xref: /linux/fs/nfs/callback_xdr.c (revision 60f0560f53e395adf4bce7282d8d4bc94a4952ac)
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 #if defined(CONFIG_NFS_V4_1)
34 #define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
35 #define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
36 #define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
37 					 NFS4_MAX_SESSIONID_LEN + \
38 					 (1 + 3) * 4) // seqid, 3 slotids
39 #define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
40 #define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
41 #define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
42 #endif /* CONFIG_NFS_V4_1 */
43 #ifdef CONFIG_NFS_V4_2
44 #define CB_OP_OFFLOAD_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
45 #endif /* CONFIG_NFS_V4_2 */
46 
47 #define NFSDBG_FACILITY NFSDBG_CALLBACK
48 
49 /* Internal error code */
50 #define NFS4ERR_RESOURCE_HDR	11050
51 
52 struct callback_op {
53 	__be32 (*process_op)(void *, void *, struct cb_process_state *);
54 	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
55 	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
56 			const void *);
57 	long res_maxsize;
58 };
59 
60 static struct callback_op callback_ops[];
61 
62 static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
63 {
64 	return htonl(NFS4_OK);
65 }
66 
67 /*
68  * svc_process_common() looks for an XDR encoder to know when
69  * not to drop a Reply.
70  */
71 static bool nfs4_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
72 {
73 	return true;
74 }
75 
76 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
77 		const char **str, size_t maxlen)
78 {
79 	ssize_t err;
80 
81 	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
82 	if (err < 0)
83 		return cpu_to_be32(NFS4ERR_RESOURCE);
84 	*len = err;
85 	return 0;
86 }
87 
88 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
89 {
90 	__be32 *p;
91 
92 	p = xdr_inline_decode(xdr, 4);
93 	if (unlikely(p == NULL))
94 		return htonl(NFS4ERR_RESOURCE);
95 	fh->size = ntohl(*p);
96 	if (fh->size > NFS4_FHSIZE)
97 		return htonl(NFS4ERR_BADHANDLE);
98 	p = xdr_inline_decode(xdr, fh->size);
99 	if (unlikely(p == NULL))
100 		return htonl(NFS4ERR_RESOURCE);
101 	memcpy(&fh->data[0], p, fh->size);
102 	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
103 	return 0;
104 }
105 
106 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
107 {
108 	__be32 *p;
109 	unsigned int attrlen;
110 
111 	p = xdr_inline_decode(xdr, 4);
112 	if (unlikely(p == NULL))
113 		return htonl(NFS4ERR_RESOURCE);
114 	attrlen = ntohl(*p);
115 	p = xdr_inline_decode(xdr, attrlen << 2);
116 	if (unlikely(p == NULL))
117 		return htonl(NFS4ERR_RESOURCE);
118 	if (likely(attrlen > 0))
119 		bitmap[0] = ntohl(*p++);
120 	if (attrlen > 1)
121 		bitmap[1] = ntohl(*p++);
122 	if (attrlen > 2)
123 		bitmap[2] = ntohl(*p);
124 	return 0;
125 }
126 
127 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
128 {
129 	__be32 *p;
130 
131 	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
132 	if (unlikely(p == NULL))
133 		return htonl(NFS4ERR_RESOURCE);
134 	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
135 	return 0;
136 }
137 
138 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
139 {
140 	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
141 	return decode_stateid(xdr, stateid);
142 }
143 
144 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
145 {
146 	__be32 *p;
147 	__be32 status;
148 
149 	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
150 	if (unlikely(status != 0))
151 		return status;
152 	p = xdr_inline_decode(xdr, 12);
153 	if (unlikely(p == NULL))
154 		return htonl(NFS4ERR_RESOURCE);
155 	hdr->minorversion = ntohl(*p++);
156 	/* Check for minor version support */
157 	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
158 		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
159 	} else {
160 		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
161 			"illegal minor version %u!\n",
162 			__func__, hdr->minorversion);
163 		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
