fs/nfs/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
  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
  42 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  43
  44 /* Internal error code */
  45 #define NFS4ERR_RESOURCE_HDR    11050
  46
  47 struct callback_op {
  48         __be32 (*process_op)(void *, void *, struct cb_process_state *);
  49         __be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
  50         __be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
  51                         const void *);
  52         long res_maxsize;
  53 };
  54
  55 static struct callback_op callback_ops[];
  56
  57 static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
  58 {
  59         return htonl(NFS4_OK);
  60 }
  61
  62 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p)
  63 {
  64         return xdr_argsize_check(rqstp, p);
  65 }
  66
  67 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p)
  68 {
  69         return xdr_ressize_check(rqstp, p);
  70 }
  71
  72 static __be32 *read_buf(struct xdr_stream *xdr, size_t nbytes)
  73 {
  74         __be32 *p;
  75
  76         p = xdr_inline_decode(xdr, nbytes);
  77         if (unlikely(p == NULL))
  78                 printk(KERN_WARNING "NFS: NFSv4 callback reply buffer overflowed!\n");
  79         return p;
  80 }
  81
  82 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
  83                 const char **str, size_t maxlen)
  84 {
  85         ssize_t err;
  86
  87         err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
  88         if (err < 0)
  89                 return cpu_to_be32(NFS4ERR_RESOURCE);
  90         *len = err;
  91         return 0;
  92 }
  93
  94 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  95 {
  96         __be32 *p;
  97
  98         p = read_buf(xdr, 4);
  99         if (unlikely(p == NULL))
 100                 return htonl(NFS4ERR_RESOURCE);
 101         fh->size = ntohl(*p);
 102         if (fh->size > NFS4_FHSIZE)
 103                 return htonl(NFS4ERR_BADHANDLE);
 104         p = read_buf(xdr, fh->size);
 105         if (unlikely(p == NULL))
 106                 return htonl(NFS4ERR_RESOURCE);
 107         memcpy(&fh->data[0], p, fh->size);
 108         memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 109         return 0;
 110 }
 111
 112 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 113 {
 114         __be32 *p;
 115         unsigned int attrlen;
 116
 117         p = read_buf(xdr, 4);
 118         if (unlikely(p == NULL))
 119                 return htonl(NFS4ERR_RESOURCE);
 120         attrlen = ntohl(*p);
 121         p = read_buf(xdr, attrlen << 2);
 122         if (unlikely(p == NULL))
 123                 return htonl(NFS4ERR_RESOURCE);
 124         if (likely(attrlen > 0))
 125                 bitmap[0] = ntohl(*p++);
 126         if (attrlen > 1)
 127                 bitmap[1] = ntohl(*p);
 128         return 0;
 129 }
 130
 131 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 132 {
 133         __be32 *p;
 134
 135         p = read_buf(xdr, NFS4_STATEID_SIZE);
 136         if (unlikely(p == NULL))
 137                 return htonl(NFS4ERR_RESOURCE);
 138         memcpy(stateid->data, p, NFS4_STATEID_SIZE);
 139         return 0;
 140 }
 141
 142 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 143 {
 144         stateid->type = NFS4_DELEGATION_STATEID_TYPE;
 145         return decode_stateid(xdr, stateid);
 146 }
 147
 148 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 149 {
 150         __be32 *p;
 151         __be32 status;
 152
 153         status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
 154         if (unlikely(status != 0))
 155                 return status;
 156         p = read_buf(xdr, 12);
 157         if (unlikely(p == NULL))
 158                 return htonl(NFS4ERR_RESOURCE);
 159         hdr->minorversion = ntohl(*p++);
 160         /* Check for minor version support */
 161         if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
 162                 hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
 163         } else {
 164                 pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
 165                         "illegal minor version %u!\n",
 166                         __func__, hdr->minorversion);
