fs/nfs/callback_xdr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/fs/nfs/callback_xdr.c
   4  *
   5  * Copyright (C) 2004 Trond Myklebust
   6  *
   7  * NFSv4 callback encode/decode procedures
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/sunrpc/svc.h>
  11 #include <linux/nfs4.h>
  12 #include <linux/nfs_fs.h>
  13 #include <linux/ratelimit.h>
  14 #include <linux/printk.h>
  15 #include <linux/slab.h>
  16 #include <linux/sunrpc/bc_xprt.h>
  17 #include "nfs4_fs.h"
  18 #include "callback.h"
  19 #include "internal.h"
  20 #include "nfs4session.h"
  21
  22 #define CB_OP_TAGLEN_MAXSZ              (512)
  23 #define CB_OP_HDR_RES_MAXSZ             (2 * 4) // opcode, status
  24 #define CB_OP_GETATTR_BITMAP_MAXSZ      (4 * 4) // bitmap length, 3 bitmaps
  25 #define CB_OP_GETATTR_RES_MAXSZ         (CB_OP_HDR_RES_MAXSZ + \
  26                                          CB_OP_GETATTR_BITMAP_MAXSZ + \
  27                                          /* change, size, ctime, mtime */\
  28                                          (2 + 2 + 3 + 3) * 4)
  29 #define CB_OP_RECALL_RES_MAXSZ          (CB_OP_HDR_RES_MAXSZ)
  30
  31 #if defined(CONFIG_NFS_V4_1)
  32 #define CB_OP_LAYOUTRECALL_RES_MAXSZ    (CB_OP_HDR_RES_MAXSZ)
  33 #define CB_OP_DEVICENOTIFY_RES_MAXSZ    (CB_OP_HDR_RES_MAXSZ)
  34 #define CB_OP_SEQUENCE_RES_MAXSZ        (CB_OP_HDR_RES_MAXSZ + \
  35                                          NFS4_MAX_SESSIONID_LEN + \
  36                                          (1 + 3) * 4) // seqid, 3 slotids
  37 #define CB_OP_RECALLANY_RES_MAXSZ       (CB_OP_HDR_RES_MAXSZ)
  38 #define CB_OP_RECALLSLOT_RES_MAXSZ      (CB_OP_HDR_RES_MAXSZ)
  39 #define CB_OP_NOTIFY_LOCK_RES_MAXSZ     (CB_OP_HDR_RES_MAXSZ)
  40 #endif /* CONFIG_NFS_V4_1 */
  41 #ifdef CONFIG_NFS_V4_2
  42 #define CB_OP_OFFLOAD_RES_MAXSZ         (CB_OP_HDR_RES_MAXSZ)
  43 #endif /* CONFIG_NFS_V4_2 */
  44
  45 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  46
  47 /* Internal error code */
  48 #define NFS4ERR_RESOURCE_HDR    11050
  49
  50 struct callback_op {
  51         __be32 (*process_op)(void *, void *, struct cb_process_state *);
  52         __be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
  53         __be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
  54                         const void *);
  55         long res_maxsize;
  56 };
  57
  58 static struct callback_op callback_ops[];
  59
  60 static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
  61 {
  62         return htonl(NFS4_OK);
  63 }
  64
  65 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p)
  66 {
  67         return xdr_argsize_check(rqstp, p);
  68 }
  69
  70 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p)
  71 {
  72         return xdr_ressize_check(rqstp, p);
  73 }
  74
  75 static __be32 *read_buf(struct xdr_stream *xdr, size_t nbytes)
  76 {
  77         __be32 *p;
  78
  79         p = xdr_inline_decode(xdr, nbytes);
  80         if (unlikely(p == NULL))
  81                 printk(KERN_WARNING "NFS: NFSv4 callback reply buffer overflowed!\n");
  82         return p;
  83 }
  84
  85 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
  86                 const char **str, size_t maxlen)
  87 {
  88         ssize_t err;
  89
  90         err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
  91         if (err < 0)
  92                 return cpu_to_be32(NFS4ERR_RESOURCE);
  93         *len = err;
  94         return 0;
  95 }
  96
  97 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  98 {
  99         __be32 *p;
 100
 101         p = read_buf(xdr, 4);
 102         if (unlikely(p == NULL))
 103                 return htonl(NFS4ERR_RESOURCE);
 104         fh->size = ntohl(*p);
 105         if (fh->size > NFS4_FHSIZE)
 106                 return htonl(NFS4ERR_BADHANDLE);
 107         p = read_buf(xdr, fh->size);
 108         if (unlikely(p == NULL))
 109                 return htonl(NFS4ERR_RESOURCE);
 110         memcpy(&fh->data[0], p, fh->size);
