fs/nfs/callback_xdr.c

   1 /*
   2  * linux/fs/nfs/callback_xdr.c
   3  *
   4  * Copyright (C) 2004 Trond Myklebust
   5  *
   6  * NFSv4 callback encode/decode procedures
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/sunrpc/svc.h>
  10 #include <linux/nfs4.h>
  11 #include <linux/nfs_fs.h>
  12 #include <linux/ratelimit.h>
  13 #include <linux/printk.h>
  14 #include <linux/slab.h>
  15 #include <linux/sunrpc/bc_xprt.h>
  16 #include "nfs4_fs.h"
  17 #include "callback.h"
  18 #include "internal.h"
  19 #include "nfs4session.h"
  20
  21 #define CB_OP_TAGLEN_MAXSZ              (512)
  22 #define CB_OP_HDR_RES_MAXSZ             (2 * 4) // opcode, status
  23 #define CB_OP_GETATTR_BITMAP_MAXSZ      (4 * 4) // bitmap length, 3 bitmaps
  24 #define CB_OP_GETATTR_RES_MAXSZ         (CB_OP_HDR_RES_MAXSZ + \
  25                                          CB_OP_GETATTR_BITMAP_MAXSZ + \
  26                                          /* change, size, ctime, mtime */\
  27                                          (2 + 2 + 3 + 3) * 4)
  28 #define CB_OP_RECALL_RES_MAXSZ          (CB_OP_HDR_RES_MAXSZ)
  29
  30 #if defined(CONFIG_NFS_V4_1)
  31 #define CB_OP_LAYOUTRECALL_RES_MAXSZ    (CB_OP_HDR_RES_MAXSZ)
  32 #define CB_OP_DEVICENOTIFY_RES_MAXSZ    (CB_OP_HDR_RES_MAXSZ)
  33 #define CB_OP_SEQUENCE_RES_MAXSZ        (CB_OP_HDR_RES_MAXSZ + \
  34                                          NFS4_MAX_SESSIONID_LEN + \
  35                                          (1 + 3) * 4) // seqid, 3 slotids
  36 #define CB_OP_RECALLANY_RES_MAXSZ       (CB_OP_HDR_RES_MAXSZ)
  37 #define CB_OP_RECALLSLOT_RES_MAXSZ      (CB_OP_HDR_RES_MAXSZ)
  38 #define CB_OP_NOTIFY_LOCK_RES_MAXSZ     (CB_OP_HDR_RES_MAXSZ)
  39 #endif /* CONFIG_NFS_V4_1 */
  40
  41 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  42
  43 /* Internal error code */
  44 #define NFS4ERR_RESOURCE_HDR    11050
  45
  46 struct callback_op {
  47         __be32 (*process_op)(void *, void *, struct cb_process_state *);
  48         __be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
  49         __be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
  50                         const void *);
  51         long res_maxsize;
  52 };
  53
  54 static struct callback_op callback_ops[];
  55
  56 static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
  57 {
  58         return htonl(NFS4_OK);
  59 }
  60
  61 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p)
  62 {
  63         return xdr_argsize_check(rqstp, p);
  64 }
  65
  66 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p)
  67 {
  68         return xdr_ressize_check(rqstp, p);
  69 }
  70
  71 static __be32 *read_buf(struct xdr_stream *xdr, size_t nbytes)
  72 {
  73         __be32 *p;
  74
  75         p = xdr_inline_decode(xdr, nbytes);
  76         if (unlikely(p == NULL))
  77                 printk(KERN_WARNING "NFS: NFSv4 callback reply buffer overflowed!\n");
  78         return p;
  79 }
  80
  81 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
  82                 const char **str, size_t maxlen)
  83 {
  84         ssize_t err;
  85
  86         err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
  87         if (err < 0)
  88                 return cpu_to_be32(NFS4ERR_RESOURCE);
  89         *len = err;
  90         return 0;
  91 }
  92
  93 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  94 {
  95         __be32 *p;
  96
  97         p = read_buf(xdr, 4);
  98         if (unlikely(p == NULL))
  99                 return htonl(NFS4ERR_RESOURCE);
 100         fh->size = ntohl(*p);
 101         if (fh->size > NFS4_FHSIZE)
 102                 return htonl(NFS4ERR_BADHANDLE);
 103         p = read_buf(xdr, fh->size);
 104         if (unlikely(p == NULL))
 105                 return htonl(NFS4ERR_RESOURCE);
 106         memcpy(&fh->data[0], p, fh->size);
 107         memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 108         return 0;
 109 }
 110
 111 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 112 {
 113         __be32 *p;
 114         unsigned int attrlen;
 115
 116         p = read_buf(xdr, 4);
