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 #define NLMDBG_FACILITY         NLMDBG_XDR
  18
  19 #if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
  20 #  error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
  21 #endif
  22
  23 #if (NLMCLNT_OHSIZE > NLM_MAXSTRLEN)
  24 #  error "NLM host name cannot be larger than NLM's maximum string length!"
  25 #endif
  26
  27 /*
  28  * Declare the space requirements for NLM arguments and replies as
  29  * number of 32bit-words
  30  */
  31 #define NLM4_void_sz            (0)
  32 #define NLM4_cookie_sz          (1+(NLM_MAXCOOKIELEN>>2))
  33 #define NLM4_caller_sz          (1+(NLMCLNT_OHSIZE>>2))
  34 #define NLM4_owner_sz           (1+(NLMCLNT_OHSIZE>>2))
  35 #define NLM4_fhandle_sz         (1+(NFS3_FHSIZE>>2))
  36 #define NLM4_lock_sz            (5+NLM4_caller_sz+NLM4_owner_sz+NLM4_fhandle_sz)
  37 #define NLM4_holder_sz          (6+NLM4_owner_sz)
  38
  39 #define NLM4_testargs_sz        (NLM4_cookie_sz+1+NLM4_lock_sz)
  40 #define NLM4_lockargs_sz        (NLM4_cookie_sz+4+NLM4_lock_sz)
  41 #define NLM4_cancargs_sz        (NLM4_cookie_sz+2+NLM4_lock_sz)
  42 #define NLM4_unlockargs_sz      (NLM4_cookie_sz+NLM4_lock_sz)
  43
  44 #define NLM4_testres_sz         (NLM4_cookie_sz+1+NLM4_holder_sz)
  45 #define NLM4_res_sz             (NLM4_cookie_sz+1)
  46 #define NLM4_norep_sz           (0)
  47
  48
  49 static s64 loff_t_to_s64(loff_t offset)
  50 {
  51         s64 res;
  52
  53         if (offset >= NLM4_OFFSET_MAX)
  54                 res = NLM4_OFFSET_MAX;
  55         else if (offset <= -NLM4_OFFSET_MAX)
  56                 res = -NLM4_OFFSET_MAX;
  57         else
  58                 res = offset;
  59         return res;
  60 }
  61
  62 static void nlm4_compute_offsets(const struct nlm_lock *lock,
  63                                  u64 *l_offset, u64 *l_len)
  64 {
  65         const struct file_lock *fl = &lock->fl;
  66
  67         BUG_ON(fl->fl_start > NLM4_OFFSET_MAX);
  68         BUG_ON(fl->fl_end > NLM4_OFFSET_MAX &&
  69                                 fl->fl_end != OFFSET_MAX);
  70
  71         *l_offset = loff_t_to_s64(fl->fl_start);
  72         if (fl->fl_end == OFFSET_MAX)
  73                 *l_len = 0;
  74         else
  75                 *l_len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
  76 }
  77
  78 /*
  79  * Handle decode buffer overflows out-of-line.
  80  */
  81 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
  82 {
  83         dprintk("lockd: %s prematurely hit the end of our receive buffer. "
  84                 "Remaining buffer length is %tu words.\n",
  85                 func, xdr->end - xdr->p);
  86 }
  87
  88
  89 /*
  90  * Encode/decode NLMv4 basic data types
  91  *
  92  * Basic NLMv4 data types are defined in Appendix II, section 6.1.4
  93  * of RFC 1813: "NFS Version 3 Protocol Specification" and in Chapter
  94  * 10 of X/Open's "Protocols for Interworking: XNFS, Version 3W".
  95  *
  96  * Not all basic data types have their own encoding and decoding
  97  * functions.  For run-time efficiency, some data types are encoded
  98  * or decoded inline.
