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 <linux/sunrpc/bc_xprt.h>
  14 #include "nfs4_fs.h"
  15 #include "callback.h"
  16 #include "internal.h"
  17
  18 #define CB_OP_TAGLEN_MAXSZ      (512)
  19 #define CB_OP_HDR_RES_MAXSZ     (2 + CB_OP_TAGLEN_MAXSZ)
  20 #define CB_OP_GETATTR_BITMAP_MAXSZ      (4)
  21 #define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \
  22                                 CB_OP_GETATTR_BITMAP_MAXSZ + \
  23                                 2 + 2 + 3 + 3)
  24 #define CB_OP_RECALL_RES_MAXSZ  (CB_OP_HDR_RES_MAXSZ)
  25
  26 #if defined(CONFIG_NFS_V4_1)
  27 #define CB_OP_LAYOUTRECALL_RES_MAXSZ    (CB_OP_HDR_RES_MAXSZ)
  28 #define CB_OP_DEVICENOTIFY_RES_MAXSZ    (CB_OP_HDR_RES_MAXSZ)
  29 #define CB_OP_SEQUENCE_RES_MAXSZ        (CB_OP_HDR_RES_MAXSZ + \
  30                                         4 + 1 + 3)
  31 #define CB_OP_RECALLANY_RES_MAXSZ       (CB_OP_HDR_RES_MAXSZ)
  32 #define CB_OP_RECALLSLOT_RES_MAXSZ      (CB_OP_HDR_RES_MAXSZ)
  33 #endif /* CONFIG_NFS_V4_1 */
  34
  35 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  36
  37 /* Internal error code */
  38 #define NFS4ERR_RESOURCE_HDR    11050
  39
  40 typedef __be32 (*callback_process_op_t)(void *, void *,
  41                                         struct cb_process_state *);
  42 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
  43 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
  44
  45
  46 struct callback_op {
  47         callback_process_op_t process_op;
  48         callback_decode_arg_t decode_args;
  49         callback_encode_res_t encode_res;
  50         long res_maxsize;
  51 };
  52
  53 static struct callback_op callback_ops[];
  54
  55 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
  56 {
  57         return htonl(NFS4_OK);
  58 }
  59
  60 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  61 {
  62         return xdr_argsize_check(rqstp, p);
  63 }
  64
  65 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  66 {
  67         return xdr_ressize_check(rqstp, p);
  68 }
  69
  70 static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
  71 {
  72         __be32 *p;
  73
  74         p = xdr_inline_decode(xdr, nbytes);
  75         if (unlikely(p == NULL))
  76                 printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
  77         return p;
  78 }
  79
  80 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
  81 {
  82         __be32 *p;
  83
  84         p = read_buf(xdr, 4);
  85         if (unlikely(p == NULL))
  86                 return htonl(NFS4ERR_RESOURCE);
  87         *len = ntohl(*p);
  88
  89         if (*len != 0) {
  90                 p = read_buf(xdr, *len);
  91                 if (unlikely(p == NULL))
  92                         return htonl(NFS4ERR_RESOURCE);
  93                 *str = (const char *)p;
  94         } else
  95                 *str = NULL;
  96
  97         return 0;
  98 }
  99
 100 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
 101 {
 102         __be32 *p;
 103
 104         p = read_buf(xdr, 4);
 105         if (unlikely(p == NULL))
 106                 return htonl(NFS4ERR_RESOURCE);
 107         fh->size = ntohl(*p);
 108         if (fh->size > NFS4_FHSIZE)
 109                 return htonl(NFS4ERR_BADHANDLE);
 110         p = read_buf(xdr, fh->size);
 111         if (unlikely(p == NULL))
 112                 return htonl(NFS4ERR_RESOURCE);
 113         memcpy(&fh->data[0], p, fh->size);
 114         memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 115         return 0;
 116 }
 117
 118 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 119 {
 120         __be32 *p;
 121         unsigned int attrlen;
 122
 123         p = read_buf(xdr, 4);
 124         if (unlikely(p == NULL))
 125                 return htonl(NFS4ERR_RESOURCE);
 126         attrlen = ntohl(*p);
 127         p = read_buf(xdr, attrlen << 2);
 128         if (unlikely(p == NULL))
 129                 return htonl(NFS4ERR_RESOURCE);
