xref: /openbmc/linux/fs/nfs/callback_xdr.c (revision 5d331b7f)
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 
22 #define CB_OP_TAGLEN_MAXSZ		(512)
23 #define CB_OP_HDR_RES_MAXSZ		(2 * 4) // opcode, status
24 #define CB_OP_GETATTR_BITMAP_MAXSZ	(4 * 4) // bitmap length, 3 bitmaps
25 #define CB_OP_GETATTR_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ + \
26 					 CB_OP_GETATTR_BITMAP_MAXSZ + \
27 					 /* change, size, ctime, mtime */\
28 					 (2 + 2 + 3 + 3) * 4)
29 #define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
30 
31 #if defined(CONFIG_NFS_V4_1)
32 #define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
33 #define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
34 #define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
35 					 NFS4_MAX_SESSIONID_LEN + \
36 					 (1 + 3) * 4) // seqid, 3 slotids
37 #define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
38 #define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
39 #define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
40 #endif /* CONFIG_NFS_V4_1 */
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 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p)
66 {
67 	return xdr_argsize_check(rqstp, p);
68 }
69 
70 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p)
71 {
72 	return xdr_ressize_check(rqstp, p);
73 }
74 
75 static __be32 *read_buf(struct xdr_stream *xdr, size_t nbytes)
76 {
77 	__be32 *p;
78 
79 	p = xdr_inline_decode(xdr, nbytes);
80 	if (unlikely(p == NULL))
81 		printk(KERN_WARNING "NFS: NFSv4 callback reply buffer overflowed!\n");
82 	return p;
83 }
84 
85 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
86 		const char **str, size_t maxlen)
87 {
88 	ssize_t err;
89 
90 	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
91 	if (err < 0)
92 		return cpu_to_be32(NFS4ERR_RESOURCE);
93 	*len = err;
94 	return 0;
95 }
96 
97 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
98 {
99 	__be32 *p;
100 
101 	p = read_buf(xdr, 4);
102 	if (unlikely(p == NULL))
103 		return htonl(NFS4ERR_RESOURCE);
104 	fh->size = ntohl(*p);
105 	if (fh->size > NFS4_FHSIZE)
106 		return htonl(NFS4ERR_BADHANDLE);
107 	p = read_buf(xdr, fh->size);
108 	if (unlikely(p == NULL))
109 		return htonl(NFS4ERR_RESOURCE);
110 	memcpy(&fh->data[0], p, fh->size);
111 	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
112 	return 0;
113 }
114 
115 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
116 {
117 	__be32 *p;
118 	unsigned int attrlen;
119 
120 	p = read_buf(xdr, 4);
121 	if (unlikely(p == NULL))
122 		return htonl(NFS4ERR_RESOURCE);
123 	attrlen = ntohl(*p);
124 	p = read_buf(xdr, attrlen << 2);
125 	if (unlikely(p == NULL))
126 		return htonl(NFS4ERR_RESOURCE);
127 	if (likely(attrlen > 0))
128 		bitmap[0] = ntohl(*p++);
129 	if (attrlen > 1)
130 		bitmap[1] = ntohl(*p);
131 	return 0;
132 }
133 
134 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
135 {
136 	__be32 *p;
137 
138 	p = read_buf(xdr, NFS4_STATEID_SIZE);
139 	if (unlikely(p == NULL))
140 		return htonl(NFS4ERR_RESOURCE);
141 	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
142 	return 0;
143 }
144 
145 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
146 {
147 	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
148 	return decode_stateid(xdr, stateid);
149 }
150 
151 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
152 {
153 	__be32 *p;
154 	__be32 status;
155 
156 	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
157 	if (unlikely(status != 0))
158 		return status;
159 	p = read_buf(xdr, 12);
160 	if (unlikely(p == NULL))
