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/slab.h>
  13 #include "nfs4_fs.h"
  14 #include "callback.h"
  15
  16 #define CB_OP_TAGLEN_MAXSZ      (512)
  17 #define CB_OP_HDR_RES_MAXSZ     (2 + CB_OP_TAGLEN_MAXSZ)
  18 #define CB_OP_GETATTR_BITMAP_MAXSZ      (4)
  19 #define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \
  20                                 CB_OP_GETATTR_BITMAP_MAXSZ + \
  21                                 2 + 2 + 3 + 3)
  22 #define CB_OP_RECALL_RES_MAXSZ  (CB_OP_HDR_RES_MAXSZ)
  23
  24 #if defined(CONFIG_NFS_V4_1)
  25 #define CB_OP_SEQUENCE_RES_MAXSZ        (CB_OP_HDR_RES_MAXSZ + \
  26                                         4 + 1 + 3)
  27 #define CB_OP_RECALLANY_RES_MAXSZ       (CB_OP_HDR_RES_MAXSZ)
  28 #define CB_OP_RECALLSLOT_RES_MAXSZ      (CB_OP_HDR_RES_MAXSZ)
  29 #endif /* CONFIG_NFS_V4_1 */
  30
  31 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  32
  33 /* Internal error code */
  34 #define NFS4ERR_RESOURCE_HDR    11050
  35
  36 typedef __be32 (*callback_process_op_t)(void *, void *);
  37 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
  38 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
  39
  40
  41 struct callback_op {
  42         callback_process_op_t process_op;
  43         callback_decode_arg_t decode_args;
  44         callback_encode_res_t encode_res;
  45         long res_maxsize;
  46 };
  47
  48 static struct callback_op callback_ops[];
  49
  50 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
  51 {
  52         return htonl(NFS4_OK);
  53 }
  54
  55 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  56 {
  57         return xdr_argsize_check(rqstp, p);
  58 }
  59
  60 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  61 {
  62         return xdr_ressize_check(rqstp, p);
  63 }
  64
  65 static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
  66 {
  67         __be32 *p;
  68
  69         p = xdr_inline_decode(xdr, nbytes);
  70         if (unlikely(p == NULL))
  71                 printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
  72         return p;
  73 }
  74
  75 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
  76 {
  77         __be32 *p;
  78
  79         p = read_buf(xdr, 4);
  80         if (unlikely(p == NULL))
  81                 return htonl(NFS4ERR_RESOURCE);
  82         *len = ntohl(*p);
  83
  84         if (*len != 0) {
  85                 p = read_buf(xdr, *len);
  86                 if (unlikely(p == NULL))
  87                         return htonl(NFS4ERR_RESOURCE);
  88                 *str = (const char *)p;
  89         } else
  90                 *str = NULL;
  91
  92         return 0;
  93 }
  94
  95 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  96 {
  97         __be32 *p;
  98
  99         p = read_buf(xdr, 4);
 100         if (unlikely(p == NULL))
 101                 return htonl(NFS4ERR_RESOURCE);
 102         fh->size = ntohl(*p);
 103         if (fh->size > NFS4_FHSIZE)
 104                 return htonl(NFS4ERR_BADHANDLE);
 105         p = read_buf(xdr, fh->size);
 106         if (unlikely(p == NULL))
 107                 return htonl(NFS4ERR_RESOURCE);
 108         memcpy(&fh->data[0], p, fh->size);
 109         memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 110         return 0;
 111 }
 112
 113 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 114 {
 115         __be32 *p;
 116         unsigned int attrlen;
 117
 118         p = read_buf(xdr, 4);
 119         if (unlikely(p == NULL))
 120                 return htonl(NFS4ERR_RESOURCE);
 121         attrlen = ntohl(*p);
 122         p = read_buf(xdr, attrlen << 2);
 123         if (unlikely(p == NULL))
 124                 return htonl(NFS4ERR_RESOURCE);
 125         if (likely(attrlen > 0))
 126                 bitmap[0] = ntohl(*p++);
 127         if (attrlen > 1)
 128                 bitmap[1] = ntohl(*p);
 129         return 0;
 130 }
 131
 132 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 133 {
 134         __be32 *p;
 135
 136         p = read_buf(xdr, 16);
 137         if (unlikely(p == NULL))
 138                 return htonl(NFS4ERR_RESOURCE);
 139         memcpy(stateid->data, p, 16);
 140         return 0;
 141 }
 142
 143 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 144 {
 145         __be32 *p;
 146         __be32 status;
 147
 148         status = decode_string(xdr, &hdr->taglen, &hdr->tag);
 149         if (unlikely(status != 0))
 150                 return status;
 151         /* We do not like overly long tags! */
 152         if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
 153                 printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