 130         if (likely(attrlen > 0))
 131                 bitmap[0] = ntohl(*p++);
 132         if (attrlen > 1)
 133                 bitmap[1] = ntohl(*p);
 134         return 0;
 135 }
 136
 137 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 138 {
 139         __be32 *p;
 140
 141         p = read_buf(xdr, 16);
 142         if (unlikely(p == NULL))
 143                 return htonl(NFS4ERR_RESOURCE);
 144         memcpy(stateid->data, p, 16);
 145         return 0;
 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);
 154         if (unlikely(status != 0))
 155                 return status;
 156         /* We do not like overly long tags! */
 157         if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
 158                 printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
 159                                 __func__, hdr->taglen);
 160                 return htonl(NFS4ERR_RESOURCE);
 161         }
 162         p = read_buf(xdr, 12);
 163         if (unlikely(p == NULL))
 164                 return htonl(NFS4ERR_RESOURCE);
 165         hdr->minorversion = ntohl(*p++);
 166         /* Check minor version is zero or one. */
 167         if (hdr->minorversion <= 1) {
 168                 hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 */
 169         } else {
 170                 printk(KERN_WARNING "%s: NFSv4 server callback with "
 171                         "illegal minor version %u!\n",
 172                         __func__, hdr->minorversion);
 173                 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 174         }
 175         hdr->nops = ntohl(*p);
 176         dprintk("%s: minorversion %d nops %d\n", __func__,
 177                 hdr->minorversion, hdr->nops);
 178         return 0;
 179 }
 180
 181 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 182 {
 183         __be32 *p;
 184         p = read_buf(xdr, 4);
 185         if (unlikely(p == NULL))
 186                 return htonl(NFS4ERR_RESOURCE_HDR);
 187         *op = ntohl(*p);
 188         return 0;
 189 }
 190
 191 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
 192 {
 193         __be32 status;
 194
 195         status = decode_fh(xdr, &args->fh);
 196         if (unlikely(status != 0))
 197                 goto out;
 198         args->addr = svc_addr(rqstp);
 199         status = decode_bitmap(xdr, args->bitmap);
 200 out:
 201         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 202         return status;
 203 }
 204
 205 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
 206 {
 207         __be32 *p;
 208         __be32 status;
 209
 210         args->addr = svc_addr(rqstp);
 211         status = decode_stateid(xdr, &args->stateid);
 212         if (unlikely(status != 0))
 213                 goto out;
 214         p = read_buf(xdr, 4);
 215         if (unlikely(p == NULL)) {
 216                 status = htonl(NFS4ERR_RESOURCE);
 217                 goto out;
 218         }
 219         args->truncate = ntohl(*p);
 220         status = decode_fh(xdr, &args->fh);
 221 out:
 222         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 223         return status;
 224 }
 225
 226 #if defined(CONFIG_NFS_V4_1)
 227
 228 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 229                                        struct xdr_stream *xdr,
 230                                        struct cb_layoutrecallargs *args)
 231 {
 232         __be32 *p;
 233         __be32 status = 0;
 234         uint32_t iomode;
 235
 236         args->cbl_addr = svc_addr(rqstp);
 237         p = read_buf(xdr, 4 * sizeof(uint32_t));
 238         if (unlikely(p == NULL)) {
 239                 status = htonl(NFS4ERR_BADXDR);
 240                 goto out;
 241         }
 242
 243         args->cbl_layout_type = ntohl(*p++);
 244         /* Depite the spec's xdr, iomode really belongs in the FILE switch,
 245          * as it is unusable and ignored with the other types.