164 	}
165 	hdr->nops = ntohl(*p);
166 	return 0;
167 }
168 
169 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
170 {
171 	__be32 *p;
172 	p = xdr_inline_decode(xdr, 4);
173 	if (unlikely(p == NULL))
174 		return htonl(NFS4ERR_RESOURCE_HDR);
175 	*op = ntohl(*p);
176 	return 0;
177 }
178 
179 static __be32 decode_getattr_args(struct svc_rqst *rqstp,
180 		struct xdr_stream *xdr, void *argp)
181 {
182 	struct cb_getattrargs *args = argp;
183 	__be32 status;
184 
185 	status = decode_fh(xdr, &args->fh);
186 	if (unlikely(status != 0))
187 		return status;
188 	return decode_bitmap(xdr, args->bitmap);
189 }
190 
191 static __be32 decode_recall_args(struct svc_rqst *rqstp,
192 		struct xdr_stream *xdr, void *argp)
193 {
194 	struct cb_recallargs *args = argp;
195 	__be32 *p;
196 	__be32 status;
197 
198 	status = decode_delegation_stateid(xdr, &args->stateid);
199 	if (unlikely(status != 0))
200 		return status;
201 	p = xdr_inline_decode(xdr, 4);
202 	if (unlikely(p == NULL))
203 		return htonl(NFS4ERR_RESOURCE);
204 	args->truncate = ntohl(*p);
205 	return decode_fh(xdr, &args->fh);
206 }
207 
208 #if defined(CONFIG_NFS_V4_1)
209 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
210 {
211 	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
212 	return decode_stateid(xdr, stateid);
213 }
214 
215 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
216 				       struct xdr_stream *xdr, void *argp)
217 {
218 	struct cb_layoutrecallargs *args = argp;
219 	__be32 *p;
220 	__be32 status = 0;
221 	uint32_t iomode;
222 
223 	p = xdr_inline_decode(xdr, 4 * sizeof(uint32_t));
224 	if (unlikely(p == NULL))
225 		return htonl(NFS4ERR_BADXDR);
226 
227 	args->cbl_layout_type = ntohl(*p++);
228 	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
229 	 * as it is unusable and ignored with the other types.
230 	 */
231 	iomode = ntohl(*p++);
232 	args->cbl_layoutchanged = ntohl(*p++);
233 	args->cbl_recall_type = ntohl(*p++);
234 
235 	if (args->cbl_recall_type == RETURN_FILE) {
236 		args->cbl_range.iomode = iomode;
237 		status = decode_fh(xdr, &args->cbl_fh);
238 		if (unlikely(status != 0))
239 			return status;
240 
241 		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
242 		if (unlikely(p == NULL))
243 			return htonl(NFS4ERR_BADXDR);
244 		p = xdr_decode_hyper(p, &args->cbl_range.offset);
245 		p = xdr_decode_hyper(p, &args->cbl_range.length);
246 		return decode_layout_stateid(xdr, &args->cbl_stateid);
247 	} else if (args->cbl_recall_type == RETURN_FSID) {
248 		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
249 		if (unlikely(p == NULL))
250 			return htonl(NFS4ERR_BADXDR);
251 		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
252 		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
253 	} else if (args->cbl_recall_type != RETURN_ALL)
254 		return htonl(NFS4ERR_BADXDR);
255 	return 0;
256 }
257 
258 static
259 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
260 				struct xdr_stream *xdr,
261 				void *argp)
262 {
263 	struct cb_devicenotifyargs *args = argp;
264 	uint32_t tmp, n, i;
265 	__be32 *p;
266 	__be32 status = 0;
267 
268 	/* Num of device notifications */
269 	p = xdr_inline_decode(xdr, sizeof(uint32_t));
270 	if (unlikely(p == NULL)) {
271 		status = htonl(NFS4ERR_BADXDR);
272 		goto out;
273 	}
274 	n = ntohl(*p++);
275 	if (n == 0)
276 		goto out;
277 
278 	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
279 	if (!args->devs) {
280 		status = htonl(NFS4ERR_DELAY);
281 		goto out;
282 	}
283 
284 	/* Decode each dev notification */
285 	for (i = 0; i < n; i++) {
286 		struct cb_devicenotifyitem *dev = &args->devs[i];
287 
288 		p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
289 				      NFS4_DEVICEID4_SIZE);
290 		if (unlikely(p == NULL)) {
291 			status = htonl(NFS4ERR_BADXDR);
292 			goto err;
293 		}
294 
295 		tmp = ntohl(*p++);	/* bitmap size */
296 		if (tmp != 1) {
297 			status = htonl(NFS4ERR_INVAL);
298 			goto err;
299 		}
300 		dev->cbd_notify_type = ntohl(*p++);
301 		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
