xref: /linux/fs/nfs/callback_xdr.c (revision ca220141fa8ebae09765a242076b2b77338106b0)
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, atime, ctime,
29 					  * mtime, deleg_atime, deleg_mtime */\
30 					 (2 + 2 + 3 + 3 + 3 + 3 + 3) * 4)
31 #define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
32 
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 #ifdef CONFIG_NFS_V4_2
42 #define CB_OP_OFFLOAD_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
43 #endif /* CONFIG_NFS_V4_2 */
44 
45 #define NFSDBG_FACILITY NFSDBG_CALLBACK
46 
47 /* Internal error code */
48 #define NFS4ERR_RESOURCE_HDR	11050
49 
50 struct callback_op {
51 	__be32 (*process_op)(void *, void *, struct cb_process_state *);
52 	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
53 	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
54 			const void *);
55 	long res_maxsize;
56 };
57 
58 static struct callback_op callback_ops[];
59 
60 static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
61 {
62 	return htonl(NFS4_OK);
63 }
64 
65 /*
66  * svc_process_common() looks for an XDR encoder to know when
67  * not to drop a Reply.
68  */
69 static bool nfs4_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
70 {
71 	return true;
72 }
73 
74 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
75 		const char **str, size_t maxlen)
76 {
77 	ssize_t err;
78 
79 	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
80 	if (err < 0)
81 		return cpu_to_be32(NFS4ERR_RESOURCE);
82 	*len = err;
83 	return 0;
84 }
85 
86 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
87 {
88 	__be32 *p;
89 
90 	p = xdr_inline_decode(xdr, 4);
91 	if (unlikely(p == NULL))
92 		return htonl(NFS4ERR_RESOURCE);
93 	fh->size = ntohl(*p);
94 	if (fh->size > NFS4_FHSIZE)
95 		return htonl(NFS4ERR_BADHANDLE);
96 	p = xdr_inline_decode(xdr, fh->size);
97 	if (unlikely(p == NULL))
98 		return htonl(NFS4ERR_RESOURCE);
99 	memcpy(&fh->data[0], p, fh->size);
100 	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
101 	return 0;
102 }
103 
104 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
105 {
106 	__be32 *p;
107 	unsigned int attrlen;
108 
109 	p = xdr_inline_decode(xdr, 4);
110 	if (unlikely(p == NULL))
111 		return htonl(NFS4ERR_RESOURCE);
112 	attrlen = ntohl(*p);
113 	p = xdr_inline_decode(xdr, attrlen << 2);
114 	if (unlikely(p == NULL))
115 		return htonl(NFS4ERR_RESOURCE);
116 	if (likely(attrlen > 0))
117 		bitmap[0] = ntohl(*p++);
118 	if (attrlen > 1)
119 		bitmap[1] = ntohl(*p++);
120 	if (attrlen > 2)
121 		bitmap[2] = ntohl(*p);
122 	return 0;
123 }
124 
125 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
126 {
127 	__be32 *p;
128 
129 	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
130 	if (unlikely(p == NULL))
131 		return htonl(NFS4ERR_RESOURCE);
132 	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
133 	return 0;
134 }
135 
136 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
137 {
138 	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
139 	return decode_stateid(xdr, stateid);
140 }
141 
142 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
143 {
144 	__be32 *p;
145 	__be32 status;
146 
147 	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
148 	if (unlikely(status != 0))
149 		return status;
150 	p = xdr_inline_decode(xdr, 12);
151 	if (unlikely(p == NULL))
152 		return htonl(NFS4ERR_RESOURCE);
153 	hdr->minorversion = ntohl(*p++);
154 	/* Check for minor version support */
155 	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
156 		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
157 	} else {
158 		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
159 			"illegal minor version %u!\n",
160 			__func__, hdr->minorversion);
161 		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
