1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * linux/fs/nfs/callback_xdr.c
   4 *
   5 * Copyright (C) 2004 Trond Myklebust
   6 *
   7 * NFSv4 callback encode/decode procedures
   8 */
   9#include <linux/kernel.h>
  10#include <linux/sunrpc/svc.h>
  11#include <linux/nfs4.h>
  12#include <linux/nfs_fs.h>
  13#include <linux/ratelimit.h>
  14#include <linux/printk.h>
  15#include <linux/slab.h>
  16#include <linux/sunrpc/bc_xprt.h>
  17#include "nfs4_fs.h"
  18#include "callback.h"
  19#include "internal.h"
  20#include "nfs4session.h"
  21
  22#define CB_OP_TAGLEN_MAXSZ		(512)
  23#define CB_OP_HDR_RES_MAXSZ		(2 * 4) // opcode, status
  24#define CB_OP_GETATTR_BITMAP_MAXSZ	(4 * 4) // bitmap length, 3 bitmaps
  25#define CB_OP_GETATTR_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ + \
  26					 CB_OP_GETATTR_BITMAP_MAXSZ + \
  27					 /* change, size, ctime, mtime */\
  28					 (2 + 2 + 3 + 3) * 4)
  29#define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
  30
  31#if defined(CONFIG_NFS_V4_1)
  32#define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  33#define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  34#define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
  35					 NFS4_MAX_SESSIONID_LEN + \
  36					 (1 + 3) * 4) // seqid, 3 slotids
  37#define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  38#define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  39#define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  40#endif /* CONFIG_NFS_V4_1 */
  41#ifdef CONFIG_NFS_V4_2
  42#define CB_OP_OFFLOAD_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
  43#endif /* CONFIG_NFS_V4_2 */
  44
  45#define NFSDBG_FACILITY NFSDBG_CALLBACK
  46
  47/* Internal error code */
  48#define NFS4ERR_RESOURCE_HDR	11050
  49
  50struct callback_op {
  51	__be32 (*process_op)(void *, void *, struct cb_process_state *);
  52	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
  53	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
  54			const void *);
  55	long res_maxsize;
  56};
  57
  58static struct callback_op callback_ops[];
  59
  60static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
  61{
  62	return htonl(NFS4_OK);
  63}
  64
  65static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p)
  66{
  67	return xdr_argsize_check(rqstp, p);
  68}
  69
  70static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p)
  71{
  72	return xdr_ressize_check(rqstp, p);
  73}
  74
  75static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
  76		const char **str, size_t maxlen)
  77{
  78	ssize_t err;
  79
  80	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
  81	if (err < 0)
  82		return cpu_to_be32(NFS4ERR_RESOURCE);
  83	*len = err;
  84	return 0;
  85}
  86
  87static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  88{
  89	__be32 *p;
  90
  91	p = xdr_inline_decode(xdr, 4);
  92	if (unlikely(p == NULL))
  93		return htonl(NFS4ERR_RESOURCE);
  94	fh->size = ntohl(*p);
  95	if (fh->size > NFS4_FHSIZE)
  96		return htonl(NFS4ERR_BADHANDLE);
  97	p = xdr_inline_decode(xdr, fh->size);
  98	if (unlikely(p == NULL))
  99		return htonl(NFS4ERR_RESOURCE);
 100	memcpy(&fh->data[0], p, fh->size);
 101	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 102	return 0;
 103}
 104
 105static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 106{
 107	__be32 *p;
 108	unsigned int attrlen;
 109
 110	p = xdr_inline_decode(xdr, 4);
 111	if (unlikely(p == NULL))
 112		return htonl(NFS4ERR_RESOURCE);
 113	attrlen = ntohl(*p);
 114	p = xdr_inline_decode(xdr, attrlen << 2);
 115	if (unlikely(p == NULL))
 116		return htonl(NFS4ERR_RESOURCE);
 117	if (likely(attrlen > 0))
 118		bitmap[0] = ntohl(*p++);
 119	if (attrlen > 1)
 120		bitmap[1] = ntohl(*p);
 121	return 0;
 122}
 123