161 		return htonl(NFS4ERR_RESOURCE);
162 	hdr->minorversion = ntohl(*p++);
163 	/* Check for minor version support */
164 	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
165 		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
166 	} else {
167 		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
168 			"illegal minor version %u!\n",
169 			__func__, hdr->minorversion);
170 		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
171 	}
172 	hdr->nops = ntohl(*p);
173 	return 0;
174 }
175 
176 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
177 {
178 	__be32 *p;
179 	p = read_buf(xdr, 4);
180 	if (unlikely(p == NULL))
181 		return htonl(NFS4ERR_RESOURCE_HDR);
182 	*op = ntohl(*p);
183 	return 0;
184 }
185 
186 static __be32 decode_getattr_args(struct svc_rqst *rqstp,
187 		struct xdr_stream *xdr, void *argp)
188 {
189 	struct cb_getattrargs *args = argp;
190 	__be32 status;
191 
192 	status = decode_fh(xdr, &args->fh);
193 	if (unlikely(status != 0))
194 		return status;
195 	return decode_bitmap(xdr, args->bitmap);
196 }
197 
198 static __be32 decode_recall_args(struct svc_rqst *rqstp,
199 		struct xdr_stream *xdr, void *argp)
200 {
201 	struct cb_recallargs *args = argp;
202 	__be32 *p;
203 	__be32 status;
204 
205 	status = decode_delegation_stateid(xdr, &args->stateid);
206 	if (unlikely(status != 0))
207 		return status;
208 	p = read_buf(xdr, 4);
209 	if (unlikely(p == NULL))
210 		return htonl(NFS4ERR_RESOURCE);
211 	args->truncate = ntohl(*p);
212 	return decode_fh(xdr, &args->fh);
213 }
214 
215 #if defined(CONFIG_NFS_V4_1)
216 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
217 {
218 	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
219 	return decode_stateid(xdr, stateid);
220 }
221 
222 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
223 				       struct xdr_stream *xdr, void *argp)
224 {
225 	struct cb_layoutrecallargs *args = argp;
226 	__be32 *p;
227 	__be32 status = 0;
228 	uint32_t iomode;
229 
230 	p = read_buf(xdr, 4 * sizeof(uint32_t));
231 	if (unlikely(p == NULL))
232 		return htonl(NFS4ERR_BADXDR);
233 
234 	args->cbl_layout_type = ntohl(*p++);
235 	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
236 	 * as it is unusable and ignored with the other types.
237 	 */
238 	iomode = ntohl(*p++);
239 	args->cbl_layoutchanged = ntohl(*p++);
240 	args->cbl_recall_type = ntohl(*p++);
241 
242 	if (args->cbl_recall_type == RETURN_FILE) {
243 		args->cbl_range.iomode = iomode;
244 		status = decode_fh(xdr, &args->cbl_fh);
245 		if (unlikely(status != 0))
246 			return status;
247 
248 		p = read_buf(xdr, 2 * sizeof(uint64_t));
249 		if (unlikely(p == NULL))
250 			return htonl(NFS4ERR_BADXDR);
251 		p = xdr_decode_hyper(p, &args->cbl_range.offset);
252 		p = xdr_decode_hyper(p, &args->cbl_range.length);
253 		return decode_layout_stateid(xdr, &args->cbl_stateid);
254 	} else if (args->cbl_recall_type == RETURN_FSID) {
255 		p = read_buf(xdr, 2 * sizeof(uint64_t));
256 		if (unlikely(p == NULL))
257 			return htonl(NFS4ERR_BADXDR);
258 		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
259 		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
260 	} else if (args->cbl_recall_type != RETURN_ALL)
261 		return htonl(NFS4ERR_BADXDR);
262 	return 0;
263 }
264 
265 static
266 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
267 				struct xdr_stream *xdr,
268 				void *argp)
269 {
270 	struct cb_devicenotifyargs *args = argp;
271 	__be32 *p;
272 	__be32 status = 0;
273 	u32 tmp;
274 	int n, i;
275 	args->ndevs = 0;
276 
277 	/* Num of device notifications */
