xref: /openbmc/linux/fs/nfs/callback_xdr.c (revision e1a0ebc8d82b64440d3ca7eac6a8489937ee2519)
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 #endif /* CONFIG_NFS_V4_1 */
39 
40 #define NFSDBG_FACILITY NFSDBG_CALLBACK
41 
42 /* Internal error code */
43 #define NFS4ERR_RESOURCE_HDR	11050
44 
45 typedef __be32 (*callback_process_op_t)(void *, void *,
46 					struct cb_process_state *);
47 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
48 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
49 
50 
51 struct callback_op {
52 	callback_process_op_t process_op;
53 	callback_decode_arg_t decode_args;
54 	callback_encode_res_t encode_res;
55 	long res_maxsize;
56 };
57 
58 static struct callback_op callback_ops[];
59 
60 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
61 {
62 	return htonl(NFS4_OK);
63 }
64 
65 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
66 {
67 	return xdr_argsize_check(rqstp, p);
68 }
69 
70 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
71 {
72 	return xdr_ressize_check(rqstp, p);
73 }
74 
75 static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
76 {
77 	__be32 *p;
78 
79 	p = xdr_inline_decode(xdr, nbytes);
80 	if (unlikely(p == NULL))
81 		printk(KERN_WARNING "NFS: NFSv4 callback reply buffer overflowed "
82 							"or truncated request.\n");
83 	return p;
84 }
85 
86 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
87 {
88 	__be32 *p;
89 
90 	p = read_buf(xdr, 4);
91 	if (unlikely(p == NULL))
92 		return htonl(NFS4ERR_RESOURCE);
93 	*len = ntohl(*p);
94 
95 	if (*len != 0) {
96 		p = read_buf(xdr, *len);
97 		if (unlikely(p == NULL))
98 			return htonl(NFS4ERR_RESOURCE);
99 		*str = (const char *)p;
100 	} else
101 		*str = NULL;
102 
103 	return 0;
104 }
105 
106 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
107 {
108 	__be32 *p;
109 
110 	p = read_buf(xdr, 4);
111 	if (unlikely(p == NULL))
112 		return htonl(NFS4ERR_RESOURCE);
113 	fh->size = ntohl(*p);
114 	if (fh->size > NFS4_FHSIZE)
115 		return htonl(NFS4ERR_BADHANDLE);
116 	p = read_buf(xdr, fh->size);
117 	if (unlikely(p == NULL))
118 		return htonl(NFS4ERR_RESOURCE);
119 	memcpy(&fh->data[0], p, fh->size);
120 	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
121 	return 0;
122 }
123 
124 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
125 {
126 	__be32 *p;
127 	unsigned int attrlen;
128 
129 	p = read_buf(xdr, 4);
130 	if (unlikely(p == NULL))
131 		return htonl(NFS4ERR_RESOURCE);
132 	attrlen = ntohl(*p);
133 	p = read_buf(xdr, attrlen << 2);
134 	if (unlikely(p == NULL))
135 		return htonl(NFS4ERR_RESOURCE);
136 	if (likely(attrlen > 0))
137 		bitmap[0] = ntohl(*p++);
138 	if (attrlen > 1)
139 		bitmap[1] = ntohl(*p);
140 	return 0;
141 }
142 
143 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
144 {
145 	__be32 *p;
146 
147 	p = read_buf(xdr, NFS4_STATEID_SIZE);
148 	if (unlikely(p == NULL))
149 		return htonl(NFS4ERR_RESOURCE);
150 	memcpy(stateid, p, NFS4_STATEID_SIZE);
151 	return 0;
152 }
153 
154 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
155 {
156 	__be32 *p;
157 	__be32 status;
158 
159 	status = decode_string(xdr, &hdr->taglen, &hdr->tag);
160 	if (unlikely(status != 0))
161 		return status;
162 	/* We do not like overly long tags! */
163 	if (hdr->taglen > CB_OP_TAGLEN_MAXSZ) {
164 		printk("NFS: NFSv4 CALLBACK %s: client sent tag of length %u\n",
165 				__func__, hdr->taglen);
166 		return htonl(NFS4ERR_RESOURCE);
167 	}
168 	p = read_buf(xdr, 12);
169 	if (unlikely(p == NULL))
170 		return htonl(NFS4ERR_RESOURCE);
171 	hdr->minorversion = ntohl(*p++);
172 	/* Check for minor version support */
