fs/lockd/clnt4xdr.c

   1 /*
   2  * linux/fs/lockd/clnt4xdr.c
   3  *
   4  * XDR functions to encode/decode NLM version 4 RPC arguments and results.
   5  *
   6  * NLM client-side only.
   7  *
   8  * Copyright (C) 2010, Oracle.  All rights reserved.
   9  */
  10
  11 #include <linux/types.h>
  12 #include <linux/sunrpc/xdr.h>
  13 #include <linux/sunrpc/clnt.h>
  14 #include <linux/sunrpc/stats.h>
  15 #include <linux/lockd/lockd.h>
  16
  17 #include <uapi/linux/nfs3.h>
  18
  19 #define NLMDBG_FACILITY         NLMDBG_XDR
  20
  21 #if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
  22 #  error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
  23 #endif
  24
  25 #if (NLMCLNT_OHSIZE > NLM_MAXSTRLEN)
  26 #  error "NLM host name cannot be larger than NLM's maximum string length!"
  27 #endif
  28
  29 /*
  30  * Declare the space requirements for NLM arguments and replies as
  31  * number of 32bit-words
  32  */
  33 #define NLM4_void_sz            (0)
  34 #define NLM4_cookie_sz          (1+(NLM_MAXCOOKIELEN>>2))
  35 #define NLM4_caller_sz          (1+(NLMCLNT_OHSIZE>>2))
  36 #define NLM4_owner_sz           (1+(NLMCLNT_OHSIZE>>2))
  37 #define NLM4_fhandle_sz         (1+(NFS3_FHSIZE>>2))
  38 #define NLM4_lock_sz            (5+NLM4_caller_sz+NLM4_owner_sz+NLM4_fhandle_sz)
  39 #define NLM4_holder_sz          (6+NLM4_owner_sz)
  40
  41 #define NLM4_testargs_sz        (NLM4_cookie_sz+1+NLM4_lock_sz)
  42 #define NLM4_lockargs_sz        (NLM4_cookie_sz+4+NLM4_lock_sz)
  43 #define NLM4_cancargs_sz        (NLM4_cookie_sz+2+NLM4_lock_sz)
  44 #define NLM4_unlockargs_sz      (NLM4_cookie_sz+NLM4_lock_sz)
  45
  46 #define NLM4_testres_sz         (NLM4_cookie_sz+1+NLM4_holder_sz)
  47 #define NLM4_res_sz             (NLM4_cookie_sz+1)
  48 #define NLM4_norep_sz           (0)
  49
  50
  51 static s64 loff_t_to_s64(loff_t offset)
  52 {
  53         s64 res;
  54
  55         if (offset >= NLM4_OFFSET_MAX)
  56                 res = NLM4_OFFSET_MAX;
  57         else if (offset <= -NLM4_OFFSET_MAX)
  58                 res = -NLM4_OFFSET_MAX;
  59         else
  60                 res = offset;
  61         return res;
  62 }
  63
  64 static void nlm4_compute_offsets(const struct nlm_lock *lock,
  65                                  u64 *l_offset, u64 *l_len)
  66 {
  67         const struct file_lock *fl = &lock->fl;
  68
  69         *l_offset = loff_t_to_s64(fl->fl_start);
  70         if (fl->fl_end == OFFSET_MAX)
  71                 *l_len = 0;
  72         else
  73                 *l_len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
  74 }
  75
  76 /*
  77  * Handle decode buffer overflows out-of-line.
  78  */
  79 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
  80 {
  81         dprintk("lockd: %s prematurely hit the end of our receive buffer. "
  82                 "Remaining buffer length is %tu words.\n",
  83                 func, xdr->end - xdr->p);
  84 }
  85
  86
  87 /*
  88  * Encode/decode NLMv4 basic data types
  89  *
  90  * Basic NLMv4 data types are defined in Appendix II, section 6.1.4
  91  * of RFC 1813: "NFS Version 3 Protocol Specification" and in Chapter
  92  * 10 of X/Open's "Protocols for Interworking: XNFS, Version 3W".
  93  *
  94  * Not all basic data types have their own encoding and decoding
  95  * functions.  For run-time efficiency, some data types are encoded
  96  * or decoded inline.
