1 /* $NetBSD: svc_dg.c,v 1.6 2001/01/04 14:42:22 lukem Exp $ */ 2 3 /* 4 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for 5 * unrestricted use provided that this legend is included on all tape 6 * media and as a part of the software program in whole or part. Users 7 * may copy or modify Sun RPC without charge, but are not authorized 8 * to license or distribute it to anyone else except as part of a product or 9 * program developed by the user. 10 * 11 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE 12 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR 13 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. 14 * 15 * Sun RPC is provided with no support and without any obligation on the 16 * part of Sun Microsystems, Inc. to assist in its use, correction, 17 * modification or enhancement. 18 * 19 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE 20 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC 21 * OR ANY PART THEREOF. 22 * 23 * In no event will Sun Microsystems, Inc. be liable for any lost revenue 24 * or profits or other special, indirect and consequential damages, even if 25 * Sun has been advised of the possibility of such damages. 26 * 27 * Sun Microsystems, Inc. 28 * 2550 Garcia Avenue 29 * Mountain View, California 94043 30 */ 31 32 /* 33 * Copyright (c) 1986-1991 by Sun Microsystems Inc. 34 */ 35 36 /* #ident "@(#)svc_dg.c 1.17 94/04/24 SMI" */ 37 38 39 /* 40 * svc_dg.c, Server side for connectionless RPC. 41 * 42 * Does some caching in the hopes of achieving execute-at-most-once semantics. 43 */ 44 45 #include "namespace.h" 46 #include "reentrant.h" 47 #include <sys/types.h> 48 #include <sys/socket.h> 49 #include <rpc/rpc.h> 50 #include <assert.h> 51 #include <errno.h> 52 #include <unistd.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #ifdef RPC_CACHE_DEBUG 57 #include <netconfig.h> 58 #include <netdir.h> 59 #endif 60 #include <err.h> 61 62 #include "rpc_com.h" 63 #include "svc_dg.h" 64 65 #define su_data(xprt) ((struct svc_dg_data *)(xprt->xp_p2)) 66 #define rpc_buffer(xprt) ((xprt)->xp_p1) 67 68 #ifdef __weak_alias 69 __weak_alias(svc_dg_create,_svc_dg_create) 70 #endif 71 72 #ifndef MAX 73 #define MAX(a, b) (((a) > (b)) ? (a) : (b)) 74 #endif 75 76 static void svc_dg_ops __P((SVCXPRT *)); 77 static enum xprt_stat svc_dg_stat __P((SVCXPRT *)); 78 static bool_t svc_dg_recv __P((SVCXPRT *, struct rpc_msg *)); 79 static bool_t svc_dg_reply __P((SVCXPRT *, struct rpc_msg *)); 80 static bool_t svc_dg_getargs __P((SVCXPRT *, xdrproc_t, caddr_t)); 81 static bool_t svc_dg_freeargs __P((SVCXPRT *, xdrproc_t, caddr_t)); 82 static void svc_dg_destroy __P((SVCXPRT *)); 83 static bool_t svc_dg_control __P((SVCXPRT *, const u_int, void *)); 84 static int cache_get __P((SVCXPRT *, struct rpc_msg *, char **, size_t *)); 85 static void cache_set __P((SVCXPRT *, size_t)); 86 87 /* 88 * Usage: 89 * xprt = svc_dg_create(sock, sendsize, recvsize); 90 * Does other connectionless specific initializations. 91 * Once *xprt is initialized, it is registered. 