xref: /linux/fs/nfs/callback_xdr.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
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/slab.h>
13 #include <linux/sunrpc/bc_xprt.h>
14 #include "nfs4_fs.h"
15 #include "callback.h"
16 #include "internal.h"
17 
18 #define CB_OP_TAGLEN_MAXSZ	(512)
19 #define CB_OP_HDR_RES_MAXSZ	(2 + CB_OP_TAGLEN_MAXSZ)
20 #define CB_OP_GETATTR_BITMAP_MAXSZ	(4)
21 #define CB_OP_GETATTR_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
22 				CB_OP_GETATTR_BITMAP_MAXSZ + \
23 				2 + 2 + 3 + 3)
24 #define CB_OP_RECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
25 
26 #if defined(CONFIG_NFS_V4_1)
27 #define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
28 #define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
29 #define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
30 					4 + 1 + 3)
31 #define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
32 #define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
33 #endif /* CONFIG_NFS_V4_1 */
34 
35 #define NFSDBG_FACILITY NFSDBG_CALLBACK
36 
37 /* Internal error code */
38 #define NFS4ERR_RESOURCE_HDR	11050
39 
40 typedef __be32 (*callback_process_op_t)(void *, void *,
41 					struct cb_process_state *);
42 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
43 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
44 
45 
46 struct callback_op {
47 	callback_process_op_t process_op;
48 	callback_decode_arg_t decode_args;
49 	callback_encode_res_t encode_res;
50 	long res_maxsize;
51 };
52 
53 static struct callback_op callback_ops[];
54 
55 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
56 {
57 	return htonl(NFS4_OK);
58 }
59 
60 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
61 {
62 	return xdr_argsize_check(rqstp, p);
63 }
64 
65 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
66 {
67 	return xdr_ressize_check(rqstp, p);
68 }
69 
70 static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
71 {
72 	__be32 *p;
73 
74 	p = xdr_inline_decode(xdr, nbytes);
75 	if (unlikely(p == NULL))
76 		printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
77 	return p;
78 }
79 
80 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
81 {
82 	__be32 *p;
83 
84 	p = read_buf(xdr, 4);
85 	if (unlikely(p == NULL))
86 		return htonl(NFS4ERR_RESOURCE);
87 	*len = ntohl(*p);
88 
89 	if (*len != 0) {
90 		p = read_buf(xdr, *len);
91 		if (unlikely(p == NULL))
92 			return htonl(NFS4ERR_RESOURCE);
93 		*str = (const char *)p;
94 	} else
95 		*str = NULL;
96 
97 	return 0;
98 }
99 
100 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
101 {
102 	__be32 *p;
103 
104 	p = read_buf(xdr, 4);
105 	if (unlikely(p == NULL))
106 		return htonl(NFS4ERR_RESOURCE);
107 	fh->size = ntohl(*p);
108 	if (fh->size > NFS4_FHSIZE)
109 		return htonl(NFS4ERR_BADHANDLE);
110 	p = read_buf(xdr, fh->size);
111 	if (unlikely(p == NULL))
112 		return htonl(NFS4ERR_RESOURCE);
113 	memcpy(&fh->data[0], p, fh->size);
114 	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
115 	return 0;
116 }
117 
118 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
119 {
120 	__be32 *p;
121 	unsigned int attrlen;
122 
123 	p = read_buf(xdr, 4);
124 	if (unlikely(p == NULL))
125 		return htonl(NFS4ERR_RESOURCE);
126 	attrlen = ntohl(*p);
127 	p = read_buf(xdr, attrlen << 2);
128 	if (unlikely(p == NULL))
129 		return htonl(NFS4ERR_RESOURCE);
130 	if (likely(attrlen > 0))
131 		bitmap[0] = ntohl(*p++);
132 	if (attrlen > 1)
133 		bitmap[1] = ntohl(*p);
134 	return 0;
135 }
136 
137 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
138 {
139 	__be32 *p;
140 
141 	p = read_buf(xdr, 16);
142 	if (unlikely(p == NULL))
143 		return htonl(NFS4ERR_RESOURCE);
144 	memcpy(stateid->data, p, 16);
145 	return 0;
146 }
147 
148 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
149 {
150 	__be32 *p;
151 	__be32 status;
152 
153 	status = decode_string(xdr, &hdr->taglen, &hdr->tag);
154 	if (unlikely(status != 0))
155 		return status;
156 	/* We do not like overly long tags! */