 124static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 125{
 126	__be32 *p;
 127
 128	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
 129	if (unlikely(p == NULL))
 130		return htonl(NFS4ERR_RESOURCE);
 131	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
 132	return 0;
 133}
 134
 135static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 136{
 137	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
 138	return decode_stateid(xdr, stateid);
 139}
 140
 141static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 142{
 143	__be32 *p;
 144	__be32 status;
 145
 146	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
 147	if (unlikely(status != 0))
 148		return status;
 149	p = xdr_inline_decode(xdr, 12);
 150	if (unlikely(p == NULL))
 151		return htonl(NFS4ERR_RESOURCE);
 152	hdr->minorversion = ntohl(*p++);
 153	/* Check for minor version support */
 154	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
 155		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
 156	} else {
 157		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
 158			"illegal minor version %u!\n",
 159			__func__, hdr->minorversion);
 160		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 161	}
 162	hdr->nops = ntohl(*p);
 163	return 0;
 164}
 165
 166static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 167{
 168	__be32 *p;
 169	p = xdr_inline_decode(xdr, 4);
 170	if (unlikely(p == NULL))
 171		return htonl(NFS4ERR_RESOURCE_HDR);
 172	*op = ntohl(*p);
 173	return 0;
 174}
 175
 176static __be32 decode_getattr_args(struct svc_rqst *rqstp,
 177		struct xdr_stream *xdr, void *argp)
 178{
 179	struct cb_getattrargs *args = argp;
 180	__be32 status;
 181
 182	status = decode_fh(xdr, &args->fh);
 183	if (unlikely(status != 0))
 184		return status;
 185	return decode_bitmap(xdr, args->bitmap);
 186}
 187
 188static __be32 decode_recall_args(struct svc_rqst *rqstp,
 189		struct xdr_stream *xdr, void *argp)
 190{
 191	struct cb_recallargs *args = argp;
 192	__be32 *p;
 193	__be32 status;
 194
 195	status = decode_delegation_stateid(xdr, &args->stateid);
 196	if (unlikely(status != 0))
 197		return status;
 198	p = xdr_inline_decode(xdr, 4);
 199	if (unlikely(p == NULL))
 200		return htonl(NFS4ERR_RESOURCE);
 201	args->truncate = ntohl(*p);
 202	return decode_fh(xdr, &args->fh);
 203}
 204
 205#if defined(CONFIG_NFS_V4_1)
 206static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 207{
 208	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
 209	return decode_stateid(xdr, stateid);
 210}
 211
 212static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 213				       struct xdr_stream *xdr, void *argp)
 214{
 215	struct cb_layoutrecallargs *args = argp;
 216	__be32 *p;
 217	__be32 status = 0;
 218	uint32_t iomode;
 219
 220	p = xdr_inline_decode(xdr, 4 * sizeof(uint32_t));
 221	if (unlikely(p == NULL))
 222		return htonl(NFS4ERR_BADXDR);
 223
 224	args->cbl_layout_type = ntohl(*p++);
 225	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
 226	 * as it is unusable and ignored with the other types.
 227	 */
 228	iomode = ntohl(*p++);
 229	args->cbl_layoutchanged = ntohl(*p++);
 230	args->cbl_recall_type = ntohl(*p++);
 231
 232	if (args->cbl_recall_type == RETURN_FILE) {
 233		args->cbl_range.iomode = iomode;
 234		status = decode_fh(xdr, &args->cbl_fh);
 235		if (unlikely(status != 0))
 236			return status;
 237
 238		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
 239		if (unlikely(p == NULL))
 240			return htonl(NFS4ERR_BADXDR);
 241		p = xdr_decode_hyper(p, &args->cbl_range.offset);
 242		p = xdr_decode_hyper(p, &args->cbl_range.length);
 243		return decode_layout_stateid(xdr, &args->cbl_stateid);
 244	} else if (args->cbl_recall_type == RETURN_FSID) {
 245		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