162 	}
163 	hdr->nops = ntohl(*p);
164 	return 0;
165 }
166 
167 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
168 {
169 	__be32 *p;
170 	p = xdr_inline_decode(xdr, 4);
171 	if (unlikely(p == NULL))
172 		return htonl(NFS4ERR_RESOURCE_HDR);
173 	*op = ntohl(*p);
174 	return 0;
175 }
176 
177 static __be32 decode_getattr_args(struct svc_rqst *rqstp,
178 		struct xdr_stream *xdr, void *argp)
179 {
180 	struct cb_getattrargs *args = argp;
181 	__be32 status;
182 
183 	status = decode_fh(xdr, &args->fh);
184 	if (unlikely(status != 0))
185 		return status;
186 	return decode_bitmap(xdr, args->bitmap);
187 }
188 
189 static __be32 decode_recall_args(struct svc_rqst *rqstp,
190 		struct xdr_stream *xdr, void *argp)
191 {
192 	struct cb_recallargs *args = argp;
193 	__be32 *p;
194 	__be32 status;
195 
196 	status = decode_delegation_stateid(xdr, &args->stateid);
197 	if (unlikely(status != 0))
198 		return status;
199 	p = xdr_inline_decode(xdr, 4);
200 	if (unlikely(p == NULL))
201 		return htonl(NFS4ERR_RESOURCE);
202 	args->truncate = ntohl(*p);
203 	return decode_fh(xdr, &args->fh);
204 }
205 
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[3];
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 #ifdef CONFIG_NFS_V4_2
522 static __be32 decode_write_response(struct xdr_stream *xdr,
523 					struct cb_offloadargs *args)
524 {
525 	__be32 *p;
526 
527 	/* skip the always zero field */
528 	p = xdr_inline_decode(xdr, 4);
529 	if (unlikely(!p))
530 		goto out;
531 	p++;
532 
533 	/* decode count, stable_how, verifier */
534 	p = xdr_inline_decode(xdr, 8 + 4);
535 	if (unlikely(!p))
536 		goto out;
537 	p = xdr_decode_hyper(p, &args->wr_count);
538 	args->wr_writeverf.committed = be32_to_cpup(p);
539 	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
540 	if (likely(p)) {
541 		memcpy(&args->wr_writeverf.verifier.data[0], p,
542 			NFS4_VERIFIER_SIZE);
543 		return 0;
544 	}
545 out:
546 	return htonl(NFS4ERR_RESOURCE);
547 }
548 
549 static __be32 decode_offload_args(struct svc_rqst *rqstp,
550 					struct xdr_stream *xdr,
551 					void *data)
552 {
553 	struct cb_offloadargs *args = data;
554 	__be32 *p;
555 	__be32 status;
556 
557 	/* decode fh */
558 	status = decode_fh(xdr, &args->coa_fh);
559 	if (unlikely(status != 0))
560 		return status;
561 
562 	/* decode stateid */
563 	status = decode_stateid(xdr, &args->coa_stateid);
564 	if (unlikely(status != 0))
565 		return status;
566 
567 	/* decode status */
568 	p = xdr_inline_decode(xdr, 4);
569 	if (unlikely(!p))
570 		goto out;
571 	args->error = ntohl(*p++);
572 	if (!args->error) {
573 		status = decode_write_response(xdr, args);
574 		if (unlikely(status != 0))
575 			return status;
576 	} else {
577 		p = xdr_inline_decode(xdr, 8);
578 		if (unlikely(!p))
579 			goto out;
580 		p = xdr_decode_hyper(p, &args->wr_count);
581 	}
582 	return 0;
583 out:
584 	return htonl(NFS4ERR_RESOURCE);
585 }
586 #endif /* CONFIG_NFS_V4_2 */
587 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
588 {
589 	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
590 		return cpu_to_be32(NFS4ERR_RESOURCE);
591 	return 0;
592 }
593 
594 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
595 {
596 	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
597 		return cpu_to_be32(NFS4ERR_RESOURCE);
598 	return 0;
599 }
600 
601 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
602 {
603 	__be32 *p;
604 
605 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
606 		return 0;
607 	p = xdr_reserve_space(xdr, 8);
608 	if (unlikely(!p))
609 		return htonl(NFS4ERR_RESOURCE);
610 	p = xdr_encode_hyper(p, change);
611 	return 0;
612 }
613 
614 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
615 {
616 	__be32 *p;
