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 "nfs4_fs.h"
14#include "callback.h"
15
16#define CB_OP_TAGLEN_MAXSZ	(512)
17#define CB_OP_HDR_RES_MAXSZ	(2 + CB_OP_TAGLEN_MAXSZ)
18#define CB_OP_GETATTR_BITMAP_MAXSZ	(4)
19#define CB_OP_GETATTR_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
20				CB_OP_GETATTR_BITMAP_MAXSZ + \
21				2 + 2 + 3 + 3)
22#define CB_OP_RECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
23
24#if defined(CONFIG_NFS_V4_1)
25#define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
26					4 + 1 + 3)
27#define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
28#define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
29#endif /* CONFIG_NFS_V4_1 */
30
31#define NFSDBG_FACILITY NFSDBG_CALLBACK
32
33/* Internal error code */
34#define NFS4ERR_RESOURCE_HDR	11050
35
36typedef __be32 (*callback_process_op_t)(void *, void *);
37typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
38typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
39
40
41struct callback_op {
42	callback_process_op_t process_op;
43	callback_decode_arg_t decode_args;
44	callback_encode_res_t encode_res;
45	long res_maxsize;
46};
47
48static struct callback_op callback_ops[];
49
50static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
51{
52	return htonl(NFS4_OK);
53}
54
55static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
56{
57	return xdr_argsize_check(rqstp, p);
58}
59
60static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
61{
62	return xdr_ressize_check(rqstp, p);
63}
64
65static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
66{
67	__be32 *p;
68
69	p = xdr_inline_decode(xdr, nbytes);
70	if (unlikely(p == NULL))
71		printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
72	return p;
73}
74
75static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
76{
77	__be32 *p;
78
79	p = read_buf(xdr, 4);
80	if (unlikely(p == NULL))
81		return htonl(NFS4ERR_RESOURCE);
82	*len = ntohl(*p);
83
84	if (*len != 0) {
85		p = read_buf(xdr, *len);
86		if (unlikely(p == NULL))
87			return htonl(NFS4ERR_RESOURCE);
88		*str = (const char *)p;
89	} else
90		*str = NULL;
91
92	return 0;
93}
94
95static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
96{
97	__be32 *p;
98
99	p = read_buf(xdr, 4);
100	if (unlikely(p == NULL))
101		return htonl(NFS4ERR_RESOURCE);
102	fh->size = ntohl(*p);
103	if (fh->size > NFS4_FHSIZE)
104		return htonl(NFS4ERR_BADHANDLE);
105	p = read_buf(xdr, fh->size);
106	if (unlikely(p == NULL))
107		return htonl(NFS4ERR_RESOURCE);
108	memcpy(&fh->data[0], p, fh->size);
109	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
110	return 0;
111}
112
113static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
114{
115	__be32 *p;
116	unsigned int attrlen;
117
118	p = read_buf(xdr, 4);
119	if (unlikely(p == NULL))
120		return htonl(NFS4ERR_RESOURCE);
121	attrlen = ntohl(*p);
122	p = read_buf(xdr, attrlen << 2);
123	if (unlikely(p == NULL))
124		return htonl(NFS4ERR_RESOURCE);
125	if (likely(attrlen > 0))
126		bitmap[0] = ntohl(*p++);
127	if (attrlen > 1)
128		bitmap[1] = ntohl(*p);
129	return 0;
130}
131
132static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
133{
134	__be32 *p;
135
136	p = read_buf(xdr, 16);
137	if (unlikely(p == NULL))
138		return htonl(NFS4ERR_RESOURCE);
139	memcpy(stateid->data, p, 16);
140	return 0;
141}
142
143static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
144{
145	__be32 *p;
146	__be32 status;
147
148	status = decode_string(xdr, &hdr->taglen, &hdr->tag);
149	if (unlikely(status != 0))
150		return status;