278 	p = read_buf(xdr, sizeof(uint32_t));
279 	if (unlikely(p == NULL)) {
280 		status = htonl(NFS4ERR_BADXDR);
281 		goto out;
282 	}
283 	n = ntohl(*p++);
284 	if (n <= 0)
285 		goto out;
286 	if (n > ULONG_MAX / sizeof(*args->devs)) {
287 		status = htonl(NFS4ERR_BADXDR);
288 		goto out;
289 	}
290 
291 	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
292 	if (!args->devs) {
293 		status = htonl(NFS4ERR_DELAY);
294 		goto out;
295 	}
296 
297 	/* Decode each dev notification */
298 	for (i = 0; i < n; i++) {
299 		struct cb_devicenotifyitem *dev = &args->devs[i];
300 
301 		p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
302 		if (unlikely(p == NULL)) {
303 			status = htonl(NFS4ERR_BADXDR);
304 			goto err;
305 		}
306 
307 		tmp = ntohl(*p++);	/* bitmap size */
308 		if (tmp != 1) {
309 			status = htonl(NFS4ERR_INVAL);
310 			goto err;
311 		}
312 		dev->cbd_notify_type = ntohl(*p++);
313 		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
314 		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
315 			status = htonl(NFS4ERR_INVAL);
316 			goto err;
317 		}
318 
319 		tmp = ntohl(*p++);	/* opaque size */
320 		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
321 		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
322 		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
323 		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
324 			status = htonl(NFS4ERR_INVAL);
325 			goto err;
326 		}
327 		dev->cbd_layout_type = ntohl(*p++);
328 		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
329 		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
330 
331 		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
332 			p = read_buf(xdr, sizeof(uint32_t));
333 			if (unlikely(p == NULL)) {
334 				status = htonl(NFS4ERR_BADXDR);
335 				goto err;
336 			}
337 			dev->cbd_immediate = ntohl(*p++);
338 		} else {
339 			dev->cbd_immediate = 0;
340 		}
341 
342 		args->ndevs++;
343 
344 		dprintk("%s: type %d layout 0x%x immediate %d\n",
345 			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
346 			dev->cbd_immediate);
347 	}
348 out:
349 	dprintk("%s: status %d ndevs %d\n",
350 		__func__, ntohl(status), args->ndevs);
351 	return status;
352 err:
353 	kfree(args->devs);
354 	goto out;
355 }
356 
357 static __be32 decode_sessionid(struct xdr_stream *xdr,
358 				 struct nfs4_sessionid *sid)
359 {
360 	__be32 *p;
361 
362 	p = read_buf(xdr, NFS4_MAX_SESSIONID_LEN);
363 	if (unlikely(p == NULL))
364 		return htonl(NFS4ERR_RESOURCE);
365 
366 	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
367 	return 0;
368 }
369 
370 static __be32 decode_rc_list(struct xdr_stream *xdr,
371 			       struct referring_call_list *rc_list)
372 {
373 	__be32 *p;
374 	int i;
375 	__be32 status;
376 
377 	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
378 	if (status)
379 		goto out;
380 
381 	status = htonl(NFS4ERR_RESOURCE);
382 	p = read_buf(xdr, sizeof(uint32_t));
383 	if (unlikely(p == NULL))
384 		goto out;
385 
386 	rc_list->rcl_nrefcalls = ntohl(*p++);
387 	if (rc_list->rcl_nrefcalls) {
388 		p = read_buf(xdr,
389 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
390 		if (unlikely(p == NULL))
391 			goto out;
392 		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
393 						sizeof(*rc_list->rcl_refcalls),
394 						GFP_KERNEL);
395 		if (unlikely(rc_list->rcl_refcalls == NULL))
396 			goto out;
397 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
398 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
399 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
400 		}
401 	}
