1 /* 2 * linux/fs/lockd/clntxdr.c 3 * 4 * XDR functions to encode/decode NLM version 3 RPC arguments and results. 5 * NLM version 3 is backwards compatible with NLM versions 1 and 2. 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 #define NLMDBG_FACILITY NLMDBG_XDR 19 20 #if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ) 21 # error "NLM host name cannot be larger than XDR_MAX_NETOBJ!" 22 #endif 23 24 /* 25 * Declare the space requirements for NLM arguments and replies as 26 * number of 32bit-words 27 */ 28 #define NLM_cookie_sz (1+(NLM_MAXCOOKIELEN>>2)) 29 #define NLM_caller_sz (1+(NLMCLNT_OHSIZE>>2)) 30 #define NLM_owner_sz (1+(NLMCLNT_OHSIZE>>2)) 31 #define NLM_fhandle_sz (1+(NFS2_FHSIZE>>2)) 32 #define NLM_lock_sz (3+NLM_caller_sz+NLM_owner_sz+NLM_fhandle_sz) 33 #define NLM_holder_sz (4+NLM_owner_sz) 34 35 #define NLM_testargs_sz (NLM_cookie_sz+1+NLM_lock_sz) 36 #define NLM_lockargs_sz (NLM_cookie_sz+4+NLM_lock_sz) 37 #define NLM_cancargs_sz (NLM_cookie_sz+2+NLM_lock_sz) 38 #define NLM_unlockargs_sz (NLM_cookie_sz+NLM_lock_sz) 39 40 #define NLM_testres_sz (NLM_cookie_sz+1+NLM_holder_sz) 41 #define NLM_res_sz (NLM_cookie_sz+1) 42 #define NLM_norep_sz (0) 43 44 45 static s32 loff_t_to_s32(loff_t offset) 46 { 47 s32 res; 48 49 if (offset >= NLM_OFFSET_MAX) 50 res = NLM_OFFSET_MAX; 51 else if (offset <= -NLM_OFFSET_MAX) 52 res = -NLM_OFFSET_MAX; 53 else 54 res = offset; 55 return res; 56 } 57 58 static void nlm_compute_offsets(const struct nlm_lock *lock, 59 u32 *l_offset, u32 *l_len) 60 { 61 const struct file_lock *fl = &lock->fl; 62 63 BUG_ON(fl->fl_start > NLM_OFFSET_MAX); 64 BUG_ON(fl->fl_end > NLM_OFFSET_MAX && 65 fl->fl_end != OFFSET_MAX); 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 * 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 NLMv3 basic data types 87 * 88 * Basic NLMv3 data types are not defined in an IETF standards 89 * document. X/Open has a description of these data types that 90 * is useful. See Chapter 10 of "Protocols for Interworking: 91 * XNFS, Version 3W". 92 * 93 * Not all basic data types have their own encoding and decoding 94 * functions. For run-time efficiency, some data types are encoded 95 * or decoded inline. 96 */ 97 98 static void encode_bool(struct xdr_stream *xdr, const int value) 99 { 100 __be32 *p; 101 102 p = xdr_reserve_space(xdr, 4); 103 *p = value ? xdr_one : xdr_zero; 104 } 105 106 static void encode_int32(struct xdr_stream *xdr, const s32 value) 107 { 108 __be32 *p; 109 110 p = xdr_reserve_space(xdr, 4); 111 *p = cpu_to_be32(value); 112 } 113 114 /* 115 * typedef opaque netobj<MAXNETOBJ_SZ> 116 */ 117 static void encode_netobj(struct xdr_stream *xdr, 118 const u8 *data, const unsigned int length) 119 { 120 __be32 *p; 121 122 BUG_ON(length > XDR_MAX_NETOBJ); 123 p = xdr_reserve_space(xdr, 4 + length); 124 xdr_encode_opaque(p, data, length); 125 } 126 127 static int decode_netobj(struct xdr_stream *xdr, 128 struct xdr_netobj *obj) 129 { 130 u32 length; 131 __be32 *p; 132 133 p = xdr_inline_decode(xdr, 4); 134 if (unlikely(p == NULL)) 135 goto out_overflow; 136 length = be32_to_cpup(p++); 137 if (unlikely(length > XDR_MAX_NETOBJ)) 138 goto out_size; 139 obj->len = length; 140 obj->data = (u8 *)p; 141 return 0; 142 out_size: 143 dprintk("NFS: returned netobj was too long: %u\n", length); 144 return -EIO; 145 out_overflow: 146 print_overflow_msg(__func__, xdr); 147 return -EIO; 148 } 149 150 /* 151 * netobj cookie; 152 */ 153 static void