151	/* We do not like overly long tags! */
152	if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
153		printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
154				__func__, hdr->taglen);
155		return htonl(NFS4ERR_RESOURCE);
156	}
157	p = read_buf(xdr, 12);
158	if (unlikely(p == NULL))
159		return htonl(NFS4ERR_RESOURCE);
160	hdr->minorversion = ntohl(*p++);
161	/* Check minor version is zero or one. */
162	if (hdr->minorversion <= 1) {
163		p++;	/* skip callback_ident */
164	} else {
165		printk(KERN_WARNING "%s: NFSv4 server callback with "
166			"illegal minor version %u!\n",
167			__func__, hdr->minorversion);
168		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
169	}
170	hdr->nops = ntohl(*p);
171	dprintk("%s: minorversion %d nops %d\n", __func__,
172		hdr->minorversion, hdr->nops);
173	return 0;
174}
175
176static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
177{
178	__be32 *p;
179	p = read_buf(xdr, 4);
180	if (unlikely(p == NULL))
181		return htonl(NFS4ERR_RESOURCE_HDR);
182	*op = ntohl(*p);
183	return 0;
184}
185
186static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
187{
188	__be32 status;
189
190	status = decode_fh(xdr, &args->fh);
191	if (unlikely(status != 0))
192		goto out;
193	args->addr = svc_addr(rqstp);
194	status = decode_bitmap(xdr, args->bitmap);
195out:
196	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
197	return status;
198}
199
200static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
201{
202	__be32 *p;
203	__be32 status;
204
205	args->addr = svc_addr(rqstp);
206	status = decode_stateid(xdr, &args->stateid);
207	if (unlikely(status != 0))
208		goto out;
209	p = read_buf(xdr, 4);
210	if (unlikely(p == NULL)) {
211		status = htonl(NFS4ERR_RESOURCE);
212		goto out;
213	}
214	args->truncate = ntohl(*p);
215	status = decode_fh(xdr, &args->fh);
216out:
217	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
218	return status;
219}
220
221#if defined(CONFIG_NFS_V4_1)
222
223static __be32 decode_sessionid(struct xdr_stream *xdr,
224				 struct nfs4_sessionid *sid)
225{
226	__be32 *p;
227	int len = NFS4_MAX_SESSIONID_LEN;
228
229	p = read_buf(xdr, len);
230	if (unlikely(p == NULL))
231		return htonl(NFS4ERR_RESOURCE);
232
233	memcpy(sid->data, p, len);
234	return 0;
235}
236
237static __be32 decode_rc_list(struct xdr_stream *xdr,
238			       struct referring_call_list *rc_list)
239{
240	__be32 *p;
241	int i;
242	__be32 status;
243
244	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
245	if (status)
246		goto out;
247
248	status = htonl(NFS4ERR_RESOURCE);
249	p = read_buf(xdr, sizeof(uint32_t));
250	if (unlikely(p == NULL))
251		goto out;
252
253	rc_list->rcl_nrefcalls = ntohl(*p++);
254	if (rc_list->rcl_nrefcalls) {
255		p = read_buf(xdr,
256			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
257		if (unlikely(p == NULL))
258			goto out;
259		rc_list->rcl_refcalls = kmalloc(rc_list->rcl_nrefcalls *
260						sizeof(*rc_list->rcl_refcalls),
261						GFP_KERNEL);
262		if (unlikely(rc_list->rcl_refcalls == NULL))
263			goto out;
264		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
265			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
266			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
267		}
268	}
269	status = 0;
270
271out:
272	return status;
273}
274
275static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
276					struct xdr_stream *xdr,
277					struct cb_sequenceargs *args)
278{
279	__be32 *p;
280	int i;
281	__be32 status;
282
283	status = decode_sessionid(xdr, &args->csa_sessionid);
284	if (status)
285		goto out;