402 	status = 0;
403 
404 out:
405 	return status;
406 }
407 
408 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
409 					struct xdr_stream *xdr,
410 					void *argp)
411 {
412 	struct cb_sequenceargs *args = argp;
413 	__be32 *p;
414 	int i;
415 	__be32 status;
416 
417 	status = decode_sessionid(xdr, &args->csa_sessionid);
418 	if (status)
419 		return status;
420 
421 	p = read_buf(xdr, 5 * sizeof(uint32_t));
422 	if (unlikely(p == NULL))
423 		return htonl(NFS4ERR_RESOURCE);
424 
425 	args->csa_addr = svc_addr(rqstp);
426 	args->csa_sequenceid = ntohl(*p++);
427 	args->csa_slotid = ntohl(*p++);
428 	args->csa_highestslotid = ntohl(*p++);
429 	args->csa_cachethis = ntohl(*p++);
430 	args->csa_nrclists = ntohl(*p++);
431 	args->csa_rclists = NULL;
432 	if (args->csa_nrclists) {
433 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
434 						  sizeof(*args->csa_rclists),
435 						  GFP_KERNEL);
436 		if (unlikely(args->csa_rclists == NULL))
437 			return htonl(NFS4ERR_RESOURCE);
438 
439 		for (i = 0; i < args->csa_nrclists; i++) {
440 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
441 			if (status) {
442 				args->csa_nrclists = i;
443 				goto out_free;
444 			}
445 		}
446 	}
447 	return 0;
448 
449 out_free:
450 	for (i = 0; i < args->csa_nrclists; i++)
451 		kfree(args->csa_rclists[i].rcl_refcalls);
452 	kfree(args->csa_rclists);
453 	return status;
454 }
455 
456 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
457 				      struct xdr_stream *xdr,
458 				      void *argp)
459 {
460 	struct cb_recallanyargs *args = argp;
461 	uint32_t bitmap[2];
462 	__be32 *p, status;
463 
464 	p = read_buf(xdr, 4);
465 	if (unlikely(p == NULL))
466 		return htonl(NFS4ERR_BADXDR);
467 	args->craa_objs_to_keep = ntohl(*p++);
468 	status = decode_bitmap(xdr, bitmap);
469 	if (unlikely(status))
470 		return status;
471 	args->craa_type_mask = bitmap[0];
472 
473 	return 0;
474 }
475 
476 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
477 					struct xdr_stream *xdr,
478 					void *argp)
479 {
480 	struct cb_recallslotargs *args = argp;
481 	__be32 *p;
482 
483 	p = read_buf(xdr, 4);
484 	if (unlikely(p == NULL))
485 		return htonl(NFS4ERR_BADXDR);
486 	args->crsa_target_highest_slotid = ntohl(*p++);
487 	return 0;
488 }
489 
490 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
491 {
492 	__be32		*p;
493 	unsigned int	len;
494 
495 	p = read_buf(xdr, 12);
496 	if (unlikely(p == NULL))
497 		return htonl(NFS4ERR_BADXDR);
498 
499 	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
500 	len = be32_to_cpu(*p);
501 
502 	p = read_buf(xdr, len);
503 	if (unlikely(p == NULL))
504 		return htonl(NFS4ERR_BADXDR);
505 
506 	/* Only try to decode if the length is right */
507 	if (len == 20) {
508 		p += 2;	/* skip "lock id:" */
509 		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
510 		xdr_decode_hyper(p, &args->cbnl_owner.id);
511 		args->cbnl_valid = true;
512 	} else {
513 		args->cbnl_owner.s_dev = 0;
514 		args->cbnl_owner.id = 0;
515 		args->cbnl_valid = false;
516 	}
517 	return 0;
518 }
519 
520 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
521 		struct xdr_stream *xdr, void *argp)
522 {
523 	struct cb_notify_lock_args *args = argp;
524 	__be32 status;
525 
526 	status = decode_fh(xdr, &args->cbnl_fh);
527 	if (unlikely(status != 0))
528 		return status;
529 	return decode_lockowner(xdr, args);
530 }
531 
532 #endif /* CONFIG_NFS_V4_1 */
533 #ifdef CONFIG_NFS_V4_2
534 static __be32 decode_write_response(struct xdr_stream *xdr,
535 					struct cb_offloadargs *args)
536 {
537 	__be32 *p;
