callback_xdr.c

   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, atime, ctime,
  29					  * mtime, deleg_atime, deleg_mtime */\
  30					 (2 + 2 + 3 + 3 + 3 + 3 + 3) * 4)
  31#define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
  32
  33#if defined(CONFIG_NFS_V4_1)
  34#define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  35#define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  36#define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
  37					 NFS4_MAX_SESSIONID_LEN + \
  38					 (1 + 3) * 4) // seqid, 3 slotids
  39#define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  40#define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  41#define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
  42#endif /* CONFIG_NFS_V4_1 */
  43#ifdef CONFIG_NFS_V4_2
  44#define CB_OP_OFFLOAD_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
  45#endif /* CONFIG_NFS_V4_2 */
  46
  47#define NFSDBG_FACILITY NFSDBG_CALLBACK
  48
  49/* Internal error code */
  50#define NFS4ERR_RESOURCE_HDR	11050
  51
  52struct callback_op {
  53	__be32 (*process_op)(void *, void *, struct cb_process_state *);
  54	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
  55	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
  56			const void *);
  57	long res_maxsize;
  58};
  59
  60static struct callback_op callback_ops[];
  61
  62static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
  63{
  64	return htonl(NFS4_OK);
  65}
  66
  67/*
  68 * svc_process_common() looks for an XDR encoder to know when
  69 * not to drop a Reply.
  70 */
  71static bool nfs4_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  72{
  73	return true;
  74}
  75
  76static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
  77		const char **str, size_t maxlen)
  78{
  79	ssize_t err;
  80
  81	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
  82	if (err < 0)
  83		return cpu_to_be32(NFS4ERR_RESOURCE);
  84	*len = err;
  85	return 0;
  86}
  87
  88static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  89{
  90	__be32 *p;
  91
  92	p = xdr_inline_decode(xdr, 4);
  93	if (unlikely(p == NULL))
  94		return htonl(NFS4ERR_RESOURCE);
  95	fh->size = ntohl(*p);
  96	if (fh->size > NFS4_FHSIZE)
  97		return htonl(NFS4ERR_BADHANDLE);
  98	p = xdr_inline_decode(xdr, fh->size);
  99	if (unlikely(p == NULL))
 100		return htonl(NFS4ERR_RESOURCE);
 101	memcpy(&fh->data[0], p, fh->size);
 102	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 103	return 0;
 104}
 105
 106static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 107{
 108	__be32 *p;
 109	unsigned int attrlen;
 110
 111	p = xdr_inline_decode(xdr, 4);
 112	if (unlikely(p == NULL))
 113		return htonl(NFS4ERR_RESOURCE);
 114	attrlen = ntohl(*p);
 115	p = xdr_inline_decode(xdr, attrlen << 2);
 116	if (unlikely(p == NULL))
 117		return htonl(NFS4ERR_RESOURCE);
 118	if (likely(attrlen > 0))
 119		bitmap[0] = ntohl(*p++);
 120	if (attrlen > 1)
 121		bitmap[1] = ntohl(*p++);
 122	if (attrlen > 2)
 123		bitmap[2] = ntohl(*p);
 124	return 0;
 125}
 126
 127static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 128{
 129	__be32 *p;
 130
 131	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
 132	if (unlikely(p == NULL))
 133		return htonl(NFS4ERR_RESOURCE);
 134	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
 135	return 0;
 136}
 137
 138static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 139{
 140	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
 141	return decode_stateid(xdr, stateid);
 142}
 143
 144static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 145{
 146	__be32 *p;
 147	__be32 status;
 148
 149	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
 150	if (unlikely(status != 0))
 151		return status;
 152	p = xdr_inline_decode(xdr, 12);
 153	if (unlikely(p == NULL))
 154		return htonl(NFS4ERR_RESOURCE);
 155	hdr->minorversion = ntohl(*p++);
 156	/* Check for minor version support */
 157	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
 158		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
 159	} else {
 160		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