  99  */
 100
 101 static void encode_bool(struct xdr_stream *xdr, const int value)
 102 {
 103         __be32 *p;
 104
 105         p = xdr_reserve_space(xdr, 4);
 106         *p = value ? xdr_one : xdr_zero;
 107 }
 108
 109 static void encode_int32(struct xdr_stream *xdr, const s32 value)
 110 {
 111         __be32 *p;
 112
 113         p = xdr_reserve_space(xdr, 4);
 114         *p = cpu_to_be32(value);
 115 }
 116
 117 /*
 118  *      typedef opaque netobj<MAXNETOBJ_SZ>
 119  */
 120 static void encode_netobj(struct xdr_stream *xdr,
 121                           const u8 *data, const unsigned int length)
 122 {
 123         __be32 *p;
 124
 125         BUG_ON(length > XDR_MAX_NETOBJ);
 126         p = xdr_reserve_space(xdr, 4 + length);
 127         xdr_encode_opaque(p, data, length);
 128 }
 129
 130 static int decode_netobj(struct xdr_stream *xdr,
 131                          struct xdr_netobj *obj)
 132 {
 133         u32 length;
 134         __be32 *p;
 135
 136         p = xdr_inline_decode(xdr, 4);
 137         if (unlikely(p == NULL))
 138                 goto out_overflow;
 139         length = be32_to_cpup(p++);
 140         if (unlikely(length > XDR_MAX_NETOBJ))
 141                 goto out_size;
 142         obj->len = length;
 143         obj->data = (u8 *)p;
 144         return 0;
 145 out_size:
 146         dprintk("NFS: returned netobj was too long: %u\n", length);
 147         return -EIO;
 148 out_overflow:
 149         print_overflow_msg(__func__, xdr);
 150         return -EIO;
 151 }
 152
 153 /*
 154  *      netobj cookie;
 155  */
 156 static void encode_cookie(struct xdr_stream *xdr,
 157                           const struct nlm_cookie *cookie)
 158 {
 159         BUG_ON(cookie->len > NLM_MAXCOOKIELEN);
 160         encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
 161 }
 162
 163 static int decode_cookie(struct xdr_stream *xdr,
 164                              struct nlm_cookie *cookie)
 165 {
 166         u32 length;
 167         __be32 *p;
 168
 169         p = xdr_inline_decode(xdr, 4);
 170         if (unlikely(p == NULL))
 171                 goto out_overflow;
 172         length = be32_to_cpup(p++);
 173         /* apparently HPUX can return empty cookies */
 174         if (length == 0)
 175                 goto out_hpux;
 176         if (length > NLM_MAXCOOKIELEN)
 177                 goto out_size;
 178         p = xdr_inline_decode(xdr, length);
 179         if (unlikely(p == NULL))
 180                 goto out_overflow;
 181         cookie->len = length;
 182         memcpy(cookie->data, p, length);
 183         return 0;
 184 out_hpux:
 185         cookie->len = 4;
 186         memset(cookie->data, 0, 4);
 187         return 0;
 188 out_size:
 189         dprintk("NFS: returned cookie was too long: %u\n", length);
 190         return -EIO;
 191 out_overflow:
 192         print_overflow_msg(__func__, xdr);
 193         return -EIO;
 194 }
 195
 196 /*
 197  *      netobj fh;
 198  */
 199 static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
 200 {
 201         BUG_ON(fh->size > NFS3_FHSIZE);
 202         encode_netobj(xdr, (u8 *)&fh->data, fh->size);
 203 }
 204
 205 /*
 206  *      enum nlm4_stats {
 207  *              NLM4_GRANTED = 0,
 208  *              NLM4_DENIED = 1,
 209  *              NLM4_DENIED_NOLOCKS = 2,
 210  *              NLM4_BLOCKED = 3,
 211  *              NLM4_DENIED_GRACE_PERIOD = 4,
 212  *              NLM4_DEADLCK = 5,
 213  *              NLM4_ROFS = 6,
 214  *              NLM4_STALE_FH = 7,
 215  *              NLM4_FBIG = 8,
 216  *              NLM4_FAILED = 9
 217  *      };
 218  *
 219  *      struct nlm4_stat {
 220  *              nlm4_stats stat;
 221  *      };
 222  *
 223  * NB: we don't swap bytes for the NLM status values.  The upper
 224  * layers deal directly with the status value in network byte
 225  * order.