173 	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
174 		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
175 	} else {
176 		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
177 			"illegal minor version %u!\n",
178 			__func__, hdr->minorversion);
179 		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
180 	}
181 	hdr->nops = ntohl(*p);
182 	dprintk("%s: minorversion %d nops %d\n", __func__,
183 		hdr->minorversion, hdr->nops);
184 	return 0;
185 }
186 
187 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
188 {
189 	__be32 *p;
190 	p = read_buf(xdr, 4);
191 	if (unlikely(p == NULL))
192 		return htonl(NFS4ERR_RESOURCE_HDR);
193 	*op = ntohl(*p);
194 	return 0;
195 }
196 
197 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
198 {
199 	__be32 status;
200 
201 	status = decode_fh(xdr, &args->fh);
202 	if (unlikely(status != 0))
203 		goto out;
204 	status = decode_bitmap(xdr, args->bitmap);
205 out:
206 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
207 	return status;
208 }
209 
210 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
211 {
212 	__be32 *p;
213 	__be32 status;
214 
215 	status = decode_stateid(xdr, &args->stateid);
216 	if (unlikely(status != 0))
217 		goto out;
218 	p = read_buf(xdr, 4);
219 	if (unlikely(p == NULL)) {
220 		status = htonl(NFS4ERR_RESOURCE);
221 		goto out;
222 	}
223 	args->truncate = ntohl(*p);
224 	status = decode_fh(xdr, &args->fh);
225 out:
226 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
227 	return status;
228 }
229 
230 #if defined(CONFIG_NFS_V4_1)
231 
232 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
233 				       struct xdr_stream *xdr,
234 				       struct cb_layoutrecallargs *args)
235 {
236 	__be32 *p;
237 	__be32 status = 0;
238 	uint32_t iomode;
239 
240 	p = read_buf(xdr, 4 * sizeof(uint32_t));
241 	if (unlikely(p == NULL)) {
242 		status = htonl(NFS4ERR_BADXDR);
243 		goto out;
244 	}
245 
246 	args->cbl_layout_type = ntohl(*p++);
247 	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
248 	 * as it is unusable and ignored with the other types.
249 	 */
250 	iomode = ntohl(*p++);
251 	args->cbl_layoutchanged = ntohl(*p++);
252 	args->cbl_recall_type = ntohl(*p++);
253 
254 	if (args->cbl_recall_type == RETURN_FILE) {
255 		args->cbl_range.iomode = iomode;
256 		status = decode_fh(xdr, &args->cbl_fh);
257 		if (unlikely(status != 0))
258 			goto out;
259 
260 		p = read_buf(xdr, 2 * sizeof(uint64_t));
261 		if (unlikely(p == NULL)) {
262 			status = htonl(NFS4ERR_BADXDR);
263 			goto out;
264 		}
265 		p = xdr_decode_hyper(p, &args->cbl_range.offset);
266 		p = xdr_decode_hyper(p, &args->cbl_range.length);
267 		status = decode_stateid(xdr, &args->cbl_stateid);
268 		if (unlikely(status != 0))
269 			goto out;
270 	} else if (args->cbl_recall_type == RETURN_FSID) {
271 		p = read_buf(xdr, 2 * sizeof(uint64_t));
272 		if (unlikely(p == NULL)) {
273 			status = htonl(NFS4ERR_BADXDR);
274 			goto out;
275 		}
276 		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
277 		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
278 	} else if (args->cbl_recall_type != RETURN_ALL) {
279 		status = htonl(NFS4ERR_BADXDR);
280 		goto out;
281 	}
282 	dprintk("%s: ltype 0x%x iomode %d changed %d recall_type %d\n",
283 		__func__,
284 		args->cbl_layout_type, iomode,
285 		args->cbl_layoutchanged, args->cbl_recall_type);
286 out:
287 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
288 	return status;
289 }
290 
291 static
292 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
293 				struct xdr_stream *xdr,
294 				struct cb_devicenotifyargs *args)
