xref: /openbmc/linux/fs/nfs/callback_xdr.c (revision b737eecd)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/fs/nfs/callback_xdr.c
4  *
5  * Copyright (C) 2004 Trond Myklebust
6  *
7  * NFSv4 callback encode/decode procedures
8  */
9 #include <linux/kernel.h>
10 #include <linux/sunrpc/svc.h>
11 #include <linux/nfs4.h>
12 #include <linux/nfs_fs.h>
13 #include <linux/ratelimit.h>
14 #include <linux/printk.h>
15 #include <linux/slab.h>
16 #include <linux/sunrpc/bc_xprt.h>
17 #include "nfs4_fs.h"
18 #include "callback.h"
19 #include "internal.h"
20 #include "nfs4session.h"
21 #include "nfs4trace.h"
22 
23 #define CB_OP_TAGLEN_MAXSZ		(512)
24 #define CB_OP_HDR_RES_MAXSZ		(2 * 4) // opcode, status
25 #define CB_OP_GETATTR_BITMAP_MAXSZ	(4 * 4) // bitmap length, 3 bitmaps
26 #define CB_OP_GETATTR_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ + \
27 					 CB_OP_GETATTR_BITMAP_MAXSZ + \
28 					 /* change, size, ctime, mtime */\
29 					 (2 + 2 + 3 + 3) * 4)
30 #define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
31 
32 #if defined(CONFIG_NFS_V4_1)
33 #define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
34 #define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
35 #define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
36 					 NFS4_MAX_SESSIONID_LEN + \
37 					 (1 + 3) * 4) // seqid, 3 slotids
38 #define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
39 #define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
40 #define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
41 #endif /* CONFIG_NFS_V4_1 */
42 #ifdef CONFIG_NFS_V4_2
43 #define CB_OP_OFFLOAD_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
44 #endif /* CONFIG_NFS_V4_2 */
45 
46 #define NFSDBG_FACILITY NFSDBG_CALLBACK
47 
48 /* Internal error code */
49 #define NFS4ERR_RESOURCE_HDR	11050
50 
51 struct callback_op {
52 	__be32 (*process_op)(void *, void *, struct cb_process_state *);
53 	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
54 	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
55 			const void *);
56 	long res_maxsize;
57 };
58 
59 static struct callback_op callback_ops[];
60 
61 static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
62 {
63 	return htonl(NFS4_OK);
64 }
65 
66 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p)
67 {
68 	return xdr_argsize_check(rqstp, p);
69 }
70 
71 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p)
72 {
73 	return xdr_ressize_check(rqstp, p);
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 	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 #if defined(CONFIG_NFS_V4_1)
207 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
208 {
209 	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
210 	return decode_stateid(xdr, stateid);
211 }
212 
213 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
214 				       struct xdr_stream *xdr, void *argp)
215 {
216 	struct cb_layoutrecallargs *args = argp;
217 	__be32 *p;
218 	__be32 status = 0;
219 	uint32_t iomode;
220 
221 	p = xdr_inline_decode(xdr, 4 * sizeof(uint32_t));
222 	if (unlikely(p == NULL))
223 		return htonl(NFS4ERR_BADXDR);
224 
225 	args->cbl_layout_type = ntohl(*p++);
226 	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
227 	 * as it is unusable and ignored with the other types.
