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#include "nfs4trace.h"
  22
  23#define CB_OP_TAGLEN_MAXSZ		(512)
  24#define CB_OP_HDR_RES_MAXSZ		(2 * 4) // opcode, status
  25#define CB_OP_GETATTR_BITMAP_MAXSZ	(4 * 4) // bitmap length, 3 bitmaps
  26#define CB_OP_GETATTR_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ + \
  27					 CB_OP_GETATTR_BITMAP_MAXSZ + \
  28					 /* change, size, ctime, mtime */\
  29					 (2 + 2 + 3 + 3) * 4)
  30#define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
  31
  32#if defined(CONFIG_NFS_V4_1)
  33#define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  34#define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  35#define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
  36					 NFS4_MAX_SESSIONID_LEN + \
  37					 (1 + 3) * 4) // seqid, 3 slotids
  38#define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  39#define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  40#define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  41#endif /* CONFIG_NFS_V4_1 */
  42#ifdef CONFIG_NFS_V4_2
  43#define CB_OP_OFFLOAD_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
  44#endif /* CONFIG_NFS_V4_2 */
  45
  46#define NFSDBG_FACILITY NFSDBG_CALLBACK
  47
  48/* Internal error code */
  49#define NFS4ERR_RESOURCE_HDR	11050
  50
  51struct callback_op {
  52	__be32 (*process_op)(void *, void *, struct cb_process_state *);
  53	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
  54	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
  55			const void *);
  56	long res_maxsize;
  57};
  58
  59static struct callback_op callback_ops[];
  60
  61static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
  62{
  63	return htonl(NFS4_OK);
  64}
  65
  66/*
  67 * svc_process_common() looks for an XDR encoder to know when
  68 * not to drop a Reply.
  69 */
  70static bool nfs4_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  71{
  72	return true;
  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	uint32_t tmp, n, i;
 262	__be32 *p;
 263	__be32 status = 0;
 264
 265	/* Num of device notifications */
 266	p = xdr_inline_decode(xdr, sizeof(uint32_t));
 267	if (unlikely(p == NULL)) {
 268		status = htonl(NFS4ERR_BADXDR);
 269		goto out;
 270	}
 271	n = ntohl(*p++);
 272	if (n == 0)
 273		goto out;
 274
 275	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
 276	if (!args->devs) {
 277		status = htonl(NFS4ERR_DELAY);
 278		goto out;
 279	}
 280
 281	/* Decode each dev notification */
 282	for (i = 0; i < n; i++) {
 283		struct cb_devicenotifyitem *dev = &args->devs[i];
 284
 285		p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
 286				      NFS4_DEVICEID4_SIZE);
 287		if (unlikely(p == NULL)) {
 288			status = htonl(NFS4ERR_BADXDR);
 289			goto err;
 290		}
 291
 292		tmp = ntohl(*p++);	/* bitmap size */
 293		if (tmp != 1) {
 294			status = htonl(NFS4ERR_INVAL);
 295			goto err;
 296		}
 297		dev->cbd_notify_type = ntohl(*p++);
 298		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
 299		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
 300			status = htonl(NFS4ERR_INVAL);
 301			goto err;
 302		}
 303
 304		tmp = ntohl(*p++);	/* opaque size */
 305		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
 306		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
 307		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
 308		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
 309			status = htonl(NFS4ERR_INVAL);
 310			goto err;
 311		}
 312		dev->cbd_layout_type = ntohl(*p++);
 313		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
 314		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 315
 316		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