617 
618 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
619 		return 0;
620 	p = xdr_reserve_space(xdr, 8);
621 	if (unlikely(!p))
622 		return htonl(NFS4ERR_RESOURCE);
623 	p = xdr_encode_hyper(p, size);
624 	return 0;
625 }
626 
627 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
628 {
629 	__be32 *p;
630 
631 	p = xdr_reserve_space(xdr, 12);
632 	if (unlikely(!p))
633 		return htonl(NFS4ERR_RESOURCE);
634 	p = xdr_encode_hyper(p, time->tv_sec);
635 	*p = htonl(time->tv_nsec);
636 	return 0;
637 }
638 
639 static __be32 encode_attr_atime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
640 {
641 	if (!(bitmap[1] & FATTR4_WORD1_TIME_ACCESS))
642 		return 0;
643 	return encode_attr_time(xdr,time);
644 }
645 
646 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
647 {
648 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
649 		return 0;
650 	return encode_attr_time(xdr,time);
651 }
652 
653 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
654 {
655 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
656 		return 0;
657 	return encode_attr_time(xdr,time);
658 }
659 
660 static __be32 encode_attr_delegatime(struct xdr_stream *xdr,
661 				     const uint32_t *bitmap,
662 				     const struct timespec64 *time)
663 {
664 	if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS))
665 		return 0;
666 	return encode_attr_time(xdr,time);
667 }
668 
669 static __be32 encode_attr_delegmtime(struct xdr_stream *xdr,
670 				     const uint32_t *bitmap,
671 				     const struct timespec64 *time)
672 {
673 	if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY))
674 		return 0;
675 	return encode_attr_time(xdr,time);
676 }
677 
678 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
679 {
680 	__be32 status;
681 
682 	hdr->status = xdr_reserve_space(xdr, 4);
683 	if (unlikely(hdr->status == NULL))
684 		return htonl(NFS4ERR_RESOURCE);
685 	status = encode_string(xdr, hdr->taglen, hdr->tag);
686 	if (unlikely(status != 0))
687 		return status;
688 	hdr->nops = xdr_reserve_space(xdr, 4);
689 	if (unlikely(hdr->nops == NULL))
690 		return htonl(NFS4ERR_RESOURCE);
691 	return 0;
692 }
693 
694 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
695 {
696 	__be32 *p;
697 
698 	p = xdr_reserve_space(xdr, 8);
699 	if (unlikely(p == NULL))
700 		return htonl(NFS4ERR_RESOURCE_HDR);
701 	*p++ = htonl(op);
702 	*p = res;
703 	return 0;
704 }
705 
706 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
707 		const void *resp)
708 {
709 	const struct cb_getattrres *res = resp;
710 	__be32 *savep = NULL;
711 	__be32 status = res->status;
712 
713 	if (unlikely(status != 0))
714 		goto out;
715 	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
716 	if (unlikely(status != 0))
717 		goto out;
718 	status = cpu_to_be32(NFS4ERR_RESOURCE);
719 	savep = xdr_reserve_space(xdr, sizeof(*savep));
720 	if (unlikely(!savep))
721 		goto out;
722 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
723 	if (unlikely(status != 0))
724 		goto out;
725 	status = encode_attr_size(xdr, res->bitmap, res->size);
726 	if (unlikely(status != 0))
727 		goto out;
728 	status = encode_attr_atime(xdr, res->bitmap, &res->atime);
729 	if (unlikely(status != 0))
730 		goto out;
731 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
732 	if (unlikely(status != 0))
733 		goto out;
734 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
735 	if (unlikely(status != 0))
736 		goto out;
737 	status = encode_attr_delegatime(xdr, res->bitmap, &res->atime);
738 	if (unlikely(status != 0))
739 		goto out;
740 	status = encode_attr_delegmtime(xdr, res->bitmap, &res->mtime);
741 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
742 out:
743 	return status;
744 }
745 
746 static __be32 encode_sessionid(struct xdr_stream *xdr,
