xref: /linux/fs/nfs/callback_xdr.c (revision 83869019c74cc2d01c96a3be2463a4eebe362224)
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 	__be32 *p;
262 	__be32 status = 0;
263 	u32 tmp;
264 	int n, i;
265 	args->ndevs = 0;
266 
267 	/* Num of device notifications */
268 	p = xdr_inline_decode(xdr, sizeof(uint32_t));
269 	if (unlikely(p == NULL)) {
270 		status = htonl(NFS4ERR_BADXDR);
271 		goto out;
272 	}
273 	n = ntohl(*p++);
274 	if (n <= 0)
275 		goto out;
276 	if (n > ULONG_MAX / sizeof(*args->devs)) {
277 		status = htonl(NFS4ERR_BADXDR);
278 		goto out;
279 	}
280 
281 	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
282 	if (!args->devs) {
283 		status = htonl(NFS4ERR_DELAY);
284 		goto out;
285 	}
286 
287 	/* Decode each dev notification */
288 	for (i = 0; i < n; i++) {
289 		struct cb_devicenotifyitem *dev = &args->devs[i];
290 
291 		p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
292 				      NFS4_DEVICEID4_SIZE);
293 		if (unlikely(p == NULL)) {
294 			status = htonl(NFS4ERR_BADXDR);
295 			goto err;
296 		}
297 
298 		tmp = ntohl(*p++);	/* bitmap size */
299 		if (tmp != 1) {
300 			status = htonl(NFS4ERR_INVAL);
301 			goto err;
302 		}
303 		dev->cbd_notify_type = ntohl(*p++);
304 		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
305 		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
306 			status = htonl(NFS4ERR_INVAL);
307 			goto err;
308 		}
309 
310 		tmp = ntohl(*p++);	/* opaque size */
311 		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
312 		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
313 		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
314 		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
315 			status = htonl(NFS4ERR_INVAL);
316 			goto err;
317 		}
318 		dev->cbd_layout_type = ntohl(*p++);
319 		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
320 		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
321 
322 		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
323 			p = xdr_inline_decode(xdr, sizeof(uint32_t));
324 			if (unlikely(p == NULL)) {
325 				status = htonl(NFS4ERR_BADXDR);
326 				goto err;
327 			}
328 			dev->cbd_immediate = ntohl(*p++);
329 		} else {
330 			dev->cbd_immediate = 0;
331 		}
332 
333 		args->ndevs++;
334 
335 		dprintk("%s: type %d layout 0x%x immediate %d\n",
336 			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
337 			dev->cbd_immediate);
338 	}
339 out:
340 	dprintk("%s: status %d ndevs %d\n",
341 		__func__, ntohl(status), args->ndevs);
342 	return status;
343 err:
344 	kfree(args->devs);
345 	goto out;
346 }
347 
348 static __be32 decode_sessionid(struct xdr_stream *xdr,
349 				 struct nfs4_sessionid *sid)
350 {
351 	__be32 *p;
352 
353 	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
354 	if (unlikely(p == NULL))
355 		return htonl(NFS4ERR_RESOURCE);
356 
357 	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
358 	return 0;
359 }
360 
361 static __be32 decode_rc_list(struct xdr_stream *xdr,
362 			       struct referring_call_list *rc_list)
363 {
364 	__be32 *p;
365 	int i;
366 	__be32 status;
367 
368 	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
369 	if (status)
370 		goto out;
371 
372 	status = htonl(NFS4ERR_RESOURCE);
373 	p = xdr_inline_decode(xdr, sizeof(uint32_t));
374 	if (unlikely(p == NULL))
375 		goto out;
376 
377 	rc_list->rcl_nrefcalls = ntohl(*p++);
378 	if (rc_list->rcl_nrefcalls) {
379 		p = xdr_inline_decode(xdr,
380 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
381 		if (unlikely(p == NULL))
382 			goto out;
383 		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
384 						sizeof(*rc_list->rcl_refcalls),
385 						GFP_KERNEL);
