (unlikely(args->csa_rclists == NULL))
424			return htonl(NFS4ERR_RESOURCE);
425
426		for (i = 0; i < args->csa_nrclists; i++) {
427			status = decode_rc_list(xdr, &args->csa_rclists[i]);
428			if (status) {
429				args->csa_nrclists = i;
430				goto out_free;
431			}
432		}
433	}
434	return 0;
435
436out_free:
437	for (i = 0; i < args->csa_nrclists; i++)
438		kfree(args->csa_rclists[i].rcl_refcalls);
439	kfree(args->csa_rclists);
440	return status;
441}
442
443static __be32 decode_recallany_args(struct svc_rqst *rqstp,
444				      struct xdr_stream *xdr,
445				      void *argp)
446{
447	struct cb_recallanyargs *args = argp;
448	uint32_t bitmap[2];
449	__be32 *p, status;
450
451	p = xdr_inline_decode(xdr, 4);
452	if (unlikely(p == NULL))
453		return htonl(NFS4ERR_BADXDR);
454	args->craa_objs_to_keep = ntohl(*p++);
455	status = decode_bitmap(xdr, bitmap);
456	if (unlikely(status))
457		return status;
458	args->craa_type_mask = bitmap[0];
459
460	return 0;
461}
462
463static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
464					struct xdr_stream *xdr,
465					void *argp)
466{
467	struct cb_recallslotargs *args = argp;
468	__be32 *p;
469
470	p = xdr_inline_decode(xdr, 4);
471	if (unlikely(p == NULL))
472		return htonl(NFS4ERR_BADXDR);
473	args->crsa_target_highest_slotid = ntohl(*p++);
474	return 0;
475}
476
477static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
478{
479	__be32		*p;
480	unsigned int	len;
481
482	p = xdr_inline_decode(xdr, 12);
483	if (unlikely(p == NULL))
484		return htonl(NFS4ERR_BADXDR);
485
486	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
487	len = be32_to_cpu(*p);
488
489	p = xdr_inline_decode(xdr, len);
490	if (unlikely(p == NULL))
491		return htonl(NFS4ERR_BADXDR);
492
493	/* Only try to decode if the length is right */
494	if (len == 20) {
495		p += 2;	/* skip "lock id:" */
496		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
497		xdr_decode_hyper(p, &args->cbnl_owner.id);
498		args->cbnl_valid = true;
499	} else {
500		args->cbnl_owner.s_dev = 0;
501		args->cbnl_owner.id = 0;
502		args->cbnl_valid = false;
503	}
504	return 0;
505}
506
507static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
508		struct xdr_stream *xdr, void *argp)
509{
510	struct cb_notify_lock_args *args = argp;
511	__be32 status;
512
513	status = decode_fh(xdr, &args->cbnl_fh);
514	if (unlikely(status != 0))
515		return status;
516	return decode_lockowner(xdr, args);
517}
518
519#endif /* CONFIG_NFS_V4_1 */
520#ifdef CONFIG_NFS_V4_2
521static __be32 decode_write_response(struct xdr_stream *xdr,
522					struct cb_offloadargs *args)
523{
524	__be32 *p;
525
526	/* skip the always zero field */
527	p = xdr_inline_decode(xdr, 4);
528	if (unlikely(!p))
529		goto out;
530	p++;
531
532	/* decode count, stable_how, verifier */
533	p = xdr_inline_decode(xdr, 8 + 4);
534	if (unlikely(!p))
535		goto out;
536	p = xdr_decode_hyper(p, &args->wr_count);
537	args->wr_writeverf.committed = be32_to_cpup(p);
538	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
539	if (likely(p)) {
540		memcpy(&args->wr_writeverf.verifier.data[0], p,
541			NFS4_VERIFIER_SIZE);
542		return 0;
543	}
544out:
545	return htonl(NFS4ERR_RESOURCE);
546}
547
548static __be32 decode_offload_args(struct svc_rqst *rqstp,
549					struct xdr_stream *xdr,
550					void *data)
551{
552	struct cb_offloadargs *args = data;
553	__be32 *p;
554	__be32 status;
555
556	/* decode fh */
557	status = decode_fh(xdr, &args->coa_fh);
558	if (unlikely(status != 0))
559		return status;
560
561	/* decode stateid */
562	status = decode_stateid(xdr, &args->coa_stateid);
563	if (unlikely(status != 0))
564		return status;
565
566	/* decode status */
567	p = xdr_inline_decode(xdr, 4);
568	if (unlikely(!p))
569		goto out;