92 * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable 93 * system defaults are chosen. 94 * The routines returns NULL if a problem occurred. 95 */ 96 static const char svc_dg_str[] = "svc_dg_create: %s"; 97 static const char svc_dg_err1[] = "could not get transport information"; 98 static const char svc_dg_err2[] = " transport does not support data transfer"; 99 static const char __no_mem_str[] = "out of memory"; 100 101 SVCXPRT * 102 svc_dg_create(fd, sendsize, recvsize) 103 int fd; 104 u_int sendsize; 105 u_int recvsize; 106 { 107 SVCXPRT *xprt; 108 struct svc_dg_data *su = NULL; 109 struct __rpc_sockinfo si; 110 struct sockaddr_storage ss; 111 socklen_t slen; 112 113 if (!__rpc_fd2sockinfo(fd, &si)) { 114 warnx(svc_dg_str, svc_dg_err1); 115 return (NULL); 116 } 117 /* 118 * Find the receive and the send size 119 */ 120 sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize); 121 recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize); 122 if ((sendsize == 0) || (recvsize == 0)) { 123 warnx(svc_dg_str, svc_dg_err2); 124 return (NULL); 125 } 126 127 xprt = mem_alloc(sizeof (SVCXPRT)); 128 if (xprt == NULL) 129 goto freedata; 130 memset(xprt, 0, sizeof (SVCXPRT)); 131 132 su = mem_alloc(sizeof (*su)); 133 if (su == NULL) 134 goto freedata; 135 su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4; 136 if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL) 137 goto freedata; 138 xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, 139 XDR_DECODE); 140 su->su_cache = NULL; 141 xprt->xp_fd = fd; 142 xprt->xp_p2 = (caddr_t)(void *)su; 143 xprt->xp_verf.oa_base = su->su_verfbody; 144 svc_dg_ops(xprt); 145 xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage); 146 147 slen = sizeof ss; 148 if (getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0) 149 goto freedata; 150 xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage)); 151 xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage); 152 xprt->xp_ltaddr.len = slen; 153 memcpy(xprt->xp_ltaddr.buf, &ss, slen); 154 155 xprt_register(xprt); 156 return (xprt); 157 freedata: 158 (void) warnx(svc_dg_str, __no_mem_str); 159 if (xprt) { 160 if (su) 161 (void) mem_free(su, sizeof (*su)); 162 (void) mem_free(xprt, sizeof (SVCXPRT)); 163 } 164 return (NULL); 165 } 166 167 /*ARGSUSED*/ 168 static enum xprt_stat 169 svc_dg_stat(xprt) 170 SVCXPRT *xprt; 171 { 172 return (XPRT_IDLE); 173 } 174 175 static bool_t 176 svc_dg_recv(xprt, msg) 177 SVCXPRT *xprt; 178 struct rpc_msg *msg; 179 { 180 struct svc_dg_data *su; 181 XDR *xdrs; 182 char *reply; 183 struct sockaddr_storage ss; 184 socklen_t alen; 185 size_t replylen; 186 int rlen; 187 188 _DIAGASSERT(xprt != NULL); 189 _DIAGASSERT(msg != NULL); 190 191 su = su_data(xprt); 192 xdrs = &(su->su_xdrs); 193 194 again: 195 alen = sizeof (struct sockaddr_storage); 196 rlen = recvfrom(xprt->xp_fd, rpc_buffer(xprt), su->su_iosz, 0, 197 (struct sockaddr *)(void *)&ss, &alen); 198 if (rlen == -1 && errno == EINTR) 199 goto again; 200 if (rlen == -1 || (rlen < 4 * sizeof (u_int32_t))) 