xref: /openbmc/linux/fs/nfs/callback_xdr.c (revision a6ca5ac746d104019e76c29e69c2a1fc6dd2b29f)
1 /*
2  * linux/fs/nfs/callback_xdr.c
3  *
4  * Copyright (C) 2004 Trond Myklebust
5  *
6  * NFSv4 callback encode/decode procedures
7  */
8 #include <linux/kernel.h>
9 #include <linux/sunrpc/svc.h>
10 #include <linux/nfs4.h>
11 #include <linux/nfs_fs.h>
12 #include <linux/ratelimit.h>
13 #include <linux/printk.h>
14 #include <linux/slab.h>
15 #include <linux/sunrpc/bc_xprt.h>
16 #include "nfs4_fs.h"
17 #include "callback.h"
18 #include "internal.h"
19 #include "nfs4session.h"
20 
21 #define CB_OP_TAGLEN_MAXSZ		(512)
22 #define CB_OP_HDR_RES_MAXSZ		(2 * 4) // opcode, status
23 #define CB_OP_GETATTR_BITMAP_MAXSZ	(4 * 4) // bitmap length, 3 bitmaps
24 #define CB_OP_GETATTR_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ + \
25 					 CB_OP_GETATTR_BITMAP_MAXSZ + \
26 					 /* change, size, ctime, mtime */\
27 					 (2 + 2 + 3 + 3) * 4)
28 #define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
29 
30 #if defined(CONFIG_NFS_V4_1)
31 #define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
32 #define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
33 #define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
34 					 NFS4_MAX_SESSIONID_LEN + \
35 					 (1 + 3) * 4) // seqid, 3 slotids
36 #define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
37 #define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
38 #define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
39 #endif /* CONFIG_NFS_V4_1 */
40 
41 #define NFSDBG_FACILITY NFSDBG_CALLBACK
42 
43 /* Internal error code */
44 #define NFS4ERR_RESOURCE_HDR	11050
45 
46 typedef __be32 (*callback_process_op_t)(void *, void *,
47 					struct cb_process_state *);
48 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
49 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
50 
51 
52 struct callback_op {
53 	callback_process_op_t process_op;
54 	callback_decode_arg_t decode_args;
55 	callback_encode_res_t encode_res;
56 	long res_maxsize;
57 };
58 
59 static struct callback_op callback_ops[];
60 
61 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
62 {
63 	return htonl(NFS4_OK);
64 }
65 
66 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
67 {
68 	return xdr_argsize_check(rqstp, p);
69 }
70 
71 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
72 {
73 	return xdr_ressize_check(rqstp, p);
74 }
75 
76 static __be32 *read_buf(struct xdr_stream *xdr, size_t nbytes)
77 {
78 	__be32 *p;
79 
80 	p = xdr_inline_decode(xdr, nbytes);
81 	if (unlikely(p == NULL))
82 		printk(KERN_WARNING "NFS: NFSv4 callback reply buffer overflowed!\n");
83 	return p;
84 }
85 
86 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
87 		const char **str, size_t maxlen)
88 {
89 	ssize_t err;
90 
91 	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
92 	if (err < 0)
93 		return cpu_to_be32(NFS4ERR_RESOURCE);
94 	*len = err;
95 	return 0;
96 }
97 
98 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
99 {
100 	__be32 *p;
101 
102 	p = read_buf(xdr, 4);
103 	if (unlikely(p == NULL))
104 		return htonl(NFS4ERR_RESOURCE);
105 	fh->size = ntohl(*p);
106 	if (fh->size > NFS4_FHSIZE)
107 		return htonl(NFS4ERR_BADHANDLE);
108 	p = read_buf(xdr, fh->size);
109 	if (unlikely(p == NULL))
110 		return htonl(NFS4ERR_RESOURCE);
111 	memcpy(&fh->data[0], p, fh->size);
