xref: /openbmc/linux/fs/nfs/callback_xdr.c (revision e5242c5f)
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 
51 struct 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 
59 static struct callback_op callback_ops[];
60 
61 static __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  */
70 static bool nfs4_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
71 {
72 	return true;
73 }
74 
75 static __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 
87 static __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 
105 static __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 
124 static __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 
135 static __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 
141 static __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 
166 static __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 
176 static __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 
188 static __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)
206 static __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 
212 static __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 
255 static
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;
334 err:
335 	kfree(args->devs);
336 out:
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 
344 static __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 
357 static __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 		if (unlikely(rc_list->rcl_nrefcalls > xdr->buf->len))
376 			goto out;
377 		p = xdr_inline_decode(xdr,
378 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
379 		if (unlikely(p == NULL))
380 			goto out;
381 		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
382 						sizeof(*rc_list->rcl_refcalls),
383 						GFP_KERNEL);
384 		if (unlikely(rc_list->rcl_refcalls == NULL))
385 			goto out;
386 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
387 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
388 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
389 		}
390 	}
391 	status = 0;
392 
393 out:
394 	return status;
395 }
396 
397 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
398 					struct xdr_stream *xdr,
399 					void *argp)
400 {
401 	struct cb_sequenceargs *args = argp;
402 	__be32 *p;
403 	int i;
404 	__be32 status;
405 
406 	status = decode_sessionid(xdr, &args->csa_sessionid);
407 	if (status)
408 		return status;
409 
410 	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
411 	if (unlikely(p == NULL))
412 		return htonl(NFS4ERR_RESOURCE);
413 
414 	args->csa_addr = svc_addr(rqstp);
415 	args->csa_sequenceid = ntohl(*p++);
416 	args->csa_slotid = ntohl(*p++);
417 	args->csa_highestslotid = ntohl(*p++);
418 	args->csa_cachethis = ntohl(*p++);
419 	args->csa_nrclists = ntohl(*p++);
420 	args->csa_rclists = NULL;
421 	if (args->csa_nrclists) {
422 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
423 						  sizeof(*args->csa_rclists),
424 						  GFP_KERNEL);
425 		if (unlikely(args->csa_rclists == NULL))
426 			return htonl(NFS4ERR_RESOURCE);
427 
428 		for (i = 0; i < args->csa_nrclists; i++) {
429 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
430 			if (status) {
431 				args->csa_nrclists = i;
432 				goto out_free;
433 			}
434 		}
435 	}
436 	return 0;
437 
438 out_free:
439 	for (i = 0; i < args->csa_nrclists; i++)
440 		kfree(args->csa_rclists[i].rcl_refcalls);
441 	kfree(args->csa_rclists);
442 	return status;
443 }
444 
445 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
446 				      struct xdr_stream *xdr,
447 				      void *argp)
448 {
449 	struct cb_recallanyargs *args = argp;
450 	uint32_t bitmap[2];