228 	 */
229 	iomode = ntohl(*p++);
230 	args->cbl_layoutchanged = ntohl(*p++);
231 	args->cbl_recall_type = ntohl(*p++);
232 
233 	if (args->cbl_recall_type == RETURN_FILE) {
234 		args->cbl_range.iomode = iomode;
235 		status = decode_fh(xdr, &args->cbl_fh);
236 		if (unlikely(status != 0))
237 			return status;
238 
239 		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
240 		if (unlikely(p == NULL))
241 			return htonl(NFS4ERR_BADXDR);
242 		p = xdr_decode_hyper(p, &args->cbl_range.offset);
243 		p = xdr_decode_hyper(p, &args->cbl_range.length);
244 		return decode_layout_stateid(xdr, &args->cbl_stateid);
245 	} else if (args->cbl_recall_type == RETURN_FSID) {
246 		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
247 		if (unlikely(p == NULL))
248 			return htonl(NFS4ERR_BADXDR);
249 		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
250 		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
251 	} else if (args->cbl_recall_type != RETURN_ALL)
252 		return htonl(NFS4ERR_BADXDR);
253 	return 0;
254 }
255 
256 static
257 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
258 				struct xdr_stream *xdr,
259 				void *argp)
260 {
261 	struct cb_devicenotifyargs *args = argp;
262 	__be32 *p;
263 	__be32 status = 0;
264 	u32 tmp;
265 	int n, i;
266 	args->ndevs = 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 	if (n > ULONG_MAX / sizeof(*args->devs)) {
278 		status = htonl(NFS4ERR_BADXDR);
279 		goto out;
280 	}
281 
282 	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
283 	if (!args->devs) {
284 		status = htonl(NFS4ERR_DELAY);
285 		goto out;
286 	}
287 
288 	/* Decode each dev notification */
289 	for (i = 0; i < n; i++) {
290 		struct cb_devicenotifyitem *dev = &args->devs[i];
291 
292 		p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
293 				      NFS4_DEVICEID4_SIZE);
294 		if (unlikely(p == NULL)) {
295 			status = htonl(NFS4ERR_BADXDR);
296 			goto err;
297 		}
298 
299 		tmp = ntohl(*p++);	/* bitmap size */
300 		if (tmp != 1) {
301 			status = htonl(NFS4ERR_INVAL);
302 			goto err;
303 		}
304 		dev->cbd_notify_type = ntohl(*p++);
305 		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
306 		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
307 			status = htonl(NFS4ERR_INVAL);
308 			goto err;
309 		}
310 
311 		tmp = ntohl(*p++);	/* opaque size */
312 		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
313 		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
314 		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
315 		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
316 			status = htonl(NFS4ERR_INVAL);
317 			goto err;
318 		}
319 		dev->cbd_layout_type = ntohl(*p++);
320 		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
321 		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
322 
323 		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
324 			p = xdr_inline_decode(xdr, sizeof(uint32_t));
325 			if (unlikely(p == NULL)) {
326 				status = htonl(NFS4ERR_BADXDR);
327 				goto err;
328 			}
329 			dev->cbd_immediate = ntohl(*p++);
330 		} else {
331 			dev->cbd_immediate = 0;
332 		}
333 
334 		args->ndevs++;
335 
336 		dprintk("%s: type %d layout 0x%x immediate %d\n",
337 			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
338 			dev->cbd_immediate);
339 	}
340 out:
341 	dprintk("%s: status %d ndevs %d\n",
342 		__func__, ntohl(status), args->ndevs);
343 	return status;
344 err:
345 	kfree(args->devs);
346 	goto out;
347 }
348 
349 static __be32 decode_sessionid(struct xdr_stream *xdr,
350 				 struct nfs4_sessionid *sid)
351 {
352 	__be32 *p;
353 
354 	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
355 	if (unlikely(p == NULL))
356 		return htonl(NFS4ERR_RESOURCE);
357 
358 	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
359 	return 0;
360 }
361 
362 static __be32 decode_rc_list(struct xdr_stream *xdr,
363 			       struct referring_call_list *rc_list)
