xref: /linux/fs/nfs/callback_xdr.c (revision d257f9bf06129613de539ea71ecea60848b662cd)
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 struct callback_op {
47 	__be32 (*process_op)(void *, void *, struct cb_process_state *);
48 	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
49 	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
50 			const void *);
51 	long res_maxsize;
52 };
53 
54 static struct callback_op callback_ops[];
55 
56 static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
57 {
58 	return htonl(NFS4_OK);
59 }
60 
61 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p)
62 {
63 	return xdr_argsize_check(rqstp, p);
64 }
65 
66 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p)
67 {
68 	return xdr_ressize_check(rqstp, p);
69 }
70 
71 static __be32 *read_buf(struct xdr_stream *xdr, size_t nbytes)
72 {
73 	__be32 *p;
74 
75 	p = xdr_inline_decode(xdr, nbytes);
76 	if (unlikely(p == NULL))
77 		printk(KERN_WARNING "NFS: NFSv4 callback reply buffer overflowed!\n");
78 	return p;
79 }
80 
81 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
82 		const char **str, size_t maxlen)
83 {
84 	ssize_t err;
85 
86 	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
87 	if (err < 0)
88 		return cpu_to_be32(NFS4ERR_RESOURCE);
89 	*len = err;
90 	return 0;
91 }
92 
93 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
94 {
95 	__be32 *p;
96 
97 	p = read_buf(xdr, 4);
98 	if (unlikely(p == NULL))
99 		return htonl(NFS4ERR_RESOURCE);
100 	fh->size = ntohl(*p);
101 	if (fh->size > NFS4_FHSIZE)
102 		return htonl(NFS4ERR_BADHANDLE);
103 	p = read_buf(xdr, fh->size);
104 	if (unlikely(p == NULL))
105 		return htonl(NFS4ERR_RESOURCE);
106 	memcpy(&fh->data[0], p, fh->size);
107 	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
108 	return 0;
109 }
110 
111 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
112 {
113 	__be32 *p;
114 	unsigned int attrlen;
115 
116 	p = read_buf(xdr, 4);
117 	if (unlikely(p == NULL))
118 		return htonl(NFS4ERR_RESOURCE);
119 	attrlen = ntohl(*p);
120 	p = read_buf(xdr, attrlen << 2);
121 	if (unlikely(p == NULL))
122 		return htonl(NFS4ERR_RESOURCE);
123 	if (likely(attrlen > 0))
124 		bitmap[0] = ntohl(*p++);
125 	if (attrlen > 1)
126 		bitmap[1] = ntohl(*p);
127 	return 0;
128 }
129 
130 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
131 {
132 	__be32 *p;
133 
134 	p = read_buf(xdr, NFS4_STATEID_SIZE);
135 	if (unlikely(p == NULL))
136 		return htonl(NFS4ERR_RESOURCE);
137 	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
138 	return 0;
139 }
140 
141 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
142 {
143 	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
144 	return decode_stateid(xdr, stateid);
145 }
146 
147 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
148 {
149 	__be32 *p;
150 	__be32 status;
151 
152 	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
153 	if (unlikely(status != 0))
154 		return status;
155 	p = read_buf(xdr, 12);
156 	if (unlikely(p == NULL))
157 		return htonl(NFS4ERR_RESOURCE);
158 	hdr->minorversion = ntohl(*p++);
159 	/* Check for minor version support */
160 	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
161 		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
162 	} else {
163 		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
164 			"illegal minor version %u!\n",
165 			__func__, hdr->minorversion);
166 		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
167 	}
168 	hdr->nops = ntohl(*p);
169 	return 0;
170 }
171 
172 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
173 {
174 	__be32 *p;
175 	p = read_buf(xdr, 4);
176 	if (unlikely(p == NULL))
177 		return htonl(NFS4ERR_RESOURCE_HDR);
178 	*op = ntohl(*p);
179 	return 0;
180 }
181 
182 static __be32 decode_getattr_args(struct svc_rqst *rqstp,
183 		struct xdr_stream *xdr, void *argp)
184 {
185 	struct cb_getattrargs *args = argp;
186 	__be32 status;
187 
188 	status = decode_fh(xdr, &args->fh);
189 	if (unlikely(status != 0))
190 		return status;
191 	return decode_bitmap(xdr, args->bitmap);
192 }
193 
194 static __be32 decode_recall_args(struct svc_rqst *rqstp,
195 		struct xdr_stream *xdr, void *argp)
196 {
197 	struct cb_recallargs *args = argp;
198 	__be32 *p;
199 	__be32 status;
200 
201 	status = decode_delegation_stateid(xdr, &args->stateid);
202 	if (unlikely(status != 0))
203 		return status;
204 	p = read_buf(xdr, 4);
205 	if (unlikely(p == NULL))
206 		return htonl(NFS4ERR_RESOURCE);
207 	args->truncate = ntohl(*p);
208 	return decode_fh(xdr, &args->fh);
209 }
210 
211 #if defined(CONFIG_NFS_V4_1)
212 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
213 {
214 	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
215 	return decode_stateid(xdr, stateid);
216 }
217 
218 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
219 				       struct xdr_stream *xdr, void *argp)
220 {
221 	struct cb_layoutrecallargs *args = argp;
222 	__be32 *p;
223 	__be32 status = 0;
224 	uint32_t iomode;
225 
226 	p = read_buf(xdr, 4 * sizeof(uint32_t));
227 	if (unlikely(p == NULL))
228 		return htonl(NFS4ERR_BADXDR);
229 
230 	args->cbl_layout_type = ntohl(*p++);
231 	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
232 	 * as it is unusable and ignored with the other types.
