xref: /openbmc/linux/fs/nfs/callback_xdr.c (revision 92b19ff5)
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 + CB_OP_TAGLEN_MAXSZ)
23 #define CB_OP_GETATTR_BITMAP_MAXSZ	(4)
24 #define CB_OP_GETATTR_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
25 				CB_OP_GETATTR_BITMAP_MAXSZ + \
26 				2 + 2 + 3 + 3)
27 #define CB_OP_RECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
28 
29 #if defined(CONFIG_NFS_V4_1)
30 #define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
31 #define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
32 #define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
33 					4 + 1 + 3)
34 #define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
35 #define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
36 #endif /* CONFIG_NFS_V4_1 */
37 
38 #define NFSDBG_FACILITY NFSDBG_CALLBACK
39 
40 /* Internal error code */
41 #define NFS4ERR_RESOURCE_HDR	11050
42 
43 typedef __be32 (*callback_process_op_t)(void *, void *,
44 					struct cb_process_state *);
45 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
46 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
47 
48 
49 struct callback_op {
50 	callback_process_op_t process_op;
51 	callback_decode_arg_t decode_args;
52 	callback_encode_res_t encode_res;
53 	long res_maxsize;
54 };
55 
56 static struct callback_op callback_ops[];
57 
58 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
59 {
60 	return htonl(NFS4_OK);
61 }
62 
63 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
64 {
65 	return xdr_argsize_check(rqstp, p);
66 }
67 
68 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
69 {
70 	return xdr_ressize_check(rqstp, p);
71 }
72 
73 static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
74 {
75 	__be32 *p;
76 
77 	p = xdr_inline_decode(xdr, nbytes);
78 	if (unlikely(p == NULL))
79 		printk(KERN_WARNING "NFS: NFSv4 callback reply buffer overflowed!\n");
80 	return p;
81 }
82 
83 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
84 {
85 	__be32 *p;
86 
87 	p = read_buf(xdr, 4);
88 	if (unlikely(p == NULL))
89 		return htonl(NFS4ERR_RESOURCE);
90 	*len = ntohl(*p);
91 
92 	if (*len != 0) {
93 		p = read_buf(xdr, *len);
94 		if (unlikely(p == NULL))
95 			return htonl(NFS4ERR_RESOURCE);
96 		*str = (const char *)p;
97 	} else
98 		*str = NULL;
99 
100 	return 0;
101 }
102 
103 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
104 {
105 	__be32 *p;
106 
107 	p = read_buf(xdr, 4);
108 	if (unlikely(p == NULL))
109 		return htonl(NFS4ERR_RESOURCE);
110 	fh->size = ntohl(*p);
111 	if (fh->size > NFS4_FHSIZE)
112 		return htonl(NFS4ERR_BADHANDLE);
113 	p = read_buf(xdr, fh->size);
114 	if (unlikely(p == NULL))
115 		return htonl(NFS4ERR_RESOURCE);
116 	memcpy(&fh->data[0], p, fh->size);
117 	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
118 	return 0;
119 }
120 
121 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
122 {
123 	__be32 *p;
124 	unsigned int attrlen;
125 
126 	p = read_buf(xdr, 4);
127 	if (unlikely(p == NULL))
128 		return htonl(NFS4ERR_RESOURCE);
129 	attrlen = ntohl(*p);
130 	p = read_buf(xdr, attrlen << 2);
131 	if (unlikely(p == NULL))
132 		return htonl(NFS4ERR_RESOURCE);
133 	if (likely(attrlen > 0))
134 		bitmap[0] = ntohl(*p++);
135 	if (attrlen > 1)
136 		bitmap[1] = ntohl(*p);
137 	return 0;
138 }
139 
140 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
141 {
142 	__be32 *p;
143 
144 	p = read_buf(xdr, NFS4_STATEID_SIZE);
145 	if (unlikely(p == NULL))
146 		return htonl(NFS4ERR_RESOURCE);
147 	memcpy(stateid, p, NFS4_STATEID_SIZE);
148 	return 0;
149 }
150 
151 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
152 {
153 	__be32 *p;
154 	__be32 status;
155 
156 	status = decode_string(xdr, &hdr->taglen, &hdr->tag);
157 	if (unlikely(status != 0))
158 		return status;
159 	/* We do not like overly long tags! */
160 	if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
161 		printk("NFS: NFSv4 CALLBACK %s: client sent tag of length %u\n",
162 				__func__, hdr->taglen);
163 		return htonl(NFS4ERR_RESOURCE);
164 	}
165 	p = read_buf(xdr, 12);
166 	if (unlikely(p == NULL))