 161			"illegal minor version %u!\n",
 162			__func__, hdr->minorversion);
 163		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 164	}
 165	hdr->nops = ntohl(*p);
 166	return 0;
 167}
 168
 169static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 170{
 171	__be32 *p;
 172	p = xdr_inline_decode(xdr, 4);
 173	if (unlikely(p == NULL))
 174		return htonl(NFS4ERR_RESOURCE_HDR);
 175	*op = ntohl(*p);
 176	return 0;
 177}
 178
 179static __be32 decode_getattr_args(struct svc_rqst *rqstp,
 180		struct xdr_stream *xdr, void *argp)
 181{
 182	struct cb_getattrargs *args = argp;
 183	__be32 status;
 184
 185	status = decode_fh(xdr, &args->fh);
 186	if (unlikely(status != 0))
 187		return status;
 188	return decode_bitmap(xdr, args->bitmap);
 189}
 190
 191static __be32 decode_recall_args(struct svc_rqst *rqstp,
 192		struct xdr_stream *xdr, void *argp)
 193{
 194	struct cb_recallargs *args = argp;
 195	__be32 *p;
 196	__be32 status;
 197
 198	status = decode_delegation_stateid(xdr, &args->stateid);
 199	if (unlikely(status != 0))
 200		return status;
 201	p = xdr_inline_decode(xdr, 4);
 202	if (unlikely(p == NULL))
 203		return htonl(NFS4ERR_RESOURCE);
 204	args->truncate = ntohl(*p);
 205	return decode_fh(xdr, &args->fh);
 206}
 207
 208#if defined(CONFIG_NFS_V4_1)
 209static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 210{
 211	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
 212	return decode_stateid(xdr, stateid);
 213}
 214
 215static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 216				       struct xdr_stream *xdr, void *argp)
 217{
 218	struct cb_layoutrecallargs *args = argp;
 219	__be32 *p;
 220	__be32 status = 0;
 221	uint32_t iomode;
 222
 223	p = xdr_inline_decode(xdr, 4 * sizeof(uint32_t));
 224	if (unlikely(p == NULL))
 225		return htonl(NFS4ERR_BADXDR);
 226
 227	args->cbl_layout_type = ntohl(*p++);
 228	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
 229	 * as it is unusable and ignored with the other types.
 230	 */
 231	iomode = ntohl(*p++);
 232	args->cbl_layoutchanged = ntohl(*p++);
 233	args->cbl_recall_type = ntohl(*p++);
 234
 235	if (args->cbl_recall_type == RETURN_FILE) {
 236		args->cbl_range.iomode = iomode;
 237		status = decode_fh(xdr, &args->cbl_fh);
 238		if (unlikely(status != 0))
 239			return status;
 240
 241		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
 242		if (unlikely(p == NULL))
 243			return htonl(NFS4ERR_BADXDR);
 244		p = xdr_decode_hyper(p, &args->cbl_range.offset);
 245		p = xdr_decode_hyper(p, &args->cbl_range.length);
 246		return decode_layout_stateid(xdr, &args->cbl_stateid);
 247	} else if (args->cbl_recall_type == RETURN_FSID) {
 248		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
 249		if (unlikely(p == NULL))
 250			return htonl(NFS4ERR_BADXDR);
 251		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
 252		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
 253	} else if (args->cbl_recall_type != RETURN_ALL)
 254		return htonl(NFS4ERR_BADXDR);
 255	return 0;
 256}
 257
 258static
 259__be32 decode_devicenotify_args(struct svc_rqst *rqstp,
 260				struct xdr_stream *xdr,
 261				void *argp)
 262{
 263	struct cb_devicenotifyargs *args = argp;
 264	uint32_t tmp, n, i;
 265	__be32 *p;
 266	__be32 status = 0;
 267
 268	/* Num of device notifications */
 269	p = xdr_inline_decode(xdr, sizeof(uint32_t));
 270	if (unlikely(p == NULL)) {
 271		status = htonl(NFS4ERR_BADXDR);
 272		goto out;
 273	}
 274	n = ntohl(*p++);
 275	if (n == 0)
 276		goto out;
 277
 278	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
 279	if (!args->devs) {
 280		status = htonl(NFS4ERR_DELAY);
 281		goto out;
 282	}
 283
 284	/* Decode each dev notification */
 285	for (i = 0; i < n; i++) {
 286		struct cb_devicenotifyitem *dev = &args->devs[i];
 287
 288		p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
 289				      NFS4_DEVICEID4_SIZE);
 290		if (unlikely(p == NULL)) {
 291			status = htonl(NFS4ERR_BADXDR);
 292			goto err;
 293		}
 294
 295		tmp = ntohl(*p++);	/* bitmap size */
 296		if (tmp != 1) {
 297			status = htonl(NFS4ERR_INVAL);