 246          */
 247         iomode = ntohl(*p++);
 248         args->cbl_layoutchanged = ntohl(*p++);
 249         args->cbl_recall_type = ntohl(*p++);
 250
 251         if (args->cbl_recall_type == RETURN_FILE) {
 252                 args->cbl_range.iomode = iomode;
 253                 status = decode_fh(xdr, &args->cbl_fh);
 254                 if (unlikely(status != 0))
 255                         goto out;
 256
 257                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 258                 if (unlikely(p == NULL)) {
 259                         status = htonl(NFS4ERR_BADXDR);
 260                         goto out;
 261                 }
 262                 p = xdr_decode_hyper(p, &args->cbl_range.offset);
 263                 p = xdr_decode_hyper(p, &args->cbl_range.length);
 264                 status = decode_stateid(xdr, &args->cbl_stateid);
 265                 if (unlikely(status != 0))
 266                         goto out;
 267         } else if (args->cbl_recall_type == RETURN_FSID) {
 268                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 269                 if (unlikely(p == NULL)) {
 270                         status = htonl(NFS4ERR_BADXDR);
 271                         goto out;
 272                 }
 273                 p = xdr_decode_hyper(p, &args->cbl_fsid.major);
 274                 p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
 275         } else if (args->cbl_recall_type != RETURN_ALL) {
 276                 status = htonl(NFS4ERR_BADXDR);
 277                 goto out;
 278         }
 279         dprintk("%s: ltype 0x%x iomode %d changed %d recall_type %d\n",
 280                 __func__,
 281                 args->cbl_layout_type, iomode,
 282                 args->cbl_layoutchanged, args->cbl_recall_type);
 283 out:
 284         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 285         return status;
 286 }
 287
 288 static
 289 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
 290                                 struct xdr_stream *xdr,
 291                                 struct cb_devicenotifyargs *args)
 292 {
 293         __be32 *p;
 294         __be32 status = 0;
 295         u32 tmp;
 296         int n, i;
 297         args->ndevs = 0;
 298
 299         /* Num of device notifications */
 300         p = read_buf(xdr, sizeof(uint32_t));
 301         if (unlikely(p == NULL)) {
 302                 status = htonl(NFS4ERR_BADXDR);
 303                 goto out;
 304         }
 305         n = ntohl(*p++);
 306         if (n <= 0)
 307                 goto out;
 308
 309         args->devs = kmalloc(n * sizeof(*args->devs), GFP_KERNEL);
 310         if (!args->devs) {
 311                 status = htonl(NFS4ERR_DELAY);
 312                 goto out;
 313         }
 314
 315         /* Decode each dev notification */
 316         for (i = 0; i < n; i++) {
 317                 struct cb_devicenotifyitem *dev = &args->devs[i];
 318
 319                 p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
 320                 if (unlikely(p == NULL)) {
 321                         status = htonl(NFS4ERR_BADXDR);
 322                         goto err;
 323                 }
 324
 325                 tmp = ntohl(*p++);      /* bitmap size */
 326                 if (tmp != 1) {
 327                         status = htonl(NFS4ERR_INVAL);
 328                         goto err;
 329                 }
 330                 dev->cbd_notify_type = ntohl(*p++);
 331                 if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
 332                     dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
 333                         status = htonl(NFS4ERR_INVAL);
 334                         goto err;
 335                 }
 336
 337                 tmp = ntohl(*p++);      /* opaque size */
 338                 if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
 339                      (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
 340                     ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
 341                      (tmp != NFS4_DEVICEID4_SIZE + 4))) {
 342                         status = htonl(NFS4ERR_INVAL);
 343                         goto err;
 344                 }
 345                 dev->cbd_layout_type = ntohl(*p++);
 346                 memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
 347                 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 348
 349                 if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
 350                         p = read_buf(xdr, sizeof(uint32_t));
 351                         if (unlikely(p == NULL)) {
 352                                 status = htonl(NFS4ERR_BADXDR);