 317			p = xdr_inline_decode(xdr, sizeof(uint32_t));
 318			if (unlikely(p == NULL)) {
 319				status = htonl(NFS4ERR_BADXDR);
 320				goto err;
 321			}
 322			dev->cbd_immediate = ntohl(*p++);
 323		} else {
 324			dev->cbd_immediate = 0;
 325		}
 326
 327		dprintk("%s: type %d layout 0x%x immediate %d\n",
 328			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
 329			dev->cbd_immediate);
 330	}
 331	args->ndevs = n;
 332	dprintk("%s: ndevs %d\n", __func__, args->ndevs);
 333	return 0;
 334err:
 335	kfree(args->devs);
 336out:
 337	args->devs = NULL;
 338	args->ndevs = 0;
 339	dprintk("%s: status %d ndevs %d\n",
 340		__func__, ntohl(status), args->ndevs);
 341	return status;
 342}
 343
 344static __be32 decode_sessionid(struct xdr_stream *xdr,
 345				 struct nfs4_sessionid *sid)
 346{
 347	__be32 *p;
 348
 349	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
 350	if (unlikely(p == NULL))
 351		return htonl(NFS4ERR_RESOURCE);
 352
 353	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
 354	return 0;
 355}
 356
 357static __be32 decode_rc_list(struct xdr_stream *xdr,
 358			       struct referring_call_list *rc_list)
 359{
 360	__be32 *p;
 361	int i;
 362	__be32 status;
 363
 364	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 365	if (status)
 366		goto out;
 367
 368	status = htonl(NFS4ERR_RESOURCE);
 369	p = xdr_inline_decode(xdr, sizeof(uint32_t));
 370	if (unlikely(p == NULL))
 371		goto out;
 372
 373	rc_list->rcl_nrefcalls = ntohl(*p++);
 374	if (rc_list->rcl_nrefcalls) {
 375		p = xdr_inline_decode(xdr,
 376			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 377		if (unlikely(p == NULL))
 378			goto out;
 379		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
 380						sizeof(*rc_list->rcl_refcalls),
 381						GFP_KERNEL);
 382		if (unlikely(rc_list->rcl_refcalls == NULL))
 383			goto out;
 384		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 385			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 386			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 387		}
 388	}
 389	status = 0;
 390
 391out:
 392	return status;
 393}
 394
 395static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 396					struct xdr_stream *xdr,
 397					void *argp)
 398{
 399	struct cb_sequenceargs *args = argp;
 400	__be32 *p;
 401	int i;
 402	__be32 status;
 403
 404	status = decode_sessionid(xdr, &args->csa_sessionid);
 405	if (status)
 406		return status;
 407
 408	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
 409	if (unlikely(p == NULL))
 410		return htonl(NFS4ERR_RESOURCE);
 411
 412	args->csa_addr = svc_addr(rqstp);
 413	args->csa_sequenceid = ntohl(*p++);
 414	args->csa_slotid = ntohl(*p++);
 415	args->csa_highestslotid = ntohl(*p++);
 416	args->csa_cachethis = ntohl(*p++);
 417	args->csa_nrclists = ntohl(*p++);
 418	args->csa_rclists = NULL;
 419	if (args->csa_nrclists) {
 420		args->csa_rclists = kmalloc_array(args->csa_nrclists,
 421						  sizeof(*args->csa_rclists),
 422						  GFP_KERNEL);
 423		if (unlikely(args->csa_rclists == NULL))
 424			return htonl(NFS4ERR_RESOURCE);
 425
 426		for (i = 0; i < args->csa_nrclists; i++) {
 427			status = decode_rc_list(xdr, &args->csa_rclists[i]);
 428			if (status) {
 429				args->csa_nrclists = i;
 430				goto out_free;
 431			}
 432		}
 433	}
 434	return 0;
 435
 436out_free:
 437	for (i = 0; i < args->csa_nrclists; i++)
 438		kfree(args->csa_rclists[i].rcl_refcalls);
 439	kfree(args->csa_rclists);
 440	return status;
 441}
 442
 443static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 444				      struct xdr_stream *xdr,
 445				      void *argp)
 446{
 447	struct cb_recallanyargs *args = argp;
 448	uint32_t bitmap[2];
 449	__be32 *p, status;