 298			goto err;
 299		}
 300		dev->cbd_notify_type = ntohl(*p++);
 301		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
 302		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
 303			status = htonl(NFS4ERR_INVAL);
 304			goto err;
 305		}
 306
 307		tmp = ntohl(*p++);	/* opaque size */
 308		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
 309		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
 310		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
 311		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
 312			status = htonl(NFS4ERR_INVAL);
 313			goto err;
 314		}
 315		dev->cbd_layout_type = ntohl(*p++);
 316		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
 317		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 318
 319		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
 320			p = xdr_inline_decode(xdr, sizeof(uint32_t));
 321			if (unlikely(p == NULL)) {
 322				status = htonl(NFS4ERR_BADXDR);
 323				goto err;
 324			}
 325			dev->cbd_immediate = ntohl(*p++);
 326		} else {
 327			dev->cbd_immediate = 0;
 328		}
 329
 330		dprintk("%s: type %d layout 0x%x immediate %d\n",
 331			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
 332			dev->cbd_immediate);
 333	}
 334	args->ndevs = n;
 335	dprintk("%s: ndevs %d\n", __func__, args->ndevs);
 336	return 0;
 337err:
 338	kfree(args->devs);
 339out:
 340	args->devs = NULL;
 341	args->ndevs = 0;
 342	dprintk("%s: status %d ndevs %d\n",
 343		__func__, ntohl(status), args->ndevs);
 344	return status;
 345}
 346
 347static __be32 decode_sessionid(struct xdr_stream *xdr,
 348				 struct nfs4_sessionid *sid)
 349{
 350	__be32 *p;
 351
 352	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
 353	if (unlikely(p == NULL))
 354		return htonl(NFS4ERR_RESOURCE);
 355
 356	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
 357	return 0;
 358}
 359
 360static __be32 decode_rc_list(struct xdr_stream *xdr,
 361			       struct referring_call_list *rc_list)
 362{
 363	__be32 *p;
 364	int i;
 365	__be32 status;
 366
 367	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 368	if (status)
 369		goto out;
 370
 371	status = htonl(NFS4ERR_RESOURCE);
 372	p = xdr_inline_decode(xdr, sizeof(uint32_t));
 373	if (unlikely(p == NULL))
 374		goto out;
 375
 376	rc_list->rcl_nrefcalls = ntohl(*p++);
 377	if (rc_list->rcl_nrefcalls) {
 378		if (unlikely(rc_list->rcl_nrefcalls > xdr->buf->len))
 379			goto out;
 380		p = xdr_inline_decode(xdr,
 381			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 382		if (unlikely(p == NULL))
 383			goto out;
 384		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
 385						sizeof(*rc_list->rcl_refcalls),
 386						GFP_KERNEL);
 387		if (unlikely(rc_list->rcl_refcalls == NULL))
 388			goto out;
 389		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 390			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 391			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 392		}
 393	}
 394	status = 0;
 395
 396out:
 397	return status;
 398}
 399
 400static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 401					struct xdr_stream *xdr,
 402					void *argp)
 403{
 404	struct cb_sequenceargs *args = argp;
 405	__be32 *p;
 406	int i;
 407	__be32 status;
 408
 409	status = decode_sessionid(xdr, &args->csa_sessionid);
 410	if (status)
 411		return status;
 412
 413	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
 414	if (unlikely(p == NULL))
 415		return htonl(NFS4ERR_RESOURCE);
 416
 417	args->csa_addr = svc_addr(rqstp);
 418	args->csa_sequenceid = ntohl(*p++);
 419	args->csa_slotid = ntohl(*p++);
 420	args->csa_highestslotid = ntohl(*p++);
 421	args->csa_cachethis = ntohl(*p++);
 422	args->csa_nrclists = ntohl(*p++);
 423	args->csa_rclists = NULL;
 424	if (args->csa_nrclists) {
 425		args->csa_rclists = kmalloc_array(args->csa_nrclists,
 426						  sizeof(*args->csa_rclists),
 427						  GFP_KERNEL);
 428		if (unlikely(args->csa_rclists == NULL))
 429			return htonl(NFS4ERR_RESOURCE);
 430
 431		for (i = 0; i < args->csa_nrclists; i++) {
 432			status = decode_rc_list(xdr, &args->csa_rclists[i]);
 433			if (status) {
