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         ssize_t ret;
 132
 133         ret = xdr_stream_decode_opaque_inline(xdr, (void *)&obj->data,
 134                                                 XDR_MAX_NETOBJ);
 135         if (unlikely(ret < 0))
 136                 return -EIO;
 137         obj->len = ret;
 138         return 0;
 139 }
 140
 141 /*
 142  *      netobj cookie;
 143  */
 144 static void encode_cookie(struct xdr_stream *xdr,
 145                           const struct nlm_cookie *cookie)
 146 {
 147         encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
 148 }
 149
 150 static int decode_cookie(struct xdr_stream *xdr,
 151                              struct nlm_cookie *cookie)
 152 {
 153         u32 length;
 154         __be32 *p;
 155
 156         p = xdr_inline_decode(xdr, 4);
 157         if (unlikely(p == NULL))
 158                 goto out_overflow;
 159         length = be32_to_cpup(p++);
 160         /* apparently HPUX can return empty cookies */
 161         if (length == 0)
 162                 goto out_hpux;
 163         if (length > NLM_MAXCOOKIELEN)
 164                 goto out_size;
 165         p = xdr_inline_decode(xdr, length);
 166         if (unlikely(p == NULL))
 167                 goto out_overflow;
 168         cookie->len = length;
 169         memcpy(cookie->data, p, length);
 170         return 0;
 171 out_hpux:
 172         cookie->len = 4;
 173         memset(cookie->data, 0, 4);
 174         return 0;
 175 out_size:
 176         dprintk("NFS: returned cookie was too long: %u\n", length);
 177         return -EIO;
 178 out_overflow:
 179         print_overflow_msg(__func__, xdr);
 180         return -EIO;
 181 }
 182
 183 /*
 184  *      netobj fh;
 185  */
 186 static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
 187 {
 188         encode_netobj(xdr, (u8 *)&fh->data, fh->size);
 189 }
 190
 191 /*
 192  *      enum nlm4_stats {
 193  *              NLM4_GRANTED = 0,
 194  *              NLM4_DENIED = 1,
 195  *              NLM4_DENIED_NOLOCKS = 2,
 196  *              NLM4_BLOCKED = 3,
 197  *              NLM4_DENIED_GRACE_PERIOD = 4,
 198  *              NLM4_DEADLCK = 5,
 199  *              NLM4_ROFS = 6,
 200  *              NLM4_STALE_FH = 7,
 201  *              NLM4_FBIG = 8,
 202  *              NLM4_FAILED = 9
 203  *      };
 204  *
 205  *      struct nlm4_stat {
 206  *              nlm4_stats stat;
 207  *      };
 208  *
 209  * NB: we don't swap bytes for the NLM status values.  The upper
 210  * layers deal directly with the status value in network byte
 211  * order.
 212  */
 213 static void encode_nlm4_stat(struct xdr_stream *xdr,
 214                              const __be32 stat)
 215 {
 216         __be32 *p;
 217
 218         BUG_ON(be32_to_cpu(stat) > NLM_FAILED);
 219         p = xdr_reserve_space(xdr, 4);
 220         *p = stat;
 221 }
 222
 223 static int decode_nlm4_stat(struct xdr_stream *xdr, __be32 *stat)
 224 {
 225         __be32 *p;
 226
 227         p = xdr_inline_decode(xdr, 4);
 228         if (unlikely(p == NULL))
 229                 goto out_overflow;
 230         if (unlikely(ntohl(*p) > ntohl(nlm4_failed)))
 231                 goto out_bad_xdr;
 232         *stat = *p;
 233         return 0;
 234 out_bad_xdr:
 235         dprintk("%s: server returned invalid nlm4_stats value: %u\n",
 236                         __func__, be32_to_cpup(p));
 237         return -EIO;
 238 out_overflow:
 239         print_overflow_msg(__func__, xdr);
 240         return -EIO;
 241 }
 242
 243 /*
 244  *      struct nlm4_holder {
 245  *              bool    exclusive;
 246  *              int32   svid;
 247  *              netobj  oh;
 248  *              uint64  l_offset;