538 
539 	/* skip the always zero field */
540 	p = read_buf(xdr, 4);
541 	if (unlikely(!p))
542 		goto out;
543 	p++;
544 
545 	/* decode count, stable_how, verifier */
546 	p = xdr_inline_decode(xdr, 8 + 4);
547 	if (unlikely(!p))
548 		goto out;
549 	p = xdr_decode_hyper(p, &args->wr_count);
550 	args->wr_writeverf.committed = be32_to_cpup(p);
551 	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
552 	if (likely(p)) {
553 		memcpy(&args->wr_writeverf.verifier.data[0], p,
554 			NFS4_VERIFIER_SIZE);
555 		return 0;
556 	}
557 out:
558 	return htonl(NFS4ERR_RESOURCE);
559 }
560 
561 static __be32 decode_offload_args(struct svc_rqst *rqstp,
562 					struct xdr_stream *xdr,
563 					void *data)
564 {
565 	struct cb_offloadargs *args = data;
566 	__be32 *p;
567 	__be32 status;
568 
569 	/* decode fh */
570 	status = decode_fh(xdr, &args->coa_fh);
571 	if (unlikely(status != 0))
572 		return status;
573 
574 	/* decode stateid */
575 	status = decode_stateid(xdr, &args->coa_stateid);
576 	if (unlikely(status != 0))
577 		return status;
578 
579 	/* decode status */
580 	p = read_buf(xdr, 4);
581 	if (unlikely(!p))
582 		goto out;
583 	args->error = ntohl(*p++);
584 	if (!args->error) {
585 		status = decode_write_response(xdr, args);
586 		if (unlikely(status != 0))
587 			return status;
588 	} else {
589 		p = xdr_inline_decode(xdr, 8);
590 		if (unlikely(!p))
591 			goto out;
592 		p = xdr_decode_hyper(p, &args->wr_count);
593 	}
594 	return 0;
595 out:
596 	return htonl(NFS4ERR_RESOURCE);
597 }
598 #endif /* CONFIG_NFS_V4_2 */
599 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
600 {
601 	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
602 		return cpu_to_be32(NFS4ERR_RESOURCE);
603 	return 0;
604 }
605 
606 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
607 {
608 	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
609 		return cpu_to_be32(NFS4ERR_RESOURCE);
610 	return 0;
611 }
612 
613 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
614 {
615 	__be32 *p;
616 
617 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
618 		return 0;
619 	p = xdr_reserve_space(xdr, 8);
620 	if (unlikely(!p))
621 		return htonl(NFS4ERR_RESOURCE);
622 	p = xdr_encode_hyper(p, change);
623 	return 0;
624 }
625 
626 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
627 {
628 	__be32 *p;
629 
630 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
631 		return 0;
632 	p = xdr_reserve_space(xdr, 8);
633 	if (unlikely(!p))
634 		return htonl(NFS4ERR_RESOURCE);
635 	p = xdr_encode_hyper(p, size);
636 	return 0;
637 }
638 
639 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
640 {
641 	__be32 *p;
642 
643 	p = xdr_reserve_space(xdr, 12);
644 	if (unlikely(!p))
645 		return htonl(NFS4ERR_RESOURCE);
646 	p = xdr_encode_hyper(p, time->tv_sec);
647 	*p = htonl(time->tv_nsec);
648 	return 0;
649 }
650 
651 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
652 {
653 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
654 		return 0;
655 	return encode_attr_time(xdr,time);
656 }
657 
658 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
659 {
660 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
661 		return 0;
662 	return encode_attr_time(xdr,time);
663 }
664 
665 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
666 {
667 	__be32 status;
668 
669 	hdr->status = xdr_reserve_space(xdr, 4);
670 	if (unlikely(hdr->status == NULL))
671 		return htonl(NFS4ERR_RESOURCE);
672 	status = encode_string(xdr, hdr->taglen, hdr->tag);
673 	if (unlikely(status != 0))
674 		return status;