 434				args->csa_nrclists = i;
 435				goto out_free;
 436			}
 437		}
 438	}
 439	return 0;
 440
 441out_free:
 442	for (i = 0; i < args->csa_nrclists; i++)
 443		kfree(args->csa_rclists[i].rcl_refcalls);
 444	kfree(args->csa_rclists);
 445	return status;
 446}
 447
 448static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 449				      struct xdr_stream *xdr,
 450				      void *argp)
 451{
 452	struct cb_recallanyargs *args = argp;
 453	uint32_t bitmap[3];
 454	__be32 *p, status;
 455
 456	p = xdr_inline_decode(xdr, 4);
 457	if (unlikely(p == NULL))
 458		return htonl(NFS4ERR_BADXDR);
 459	args->craa_objs_to_keep = ntohl(*p++);
 460	status = decode_bitmap(xdr, bitmap);
 461	if (unlikely(status))
 462		return status;
 463	args->craa_type_mask = bitmap[0];
 464
 465	return 0;
 466}
 467
 468static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 469					struct xdr_stream *xdr,
 470					void *argp)
 471{
 472	struct cb_recallslotargs *args = argp;
 473	__be32 *p;
 474
 475	p = xdr_inline_decode(xdr, 4);
 476	if (unlikely(p == NULL))
 477		return htonl(NFS4ERR_BADXDR);
 478	args->crsa_target_highest_slotid = ntohl(*p++);
 479	return 0;
 480}
 481
 482static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
 483{
 484	__be32		*p;
 485	unsigned int	len;
 486
 487	p = xdr_inline_decode(xdr, 12);
 488	if (unlikely(p == NULL))
 489		return htonl(NFS4ERR_BADXDR);
 490
 491	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
 492	len = be32_to_cpu(*p);
 493
 494	p = xdr_inline_decode(xdr, len);
 495	if (unlikely(p == NULL))
 496		return htonl(NFS4ERR_BADXDR);
 497
 498	/* Only try to decode if the length is right */
 499	if (len == 20) {
 500		p += 2;	/* skip "lock id:" */
 501		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
 502		xdr_decode_hyper(p, &args->cbnl_owner.id);
 503		args->cbnl_valid = true;
 504	} else {
 505		args->cbnl_owner.s_dev = 0;
 506		args->cbnl_owner.id = 0;
 507		args->cbnl_valid = false;
 508	}
 509	return 0;
 510}
 511
 512static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
 513		struct xdr_stream *xdr, void *argp)
 514{
 515	struct cb_notify_lock_args *args = argp;
 516	__be32 status;
 517
 518	status = decode_fh(xdr, &args->cbnl_fh);
 519	if (unlikely(status != 0))
 520		return status;
 521	return decode_lockowner(xdr, args);
 522}
 523
 524#endif /* CONFIG_NFS_V4_1 */
 525#ifdef CONFIG_NFS_V4_2
 526static __be32 decode_write_response(struct xdr_stream *xdr,
 527					struct cb_offloadargs *args)
 528{
 529	__be32 *p;
 530
 531	/* skip the always zero field */
 532	p = xdr_inline_decode(xdr, 4);
 533	if (unlikely(!p))
 534		goto out;
 535	p++;
 536
 537	/* decode count, stable_how, verifier */
 538	p = xdr_inline_decode(xdr, 8 + 4);
 539	if (unlikely(!p))
 540		goto out;
 541	p = xdr_decode_hyper(p, &args->wr_count);
 542	args->wr_writeverf.committed = be32_to_cpup(p);
 543	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
 544	if (likely(p)) {
 545		memcpy(&args->wr_writeverf.verifier.data[0], p,
 546			NFS4_VERIFIER_SIZE);
 547		return 0;
 548	}
 549out:
 550	return htonl(NFS4ERR_RESOURCE);
 551}
 552
 553static __be32 decode_offload_args(struct svc_rqst *rqstp,
 554					struct xdr_stream *xdr,
 555					void *data)
 556{
 557	struct cb_offloadargs *args = data;
 558	__be32 *p;
 559	__be32 status;
 560
 561	/* decode fh */
 562	status = decode_fh(xdr, &args->coa_fh);
 563	if (unlikely(status != 0))
 564		return status;
 565
 566	/* decode stateid */
 567	status = decode_stateid(xdr, &args->coa_stateid);
 568	if (unlikely(status != 0))
 569		return status;
 570
 571	/* decode status */
 572	p = xdr_inline_decode(xdr, 4);
 573	if (unlikely(!p))
 574		goto out;
 575	args->error = ntohl(*p++);
 576	if (!args->error) {
 577		status = decode_write_response(xdr, args);
 578		if (unlikely(status != 0))
 579			return status;
 580	} else {
 581		p = xdr_inline_decode(xdr, 8);
 582		if (unlikely(!p))
 583			goto out;
 584		p = xdr_decode_hyper(p, &args->wr_count);
 585	}
 586	return 0;
 587out:
 588	return htonl(NFS4ERR_RESOURCE);
 589}
 590#endif /* CONFIG_NFS_V4_2 */
 591static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 592{