747 				 const struct nfs4_sessionid *sid)
748 {
749 	__be32 *p;
750 
751 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
752 	if (unlikely(p == NULL))
753 		return htonl(NFS4ERR_RESOURCE);
754 
755 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
756 	return 0;
757 }
758 
759 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
760 				       struct xdr_stream *xdr,
761 				       const void *resp)
762 {
763 	const struct cb_sequenceres *res = resp;
764 	__be32 *p;
765 	__be32 status = res->csr_status;
766 
767 	if (unlikely(status != 0))
768 		return status;
769 
770 	status = encode_sessionid(xdr, &res->csr_sessionid);
771 	if (status)
772 		return status;
773 
774 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
775 	if (unlikely(p == NULL))
776 		return htonl(NFS4ERR_RESOURCE);
777 
778 	*p++ = htonl(res->csr_sequenceid);
779 	*p++ = htonl(res->csr_slotid);
780 	*p++ = htonl(res->csr_highestslotid);
781 	*p++ = htonl(res->csr_target_highestslotid);
782 	return 0;
783 }
784 
785 static __be32
786 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
787 {
788 	if (op_nr == OP_CB_SEQUENCE) {
789 		if (nop != 0)
790 			return htonl(NFS4ERR_SEQUENCE_POS);
791 	} else {
792 		if (nop == 0)
793 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
794 	}
795 
796 	switch (op_nr) {
797 	case OP_CB_GETATTR:
798 	case OP_CB_RECALL:
799 	case OP_CB_SEQUENCE:
800 	case OP_CB_RECALL_ANY:
801 	case OP_CB_RECALL_SLOT:
802 	case OP_CB_LAYOUTRECALL:
803 	case OP_CB_NOTIFY_DEVICEID:
804 	case OP_CB_NOTIFY_LOCK:
805 		*op = &callback_ops[op_nr];
806 		break;
807 
808 	case OP_CB_NOTIFY:
809 	case OP_CB_PUSH_DELEG:
810 	case OP_CB_RECALLABLE_OBJ_AVAIL:
811 	case OP_CB_WANTS_CANCELLED:
812 		return htonl(NFS4ERR_NOTSUPP);
813 
814 	default:
815 		return htonl(NFS4ERR_OP_ILLEGAL);
816 	}
817 
818 	return htonl(NFS_OK);
819 }
820 
821 static void nfs4_callback_free_slot(struct nfs4_session *session,
822 		struct nfs4_slot *slot)
823 {
824 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
825 
826 	spin_lock(&tbl->slot_tbl_lock);
827 	/*
828 	 * Let the state manager know callback processing done.
829 	 * A single slot, so highest used slotid is either 0 or -1
830 	 */
831 	nfs4_free_slot(tbl, slot);
832 	spin_unlock(&tbl->slot_tbl_lock);
833 }
834 
835 static void nfs4_cb_free_slot(struct cb_process_state *cps)
836 {
837 	if (cps->slot) {
838 		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
839 		cps->slot = NULL;
840 	}
841 }
842 
843 #ifdef CONFIG_NFS_V4_2
844 static __be32
845 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
846 {
847 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
848 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
849 		return status;
850 
851 	if (op_nr == OP_CB_OFFLOAD) {
852 		*op = &callback_ops[op_nr];
853 		return htonl(NFS_OK);
854 	} else
855 		return htonl(NFS4ERR_NOTSUPP);
856 	return htonl(NFS4ERR_OP_ILLEGAL);
857 }
858 #else /* CONFIG_NFS_V4_2 */
859 static __be32
860 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
861 {
862 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
863 }
864 #endif /* CONFIG_NFS_V4_2 */
865 
866 static __be32
867 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
868 {
869 	switch (op_nr) {
870 	case OP_CB_GETATTR:
871 	case OP_CB_RECALL:
872 		*op = &callback_ops[op_nr];
873 		break;
874 	default:
875 		return htonl(NFS4ERR_OP_ILLEGAL);
876 	}
877 
878 	return htonl(NFS_OK);
879 }
880 
881 static __be32 process_op(int nop, struct svc_rqst *rqstp,
882 			 struct cb_process_state *cps)
883 {
884 	struct xdr_stream *xdr_out = &rqstp->rq_res_stream;
885 	struct callback_op *op = &callback_ops[0];
886 	unsigned int op_nr;
887 	__be32 status;
888 	long maxlen;
889 	__be32 res;
890 