  97  */
  98
  99 static void encode_bool(struct xdr_stream *xdr, const int value)
 100 {
 101         __be32 *p;
 102
 103         p = xdr_reserve_space(xdr, 4);
 104         *p = value ? xdr_one : xdr_zero;
 105 }
 106
 107 static void encode_int32(struct xdr_stream *xdr, const s32 value)
 108 {
 109         __be32 *p;
 110
 111         p = xdr_reserve_space(xdr, 4);
 112         *p = cpu_to_be32(value);
 113 }
 114
 115 /*
 116  *      typedef opaque netobj<MAXNETOBJ_SZ>
 117  */
 118 static void encode_netobj(struct xdr_stream *xdr,
 119                           const u8 *data, const unsigned int length)
 120 {
 121         __be32 *p;
 122
 123         p = xdr_reserve_space(xdr, 4 + length);
 124         xdr_encode_opaque(p, data, length);
 125 }
 126
 127 static int decode_netobj(struct xdr_stream *xdr,
 128                          struct xdr_netobj *obj)
 129 {
 130         u32 length;
 131         __be32 *p;
 132
 133         p = xdr_inline_decode(xdr, 4);
 134         if (unlikely(p == NULL))
 135                 goto out_overflow;
 136         length = be32_to_cpup(p++);
 137         if (unlikely(length > XDR_MAX_NETOBJ))
 138                 goto out_size;
 139         obj->len = length;
 140         obj->data = (u8 *)p;
 141         return 0;
 142 out_size:
 143         dprintk("NFS: returned netobj was too long: %u\n", length);
 144         return -EIO;
 145 out_overflow:
 146         print_overflow_msg(__func__, xdr);
 147         return -EIO;
 148 }
 149
 150 /*
 151  *      netobj cookie;
 152  */
 153 static void encode_cookie(struct xdr_stream *xdr,
 154                           const struct nlm_cookie *cookie)
 155 {
 156         encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
 157 }
 158
 159 static int decode_cookie(struct xdr_stream *xdr,
 160                              struct nlm_cookie *cookie)
 161 {
 162         u32 length;
 163         __be32 *p;
 164
 165         p = xdr_inline_decode(xdr, 4);
 166         if (unlikely(p == NULL))
 167                 goto out_overflow;
 168         length = be32_to_cpup(p++);
 169         /* apparently HPUX can return empty cookies */
 170         if (length == 0)
 171                 goto out_hpux;
 172         if (length > NLM_MAXCOOKIELEN)
 173                 goto out_size;
 174         p = xdr_inline_decode(xdr, length);
 175         if (unlikely(p == NULL))
 176                 goto out_overflow;
 177         cookie->len = length;
 178         memcpy(cookie->data, p, length);
 179         return 0;
 180 out_hpux:
 181         cookie->len = 4;
 182         memset(cookie->data, 0, 4);
 183         return 0;
 184 out_size:
 185         dprintk("NFS: returned cookie was too long: %u\n", length);
 186         return -EIO;
 187 out_overflow:
 188         print_overflow_msg(__func__, xdr);
 189         return -EIO;
 190 }
 191
 192 /*
 193  *      netobj fh;
 194  */
 195 static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
 196 {
 197         encode_netobj(xdr, (u8 *)&fh->data, fh->size);
 198 }
 199
 200 /*
 201  *      enum nlm4_stats {
 202  *              NLM4_GRANTED = 0,
 203  *              NLM4_DENIED = 1,
 204  *              NLM4_DENIED_NOLOCKS = 2,
 205  *              NLM4_BLOCKED = 3,
 206  *              NLM4_DENIED_GRACE_PERIOD = 4,
 207  *              NLM4_DEADLCK = 5,
 208  *              NLM4_ROFS = 6,
 209  *              NLM4_STALE_FH = 7,
 210  *              NLM4_FBIG = 8,
 211  *              NLM4_FAILED = 9
 212  *      };
 213  *
 214  *      struct nlm4_stat {
 215  *              nlm4_stats stat;
 216  *      };
 217  *
 218  * NB: we don't swap bytes for the NLM status values.  The upper
 219  * layers deal directly with the status value in network byte
 220  * order.