 154                                 __func__, hdr->taglen);
 155                 return htonl(NFS4ERR_RESOURCE);
 156         }
 157         p = read_buf(xdr, 12);
 158         if (unlikely(p == NULL))
 159                 return htonl(NFS4ERR_RESOURCE);
 160         hdr->minorversion = ntohl(*p++);
 161         /* Check minor version is zero or one. */
 162         if (hdr->minorversion <= 1) {
 163                 p++;    /* skip callback_ident */
 164         } else {
 165                 printk(KERN_WARNING "%s: NFSv4 server callback with "
 166                         "illegal minor version %u!\n",
 167                         __func__, hdr->minorversion);
 168                 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 169         }
 170         hdr->nops = ntohl(*p);
 171         dprintk("%s: minorversion %d nops %d\n", __func__,
 172                 hdr->minorversion, hdr->nops);
 173         return 0;
 174 }
 175
 176 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 177 {
 178         __be32 *p;
 179         p = read_buf(xdr, 4);
 180         if (unlikely(p == NULL))
 181                 return htonl(NFS4ERR_RESOURCE_HDR);
 182         *op = ntohl(*p);
 183         return 0;
 184 }
 185
 186 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
 187 {
 188         __be32 status;
 189
 190         status = decode_fh(xdr, &args->fh);
 191         if (unlikely(status != 0))
 192                 goto out;
 193         args->addr = svc_addr(rqstp);
 194         status = decode_bitmap(xdr, args->bitmap);
 195 out:
 196         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 197         return status;
 198 }
 199
 200 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
 201 {
 202         __be32 *p;
 203         __be32 status;
 204
 205         args->addr = svc_addr(rqstp);
 206         status = decode_stateid(xdr, &args->stateid);
 207         if (unlikely(status != 0))
 208                 goto out;
 209         p = read_buf(xdr, 4);
 210         if (unlikely(p == NULL)) {
 211                 status = htonl(NFS4ERR_RESOURCE);
 212                 goto out;
 213         }
 214         args->truncate = ntohl(*p);
 215         status = decode_fh(xdr, &args->fh);
 216 out:
 217         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 218         return status;
 219 }
 220
 221 #if defined(CONFIG_NFS_V4_1)
 222
 223 static __be32 decode_sessionid(struct xdr_stream *xdr,
 224                                  struct nfs4_sessionid *sid)
 225 {
 226         __be32 *p;
 227         int len = NFS4_MAX_SESSIONID_LEN;
 228
 229         p = read_buf(xdr, len);
 230         if (unlikely(p == NULL))
 231                 return htonl(NFS4ERR_RESOURCE);
 232
 233         memcpy(sid->data, p, len);
 234         return 0;
 235 }
 236
 237 static __be32 decode_rc_list(struct xdr_stream *xdr,
 238                                struct referring_call_list *rc_list)
 239 {
 240         __be32 *p;
 241         int i;
 242         __be32 status;
 243
 244         status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 245         if (status)
 246                 goto out;
 247
 248         status = htonl(NFS4ERR_RESOURCE);
 249         p = read_buf(xdr, sizeof(uint32_t));
 250         if (unlikely(p == NULL))
 251                 goto out;
 252
 253         rc_list->rcl_nrefcalls = ntohl(*p++);
 254         if (rc_list->rcl_nrefcalls) {
 255                 p = read_buf(xdr,
 256                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 257                 if (unlikely(p == NULL))
 258                         goto out;
 259                 rc_list->rcl_refcalls = kmalloc(rc_list->rcl_nrefcalls *
 260                                                 sizeof(*rc_list->rcl_refcalls),
 261                                                 GFP_KERNEL);
 262                 if (unlikely(rc_list->rcl_refcalls == NULL))
 263                         goto out;
 264                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 265                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 266                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 267                 }
 268         }
 269         status = 0;
 270
 271 out:
 272         return status;
 273 }
 274
 275 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 276                                         struct xdr_stream *xdr,
 277                                         struct cb_sequenceargs *args)
 278 {
 279         __be32 *p;
 280         int i;
 281         __be32 status;
 282
 283         status = decode_sessionid(xdr, &args->csa_sessionid);
 284         if (status)