 249  *              uint64  l_len;
 250  *      };
 251  */
 252 static void encode_nlm4_holder(struct xdr_stream *xdr,
 253                                const struct nlm_res *result)
 254 {
 255         const struct nlm_lock *lock = &result->lock;
 256         u64 l_offset, l_len;
 257         __be32 *p;
 258
 259         encode_bool(xdr, lock->fl.fl_type == F_RDLCK);
 260         encode_int32(xdr, lock->svid);
 261         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 262
 263         p = xdr_reserve_space(xdr, 4 + 4);
 264         nlm4_compute_offsets(lock, &l_offset, &l_len);
 265         p = xdr_encode_hyper(p, l_offset);
 266         xdr_encode_hyper(p, l_len);
 267 }
 268
 269 static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
 270 {
 271         struct nlm_lock *lock = &result->lock;
 272         struct file_lock *fl = &lock->fl;
 273         u64 l_offset, l_len;
 274         u32 exclusive;
 275         int error;
 276         __be32 *p;
 277         s32 end;
 278
 279         memset(lock, 0, sizeof(*lock));
 280         locks_init_lock(fl);
 281
 282         p = xdr_inline_decode(xdr, 4 + 4);
 283         if (unlikely(p == NULL))
 284                 goto out_overflow;
 285         exclusive = be32_to_cpup(p++);
 286         lock->svid = be32_to_cpup(p);
 287         fl->fl_pid = (pid_t)lock->svid;
 288
 289         error = decode_netobj(xdr, &lock->oh);
 290         if (unlikely(error))
 291                 goto out;
 292
 293         p = xdr_inline_decode(xdr, 8 + 8);
 294         if (unlikely(p == NULL))
 295                 goto out_overflow;
 296
 297         fl->fl_flags = FL_POSIX;
 298         fl->fl_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
 299         p = xdr_decode_hyper(p, &l_offset);
 300         xdr_decode_hyper(p, &l_len);
 301         end = l_offset + l_len - 1;
 302
 303         fl->fl_start = (loff_t)l_offset;
 304         if (l_len == 0 || end < 0)
 305                 fl->fl_end = OFFSET_MAX;
 306         else
 307                 fl->fl_end = (loff_t)end;
 308         error = 0;
 309 out:
 310         return error;
 311 out_overflow:
 312         print_overflow_msg(__func__, xdr);
 313         return -EIO;
 314 }
 315
 316 /*
 317  *      string caller_name<LM_MAXSTRLEN>;
 318  */
 319 static void encode_caller_name(struct xdr_stream *xdr, const char *name)
 320 {
 321         /* NB: client-side does not set lock->len */
 322         u32 length = strlen(name);
 323         __be32 *p;
 324
 325         p = xdr_reserve_space(xdr, 4 + length);
 326         xdr_encode_opaque(p, name, length);
 327 }
 328
 329 /*
 330  *      struct nlm4_lock {
 331  *              string  caller_name<LM_MAXSTRLEN>;
 332  *              netobj  fh;
 333  *              netobj  oh;
 334  *              int32   svid;
 335  *              uint64  l_offset;
 336  *              uint64  l_len;
 337  *      };
 338  */
 339 static void encode_nlm4_lock(struct xdr_stream *xdr,
 340                              const struct nlm_lock *lock)
 341 {
 342         u64 l_offset, l_len;
 343         __be32 *p;
 344
 345         encode_caller_name(xdr, lock->caller);
 346         encode_fh(xdr, &lock->fh);
 347         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 348
 349         p = xdr_reserve_space(xdr, 4 + 8 + 8);
 350         *p++ = cpu_to_be32(lock->svid);
 351
 352         nlm4_compute_offsets(lock, &l_offset, &l_len);
 353         p = xdr_encode_hyper(p, l_offset);
 354         xdr_encode_hyper(p, l_len);
 355 }
 356
 357
 358 /*
 359  * NLMv4 XDR encode functions
 360  *
 361  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 362  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 363  * "Protocols for Interworking: XNFS, Version 3W".