302 		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
303 			status = htonl(NFS4ERR_INVAL);
304 			goto err;
305 		}
306 
307 		tmp = ntohl(*p++);	/* opaque size */
308 		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
309 		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
310 		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
311 		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
312 			status = htonl(NFS4ERR_INVAL);
313 			goto err;
314 		}
315 		dev->cbd_layout_type = ntohl(*p++);
316 		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
317 		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
318 
319 		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
320 			p = xdr_inline_decode(xdr, sizeof(uint32_t));
321 			if (unlikely(p == NULL)) {
322 				status = htonl(NFS4ERR_BADXDR);
323 				goto err;
324 			}
325 			dev->cbd_immediate = ntohl(*p++);
326 		} else {
327 			dev->cbd_immediate = 0;
328 		}
329 
330 		dprintk("%s: type %d layout 0x%x immediate %d\n",
331 			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
332 			dev->cbd_immediate);
333 	}
334 	args->ndevs = n;
335 	dprintk("%s: ndevs %d\n", __func__, args->ndevs);
336 	return 0;
337 err:
338 	kfree(args->devs);
339 out:
340 	args->devs = NULL;
341 	args->ndevs = 0;
342 	dprintk("%s: status %d ndevs %d\n",
343 		__func__, ntohl(status), args->ndevs);
344 	return status;
345 }
346 
347 static __be32 decode_sessionid(struct xdr_stream *xdr,
348 				 struct nfs4_sessionid *sid)
349 {
350 	__be32 *p;
351 
352 	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
353 	if (unlikely(p == NULL))
354 		return htonl(NFS4ERR_RESOURCE);
355 
356 	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
357 	return 0;
358 }
359 
360 static __be32 decode_rc_list(struct xdr_stream *xdr,
361 			       struct referring_call_list *rc_list)
362 {
363 	__be32 *p;
364 	int i;
365 	__be32 status;
366 
367 	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
368 	if (status)
369 		goto out;
370 
371 	status = htonl(NFS4ERR_RESOURCE);
372 	p = xdr_inline_decode(xdr, sizeof(uint32_t));
373 	if (unlikely(p == NULL))
374 		goto out;
375 
376 	rc_list->rcl_nrefcalls = ntohl(*p++);
377 	if (rc_list->rcl_nrefcalls) {
378 		p = xdr_inline_decode(xdr,
379 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
380 		if (unlikely(p == NULL))
381 			goto out;
382 		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
383 						sizeof(*rc_list->rcl_refcalls),
384 						GFP_KERNEL);
385 		if (unlikely(rc_list->rcl_refcalls == NULL))
386 			goto out;
387 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
388 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
389 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
390 		}
391 	}
392 	status = 0;
393 
394 out:
395 	return status;
396 }
397 
398 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
399 					struct xdr_stream *xdr,
400 					void *argp)
401 {
402 	struct cb_sequenceargs *args = argp;
403 	__be32 *p;
404 	int i;
405 	__be32 status;
406 
407 	status = decode_sessionid(xdr, &args->csa_sessionid);
408 	if (status)
409 		return status;
410 
411 	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
412 	if (unlikely(p == NULL))
413 		return htonl(NFS4ERR_RESOURCE);
414 
415 	args->csa_addr = svc_addr(rqstp);
416 	args->csa_sequenceid = ntohl(*p++);
417 	args->csa_slotid = ntohl(*p++);
418 	args->csa_highestslotid = ntohl(*p++);
419 	args->csa_cachethis = ntohl(*p++);
420 	args->csa_nrclists = ntohl(*p++);
421 	args->csa_rclists = NULL;
422 	if (args->csa_nrclists) {
423 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
424 						  sizeof(*args->csa_rclists),
425 						  GFP_KERNEL);
426 		if (unlikely(args->csa_rclists == NULL))
427 			return htonl(NFS4ERR_RESOURCE);
428 
429 		for (i = 0; i < args->csa_nrclists; i++) {
430 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
431 			if (status) {
432 				args->csa_nrclists = i;
433 				goto out_free;
434 			}
435 		}
436 	}
437 	return 0;
438 
439 out_free:
440 	for (i = 0; i < args->csa_nrclists; i++)
