fs/lockd/clntxdr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/fs/lockd/clntxdr.c
   4  *
   5  * XDR functions to encode/decode NLM version 1 and 3 RPC
   6  * arguments and results. NLM version 2 is not specified
   7  * by a standard, thus it is not implemented.
   8  *
   9  * NLM client-side only.
  10  *
  11  * Copyright (C) 2010, Oracle.  All rights reserved.
  12  */
  13
  14 #include <linux/types.h>
  15 #include <linux/sunrpc/xdr.h>
  16 #include <linux/sunrpc/clnt.h>
  17 #include <linux/sunrpc/stats.h>
  18 #include <linux/lockd/lockd.h>
  19
  20 #include <uapi/linux/nfs2.h>
  21
  22 #define NLMDBG_FACILITY         NLMDBG_XDR
  23
  24 #if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
  25 #  error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
  26 #endif
  27
  28 /*
  29  * Declare the space requirements for NLM arguments and replies as
  30  * number of 32bit-words
  31  */
  32 #define NLM_cookie_sz           (1+(NLM_MAXCOOKIELEN>>2))
  33 #define NLM_caller_sz           (1+(NLMCLNT_OHSIZE>>2))
  34 #define NLM_owner_sz            (1+(NLMCLNT_OHSIZE>>2))
  35 #define NLM_fhandle_sz          (1+(NFS2_FHSIZE>>2))
  36 #define NLM_lock_sz             (3+NLM_caller_sz+NLM_owner_sz+NLM_fhandle_sz)
  37 #define NLM_holder_sz           (4+NLM_owner_sz)
  38
  39 #define NLM_testargs_sz         (NLM_cookie_sz+1+NLM_lock_sz)
  40 #define NLM_lockargs_sz         (NLM_cookie_sz+4+NLM_lock_sz)
  41 #define NLM_cancargs_sz         (NLM_cookie_sz+2+NLM_lock_sz)
  42 #define NLM_unlockargs_sz       (NLM_cookie_sz+NLM_lock_sz)
  43
  44 #define NLM_testres_sz          (NLM_cookie_sz+1+NLM_holder_sz)
  45 #define NLM_res_sz              (NLM_cookie_sz+1)
  46 #define NLM_norep_sz            (0)
  47
  48
  49 static s32 loff_t_to_s32(loff_t offset)
  50 {
  51         s32 res;
  52
  53         if (offset >= NLM_OFFSET_MAX)
  54                 res = NLM_OFFSET_MAX;
  55         else if (offset <= -NLM_OFFSET_MAX)
  56                 res = -NLM_OFFSET_MAX;
  57         else
  58                 res = offset;
  59         return res;
  60 }
  61
  62 static void nlm_compute_offsets(const struct nlm_lock *lock,
  63                                 u32 *l_offset, u32 *l_len)
  64 {
  65         const struct file_lock *fl = &lock->fl;
  66
  67         *l_offset = loff_t_to_s32(fl->fl_start);
  68         if (fl->fl_end == OFFSET_MAX)
  69                 *l_len = 0;
  70         else
  71                 *l_len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
  72 }
  73
  74 /*
  75  * Encode/decode NLMv3 basic data types
  76  *
  77  * Basic NLMv3 data types are not defined in an IETF standards
  78  * document.  X/Open has a description of these data types that
  79  * is useful.  See Chapter 10 of "Protocols for Interworking:
  80  * XNFS, Version 3W".
  81  *
  82  * Not all basic data types have their own encoding and decoding
  83  * functions.  For run-time efficiency, some data types are encoded
  84  * or decoded inline.