 167                 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 168         }
 169         hdr->nops = ntohl(*p);
 170         return 0;
 171 }
 172
 173 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 174 {
 175         __be32 *p;
 176         p = read_buf(xdr, 4);
 177         if (unlikely(p == NULL))
 178                 return htonl(NFS4ERR_RESOURCE_HDR);
 179         *op = ntohl(*p);
 180         return 0;
 181 }
 182
 183 static __be32 decode_getattr_args(struct svc_rqst *rqstp,
 184                 struct xdr_stream *xdr, void *argp)
 185 {
 186         struct cb_getattrargs *args = argp;
 187         __be32 status;
 188
 189         status = decode_fh(xdr, &args->fh);
 190         if (unlikely(status != 0))
 191                 return status;
 192         return decode_bitmap(xdr, args->bitmap);
 193 }
 194
 195 static __be32 decode_recall_args(struct svc_rqst *rqstp,
 196                 struct xdr_stream *xdr, void *argp)
 197 {
 198         struct cb_recallargs *args = argp;
 199         __be32 *p;
 200         __be32 status;
 201
 202         status = decode_delegation_stateid(xdr, &args->stateid);
 203         if (unlikely(status != 0))
 204                 return status;
 205         p = read_buf(xdr, 4);
 206         if (unlikely(p == NULL))
 207                 return htonl(NFS4ERR_RESOURCE);
 208         args->truncate = ntohl(*p);
 209         return decode_fh(xdr, &args->fh);
 210 }
 211
 212 #if defined(CONFIG_NFS_V4_1)
 213 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 214 {
 215         stateid->type = NFS4_LAYOUT_STATEID_TYPE;
 216         return decode_stateid(xdr, stateid);
 217 }
 218
 219 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 220                                        struct xdr_stream *xdr, void *argp)
 221 {
 222         struct cb_layoutrecallargs *args = argp;
 223         __be32 *p;
 224         __be32 status = 0;
 225         uint32_t iomode;
 226
 227         p = read_buf(xdr, 4 * sizeof(uint32_t));
 228         if (unlikely(p == NULL))
 229                 return htonl(NFS4ERR_BADXDR);
 230
 231         args->cbl_layout_type = ntohl(*p++);
 232         /* Depite the spec's xdr, iomode really belongs in the FILE switch,
 233          * as it is unusable and ignored with the other types.
 234          */
 235         iomode = ntohl(*p++);
 236         args->cbl_layoutchanged = ntohl(*p++);
 237         args->cbl_recall_type = ntohl(*p++);
 238
 239         if (args->cbl_recall_type == RETURN_FILE) {
 240                 args->cbl_range.iomode = iomode;
 241                 status = decode_fh(xdr, &args->cbl_fh);
 242                 if (unlikely(status != 0))
 243                         return status;
 244
 245                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 246                 if (unlikely(p == NULL))
 247                         return htonl(NFS4ERR_BADXDR);
 248                 p = xdr_decode_hyper(p, &args->cbl_range.offset);
 249                 p = xdr_decode_hyper(p, &args->cbl_range.length);
 250                 return decode_layout_stateid(xdr, &args->cbl_stateid);
 251         } else if (args->cbl_recall_type == RETURN_FSID) {
 252                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 253                 if (unlikely(p == NULL))
 254                         return htonl(NFS4ERR_BADXDR);
 255                 p = xdr_decode_hyper(p, &args->cbl_fsid.major);
 256                 p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
 257         } else if (args->cbl_recall_type != RETURN_ALL)
 258                 return htonl(NFS4ERR_BADXDR);
 259         return 0;
 260 }
 261
 262 static
 263 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
 264                                 struct xdr_stream *xdr,
 265                                 void *argp)
 266 {
 267         struct cb_devicenotifyargs *args = argp;
 268         __be32 *p;
 269         __be32 status = 0;
 270         u32 tmp;
 271         int n, i;
 272         args->ndevs = 0;
 273
 274         /* Num of device notifications */
 275         p = read_buf(xdr, sizeof(uint32_t));
 276         if (unlikely(p == NULL)) {
 277                 status = htonl(NFS4ERR_BADXDR);
 278                 goto out;
 279         }
 280         n = ntohl(*p++);
 281         if (n <= 0)
 282                 goto out;
