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 int nlm4_xdr_enc_testargs(struct rpc_rqst *req, __be32 *p,
 389                                  const struct nlm_args *args)
 390 {
 391         const struct nlm_lock *lock = &args->lock;
 392         struct xdr_stream xdr;
 393
 394         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 395         encode_cookie(&xdr, &args->cookie);
 396         encode_bool(&xdr, lock->fl.fl_type == F_WRLCK);
 397         encode_nlm4_lock(&xdr, lock);
 398         return 0;
 399 }
 400
 401 /*
 402  *      struct nlm4_lockargs {
 403  *              netobj cookie;
 404  *              bool block;
 405  *              bool exclusive;
 406  *              struct nlm4_lock alock;
 407  *              bool reclaim;
 408  *              int state;
 409  *      };
 410  */
 411 static int nlm4_xdr_enc_lockargs(struct rpc_rqst *req, __be32 *p,
 412                                  const struct nlm_args *args)
 413 {
 414         const struct nlm_lock *lock = &args->lock;
 415         struct xdr_stream xdr;
 416
 417         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 418         encode_cookie(&xdr, &args->cookie);
 419         encode_bool(&xdr, args->block);
 420         encode_bool(&xdr, lock->fl.fl_type == F_WRLCK);
 421         encode_nlm4_lock(&xdr, lock);
 422         encode_bool(&xdr, args->reclaim);
 423         encode_int32(&xdr, args->state);
 424         return 0;
 425 }
 426
 427 /*
 428  *      struct nlm4_cancargs {
 429  *              netobj cookie;
 430  *              bool block;
 431  *              bool exclusive;
 432  *              struct nlm4_lock alock;
 433  *      };
 434  */
 435 static int nlm4_xdr_enc_cancargs(struct rpc_rqst *req, __be32 *p,
 436                                  const struct nlm_args *args)
 437 {
 438         const struct nlm_lock *lock = &args->lock;
 439         struct xdr_stream xdr;
 440
 441         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 442         encode_cookie(&xdr, &args->cookie);
 443         encode_bool(&xdr, args->block);
 444         encode_bool(&xdr, lock->fl.fl_type == F_WRLCK);
 445         encode_nlm4_lock(&xdr, lock);
 446         return 0;
 447 }
 448
 449 /*
 450  *      struct nlm4_unlockargs {
 451  *              netobj cookie;
 452  *              struct nlm4_lock alock;
 453  *      };
 454  */
 455 static int nlm4_xdr_enc_unlockargs(struct rpc_rqst *req, __be32 *p,
 456                                    const struct nlm_args *args)
 457 {
 458         const struct nlm_lock *lock = &args->lock;
 459         struct xdr_stream xdr;
 460
 461         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 462         encode_cookie(&xdr, &args->cookie);
 463         encode_nlm4_lock(&xdr, lock);
 464         return 0;
 465 }
 466
 467 /*
 468  *      struct nlm4_res {
 469  *              netobj cookie;
 470  *              nlm4_stat stat;
 471  *      };
 472  */
 473 static int nlm4_xdr_enc_res(struct rpc_rqst *req, __be32 *p,
 474                             const struct nlm_res *result)
 475 {
 476         struct xdr_stream xdr;
 477
 478         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 479         encode_cookie(&xdr, &result->cookie);
 480         encode_nlm4_stat(&xdr, result->status);
 481         return 0;
 482 }
 483
 484 /*
 485  *      union nlm4_testrply switch (nlm4_stats stat) {
 486  *      case NLM4_DENIED:
 487  *              struct nlm4_holder holder;
 488  *      default:
 489  *              void;
 490  *      };
 491  *
 492  *      struct nlm4_testres {
 493  *              netobj cookie;
 494  *              nlm4_testrply test_stat;
 495  *      };
 496  */
 497 static int nlm4_xdr_enc_testres(struct rpc_rqst *req, __be32 *p,
 498                                 const struct nlm_res *result)
 499 {
 500         struct xdr_stream xdr;
 501
 502         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 503         encode_cookie(&xdr, &result->cookie);
 504         encode_nlm4_stat(&xdr, result->status);
 505         if (result->status == nlm_lck_denied)
 506                 encode_nlm4_holder(&xdr, result);
 507         return 0;
 508 }
 509
 510
 511 /*
 512  * NLMv4 XDR decode functions
 513  *
 514  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 515  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 516  * "Protocols for Interworking: XNFS, Version 3W".