451 	__be32 *p, status;
452 
453 	p = xdr_inline_decode(xdr, 4);
454 	if (unlikely(p == NULL))
455 		return htonl(NFS4ERR_BADXDR);
456 	args->craa_objs_to_keep = ntohl(*p++);
457 	status = decode_bitmap(xdr, bitmap);
458 	if (unlikely(status))
459 		return status;
460 	args->craa_type_mask = bitmap[0];
461 
462 	return 0;
463 }
464 
465 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
466 					struct xdr_stream *xdr,
467 					void *argp)
468 {
469 	struct cb_recallslotargs *args = argp;
470 	__be32 *p;
471 
472 	p = xdr_inline_decode(xdr, 4);
473 	if (unlikely(p == NULL))
474 		return htonl(NFS4ERR_BADXDR);
475 	args->crsa_target_highest_slotid = ntohl(*p++);
476 	return 0;
477 }
478 
479 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
480 {
481 	__be32		*p;
482 	unsigned int	len;
483 
484 	p = xdr_inline_decode(xdr, 12);
485 	if (unlikely(p == NULL))
486 		return htonl(NFS4ERR_BADXDR);
487 
488 	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
489 	len = be32_to_cpu(*p);
490 
491 	p = xdr_inline_decode(xdr, len);
492 	if (unlikely(p == NULL))
493 		return htonl(NFS4ERR_BADXDR);
494 
495 	/* Only try to decode if the length is right */
496 	if (len == 20) {
497 		p += 2;	/* skip "lock id:" */
498 		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
499 		xdr_decode_hyper(p, &args->cbnl_owner.id);
500 		args->cbnl_valid = true;
501 	} else {
502 		args->cbnl_owner.s_dev = 0;
503 		args->cbnl_owner.id = 0;
504 		args->cbnl_valid = false;
505 	}
506 	return 0;
507 }
508 
509 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
510 		struct xdr_stream *xdr, void *argp)
511 {
512 	struct cb_notify_lock_args *args = argp;
513 	__be32 status;
514 
515 	status = decode_fh(xdr, &args->cbnl_fh);
516 	if (unlikely(status != 0))
517 		return status;
518 	return decode_lockowner(xdr, args);
519 }
520 
521 #endif /* CONFIG_NFS_V4_1 */
522 #ifdef CONFIG_NFS_V4_2
523 static __be32 decode_write_response(struct xdr_stream *xdr,
524 					struct cb_offloadargs *args)
525 {
526 	__be32 *p;
527 
528 	/* skip the always zero field */
529 	p = xdr_inline_decode(xdr, 4);
530 	if (unlikely(!p))
531 		goto out;
532 	p++;
533 
534 	/* decode count, stable_how, verifier */
535 	p = xdr_inline_decode(xdr, 8 + 4);
536 	if (unlikely(!p))
537 		goto out;
538 	p = xdr_decode_hyper(p, &args->wr_count);
539 	args->wr_writeverf.committed = be32_to_cpup(p);
540 	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
541 	if (likely(p)) {
542 		memcpy(&args->wr_writeverf.verifier.data[0], p,
543 			NFS4_VERIFIER_SIZE);
544 		return 0;
545 	}
546 out:
547 	return htonl(NFS4ERR_RESOURCE);
548 }
549 
550 static __be32 decode_offload_args(struct svc_rqst *rqstp,
551 					struct xdr_stream *xdr,
552 					void *data)
553 {
554 	struct cb_offloadargs *args = data;
555 	__be32 *p;
556 	__be32 status;
557 
558 	/* decode fh */
559 	status = decode_fh(xdr, &args->coa_fh);
560 	if (unlikely(status != 0))
561 		return status;
562 
563 	/* decode stateid */
564 	status = decode_stateid(xdr, &args->coa_stateid);
565 	if (unlikely(status != 0))
566 		return status;
567 
568 	/* decode status */
569 	p = xdr_inline_decode(xdr, 4);
570 	if (unlikely(!p))
571 		goto out;
572 	args->error = ntohl(*p++);
573 	if (!args->error) {
574 		status = decode_write_response(xdr, args);
575 		if (unlikely(status != 0))
576 			return status;
577 	} else {
578 		p = xdr_inline_decode(xdr, 8);
579 		if (unlikely(!p))
580 			goto out;
581 		p = xdr_decode_hyper(p, &args->wr_count);
582 	}
583 	return 0;
584 out:
585 	return htonl(NFS4ERR_RESOURCE);
586 }
587 #endif /* CONFIG_NFS_V4_2 */
588 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