 246		if (unlikely(p == NULL))
 247			return htonl(NFS4ERR_BADXDR);
 248		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
 249		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
 250	} else if (args->cbl_recall_type != RETURN_ALL)
 251		return htonl(NFS4ERR_BADXDR);
 252	return 0;
 253}
 254
 255static
 256__be32 decode_devicenotify_args(struct svc_rqst *rqstp,
 257				struct xdr_stream *xdr,
 258				void *argp)
 259{
 260	struct cb_devicenotifyargs *args = argp;
 261	__be32 *p;
 262	__be32 status = 0;
 263	u32 tmp;
 264	int n, i;
 265	args->ndevs = 0;
 266
 267	/* Num of device notifications */
 268	p = xdr_inline_decode(xdr, sizeof(uint32_t));
 269	if (unlikely(p == NULL)) {
 270		status = htonl(NFS4ERR_BADXDR);
 271		goto out;
 272	}
 273	n = ntohl(*p++);
 274	if (n <= 0)
 275		goto out;
 276	if (n > ULONG_MAX / sizeof(*args->devs)) {
 277		status = htonl(NFS4ERR_BADXDR);
 278		goto out;
 279	}
 280
 281	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
 282	if (!args->devs) {
 283		status = htonl(NFS4ERR_DELAY);
 284		goto out;
 285	}
 286
 287	/* Decode each dev notification */
 288	for (i = 0; i < n; i++) {
 289		struct cb_devicenotifyitem *dev = &args->devs[i];
 290
 291		p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
 292				      NFS4_DEVICEID4_SIZE);
 293		if (unlikely(p == NULL)) {
 294			status = htonl(NFS4ERR_BADXDR);
 295			goto err;
 296		}
 297
 298		tmp = ntohl(*p++);	/* bitmap size */
 299		if (tmp != 1) {
 300			status = htonl(NFS4ERR_INVAL);
 301			goto err;
 302		}
 303		dev->cbd_notify_type = ntohl(*p++);
 304		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
 305		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
 306			status = htonl(NFS4ERR_INVAL);
 307			goto err;
 308		}
 309
 310		tmp = ntohl(*p++);	/* opaque size */
 311		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
 312		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
 313		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
 314		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
 315			status = htonl(NFS4ERR_INVAL);
 316			goto err;
 317		}
 318		dev->cbd_layout_type = ntohl(*p++);
 319		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
 320		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 321
 322		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
 323			p = xdr_inline_decode(xdr, sizeof(uint32_t));
 324			if (unlikely(p == NULL)) {
 325				status = htonl(NFS4ERR_BADXDR);
 326				goto err;
 327			}
 328			dev->cbd_immediate = ntohl(*p++);
 329		} else {
 330			dev->cbd_immediate = 0;
 331		}
 332
 333		args->ndevs++;
 334
 335		dprintk("%s: type %d layout 0x%x immediate %d\n",
 336			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
 337			dev->cbd_immediate);
 338	}
 339out:
 340	dprintk("%s: status %d ndevs %d\n",
 341		__func__, ntohl(status), args->ndevs);
 342	return status;
 343err:
 344	kfree(args->devs);
 345	goto out;
 346}
 347
 348static __be32 decode_sessionid(struct xdr_stream *xdr,
 349				 struct nfs4_sessionid *sid)
 350{
 351	__be32 *p;
 352
 353	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
 354	if (unlikely(p == NULL))
 355		return htonl(NFS4ERR_RESOURCE);
 356
 357	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
 358	return 0;
 359}
 360
 361static __be32 decode_rc_list(struct xdr_stream *xdr,
 362			       struct referring_call_list *rc_list)
 363{
 364	__be32 *p;
 365	int i;
 366	__be32 status;
 367
 368	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 369	if (status)
 370		goto out;
 371
 372	status = htonl(NFS4ERR_RESOURCE);
 373	p = xdr_inline_decode(xdr, sizeof(uint32_t));
 374	if (unlikely(p == NULL))
 375		goto out;
 376
 377	rc_list->rcl_nrefcalls = ntohl(*p++);
 378	if (rc_list->rcl_nrefcalls) {
 379		p = xdr_inline_decode(xdr,