  85  */
  86
  87 static void encode_bool(struct xdr_stream *xdr, const int value)
  88 {
  89         __be32 *p;
  90
  91         p = xdr_reserve_space(xdr, 4);
  92         *p = value ? xdr_one : xdr_zero;
  93 }
  94
  95 static void encode_int32(struct xdr_stream *xdr, const s32 value)
  96 {
  97         __be32 *p;
  98
  99         p = xdr_reserve_space(xdr, 4);
 100         *p = cpu_to_be32(value);
 101 }
 102
 103 /*
 104  *      typedef opaque netobj<MAXNETOBJ_SZ>
 105  */
 106 static void encode_netobj(struct xdr_stream *xdr,
 107                           const u8 *data, const unsigned int length)
 108 {
 109         __be32 *p;
 110
 111         p = xdr_reserve_space(xdr, 4 + length);
 112         xdr_encode_opaque(p, data, length);
 113 }
 114
 115 static int decode_netobj(struct xdr_stream *xdr,
 116                          struct xdr_netobj *obj)
 117 {
 118         ssize_t ret;
 119
 120         ret = xdr_stream_decode_opaque_inline(xdr, (void *)&obj->data,
 121                         XDR_MAX_NETOBJ);
 122         if (unlikely(ret < 0))
 123                 return -EIO;
 124         obj->len = ret;
 125         return 0;
 126 }
 127
 128 /*
 129  *      netobj cookie;
 130  */
 131 static void encode_cookie(struct xdr_stream *xdr,
 132                           const struct nlm_cookie *cookie)
 133 {
 134         encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
 135 }
 136
 137 static int decode_cookie(struct xdr_stream *xdr,
 138                          struct nlm_cookie *cookie)
 139 {
 140         u32 length;
 141         __be32 *p;
 142
 143         p = xdr_inline_decode(xdr, 4);
 144         if (unlikely(p == NULL))
 145                 goto out_overflow;
 146         length = be32_to_cpup(p++);
 147         /* apparently HPUX can return empty cookies */
 148         if (length == 0)
 149                 goto out_hpux;
 150         if (length > NLM_MAXCOOKIELEN)
 151                 goto out_size;
 152         p = xdr_inline_decode(xdr, length);
 153         if (unlikely(p == NULL))
 154                 goto out_overflow;
 155         cookie->len = length;
 156         memcpy(cookie->data, p, length);
 157         return 0;
 158 out_hpux:
 159         cookie->len = 4;
 160         memset(cookie->data, 0, 4);
 161         return 0;
 162 out_size:
 163         dprintk("NFS: returned cookie was too long: %u\n", length);
 164         return -EIO;
 165 out_overflow:
 166         return -EIO;
 167 }
 168
 169 /*
 170  *      netobj fh;
 171  */
 172 static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
 173 {
 174         encode_netobj(xdr, (u8 *)&fh->data, NFS2_FHSIZE);
 175 }
 176
 177 /*
 178  *      enum nlm_stats {
 179  *              LCK_GRANTED = 0,
 180  *              LCK_DENIED = 1,
 181  *              LCK_DENIED_NOLOCKS = 2,
 182  *              LCK_BLOCKED = 3,
 183  *              LCK_DENIED_GRACE_PERIOD = 4
 184  *      };
 185  *
 186  *
 187  *      struct nlm_stat {
 188  *              nlm_stats stat;
 189  *      };
 190  *
 191  * NB: we don't swap bytes for the NLM status values.  The upper
 192  * layers deal directly with the status value in network byte
 193  * order.
 194  */
 195
 196 static void encode_nlm_stat(struct xdr_stream *xdr,
 197                             const __be32 stat)
 198 {
 199         __be32 *p;
 200
 201         WARN_ON_ONCE(be32_to_cpu(stat) > NLM_LCK_DENIED_GRACE_PERIOD);
 202         p = xdr_reserve_space(xdr, 4);
 203         *p = stat;
 204 }
 205
 206 static int decode_nlm_stat(struct xdr_stream *xdr,
 207                            __be32 *stat)
 208 {
 209         __be32 *p;
 210
 211         p = xdr_inline_decode(xdr, 4);
 212         if (unlikely(p == NULL))
 213                 goto out_overflow;
 214         if (unlikely(ntohl(*p) > ntohl(nlm_lck_denied_grace_period)))
 215                 goto out_enum;
 216         *stat = *p;
 217         return 0;
 218 out_enum:
 219         dprintk("%s: server returned invalid nlm_stats value: %u\n",