112 	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
113 	return 0;
114 }
115 
116 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
117 {
118 	__be32 *p;
119 	unsigned int attrlen;
120 
121 	p = read_buf(xdr, 4);
122 	if (unlikely(p == NULL))
123 		return htonl(NFS4ERR_RESOURCE);
124 	attrlen = ntohl(*p);
125 	p = read_buf(xdr, attrlen << 2);
126 	if (unlikely(p == NULL))
127 		return htonl(NFS4ERR_RESOURCE);
128 	if (likely(attrlen > 0))
129 		bitmap[0] = ntohl(*p++);
130 	if (attrlen > 1)
131 		bitmap[1] = ntohl(*p);
132 	return 0;
133 }
134 
135 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
136 {
137 	__be32 *p;
138 
139 	p = read_buf(xdr, NFS4_STATEID_SIZE);
140 	if (unlikely(p == NULL))
141 		return htonl(NFS4ERR_RESOURCE);
142 	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
143 	return 0;
144 }
145 
146 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
147 {
148 	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
149 	return decode_stateid(xdr, stateid);
150 }
151 
152 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
153 {
154 	__be32 *p;
155 	__be32 status;
156 
157 	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
158 	if (unlikely(status != 0))
159 		return status;
160 	p = read_buf(xdr, 12);
161 	if (unlikely(p == NULL))
162 		return htonl(NFS4ERR_RESOURCE);
163 	hdr->minorversion = ntohl(*p++);
164 	/* Check for minor version support */
165 	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
166 		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
167 	} else {
168 		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
169 			"illegal minor version %u!\n",
170 			__func__, hdr->minorversion);
171 		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
172 	}
173 	hdr->nops = ntohl(*p);
174 	return 0;
175 }
176 
177 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
178 {
179 	__be32 *p;
180 	p = read_buf(xdr, 4);
181 	if (unlikely(p == NULL))
182 		return htonl(NFS4ERR_RESOURCE_HDR);
183 	*op = ntohl(*p);
184 	return 0;
185 }
186 
187 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
188 {
189 	__be32 status;
190 
191 	status = decode_fh(xdr, &args->fh);
192 	if (unlikely(status != 0))
193 		return status;
194 	return decode_bitmap(xdr, args->bitmap);
195 }
196 
197 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
198 {
199 	__be32 *p;
200 	__be32 status;
201 
202 	status = decode_delegation_stateid(xdr, &args->stateid);
203 	if (unlikely(status != 0))
204 		return status;
205 	p = read_buf(xdr, 4);
206 	if (unlikely(p == NULL))
207 		return htonl(NFS4ERR_RESOURCE);
208 	args->truncate = ntohl(*p);
209 	return decode_fh(xdr, &args->fh);
210 }
211 
212 #if defined(CONFIG_NFS_V4_1)
213 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
214 {
215 	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
216 	return decode_stateid(xdr, stateid);
217 }
218 
219 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
220 				       struct xdr_stream *xdr,
221 				       struct cb_layoutrecallargs *args)
222 {
223 	__be32 *p;
224 	__be32 status = 0;
225 	uint32_t iomode;
226 
227 	p = read_buf(xdr, 4 * sizeof(uint32_t));
228 	if (unlikely(p == NULL))
229 		return htonl(NFS4ERR_BADXDR);
230 
231 	args->cbl_layout_type = ntohl(*p++);
232 	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
233 	 * as it is unusable and ignored with the other types.