 111         memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 112         return 0;
 113 }
 114
 115 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 116 {
 117         __be32 *p;
 118         unsigned int attrlen;
 119
 120         p = read_buf(xdr, 4);
 121         if (unlikely(p == NULL))
 122                 return htonl(NFS4ERR_RESOURCE);
 123         attrlen = ntohl(*p);
 124         p = read_buf(xdr, attrlen << 2);
 125         if (unlikely(p == NULL))
 126                 return htonl(NFS4ERR_RESOURCE);
 127         if (likely(attrlen > 0))
 128                 bitmap[0] = ntohl(*p++);
 129         if (attrlen > 1)
 130                 bitmap[1] = ntohl(*p);
 131         return 0;
 132 }
 133
 134 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 135 {
 136         __be32 *p;
 137
 138         p = read_buf(xdr, NFS4_STATEID_SIZE);
 139         if (unlikely(p == NULL))
 140                 return htonl(NFS4ERR_RESOURCE);
 141         memcpy(stateid->data, p, NFS4_STATEID_SIZE);
 142         return 0;
 143 }
 144
 145 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 146 {
 147         stateid->type = NFS4_DELEGATION_STATEID_TYPE;
 148         return decode_stateid(xdr, stateid);
 149 }
 150
 151 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 152 {
 153         __be32 *p;
 154         __be32 status;
 155
 156         status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
 157         if (unlikely(status != 0))
 158                 return status;
 159         p = read_buf(xdr, 12);
 160         if (unlikely(p == NULL))
 161                 return htonl(NFS4ERR_RESOURCE);
 162         hdr->minorversion = ntohl(*p++);
 163         /* Check for minor version support */
 164         if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
 165                 hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
 166         } else {
 167                 pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
 168                         "illegal minor version %u!\n",
 169                         __func__, hdr->minorversion);
 170                 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 171         }
 172         hdr->nops = ntohl(*p);
 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,
 187                 struct xdr_stream *xdr, void *argp)
 188 {
 189         struct cb_getattrargs *args = argp;
 190         __be32 status;
 191
 192         status = decode_fh(xdr, &args->fh);
 193         if (unlikely(status != 0))
 194                 return status;
 195         return decode_bitmap(xdr, args->bitmap);
 196 }
 197
 198 static __be32 decode_recall_args(struct svc_rqst *rqstp,
 199                 struct xdr_stream *xdr, void *argp)
 200 {
 201         struct cb_recallargs *args = argp;
 202         __be32 *p;
 203         __be32 status;
 204
 205         status = decode_delegation_stateid(xdr, &args->stateid);
 206         if (unlikely(status != 0))
 207                 return status;
 208         p = read_buf(xdr, 4);
 209         if (unlikely(p == NULL))
 210                 return htonl(NFS4ERR_RESOURCE);
 211         args->truncate = ntohl(*p);
 212         return decode_fh(xdr, &args->fh);
 213 }
 214
 215 #if defined(CONFIG_NFS_V4_1)
 216 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 217 {
 218         stateid->type = NFS4_LAYOUT_STATEID_TYPE;
 219         return decode_stateid(xdr, stateid);
 220 }
 221
 222 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 223                                        struct xdr_stream *xdr, void *argp)
 224 {
 225         struct cb_layoutrecallargs *args = argp;
 226         __be32 *p;
 227         __be32 status = 0;
 228         uint32_t iomode;
 229
 230         p = read_buf(xdr, 4 * sizeof(uint32_t));
 231         if (unlikely(p == NULL))
 232                 return htonl(NFS4ERR_BADXDR);
 233
 234         args->cbl_layout_type = ntohl(*p++);
 235         /* Depite the spec's xdr, iomode really belongs in the FILE switch,
 236          * as it is unusable and ignored with the other types.