286
287	status = htonl(NFS4ERR_RESOURCE);
288	p = read_buf(xdr, 5 * sizeof(uint32_t));
289	if (unlikely(p == NULL))
290		goto out;
291
292	args->csa_addr = svc_addr(rqstp);
293	args->csa_sequenceid = ntohl(*p++);
294	args->csa_slotid = ntohl(*p++);
295	args->csa_highestslotid = ntohl(*p++);
296	args->csa_cachethis = ntohl(*p++);
297	args->csa_nrclists = ntohl(*p++);
298	args->csa_rclists = NULL;
299	if (args->csa_nrclists) {
300		args->csa_rclists = kmalloc(args->csa_nrclists *
301					    sizeof(*args->csa_rclists),
302					    GFP_KERNEL);
303		if (unlikely(args->csa_rclists == NULL))
304			goto out;
305
306		for (i = 0; i < args->csa_nrclists; i++) {
307			status = decode_rc_list(xdr, &args->csa_rclists[i]);
308			if (status)
309				goto out_free;
310		}
311	}
312	status = 0;
313
314	dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
315		"highestslotid %u cachethis %d nrclists %u\n",
316		__func__,
317		((u32 *)&args->csa_sessionid)[0],
318		((u32 *)&args->csa_sessionid)[1],
319		((u32 *)&args->csa_sessionid)[2],
320		((u32 *)&args->csa_sessionid)[3],
321		args->csa_sequenceid, args->csa_slotid,
322		args->csa_highestslotid, args->csa_cachethis,
323		args->csa_nrclists);
324out:
325	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
326	return status;
327
328out_free:
329	for (i = 0; i < args->csa_nrclists; i++)
330		kfree(args->csa_rclists[i].rcl_refcalls);
331	kfree(args->csa_rclists);
332	goto out;
333}
334
335static __be32 decode_recallany_args(struct svc_rqst *rqstp,
336				      struct xdr_stream *xdr,
337				      struct cb_recallanyargs *args)
338{
339	__be32 *p;
340
341	args->craa_addr = svc_addr(rqstp);
342	p = read_buf(xdr, 4);
343	if (unlikely(p == NULL))
344		return htonl(NFS4ERR_BADXDR);
345	args->craa_objs_to_keep = ntohl(*p++);
346	p = read_buf(xdr, 4);
347	if (unlikely(p == NULL))
348		return htonl(NFS4ERR_BADXDR);
349	args->craa_type_mask = ntohl(*p);
350
351	return 0;
352}
353
354static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
355					struct xdr_stream *xdr,
356					struct cb_recallslotargs *args)
357{
358	__be32 *p;
359
360	args->crsa_addr = svc_addr(rqstp);
361	p = read_buf(xdr, 4);
362	if (unlikely(p == NULL))
363		return htonl(NFS4ERR_BADXDR);
364	args->crsa_target_max_slots = ntohl(*p++);
365	return 0;
366}
367
368#endif /* CONFIG_NFS_V4_1 */
369
370static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
371{
372	__be32 *p;
373
374	p = xdr_reserve_space(xdr, 4 + len);
375	if (unlikely(p == NULL))
376		return htonl(NFS4ERR_RESOURCE);
377	xdr_encode_opaque(p, str, len);
378	return 0;
379}
380
381#define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
382#define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
383static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
384{
385	__be32 bm[2];
386	__be32 *p;
387
388	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
389	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
390	if (bm[1] != 0) {
391		p = xdr_reserve_space(xdr, 16);
392		if (unlikely(p == NULL))
393			return htonl(NFS4ERR_RESOURCE);
394		*p++ = htonl(2);
395		*p++ = bm[0];
396		*p++ = bm[1];
397	} else if (bm[0] != 0) {
398		p = xdr_reserve_space(xdr, 12);
399		if (unlikely(p == NULL))
400			return htonl(NFS4ERR_RESOURCE);
401		*p++ = htonl(1);
402		*p++ = bm[0];
403	} else {
404		p = xdr_reserve_space(xdr, 8);
405		if (unlikely(p == NULL))
406			return htonl(NFS4ERR_RESOURCE);
407		*p++ = htonl(0);
408	}
409	*savep = p;
410	return 0;
411}
412
413static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
414{
415	__be32 *p;
416