570	args->error = ntohl(*p++);
571	if (!args->error) {
572		status = decode_write_response(xdr, args);
573		if (unlikely(status != 0))
574			return status;
575	} else {
576		p = xdr_inline_decode(xdr, 8);
577		if (unlikely(!p))
578			goto out;
579		p = xdr_decode_hyper(p, &args->wr_count);
580	}
581	return 0;
582out:
583	return htonl(NFS4ERR_RESOURCE);
584}
585#endif /* CONFIG_NFS_V4_2 */
586static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
587{
588	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
589		return cpu_to_be32(NFS4ERR_RESOURCE);
590	return 0;
591}
592
593static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
594{
595	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
596		return cpu_to_be32(NFS4ERR_RESOURCE);
597	return 0;
598}
599
600static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
601{
602	__be32 *p;
603
604	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
605		return 0;
606	p = xdr_reserve_space(xdr, 8);
607	if (unlikely(!p))
608		return htonl(NFS4ERR_RESOURCE);
609	p = xdr_encode_hyper(p, change);
610	return 0;
611}
612
613static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
614{
615	__be32 *p;
616
617	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
618		return 0;
619	p = xdr_reserve_space(xdr, 8);
620	if (unlikely(!p))
621		return htonl(NFS4ERR_RESOURCE);
622	p = xdr_encode_hyper(p, size);
623	return 0;
624}
625
626static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
627{
628	__be32 *p;
629
630	p = xdr_reserve_space(xdr, 12);
631	if (unlikely(!p))
632		return htonl(NFS4ERR_RESOURCE);
633	p = xdr_encode_hyper(p, time->tv_sec);
634	*p = htonl(time->tv_nsec);
635	return 0;
636}
637
638static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
639{
640	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
641		return 0;
642	return encode_attr_time(xdr,time);
643}
644
645static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
646{
647	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
648		return 0;
649	return encode_attr_time(xdr,time);
650}
651
652static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
653{
654	__be32 status;
655
656	hdr->status = xdr_reserve_space(xdr, 4);
657	if (unlikely(hdr->status == NULL))
658		return htonl(NFS4ERR_RESOURCE);
659	status = encode_string(xdr, hdr->taglen, hdr->tag);
660	if (unlikely(status != 0))
661		return status;
662	hdr->nops = xdr_reserve_space(xdr, 4);
663	if (unlikely(hdr->nops == NULL))
664		return htonl(NFS4ERR_RESOURCE);
665	return 0;
666}
667
668static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
669{
670	__be32 *p;
671
672	p = xdr_reserve_space(xdr, 8);
673	if (unlikely(p == NULL))
674		return htonl(NFS4ERR_RESOURCE_HDR);
675	*p++ = htonl(op);
676	*p = res;
677	return 0;
678}
679
680static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
681		const void *resp)
682{
683	const struct cb_getattrres *res = resp;
684	__be32 *savep = NULL;
685	__be32 status = res->status;
686
687	if (unlikely(status != 0))
688		goto out;
689	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
690	if (unlikely(status != 0))
691		goto out;
692	status = cpu_to_be32(NFS4ERR_RESOURCE);
693	savep = xdr_reserve_space(xdr, sizeof(*savep));
694	if (unlikely(!savep))
695		goto out;
696	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
697	if (unlikely(status != 0))
698		goto out;
699	status = encode_attr_size(xdr, res->bitmap, res->size);
700	if (unlikely(status != 0))
701		goto out;
702	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
703	if (unlikely(status != 0))
704		goto out;
705	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
706	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
707out:
708	return status;
709}
710
711#if defined(CONFIG_NFS_V4_1)
712