 380			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 381		if (unlikely(p == NULL))
 382			goto out;
 383		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
 384						sizeof(*rc_list->rcl_refcalls),
 385						GFP_KERNEL);
 386		if (unlikely(rc_list->rcl_refcalls == NULL))
 387			goto out;
 388		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 389			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 390			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 391		}
 392	}
 393	status = 0;
 394
 395out:
 396	return status;
 397}
 398
 399static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 400					struct xdr_stream *xdr,
 401					void *argp)
 402{
 403	struct cb_sequenceargs *args = argp;
 404	__be32 *p;
 405	int i;
 406	__be32 status;
 407
 408	status = decode_sessionid(xdr, &args->csa_sessionid);
 409	if (status)
 410		return status;
 411
 412	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
 413	if (unlikely(p == NULL))
 414		return htonl(NFS4ERR_RESOURCE);
 415
 416	args->csa_addr = svc_addr(rqstp);
 417	args->csa_sequenceid = ntohl(*p++);
 418	args->csa_slotid = ntohl(*p++);
 419	args->csa_highestslotid = ntohl(*p++);
 420	args->csa_cachethis = ntohl(*p++);
 421	args->csa_nrclists = ntohl(*p++);
 422	args->csa_rclists = NULL;
 423	if (args->csa_nrclists) {
 424		args->csa_rclists = kmalloc_array(args->csa_nrclists,
 425						  sizeof(*args->csa_rclists),
 426						  GFP_KERNEL);
 427		if (unlikely(args->csa_rclists == NULL))
 428			return htonl(NFS4ERR_RESOURCE);
 429
 430		for (i = 0; i < args->csa_nrclists; i++) {
 431			status = decode_rc_list(xdr, &args->csa_rclists[i]);
 432			if (status) {
 433				args->csa_nrclists = i;
 434				goto out_free;
 435			}
 436		}
 437	}
 438	return 0;
 439
 440out_free:
 441	for (i = 0; i < args->csa_nrclists; i++)
 442		kfree(args->csa_rclists[i].rcl_refcalls);
 443	kfree(args->csa_rclists);
 444	return status;
 445}
 446
 447static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 448				      struct xdr_stream *xdr,
 449				      void *argp)
 450{
 451	struct cb_recallanyargs *args = argp;
 452	uint32_t bitmap[2];
 453	__be32 *p, status;
 454
 455	p = xdr_inline_decode(xdr, 4);
 456	if (unlikely(p == NULL))
 457		return htonl(NFS4ERR_BADXDR);
 458	args->craa_objs_to_keep = ntohl(*p++);
 459	status = decode_bitmap(xdr, bitmap);
 460	if (unlikely(status))
 461		return status;
 462	args->craa_type_mask = bitmap[0];
 463
 464	return 0;
 465}
 466
 467static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 468					struct xdr_stream *xdr,
 469					void *argp)
 470{
 471	struct cb_recallslotargs *args = argp;
 472	__be32 *p;
 473
 474	p = xdr_inline_decode(xdr, 4);
 475	if (unlikely(p == NULL))
 476		return htonl(NFS4ERR_BADXDR);
 477	args->crsa_target_highest_slotid = ntohl(*p++);
 478	return 0;
 479}
 480
 481static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
 482{
 483	__be32		*p;
 484	unsigned int	len;
 485
 486	p = xdr_inline_decode(xdr, 12);
 487	if (unlikely(p == NULL))
 488		return htonl(NFS4ERR_BADXDR);
 489
 490	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
 491	len = be32_to_cpu(*p);
 492
 493	p = xdr_inline_decode(xdr, len);
 494	if (unlikely(p == NULL))
 495		return htonl(NFS4ERR_BADXDR);
 496
 497	/* Only try to decode if the length is right */
 498	if (len == 20) {
 499		p += 2;	/* skip "lock id:" */
 500		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
 501		xdr_decode_hyper(p, &args->cbnl_owner.id);
 502		args->cbnl_valid = true;
 503	} else {
 504		args->cbnl_owner.s_dev = 0;
 505		args->cbnl_owner.id = 0;
 506		args->cbnl_valid = false;
 507	}
 508	return 0;
 509}
 510
 511static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
 512		struct xdr_stream *xdr, void *argp)
 513{
 514	struct cb_notify_lock_args *args = argp;
 515	__be32 status;