295 {
296 	__be32 *p;
297 	__be32 status = 0;
298 	u32 tmp;
299 	int n, i;
300 	args->ndevs = 0;
301 
302 	/* Num of device notifications */
303 	p = read_buf(xdr, sizeof(uint32_t));
304 	if (unlikely(p == NULL)) {
305 		status = htonl(NFS4ERR_BADXDR);
306 		goto out;
307 	}
308 	n = ntohl(*p++);
309 	if (n <= 0)
310 		goto out;
311 	if (n > ULONG_MAX / sizeof(*args->devs)) {
312 		status = htonl(NFS4ERR_BADXDR);
313 		goto out;
314 	}
315 
316 	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
317 	if (!args->devs) {
318 		status = htonl(NFS4ERR_DELAY);
319 		goto out;
320 	}
321 
322 	/* Decode each dev notification */
323 	for (i = 0; i < n; i++) {
324 		struct cb_devicenotifyitem *dev = &args->devs[i];
325 
326 		p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
327 		if (unlikely(p == NULL)) {
328 			status = htonl(NFS4ERR_BADXDR);
329 			goto err;
330 		}
331 
332 		tmp = ntohl(*p++);	/* bitmap size */
333 		if (tmp != 1) {
334 			status = htonl(NFS4ERR_INVAL);
335 			goto err;
336 		}
337 		dev->cbd_notify_type = ntohl(*p++);
338 		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
339 		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
340 			status = htonl(NFS4ERR_INVAL);
341 			goto err;
342 		}
343 
344 		tmp = ntohl(*p++);	/* opaque size */
345 		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
346 		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
347 		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
348 		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
349 			status = htonl(NFS4ERR_INVAL);
350 			goto err;
351 		}
352 		dev->cbd_layout_type = ntohl(*p++);
353 		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
354 		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
355 
356 		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
357 			p = read_buf(xdr, sizeof(uint32_t));
358 			if (unlikely(p == NULL)) {
359 				status = htonl(NFS4ERR_BADXDR);
360 				goto err;
361 			}
362 			dev->cbd_immediate = ntohl(*p++);
363 		} else {
364 			dev->cbd_immediate = 0;
365 		}
366 
367 		args->ndevs++;
368 
369 		dprintk("%s: type %d layout 0x%x immediate %d\n",
370 			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
371 			dev->cbd_immediate);
372 	}
373 out:
374 	dprintk("%s: status %d ndevs %d\n",
375 		__func__, ntohl(status), args->ndevs);
376 	return status;
377 err:
378 	kfree(args->devs);
379 	goto out;
380 }
381 
382 static __be32 decode_sessionid(struct xdr_stream *xdr,
383 				 struct nfs4_sessionid *sid)
384 {
385 	__be32 *p;
386 
387 	p = read_buf(xdr, NFS4_MAX_SESSIONID_LEN);
388 	if (unlikely(p == NULL))
389 		return htonl(NFS4ERR_RESOURCE);
390 
391 	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
392 	return 0;
393 }
394 
395 static __be32 decode_rc_list(struct xdr_stream *xdr,
396 			       struct referring_call_list *rc_list)
397 {
398 	__be32 *p;
399 	int i;
400 	__be32 status;
401 
402 	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
403 	if (status)
404 		goto out;
405 
406 	status = htonl(NFS4ERR_RESOURCE);
407 	p = read_buf(xdr, sizeof(uint32_t));
408 	if (unlikely(p == NULL))
409 		goto out;
410 
411 	rc_list->rcl_nrefcalls = ntohl(*p++);
412 	if (rc_list->rcl_nrefcalls) {
413 		p = read_buf(xdr,
414 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
415 		if (unlikely(p == NULL))
416 			goto out;
417 		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
418 						sizeof(*rc_list->rcl_refcalls),
419 						GFP_KERNEL);
420 		if (unlikely(rc_list->rcl_refcalls == NULL))
421 			goto out;
422 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