891 	status = decode_op_hdr(&rqstp->rq_arg_stream, &op_nr);
892 	if (unlikely(status))
893 		return status;
894 
895 	switch (cps->minorversion) {
896 	case 0:
897 		status = preprocess_nfs4_op(op_nr, &op);
898 		break;
899 	case 1:
900 		status = preprocess_nfs41_op(nop, op_nr, &op);
901 		break;
902 	case 2:
903 		status = preprocess_nfs42_op(nop, op_nr, &op);
904 		break;
905 	default:
906 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
907 	}
908 
909 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
910 		op_nr = OP_CB_ILLEGAL;
911 	if (status)
912 		goto encode_hdr;
913 
914 	if (cps->drc_status) {
915 		status = cps->drc_status;
916 		goto encode_hdr;
917 	}
918 
919 	maxlen = xdr_out->end - xdr_out->p;
920 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
921 		status = op->decode_args(rqstp, &rqstp->rq_arg_stream,
922 					 rqstp->rq_argp);
923 		if (likely(status == 0))
924 			status = op->process_op(rqstp->rq_argp, rqstp->rq_resp,
925 						cps);
926 	} else
927 		status = htonl(NFS4ERR_RESOURCE);
928 
929 encode_hdr:
930 	res = encode_op_hdr(xdr_out, op_nr, status);
931 	if (unlikely(res))
932 		return res;
933 	if (op->encode_res != NULL && status == 0)
934 		status = op->encode_res(rqstp, xdr_out, rqstp->rq_resp);
935 	return status;
936 }
937 
938 /*
939  * Decode, process and encode a COMPOUND
940  */
941 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
942 {
943 	struct cb_compound_hdr_arg hdr_arg = { 0 };
944 	struct cb_compound_hdr_res hdr_res = { NULL };
945 	struct cb_process_state cps = {
946 		.drc_status = 0,
947 		.clp = NULL,
948 		.net = SVC_NET(rqstp),
949 	};
950 	unsigned int nops = 0;
951 	__be32 status;
952 
953 	status = decode_compound_hdr_arg(&rqstp->rq_arg_stream, &hdr_arg);
954 	if (status == htonl(NFS4ERR_RESOURCE))
955 		return rpc_garbage_args;
956 
957 	if (hdr_arg.minorversion == 0) {
958 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
959 		if (!cps.clp) {
960 			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
961 			goto out_invalidcred;
962 		}
963 		if (!check_gss_callback_principal(cps.clp, rqstp)) {
964 			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
965 			nfs_put_client(cps.clp);
966 			goto out_invalidcred;
967 		}
968 		svc_xprt_set_valid(rqstp->rq_xprt);
969 	}
970 
971 	cps.minorversion = hdr_arg.minorversion;
972 	hdr_res.taglen = hdr_arg.taglen;
973 	hdr_res.tag = hdr_arg.tag;
974 	if (encode_compound_hdr_res(&rqstp->rq_res_stream, &hdr_res) != 0) {
975 		if (cps.clp)
976 			nfs_put_client(cps.clp);
977 		return rpc_system_err;
978 	}
979 	while (status == 0 && nops != hdr_arg.nops) {
980 		status = process_op(nops, rqstp, &cps);
981 		nops++;
982 	}
983 
984 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
985 	* resource error in cb_compound status without returning op */
986 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
987 		status = htonl(NFS4ERR_RESOURCE);
988 		nops--;
989 	}
990 
991 	if (svc_is_backchannel(rqstp) && cps.clp) {
992 		rqstp->bc_to_initval = cps.clp->cl_rpcclient->cl_timeout->to_initval;
993 		rqstp->bc_to_retries = cps.clp->cl_rpcclient->cl_timeout->to_retries;
994 	}
995 
996 	*hdr_res.status = status;
997 	*hdr_res.nops = htonl(nops);
998 	nfs4_cb_free_slot(&cps);
999 	nfs_put_client(cps.clp);
1000 	return rpc_success;
1001 
1002 out_invalidcred:
1003 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
1004 	rqstp->rq_auth_stat = rpc_autherr_badcred;
1005 	return rpc_success;
1006 }
1007 
1008 static int
1009 nfs_callback_dispatch(struct svc_rqst *rqstp)
1010 {
1011 	const struct svc_procedure *procp = rqstp->rq_procinfo;
1012 
1013 	*rqstp->rq_accept_statp = procp->pc_func(rqstp);
1014 	return 1;
1015 }
1016 
1017 /*
1018  * Define NFS4 callback COMPOUND ops.