233 	 */
234 	iomode = ntohl(*p++);
235 	args->cbl_layoutchanged = ntohl(*p++);
236 	args->cbl_recall_type = ntohl(*p++);
237 
238 	if (args->cbl_recall_type == RETURN_FILE) {
239 		args->cbl_range.iomode = iomode;
240 		status = decode_fh(xdr, &args->cbl_fh);
241 		if (unlikely(status != 0))
242 			return status;
243 
244 		p = read_buf(xdr, 2 * sizeof(uint64_t));
245 		if (unlikely(p == NULL))
246 			return htonl(NFS4ERR_BADXDR);
247 		p = xdr_decode_hyper(p, &args->cbl_range.offset);
248 		p = xdr_decode_hyper(p, &args->cbl_range.length);
249 		return decode_layout_stateid(xdr, &args->cbl_stateid);
250 	} else if (args->cbl_recall_type == RETURN_FSID) {
251 		p = read_buf(xdr, 2 * sizeof(uint64_t));
252 		if (unlikely(p == NULL))
253 			return htonl(NFS4ERR_BADXDR);
254 		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
255 		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
256 	} else if (args->cbl_recall_type != RETURN_ALL)
257 		return htonl(NFS4ERR_BADXDR);
258 	return 0;
259 }
260 
261 static
262 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
263 				struct xdr_stream *xdr,
264 				void *argp)
265 {
266 	struct cb_devicenotifyargs *args = argp;
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 					void *argp)
407 {
408 	struct cb_sequenceargs *args = argp;
409 	__be32 *p;
410 	int i;
411 	__be32 status;
412 
413 	status = decode_sessionid(xdr, &args->csa_sessionid);
414 	if (status)
415 		return status;
416 
417 	p = read_buf(xdr, 5 * sizeof(uint32_t));
418 	if (unlikely(p == NULL))
419 		return htonl(NFS4ERR_RESOURCE);
420 
421 	args->csa_addr = svc_addr(rqstp);
422 	args->csa_sequenceid = ntohl(*p++);
423 	args->csa_slotid = ntohl(*p++);
424 	args->csa_highestslotid = ntohl(*p++);
425 	args->csa_cachethis = ntohl(*p++);
426 	args->csa_nrclists = ntohl(*p++);
427 	args->csa_rclists = NULL;
428 	if (args->csa_nrclists) {
429 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
430 						  sizeof(*args->csa_rclists),
431 						  GFP_KERNEL);
432 		if (unlikely(args->csa_rclists == NULL))
433 			return htonl(NFS4ERR_RESOURCE);
434 
435 		for (i = 0; i < args->csa_nrclists; i++) {
436 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
437 			if (status) {
438 				args->csa_nrclists = i;
439 				goto out_free;
440 			}
441 		}
442 	}
443 	return 0;
444 
445 out_free:
446 	for (i = 0; i < args->csa_nrclists; i++)
447 		kfree(args->csa_rclists[i].rcl_refcalls);
448 	kfree(args->csa_rclists);
449 	return status;
450 }
451 
452 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
453 				      struct xdr_stream *xdr,
454 				      void *argp)
455 {
456 	struct cb_recallanyargs *args = argp;
457 	uint32_t bitmap[2];
458 	__be32 *p, status;
459 
460 	p = read_buf(xdr, 4);
461 	if (unlikely(p == NULL))
462 		return htonl(NFS4ERR_BADXDR);
463 	args->craa_objs_to_keep = ntohl(*p++);
464 	status = decode_bitmap(xdr, bitmap);
465 	if (unlikely(status))
466 		return status;
467 	args->craa_type_mask = bitmap[0];
468 
469 	return 0;
470 }
471 
472 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
473 					struct xdr_stream *xdr,
474 					void *argp)
475 {
476 	struct cb_recallslotargs *args = argp;
477 	__be32 *p;
478 
479 	p = read_buf(xdr, 4);
480 	if (unlikely(p == NULL))
481 		return htonl(NFS4ERR_BADXDR);
482 	args->crsa_target_highest_slotid = ntohl(*p++);
483 	return 0;
484 }
485 
486 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
487 {
488 	__be32		*p;
489 	unsigned int	len;
490 
491 	p = read_buf(xdr, 12);
492 	if (unlikely(p == NULL))
493 		return htonl(NFS4ERR_BADXDR);