157 	if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
158 		printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
159 				__func__, hdr->taglen);
160 		return htonl(NFS4ERR_RESOURCE);
161 	}
162 	p = read_buf(xdr, 12);
163 	if (unlikely(p == NULL))
164 		return htonl(NFS4ERR_RESOURCE);
165 	hdr->minorversion = ntohl(*p++);
166 	/* Check minor version is zero or one. */
167 	if (hdr->minorversion <= 1) {
168 		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 */
169 	} else {
170 		printk(KERN_WARNING "%s: NFSv4 server callback with "
171 			"illegal minor version %u!\n",
172 			__func__, hdr->minorversion);
173 		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
174 	}
175 	hdr->nops = ntohl(*p);
176 	dprintk("%s: minorversion %d nops %d\n", __func__,
177 		hdr->minorversion, hdr->nops);
178 	return 0;
179 }
180 
181 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
182 {
183 	__be32 *p;
184 	p = read_buf(xdr, 4);
185 	if (unlikely(p == NULL))
186 		return htonl(NFS4ERR_RESOURCE_HDR);
187 	*op = ntohl(*p);
188 	return 0;
189 }
190 
191 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
192 {
193 	__be32 status;
194 
195 	status = decode_fh(xdr, &args->fh);
196 	if (unlikely(status != 0))
197 		goto out;
198 	args->addr = svc_addr(rqstp);
199 	status = decode_bitmap(xdr, args->bitmap);
200 out:
201 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
202 	return status;
203 }
204 
205 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
206 {
207 	__be32 *p;
208 	__be32 status;
209 
210 	args->addr = svc_addr(rqstp);
211 	status = decode_stateid(xdr, &args->stateid);
212 	if (unlikely(status != 0))
213 		goto out;
214 	p = read_buf(xdr, 4);
215 	if (unlikely(p == NULL)) {
216 		status = htonl(NFS4ERR_RESOURCE);
217 		goto out;
218 	}
219 	args->truncate = ntohl(*p);
220 	status = decode_fh(xdr, &args->fh);
221 out:
222 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
223 	return status;
224 }
225 
226 #if defined(CONFIG_NFS_V4_1)
227 
228 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
229 				       struct xdr_stream *xdr,
230 				       struct cb_layoutrecallargs *args)
231 {
232 	__be32 *p;
233 	__be32 status = 0;
234 	uint32_t iomode;
235 
236 	args->cbl_addr = svc_addr(rqstp);
237 	p = read_buf(xdr, 4 * sizeof(uint32_t));
238 	if (unlikely(p == NULL)) {
239 		status = htonl(NFS4ERR_BADXDR);
240 		goto out;
241 	}
242 
243 	args->cbl_layout_type = ntohl(*p++);
244 	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
245 	 * as it is unusable and ignored with the other types.
246 	 */
247 	iomode = ntohl(*p++);
248 	args->cbl_layoutchanged = ntohl(*p++);
249 	args->cbl_recall_type = ntohl(*p++);
250 
251 	if (args->cbl_recall_type == RETURN_FILE) {
252 		args->cbl_range.iomode = iomode;
253 		status = decode_fh(xdr, &args->cbl_fh);
254 		if (unlikely(status != 0))
255 			goto out;
256 
257 		p = read_buf(xdr, 2 * sizeof(uint64_t));
258 		if (unlikely(p == NULL)) {
259 			status = htonl(NFS4ERR_BADXDR);
260 			goto out;
261 		}
262 		p = xdr_decode_hyper(p, &args->cbl_range.offset);
263 		p = xdr_decode_hyper(p, &args->cbl_range.length);
264 		status = decode_stateid(xdr, &args->cbl_stateid);
265 		if (unlikely(status != 0))
266 			goto out;
267 	} else if (args->cbl_recall_type == RETURN_FSID) {
268 		p = read_buf(xdr, 2 * sizeof(uint64_t));
269 		if (unlikely(p == NULL)) {
270 			status = htonl(NFS4ERR_BADXDR);
271 			goto out;
272 		}
273 		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
274 		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
275 	} else if (args->cbl_recall_type != RETURN_ALL) {
276 		status = htonl(NFS4ERR_BADXDR);
277 		goto out;
278 	}
279 	dprintk("%s: ltype 0x%x iomode %d changed %d recall_type %d\n",
280 		__func__,
281 		args->cbl_layout_type, iomode,
282 		args->cbl_layoutchanged, args->cbl_recall_type);
283 out:
284 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
285 	return status;
286 }
287 
288 static
289 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
