fs/lockd/clnt4xdr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/fs/lockd/clnt4xdr.c
   4  *
   5  * XDR functions to encode/decode NLM version 4 RPC arguments and results.
   6  *
   7  * NLM client-side only.
   8  *
   9  * Copyright (C) 2010, Oracle.  All rights reserved.
  10  */
  11
  12 #include <linux/types.h>
  13 #include <linux/sunrpc/xdr.h>
  14 #include <linux/sunrpc/clnt.h>
  15 #include <linux/sunrpc/stats.h>
  16 #include <linux/lockd/lockd.h>
  17
  18 #include <uapi/linux/nfs3.h>
  19
  20 #define NLMDBG_FACILITY         NLMDBG_XDR
  21
  22 #if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
  23 #  error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
  24 #endif
  25
  26 #if (NLMCLNT_OHSIZE > NLM_MAXSTRLEN)
  27 #  error "NLM host name cannot be larger than NLM's maximum string length!"
  28 #endif
  29
  30 /*
  31  * Declare the space requirements for NLM arguments and replies as
  32  * number of 32bit-words
  33  */
  34 #define NLM4_void_sz            (0)
  35 #define NLM4_cookie_sz          (1+(NLM_MAXCOOKIELEN>>2))
  36 #define NLM4_caller_sz          (1+(NLMCLNT_OHSIZE>>2))
  37 #define NLM4_owner_sz           (1+(NLMCLNT_OHSIZE>>2))
  38 #define NLM4_fhandle_sz         (1+(NFS3_FHSIZE>>2))
  39 #define NLM4_lock_sz            (5+NLM4_caller_sz+NLM4_owner_sz+NLM4_fhandle_sz)
  40 #define NLM4_holder_sz          (6+NLM4_owner_sz)
  41
  42 #define NLM4_testargs_sz        (NLM4_cookie_sz+1+NLM4_lock_sz)
  43 #define NLM4_lockargs_sz        (NLM4_cookie_sz+4+NLM4_lock_sz)
  44 #define NLM4_cancargs_sz        (NLM4_cookie_sz+2+NLM4_lock_sz)
  45 #define NLM4_unlockargs_sz      (NLM4_cookie_sz+NLM4_lock_sz)
  46
  47 #define NLM4_testres_sz         (NLM4_cookie_sz+1+NLM4_holder_sz)
  48 #define NLM4_res_sz             (NLM4_cookie_sz+1)
  49 #define NLM4_norep_sz           (0)
  50
  51
  52 static s64 loff_t_to_s64(loff_t offset)
  53 {
  54         s64 res;
  55
  56         if (offset >= NLM4_OFFSET_MAX)
  57                 res = NLM4_OFFSET_MAX;
  58         else if (offset <= -NLM4_OFFSET_MAX)
  59                 res = -NLM4_OFFSET_MAX;
  60         else
  61                 res = offset;
  62         return res;
  63 }
  64
  65 static void nlm4_compute_offsets(const struct nlm_lock *lock,
  66                                  u64 *l_offset, u64 *l_len)
  67 {
  68         const struct file_lock *fl = &lock->fl;
  69
  70         *l_offset = loff_t_to_s64(fl->fl_start);
  71         if (fl->fl_end == OFFSET_MAX)
  72                 *l_len = 0;
  73         else
  74                 *l_len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
  75 }
  76
  77 /*
  78  * Handle decode buffer overflows out-of-line.
  79  */
  80 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
  81 {
  82         dprintk("lockd: %s prematurely hit the end of our receive buffer. "
  83                 "Remaining buffer length is %tu words.\n",
  84                 func, xdr->end - xdr->p);
  85 }
  86
  87
  88 /*
  89  * Encode/decode NLMv4 basic data types
  90  *
  91  * Basic NLMv4 data types are defined in Appendix II, section 6.1.4
  92  * of RFC 1813: "NFS Version 3 Protocol Specification" and in Chapter
  93  * 10 of X/Open's "Protocols for Interworking: XNFS, Version 3W".
  94  *
  95  * Not all basic data types have their own encoding and decoding
  96  * functions.  For run-time efficiency, some data types are encoded
  97  * or decoded inline.