386 		if (unlikely(rc_list->rcl_refcalls == NULL))
387 			goto out;
388 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
389 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
390 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
391 		}
392 	}
393 	status = 0;
394 
395 out:
396 	return status;
397 }
398 
399 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
400 					struct xdr_stream *xdr,
401 					void *argp)
402 {
403 	struct cb_sequenceargs *args = argp;
404 	__be32 *p;
405 	int i;
406 	__be32 status;
407 
408 	status = decode_sessionid(xdr, &args->csa_sessionid);
409 	if (status)
410 		return status;
411 
412 	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
413 	if (unlikely(p == NULL))
414 		return htonl(NFS4ERR_RESOURCE);
415 
416 	args->csa_addr = svc_addr(rqstp);
417 	args->csa_sequenceid = ntohl(*p++);
418 	args->csa_slotid = ntohl(*p++);
419 	args->csa_highestslotid = ntohl(*p++);
420 	args->csa_cachethis = ntohl(*p++);
421 	args->csa_nrclists = ntohl(*p++);
422 	args->csa_rclists = NULL;
423 	if (args->csa_nrclists) {
424 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
425 						  sizeof(*args->csa_rclists),
426 						  GFP_KERNEL);
427 		if (unlikely(args->csa_rclists == NULL))
428 			return htonl(NFS4ERR_RESOURCE);
429 
430 		for (i = 0; i < args->csa_nrclists; i++) {
431 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
432 			if (status) {
433 				args->csa_nrclists = i;
434 				goto out_free;
435 			}
436 		}
437 	}
438 	return 0;
439 
440 out_free:
441 	for (i = 0; i < args->csa_nrclists; i++)
442 		kfree(args->csa_rclists[i].rcl_refcalls);
443 	kfree(args->csa_rclists);
444 	return status;
445 }
446 
447 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
448 				      struct xdr_stream *xdr,
449 				      void *argp)
450 {
451 	struct cb_recallanyargs *args = argp;
452 	uint32_t bitmap[2];
453 	__be32 *p, status;
454 
455 	p = xdr_inline_decode(xdr, 4);
456 	if (unlikely(p == NULL))
457 		return htonl(NFS4ERR_BADXDR);
458 	args->craa_objs_to_keep = ntohl(*p++);
459 	status = decode_bitmap(xdr, bitmap);
460 	if (unlikely(status))
461 		return status;
462 	args->craa_type_mask = bitmap[0];
463 
464 	return 0;
465 }
466 
467 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
468 					struct xdr_stream *xdr,
469 					void *argp)
470 {
471 	struct cb_recallslotargs *args = argp;
472 	__be32 *p;
473 
474 	p = xdr_inline_decode(xdr, 4);
475 	if (unlikely(p == NULL))
476 		return htonl(NFS4ERR_BADXDR);
477 	args->crsa_target_highest_slotid = ntohl(*p++);
478 	return 0;
479 }
480 
481 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
482 {
483 	__be32		*p;
484 	unsigned int	len;
485 
486 	p = xdr_inline_decode(xdr, 12);
487 	if (unlikely(p == NULL))
488 		return htonl(NFS4ERR_BADXDR);
489 
490 	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
491 	len = be32_to_cpu(*p);
492 
493 	p = xdr_inline_decode(xdr, len);
494 	if (unlikely(p == NULL))
495 		return htonl(NFS4ERR_BADXDR);
496 
497 	/* Only try to decode if the length is right */
498 	if (len == 20) {
499 		p += 2;	/* skip "lock id:" */
500 		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
501 		xdr_decode_hyper(p, &args->cbnl_owner.id);
502 		args->cbnl_valid = true;
503 	} else {
504 		args->cbnl_owner.s_dev = 0;
505 		args->cbnl_owner.id = 0;
506 		args->cbnl_valid = false;
507 	}
508 	return 0;
509 }
510 
511 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
512 		struct xdr_stream *xdr, void *argp)
513 {
514 	struct cb_notify_lock_args *args = argp;
515 	__be32 status;
516 
517 	status = decode_fh(xdr, &args->cbnl_fh);
518 	if (unlikely(status != 0))
519 		return status;
520 	return decode_lockowner(xdr, args);