167 		return htonl(NFS4ERR_RESOURCE);
168 	hdr->minorversion = ntohl(*p++);
169 	/* Check for minor version support */
170 	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
171 		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
172 	} else {
173 		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
174 			"illegal minor version %u!\n",
175 			__func__, hdr->minorversion);
176 		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
177 	}
178 	hdr->nops = ntohl(*p);
179 	dprintk("%s: minorversion %d nops %d\n", __func__,
180 		hdr->minorversion, hdr->nops);
181 	return 0;
182 }
183 
184 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
185 {
186 	__be32 *p;
187 	p = read_buf(xdr, 4);
188 	if (unlikely(p == NULL))
189 		return htonl(NFS4ERR_RESOURCE_HDR);
190 	*op = ntohl(*p);
191 	return 0;
192 }
193 
194 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
195 {
196 	__be32 status;
197 
198 	status = decode_fh(xdr, &args->fh);
199 	if (unlikely(status != 0))
200 		goto out;
201 	args->addr = svc_addr(rqstp);
202 	status = decode_bitmap(xdr, args->bitmap);
203 out:
204 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
205 	return status;
206 }
207 
208 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
209 {
210 	__be32 *p;
211 	__be32 status;
212 
213 	args->addr = svc_addr(rqstp);
214 	status = decode_stateid(xdr, &args->stateid);
215 	if (unlikely(status != 0))
216 		goto out;
217 	p = read_buf(xdr, 4);
218 	if (unlikely(p == NULL)) {
219 		status = htonl(NFS4ERR_RESOURCE);
220 		goto out;
221 	}
222 	args->truncate = ntohl(*p);
223 	status = decode_fh(xdr, &args->fh);
224 out:
225 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
226 	return status;
227 }
228 
229 #if defined(CONFIG_NFS_V4_1)
230 
231 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
232 				       struct xdr_stream *xdr,
233 				       struct cb_layoutrecallargs *args)
234 {
235 	__be32 *p;
236 	__be32 status = 0;
237 	uint32_t iomode;
238 
239 	args->cbl_addr = svc_addr(rqstp);
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 	int len = NFS4_MAX_SESSIONID_LEN;
387 
388 	p = read_buf(xdr, len);
389 	if (unlikely(p == NULL))
390 		return htonl(NFS4ERR_RESOURCE);
391 
392 	memcpy(sid->data, p, len);
393 	return 0;
394 }
395 
396 static __be32 decode_rc_list(struct xdr_stream *xdr,
397 			       struct referring_call_list *rc_list)
398 {
399 	__be32 *p;
400 	int i;
401 	__be32 status;
402 
403 	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
404 	if (status)
405 		goto out;
406 
407 	status = htonl(NFS4ERR_RESOURCE);
408 	p = read_buf(xdr, sizeof(uint32_t));
409 	if (unlikely(p == NULL))
410 		goto out;
411 
412 	rc_list->rcl_nrefcalls = ntohl(*p++);
413 	if (rc_list->rcl_nrefcalls) {
414 		p = read_buf(xdr,
415 			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
416 		if (unlikely(p == NULL))
417 			goto out;
418 		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
419 						sizeof(*rc_list->rcl_refcalls),
420 						GFP_KERNEL);
421 		if (unlikely(rc_list->rcl_refcalls == NULL))
422 			goto out;
423 		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
424 			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
425 			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
426 		}
427 	}
428 	status = 0;
429 
430 out:
431 	return status;
432 }
433 
434 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
435 					struct xdr_stream *xdr,
436 					struct cb_sequenceargs *args)
437 {
438 	__be32 *p;
439 	int i;
440 	__be32 status;
441 
442 	status = decode_sessionid(xdr, &args->csa_sessionid);
443 	if (status)
444 		goto out;
445 
446 	status = htonl(NFS4ERR_RESOURCE);
447 	p = read_buf(xdr, 5 * sizeof(uint32_t));
448 	if (unlikely(p == NULL))
449 		goto out;
450 
451 	args->csa_addr = svc_addr(rqstp);
452 	args->csa_sequenceid = ntohl(*p++);
453 	args->csa_slotid = ntohl(*p++);
454 	args->csa_highestslotid = ntohl(*p++);
455 	args->csa_cachethis = ntohl(*p++);
456 	args->csa_nrclists = ntohl(*p++);
457 	args->csa_rclists = NULL;
458 	if (args->csa_nrclists) {
459 		args->csa_rclists = kmalloc_array(args->csa_nrclists,