 593	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
 594		return cpu_to_be32(NFS4ERR_RESOURCE);
 595	return 0;
 596}
 597
 598static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
 599{
 600	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
 601		return cpu_to_be32(NFS4ERR_RESOURCE);
 602	return 0;
 603}
 604
 605static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 606{
 607	__be32 *p;
 608
 609	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 610		return 0;
 611	p = xdr_reserve_space(xdr, 8);
 612	if (unlikely(!p))
 613		return htonl(NFS4ERR_RESOURCE);
 614	p = xdr_encode_hyper(p, change);
 615	return 0;
 616}
 617
 618static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 619{
 620	__be32 *p;
 621
 622	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 623		return 0;
 624	p = xdr_reserve_space(xdr, 8);
 625	if (unlikely(!p))
 626		return htonl(NFS4ERR_RESOURCE);
 627	p = xdr_encode_hyper(p, size);
 628	return 0;
 629}
 630
 631static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
 632{
 633	__be32 *p;
 634
 635	p = xdr_reserve_space(xdr, 12);
 636	if (unlikely(!p))
 637		return htonl(NFS4ERR_RESOURCE);
 638	p = xdr_encode_hyper(p, time->tv_sec);
 639	*p = htonl(time->tv_nsec);
 640	return 0;
 641}
 642
 643static __be32 encode_attr_atime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 644{
 645	if (!(bitmap[1] & FATTR4_WORD1_TIME_ACCESS))
 646		return 0;
 647	return encode_attr_time(xdr,time);
 648}
 649
 650static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 651{
 652	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 653		return 0;
 654	return encode_attr_time(xdr,time);
 655}
 656
 657static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 658{
 659	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 660		return 0;
 661	return encode_attr_time(xdr,time);
 662}
 663
 664static __be32 encode_attr_delegatime(struct xdr_stream *xdr,
 665				     const uint32_t *bitmap,
 666				     const struct timespec64 *time)
 667{
 668	if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS))
 669		return 0;
 670	return encode_attr_time(xdr,time);
 671}
 672
 673static __be32 encode_attr_delegmtime(struct xdr_stream *xdr,
 674				     const uint32_t *bitmap,
 675				     const struct timespec64 *time)
 676{
 677	if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY))
 678		return 0;
 679	return encode_attr_time(xdr,time);
 680}
 681
 682static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 683{
 684	__be32 status;
 685
 686	hdr->status = xdr_reserve_space(xdr, 4);
 687	if (unlikely(hdr->status == NULL))
 688		return htonl(NFS4ERR_RESOURCE);
 689	status = encode_string(xdr, hdr->taglen, hdr->tag);
 690	if (unlikely(status != 0))
 691		return status;
 692	hdr->nops = xdr_reserve_space(xdr, 4);
 693	if (unlikely(hdr->nops == NULL))
 694		return htonl(NFS4ERR_RESOURCE);
 695	return 0;
 696}
 697
 698static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 699{
 700	__be32 *p;
 701	
 702	p = xdr_reserve_space(xdr, 8);
 703	if (unlikely(p == NULL))
 704		return htonl(NFS4ERR_RESOURCE_HDR);
 705	*p++ = htonl(op);
 706	*p = res;
 707	return 0;
 708}
 709
 710static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 711		const void *resp)
 712{
 713	const struct cb_getattrres *res = resp;
 714	__be32 *savep = NULL;
 715	__be32 status = res->status;
 716	
 717	if (unlikely(status != 0))
 718		goto out;
 719	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
 720	if (unlikely(status != 0))
 721		goto out;
 722	status = cpu_to_be32(NFS4ERR_RESOURCE);
 723	savep = xdr_reserve_space(xdr, sizeof(*savep));
 724	if (unlikely(!savep))
 725		goto out;
 726	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 727	if (unlikely(status != 0))
 728		goto out;
 729	status = encode_attr_size(xdr, res->bitmap, res->size);
 730	if (unlikely(status != 0))
 731		goto out;
 732	status = encode_attr_atime(xdr, res->bitmap, &res->atime);
 733	if (unlikely(status != 0))
 734		goto out;
 735	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 736	if (unlikely(status != 0))
 737		goto out;