 450
 451	p = xdr_inline_decode(xdr, 4);
 452	if (unlikely(p == NULL))
 453		return htonl(NFS4ERR_BADXDR);
 454	args->craa_objs_to_keep = ntohl(*p++);
 455	status = decode_bitmap(xdr, bitmap);
 456	if (unlikely(status))
 457		return status;
 458	args->craa_type_mask = bitmap[0];
 459
 460	return 0;
 461}
 462
 463static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 464					struct xdr_stream *xdr,
 465					void *argp)
 466{
 467	struct cb_recallslotargs *args = argp;
 468	__be32 *p;
 469
 470	p = xdr_inline_decode(xdr, 4);
 471	if (unlikely(p == NULL))
 472		return htonl(NFS4ERR_BADXDR);
 473	args->crsa_target_highest_slotid = ntohl(*p++);
 474	return 0;
 475}
 476
 477static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
 478{
 479	__be32		*p;
 480	unsigned int	len;
 481
 482	p = xdr_inline_decode(xdr, 12);
 483	if (unlikely(p == NULL))
 484		return htonl(NFS4ERR_BADXDR);
 485
 486	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
 487	len = be32_to_cpu(*p);
 488
 489	p = xdr_inline_decode(xdr, len);
 490	if (unlikely(p == NULL))
 491		return htonl(NFS4ERR_BADXDR);
 492
 493	/* Only try to decode if the length is right */
 494	if (len == 20) {
 495		p += 2;	/* skip "lock id:" */
 496		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
 497		xdr_decode_hyper(p, &args->cbnl_owner.id);
 498		args->cbnl_valid = true;
 499	} else {
 500		args->cbnl_owner.s_dev = 0;
 501		args->cbnl_owner.id = 0;
 502		args->cbnl_valid = false;
 503	}
 504	return 0;
 505}
 506
 507static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
 508		struct xdr_stream *xdr, void *argp)
 509{
 510	struct cb_notify_lock_args *args = argp;
 511	__be32 status;
 512
 513	status = decode_fh(xdr, &args->cbnl_fh);
 514	if (unlikely(status != 0))
 515		return status;
 516	return decode_lockowner(xdr, args);
 517}
 518
 519#endif /* CONFIG_NFS_V4_1 */
 520#ifdef CONFIG_NFS_V4_2
 521static __be32 decode_write_response(struct xdr_stream *xdr,
 522					struct cb_offloadargs *args)
 523{
 524	__be32 *p;
 525
 526	/* skip the always zero field */
 527	p = xdr_inline_decode(xdr, 4);
 528	if (unlikely(!p))
 529		goto out;
 530	p++;
 531
 532	/* decode count, stable_how, verifier */
 533	p = xdr_inline_decode(xdr, 8 + 4);
 534	if (unlikely(!p))
 535		goto out;
 536	p = xdr_decode_hyper(p, &args->wr_count);
 537	args->wr_writeverf.committed = be32_to_cpup(p);
 538	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
 539	if (likely(p)) {
 540		memcpy(&args->wr_writeverf.verifier.data[0], p,
 541			NFS4_VERIFIER_SIZE);
 542		return 0;
 543	}
 544out:
 545	return htonl(NFS4ERR_RESOURCE);
 546}
 547
 548static __be32 decode_offload_args(struct svc_rqst *rqstp,
 549					struct xdr_stream *xdr,
 550					void *data)
 551{
 552	struct cb_offloadargs *args = data;
 553	__be32 *p;
 554	__be32 status;
 555
 556	/* decode fh */
 557	status = decode_fh(xdr, &args->coa_fh);
 558	if (unlikely(status != 0))
 559		return status;
 560
 561	/* decode stateid */
 562	status = decode_stateid(xdr, &args->coa_stateid);
 563	if (unlikely(status != 0))
 564		return status;
 565
 566	/* decode status */
 567	p = xdr_inline_decode(xdr, 4);
 568	if (unlikely(!p))
 569		goto out;
 570	args->error = ntohl(*p++);
 571	if (!args->error) {
 572		status = decode_write_response(xdr, args);
 573		if (unlikely(status != 0))
 574			return status;
 575	} else {
 576		p = xdr_inline_decode(xdr, 8);
 577		if (unlikely(!p))
 578			goto out;
 579		p = xdr_decode_hyper(p, &args->wr_count);
 580	}
 581	return 0;
 582out:
 583	return htonl(NFS4ERR_RESOURCE);
 584}
 585#endif /* CONFIG_NFS_V4_2 */
 586static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 587{
 588	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