 237          */
 238         iomode = ntohl(*p++);
 239         args->cbl_layoutchanged = ntohl(*p++);
 240         args->cbl_recall_type = ntohl(*p++);
 241
 242         if (args->cbl_recall_type == RETURN_FILE) {
 243                 args->cbl_range.iomode = iomode;
 244                 status = decode_fh(xdr, &args->cbl_fh);
 245                 if (unlikely(status != 0))
 246                         return status;
 247
 248                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 249                 if (unlikely(p == NULL))
 250                         return htonl(NFS4ERR_BADXDR);
 251                 p = xdr_decode_hyper(p, &args->cbl_range.offset);
 252                 p = xdr_decode_hyper(p, &args->cbl_range.length);
 253                 return decode_layout_stateid(xdr, &args->cbl_stateid);
 254         } else if (args->cbl_recall_type == RETURN_FSID) {
 255                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 256                 if (unlikely(p == NULL))
 257                         return htonl(NFS4ERR_BADXDR);
 258                 p = xdr_decode_hyper(p, &args->cbl_fsid.major);
 259                 p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
 260         } else if (args->cbl_recall_type != RETURN_ALL)
 261                 return htonl(NFS4ERR_BADXDR);
 262         return 0;
 263 }
 264
 265 static
 266 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
 267                                 struct xdr_stream *xdr,
 268                                 void *argp)
 269 {
 270         struct cb_devicenotifyargs *args = argp;
 271         __be32 *p;
 272         __be32 status = 0;
 273         u32 tmp;
 274         int n, i;
 275         args->ndevs = 0;
 276
 277         /* Num of device notifications */
 278         p = read_buf(xdr, sizeof(uint32_t));
 279         if (unlikely(p == NULL)) {
 280                 status = htonl(NFS4ERR_BADXDR);
 281                 goto out;
 282         }
 283         n = ntohl(*p++);
 284         if (n <= 0)
 285                 goto out;
 286         if (n > ULONG_MAX / sizeof(*args->devs)) {
 287                 status = htonl(NFS4ERR_BADXDR);
 288                 goto out;
 289         }
 290
 291         args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
 292         if (!args->devs) {
 293                 status = htonl(NFS4ERR_DELAY);
 294                 goto out;
 295         }
 296
 297         /* Decode each dev notification */
 298         for (i = 0; i < n; i++) {
 299                 struct cb_devicenotifyitem *dev = &args->devs[i];
 300
 301                 p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
 302                 if (unlikely(p == NULL)) {
 303                         status = htonl(NFS4ERR_BADXDR);
 304                         goto err;
 305                 }
 306
 307                 tmp = ntohl(*p++);      /* bitmap size */
 308                 if (tmp != 1) {
 309                         status = htonl(NFS4ERR_INVAL);
 310                         goto err;
 311                 }
 312                 dev->cbd_notify_type = ntohl(*p++);
 313                 if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
 314                     dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
 315                         status = htonl(NFS4ERR_INVAL);
 316                         goto err;
 317                 }
 318
 319                 tmp = ntohl(*p++);      /* opaque size */
 320                 if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
 321                      (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
 322                     ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
 323                      (tmp != NFS4_DEVICEID4_SIZE + 4))) {
 324                         status = htonl(NFS4ERR_INVAL);
 325                         goto err;
 326                 }
 327                 dev->cbd_layout_type = ntohl(*p++);
 328                 memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
 329                 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 330
 331                 if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
 332                         p = read_buf(xdr, sizeof(uint32_t));
 333                         if (unlikely(p == NULL)) {
 334                                 status = htonl(NFS4ERR_BADXDR);
 335                                 goto err;
 336                         }
 337                         dev->cbd_immediate = ntohl(*p++);
 338                 } else {
 339                         dev->cbd_immediate = 0;
 340                 }
 341
 342                 args->ndevs++;
 343
 344                 dprintk("%s: type %d layout 0x%x immediate %d\n",
 345                         __func__, dev->cbd_notify_type, dev->cbd_layout_type,
 346                         dev->cbd_immediate);
 347         }
 348 out:
 349         dprintk("%s: status %d ndevs %d\n",
 350                 __func__, ntohl(status), args->ndevs);
 351         return status;
 352 err:
 353         kfree(args->devs);
 354         goto out;
 355 }
 356
 357 static __be32 decode_sessionid(struct xdr_stream *xdr,
 358                                  struct nfs4_sessionid *sid)
 359 {