 738	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 739	if (unlikely(status != 0))
 740		goto out;
 741	status = encode_attr_delegatime(xdr, res->bitmap, &res->atime);
 742	if (unlikely(status != 0))
 743		goto out;
 744	status = encode_attr_delegmtime(xdr, res->bitmap, &res->mtime);
 745	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 746out:
 747	return status;
 748}
 749
 750#if defined(CONFIG_NFS_V4_1)
 751
 752static __be32 encode_sessionid(struct xdr_stream *xdr,
 753				 const struct nfs4_sessionid *sid)
 754{
 755	__be32 *p;
 756
 757	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
 758	if (unlikely(p == NULL))
 759		return htonl(NFS4ERR_RESOURCE);
 760
 761	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
 762	return 0;
 763}
 764
 765static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 766				       struct xdr_stream *xdr,
 767				       const void *resp)
 768{
 769	const struct cb_sequenceres *res = resp;
 770	__be32 *p;
 771	__be32 status = res->csr_status;
 772
 773	if (unlikely(status != 0))
 774		return status;
 775
 776	status = encode_sessionid(xdr, &res->csr_sessionid);
 777	if (status)
 778		return status;
 779
 780	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 781	if (unlikely(p == NULL))
 782		return htonl(NFS4ERR_RESOURCE);
 783
 784	*p++ = htonl(res->csr_sequenceid);
 785	*p++ = htonl(res->csr_slotid);
 786	*p++ = htonl(res->csr_highestslotid);
 787	*p++ = htonl(res->csr_target_highestslotid);
 788	return 0;
 789}
 790
 791static __be32
 792preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 793{
 794	if (op_nr == OP_CB_SEQUENCE) {
 795		if (nop != 0)
 796			return htonl(NFS4ERR_SEQUENCE_POS);
 797	} else {
 798		if (nop == 0)
 799			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 800	}
 801
 802	switch (op_nr) {
 803	case OP_CB_GETATTR:
 804	case OP_CB_RECALL:
 805	case OP_CB_SEQUENCE:
 806	case OP_CB_RECALL_ANY:
 807	case OP_CB_RECALL_SLOT:
 808	case OP_CB_LAYOUTRECALL:
 809	case OP_CB_NOTIFY_DEVICEID:
 810	case OP_CB_NOTIFY_LOCK:
 811		*op = &callback_ops[op_nr];
 812		break;
 813
 814	case OP_CB_NOTIFY:
 815	case OP_CB_PUSH_DELEG:
 816	case OP_CB_RECALLABLE_OBJ_AVAIL:
 817	case OP_CB_WANTS_CANCELLED:
 818		return htonl(NFS4ERR_NOTSUPP);
 819
 820	default:
 821		return htonl(NFS4ERR_OP_ILLEGAL);
 822	}
 823
 824	return htonl(NFS_OK);
 825}
 826
 827static void nfs4_callback_free_slot(struct nfs4_session *session,
 828		struct nfs4_slot *slot)
 829{
 830	struct nfs4_slot_table *tbl = &session->bc_slot_table;
 831
 832	spin_lock(&tbl->slot_tbl_lock);
 833	/*
 834	 * Let the state manager know callback processing done.
 835	 * A single slot, so highest used slotid is either 0 or -1
 836	 */
 837	nfs4_free_slot(tbl, slot);
 838	spin_unlock(&tbl->slot_tbl_lock);
 839}
 840
 841static void nfs4_cb_free_slot(struct cb_process_state *cps)
 842{
 843	if (cps->slot) {
 844		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
 845		cps->slot = NULL;
 846	}
 847}
 848
 849#else /* CONFIG_NFS_V4_1 */
 850
 851static __be32
 852preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 853{
 854	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 855}
 856
 857static void nfs4_cb_free_slot(struct cb_process_state *cps)
 858{
 859}
 860#endif /* CONFIG_NFS_V4_1 */
 861
 862#ifdef CONFIG_NFS_V4_2
 863static __be32
 864preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 865{
 866	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
 867	if (status != htonl(NFS4ERR_OP_ILLEGAL))
 868		return status;
 869
 870	if (op_nr == OP_CB_OFFLOAD) {
 871		*op = &callback_ops[op_nr];
 872		return htonl(NFS_OK);
 873	} else
 874		return htonl(NFS4ERR_NOTSUPP);
 875	return htonl(NFS4ERR_OP_ILLEGAL);
 876}
 877#else /* CONFIG_NFS_V4_2 */
 878static __be32
 879preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 880{
 881	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 882}
 883#endif /* CONFIG_NFS_V4_2 */
 884
 885static __be32
 886preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 887{
 888	switch (op_nr) {
 889	case OP_CB_GETATTR:
 890	case OP_CB_RECALL:
 891		*op = &callback_ops[op_nr];
 892		break;