 117         if (unlikely(p == NULL))
 118                 return htonl(NFS4ERR_RESOURCE);
 119         attrlen = ntohl(*p);
 120         p = read_buf(xdr, attrlen << 2);
 121         if (unlikely(p == NULL))
 122                 return htonl(NFS4ERR_RESOURCE);
 123         if (likely(attrlen > 0))
 124                 bitmap[0] = ntohl(*p++);
 125         if (attrlen > 1)
 126                 bitmap[1] = ntohl(*p);
 127         return 0;
 128 }
 129
 130 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 131 {
 132         __be32 *p;
 133
 134         p = read_buf(xdr, NFS4_STATEID_SIZE);
 135         if (unlikely(p == NULL))
 136                 return htonl(NFS4ERR_RESOURCE);
 137         memcpy(stateid->data, p, NFS4_STATEID_SIZE);
 138         return 0;
 139 }
 140
 141 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 142 {
 143         stateid->type = NFS4_DELEGATION_STATEID_TYPE;
 144         return decode_stateid(xdr, stateid);
 145 }
 146
 147 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 148 {
 149         __be32 *p;
 150         __be32 status;
 151
 152         status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
 153         if (unlikely(status != 0))
 154                 return status;
 155         p = read_buf(xdr, 12);
 156         if (unlikely(p == NULL))
 157                 return htonl(NFS4ERR_RESOURCE);
 158         hdr->minorversion = ntohl(*p++);
 159         /* Check for minor version support */
 160         if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
 161                 hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
 162         } else {
 163                 pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
 164                         "illegal minor version %u!\n",
 165                         __func__, hdr->minorversion);
 166                 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 167         }
 168         hdr->nops = ntohl(*p);
 169         return 0;
 170 }
 171
 172 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 173 {
 174         __be32 *p;
 175         p = read_buf(xdr, 4);
 176         if (unlikely(p == NULL))
 177                 return htonl(NFS4ERR_RESOURCE_HDR);
 178         *op = ntohl(*p);
 179         return 0;
 180 }
 181
 182 static __be32 decode_getattr_args(struct svc_rqst *rqstp,
 183                 struct xdr_stream *xdr, void *argp)
 184 {
 185         struct cb_getattrargs *args = argp;
 186         __be32 status;
 187
 188         status = decode_fh(xdr, &args->fh);
 189         if (unlikely(status != 0))
 190                 return status;
 191         return decode_bitmap(xdr, args->bitmap);
 192 }
 193
 194 static __be32 decode_recall_args(struct svc_rqst *rqstp,
 195                 struct xdr_stream *xdr, void *argp)
 196 {
 197         struct cb_recallargs *args = argp;
 198         __be32 *p;
 199         __be32 status;
 200
 201         status = decode_delegation_stateid(xdr, &args->stateid);
 202         if (unlikely(status != 0))
 203                 return status;
 204         p = read_buf(xdr, 4);
 205         if (unlikely(p == NULL))
 206                 return htonl(NFS4ERR_RESOURCE);
 207         args->truncate = ntohl(*p);
 208         return decode_fh(xdr, &args->fh);
 209 }
 210
 211 #if defined(CONFIG_NFS_V4_1)
 212 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 213 {
 214         stateid->type = NFS4_LAYOUT_STATEID_TYPE;
 215         return decode_stateid(xdr, stateid);
 216 }
 217
 218 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 219                                        struct xdr_stream *xdr, void *argp)
 220 {
 221         struct cb_layoutrecallargs *args = argp;
 222         __be32 *p;
 223         __be32 status = 0;
 224         uint32_t iomode;
 225
 226         p = read_buf(xdr, 4 * sizeof(uint32_t));
 227         if (unlikely(p == NULL))
 228                 return htonl(NFS4ERR_BADXDR);
 229
 230         args->cbl_layout_type = ntohl(*p++);
 231         /* Depite the spec's xdr, iomode really belongs in the FILE switch,
 232          * as it is unusable and ignored with the other types.