 589		return cpu_to_be32(NFS4ERR_RESOURCE);
 590	return 0;
 591}
 592
 593static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
 594{
 595	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
 596		return cpu_to_be32(NFS4ERR_RESOURCE);
 597	return 0;
 598}
 599
 600static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 601{
 602	__be32 *p;
 603
 604	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 605		return 0;
 606	p = xdr_reserve_space(xdr, 8);
 607	if (unlikely(!p))
 608		return htonl(NFS4ERR_RESOURCE);
 609	p = xdr_encode_hyper(p, change);
 610	return 0;
 611}
 612
 613static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 614{
 615	__be32 *p;
 616
 617	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 618		return 0;
 619	p = xdr_reserve_space(xdr, 8);
 620	if (unlikely(!p))
 621		return htonl(NFS4ERR_RESOURCE);
 622	p = xdr_encode_hyper(p, size);
 623	return 0;
 624}
 625
 626static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
 627{
 628	__be32 *p;
 629
 630	p = xdr_reserve_space(xdr, 12);
 631	if (unlikely(!p))
 632		return htonl(NFS4ERR_RESOURCE);
 633	p = xdr_encode_hyper(p, time->tv_sec);
 634	*p = htonl(time->tv_nsec);
 635	return 0;
 636}
 637
 638static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 639{
 640	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 641		return 0;
 642	return encode_attr_time(xdr,time);
 643}
 644
 645static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 646{
 647	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 648		return 0;
 649	return encode_attr_time(xdr,time);
 650}
 651
 652static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 653{
 654	__be32 status;
 655
 656	hdr->status = xdr_reserve_space(xdr, 4);
 657	if (unlikely(hdr->status == NULL))
 658		return htonl(NFS4ERR_RESOURCE);
 659	status = encode_string(xdr, hdr->taglen, hdr->tag);
 660	if (unlikely(status != 0))
 661		return status;
 662	hdr->nops = xdr_reserve_space(xdr, 4);
 663	if (unlikely(hdr->nops == NULL))
 664		return htonl(NFS4ERR_RESOURCE);
 665	return 0;
 666}
 667
 668static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 669{
 670	__be32 *p;
 671	
 672	p = xdr_reserve_space(xdr, 8);
 673	if (unlikely(p == NULL))
 674		return htonl(NFS4ERR_RESOURCE_HDR);
 675	*p++ = htonl(op);
 676	*p = res;
 677	return 0;
 678}
 679
 680static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 681		const void *resp)
 682{
 683	const struct cb_getattrres *res = resp;
 684	__be32 *savep = NULL;
 685	__be32 status = res->status;
 686	
 687	if (unlikely(status != 0))
 688		goto out;
 689	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
 690	if (unlikely(status != 0))
 691		goto out;
 692	status = cpu_to_be32(NFS4ERR_RESOURCE);
 693	savep = xdr_reserve_space(xdr, sizeof(*savep));
 694	if (unlikely(!savep))
 695		goto out;
 696	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 697	if (unlikely(status != 0))
 698		goto out;
 699	status = encode_attr_size(xdr, res->bitmap, res->size);
 700	if (unlikely(status != 0))
 701		goto out;
 702	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 703	if (unlikely(status != 0))
 704		goto out;
 705	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 706	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 707out:
 708	return status;
 709}
 710
 711#if defined(CONFIG_NFS_V4_1)
 712
 713static __be32 encode_sessionid(struct xdr_stream *xdr,
 714				 const struct nfs4_sessionid *sid)
 715{
 716	__be32 *p;
 717
 718	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
 719	if (unlikely(p == NULL))
 720		return htonl(NFS4ERR_RESOURCE);
 721
 722	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
 723	return 0;
 724}
 725