460 						  sizeof(*args->csa_rclists),
461 						  GFP_KERNEL);
462 		if (unlikely(args->csa_rclists == NULL))
463 			goto out;
464 
465 		for (i = 0; i < args->csa_nrclists; i++) {
466 			status = decode_rc_list(xdr, &args->csa_rclists[i]);
467 			if (status) {
468 				args->csa_nrclists = i;
469 				goto out_free;
470 			}
471 		}
472 	}
473 	status = 0;
474 
475 	dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
476 		"highestslotid %u cachethis %d nrclists %u\n",
477 		__func__,
478 		((u32 *)&args->csa_sessionid)[0],
479 		((u32 *)&args->csa_sessionid)[1],
480 		((u32 *)&args->csa_sessionid)[2],
481 		((u32 *)&args->csa_sessionid)[3],
482 		args->csa_sequenceid, args->csa_slotid,
483 		args->csa_highestslotid, args->csa_cachethis,
484 		args->csa_nrclists);
485 out:
486 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
487 	return status;
488 
489 out_free:
490 	for (i = 0; i < args->csa_nrclists; i++)
491 		kfree(args->csa_rclists[i].rcl_refcalls);
492 	kfree(args->csa_rclists);
493 	goto out;
494 }
495 
496 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
497 				      struct xdr_stream *xdr,
498 				      struct cb_recallanyargs *args)
499 {
500 	uint32_t bitmap[2];
501 	__be32 *p, status;
502 
503 	args->craa_addr = svc_addr(rqstp);
504 	p = read_buf(xdr, 4);
505 	if (unlikely(p == NULL))
506 		return htonl(NFS4ERR_BADXDR);
507 	args->craa_objs_to_keep = ntohl(*p++);
508 	status = decode_bitmap(xdr, bitmap);
509 	if (unlikely(status))
510 		return status;
511 	args->craa_type_mask = bitmap[0];
512 
513 	return 0;
514 }
515 
516 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
517 					struct xdr_stream *xdr,
518 					struct cb_recallslotargs *args)
519 {
520 	__be32 *p;
521 
522 	args->crsa_addr = svc_addr(rqstp);
523 	p = read_buf(xdr, 4);
524 	if (unlikely(p == NULL))
525 		return htonl(NFS4ERR_BADXDR);
526 	args->crsa_target_highest_slotid = ntohl(*p++);
527 	return 0;
528 }
529 
530 #endif /* CONFIG_NFS_V4_1 */
531 
532 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
533 {
534 	__be32 *p;
535 
536 	p = xdr_reserve_space(xdr, 4 + len);
537 	if (unlikely(p == NULL))
538 		return htonl(NFS4ERR_RESOURCE);
539 	xdr_encode_opaque(p, str, len);
540 	return 0;
541 }
542 
543 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
544 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
545 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
546 {
547 	__be32 bm[2];
548 	__be32 *p;
549 
550 	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
551 	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
552 	if (bm[1] != 0) {
553 		p = xdr_reserve_space(xdr, 16);
554 		if (unlikely(p == NULL))
555 			return htonl(NFS4ERR_RESOURCE);
556 		*p++ = htonl(2);
557 		*p++ = bm[0];
558 		*p++ = bm[1];
559 	} else if (bm[0] != 0) {
560 		p = xdr_reserve_space(xdr, 12);
561 		if (unlikely(p == NULL))
562 			return htonl(NFS4ERR_RESOURCE);
563 		*p++ = htonl(1);
564 		*p++ = bm[0];
565 	} else {
566 		p = xdr_reserve_space(xdr, 8);
567 		if (unlikely(p == NULL))
568 			return htonl(NFS4ERR_RESOURCE);
569 		*p++ = htonl(0);
570 	}
571 	*savep = p;
572 	return 0;
573 }
574 
575 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
576 {
577 	__be32 *p;
578 
579 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
580 		return 0;
581 	p = xdr_reserve_space(xdr, 8);
582 	if (unlikely(!p))
583 		return htonl(NFS4ERR_RESOURCE);
584 	p = xdr_encode_hyper(p, change);
585 	return 0;
586 }
587 
588 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
589 {
590 	__be32 *p;
591 
592 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
593 		return 0;
594 	p = xdr_reserve_space(xdr, 8);
595 	if (unlikely(!p))
596 		return htonl(NFS4ERR_RESOURCE);
597 	p = xdr_encode_hyper(p, size);
598 	return 0;
599 }
600 
601 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
602 {
603 	__be32 *p;
604 
605 	p = xdr_reserve_space(xdr, 12);
606 	if (unlikely(!p))
607 		return htonl(NFS4ERR_RESOURCE);
608 	p = xdr_encode_hyper(p, time->tv_sec);
609 	*p = htonl(time->tv_nsec);
610 	return 0;
611 }
612 