 360         __be32 *p;
 361
 362         p = read_buf(xdr, NFS4_MAX_SESSIONID_LEN);
 363         if (unlikely(p == NULL))
 364                 return htonl(NFS4ERR_RESOURCE);
 365
 366         memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
 367         return 0;
 368 }
 369
 370 static __be32 decode_rc_list(struct xdr_stream *xdr,
 371                                struct referring_call_list *rc_list)
 372 {
 373         __be32 *p;
 374         int i;
 375         __be32 status;
 376
 377         status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 378         if (status)
 379                 goto out;
 380
 381         status = htonl(NFS4ERR_RESOURCE);
 382         p = read_buf(xdr, sizeof(uint32_t));
 383         if (unlikely(p == NULL))
 384                 goto out;
 385
 386         rc_list->rcl_nrefcalls = ntohl(*p++);
 387         if (rc_list->rcl_nrefcalls) {
 388                 p = read_buf(xdr,
 389                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 390                 if (unlikely(p == NULL))
 391                         goto out;
 392                 rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
 393                                                 sizeof(*rc_list->rcl_refcalls),
 394                                                 GFP_KERNEL);
 395                 if (unlikely(rc_list->rcl_refcalls == NULL))
 396                         goto out;
 397                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 398                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 399                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 400                 }
 401         }
 402         status = 0;
 403
 404 out:
 405         return status;
 406 }
 407
 408 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 409                                         struct xdr_stream *xdr,
 410                                         void *argp)
 411 {
 412         struct cb_sequenceargs *args = argp;
 413         __be32 *p;
 414         int i;
 415         __be32 status;
 416
 417         status = decode_sessionid(xdr, &args->csa_sessionid);
 418         if (status)
 419                 return status;
 420
 421         p = read_buf(xdr, 5 * sizeof(uint32_t));
 422         if (unlikely(p == NULL))
 423                 return htonl(NFS4ERR_RESOURCE);
 424
 425         args->csa_addr = svc_addr(rqstp);
 426         args->csa_sequenceid = ntohl(*p++);
 427         args->csa_slotid = ntohl(*p++);
 428         args->csa_highestslotid = ntohl(*p++);
 429         args->csa_cachethis = ntohl(*p++);
 430         args->csa_nrclists = ntohl(*p++);
 431         args->csa_rclists = NULL;
 432         if (args->csa_nrclists) {
 433                 args->csa_rclists = kmalloc_array(args->csa_nrclists,
 434                                                   sizeof(*args->csa_rclists),
 435                                                   GFP_KERNEL);
 436                 if (unlikely(args->csa_rclists == NULL))
 437                         return htonl(NFS4ERR_RESOURCE);
 438
 439                 for (i = 0; i < args->csa_nrclists; i++) {
 440                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 441                         if (status) {
 442                                 args->csa_nrclists = i;
 443                                 goto out_free;
 444                         }
 445                 }
 446         }
 447         return 0;
 448
 449 out_free:
 450         for (i = 0; i < args->csa_nrclists; i++)
 451                 kfree(args->csa_rclists[i].rcl_refcalls);
 452         kfree(args->csa_rclists);
 453         return status;
 454 }
 455
 456 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 457                                       struct xdr_stream *xdr,
 458                                       void *argp)
 459 {
 460         struct cb_recallanyargs *args = argp;
 461         uint32_t bitmap[2];
 462         __be32 *p, status;
 463
 464         p = read_buf(xdr, 4);
 465         if (unlikely(p == NULL))
 466                 return htonl(NFS4ERR_BADXDR);
 467         args->craa_objs_to_keep = ntohl(*p++);
 468         status = decode_bitmap(xdr, bitmap);
 469         if (unlikely(status))
 470                 return status;
 471         args->craa_type_mask = bitmap[0];
 472
 473         return 0;
 474 }
 475
 476 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 477                                         struct xdr_stream *xdr,
 478                                         void *argp)
 479 {
 480         struct cb_recallslotargs *args = argp;
 481         __be32 *p;
 482
 483         p = read_buf(xdr, 4);
 484         if (unlikely(p == NULL))
 485                 return htonl(NFS4ERR_BADXDR);
 486         args->crsa_target_highest_slotid = ntohl(*p++);
 487         return 0;
 488 }
 489
 490 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
 491 {
 492         __be32          *p;
 493         unsigned int    len;
 494
 495         p = read_buf(xdr, 12);
 496         if (unlikely(p == NULL))
 497                 return htonl(NFS4ERR_BADXDR);
 498
 499         p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
 500         len = be32_to_cpu(*p);