441 		kfree(args->csa_rclists[i].rcl_refcalls);
442 	kfree(args->csa_rclists);
443 	return status;
444 }
445 
446 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
447 				      struct xdr_stream *xdr,
448 				      void *argp)
449 {
450 	struct cb_recallanyargs *args = argp;
451 	uint32_t bitmap[3];
452 	__be32 *p, status;
453 
454 	p = xdr_inline_decode(xdr, 4);
455 	if (unlikely(p == NULL))
456 		return htonl(NFS4ERR_BADXDR);
457 	args->craa_objs_to_keep = ntohl(*p++);
458 	status = decode_bitmap(xdr, bitmap);
459 	if (unlikely(status))
460 		return status;
461 	args->craa_type_mask = bitmap[0];
462 
463 	return 0;
464 }
465 
466 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
467 					struct xdr_stream *xdr,
468 					void *argp)
469 {
470 	struct cb_recallslotargs *args = argp;
471 	__be32 *p;
472 
473 	p = xdr_inline_decode(xdr, 4);
474 	if (unlikely(p == NULL))
475 		return htonl(NFS4ERR_BADXDR);
476 	args->crsa_target_highest_slotid = ntohl(*p++);
477 	return 0;
478 }
479 
480 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
481 {
482 	__be32		*p;
483 	unsigned int	len;
484 
485 	p = xdr_inline_decode(xdr, 12);
486 	if (unlikely(p == NULL))
487 		return htonl(NFS4ERR_BADXDR);
488 
489 	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
490 	len = be32_to_cpu(*p);
491 
492 	p = xdr_inline_decode(xdr, len);
493 	if (unlikely(p == NULL))
494 		return htonl(NFS4ERR_BADXDR);
495 
496 	/* Only try to decode if the length is right */
497 	if (len == 20) {
498 		p += 2;	/* skip "lock id:" */
499 		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
500 		xdr_decode_hyper(p, &args->cbnl_owner.id);
501 		args->cbnl_valid = true;
502 	} else {
503 		args->cbnl_owner.s_dev = 0;
504 		args->cbnl_owner.id = 0;
505 		args->cbnl_valid = false;
506 	}
507 	return 0;
508 }
509 
510 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
511 		struct xdr_stream *xdr, void *argp)
512 {
513 	struct cb_notify_lock_args *args = argp;
514 	__be32 status;
515 
516 	status = decode_fh(xdr, &args->cbnl_fh);
517 	if (unlikely(status != 0))
518 		return status;
519 	return decode_lockowner(xdr, args);
520 }
521 
522 #endif /* CONFIG_NFS_V4_1 */
523 #ifdef CONFIG_NFS_V4_2
524 static __be32 decode_write_response(struct xdr_stream *xdr,
525 					struct cb_offloadargs *args)
526 {
527 	__be32 *p;
528 
529 	/* skip the always zero field */
530 	p = xdr_inline_decode(xdr, 4);
531 	if (unlikely(!p))
532 		goto out;
533 	p++;
534 
535 	/* decode count, stable_how, verifier */
536 	p = xdr_inline_decode(xdr, 8 + 4);
537 	if (unlikely(!p))
538 		goto out;
539 	p = xdr_decode_hyper(p, &args->wr_count);
540 	args->wr_writeverf.committed = be32_to_cpup(p);
541 	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
542 	if (likely(p)) {
543 		memcpy(&args->wr_writeverf.verifier.data[0], p,
544 			NFS4_VERIFIER_SIZE);
545 		return 0;
546 	}
547 out:
548 	return htonl(NFS4ERR_RESOURCE);
549 }
550 
551 static __be32 decode_offload_args(struct svc_rqst *rqstp,
552 					struct xdr_stream *xdr,
553 					void *data)
554 {
555 	struct cb_offloadargs *args = data;
556 	__be32 *p;
557 	__be32 status;
558 
559 	/* decode fh */
560 	status = decode_fh(xdr, &args->coa_fh);
561 	if (unlikely(status != 0))
562 		return status;
563 
564 	/* decode stateid */
565 	status = decode_stateid(xdr, &args->coa_stateid);
566 	if (unlikely(status != 0))
567 		return status;
568 
569 	/* decode status */
570 	p = xdr_inline_decode(xdr, 4);
571 	if (unlikely(!p))
572 		goto out;
573 	args->error = ntohl(*p++);
574 	if (!args->error) {
575 		status = decode_write_response(xdr, args);
576 		if (unlikely(status != 0))
577 			return status;
578 	} else {
579 		p = xdr_inline_decode(xdr, 8);
580 		if (unlikely(!p))
581 			goto out;
582 		p = xdr_decode_hyper(p, &args->wr_count);
583 	}
584 	return 0;
585 out:
586 	return htonl(NFS4ERR_RESOURCE);
587 }
588 #endif /* CONFIG_NFS_V4_2 */
589 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
590 {
591 	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
592 		return cpu_to_be32(NFS4ERR_RESOURCE);