290 				struct xdr_stream *xdr,
291 				struct cb_devicenotifyargs *args)
292 {
293 	__be32 *p;
294 	__be32 status = 0;
295 	u32 tmp;
296 	int n, i;
297 	args->ndevs = 0;
298 
299 	/* Num of device notifications */
300 	p = read_buf(xdr, sizeof(uint32_t));
301 	if (unlikely(p == NULL)) {
302 		status = htonl(NFS4ERR_BADXDR);
303 		goto out;
304 	}
305 	n = ntohl(*p++);
306 	if (n <= 0)
307 		goto out;
308 	if (n > ULONG_MAX / sizeof(*args->devs)) {
309 		status = htonl(NFS4ERR_BADXDR);
310 		goto out;
311 	}
312 
313 	args->devs = kmalloc(n * sizeof(*args->devs), GFP_KERNEL);
314 	if (!args->devs) {
315 		status = htonl(NFS4ERR_DELAY);
316 		goto out;
317 	}
318 
319 	/* Decode each dev notification */
320 	for (i = 0; i < n; i++) {
321 		struct cb_devicenotifyitem *dev = &args->devs[i];
322 
323 		p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
324 		if (unlikely(p == NULL)) {
325 			status = htonl(NFS4ERR_BADXDR);
326 			goto err;
327 		}
328 
329 		tmp = ntohl(*p++);	/* bitmap size */
330 		if (tmp != 1) {
331 			status = htonl(NFS4ERR_INVAL);
332 			goto err;
333 		}
334 		dev->cbd_notify_type = ntohl(*p++);
335 		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
336 		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
337 			status = htonl(NFS4ERR_INVAL);
338 			goto err;
339 		}
340 
341 		tmp = ntohl(*p++);	/* opaque size */
342 		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
343 		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
344 		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
345 		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
346 			status = htonl(NFS4ERR_INVAL);
347 			goto err;
348 		}
349 		dev->cbd_layout_type = ntohl(*p++);
350 		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
351 		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
352 
353 		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
354 			p = read_buf(xdr, sizeof(uint32_t));
355 			if (unlikely(p == NULL)) {
356 				status = htonl(NFS4ERR_BADXDR);
357 				goto err;
358 			}
359 			dev->cbd_immediate = ntohl(*p++);
360 		} else {
361 			dev->cbd_immediate = 0;
362 		}
363 
364 		args->ndevs++;
365 
366 		dprintk("%s: type %d layout 0x%x immediate %d\n",
367 			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
368 			dev->cbd_immediate);
369 	}
370 out:
371 	dprintk("%s: status %d ndevs %d\n",
372 		__func__, ntohl(status), args->ndevs);
373 	return status;
374 err:
375 	kfree(args->devs);
376 	goto out;
377 }
378 
379 static __be32 decode_sessionid(struct xdr_stream *xdr,
380 				 struct nfs4_sessionid *sid)
381 {
382 	__be32 *p;
383 	int len = NFS4_MAX_SESSIONID_LEN;
384 
385 	p = read_buf(xdr, len);
386 	if (unlikely(p == NULL))
387 		return htonl(NFS4ERR_RESOURCE);
388 
389 	memcpy(sid->data, p, len);
390 	return 0;
391 }
392 
393 static __be32 decode_rc_list(struct xdr_stream *xdr,
394 			       struct referring_call_list *rc_list)
395 {
396 	__be32 *p;
397 	int i;
398 	__be32 status;
399 
400 	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
401 	if (status)
402 		goto out;
403 
404 	status = htonl(NFS4ERR_RESOURCE);
405 	p = read_buf(xdr, sizeof(uint32_t));
406 	if (unlikely(p == NULL))
407 		goto out;
408 
409 	rc_list->rcl_nrefcalls = ntohl(*p++);
410 	if (rc_list->rcl_nrefcalls) {
411 		p = read_buf(xdr,
412 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
413 		if (unlikely(p == NULL))
414 			goto out;
415 		rc_list->rcl_refcalls = kmalloc(rc_list->rcl_nrefcalls *
416 						sizeof(*rc_list->rcl_refcalls),
417 						GFP_KERNEL);
418 		if (unlikely(rc_list->rcl_refcalls == NULL))
419 			goto out;
420 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
421 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
422 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
423 		}
424 	}
425 	status = 0;
426 
427 out:
428 	return status;
429 }
430 
431 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
432 					struct xdr_stream *xdr,
433 					struct cb_sequenceargs *args)