 353                                 goto err;
 354                         }
 355                         dev->cbd_immediate = ntohl(*p++);
 356                 } else {
 357                         dev->cbd_immediate = 0;
 358                 }
 359
 360                 args->ndevs++;
 361
 362                 dprintk("%s: type %d layout 0x%x immediate %d\n",
 363                         __func__, dev->cbd_notify_type, dev->cbd_layout_type,
 364                         dev->cbd_immediate);
 365         }
 366 out:
 367         dprintk("%s: status %d ndevs %d\n",
 368                 __func__, ntohl(status), args->ndevs);
 369         return status;
 370 err:
 371         kfree(args->devs);
 372         goto out;
 373 }
 374
 375 static __be32 decode_sessionid(struct xdr_stream *xdr,
 376                                  struct nfs4_sessionid *sid)
 377 {
 378         __be32 *p;
 379         int len = NFS4_MAX_SESSIONID_LEN;
 380
 381         p = read_buf(xdr, len);
 382         if (unlikely(p == NULL))
 383                 return htonl(NFS4ERR_RESOURCE);
 384
 385         memcpy(sid->data, p, len);
 386         return 0;
 387 }
 388
 389 static __be32 decode_rc_list(struct xdr_stream *xdr,
 390                                struct referring_call_list *rc_list)
 391 {
 392         __be32 *p;
 393         int i;
 394         __be32 status;
 395
 396         status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 397         if (status)
 398                 goto out;
 399
 400         status = htonl(NFS4ERR_RESOURCE);
 401         p = read_buf(xdr, sizeof(uint32_t));
 402         if (unlikely(p == NULL))
 403                 goto out;
 404
 405         rc_list->rcl_nrefcalls = ntohl(*p++);
 406         if (rc_list->rcl_nrefcalls) {
 407                 p = read_buf(xdr,
 408                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 409                 if (unlikely(p == NULL))
 410                         goto out;
 411                 rc_list->rcl_refcalls = kmalloc(rc_list->rcl_nrefcalls *
 412                                                 sizeof(*rc_list->rcl_refcalls),
 413                                                 GFP_KERNEL);
 414                 if (unlikely(rc_list->rcl_refcalls == NULL))
 415                         goto out;
 416                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 417                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 418                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 419                 }
 420         }
 421         status = 0;
 422
 423 out:
 424         return status;
 425 }
 426
 427 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 428                                         struct xdr_stream *xdr,
 429                                         struct cb_sequenceargs *args)
 430 {
 431         __be32 *p;
 432         int i;
 433         __be32 status;
 434
 435         status = decode_sessionid(xdr, &args->csa_sessionid);
 436         if (status)
 437                 goto out;
 438
 439         status = htonl(NFS4ERR_RESOURCE);
 440         p = read_buf(xdr, 5 * sizeof(uint32_t));
 441         if (unlikely(p == NULL))
 442                 goto out;
 443
 444         args->csa_addr = svc_addr(rqstp);
 445         args->csa_sequenceid = ntohl(*p++);
 446         args->csa_slotid = ntohl(*p++);
 447         args->csa_highestslotid = ntohl(*p++);
 448         args->csa_cachethis = ntohl(*p++);
 449         args->csa_nrclists = ntohl(*p++);
 450         args->csa_rclists = NULL;
 451         if (args->csa_nrclists) {
 452                 args->csa_rclists = kmalloc(args->csa_nrclists *
 453                                             sizeof(*args->csa_rclists),
 454                                             GFP_KERNEL);
 455                 if (unlikely(args->csa_rclists == NULL))
 456                         goto out;
 457
 458                 for (i = 0; i < args->csa_nrclists; i++) {
 459                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 460                         if (status)
 461                                 goto out_free;
 462                 }
 463         }
 464         status = 0;
 465
 466         dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
 467                 "highestslotid %u cachethis %d nrclists %u\n",
 468                 __func__,
 469                 ((u32 *)&args->csa_sessionid)[0],
 470                 ((u32 *)&args->csa_sessionid)[1],
 471                 ((u32 *)&args->csa_sessionid)[2],
 472                 ((u32 *)&args->csa_sessionid)[3],
 473                 args->csa_sequenceid, args->csa_slotid,
 474                 args->csa_highestslotid, args->csa_cachethis,