201 return (FALSE); 202 if (xprt->xp_rtaddr.len < alen) { 203 if (xprt->xp_rtaddr.len != 0) 204 mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.len); 205 xprt->xp_rtaddr.buf = mem_alloc(alen); 206 xprt->xp_rtaddr.len = alen; 207 } 208 memcpy(xprt->xp_rtaddr.buf, &ss, alen); 209 #ifdef PORTMAP 210 if (ss.ss_family == AF_INET) { 211 xprt->xp_raddr = *(struct sockaddr_in *)xprt->xp_rtaddr.buf; 212 xprt->xp_addrlen = sizeof (struct sockaddr_in); 213 } 214 #endif 215 xdrs->x_op = XDR_DECODE; 216 XDR_SETPOS(xdrs, 0); 217 if (! xdr_callmsg(xdrs, msg)) { 218 return (FALSE); 219 } 220 su->su_xid = msg->rm_xid; 221 if (su->su_cache != NULL) { 222 if (cache_get(xprt, msg, &reply, &replylen)) { 223 (void)sendto(xprt->xp_fd, reply, replylen, 0, 224 (struct sockaddr *)(void *)&ss, alen); 225 return (FALSE); 226 } 227 } 228 return (TRUE); 229 } 230 231 static bool_t 232 svc_dg_reply(xprt, msg) 233 SVCXPRT *xprt; 234 struct rpc_msg *msg; 235 { 236 struct svc_dg_data *su; 237 XDR *xdrs; 238 bool_t stat = FALSE; 239 size_t slen; 240 241 _DIAGASSERT(xprt != NULL); 242 _DIAGASSERT(msg != NULL); 243 244 su = su_data(xprt); 245 xdrs = &(su->su_xdrs); 246 247 xdrs->x_op = XDR_ENCODE; 248 XDR_SETPOS(xdrs, 0); 249 msg->rm_xid = su->su_xid; 250 if (xdr_replymsg(xdrs, msg)) { 251 slen = XDR_GETPOS(xdrs); 252 if (sendto(xprt->xp_fd, rpc_buffer(xprt), slen, 0, 253 (struct sockaddr *)xprt->xp_rtaddr.buf, 254 (socklen_t)xprt->xp_rtaddr.len) == slen) { 255 stat = TRUE; 256 if (su->su_cache) 257 cache_set(xprt, slen); 258 } 259 } 260 return (stat); 261 } 262 263 static bool_t 264 svc_dg_getargs(xprt, xdr_args, args_ptr) 265 SVCXPRT *xprt; 266 xdrproc_t xdr_args; 267 caddr_t args_ptr; 268 { 269 return (*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr); 270 } 271 272 static bool_t 273 svc_dg_freeargs(xprt, xdr_args, args_ptr) 274 SVCXPRT *xprt; 275 xdrproc_t xdr_args; 276 caddr_t args_ptr; 277 { 278 XDR *xdrs; 279 280 _DIAGASSERT(xprt != NULL); 281 282 xdrs = &(su_data(xprt)->su_xdrs); 283 xdrs->x_op = XDR_FREE; 284 return (*xdr_args)(xdrs, args_ptr); 285 } 286 287 static void 288 svc_dg_destroy(xprt) 289 SVCXPRT *xprt; 290 { 291 struct svc_dg_data *su; 292 293 _DIAGASSERT(xprt != NULL); 294 295 su = su_data(xprt); 296 297 xprt_unregister(xprt); 298 if (xprt->xp_fd != -1) 299 (void)close(xprt->xp_fd); 300 XDR_DESTROY(&(su->su_xdrs)); 301 (void) mem_free(rpc_buffer(xprt), su->su_iosz); 302 (void) mem_free(su, sizeof (*su)); 303 if (xprt->xp_rtaddr.buf) 304 (void) mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen); 305 if (xprt->xp_ltaddr.buf) 306 (void) mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen); 307 if (xprt->xp_tp) 308 (void) free(xprt->xp_tp); 309 (void) mem_free(xprt, sizeof (SVCXPRT)); 310 } 311 312 static bool_t 313 /*ARGSUSED*/ 314 svc_dg_control(xprt, rq, in) 315 SVCXPRT *xprt; 316 const u_int rq; 317 void *in; 318 { 319 return (FALSE); 320 } 321 322 static void 323 svc_dg_ops(xprt) 324 SVCXPRT *xprt; 325 { 326 static struct xp_ops ops; 327 static struct xp_ops2 ops2; 328 #ifdef __REENT 329 extern mutex_t ops_lock; 330 #endif 331 332 _DIAGASSERT(xprt != NULL); 333 334 /* VARIABLES PROTECTED BY ops_lock: ops */ 335 336 mutex_lock(&ops_lock); 337 if (ops.xp_recv == NULL) { 338 ops.xp_recv = svc_dg_recv; 339 ops.xp_stat = svc_dg_stat; 340 ops.xp_getargs = svc_dg_getargs; 341 ops.xp_reply = svc_dg_reply; 342 ops.xp_freeargs = svc_dg_freeargs; 343 ops.xp_destroy = svc_dg_destroy; 344 ops2.xp_control = svc_dg_control; 345 } 346 xprt->xp_ops = &ops; 347 xprt->xp_ops2 = &ops2; 348 mutex_unlock(&ops_lock); 349 } 350 351 /* The CACHING COMPONENT */ 352 353 /* 354 * Could have been a separate file, but some part of it depends upon the 355 * private structure of the client handle. 356 * 357 * Fifo cache for cl server 358 * Copies pointers to reply buffers into fifo cache 359 * Buffers are sent again if retransmissions are detected. 360 */ 361 362 #define SPARSENESS 4 /* 75% sparse */ 363 364 #define ALLOC(type, size) \ 365 (type *) mem_alloc((sizeof (type) * (size))) 366 367 #define MEMZERO(addr, type, size) \ 368 (void) memset((void *) (addr), 0, sizeof (type) * (int) (size)) 369 370 #define FREE(addr, type, size) \ 371 mem_free((addr), (sizeof (type) * (size))) 372 373 /* 374 * An entry in the cache 375 */ 376 typedef struct cache_node *cache_ptr; 377 struct cache_node { 378 /* 379 * Index into cache is xid, proc, vers, prog and address 380 */ 381 u_int32_t cache_xid; 382 rpcproc_t cache_proc; 383 rpcvers_t cache_vers; 384 rpcprog_t cache_prog; 385 struct netbuf cache_addr; 386 /* 387 * The cached reply and length 388 */ 389 char *cache_reply; 390 size_t cache_replylen; 391 /* 392 * Next node on the list, if there is a collision 393 */ 394 cache_ptr cache_next; 395 }; 396 397 /* 398 * The entire cache 399 */ 400 struct cl_cache { 401 u_int uc_size; /* size of cache */ 402 cache_ptr *uc_entries; /* hash table of entries in cache */ 403 cache_ptr *uc_fifo; /* fifo list of entries in cache */ 404 u_int uc_nextvictim; /* points to next victim in fifo list */ 405 rpcprog_t uc_prog; /* saved program number */ 406 rpcvers_t uc_vers; /* saved version number */ 407 rpcproc_t uc_proc; /* saved procedure number */ 408 }; 409 410 411 /* 412 * the hashing function 413 */ 414 #define CACHE_LOC(transp, xid) \ 415 (xid % (SPARSENESS * ((struct cl_cache *) \ 416 su_data(transp)->su_cache)->uc_size)) 417 418 #ifdef __REENT 419 extern mutex_t dupreq_lock; 420 #endif 421 422 /* 423 * Enable use of the cache. Returns 1 on success, 0 on failure. 424 * Note: there is no disable. 425 */ 426 static const char cache_enable_str[] = "svc_enablecache: %s %s"; 427 static const char alloc_err[] = "could not allocate cache "; 428 static const char enable_err[] = "cache already enabled"; 429 430 int 431 svc_dg_enablecache(transp, size) 432 SVCXPRT *transp; 433 u_int size; 434 { 435 struct svc_dg_data *su; 436 struct cl_cache *uc; 437 438 _DIAGASSERT(transp != NULL); 439 440 su = su_data(transp); 441 442 mutex_lock(&dupreq_lock); 443 if (su->su_cache != NULL) { 444 (void) warnx(cache_enable_str, enable_err, " "); 