 220                 __func__, be32_to_cpup(p));
 221         return -EIO;
 222 out_overflow:
 223         return -EIO;
 224 }
 225
 226 /*
 227  *      struct nlm_holder {
 228  *              bool exclusive;
 229  *              int uppid;
 230  *              netobj oh;
 231  *              unsigned l_offset;
 232  *              unsigned l_len;
 233  *      };
 234  */
 235 static void encode_nlm_holder(struct xdr_stream *xdr,
 236                               const struct nlm_res *result)
 237 {
 238         const struct nlm_lock *lock = &result->lock;
 239         u32 l_offset, l_len;
 240         __be32 *p;
 241
 242         encode_bool(xdr, lock->fl.c.flc_type == F_RDLCK);
 243         encode_int32(xdr, lock->svid);
 244         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 245
 246         p = xdr_reserve_space(xdr, 4 + 4);
 247         nlm_compute_offsets(lock, &l_offset, &l_len);
 248         *p++ = cpu_to_be32(l_offset);
 249         *p   = cpu_to_be32(l_len);
 250 }
 251
 252 static int decode_nlm_holder(struct xdr_stream *xdr, struct nlm_res *result)
 253 {
 254         struct nlm_lock *lock = &result->lock;
 255         struct file_lock *fl = &lock->fl;
 256         u32 exclusive, l_offset, l_len;
 257         int error;
 258         __be32 *p;
 259         s32 end;
 260
 261         memset(lock, 0, sizeof(*lock));
 262         locks_init_lock(fl);
 263
 264         p = xdr_inline_decode(xdr, 4 + 4);
 265         if (unlikely(p == NULL))
 266                 goto out_overflow;
 267         exclusive = be32_to_cpup(p++);
 268         lock->svid = be32_to_cpup(p);
 269         fl->c.flc_pid = (pid_t)lock->svid;
 270
 271         error = decode_netobj(xdr, &lock->oh);
 272         if (unlikely(error))
 273                 goto out;
 274
 275         p = xdr_inline_decode(xdr, 4 + 4);
 276         if (unlikely(p == NULL))
 277                 goto out_overflow;
 278
 279         fl->c.flc_flags = FL_POSIX;
 280         fl->c.flc_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
 281         l_offset = be32_to_cpup(p++);
 282         l_len = be32_to_cpup(p);
 283         end = l_offset + l_len - 1;
 284
 285         fl->fl_start = (loff_t)l_offset;
 286         if (l_len == 0 || end < 0)
 287                 fl->fl_end = OFFSET_MAX;
 288         else
 289                 fl->fl_end = (loff_t)end;
 290         error = 0;
 291 out:
 292         return error;
 293 out_overflow:
 294         return -EIO;
 295 }
 296
 297 /*
 298  *      string caller_name<LM_MAXSTRLEN>;
 299  */
 300 static void encode_caller_name(struct xdr_stream *xdr, const char *name)
 301 {
 302         /* NB: client-side does not set lock->len */
 303         u32 length = strlen(name);
 304         __be32 *p;
 305
 306         p = xdr_reserve_space(xdr, 4 + length);
 307         xdr_encode_opaque(p, name, length);
 308 }
 309
 310 /*
 311  *      struct nlm_lock {
 312  *              string caller_name<LM_MAXSTRLEN>;
 313  *              netobj fh;
 314  *              netobj oh;
 315  *              int uppid;
 316  *              unsigned l_offset;
 317  *              unsigned l_len;
 318  *      };
 319  */
 320 static void encode_nlm_lock(struct xdr_stream *xdr,
 321                             const struct nlm_lock *lock)
 322 {
 323         u32 l_offset, l_len;
 324         __be32 *p;
 325
 326         encode_caller_name(xdr, lock->caller);
 327         encode_fh(xdr, &lock->fh);
 328         encode_netobj(xdr, lock->oh.data, lock->oh.len);
 329
 330         p = xdr_reserve_space(xdr, 4 + 4 + 4);
 331         *p++ = cpu_to_be32(lock->svid);
 332
 333         nlm_compute_offsets(lock, &l_offset, &l_len);
 334         *p++ = cpu_to_be32(l_offset);
 335         *p   = cpu_to_be32(l_len);
 336 }
 337
 338
 339 /*
 340  * NLMv3 XDR encode functions
 341  *
 342  * NLMv3 argument types are defined in Chapter 10 of The Open Group's
 343  * "Protocols for Interworking: XNFS, Version 3W".