423 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
424 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
425 		}
426 	}
427 	status = 0;
428 
429 out:
430 	return status;
431 }
432 
433 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
434 					struct xdr_stream *xdr,
435 					struct cb_sequenceargs *args)
436 {
437 	__be32 *p;
438 	int i;
439 	__be32 status;
440 
441 	status = decode_sessionid(xdr, &args->csa_sessionid);
442 	if (status)
443 		goto out;
444 
445 	status = htonl(NFS4ERR_RESOURCE);
446 	p = read_buf(xdr, 5 * sizeof(uint32_t));
447 	if (unlikely(p == NULL))
448 		goto out;
449 
450 	args->csa_addr = svc_addr(rqstp);
451 	args->csa_sequenceid = ntohl(*p++);
452 	args->csa_slotid = ntohl(*p++);
453 	args->csa_highestslotid = ntohl(*p++);
454 	args->csa_cachethis = ntohl(*p++);
455 	args->csa_nrclists = ntohl(*p++);
456 	args->csa_rclists = NULL;
457 	if (args->csa_nrclists) {
458 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
459 						  sizeof(*args->csa_rclists),
460 						  GFP_KERNEL);
461 		if (unlikely(args->csa_rclists == NULL))
462 			goto out;
463 
464 		for (i = 0; i < args->csa_nrclists; i++) {
465 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
466 			if (status) {
467 				args->csa_nrclists = i;
468 				goto out_free;
469 			}
470 		}
471 	}
472 	status = 0;
473 
474 	dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
475 		"highestslotid %u cachethis %d nrclists %u\n",
476 		__func__,
477 		((u32 *)&args->csa_sessionid)[0],
478 		((u32 *)&args->csa_sessionid)[1],
479 		((u32 *)&args->csa_sessionid)[2],
480 		((u32 *)&args->csa_sessionid)[3],
481 		args->csa_sequenceid, args->csa_slotid,
482 		args->csa_highestslotid, args->csa_cachethis,
483 		args->csa_nrclists);
484 out:
485 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
486 	return status;
487 
488 out_free:
489 	for (i = 0; i < args->csa_nrclists; i++)
490 		kfree(args->csa_rclists[i].rcl_refcalls);
491 	kfree(args->csa_rclists);
492 	goto out;
493 }
494 
495 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
496 				      struct xdr_stream *xdr,
497 				      struct cb_recallanyargs *args)
498 {
499 	uint32_t bitmap[2];
500 	__be32 *p, status;
501 
502 	p = read_buf(xdr, 4);
503 	if (unlikely(p == NULL))
504 		return htonl(NFS4ERR_BADXDR);
505 	args->craa_objs_to_keep = ntohl(*p++);
506 	status = decode_bitmap(xdr, bitmap);
507 	if (unlikely(status))
508 		return status;
509 	args->craa_type_mask = bitmap[0];
510 
511 	return 0;
512 }
513 
514 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
515 					struct xdr_stream *xdr,
516 					struct cb_recallslotargs *args)
517 {
518 	__be32 *p;
519 
520 	p = read_buf(xdr, 4);
521 	if (unlikely(p == NULL))
522 		return htonl(NFS4ERR_BADXDR);
523 	args->crsa_target_highest_slotid = ntohl(*p++);
524 	return 0;
525 }
526 
527 #endif /* CONFIG_NFS_V4_1 */
528 
529 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
530 {
531 	__be32 *p;
532 
533 	p = xdr_reserve_space(xdr, 4 + len);
534 	if (unlikely(p == NULL))
535 		return htonl(NFS4ERR_RESOURCE);
536 	xdr_encode_opaque(p, str, len);
537 	return 0;
538 }
539 
540 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
541 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
542 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
543 {
544 	__be32 bm[2];
545 	__be32 *p;
546 
547 	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
548 	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
549 	if (bm[1] != 0) {
550 		p = xdr_reserve_space(xdr, 16);
551 		if (unlikely(p == NULL))
552 			return htonl(NFS4ERR_RESOURCE);
553 		*p++ = htonl(2);