 233          */
 234         iomode = ntohl(*p++);
 235         args->cbl_layoutchanged = ntohl(*p++);
 236         args->cbl_recall_type = ntohl(*p++);
 237
 238         if (args->cbl_recall_type == RETURN_FILE) {
 239                 args->cbl_range.iomode = iomode;
 240                 status = decode_fh(xdr, &args->cbl_fh);
 241                 if (unlikely(status != 0))
 242                         return status;
 243
 244                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 245                 if (unlikely(p == NULL))
 246                         return htonl(NFS4ERR_BADXDR);
 247                 p = xdr_decode_hyper(p, &args->cbl_range.offset);
 248                 p = xdr_decode_hyper(p, &args->cbl_range.length);
 249                 return decode_layout_stateid(xdr, &args->cbl_stateid);
 250         } else if (args->cbl_recall_type == RETURN_FSID) {
 251                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 252                 if (unlikely(p == NULL))
 253                         return htonl(NFS4ERR_BADXDR);
 254                 p = xdr_decode_hyper(p, &args->cbl_fsid.major);
 255                 p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
 256         } else if (args->cbl_recall_type != RETURN_ALL)
 257                 return htonl(NFS4ERR_BADXDR);
 258         return 0;
 259 }
 260
 261 static
 262 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
 263                                 struct xdr_stream *xdr,
 264                                 void *argp)
 265 {
 266         struct cb_devicenotifyargs *args = argp;
 267         __be32 *p;
 268         __be32 status = 0;
 269         u32 tmp;
 270         int n, i;
 271         args->ndevs = 0;
 272
 273         /* Num of device notifications */
 274         p = read_buf(xdr, sizeof(uint32_t));
 275         if (unlikely(p == NULL)) {
 276                 status = htonl(NFS4ERR_BADXDR);
 277                 goto out;
 278         }
 279         n = ntohl(*p++);
 280         if (n <= 0)
 281                 goto out;
 282         if (n > ULONG_MAX / sizeof(*args->devs)) {
 283                 status = htonl(NFS4ERR_BADXDR);
 284                 goto out;
 285         }
 286
 287         args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
 288         if (!args->devs) {
 289                 status = htonl(NFS4ERR_DELAY);
 290                 goto out;
 291         }
 292
 293         /* Decode each dev notification */
 294         for (i = 0; i < n; i++) {
 295                 struct cb_devicenotifyitem *dev = &args->devs[i];
 296
 297                 p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
 298                 if (unlikely(p == NULL)) {
 299                         status = htonl(NFS4ERR_BADXDR);
 300                         goto err;
 301                 }
 302
 303                 tmp = ntohl(*p++);      /* bitmap size */
 304                 if (tmp != 1) {
 305                         status = htonl(NFS4ERR_INVAL);
 306                         goto err;
 307                 }
 308                 dev->cbd_notify_type = ntohl(*p++);
 309                 if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
 310                     dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
 311                         status = htonl(NFS4ERR_INVAL);
 312                         goto err;
 313                 }
 314
 315                 tmp = ntohl(*p++);      /* opaque size */
 316                 if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
 317                      (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
 318                     ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
 319                      (tmp != NFS4_DEVICEID4_SIZE + 4))) {
 320                         status = htonl(NFS4ERR_INVAL);
 321                         goto err;
 322                 }
 323                 dev->cbd_layout_type = ntohl(*p++);
 324                 memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
 325                 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 326
 327                 if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
 328                         p = read_buf(xdr, sizeof(uint32_t));
 329                         if (unlikely(p == NULL)) {
 330                                 status = htonl(NFS4ERR_BADXDR);
 331                                 goto err;
 332                         }
 333                         dev->cbd_immediate = ntohl(*p++);
 334                 } else {
 335                         dev->cbd_immediate = 0;
 336                 }
 337
 338                 args->ndevs++;
 339
 340                 dprintk("%s: type %d layout 0x%x immediate %d\n",
 341                         __func__, dev->cbd_notify_type, dev->cbd_layout_type,
 342                         dev->cbd_immediate);
