1 /* 2 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for 3 * unrestricted use provided that this legend is included on all tape 4 * media and as a part of the software program in whole or part. Users 5 * may copy or modify Sun RPC without charge, but are not authorized 6 * to license or distribute it to anyone else except as part of a product or 7 * program developed by the user. 8 * 9 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE 10 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR 11 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. 12 * 13 * Sun RPC is provided with no support and without any obligation on the 14 * part of Sun Microsystems, Inc. to assist in its use, correction, 15 * modification or enhancement. 16 * 17 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE 18 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC 19 * OR ANY PART THEREOF. 20 * 21 * In no event will Sun Microsystems, Inc. be liable for any lost revenue 22 * or profits or other special, indirect and consequential damages, even if 23 * Sun has been advised of the possibility of such damages. 24 * 25 * Sun Microsystems, Inc. 26 * 2550 Garcia Avenue 27 * Mountain View, California 94043 28 * 29 * @(#)svc_dg.c 1.17 94/04/24 SMI 30 * $NetBSD: svc_dg.c,v 1.4 2000/07/06 03:10:35 christos Exp $ 31 * $FreeBSD: src/lib/libc/rpc/svc_dg.c,v 1.8 2006/02/27 22:10:59 deischen Exp $ 32 */ 33 34 /* 35 * Copyright (c) 1986-1991 by Sun Microsystems Inc. 36 */ 37 38 /* 39 * svc_dg.c, Server side for connectionless RPC. 40 * 41 * Does some caching in the hopes of achieving execute-at-most-once semantics. 42 */ 43 44 #include "namespace.h" 45 #include "reentrant.h" 46 #include <sys/types.h> 47 #include <sys/socket.h> 48 #include <rpc/rpc.h> 49 #include <rpc/svc_dg.h> 50 #include <errno.h> 51 #include <unistd.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #ifdef RPC_CACHE_DEBUG 56 #include <netconfig.h> 57 #include <netdir.h> 58 #endif 59 #include <err.h> 60 #include "un-namespace.h" 61 62 #include "rpc_com.h" 63 #include "mt_misc.h" 64 65 #define su_data(xprt) ((struct svc_dg_data *)(xprt->xp_p2)) 66 #define rpc_buffer(xprt) ((xprt)->xp_p1) 67 68 #ifndef MAX 69 #define MAX(a, b) (((a) > (b)) ? (a) : (b)) 70 #endif 71 72 static void svc_dg_ops(SVCXPRT *); 73 static enum xprt_stat svc_dg_stat(SVCXPRT *); 74 static bool_t svc_dg_recv(SVCXPRT *, struct rpc_msg *); 75 static bool_t svc_dg_reply(SVCXPRT *, struct rpc_msg *); 76 static bool_t svc_dg_getargs(SVCXPRT *, xdrproc_t, void *); 77 static bool_t svc_dg_freeargs(SVCXPRT *, xdrproc_t, void *); 78 static void svc_dg_destroy(SVCXPRT *); 79 static bool_t svc_dg_control(SVCXPRT *, const u_int, void *); 80 static int cache_get(SVCXPRT *, struct rpc_msg *, char **, size_t *); 81 static void cache_set(SVCXPRT *, size_t); 82 int svc_dg_enablecache(SVCXPRT *, u_int); 83 84 /* 85 * Usage: 86 * xprt = svc_dg_create(sock, sendsize, recvsize); 87 * Does other connectionless specific initializations. 88 * Once *xprt is initialized, it is registered. 89 * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable 90 * system defaults are chosen. 91 * The routines returns NULL if a problem occurred. 92 */ 93 static const char svc_dg_str[] = "svc_dg_create: %s"; 94 static const char svc_dg_err1[] = "could not get transport information"; 95 static const char svc_dg_err2[] = " transport does not support data transfer"; 96 static const char __no_mem_str[] = "out of memory"; 97 98 SVCXPRT * 99 svc_dg_create(int fd, u_int sendsize, u_int recvsize) 100 { 101 SVCXPRT *xprt; 102 struct svc_dg_data *su = NULL; 103 struct __rpc_sockinfo si; 104 struct sockaddr_storage ss; 105 socklen_t slen; 106 107 if (!