364 {
365 	__be32 *p;
366 	int i;
367 	__be32 status;
368 
369 	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
370 	if (status)
371 		goto out;
372 
373 	status = htonl(NFS4ERR_RESOURCE);
374 	p = xdr_inline_decode(xdr, sizeof(uint32_t));
375 	if (unlikely(p == NULL))
376 		goto out;
377 
378 	rc_list->rcl_nrefcalls = ntohl(*p++);
379 	if (rc_list->rcl_nrefcalls) {
380 		p = xdr_inline_decode(xdr,
381 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
382 		if (unlikely(p == NULL))
383 			goto out;
384 		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
385 						sizeof(*rc_list->rcl_refcalls),
386 						GFP_KERNEL);
387 		if (unlikely(rc_list->rcl_refcalls == NULL))
388 			goto out;
389 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
390 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
391 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
392 		}
393 	}
394 	status = 0;
395 
396 out:
397 	return status;
398 }
399 
400 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
401 					struct xdr_stream *xdr,
402 					void *argp)
403 {
404 	struct cb_sequenceargs *args = argp;
405 	__be32 *p;
406 	int i;
407 	__be32 status;
408 
409 	status = decode_sessionid(xdr, &args->csa_sessionid);
410 	if (status)
411 		return status;
412 
413 	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
414 	if (unlikely(p == NULL))
415 		return htonl(NFS4ERR_RESOURCE);
416 
417 	args->csa_addr = svc_addr(rqstp);
418 	args->csa_sequenceid = ntohl(*p++);
419 	args->csa_slotid = ntohl(*p++);
420 	args->csa_highestslotid = ntohl(*p++);
421 	args->csa_cachethis = ntohl(*p++);
422 	args->csa_nrclists = ntohl(*p++);
423 	args->csa_rclists = NULL;
424 	if (args->csa_nrclists) {
425 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
426 						  sizeof(*args->csa_rclists),
427 						  GFP_KERNEL);
428 		if (unlikely(args->csa_rclists == NULL))
429 			return htonl(NFS4ERR_RESOURCE);
430 
431 		for (i = 0; i < args->csa_nrclists; i++) {
432 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
433 			if (status) {
434 				args->csa_nrclists = i;
435 				goto out_free;
436 			}
437 		}
438 	}
439 	return 0;
440 
441 out_free:
442 	for (i = 0; i < args->csa_nrclists; i++)
443 		kfree(args->csa_rclists[i].rcl_refcalls);
444 	kfree(args->csa_rclists);
445 	return status;
446 }
447 
448 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
449 				      struct xdr_stream *xdr,
450 				      void *argp)
451 {
452 	struct cb_recallanyargs *args = argp;
453 	uint32_t bitmap[2];
454 	__be32 *p, status;
455 
456 	p = xdr_inline_decode(xdr, 4);
457 	if (unlikely(p == NULL))
458 		return htonl(NFS4ERR_BADXDR);
459 	args->craa_objs_to_keep = ntohl(*p++);
460 	status = decode_bitmap(xdr, bitmap);
461 	if (unlikely(status))
462 		return status;
463 	args->craa_type_mask = bitmap[0];
464 
465 	return 0;
466 }
467 
468 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
469 					struct xdr_stream *xdr,
470 					void *argp)
471 {
472 	struct cb_recallslotargs *args = argp;
473 	__be32 *p;
474 
475 	p = xdr_inline_decode(xdr, 4);
476 	if (unlikely(p == NULL))
477 		return htonl(NFS4ERR_BADXDR);
478 	args->crsa_target_highest_slotid = ntohl(*p++);
479 	return 0;
480 }
481 
482 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
483 {
484 	__be32		*p;
485 	unsigned int	len;
486 
487 	p = xdr_inline_decode(xdr, 12);
488 	if (unlikely(p == NULL))
489 		return htonl(NFS4ERR_BADXDR);
490 
491 	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
492 	len = be32_to_cpu(*p);
493 
494 	p = xdr_inline_decode(xdr, len);
495 	if (unlikely(p == NULL))
496 		return htonl(NFS4ERR_BADXDR);
497 
498 	/* Only try to decode if the length is right */
499 	if (len == 20) {
500 		p += 2;	/* skip "lock id:" */
501 		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
502 		xdr_decode_hyper(p, &args->cbnl_owner.id);
503 		args->cbnl_valid = true;
504 	} else {