 893	default:
 894		return htonl(NFS4ERR_OP_ILLEGAL);
 895	}
 896
 897	return htonl(NFS_OK);
 898}
 899
 900static __be32 process_op(int nop, struct svc_rqst *rqstp,
 901			 struct cb_process_state *cps)
 902{
 903	struct xdr_stream *xdr_out = &rqstp->rq_res_stream;
 904	struct callback_op *op = &callback_ops[0];
 905	unsigned int op_nr;
 906	__be32 status;
 907	long maxlen;
 908	__be32 res;
 909
 910	status = decode_op_hdr(&rqstp->rq_arg_stream, &op_nr);
 911	if (unlikely(status))
 912		return status;
 913
 914	switch (cps->minorversion) {
 915	case 0:
 916		status = preprocess_nfs4_op(op_nr, &op);
 917		break;
 918	case 1:
 919		status = preprocess_nfs41_op(nop, op_nr, &op);
 920		break;
 921	case 2:
 922		status = preprocess_nfs42_op(nop, op_nr, &op);
 923		break;
 924	default:
 925		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 926	}
 927
 928	if (status == htonl(NFS4ERR_OP_ILLEGAL))
 929		op_nr = OP_CB_ILLEGAL;
 930	if (status)
 931		goto encode_hdr;
 932
 933	if (cps->drc_status) {
 934		status = cps->drc_status;
 935		goto encode_hdr;
 936	}
 937
 938	maxlen = xdr_out->end - xdr_out->p;
 939	if (maxlen > 0 && maxlen < PAGE_SIZE) {
 940		status = op->decode_args(rqstp, &rqstp->rq_arg_stream,
 941					 rqstp->rq_argp);
 942		if (likely(status == 0))
 943			status = op->process_op(rqstp->rq_argp, rqstp->rq_resp,
 944						cps);
 945	} else
 946		status = htonl(NFS4ERR_RESOURCE);
 947
 948encode_hdr:
 949	res = encode_op_hdr(xdr_out, op_nr, status);
 950	if (unlikely(res))
 951		return res;
 952	if (op->encode_res != NULL && status == 0)
 953		status = op->encode_res(rqstp, xdr_out, rqstp->rq_resp);
 954	return status;
 955}
 956
 957/*
 958 * Decode, process and encode a COMPOUND
 959 */
 960static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
 961{
 962	struct cb_compound_hdr_arg hdr_arg = { 0 };
 963	struct cb_compound_hdr_res hdr_res = { NULL };
 964	struct cb_process_state cps = {
 965		.drc_status = 0,
 966		.clp = NULL,
 967		.net = SVC_NET(rqstp),
 968	};
 969	unsigned int nops = 0;
 970	__be32 status;
 971
 972	status = decode_compound_hdr_arg(&rqstp->rq_arg_stream, &hdr_arg);
 973	if (status == htonl(NFS4ERR_RESOURCE))
 974		return rpc_garbage_args;
 975
 976	if (hdr_arg.minorversion == 0) {
 977		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
 978		if (!cps.clp) {
 979			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
 980			goto out_invalidcred;
 981		}
 982		if (!check_gss_callback_principal(cps.clp, rqstp)) {
 983			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
 984			nfs_put_client(cps.clp);
 985			goto out_invalidcred;
 986		}
 987		svc_xprt_set_valid(rqstp->rq_xprt);
 988	}
 989
 990	cps.minorversion = hdr_arg.minorversion;
 991	hdr_res.taglen = hdr_arg.taglen;
 992	hdr_res.tag = hdr_arg.tag;
 993	if (encode_compound_hdr_res(&rqstp->rq_res_stream, &hdr_res) != 0) {
 994		if (cps.clp)
 995			nfs_put_client(cps.clp);
 996		return rpc_system_err;
 997	}
 998	while (status == 0 && nops != hdr_arg.nops) {
 999		status = process_op(nops, rqstp, &cps);
1000		nops++;
1001	}
1002
1003	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
1004	* resource error in cb_compound status without returning op */
1005	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
1006		status = htonl(NFS4ERR_RESOURCE);
1007		nops--;
1008	}
1009
1010	if (svc_is_backchannel(rqstp) && cps.clp) {
1011		rqstp->bc_to_initval = cps.clp->cl_rpcclient->cl_timeout->to_initval;
1012		rqstp->bc_to_retries = cps.clp->cl_rpcclient->cl_timeout->to_retries;
1013	}
1014
1015	*hdr_res.status = status;
1016	*hdr_res.nops = htonl(nops);
1017	nfs4_cb_free_slot(&cps);
1018	nfs_put_client(cps.clp);
1019	return rpc_success;
1020
1021out_invalidcred:
1022	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
1023	rqstp->rq_auth_stat = rpc_autherr_badcred;
1024	return rpc_success;
1025}
1026
1027static int
1028nfs_callback_dispatch(struct svc_rqst *rqstp)
1029{
1030	const struct svc_procedure *procp = rqstp->rq_procinfo;
1031
1032	*rqstp->rq_accept_statp = procp->pc_func(rqstp);
1033	return 1;
1034}
1035
1036/*
1037 * Define NFS4 callback COMPOUND ops.