 475                 args->csa_nrclists);
 476 out:
 477         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 478         return status;
 479
 480 out_free:
 481         for (i = 0; i < args->csa_nrclists; i++)
 482                 kfree(args->csa_rclists[i].rcl_refcalls);
 483         kfree(args->csa_rclists);
 484         goto out;
 485 }
 486
 487 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 488                                       struct xdr_stream *xdr,
 489                                       struct cb_recallanyargs *args)
 490 {
 491         __be32 *p;
 492
 493         args->craa_addr = svc_addr(rqstp);
 494         p = read_buf(xdr, 4);
 495         if (unlikely(p == NULL))
 496                 return htonl(NFS4ERR_BADXDR);
 497         args->craa_objs_to_keep = ntohl(*p++);
 498         p = read_buf(xdr, 4);
 499         if (unlikely(p == NULL))
 500                 return htonl(NFS4ERR_BADXDR);
 501         args->craa_type_mask = ntohl(*p);
 502
 503         return 0;
 504 }
 505
 506 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 507                                         struct xdr_stream *xdr,
 508                                         struct cb_recallslotargs *args)
 509 {
 510         __be32 *p;
 511
 512         args->crsa_addr = svc_addr(rqstp);
 513         p = read_buf(xdr, 4);
 514         if (unlikely(p == NULL))
 515                 return htonl(NFS4ERR_BADXDR);
 516         args->crsa_target_max_slots = ntohl(*p++);
 517         return 0;
 518 }
 519
 520 #endif /* CONFIG_NFS_V4_1 */
 521
 522 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 523 {
 524         __be32 *p;
 525
 526         p = xdr_reserve_space(xdr, 4 + len);
 527         if (unlikely(p == NULL))
 528                 return htonl(NFS4ERR_RESOURCE);
 529         xdr_encode_opaque(p, str, len);
 530         return 0;
 531 }
 532
 533 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
 534 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
 535 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
 536 {
 537         __be32 bm[2];
 538         __be32 *p;
 539
 540         bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
 541         bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
 542         if (bm[1] != 0) {
 543                 p = xdr_reserve_space(xdr, 16);
 544                 if (unlikely(p == NULL))
 545                         return htonl(NFS4ERR_RESOURCE);
 546                 *p++ = htonl(2);
 547                 *p++ = bm[0];
 548                 *p++ = bm[1];
 549         } else if (bm[0] != 0) {
 550                 p = xdr_reserve_space(xdr, 12);
 551                 if (unlikely(p == NULL))
 552                         return htonl(NFS4ERR_RESOURCE);
 553                 *p++ = htonl(1);
 554                 *p++ = bm[0];
 555         } else {
 556                 p = xdr_reserve_space(xdr, 8);
 557                 if (unlikely(p == NULL))
 558                         return htonl(NFS4ERR_RESOURCE);
 559                 *p++ = htonl(0);
 560         }
 561         *savep = p;
 562         return 0;
 563 }
 564
 565 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 566 {
 567         __be32 *p;
 568
 569         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 570                 return 0;
 571         p = xdr_reserve_space(xdr, 8);
 572         if (unlikely(!p))
 573                 return htonl(NFS4ERR_RESOURCE);
 574         p = xdr_encode_hyper(p, change);
 575         return 0;
 576 }
 577
 578 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 579 {
 580         __be32 *p;
 581
 582         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 583                 return 0;
 584         p = xdr_reserve_space(xdr, 8);
 585         if (unlikely(!p))
 586                 return htonl(NFS4ERR_RESOURCE);
 587         p = xdr_encode_hyper(p, size);
 588         return 0;
 589 }
 590
 591 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
 592 {
 593         __be32 *p;
 594
 595         p = xdr_reserve_space(xdr, 12);
 596         if (unlikely(!p))
 597                 return htonl(NFS4ERR_RESOURCE);
 598         p = xdr_encode_hyper(p, time->tv_sec);
 599         *p = htonl(time->tv_nsec);
 600         return 0;
 601 }
 602
 603 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 604 {
 605         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 606                 return 0;
 607         return encode_attr_time(xdr,time);
 608 }
 609
 610 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 611 {
 612         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 613                 return 0;
 614         return encode_attr_time(xdr,time);