593 	return 0;
594 }
595 
596 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
597 {
598 	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
599 		return cpu_to_be32(NFS4ERR_RESOURCE);
600 	return 0;
601 }
602 
603 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
604 {
605 	__be32 *p;
606 
607 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
608 		return 0;
609 	p = xdr_reserve_space(xdr, 8);
610 	if (unlikely(!p))
611 		return htonl(NFS4ERR_RESOURCE);
612 	p = xdr_encode_hyper(p, change);
613 	return 0;
614 }
615 
616 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
617 {
618 	__be32 *p;
619 
620 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
621 		return 0;
622 	p = xdr_reserve_space(xdr, 8);
623 	if (unlikely(!p))
624 		return htonl(NFS4ERR_RESOURCE);
625 	p = xdr_encode_hyper(p, size);
626 	return 0;
627 }
628 
629 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
630 {
631 	__be32 *p;
632 
633 	p = xdr_reserve_space(xdr, 12);
634 	if (unlikely(!p))
635 		return htonl(NFS4ERR_RESOURCE);
636 	p = xdr_encode_hyper(p, time->tv_sec);
637 	*p = htonl(time->tv_nsec);
638 	return 0;
639 }
640 
641 static __be32 encode_attr_atime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
642 {
643 	if (!(bitmap[1] & FATTR4_WORD1_TIME_ACCESS))
644 		return 0;
645 	return encode_attr_time(xdr,time);
646 }
647 
648 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
649 {
650 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
651 		return 0;
652 	return encode_attr_time(xdr,time);
653 }
654 
655 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
656 {
657 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
658 		return 0;
659 	return encode_attr_time(xdr,time);
660 }
661 
662 static __be32 encode_attr_delegatime(struct xdr_stream *xdr,
663 				     const uint32_t *bitmap,
664 				     const struct timespec64 *time)
665 {
666 	if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS))
667 		return 0;
668 	return encode_attr_time(xdr,time);
669 }
670 
671 static __be32 encode_attr_delegmtime(struct xdr_stream *xdr,
672 				     const uint32_t *bitmap,
673 				     const struct timespec64 *time)
674 {
675 	if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY))
676 		return 0;
677 	return encode_attr_time(xdr,time);
678 }
679 
680 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
681 {
682 	__be32 status;
683 
684 	hdr->status = xdr_reserve_space(xdr, 4);
685 	if (unlikely(hdr->status == NULL))
686 		return htonl(NFS4ERR_RESOURCE);
687 	status = encode_string(xdr, hdr->taglen, hdr->tag);
688 	if (unlikely(status != 0))
689 		return status;
690 	hdr->nops = xdr_reserve_space(xdr, 4);
691 	if (unlikely(hdr->nops == NULL))
692 		return htonl(NFS4ERR_RESOURCE);
693 	return 0;
694 }
695 
696 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
697 {
698 	__be32 *p;
699 
700 	p = xdr_reserve_space(xdr, 8);
701 	if (unlikely(p == NULL))
702 		return htonl(NFS4ERR_RESOURCE_HDR);
703 	*p++ = htonl(op);
704 	*p = res;
705 	return 0;
706 }
707 
708 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
709 		const void *resp)
710 {
711 	const struct cb_getattrres *res = resp;
712 	__be32 *savep = NULL;
713 	__be32 status = res->status;
714 
715 	if (unlikely(status != 0))
716 		goto out;
717 	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
718 	if (unlikely(status != 0))
719 		goto out;
720 	status = cpu_to_be32(NFS4ERR_RESOURCE);
721 	savep = xdr_reserve_space(xdr, sizeof(*savep));
722 	if (unlikely(!savep))
723 		goto out;
724 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
725 	if (unlikely(status != 0))
726 		goto out;
727 	status = encode_attr_size(xdr, res->bitmap, res->size);
728 	if (unlikely(status != 0))
729 		goto out;
730 	status = encode_attr_atime(xdr, res->bitmap, &res->atime);
731 	if (unlikely(status != 0))
732 		goto out;
733 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
734 	if (unlikely(status != 0))
735 		goto out;
736 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
737 	if (unlikely(status != 0))
738 		goto out;