 283         if (n > ULONG_MAX / sizeof(*args->devs)) {
 284                 status = htonl(NFS4ERR_BADXDR);
 285                 goto out;
 286         }
 287
 288         args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
 289         if (!args->devs) {
 290                 status = htonl(NFS4ERR_DELAY);
 291                 goto out;
 292         }
 293
 294         /* Decode each dev notification */
 295         for (i = 0; i < n; i++) {
 296                 struct cb_devicenotifyitem *dev = &args->devs[i];
 297
 298                 p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
 299                 if (unlikely(p == NULL)) {
 300                         status = htonl(NFS4ERR_BADXDR);
 301                         goto err;
 302                 }
 303
 304                 tmp = ntohl(*p++);      /* bitmap size */
 305                 if (tmp != 1) {
 306                         status = htonl(NFS4ERR_INVAL);
 307                         goto err;
 308                 }
 309                 dev->cbd_notify_type = ntohl(*p++);
 310                 if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
 311                     dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
 312                         status = htonl(NFS4ERR_INVAL);
 313                         goto err;
 314                 }
 315
 316                 tmp = ntohl(*p++);      /* opaque size */
 317                 if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
 318                      (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
 319                     ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
 320                      (tmp != NFS4_DEVICEID4_SIZE + 4))) {
 321                         status = htonl(NFS4ERR_INVAL);
 322                         goto err;
 323                 }
 324                 dev->cbd_layout_type = ntohl(*p++);
 325                 memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
 326                 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 327
 328                 if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
 329                         p = read_buf(xdr, sizeof(uint32_t));
 330                         if (unlikely(p == NULL)) {
 331                                 status = htonl(NFS4ERR_BADXDR);
 332                                 goto err;
 333                         }
 334                         dev->cbd_immediate = ntohl(*p++);
 335                 } else {
 336                         dev->cbd_immediate = 0;
 337                 }
 338
 339                 args->ndevs++;
 340
 341                 dprintk("%s: type %d layout 0x%x immediate %d\n",
 342                         __func__, dev->cbd_notify_type, dev->cbd_layout_type,
 343                         dev->cbd_immediate);
 344         }
 345 out:
 346         dprintk("%s: status %d ndevs %d\n",
 347                 __func__, ntohl(status), args->ndevs);
 348         return status;
 349 err:
 350         kfree(args->devs);
 351         goto out;
 352 }
 353
 354 static __be32 decode_sessionid(struct xdr_stream *xdr,
 355                                  struct nfs4_sessionid *sid)
 356 {
 357         __be32 *p;
 358
 359         p = read_buf(xdr, NFS4_MAX_SESSIONID_LEN);
 360         if (unlikely(p == NULL))
 361                 return htonl(NFS4ERR_RESOURCE);
 362
 363         memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
 364         return 0;
 365 }
 366
 367 static __be32 decode_rc_list(struct xdr_stream *xdr,
 368                                struct referring_call_list *rc_list)
 369 {
 370         __be32 *p;
 371         int i;
 372         __be32 status;
 373
 374         status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 375         if (status)
 376                 goto out;
 377
 378         status = htonl(NFS4ERR_RESOURCE);
 379         p = read_buf(xdr, sizeof(uint32_t));
 380         if (unlikely(p == NULL))
 381                 goto out;
 382
 383         rc_list->rcl_nrefcalls = ntohl(*p++);
 384         if (rc_list->rcl_nrefcalls) {
 385                 p = read_buf(xdr,
 386                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 387                 if (unlikely(p == NULL))
 388                         goto out;
 389                 rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