505 		args->cbnl_owner.s_dev = 0;
506 		args->cbnl_owner.id = 0;
507 		args->cbnl_valid = false;
508 	}
509 	return 0;
510 }
511 
512 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
513 		struct xdr_stream *xdr, void *argp)
514 {
515 	struct cb_notify_lock_args *args = argp;
516 	__be32 status;
517 
518 	status = decode_fh(xdr, &args->cbnl_fh);
519 	if (unlikely(status != 0))
520 		return status;
521 	return decode_lockowner(xdr, args);
522 }
523 
524 #endif /* CONFIG_NFS_V4_1 */
525 #ifdef CONFIG_NFS_V4_2
526 static __be32 decode_write_response(struct xdr_stream *xdr,
527 					struct cb_offloadargs *args)
528 {
529 	__be32 *p;
530 
531 	/* skip the always zero field */
532 	p = xdr_inline_decode(xdr, 4);
533 	if (unlikely(!p))
534 		goto out;
535 	p++;
536 
537 	/* decode count, stable_how, verifier */
538 	p = xdr_inline_decode(xdr, 8 + 4);
539 	if (unlikely(!p))
540 		goto out;
541 	p = xdr_decode_hyper(p, &args->wr_count);
542 	args->wr_writeverf.committed = be32_to_cpup(p);
543 	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
544 	if (likely(p)) {
545 		memcpy(&args->wr_writeverf.verifier.data[0], p,
546 			NFS4_VERIFIER_SIZE);
547 		return 0;
548 	}
549 out:
550 	return htonl(NFS4ERR_RESOURCE);
551 }
552 
553 static __be32 decode_offload_args(struct svc_rqst *rqstp,
554 					struct xdr_stream *xdr,
555 					void *data)
556 {
557 	struct cb_offloadargs *args = data;
558 	__be32 *p;
559 	__be32 status;
560 
561 	/* decode fh */
562 	status = decode_fh(xdr, &args->coa_fh);
563 	if (unlikely(status != 0))
564 		return status;
565 
566 	/* decode stateid */
567 	status = decode_stateid(xdr, &args->coa_stateid);
568 	if (unlikely(status != 0))
569 		return status;
570 
571 	/* decode status */
572 	p = xdr_inline_decode(xdr, 4);
573 	if (unlikely(!p))
574 		goto out;
575 	args->error = ntohl(*p++);
576 	if (!args->error) {
577 		status = decode_write_response(xdr, args);
578 		if (unlikely(status != 0))
579 			return status;
580 	} else {
581 		p = xdr_inline_decode(xdr, 8);
582 		if (unlikely(!p))
583 			goto out;
584 		p = xdr_decode_hyper(p, &args->wr_count);
585 	}
586 	return 0;
587 out:
588 	return htonl(NFS4ERR_RESOURCE);
589 }
590 #endif /* CONFIG_NFS_V4_2 */
591 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
592 {
593 	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
594 		return cpu_to_be32(NFS4ERR_RESOURCE);
595 	return 0;
596 }
597 
598 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
599 {
600 	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
601 		return cpu_to_be32(NFS4ERR_RESOURCE);
602 	return 0;
603 }
604 
605 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
606 {
607 	__be32 *p;
608 
609 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
610 		return 0;
611 	p = xdr_reserve_space(xdr, 8);
612 	if (unlikely(!p))
613 		return htonl(NFS4ERR_RESOURCE);
614 	p = xdr_encode_hyper(p, change);
615 	return 0;
616 }
617 
618 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
619 {
620 	__be32 *p;
621 
622 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
623 		return 0;
624 	p = xdr_reserve_space(xdr, 8);
625 	if (unlikely(!p))
626 		return htonl(NFS4ERR_RESOURCE);
627 	p = xdr_encode_hyper(p, size);
628 	return 0;
629 }
630 
631 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
632 {
633 	__be32 *p;
634 
635 	p = xdr_reserve_space(xdr, 12);
636 	if (unlikely(!p))
637 		return htonl(NFS4ERR_RESOURCE);
638 	p = xdr_encode_hyper(p, time->tv_sec);
639 	*p = htonl(time->tv_nsec);
640 	return 0;
641 }
642 
643 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
644 {
645 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
646 		return 0;
647 	return encode_attr_time(xdr,time);
648 }
649 
650 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
651 {
652 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
653 		return 0;
654 	return encode_attr_time(xdr,time);
655 }
656 