 364  */
 365
 366 /*
 367  *      struct nlm4_testargs {
 368  *              netobj cookie;
 369  *              bool exclusive;
 370  *              struct nlm4_lock alock;
 371  *      };
 372  */
 373 static void nlm4_xdr_enc_testargs(struct rpc_rqst *req,
 374                                   struct xdr_stream *xdr,
 375                                   const void *data)
 376 {
 377         const struct nlm_args *args = data;
 378         const struct nlm_lock *lock = &args->lock;
 379
 380         encode_cookie(xdr, &args->cookie);
 381         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 382         encode_nlm4_lock(xdr, lock);
 383 }
 384
 385 /*
 386  *      struct nlm4_lockargs {
 387  *              netobj cookie;
 388  *              bool block;
 389  *              bool exclusive;
 390  *              struct nlm4_lock alock;
 391  *              bool reclaim;
 392  *              int state;
 393  *      };
 394  */
 395 static void nlm4_xdr_enc_lockargs(struct rpc_rqst *req,
 396                                   struct xdr_stream *xdr,
 397                                   const void *data)
 398 {
 399         const struct nlm_args *args = data;
 400         const struct nlm_lock *lock = &args->lock;
 401
 402         encode_cookie(xdr, &args->cookie);
 403         encode_bool(xdr, args->block);
 404         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 405         encode_nlm4_lock(xdr, lock);
 406         encode_bool(xdr, args->reclaim);
 407         encode_int32(xdr, args->state);
 408 }
 409
 410 /*
 411  *      struct nlm4_cancargs {
 412  *              netobj cookie;
 413  *              bool block;
 414  *              bool exclusive;
 415  *              struct nlm4_lock alock;
 416  *      };
 417  */
 418 static void nlm4_xdr_enc_cancargs(struct rpc_rqst *req,
 419                                   struct xdr_stream *xdr,
 420                                   const void *data)
 421 {
 422         const struct nlm_args *args = data;
 423         const struct nlm_lock *lock = &args->lock;
 424
 425         encode_cookie(xdr, &args->cookie);
 426         encode_bool(xdr, args->block);
 427         encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
 428         encode_nlm4_lock(xdr, lock);
 429 }
 430
 431 /*
 432  *      struct nlm4_unlockargs {
 433  *              netobj cookie;
 434  *              struct nlm4_lock alock;
 435  *      };
 436  */
 437 static void nlm4_xdr_enc_unlockargs(struct rpc_rqst *req,
 438                                     struct xdr_stream *xdr,
 439                                     const void *data)
 440 {
 441         const struct nlm_args *args = data;
 442         const struct nlm_lock *lock = &args->lock;
 443
 444         encode_cookie(xdr, &args->cookie);
 445         encode_nlm4_lock(xdr, lock);
 446 }
 447
 448 /*
 449  *      struct nlm4_res {
 450  *              netobj cookie;
 451  *              nlm4_stat stat;
 452  *      };
 453  */
 454 static void nlm4_xdr_enc_res(struct rpc_rqst *req,
 455                              struct xdr_stream *xdr,
 456                              const void *data)
 457 {
 458         const struct nlm_res *result = data;
 459
 460         encode_cookie(xdr, &result->cookie);
 461         encode_nlm4_stat(xdr, result->status);
 462 }
 463
 464 /*
 465  *      union nlm4_testrply switch (nlm4_stats stat) {
 466  *      case NLM4_DENIED:
 467  *              struct nlm4_holder holder;
 468  *      default:
 469  *              void;
 470  *      };
 471  *
 472  *      struct nlm4_testres {
 473  *              netobj cookie;
 474  *              nlm4_testrply test_stat;
 475  *      };
 476  */
 477 static void nlm4_xdr_enc_testres(struct rpc_rqst *req,
 478                                  struct xdr_stream *xdr,
 479                                  const void *data)
 480 {
 481         const struct nlm_res *result = data;
 482
 483         encode_cookie(xdr, &result->cookie);
 484         encode_nlm4_stat(xdr, result->status);
 485         if (result->status == nlm_lck_denied)
 486                 encode_nlm4_holder(xdr, result);
 487 }
 488
 489
 490 /*
 491  * NLMv4 XDR decode functions
 492  *
 493  * NLMv4 argument types are defined in Appendix II of RFC 1813:
 494  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 495  * "Protocols for Interworking: XNFS, Version 3W".