 726static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 727				       struct xdr_stream *xdr,
 728				       const void *resp)
 729{
 730	const struct cb_sequenceres *res = resp;
 731	__be32 *p;
 732	__be32 status = res->csr_status;
 733
 734	if (unlikely(status != 0))
 735		return status;
 736
 737	status = encode_sessionid(xdr, &res->csr_sessionid);
 738	if (status)
 739		return status;
 740
 741	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 742	if (unlikely(p == NULL))
 743		return htonl(NFS4ERR_RESOURCE);
 744
 745	*p++ = htonl(res->csr_sequenceid);
 746	*p++ = htonl(res->csr_slotid);
 747	*p++ = htonl(res->csr_highestslotid);
 748	*p++ = htonl(res->csr_target_highestslotid);
 749	return 0;
 750}
 751
 752static __be32
 753preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 754{
 755	if (op_nr == OP_CB_SEQUENCE) {
 756		if (nop != 0)
 757			return htonl(NFS4ERR_SEQUENCE_POS);
 758	} else {
 759		if (nop == 0)
 760			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 761	}
 762
 763	switch (op_nr) {
 764	case OP_CB_GETATTR:
 765	case OP_CB_RECALL:
 766	case OP_CB_SEQUENCE:
 767	case OP_CB_RECALL_ANY:
 768	case OP_CB_RECALL_SLOT:
 769	case OP_CB_LAYOUTRECALL:
 770	case OP_CB_NOTIFY_DEVICEID:
 771	case OP_CB_NOTIFY_LOCK:
 772		*op = &callback_ops[op_nr];
 773		break;
 774
 775	case OP_CB_NOTIFY:
 776	case OP_CB_PUSH_DELEG:
 777	case OP_CB_RECALLABLE_OBJ_AVAIL:
 778	case OP_CB_WANTS_CANCELLED:
 779		return htonl(NFS4ERR_NOTSUPP);
 780
 781	default:
 782		return htonl(NFS4ERR_OP_ILLEGAL);
 783	}
 784
 785	return htonl(NFS_OK);
 786}
 787
 788static void nfs4_callback_free_slot(struct nfs4_session *session,
 789		struct nfs4_slot *slot)
 790{
 791	struct nfs4_slot_table *tbl = &session->bc_slot_table;
 792
 793	spin_lock(&tbl->slot_tbl_lock);
 794	/*
 795	 * Let the state manager know callback processing done.
 796	 * A single slot, so highest used slotid is either 0 or -1
 797	 */
 798	nfs4_free_slot(tbl, slot);
 799	spin_unlock(&tbl->slot_tbl_lock);
 800}
 801
 802static void nfs4_cb_free_slot(struct cb_process_state *cps)
 803{
 804	if (cps->slot) {
 805		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
 806		cps->slot = NULL;
 807	}
 808}
 809
 810#else /* CONFIG_NFS_V4_1 */
 811
 812static __be32
 813preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 814{
 815	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 816}
 817
 818static void nfs4_cb_free_slot(struct cb_process_state *cps)
 819{
 820}
 821#endif /* CONFIG_NFS_V4_1 */
 822
 823#ifdef CONFIG_NFS_V4_2
 824static __be32
 825preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 826{
 827	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
 828	if (status != htonl(NFS4ERR_OP_ILLEGAL))
 829		return status;
 830
 831	if (op_nr == OP_CB_OFFLOAD) {
 832		*op = &callback_ops[op_nr];
 833		return htonl(NFS_OK);
 834	} else
 835		return htonl(NFS4ERR_NOTSUPP);
 836	return htonl(NFS4ERR_OP_ILLEGAL);
 837}
 838#else /* CONFIG_NFS_V4_2 */
 839static __be32
 840preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 841{
 842	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 843}
 844#endif /* CONFIG_NFS_V4_2 */
 845
 846static __be32
 847preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 848{
 849	switch (op_nr) {
 850	case OP_CB_GETATTR:
 851	case OP_CB_RECALL:
 852		*op = &callback_ops[op_nr];
 853		break;
 854	default:
 855		return htonl(NFS4ERR_OP_ILLEGAL);
 856	}
 857
 858	return htonl(NFS_OK);
 859}
 860
 861static __be32 process_op(int nop, struct svc_rqst *rqstp,
 862			 struct cb_process_state *cps)
 863{
 864	struct xdr_stream *xdr_out = &rqstp->rq_res_stream;
 865	struct callback_op *op = &callback_ops[0];
 866	unsigned int op_nr;
 867	__be32 status;
 868	long maxlen;