739 	status = encode_attr_delegatime(xdr, res->bitmap, &res->atime);
740 	if (unlikely(status != 0))
741 		goto out;
742 	status = encode_attr_delegmtime(xdr, res->bitmap, &res->mtime);
743 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
744 out:
745 	return status;
746 }
747 
748 #if defined(CONFIG_NFS_V4_1)
749 
750 static __be32 encode_sessionid(struct xdr_stream *xdr,
751 				 const struct nfs4_sessionid *sid)
752 {
753 	__be32 *p;
754 
755 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
756 	if (unlikely(p == NULL))
757 		return htonl(NFS4ERR_RESOURCE);
758 
759 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
760 	return 0;
761 }
762 
763 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
764 				       struct xdr_stream *xdr,
765 				       const void *resp)
766 {
767 	const struct cb_sequenceres *res = resp;
768 	__be32 *p;
769 	__be32 status = res->csr_status;
770 
771 	if (unlikely(status != 0))
772 		return status;
773 
774 	status = encode_sessionid(xdr, &res->csr_sessionid);
775 	if (status)
776 		return status;
777 
778 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
779 	if (unlikely(p == NULL))
780 		return htonl(NFS4ERR_RESOURCE);
781 
782 	*p++ = htonl(res->csr_sequenceid);
783 	*p++ = htonl(res->csr_slotid);
784 	*p++ = htonl(res->csr_highestslotid);
785 	*p++ = htonl(res->csr_target_highestslotid);
786 	return 0;
787 }
788 
789 static __be32
790 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
791 {
792 	if (op_nr == OP_CB_SEQUENCE) {
793 		if (nop != 0)
794 			return htonl(NFS4ERR_SEQUENCE_POS);
795 	} else {
796 		if (nop == 0)
797 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
798 	}
799 
800 	switch (op_nr) {
801 	case OP_CB_GETATTR:
802 	case OP_CB_RECALL:
803 	case OP_CB_SEQUENCE:
804 	case OP_CB_RECALL_ANY:
805 	case OP_CB_RECALL_SLOT:
806 	case OP_CB_LAYOUTRECALL:
807 	case OP_CB_NOTIFY_DEVICEID:
808 	case OP_CB_NOTIFY_LOCK:
809 		*op = &callback_ops[op_nr];
810 		break;
811 
812 	case OP_CB_NOTIFY:
813 	case OP_CB_PUSH_DELEG:
814 	case OP_CB_RECALLABLE_OBJ_AVAIL:
815 	case OP_CB_WANTS_CANCELLED:
816 		return htonl(NFS4ERR_NOTSUPP);
817 
818 	default:
819 		return htonl(NFS4ERR_OP_ILLEGAL);
820 	}
821 
822 	return htonl(NFS_OK);
823 }
824 
825 static void nfs4_callback_free_slot(struct nfs4_session *session,
826 		struct nfs4_slot *slot)
827 {
828 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
829 
830 	spin_lock(&tbl->slot_tbl_lock);
831 	/*
832 	 * Let the state manager know callback processing done.
833 	 * A single slot, so highest used slotid is either 0 or -1
834 	 */
835 	nfs4_free_slot(tbl, slot);
836 	spin_unlock(&tbl->slot_tbl_lock);
837 }
838 
839 static void nfs4_cb_free_slot(struct cb_process_state *cps)
840 {
841 	if (cps->slot) {
842 		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
843 		cps->slot = NULL;
844 	}
845 }
846 
847 #else /* CONFIG_NFS_V4_1 */
848 
849 static __be32
850 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
851 {
852 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
853 }
854 
855 static void nfs4_cb_free_slot(struct cb_process_state *cps)
856 {
857 }
858 #endif /* CONFIG_NFS_V4_1 */
859 
860 #ifdef CONFIG_NFS_V4_2
861 static __be32
862 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
863 {
864 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
865 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
866 		return status;
867 
868 	if (op_nr == OP_CB_OFFLOAD) {
869 		*op = &callback_ops[op_nr];
870 		return htonl(NFS_OK);
871 	} else
872 		return htonl(NFS4ERR_NOTSUPP);
873 	return htonl(NFS4ERR_OP_ILLEGAL);
874 }
875 #else /* CONFIG_NFS_V4_2 */
876 static __be32
877 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
878 {
879 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
880 }
881 #endif /* CONFIG_NFS_V4_2 */
882 
883 static __be32
884 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
885 {
886 	switch (op_nr) {
887 	case OP_CB_GETATTR:
888 	case OP_CB_RECALL:
889 		*op = &callback_ops[op_nr];
890 		break;
891 	default:
892 		return htonl(NFS4ERR_OP_ILLEGAL);
893 	}
