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