675 	hdr->nops = xdr_reserve_space(xdr, 4);
676 	if (unlikely(hdr->nops == NULL))
677 		return htonl(NFS4ERR_RESOURCE);
678 	return 0;
679 }
680 
681 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
682 {
683 	__be32 *p;
684 
685 	p = xdr_reserve_space(xdr, 8);
686 	if (unlikely(p == NULL))
687 		return htonl(NFS4ERR_RESOURCE_HDR);
688 	*p++ = htonl(op);
689 	*p = res;
690 	return 0;
691 }
692 
693 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
694 		const void *resp)
695 {
696 	const struct cb_getattrres *res = resp;
697 	__be32 *savep = NULL;
698 	__be32 status = res->status;
699 
700 	if (unlikely(status != 0))
701 		goto out;
702 	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
703 	if (unlikely(status != 0))
704 		goto out;
705 	status = cpu_to_be32(NFS4ERR_RESOURCE);
706 	savep = xdr_reserve_space(xdr, sizeof(*savep));
707 	if (unlikely(!savep))
708 		goto out;
709 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
710 	if (unlikely(status != 0))
711 		goto out;
712 	status = encode_attr_size(xdr, res->bitmap, res->size);
713 	if (unlikely(status != 0))
714 		goto out;
715 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
716 	if (unlikely(status != 0))
717 		goto out;
718 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
719 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
720 out:
721 	return status;
722 }
723 
724 #if defined(CONFIG_NFS_V4_1)
725 
726 static __be32 encode_sessionid(struct xdr_stream *xdr,
727 				 const struct nfs4_sessionid *sid)
728 {
729 	__be32 *p;
730 
731 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
732 	if (unlikely(p == NULL))
733 		return htonl(NFS4ERR_RESOURCE);
734 
735 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
736 	return 0;
737 }
738 
739 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
740 				       struct xdr_stream *xdr,
741 				       const void *resp)
742 {
743 	const struct cb_sequenceres *res = resp;
744 	__be32 *p;
745 	__be32 status = res->csr_status;
746 
747 	if (unlikely(status != 0))
748 		return status;
749 
750 	status = encode_sessionid(xdr, &res->csr_sessionid);
751 	if (status)
752 		return status;
753 
754 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
755 	if (unlikely(p == NULL))
756 		return htonl(NFS4ERR_RESOURCE);
757 
758 	*p++ = htonl(res->csr_sequenceid);
759 	*p++ = htonl(res->csr_slotid);
760 	*p++ = htonl(res->csr_highestslotid);
761 	*p++ = htonl(res->csr_target_highestslotid);
762 	return 0;
763 }
764 
765 static __be32
766 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
767 {
768 	if (op_nr == OP_CB_SEQUENCE) {
769 		if (nop != 0)
770 			return htonl(NFS4ERR_SEQUENCE_POS);
771 	} else {
772 		if (nop == 0)
773 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
774 	}
775 
776 	switch (op_nr) {
777 	case OP_CB_GETATTR:
778 	case OP_CB_RECALL:
779 	case OP_CB_SEQUENCE:
780 	case OP_CB_RECALL_ANY:
781 	case OP_CB_RECALL_SLOT:
782 	case OP_CB_LAYOUTRECALL:
783 	case OP_CB_NOTIFY_DEVICEID:
784 	case OP_CB_NOTIFY_LOCK:
785 		*op = &callback_ops[op_nr];
786 		break;
787 
788 	case OP_CB_NOTIFY:
789 	case OP_CB_PUSH_DELEG:
790 	case OP_CB_RECALLABLE_OBJ_AVAIL:
791 	case OP_CB_WANTS_CANCELLED:
792 		return htonl(NFS4ERR_NOTSUPP);
793 
794 	default:
795 		return htonl(NFS4ERR_OP_ILLEGAL);
796 	}
797 
798 	return htonl(NFS_OK);
799 }
800 
801 static void nfs4_callback_free_slot(struct nfs4_session *session,
802 		struct nfs4_slot *slot)
803 {
804 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
805 
806 	spin_lock(&tbl->slot_tbl_lock);
807 	/*
808 	 * Let the state manager know callback processing done.