 869	__be32 res;
 870
 871	status = decode_op_hdr(&rqstp->rq_arg_stream, &op_nr);
 872	if (unlikely(status))
 873		return status;
 874
 875	switch (cps->minorversion) {
 876	case 0:
 877		status = preprocess_nfs4_op(op_nr, &op);
 878		break;
 879	case 1:
 880		status = preprocess_nfs41_op(nop, op_nr, &op);
 881		break;
 882	case 2:
 883		status = preprocess_nfs42_op(nop, op_nr, &op);
 884		break;
 885	default:
 886		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 887	}
 888
 889	if (status == htonl(NFS4ERR_OP_ILLEGAL))
 890		op_nr = OP_CB_ILLEGAL;
 891	if (status)
 892		goto encode_hdr;
 893
 894	if (cps->drc_status) {
 895		status = cps->drc_status;
 896		goto encode_hdr;
 897	}
 898
 899	maxlen = xdr_out->end - xdr_out->p;
 900	if (maxlen > 0 && maxlen < PAGE_SIZE) {
 901		status = op->decode_args(rqstp, &rqstp->rq_arg_stream,
 902					 rqstp->rq_argp);
 903		if (likely(status == 0))
 904			status = op->process_op(rqstp->rq_argp, rqstp->rq_resp,
 905						cps);
 906	} else
 907		status = htonl(NFS4ERR_RESOURCE);
 908
 909encode_hdr:
 910	res = encode_op_hdr(xdr_out, op_nr, status);
 911	if (unlikely(res))
 912		return res;
 913	if (op->encode_res != NULL && status == 0)
 914		status = op->encode_res(rqstp, xdr_out, rqstp->rq_resp);
 915	return status;
 916}
 917
 918/*
 919 * Decode, process and encode a COMPOUND
 920 */
 921static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
 922{
 923	struct cb_compound_hdr_arg hdr_arg = { 0 };
 924	struct cb_compound_hdr_res hdr_res = { NULL };
 925	struct cb_process_state cps = {
 926		.drc_status = 0,
 927		.clp = NULL,
 928		.net = SVC_NET(rqstp),
 929	};
 930	unsigned int nops = 0;
 931	__be32 status;
 932
 933	status = decode_compound_hdr_arg(&rqstp->rq_arg_stream, &hdr_arg);
 934	if (status == htonl(NFS4ERR_RESOURCE))
 935		return rpc_garbage_args;
 936
 937	if (hdr_arg.minorversion == 0) {
 938		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
 939		if (!cps.clp) {
 940			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
 941			goto out_invalidcred;
 942		}
 943		if (!check_gss_callback_principal(cps.clp, rqstp)) {
 944			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
 945			nfs_put_client(cps.clp);
 946			goto out_invalidcred;
 947		}
 948	}
 949
 950	cps.minorversion = hdr_arg.minorversion;
 951	hdr_res.taglen = hdr_arg.taglen;
 952	hdr_res.tag = hdr_arg.tag;
 953	if (encode_compound_hdr_res(&rqstp->rq_res_stream, &hdr_res) != 0) {
 954		if (cps.clp)
 955			nfs_put_client(cps.clp);
 956		return rpc_system_err;
 957	}
 958	while (status == 0 && nops != hdr_arg.nops) {
 959		status = process_op(nops, rqstp, &cps);
 960		nops++;
 961	}
 962
 963	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
 964	* resource error in cb_compound status without returning op */
 965	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
 966		status = htonl(NFS4ERR_RESOURCE);
 967		nops--;
 968	}
 969
 970	if (svc_is_backchannel(rqstp) && cps.clp) {
 971		rqstp->bc_to_initval = cps.clp->cl_rpcclient->cl_timeout->to_initval;
 972		rqstp->bc_to_retries = cps.clp->cl_rpcclient->cl_timeout->to_retries;
 973	}
 974
 975	*hdr_res.status = status;
 976	*hdr_res.nops = htonl(nops);
 977	nfs4_cb_free_slot(&cps);
 978	nfs_put_client(cps.clp);
 979	return rpc_success;
 980
 981out_invalidcred:
 982	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
 983	rqstp->rq_auth_stat = rpc_autherr_badcred;
 984	return rpc_success;
 985}
 986
 987static int
 988nfs_callback_dispatch(struct svc_rqst *rqstp)
 989{
 990	const struct svc_procedure *procp = rqstp->rq_procinfo;
 991
 992	*rqstp->rq_accept_statp = procp->pc_func(rqstp);
 
 
 
 993	return 1;
 994}
 995
 996/*
 997 * Define NFS4 callback COMPOUND ops.