 501
 502         p = read_buf(xdr, len);
 503         if (unlikely(p == NULL))
 504                 return htonl(NFS4ERR_BADXDR);
 505
 506         /* Only try to decode if the length is right */
 507         if (len == 20) {
 508                 p += 2; /* skip "lock id:" */
 509                 args->cbnl_owner.s_dev = be32_to_cpu(*p++);
 510                 xdr_decode_hyper(p, &args->cbnl_owner.id);
 511                 args->cbnl_valid = true;
 512         } else {
 513                 args->cbnl_owner.s_dev = 0;
 514                 args->cbnl_owner.id = 0;
 515                 args->cbnl_valid = false;
 516         }
 517         return 0;
 518 }
 519
 520 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
 521                 struct xdr_stream *xdr, void *argp)
 522 {
 523         struct cb_notify_lock_args *args = argp;
 524         __be32 status;
 525
 526         status = decode_fh(xdr, &args->cbnl_fh);
 527         if (unlikely(status != 0))
 528                 return status;
 529         return decode_lockowner(xdr, args);
 530 }
 531
 532 #endif /* CONFIG_NFS_V4_1 */
 533 #ifdef CONFIG_NFS_V4_2
 534 static __be32 decode_write_response(struct xdr_stream *xdr,
 535                                         struct cb_offloadargs *args)
 536 {
 537         __be32 *p;
 538
 539         /* skip the always zero field */
 540         p = read_buf(xdr, 4);
 541         if (unlikely(!p))
 542                 goto out;
 543         p++;
 544
 545         /* decode count, stable_how, verifier */
 546         p = xdr_inline_decode(xdr, 8 + 4);
 547         if (unlikely(!p))
 548                 goto out;
 549         p = xdr_decode_hyper(p, &args->wr_count);
 550         args->wr_writeverf.committed = be32_to_cpup(p);
 551         p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
 552         if (likely(p)) {
 553                 memcpy(&args->wr_writeverf.verifier.data[0], p,
 554                         NFS4_VERIFIER_SIZE);
 555                 return 0;
 556         }
 557 out:
 558         return htonl(NFS4ERR_RESOURCE);
 559 }
 560
 561 static __be32 decode_offload_args(struct svc_rqst *rqstp,
 562                                         struct xdr_stream *xdr,
 563                                         void *data)
 564 {
 565         struct cb_offloadargs *args = data;
 566         __be32 *p;
 567         __be32 status;
 568
 569         /* decode fh */
 570         status = decode_fh(xdr, &args->coa_fh);
 571         if (unlikely(status != 0))
 572                 return status;
 573
 574         /* decode stateid */
 575         status = decode_stateid(xdr, &args->coa_stateid);
 576         if (unlikely(status != 0))
 577                 return status;
 578
 579         /* decode status */
 580         p = read_buf(xdr, 4);
 581         if (unlikely(!p))
 582                 goto out;
 583         args->error = ntohl(*p++);
 584         if (!args->error) {
 585                 status = decode_write_response(xdr, args);
 586                 if (unlikely(status != 0))
 587                         return status;
 588         } else {
 589                 p = xdr_inline_decode(xdr, 8);
 590                 if (unlikely(!p))
 591                         goto out;
 592                 p = xdr_decode_hyper(p, &args->wr_count);
 593         }
 594         return 0;
 595 out:
 596         return htonl(NFS4ERR_RESOURCE);
 597 }
 598 #endif /* CONFIG_NFS_V4_2 */
 599 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 600 {
 601         if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
 602                 return cpu_to_be32(NFS4ERR_RESOURCE);
 603         return 0;
 604 }
 605
 606 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
 607 {
 608         if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
 609                 return cpu_to_be32(NFS4ERR_RESOURCE);
 610         return 0;
 611 }
 612
 613 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 614 {
 615         __be32 *p;
 616
 617         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 618                 return 0;
 619         p = xdr_reserve_space(xdr, 8);
 620         if (unlikely(!p))
 621                 return htonl(NFS4ERR_RESOURCE);
 622         p = xdr_encode_hyper(p, change);
 623         return 0;
 624 }
 625
 626 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 627 {
 628         __be32 *p;
 629
 630         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 631                 return 0;
 632         p = xdr_reserve_space(xdr, 8);
 633         if (unlikely(!p))
 634                 return htonl(NFS4ERR_RESOURCE);
 635         p = xdr_encode_hyper(p, size);
 636         return 0;
 637 }
 638
 639 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
 640 {
 641         __be32 *p;
 642
 643         p = xdr_reserve_space(xdr, 12);
 644         if (unlikely(!p))
 645                 return htonl(NFS4ERR_RESOURCE);
 646         p = xdr_encode_hyper(p, time->tv_sec);
 647         *p = htonl(time->tv_nsec);
 648         return 0;
 649 }
 650
 651 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 652 {
 653         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 654                 return 0;
 655         return encode_attr_time(xdr,time);