657 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
658 {
659 	__be32 status;
660 
661 	hdr->status = xdr_reserve_space(xdr, 4);
662 	if (unlikely(hdr->status == NULL))
663 		return htonl(NFS4ERR_RESOURCE);
664 	status = encode_string(xdr, hdr->taglen, hdr->tag);
665 	if (unlikely(status != 0))
666 		return status;
667 	hdr->nops = xdr_reserve_space(xdr, 4);
668 	if (unlikely(hdr->nops == NULL))
669 		return htonl(NFS4ERR_RESOURCE);
670 	return 0;
671 }
672 
673 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
674 {
675 	__be32 *p;
676 
677 	p = xdr_reserve_space(xdr, 8);
678 	if (unlikely(p == NULL))
679 		return htonl(NFS4ERR_RESOURCE_HDR);
680 	*p++ = htonl(op);
681 	*p = res;
682 	return 0;
683 }
684 
685 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
686 		const void *resp)
687 {
688 	const struct cb_getattrres *res = resp;
689 	__be32 *savep = NULL;
690 	__be32 status = res->status;
691 
692 	if (unlikely(status != 0))
693 		goto out;
694 	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
695 	if (unlikely(status != 0))
696 		goto out;
697 	status = cpu_to_be32(NFS4ERR_RESOURCE);
698 	savep = xdr_reserve_space(xdr, sizeof(*savep));
699 	if (unlikely(!savep))
700 		goto out;
701 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
702 	if (unlikely(status != 0))
703 		goto out;
704 	status = encode_attr_size(xdr, res->bitmap, res->size);
705 	if (unlikely(status != 0))
706 		goto out;
707 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
708 	if (unlikely(status != 0))
709 		goto out;
710 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
711 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
712 out:
713 	return status;
714 }
715 
716 #if defined(CONFIG_NFS_V4_1)
717 
718 static __be32 encode_sessionid(struct xdr_stream *xdr,
719 				 const struct nfs4_sessionid *sid)
720 {
721 	__be32 *p;
722 
723 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
724 	if (unlikely(p == NULL))
725 		return htonl(NFS4ERR_RESOURCE);
726 
727 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
728 	return 0;
729 }
730 
731 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
732 				       struct xdr_stream *xdr,
733 				       const void *resp)
734 {
735 	const struct cb_sequenceres *res = resp;
736 	__be32 *p;
737 	__be32 status = res->csr_status;
738 
739 	if (unlikely(status != 0))
740 		return status;
741 
742 	status = encode_sessionid(xdr, &res->csr_sessionid);
743 	if (status)
744 		return status;
745 
746 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
747 	if (unlikely(p == NULL))
748 		return htonl(NFS4ERR_RESOURCE);
749 
750 	*p++ = htonl(res->csr_sequenceid);
751 	*p++ = htonl(res->csr_slotid);
752 	*p++ = htonl(res->csr_highestslotid);
753 	*p++ = htonl(res->csr_target_highestslotid);
754 	return 0;
755 }
756 
757 static __be32
758 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
759 {
760 	if (op_nr == OP_CB_SEQUENCE) {
761 		if (nop != 0)
762 			return htonl(NFS4ERR_SEQUENCE_POS);
763 	} else {
764 		if (nop == 0)
765 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
766 	}
767 
768 	switch (op_nr) {
769 	case OP_CB_GETATTR:
770 	case OP_CB_RECALL:
771 	case OP_CB_SEQUENCE:
772 	case OP_CB_RECALL_ANY:
773 	case OP_CB_RECALL_SLOT:
774 	case OP_CB_LAYOUTRECALL:
775 	case OP_CB_NOTIFY_DEVICEID:
776 	case OP_CB_NOTIFY_LOCK:
777 		*op = &callback_ops[op_nr];
778 		break;
779 
780 	case OP_CB_NOTIFY:
781 	case OP_CB_PUSH_DELEG:
782 	case OP_CB_RECALLABLE_OBJ_AVAIL:
783 	case OP_CB_WANTS_CANCELLED:
784 		return htonl(NFS4ERR_NOTSUPP);
785 
786 	default:
787 		return htonl(NFS4ERR_OP_ILLEGAL);
788 	}
789 
790 	return htonl(NFS_OK);
791 }
792 
793 static void nfs4_callback_free_slot(struct nfs4_session *session,
794 		struct nfs4_slot *slot)
795 {
796 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
797 
798 	spin_lock(&tbl->slot_tbl_lock);
799 	/*
800 	 * Let the state manager know callback processing done.