 517  */
 518
 519 /*
 520  *      union nlm4_testrply switch (nlm4_stats stat) {
 521  *      case NLM4_DENIED:
 522  *              struct nlm4_holder holder;
 523  *      default:
 524  *              void;
 525  *      };
 526  *
 527  *      struct nlm4_testres {
 528  *              netobj cookie;
 529  *              nlm4_testrply test_stat;
 530  *      };
 531  */
 532 static int decode_nlm4_testrply(struct xdr_stream *xdr,
 533                                 struct nlm_res *result)
 534 {
 535         int error;
 536
 537         error = decode_nlm4_stat(xdr, &result->status);
 538         if (unlikely(error))
 539                 goto out;
 540         if (result->status == nlm_lck_denied)
 541                 error = decode_nlm4_holder(xdr, result);
 542 out:
 543         return error;
 544 }
 545
 546 static int nlm4_xdr_dec_testres(struct rpc_rqst *req, __be32 *p,
 547                                 struct nlm_res *result)
 548 {
 549         struct xdr_stream xdr;
 550         int error;
 551
 552         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 553         error = decode_cookie(&xdr, &result->cookie);
 554         if (unlikely(error))
 555                 goto out;
 556         error = decode_nlm4_testrply(&xdr, result);
 557 out:
 558         return error;
 559 }
 560
 561 /*
 562  *      struct nlm4_res {
 563  *              netobj cookie;
 564  *              nlm4_stat stat;
 565  *      };
 566  */
 567 static int nlm4_xdr_dec_res(struct rpc_rqst *req, __be32 *p,
 568                             struct nlm_res *result)
 569 {
 570         struct xdr_stream xdr;
 571         int error;
 572
 573         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 574         error = decode_cookie(&xdr, &result->cookie);
 575         if (unlikely(error))
 576                 goto out;
 577         error = decode_nlm4_stat(&xdr, &result->status);
 578 out:
 579         return error;
 580 }
 581
 582
 583 /*
 584  * For NLM, a void procedure really returns nothing
 585  */
 586 #define nlm4_xdr_dec_norep      NULL
 587
 588 #define PROC(proc, argtype, restype)                                    \
 589 [NLMPROC_##proc] = {                                                    \
 590         .p_proc      = NLMPROC_##proc,                                  \
 591         .p_encode    = (kxdrproc_t)nlm4_xdr_enc_##argtype,              \
 592         .p_decode    = (kxdrproc_t)nlm4_xdr_dec_##restype,              \
 593         .p_arglen    = NLM4_##argtype##_sz,                             \
 594         .p_replen    = NLM4_##restype##_sz,                             \
 595         .p_statidx   = NLMPROC_##proc,                                  \
 596         .p_name      = #proc,                                           \
 597         }
 598
 599 static struct rpc_procinfo      nlm4_procedures[] = {
 600         PROC(TEST,              testargs,       testres),
 601         PROC(LOCK,              lockargs,       res),
 602         PROC(CANCEL,            cancargs,       res),
 603         PROC(UNLOCK,            unlockargs,     res),
 604         PROC(GRANTED,           testargs,       res),
 605         PROC(TEST_MSG,          testargs,       norep),
 606         PROC(LOCK_MSG,          lockargs,       norep),
 607         PROC(CANCEL_MSG,        cancargs,       norep),
 608         PROC(UNLOCK_MSG,        unlockargs,     norep),
 609         PROC(GRANTED_MSG,       testargs,       norep),
 610         PROC(TEST_RES,          testres,        norep),
 611         PROC(LOCK_RES,          res,            norep),
 612         PROC(CANCEL_RES,        res,            norep),
 613         PROC(UNLOCK_RES,        res,            norep),
 614         PROC(GRANTED_RES,       res,            norep),
 615 };
 616
 617 struct rpc_version      nlm_version4 = {
 618         .number         = 4,
 619         .nrprocs        = ARRAY_SIZE(nlm4_procedures),
 620         .procs          = nlm4_procedures,
 621 };