417	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
418		return 0;
419	p = xdr_reserve_space(xdr, 8);
420	if (unlikely(!p))
421		return htonl(NFS4ERR_RESOURCE);
422	p = xdr_encode_hyper(p, change);
423	return 0;
424}
425
426static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
427{
428	__be32 *p;
429
430	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
431		return 0;
432	p = xdr_reserve_space(xdr, 8);
433	if (unlikely(!p))
434		return htonl(NFS4ERR_RESOURCE);
435	p = xdr_encode_hyper(p, size);
436	return 0;
437}
438
439static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
440{
441	__be32 *p;
442
443	p = xdr_reserve_space(xdr, 12);
444	if (unlikely(!p))
445		return htonl(NFS4ERR_RESOURCE);
446	p = xdr_encode_hyper(p, time->tv_sec);
447	*p = htonl(time->tv_nsec);
448	return 0;
449}
450
451static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
452{
453	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
454		return 0;
455	return encode_attr_time(xdr,time);
456}
457
458static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
459{
460	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
461		return 0;
462	return encode_attr_time(xdr,time);
463}
464
465static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
466{
467	__be32 status;
468
469	hdr->status = xdr_reserve_space(xdr, 4);
470	if (unlikely(hdr->status == NULL))
471		return htonl(NFS4ERR_RESOURCE);
472	status = encode_string(xdr, hdr->taglen, hdr->tag);
473	if (unlikely(status != 0))
474		return status;
475	hdr->nops = xdr_reserve_space(xdr, 4);
476	if (unlikely(hdr->nops == NULL))
477		return htonl(NFS4ERR_RESOURCE);
478	return 0;
479}
480
481static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
482{
483	__be32 *p;
484
485	p = xdr_reserve_space(xdr, 8);
486	if (unlikely(p == NULL))
487		return htonl(NFS4ERR_RESOURCE_HDR);
488	*p++ = htonl(op);
489	*p = res;
490	return 0;
491}
492
493static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
494{
495	__be32 *savep = NULL;
496	__be32 status = res->status;
497
498	if (unlikely(status != 0))
499		goto out;
500	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
501	if (unlikely(status != 0))
502		goto out;
503	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
504	if (unlikely(status != 0))
505		goto out;
506	status = encode_attr_size(xdr, res->bitmap, res->size);
507	if (unlikely(status != 0))
508		goto out;
509	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
510	if (unlikely(status != 0))
511		goto out;
512	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
513	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
514out:
515	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
516	return status;
517}
518
519#if defined(CONFIG_NFS_V4_1)
520
521static __be32 encode_sessionid(struct xdr_stream *xdr,
522				 const struct nfs4_sessionid *sid)
523{
524	__be32 *p;
525	int len = NFS4_MAX_SESSIONID_LEN;
526
527	p = xdr_reserve_space(xdr, len);
528	if (unlikely(p == NULL))
529		return htonl(NFS4ERR_RESOURCE);
530
531	memcpy(p, sid, len);
532	return 0;
533}
534
535static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
536				       struct xdr_stream *xdr,
537				       const struct cb_sequenceres *res)
538{
539	__be32 *p;
540	unsigned status = res->csr_status;
541
542	if (unlikely(status != 0))
543		goto out;
544
545	encode_sessionid(xdr, &res->csr_sessionid);
546
547	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
548	if (unlikely(p == NULL))
549		return htonl(NFS4ERR_RESOURCE);
550
551	*p++ = htonl(res->csr_sequenceid);
552	*p++ = htonl(res->csr_slotid);