 390                                                 sizeof(*rc_list->rcl_refcalls),
 391                                                 GFP_KERNEL);
 392                 if (unlikely(rc_list->rcl_refcalls == NULL))
 393                         goto out;
 394                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 395                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 396                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 397                 }
 398         }
 399         status = 0;
 400
 401 out:
 402         return status;
 403 }
 404
 405 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 406                                         struct xdr_stream *xdr,
 407                                         void *argp)
 408 {
 409         struct cb_sequenceargs *args = argp;
 410         __be32 *p;
 411         int i;
 412         __be32 status;
 413
 414         status = decode_sessionid(xdr, &args->csa_sessionid);
 415         if (status)
 416                 return status;
 417
 418         p = read_buf(xdr, 5 * sizeof(uint32_t));
 419         if (unlikely(p == NULL))
 420                 return htonl(NFS4ERR_RESOURCE);
 421
 422         args->csa_addr = svc_addr(rqstp);
 423         args->csa_sequenceid = ntohl(*p++);
 424         args->csa_slotid = ntohl(*p++);
 425         args->csa_highestslotid = ntohl(*p++);
 426         args->csa_cachethis = ntohl(*p++);
 427         args->csa_nrclists = ntohl(*p++);
 428         args->csa_rclists = NULL;
 429         if (args->csa_nrclists) {
 430                 args->csa_rclists = kmalloc_array(args->csa_nrclists,
 431                                                   sizeof(*args->csa_rclists),
 432                                                   GFP_KERNEL);
 433                 if (unlikely(args->csa_rclists == NULL))
 434                         return htonl(NFS4ERR_RESOURCE);
 435
 436                 for (i = 0; i < args->csa_nrclists; i++) {
 437                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 438                         if (status) {
 439                                 args->csa_nrclists = i;
 440                                 goto out_free;
 441                         }
 442                 }
 443         }
 444         return 0;
 445
 446 out_free:
 447         for (i = 0; i < args->csa_nrclists; i++)
 448                 kfree(args->csa_rclists[i].rcl_refcalls);
 449         kfree(args->csa_rclists);
 450         return status;
 451 }
 452
 453 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 454                                       struct xdr_stream *xdr,
 455                                       void *argp)
 456 {
 457         struct cb_recallanyargs *args = argp;
 458         uint32_t bitmap[2];
 459         __be32 *p, status;
 460
 461         p = read_buf(xdr, 4);
 462         if (unlikely(p == NULL))
 463                 return htonl(NFS4ERR_BADXDR);
 464         args->craa_objs_to_keep = ntohl(*p++);
 465         status = decode_bitmap(xdr, bitmap);
 466         if (unlikely(status))
 467                 return status;
 468         args->craa_type_mask = bitmap[0];
 469
 470         return 0;
 471 }
 472
 473 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 474                                         struct xdr_stream *xdr,
 475                                         void *argp)
 476 {
 477         struct cb_recallslotargs *args = argp;
 478         __be32 *p;
 479
 480         p = read_buf(xdr, 4);
 481         if (unlikely(p == NULL))
 482                 return htonl(NFS4ERR_BADXDR);
 483         args->crsa_target_highest_slotid = ntohl(*p++);
 484         return 0;
 485 }
 486
 487 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
 488 {
 489         __be32          *p;
 490         unsigned int    len;
 491
 492         p = read_buf(xdr, 12);
 493         if (unlikely(p == NULL))
 494                 return htonl(NFS4ERR_BADXDR);
 495
 496         p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
 497         len = be32_to_cpu(*p);
 498
 499         p = read_buf(xdr, len);
 500         if (unlikely(p == NULL))
 501                 return htonl(NFS4ERR_BADXDR);
 502
 503         /* Only try to decode if the length is right */
 504         if (len == 20) {
 505                 p += 2; /* skip "lock id:" */