  98  */
  99
 100 static void encode_bool(struct xdr_stream *xdr, const int value)
 101 {
 102         __be32 *p;
 103
 104         p = xdr_reserve_space(xdr, 4);
 105         *p = value ? xdr_one : xdr_zero;
 106 }
 107
 108 static void encode_int32(struct xdr_stream *xdr, const s32 value)
 109 {
 110         __be32 *p;
 111
 112         p = xdr_reserve_space(xdr, 4);
 113         *p = cpu_to_be32(value);
 114 }
 115
 116 /*
 117  *      typedef opaque netobj<MAXNETOBJ_SZ>
 118  */
 119 static void encode_netobj(struct xdr_stream *xdr,
 120                           const u8 *data, const unsigned int length)
 121 {
 122         __be32 *p;
 123
 124         p = xdr_reserve_space(xdr, 4 + length);
 125         xdr_encode_opaque(p, data, length);
 126 }
 127
 128 static int decode_netobj(struct xdr_stream *xdr,
 129                          struct xdr_netobj *obj)
 130 {
 131         u32 length;
 132         __be32 *p;
 133
 134         p = xdr_inline_decode(xdr, 4);
 135         if (unlikely(p == NULL))
 136                 goto out_overflow;
 137         length = be32_to_cpup(p++);
 138         if (unlikely(length > XDR_MAX_NETOBJ))
 139                 goto out_size;
 140         obj->len = length;
 141         obj->data = (u8 *)p;
 142         return 0;
 143 out_size:
 144         dprintk("NFS: returned netobj was too long: %u\n", length);
 145         return -EIO;
 146 out_overflow:
 147         print_overflow_msg(__func__, xdr);
 148         return -EIO;
 149 }
 150
 151 /*
 152  *      netobj cookie;
 153  */
 154 static void encode_cookie(struct xdr_stream *xdr,
 155                           const struct nlm_cookie *cookie)
 156 {
 157         encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
 158 }
 159
 160 static int decode_cookie(struct xdr_stream *xdr,
 161                              struct nlm_cookie *cookie)
 162 {
 163         u32 length;
 164         __be32 *p;
 165
 166         p = xdr_inline_decode(xdr, 4);
 167         if (unlikely(p == NULL))
 168                 goto out_overflow;
 169         length = be32_to_cpup(p++);
 170         /* apparently HPUX can return empty cookies */
 171         if (length == 0)
 172                 goto out_hpux;
 173         if (length > NLM_MAXCOOKIELEN)
 174                 goto out_size;
 175         p = xdr_inline_decode(xdr, length);
 176         if (unlikely(p == NULL))
 177                 goto out_overflow;
 178         cookie->len = length;
 179         memcpy(cookie->data, p, length);
 180         return 0;
 181 out_hpux:
 182         cookie->len = 4;
 183         memset(cookie->data, 0, 4);
 184         return 0;
 185 out_size:
 186         dprintk("NFS: returned cookie was too long: %u\n", length);
 187         return -EIO;
 188 out_overflow:
 189         print_overflow_msg(__func__, xdr);
 190         return -EIO;
 191 }
 192
 193 /*
 194  *      netobj fh;
 195  */
 196 static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
 197 {
 198         encode_netobj(xdr, (u8 *)&fh->data, fh->size);
 199 }
 200
 201 /*
 202  *      enum nlm4_stats {
 203  *              NLM4_GRANTED = 0,
 204  *              NLM4_DENIED = 1,
 205  *              NLM4_DENIED_NOLOCKS = 2,
 206  *              NLM4_BLOCKED = 3,
 207  *              NLM4_DENIED_GRACE_PERIOD = 4,
 208  *              NLM4_DEADLCK = 5,
 209  *              NLM4_ROFS = 6,
 210  *              NLM4_STALE_FH = 7,
 211  *              NLM4_FBIG = 8,
 212  *              NLM4_FAILED = 9
 213  *      };
 214  *
 215  *      struct nlm4_stat {
 216  *              nlm4_stats stat;
 217  *      };
 218  *
 219  * NB: we don't swap bytes for the NLM status values.  The upper
 220  * layers deal directly with the status value in network byte
 221  * order.