613 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
614 {
615 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
616 		return 0;
617 	return encode_attr_time(xdr,time);
618 }
619 
620 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
621 {
622 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
623 		return 0;
624 	return encode_attr_time(xdr,time);
625 }
626 
627 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
628 {
629 	__be32 status;
630 
631 	hdr->status = xdr_reserve_space(xdr, 4);
632 	if (unlikely(hdr->status == NULL))
633 		return htonl(NFS4ERR_RESOURCE);
634 	status = encode_string(xdr, hdr->taglen, hdr->tag);
635 	if (unlikely(status != 0))
636 		return status;
637 	hdr->nops = xdr_reserve_space(xdr, 4);
638 	if (unlikely(hdr->nops == NULL))
639 		return htonl(NFS4ERR_RESOURCE);
640 	return 0;
641 }
642 
643 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
644 {
645 	__be32 *p;
646 
647 	p = xdr_reserve_space(xdr, 8);
648 	if (unlikely(p == NULL))
649 		return htonl(NFS4ERR_RESOURCE_HDR);
650 	*p++ = htonl(op);
651 	*p = res;
652 	return 0;
653 }
654 
655 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
656 {
657 	__be32 *savep = NULL;
658 	__be32 status = res->status;
659 
660 	if (unlikely(status != 0))
661 		goto out;
662 	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
663 	if (unlikely(status != 0))
664 		goto out;
665 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
666 	if (unlikely(status != 0))
667 		goto out;
668 	status = encode_attr_size(xdr, res->bitmap, res->size);
669 	if (unlikely(status != 0))
670 		goto out;
671 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
672 	if (unlikely(status != 0))
673 		goto out;
674 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
675 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
676 out:
677 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
678 	return status;
679 }
680 
681 #if defined(CONFIG_NFS_V4_1)
682 
683 static __be32 encode_sessionid(struct xdr_stream *xdr,
684 				 const struct nfs4_sessionid *sid)
685 {
686 	__be32 *p;
687 	int len = NFS4_MAX_SESSIONID_LEN;
688 
689 	p = xdr_reserve_space(xdr, len);
690 	if (unlikely(p == NULL))
691 		return htonl(NFS4ERR_RESOURCE);
692 
693 	memcpy(p, sid, len);
694 	return 0;
695 }
696 
697 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
698 				       struct xdr_stream *xdr,
699 				       const struct cb_sequenceres *res)
700 {
701 	__be32 *p;
702 	__be32 status = res->csr_status;
703 
704 	if (unlikely(status != 0))
705 		goto out;
706 
707 	encode_sessionid(xdr, &res->csr_sessionid);
708 
709 	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
710 	if (unlikely(p == NULL))
711 		return htonl(NFS4ERR_RESOURCE);
712 
713 	*p++ = htonl(res->csr_sequenceid);
714 	*p++ = htonl(res->csr_slotid);
715 	*p++ = htonl(res->csr_highestslotid);
716 	*p++ = htonl(res->csr_target_highestslotid);
717 out:
718 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
719 	return status;
720 }
721 
722 static __be32
723 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
724 {
725 	if (op_nr == OP_CB_SEQUENCE) {
726 		if (nop != 0)
727 			return htonl(NFS4ERR_SEQUENCE_POS);
728 	} else {
729 		if (nop == 0)
730 			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
731 	}
732 
733 	switch (op_nr) {
734 	case OP_CB_GETATTR:
735 	case OP_CB_RECALL:
736 	case OP_CB_SEQUENCE:
737 	case OP_CB_RECALL_ANY:
738 	case OP_CB_RECALL_SLOT:
739 	case OP_CB_LAYOUTRECALL:
740 	case OP_CB_NOTIFY_DEVICEID:
741 		*op = &callback_ops[op_nr];
742 		break;
743 
744 	case OP_CB_NOTIFY:
745 	case OP_CB_PUSH_DELEG:
746 	case OP_CB_RECALLABLE_OBJ_AVAIL:
747 	case OP_CB_WANTS_CANCELLED:
748 	case OP_CB_NOTIFY_LOCK:
749 		return htonl(NFS4ERR_NOTSUPP);
750 
751 	default:
752 		return htonl(NFS4ERR_OP_ILLEGAL);
753 	}
754 
755 	return htonl(NFS_OK);
756 }
757 
758 static void nfs4_callback_free_slot(struct nfs4_session *session)
759 {
760 	struct nfs4_slot_table *tbl = &session->bc_slot_table;
761 
762 	spin_lock(&tbl->slot_tbl_lock);
763 	/*
764 	 * Let the state manager know callback processing done.