 615 }
 616
 617 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 618 {
 619         __be32 status;
 620
 621         hdr->status = xdr_reserve_space(xdr, 4);
 622         if (unlikely(hdr->status == NULL))
 623                 return htonl(NFS4ERR_RESOURCE);
 624         status = encode_string(xdr, hdr->taglen, hdr->tag);
 625         if (unlikely(status != 0))
 626                 return status;
 627         hdr->nops = xdr_reserve_space(xdr, 4);
 628         if (unlikely(hdr->nops == NULL))
 629                 return htonl(NFS4ERR_RESOURCE);
 630         return 0;
 631 }
 632
 633 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 634 {
 635         __be32 *p;
 636
 637         p = xdr_reserve_space(xdr, 8);
 638         if (unlikely(p == NULL))
 639                 return htonl(NFS4ERR_RESOURCE_HDR);
 640         *p++ = htonl(op);
 641         *p = res;
 642         return 0;
 643 }
 644
 645 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
 646 {
 647         __be32 *savep = NULL;
 648         __be32 status = res->status;
 649
 650         if (unlikely(status != 0))
 651                 goto out;
 652         status = encode_attr_bitmap(xdr, res->bitmap, &savep);
 653         if (unlikely(status != 0))
 654                 goto out;
 655         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 656         if (unlikely(status != 0))
 657                 goto out;
 658         status = encode_attr_size(xdr, res->bitmap, res->size);
 659         if (unlikely(status != 0))
 660                 goto out;
 661         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 662         if (unlikely(status != 0))
 663                 goto out;
 664         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 665         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 666 out:
 667         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 668         return status;
 669 }
 670
 671 #if defined(CONFIG_NFS_V4_1)
 672
 673 static __be32 encode_sessionid(struct xdr_stream *xdr,
 674                                  const struct nfs4_sessionid *sid)
 675 {
 676         __be32 *p;
 677         int len = NFS4_MAX_SESSIONID_LEN;
 678
 679         p = xdr_reserve_space(xdr, len);
 680         if (unlikely(p == NULL))
 681                 return htonl(NFS4ERR_RESOURCE);
 682
 683         memcpy(p, sid, len);
 684         return 0;
 685 }
 686
 687 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 688                                        struct xdr_stream *xdr,
 689                                        const struct cb_sequenceres *res)
 690 {
 691         __be32 *p;
 692         unsigned status = res->csr_status;
 693
 694         if (unlikely(status != 0))
 695                 goto out;
 696
 697         encode_sessionid(xdr, &res->csr_sessionid);
 698
 699         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 700         if (unlikely(p == NULL))
 701                 return htonl(NFS4ERR_RESOURCE);
 702
 703         *p++ = htonl(res->csr_sequenceid);
 704         *p++ = htonl(res->csr_slotid);
 705         *p++ = htonl(res->csr_highestslotid);
 706         *p++ = htonl(res->csr_target_highestslotid);
 707 out:
 708         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 709         return status;
 710 }
 711
 712 static __be32
 713 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 714 {
 715         if (op_nr == OP_CB_SEQUENCE) {
 716                 if (nop != 0)
 717                         return htonl(NFS4ERR_SEQUENCE_POS);
 718         } else {
 719                 if (nop == 0)
 720                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 721         }
 722
 723         switch (op_nr) {
 724         case OP_CB_GETATTR:
 725         case OP_CB_RECALL:
 726         case OP_CB_SEQUENCE:
 727         case OP_CB_RECALL_ANY:
 728         case OP_CB_RECALL_SLOT:
 729         case OP_CB_LAYOUTRECALL:
 730         case OP_CB_NOTIFY_DEVICEID:
 731                 *op = &callback_ops[op_nr];
 732                 break;
 733
 734         case OP_CB_NOTIFY:
 735         case OP_CB_PUSH_DELEG:
 736         case OP_CB_RECALLABLE_OBJ_AVAIL:
 737         case OP_CB_WANTS_CANCELLED:
 738         case OP_CB_NOTIFY_LOCK:
 739                 return htonl(NFS4ERR_NOTSUPP);
 740
 741         default:
 742                 return htonl(NFS4ERR_OP_ILLEGAL);
 743         }
 744
 745         return htonl(NFS_OK);
 746 }
 747
 748 static void nfs4_callback_free_slot(struct nfs4_session *session)
 749 {
 750         struct nfs4_slot_table *tbl = &session->bc_slot_table;
 751
 752         spin_lock(&tbl->slot_tbl_lock);
 753         /*
 754          * Let the state manager know callback processing done.