553	*p++ = htonl(res->csr_highestslotid);
554	*p++ = htonl(res->csr_target_highestslotid);
555out:
556	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
557	return status;
558}
559
560static __be32
561preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
562{
563	if (op_nr == OP_CB_SEQUENCE) {
564		if (nop != 0)
565			return htonl(NFS4ERR_SEQUENCE_POS);
566	} else {
567		if (nop == 0)
568			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
569	}
570
571	switch (op_nr) {
572	case OP_CB_GETATTR:
573	case OP_CB_RECALL:
574	case OP_CB_SEQUENCE:
575	case OP_CB_RECALL_ANY:
576	case OP_CB_RECALL_SLOT:
577		*op = &callback_ops[op_nr];
578		break;
579
580	case OP_CB_LAYOUTRECALL:
581	case OP_CB_NOTIFY_DEVICEID:
582	case OP_CB_NOTIFY:
583	case OP_CB_PUSH_DELEG:
584	case OP_CB_RECALLABLE_OBJ_AVAIL:
585	case OP_CB_WANTS_CANCELLED:
586	case OP_CB_NOTIFY_LOCK:
587		return htonl(NFS4ERR_NOTSUPP);
588
589	default:
590		return htonl(NFS4ERR_OP_ILLEGAL);
591	}
592
593	return htonl(NFS_OK);
594}
595
596#else /* CONFIG_NFS_V4_1 */
597
598static __be32
599preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
600{
601	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
602}
603
604#endif /* CONFIG_NFS_V4_1 */
605
606static __be32
607preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
608{
609	switch (op_nr) {
610	case OP_CB_GETATTR:
611	case OP_CB_RECALL:
612		*op = &callback_ops[op_nr];
613		break;
614	default:
615		return htonl(NFS4ERR_OP_ILLEGAL);
616	}
617
618	return htonl(NFS_OK);
619}
620
621static __be32 process_op(uint32_t minorversion, int nop,
622		struct svc_rqst *rqstp,
623		struct xdr_stream *xdr_in, void *argp,
624		struct xdr_stream *xdr_out, void *resp, int* drc_status)
625{
626	struct callback_op *op = &callback_ops[0];
627	unsigned int op_nr;
628	__be32 status;
629	long maxlen;
630	__be32 res;
631
632	dprintk("%s: start\n", __func__);
633	status = decode_op_hdr(xdr_in, &op_nr);
634	if (unlikely(status))
635		return status;
636
637	dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
638		__func__, minorversion, nop, op_nr);
639
640	status = minorversion ? preprocess_nfs41_op(nop, op_nr, &op) :
641				preprocess_nfs4_op(op_nr, &op);
642	if (status == htonl(NFS4ERR_OP_ILLEGAL))
643		op_nr = OP_CB_ILLEGAL;
644	if (status)
645		goto encode_hdr;
646
647	if (*drc_status) {
648		status = *drc_status;
649		goto encode_hdr;
650	}
651
652	maxlen = xdr_out->end - xdr_out->p;
653	if (maxlen > 0 && maxlen < PAGE_SIZE) {
654		status = op->decode_args(rqstp, xdr_in, argp);
655		if (likely(status == 0))
656			status = op->process_op(argp, resp);
657	} else
658		status = htonl(NFS4ERR_RESOURCE);
659
660	/* Only set by OP_CB_SEQUENCE processing */
661	if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
662		*drc_status = status;
663		status = 0;
664	}
665
666encode_hdr:
667	res = encode_op_hdr(xdr_out, op_nr, status);
668	if (unlikely(res))
669		return res;
670	if (op->encode_res != NULL && status == 0)
671		status = op->encode_res(rqstp, xdr_out, resp);
672	dprintk("%s: done, status = %d\n", __func__, ntohl(status));
673	return status;
674}
675
676/*
677 * Decode, process and encode a COMPOUND
678 */
679static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
680{
681	struct cb_compound_hdr_arg hdr_arg = { 0 };
682	struct cb_compound_hdr_res hdr_res = { NULL };
683	struct xdr_stream xdr_in, xdr_out;
684	__be32 *p;
685	__be32 status, drc_status = 0;
686	unsigned int nops = 0;
687
688	dprintk("%s: start\n", __func__);
689
690	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
691