809 	 * A single slot, so highest used slotid is either 0 or -1
810 	 */
811 	nfs4_free_slot(tbl, slot);
812 	spin_unlock(&tbl->slot_tbl_lock);
813 }
814 
815 static void nfs4_cb_free_slot(struct cb_process_state *cps)
816 {
817 	if (cps->slot) {
818 		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
819 		cps->slot = NULL;
820 	}
821 }
822 
823 #else /* CONFIG_NFS_V4_1 */
824 
825 static __be32
826 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
827 {
828 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
829 }
830 
831 static void nfs4_cb_free_slot(struct cb_process_state *cps)
832 {
833 }
834 #endif /* CONFIG_NFS_V4_1 */
835 
836 #ifdef CONFIG_NFS_V4_2
837 static __be32
838 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
839 {
840 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
841 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
842 		return status;
843 
844 	if (op_nr == OP_CB_OFFLOAD) {
845 		*op = &callback_ops[op_nr];
846 		return htonl(NFS_OK);
847 	} else
848 		return htonl(NFS4ERR_NOTSUPP);
849 	return htonl(NFS4ERR_OP_ILLEGAL);
850 }
851 #else /* CONFIG_NFS_V4_2 */
852 static __be32
853 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
854 {
855 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
856 }
857 #endif /* CONFIG_NFS_V4_2 */
858 
859 static __be32
860 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
861 {
862 	switch (op_nr) {
863 	case OP_CB_GETATTR:
864 	case OP_CB_RECALL:
865 		*op = &callback_ops[op_nr];
866 		break;
867 	default:
868 		return htonl(NFS4ERR_OP_ILLEGAL);
869 	}
870 
871 	return htonl(NFS_OK);
872 }
873 
874 static __be32 process_op(int nop, struct svc_rqst *rqstp,
875 		struct xdr_stream *xdr_in, void *argp,
876 		struct xdr_stream *xdr_out, void *resp,
877 		struct cb_process_state *cps)
878 {
879 	struct callback_op *op = &callback_ops[0];
880 	unsigned int op_nr;
881 	__be32 status;
882 	long maxlen;
883 	__be32 res;
884 
885 	status = decode_op_hdr(xdr_in, &op_nr);
886 	if (unlikely(status))
887 		return status;
888 
889 	switch (cps->minorversion) {
890 	case 0:
891 		status = preprocess_nfs4_op(op_nr, &op);
892 		break;
893 	case 1:
894 		status = preprocess_nfs41_op(nop, op_nr, &op);
895 		break;
896 	case 2:
897 		status = preprocess_nfs42_op(nop, op_nr, &op);
898 		break;
899 	default:
900 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
901 	}
902 
903 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
904 		op_nr = OP_CB_ILLEGAL;
905 	if (status)
906 		goto encode_hdr;
907 
908 	if (cps->drc_status) {
909 		status = cps->drc_status;
910 		goto encode_hdr;
911 	}
912 
913 	maxlen = xdr_out->end - xdr_out->p;
914 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
915 		status = op->decode_args(rqstp, xdr_in, argp);
916 		if (likely(status == 0))
917 			status = op->process_op(argp, resp, cps);
918 	} else
919 		status = htonl(NFS4ERR_RESOURCE);
920 
921 encode_hdr:
922 	res = encode_op_hdr(xdr_out, op_nr, status);
923 	if (unlikely(res))
924 		return res;
925 	if (op->encode_res != NULL && status == 0)
926 		status = op->encode_res(rqstp, xdr_out, resp);
927 	return status;
928 }
929 
930 /*
931  * Decode, process and encode a COMPOUND
932  */
933 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
934 {
935 	struct cb_compound_hdr_arg hdr_arg = { 0 };
936 	struct cb_compound_hdr_res hdr_res = { NULL };
937 	struct xdr_stream xdr_in, xdr_out;
938 	__be32 *p, status;
939 	struct cb_process_state cps = {
940 		.drc_status = 0,
941 		.clp = NULL,
942 		.net = SVC_NET(rqstp),
943 	};
944 	unsigned int nops = 0;
945 
946 	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
947 
948 	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
949 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
950 
951 	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
952 	if (status == htonl(NFS4ERR_RESOURCE))
953 		return rpc_garbage_args;
954 
955 	if (hdr_arg.minorversion == 0) {
956 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
957 		if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp)) {
958 			if (cps.clp)
959 				nfs_put_client(cps.clp);
960 			goto out_invalidcred;
961 		}
962 	}
963 
964 	cps.minorversion = hdr_arg.minorversion;
965 	hdr_res.taglen = hdr_arg.taglen;
966 	hdr_res.tag = hdr_arg.tag;
967 	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0) {
968 		if (cps.clp)
969 			nfs_put_client(cps.clp);
970 		return rpc_system_err;
971 	}
972 	while (status == 0 && nops != hdr_arg.nops) {
973 		status = process_op(nops, rqstp, &xdr_in,
974 				    rqstp->rq_argp, &xdr_out, rqstp->rq_resp,
975 				    &cps);
976 		nops++;
977 	}
978 
979 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
980 	* resource error in cb_compound status without returning op */
981 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
982 		status = htonl(NFS4ERR_RESOURCE);
983 		nops--;
984 	}
985 
986 	*hdr_res.status = status;
987 	*hdr_res.nops = htonl(nops);
988 	nfs4_cb_free_slot(&cps);
989 	nfs_put_client(cps.clp);
990 	return rpc_success;
991 
992 out_invalidcred:
993 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
994 	return rpc_autherr_badcred;
995 }
996 
997 /*
998  * Define NFS4 callback COMPOUND ops.