234 	 */
235 	iomode = ntohl(*p++);
236 	args->cbl_layoutchanged = ntohl(*p++);
237 	args->cbl_recall_type = ntohl(*p++);
238 
239 	if (args->cbl_recall_type == RETURN_FILE) {
240 		args->cbl_range.iomode = iomode;
241 		status = decode_fh(xdr, &args->cbl_fh);
242 		if (unlikely(status != 0))
243 			return status;
244 
245 		p = read_buf(xdr, 2 * sizeof(uint64_t));
246 		if (unlikely(p == NULL))
247 			return htonl(NFS4ERR_BADXDR);
248 		p = xdr_decode_hyper(p, &args->cbl_range.offset);
249 		p = xdr_decode_hyper(p, &args->cbl_range.length);
250 		return decode_layout_stateid(xdr, &args->cbl_stateid);
251 	} else if (args->cbl_recall_type == RETURN_FSID) {
252 		p = read_buf(xdr, 2 * sizeof(uint64_t));
253 		if (unlikely(p == NULL))
254 			return htonl(NFS4ERR_BADXDR);
255 		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
256 		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
257 	} else if (args->cbl_recall_type != RETURN_ALL)
258 		return htonl(NFS4ERR_BADXDR);
259 	return 0;
260 }
261 
262 static
263 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
264 				struct xdr_stream *xdr,
265 				struct cb_devicenotifyargs *args)
266 {
267 	__be32 *p;
268 	__be32 status = 0;
269 	u32 tmp;
270 	int n, i;
271 	args->ndevs = 0;
272 
273 	/* Num of device notifications */
274 	p = read_buf(xdr, sizeof(uint32_t));
275 	if (unlikely(p == NULL)) {
276 		status = htonl(NFS4ERR_BADXDR);
277 		goto out;
278 	}
279 	n = ntohl(*p++);
280 	if (n <= 0)
281 		goto out;
282 	if (n > ULONG_MAX / sizeof(*args->devs)) {
283 		status = htonl(NFS4ERR_BADXDR);
284 		goto out;
285 	}
286 
287 	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
288 	if (!args->devs) {
289 		status = htonl(NFS4ERR_DELAY);
290 		goto out;
291 	}
292 
293 	/* Decode each dev notification */
294 	for (i = 0; i < n; i++) {
295 		struct cb_devicenotifyitem *dev = &args->devs[i];
296 
297 		p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
298 		if (unlikely(p == NULL)) {
299 			status = htonl(NFS4ERR_BADXDR);
300 			goto err;
301 		}
302 
303 		tmp = ntohl(*p++);	/* bitmap size */
304 		if (tmp != 1) {
305 			status = htonl(NFS4ERR_INVAL);
306 			goto err;
307 		}
308 		dev->cbd_notify_type = ntohl(*p++);
309 		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
310 		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
311 			status = htonl(NFS4ERR_INVAL);
312 			goto err;
313 		}
314 
315 		tmp = ntohl(*p++);	/* opaque size */
316 		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
317 		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
318 		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
319 		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
320 			status = htonl(NFS4ERR_INVAL);
321 			goto err;
322 		}
323 		dev->cbd_layout_type = ntohl(*p++);
324 		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
325 		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
326 
327 		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
328 			p = read_buf(xdr, sizeof(uint32_t));
329 			if (unlikely(p == NULL)) {
330 				status = htonl(NFS4ERR_BADXDR);
331 				goto err;
332 			}
333 			dev->cbd_immediate = ntohl(*p++);
334 		} else {
335 			dev->cbd_immediate = 0;
336 		}
337 
338 		args->ndevs++;
339 
340 		dprintk("%s: type %d layout 0x%x immediate %d\n",
341 			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
342 			dev->cbd_immediate);
343 	}
344 out:
345 	dprintk("%s: status %d ndevs %d\n",
346 		__func__, ntohl(status), args->ndevs);
347 	return status;
348 err:
349 	kfree(args->devs);
350 	goto out;
351 }
352 