 222  */
 223 static void encode_nlm4_stat(struct xdr_stream *xdr,
 224                              const __be32 stat)
 225 {
 226         __be32 *p;
 227
 228         BUG_ON(be32_to_cpu(stat) > NLM_FAILED);
 229         p = xdr_reserve_space(xdr, 4);
 230         *p = stat;
 231 }
 232
 233 static int decode_nlm4_stat(struct xdr_stream *xdr, __be32 *stat)
 234 {
 235         __be32 *p;
 236
 237         p = xdr_inline_decode(xdr, 4);
 238         if (unlikely(p == NULL))
 239                 goto out_overflow;
 240         if (unlikely(ntohl(*p) > ntohl(nlm4_failed)))
 241                 goto out_bad_xdr;
 242         *stat = *p;
 243         return 0;
 244 out_bad_xdr:
 245         dprintk("%s: server returned invalid nlm4_stats value: %u\n",
 246                         __func__, be32_to_cpup(p));
 247         return -EIO;
 248 out_overflow:
 249         print_overflow_msg(__func__, xdr);
 250         return -EIO;
 251 }
 252
 253 /*
 254  *      struct nlm4_holder {
 255  *              bool    exclusive;
 256  *              int32   svid;
 257  *              netobj  oh;
 258  *              uint64  l_offset;
 259  *              uint64  l_len;
 260  *      };
 261  */
 262 static void encode_nlm4_holder(struct xdr_stream *xdr,
 263                                const struct nlm_res *result)
 264 {
 265         const struct nlm_lock *lock = &result->lock;
 266         u64 l_offset, l_len;
 267         __be32 *p;
 268
 269         encode_bool(xdr, lock->fl.fl_type == F_RDLCK);
 270         encode_int32(xdr, lock->svid);
 271         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 272
 273         p = xdr_reserve_space(xdr, 4 + 4);
 274         nlm4_compute_offsets(lock, &l_offset, &l_len);
 275         p = xdr_encode_hyper(p, l_offset);
 276         xdr_encode_hyper(p, l_len);
 277 }
 278
 279 static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
 280 {
 281         struct nlm_lock *lock = &result->lock;
 282         struct file_lock *fl = &lock->fl;
 283         u64 l_offset, l_len;
 284         u32 exclusive;
 285         int error;
 286         __be32 *p;
 287         s32 end;
 288
 289         memset(lock, 0, sizeof(*lock));
 290         locks_init_lock(fl);
 291
 292         p = xdr_inline_decode(xdr, 4 + 4);
 293         if (unlikely(p == NULL))
 294                 goto out_overflow;
 295         exclusive = be32_to_cpup(p++);
 296         lock->svid = be32_to_cpup(p);
 297         fl->fl_pid = (pid_t)lock->svid;
 298
 299         error = decode_netobj(xdr, &lock->oh);
 300         if (unlikely(error))
 301                 goto out;
 302
 303         p = xdr_inline_decode(xdr, 8 + 8);
 304         if (unlikely(p == NULL))
 305                 goto out_overflow;
 306
 307         fl->fl_flags = FL_POSIX;
 308         fl->fl_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
 309         p = xdr_decode_hyper(p, &l_offset);
 310         xdr_decode_hyper(p, &l_len);
 311         end = l_offset + l_len - 1;
 312
 313         fl->fl_start = (loff_t)l_offset;
 314         if (l_len == 0 || end < 0)
 315                 fl->fl_end = OFFSET_MAX;
 316         else
 317                 fl->fl_end = (loff_t)end;
 318         error = 0;
 319 out:
 320         return error;
 321 out_overflow:
 322         print_overflow_msg(__func__, xdr);
 323         return -EIO;
 324 }
 325
 326 /*
 327  *      string caller_name<LM_MAXSTRLEN>;
 328  */
 329 static void encode_caller_name(struct xdr_stream *xdr, const char *name)
 330 {
 331         /* NB: client-side does not set lock->len */
 332         u32 length = strlen(name);
 333         __be32 *p;
 334
 335         p = xdr_reserve_space(xdr, 4 + length);
 336         xdr_encode_opaque(p, name, length);
 337 }
 338
 339 /*
 340  *      struct nlm4_lock {
 341  *              string  caller_name<LM_MAXSTRLEN>;
 342  *              netobj  fh;
 343  *              netobj  oh;
 344  *              int32   svid;
 345  *              uint64  l_offset;
 346  *              uint64  l_len;
 347  *      };
 348  */
 349 static void encode_nlm4_lock(struct xdr_stream *xdr,
 350                              const struct nlm_lock *lock)
 351 {
 352         u64 l_offset, l_len;
 353         __be32 *p;
 354
 355         encode_caller_name(xdr, lock->caller);
 356         encode_fh(xdr, &lock->fh);
 357         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 358
 359         p = xdr_reserve_space(xdr, 4 + 8 + 8);
 360         *p++ = cpu_to_be32(lock->svid);
 361
 362         nlm4_compute_offsets(lock, &l_offset, &l_len);
 363         p = xdr_encode_hyper(p, l_offset);
 364         xdr_encode_hyper(p, l_len);
 365 }
 366
 367
 368 /*
 369  * NLMv4 XDR encode functions
 370  *
 371  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 372  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 373  * "Protocols for Interworking: XNFS, Version 3W".