494 
495 	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
496 	len = be32_to_cpu(*p);
497 
498 	p = read_buf(xdr, len);
499 	if (unlikely(p == NULL))
500 		return htonl(NFS4ERR_BADXDR);
501 
502 	/* Only try to decode if the length is right */
503 	if (len == 20) {
504 		p += 2;	/* skip "lock id:" */
505 		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
506 		xdr_decode_hyper(p, &args->cbnl_owner.id);
507 		args->cbnl_valid = true;
508 	} else {
509 		args->cbnl_owner.s_dev = 0;
510 		args->cbnl_owner.id = 0;
511 		args->cbnl_valid = false;
512 	}
513 	return 0;
514 }
515 
516 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
517 		struct xdr_stream *xdr, void *argp)
518 {
519 	struct cb_notify_lock_args *args = argp;
520 	__be32 status;
521 
522 	status = decode_fh(xdr, &args->cbnl_fh);
523 	if (unlikely(status != 0))
524 		return status;
525 	return decode_lockowner(xdr, args);
526 }
527 
528 #endif /* CONFIG_NFS_V4_1 */
529 
530 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
531 {
532 	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
533 		return cpu_to_be32(NFS4ERR_RESOURCE);
534 	return 0;
535 }
536 
537 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
538 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
539 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
540 {
541 	__be32 bm[2];
542 	__be32 *p;
543 
544 	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
545 	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
546 	if (bm[1] != 0) {
547 		p = xdr_reserve_space(xdr, 16);
548 		if (unlikely(p == NULL))
549 			return htonl(NFS4ERR_RESOURCE);
550 		*p++ = htonl(2);
551 		*p++ = bm[0];
552 		*p++ = bm[1];
553 	} else if (bm[0] != 0) {
554 		p = xdr_reserve_space(xdr, 12);
555 		if (unlikely(p == NULL))
556 			return htonl(NFS4ERR_RESOURCE);
557 		*p++ = htonl(1);
558 		*p++ = bm[0];
559 	} else {
560 		p = xdr_reserve_space(xdr, 8);
561 		if (unlikely(p == NULL))
562 			return htonl(NFS4ERR_RESOURCE);
563 		*p++ = htonl(0);
564 	}
565 	*savep = p;
566 	return 0;
567 }
568 
569 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
570 {
571 	__be32 *p;
572 
573 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
574 		return 0;
575 	p = xdr_reserve_space(xdr, 8);
576 	if (unlikely(!p))
577 		return htonl(NFS4ERR_RESOURCE);
578 	p = xdr_encode_hyper(p, change);
579 	return 0;
580 }
581 
582 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
583 {
584 	__be32 *p;
585 
586 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
587 		return 0;
588 	p = xdr_reserve_space(xdr, 8);
589 	if (unlikely(!p))
590 		return htonl(NFS4ERR_RESOURCE);
591 	p = xdr_encode_hyper(p, size);
592 	return 0;
593 }
594 
595 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
596 {
597 	__be32 *p;
598 
599 	p = xdr_reserve_space(xdr, 12);
600 	if (unlikely(!p))
601 		return htonl(NFS4ERR_RESOURCE);
602 	p = xdr_encode_hyper(p, time->tv_sec);
603 	*p = htonl(time->tv_nsec);
604 	return 0;
605 }
606 
607 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
608 {
609 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
610 		return 0;
611 	return encode_attr_time(xdr,time);
612 }
613 
614 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
615 {
616 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
617 		return 0;
618 	return encode_attr_time(xdr,time);
619 }
620 
621 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
622 {
623 	__be32 status;
624 
625 	hdr->status = xdr_reserve_space(xdr, 4);
626 	if (unlikely(hdr->status == NULL))
627 		return htonl(NFS4ERR_RESOURCE);