 506                 args->cbnl_owner.s_dev = be32_to_cpu(*p++);
 507                 xdr_decode_hyper(p, &args->cbnl_owner.id);
 508                 args->cbnl_valid = true;
 509         } else {
 510                 args->cbnl_owner.s_dev = 0;
 511                 args->cbnl_owner.id = 0;
 512                 args->cbnl_valid = false;
 513         }
 514         return 0;
 515 }
 516
 517 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
 518                 struct xdr_stream *xdr, void *argp)
 519 {
 520         struct cb_notify_lock_args *args = argp;
 521         __be32 status;
 522
 523         status = decode_fh(xdr, &args->cbnl_fh);
 524         if (unlikely(status != 0))
 525                 return status;
 526         return decode_lockowner(xdr, args);
 527 }
 528
 529 #endif /* CONFIG_NFS_V4_1 */
 530
 531 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 532 {
 533         if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
 534                 return cpu_to_be32(NFS4ERR_RESOURCE);
 535         return 0;
 536 }
 537
 538 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
 539 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
 540 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
 541 {
 542         __be32 bm[2];
 543         __be32 *p;
 544
 545         bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
 546         bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
 547         if (bm[1] != 0) {
 548                 p = xdr_reserve_space(xdr, 16);
 549                 if (unlikely(p == NULL))
 550                         return htonl(NFS4ERR_RESOURCE);
 551                 *p++ = htonl(2);
 552                 *p++ = bm[0];
 553                 *p++ = bm[1];
 554         } else if (bm[0] != 0) {
 555                 p = xdr_reserve_space(xdr, 12);
 556                 if (unlikely(p == NULL))
 557                         return htonl(NFS4ERR_RESOURCE);
 558                 *p++ = htonl(1);
 559                 *p++ = bm[0];
 560         } else {
 561                 p = xdr_reserve_space(xdr, 8);
 562                 if (unlikely(p == NULL))
 563                         return htonl(NFS4ERR_RESOURCE);
 564                 *p++ = htonl(0);
 565         }
 566         *savep = p;
 567         return 0;
 568 }
 569
 570 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 571 {
 572         __be32 *p;
 573
 574         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 575                 return 0;
 576         p = xdr_reserve_space(xdr, 8);
 577         if (unlikely(!p))
 578                 return htonl(NFS4ERR_RESOURCE);
 579         p = xdr_encode_hyper(p, change);
 580         return 0;
 581 }
 582
 583 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 584 {
 585         __be32 *p;
 586
 587         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 588                 return 0;
 589         p = xdr_reserve_space(xdr, 8);
 590         if (unlikely(!p))
 591                 return htonl(NFS4ERR_RESOURCE);
 592         p = xdr_encode_hyper(p, size);
 593         return 0;
 594 }
 595
 596 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
 597 {
 598         __be32 *p;
 599
 600         p = xdr_reserve_space(xdr, 12);
 601         if (unlikely(!p))
 602                 return htonl(NFS4ERR_RESOURCE);
 603         p = xdr_encode_hyper(p, time->tv_sec);
 604         *p = htonl(time->tv_nsec);
 605         return 0;
 606 }
 607
 608 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 609 {
 610         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 611                 return 0;
 612         return encode_attr_time(xdr,time);
 613 }
 614
 615 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 616 {
 617         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 618                 return 0;
 619         return encode_attr_time(xdr,time);
 620 }
 621
 622 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 623 {
 624         __be32 status;
 625
 626         hdr->status = xdr_reserve_space(xdr, 4);
 627         if (unlikely(hdr->status == NULL))
 628                 return htonl(NFS4ERR_RESOURCE);
 629         status = encode_string(xdr, hdr->taglen, hdr->tag);
 630         if (unlikely(status != 0))
 631                 return status;
 632         hdr->nops = xdr_reserve_space(xdr, 4);
