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 void *data)
 385 {
 386         const struct nlm_args *args = data;
 387         const struct nlm_lock *lock = &args->lock;
 388
 389         encode_cookie(xdr, &args->cookie);
 390         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 391         encode_nlm4_lock(xdr, lock);
 392 }
 393
 394 /*
 395  *      struct nlm4_lockargs {
 396  *              netobj cookie;
 397  *              bool block;
 398  *              bool exclusive;
 399  *              struct nlm4_lock alock;
 400  *              bool reclaim;
 401  *              int state;
 402  *      };
 403  */
 404 static void nlm4_xdr_enc_lockargs(struct rpc_rqst *req,
 405                                   struct xdr_stream *xdr,
 406                                   const void *data)
 407 {
 408         const struct nlm_args *args = data;
 409         const struct nlm_lock *lock = &args->lock;
 410
 411         encode_cookie(xdr, &args->cookie);
 412         encode_bool(xdr, args->block);
 413         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 414         encode_nlm4_lock(xdr, lock);
 415         encode_bool(xdr, args->reclaim);
 416         encode_int32(xdr, args->state);
 417 }
 418
 419 /*
 420  *      struct nlm4_cancargs {
 421  *              netobj cookie;
 422  *              bool block;
 423  *              bool exclusive;
 424  *              struct nlm4_lock alock;
 425  *      };
 426  */
 427 static void nlm4_xdr_enc_cancargs(struct rpc_rqst *req,
 428                                   struct xdr_stream *xdr,
 429                                   const void *data)
 430 {
 431         const struct nlm_args *args = data;
 432         const struct nlm_lock *lock = &args->lock;
 433
 434         encode_cookie(xdr, &args->cookie);
 435         encode_bool(xdr, args->block);
 436         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 437         encode_nlm4_lock(xdr, lock);
 438 }
 439
 440 /*
 441  *      struct nlm4_unlockargs {
 442  *              netobj cookie;
 443  *              struct nlm4_lock alock;
 444  *      };
 445  */
 446 static void nlm4_xdr_enc_unlockargs(struct rpc_rqst *req,
 447                                     struct xdr_stream *xdr,
 448                                     const void *data)
 449 {
 450         const struct nlm_args *args = data;
 451         const struct nlm_lock *lock = &args->lock;
 452
 453         encode_cookie(xdr, &args->cookie);
 454         encode_nlm4_lock(xdr, lock);
 455 }
 456
 457 /*
 458  *      struct nlm4_res {
 459  *              netobj cookie;
 460  *              nlm4_stat stat;
 461  *      };
 462  */
 463 static void nlm4_xdr_enc_res(struct rpc_rqst *req,
 464                              struct xdr_stream *xdr,
 465                              const void *data)
 466 {
 467         const struct nlm_res *result = data;
 468
 469         encode_cookie(xdr, &result->cookie);
 470         encode_nlm4_stat(xdr, result->status);
 471 }
 472
 473 /*
 474  *      union nlm4_testrply switch (nlm4_stats stat) {
 475  *      case NLM4_DENIED:
 476  *              struct nlm4_holder holder;
 477  *      default:
 478  *              void;
 479  *      };
 480  *
 481  *      struct nlm4_testres {
 482  *              netobj cookie;
 483  *              nlm4_testrply test_stat;
 484  *      };
 485  */
 486 static void nlm4_xdr_enc_testres(struct rpc_rqst *req,
 487                                  struct xdr_stream *xdr,
 488                                  const void *data)
 489 {
 490         const struct nlm_res *result = data;
 491
 492         encode_cookie(xdr, &result->cookie);
 493         encode_nlm4_stat(xdr, result->status);
 494         if (result->status == nlm_lck_denied)
 495                 encode_nlm4_holder(xdr, result);
 496 }
 497
 498
 499 /*
 500  * NLMv4 XDR decode functions
 501  *
 502  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 503  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 504  * "Protocols for Interworking: XNFS, Version 3W".