521 }
522 
523 #endif /* CONFIG_NFS_V4_1 */
524 #ifdef CONFIG_NFS_V4_2
525 static __be32 decode_write_response(struct xdr_stream *xdr,
526 					struct cb_offloadargs *args)
527 {
528 	__be32 *p;
529 
530 	/* skip the always zero field */
531 	p = xdr_inline_decode(xdr, 4);
532 	if (unlikely(!p))
533 		goto out;
534 	p++;
535 
536 	/* decode count, stable_how, verifier */
537 	p = xdr_inline_decode(xdr, 8 + 4);
538 	if (unlikely(!p))
539 		goto out;
540 	p = xdr_decode_hyper(p, &args->wr_count);
541 	args->wr_writeverf.committed = be32_to_cpup(p);
542 	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
543 	if (likely(p)) {
544 		memcpy(&args->wr_writeverf.verifier.data[0], p,
545 			NFS4_VERIFIER_SIZE);
546 		return 0;
547 	}
548 out:
549 	return htonl(NFS4ERR_RESOURCE);
550 }
551 
552 static __be32 decode_offload_args(struct svc_rqst *rqstp,
553 					struct xdr_stream *xdr,
554 					void *data)
555 {
556 	struct cb_offloadargs *args = data;
557 	__be32 *p;
558 	__be32 status;
559 
560 	/* decode fh */
561 	status = decode_fh(xdr, &args->coa_fh);
562 	if (unlikely(status != 0))
563 		return status;
564 
565 	/* decode stateid */
566 	status = decode_stateid(xdr, &args->coa_stateid);
567 	if (unlikely(status != 0))
568 		return status;
569 
570 	/* decode status */
571 	p = xdr_inline_decode(xdr, 4);
572 	if (unlikely(!p))
573 		goto out;
574 	args->error = ntohl(*p++);
575 	if (!args->error) {
576 		status = decode_write_response(xdr, args);
577 		if (unlikely(status != 0))
578 			return status;
579 	} else {
580 		p = xdr_inline_decode(xdr, 8);
581 		if (unlikely(!p))
582 			goto out;
583 		p = xdr_decode_hyper(p, &args->wr_count);
584 	}
585 	return 0;
586 out:
587 	return htonl(NFS4ERR_RESOURCE);
588 }
589 #endif /* CONFIG_NFS_V4_2 */
590 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
591 {
592 	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
593 		return cpu_to_be32(NFS4ERR_RESOURCE);
594 	return 0;
595 }
596 
597 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
598 {
599 	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
600 		return cpu_to_be32(NFS4ERR_RESOURCE);
601 	return 0;
602 }
603 
604 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
605 {
606 	__be32 *p;
607 
608 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
609 		return 0;
610 	p = xdr_reserve_space(xdr, 8);
611 	if (unlikely(!p))
612 		return htonl(NFS4ERR_RESOURCE);
613 	p = xdr_encode_hyper(p, change);
614 	return 0;
615 }
616 
617 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
618 {
619 	__be32 *p;
620 
621 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
622 		return 0;
623 	p = xdr_reserve_space(xdr, 8);
624 	if (unlikely(!p))
625 		return htonl(NFS4ERR_RESOURCE);
626 	p = xdr_encode_hyper(p, size);
627 	return 0;
628 }
629 
630 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
631 {
632 	__be32 *p;
633 
634 	p = xdr_reserve_space(xdr, 12);
635 	if (unlikely(!p))
636 		return htonl(NFS4ERR_RESOURCE);
637 	p = xdr_encode_hyper(p, time->tv_sec);
638 	*p = htonl(time->tv_nsec);
639 	return 0;
640 }
641 
642 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
643 {
644 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
645 		return 0;
646 	return encode_attr_time(xdr,time);
647 }
648 
649 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
650 {
651 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
652 		return 0;
653 	return encode_attr_time(xdr,time);
654 }
655 
656 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
657 {
658 	__be32 status;
659 
660 	hdr->status = xdr_reserve_space(xdr, 4);
661 	if (unlikely(hdr->status == NULL))
662 		return htonl(NFS4ERR_RESOURCE);