 633         if (unlikely(hdr->nops == NULL))
 634                 return htonl(NFS4ERR_RESOURCE);
 635         return 0;
 636 }
 637
 638 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 639 {
 640         __be32 *p;
 641
 642         p = xdr_reserve_space(xdr, 8);
 643         if (unlikely(p == NULL))
 644                 return htonl(NFS4ERR_RESOURCE_HDR);
 645         *p++ = htonl(op);
 646         *p = res;
 647         return 0;
 648 }
 649
 650 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 651                 const void *resp)
 652 {
 653         const struct cb_getattrres *res = resp;
 654         __be32 *savep = NULL;
 655         __be32 status = res->status;
 656
 657         if (unlikely(status != 0))
 658                 goto out;
 659         status = encode_attr_bitmap(xdr, res->bitmap, &savep);
 660         if (unlikely(status != 0))
 661                 goto out;
 662         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 663         if (unlikely(status != 0))
 664                 goto out;
 665         status = encode_attr_size(xdr, res->bitmap, res->size);
 666         if (unlikely(status != 0))
 667                 goto out;
 668         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 669         if (unlikely(status != 0))
 670                 goto out;
 671         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 672         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 673 out:
 674         return status;
 675 }
 676
 677 #if defined(CONFIG_NFS_V4_1)
 678
 679 static __be32 encode_sessionid(struct xdr_stream *xdr,
 680                                  const struct nfs4_sessionid *sid)
 681 {
 682         __be32 *p;
 683
 684         p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
 685         if (unlikely(p == NULL))
 686                 return htonl(NFS4ERR_RESOURCE);
 687
 688         memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
 689         return 0;
 690 }
 691
 692 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 693                                        struct xdr_stream *xdr,
 694                                        const void *resp)
 695 {
 696         const struct cb_sequenceres *res = resp;
 697         __be32 *p;
 698         __be32 status = res->csr_status;
 699
 700         if (unlikely(status != 0))
 701                 return status;
 702
 703         status = encode_sessionid(xdr, &res->csr_sessionid);
 704         if (status)
 705                 return status;
 706
 707         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 708         if (unlikely(p == NULL))
 709                 return htonl(NFS4ERR_RESOURCE);
 710
 711         *p++ = htonl(res->csr_sequenceid);
 712         *p++ = htonl(res->csr_slotid);
 713         *p++ = htonl(res->csr_highestslotid);
 714         *p++ = htonl(res->csr_target_highestslotid);
 715         return 0;
 716 }
 717
 718 static __be32
 719 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 720 {
 721         if (op_nr == OP_CB_SEQUENCE) {
 722                 if (nop != 0)
 723                         return htonl(NFS4ERR_SEQUENCE_POS);
 724         } else {
 725                 if (nop == 0)
 726                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 727         }
 728
 729         switch (op_nr) {
 730         case OP_CB_GETATTR:
 731         case OP_CB_RECALL:
 732         case OP_CB_SEQUENCE:
 733         case OP_CB_RECALL_ANY:
 734         case OP_CB_RECALL_SLOT:
 735         case OP_CB_LAYOUTRECALL:
 736         case OP_CB_NOTIFY_DEVICEID:
 737         case OP_CB_NOTIFY_LOCK:
 738                 *op = &callback_ops[op_nr];
 739                 break;
 740
 741         case OP_CB_NOTIFY:
 742         case OP_CB_PUSH_DELEG:
 743         case OP_CB_RECALLABLE_OBJ_AVAIL:
 744         case OP_CB_WANTS_CANCELLED:
 745                 return htonl(NFS4ERR_NOTSUPP);
 746
 747         default:
 748                 return htonl(NFS4ERR_OP_ILLEGAL);
 749         }
 750
 751         return htonl(NFS_OK);
 752 }
 753
 754 static void nfs4_callback_free_slot(struct nfs4_session *session,
 755                 struct nfs4_slot *slot)
 756 {
 757         struct nfs4_slot_table *tbl = &session->bc_slot_table;
 758
 759         spin_lock(&tbl->slot_tbl_lock);
 760         /*
 761          * Let the state manager know callback processing done.