765 	 * A single slot, so highest used slotid is either 0 or -1
766 	 */
767 	tbl->highest_used_slotid = NFS4_NO_SLOT;
768 	nfs4_slot_tbl_drain_complete(tbl);
769 	spin_unlock(&tbl->slot_tbl_lock);
770 }
771 
772 static void nfs4_cb_free_slot(struct cb_process_state *cps)
773 {
774 	if (cps->slotid != NFS4_NO_SLOT)
775 		nfs4_callback_free_slot(cps->clp->cl_session);
776 }
777 
778 #else /* CONFIG_NFS_V4_1 */
779 
780 static __be32
781 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
782 {
783 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
784 }
785 
786 static void nfs4_cb_free_slot(struct cb_process_state *cps)
787 {
788 }
789 #endif /* CONFIG_NFS_V4_1 */
790 
791 #ifdef CONFIG_NFS_V4_2
792 static __be32
793 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
794 {
795 	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
796 	if (status != htonl(NFS4ERR_OP_ILLEGAL))
797 		return status;
798 
799 	if (op_nr == OP_CB_OFFLOAD)
800 		return htonl(NFS4ERR_NOTSUPP);
801 	return htonl(NFS4ERR_OP_ILLEGAL);
802 }
803 #else /* CONFIG_NFS_V4_2 */
804 static __be32
805 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
806 {
807 	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
808 }
809 #endif /* CONFIG_NFS_V4_2 */
810 
811 static __be32
812 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
813 {
814 	switch (op_nr) {
815 	case OP_CB_GETATTR:
816 	case OP_CB_RECALL:
817 		*op = &callback_ops[op_nr];
818 		break;
819 	default:
820 		return htonl(NFS4ERR_OP_ILLEGAL);
821 	}
822 
823 	return htonl(NFS_OK);
824 }
825 
826 static __be32 process_op(int nop, struct svc_rqst *rqstp,
827 		struct xdr_stream *xdr_in, void *argp,
828 		struct xdr_stream *xdr_out, void *resp,
829 		struct cb_process_state *cps)
830 {
831 	struct callback_op *op = &callback_ops[0];
832 	unsigned int op_nr;
833 	__be32 status;
834 	long maxlen;
835 	__be32 res;
836 
837 	dprintk("%s: start\n", __func__);
838 	status = decode_op_hdr(xdr_in, &op_nr);
839 	if (unlikely(status))
840 		return status;
841 
842 	dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
843 		__func__, cps->minorversion, nop, op_nr);
844 
845 	switch (cps->minorversion) {
846 	case 0:
847 		status = preprocess_nfs4_op(op_nr, &op);
848 		break;
849 	case 1:
850 		status = preprocess_nfs41_op(nop, op_nr, &op);
851 		break;
852 	case 2:
853 		status = preprocess_nfs42_op(nop, op_nr, &op);
854 		break;
855 	default:
856 		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
857 	}
858 
859 	if (status == htonl(NFS4ERR_OP_ILLEGAL))
860 		op_nr = OP_CB_ILLEGAL;
861 	if (status)
862 		goto encode_hdr;
863 
864 	if (cps->drc_status) {
865 		status = cps->drc_status;
866 		goto encode_hdr;
867 	}
868 
869 	maxlen = xdr_out->end - xdr_out->p;
870 	if (maxlen > 0 && maxlen < PAGE_SIZE) {
871 		status = op->decode_args(rqstp, xdr_in, argp);
872 		if (likely(status == 0))
873 			status = op->process_op(argp, resp, cps);
874 	} else
875 		status = htonl(NFS4ERR_RESOURCE);
876 
877 encode_hdr:
878 	res = encode_op_hdr(xdr_out, op_nr, status);
879 	if (unlikely(res))
880 		return res;
881 	if (op->encode_res != NULL && status == 0)
882 		status = op->encode_res(rqstp, xdr_out, resp);
883 	dprintk("%s: done, status = %d\n", __func__, ntohl(status));
884 	return status;
885 }
886 
887 /*
888  * Decode, process and encode a COMPOUND
889  */
890 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
891 {
892 	struct cb_compound_hdr_arg hdr_arg = { 0 };
893 	struct cb_compound_hdr_res hdr_res = { NULL };
894 	struct xdr_stream xdr_in, xdr_out;
895 	__be32 *p, status;
896 	struct cb_process_state cps = {
897 		.drc_status = 0,
898 		.clp = NULL,
899 		.slotid = NFS4_NO_SLOT,
900 		.net = SVC_NET(rqstp),
901 	};
902 	unsigned int nops = 0;
903 
904 	dprintk("%s: start\n", __func__);
905 
906 	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->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