663 	status = encode_string(xdr, hdr->taglen, hdr->tag);
664 	if (unlikely(status != 0))
665 		return status;
666 	hdr->nops = xdr_reserve_space(xdr, 4);
667 	if (unlikely(hdr->nops == NULL))
668 		return htonl(NFS4ERR_RESOURCE);
669 	return 0;
670 }
671 
672 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
673 {
674 	__be32 *p;
675 
676 	p = xdr_reserve_space(xdr, 8);
677 	if (unlikely(p == NULL))
678 		return htonl(NFS4ERR_RESOURCE_HDR);
679 	*p++ = htonl(op);
680 	*p = res;
681 	return 0;
682 }
683 
684 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
685 		const void *resp)
686 {
687 	const struct cb_getattrres *res = resp;
688 	__be32 *savep = NULL;
689 	__be32 status = res->status;
690 
691 	if (unlikely(status != 0))
692 		goto out;
693 	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
694 	if (unlikely(status != 0))
695 		goto out;
696 	status = cpu_to_be32(NFS4ERR_RESOURCE);
697 	savep = xdr_reserve_space(xdr, sizeof(*savep));
698 	if (unlikely(!savep))
699 		goto out;
700 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
701 	if (unlikely(status != 0))
702 		goto out;
703 	status = encode_attr_size(xdr, res->bitmap, res->size);
704 	if (unlikely(status != 0))
705 		goto out;
706 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
707 	if (unlikely(status != 0))
708 		goto out;
709 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
710 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
711 out:
712 	return status;
713 }
714 
715 #if defined(CONFIG_NFS_V4_1)
716 
717 static __be32 encode_sessionid(struct xdr_stream *xdr,
718 				 const struct nfs4_sessionid *sid)
719 {
720 	__be32 *p;
721 
722 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
723 	if (unlikely(p == NULL))
724 		return htonl(NFS4ERR_RESOURCE);
725 
726 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
727 	return 0;
728 }
729 
730 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
731 				       struct xdr_stream *xdr,
732 				       const void *resp)
733 {
734 	const struct cb_sequenceres *res = resp;
735 	__be32 *p;
736 	__be32 status = res->csr_status;
737 
738 	if (unlikely(status != 0))
739 		return status;
740 
741 	status = encode_sessionid(xdr, &res->csr_sessionid);
742 	if (status)
743 		return status;
744 
745 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
746 	if (unlikely(p == NULL))
747 		return htonl(NFS4ERR_RESOURCE);
748 
749 	*p++ = htonl(res->csr_sequenceid);
750 	*p++ = htonl(res->csr_slotid);
751 	*p++ = htonl(res->csr_highestslotid);
752 	*p++ = htonl(res->csr_target_highestslotid);
753 	return 0;
754 }
755 
756 static __be32
757 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
758 {
759 	if (op_nr == OP_CB_SEQUENCE) {
760 		if (nop != 0)
761 			return htonl(NFS4ERR_SEQUENCE_POS);
762 	} else {
763 		if (nop == 0)
764 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
765 	}
766 
767 	switch (op_nr) {
768 	case OP_CB_GETATTR:
769 	case OP_CB_RECALL:
770 	case OP_CB_SEQUENCE:
771 	case OP_CB_RECALL_ANY:
772 	case OP_CB_RECALL_SLOT:
773 	case OP_CB_LAYOUTRECALL:
774 	case OP_CB_NOTIFY_DEVICEID:
775 	case OP_CB_NOTIFY_LOCK:
776 		*op = &callback_ops[op_nr];
777 		break;
778 
779 	case OP_CB_NOTIFY:
780 	case OP_CB_PUSH_DELEG:
781 	case OP_CB_RECALLABLE_OBJ_AVAIL:
782 	case OP_CB_WANTS_CANCELLED:
783 		return htonl(NFS4ERR_NOTSUPP);
784 
785 	default:
786 		return htonl(NFS4ERR_OP_ILLEGAL);
787 	}
788 
789 	return htonl(NFS_OK);
790 }
791 
792 static void nfs4_callback_free_slot(struct nfs4_session *session,
793 		struct nfs4_slot *slot)
794 {
795 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
796 
797 	spin_lock(&tbl->slot_tbl_lock);
798 	/*
799 	 * Let the state manager know callback processing done.