801 	 * A single slot, so highest used slotid is either 0 or -1
802 	 */
803 	nfs4_free_slot(tbl, slot);
804 	spin_unlock(&tbl->slot_tbl_lock);
805 }
806 
807 static void nfs4_cb_free_slot(struct cb_process_state *cps)
808 {
809 	if (cps->slot) {
810 		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
811 		cps->slot = NULL;
812 	}
813 }
814 
815 #else /* CONFIG_NFS_V4_1 */
816 
817 static __be32
818 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
819 {
820 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
821 }
822 
823 static void nfs4_cb_free_slot(struct cb_process_state *cps)
824 {
825 }
826 #endif /* CONFIG_NFS_V4_1 */
827 
828 #ifdef CONFIG_NFS_V4_2
829 static __be32
830 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
831 {
832 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
833 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
834 		return status;
835 
836 	if (op_nr == OP_CB_OFFLOAD) {
837 		*op = &callback_ops[op_nr];
838 		return htonl(NFS_OK);
839 	} else
840 		return htonl(NFS4ERR_NOTSUPP);
841 	return htonl(NFS4ERR_OP_ILLEGAL);
842 }
843 #else /* CONFIG_NFS_V4_2 */
844 static __be32
845 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
846 {
847 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
848 }
849 #endif /* CONFIG_NFS_V4_2 */
850 
851 static __be32
852 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
853 {
854 	switch (op_nr) {
855 	case OP_CB_GETATTR:
856 	case OP_CB_RECALL:
857 		*op = &callback_ops[op_nr];
858 		break;
859 	default:
860 		return htonl(NFS4ERR_OP_ILLEGAL);
861 	}
862 
863 	return htonl(NFS_OK);
864 }
865 
866 static __be32 process_op(int nop, struct svc_rqst *rqstp,
867 		struct xdr_stream *xdr_in, void *argp,
868 		struct xdr_stream *xdr_out, void *resp,
869 		struct cb_process_state *cps)
870 {
871 	struct callback_op *op = &callback_ops[0];
872 	unsigned int op_nr;
873 	__be32 status;
874 	long maxlen;
875 	__be32 res;
876 
877 	status = decode_op_hdr(xdr_in, &op_nr);
878 	if (unlikely(status))
879 		return status;
880 
881 	switch (cps->minorversion) {
882 	case 0:
883 		status = preprocess_nfs4_op(op_nr, &op);
884 		break;
885 	case 1:
886 		status = preprocess_nfs41_op(nop, op_nr, &op);
887 		break;
888 	case 2:
889 		status = preprocess_nfs42_op(nop, op_nr, &op);
890 		break;
891 	default:
892 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
893 	}
894 
895 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
896 		op_nr = OP_CB_ILLEGAL;
897 	if (status)
898 		goto encode_hdr;
899 
900 	if (cps->drc_status) {
901 		status = cps->drc_status;
902 		goto encode_hdr;
903 	}
904 
905 	maxlen = xdr_out->end - xdr_out->p;
906 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
907 		status = op->decode_args(rqstp, xdr_in, argp);
908 		if (likely(status == 0))
909 			status = op->process_op(argp, resp, cps);
910 	} else
911 		status = htonl(NFS4ERR_RESOURCE);
912 
913 encode_hdr:
914 	res = encode_op_hdr(xdr_out, op_nr, status);
915 	if (unlikely(res))
916 		return res;
917 	if (op->encode_res != NULL && status == 0)
918 		status = op->encode_res(rqstp, xdr_out, resp);
919 	return status;
920 }
921 
922 /*
923  * Decode, process and encode a COMPOUND
924  */
925 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
926 {
927 	struct cb_compound_hdr_arg hdr_arg = { 0 };
928 	struct cb_compound_hdr_res hdr_res = { NULL };
929 	struct xdr_stream xdr_in, xdr_out;
930 	__be32 *p, status;
931 	struct cb_process_state cps = {
932 		.drc_status = 0,
933 		.clp = NULL,
934 		.net = SVC_NET(rqstp),
935 	};
936 	unsigned int nops = 0;
937 
938 	xdr_init_decode(&xdr_in, &rqstp->rq_arg,
939 			rqstp->rq_arg.head[0].iov_base, NULL);
940 
941 	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
942 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p, NULL);
943 
944 	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
945 	if (status == htonl(NFS4ERR_RESOURCE))
946 		return rpc_garbage_args;
947 
948 	if (hdr_arg.minorversion == 0) {
949 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
950 		if (!cps.clp) {
951 			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
952 			goto out_invalidcred;
953 		}
954 		if (!check_gss_callback_principal(cps.clp, rqstp)) {
955 			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
956 			nfs_put_client(cps.clp);
957 			goto out_invalidcred;
958 		}
959 	}
960 
961 	cps.minorversion = hdr_arg.minorversion;
962 	hdr_res.taglen = hdr_arg.taglen;
963 	hdr_res.tag = hdr_arg.tag;
964 	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0) {
965 		if (cps.clp)
966 			nfs_put_client(cps.clp);
967 		return rpc_system_err;
968 	}
969 	while (status == 0 && nops != hdr_arg.nops) {
970 		status = process_op(nops, rqstp, &xdr_in,
971 				    rqstp->rq_argp, &xdr_out, rqstp->rq_resp,
972 				    &cps);
973 		nops++;
974 	}
975 
976 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
977 	* resource error in cb_compound status without returning op */
978 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
979 		status = htonl(NFS4ERR_RESOURCE);
980 		nops--;
981 	}
982 
983 	*hdr_res.status = status;
984 	*hdr_res.nops = htonl(nops);
985 	nfs4_cb_free_slot(&cps);
986 	nfs_put_client(cps.clp);
987 	return rpc_success;
988 
989 out_invalidcred:
990 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
991 	return svc_return_autherr(rqstp, rpc_autherr_badcred);
992 }
993 
994 /*
995  * Define NFS4 callback COMPOUND ops.