 221  */
 222 static void encode_nlm4_stat(struct xdr_stream *xdr,
 223                              const __be32 stat)
 224 {
 225         __be32 *p;
 226
 227         BUG_ON(be32_to_cpu(stat) > NLM_FAILED);
 228         p = xdr_reserve_space(xdr, 4);
 229         *p = stat;
 230 }
 231
 232 static int decode_nlm4_stat(struct xdr_stream *xdr, __be32 *stat)
 233 {
 234         __be32 *p;
 235
 236         p = xdr_inline_decode(xdr, 4);
 237         if (unlikely(p == NULL))
 238                 goto out_overflow;
 239         if (unlikely(ntohl(*p) > ntohl(nlm4_failed)))
 240                 goto out_bad_xdr;
 241         *stat = *p;
 242         return 0;
 243 out_bad_xdr:
 244         dprintk("%s: server returned invalid nlm4_stats value: %u\n",
 245                         __func__, be32_to_cpup(p));
 246         return -EIO;
 247 out_overflow:
 248         print_overflow_msg(__func__, xdr);
 249         return -EIO;
 250 }
 251
 252 /*
 253  *      struct nlm4_holder {
 254  *              bool    exclusive;
 255  *              int32   svid;
 256  *              netobj  oh;
 257  *              uint64  l_offset;
 258  *              uint64  l_len;
 259  *      };
 260  */
 261 static void encode_nlm4_holder(struct xdr_stream *xdr,
 262                                const struct nlm_res *result)
 263 {
 264         const struct nlm_lock *lock = &result->lock;
 265         u64 l_offset, l_len;
 266         __be32 *p;
 267
 268         encode_bool(xdr, lock->fl.fl_type == F_RDLCK);
 269         encode_int32(xdr, lock->svid);
 270         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 271
 272         p = xdr_reserve_space(xdr, 4 + 4);
 273         nlm4_compute_offsets(lock, &l_offset, &l_len);
 274         p = xdr_encode_hyper(p, l_offset);
 275         xdr_encode_hyper(p, l_len);
 276 }
 277
 278 static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
 279 {
 280         struct nlm_lock *lock = &result->lock;
 281         struct file_lock *fl = &lock->fl;
 282         u64 l_offset, l_len;
 283         u32 exclusive;
 284         int error;
 285         __be32 *p;
 286         s32 end;
 287
 288         memset(lock, 0, sizeof(*lock));
 289         locks_init_lock(fl);
 290
 291         p = xdr_inline_decode(xdr, 4 + 4);
 292         if (unlikely(p == NULL))
 293                 goto out_overflow;
 294         exclusive = be32_to_cpup(p++);
 295         lock->svid = be32_to_cpup(p);
 296         fl->fl_pid = (pid_t)lock->svid;
 297
 298         error = decode_netobj(xdr, &lock->oh);
 299         if (unlikely(error))
 300                 goto out;
 301
 302         p = xdr_inline_decode(xdr, 8 + 8);
 303         if (unlikely(p == NULL))
 304                 goto out_overflow;
 305
 306         fl->fl_flags = FL_POSIX;
 307         fl->fl_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
 308         p = xdr_decode_hyper(p, &l_offset);
 309         xdr_decode_hyper(p, &l_len);
 310         end = l_offset + l_len - 1;
 311
 312         fl->fl_start = (loff_t)l_offset;
 313         if (l_len == 0 || end < 0)
 314                 fl->fl_end = OFFSET_MAX;
 315         else
 316                 fl->fl_end = (loff_t)end;
 317         error = 0;
 318 out:
 319         return error;
 320 out_overflow:
 321         print_overflow_msg(__func__, xdr);
 322         return -EIO;
 323 }
 324
 325 /*
 326  *      string caller_name<LM_MAXSTRLEN>;
 327  */
 328 static void encode_caller_name(struct xdr_stream *xdr, const char *name)
 329 {
 330         /* NB: client-side does not set lock->len */
 331         u32 length = strlen(name);
 332         __be32 *p;
 333
 334         p = xdr_reserve_space(xdr, 4 + length);
 335         xdr_encode_opaque(p, name, length);
 336 }
 337
 338 /*
 339  *      struct nlm4_lock {
 340  *              string  caller_name<LM_MAXSTRLEN>;
 341  *              netobj  fh;
 342  *              netobj  oh;
 343  *              int32   svid;
 344  *              uint64  l_offset;
 345  *              uint64  l_len;
 346  *      };
 347  */
 348 static void encode_nlm4_lock(struct xdr_stream *xdr,
 349                              const struct nlm_lock *lock)
 350 {
 351         u64 l_offset, l_len;
 352         __be32 *p;
 353
 354         encode_caller_name(xdr, lock->caller);
 355         encode_fh(xdr, &lock->fh);
 356         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 357
 358         p = xdr_reserve_space(xdr, 4 + 8 + 8);
 359         *p++ = cpu_to_be32(lock->svid);
 360
 361         nlm4_compute_offsets(lock, &l_offset, &l_len);
 362         p = xdr_encode_hyper(p, l_offset);
 363         xdr_encode_hyper(p, l_len);
 364 }
 365
 366
 367 /*
 368  * NLMv4 XDR encode functions
 369  *
 370  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 371  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 372  * "Protocols for Interworking: XNFS, Version 3W".