 343         }
 344 out:
 345         dprintk("%s: status %d ndevs %d\n",
 346                 __func__, ntohl(status), args->ndevs);
 347         return status;
 348 err:
 349         kfree(args->devs);
 350         goto out;
 351 }
 352
 353 static __be32 decode_sessionid(struct xdr_stream *xdr,
 354                                  struct nfs4_sessionid *sid)
 355 {
 356         __be32 *p;
 357
 358         p = read_buf(xdr, NFS4_MAX_SESSIONID_LEN);
 359         if (unlikely(p == NULL))
 360                 return htonl(NFS4ERR_RESOURCE);
 361
 362         memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
 363         return 0;
 364 }
 365
 366 static __be32 decode_rc_list(struct xdr_stream *xdr,
 367                                struct referring_call_list *rc_list)
 368 {
 369         __be32 *p;
 370         int i;
 371         __be32 status;
 372
 373         status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 374         if (status)
 375                 goto out;
 376
 377         status = htonl(NFS4ERR_RESOURCE);
 378         p = read_buf(xdr, sizeof(uint32_t));
 379         if (unlikely(p == NULL))
 380                 goto out;
 381
 382         rc_list->rcl_nrefcalls = ntohl(*p++);
 383         if (rc_list->rcl_nrefcalls) {
 384                 p = read_buf(xdr,
 385                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 386                 if (unlikely(p == NULL))
 387                         goto out;
 388                 rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
 389                                                 sizeof(*rc_list->rcl_refcalls),
 390                                                 GFP_KERNEL);
 391                 if (unlikely(rc_list->rcl_refcalls == NULL))
 392                         goto out;
 393                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 394                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 395                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 396                 }
 397         }
 398         status = 0;
 399
 400 out:
 401         return status;
 402 }
 403
 404 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 405                                         struct xdr_stream *xdr,
 406                                         void *argp)
 407 {
 408         struct cb_sequenceargs *args = argp;
 409         __be32 *p;
 410         int i;
 411         __be32 status;
 412
 413         status = decode_sessionid(xdr, &args->csa_sessionid);
 414         if (status)
 415                 return status;
 416
 417         p = read_buf(xdr, 5 * sizeof(uint32_t));
 418         if (unlikely(p == NULL))
 419                 return htonl(NFS4ERR_RESOURCE);
 420
 421         args->csa_addr = svc_addr(rqstp);
 422         args->csa_sequenceid = ntohl(*p++);
 423         args->csa_slotid = ntohl(*p++);
 424         args->csa_highestslotid = ntohl(*p++);
 425         args->csa_cachethis = ntohl(*p++);
 426         args->csa_nrclists = ntohl(*p++);
 427         args->csa_rclists = NULL;
 428         if (args->csa_nrclists) {
 429                 args->csa_rclists = kmalloc_array(args->csa_nrclists,
 430                                                   sizeof(*args->csa_rclists),
 431                                                   GFP_KERNEL);
 432                 if (unlikely(args->csa_rclists == NULL))
 433                         return htonl(NFS4ERR_RESOURCE);
 434
 435                 for (i = 0; i < args->csa_nrclists; i++) {
 436                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 437                         if (status) {
 438                                 args->csa_nrclists = i;
 439                                 goto out_free;
 440                         }
 441                 }
 442         }
 443         return 0;
 444
 445 out_free:
 446         for (i = 0; i < args->csa_nrclists; i++)
 447                 kfree(args->csa_rclists[i].rcl_refcalls);
 448         kfree(args->csa_rclists);
 449         return status;
 450 }
 451
 452 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 453                                       struct xdr_stream *xdr,
 454                                       void *argp)
 455 {
 456         struct cb_recallanyargs *args = argp;
 457         uint32_t bitmap[2];
 458         __be32 *p, status;
 459
 460         p = read_buf(xdr, 4);
 461         if (unlikely(p == NULL))
 462                 return htonl(NFS4ERR_BADXDR);
 463         args->craa_objs_to_keep = ntohl(*p++);
 464         status = decode_bitmap(xdr, bitmap);
 465         if (unlikely(status))
 466                 return status;
 467         args->craa_type_mask = bitmap[0];
 468
 469         return 0;
 470 }
 471
 472 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 473                                         struct xdr_stream *xdr,