 516
 517	status = decode_fh(xdr, &args->cbnl_fh);
 518	if (unlikely(status != 0))
 519		return status;
 520	return decode_lockowner(xdr, args);
 521}
 522
 523#endif /* CONFIG_NFS_V4_1 */
 524#ifdef CONFIG_NFS_V4_2
 525static __be32 decode_write_response(struct xdr_stream *xdr,
 526					struct cb_offloadargs *args)
 527{
 528	__be32 *p;
 529
 530	/* skip the always zero field */
 531	p = xdr_inline_decode(xdr, 4);
 532	if (unlikely(!p))
 533		goto out;
 534	p++;
 535
 536	/* decode count, stable_how, verifier */
 537	p = xdr_inline_decode(xdr, 8 + 4);
 538	if (unlikely(!p))
 539		goto out;
 540	p = xdr_decode_hyper(p, &args->wr_count);
 541	args->wr_writeverf.committed = be32_to_cpup(p);
 542	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
 543	if (likely(p)) {
 544		memcpy(&args->wr_writeverf.verifier.data[0], p,
 545			NFS4_VERIFIER_SIZE);
 546		return 0;
 547	}
 548out:
 549	return htonl(NFS4ERR_RESOURCE);
 550}
 551
 552static __be32 decode_offload_args(struct svc_rqst *rqstp,
 553					struct xdr_stream *xdr,
 554					void *data)
 555{
 556	struct cb_offloadargs *args = data;
 557	__be32 *p;
 558	__be32 status;
 559
 560	/* decode fh */
 561	status = decode_fh(xdr, &args->coa_fh);
 562	if (unlikely(status != 0))
 563		return status;
 564
 565	/* decode stateid */
 566	status = decode_stateid(xdr, &args->coa_stateid);
 567	if (unlikely(status != 0))
 568		return status;
 569
 570	/* decode status */
 571	p = xdr_inline_decode(xdr, 4);
 572	if (unlikely(!p))
 573		goto out;
 574	args->error = ntohl(*p++);
 575	if (!args->error) {
 576		status = decode_write_response(xdr, args);
 577		if (unlikely(status != 0))
 578			return status;
 579	} else {
 580		p = xdr_inline_decode(xdr, 8);
 581		if (unlikely(!p))
 582			goto out;
 583		p = xdr_decode_hyper(p, &args->wr_count);
 584	}
 585	return 0;
 586out:
 587	return htonl(NFS4ERR_RESOURCE);
 588}
 589#endif /* CONFIG_NFS_V4_2 */
 590static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 591{
 592	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
 593		return cpu_to_be32(NFS4ERR_RESOURCE);
 594	return 0;
 595}
 596
 597static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
 598{
 599	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
 600		return cpu_to_be32(NFS4ERR_RESOURCE);
 601	return 0;
 602}
 603
 604static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 605{
 606	__be32 *p;
 607
 608	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 609		return 0;
 610	p = xdr_reserve_space(xdr, 8);
 611	if (unlikely(!p))
 612		return htonl(NFS4ERR_RESOURCE);
 613	p = xdr_encode_hyper(p, change);
 614	return 0;
 615}
 616
 617static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 618{
 619	__be32 *p;
 620
 621	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 622		return 0;
 623	p = xdr_reserve_space(xdr, 8);
 624	if (unlikely(!p))
 625		return htonl(NFS4ERR_RESOURCE);
 626	p = xdr_encode_hyper(p, size);
 627	return 0;
 628}
 629
 630static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
 631{
 632	__be32 *p;
 633
 634	p = xdr_reserve_space(xdr, 12);
 635	if (unlikely(!p))
 636		return htonl(NFS4ERR_RESOURCE);
 637	p = xdr_encode_hyper(p, time->tv_sec);
 638	*p = htonl(time->tv_nsec);
 639	return 0;
 640}
 641
 642static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 643{
 644	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 645		return 0;
 646	return encode_attr_time(xdr,time);
 647}
 648
 649static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 650{
 651	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 652		return 0;
 653	return encode_attr_time(xdr,time);
 654}
 655
 656static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 657{
 658	__be32 status;
 659
 660	hdr->status = xdr_reserve_space(xdr, 4);