713static __be32 encode_sessionid(struct xdr_stream *xdr,
714				 const struct nfs4_sessionid *sid)
715{
716	__be32 *p;
717
718	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
719	if (unlikely(p == NULL))
720		return htonl(NFS4ERR_RESOURCE);
721
722	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
723	return 0;
724}
725
726static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
727				       struct xdr_stream *xdr,
728				       const void *resp)
729{
730	const struct cb_sequenceres *res = resp;
731	__be32 *p;
732	__be32 status = res->csr_status;
733
734	if (unlikely(status != 0))
735		return status;
736
737	status = encode_sessionid(xdr, &res->csr_sessionid);
738	if (status)
739		return status;
740
741	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
742	if (unlikely(p == NULL))
743		return htonl(NFS4ERR_RESOURCE);
744
745	*p++ = htonl(res->csr_sequenceid);
746	*p++ = htonl(res->csr_slotid);
747	*p++ = htonl(res->csr_highestslotid);
748	*p++ = htonl(res->csr_target_highestslotid);
749	return 0;
750}
751
752static __be32
753preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
754{
755	if (op_nr == OP_CB_SEQUENCE) {
756		if (nop != 0)
757			return htonl(NFS4ERR_SEQUENCE_POS);
758	} else {
759		if (nop == 0)
760			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
761	}
762
763	switch (op_nr) {
764	case OP_CB_GETATTR:
765	case OP_CB_RECALL:
766	case OP_CB_SEQUENCE:
767	case OP_CB_RECALL_ANY:
768	case OP_CB_RECALL_SLOT:
769	case OP_CB_LAYOUTRECALL:
770	case OP_CB_NOTIFY_DEVICEID:
771	case OP_CB_NOTIFY_LOCK:
772		*op = &callback_ops[op_nr];
773		break;
774
775	case OP_CB_NOTIFY:
776	case OP_CB_PUSH_DELEG:
777	case OP_CB_RECALLABLE_OBJ_AVAIL:
778	case OP_CB_WANTS_CANCELLED:
779		return htonl(NFS4ERR_NOTSUPP);
780
781	default:
782		return htonl(NFS4ERR_OP_ILLEGAL);
783	}
784
785	return htonl(NFS_OK);
786}
787
788static void nfs4_callback_free_slot(struct nfs4_session *session,
789		struct nfs4_slot *slot)
790{
791	struct nfs4_slot_table *tbl = &session->bc_slot_table;
792
793	spin_lock(&tbl->slot_tbl_lock);
794	/*
795	 * Let the state manager know callback processing done.
796	 * A single slot, so highest used slotid is either 0 or -1
797	 */
798	nfs4_free_slot(tbl, slot);
799	spin_unlock(&tbl->slot_tbl_lock);
800}
801
802static void nfs4_cb_free_slot(struct cb_process_state *cps)
803{
804	if (cps->slot) {
805		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
806		cps->slot = NULL;
807	}
808}
809
810#else /* CONFIG_NFS_V4_1 */
811
812static __be32
813preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
814{
815	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
816}
817
818static void nfs4_cb_free_slot(struct cb_process_state *cps)
819{
820}
821#endif /* CONFIG_NFS_V4_1 */
822
823#ifdef CONFIG_NFS_V4_2
824static __be32
825preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
826{
827	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
828	if (status != htonl(NFS4ERR_OP_ILLEGAL))
829		return status;
830
831	if (op_nr == OP_CB_OFFLOAD) {
832		*op = &callback_ops[op_nr];
833		return htonl(NFS_OK);
834	} else
835		return htonl(NFS4ERR_NOTSUPP);
836	return htonl(NFS4ERR_OP_ILLEGAL);
837}
838#else /* CONFIG_NFS_V4_2 */
839static __be32
840preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
841{
842	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
843}
844#endif /* CONFIG_NFS_V4_2 */
845
846static __be32
847preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
848{
849	switch (op_nr) {
850	case OP_CB_GETATTR:
851	case OP_CB_RECALL:
852		*op = &callback_ops[op_nr];
853		break;
854	default:
855		return htonl(NFS4ERR_OP_ILLEGAL);
856	}
857
858	return htonl(NFS_OK);
859}
860
861static __be32 process_op(int nop, struct svc_rqst *rqstp,
862			 struct cb_process_state *cps)