434 {
435 	__be32 *p;
436 	int i;
437 	__be32 status;
438 
439 	status = decode_sessionid(xdr, &args->csa_sessionid);
440 	if (status)
441 		goto out;
442 
443 	status = htonl(NFS4ERR_RESOURCE);
444 	p = read_buf(xdr, 5 * sizeof(uint32_t));
445 	if (unlikely(p == NULL))
446 		goto out;
447 
448 	args->csa_addr = svc_addr(rqstp);
449 	args->csa_sequenceid = ntohl(*p++);
450 	args->csa_slotid = ntohl(*p++);
451 	args->csa_highestslotid = ntohl(*p++);
452 	args->csa_cachethis = ntohl(*p++);
453 	args->csa_nrclists = ntohl(*p++);
454 	args->csa_rclists = NULL;
455 	if (args->csa_nrclists) {
456 		args->csa_rclists = kmalloc(args->csa_nrclists *
457 					    sizeof(*args->csa_rclists),
458 					    GFP_KERNEL);
459 		if (unlikely(args->csa_rclists == NULL))
460 			goto out;
461 
462 		for (i = 0; i < args->csa_nrclists; i++) {
463 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
464 			if (status)
465 				goto out_free;
466 		}
467 	}
468 	status = 0;
469 
470 	dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
471 		"highestslotid %u cachethis %d nrclists %u\n",
472 		__func__,
473 		((u32 *)&args->csa_sessionid)[0],
474 		((u32 *)&args->csa_sessionid)[1],
475 		((u32 *)&args->csa_sessionid)[2],
476 		((u32 *)&args->csa_sessionid)[3],
477 		args->csa_sequenceid, args->csa_slotid,
478 		args->csa_highestslotid, args->csa_cachethis,
479 		args->csa_nrclists);
480 out:
481 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
482 	return status;
483 
484 out_free:
485 	for (i = 0; i < args->csa_nrclists; i++)
486 		kfree(args->csa_rclists[i].rcl_refcalls);
487 	kfree(args->csa_rclists);
488 	goto out;
489 }
490 
491 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
492 				      struct xdr_stream *xdr,
493 				      struct cb_recallanyargs *args)
494 {
495 	uint32_t bitmap[2];
496 	__be32 *p, status;
497 
498 	args->craa_addr = svc_addr(rqstp);
499 	p = read_buf(xdr, 4);
500 	if (unlikely(p == NULL))
501 		return htonl(NFS4ERR_BADXDR);
502 	args->craa_objs_to_keep = ntohl(*p++);
503 	status = decode_bitmap(xdr, bitmap);
504 	if (unlikely(status))
505 		return status;
506 	args->craa_type_mask = bitmap[0];
507 
508 	return 0;
509 }
510 
511 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
512 					struct xdr_stream *xdr,
513 					struct cb_recallslotargs *args)
514 {
515 	__be32 *p;
516 
517 	args->crsa_addr = svc_addr(rqstp);
518 	p = read_buf(xdr, 4);
519 	if (unlikely(p == NULL))
520 		return htonl(NFS4ERR_BADXDR);
521 	args->crsa_target_max_slots = ntohl(*p++);
522 	return 0;
523 }
524 
525 #endif /* CONFIG_NFS_V4_1 */
526 
527 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
528 {
529 	__be32 *p;
530 
531 	p = xdr_reserve_space(xdr, 4 + len);
532 	if (unlikely(p == NULL))
533 		return htonl(NFS4ERR_RESOURCE);
534 	xdr_encode_opaque(p, str, len);
535 	return 0;
536 }
537 
538 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
539 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
540 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
541 {
542 	__be32 bm[2];
543 	__be32 *p;
544 
545 	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
546 	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
547 	if (bm[1] != 0) {
548 		p = xdr_reserve_space(xdr, 16);
549 		if (unlikely(p == NULL))
550 			return htonl(NFS4ERR_RESOURCE);
551 		*p++ = htonl(2);
552 		*p++ = bm[0];
553 		*p++ = bm[1];
554 	} else if (bm[0] != 0) {
555 		p = xdr_reserve_space(xdr, 12);
556 		if (unlikely(p == NULL))
557 			return htonl(NFS4ERR_RESOURCE);
558 		*p++ = htonl(1);
559 		*p++ = bm[0];
560 	} else {
561 		p = xdr_reserve_space(xdr, 8);
562 		if (unlikely(p == NULL))
563 			return htonl(NFS4ERR_RESOURCE);
564 		*p++ = htonl(0);
565 	}
566 	*savep = p;
567 	return 0;
568 }
569 
570 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
571 {
572 	__be32 *p;
573 
574 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
575 		return 0;
576 	p = xdr_reserve_space(xdr, 8);
577 	if (unlikely(!p))
578 		return htonl(NFS4ERR_RESOURCE);