 285                 goto out;
 286
 287         status = htonl(NFS4ERR_RESOURCE);
 288         p = read_buf(xdr, 5 * sizeof(uint32_t));
 289         if (unlikely(p == NULL))
 290                 goto out;
 291
 292         args->csa_addr = svc_addr(rqstp);
 293         args->csa_sequenceid = ntohl(*p++);
 294         args->csa_slotid = ntohl(*p++);
 295         args->csa_highestslotid = ntohl(*p++);
 296         args->csa_cachethis = ntohl(*p++);
 297         args->csa_nrclists = ntohl(*p++);
 298         args->csa_rclists = NULL;
 299         if (args->csa_nrclists) {
 300                 args->csa_rclists = kmalloc(args->csa_nrclists *
 301                                             sizeof(*args->csa_rclists),
 302                                             GFP_KERNEL);
 303                 if (unlikely(args->csa_rclists == NULL))
 304                         goto out;
 305
 306                 for (i = 0; i < args->csa_nrclists; i++) {
 307                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 308                         if (status)
 309                                 goto out_free;
 310                 }
 311         }
 312         status = 0;
 313
 314         dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
 315                 "highestslotid %u cachethis %d nrclists %u\n",
 316                 __func__,
 317                 ((u32 *)&args->csa_sessionid)[0],
 318                 ((u32 *)&args->csa_sessionid)[1],
 319                 ((u32 *)&args->csa_sessionid)[2],
 320                 ((u32 *)&args->csa_sessionid)[3],
 321                 args->csa_sequenceid, args->csa_slotid,
 322                 args->csa_highestslotid, args->csa_cachethis,
 323                 args->csa_nrclists);
 324 out:
 325         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 326         return status;
 327
 328 out_free:
 329         for (i = 0; i < args->csa_nrclists; i++)
 330                 kfree(args->csa_rclists[i].rcl_refcalls);
 331         kfree(args->csa_rclists);
 332         goto out;
 333 }
 334
 335 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 336                                       struct xdr_stream *xdr,
 337                                       struct cb_recallanyargs *args)
 338 {
 339         __be32 *p;
 340
 341         args->craa_addr = svc_addr(rqstp);
 342         p = read_buf(xdr, 4);
 343         if (unlikely(p == NULL))
 344                 return htonl(NFS4ERR_BADXDR);
 345         args->craa_objs_to_keep = ntohl(*p++);
 346         p = read_buf(xdr, 4);
 347         if (unlikely(p == NULL))
 348                 return htonl(NFS4ERR_BADXDR);
 349         args->craa_type_mask = ntohl(*p);
 350
 351         return 0;
 352 }
 353
 354 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 355                                         struct xdr_stream *xdr,
 356                                         struct cb_recallslotargs *args)
 357 {
 358         __be32 *p;
 359
 360         args->crsa_addr = svc_addr(rqstp);
 361         p = read_buf(xdr, 4);
 362         if (unlikely(p == NULL))
 363                 return htonl(NFS4ERR_BADXDR);
 364         args->crsa_target_max_slots = ntohl(*p++);
 365         return 0;
 366 }
 367
 368 #endif /* CONFIG_NFS_V4_1 */
 369
 370 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 371 {
 372         __be32 *p;
 373
 374         p = xdr_reserve_space(xdr, 4 + len);
 375         if (unlikely(p == NULL))
 376                 return htonl(NFS4ERR_RESOURCE);
 377         xdr_encode_opaque(p, str, len);
 378         return 0;
 379 }
 380
 381 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
 382 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
 383 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
 384 {
 385         __be32 bm[2];
 386         __be32 *p;
 387
 388         bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
 389         bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
 390         if (bm[1] != 0) {
 391                 p = xdr_reserve_space(xdr, 16);
 392                 if (unlikely(p == NULL))
 393                         return htonl(NFS4ERR_RESOURCE);
 394                 *p++ = htonl(2);
 395                 *p++ = bm[0];
 396                 *p++ = bm[1];
 397         } else if (bm[0] != 0) {
 398                 p = xdr_reserve_space(xdr, 12);
 399                 if (unlikely(p == NULL))
 400                         return htonl(NFS4ERR_RESOURCE);
 401                 *p++ = htonl(1);
 402                 *p++ = bm[0];
 403         } else {
 404                 p = xdr_reserve_space(xdr, 8);
 405                 if (unlikely(p == NULL))
 406                         return htonl(NFS4ERR_RESOURCE);