353 static __be32 decode_sessionid(struct xdr_stream *xdr,
354 				 struct nfs4_sessionid *sid)
355 {
356 	__be32 *p;
357 
358 	p = read_buf(xdr, NFS4_MAX_SESSIONID_LEN);
359 	if (unlikely(p == NULL))
360 		return htonl(NFS4ERR_RESOURCE);
361 
362 	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
363 	return 0;
364 }
365 
366 static __be32 decode_rc_list(struct xdr_stream *xdr,
367 			       struct referring_call_list *rc_list)
368 {
369 	__be32 *p;
370 	int i;
371 	__be32 status;
372 
373 	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
374 	if (status)
375 		goto out;
376 
377 	status = htonl(NFS4ERR_RESOURCE);
378 	p = read_buf(xdr, sizeof(uint32_t));
379 	if (unlikely(p == NULL))
380 		goto out;
381 
382 	rc_list->rcl_nrefcalls = ntohl(*p++);
383 	if (rc_list->rcl_nrefcalls) {
384 		p = read_buf(xdr,
385 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
386 		if (unlikely(p == NULL))
387 			goto out;
388 		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
389 						sizeof(*rc_list->rcl_refcalls),
390 						GFP_KERNEL);
391 		if (unlikely(rc_list->rcl_refcalls == NULL))
392 			goto out;
393 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
394 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
395 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
396 		}
397 	}
398 	status = 0;
399 
400 out:
401 	return status;
402 }
403 
404 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
405 					struct xdr_stream *xdr,
406 					struct cb_sequenceargs *args)
407 {
408 	__be32 *p;
409 	int i;
410 	__be32 status;
411 
412 	status = decode_sessionid(xdr, &args->csa_sessionid);
413 	if (status)
414 		return status;
415 
416 	p = read_buf(xdr, 5 * sizeof(uint32_t));
417 	if (unlikely(p == NULL))
418 		return htonl(NFS4ERR_RESOURCE);
419 
420 	args->csa_addr = svc_addr(rqstp);
421 	args->csa_sequenceid = ntohl(*p++);
422 	args->csa_slotid = ntohl(*p++);
423 	args->csa_highestslotid = ntohl(*p++);
424 	args->csa_cachethis = ntohl(*p++);
425 	args->csa_nrclists = ntohl(*p++);
426 	args->csa_rclists = NULL;
427 	if (args->csa_nrclists) {
428 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
429 						  sizeof(*args->csa_rclists),
430 						  GFP_KERNEL);
431 		if (unlikely(args->csa_rclists == NULL))
432 			return htonl(NFS4ERR_RESOURCE);
433 
434 		for (i = 0; i < args->csa_nrclists; i++) {
435 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
436 			if (status) {
437 				args->csa_nrclists = i;
438 				goto out_free;
439 			}
440 		}
441 	}
442 	return 0;
443 
444 out_free:
445 	for (i = 0; i < args->csa_nrclists; i++)
446 		kfree(args->csa_rclists[i].rcl_refcalls);
447 	kfree(args->csa_rclists);
448 	return status;
449 }
450 
451 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
452 				      struct xdr_stream *xdr,
453 				      struct cb_recallanyargs *args)
454 {
455 	uint32_t bitmap[2];
456 	__be32 *p, status;
457 
458 	p = read_buf(xdr, 4);
459 	if (unlikely(p == NULL))
460 		return htonl(NFS4ERR_BADXDR);
461 	args->craa_objs_to_keep = ntohl(*p++);
462 	status = decode_bitmap(xdr, bitmap);
463 	if (unlikely(status))
464 		return status;
465 	args->craa_type_mask = bitmap[0];
466 
467 	return 0;
468 }
469 
470 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
471 					struct xdr_stream *xdr,
472 					struct cb_recallslotargs *args)
473 {
474 	__be32 *p;
475 
476 	p = read_buf(xdr, 4);
477 	if (unlikely(p == NULL))
478 		return htonl(NFS4ERR_BADXDR);
479 	args->crsa_target_highest_slotid = ntohl(*p++);
480 	return 0;
481 }
482 
483 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