863{
864	struct xdr_stream *xdr_out = &rqstp->rq_res_stream;
865	struct callback_op *op = &callback_ops[0];
866	unsigned int op_nr;
867	__be32 status;
868	long maxlen;
869	__be32 res;
870
871	status = decode_op_hdr(&rqstp->rq_arg_stream, &op_nr);
872	if (unlikely(status))
873		return status;
874
875	switch (cps->minorversion) {
876	case 0:
877		status = preprocess_nfs4_op(op_nr, &op);
878		break;
879	case 1:
880		status = preprocess_nfs41_op(nop, op_nr, &op);
881		break;
882	case 2:
883		status = preprocess_nfs42_op(nop, op_nr, &op);
884		break;
885	default:
886		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
887	}
888
889	if (status == htonl(NFS4ERR_OP_ILLEGAL))
890		op_nr = OP_CB_ILLEGAL;
891	if (status)
892		goto encode_hdr;
893
894	if (cps->drc_status) {
895		status = cps->drc_status;
896		goto encode_hdr;
897	}
898
899	maxlen = xdr_out->end - xdr_out->p;
900	if (maxlen > 0 && maxlen < PAGE_SIZE) {
901		status = op->decode_args(rqstp, &rqstp->rq_arg_stream,
902					 rqstp->rq_argp);
903		if (likely(status == 0))
904			status = op->process_op(rqstp->rq_argp, rqstp->rq_resp,
905						cps);
906	} else
907		status = htonl(NFS4ERR_RESOURCE);
908
909encode_hdr:
910	res = encode_op_hdr(xdr_out, op_nr, status);
911	if (unlikely(res))
912		return res;
913	if (op->encode_res != NULL && status == 0)
914		status = op->encode_res(rqstp, xdr_out, rqstp->rq_resp);
915	return status;
916}
917
918/*
919 * Decode, process and encode a COMPOUND
920 */
921static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
922{
923	struct cb_compound_hdr_arg hdr_arg = { 0 };
924	struct cb_compound_hdr_res hdr_res = { NULL };
925	struct cb_process_state cps = {
926		.drc_status = 0,
927		.clp = NULL,
928		.net = SVC_NET(rqstp),
929	};
930	unsigned int nops = 0;
931	__be32 status;
932
933	status = decode_compound_hdr_arg(&rqstp->rq_arg_stream, &hdr_arg);
934	if (status == htonl(NFS4ERR_RESOURCE))
935		return rpc_garbage_args;
936
937	if (hdr_arg.minorversion == 0) {
938		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
939		if (!cps.clp) {
940			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
941			goto out_invalidcred;
942		}
943		if (!check_gss_callback_principal(cps.clp, rqstp)) {
944			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
945			nfs_put_client(cps.clp);
946			goto out_invalidcred;
947		}
948	}
949
950	cps.minorversion = hdr_arg.minorversion;
951	hdr_res.taglen = hdr_arg.taglen;
952	hdr_res.tag = hdr_arg.tag;
953	if (encode_compound_hdr_res(&rqstp->rq_res_stream, &hdr_res) != 0) {
954		if (cps.clp)
955			nfs_put_client(cps.clp);
956		return rpc_system_err;
957	}
958	while (status == 0 && nops != hdr_arg.nops) {
959		status = process_op(nops, rqstp, &cps);
960		nops++;
961	}
962
963	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
964	* resource error in cb_compound status without returning op */
965	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
966		status = htonl(NFS4ERR_RESOURCE);
967		nops--;
968	}
969
970	if (svc_is_backchannel(rqstp) && cps.clp) {
971		rqstp->bc_to_initval = cps.clp->cl_rpcclient->cl_timeout->to_initval;
972		rqstp->bc_to_retries = cps.clp->cl_rpcclient->cl_timeout->to_retries;
973	}
974
975	*hdr_res.status = status;
976	*hdr_res.nops = htonl(nops);
977	nfs4_cb_free_slot(&cps);
978	nfs_put_client(cps.clp);
979	return rpc_success;
980
981out_invalidcred:
982	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
983	rqstp->rq_auth_stat = rpc_autherr_badcred;
984	return rpc_success;
985}
986
987static int
988nfs_callback_dispatch(struct svc_rqst *rqstp)
989{
990	const struct svc_procedure *procp = rqstp->rq_procinfo;
991
992	*rqstp->rq_accept_statp = procp->pc_func(rqstp);
993	return 1;
994}
995
996/*
997 * Define NFS4 callback COMPOUND ops.