 755          * A single slot, so highest used slotid is either 0 or -1
 756          */
 757         tbl->highest_used_slotid--;
 758         nfs4_check_drain_bc_complete(session);
 759         spin_unlock(&tbl->slot_tbl_lock);
 760 }
 761
 762 static void nfs4_cb_free_slot(struct nfs_client *clp)
 763 {
 764         if (clp && clp->cl_session)
 765                 nfs4_callback_free_slot(clp->cl_session);
 766 }
 767
 768 /* A single slot, so highest used slotid is either 0 or -1 */
 769 void nfs4_cb_take_slot(struct nfs_client *clp)
 770 {
 771         struct nfs4_slot_table *tbl = &clp->cl_session->bc_slot_table;
 772
 773         spin_lock(&tbl->slot_tbl_lock);
 774         tbl->highest_used_slotid++;
 775         BUG_ON(tbl->highest_used_slotid != 0);
 776         spin_unlock(&tbl->slot_tbl_lock);
 777 }
 778
 779 #else /* CONFIG_NFS_V4_1 */
 780
 781 static __be32
 782 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 783 {
 784         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 785 }
 786
 787 static void nfs4_cb_free_slot(struct nfs_client *clp)
 788 {
 789 }
 790 #endif /* CONFIG_NFS_V4_1 */
 791
 792 static __be32
 793 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 794 {
 795         switch (op_nr) {
 796         case OP_CB_GETATTR:
 797         case OP_CB_RECALL:
 798                 *op = &callback_ops[op_nr];
 799                 break;
 800         default:
 801                 return htonl(NFS4ERR_OP_ILLEGAL);
 802         }
 803
 804         return htonl(NFS_OK);
 805 }
 806
 807 static __be32 process_op(uint32_t minorversion, int nop,
 808                 struct svc_rqst *rqstp,
 809                 struct xdr_stream *xdr_in, void *argp,
 810                 struct xdr_stream *xdr_out, void *resp,
 811                 struct cb_process_state *cps)
 812 {
 813         struct callback_op *op = &callback_ops[0];
 814         unsigned int op_nr;
 815         __be32 status;
 816         long maxlen;
 817         __be32 res;
 818
 819         dprintk("%s: start\n", __func__);
 820         status = decode_op_hdr(xdr_in, &op_nr);
 821         if (unlikely(status))
 822                 return status;
 823
 824         dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
 825                 __func__, minorversion, nop, op_nr);
 826
 827         status = minorversion ? preprocess_nfs41_op(nop, op_nr, &op) :
 828                                 preprocess_nfs4_op(op_nr, &op);
 829         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 830                 op_nr = OP_CB_ILLEGAL;
 831         if (status)
 832                 goto encode_hdr;
 833
 834         if (cps->drc_status) {
 835                 status = cps->drc_status;
 836                 goto encode_hdr;
 837         }
 838
 839         maxlen = xdr_out->end - xdr_out->p;
 840         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 841                 status = op->decode_args(rqstp, xdr_in, argp);
 842                 if (likely(status == 0))
 843                         status = op->process_op(argp, resp, cps);
 844         } else
 845                 status = htonl(NFS4ERR_RESOURCE);
 846
 847 encode_hdr:
 848         res = encode_op_hdr(xdr_out, op_nr, status);
 849         if (unlikely(res))
 850                 return res;
 851         if (op->encode_res != NULL && status == 0)
 852                 status = op->encode_res(rqstp, xdr_out, resp);
 853         dprintk("%s: done, status = %d\n", __func__, ntohl(status));
 854         return status;
 855 }
 856
 857 /*
 858  * Decode, process and encode a COMPOUND
 859  */
 860 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
 861 {
 862         struct cb_compound_hdr_arg hdr_arg = { 0 };
 863         struct cb_compound_hdr_res hdr_res = { NULL };
 864         struct xdr_stream xdr_in, xdr_out;
 865         __be32 *p, status;
 866         struct cb_process_state cps = {
 867                 .drc_status = 0,
 868                 .clp = NULL,
 869         };
 870         unsigned int nops = 0;
 871
 872         dprintk("%s: start\n", __func__);
 873
 874         xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
 875
 876         p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
 877         xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 878
 879         status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
 880         if (status == __constant_htonl(NFS4ERR_RESOURCE))
 881                 return rpc_garbage_args;
 882
 883         if (hdr_arg.minorversion == 0) {
 884                 cps.clp = nfs4_find_client_ident(hdr_arg.cb_ident);
 885                 if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
 886                         return rpc_drop_reply;
 887         }
 888
 889         hdr_res.taglen = hdr_arg.taglen;
 890         hdr_res.tag = hdr_arg.tag;
 891         if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
 892                 return rpc_system_err;
 893
 894         while (status == 0 && nops != hdr_arg.nops) {
 895                 status = process_op(hdr_arg.minorversion, nops, rqstp,
 896                                     &xdr_in, argp, &xdr_out, resp, &cps);
 897                 nops++;
 898         }
 899
 900         /* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
 901         * resource error in cb_compound status without returning op */
 902         if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
 903                 status = htonl(NFS4ERR_RESOURCE);
 904                 nops--;
 905         }
 906
 907         *hdr_res.status = status;
 908         *hdr_res.nops = htonl(nops);
 909         nfs4_cb_free_slot(cps.clp);
 910         nfs_put_client(cps.clp);
 911         dprintk("%s: done, status = %u\n", __func__, ntohl(status));
 912         return rpc_success;
 913 }
 914
 915 /*
 916  * Define NFS4 callback COMPOUND ops.