484 {
485 	__be32		*p;
486 	unsigned int	len;
487 
488 	p = read_buf(xdr, 12);
489 	if (unlikely(p == NULL))
490 		return htonl(NFS4ERR_BADXDR);
491 
492 	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
493 	len = be32_to_cpu(*p);
494 
495 	p = read_buf(xdr, len);
496 	if (unlikely(p == NULL))
497 		return htonl(NFS4ERR_BADXDR);
498 
499 	/* Only try to decode if the length is right */
500 	if (len == 20) {
501 		p += 2;	/* skip "lock id:" */
502 		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
503 		xdr_decode_hyper(p, &args->cbnl_owner.id);
504 		args->cbnl_valid = true;
505 	} else {
506 		args->cbnl_owner.s_dev = 0;
507 		args->cbnl_owner.id = 0;
508 		args->cbnl_valid = false;
509 	}
510 	return 0;
511 }
512 
513 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_notify_lock_args *args)
514 {
515 	__be32 status;
516 
517 	status = decode_fh(xdr, &args->cbnl_fh);
518 	if (unlikely(status != 0))
519 		return status;
520 	return decode_lockowner(xdr, args);
521 }
522 
523 #endif /* CONFIG_NFS_V4_1 */
524 
525 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
526 {
527 	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
528 		return cpu_to_be32(NFS4ERR_RESOURCE);
529 	return 0;
530 }
531 
532 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
533 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
534 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
535 {
536 	__be32 bm[2];
537 	__be32 *p;
538 
539 	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
540 	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
541 	if (bm[1] != 0) {
542 		p = xdr_reserve_space(xdr, 16);
543 		if (unlikely(p == NULL))
544 			return htonl(NFS4ERR_RESOURCE);
545 		*p++ = htonl(2);
546 		*p++ = bm[0];
547 		*p++ = bm[1];
548 	} else if (bm[0] != 0) {
549 		p = xdr_reserve_space(xdr, 12);
550 		if (unlikely(p == NULL))
551 			return htonl(NFS4ERR_RESOURCE);
552 		*p++ = htonl(1);
553 		*p++ = bm[0];
554 	} else {
555 		p = xdr_reserve_space(xdr, 8);
556 		if (unlikely(p == NULL))
557 			return htonl(NFS4ERR_RESOURCE);
558 		*p++ = htonl(0);
559 	}
560 	*savep = p;
561 	return 0;
562 }
563 
564 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
565 {
566 	__be32 *p;
567 
568 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
569 		return 0;
570 	p = xdr_reserve_space(xdr, 8);
571 	if (unlikely(!p))
572 		return htonl(NFS4ERR_RESOURCE);
573 	p = xdr_encode_hyper(p, change);
574 	return 0;
575 }
576 
577 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
578 {
579 	__be32 *p;
580 
581 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
582 		return 0;
583 	p = xdr_reserve_space(xdr, 8);
584 	if (unlikely(!p))
585 		return htonl(NFS4ERR_RESOURCE);
586 	p = xdr_encode_hyper(p, size);
587 	return 0;
588 }
589 
590 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
591 {
592 	__be32 *p;
593 
594 	p = xdr_reserve_space(xdr, 12);
595 	if (unlikely(!p))
596 		return htonl(NFS4ERR_RESOURCE);
597 	p = xdr_encode_hyper(p, time->tv_sec);
598 	*p = htonl(time->tv_nsec);
599 	return 0;
600 }
601 
602 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
603 {
604 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
605 		return 0;
606 	return encode_attr_time(xdr,time);
607 }
608 
609 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
610 {
611 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
612 		return 0;
613 	return encode_attr_time(xdr,time);
614 }
615 
616 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
617 {
618 	__be32 status;
619 
620 	hdr->status = xdr_reserve_space(xdr, 4);