800 	 * A single slot, so highest used slotid is either 0 or -1
801 	 */
802 	nfs4_free_slot(tbl, slot);
803 	spin_unlock(&tbl->slot_tbl_lock);
804 }
805 
806 static void nfs4_cb_free_slot(struct cb_process_state *cps)
807 {
808 	if (cps->slot) {
809 		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
810 		cps->slot = NULL;
811 	}
812 }
813 
814 #else /* CONFIG_NFS_V4_1 */
815 
816 static __be32
817 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
818 {
819 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
820 }
821 
822 static void nfs4_cb_free_slot(struct cb_process_state *cps)
823 {
824 }
825 #endif /* CONFIG_NFS_V4_1 */
826 
827 #ifdef CONFIG_NFS_V4_2
828 static __be32
829 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
830 {
831 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
832 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
833 		return status;
834 
835 	if (op_nr == OP_CB_OFFLOAD) {
836 		*op = &callback_ops[op_nr];
837 		return htonl(NFS_OK);
838 	} else
839 		return htonl(NFS4ERR_NOTSUPP);
840 	return htonl(NFS4ERR_OP_ILLEGAL);
841 }
842 #else /* CONFIG_NFS_V4_2 */
843 static __be32
844 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
845 {
846 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
847 }
848 #endif /* CONFIG_NFS_V4_2 */
849 
850 static __be32
851 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
852 {
853 	switch (op_nr) {
854 	case OP_CB_GETATTR:
855 	case OP_CB_RECALL:
856 		*op = &callback_ops[op_nr];
857 		break;
858 	default:
859 		return htonl(NFS4ERR_OP_ILLEGAL);
860 	}
861 
862 	return htonl(NFS_OK);
863 }
864 
865 static __be32 process_op(int nop, struct svc_rqst *rqstp,
866 			 struct cb_process_state *cps)
867 {
868 	struct xdr_stream *xdr_out = &rqstp->rq_res_stream;
869 	struct callback_op *op = &callback_ops[0];
870 	unsigned int op_nr;
871 	__be32 status;
872 	long maxlen;
873 	__be32 res;
874 
875 	status = decode_op_hdr(&rqstp->rq_arg_stream, &op_nr);
876 	if (unlikely(status))
877 		return status;
878 
879 	switch (cps->minorversion) {
880 	case 0:
881 		status = preprocess_nfs4_op(op_nr, &op);
882 		break;
883 	case 1:
884 		status = preprocess_nfs41_op(nop, op_nr, &op);
885 		break;
886 	case 2:
887 		status = preprocess_nfs42_op(nop, op_nr, &op);
888 		break;
889 	default:
890 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
891 	}
892 
893 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
894 		op_nr = OP_CB_ILLEGAL;
895 	if (status)
896 		goto encode_hdr;
897 
898 	if (cps->drc_status) {
899 		status = cps->drc_status;
900 		goto encode_hdr;
901 	}
902 
903 	maxlen = xdr_out->end - xdr_out->p;
904 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
905 		status = op->decode_args(rqstp, &rqstp->rq_arg_stream,
906 					 rqstp->rq_argp);
907 		if (likely(status == 0))
908 			status = op->process_op(rqstp->rq_argp, rqstp->rq_resp,
909 						cps);
910 	} else
911 		status = htonl(NFS4ERR_RESOURCE);
912 
913 encode_hdr:
914 	res = encode_op_hdr(xdr_out, op_nr, status);
915 	if (unlikely(res))
916 		return res;
917 	if (op->encode_res != NULL && status == 0)
918 		status = op->encode_res(rqstp, xdr_out, rqstp->rq_resp);
919 	return status;
920 }
921 
922 /*
923  * Decode, process and encode a COMPOUND
924  */
925 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
926 {
927 	struct cb_compound_hdr_arg hdr_arg = { 0 };
928 	struct cb_compound_hdr_res hdr_res = { NULL };
929 	struct cb_process_state cps = {
930 		.drc_status = 0,
931 		.clp = NULL,
932 		.net = SVC_NET(rqstp),
933 	};
934 	unsigned int nops = 0;
935 	__be32 status;
936 
937 	status = decode_compound_hdr_arg(&rqstp->rq_arg_stream, &hdr_arg);
938 	if (status == htonl(NFS4ERR_RESOURCE))
939 		return rpc_garbage_args;
940 
941 	if (hdr_arg.minorversion == 0) {
942 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
943 		if (!cps.clp) {
944 			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
945 			goto out_invalidcred;
946 		}
947 		if (!check_gss_callback_principal(cps.clp, rqstp)) {
948 			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
949 			nfs_put_client(cps.clp);
950 			goto out_invalidcred;
951 		}
952 	}
953 
954 	cps.minorversion = hdr_arg.minorversion;
955 	hdr_res.taglen = hdr_arg.taglen;
956 	hdr_res.tag = hdr_arg.tag;
957 	if (encode_compound_hdr_res(&rqstp->rq_res_stream, &hdr_res) != 0) {
958 		if (cps.clp)
959 			nfs_put_client(cps.clp);
960 		return rpc_system_err;
961 	}
962 	while (status == 0 && nops != hdr_arg.nops) {
963 		status = process_op(nops, rqstp, &cps);
964 		nops++;
965 	}
966 
967 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
968 	* resource error in cb_compound status without returning op */
969 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
970 		status = htonl(NFS4ERR_RESOURCE);
971 		nops--;
972 	}
973 
974 	*hdr_res.status = status;
975 	*hdr_res.nops = htonl(nops);
976 	nfs4_cb_free_slot(&cps);
977 	nfs_put_client(cps.clp);
978 	return rpc_success;
979 
980 out_invalidcred:
981 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
982 	rqstp->rq_auth_stat = rpc_autherr_badcred;
983 	return rpc_success;
984 }
985 
986 static int
987 nfs_callback_dispatch(struct svc_rqst *rqstp, __be32 *statp)
988 {
989 	const struct svc_procedure *procp = rqstp->rq_procinfo;
990 
991 	svcxdr_init_decode(rqstp);
992 	svcxdr_init_encode(rqstp);
993 
994 	*statp = procp->pc_func(rqstp);
995 	return 1;
996 }
997 
998 /*
999  * Define NFS4 callback COMPOUND ops.