589 {
590 	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
591 		return cpu_to_be32(NFS4ERR_RESOURCE);
592 	return 0;
593 }
594 
595 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
596 {
597 	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
598 		return cpu_to_be32(NFS4ERR_RESOURCE);
599 	return 0;
600 }
601 
602 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
603 {
604 	__be32 *p;
605 
606 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
607 		return 0;
608 	p = xdr_reserve_space(xdr, 8);
609 	if (unlikely(!p))
610 		return htonl(NFS4ERR_RESOURCE);
611 	p = xdr_encode_hyper(p, change);
612 	return 0;
613 }
614 
615 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
616 {
617 	__be32 *p;
618 
619 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
620 		return 0;
621 	p = xdr_reserve_space(xdr, 8);
622 	if (unlikely(!p))
623 		return htonl(NFS4ERR_RESOURCE);
624 	p = xdr_encode_hyper(p, size);
625 	return 0;
626 }
627 
628 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
629 {
630 	__be32 *p;
631 
632 	p = xdr_reserve_space(xdr, 12);
633 	if (unlikely(!p))
634 		return htonl(NFS4ERR_RESOURCE);
635 	p = xdr_encode_hyper(p, time->tv_sec);
636 	*p = htonl(time->tv_nsec);
637 	return 0;
638 }
639 
640 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
641 {
642 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
643 		return 0;
644 	return encode_attr_time(xdr,time);
645 }
646 
647 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
648 {
649 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
650 		return 0;
651 	return encode_attr_time(xdr,time);
652 }
653 
654 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
655 {
656 	__be32 status;
657 
658 	hdr->status = xdr_reserve_space(xdr, 4);
659 	if (unlikely(hdr->status == NULL))
660 		return htonl(NFS4ERR_RESOURCE);
661 	status = encode_string(xdr, hdr->taglen, hdr->tag);
662 	if (unlikely(status != 0))
663 		return status;
664 	hdr->nops = xdr_reserve_space(xdr, 4);
665 	if (unlikely(hdr->nops == NULL))
666 		return htonl(NFS4ERR_RESOURCE);
667 	return 0;
668 }
669 
670 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
671 {
672 	__be32 *p;
673 
674 	p = xdr_reserve_space(xdr, 8);
675 	if (unlikely(p == NULL))
676 		return htonl(NFS4ERR_RESOURCE_HDR);
677 	*p++ = htonl(op);
678 	*p = res;
679 	return 0;
680 }
681 
682 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
683 		const void *resp)
684 {
685 	const struct cb_getattrres *res = resp;
686 	__be32 *savep = NULL;
687 	__be32 status = res->status;
688 
689 	if (unlikely(status != 0))
690 		goto out;
691 	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
692 	if (unlikely(status != 0))
693 		goto out;
694 	status = cpu_to_be32(NFS4ERR_RESOURCE);
695 	savep = xdr_reserve_space(xdr, sizeof(*savep));
696 	if (unlikely(!savep))
697 		goto out;
698 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
699 	if (unlikely(status != 0))
700 		goto out;
701 	status = encode_attr_size(xdr, res->bitmap, res->size);
702 	if (unlikely(status != 0))
703 		goto out;
704 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
705 	if (unlikely(status != 0))
706 		goto out;
707 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
708 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
709 out:
710 	return status;
711 }
712 
713 #if defined(CONFIG_NFS_V4_1)
714 
715 static __be32 encode_sessionid(struct xdr_stream *xdr,
716 				 const struct nfs4_sessionid *sid)
717 {
718 	__be32 *p;
719 
720 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
721 	if (unlikely(p == NULL))
722 		return htonl(NFS4ERR_RESOURCE);
723 