1038 */
1039static struct callback_op callback_ops[] = {
1040	[0] = {
1041		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
1042	},
1043	[OP_CB_GETATTR] = {
1044		.process_op = nfs4_callback_getattr,
1045		.decode_args = decode_getattr_args,
1046		.encode_res = encode_getattr_res,
1047		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1048	},
1049	[OP_CB_RECALL] = {
1050		.process_op = nfs4_callback_recall,
1051		.decode_args = decode_recall_args,
1052		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1053	},
1054#if defined(CONFIG_NFS_V4_1)
1055	[OP_CB_LAYOUTRECALL] = {
1056		.process_op = nfs4_callback_layoutrecall,
1057		.decode_args = decode_layoutrecall_args,
1058		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1059	},
1060	[OP_CB_NOTIFY_DEVICEID] = {
1061		.process_op = nfs4_callback_devicenotify,
1062		.decode_args = decode_devicenotify_args,
1063		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1064	},
1065	[OP_CB_SEQUENCE] = {
1066		.process_op = nfs4_callback_sequence,
1067		.decode_args = decode_cb_sequence_args,
1068		.encode_res = encode_cb_sequence_res,
1069		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1070	},
1071	[OP_CB_RECALL_ANY] = {
1072		.process_op = nfs4_callback_recallany,
1073		.decode_args = decode_recallany_args,
1074		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1075	},
1076	[OP_CB_RECALL_SLOT] = {
1077		.process_op = nfs4_callback_recallslot,
1078		.decode_args = decode_recallslot_args,
1079		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1080	},
1081	[OP_CB_NOTIFY_LOCK] = {
1082		.process_op = nfs4_callback_notify_lock,
1083		.decode_args = decode_notify_lock_args,
1084		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1085	},
1086#endif /* CONFIG_NFS_V4_1 */
1087#ifdef CONFIG_NFS_V4_2
1088	[OP_CB_OFFLOAD] = {
1089		.process_op = nfs4_callback_offload,
1090		.decode_args = decode_offload_args,
1091		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1092	},
1093#endif /* CONFIG_NFS_V4_2 */
1094};
1095
1096/*
1097 * Define NFS4 callback procedures
1098 */
1099static const struct svc_procedure nfs4_callback_procedures1[] = {
1100	[CB_NULL] = {
1101		.pc_func = nfs4_callback_null,
1102		.pc_encode = nfs4_encode_void,
1103		.pc_xdrressize = 1,
1104		.pc_name = "NULL",
1105	},
1106	[CB_COMPOUND] = {
1107		.pc_func = nfs4_callback_compound,
1108		.pc_encode = nfs4_encode_void,
1109		.pc_argsize = 256,
1110		.pc_argzero = 256,
1111		.pc_ressize = 256,
1112		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1113		.pc_name = "COMPOUND",
1114	}
1115};
1116
1117static DEFINE_PER_CPU_ALIGNED(unsigned long,
1118			      nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)]);
1119const struct svc_version nfs4_callback_version1 = {
1120	.vs_vers = 1,
1121	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1122	.vs_proc = nfs4_callback_procedures1,
1123	.vs_count = nfs4_callback_count1,
1124	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1125	.vs_dispatch = nfs_callback_dispatch,
1126	.vs_hidden = true,
1127	.vs_need_cong_ctrl = true,
1128};
1129
1130static DEFINE_PER_CPU_ALIGNED(unsigned long,
1131			      nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)]);
1132const struct svc_version nfs4_callback_version4 = {
1133	.vs_vers = 4,
1134	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1135	.vs_proc = nfs4_callback_procedures1,
1136	.vs_count = nfs4_callback_count4,
1137	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1138	.vs_dispatch = nfs_callback_dispatch,
1139	.vs_hidden = true,
1140	.vs_need_cong_ctrl = true,
1141};