579 	p = xdr_encode_hyper(p, change);
580 	return 0;
581 }
582 
583 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
584 {
585 	__be32 *p;
586 
587 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
588 		return 0;
589 	p = xdr_reserve_space(xdr, 8);
590 	if (unlikely(!p))
591 		return htonl(NFS4ERR_RESOURCE);
592 	p = xdr_encode_hyper(p, size);
593 	return 0;
594 }
595 
596 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
597 {
598 	__be32 *p;
599 
600 	p = xdr_reserve_space(xdr, 12);
601 	if (unlikely(!p))
602 		return htonl(NFS4ERR_RESOURCE);
603 	p = xdr_encode_hyper(p, time->tv_sec);
604 	*p = htonl(time->tv_nsec);
605 	return 0;
606 }
607 
608 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
609 {
610 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
611 		return 0;
612 	return encode_attr_time(xdr,time);
613 }
614 
615 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
616 {
617 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
618 		return 0;
619 	return encode_attr_time(xdr,time);
620 }
621 
622 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
623 {
624 	__be32 status;
625 
626 	hdr->status = xdr_reserve_space(xdr, 4);
627 	if (unlikely(hdr->status == NULL))
628 		return htonl(NFS4ERR_RESOURCE);
629 	status = encode_string(xdr, hdr->taglen, hdr->tag);
630 	if (unlikely(status != 0))
631 		return status;
632 	hdr->nops = xdr_reserve_space(xdr, 4);
633 	if (unlikely(hdr->nops == NULL))
634 		return htonl(NFS4ERR_RESOURCE);
635 	return 0;
636 }
637 
638 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
639 {
640 	__be32 *p;
641 
642 	p = xdr_reserve_space(xdr, 8);
643 	if (unlikely(p == NULL))
644 		return htonl(NFS4ERR_RESOURCE_HDR);
645 	*p++ = htonl(op);
646 	*p = res;
647 	return 0;
648 }
649 
650 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
651 {
652 	__be32 *savep = NULL;
653 	__be32 status = res->status;
654 
655 	if (unlikely(status != 0))
656 		goto out;
657 	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
658 	if (unlikely(status != 0))
659 		goto out;
660 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
661 	if (unlikely(status != 0))
662 		goto out;
663 	status = encode_attr_size(xdr, res->bitmap, res->size);
664 	if (unlikely(status != 0))
665 		goto out;
666 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
667 	if (unlikely(status != 0))
668 		goto out;
669 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
670 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
671 out:
672 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
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 	int len = NFS4_MAX_SESSIONID_LEN;
683 
684 	p = xdr_reserve_space(xdr, len);
685 	if (unlikely(p == NULL))
686 		return htonl(NFS4ERR_RESOURCE);
687 
688 	memcpy(p, sid, len);
689 	return 0;
690 }
691 
692 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
693 				       struct xdr_stream *xdr,
694 				       const struct cb_sequenceres *res)
695 {
696 	__be32 *p;
697 	unsigned status = res->csr_status;
698 
699 	if (unlikely(status != 0))
700 		goto out;
701 
702 	encode_sessionid(xdr, &res->csr_sessionid);
703 
704 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
705 	if (unlikely(p == NULL))
706 		return htonl(NFS4ERR_RESOURCE);
707 
708 	*p++ = htonl(res->csr_sequenceid);
709 	*p++ = htonl(res->csr_slotid);
710 	*p++ = htonl(res->csr_highestslotid);
711 	*p++ = htonl(res->csr_target_highestslotid);
712 out:
713 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
714 	return status;
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 		*op = &callback_ops[op_nr];
737 		break;
738 
739 	case OP_CB_NOTIFY:
740 	case OP_CB_PUSH_DELEG:
741 	case OP_CB_RECALLABLE_OBJ_AVAIL:
742 	case OP_CB_WANTS_CANCELLED:
743 	case OP_CB_NOTIFY_LOCK:
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 {
755 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
756 
757 	spin_lock(&tbl->slot_tbl_lock);
758 	/*
759 	 * Let the state manager know callback processing done.