554 		*p++ = bm[0];
555 		*p++ = bm[1];
556 	} else if (bm[0] != 0) {
557 		p = xdr_reserve_space(xdr, 12);
558 		if (unlikely(p == NULL))
559 			return htonl(NFS4ERR_RESOURCE);
560 		*p++ = htonl(1);
561 		*p++ = bm[0];
562 	} else {
563 		p = xdr_reserve_space(xdr, 8);
564 		if (unlikely(p == NULL))
565 			return htonl(NFS4ERR_RESOURCE);
566 		*p++ = htonl(0);
567 	}
568 	*savep = p;
569 	return 0;
570 }
571 
572 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
573 {
574 	__be32 *p;
575 
576 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
577 		return 0;
578 	p = xdr_reserve_space(xdr, 8);
579 	if (unlikely(!p))
580 		return htonl(NFS4ERR_RESOURCE);
581 	p = xdr_encode_hyper(p, change);
582 	return 0;
583 }
584 
585 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
586 {
587 	__be32 *p;
588 
589 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
590 		return 0;
591 	p = xdr_reserve_space(xdr, 8);
592 	if (unlikely(!p))
593 		return htonl(NFS4ERR_RESOURCE);
594 	p = xdr_encode_hyper(p, size);
595 	return 0;
596 }
597 
598 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
599 {
600 	__be32 *p;
601 
602 	p = xdr_reserve_space(xdr, 12);
603 	if (unlikely(!p))
604 		return htonl(NFS4ERR_RESOURCE);
605 	p = xdr_encode_hyper(p, time->tv_sec);
606 	*p = htonl(time->tv_nsec);
607 	return 0;
608 }
609 
610 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
611 {
612 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
613 		return 0;
614 	return encode_attr_time(xdr,time);
615 }
616 
617 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
618 {
619 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
620 		return 0;
621 	return encode_attr_time(xdr,time);
622 }
623 
624 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
625 {
626 	__be32 status;
627 
628 	hdr->status = xdr_reserve_space(xdr, 4);
629 	if (unlikely(hdr->status == NULL))
630 		return htonl(NFS4ERR_RESOURCE);
631 	status = encode_string(xdr, hdr->taglen, hdr->tag);
632 	if (unlikely(status != 0))
633 		return status;
634 	hdr->nops = xdr_reserve_space(xdr, 4);
635 	if (unlikely(hdr->nops == NULL))
636 		return htonl(NFS4ERR_RESOURCE);
637 	return 0;
638 }
639 
640 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
641 {
642 	__be32 *p;
643 
644 	p = xdr_reserve_space(xdr, 8);
645 	if (unlikely(p == NULL))
646 		return htonl(NFS4ERR_RESOURCE_HDR);
647 	*p++ = htonl(op);
648 	*p = res;
649 	return 0;
650 }
651 
652 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
653 {
654 	__be32 *savep = NULL;
655 	__be32 status = res->status;
656 
657 	if (unlikely(status != 0))
658 		goto out;
659 	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
660 	if (unlikely(status != 0))
661 		goto out;
662 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
663 	if (unlikely(status != 0))
664 		goto out;
665 	status = encode_attr_size(xdr, res->bitmap, res->size);
666 	if (unlikely(status != 0))
667 		goto out;
668 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
669 	if (unlikely(status != 0))
670 		goto out;
671 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
672 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
673 out:
674 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
675 	return status;
676 }
677 
678 #if defined(CONFIG_NFS_V4_1)
679 
680 static __be32 encode_sessionid(struct xdr_stream *xdr,
681 				 const struct nfs4_sessionid *sid)
682 {
683 	__be32 *p;
684 
685 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
686 	if (unlikely(p == NULL))
687 		return htonl(NFS4ERR_RESOURCE);
688 
689 	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