 374  */
 375
 376 /*
 377  *      struct nlm4_testargs {
 378  *              netobj cookie;
 379  *              bool exclusive;
 380  *              struct nlm4_lock alock;
 381  *      };
 382  */
 383 static void nlm4_xdr_enc_testargs(struct rpc_rqst *req,
 384                                   struct xdr_stream *xdr,
 385                                   const void *data)
 386 {
 387         const struct nlm_args *args = data;
 388         const struct nlm_lock *lock = &args->lock;
 389
 390         encode_cookie(xdr, &args->cookie);
 391         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 392         encode_nlm4_lock(xdr, lock);
 393 }
 394
 395 /*
 396  *      struct nlm4_lockargs {
 397  *              netobj cookie;
 398  *              bool block;
 399  *              bool exclusive;
 400  *              struct nlm4_lock alock;
 401  *              bool reclaim;
 402  *              int state;
 403  *      };
 404  */
 405 static void nlm4_xdr_enc_lockargs(struct rpc_rqst *req,
 406                                   struct xdr_stream *xdr,
 407                                   const void *data)
 408 {
 409         const struct nlm_args *args = data;
 410         const struct nlm_lock *lock = &args->lock;
 411
 412         encode_cookie(xdr, &args->cookie);
 413         encode_bool(xdr, args->block);
 414         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 415         encode_nlm4_lock(xdr, lock);
 416         encode_bool(xdr, args->reclaim);
 417         encode_int32(xdr, args->state);
 418 }
 419
 420 /*
 421  *      struct nlm4_cancargs {
 422  *              netobj cookie;
 423  *              bool block;
 424  *              bool exclusive;
 425  *              struct nlm4_lock alock;
 426  *      };
 427  */
 428 static void nlm4_xdr_enc_cancargs(struct rpc_rqst *req,
 429                                   struct xdr_stream *xdr,
 430                                   const void *data)
 431 {
 432         const struct nlm_args *args = data;
 433         const struct nlm_lock *lock = &args->lock;
 434
 435         encode_cookie(xdr, &args->cookie);
 436         encode_bool(xdr, args->block);
 437         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 438         encode_nlm4_lock(xdr, lock);
 439 }
 440
 441 /*
 442  *      struct nlm4_unlockargs {
 443  *              netobj cookie;
 444  *              struct nlm4_lock alock;
 445  *      };
 446  */
 447 static void nlm4_xdr_enc_unlockargs(struct rpc_rqst *req,
 448                                     struct xdr_stream *xdr,
 449                                     const void *data)
 450 {
 451         const struct nlm_args *args = data;
 452         const struct nlm_lock *lock = &args->lock;
 453
 454         encode_cookie(xdr, &args->cookie);
 455         encode_nlm4_lock(xdr, lock);
 456 }
 457
 458 /*
 459  *      struct nlm4_res {
 460  *              netobj cookie;
 461  *              nlm4_stat stat;
 462  *      };
 463  */
 464 static void nlm4_xdr_enc_res(struct rpc_rqst *req,
 465                              struct xdr_stream *xdr,
 466                              const void *data)
 467 {
 468         const struct nlm_res *result = data;
 469
 470         encode_cookie(xdr, &result->cookie);
 471         encode_nlm4_stat(xdr, result->status);
 472 }
 473
 474 /*
 475  *      union nlm4_testrply switch (nlm4_stats stat) {
 476  *      case NLM4_DENIED:
 477  *              struct nlm4_holder holder;
 478  *      default:
 479  *              void;
 480  *      };
 481  *
 482  *      struct nlm4_testres {
 483  *              netobj cookie;
 484  *              nlm4_testrply test_stat;
 485  *      };
 486  */
 487 static void nlm4_xdr_enc_testres(struct rpc_rqst *req,
 488                                  struct xdr_stream *xdr,
 489                                  const void *data)
 490 {
 491         const struct nlm_res *result = data;
 492
 493         encode_cookie(xdr, &result->cookie);
 494         encode_nlm4_stat(xdr, result->status);
 495         if (result->status == nlm_lck_denied)
 496                 encode_nlm4_holder(xdr, result);
 497 }
 498
 499
 500 /*
 501  * NLMv4 XDR decode functions
 502  *
 503  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 504  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 505  * "Protocols for Interworking: XNFS, Version 3W".