760 	 * A single slot, so highest used slotid is either 0 or -1
761 	 */
762 	tbl->highest_used_slotid = -1;
763 	nfs4_check_drain_bc_complete(session);
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->slotid != -1)
770 		nfs4_callback_free_slot(cps->clp->cl_session);
771 }
772 
773 #else /* CONFIG_NFS_V4_1 */
774 
775 static __be32
776 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
777 {
778 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
779 }
780 
781 static void nfs4_cb_free_slot(struct cb_process_state *cps)
782 {
783 }
784 #endif /* CONFIG_NFS_V4_1 */
785 
786 static __be32
787 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
788 {
789 	switch (op_nr) {
790 	case OP_CB_GETATTR:
791 	case OP_CB_RECALL:
792 		*op = &callback_ops[op_nr];
793 		break;
794 	default:
795 		return htonl(NFS4ERR_OP_ILLEGAL);
796 	}
797 
798 	return htonl(NFS_OK);
799 }
800 
801 static __be32 process_op(uint32_t minorversion, int nop,
802 		struct svc_rqst *rqstp,
803 		struct xdr_stream *xdr_in, void *argp,
804 		struct xdr_stream *xdr_out, void *resp,
805 		struct cb_process_state *cps)
806 {
807 	struct callback_op *op = &callback_ops[0];
808 	unsigned int op_nr;
809 	__be32 status;
810 	long maxlen;
811 	__be32 res;
812 
813 	dprintk("%s: start\n", __func__);
814 	status = decode_op_hdr(xdr_in, &op_nr);
815 	if (unlikely(status))
816 		return status;
817 
818 	dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
819 		__func__, minorversion, nop, op_nr);
820 
821 	status = minorversion ? preprocess_nfs41_op(nop, op_nr, &op) :
822 				preprocess_nfs4_op(op_nr, &op);
823 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
824 		op_nr = OP_CB_ILLEGAL;
825 	if (status)
826 		goto encode_hdr;
827 
828 	if (cps->drc_status) {
829 		status = cps->drc_status;
830 		goto encode_hdr;
831 	}
832 
833 	maxlen = xdr_out->end - xdr_out->p;
834 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
835 		status = op->decode_args(rqstp, xdr_in, argp);
836 		if (likely(status == 0))
837 			status = op->process_op(argp, resp, cps);
838 	} else
839 		status = htonl(NFS4ERR_RESOURCE);
840 
841 encode_hdr:
842 	res = encode_op_hdr(xdr_out, op_nr, status);
843 	if (unlikely(res))
844 		return res;
845 	if (op->encode_res != NULL && status == 0)
846 		status = op->encode_res(rqstp, xdr_out, resp);
847 	dprintk("%s: done, status = %d\n", __func__, ntohl(status));
848 	return status;
849 }
850 
851 /*
852  * Decode, process and encode a COMPOUND
853  */
854 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
855 {
856 	struct cb_compound_hdr_arg hdr_arg = { 0 };
857 	struct cb_compound_hdr_res hdr_res = { NULL };
858 	struct xdr_stream xdr_in, xdr_out;
859 	__be32 *p, status;
860 	struct cb_process_state cps = {
861 		.drc_status = 0,
862 		.clp = NULL,
863 		.slotid = -1,
864 	};
865 	unsigned int nops = 0;
866 
867 	dprintk("%s: start\n", __func__);
868 
869 	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
870 
871 	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
872 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
873 
874 	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
875 	if (status == __constant_htonl(NFS4ERR_RESOURCE))
876 		return rpc_garbage_args;
877 
878 	if (hdr_arg.minorversion == 0) {
879 		cps.clp = nfs4_find_client_ident(hdr_arg.cb_ident);
880 		if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
881 			return rpc_drop_reply;
882 	}
883 
884 	hdr_res.taglen = hdr_arg.taglen;
885 	hdr_res.tag = hdr_arg.tag;
886 	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
887 		return rpc_system_err;
888 
889 	while (status == 0 && nops != hdr_arg.nops) {
890 		status = process_op(hdr_arg.minorversion, nops, rqstp,
891 				    &xdr_in, argp, &xdr_out, resp, &cps);
892 		nops++;
893 	}
894 
895 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
896 	* resource error in cb_compound status without returning op */
897 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
898 		status = htonl(NFS4ERR_RESOURCE);
899 		nops--;
900 	}
901 
902 	*hdr_res.status = status;
903 	*hdr_res.nops = htonl(nops);
904 	nfs4_cb_free_slot(&cps);
905 	nfs_put_client(cps.clp);
906 	dprintk("%s: done, status = %u\n", __func__, ntohl(status));
907 	return rpc_success;
908 }
909 
910 /*
911  * Define NFS4 callback COMPOUND ops.