999  */
1000 static struct callback_op callback_ops[] = {
1001 	[0] = {
1002 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
1003 	},
1004 	[OP_CB_GETATTR] = {
1005 		.process_op = nfs4_callback_getattr,
1006 		.decode_args = decode_getattr_args,
1007 		.encode_res = encode_getattr_res,
1008 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1009 	},
1010 	[OP_CB_RECALL] = {
1011 		.process_op = nfs4_callback_recall,
1012 		.decode_args = decode_recall_args,
1013 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1014 	},
1015 #if defined(CONFIG_NFS_V4_1)
1016 	[OP_CB_LAYOUTRECALL] = {
1017 		.process_op = nfs4_callback_layoutrecall,
1018 		.decode_args = decode_layoutrecall_args,
1019 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1020 	},
1021 	[OP_CB_NOTIFY_DEVICEID] = {
1022 		.process_op = nfs4_callback_devicenotify,
1023 		.decode_args = decode_devicenotify_args,
1024 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1025 	},
1026 	[OP_CB_SEQUENCE] = {
1027 		.process_op = nfs4_callback_sequence,
1028 		.decode_args = decode_cb_sequence_args,
1029 		.encode_res = encode_cb_sequence_res,
1030 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1031 	},
1032 	[OP_CB_RECALL_ANY] = {
1033 		.process_op = nfs4_callback_recallany,
1034 		.decode_args = decode_recallany_args,
1035 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1036 	},
1037 	[OP_CB_RECALL_SLOT] = {
1038 		.process_op = nfs4_callback_recallslot,
1039 		.decode_args = decode_recallslot_args,
1040 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1041 	},
1042 	[OP_CB_NOTIFY_LOCK] = {
1043 		.process_op = nfs4_callback_notify_lock,
1044 		.decode_args = decode_notify_lock_args,
1045 		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1046 	},
1047 #endif /* CONFIG_NFS_V4_1 */
1048 #ifdef CONFIG_NFS_V4_2
1049 	[OP_CB_OFFLOAD] = {
1050 		.process_op = nfs4_callback_offload,
1051 		.decode_args = decode_offload_args,
1052 		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1053 	},
1054 #endif /* CONFIG_NFS_V4_2 */
1055 };
1056 
1057 /*
1058  * Define NFS4 callback procedures
1059  */
1060 static const struct svc_procedure nfs4_callback_procedures1[] = {
1061 	[CB_NULL] = {
1062 		.pc_func = nfs4_callback_null,
1063 		.pc_decode = nfs4_decode_void,
1064 		.pc_encode = nfs4_encode_void,
1065 		.pc_xdrressize = 1,
1066 	},
1067 	[CB_COMPOUND] = {
1068 		.pc_func = nfs4_callback_compound,
1069 		.pc_encode = nfs4_encode_void,
1070 		.pc_argsize = 256,
1071 		.pc_ressize = 256,
1072 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1073 	}
1074 };
1075 
1076 static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
1077 const struct svc_version nfs4_callback_version1 = {
1078 	.vs_vers = 1,
1079 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1080 	.vs_proc = nfs4_callback_procedures1,
1081 	.vs_count = nfs4_callback_count1,
1082 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1083 	.vs_dispatch = NULL,
1084 	.vs_hidden = true,
1085 	.vs_need_cong_ctrl = true,
1086 };
1087 
1088 static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
1089 const struct svc_version nfs4_callback_version4 = {
1090 	.vs_vers = 4,
1091 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1092 	.vs_proc = nfs4_callback_procedures1,
1093 	.vs_count = nfs4_callback_count4,
1094 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1095 	.vs_dispatch = NULL,
1096 	.vs_hidden = true,
1097 	.vs_need_cong_ctrl = true,
1098 };
1099