621 	if (unlikely(hdr->status == NULL))
622 		return htonl(NFS4ERR_RESOURCE);
623 	status = encode_string(xdr, hdr->taglen, hdr->tag);
624 	if (unlikely(status != 0))
625 		return status;
626 	hdr->nops = xdr_reserve_space(xdr, 4);
627 	if (unlikely(hdr->nops == NULL))
628 		return htonl(NFS4ERR_RESOURCE);
629 	return 0;
630 }
631 
632 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
633 {
634 	__be32 *p;
635 
636 	p = xdr_reserve_space(xdr, 8);
637 	if (unlikely(p == NULL))
638 		return htonl(NFS4ERR_RESOURCE_HDR);
639 	*p++ = htonl(op);
640 	*p = res;
641 	return 0;
642 }
643 
644 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
645 {
646 	__be32 *savep = NULL;
647 	__be32 status = res->status;
648 
649 	if (unlikely(status != 0))
650 		goto out;
651 	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
652 	if (unlikely(status != 0))
653 		goto out;
654 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
655 	if (unlikely(status != 0))
656 		goto out;
657 	status = encode_attr_size(xdr, res->bitmap, res->size);
658 	if (unlikely(status != 0))
659 		goto out;
660 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
661 	if (unlikely(status != 0))
662 		goto out;
663 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
664 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
665 out:
666 	return status;
667 }
668 
669 #if defined(CONFIG_NFS_V4_1)
670 
671 static __be32 encode_sessionid(struct xdr_stream *xdr,
672 				 const struct nfs4_sessionid *sid)
673 {
674 	__be32 *p;
675 
676 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
677 	if (unlikely(p == NULL))
678 		return htonl(NFS4ERR_RESOURCE);
679 
680 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
681 	return 0;
682 }
683 
684 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
685 				       struct xdr_stream *xdr,
686 				       const struct cb_sequenceres *res)
687 {
688 	__be32 *p;
689 	__be32 status = res->csr_status;
690 
691 	if (unlikely(status != 0))
692 		return status;
693 
694 	status = encode_sessionid(xdr, &res->csr_sessionid);
695 	if (status)
696 		return status;
697 
698 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
699 	if (unlikely(p == NULL))
700 		return htonl(NFS4ERR_RESOURCE);
701 
702 	*p++ = htonl(res->csr_sequenceid);
703 	*p++ = htonl(res->csr_slotid);
704 	*p++ = htonl(res->csr_highestslotid);
705 	*p++ = htonl(res->csr_target_highestslotid);
706 	return 0;
707 }
708 
709 static __be32
710 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
711 {
712 	if (op_nr == OP_CB_SEQUENCE) {
713 		if (nop != 0)
714 			return htonl(NFS4ERR_SEQUENCE_POS);
715 	} else {
716 		if (nop == 0)
717 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
718 	}
719 
720 	switch (op_nr) {
721 	case OP_CB_GETATTR:
722 	case OP_CB_RECALL:
723 	case OP_CB_SEQUENCE:
724 	case OP_CB_RECALL_ANY:
725 	case OP_CB_RECALL_SLOT:
726 	case OP_CB_LAYOUTRECALL:
727 	case OP_CB_NOTIFY_DEVICEID:
728 	case OP_CB_NOTIFY_LOCK:
729 		*op = &callback_ops[op_nr];
730 		break;
731 
732 	case OP_CB_NOTIFY:
733 	case OP_CB_PUSH_DELEG:
734 	case OP_CB_RECALLABLE_OBJ_AVAIL:
735 	case OP_CB_WANTS_CANCELLED:
736 		return htonl(NFS4ERR_NOTSUPP);
737 
738 	default:
739 		return htonl(NFS4ERR_OP_ILLEGAL);
740 	}
741 
742 	return htonl(NFS_OK);
743 }
744 
745 static void nfs4_callback_free_slot(struct nfs4_session *session,
746 		struct nfs4_slot *slot)
747 {
748 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
749 
750 	spin_lock(&tbl->slot_tbl_lock);
751 	/*
752 	 * Let the state manager know callback processing done.