 474                                         void *argp)
 475 {
 476         struct cb_recallslotargs *args = argp;
 477         __be32 *p;
 478
 479         p = read_buf(xdr, 4);
 480         if (unlikely(p == NULL))
 481                 return htonl(NFS4ERR_BADXDR);
 482         args->crsa_target_highest_slotid = ntohl(*p++);
 483         return 0;
 484 }
 485
 486 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
 487 {
 488         __be32          *p;
 489         unsigned int    len;
 490
 491         p = read_buf(xdr, 12);
 492         if (unlikely(p == NULL))
 493                 return htonl(NFS4ERR_BADXDR);
 494
 495         p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
 496         len = be32_to_cpu(*p);
 497
 498         p = read_buf(xdr, len);
 499         if (unlikely(p == NULL))
 500                 return htonl(NFS4ERR_BADXDR);
 501
 502         /* Only try to decode if the length is right */
 503         if (len == 20) {
 504                 p += 2; /* skip "lock id:" */
 505                 args->cbnl_owner.s_dev = be32_to_cpu(*p++);
 506                 xdr_decode_hyper(p, &args->cbnl_owner.id);
 507                 args->cbnl_valid = true;
 508         } else {
 509                 args->cbnl_owner.s_dev = 0;
 510                 args->cbnl_owner.id = 0;
 511                 args->cbnl_valid = false;
 512         }
 513         return 0;
 514 }
 515
 516 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
 517                 struct xdr_stream *xdr, void *argp)
 518 {
 519         struct cb_notify_lock_args *args = argp;
 520         __be32 status;
 521
 522         status = decode_fh(xdr, &args->cbnl_fh);
 523         if (unlikely(status != 0))
 524                 return status;
 525         return decode_lockowner(xdr, args);
 526 }
 527
 528 #endif /* CONFIG_NFS_V4_1 */
 529
 530 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 531 {
 532         if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
 533                 return cpu_to_be32(NFS4ERR_RESOURCE);
 534         return 0;
 535 }
 536
 537 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
 538 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
 539 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
 540 {
 541         __be32 bm[2];
 542         __be32 *p;
 543
 544         bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
 545         bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
 546         if (bm[1] != 0) {
 547                 p = xdr_reserve_space(xdr, 16);
 548                 if (unlikely(p == NULL))
 549                         return htonl(NFS4ERR_RESOURCE);
 550                 *p++ = htonl(2);
 551                 *p++ = bm[0];
 552                 *p++ = bm[1];
 553         } else if (bm[0] != 0) {
 554                 p = xdr_reserve_space(xdr, 12);
 555                 if (unlikely(p == NULL))
 556                         return htonl(NFS4ERR_RESOURCE);
 557                 *p++ = htonl(1);
 558                 *p++ = bm[0];
 559         } else {
 560                 p = xdr_reserve_space(xdr, 8);
 561                 if (unlikely(p == NULL))
 562                         return htonl(NFS4ERR_RESOURCE);
 563                 *p++ = htonl(0);
 564         }
 565         *savep = p;
 566         return 0;
 567 }
 568
 569 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 570 {
 571         __be32 *p;
 572
 573         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 574                 return 0;
 575         p = xdr_reserve_space(xdr, 8);
 576         if (unlikely(!p))
 577                 return htonl(NFS4ERR_RESOURCE);
 578         p = xdr_encode_hyper(p, change);
 579         return 0;
 580 }
 581
 582 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 583 {
 584         __be32 *p;
 585
 586         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 587                 return 0;
 588         p = xdr_reserve_space(xdr, 8);
 589         if (unlikely(!p))
 590                 return htonl(NFS4ERR_RESOURCE);
 591         p = xdr_encode_hyper(p, size);
 592         return 0;
 593 }
 594
 595 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
 596 {
 597         __be32 *p;
 598
 599         p = xdr_reserve_space(xdr, 12);
 600         if (unlikely(!p))
 601                 return htonl(NFS4ERR_RESOURCE);
 602         p = xdr_encode_hyper(p, time->tv_sec);
 603         *p = htonl(time->tv_nsec);
 604         return 0;
 605 }
 606
 607 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 608 {
 609         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 610                 return 0;
 611         return encode_attr_time(xdr,time);
 612 }
 613
 614 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 615 {
 616         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 617                 return 0;