724 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
725 	return 0;
726 }
727 
728 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
729 				       struct xdr_stream *xdr,
730 				       const void *resp)
731 {
732 	const struct cb_sequenceres *res = resp;
733 	__be32 *p;
734 	__be32 status = res->csr_status;
735 
736 	if (unlikely(status != 0))
737 		return status;
738 
739 	status = encode_sessionid(xdr, &res->csr_sessionid);
740 	if (status)
741 		return status;
742 
743 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
744 	if (unlikely(p == NULL))
745 		return htonl(NFS4ERR_RESOURCE);
746 
747 	*p++ = htonl(res->csr_sequenceid);
748 	*p++ = htonl(res->csr_slotid);
749 	*p++ = htonl(res->csr_highestslotid);
750 	*p++ = htonl(res->csr_target_highestslotid);
751 	return 0;
752 }
753 
754 static __be32
755 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
756 {
757 	if (op_nr == OP_CB_SEQUENCE) {
758 		if (nop != 0)
759 			return htonl(NFS4ERR_SEQUENCE_POS);
760 	} else {
761 		if (nop == 0)
762 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
763 	}
764 
765 	switch (op_nr) {
766 	case OP_CB_GETATTR:
767 	case OP_CB_RECALL:
768 	case OP_CB_SEQUENCE:
769 	case OP_CB_RECALL_ANY:
770 	case OP_CB_RECALL_SLOT:
771 	case OP_CB_LAYOUTRECALL:
772 	case OP_CB_NOTIFY_DEVICEID:
773 	case OP_CB_NOTIFY_LOCK:
774 		*op = &callback_ops[op_nr];
775 		break;
776 
777 	case OP_CB_NOTIFY:
778 	case OP_CB_PUSH_DELEG:
779 	case OP_CB_RECALLABLE_OBJ_AVAIL:
780 	case OP_CB_WANTS_CANCELLED:
781 		return htonl(NFS4ERR_NOTSUPP);
782 
783 	default:
784 		return htonl(NFS4ERR_OP_ILLEGAL);
785 	}
786 
787 	return htonl(NFS_OK);
788 }
789 
790 static void nfs4_callback_free_slot(struct nfs4_session *session,
791 		struct nfs4_slot *slot)
792 {
793 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
794 
795 	spin_lock(&tbl->slot_tbl_lock);
796 	/*
797 	 * Let the state manager know callback processing done.
798 	 * A single slot, so highest used slotid is either 0 or -1
799 	 */
800 	nfs4_free_slot(tbl, slot);
801 	spin_unlock(&tbl->slot_tbl_lock);
802 }
803 
804 static void nfs4_cb_free_slot(struct cb_process_state *cps)
805 {
806 	if (cps->slot) {
807 		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
808 		cps->slot = NULL;
809 	}
810 }
811 
812 #else /* CONFIG_NFS_V4_1 */
813 
814 static __be32
815 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
816 {
817 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
818 }
819 
820 static void nfs4_cb_free_slot(struct cb_process_state *cps)
821 {
822 }
823 #endif /* CONFIG_NFS_V4_1 */
824 
825 #ifdef CONFIG_NFS_V4_2
826 static __be32
827 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
828 {
829 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
830 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
831 		return status;
832 
833 	if (op_nr == OP_CB_OFFLOAD) {
834 		*op = &callback_ops[op_nr];
835 		return htonl(NFS_OK);
836 	} else
837 		return htonl(NFS4ERR_NOTSUPP);
838 	return htonl(NFS4ERR_OP_ILLEGAL);
839 }
840 #else /* CONFIG_NFS_V4_2 */
841 static __be32
842 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
843 {
844 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
845 }
846 #endif /* CONFIG_NFS_V4_2 */
847 
848 static __be32
849 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
850 {
851 	switch (op_nr) {
852 	case OP_CB_GETATTR:
853 	case OP_CB_RECALL:
854 		*op = &callback_ops[op_nr];
855 		break;
856 	default:
857 		return htonl(NFS4ERR_OP_ILLEGAL);
858 	}
859 
860 	return htonl(NFS_OK);
861 }
862 
863 static __be32 process_op(int nop, struct svc_rqst *rqstp,
864 			 struct cb_process_state *cps)
865 {