753 	 * A single slot, so highest used slotid is either 0 or -1
754 	 */
755 	nfs4_free_slot(tbl, slot);
756 	nfs4_slot_tbl_drain_complete(tbl);
757 	spin_unlock(&tbl->slot_tbl_lock);
758 }
759 
760 static void nfs4_cb_free_slot(struct cb_process_state *cps)
761 {
762 	if (cps->slot) {
763 		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
764 		cps->slot = NULL;
765 	}
766 }
767 
768 #else /* CONFIG_NFS_V4_1 */
769 
770 static __be32
771 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
772 {
773 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
774 }
775 
776 static void nfs4_cb_free_slot(struct cb_process_state *cps)
777 {
778 }
779 #endif /* CONFIG_NFS_V4_1 */
780 
781 #ifdef CONFIG_NFS_V4_2
782 static __be32
783 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
784 {
785 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
786 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
787 		return status;
788 
789 	if (op_nr == OP_CB_OFFLOAD)
790 		return htonl(NFS4ERR_NOTSUPP);
791 	return htonl(NFS4ERR_OP_ILLEGAL);
792 }
793 #else /* CONFIG_NFS_V4_2 */
794 static __be32
795 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
796 {
797 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
798 }
799 #endif /* CONFIG_NFS_V4_2 */
800 
801 static __be32
802 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
803 {
804 	switch (op_nr) {
805 	case OP_CB_GETATTR:
806 	case OP_CB_RECALL:
807 		*op = &callback_ops[op_nr];
808 		break;
809 	default:
810 		return htonl(NFS4ERR_OP_ILLEGAL);
811 	}
812 
813 	return htonl(NFS_OK);
814 }
815 
816 static __be32 process_op(int nop, struct svc_rqst *rqstp,
817 		struct xdr_stream *xdr_in, void *argp,
818 		struct xdr_stream *xdr_out, void *resp,
819 		struct cb_process_state *cps)
820 {
821 	struct callback_op *op = &callback_ops[0];
822 	unsigned int op_nr;
823 	__be32 status;
824 	long maxlen;
825 	__be32 res;
826 
827 	status = decode_op_hdr(xdr_in, &op_nr);
828 	if (unlikely(status))
829 		return status;
830 
831 	switch (cps->minorversion) {
832 	case 0:
833 		status = preprocess_nfs4_op(op_nr, &op);
834 		break;
835 	case 1:
836 		status = preprocess_nfs41_op(nop, op_nr, &op);
837 		break;
838 	case 2:
839 		status = preprocess_nfs42_op(nop, op_nr, &op);
840 		break;
841 	default:
842 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
843 	}
844 
845 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
846 		op_nr = OP_CB_ILLEGAL;
847 	if (status)
848 		goto encode_hdr;
849 
850 	if (cps->drc_status) {
851 		status = cps->drc_status;
852 		goto encode_hdr;
853 	}
854 
855 	maxlen = xdr_out->end - xdr_out->p;
856 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
857 		status = op->decode_args(rqstp, xdr_in, argp);
858 		if (likely(status == 0))
859 			status = op->process_op(argp, resp, cps);
860 	} else
861 		status = htonl(NFS4ERR_RESOURCE);
862 
863 encode_hdr:
864 	res = encode_op_hdr(xdr_out, op_nr, status);
865 	if (unlikely(res))
866 		return res;
867 	if (op->encode_res != NULL && status == 0)
868 		status = op->encode_res(rqstp, xdr_out, resp);
869 	return status;
870 }
871 
872 /*
873  * Decode, process and encode a COMPOUND
874  */
875 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
876 {
877 	struct cb_compound_hdr_arg hdr_arg = { 0 };
878 	struct cb_compound_hdr_res hdr_res = { NULL };
879 	struct xdr_stream xdr_in, xdr_out;
880 	__be32 *p, status;
881 	struct cb_process_state cps = {
882 		.drc_status = 0,
883 		.clp = NULL,
884 		.net = SVC_NET(rqstp),
885 	};
886 	unsigned int nops = 0;
887 
888 	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
889 
890 	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
891 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
892 
893 	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
894 	if (status == htonl(NFS4ERR_RESOURCE))
895 		return rpc_garbage_args;
896 
897 	if (hdr_arg.minorversion == 0) {
898 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
899 		if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
900 			goto out_invalidcred;
901 	}
902 
903 	cps.minorversion = hdr_arg.minorversion;
904 	hdr_res.taglen = hdr_arg.taglen;
905 	hdr_res.tag = hdr_arg.tag;
906 	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
907 		return rpc_system_err;
908 
909 	while (status == 0 && nops != hdr_arg.nops) {
910 		status = process_op(nops, rqstp, &xdr_in,
911 				    argp, &xdr_out, resp, &cps);
912 		nops++;
913 	}
914 
915 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
916 	* resource error in cb_compound status without returning op */
917 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
918 		status = htonl(NFS4ERR_RESOURCE);
919 		nops--;
920 	}
921 
922 	*hdr_res.status = status;
923 	*hdr_res.nops = htonl(nops);
924 	nfs4_cb_free_slot(&cps);
925 	nfs_put_client(cps.clp);
926 	return rpc_success;
927 
928 out_invalidcred:
929 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
930 	return rpc_autherr_badcred;
931 }
932 
933 /*
934  * Define NFS4 callback COMPOUND ops.