1000  */
1001 static struct callback_op callback_ops[] = {
1002 	[0] = {
1003 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
1004 	},
1005 	[OP_CB_GETATTR] = {
1006 		.process_op = nfs4_callback_getattr,
1007 		.decode_args = decode_getattr_args,
1008 		.encode_res = encode_getattr_res,
1009 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1010 	},
1011 	[OP_CB_RECALL] = {
1012 		.process_op = nfs4_callback_recall,
1013 		.decode_args = decode_recall_args,
1014 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1015 	},
1016 #if defined(CONFIG_NFS_V4_1)
1017 	[OP_CB_LAYOUTRECALL] = {
1018 		.process_op = nfs4_callback_layoutrecall,
1019 		.decode_args = decode_layoutrecall_args,
1020 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1021 	},
1022 	[OP_CB_NOTIFY_DEVICEID] = {
1023 		.process_op = nfs4_callback_devicenotify,
1024 		.decode_args = decode_devicenotify_args,
1025 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1026 	},
1027 	[OP_CB_SEQUENCE] = {
1028 		.process_op = nfs4_callback_sequence,
1029 		.decode_args = decode_cb_sequence_args,
1030 		.encode_res = encode_cb_sequence_res,
1031 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1032 	},
1033 	[OP_CB_RECALL_ANY] = {
1034 		.process_op = nfs4_callback_recallany,
1035 		.decode_args = decode_recallany_args,
1036 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1037 	},
1038 	[OP_CB_RECALL_SLOT] = {
1039 		.process_op = nfs4_callback_recallslot,
1040 		.decode_args = decode_recallslot_args,
1041 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1042 	},
1043 	[OP_CB_NOTIFY_LOCK] = {
1044 		.process_op = nfs4_callback_notify_lock,
1045 		.decode_args = decode_notify_lock_args,
1046 		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1047 	},
1048 #endif /* CONFIG_NFS_V4_1 */
1049 #ifdef CONFIG_NFS_V4_2
1050 	[OP_CB_OFFLOAD] = {
1051 		.process_op = nfs4_callback_offload,
1052 		.decode_args = decode_offload_args,
1053 		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1054 	},
1055 #endif /* CONFIG_NFS_V4_2 */
1056 };
1057 
1058 /*
1059  * Define NFS4 callback procedures
1060  */
1061 static const struct svc_procedure nfs4_callback_procedures1[] = {
1062 	[CB_NULL] = {
1063 		.pc_func = nfs4_callback_null,
1064 		.pc_encode = nfs4_encode_void,
1065 		.pc_xdrressize = 1,
1066 		.pc_name = "NULL",
1067 	},
1068 	[CB_COMPOUND] = {
1069 		.pc_func = nfs4_callback_compound,
1070 		.pc_encode = nfs4_encode_void,
1071 		.pc_argsize = 256,
1072 		.pc_ressize = 256,
1073 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1074 		.pc_name = "COMPOUND",
1075 	}
1076 };
1077 
1078 static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
1079 const 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 
1090 static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
1091 const struct svc_version nfs4_callback_version4 = {
1092 	.vs_vers = 4,
1093 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1094 	.vs_proc = nfs4_callback_procedures1,
1095 	.vs_count = nfs4_callback_count4,
1096 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1097 	.vs_dispatch = nfs_callback_dispatch,
1098 	.vs_hidden = true,
1099 	.vs_need_cong_ctrl = true,
1100 };
1101