__rpc_fd2sockinfo(fd, &si)) { 108 warnx(svc_dg_str, svc_dg_err1); 109 return (NULL); 110 } 111 /* 112 * Find the receive and the send size 113 */ 114 sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize); 115 recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize); 116 if ((sendsize == 0) || (recvsize == 0)) { 117 warnx(svc_dg_str, svc_dg_err2); 118 return (NULL); 119 } 120 121 xprt = mem_alloc(sizeof (SVCXPRT)); 122 if (xprt == NULL) 123 goto freedata; 124 memset(xprt, 0, sizeof (SVCXPRT)); 125 126 su = mem_alloc(sizeof (*su)); 127 if (su == NULL) 128 goto freedata; 129 su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4; 130 if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL) 131 goto freedata; 132 xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, 133 XDR_DECODE); 134 su->su_cache = NULL; 135 xprt->xp_fd = fd; 136 xprt->xp_p2 = su; 137 xprt->xp_verf.oa_base = su->su_verfbody; 138 svc_dg_ops(xprt); 139 xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage); 140 141 slen = sizeof ss; 142 if (_getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0) 143 goto freedata; 144 xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage)); 145 xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage); 146 xprt->xp_ltaddr.len = slen; 147 memcpy(xprt->xp_ltaddr.buf, &ss, slen); 148 149 xprt_register(xprt); 150 return (xprt); 151 freedata: 152 warnx(svc_dg_str, __no_mem_str); 153 if (xprt) { 154 if (su) 155 mem_free(su, sizeof (*su)); 156 mem_free(xprt, sizeof (SVCXPRT)); 157 } 158 return (NULL); 159 } 160 161 /*ARGSUSED*/ 162 static enum xprt_stat 163 svc_dg_stat(SVCXPRT *xprt) 164 { 165 return (XPRT_IDLE); 166 } 167 168 static bool_t 169 svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg) 170 { 171 struct svc_dg_data *su = su_data(xprt); 172 XDR *xdrs = &(su->su_xdrs); 173 char *reply; 174 struct sockaddr_storage ss; 175 socklen_t alen; 176 size_t replylen; 177 ssize_t rlen; 178 179 again: 180 alen = sizeof (struct sockaddr_storage); 181 rlen = _recvfrom(xprt->xp_fd, rpc_buffer(xprt), su->su_iosz, 0, 182 (struct sockaddr *)(void *)&ss, &alen); 183 if (rlen == -1 && errno == EINTR) 184 goto again; 185 if (rlen == -1 || (rlen < (ssize_t)(4 * sizeof (u_int32_t)))) 186 return (FALSE); 187 if (xprt->xp_rtaddr.len < alen) { 188 if (xprt->xp_rtaddr.len != 0) 189 mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.len); 190 xprt->xp_rtaddr.buf = mem_alloc(alen); 191 xprt->xp_rtaddr.len = alen; 192 } 193 memcpy(xprt->xp_rtaddr.buf, &ss, alen); 194 #ifdef PORTMAP 195 if (ss.ss_family == AF_INET) { 196 xprt->xp_raddr = *(struct sockaddr_in *)xprt->xp_rtaddr.buf; 197 xprt->xp_addrlen = sizeof (struct sockaddr_in); 198 } 199 #endif /* PORTMAP */ 200 xdrs->x_op = XDR_DECODE; 201 XDR_SETPOS(xdrs, 0); 202 if (! xdr_callmsg(xdrs, msg)) { 203 return (FALSE); 204 } 205 su->su_xid = msg->rm_xid; 206 if (su->su_cache != NULL) { 207 if (cache_get(xprt, msg, &reply, &replylen)) { 208 _sendto(xprt->xp_fd, reply, replylen, 0, 209 (struct sockaddr *)(void *)&ss, alen); 210 return (FALSE); 211 } 212 } 213 return (TRUE); 214 } 215 216 static bool_t 217 svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg) 218 { 219 struct svc_dg_data *su = su_data(xprt); 220 XDR *xdrs = &(su->su_xdrs); 221 bool_t stat = FALSE; 222 size_t slen; 223 224 xdrs->x_op = XDR_ENCODE; 225 XDR_SETPOS(xdrs, 0); 226 msg->rm_xid = su->su_xid; 227 if (xdr_replymsg(xdrs, msg)) { 228 slen = XDR_GETPOS(xdrs); 229 if (_sendto(xprt->xp_fd, rpc_buffer(xprt), slen, 0, 230 (struct sockaddr *)xprt->xp_rtaddr.buf, 231 (socklen_t)xprt->xp_rtaddr.len) == (ssize_t) slen) { 232 stat = TRUE; 233 if (su->su_cache) 234 cache_set(xprt, slen); 235 } 236 } 237 return (stat); 238 } 239 240 static bool_t 241 svc_dg_getargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr) 242 { 243 return (*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr); 244 } 245 246 static bool_t 247 svc_dg_freeargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr) 248 { 249 XDR *xdrs = &(su_data(xprt)->su_xdrs); 250 251 xdrs->x_op = XDR_FREE; 252 return (*xdr_args)(xdrs, args_ptr); 253 } 254 255 static void 256 svc_dg_destroy(SVCXPRT *xprt) 257 { 258 struct svc_dg_data *su = su_data(xprt); 259 260 xprt_unregister(xprt); 261 if (xprt->xp_fd != -1) 262 _close(xprt->xp_fd); 263 XDR_DESTROY(&(su->su_xdrs)); 264 mem_free(rpc_buffer(xprt), su->su_iosz); 265 mem_free(su, sizeof (*su)); 266 if (xprt->xp_rtaddr.buf) 267 mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen); 268 if (xprt->xp_ltaddr.buf) 269 mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen); 270 if (xprt->xp_tp) 271 free(xprt->xp_tp); 272 mem_free(xprt, sizeof (SVCXPRT)); 273 } 274 275 static bool_t 276 /*ARGSUSED*/ 277 svc_dg_control(SVCXPRT *xprt, const u_int rq, void *in) 278 { 279 return (FALSE); 280 } 281 282 static void 283 svc_dg_ops(SVCXPRT *xprt) 284 { 285 static struct xp_ops ops; 286 static struct xp_ops2 ops2; 287 288 /* VARIABLES PROTECTED BY ops_lock: ops */ 289 290 mutex_lock(&ops_lock); 291 if (ops.xp_recv == NULL) { 292 ops.xp_recv = svc_dg_recv; 293 ops.xp_stat = svc_dg_stat; 294 ops.xp_getargs = svc_dg_getargs; 295 ops.xp_reply = svc_dg_reply; 296 ops.xp_freeargs = svc_dg_freeargs; 297 ops.xp_destroy = svc_dg_destroy; 298 ops2.xp_control = svc_dg_control; 299 } 300 xprt->xp_ops = &ops; 301 xprt->xp_ops2 = &ops2; 302 mutex_unlock(&ops_lock); 303 } 304 305 /* The CACHING COMPONENT */ 306 307 /* 308 * Could have been a separate file, but some part of it depends upon the 309 * private structure of the client handle. 310 * 311 * Fifo cache for cl server 312 * Copies pointers to reply buffers into fifo cache 313 * Buffers are sent again if retransmissions are detected. 314 */ 315 316 #define SPARSENESS 4 /* 75% sparse */ 317 318 #define ALLOC(type, size) \ 319 (type *) mem_alloc((sizeof (type) * (size))) 320 321 #define MEMZERO(addr, type, size) \ 322 memset((void *) (addr), 0, sizeof (type) * (int) (size)) 323 324 #define FREE(addr, type, size) \ 325 mem_free((addr), (sizeof (type) * (size))) 326 327 /* 328 * An entry in the cache 329 */ 330 typedef struct cache_node *cache_ptr; 331 struct cache_node { 332 /* 333 * Index into cache is xid, proc, vers, prog and address 334 */ 335 u_int32_t cache_xid; 336 rpcproc_t cache_proc; 337 rpcvers_t cache_vers; 338 rpcprog_t cache_prog; 339 struct netbuf cache_addr; 340 /* 341 * The cached reply and length 342 */ 343 char *cache_reply; 344 size_t cache_replylen; 345 /* 346 * Next node on the list, if there is a collision 347 */ 348 cache_ptr cache_next; 349 }; 350 351 /* 352 * The entire cache 353 */ 354 struct cl_cache { 355 u_int uc_size; /* size of cache */ 356 cache_ptr *uc_entries; /* hash table of entries in cache */ 357 cache_ptr *uc_fifo; /* fifo list of entries in cache */ 358 u_int uc_nextvictim; /* points to next victim in fifo list */ 359 rpcprog_t uc_prog; /* saved program number */ 360 rpcvers_t uc_vers; /* saved version number */ 361 rpcproc_t uc_proc; /* saved procedure number */ 362 }; 363 364 365 /* 366 * the hashing function 367 */ 368 #define CACHE_LOC(transp, xid) \ 369 (xid % (SPARSENESS * ((struct cl_cache *) \ 370 su_data(transp)->su_cache)->uc_size)) 371 372 /* 373 * Enable use of the cache. Returns 1 on success, 0 on failure. 374 * Note: there is no disable. 