445 mutex_unlock(&dupreq_lock); 446 return (0); 447 } 448 uc = ALLOC(struct cl_cache, 1); 449 if (uc == NULL) { 450 warnx(cache_enable_str, alloc_err, " "); 451 mutex_unlock(&dupreq_lock); 452 return (0); 453 } 454 uc->uc_size = size; 455 uc->uc_nextvictim = 0; 456 uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS); 457 if (uc->uc_entries == NULL) { 458 warnx(cache_enable_str, alloc_err, "data"); 459 FREE(uc, struct cl_cache, 1); 460 mutex_unlock(&dupreq_lock); 461 return (0); 462 } 463 MEMZERO(uc->uc_entries, cache_ptr, size * SPARSENESS); 464 uc->uc_fifo = ALLOC(cache_ptr, size); 465 if (uc->uc_fifo == NULL) { 466 warnx(cache_enable_str, alloc_err, "fifo"); 467 FREE(uc->uc_entries, cache_ptr, size * SPARSENESS); 468 FREE(uc, struct cl_cache, 1); 469 mutex_unlock(&dupreq_lock); 470 return (0); 471 } 472 MEMZERO(uc->uc_fifo, cache_ptr, size); 473 su->su_cache = (char *)(void *)uc; 474 mutex_unlock(&dupreq_lock); 475 return (1); 476 } 477 478 /* 479 * Set an entry in the cache. It assumes that the uc entry is set from 480 * the earlier call to cache_get() for the same procedure. This will always 481 * happen because cache_get() is calle by svc_dg_recv and cache_set() is called 482 * by svc_dg_reply(). All this hoopla because the right RPC parameters are 483 * not available at svc_dg_reply time. 484 */ 485 486 static const char cache_set_str[] = "cache_set: %s"; 487 static const char cache_set_err1[] = "victim not found"; 488 static const char cache_set_err2[] = "victim alloc failed"; 489 static const char cache_set_err3[] = "could not allocate new rpc buffer"; 490 491 static void 492 cache_set(xprt, replylen) 493 SVCXPRT *xprt; 494 size_t replylen; 495 { 496 cache_ptr victim; 497 cache_ptr *vicp; 498 struct svc_dg_data *su; 499 struct cl_cache *uc; 500 u_int loc; 501 char *newbuf; 502 #ifdef RPC_CACHE_DEBUG 503 struct netconfig *nconf; 504 char *uaddr; 505 #endif 506 507 _DIAGASSERT(xprt != NULL); 508 509 su = su_data(xprt); 510 uc = (struct cl_cache *) su->su_cache; 511 512 mutex_lock(&dupreq_lock); 513 /* 514 * Find space for the new entry, either by 515 * reusing an old entry, or by mallocing a new one 516 */ 517 victim = uc->uc_fifo[uc->uc_nextvictim]; 518 if (victim != NULL) { 519 loc = CACHE_LOC(xprt, victim->cache_xid); 520 for (vicp = &uc->uc_entries[loc]; 521 *vicp != NULL && *vicp != victim; 522 vicp = &(*vicp)->cache_next) 523 ; 524 if (*vicp == NULL) { 525 warnx(cache_set_str, cache_set_err1); 526 mutex_unlock(&dupreq_lock); 527 return; 528 } 529 *vicp = victim->cache_next; /* remove from cache */ 530 newbuf = victim->cache_reply; 531 } else { 532 victim = ALLOC(struct cache_node, 1); 533 if (victim == NULL) { 534 warnx(cache_set_str, cache_set_err2); 535 mutex_unlock(&dupreq_lock); 536 return; 537 } 538 newbuf = mem_alloc(su->su_iosz); 539 if (newbuf == NULL) { 540 warnx(cache_set_str, cache_set_err3); 541 FREE(victim, struct cache_node, 1); 542 mutex_unlock(&dupreq_lock); 543 return; 544 } 545 } 546 547 /* 548 * Store it away 549 */ 550 #ifdef RPC_CACHE_DEBUG 