628 	status = encode_string(xdr, hdr->taglen, hdr->tag);
629 	if (unlikely(status != 0))
630 		return status;
631 	hdr->nops = xdr_reserve_space(xdr, 4);
632 	if (unlikely(hdr->nops == NULL))
633 		return htonl(NFS4ERR_RESOURCE);
634 	return 0;
635 }
636 
637 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
638 {
639 	__be32 *p;
640 
641 	p = xdr_reserve_space(xdr, 8);
642 	if (unlikely(p == NULL))
643 		return htonl(NFS4ERR_RESOURCE_HDR);
644 	*p++ = htonl(op);
645 	*p = res;
646 	return 0;
647 }
648 
649 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
650 		const void *resp)
651 {
652 	const struct cb_getattrres *res = resp;
653 	__be32 *savep = NULL;
654 	__be32 status = res->status;
655 
656 	if (unlikely(status != 0))
657 		goto out;
658 	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
659 	if (unlikely(status != 0))
660 		goto out;
661 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
662 	if (unlikely(status != 0))
663 		goto out;
664 	status = encode_attr_size(xdr, res->bitmap, res->size);
665 	if (unlikely(status != 0))
666 		goto out;
667 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
668 	if (unlikely(status != 0))
669 		goto out;
670 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
671 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
672 out:
673 	return status;
674 }
675 
676 #if defined(CONFIG_NFS_V4_1)
677 
678 static __be32 encode_sessionid(struct xdr_stream *xdr,
679 				 const struct nfs4_sessionid *sid)
680 {
681 	__be32 *p;
682 
683 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
684 	if (unlikely(p == NULL))
685 		return htonl(NFS4ERR_RESOURCE);
686 
687 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
688 	return 0;
689 }
690 
691 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
692 				       struct xdr_stream *xdr,
693 				       const void *resp)
694 {
695 	const struct cb_sequenceres *res = resp;
696 	__be32 *p;
697 	__be32 status = res->csr_status;
698 
699 	if (unlikely(status != 0))
700 		return status;
701 
702 	status = encode_sessionid(xdr, &res->csr_sessionid);
703 	if (status)
704 		return status;
705 
706 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
707 	if (unlikely(p == NULL))
708 		return htonl(NFS4ERR_RESOURCE);
709 
710 	*p++ = htonl(res->csr_sequenceid);
711 	*p++ = htonl(res->csr_slotid);
712 	*p++ = htonl(res->csr_highestslotid);
713 	*p++ = htonl(res->csr_target_highestslotid);
714 	return 0;
715 }
716 
717 static __be32
718 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
719 {
720 	if (op_nr == OP_CB_SEQUENCE) {
721 		if (nop != 0)
722 			return htonl(NFS4ERR_SEQUENCE_POS);
723 	} else {
724 		if (nop == 0)
725 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
726 	}
727 
728 	switch (op_nr) {
729 	case OP_CB_GETATTR:
730 	case OP_CB_RECALL:
731 	case OP_CB_SEQUENCE:
732 	case OP_CB_RECALL_ANY:
733 	case OP_CB_RECALL_SLOT:
734 	case OP_CB_LAYOUTRECALL:
735 	case OP_CB_NOTIFY_DEVICEID:
736 	case OP_CB_NOTIFY_LOCK:
737 		*op = &callback_ops[op_nr];
738 		break;
739 
740 	case OP_CB_NOTIFY:
741 	case OP_CB_PUSH_DELEG:
742 	case OP_CB_RECALLABLE_OBJ_AVAIL:
743 	case OP_CB_WANTS_CANCELLED:
744 		return htonl(NFS4ERR_NOTSUPP);
745 
746 	default:
747 		return htonl(NFS4ERR_OP_ILLEGAL);
748 	}
749 
750 	return htonl(NFS_OK);
751 }
752 
753 static void nfs4_callback_free_slot(struct nfs4_session *session,
754 		struct nfs4_slot *slot)
755 {
756 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
757 
758 	spin_lock(&tbl->slot_tbl_lock);
759 	/*
760 	 * Let the state manager know callback processing done.