692	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
693	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
694
695	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
696	if (status == __constant_htonl(NFS4ERR_RESOURCE))
697		return rpc_garbage_args;
698
699	hdr_res.taglen = hdr_arg.taglen;
700	hdr_res.tag = hdr_arg.tag;
701	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
702		return rpc_system_err;
703
704	while (status == 0 && nops != hdr_arg.nops) {
705		status = process_op(hdr_arg.minorversion, nops, rqstp,
706				    &xdr_in, argp, &xdr_out, resp, &drc_status);
707		nops++;
708	}
709
710	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
711	* resource error in cb_compound status without returning op */
712	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
713		status = htonl(NFS4ERR_RESOURCE);
714		nops--;
715	}
716
717	*hdr_res.status = status;
718	*hdr_res.nops = htonl(nops);
719	dprintk("%s: done, status = %u\n", __func__, ntohl(status));
720	return rpc_success;
721}
722
723/*
724 * Define NFS4 callback COMPOUND ops.
725 */
726static struct callback_op callback_ops[] = {
727	[0] = {
728		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
729	},
730	[OP_CB_GETATTR] = {
731		.process_op = (callback_process_op_t)nfs4_callback_getattr,
732		.decode_args = (callback_decode_arg_t)decode_getattr_args,
733		.encode_res = (callback_encode_res_t)encode_getattr_res,
734		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
735	},
736	[OP_CB_RECALL] = {
737		.process_op = (callback_process_op_t)nfs4_callback_recall,
738		.decode_args = (callback_decode_arg_t)decode_recall_args,
739		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
740	},
741#if defined(CONFIG_NFS_V4_1)
742	[OP_CB_SEQUENCE] = {
743		.process_op = (callback_process_op_t)nfs4_callback_sequence,
744		.decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
745		.encode_res = (callback_encode_res_t)encode_cb_sequence_res,
746		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
747	},
748	[OP_CB_RECALL_ANY] = {
749		.process_op = (callback_process_op_t)nfs4_callback_recallany,
750		.decode_args = (callback_decode_arg_t)decode_recallany_args,
751		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
752	},
753	[OP_CB_RECALL_SLOT] = {
754		.process_op = (callback_process_op_t)nfs4_callback_recallslot,
755		.decode_args = (callback_decode_arg_t)decode_recallslot_args,
756		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
757	},
758#endif /* CONFIG_NFS_V4_1 */
759};
760
761/*
762 * Define NFS4 callback procedures
763 */
764static struct svc_procedure nfs4_callback_procedures1[] = {
765	[CB_NULL] = {
766		.pc_func = nfs4_callback_null,
767		.pc_decode = (kxdrproc_t)nfs4_decode_void,
768		.pc_encode = (kxdrproc_t)nfs4_encode_void,
769		.pc_xdrressize = 1,
770	},
771	[CB_COMPOUND] = {
772		.pc_func = nfs4_callback_compound,
773		.pc_encode = (kxdrproc_t)nfs4_encode_void,
774		.pc_argsize = 256,
775		.pc_ressize = 256,
776		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
777	}
778};
779
780struct svc_version nfs4_callback_version1 = {
781	.vs_vers = 1,
782	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
783	.vs_proc = nfs4_callback_procedures1,
784	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
785	.vs_dispatch = NULL,
786	.vs_hidden = 1,
787};
788
789struct svc_version nfs4_callback_version4 = {
790	.vs_vers = 4,
791	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
792	.vs_proc = nfs4_callback_procedures1,
793	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
794	.vs_dispatch = NULL,
795};
796