 618         return encode_attr_time(xdr,time);
 619 }
 620
 621 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 622 {
 623         __be32 status;
 624
 625         hdr->status = xdr_reserve_space(xdr, 4);
 626         if (unlikely(hdr->status == NULL))
 627                 return htonl(NFS4ERR_RESOURCE);
 628         status = encode_string(xdr, hdr->taglen, hdr->tag);
 629         if (unlikely(status != 0))
 630                 return status;
 631         hdr->nops = xdr_reserve_space(xdr, 4);
 632         if (unlikely(hdr->nops == NULL))
 633                 return htonl(NFS4ERR_RESOURCE);
 634         return 0;
 635 }
 636
 637 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 638 {
 639         __be32 *p;
 640
 641         p = xdr_reserve_space(xdr, 8);
 642         if (unlikely(p == NULL))
 643                 return htonl(NFS4ERR_RESOURCE_HDR);
 644         *p++ = htonl(op);
 645         *p = res;
 646         return 0;
 647 }
 648
 649 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 650                 const void *resp)
 651 {
 652         const struct cb_getattrres *res = resp;
 653         __be32 *savep = NULL;
 654         __be32 status = res->status;
 655
 656         if (unlikely(status != 0))
 657                 goto out;
 658         status = encode_attr_bitmap(xdr, res->bitmap, &savep);
 659         if (unlikely(status != 0))
 660                 goto out;
 661         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 662         if (unlikely(status != 0))
 663                 goto out;
 664         status = encode_attr_size(xdr, res->bitmap, res->size);
 665         if (unlikely(status != 0))
 666                 goto out;
 667         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 668         if (unlikely(status != 0))
 669                 goto out;
 670         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 671         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 672 out:
 673         return status;
 674 }
 675
 676 #if defined(CONFIG_NFS_V4_1)
 677
 678 static __be32 encode_sessionid(struct xdr_stream *xdr,
 679                                  const struct nfs4_sessionid *sid)
 680 {
 681         __be32 *p;
 682
 683         p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
 684         if (unlikely(p == NULL))
 685                 return htonl(NFS4ERR_RESOURCE);
 686
 687         memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
 688         return 0;
 689 }
 690
 691 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 692                                        struct xdr_stream *xdr,
 693                                        const void *resp)
 694 {
 695         const struct cb_sequenceres *res = resp;
 696         __be32 *p;
 697         __be32 status = res->csr_status;
 698
 699         if (unlikely(status != 0))
 700                 return status;
 701
 702         status = encode_sessionid(xdr, &res->csr_sessionid);
 703         if (status)
 704                 return status;
 705
 706         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 707         if (unlikely(p == NULL))
 708                 return htonl(NFS4ERR_RESOURCE);
 709
 710         *p++ = htonl(res->csr_sequenceid);
 711         *p++ = htonl(res->csr_slotid);
 712         *p++ = htonl(res->csr_highestslotid);
 713         *p++ = htonl(res->csr_target_highestslotid);
 714         return 0;
 715 }
 716
 717 static __be32
 718 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 719 {
 720         if (op_nr == OP_CB_SEQUENCE) {
 721                 if (nop != 0)
 722                         return htonl(NFS4ERR_SEQUENCE_POS);
 723         } else {
 724                 if (nop == 0)
 725                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 726         }
 727
 728         switch (op_nr) {
 729         case OP_CB_GETATTR:
 730         case OP_CB_RECALL:
 731         case OP_CB_SEQUENCE:
 732         case OP_CB_RECALL_ANY:
 733         case OP_CB_RECALL_SLOT:
 734         case OP_CB_LAYOUTRECALL:
 735         case OP_CB_NOTIFY_DEVICEID:
 736         case OP_CB_NOTIFY_LOCK:
 737                 *op = &callback_ops[op_nr];
 738                 break;
 739
 740         case OP_CB_NOTIFY:
 741         case OP_CB_PUSH_DELEG:
 742         case OP_CB_RECALLABLE_OBJ_AVAIL:
 743         case OP_CB_WANTS_CANCELLED:
 744                 return htonl(NFS4ERR_NOTSUPP);
 745
 746         default:
 747                 return htonl(NFS4ERR_OP_ILLEGAL);
 748         }
 749
 750         return htonl(NFS_OK);
 751 }
 752
 753 static void nfs4_callback_free_slot(struct nfs4_session *session,
 754                 struct nfs4_slot *slot)
 755 {
 756         struct nfs4_slot_table *tbl = &session->bc_slot_table;
 757
 758         spin_lock(&tbl->slot_tbl_lock);
 759         /*
 760          * Let the state manager know callback processing done.