866 	struct xdr_stream *xdr_out = &rqstp->rq_res_stream;
867 	struct callback_op *op = &callback_ops[0];
868 	unsigned int op_nr;
869 	__be32 status;
870 	long maxlen;
871 	__be32 res;
872 
873 	status = decode_op_hdr(&rqstp->rq_arg_stream, &op_nr);
874 	if (unlikely(status))
875 		return status;
876 
877 	switch (cps->minorversion) {
878 	case 0:
879 		status = preprocess_nfs4_op(op_nr, &op);
880 		break;
881 	case 1:
882 		status = preprocess_nfs41_op(nop, op_nr, &op);
883 		break;
884 	case 2:
885 		status = preprocess_nfs42_op(nop, op_nr, &op);
886 		break;
887 	default:
888 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
889 	}
890 
891 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
892 		op_nr = OP_CB_ILLEGAL;
893 	if (status)
894 		goto encode_hdr;
895 
896 	if (cps->drc_status) {
897 		status = cps->drc_status;
898 		goto encode_hdr;
899 	}
900 
901 	maxlen = xdr_out->end - xdr_out->p;
902 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
903 		status = op->decode_args(rqstp, &rqstp->rq_arg_stream,
904 					 rqstp->rq_argp);
905 		if (likely(status == 0))
906 			status = op->process_op(rqstp->rq_argp, rqstp->rq_resp,
907 						cps);
908 	} else
909 		status = htonl(NFS4ERR_RESOURCE);
910 
911 encode_hdr:
912 	res = encode_op_hdr(xdr_out, op_nr, status);
913 	if (unlikely(res))
914 		return res;
915 	if (op->encode_res != NULL && status == 0)
916 		status = op->encode_res(rqstp, xdr_out, rqstp->rq_resp);
917 	return status;
918 }
919 
920 /*
921  * Decode, process and encode a COMPOUND
922  */
923 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
924 {
925 	struct cb_compound_hdr_arg hdr_arg = { 0 };
926 	struct cb_compound_hdr_res hdr_res = { NULL };
927 	struct cb_process_state cps = {
928 		.drc_status = 0,
929 		.clp = NULL,
930 		.net = SVC_NET(rqstp),
931 	};
932 	unsigned int nops = 0;
933 	__be32 status;
934 
935 	status = decode_compound_hdr_arg(&rqstp->rq_arg_stream, &hdr_arg);
936 	if (status == htonl(NFS4ERR_RESOURCE))
937 		return rpc_garbage_args;
938 
939 	if (hdr_arg.minorversion == 0) {
940 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
941 		if (!cps.clp) {
942 			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
943 			goto out_invalidcred;
944 		}
945 		if (!check_gss_callback_principal(cps.clp, rqstp)) {
946 			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
947 			nfs_put_client(cps.clp);
948 			goto out_invalidcred;
949 		}
950 	}
951 
952 	cps.minorversion = hdr_arg.minorversion;
953 	hdr_res.taglen = hdr_arg.taglen;
954 	hdr_res.tag = hdr_arg.tag;
955 	if (encode_compound_hdr_res(&rqstp->rq_res_stream, &hdr_res) != 0) {
956 		if (cps.clp)
957 			nfs_put_client(cps.clp);
958 		return rpc_system_err;
959 	}
960 	while (status == 0 && nops != hdr_arg.nops) {
961 		status = process_op(nops, rqstp, &cps);
962 		nops++;
963 	}
964 
965 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
966 	* resource error in cb_compound status without returning op */
967 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
968 		status = htonl(NFS4ERR_RESOURCE);
969 		nops--;
970 	}
971 
972 	*hdr_res.status = status;
973 	*hdr_res.nops = htonl(nops);
974 	nfs4_cb_free_slot(&cps);
975 	nfs_put_client(cps.clp);
976 	return rpc_success;
977 
978 out_invalidcred:
979 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
980 	rqstp->rq_auth_stat = rpc_autherr_badcred;
981 	return rpc_success;
982 }
983 
984 static int
985 nfs_callback_dispatch(struct svc_rqst *rqstp)
986 {
987 	const struct svc_procedure *procp = rqstp->rq_procinfo;
988 
989 	*rqstp->rq_accept_statp = procp->pc_func(rqstp);
990 	return 1;
991 }
992 
993 /*
994  * Define NFS4 callback COMPOUND ops.