 998 */
 999static struct callback_op callback_ops[] = {
1000	[0] = {
1001		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
1002	},
1003	[OP_CB_GETATTR] = {
1004		.process_op = nfs4_callback_getattr,
1005		.decode_args = decode_getattr_args,
1006		.encode_res = encode_getattr_res,
1007		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1008	},
1009	[OP_CB_RECALL] = {
1010		.process_op = nfs4_callback_recall,
1011		.decode_args = decode_recall_args,
1012		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1013	},
1014#if defined(CONFIG_NFS_V4_1)
1015	[OP_CB_LAYOUTRECALL] = {
1016		.process_op = nfs4_callback_layoutrecall,
1017		.decode_args = decode_layoutrecall_args,
1018		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1019	},
1020	[OP_CB_NOTIFY_DEVICEID] = {
1021		.process_op = nfs4_callback_devicenotify,
1022		.decode_args = decode_devicenotify_args,
1023		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1024	},
1025	[OP_CB_SEQUENCE] = {
1026		.process_op = nfs4_callback_sequence,
1027		.decode_args = decode_cb_sequence_args,
1028		.encode_res = encode_cb_sequence_res,
1029		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1030	},
1031	[OP_CB_RECALL_ANY] = {
1032		.process_op = nfs4_callback_recallany,
1033		.decode_args = decode_recallany_args,
1034		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1035	},
1036	[OP_CB_RECALL_SLOT] = {
1037		.process_op = nfs4_callback_recallslot,
1038		.decode_args = decode_recallslot_args,
1039		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1040	},
1041	[OP_CB_NOTIFY_LOCK] = {
1042		.process_op = nfs4_callback_notify_lock,
1043		.decode_args = decode_notify_lock_args,
1044		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1045	},
1046#endif /* CONFIG_NFS_V4_1 */
1047#ifdef CONFIG_NFS_V4_2
1048	[OP_CB_OFFLOAD] = {
1049		.process_op = nfs4_callback_offload,
1050		.decode_args = decode_offload_args,
1051		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1052	},
1053#endif /* CONFIG_NFS_V4_2 */
1054};
1055
1056/*
1057 * Define NFS4 callback procedures
1058 */
1059static const struct svc_procedure nfs4_callback_procedures1[] = {
1060	[CB_NULL] = {
1061		.pc_func = nfs4_callback_null,
1062		.pc_encode = nfs4_encode_void,
1063		.pc_xdrressize = 1,
1064		.pc_name = "NULL",
1065	},
1066	[CB_COMPOUND] = {
1067		.pc_func = nfs4_callback_compound,
1068		.pc_encode = nfs4_encode_void,
1069		.pc_argsize = 256,
1070		.pc_argzero = 256,
1071		.pc_ressize = 256,
1072		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1073		.pc_name = "COMPOUND",
1074	}
1075};
1076
1077static DEFINE_PER_CPU_ALIGNED(unsigned long,
1078			      nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)]);
1079const struct svc_version nfs4_callback_version1 = {
1080	.vs_vers = 1,
1081	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1082	.vs_proc = nfs4_callback_procedures1,
1083	.vs_count = nfs4_callback_count1,
1084	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1085	.vs_dispatch = nfs_callback_dispatch,
1086	.vs_hidden = true,
1087	.vs_need_cong_ctrl = true,
1088};
1089
1090static DEFINE_PER_CPU_ALIGNED(unsigned long,
1091			      nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)]);
1092const struct svc_version nfs4_callback_version4 = {
1093	.vs_vers = 4,
1094	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1095	.vs_proc = nfs4_callback_procedures1,
1096	.vs_count = nfs4_callback_count4,
1097	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1098	.vs_dispatch = nfs_callback_dispatch,
1099	.vs_hidden = true,
1100	.vs_need_cong_ctrl = true,
1101};