 344  */
 345
 346 /*
 347  *      struct nlm_testargs {
 348  *              netobj cookie;
 349  *              bool exclusive;
 350  *              struct nlm_lock alock;
 351  *      };
 352  */
 353 static void nlm_xdr_enc_testargs(struct rpc_rqst *req,
 354                                  struct xdr_stream *xdr,
 355                                  const void *data)
 356 {
 357         const struct nlm_args *args = data;
 358         const struct nlm_lock *lock = &args->lock;
 359
 360         encode_cookie(xdr, &args->cookie);
 361         encode_bool(xdr, lock->fl.c.flc_type == F_WRLCK);
 362         encode_nlm_lock(xdr, lock);
 363 }
 364
 365 /*
 366  *      struct nlm_lockargs {
 367  *              netobj cookie;
 368  *              bool block;
 369  *              bool exclusive;
 370  *              struct nlm_lock alock;
 371  *              bool reclaim;
 372  *              int state;
 373  *      };
 374  */
 375 static void nlm_xdr_enc_lockargs(struct rpc_rqst *req,
 376                                  struct xdr_stream *xdr,
 377                                  const void *data)
 378 {
 379         const struct nlm_args *args = data;
 380         const struct nlm_lock *lock = &args->lock;
 381
 382         encode_cookie(xdr, &args->cookie);
 383         encode_bool(xdr, args->block);
 384         encode_bool(xdr, lock->fl.c.flc_type == F_WRLCK);
 385         encode_nlm_lock(xdr, lock);
 386         encode_bool(xdr, args->reclaim);
 387         encode_int32(xdr, args->state);
 388 }
 389
 390 /*
 391  *      struct nlm_cancargs {
 392  *              netobj cookie;
 393  *              bool block;
 394  *              bool exclusive;
 395  *              struct nlm_lock alock;
 396  *      };
 397  */
 398 static void nlm_xdr_enc_cancargs(struct rpc_rqst *req,
 399                                  struct xdr_stream *xdr,
 400                                  const void *data)
 401 {
 402         const struct nlm_args *args = data;
 403         const struct nlm_lock *lock = &args->lock;
 404
 405         encode_cookie(xdr, &args->cookie);
 406         encode_bool(xdr, args->block);
 407         encode_bool(xdr, lock->fl.c.flc_type == F_WRLCK);
 408         encode_nlm_lock(xdr, lock);
 409 }
 410
 411 /*
 412  *      struct nlm_unlockargs {
 413  *              netobj cookie;
 414  *              struct nlm_lock alock;
 415  *      };
 416  */
 417 static void nlm_xdr_enc_unlockargs(struct rpc_rqst *req,
 418                                    struct xdr_stream *xdr,
 419                                    const void *data)
 420 {
 421         const struct nlm_args *args = data;
 422         const struct nlm_lock *lock = &args->lock;
 423
 424         encode_cookie(xdr, &args->cookie);
 425         encode_nlm_lock(xdr, lock);
 426 }
 427
 428 /*
 429  *      struct nlm_res {
 430  *              netobj cookie;
 431  *              nlm_stat stat;
 432  *      };
 433  */
 434 static void nlm_xdr_enc_res(struct rpc_rqst *req,
 435                             struct xdr_stream *xdr,
 436                             const void *data)
 437 {
 438         const struct nlm_res *result = data;
 439
 440         encode_cookie(xdr, &result->cookie);
 441         encode_nlm_stat(xdr, result->status);
 442 }
 443
 444 /*
 445  *      union nlm_testrply switch (nlm_stats stat) {
 446  *      case LCK_DENIED:
 447  *              struct nlm_holder holder;
 448  *      default:
 449  *              void;
 450  *      };
 451  *
 452  *      struct nlm_testres {
 453  *              netobj cookie;
 454  *              nlm_testrply test_stat;
 455  *      };
 456  */
 457 static void encode_nlm_testrply(struct xdr_stream *xdr,
 458                                 const struct nlm_res *result)
 459 {
 460         if (result->status == nlm_lck_denied)
 461                 encode_nlm_holder(xdr, result);
 462 }
 463
 464 static void nlm_xdr_enc_testres(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_nlm_stat(xdr, result->status);
 472         encode_nlm_testrply(xdr, result);
 473 }
 474
 475
 476 /*
 477  * NLMv3 XDR decode functions
 478  *
 479  * NLMv3 result types are defined in Chapter 10 of The Open Group's
 480  * "Protocols for Interworking: XNFS, Version 3W".