996  */
997 static struct callback_op callback_ops[] = {
998 	[0] = {
999 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
1000 	},
1001 	[OP_CB_GETATTR] = {
1002 		.process_op = nfs4_callback_getattr,
1003 		.decode_args = decode_getattr_args,
1004 		.encode_res = encode_getattr_res,
1005 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1006 	},
1007 	[OP_CB_RECALL] = {
1008 		.process_op = nfs4_callback_recall,
1009 		.decode_args = decode_recall_args,
1010 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1011 	},
1012 #if defined(CONFIG_NFS_V4_1)
1013 	[OP_CB_LAYOUTRECALL] = {
1014 		.process_op = nfs4_callback_layoutrecall,
1015 		.decode_args = decode_layoutrecall_args,
1016 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1017 	},
1018 	[OP_CB_NOTIFY_DEVICEID] = {
1019 		.process_op = nfs4_callback_devicenotify,
1020 		.decode_args = decode_devicenotify_args,
1021 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1022 	},
1023 	[OP_CB_SEQUENCE] = {
1024 		.process_op = nfs4_callback_sequence,
1025 		.decode_args = decode_cb_sequence_args,
1026 		.encode_res = encode_cb_sequence_res,
1027 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1028 	},
1029 	[OP_CB_RECALL_ANY] = {
1030 		.process_op = nfs4_callback_recallany,
1031 		.decode_args = decode_recallany_args,
1032 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1033 	},
1034 	[OP_CB_RECALL_SLOT] = {
1035 		.process_op = nfs4_callback_recallslot,
1036 		.decode_args = decode_recallslot_args,
1037 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1038 	},
1039 	[OP_CB_NOTIFY_LOCK] = {
1040 		.process_op = nfs4_callback_notify_lock,
1041 		.decode_args = decode_notify_lock_args,
1042 		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1043 	},
1044 #endif /* CONFIG_NFS_V4_1 */
1045 #ifdef CONFIG_NFS_V4_2
1046 	[OP_CB_OFFLOAD] = {
1047 		.process_op = nfs4_callback_offload,
1048 		.decode_args = decode_offload_args,
1049 		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1050 	},
1051 #endif /* CONFIG_NFS_V4_2 */
1052 };
1053 
1054 /*
1055  * Define NFS4 callback procedures
1056  */
1057 static const struct svc_procedure nfs4_callback_procedures1[] = {
1058 	[CB_NULL] = {
1059 		.pc_func = nfs4_callback_null,
1060 		.pc_decode = nfs4_decode_void,
1061 		.pc_encode = nfs4_encode_void,
1062 		.pc_xdrressize = 1,
1063 		.pc_name = "NULL",
1064 	},
1065 	[CB_COMPOUND] = {
1066 		.pc_func = nfs4_callback_compound,
1067 		.pc_encode = nfs4_encode_void,
1068 		.pc_argsize = 256,
1069 		.pc_ressize = 256,
1070 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1071 		.pc_name = "COMPOUND",
1072 	}
1073 };
1074 
1075 static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
1076 const struct svc_version nfs4_callback_version1 = {
1077 	.vs_vers = 1,
1078 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1079 	.vs_proc = nfs4_callback_procedures1,
1080 	.vs_count = nfs4_callback_count1,
1081 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1082 	.vs_dispatch = NULL,
1083 	.vs_hidden = true,
1084 	.vs_need_cong_ctrl = true,
1085 };
1086 
1087 static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
1088 const struct svc_version nfs4_callback_version4 = {
1089 	.vs_vers = 4,
1090 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1091 	.vs_proc = nfs4_callback_procedures1,
1092 	.vs_count = nfs4_callback_count4,
1093 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1094 	.vs_dispatch = NULL,
1095 	.vs_hidden = true,
1096 	.vs_need_cong_ctrl = true,
1097 };
1098