690 	return 0;
691 }
692 
693 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
694 				       struct xdr_stream *xdr,
695 				       const struct cb_sequenceres *res)
696 {
697 	__be32 *p;
698 	__be32 status = res->csr_status;
699 
700 	if (unlikely(status != 0))
701 		goto out;
702 
703 	status = encode_sessionid(xdr, &res->csr_sessionid);
704 	if (status)
705 		goto out;
706 
707 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
708 	if (unlikely(p == NULL))
709 		return htonl(NFS4ERR_RESOURCE);
710 
711 	*p++ = htonl(res->csr_sequenceid);
712 	*p++ = htonl(res->csr_slotid);
713 	*p++ = htonl(res->csr_highestslotid);
714 	*p++ = htonl(res->csr_target_highestslotid);
715 out:
716 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
717 	return status;
718 }
719 
720 static __be32
721 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
722 {
723 	if (op_nr == OP_CB_SEQUENCE) {
724 		if (nop != 0)
725 			return htonl(NFS4ERR_SEQUENCE_POS);
726 	} else {
727 		if (nop == 0)
728 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
729 	}
730 
731 	switch (op_nr) {
732 	case OP_CB_GETATTR:
733 	case OP_CB_RECALL:
734 	case OP_CB_SEQUENCE:
735 	case OP_CB_RECALL_ANY:
736 	case OP_CB_RECALL_SLOT:
737 	case OP_CB_LAYOUTRECALL:
738 	case OP_CB_NOTIFY_DEVICEID:
739 		*op = &callback_ops[op_nr];
740 		break;
741 
742 	case OP_CB_NOTIFY:
743 	case OP_CB_PUSH_DELEG:
744 	case OP_CB_RECALLABLE_OBJ_AVAIL:
745 	case OP_CB_WANTS_CANCELLED:
746 	case OP_CB_NOTIFY_LOCK:
747 		return htonl(NFS4ERR_NOTSUPP);
748 
749 	default:
750 		return htonl(NFS4ERR_OP_ILLEGAL);
751 	}
752 
753 	return htonl(NFS_OK);
754 }
755 
756 static void nfs4_callback_free_slot(struct nfs4_session *session)
757 {
758 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
759 
760 	spin_lock(&tbl->slot_tbl_lock);
761 	/*
762 	 * Let the state manager know callback processing done.
763 	 * A single slot, so highest used slotid is either 0 or -1
764 	 */
765 	tbl->highest_used_slotid = NFS4_NO_SLOT;
766 	nfs4_slot_tbl_drain_complete(tbl);
767 	spin_unlock(&tbl->slot_tbl_lock);
768 }
769 
770 static void nfs4_cb_free_slot(struct cb_process_state *cps)
771 {
772 	if (cps->slotid != NFS4_NO_SLOT)
773 		nfs4_callback_free_slot(cps->clp->cl_session);
774 }
775 
776 #else /* CONFIG_NFS_V4_1 */
777 
778 static __be32
779 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
780 {
781 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
782 }
783 
784 static void nfs4_cb_free_slot(struct cb_process_state *cps)
785 {
786 }
787 #endif /* CONFIG_NFS_V4_1 */
788 
789 #ifdef CONFIG_NFS_V4_2
790 static __be32
791 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
792 {
793 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
794 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
795 		return status;
796 
797 	if (op_nr == OP_CB_OFFLOAD)
798 		return htonl(NFS4ERR_NOTSUPP);
799 	return htonl(NFS4ERR_OP_ILLEGAL);
800 }
801 #else /* CONFIG_NFS_V4_2 */
802 static __be32
803 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
804 {
805 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
806 }
807 #endif /* CONFIG_NFS_V4_2 */
808 
809 static __be32
810 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
811 {
812 	switch (op_nr) {
813 	case OP_CB_GETATTR:
814 	case OP_CB_RECALL:
815 		*op = &callback_ops[op_nr];
816 		break;
817 	default:
818 		return htonl(NFS4ERR_OP_ILLEGAL);
819 	}
820 
821 	return htonl(NFS_OK);
822 }
823 
824 static __be32 process_op(int nop, struct svc_rqst *rqstp,
825 		struct xdr_stream *xdr_in, void *argp,
826 		struct xdr_stream *xdr_out, void *resp,
827 		struct cb_process_state *cps)