998 */
999static struct callback_op callback_ops[] = {
1000	[0] = {
1001		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
1002	},
1003	[OP_CB_GETATTR] = {
1004		.process_op = nfs4_callback_getattr,
1005		.decode_args = decode_getattr_args,
1006		.encode_res = encode_getattr_res,
1007		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1008	},
1009	[OP_CB_RECALL] = {
1010		.process_op = nfs4_callback_recall,
1011		.decode_args = decode_recall_args,
1012		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1013	},
1014#if defined(CONFIG_NFS_V4_1)
1015	[OP_CB_LAYOUTRECALL] = {
1016		.process_op = nfs4_callback_layoutrecall,
1017		.decode_args = decode_layoutrecall_args,
1018		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1019	},
1020	[OP_CB_NOTIFY_DEVICEID] = {
1021		.process_op = nfs4_callback_devicenotify,
1022		.decode_args = decode_devicenotify_args,
1023		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1024	},
1025	[OP_CB_SEQUENCE] = {
1026		.process_op = nfs4_callback_sequence,
1027		.decode_args = decode_cb_sequence_args,
1028		.encode_res = encode_cb_sequence_res,
1029		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1030	},
1031	[OP_CB_RECALL_ANY] = {
1032		.process_op = nfs4_callback_recallany,
1033		.decode_args = decode_recallany_args,
1034		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1035	},
1036	[OP_CB_RECALL_SLOT] = {
1037		.process_op = nfs4_callback_recallslot,
1038		.decode_args = decode_recallslot_args,
1039		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1040	},
1041	[OP_CB_NOTIFY_LOCK] = {
1042		.process_op = nfs4_callback_notify_lock,
1043		.decode_args = decode_notify_lock_args,
1044		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1045	},
1046#endif /* CONFIG_NFS_V4_1 */
1047#ifdef CONFIG_NFS_V4_2
1048	[OP_CB_OFFLOAD] = {
1049		.process_op = nfs4_callback_offload,
1050		.decode_args = decode_offload_args,
1051		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1052	},
1053#endif /* CONFIG_NFS_V4_2 */
1054};
1055
1056/*
1057 * Define NFS4 callback procedures
1058 */
1059static const struct svc_procedure nfs4_callback_procedures1[] = {
1060	[CB_NULL] = {
1061		.pc_func = nfs4_callback_null,
1062		.pc_encode = nfs4_encode_void,
1063		.pc_xdrressize = 1,
1064		.pc_name = "NULL",
1065	},
1066	[CB_COMPOUND] = {
1067		.pc_func = nfs4_callback_compound,
1068		.pc_encode = nfs4_encode_void,
1069		.pc_argsize = 256,
1070		.pc_argzero = 256,
1071		.pc_ressize = 256,
1072		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1073		.pc_name = "COMPOUND",
1074	}
1075};
1076
1077static DEFINE_PER_CPU_ALIGNED(unsigned long,
1078			      nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)]);
1079const struct svc_version nfs4_callback_version1 = {
1080	.vs_vers = 1,
1081	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1082	.vs_proc = nfs4_callback_procedures1,
1083	.vs_count = nfs4_callback_count1,
1084	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1085	.vs_dispatch = nfs_callback_dispatch,
1086	.vs_hidden = true,
1087	.vs_need_cong_ctrl = true,
1088};
1089
1090static DEFINE_PER_CPU_ALIGNED(unsigned long,
1091			      nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)]);
1092const struct svc_version nfs4_callback_version4 = {
1093	.vs_vers = 4,
1094	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1095	.vs_proc = nfs4_callback_procedures1,
1096	.vs_count = nfs4_callback_count4,
1097	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1098	.vs_dispatch = nfs_callback_dispatch,
1099	.vs_hidden = true,
1100	.vs_need_cong_ctrl = true,
1101};
1102