 505  */
 506
 507 /*
 508  *      union nlm4_testrply switch (nlm4_stats stat) {
 509  *      case NLM4_DENIED:
 510  *              struct nlm4_holder holder;
 511  *      default:
 512  *              void;
 513  *      };
 514  *
 515  *      struct nlm4_testres {
 516  *              netobj cookie;
 517  *              nlm4_testrply test_stat;
 518  *      };
 519  */
 520 static int decode_nlm4_testrply(struct xdr_stream *xdr,
 521                                 struct nlm_res *result)
 522 {
 523         int error;
 524
 525         error = decode_nlm4_stat(xdr, &result->status);
 526         if (unlikely(error))
 527                 goto out;
 528         if (result->status == nlm_lck_denied)
 529                 error = decode_nlm4_holder(xdr, result);
 530 out:
 531         return error;
 532 }
 533
 534 static int nlm4_xdr_dec_testres(struct rpc_rqst *req,
 535                                 struct xdr_stream *xdr,
 536                                 void *data)
 537 {
 538         struct nlm_res *result = data;
 539         int error;
 540
 541         error = decode_cookie(xdr, &result->cookie);
 542         if (unlikely(error))
 543                 goto out;
 544         error = decode_nlm4_testrply(xdr, result);
 545 out:
 546         return error;
 547 }
 548
 549 /*
 550  *      struct nlm4_res {
 551  *              netobj cookie;
 552  *              nlm4_stat stat;
 553  *      };
 554  */
 555 static int nlm4_xdr_dec_res(struct rpc_rqst *req,
 556                             struct xdr_stream *xdr,
 557                             void *data)
 558 {
 559         struct nlm_res *result = data;
 560         int error;
 561
 562         error = decode_cookie(xdr, &result->cookie);
 563         if (unlikely(error))
 564                 goto out;
 565         error = decode_nlm4_stat(xdr, &result->status);
 566 out:
 567         return error;
 568 }
 569
 570
 571 /*
 572  * For NLM, a void procedure really returns nothing
 573  */
 574 #define nlm4_xdr_dec_norep      NULL
 575
 576 #define PROC(proc, argtype, restype)                                    \
 577 [NLMPROC_##proc] = {                                                    \
 578         .p_proc      = NLMPROC_##proc,                                  \
 579         .p_encode    = nlm4_xdr_enc_##argtype,                          \
 580         .p_decode    = nlm4_xdr_dec_##restype,                          \
 581         .p_arglen    = NLM4_##argtype##_sz,                             \
 582         .p_replen    = NLM4_##restype##_sz,                             \
 583         .p_statidx   = NLMPROC_##proc,                                  \
 584         .p_name      = #proc,                                           \
 585         }
 586
 587 static const struct rpc_procinfo nlm4_procedures[] = {
 588         PROC(TEST,              testargs,       testres),
 589         PROC(LOCK,              lockargs,       res),
 590         PROC(CANCEL,            cancargs,       res),
 591         PROC(UNLOCK,            unlockargs,     res),
 592         PROC(GRANTED,           testargs,       res),
 593         PROC(TEST_MSG,          testargs,       norep),
 594         PROC(LOCK_MSG,          lockargs,       norep),
 595         PROC(CANCEL_MSG,        cancargs,       norep),
 596         PROC(UNLOCK_MSG,        unlockargs,     norep),
 597         PROC(GRANTED_MSG,       testargs,       norep),
 598         PROC(TEST_RES,          testres,        norep),
 599         PROC(LOCK_RES,          res,            norep),
 600         PROC(CANCEL_RES,        res,            norep),
 601         PROC(UNLOCK_RES,        res,            norep),
 602         PROC(GRANTED_RES,       res,            norep),
 603 };
 604
 605 static unsigned int nlm_version4_counts[ARRAY_SIZE(nlm4_procedures)];
 606 const struct rpc_version nlm_version4 = {
 607         .number         = 4,
 608         .nrprocs        = ARRAY_SIZE(nlm4_procedures),
 609         .procs          = nlm4_procedures,
 610         .counts         = nlm_version4_counts,
 611 };