 661	if (unlikely(hdr->status == NULL))
 662		return htonl(NFS4ERR_RESOURCE);
 663	status = encode_string(xdr, hdr->taglen, hdr->tag);
 664	if (unlikely(status != 0))
 665		return status;
 666	hdr->nops = xdr_reserve_space(xdr, 4);
 667	if (unlikely(hdr->nops == NULL))
 668		return htonl(NFS4ERR_RESOURCE);
 669	return 0;
 670}
 671
 672static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 673{
 674	__be32 *p;
 675	
 676	p = xdr_reserve_space(xdr, 8);
 677	if (unlikely(p == NULL))
 678		return htonl(NFS4ERR_RESOURCE_HDR);
 679	*p++ = htonl(op);
 680	*p = res;
 681	return 0;
 682}
 683
 684static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 685		const void *resp)
 686{
 687	const struct cb_getattrres *res = resp;
 688	__be32 *savep = NULL;
 689	__be32 status = res->status;
 690	
 691	if (unlikely(status != 0))
 692		goto out;
 693	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
 694	if (unlikely(status != 0))
 695		goto out;
 696	status = cpu_to_be32(NFS4ERR_RESOURCE);
 697	savep = xdr_reserve_space(xdr, sizeof(*savep));
 698	if (unlikely(!savep))
 699		goto out;
 700	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 701	if (unlikely(status != 0))
 702		goto out;
 703	status = encode_attr_size(xdr, res->bitmap, res->size);
 704	if (unlikely(status != 0))
 705		goto out;
 706	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 707	if (unlikely(status != 0))
 708		goto out;
 709	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 710	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 711out:
 712	return status;
 713}
 714
 715#if defined(CONFIG_NFS_V4_1)
 716
 717static __be32 encode_sessionid(struct xdr_stream *xdr,
 718				 const struct nfs4_sessionid *sid)
 719{
 720	__be32 *p;
 721
 722	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
 723	if (unlikely(p == NULL))
 724		return htonl(NFS4ERR_RESOURCE);
 725
 726	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
 727	return 0;
 728}
 729
 730static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 731				       struct xdr_stream *xdr,
 732				       const void *resp)
 733{
 734	const struct cb_sequenceres *res = resp;
 735	__be32 *p;
 736	__be32 status = res->csr_status;
 737
 738	if (unlikely(status != 0))
 739		return status;
 740
 741	status = encode_sessionid(xdr, &res->csr_sessionid);
 742	if (status)
 743		return status;
 744
 745	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 746	if (unlikely(p == NULL))
 747		return htonl(NFS4ERR_RESOURCE);
 748
 749	*p++ = htonl(res->csr_sequenceid);
 750	*p++ = htonl(res->csr_slotid);
 751	*p++ = htonl(res->csr_highestslotid);
 752	*p++ = htonl(res->csr_target_highestslotid);
 753	return 0;
 754}
 755
 756static __be32
 757preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 758{
 759	if (op_nr == OP_CB_SEQUENCE) {
 760		if (nop != 0)
 761			return htonl(NFS4ERR_SEQUENCE_POS);
 762	} else {
 763		if (nop == 0)
 764			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 765	}
 766
 767	switch (op_nr) {
 768	case OP_CB_GETATTR:
 769	case OP_CB_RECALL:
 770	case OP_CB_SEQUENCE:
 771	case OP_CB_RECALL_ANY:
 772	case OP_CB_RECALL_SLOT:
 773	case OP_CB_LAYOUTRECALL:
 774	case OP_CB_NOTIFY_DEVICEID:
 775	case OP_CB_NOTIFY_LOCK:
 776		*op = &callback_ops[op_nr];
 777		break;
 778
 779	case OP_CB_NOTIFY:
 780	case OP_CB_PUSH_DELEG:
 781	case OP_CB_RECALLABLE_OBJ_AVAIL:
 782	case OP_CB_WANTS_CANCELLED:
 783		return htonl(NFS4ERR_NOTSUPP);
 784
 785	default:
 786		return htonl(NFS4ERR_OP_ILLEGAL);
 787	}
 788
 789	return htonl(NFS_OK);
 790}
 791
 792static void nfs4_callback_free_slot(struct nfs4_session *session,
 793		struct nfs4_slot *slot)
 794{
 795	struct nfs4_slot_table *tbl = &session->bc_slot_table;
 796
 797	spin_lock(&tbl->slot_tbl_lock);
 798	/*
 799	 * Let the state manager know callback processing done.