 656 }
 657
 658 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 659 {
 660         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 661                 return 0;
 662         return encode_attr_time(xdr,time);
 663 }
 664
 665 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 666 {
 667         __be32 status;
 668
 669         hdr->status = xdr_reserve_space(xdr, 4);
 670         if (unlikely(hdr->status == NULL))
 671                 return htonl(NFS4ERR_RESOURCE);
 672         status = encode_string(xdr, hdr->taglen, hdr->tag);
 673         if (unlikely(status != 0))
 674                 return status;
 675         hdr->nops = xdr_reserve_space(xdr, 4);
 676         if (unlikely(hdr->nops == NULL))
 677                 return htonl(NFS4ERR_RESOURCE);
 678         return 0;
 679 }
 680
 681 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 682 {
 683         __be32 *p;
 684
 685         p = xdr_reserve_space(xdr, 8);
 686         if (unlikely(p == NULL))
 687                 return htonl(NFS4ERR_RESOURCE_HDR);
 688         *p++ = htonl(op);
 689         *p = res;
 690         return 0;
 691 }
 692
 693 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 694                 const void *resp)
 695 {
 696         const struct cb_getattrres *res = resp;
 697         __be32 *savep = NULL;
 698         __be32 status = res->status;
 699
 700         if (unlikely(status != 0))
 701                 goto out;
 702         status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
 703         if (unlikely(status != 0))
 704                 goto out;
 705         status = cpu_to_be32(NFS4ERR_RESOURCE);
 706         savep = xdr_reserve_space(xdr, sizeof(*savep));
 707         if (unlikely(!savep))
 708                 goto out;
 709         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 710         if (unlikely(status != 0))
 711                 goto out;
 712         status = encode_attr_size(xdr, res->bitmap, res->size);
 713         if (unlikely(status != 0))
 714                 goto out;
 715         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 716         if (unlikely(status != 0))
 717                 goto out;
 718         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 719         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 720 out:
 721         return status;
 722 }
 723
 724 #if defined(CONFIG_NFS_V4_1)
 725
 726 static __be32 encode_sessionid(struct xdr_stream *xdr,
 727                                  const struct nfs4_sessionid *sid)
 728 {
 729         __be32 *p;
 730
 731         p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
 732         if (unlikely(p == NULL))
 733                 return htonl(NFS4ERR_RESOURCE);
 734
 735         memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
 736         return 0;
 737 }
 738
 739 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 740                                        struct xdr_stream *xdr,
 741                                        const void *resp)
 742 {
 743         const struct cb_sequenceres *res = resp;
 744         __be32 *p;
 745         __be32 status = res->csr_status;
 746
 747         if (unlikely(status != 0))
 748                 return status;
 749
 750         status = encode_sessionid(xdr, &res->csr_sessionid);
 751         if (status)
 752                 return status;
 753
 754         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 755         if (unlikely(p == NULL))
 756                 return htonl(NFS4ERR_RESOURCE);
 757
 758         *p++ = htonl(res->csr_sequenceid);
 759         *p++ = htonl(res->csr_slotid);
 760         *p++ = htonl(res->csr_highestslotid);
 761         *p++ = htonl(res->csr_target_highestslotid);
 762         return 0;
 763 }
 764
 765 static __be32
 766 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 767 {
 768         if (op_nr == OP_CB_SEQUENCE) {
 769                 if (nop != 0)
 770                         return htonl(NFS4ERR_SEQUENCE_POS);
 771         } else {
 772                 if (nop == 0)
 773                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 774         }
 775
 776         switch (op_nr) {
 777         case OP_CB_GETATTR:
 778         case OP_CB_RECALL:
 779         case OP_CB_SEQUENCE:
 780         case OP_CB_RECALL_ANY:
 781         case OP_CB_RECALL_SLOT:
 782         case OP_CB_LAYOUTRECALL:
 783         case OP_CB_NOTIFY_DEVICEID:
 784         case OP_CB_NOTIFY_LOCK:
 785                 *op = &callback_ops[op_nr];
 786                 break;
 787
 788         case OP_CB_NOTIFY:
 789         case OP_CB_PUSH_DELEG:
 790         case OP_CB_RECALLABLE_OBJ_AVAIL:
 791         case OP_CB_WANTS_CANCELLED:
 792                 return htonl(NFS4ERR_NOTSUPP);
 793
 794         default:
 795                 return htonl(NFS4ERR_OP_ILLEGAL);
 796         }
 797
 798         return htonl(NFS_OK);
 799 }
 800
 801 static void nfs4_callback_free_slot(struct nfs4_session *session,
 802                 struct nfs4_slot *slot)
 803 {
 804         struct nfs4_slot_table *tbl = &session->bc_slot_table;
 805
 806         spin_lock(&tbl->slot_tbl_lock);
 807         /*
 808          * Let the state manager know callback processing done.