 761          * A single slot, so highest used slotid is either 0 or -1
 762          */
 763         nfs4_free_slot(tbl, slot);
 764         spin_unlock(&tbl->slot_tbl_lock);
 765 }
 766
 767 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 768 {
 769         if (cps->slot) {
 770                 nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
 771                 cps->slot = NULL;
 772         }
 773 }
 774
 775 #else /* CONFIG_NFS_V4_1 */
 776
 777 static __be32
 778 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 779 {
 780         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 781 }
 782
 783 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 784 {
 785 }
 786 #endif /* CONFIG_NFS_V4_1 */
 787
 788 #ifdef CONFIG_NFS_V4_2
 789 static __be32
 790 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 791 {
 792         __be32 status = preprocess_nfs41_op(nop, op_nr, op);
 793         if (status != htonl(NFS4ERR_OP_ILLEGAL))
 794                 return status;
 795
 796         if (op_nr == OP_CB_OFFLOAD)
 797                 return htonl(NFS4ERR_NOTSUPP);
 798         return htonl(NFS4ERR_OP_ILLEGAL);
 799 }
 800 #else /* CONFIG_NFS_V4_2 */
 801 static __be32
 802 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 803 {
 804         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 805 }
 806 #endif /* CONFIG_NFS_V4_2 */
 807
 808 static __be32
 809 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 810 {
 811         switch (op_nr) {
 812         case OP_CB_GETATTR:
 813         case OP_CB_RECALL:
 814                 *op = &callback_ops[op_nr];
 815                 break;
 816         default:
 817                 return htonl(NFS4ERR_OP_ILLEGAL);
 818         }
 819
 820         return htonl(NFS_OK);
 821 }
 822
 823 static __be32 process_op(int nop, struct svc_rqst *rqstp,
 824                 struct xdr_stream *xdr_in, void *argp,
 825                 struct xdr_stream *xdr_out, void *resp,
 826                 struct cb_process_state *cps)
 827 {
 828         struct callback_op *op = &callback_ops[0];
 829         unsigned int op_nr;
 830         __be32 status;
 831         long maxlen;
 832         __be32 res;
 833
 834         status = decode_op_hdr(xdr_in, &op_nr);
 835         if (unlikely(status))
 836                 return status;
 837
 838         switch (cps->minorversion) {
 839         case 0:
 840                 status = preprocess_nfs4_op(op_nr, &op);
 841                 break;
 842         case 1:
 843                 status = preprocess_nfs41_op(nop, op_nr, &op);
 844                 break;
 845         case 2:
 846                 status = preprocess_nfs42_op(nop, op_nr, &op);
 847                 break;
 848         default:
 849                 status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 850         }
 851
 852         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 853                 op_nr = OP_CB_ILLEGAL;
 854         if (status)
 855                 goto encode_hdr;
 856
 857         if (cps->drc_status) {
 858                 status = cps->drc_status;
 859                 goto encode_hdr;
 860         }
 861
 862         maxlen = xdr_out->end - xdr_out->p;
 863         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 864                 status = op->decode_args(rqstp, xdr_in, argp);
 865                 if (likely(status == 0))
 866                         status = op->process_op(argp, resp, cps);
 867         } else
 868                 status = htonl(NFS4ERR_RESOURCE);
 869
 870 encode_hdr:
 871         res = encode_op_hdr(xdr_out, op_nr, status);
 872         if (unlikely(res))
 873                 return res;
 874         if (op->encode_res != NULL && status == 0)
 875                 status = op->encode_res(rqstp, xdr_out, resp);
 876         return status;
 877 }
 878
 879 /*
 880  * Decode, process and encode a COMPOUND
 881  */
 882 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
 883 {
 884         struct cb_compound_hdr_arg hdr_arg = { 0 };
 885         struct cb_compound_hdr_res hdr_res = { NULL };
 886         struct xdr_stream xdr_in, xdr_out;
 887         __be32 *p, status;
 888         struct cb_process_state cps = {
 889                 .drc_status = 0,
 890                 .clp = NULL,
 891                 .net = SVC_NET(rqstp),
 892         };
 893         unsigned int nops = 0;
 894
 895         xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
 896
 897         p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
 898         xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 899
 900         status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
 901         if (status == htonl(NFS4ERR_RESOURCE))
 902                 return rpc_garbage_args;
 903
 904         if (hdr_arg.minorversion == 0) {
 905                 cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
 906                 if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
 907                         goto out_invalidcred;
 908         }
 909
 910         cps.minorversion = hdr_arg.minorversion;
 911         hdr_res.taglen = hdr_arg.taglen;
 912         hdr_res.tag = hdr_arg.tag;
 913         if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
 914                 return rpc_system_err;
 915
 916         while (status == 0 && nops != hdr_arg.nops) {
 917                 status = process_op(nops, rqstp, &xdr_in,
 918                                     rqstp->rq_argp, &xdr_out, rqstp->rq_resp,
 919                                     &cps);
 920                 nops++;
 921         }
 922
 923         /* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
 924         * resource error in cb_compound status without returning op */
 925         if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
 926                 status = htonl(NFS4ERR_RESOURCE);
 927                 nops--;
 928         }
 929
 930         *hdr_res.status = status;
 931         *hdr_res.nops = htonl(nops);
 932         nfs4_cb_free_slot(&cps);
 933         nfs_put_client(cps.clp);
 934         return rpc_success;
 935
 936 out_invalidcred:
 937         pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
 938         return rpc_autherr_badcred;
 939 }
 940
 941 /*
 942  * Define NFS4 callback COMPOUND ops.