894 
895 	return htonl(NFS_OK);
896 }
897 
898 static __be32 process_op(int nop, struct svc_rqst *rqstp,
899 			 struct cb_process_state *cps)
900 {
901 	struct xdr_stream *xdr_out = &rqstp->rq_res_stream;
902 	struct callback_op *op = &callback_ops[0];
903 	unsigned int op_nr;
904 	__be32 status;
905 	long maxlen;
906 	__be32 res;
907 
908 	status = decode_op_hdr(&rqstp->rq_arg_stream, &op_nr);
909 	if (unlikely(status))
910 		return status;
911 
912 	switch (cps->minorversion) {
913 	case 0:
914 		status = preprocess_nfs4_op(op_nr, &op);
915 		break;
916 	case 1:
917 		status = preprocess_nfs41_op(nop, op_nr, &op);
918 		break;
919 	case 2:
920 		status = preprocess_nfs42_op(nop, op_nr, &op);
921 		break;
922 	default:
923 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
924 	}
925 
926 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
927 		op_nr = OP_CB_ILLEGAL;
928 	if (status)
929 		goto encode_hdr;
930 
931 	if (cps->drc_status) {
932 		status = cps->drc_status;
933 		goto encode_hdr;
934 	}
935 
936 	maxlen = xdr_out->end - xdr_out->p;
937 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
938 		status = op->decode_args(rqstp, &rqstp->rq_arg_stream,
939 					 rqstp->rq_argp);
940 		if (likely(status == 0))
941 			status = op->process_op(rqstp->rq_argp, rqstp->rq_resp,
942 						cps);
943 	} else
944 		status = htonl(NFS4ERR_RESOURCE);
945 
946 encode_hdr:
947 	res = encode_op_hdr(xdr_out, op_nr, status);
948 	if (unlikely(res))
949 		return res;
950 	if (op->encode_res != NULL && status == 0)
951 		status = op->encode_res(rqstp, xdr_out, rqstp->rq_resp);
952 	return status;
953 }
954 
955 /*
956  * Decode, process and encode a COMPOUND
957  */
958 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
959 {
960 	struct cb_compound_hdr_arg hdr_arg = { 0 };
961 	struct cb_compound_hdr_res hdr_res = { NULL };
962 	struct cb_process_state cps = {
963 		.drc_status = 0,
964 		.clp = NULL,
965 		.net = SVC_NET(rqstp),
966 	};
967 	unsigned int nops = 0;
968 	__be32 status;
969 
970 	status = decode_compound_hdr_arg(&rqstp->rq_arg_stream, &hdr_arg);
971 	if (status == htonl(NFS4ERR_RESOURCE))
972 		return rpc_garbage_args;
973 
974 	if (hdr_arg.minorversion == 0) {
975 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
976 		if (!cps.clp) {
977 			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
978 			goto out_invalidcred;
979 		}
980 		if (!check_gss_callback_principal(cps.clp, rqstp)) {
981 			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
982 			nfs_put_client(cps.clp);
983 			goto out_invalidcred;
984 		}
985 	}
986 
987 	cps.minorversion = hdr_arg.minorversion;
988 	hdr_res.taglen = hdr_arg.taglen;
989 	hdr_res.tag = hdr_arg.tag;
990 	if (encode_compound_hdr_res(&rqstp->rq_res_stream, &hdr_res) != 0) {
991 		if (cps.clp)
992 			nfs_put_client(cps.clp);
993 		return rpc_system_err;
994 	}
995 	while (status == 0 && nops != hdr_arg.nops) {
996 		status = process_op(nops, rqstp, &cps);
997 		nops++;
998 	}
999 
1000 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
1001 	* resource error in cb_compound status without returning op */
1002 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
1003 		status = htonl(NFS4ERR_RESOURCE);
1004 		nops--;
1005 	}
1006 
1007 	if (svc_is_backchannel(rqstp) && cps.clp) {
1008 		rqstp->bc_to_initval = cps.clp->cl_rpcclient->cl_timeout->to_initval;
1009 		rqstp->bc_to_retries = cps.clp->cl_rpcclient->cl_timeout->to_retries;
1010 	}
1011 
1012 	*hdr_res.status = status;
1013 	*hdr_res.nops = htonl(nops);
1014 	nfs4_cb_free_slot(&cps);
1015 	nfs_put_client(cps.clp);
1016 	return rpc_success;
1017 
1018 out_invalidcred:
1019 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
1020 	rqstp->rq_auth_stat = rpc_autherr_badcred;
1021 	return rpc_success;
1022 }
1023 
1024 static int
1025 nfs_callback_dispatch(struct svc_rqst *rqstp)
1026 {
1027 	const struct svc_procedure *procp = rqstp->rq_procinfo;
1028 
1029 	*rqstp->rq_accept_statp = procp->pc_func(rqstp);
1030 	return 1;
1031 }
1032 
1033 /*
1034  * Define NFS4 callback COMPOUND ops.