 809          * A single slot, so highest used slotid is either 0 or -1
 810          */
 811         nfs4_free_slot(tbl, slot);
 812         spin_unlock(&tbl->slot_tbl_lock);
 813 }
 814
 815 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 816 {
 817         if (cps->slot) {
 818                 nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
 819                 cps->slot = NULL;
 820         }
 821 }
 822
 823 #else /* CONFIG_NFS_V4_1 */
 824
 825 static __be32
 826 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 827 {
 828         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 829 }
 830
 831 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 832 {
 833 }
 834 #endif /* CONFIG_NFS_V4_1 */
 835
 836 #ifdef CONFIG_NFS_V4_2
 837 static __be32
 838 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 839 {
 840         __be32 status = preprocess_nfs41_op(nop, op_nr, op);
 841         if (status != htonl(NFS4ERR_OP_ILLEGAL))
 842                 return status;
 843
 844         if (op_nr == OP_CB_OFFLOAD) {
 845                 *op = &callback_ops[op_nr];
 846                 return htonl(NFS_OK);
 847         } else
 848                 return htonl(NFS4ERR_NOTSUPP);
 849         return htonl(NFS4ERR_OP_ILLEGAL);
 850 }
 851 #else /* CONFIG_NFS_V4_2 */
 852 static __be32
 853 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 854 {
 855         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 856 }
 857 #endif /* CONFIG_NFS_V4_2 */
 858
 859 static __be32
 860 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 861 {
 862         switch (op_nr) {
 863         case OP_CB_GETATTR:
 864         case OP_CB_RECALL:
 865                 *op = &callback_ops[op_nr];
 866                 break;
 867         default:
 868                 return htonl(NFS4ERR_OP_ILLEGAL);
 869         }
 870
 871         return htonl(NFS_OK);
 872 }
 873
 874 static __be32 process_op(int nop, struct svc_rqst *rqstp,
 875                 struct xdr_stream *xdr_in, void *argp,
 876                 struct xdr_stream *xdr_out, void *resp,
 877                 struct cb_process_state *cps)
 878 {
 879         struct callback_op *op = &callback_ops[0];
 880         unsigned int op_nr;
 881         __be32 status;
 882         long maxlen;
 883         __be32 res;
 884
 885         status = decode_op_hdr(xdr_in, &op_nr);
 886         if (unlikely(status))
 887                 return status;
 888
 889         switch (cps->minorversion) {
 890         case 0:
 891                 status = preprocess_nfs4_op(op_nr, &op);
 892                 break;
 893         case 1:
 894                 status = preprocess_nfs41_op(nop, op_nr, &op);
 895                 break;
 896         case 2:
 897                 status = preprocess_nfs42_op(nop, op_nr, &op);
 898                 break;
 899         default:
 900                 status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 901         }
 902
 903         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 904                 op_nr = OP_CB_ILLEGAL;
 905         if (status)
 906                 goto encode_hdr;
 907
 908         if (cps->drc_status) {
 909                 status = cps->drc_status;
 910                 goto encode_hdr;
 911         }
 912
 913         maxlen = xdr_out->end - xdr_out->p;
 914         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 915                 status = op->decode_args(rqstp, xdr_in, argp);
 916                 if (likely(status == 0))
 917                         status = op->process_op(argp, resp, cps);
 918         } else
 919                 status = htonl(NFS4ERR_RESOURCE);
 920
 921 encode_hdr:
 922         res = encode_op_hdr(xdr_out, op_nr, status);
 923         if (unlikely(res))
 924                 return res;
 925         if (op->encode_res != NULL && status == 0)
 926                 status = op->encode_res(rqstp, xdr_out, resp);
 927         return status;
 928 }
 929
 930 /*
 931  * Decode, process and encode a COMPOUND
 932  */
 933 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
 934 {
 935         struct cb_compound_hdr_arg hdr_arg = { 0 };
 936         struct cb_compound_hdr_res hdr_res = { NULL };
 937         struct xdr_stream xdr_in, xdr_out;
 938         __be32 *p, status;
 939         struct cb_process_state cps = {
 940                 .drc_status = 0,
 941                 .clp = NULL,
 942                 .net = SVC_NET(rqstp),
 943         };
 944         unsigned int nops = 0;
 945
 946         xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
 947
 948         p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
 949         xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 950
 951         status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
 952         if (status == htonl(NFS4ERR_RESOURCE))
 953                 return rpc_garbage_args;
 954
 955         if (hdr_arg.minorversion == 0) {
 956                 cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
 957                 if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp)) {
 958                         if (cps.clp)
 959                                 nfs_put_client(cps.clp);
 960                         goto out_invalidcred;
 961                 }
 962         }
 963
 964         cps.minorversion = hdr_arg.minorversion;
 965         hdr_res.taglen = hdr_arg.taglen;
 966         hdr_res.tag = hdr_arg.tag;
 967         if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0) {
 968                 if (cps.clp)
 969                         nfs_put_client(cps.clp);
 970                 return rpc_system_err;
 971         }
 972         while (status == 0 && nops != hdr_arg.nops) {
 973                 status = process_op(nops, rqstp, &xdr_in,
 974                                     rqstp->rq_argp, &xdr_out, rqstp->rq_resp,
 975                                     &cps);
 976                 nops++;
 977         }
 978
 979         /* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
 980         * resource error in cb_compound status without returning op */
 981         if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
 982                 status = htonl(NFS4ERR_RESOURCE);
 983                 nops--;
 984         }
 985
 986         *hdr_res.status = status;
 987         *hdr_res.nops = htonl(nops);
 988         nfs4_cb_free_slot(&cps);
 989         nfs_put_client(cps.clp);
 990         return rpc_success;
 991
 992 out_invalidcred:
 993         pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
 994         return rpc_autherr_badcred;
 995 }
 996
 997 /*
 998  * Define NFS4 callback COMPOUND ops.