 496  */
 497
 498 /*
 499  *      union nlm4_testrply switch (nlm4_stats stat) {
 500  *      case NLM4_DENIED:
 501  *              struct nlm4_holder holder;
 502  *      default:
 503  *              void;
 504  *      };
 505  *
 506  *      struct nlm4_testres {
 507  *              netobj cookie;
 508  *              nlm4_testrply test_stat;
 509  *      };
 510  */
 511 static int decode_nlm4_testrply(struct xdr_stream *xdr,
 512                                 struct nlm_res *result)
 513 {
 514         int error;
 515
 516         error = decode_nlm4_stat(xdr, &result->status);
 517         if (unlikely(error))
 518                 goto out;
 519         if (result->status == nlm_lck_denied)
 520                 error = decode_nlm4_holder(xdr, result);
 521 out:
 522         return error;
 523 }
 524
 525 static int nlm4_xdr_dec_testres(struct rpc_rqst *req,
 526                                 struct xdr_stream *xdr,
 527                                 void *data)
 528 {
 529         struct nlm_res *result = data;
 530         int error;
 531
 532         error = decode_cookie(xdr, &result->cookie);
 533         if (unlikely(error))
 534                 goto out;
 535         error = decode_nlm4_testrply(xdr, result);
 536 out:
 537         return error;
 538 }
 539
 540 /*
 541  *      struct nlm4_res {
 542  *              netobj cookie;
 543  *              nlm4_stat stat;
 544  *      };
 545  */
 546 static int nlm4_xdr_dec_res(struct rpc_rqst *req,
 547                             struct xdr_stream *xdr,
 548                             void *data)
 549 {
 550         struct nlm_res *result = data;
 551         int error;
 552
 553         error = decode_cookie(xdr, &result->cookie);
 554         if (unlikely(error))
 555                 goto out;
 556         error = decode_nlm4_stat(xdr, &result->status);
 557 out:
 558         return error;
 559 }
 560
 561
 562 /*
 563  * For NLM, a void procedure really returns nothing
 564  */
 565 #define nlm4_xdr_dec_norep      NULL
 566
 567 #define PROC(proc, argtype, restype)                                    \
 568 [NLMPROC_##proc] = {                                                    \
 569         .p_proc      = NLMPROC_##proc,                                  \
 570         .p_encode    = nlm4_xdr_enc_##argtype,                          \
 571         .p_decode    = nlm4_xdr_dec_##restype,                          \
 572         .p_arglen    = NLM4_##argtype##_sz,                             \
 573         .p_replen    = NLM4_##restype##_sz,                             \
 574         .p_statidx   = NLMPROC_##proc,                                  \
 575         .p_name      = #proc,                                           \
 576         }
 577
 578 static const struct rpc_procinfo nlm4_procedures[] = {
 579         PROC(TEST,              testargs,       testres),
 580         PROC(LOCK,              lockargs,       res),
 581         PROC(CANCEL,            cancargs,       res),
 582         PROC(UNLOCK,            unlockargs,     res),
 583         PROC(GRANTED,           testargs,       res),
 584         PROC(TEST_MSG,          testargs,       norep),
 585         PROC(LOCK_MSG,          lockargs,       norep),
 586         PROC(CANCEL_MSG,        cancargs,       norep),
 587         PROC(UNLOCK_MSG,        unlockargs,     norep),
 588         PROC(GRANTED_MSG,       testargs,       norep),
 589         PROC(TEST_RES,          testres,        norep),
 590         PROC(LOCK_RES,          res,            norep),
 591         PROC(CANCEL_RES,        res,            norep),
 592         PROC(UNLOCK_RES,        res,            norep),
 593         PROC(GRANTED_RES,       res,            norep),
 594 };
 595
 596 static unsigned int nlm_version4_counts[ARRAY_SIZE(nlm4_procedures)];
 597 const struct rpc_version nlm_version4 = {
 598         .number         = 4,
 599         .nrprocs        = ARRAY_SIZE(nlm4_procedures),
 600         .procs          = nlm4_procedures,
 601         .counts         = nlm_version4_counts,
 602 };