912  */
913 static struct callback_op callback_ops[] = {
914 	[0] = {
915 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
916 	},
917 	[OP_CB_GETATTR] = {
918 		.process_op = (callback_process_op_t)nfs4_callback_getattr,
919 		.decode_args = (callback_decode_arg_t)decode_getattr_args,
920 		.encode_res = (callback_encode_res_t)encode_getattr_res,
921 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
922 	},
923 	[OP_CB_RECALL] = {
924 		.process_op = (callback_process_op_t)nfs4_callback_recall,
925 		.decode_args = (callback_decode_arg_t)decode_recall_args,
926 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
927 	},
928 #if defined(CONFIG_NFS_V4_1)
929 	[OP_CB_LAYOUTRECALL] = {
930 		.process_op = (callback_process_op_t)nfs4_callback_layoutrecall,
931 		.decode_args =
932 			(callback_decode_arg_t)decode_layoutrecall_args,
933 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
934 	},
935 	[OP_CB_NOTIFY_DEVICEID] = {
936 		.process_op = (callback_process_op_t)nfs4_callback_devicenotify,
937 		.decode_args =
938 			(callback_decode_arg_t)decode_devicenotify_args,
939 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
940 	},
941 	[OP_CB_SEQUENCE] = {
942 		.process_op = (callback_process_op_t)nfs4_callback_sequence,
943 		.decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
944 		.encode_res = (callback_encode_res_t)encode_cb_sequence_res,
945 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
946 	},
947 	[OP_CB_RECALL_ANY] = {
948 		.process_op = (callback_process_op_t)nfs4_callback_recallany,
949 		.decode_args = (callback_decode_arg_t)decode_recallany_args,
950 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
951 	},
952 	[OP_CB_RECALL_SLOT] = {
953 		.process_op = (callback_process_op_t)nfs4_callback_recallslot,
954 		.decode_args = (callback_decode_arg_t)decode_recallslot_args,
955 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
956 	},
957 #endif /* CONFIG_NFS_V4_1 */
958 };
959 
960 /*
961  * Define NFS4 callback procedures
962  */
963 static struct svc_procedure nfs4_callback_procedures1[] = {
964 	[CB_NULL] = {
965 		.pc_func = nfs4_callback_null,
966 		.pc_decode = (kxdrproc_t)nfs4_decode_void,
967 		.pc_encode = (kxdrproc_t)nfs4_encode_void,
968 		.pc_xdrressize = 1,
969 	},
970 	[CB_COMPOUND] = {
971 		.pc_func = nfs4_callback_compound,
972 		.pc_encode = (kxdrproc_t)nfs4_encode_void,
973 		.pc_argsize = 256,
974 		.pc_ressize = 256,
975 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
976 	}
977 };
978 
979 struct svc_version nfs4_callback_version1 = {
980 	.vs_vers = 1,
981 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
982 	.vs_proc = nfs4_callback_procedures1,
983 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
984 	.vs_dispatch = NULL,
985 	.vs_hidden = 1,
986 };
987 
988 struct svc_version nfs4_callback_version4 = {
989 	.vs_vers = 4,
990 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
991 	.vs_proc = nfs4_callback_procedures1,
992 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
993 	.vs_dispatch = NULL,
994 	.vs_hidden = 1,
995 };
996