 762          * A single slot, so highest used slotid is either 0 or -1
 763          */
 764         nfs4_free_slot(tbl, slot);
 765         spin_unlock(&tbl->slot_tbl_lock);
 766 }
 767
 768 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 769 {
 770         if (cps->slot) {
 771                 nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
 772                 cps->slot = NULL;
 773         }
 774 }
 775
 776 #else /* CONFIG_NFS_V4_1 */
 777
 778 static __be32
 779 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 780 {
 781         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 782 }
 783
 784 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 785 {
 786 }
 787 #endif /* CONFIG_NFS_V4_1 */
 788
 789 #ifdef CONFIG_NFS_V4_2
 790 static __be32
 791 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 792 {
 793         __be32 status = preprocess_nfs41_op(nop, op_nr, op);
 794         if (status != htonl(NFS4ERR_OP_ILLEGAL))
 795                 return status;
 796
 797         if (op_nr == OP_CB_OFFLOAD)
 798                 return htonl(NFS4ERR_NOTSUPP);
 799         return htonl(NFS4ERR_OP_ILLEGAL);
 800 }
 801 #else /* CONFIG_NFS_V4_2 */
 802 static __be32
 803 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 804 {
 805         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 806 }
 807 #endif /* CONFIG_NFS_V4_2 */
 808
 809 static __be32
 810 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 811 {
 812         switch (op_nr) {
 813         case OP_CB_GETATTR:
 814         case OP_CB_RECALL:
 815                 *op = &callback_ops[op_nr];
 816                 break;
 817         default:
 818                 return htonl(NFS4ERR_OP_ILLEGAL);
 819         }
 820
 821         return htonl(NFS_OK);
 822 }
 823
 824 static __be32 process_op(int nop, struct svc_rqst *rqstp,
 825                 struct xdr_stream *xdr_in, void *argp,
 826                 struct xdr_stream *xdr_out, void *resp,
 827                 struct cb_process_state *cps)
 828 {
 829         struct callback_op *op = &callback_ops[0];
 830         unsigned int op_nr;
 831         __be32 status;
 832         long maxlen;
 833         __be32 res;
 834
 835         status = decode_op_hdr(xdr_in, &op_nr);
 836         if (unlikely(status))
 837                 return status;
 838
 839         switch (cps->minorversion) {
 840         case 0:
 841                 status = preprocess_nfs4_op(op_nr, &op);
 842                 break;
 843         case 1:
 844                 status = preprocess_nfs41_op(nop, op_nr, &op);
 845                 break;
 846         case 2:
 847                 status = preprocess_nfs42_op(nop, op_nr, &op);
 848                 break;
 849         default:
 850                 status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 851         }
 852
 853         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 854                 op_nr = OP_CB_ILLEGAL;
 855         if (status)
 856                 goto encode_hdr;
 857
 858         if (cps->drc_status) {
 859                 status = cps->drc_status;
 860                 goto encode_hdr;
 861         }
 862
 863         maxlen = xdr_out->end - xdr_out->p;
 864         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 865                 status = op->decode_args(rqstp, xdr_in, argp);
 866                 if (likely(status == 0))
 867                         status = op->process_op(argp, resp, cps);
 868         } else
 869                 status = htonl(NFS4ERR_RESOURCE);
 870
 871 encode_hdr:
 872         res = encode_op_hdr(xdr_out, op_nr, status);
 873         if (unlikely(res))
 874                 return res;
 875         if (op->encode_res != NULL && status == 0)
 876                 status = op->encode_res(rqstp, xdr_out, resp);
 877         return status;
 878 }
 879
 880 /*
 881  * Decode, process and encode a COMPOUND
 882  */
 883 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
 884 {
 885         struct cb_compound_hdr_arg hdr_arg = { 0 };
 886         struct cb_compound_hdr_res hdr_res = { NULL };
 887         struct xdr_stream xdr_in, xdr_out;
 888         __be32 *p, status;
 889         struct cb_process_state cps = {
 890                 .drc_status = 0,
 891                 .clp = NULL,
 892                 .net = SVC_NET(rqstp),
 893         };
 894         unsigned int nops = 0;
 895
 896         xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
 897
 898         p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
 899         xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 900
 901         status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
 902         if (status == htonl(NFS4ERR_RESOURCE))
 903                 return rpc_garbage_args;
 904
 905         if (hdr_arg.minorversion == 0) {
 906                 cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
 907                 if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp)) {
 908                         if (cps.clp)
 909                                 nfs_put_client(cps.clp);
 910                         goto out_invalidcred;
 911                 }
 912         }
 913
 914         cps.minorversion = hdr_arg.minorversion;
 915         hdr_res.taglen = hdr_arg.taglen;
 916         hdr_res.tag = hdr_arg.tag;
 917         if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0) {
 918                 if (cps.clp)
 919                         nfs_put_client(cps.clp);
 920                 return rpc_system_err;
 921         }
 922         while (status == 0 && nops != hdr_arg.nops) {
 923                 status = process_op(nops, rqstp, &xdr_in,
 924                                     rqstp->rq_argp, &xdr_out, rqstp->rq_resp,
 925                                     &cps);
 926                 nops++;
 927         }
 928
 929         /* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
 930         * resource error in cb_compound status without returning op */
 931         if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
 932                 status = htonl(NFS4ERR_RESOURCE);
 933                 nops--;
 934         }
 935
 936         *hdr_res.status = status;
 937         *hdr_res.nops = htonl(nops);
 938         nfs4_cb_free_slot(&cps);
 939         nfs_put_client(cps.clp);
 940         return rpc_success;
 941
 942 out_invalidcred:
 943         pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
 944         return rpc_autherr_badcred;
 945 }
 946
 947 /*
 948  * Define NFS4 callback COMPOUND ops.