761 	 * A single slot, so highest used slotid is either 0 or -1
762 	 */
763 	nfs4_free_slot(tbl, slot);
764 	spin_unlock(&tbl->slot_tbl_lock);
765 }
766 
767 static void nfs4_cb_free_slot(struct cb_process_state *cps)
768 {
769 	if (cps->slot) {
770 		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
771 		cps->slot = NULL;
772 	}
773 }
774 
775 #else /* CONFIG_NFS_V4_1 */
776 
777 static __be32
778 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
779 {
780 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
781 }
782 
783 static void nfs4_cb_free_slot(struct cb_process_state *cps)
784 {
785 }
786 #endif /* CONFIG_NFS_V4_1 */
787 
788 #ifdef CONFIG_NFS_V4_2
789 static __be32
790 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
791 {
792 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
793 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
794 		return status;
795 
796 	if (op_nr == OP_CB_OFFLOAD)
797 		return htonl(NFS4ERR_NOTSUPP);
798 	return htonl(NFS4ERR_OP_ILLEGAL);
799 }
800 #else /* CONFIG_NFS_V4_2 */
801 static __be32
802 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
803 {
804 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
805 }
806 #endif /* CONFIG_NFS_V4_2 */
807 
808 static __be32
809 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
810 {
811 	switch (op_nr) {
812 	case OP_CB_GETATTR:
813 	case OP_CB_RECALL:
814 		*op = &callback_ops[op_nr];
815 		break;
816 	default:
817 		return htonl(NFS4ERR_OP_ILLEGAL);
818 	}
819 
820 	return htonl(NFS_OK);
821 }
822 
823 static __be32 process_op(int nop, struct svc_rqst *rqstp,
824 		struct xdr_stream *xdr_in, void *argp,
825 		struct xdr_stream *xdr_out, void *resp,
826 		struct cb_process_state *cps)
827 {
828 	struct callback_op *op = &callback_ops[0];
829 	unsigned int op_nr;
830 	__be32 status;
831 	long maxlen;
832 	__be32 res;
833 
834 	status = decode_op_hdr(xdr_in, &op_nr);
835 	if (unlikely(status))
836 		return status;
837 
838 	switch (cps->minorversion) {
839 	case 0:
840 		status = preprocess_nfs4_op(op_nr, &op);
841 		break;
842 	case 1:
843 		status = preprocess_nfs41_op(nop, op_nr, &op);
844 		break;
845 	case 2:
846 		status = preprocess_nfs42_op(nop, op_nr, &op);
847 		break;
848 	default:
849 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
850 	}
851 
852 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
853 		op_nr = OP_CB_ILLEGAL;
854 	if (status)
855 		goto encode_hdr;
856 
857 	if (cps->drc_status) {
858 		status = cps->drc_status;
859 		goto encode_hdr;
860 	}
861 
862 	maxlen = xdr_out->end - xdr_out->p;
863 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
864 		status = op->decode_args(rqstp, xdr_in, argp);
865 		if (likely(status == 0))
866 			status = op->process_op(argp, resp, cps);
867 	} else
868 		status = htonl(NFS4ERR_RESOURCE);
869 
870 encode_hdr:
871 	res = encode_op_hdr(xdr_out, op_nr, status);
872 	if (unlikely(res))
873 		return res;
874 	if (op->encode_res != NULL && status == 0)
875 		status = op->encode_res(rqstp, xdr_out, resp);
876 	return status;
877 }
878 
879 /*
880  * Decode, process and encode a COMPOUND
881  */
882 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
883 {
884 	struct cb_compound_hdr_arg hdr_arg = { 0 };
885 	struct cb_compound_hdr_res hdr_res = { NULL };
886 	struct xdr_stream xdr_in, xdr_out;
887 	__be32 *p, status;
888 	struct cb_process_state cps = {
889 		.drc_status = 0,
890 		.clp = NULL,
891 		.net = SVC_NET(rqstp),
892 	};
893 	unsigned int nops = 0;
894 
895 	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
896 
897 	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
898 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
899 
900 	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
901 	if (status == htonl(NFS4ERR_RESOURCE))
902 		return rpc_garbage_args;
903 
904 	if (hdr_arg.minorversion == 0) {
905 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
906 		if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
907 			goto out_invalidcred;
908 	}
909 
910 	cps.minorversion = hdr_arg.minorversion;
911 	hdr_res.taglen = hdr_arg.taglen;
912 	hdr_res.tag = hdr_arg.tag;
913 	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
914 		return rpc_system_err;
915 
916 	while (status == 0 && nops != hdr_arg.nops) {
917 		status = process_op(nops, rqstp, &xdr_in,
918 				    rqstp->rq_argp, &xdr_out, rqstp->rq_resp,
919 				    &cps);
920 		nops++;
921 	}
922 
923 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
924 	* resource error in cb_compound status without returning op */
925 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
926 		status = htonl(NFS4ERR_RESOURCE);
927 		nops--;
928 	}
929 
930 	*hdr_res.status = status;
931 	*hdr_res.nops = htonl(nops);
932 	nfs4_cb_free_slot(&cps);
933 	nfs_put_client(cps.clp);
934 	return rpc_success;
935 
936 out_invalidcred:
937 	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
938 	return rpc_autherr_badcred;
939 }
940 
941 /*
942  * Define NFS4 callback COMPOUND ops.