 481  */
 482
 483 /*
 484  *      union nlm_testrply switch (nlm_stats stat) {
 485  *      case LCK_DENIED:
 486  *              struct nlm_holder holder;
 487  *      default:
 488  *              void;
 489  *      };
 490  *
 491  *      struct nlm_testres {
 492  *              netobj cookie;
 493  *              nlm_testrply test_stat;
 494  *      };
 495  */
 496 static int decode_nlm_testrply(struct xdr_stream *xdr,
 497                                struct nlm_res *result)
 498 {
 499         int error;
 500
 501         error = decode_nlm_stat(xdr, &result->status);
 502         if (unlikely(error))
 503                 goto out;
 504         if (result->status == nlm_lck_denied)
 505                 error = decode_nlm_holder(xdr, result);
 506 out:
 507         return error;
 508 }
 509
 510 static int nlm_xdr_dec_testres(struct rpc_rqst *req,
 511                                struct xdr_stream *xdr,
 512                                void *data)
 513 {
 514         struct nlm_res *result = data;
 515         int error;
 516
 517         error = decode_cookie(xdr, &result->cookie);
 518         if (unlikely(error))
 519                 goto out;
 520         error = decode_nlm_testrply(xdr, result);
 521 out:
 522         return error;
 523 }
 524
 525 /*
 526  *      struct nlm_res {
 527  *              netobj cookie;
 528  *              nlm_stat stat;
 529  *      };
 530  */
 531 static int nlm_xdr_dec_res(struct rpc_rqst *req,
 532                            struct xdr_stream *xdr,
 533                            void *data)
 534 {
 535         struct nlm_res *result = data;
 536         int error;
 537
 538         error = decode_cookie(xdr, &result->cookie);
 539         if (unlikely(error))
 540                 goto out;
 541         error = decode_nlm_stat(xdr, &result->status);
 542 out:
 543         return error;
 544 }
 545
 546
 547 /*
 548  * For NLM, a void procedure really returns nothing
 549  */
 550 #define nlm_xdr_dec_norep       NULL
 551
 552 #define PROC(proc, argtype, restype)    \
 553 [NLMPROC_##proc] = {                                                    \
 554         .p_proc      = NLMPROC_##proc,                                  \
 555         .p_encode    = nlm_xdr_enc_##argtype,           \
 556         .p_decode    = nlm_xdr_dec_##restype,                           \
 557         .p_arglen    = NLM_##argtype##_sz,                              \
 558         .p_replen    = NLM_##restype##_sz,                              \
 559         .p_statidx   = NLMPROC_##proc,                                  \
 560         .p_name      = #proc,                                           \
 561         }
 562
 563 static const struct rpc_procinfo nlm_procedures[] = {
 564         PROC(TEST,              testargs,       testres),
 565         PROC(LOCK,              lockargs,       res),
 566         PROC(CANCEL,            cancargs,       res),
 567         PROC(UNLOCK,            unlockargs,     res),
 568         PROC(GRANTED,           testargs,       res),
 569         PROC(TEST_MSG,          testargs,       norep),
 570         PROC(LOCK_MSG,          lockargs,       norep),
 571         PROC(CANCEL_MSG,        cancargs,       norep),
 572         PROC(UNLOCK_MSG,        unlockargs,     norep),
 573         PROC(GRANTED_MSG,       testargs,       norep),
 574         PROC(TEST_RES,          testres,        norep),
 575         PROC(LOCK_RES,          res,            norep),
 576         PROC(CANCEL_RES,        res,            norep),
 577         PROC(UNLOCK_RES,        res,            norep),
 578         PROC(GRANTED_RES,       res,            norep),
 579 };
 580
 581 static unsigned int nlm_version1_counts[ARRAY_SIZE(nlm_procedures)];
 582 static const struct rpc_version nlm_version1 = {
 583         .number         = 1,
 584         .nrprocs        = ARRAY_SIZE(nlm_procedures),
 585         .procs          = nlm_procedures,
 586         .counts         = nlm_version1_counts,
 587 };
 588
 589 static unsigned int nlm_version3_counts[ARRAY_SIZE(nlm_procedures)];
 590 static const struct rpc_version nlm_version3 = {
 591         .number         = 3,
 592         .nrprocs        = ARRAY_SIZE(nlm_procedures),
 593         .procs          = nlm_procedures,
 594         .counts         = nlm_version3_counts,
 595 };
 596
 597 static const struct rpc_version *nlm_versions[] = {
 598         [1] = &nlm_version1,
 599         [3] = &nlm_version3,
 600 #ifdef CONFIG_LOCKD_V4
 601         [4] = &nlm_version4,
 602 #endif
 603 };
 604
 605 static struct rpc_stat          nlm_rpc_stats;
 606
 607 const struct rpc_program        nlm_program = {
 608         .name           = "lockd",
 609         .number         = NLM_PROGRAM,
 610         .nrvers         = ARRAY_SIZE(nlm_versions),
 611         .version        = nlm_versions,
 612         .stats          = &nlm_rpc_stats,
 613 };