 407                 *p++ = htonl(0);
 408         }
 409         *savep = p;
 410         return 0;
 411 }
 412
 413 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 414 {
 415         __be32 *p;
 416
 417         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 418                 return 0;
 419         p = xdr_reserve_space(xdr, 8);
 420         if (unlikely(!p))
 421                 return htonl(NFS4ERR_RESOURCE);
 422         p = xdr_encode_hyper(p, change);
 423         return 0;
 424 }
 425
 426 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 427 {
 428         __be32 *p;
 429
 430         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 431                 return 0;
 432         p = xdr_reserve_space(xdr, 8);
 433         if (unlikely(!p))
 434                 return htonl(NFS4ERR_RESOURCE);
 435         p = xdr_encode_hyper(p, size);
 436         return 0;
 437 }
 438
 439 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
 440 {
 441         __be32 *p;
 442
 443         p = xdr_reserve_space(xdr, 12);
 444         if (unlikely(!p))
 445                 return htonl(NFS4ERR_RESOURCE);
 446         p = xdr_encode_hyper(p, time->tv_sec);
 447         *p = htonl(time->tv_nsec);
 448         return 0;
 449 }
 450
 451 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 452 {
 453         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 454                 return 0;
 455         return encode_attr_time(xdr,time);
 456 }
 457
 458 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 459 {
 460         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 461                 return 0;
 462         return encode_attr_time(xdr,time);
 463 }
 464
 465 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 466 {
 467         __be32 status;
 468
 469         hdr->status = xdr_reserve_space(xdr, 4);
 470         if (unlikely(hdr->status == NULL))
 471                 return htonl(NFS4ERR_RESOURCE);
 472         status = encode_string(xdr, hdr->taglen, hdr->tag);
 473         if (unlikely(status != 0))
 474                 return status;
 475         hdr->nops = xdr_reserve_space(xdr, 4);
 476         if (unlikely(hdr->nops == NULL))
 477                 return htonl(NFS4ERR_RESOURCE);
 478         return 0;
 479 }
 480
 481 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 482 {
 483         __be32 *p;
 484
 485         p = xdr_reserve_space(xdr, 8);
 486         if (unlikely(p == NULL))
 487                 return htonl(NFS4ERR_RESOURCE_HDR);
 488         *p++ = htonl(op);
 489         *p = res;
 490         return 0;
 491 }
 492
 493 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
 494 {
 495         __be32 *savep = NULL;
 496         __be32 status = res->status;
 497
 498         if (unlikely(status != 0))
 499                 goto out;
 500         status = encode_attr_bitmap(xdr, res->bitmap, &savep);
 501         if (unlikely(status != 0))
 502                 goto out;
 503         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 504         if (unlikely(status != 0))
 505                 goto out;
 506         status = encode_attr_size(xdr, res->bitmap, res->size);
 507         if (unlikely(status != 0))
 508                 goto out;
 509         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 510         if (unlikely(status != 0))
 511                 goto out;
 512         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 513         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 514 out:
 515         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 516         return status;
 517 }
 518
 519 #if defined(CONFIG_NFS_V4_1)
 520
 521 static __be32 encode_sessionid(struct xdr_stream *xdr,
 522                                  const struct nfs4_sessionid *sid)
 523 {
 524         __be32 *p;
 525         int len = NFS4_MAX_SESSIONID_LEN;
 526
 527         p = xdr_reserve_space(xdr, len);
 528         if (unlikely(p == NULL))
 529                 return htonl(NFS4ERR_RESOURCE);
 530
 531         memcpy(p, sid, len);
 532         return 0;
 533 }
 534
 535 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 536                                        struct xdr_stream *xdr,
 537                                        const struct cb_sequenceres *res)
 538 {
 539         __be32 *p;
 540         unsigned status = res->csr_status;
 541
 542         if (unlikely(status != 0))
 543                 goto out;
 544
 545         encode_sessionid(xdr, &res->csr_sessionid);
 546
 547         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 548         if (unlikely(p == NULL))
 549                 return htonl(NFS4ERR_RESOURCE);
 550