encode_cookie(struct xdr_stream *xdr, 154 const struct nlm_cookie *cookie) 155 { 156 BUG_ON(cookie->len > NLM_MAXCOOKIELEN); 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 BUG_ON(fh->size != NFS2_FHSIZE); 199 encode_netobj(xdr, (u8 *)&fh->data, NFS2_FHSIZE); 200 } 201 202 /* 203 * enum nlm_stats { 204 * LCK_GRANTED = 0, 205 * LCK_DENIED = 1, 206 * LCK_DENIED_NOLOCKS = 2, 207 * LCK_BLOCKED = 3, 208 * LCK_DENIED_GRACE_PERIOD = 4 209 * }; 210 * 211 * 212 * struct nlm_stat { 213 * nlm_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 */ 220 221 static void encode_nlm_stat(struct xdr_stream *xdr, 222 const __be32 stat) 223 { 224 __be32 *p; 225 226 BUG_ON(be32_to_cpu(stat) > NLM_LCK_DENIED_GRACE_PERIOD); 227 p = xdr_reserve_space(xdr, 4); 228 *p = stat; 229 } 230 231 static int decode_nlm_stat(struct xdr_stream *xdr, 232 __be32 *stat) 233 { 234 __be32 *p; 235 236 p = xdr_inline_decode(xdr, 4); 237 if (unlikely(p == NULL)) 238 goto out_overflow; 239 if (unlikely(ntohl(*p) > ntohl(nlm_lck_denied_grace_period))) 240 goto out_enum; 241 *stat = *p; 242 return 0; 243 out_enum: 244 dprintk("%s: server returned invalid nlm_stats value: %u\n", 245 __func__, be32_to_cpup(p)); 246 return -EIO; 247 out_overflow: 248 print_overflow_msg(__func__, xdr); 249 return -EIO; 250 } 251 252 /* 253 * struct nlm_holder { 254 * bool exclusive; 255 * int uppid; 256 * netobj oh; 257 * unsigned l_offset; 258 * unsigned l_len; 259 * }; 260 */ 261 static void encode_nlm_holder(struct xdr_stream *xdr, 262 const struct nlm_res *result) 263 { 264 const struct nlm_lock *lock = &result->lock; 265 u32 l_offset, l_len; 266 __be32 *p; 267 268 encode_bool(xdr, lock->fl.fl_type == F_RDLCK); 269 encode_int32(xdr, lock->svid); 270 encode_netobj(xdr, lock->oh.data, lock->oh.len); 271 272 p = xdr_reserve_space(xdr, 4 + 4); 273 nlm_compute_offsets(lock, &l_offset, &l_len); 274 *p++ = cpu_to_be32(l_offset); 275 *p = cpu_to_be32(l_len); 276 } 277 278 static int decode_nlm_holder(struct xdr_stream *xdr, struct nlm_res *result) 279 { 280 struct nlm_lock *lock = &result->lock; 281 struct file_lock *fl = &lock->fl; 282 u32 exclusive, l_offset, l_len; 283 int error; 284 __be32 *p; 285 s32 end; 286 287 memset(lock, 0, sizeof(*lock)); 288 locks_init_lock(fl); 289 290 p = xdr_inline_decode(xdr, 4 + 4); 291 if (unlikely(p == NULL)) 292 goto out_overflow; 293 exclusive = be32_to_cpup(p++); 294 lock->svid = be32_to_cpup(p); 295 fl->fl_pid = (pid_t)lock->svid; 296 297 error = decode_netobj(xdr, &lock->oh); 298 if (unlikely(error)) 299 goto out; 300 301 p = xdr_inline_decode(xdr, 4 + 4); 302 if (unlikely(p == NULL)) 303 goto out_overflow; 304 305 fl->fl_flags = FL_POSIX; 306 fl->fl_type = exclusive != 0 ? F_WRLCK : F_RDLCK; 307 l_offset = be32_to_cpup(p++); 308 l_len = be32_to_cpup(p); 309 end = l_offset + l_len - 1; 310 311 fl->fl_start = (loff_t)l_offset; 312 if (l_len == 0 || end < 0) 313 fl->fl_end = OFFSET_MAX; 314 else 315 fl->fl_end = (loff_t)end; 316 error = 0; 317 out: 318 return error; 319 out_overflow: 320 print_overflow_msg(__func__, xdr); 321 return -EIO; 322 } 323 324 /* 325 * string caller_name<LM_MAXSTRLEN>; 326 */ 327 static void encode_caller_name(struct xdr_stream *xdr, const char *name) 328 { 329 /* NB: client-side does not set lock->len */ 330 u32 length = strlen(name); 331 __be32 *p; 332 333 BUG_ON(length > NLM_MAXSTRLEN); 334 p = xdr_reserve_space(xdr, 4 + length); 335 xdr_encode_opaque(p, name, length); 336 } 337 338 /* 339 * struct nlm_lock { 340 * string caller_name<LM_MAXSTRLEN>; 341 * netobj fh; 342 * netobj oh; 343 * int uppid; 344 * unsigned l_offset; 345 * unsigned l_len; 346 * }; 347 */ 348 static void encode_nlm_lock(struct xdr_stream *xdr, 349 const struct nlm_lock *lock) 350 { 351 u32 l_offset, l_len; 352 __be32 *p; 353 354 encode_caller_name(xdr, lock->caller); 355 encode_fh(xdr, &lock->fh); 356 encode_netobj(xdr, lock->oh.data, lock->oh.len); 357 358 p = xdr_reserve_space(xdr, 4 + 4 + 4); 359 *p++ = cpu_to_be32(lock->svid); 360 361 nlm_compute_offsets(lock, &l_offset, &l_len); 362 *p++ = cpu_to_be32(l_offset); 363 *p = cpu_to_be32(l_len); 364 } 365 366 367 /* 368 * NLMv3 XDR encode functions 369 * 370 * NLMv3 argument types are defined in Chapter 10 of The Open Group's 371 * "Protocols for Interworking: XNFS, Version 3W". 372 */ 373 374 /* 375 * struct nlm_testargs { 376 * netobj cookie; 377 * bool exclusive; 378 * struct nlm_lock alock; 379 * }; 380 */ 381 static void nlm_xdr_enc_testargs(struct rpc_rqst *req, 382 struct xdr_stream *xdr, 383 const struct nlm_args *args) 384 { 385 const struct nlm_lock *lock = &args->lock; 386 387 encode_cookie(xdr, &args->cookie); 388 encode_bool(xdr, lock->fl.fl_type == F_WRLCK); 389 encode_nlm_lock(xdr, lock); 390 } 391 392 /* 393 * struct nlm_lockargs { 394 * netobj cookie; 395 * bool block; 396 * bool exclusive; 397 * struct nlm_lock alock; 398 * bool reclaim; 399 * int state; 400 * }; 401 */ 402 static void nlm_xdr_enc_lockargs(struct rpc_rqst *req, 403 struct xdr_stream *xdr, 404 const struct nlm_args *args) 405 { 406 const struct nlm_lock *lock = &args->lock; 407 408 encode_cookie(xdr, &args->cookie); 409 encode_bool(xdr, args->block); 410 encode_bool(xdr, lock->fl.fl_type == F_WRLCK); 411 encode_nlm_lock(xdr, lock); 412 encode_bool(xdr, args->reclaim); 413 encode_int32(xdr, args->state); 414 } 415 416 /* 417 * struct nlm_cancargs { 418 * netobj cookie; 419 * bool block; 420 * bool exclusive; 421 * struct nlm_lock alock; 422 * }; 423 */ 424 static void nlm_xdr_enc_cancargs(struct rpc_rqst *req, 425 struct xdr_stream *xdr, 426 const struct nlm_args *args) 427 { 428 const struct nlm_lock *lock = &args->lock; 429 430 encode_cookie(xdr, &args->cookie); 431 encode_bool(xdr, args->block); 432 encode_bool(xdr, lock->fl.fl_type == F_WRLCK); 433 encode_nlm_lock(xdr, lock); 434 } 435 436 /* 437 * struct nlm_unlockargs { 438 * netobj cookie; 439 * struct nlm_lock alock; 440 * }; 441 */ 442 static void nlm_xdr_enc_unlockargs(struct rpc_rqst *req, 443 struct xdr_stream *xdr, 444 const struct nlm_args *args) 445 { 446 const struct nlm_lock *lock = &args->lock; 447 448 encode_cookie(xdr, &args->cookie); 449 encode_nlm_lock(xdr, lock); 450 } 451 452 /* 453 * struct nlm_res { 454 * netobj cookie; 455 * nlm_stat stat; 456 * }; 457 */ 458 static void nlm_xdr_enc_res(struct rpc_rqst *req, 459 struct xdr_stream *xdr, 460 const struct nlm_res *result) 461 { 462 encode_cookie(xdr, &result->cookie); 463 encode_nlm_stat(xdr, result->status); 464 } 465 466 /* 467 * union nlm_testrply switch (nlm_stats stat) { 468 * case LCK_DENIED: 469 * struct nlm_holder holder; 470 * default: 471 * void; 472 * }; 473 * 474 * struct nlm_testres { 475 * netobj cookie; 476 * nlm_testrply test_stat; 477 * }; 478 */ 479 static void encode_nlm_testrply(struct xdr_stream *xdr, 480 const struct nlm_res *result) 481 { 482 if (result->status == nlm_lck_denied) 483 encode_nlm_holder(xdr, result); 484 } 485 486 static void nlm_xdr_enc_testres(struct rpc_rqst *req, 487 struct xdr_stream *xdr, 488 const struct nlm_res *result) 489 { 490 encode_cookie(xdr, &result->cookie); 491 encode_nlm_stat(xdr, result->status); 492 encode_nlm_testrply(xdr, result); 493 } 494 495 496 /* 497 * NLMv3 XDR decode functions 498 * 499 * NLMv3 result types are defined in Chapter 10 of The Open Group's 500 * "Protocols for Interworking: XNFS, Version 3W". 