1019  */
1020 static struct callback_op callback_ops[] = {
1021 	[0] = {
1022 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
1023 	},
1024 	[OP_CB_GETATTR] = {
1025 		.process_op = nfs4_callback_getattr,
1026 		.decode_args = decode_getattr_args,
1027 		.encode_res = encode_getattr_res,
1028 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1029 	},
1030 	[OP_CB_RECALL] = {
1031 		.process_op = nfs4_callback_recall,
1032 		.decode_args = decode_recall_args,
1033 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1034 	},
1035 	[OP_CB_LAYOUTRECALL] = {
1036 		.process_op = nfs4_callback_layoutrecall,
1037 		.decode_args = decode_layoutrecall_args,
1038 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1039 	},
1040 	[OP_CB_NOTIFY_DEVICEID] = {
1041 		.process_op = nfs4_callback_devicenotify,
1042 		.decode_args = decode_devicenotify_args,
1043 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1044 	},
1045 	[OP_CB_SEQUENCE] = {
1046 		.process_op = nfs4_callback_sequence,
1047 		.decode_args = decode_cb_sequence_args,
1048 		.encode_res = encode_cb_sequence_res,
1049 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1050 	},
1051 	[OP_CB_RECALL_ANY] = {
1052 		.process_op = nfs4_callback_recallany,
1053 		.decode_args = decode_recallany_args,
1054 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1055 	},
1056 	[OP_CB_RECALL_SLOT] = {
1057 		.process_op = nfs4_callback_recallslot,
1058 		.decode_args = decode_recallslot_args,
1059 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1060 	},
1061 	[OP_CB_NOTIFY_LOCK] = {
1062 		.process_op = nfs4_callback_notify_lock,
1063 		.decode_args = decode_notify_lock_args,
1064 		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1065 	},
1066 #ifdef CONFIG_NFS_V4_2
1067 	[OP_CB_OFFLOAD] = {
1068 		.process_op = nfs4_callback_offload,
1069 		.decode_args = decode_offload_args,
1070 		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1071 	},
1072 #endif /* CONFIG_NFS_V4_2 */
1073 };
1074 
1075 /*
1076  * Define NFS4 callback procedures
1077  */
1078 static const struct svc_procedure nfs4_callback_procedures1[] = {
1079 	[CB_NULL] = {
1080 		.pc_func = nfs4_callback_null,
1081 		.pc_encode = nfs4_encode_void,
1082 		.pc_xdrressize = 1,
1083 		.pc_name = "NULL",
1084 	},
1085 	[CB_COMPOUND] = {
1086 		.pc_func = nfs4_callback_compound,
1087 		.pc_encode = nfs4_encode_void,
1088 		.pc_argsize = 256,
1089 		.pc_argzero = 256,
1090 		.pc_ressize = 256,
1091 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1092 		.pc_name = "COMPOUND",
1093 	}
1094 };
1095 
1096 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1097 			      nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)]);
1098 const struct svc_version nfs4_callback_version1 = {
1099 	.vs_vers = 1,
1100 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1101 	.vs_proc = nfs4_callback_procedures1,
1102 	.vs_count = nfs4_callback_count1,
1103 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1104 	.vs_dispatch = nfs_callback_dispatch,
1105 	.vs_hidden = true,
1106 	.vs_need_cong_ctrl = true,
1107 };
1108 
1109 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1110 			      nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)]);
1111 const struct svc_version nfs4_callback_version4 = {
1112 	.vs_vers = 4,
1113 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1114 	.vs_proc = nfs4_callback_procedures1,
1115 	.vs_count = nfs4_callback_count4,
1116 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1117 	.vs_dispatch = nfs_callback_dispatch,
1118 	.vs_hidden = true,
1119 	.vs_need_cong_ctrl = true,
1120 };
1121