995  */
996 static struct callback_op callback_ops[] = {
997 	[0] = {
998 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
999 	},
1000 	[OP_CB_GETATTR] = {
1001 		.process_op = nfs4_callback_getattr,
1002 		.decode_args = decode_getattr_args,
1003 		.encode_res = encode_getattr_res,
1004 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1005 	},
1006 	[OP_CB_RECALL] = {
1007 		.process_op = nfs4_callback_recall,
1008 		.decode_args = decode_recall_args,
1009 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1010 	},
1011 #if defined(CONFIG_NFS_V4_1)
1012 	[OP_CB_LAYOUTRECALL] = {
1013 		.process_op = nfs4_callback_layoutrecall,
1014 		.decode_args = decode_layoutrecall_args,
1015 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1016 	},
1017 	[OP_CB_NOTIFY_DEVICEID] = {
1018 		.process_op = nfs4_callback_devicenotify,
1019 		.decode_args = decode_devicenotify_args,
1020 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1021 	},
1022 	[OP_CB_SEQUENCE] = {
1023 		.process_op = nfs4_callback_sequence,
1024 		.decode_args = decode_cb_sequence_args,
1025 		.encode_res = encode_cb_sequence_res,
1026 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1027 	},
1028 	[OP_CB_RECALL_ANY] = {
1029 		.process_op = nfs4_callback_recallany,
1030 		.decode_args = decode_recallany_args,
1031 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1032 	},
1033 	[OP_CB_RECALL_SLOT] = {
1034 		.process_op = nfs4_callback_recallslot,
1035 		.decode_args = decode_recallslot_args,
1036 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1037 	},
1038 	[OP_CB_NOTIFY_LOCK] = {
1039 		.process_op = nfs4_callback_notify_lock,
1040 		.decode_args = decode_notify_lock_args,
1041 		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1042 	},
1043 #endif /* CONFIG_NFS_V4_1 */
1044 #ifdef CONFIG_NFS_V4_2
1045 	[OP_CB_OFFLOAD] = {
1046 		.process_op = nfs4_callback_offload,
1047 		.decode_args = decode_offload_args,
1048 		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1049 	},
1050 #endif /* CONFIG_NFS_V4_2 */
1051 };
1052 
1053 /*
1054  * Define NFS4 callback procedures
1055  */
1056 static const struct svc_procedure nfs4_callback_procedures1[] = {
1057 	[CB_NULL] = {
1058 		.pc_func = nfs4_callback_null,
1059 		.pc_encode = nfs4_encode_void,
1060 		.pc_xdrressize = 1,
1061 		.pc_name = "NULL",
1062 	},
1063 	[CB_COMPOUND] = {
1064 		.pc_func = nfs4_callback_compound,
1065 		.pc_encode = nfs4_encode_void,
1066 		.pc_argsize = 256,
1067 		.pc_argzero = 256,
1068 		.pc_ressize = 256,
1069 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1070 		.pc_name = "COMPOUND",
1071 	}
1072 };
1073 
1074 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1075 			      nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)]);
1076 const struct svc_version nfs4_callback_version1 = {
1077 	.vs_vers = 1,
1078 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1079 	.vs_proc = nfs4_callback_procedures1,
1080 	.vs_count = nfs4_callback_count1,
1081 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1082 	.vs_dispatch = nfs_callback_dispatch,
1083 	.vs_hidden = true,
1084 	.vs_need_cong_ctrl = true,
1085 };
1086 
1087 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1088 			      nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)]);
1089 const struct svc_version nfs4_callback_version4 = {
1090 	.vs_vers = 4,
1091 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1092 	.vs_proc = nfs4_callback_procedures1,
1093 	.vs_count = nfs4_callback_count4,
1094 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1095 	.vs_dispatch = nfs_callback_dispatch,
1096 	.vs_hidden = true,
1097 	.vs_need_cong_ctrl = true,
1098 };
1099