1035  */
1036 static struct callback_op callback_ops[] = {
1037 	[0] = {
1038 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
1039 	},
1040 	[OP_CB_GETATTR] = {
1041 		.process_op = nfs4_callback_getattr,
1042 		.decode_args = decode_getattr_args,
1043 		.encode_res = encode_getattr_res,
1044 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1045 	},
1046 	[OP_CB_RECALL] = {
1047 		.process_op = nfs4_callback_recall,
1048 		.decode_args = decode_recall_args,
1049 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1050 	},
1051 #if defined(CONFIG_NFS_V4_1)
1052 	[OP_CB_LAYOUTRECALL] = {
1053 		.process_op = nfs4_callback_layoutrecall,
1054 		.decode_args = decode_layoutrecall_args,
1055 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1056 	},
1057 	[OP_CB_NOTIFY_DEVICEID] = {
1058 		.process_op = nfs4_callback_devicenotify,
1059 		.decode_args = decode_devicenotify_args,
1060 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1061 	},
1062 	[OP_CB_SEQUENCE] = {
1063 		.process_op = nfs4_callback_sequence,
1064 		.decode_args = decode_cb_sequence_args,
1065 		.encode_res = encode_cb_sequence_res,
1066 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1067 	},
1068 	[OP_CB_RECALL_ANY] = {
1069 		.process_op = nfs4_callback_recallany,
1070 		.decode_args = decode_recallany_args,
1071 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1072 	},
1073 	[OP_CB_RECALL_SLOT] = {
1074 		.process_op = nfs4_callback_recallslot,
1075 		.decode_args = decode_recallslot_args,
1076 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1077 	},
1078 	[OP_CB_NOTIFY_LOCK] = {
1079 		.process_op = nfs4_callback_notify_lock,
1080 		.decode_args = decode_notify_lock_args,
1081 		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1082 	},
1083 #endif /* CONFIG_NFS_V4_1 */
1084 #ifdef CONFIG_NFS_V4_2
1085 	[OP_CB_OFFLOAD] = {
1086 		.process_op = nfs4_callback_offload,
1087 		.decode_args = decode_offload_args,
1088 		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1089 	},
1090 #endif /* CONFIG_NFS_V4_2 */
1091 };
1092 
1093 /*
1094  * Define NFS4 callback procedures
1095  */
1096 static const struct svc_procedure nfs4_callback_procedures1[] = {
1097 	[CB_NULL] = {
1098 		.pc_func = nfs4_callback_null,
1099 		.pc_encode = nfs4_encode_void,
1100 		.pc_xdrressize = 1,
1101 		.pc_name = "NULL",
1102 	},
1103 	[CB_COMPOUND] = {
1104 		.pc_func = nfs4_callback_compound,
1105 		.pc_encode = nfs4_encode_void,
1106 		.pc_argsize = 256,
1107 		.pc_argzero = 256,
1108 		.pc_ressize = 256,
1109 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1110 		.pc_name = "COMPOUND",
1111 	}
1112 };
1113 
1114 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1115 			      nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)]);
1116 const struct svc_version nfs4_callback_version1 = {
1117 	.vs_vers = 1,
1118 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1119 	.vs_proc = nfs4_callback_procedures1,
1120 	.vs_count = nfs4_callback_count1,
1121 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1122 	.vs_dispatch = nfs_callback_dispatch,
1123 	.vs_hidden = true,
1124 	.vs_need_cong_ctrl = true,
1125 };
1126 
1127 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1128 			      nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)]);
1129 const struct svc_version nfs4_callback_version4 = {
1130 	.vs_vers = 4,
1131 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1132 	.vs_proc = nfs4_callback_procedures1,
1133 	.vs_count = nfs4_callback_count4,
1134 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1135 	.vs_dispatch = nfs_callback_dispatch,
1136 	.vs_hidden = true,
1137 	.vs_need_cong_ctrl = true,
1138 };
1139