xref: /linux/fs/nfs/callback_xdr.c (revision c4c11dd160a8cc98f402c4e12f94b1572e822ffd)
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(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(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 				goto out_free;
469 		}
470 	}
471 	status = 0;
472 
473 	dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
474 		"highestslotid %u cachethis %d nrclists %u\n",
475 		__func__,
476 		((u32 *)&args->csa_sessionid)[0],
477 		((u32 *)&args->csa_sessionid)[1],
478 		((u32 *)&args->csa_sessionid)[2],
479 		((u32 *)&args->csa_sessionid)[3],
480 		args->csa_sequenceid, args->csa_slotid,
481 		args->csa_highestslotid, args->csa_cachethis,
482 		args->csa_nrclists);
483 out:
484 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
485 	return status;
486 
487 out_free:
488 	for (i = 0; i < args->csa_nrclists; i++)
489 		kfree(args->csa_rclists[i].rcl_refcalls);
490 	kfree(args->csa_rclists);
491 	goto out;
492 }
493 
494 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
495 				      struct xdr_stream *xdr,
496 				      struct cb_recallanyargs *args)
497 {
498 	uint32_t bitmap[2];
499 	__be32 *p, status;
500 
501 	args->craa_addr = svc_addr(rqstp);
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 	args->crsa_addr = svc_addr(rqstp);
521 	p = read_buf(xdr, 4);
522 	if (unlikely(p == NULL))
523 		return htonl(NFS4ERR_BADXDR);
524 	args->crsa_target_highest_slotid = ntohl(*p++);
525 	return 0;
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 	__be32 *p;
533 
534 	p = xdr_reserve_space(xdr, 4 + len);
535 	if (unlikely(p == NULL))
536 		return htonl(NFS4ERR_RESOURCE);
537 	xdr_encode_opaque(p, str, len);
538 	return 0;
539 }
540 
541 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
542 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
543 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
544 {
545 	__be32 bm[2];
546 	__be32 *p;
547 
548 	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
549 	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
550 	if (bm[1] != 0) {
551 		p = xdr_reserve_space(xdr, 16);
552 		if (unlikely(p == NULL))
553 			return htonl(NFS4ERR_RESOURCE);
554 		*p++ = htonl(2);
555 		*p++ = bm[0];
556 		*p++ = bm[1];
557 	} else if (bm[0] != 0) {
558 		p = xdr_reserve_space(xdr, 12);
559 		if (unlikely(p == NULL))
560 			return htonl(NFS4ERR_RESOURCE);
561 		*p++ = htonl(1);
562 		*p++ = bm[0];
563 	} else {
564 		p = xdr_reserve_space(xdr, 8);
565 		if (unlikely(p == NULL))
566 			return htonl(NFS4ERR_RESOURCE);
567 		*p++ = htonl(0);
568 	}
569 	*savep = p;
570 	return 0;
571 }
572 
573 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
574 {
575 	__be32 *p;
576 
577 	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
578 		return 0;
579 	p = xdr_reserve_space(xdr, 8);
580 	if (unlikely(!p))
581 		return htonl(NFS4ERR_RESOURCE);
582 	p = xdr_encode_hyper(p, change);
583 	return 0;
584 }
585 
586 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
587 {
588 	__be32 *p;
589 
590 	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
591 		return 0;
592 	p = xdr_reserve_space(xdr, 8);
593 	if (unlikely(!p))
594 		return htonl(NFS4ERR_RESOURCE);
595 	p = xdr_encode_hyper(p, size);
596 	return 0;
597 }
598 
599 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
600 {
601 	__be32 *p;
602 
603 	p = xdr_reserve_space(xdr, 12);
604 	if (unlikely(!p))
605 		return htonl(NFS4ERR_RESOURCE);
606 	p = xdr_encode_hyper(p, time->tv_sec);
607 	*p = htonl(time->tv_nsec);
608 	return 0;
609 }
610 
611 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
612 {
613 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
614 		return 0;
615 	return encode_attr_time(xdr,time);
616 }
617 
618 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
619 {
620 	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
621 		return 0;
622 	return encode_attr_time(xdr,time);
623 }
624 
625 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
626 {
627 	__be32 status;
628 
629 	hdr->status = xdr_reserve_space(xdr, 4);
630 	if (unlikely(hdr->status == NULL))
631 		return htonl(NFS4ERR_RESOURCE);
632 	status = encode_string(xdr, hdr->taglen, hdr->tag);
633 	if (unlikely(status != 0))
634 		return status;
635 	hdr->nops = xdr_reserve_space(xdr, 4);
636 	if (unlikely(hdr->nops == NULL))
637 		return htonl(NFS4ERR_RESOURCE);
638 	return 0;
639 }
640 
641 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
642 {
643 	__be32 *p;
644 
645 	p = xdr_reserve_space(xdr, 8);
646 	if (unlikely(p == NULL))
647 		return htonl(NFS4ERR_RESOURCE_HDR);
648 	*p++ = htonl(op);
649 	*p = res;
650 	return 0;
651 }
652 
653 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
654 {
655 	__be32 *savep = NULL;
656 	__be32 status = res->status;
657 
658 	if (unlikely(status != 0))
659 		goto out;
660 	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
661 	if (unlikely(status != 0))
662 		goto out;
663 	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
664 	if (unlikely(status != 0))
665 		goto out;
666 	status = encode_attr_size(xdr, res->bitmap, res->size);
667 	if (unlikely(status != 0))
668 		goto out;
669 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
670 	if (unlikely(status != 0))
671 		goto out;
672 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
673 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
674 out:
675 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
676 	return status;
677 }
678 
679 #if defined(CONFIG_NFS_V4_1)
680 