 999  */
1000 static struct callback_op callback_ops[] = {
1001         [0] = {
1002                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
1003         },
1004         [OP_CB_GETATTR] = {
1005                 .process_op = nfs4_callback_getattr,
1006                 .decode_args = decode_getattr_args,
1007                 .encode_res = encode_getattr_res,
1008                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1009         },
1010         [OP_CB_RECALL] = {
1011                 .process_op = nfs4_callback_recall,
1012                 .decode_args = decode_recall_args,
1013                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1014         },
1015 #if defined(CONFIG_NFS_V4_1)
1016         [OP_CB_LAYOUTRECALL] = {
1017                 .process_op = nfs4_callback_layoutrecall,
1018                 .decode_args = decode_layoutrecall_args,
1019                 .res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1020         },
1021         [OP_CB_NOTIFY_DEVICEID] = {
1022                 .process_op = nfs4_callback_devicenotify,
1023                 .decode_args = decode_devicenotify_args,
1024                 .res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1025         },
1026         [OP_CB_SEQUENCE] = {
1027                 .process_op = nfs4_callback_sequence,
1028                 .decode_args = decode_cb_sequence_args,
1029                 .encode_res = encode_cb_sequence_res,
1030                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1031         },
1032         [OP_CB_RECALL_ANY] = {
1033                 .process_op = nfs4_callback_recallany,
1034                 .decode_args = decode_recallany_args,
1035                 .res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1036         },
1037         [OP_CB_RECALL_SLOT] = {
1038                 .process_op = nfs4_callback_recallslot,
1039                 .decode_args = decode_recallslot_args,
1040                 .res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1041         },
1042         [OP_CB_NOTIFY_LOCK] = {
1043                 .process_op = nfs4_callback_notify_lock,
1044                 .decode_args = decode_notify_lock_args,
1045                 .res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1046         },
1047 #endif /* CONFIG_NFS_V4_1 */
1048 #ifdef CONFIG_NFS_V4_2
1049         [OP_CB_OFFLOAD] = {
1050                 .process_op = nfs4_callback_offload,
1051                 .decode_args = decode_offload_args,
1052                 .res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1053         },
1054 #endif /* CONFIG_NFS_V4_2 */
1055 };
1056
1057 /*
1058  * Define NFS4 callback procedures
1059  */
1060 static const struct svc_procedure nfs4_callback_procedures1[] = {
1061         [CB_NULL] = {
1062                 .pc_func = nfs4_callback_null,
1063                 .pc_decode = nfs4_decode_void,
1064                 .pc_encode = nfs4_encode_void,
1065                 .pc_xdrressize = 1,
1066         },
1067         [CB_COMPOUND] = {
1068                 .pc_func = nfs4_callback_compound,
1069                 .pc_encode = nfs4_encode_void,
1070                 .pc_argsize = 256,
1071                 .pc_ressize = 256,
1072                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1073         }
1074 };
1075
1076 static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
1077 const struct svc_version nfs4_callback_version1 = {
1078         .vs_vers = 1,
1079         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1080         .vs_proc = nfs4_callback_procedures1,
1081         .vs_count = nfs4_callback_count1,
1082         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1083         .vs_dispatch = NULL,
1084         .vs_hidden = true,
1085         .vs_need_cong_ctrl = true,
1086 };
1087
1088 static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
1089 const struct svc_version nfs4_callback_version4 = {
1090         .vs_vers = 4,
1091         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1092         .vs_proc = nfs4_callback_procedures1,
1093         .vs_count = nfs4_callback_count4,
1094         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1095         .vs_dispatch = NULL,
1096         .vs_hidden = true,
1097         .vs_need_cong_ctrl = true,
1098 };