 917  */
 918 static struct callback_op callback_ops[] = {
 919         [0] = {
 920                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
 921         },
 922         [OP_CB_GETATTR] = {
 923                 .process_op = (callback_process_op_t)nfs4_callback_getattr,
 924                 .decode_args = (callback_decode_arg_t)decode_getattr_args,
 925                 .encode_res = (callback_encode_res_t)encode_getattr_res,
 926                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
 927         },
 928         [OP_CB_RECALL] = {
 929                 .process_op = (callback_process_op_t)nfs4_callback_recall,
 930                 .decode_args = (callback_decode_arg_t)decode_recall_args,
 931                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
 932         },
 933 #if defined(CONFIG_NFS_V4_1)
 934         [OP_CB_LAYOUTRECALL] = {
 935                 .process_op = (callback_process_op_t)nfs4_callback_layoutrecall,
 936                 .decode_args =
 937                         (callback_decode_arg_t)decode_layoutrecall_args,
 938                 .res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
 939         },
 940         [OP_CB_NOTIFY_DEVICEID] = {
 941                 .process_op = (callback_process_op_t)nfs4_callback_devicenotify,
 942                 .decode_args =
 943                         (callback_decode_arg_t)decode_devicenotify_args,
 944                 .res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
 945         },
 946         [OP_CB_SEQUENCE] = {
 947                 .process_op = (callback_process_op_t)nfs4_callback_sequence,
 948                 .decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
 949                 .encode_res = (callback_encode_res_t)encode_cb_sequence_res,
 950                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
 951         },
 952         [OP_CB_RECALL_ANY] = {
 953                 .process_op = (callback_process_op_t)nfs4_callback_recallany,
 954                 .decode_args = (callback_decode_arg_t)decode_recallany_args,
 955                 .res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
 956         },
 957         [OP_CB_RECALL_SLOT] = {
 958                 .process_op = (callback_process_op_t)nfs4_callback_recallslot,
 959                 .decode_args = (callback_decode_arg_t)decode_recallslot_args,
 960                 .res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
 961         },
 962 #endif /* CONFIG_NFS_V4_1 */
 963 };
 964
 965 /*
 966  * Define NFS4 callback procedures
 967  */
 968 static struct svc_procedure nfs4_callback_procedures1[] = {
 969         [CB_NULL] = {
 970                 .pc_func = nfs4_callback_null,
 971                 .pc_decode = (kxdrproc_t)nfs4_decode_void,
 972                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 973                 .pc_xdrressize = 1,
 974         },
 975         [CB_COMPOUND] = {
 976                 .pc_func = nfs4_callback_compound,
 977                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 978                 .pc_argsize = 256,
 979                 .pc_ressize = 256,
 980                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
 981         }
 982 };
 983
 984 struct svc_version nfs4_callback_version1 = {
 985         .vs_vers = 1,
 986         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
 987         .vs_proc = nfs4_callback_procedures1,
 988         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
 989         .vs_dispatch = NULL,
 990         .vs_hidden = 1,
 991 };
 992
 993 struct svc_version nfs4_callback_version4 = {
 994         .vs_vers = 4,
 995         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
 996         .vs_proc = nfs4_callback_procedures1,
 997         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
 998         .vs_dispatch = NULL,
 999 };