681 static __be32 encode_sessionid(struct xdr_stream *xdr,
682 				 const struct nfs4_sessionid *sid)
683 {
684 	__be32 *p;
685 	int len = NFS4_MAX_SESSIONID_LEN;
686 
687 	p = xdr_reserve_space(xdr, len);
688 	if (unlikely(p == NULL))
689 		return htonl(NFS4ERR_RESOURCE);
690 
691 	memcpy(p, sid, len);
692 	return 0;
693 }
694 
695 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
696 				       struct xdr_stream *xdr,
697 				       const struct cb_sequenceres *res)
698 {
699 	__be32 *p;
700 	__be32 status = res->csr_status;
701 
702 	if (unlikely(status != 0))
703 		goto out;
704 
705 	encode_sessionid(xdr, &res->csr_sessionid);
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 	__be32 *p, status;
894 	struct cb_process_state cps = {
895 		.drc_status = 0,
896 		.clp = NULL,
897 		.slotid = NFS4_NO_SLOT,
898 		.net = SVC_NET(rqstp),
899 	};
900 	unsigned int nops = 0;
901 
902 	dprintk("%s: start\n", __func__);
903 
904 	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
905 
906 	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
907 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
908 
909 	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
910 	if (status == __constant_htonl(NFS4ERR_RESOURCE))
911 		return rpc_garbage_args;
912 
913 	if (hdr_arg.minorversion == 0) {
914 		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
915 		if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
916 			return rpc_drop_reply;
917 	}
918 
919 	cps.minorversion = hdr_arg.minorversion;
920 	hdr_res.taglen = hdr_arg.taglen;
921 	hdr_res.tag = hdr_arg.tag;
922 	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
923 		return rpc_system_err;
924 
925 	while (status == 0 && nops != hdr_arg.nops) {
926 		status = process_op(nops, rqstp, &xdr_in,
927 				    argp, &xdr_out, resp, &cps);
928 		nops++;
929 	}
930 
931 	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
932 	* resource error in cb_compound status without returning op */
933 	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
934 		status = htonl(NFS4ERR_RESOURCE);
935 		nops--;
936 	}
937 
938 	*hdr_res.status = status;
939 	*hdr_res.nops = htonl(nops);
940 	nfs4_cb_free_slot(&cps);
941 	nfs_put_client(cps.clp);
942 	dprintk("%s: done, status = %u\n", __func__, ntohl(status));
943 	return rpc_success;
944 }
945 
946 /*
947  * Define NFS4 callback COMPOUND ops.
948  */
949 static struct callback_op callback_ops[] = {
950 	[0] = {
951 		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
952 	},
953 	[OP_CB_GETATTR] = {
954 		.process_op = (callback_process_op_t)nfs4_callback_getattr,
955 		.decode_args = (callback_decode_arg_t)decode_getattr_args,
956 		.encode_res = (callback_encode_res_t)encode_getattr_res,
957 		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
958 	},
959 	[OP_CB_RECALL] = {
960 		.process_op = (callback_process_op_t)nfs4_callback_recall,
961 		.decode_args = (callback_decode_arg_t)decode_recall_args,
962 		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
963 	},
964 #if defined(CONFIG_NFS_V4_1)
965 	[OP_CB_LAYOUTRECALL] = {
966 		.process_op = (callback_process_op_t)nfs4_callback_layoutrecall,
967 		.decode_args =
968 			(callback_decode_arg_t)decode_layoutrecall_args,
969 		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
970 	},
971 	[OP_CB_NOTIFY_DEVICEID] = {
972 		.process_op = (callback_process_op_t)nfs4_callback_devicenotify,
973 		.decode_args =
974 			(callback_decode_arg_t)decode_devicenotify_args,
975 		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
976 	},
977 	[OP_CB_SEQUENCE] = {
978 		.process_op = (callback_process_op_t)nfs4_callback_sequence,
979 		.decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
980 		.encode_res = (callback_encode_res_t)encode_cb_sequence_res,
981 		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
982 	},
983 	[OP_CB_RECALL_ANY] = {
984 		.process_op = (callback_process_op_t)nfs4_callback_recallany,
985 		.decode_args = (callback_decode_arg_t)decode_recallany_args,
986 		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
987 	},
988 	[OP_CB_RECALL_SLOT] = {
989 		.process_op = (callback_process_op_t)nfs4_callback_recallslot,
990 		.decode_args = (callback_decode_arg_t)decode_recallslot_args,
991 		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
992 	},
993 #endif /* CONFIG_NFS_V4_1 */
994 };
995 
996 /*
997  * Define NFS4 callback procedures
998  */
999 static struct svc_procedure nfs4_callback_procedures1[] = {
1000 	[CB_NULL] = {
1001 		.pc_func = nfs4_callback_null,
1002 		.pc_decode = (kxdrproc_t)nfs4_decode_void,
1003 		.pc_encode = (kxdrproc_t)nfs4_encode_void,
1004 		.pc_xdrressize = 1,
1005 	},
1006 	[CB_COMPOUND] = {
1007 		.pc_func = nfs4_callback_compound,
1008 		.pc_encode = (kxdrproc_t)nfs4_encode_void,
1009 		.pc_argsize = 256,
1010 		.pc_ressize = 256,
1011 		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1012 	}
1013 };
1014 
1015 struct svc_version nfs4_callback_version1 = {
1016 	.vs_vers = 1,
1017 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1018 	.vs_proc = nfs4_callback_procedures1,
1019 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1020 	.vs_dispatch = NULL,
1021 	.vs_hidden = 1,
1022 };
1023 
1024 struct svc_version nfs4_callback_version4 = {
1025 	.vs_vers = 4,
1026 	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1027 	.vs_proc = nfs4_callback_procedures1,
1028 	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1029 	.vs_dispatch = NULL,
1030 	.vs_hidden = 1,
1031 };
1032