 373  */
 374
 375 /*
 376  *      struct nlm4_testargs {
 377  *              netobj cookie;
 378  *              bool exclusive;
 379  *              struct nlm4_lock alock;
 380  *      };
 381  */
 382 static void nlm4_xdr_enc_testargs(struct rpc_rqst *req,
 383                                   struct xdr_stream *xdr,
 384                                   const struct nlm_args *args)
 385 {
 386         const struct nlm_lock *lock = &args->lock;
 387
 388         encode_cookie(xdr, &args->cookie);
 389         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 390         encode_nlm4_lock(xdr, lock);
 391 }
 392
 393 /*
 394  *      struct nlm4_lockargs {
 395  *              netobj cookie;
 396  *              bool block;
 397  *              bool exclusive;
 398  *              struct nlm4_lock alock;
 399  *              bool reclaim;
 400  *              int state;
 401  *      };
 402  */
 403 static void nlm4_xdr_enc_lockargs(struct rpc_rqst *req,
 404                                   struct xdr_stream *xdr,
 405                                   const struct nlm_args *args)
 406 {
 407         const struct nlm_lock *lock = &args->lock;
 408
 409         encode_cookie(xdr, &args->cookie);
 410         encode_bool(xdr, args->block);
 411         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 412         encode_nlm4_lock(xdr, lock);
 413         encode_bool(xdr, args->reclaim);
 414         encode_int32(xdr, args->state);
 415 }
 416
 417 /*
 418  *      struct nlm4_cancargs {
 419  *              netobj cookie;
 420  *              bool block;
 421  *              bool exclusive;
 422  *              struct nlm4_lock alock;
 423  *      };
 424  */
 425 static void nlm4_xdr_enc_cancargs(struct rpc_rqst *req,
 426                                   struct xdr_stream *xdr,
 427                                   const struct nlm_args *args)
 428 {
 429         const struct nlm_lock *lock = &args->lock;
 430
 431         encode_cookie(xdr, &args->cookie);
 432         encode_bool(xdr, args->block);
 433         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 434         encode_nlm4_lock(xdr, lock);
 435 }
 436
 437 /*
 438  *      struct nlm4_unlockargs {
 439  *              netobj cookie;
 440  *              struct nlm4_lock alock;
 441  *      };
 442  */
 443 static void nlm4_xdr_enc_unlockargs(struct rpc_rqst *req,
 444                                     struct xdr_stream *xdr,
 445                                     const struct nlm_args *args)
 446 {
 447         const struct nlm_lock *lock = &args->lock;
 448
 449         encode_cookie(xdr, &args->cookie);
 450         encode_nlm4_lock(xdr, lock);
 451 }
 452
 453 /*
 454  *      struct nlm4_res {
 455  *              netobj cookie;
 456  *              nlm4_stat stat;
 457  *      };
 458  */
 459 static void nlm4_xdr_enc_res(struct rpc_rqst *req,
 460                              struct xdr_stream *xdr,
 461                              const struct nlm_res *result)
 462 {
 463         encode_cookie(xdr, &result->cookie);
 464         encode_nlm4_stat(xdr, result->status);
 465 }
 466
 467 /*
 468  *      union nlm4_testrply switch (nlm4_stats stat) {
 469  *      case NLM4_DENIED:
 470  *              struct nlm4_holder holder;
 471  *      default:
 472  *              void;
 473  *      };
 474  *
 475  *      struct nlm4_testres {
 476  *              netobj cookie;
 477  *              nlm4_testrply test_stat;
 478  *      };
 479  */
 480 static void nlm4_xdr_enc_testres(struct rpc_rqst *req,
 481                                  struct xdr_stream *xdr,
 482                                  const struct nlm_res *result)
 483 {
 484         encode_cookie(xdr, &result->cookie);
 485         encode_nlm4_stat(xdr, result->status);
 486         if (result->status == nlm_lck_denied)
 487                 encode_nlm4_holder(xdr, result);
 488 }
 489
 490
 491 /*
 492  * NLMv4 XDR decode functions
 493  *
 494  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 495  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 496  * "Protocols for Interworking: XNFS, Version 3W".