 226  */
 227 static void encode_nlm4_stat(struct xdr_stream *xdr,
 228                              const __be32 stat)
 229 {
 230         __be32 *p;
 231
 232         BUG_ON(be32_to_cpu(stat) > NLM_FAILED);
 233         p = xdr_reserve_space(xdr, 4);
 234         *p = stat;
 235 }
 236
 237 static int decode_nlm4_stat(struct xdr_stream *xdr, __be32 *stat)
 238 {
 239         __be32 *p;
 240
 241         p = xdr_inline_decode(xdr, 4);
 242         if (unlikely(p == NULL))
 243                 goto out_overflow;
 244         if (unlikely(*p > nlm4_failed))
 245                 goto out_bad_xdr;
 246         *stat = *p;
 247         return 0;
 248 out_bad_xdr:
 249         dprintk("%s: server returned invalid nlm4_stats value: %u\n",
 250                         __func__, be32_to_cpup(p));
 251         return -EIO;
 252 out_overflow:
 253         print_overflow_msg(__func__, xdr);
 254         return -EIO;
 255 }
 256
 257 /*
 258  *      struct nlm4_holder {
 259  *              bool    exclusive;
 260  *              int32   svid;
 261  *              netobj  oh;
 262  *              uint64  l_offset;
 263  *              uint64  l_len;
 264  *      };
 265  */
 266 static void encode_nlm4_holder(struct xdr_stream *xdr,
 267                                const struct nlm_res *result)
 268 {
 269         const struct nlm_lock *lock = &result->lock;
 270         u64 l_offset, l_len;
 271         __be32 *p;
 272
 273         encode_bool(xdr, lock->fl.fl_type == F_RDLCK);
 274         encode_int32(xdr, lock->svid);
 275         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 276
 277         p = xdr_reserve_space(xdr, 4 + 4);
 278         nlm4_compute_offsets(lock, &l_offset, &l_len);
 279         p = xdr_encode_hyper(p, l_offset);
 280         xdr_encode_hyper(p, l_len);
 281 }
 282
 283 static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
 284 {
 285         struct nlm_lock *lock = &result->lock;
 286         struct file_lock *fl = &lock->fl;
 287         u64 l_offset, l_len;
 288         u32 exclusive;
 289         int error;
 290         __be32 *p;
 291         s32 end;
 292
 293         memset(lock, 0, sizeof(*lock));
 294         locks_init_lock(fl);
 295
 296         p = xdr_inline_decode(xdr, 4 + 4);
 297         if (unlikely(p == NULL))
 298                 goto out_overflow;
 299         exclusive = be32_to_cpup(p++);
 300         lock->svid = be32_to_cpup(p);
 301         fl->fl_pid = (pid_t)lock->svid;
 302
 303         error = decode_netobj(xdr, &lock->oh);
 304         if (unlikely(error))
 305                 goto out;
 306
 307         p = xdr_inline_decode(xdr, 8 + 8);
 308         if (unlikely(p == NULL))
 309                 goto out_overflow;
 310
 311         fl->fl_flags = FL_POSIX;
 312         fl->fl_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
 313         p = xdr_decode_hyper(p, &l_offset);
 314         xdr_decode_hyper(p, &l_len);
 315         end = l_offset + l_len - 1;
 316
 317         fl->fl_start = (loff_t)l_offset;
 318         if (l_len == 0 || end < 0)
 319                 fl->fl_end = OFFSET_MAX;
 320         else
 321                 fl->fl_end = (loff_t)end;
 322         error = 0;
 323 out:
 324         return error;
 325 out_overflow:
 326         print_overflow_msg(__func__, xdr);
 327         return -EIO;
 328 }
 329
 330 /*
 331  *      string caller_name<LM_MAXSTRLEN>;
 332  */
 333 static void encode_caller_name(struct xdr_stream *xdr, const char *name)
 334 {
 335         /* NB: client-side does not set lock->len */
 336         u32 length = strlen(name);
 337         __be32 *p;
 338
 339         BUG_ON(length > NLM_MAXSTRLEN);
 340         p = xdr_reserve_space(xdr, 4 + length);
 341         xdr_encode_opaque(p, name, length);
 342 }
 343
 344 /*
 345  *      struct nlm4_lock {
 346  *              string  caller_name<LM_MAXSTRLEN>;
 347  *              netobj  fh;
 348  *              netobj  oh;
 349  *              int32   svid;
 350  *              uint64  l_offset;
 351  *              uint64  l_len;
 352  *      };
 353  */
 354 static void encode_nlm4_lock(struct xdr_stream *xdr,
 355                              const struct nlm_lock *lock)
 356 {
 357         u64 l_offset, l_len;
 358         __be32 *p;
 359
 360         encode_caller_name(xdr, lock->caller);
 361         encode_fh(xdr, &lock->fh);
 362         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 363
 364         p = xdr_reserve_space(xdr, 4 + 8 + 8);
 365         *p++ = cpu_to_be32(lock->svid);
 366
 367         nlm4_compute_offsets(lock, &l_offset, &l_len);
 368         p = xdr_encode_hyper(p, l_offset);
 369         xdr_encode_hyper(p, l_len);
 370 }
 371
 372
 373 /*
 374  * NLMv4 XDR encode functions
 375  *
 376  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 377  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 378  * "Protocols for Interworking: XNFS, Version 3W".