935  */
936 static struct callback_op callback_ops[] = {
937 	[0] = {
938 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
939 	},
940 	[OP_CB_GETATTR] = {
941 		.process_op = (callback_process_op_t)nfs4_callback_getattr,
942 		.decode_args = (callback_decode_arg_t)decode_getattr_args,
943 		.encode_res = (callback_encode_res_t)encode_getattr_res,
944 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
945 	},
946 	[OP_CB_RECALL] = {
947 		.process_op = (callback_process_op_t)nfs4_callback_recall,
948 		.decode_args = (callback_decode_arg_t)decode_recall_args,
949 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
950 	},
951 #if defined(CONFIG_NFS_V4_1)
952 	[OP_CB_LAYOUTRECALL] = {
953 		.process_op = (callback_process_op_t)nfs4_callback_layoutrecall,
954 		.decode_args =
955 			(callback_decode_arg_t)decode_layoutrecall_args,
956 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
957 	},
958 	[OP_CB_NOTIFY_DEVICEID] = {
959 		.process_op = (callback_process_op_t)nfs4_callback_devicenotify,
960 		.decode_args =
961 			(callback_decode_arg_t)decode_devicenotify_args,
962 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
963 	},
964 	[OP_CB_SEQUENCE] = {
965 		.process_op = (callback_process_op_t)nfs4_callback_sequence,
966 		.decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
967 		.encode_res = (callback_encode_res_t)encode_cb_sequence_res,
968 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
969 	},
970 	[OP_CB_RECALL_ANY] = {
971 		.process_op = (callback_process_op_t)nfs4_callback_recallany,
972 		.decode_args = (callback_decode_arg_t)decode_recallany_args,
973 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
974 	},
975 	[OP_CB_RECALL_SLOT] = {
976 		.process_op = (callback_process_op_t)nfs4_callback_recallslot,
977 		.decode_args = (callback_decode_arg_t)decode_recallslot_args,
978 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
979 	},
980 	[OP_CB_NOTIFY_LOCK] = {
981 		.process_op = (callback_process_op_t)nfs4_callback_notify_lock,
982 		.decode_args = (callback_decode_arg_t)decode_notify_lock_args,
983 		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
984 	},
985 #endif /* CONFIG_NFS_V4_1 */
986 };
987 
988 /*
989  * Define NFS4 callback procedures
990  */
991 static struct svc_procedure nfs4_callback_procedures1[] = {
992 	[CB_NULL] = {
993 		.pc_func = nfs4_callback_null,
994 		.pc_decode = (kxdrproc_t)nfs4_decode_void,
995 		.pc_encode = (kxdrproc_t)nfs4_encode_void,
996 		.pc_xdrressize = 1,
997 	},
998 	[CB_COMPOUND] = {
999 		.pc_func = nfs4_callback_compound,
1000 		.pc_encode = (kxdrproc_t)nfs4_encode_void,
1001 		.pc_argsize = 256,
1002 		.pc_ressize = 256,
1003 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1004 	}
1005 };
1006 
1007 struct svc_version nfs4_callback_version1 = {
1008 	.vs_vers = 1,
1009 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1010 	.vs_proc = nfs4_callback_procedures1,
1011 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1012 	.vs_dispatch = NULL,
1013 	.vs_hidden = true,
1014 	.vs_need_cong_ctrl = true,
1015 };
1016 
1017 struct svc_version nfs4_callback_version4 = {
1018 	.vs_vers = 4,
1019 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1020 	.vs_proc = nfs4_callback_procedures1,
1021 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1022 	.vs_dispatch = NULL,
1023 	.vs_hidden = true,
1024 	.vs_need_cong_ctrl = true,
1025 };
1026