828 {
829 	struct callback_op *op = &callback_ops[0];
830 	unsigned int op_nr;
831 	__be32 status;
832 	long maxlen;
833 	__be32 res;
834 
835 	dprintk("%s: start\n", __func__);
836 	status = decode_op_hdr(xdr_in, &op_nr);
837 	if (unlikely(status))
838 		return status;
839 
840 	dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
841 		__func__, cps->minorversion, nop, op_nr);
842 
843 	switch (cps->minorversion) {
844 	case 0:
845 		status = preprocess_nfs4_op(op_nr, &op);
846 		break;
847 	case 1:
848 		status = preprocess_nfs41_op(nop, op_nr, &op);
849 		break;
850 	case 2:
851 		status = preprocess_nfs42_op(nop, op_nr, &op);
852 		break;
853 	default:
854 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
855 	}
856 
857 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
858 		op_nr = OP_CB_ILLEGAL;
859 	if (status)
860 		goto encode_hdr;
861 
862 	if (cps->drc_status) {
863 		status = cps->drc_status;
864 		goto encode_hdr;
865 	}
866 
867 	maxlen = xdr_out->end - xdr_out->p;
868 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
869 		status = op->decode_args(rqstp, xdr_in, argp);
870 		if (likely(status == 0))
871 			status = op->process_op(argp, resp, cps);
872 	} else
873 		status = htonl(NFS4ERR_RESOURCE);
874 
875 encode_hdr:
876 	res = encode_op_hdr(xdr_out, op_nr, status);
877 	if (unlikely(res))
878 		return res;
879 	if (op->encode_res != NULL && status == 0)
880 		status = op->encode_res(rqstp, xdr_out, resp);
881 	dprintk("%s: done, status = %d\n", __func__, ntohl(status));
882 	return status;
883 }
884 
885 /*
886  * Decode, process and encode a COMPOUND
887  */
888 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
889 {
890 	struct cb_compound_hdr_arg hdr_arg = { 0 };
891 	struct cb_compound_hdr_res hdr_res = { NULL };
892 	struct xdr_stream xdr_in, xdr_out;
893 	struct xdr_buf *rq_arg = &rqstp->rq_arg;
894 	__be32 *p, status;
895 	struct cb_process_state cps = {
896 		.drc_status = 0,
897 		.clp = NULL,
898 		.slotid = NFS4_NO_SLOT,
899 		.net = SVC_NET(rqstp),
900 	};
901 	unsigned int nops = 0;
902 
903 	dprintk("%s: start\n", __func__);
904 
905 	rq_arg->len = rq_arg->head[0].iov_len + rq_arg->page_len;
906 	xdr_init_decode(&xdr_in, rq_arg, rq_arg->head[0].iov_base);
907 
908 	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
909 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
910 
911 	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
912 	if (status == htonl(NFS4ERR_RESOURCE))
913 		return rpc_garbage_args;
914 
915 	if (hdr_arg.minorversion == 0) {
916 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
917 		if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
918 			return rpc_drop_reply;
919 	}
920 
921 	cps.minorversion = hdr_arg.minorversion;
922 	hdr_res.taglen = hdr_arg.taglen;
923 	hdr_res.tag = hdr_arg.tag;
924 	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
925 		return rpc_system_err;
926 
927 	while (status == 0 && nops != hdr_arg.nops) {
928 		status = process_op(nops, rqstp, &xdr_in,
929 				    argp, &xdr_out, resp, &cps);
930 		nops++;
931 	}
932 
933 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
934 	* resource error in cb_compound status without returning op */
935 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
936 		status = htonl(NFS4ERR_RESOURCE);
937 		nops--;
938 	}
939 
940 	*hdr_res.status = status;
941 	*hdr_res.nops = htonl(nops);
942 	nfs4_cb_free_slot(&cps);
943 	nfs_put_client(cps.clp);
944 	dprintk("%s: done, status = %u\n", __func__, ntohl(status));
945 	return rpc_success;
946 }
947 
948 /*
949  * Define NFS4 callback COMPOUND ops.