 379  */
 380
 381 /*
 382  *      struct nlm4_testargs {
 383  *              netobj cookie;
 384  *              bool exclusive;
 385  *              struct nlm4_lock alock;
 386  *      };
 387  */
 388 static void nlm4_xdr_enc_testargs(struct rpc_rqst *req,
 389                                   struct xdr_stream *xdr,
 390                                   const struct nlm_args *args)
 391 {
 392         const struct nlm_lock *lock = &args->lock;
 393
 394         encode_cookie(xdr, &args->cookie);
 395         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 396         encode_nlm4_lock(xdr, lock);
 397 }
 398
 399 /*
 400  *      struct nlm4_lockargs {
 401  *              netobj cookie;
 402  *              bool block;
 403  *              bool exclusive;
 404  *              struct nlm4_lock alock;
 405  *              bool reclaim;
 406  *              int state;
 407  *      };
 408  */
 409 static void nlm4_xdr_enc_lockargs(struct rpc_rqst *req,
 410                                   struct xdr_stream *xdr,
 411                                   const struct nlm_args *args)
 412 {
 413         const struct nlm_lock *lock = &args->lock;
 414
 415         encode_cookie(xdr, &args->cookie);
 416         encode_bool(xdr, args->block);
 417         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 418         encode_nlm4_lock(xdr, lock);
 419         encode_bool(xdr, args->reclaim);
 420         encode_int32(xdr, args->state);
 421 }
 422
 423 /*
 424  *      struct nlm4_cancargs {
 425  *              netobj cookie;
 426  *              bool block;
 427  *              bool exclusive;
 428  *              struct nlm4_lock alock;
 429  *      };
 430  */
 431 static void nlm4_xdr_enc_cancargs(struct rpc_rqst *req,
 432                                   struct xdr_stream *xdr,
 433                                   const struct nlm_args *args)
 434 {
 435         const struct nlm_lock *lock = &args->lock;
 436
 437         encode_cookie(xdr, &args->cookie);
 438         encode_bool(xdr, args->block);
 439         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 440         encode_nlm4_lock(xdr, lock);
 441 }
 442
 443 /*
 444  *      struct nlm4_unlockargs {
 445  *              netobj cookie;
 446  *              struct nlm4_lock alock;
 447  *      };
 448  */
 449 static void nlm4_xdr_enc_unlockargs(struct rpc_rqst *req,
 450                                     struct xdr_stream *xdr,
 451                                     const struct nlm_args *args)
 452 {
 453         const struct nlm_lock *lock = &args->lock;
 454
 455         encode_cookie(xdr, &args->cookie);
 456         encode_nlm4_lock(xdr, lock);
 457 }
 458
 459 /*
 460  *      struct nlm4_res {
 461  *              netobj cookie;
 462  *              nlm4_stat stat;
 463  *      };
 464  */
 465 static void nlm4_xdr_enc_res(struct rpc_rqst *req,
 466                              struct xdr_stream *xdr,
 467                              const struct nlm_res *result)
 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 struct nlm_res *result)
 489 {
 490         encode_cookie(xdr, &result->cookie);
 491         encode_nlm4_stat(xdr, result->status);
 492         if (result->status == nlm_lck_denied)
 493                 encode_nlm4_holder(xdr, result);
 494 }
 495
 496
 497 /*
 498  * NLMv4 XDR decode functions
 499  *
 500  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 501  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 502  * "Protocols for Interworking: XNFS, Version 3W".