943  */
944 static struct callback_op callback_ops[] = {
945 	[0] = {
946 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
947 	},
948 	[OP_CB_GETATTR] = {
949 		.process_op = nfs4_callback_getattr,
950 		.decode_args = decode_getattr_args,
951 		.encode_res = encode_getattr_res,
952 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
953 	},
954 	[OP_CB_RECALL] = {
955 		.process_op = nfs4_callback_recall,
956 		.decode_args = decode_recall_args,
957 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
958 	},
959 #if defined(CONFIG_NFS_V4_1)
960 	[OP_CB_LAYOUTRECALL] = {
961 		.process_op = nfs4_callback_layoutrecall,
962 		.decode_args = decode_layoutrecall_args,
963 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
964 	},
965 	[OP_CB_NOTIFY_DEVICEID] = {
966 		.process_op = nfs4_callback_devicenotify,
967 		.decode_args = decode_devicenotify_args,
968 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
969 	},
970 	[OP_CB_SEQUENCE] = {
971 		.process_op = nfs4_callback_sequence,
972 		.decode_args = decode_cb_sequence_args,
973 		.encode_res = encode_cb_sequence_res,
974 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
975 	},
976 	[OP_CB_RECALL_ANY] = {
977 		.process_op = nfs4_callback_recallany,
978 		.decode_args = decode_recallany_args,
979 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
980 	},
981 	[OP_CB_RECALL_SLOT] = {
982 		.process_op = nfs4_callback_recallslot,
983 		.decode_args = decode_recallslot_args,
984 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
985 	},
986 	[OP_CB_NOTIFY_LOCK] = {
987 		.process_op = nfs4_callback_notify_lock,
988 		.decode_args = decode_notify_lock_args,
989 		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
990 	},
991 #endif /* CONFIG_NFS_V4_1 */
992 };
993 
994 /*
995  * Define NFS4 callback procedures
996  */
997 static const struct svc_procedure nfs4_callback_procedures1[] = {
998 	[CB_NULL] = {
999 		.pc_func = nfs4_callback_null,
1000 		.pc_decode = nfs4_decode_void,
1001 		.pc_encode = nfs4_encode_void,
1002 		.pc_xdrressize = 1,
1003 	},
1004 	[CB_COMPOUND] = {
1005 		.pc_func = nfs4_callback_compound,
1006 		.pc_encode = nfs4_encode_void,
1007 		.pc_argsize = 256,
1008 		.pc_ressize = 256,
1009 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1010 	}
1011 };
1012 
1013 static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
1014 const struct svc_version nfs4_callback_version1 = {
1015 	.vs_vers = 1,
1016 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1017 	.vs_proc = nfs4_callback_procedures1,
1018 	.vs_count = nfs4_callback_count1,
1019 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1020 	.vs_dispatch = NULL,
1021 	.vs_hidden = true,
1022 	.vs_need_cong_ctrl = true,
1023 };
1024 
1025 static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
1026 const struct svc_version nfs4_callback_version4 = {
1027 	.vs_vers = 4,
1028 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1029 	.vs_proc = nfs4_callback_procedures1,
1030 	.vs_count = nfs4_callback_count4,
1031 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1032 	.vs_dispatch = NULL,
1033 	.vs_hidden = true,
1034 	.vs_need_cong_ctrl = true,
1035 };
1036