 943  */
 944 static struct callback_op callback_ops[] = {
 945         [0] = {
 946                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
 947         },
 948         [OP_CB_GETATTR] = {
 949                 .process_op = nfs4_callback_getattr,
 950                 .decode_args = decode_getattr_args,
 951                 .encode_res = encode_getattr_res,
 952                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
 953         },
 954         [OP_CB_RECALL] = {
 955                 .process_op = nfs4_callback_recall,
 956                 .decode_args = decode_recall_args,
 957                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
 958         },
 959 #if defined(CONFIG_NFS_V4_1)
 960         [OP_CB_LAYOUTRECALL] = {
 961                 .process_op = nfs4_callback_layoutrecall,
 962                 .decode_args = decode_layoutrecall_args,
 963                 .res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
 964         },
 965         [OP_CB_NOTIFY_DEVICEID] = {
 966                 .process_op = nfs4_callback_devicenotify,
 967                 .decode_args = decode_devicenotify_args,
 968                 .res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
 969         },
 970         [OP_CB_SEQUENCE] = {
 971                 .process_op = nfs4_callback_sequence,
 972                 .decode_args = decode_cb_sequence_args,
 973                 .encode_res = encode_cb_sequence_res,
 974                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
 975         },
 976         [OP_CB_RECALL_ANY] = {
 977                 .process_op = nfs4_callback_recallany,
 978                 .decode_args = decode_recallany_args,
 979                 .res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
 980         },
 981         [OP_CB_RECALL_SLOT] = {
 982                 .process_op = nfs4_callback_recallslot,
 983                 .decode_args = decode_recallslot_args,
 984                 .res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
 985         },
 986         [OP_CB_NOTIFY_LOCK] = {
 987                 .process_op = nfs4_callback_notify_lock,
 988                 .decode_args = decode_notify_lock_args,
 989                 .res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
 990         },
 991 #endif /* CONFIG_NFS_V4_1 */
 992 };
 993
 994 /*
 995  * Define NFS4 callback procedures
 996  */
 997 static const struct svc_procedure nfs4_callback_procedures1[] = {
 998         [CB_NULL] = {
 999                 .pc_func = nfs4_callback_null,
1000                 .pc_decode = nfs4_decode_void,
1001                 .pc_encode = nfs4_encode_void,
1002                 .pc_xdrressize = 1,
1003         },
1004         [CB_COMPOUND] = {
1005                 .pc_func = nfs4_callback_compound,
1006                 .pc_encode = nfs4_encode_void,
1007                 .pc_argsize = 256,
1008                 .pc_ressize = 256,
1009                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1010         }
1011 };
1012
1013 static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
1014 const struct svc_version nfs4_callback_version1 = {
1015         .vs_vers = 1,
1016         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1017         .vs_proc = nfs4_callback_procedures1,
1018         .vs_count = nfs4_callback_count1,
1019         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1020         .vs_dispatch = NULL,
1021         .vs_hidden = true,
1022         .vs_need_cong_ctrl = true,
1023 };
1024
1025 static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
1026 const struct svc_version nfs4_callback_version4 = {
1027         .vs_vers = 4,
1028         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1029         .vs_proc = nfs4_callback_procedures1,
1030         .vs_count = nfs4_callback_count4,
1031         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1032         .vs_dispatch = NULL,
1033         .vs_hidden = true,
1034         .vs_need_cong_ctrl = true,
1035 };