 551         *p++ = htonl(res->csr_sequenceid);
 552         *p++ = htonl(res->csr_slotid);
 553         *p++ = htonl(res->csr_highestslotid);
 554         *p++ = htonl(res->csr_target_highestslotid);
 555 out:
 556         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 557         return status;
 558 }
 559
 560 static __be32
 561 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 562 {
 563         if (op_nr == OP_CB_SEQUENCE) {
 564                 if (nop != 0)
 565                         return htonl(NFS4ERR_SEQUENCE_POS);
 566         } else {
 567                 if (nop == 0)
 568                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 569         }
 570
 571         switch (op_nr) {
 572         case OP_CB_GETATTR:
 573         case OP_CB_RECALL:
 574         case OP_CB_SEQUENCE:
 575         case OP_CB_RECALL_ANY:
 576         case OP_CB_RECALL_SLOT:
 577                 *op = &callback_ops[op_nr];
 578                 break;
 579
 580         case OP_CB_LAYOUTRECALL:
 581         case OP_CB_NOTIFY_DEVICEID:
 582         case OP_CB_NOTIFY:
 583         case OP_CB_PUSH_DELEG:
 584         case OP_CB_RECALLABLE_OBJ_AVAIL:
 585         case OP_CB_WANTS_CANCELLED:
 586         case OP_CB_NOTIFY_LOCK:
 587                 return htonl(NFS4ERR_NOTSUPP);
 588
 589         default:
 590                 return htonl(NFS4ERR_OP_ILLEGAL);
 591         }
 592
 593         return htonl(NFS_OK);
 594 }
 595
 596 #else /* CONFIG_NFS_V4_1 */
 597
 598 static __be32
 599 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 600 {
 601         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 602 }
 603
 604 #endif /* CONFIG_NFS_V4_1 */
 605
 606 static __be32
 607 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 608 {
 609         switch (op_nr) {
 610         case OP_CB_GETATTR:
 611         case OP_CB_RECALL:
 612                 *op = &callback_ops[op_nr];
 613                 break;
 614         default:
 615                 return htonl(NFS4ERR_OP_ILLEGAL);
 616         }
 617
 618         return htonl(NFS_OK);
 619 }
 620
 621 static __be32 process_op(uint32_t minorversion, int nop,
 622                 struct svc_rqst *rqstp,
 623                 struct xdr_stream *xdr_in, void *argp,
 624                 struct xdr_stream *xdr_out, void *resp, int* drc_status)
 625 {
 626         struct callback_op *op = &callback_ops[0];
 627         unsigned int op_nr;
 628         __be32 status;
 629         long maxlen;
 630         __be32 res;
 631
 632         dprintk("%s: start\n", __func__);
 633         status = decode_op_hdr(xdr_in, &op_nr);
 634         if (unlikely(status))
 635                 return status;
 636
 637         dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
 638                 __func__, minorversion, nop, op_nr);
 639
 640         status = minorversion ? preprocess_nfs41_op(nop, op_nr, &op) :
 641                                 preprocess_nfs4_op(op_nr, &op);
 642         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 643                 op_nr = OP_CB_ILLEGAL;
 644         if (status)
 645                 goto encode_hdr;
 646
 647         if (*drc_status) {
 648                 status = *drc_status;
 649                 goto encode_hdr;
 650         }
 651
 652         maxlen = xdr_out->end - xdr_out->p;
 653         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 654                 status = op->decode_args(rqstp, xdr_in, argp);
 655                 if (likely(status == 0))
 656                         status = op->process_op(argp, resp);
 657         } else
 658                 status = htonl(NFS4ERR_RESOURCE);
 659
 660         /* Only set by OP_CB_SEQUENCE processing */
 661         if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
 662                 *drc_status = status;
 663                 status = 0;
 664         }
 665
 666 encode_hdr:
 667         res = encode_op_hdr(xdr_out, op_nr, status);
 668         if (unlikely(res))
 669                 return res;
 670         if (op->encode_res != NULL && status == 0)
 671                 status = op->encode_res(rqstp, xdr_out, resp);
 672         dprintk("%s: done, status = %d\n", __func__, ntohl(status));
 673         return status;
 674 }
 675
 676 /*
 677  * Decode, process and encode a COMPOUND
 678  */
 679 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
 680 {
 681         struct cb_compound_hdr_arg hdr_arg = { 0 };
 682         struct cb_compound_hdr_res hdr_res = { NULL };
 683         struct xdr_stream xdr_in, xdr_out;
 684         __be32 *p;
 685         __be32 status, drc_status = 0;
 686         unsigned int nops = 0;
 687
 688         dprintk("%s: start\n", __func__);