551 if (nconf = getnetconfigent(xprt->xp_netid)) { 552 uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr); 553 freenetconfigent(nconf); 554 printf( 555 "cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n", 556 su->su_xid, uc->uc_prog, uc->uc_vers, 557 uc->uc_proc, uaddr); 558 free(uaddr); 559 } 560 #endif 561 victim->cache_replylen = replylen; 562 victim->cache_reply = rpc_buffer(xprt); 563 rpc_buffer(xprt) = newbuf; 564 xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), 565 su->su_iosz, XDR_ENCODE); 566 victim->cache_xid = su->su_xid; 567 victim->cache_proc = uc->uc_proc; 568 victim->cache_vers = uc->uc_vers; 569 victim->cache_prog = uc->uc_prog; 570 victim->cache_addr = xprt->xp_rtaddr; 571 victim->cache_addr.buf = ALLOC(char, xprt->xp_rtaddr.len); 572 (void) memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf, 573 (size_t)xprt->xp_rtaddr.len); 574 loc = CACHE_LOC(xprt, victim->cache_xid); 575 victim->cache_next = uc->uc_entries[loc]; 576 uc->uc_entries[loc] = victim; 577 uc->uc_fifo[uc->uc_nextvictim++] = victim; 578 uc->uc_nextvictim %= uc->uc_size; 579 mutex_unlock(&dupreq_lock); 580 } 581 582 /* 583 * Try to get an entry from the cache 584 * return 1 if found, 0 if not found and set the stage for cache_set() 585 */ 586 static int 587 cache_get(xprt, msg, replyp, replylenp) 588 SVCXPRT *xprt; 589 struct rpc_msg *msg; 590 char **replyp; 591 size_t *replylenp; 592 { 593 u_int loc; 594 cache_ptr ent; 595 struct svc_dg_data *su; 596 struct cl_cache *uc; 597 #ifdef RPC_CACHE_DEBUG 598 struct netconfig *nconf; 599 char *uaddr; 600 #endif 601 602 _DIAGASSERT(xprt != NULL); 603 _DIAGASSERT(msg != NULL); 604 _DIAGASSERT(replyp != NULL); 605 _DIAGASSERT(replylenp != NULL); 606 607 su = su_data(xprt); 608 uc = (struct cl_cache *) su->su_cache; 609 610 mutex_lock(&dupreq_lock); 611 loc = CACHE_LOC(xprt, su->su_xid); 612 for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) { 613 if (ent->cache_xid == su->su_xid && 614 ent->cache_proc == msg->rm_call.cb_proc && 615 ent->cache_vers == msg->rm_call.cb_vers && 616 ent->cache_prog == msg->rm_call.cb_prog && 617 ent->cache_addr.len == xprt->xp_rtaddr.len && 618 (memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf, 619 xprt->xp_rtaddr.len) == 0)) { 620 #ifdef RPC_CACHE_DEBUG 621 if (nconf = getnetconfigent(xprt->xp_netid)) { 622 uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr); 623 freenetconfigent(nconf); 624 printf( 625 "cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n", 626 su->su_xid, msg->rm_call.cb_prog, 627 msg->rm_call.cb_vers, 628 msg->rm_call.cb_proc, uaddr); 629 free(uaddr); 630 } 631 #endif 632 *replyp = ent->cache_reply; 633 *replylenp = ent->cache_replylen; 634 mutex_unlock(&dupreq_lock); 635 return (1); 636 } 637 } 638 /* 639 * Failed to find entry 640 * Remember a few things so we can do a set later 641 */ 642 uc->uc_proc = msg->rm_call.cb_proc; 643 uc->uc_vers = msg->rm_call.cb_vers; 644 uc->uc_prog = msg->rm_call.cb_prog; 645 mutex_unlock(&dupreq_lock); 646 return (0); 647 } 648