950  */
951 static struct callback_op callback_ops[] = {
952 	[0] = {
953 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
954 	},
955 	[OP_CB_GETATTR] = {
956 		.process_op = (callback_process_op_t)nfs4_callback_getattr,
957 		.decode_args = (callback_decode_arg_t)decode_getattr_args,
958 		.encode_res = (callback_encode_res_t)encode_getattr_res,
959 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
960 	},
961 	[OP_CB_RECALL] = {
962 		.process_op = (callback_process_op_t)nfs4_callback_recall,
963 		.decode_args = (callback_decode_arg_t)decode_recall_args,
964 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
965 	},
966 #if defined(CONFIG_NFS_V4_1)
967 	[OP_CB_LAYOUTRECALL] = {
968 		.process_op = (callback_process_op_t)nfs4_callback_layoutrecall,
969 		.decode_args =
970 			(callback_decode_arg_t)decode_layoutrecall_args,
971 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
972 	},
973 	[OP_CB_NOTIFY_DEVICEID] = {
974 		.process_op = (callback_process_op_t)nfs4_callback_devicenotify,
975 		.decode_args =
976 			(callback_decode_arg_t)decode_devicenotify_args,
977 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
978 	},
979 	[OP_CB_SEQUENCE] = {
980 		.process_op = (callback_process_op_t)nfs4_callback_sequence,
981 		.decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
982 		.encode_res = (callback_encode_res_t)encode_cb_sequence_res,
983 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
984 	},
985 	[OP_CB_RECALL_ANY] = {
986 		.process_op = (callback_process_op_t)nfs4_callback_recallany,
987 		.decode_args = (callback_decode_arg_t)decode_recallany_args,
988 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
989 	},
990 	[OP_CB_RECALL_SLOT] = {
991 		.process_op = (callback_process_op_t)nfs4_callback_recallslot,
992 		.decode_args = (callback_decode_arg_t)decode_recallslot_args,
993 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
994 	},
995 #endif /* CONFIG_NFS_V4_1 */
996 };
997 
998 /*
999  * Define NFS4 callback procedures
1000  */
1001 static struct svc_procedure nfs4_callback_procedures1[] = {
1002 	[CB_NULL] = {
1003 		.pc_func = nfs4_callback_null,
1004 		.pc_decode = (kxdrproc_t)nfs4_decode_void,
1005 		.pc_encode = (kxdrproc_t)nfs4_encode_void,
1006 		.pc_xdrressize = 1,
1007 	},
1008 	[CB_COMPOUND] = {
1009 		.pc_func = nfs4_callback_compound,
1010 		.pc_encode = (kxdrproc_t)nfs4_encode_void,
1011 		.pc_argsize = 256,
1012 		.pc_ressize = 256,
1013 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1014 	}
1015 };
1016 
1017 struct svc_version nfs4_callback_version1 = {
1018 	.vs_vers = 1,
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 = 1,
1024 };
1025 
1026 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_xdrsize = NFS4_CALLBACK_XDRSIZE,
1031 	.vs_dispatch = NULL,
1032 	.vs_hidden = 1,
1033 };
1034