 800	 * A single slot, so highest used slotid is either 0 or -1
 801	 */
 802	nfs4_free_slot(tbl, slot);
 803	spin_unlock(&tbl->slot_tbl_lock);
 804}
 805
 806static void nfs4_cb_free_slot(struct cb_process_state *cps)
 807{
 808	if (cps->slot) {
 809		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
 810		cps->slot = NULL;
 811	}
 812}
 813
 814#else /* CONFIG_NFS_V4_1 */
 815
 816static __be32
 817preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 818{
 819	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 820}
 821
 822static void nfs4_cb_free_slot(struct cb_process_state *cps)
 823{
 824}
 825#endif /* CONFIG_NFS_V4_1 */
 826
 827#ifdef CONFIG_NFS_V4_2
 828static __be32
 829preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 830{
 831	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
 832	if (status != htonl(NFS4ERR_OP_ILLEGAL))
 833		return status;
 834
 835	if (op_nr == OP_CB_OFFLOAD) {
 836		*op = &callback_ops[op_nr];
 837		return htonl(NFS_OK);
 838	} else
 839		return htonl(NFS4ERR_NOTSUPP);
 840	return htonl(NFS4ERR_OP_ILLEGAL);
 841}
 842#else /* CONFIG_NFS_V4_2 */
 843static __be32
 844preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 845{
 846	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 847}
 848#endif /* CONFIG_NFS_V4_2 */
 849
 850static __be32
 851preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 852{
 853	switch (op_nr) {
 854	case OP_CB_GETATTR:
 855	case OP_CB_RECALL:
 856		*op = &callback_ops[op_nr];
 857		break;
 858	default:
 859		return htonl(NFS4ERR_OP_ILLEGAL);
 860	}
 861
 862	return htonl(NFS_OK);
 863}
 864
 865static __be32 process_op(int nop, struct svc_rqst *rqstp,
 866		struct xdr_stream *xdr_in, void *argp,
 867		struct xdr_stream *xdr_out, void *resp,
 868		struct cb_process_state *cps)
 869{
 870	struct callback_op *op = &callback_ops[0];
 871	unsigned int op_nr;
 872	__be32 status;
 873	long maxlen;
 874	__be32 res;
 875
 876	status = decode_op_hdr(xdr_in, &op_nr);
 877	if (unlikely(status))
 878		return status;
 879
 880	switch (cps->minorversion) {
 881	case 0:
 882		status = preprocess_nfs4_op(op_nr, &op);
 883		break;
 884	case 1:
 885		status = preprocess_nfs41_op(nop, op_nr, &op);
 886		break;
 887	case 2:
 888		status = preprocess_nfs42_op(nop, op_nr, &op);
 889		break;
 890	default:
 891		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 892	}
 893
 894	if (status == htonl(NFS4ERR_OP_ILLEGAL))
 895		op_nr = OP_CB_ILLEGAL;
 896	if (status)
 897		goto encode_hdr;
 898
 899	if (cps->drc_status) {
 900		status = cps->drc_status;
 901		goto encode_hdr;
 902	}
 903
 904	maxlen = xdr_out->end - xdr_out->p;
 905	if (maxlen > 0 && maxlen < PAGE_SIZE) {
 906		status = op->decode_args(rqstp, xdr_in, argp);
 907		if (likely(status == 0))
 908			status = op->process_op(argp, resp, cps);
 909	} else
 910		status = htonl(NFS4ERR_RESOURCE);
 911
 912encode_hdr:
 913	res = encode_op_hdr(xdr_out, op_nr, status);
 914	if (unlikely(res))
 915		return res;
 916	if (op->encode_res != NULL && status == 0)
 917		status = op->encode_res(rqstp, xdr_out, resp);
 918	return status;
 919}
 920
 921/*
 922 * Decode, process and encode a COMPOUND
 923 */
 924static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
 925{
 926	struct cb_compound_hdr_arg hdr_arg = { 0 };
 927	struct cb_compound_hdr_res hdr_res = { NULL };
 928	struct xdr_stream xdr_in, xdr_out;
 929	__be32 *p, status;
 930	struct cb_process_state cps = {
 931		.drc_status = 0,
 932		.clp = NULL,
 933		.net = SVC_NET(rqstp),
 934	};
 935	unsigned int nops = 0;
 936
 937	xdr_init_decode(&xdr_in, &rqstp->rq_arg,
 938			rqstp->rq_arg.head[0].iov_base, NULL);
 939
 940	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
 941	xdr_init_encode(&xdr_out, &rqstp->rq_res, p, NULL);
 942
 943	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
 944	if (status == htonl(NFS4ERR_RESOURCE))
 945		return rpc_garbage_args;
 946
 947	if (hdr_arg.minorversion == 0) {
 948		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
 949		if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp)) {
 950			if (cps.clp)
 951				nfs_put_client(cps.clp);
 952			goto out_invalidcred;
 953		}
 954	}
 955
 956	cps.minorversion = hdr_arg.minorversion;
 957	hdr_res.taglen = hdr_arg.taglen;
 958	hdr_res.tag = hdr_arg.tag;
 959	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0) {
 960		if (cps.clp)
 961			nfs_put_client(cps.clp);
 962		return rpc_system_err;
 963	}
 964	while (status == 0 && nops != hdr_arg.nops) {
 965		status = process_op(nops, rqstp, &xdr_in,
 966				    rqstp->rq_argp, &xdr_out, rqstp->rq_resp,
 967				    &cps);
 968		nops++;
 969	}
 970
 971	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
 972	* resource error in cb_compound status without returning op */
 973	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
 974		status = htonl(NFS4ERR_RESOURCE);
 975		nops--;
 976	}
 977
 978	*hdr_res.status = status;
 979	*hdr_res.nops = htonl(nops);
 980	nfs4_cb_free_slot(&cps);
 981	nfs_put_client(cps.clp);
 982	return rpc_success;
 983
 984out_invalidcred:
 985	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
 986	return svc_return_autherr(rqstp, rpc_autherr_badcred);
 987}
 988
 989/*
 990 * Define NFS4 callback COMPOUND ops.