 503  */
 504
 505 /*
 506  *      union nlm4_testrply switch (nlm4_stats stat) {
 507  *      case NLM4_DENIED:
 508  *              struct nlm4_holder holder;
 509  *      default:
 510  *              void;
 511  *      };
 512  *
 513  *      struct nlm4_testres {
 514  *              netobj cookie;
 515  *              nlm4_testrply test_stat;
 516  *      };
 517  */
 518 static int decode_nlm4_testrply(struct xdr_stream *xdr,
 519                                 struct nlm_res *result)
 520 {
 521         int error;
 522
 523         error = decode_nlm4_stat(xdr, &result->status);
 524         if (unlikely(error))
 525                 goto out;
 526         if (result->status == nlm_lck_denied)
 527                 error = decode_nlm4_holder(xdr, result);
 528 out:
 529         return error;
 530 }
 531
 532 static int nlm4_xdr_dec_testres(struct rpc_rqst *req,
 533                                 struct xdr_stream *xdr,
 534                                 struct nlm_res *result)
 535 {
 536         int error;
 537
 538         error = decode_cookie(xdr, &result->cookie);
 539         if (unlikely(error))
 540                 goto out;
 541         error = decode_nlm4_testrply(xdr, result);
 542 out:
 543         return error;
 544 }
 545
 546 /*
 547  *      struct nlm4_res {
 548  *              netobj cookie;
 549  *              nlm4_stat stat;
 550  *      };
 551  */
 552 static int nlm4_xdr_dec_res(struct rpc_rqst *req,
 553                             struct xdr_stream *xdr,
 554                             struct nlm_res *result)
 555 {
 556         int error;
 557
 558         error = decode_cookie(xdr, &result->cookie);
 559         if (unlikely(error))
 560                 goto out;
 561         error = decode_nlm4_stat(xdr, &result->status);
 562 out:
 563         return error;
 564 }
 565
 566
 567 /*
 568  * For NLM, a void procedure really returns nothing
 569  */
 570 #define nlm4_xdr_dec_norep      NULL
 571
 572 #define PROC(proc, argtype, restype)                                    \
 573 [NLMPROC_##proc] = {                                                    \
 574         .p_proc      = NLMPROC_##proc,                                  \
 575         .p_encode    = (kxdreproc_t)nlm4_xdr_enc_##argtype,             \
 576         .p_decode    = (kxdrdproc_t)nlm4_xdr_dec_##restype,             \
 577         .p_arglen    = NLM4_##argtype##_sz,                             \
 578         .p_replen    = NLM4_##restype##_sz,                             \
 579         .p_statidx   = NLMPROC_##proc,                                  \
 580         .p_name      = #proc,                                           \
 581         }
 582
 583 static struct rpc_procinfo      nlm4_procedures[] = {
 584         PROC(TEST,              testargs,       testres),
 585         PROC(LOCK,              lockargs,       res),
 586         PROC(CANCEL,            cancargs,       res),
 587         PROC(UNLOCK,            unlockargs,     res),
 588         PROC(GRANTED,           testargs,       res),
 589         PROC(TEST_MSG,          testargs,       norep),
 590         PROC(LOCK_MSG,          lockargs,       norep),
 591         PROC(CANCEL_MSG,        cancargs,       norep),
 592         PROC(UNLOCK_MSG,        unlockargs,     norep),
 593         PROC(GRANTED_MSG,       testargs,       norep),
 594         PROC(TEST_RES,          testres,        norep),
 595         PROC(LOCK_RES,          res,            norep),
 596         PROC(CANCEL_RES,        res,            norep),
 597         PROC(UNLOCK_RES,        res,            norep),
 598         PROC(GRANTED_RES,       res,            norep),
 599 };
 600
 601 struct rpc_version      nlm_version4 = {
 602         .number         = 4,
 603         .nrprocs        = ARRAY_SIZE(nlm4_procedures),
 604         .procs          = nlm4_procedures,
 605 };