 689
 690         xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
 691
 692         p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
 693         xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 694
 695         status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
 696         if (status == __constant_htonl(NFS4ERR_RESOURCE))
 697                 return rpc_garbage_args;
 698
 699         hdr_res.taglen = hdr_arg.taglen;
 700         hdr_res.tag = hdr_arg.tag;
 701         if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
 702                 return rpc_system_err;
 703
 704         while (status == 0 && nops != hdr_arg.nops) {
 705                 status = process_op(hdr_arg.minorversion, nops, rqstp,
 706                                     &xdr_in, argp, &xdr_out, resp, &drc_status);
 707                 nops++;
 708         }
 709
 710         /* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
 711         * resource error in cb_compound status without returning op */
 712         if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
 713                 status = htonl(NFS4ERR_RESOURCE);
 714                 nops--;
 715         }
 716
 717         *hdr_res.status = status;
 718         *hdr_res.nops = htonl(nops);
 719         dprintk("%s: done, status = %u\n", __func__, ntohl(status));
 720         return rpc_success;
 721 }
 722
 723 /*
 724  * Define NFS4 callback COMPOUND ops.
 725  */
 726 static struct callback_op callback_ops[] = {
 727         [0] = {
 728                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
 729         },
 730         [OP_CB_GETATTR] = {
 731                 .process_op = (callback_process_op_t)nfs4_callback_getattr,
 732                 .decode_args = (callback_decode_arg_t)decode_getattr_args,
 733                 .encode_res = (callback_encode_res_t)encode_getattr_res,
 734                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
 735         },
 736         [OP_CB_RECALL] = {
 737                 .process_op = (callback_process_op_t)nfs4_callback_recall,
 738                 .decode_args = (callback_decode_arg_t)decode_recall_args,
 739                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
 740         },
 741 #if defined(CONFIG_NFS_V4_1)
 742         [OP_CB_SEQUENCE] = {
 743                 .process_op = (callback_process_op_t)nfs4_callback_sequence,
 744                 .decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
 745                 .encode_res = (callback_encode_res_t)encode_cb_sequence_res,
 746                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
 747         },
 748         [OP_CB_RECALL_ANY] = {
 749                 .process_op = (callback_process_op_t)nfs4_callback_recallany,
 750                 .decode_args = (callback_decode_arg_t)decode_recallany_args,
 751                 .res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
 752         },
 753         [OP_CB_RECALL_SLOT] = {
 754                 .process_op = (callback_process_op_t)nfs4_callback_recallslot,
 755                 .decode_args = (callback_decode_arg_t)decode_recallslot_args,
 756                 .res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
 757         },
 758 #endif /* CONFIG_NFS_V4_1 */
 759 };
 760
 761 /*
 762  * Define NFS4 callback procedures
 763  */
 764 static struct svc_procedure nfs4_callback_procedures1[] = {
 765         [CB_NULL] = {
 766                 .pc_func = nfs4_callback_null,
 767                 .pc_decode = (kxdrproc_t)nfs4_decode_void,
 768                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 769                 .pc_xdrressize = 1,
 770         },
 771         [CB_COMPOUND] = {
 772                 .pc_func = nfs4_callback_compound,
 773                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 774                 .pc_argsize = 256,
 775                 .pc_ressize = 256,
 776                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
 777         }
 778 };
 779
 780 struct svc_version nfs4_callback_version1 = {
 781         .vs_vers = 1,
 782         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
 783         .vs_proc = nfs4_callback_procedures1,
 784         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
 785         .vs_dispatch = NULL,
 786         .vs_hidden = 1,
 787 };
 788
 789 struct svc_version nfs4_callback_version4 = {
 790         .vs_vers = 4,
 791         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
 792         .vs_proc = nfs4_callback_procedures1,
 793         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
 794         .vs_dispatch = NULL,
 795 };