 949  */
 950 static struct callback_op callback_ops[] = {
 951         [0] = {
 952                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
 953         },
 954         [OP_CB_GETATTR] = {
 955                 .process_op = nfs4_callback_getattr,
 956                 .decode_args = decode_getattr_args,
 957                 .encode_res = encode_getattr_res,
 958                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
 959         },
 960         [OP_CB_RECALL] = {
 961                 .process_op = nfs4_callback_recall,
 962                 .decode_args = decode_recall_args,
 963                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
 964         },
 965 #if defined(CONFIG_NFS_V4_1)
 966         [OP_CB_LAYOUTRECALL] = {
 967                 .process_op = nfs4_callback_layoutrecall,
 968                 .decode_args = decode_layoutrecall_args,
 969                 .res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
 970         },
 971         [OP_CB_NOTIFY_DEVICEID] = {
 972                 .process_op = nfs4_callback_devicenotify,
 973                 .decode_args = decode_devicenotify_args,
 974                 .res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
 975         },
 976         [OP_CB_SEQUENCE] = {
 977                 .process_op = nfs4_callback_sequence,
 978                 .decode_args = decode_cb_sequence_args,
 979                 .encode_res = encode_cb_sequence_res,
 980                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
 981         },
 982         [OP_CB_RECALL_ANY] = {
 983                 .process_op = nfs4_callback_recallany,
 984                 .decode_args = decode_recallany_args,
 985                 .res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
 986         },
 987         [OP_CB_RECALL_SLOT] = {
 988                 .process_op = nfs4_callback_recallslot,
 989                 .decode_args = decode_recallslot_args,
 990                 .res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
 991         },
 992         [OP_CB_NOTIFY_LOCK] = {
 993                 .process_op = nfs4_callback_notify_lock,
 994                 .decode_args = decode_notify_lock_args,
 995                 .res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
 996         },
 997 #endif /* CONFIG_NFS_V4_1 */
 998 };
 999
1000 /*
1001  * Define NFS4 callback procedures
1002  */
1003 static const struct svc_procedure nfs4_callback_procedures1[] = {
1004         [CB_NULL] = {
1005                 .pc_func = nfs4_callback_null,
1006                 .pc_decode = nfs4_decode_void,
1007                 .pc_encode = nfs4_encode_void,
1008                 .pc_xdrressize = 1,
1009         },
1010         [CB_COMPOUND] = {
1011                 .pc_func = nfs4_callback_compound,
1012                 .pc_encode = nfs4_encode_void,
1013                 .pc_argsize = 256,
1014                 .pc_ressize = 256,
1015                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1016         }
1017 };
1018
1019 static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
1020 const struct svc_version nfs4_callback_version1 = {
1021         .vs_vers = 1,
1022         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1023         .vs_proc = nfs4_callback_procedures1,
1024         .vs_count = nfs4_callback_count1,
1025         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1026         .vs_dispatch = NULL,
1027         .vs_hidden = true,
1028         .vs_need_cong_ctrl = true,
1029 };
1030
1031 static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
1032 const struct svc_version nfs4_callback_version4 = {
1033         .vs_vers = 4,
1034         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1035         .vs_proc = nfs4_callback_procedures1,
1036         .vs_count = nfs4_callback_count4,
1037         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1038         .vs_dispatch = NULL,
1039         .vs_hidden = true,
1040         .vs_need_cong_ctrl = true,
1041 };