 991 */
 992static struct callback_op callback_ops[] = {
 993	[0] = {
 994		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
 995	},
 996	[OP_CB_GETATTR] = {
 997		.process_op = nfs4_callback_getattr,
 998		.decode_args = decode_getattr_args,
 999		.encode_res = encode_getattr_res,
1000		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1001	},
1002	[OP_CB_RECALL] = {
1003		.process_op = nfs4_callback_recall,
1004		.decode_args = decode_recall_args,
1005		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1006	},
1007#if defined(CONFIG_NFS_V4_1)
1008	[OP_CB_LAYOUTRECALL] = {
1009		.process_op = nfs4_callback_layoutrecall,
1010		.decode_args = decode_layoutrecall_args,
1011		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1012	},
1013	[OP_CB_NOTIFY_DEVICEID] = {
1014		.process_op = nfs4_callback_devicenotify,
1015		.decode_args = decode_devicenotify_args,
1016		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1017	},
1018	[OP_CB_SEQUENCE] = {
1019		.process_op = nfs4_callback_sequence,
1020		.decode_args = decode_cb_sequence_args,
1021		.encode_res = encode_cb_sequence_res,
1022		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1023	},
1024	[OP_CB_RECALL_ANY] = {
1025		.process_op = nfs4_callback_recallany,
1026		.decode_args = decode_recallany_args,
1027		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1028	},
1029	[OP_CB_RECALL_SLOT] = {
1030		.process_op = nfs4_callback_recallslot,
1031		.decode_args = decode_recallslot_args,
1032		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1033	},
1034	[OP_CB_NOTIFY_LOCK] = {
1035		.process_op = nfs4_callback_notify_lock,
1036		.decode_args = decode_notify_lock_args,
1037		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1038	},
1039#endif /* CONFIG_NFS_V4_1 */
1040#ifdef CONFIG_NFS_V4_2
1041	[OP_CB_OFFLOAD] = {
1042		.process_op = nfs4_callback_offload,
1043		.decode_args = decode_offload_args,
1044		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1045	},
1046#endif /* CONFIG_NFS_V4_2 */
1047};
1048
1049/*
1050 * Define NFS4 callback procedures
1051 */
1052static const struct svc_procedure nfs4_callback_procedures1[] = {
1053	[CB_NULL] = {
1054		.pc_func = nfs4_callback_null,
1055		.pc_decode = nfs4_decode_void,
1056		.pc_encode = nfs4_encode_void,
1057		.pc_xdrressize = 1,
1058	},
1059	[CB_COMPOUND] = {
1060		.pc_func = nfs4_callback_compound,
1061		.pc_encode = nfs4_encode_void,
1062		.pc_argsize = 256,
1063		.pc_ressize = 256,
1064		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1065	}
1066};
1067
1068static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
1069const struct svc_version nfs4_callback_version1 = {
1070	.vs_vers = 1,
1071	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1072	.vs_proc = nfs4_callback_procedures1,
1073	.vs_count = nfs4_callback_count1,
1074	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1075	.vs_dispatch = NULL,
1076	.vs_hidden = true,
1077	.vs_need_cong_ctrl = true,
1078};
1079
1080static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
1081const struct svc_version nfs4_callback_version4 = {
1082	.vs_vers = 4,
1083	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1084	.vs_proc = nfs4_callback_procedures1,
1085	.vs_count = nfs4_callback_count4,
1086	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1087	.vs_dispatch = NULL,
1088	.vs_hidden = true,
1089	.vs_need_cong_ctrl = true,
1090};