501 */ 502 503 /* 504 * union nlm_testrply switch (nlm_stats stat) { 505 * case LCK_DENIED: 506 * struct nlm_holder holder; 507 * default: 508 * void; 509 * }; 510 * 511 * struct nlm_testres { 512 * netobj cookie; 513 * nlm_testrply test_stat; 514 * }; 515 */ 516 static int decode_nlm_testrply(struct xdr_stream *xdr, 517 struct nlm_res *result) 518 { 519 int error; 520 521 error = decode_nlm_stat(xdr, &result->status); 522 if (unlikely(error)) 523 goto out; 524 if (result->status == nlm_lck_denied) 525 error = decode_nlm_holder(xdr, result); 526 out: 527 return error; 528 } 529 530 static int nlm_xdr_dec_testres(struct rpc_rqst *req, 531 struct xdr_stream *xdr, 532 struct nlm_res *result) 533 { 534 int error; 535 536 error = decode_cookie(xdr, &result->cookie); 537 if (unlikely(error)) 538 goto out; 539 error = decode_nlm_testrply(xdr, result); 540 out: 541 return error; 542 } 543 544 /* 545 * struct nlm_res { 546 * netobj cookie; 547 * nlm_stat stat; 548 * }; 549 */ 550 static int nlm_xdr_dec_res(struct rpc_rqst *req, 551 struct xdr_stream *xdr, 552 struct nlm_res *result) 553 { 554 int error; 555 556 error = decode_cookie(xdr, &result->cookie); 557 if (unlikely(error)) 558 goto out; 559 error = decode_nlm_stat(xdr, &result->status); 560 out: 561 return error; 562 } 563 564 565 /* 566 * For NLM, a void procedure really returns nothing 567 */ 568 #define nlm_xdr_dec_norep NULL 569 570 #define PROC(proc, argtype, restype) \ 571 [NLMPROC_##proc] = { \ 572 .p_proc = NLMPROC_##proc, \ 573 .p_encode = (kxdreproc_t)nlm_xdr_enc_##argtype, \ 574 .p_decode = (kxdrdproc_t)nlm_xdr_dec_##restype, \ 575 .p_arglen = NLM_##argtype##_sz, \ 576 .p_replen = NLM_##restype##_sz, \ 577 .p_statidx = NLMPROC_##proc, \ 578 .p_name = #proc, \ 579 } 580 581 static struct rpc_procinfo nlm_procedures[] = { 582 PROC(TEST, testargs, testres), 583 PROC(LOCK, lockargs, res), 584 PROC(CANCEL, cancargs, res), 585 PROC(UNLOCK, unlockargs, res), 586 PROC(GRANTED, testargs, res), 587 PROC(TEST_MSG, testargs, norep), 588 PROC(LOCK_MSG, lockargs, norep), 589 PROC(CANCEL_MSG, cancargs, norep), 590 PROC(UNLOCK_MSG, unlockargs, norep), 591 PROC(GRANTED_MSG, testargs, norep), 592 PROC(TEST_RES, testres, norep), 593 PROC(LOCK_RES, res, norep), 594 PROC(CANCEL_RES, res, norep), 595 PROC(UNLOCK_RES, res, norep), 596 PROC(GRANTED_RES, res, norep), 597 }; 598 599 static const struct rpc_version nlm_version1 = { 600 .number = 1, 601 .nrprocs = ARRAY_SIZE(nlm_procedures), 602 .procs = nlm_procedures, 603 }; 604 605 static const struct rpc_version nlm_version3 = { 606 .number = 3, 607 .nrprocs = ARRAY_SIZE(nlm_procedures), 608 .procs = nlm_procedures, 609 }; 610 611 static const struct rpc_version *nlm_versions[] = { 612 [1] = &nlm_version1, 613 [3] = &nlm_version3, 614 #ifdef CONFIG_LOCKD_V4 615 [4] = &nlm_version4, 616 #endif 617 }; 618 619 static struct rpc_stat nlm_rpc_stats; 620 621 const struct rpc_program nlm_program = { 622 .name = "lockd", 623 .number = NLM_PROGRAM, 624 .nrvers = ARRAY_SIZE(nlm_versions), 625 .version = nlm_versions, 626 .stats = &nlm_rpc_stats, 627 }; 628