 506  */
 507
 508 /*
 509  *      union nlm4_testrply switch (nlm4_stats stat) {
 510  *      case NLM4_DENIED:
 511  *              struct nlm4_holder holder;
 512  *      default:
 513  *              void;
 514  *      };
 515  *
 516  *      struct nlm4_testres {
 517  *              netobj cookie;
 518  *              nlm4_testrply test_stat;
 519  *      };
 520  */
 521 static int decode_nlm4_testrply(struct xdr_stream *xdr,
 522                                 struct nlm_res *result)
 523 {
 524         int error;
 525
 526         error = decode_nlm4_stat(xdr, &result->status);
 527         if (unlikely(error))
 528                 goto out;
 529         if (result->status == nlm_lck_denied)
 530                 error = decode_nlm4_holder(xdr, result);
 531 out:
 532         return error;
 533 }
 534
 535 static int nlm4_xdr_dec_testres(struct rpc_rqst *req,
 536                                 struct xdr_stream *xdr,
 537                                 void *data)
 538 {
 539         struct nlm_res *result = data;
 540         int error;
 541
 542         error = decode_cookie(xdr, &result->cookie);
 543         if (unlikely(error))
 544                 goto out;
 545         error = decode_nlm4_testrply(xdr, result);
 546 out:
 547         return error;
 548 }
 549
 550 /*
 551  *      struct nlm4_res {
 552  *              netobj cookie;
 553  *              nlm4_stat stat;
 554  *      };
 555  */
 556 static int nlm4_xdr_dec_res(struct rpc_rqst *req,
 557                             struct xdr_stream *xdr,
 558                             void *data)
 559 {
 560         struct nlm_res *result = data;
 561         int error;
 562
 563         error = decode_cookie(xdr, &result->cookie);
 564         if (unlikely(error))
 565                 goto out;
 566         error = decode_nlm4_stat(xdr, &result->status);
 567 out:
 568         return error;
 569 }
 570
 571
 572 /*
 573  * For NLM, a void procedure really returns nothing
 574  */
 575 #define nlm4_xdr_dec_norep      NULL
 576
 577 #define PROC(proc, argtype, restype)                                    \
 578 [NLMPROC_##proc] = {                                                    \
 579         .p_proc      = NLMPROC_##proc,                                  \
 580         .p_encode    = nlm4_xdr_enc_##argtype,                          \
 581         .p_decode    = nlm4_xdr_dec_##restype,                          \
 582         .p_arglen    = NLM4_##argtype##_sz,                             \
 583         .p_replen    = NLM4_##restype##_sz,                             \
 584         .p_statidx   = NLMPROC_##proc,                                  \
 585         .p_name      = #proc,                                           \
 586         }
 587
 588 static const struct rpc_procinfo nlm4_procedures[] = {
 589         PROC(TEST,              testargs,       testres),
 590         PROC(LOCK,              lockargs,       res),
 591         PROC(CANCEL,            cancargs,       res),
 592         PROC(UNLOCK,            unlockargs,     res),
 593         PROC(GRANTED,           testargs,       res),
 594         PROC(TEST_MSG,          testargs,       norep),
 595         PROC(LOCK_MSG,          lockargs,       norep),
 596         PROC(CANCEL_MSG,        cancargs,       norep),
 597         PROC(UNLOCK_MSG,        unlockargs,     norep),
 598         PROC(GRANTED_MSG,       testargs,       norep),
 599         PROC(TEST_RES,          testres,        norep),
 600         PROC(LOCK_RES,          res,            norep),
 601         PROC(CANCEL_RES,        res,            norep),
 602         PROC(UNLOCK_RES,        res,            norep),
 603         PROC(GRANTED_RES,       res,            norep),
 604 };
 605
 606 static unsigned int nlm_version4_counts[ARRAY_SIZE(nlm4_procedures)];
 607 const struct rpc_version nlm_version4 = {
 608         .number         = 4,
 609         .nrprocs        = ARRAY_SIZE(nlm4_procedures),
 610         .procs          = nlm4_procedures,
 611         .counts         = nlm_version4_counts,
 612 };