 497  */
 498
 499 /*
 500  *      union nlm4_testrply switch (nlm4_stats stat) {
 501  *      case NLM4_DENIED:
 502  *              struct nlm4_holder holder;
 503  *      default:
 504  *              void;
 505  *      };
 506  *
 507  *      struct nlm4_testres {
 508  *              netobj cookie;
 509  *              nlm4_testrply test_stat;
 510  *      };
 511  */
 512 static int decode_nlm4_testrply(struct xdr_stream *xdr,
 513                                 struct nlm_res *result)
 514 {
 515         int error;
 516
 517         error = decode_nlm4_stat(xdr, &result->status);
 518         if (unlikely(error))
 519                 goto out;
 520         if (result->status == nlm_lck_denied)
 521                 error = decode_nlm4_holder(xdr, result);
 522 out:
 523         return error;
 524 }
 525
 526 static int nlm4_xdr_dec_testres(struct rpc_rqst *req,
 527                                 struct xdr_stream *xdr,
 528                                 struct nlm_res *result)
 529 {
 530         int error;
 531
 532         error = decode_cookie(xdr, &result->cookie);
 533         if (unlikely(error))
 534                 goto out;
 535         error = decode_nlm4_testrply(xdr, result);
 536 out:
 537         return error;
 538 }
 539
 540 /*
 541  *      struct nlm4_res {
 542  *              netobj cookie;
 543  *              nlm4_stat stat;
 544  *      };
 545  */
 546 static int nlm4_xdr_dec_res(struct rpc_rqst *req,
 547                             struct xdr_stream *xdr,
 548                             struct nlm_res *result)
 549 {
 550         int error;
 551
 552         error = decode_cookie(xdr, &result->cookie);
 553         if (unlikely(error))
 554                 goto out;
 555         error = decode_nlm4_stat(xdr, &result->status);
 556 out:
 557         return error;
 558 }
 559
 560
 561 /*
 562  * For NLM, a void procedure really returns nothing
 563  */
 564 #define nlm4_xdr_dec_norep      NULL
 565
 566 #define PROC(proc, argtype, restype)                                    \
 567 [NLMPROC_##proc] = {                                                    \
 568         .p_proc      = NLMPROC_##proc,                                  \
 569         .p_encode    = (kxdreproc_t)nlm4_xdr_enc_##argtype,             \
 570         .p_decode    = (kxdrdproc_t)nlm4_xdr_dec_##restype,             \
 571         .p_arglen    = NLM4_##argtype##_sz,                             \
 572         .p_replen    = NLM4_##restype##_sz,                             \
 573         .p_statidx   = NLMPROC_##proc,                                  \
 574         .p_name      = #proc,                                           \
 575         }
 576
 577 static struct rpc_procinfo      nlm4_procedures[] = {
 578         PROC(TEST,              testargs,       testres),
 579         PROC(LOCK,              lockargs,       res),
 580         PROC(CANCEL,            cancargs,       res),
 581         PROC(UNLOCK,            unlockargs,     res),
 582         PROC(GRANTED,           testargs,       res),
 583         PROC(TEST_MSG,          testargs,       norep),
 584         PROC(LOCK_MSG,          lockargs,       norep),
 585         PROC(CANCEL_MSG,        cancargs,       norep),
 586         PROC(UNLOCK_MSG,        unlockargs,     norep),
 587         PROC(GRANTED_MSG,       testargs,       norep),
 588         PROC(TEST_RES,          testres,        norep),
 589         PROC(LOCK_RES,          res,            norep),
 590         PROC(CANCEL_RES,        res,            norep),
 591         PROC(UNLOCK_RES,        res,            norep),
 592         PROC(GRANTED_RES,       res,            norep),
 593 };
 594
 595 const struct rpc_version nlm_version4 = {
 596         .number         = 4,
 597         .nrprocs        = ARRAY_SIZE(nlm4_procedures),
 598         .procs          = nlm4_procedures,
 599 };