375 */ 376 static const char cache_enable_str[] = "svc_enablecache: %s %s"; 377 static const char alloc_err[] = "could not allocate cache "; 378 static const char enable_err[] = "cache already enabled"; 379 380 int 381 svc_dg_enablecache(SVCXPRT *transp, u_int size) 382 { 383 struct svc_dg_data *su = su_data(transp); 384 struct cl_cache *uc; 385 386 mutex_lock(&dupreq_lock); 387 if (su->su_cache != NULL) { 388 warnx(cache_enable_str, enable_err, " "); 389 mutex_unlock(&dupreq_lock); 390 return (0); 391 } 392 uc = ALLOC(struct cl_cache, 1); 393 if (uc == NULL) { 394 warnx(cache_enable_str, alloc_err, " "); 395 mutex_unlock(&dupreq_lock); 396 return (0); 397 } 398 uc->uc_size = size; 399 uc->uc_nextvictim = 0; 400 uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS); 401 if (uc->uc_entries == NULL) { 402 warnx(cache_enable_str, alloc_err, "data"); 403 FREE(uc, struct cl_cache, 1); 404 mutex_unlock(&dupreq_lock); 405 return (0); 406 } 407 MEMZERO(uc->uc_entries, cache_ptr, size * SPARSENESS); 408 uc->uc_fifo = ALLOC(cache_ptr, size); 409 if (uc->uc_fifo == NULL) { 410 warnx(cache_enable_str, alloc_err, "fifo"); 411 FREE(uc->uc_entries, cache_ptr, size * SPARSENESS); 412 FREE(uc, struct cl_cache, 1); 413 mutex_unlock(&dupreq_lock); 414 return (0); 415 } 416 MEMZERO(uc->uc_fifo, cache_ptr, size); 417 su->su_cache = (char *)(void *)uc; 418 mutex_unlock(&dupreq_lock); 419 return (1); 420 } 421 422 /* 423 * Set an entry in the cache. It assumes that the uc entry is set from 424 * the earlier call to cache_get() for the same procedure. This will always 425 * happen because cache_get() is calle by svc_dg_recv and cache_set() is called 426 * by svc_dg_reply(). All this hoopla because the right RPC parameters are 427 * not available at svc_dg_reply time. 428 */ 429 430 static const char cache_set_str[] = "cache_set: %s"; 431 static const char cache_set_err1[] = "victim not found"; 432 static const char cache_set_err2[] = "victim alloc failed"; 433 static const char cache_set_err3[] = "could not allocate new rpc buffer"; 434 435 static void 436 cache_set(SVCXPRT *xprt, size_t replylen) 437 { 438 cache_ptr victim; 439 cache_ptr *vicp; 440 struct svc_dg_data *su = su_data(xprt); 441 struct cl_cache *uc = (struct cl_cache *) su->su_cache; 442 u_int loc; 443 char *newbuf; 444 #ifdef RPC_CACHE_DEBUG 445 struct netconfig *nconf; 446 char *uaddr; 447 #endif 448 449 mutex_lock(&dupreq_lock); 450 /* 451 * Find space for the new entry, either by 452 * reusing an old entry, or by mallocing a new one 453 */ 454 victim = uc->uc_fifo[uc->uc_nextvictim]; 455 if (victim != NULL) { 456 loc = CACHE_LOC(xprt, victim->cache_xid); 457 for (vicp = &uc->uc_entries[loc]; 458 *vicp != NULL && *vicp != victim; 459 vicp = &(*vicp)->cache_next) 460 ; 461 if (*vicp == NULL) { 462 warnx(cache_set_str, cache_set_err1); 463 mutex_unlock(&dupreq_lock); 464 return; 465 } 466 *vicp = victim->cache_next; /* remove from cache */ 467 newbuf = victim->cache_reply; 468 } else { 469 victim = ALLOC(struct cache_node, 1); 470 if (victim == NULL) { 471 warnx(cache_set_str, cache_set_err2); 472 mutex_unlock(&dupreq_lock); 473 return; 474 } 475 newbuf = mem_alloc(su->su_iosz); 476 if (newbuf == NULL) { 477 warnx(cache_set_str, cache_set_err3); 478 FREE(victim, struct cache_node, 1); 479 mutex_unlock(&dupreq_lock); 480 return; 481 } 482 } 483 484 /* 485 * Store it away 486 */ 487 #ifdef RPC_CACHE_DEBUG 488 if (nconf = getnetconfigent(xprt->xp_netid)) { 489 uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr); 490 freenetconfigent(nconf); 491 printf( 492 "cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n", 493 su->su_xid, uc->uc_prog, uc->uc_vers, 494 uc->uc_proc, uaddr); 495 free(uaddr); 496 } 497 #endif 498 victim->cache_replylen = replylen; 499 victim->cache_reply = rpc_buffer(xprt); 500 rpc_buffer(xprt) = newbuf; 501 xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), 502 su->su_iosz, XDR_ENCODE); 503 victim->cache_xid = su->su_xid; 504 victim->cache_proc = uc->uc_proc; 505 victim->cache_vers = uc->uc_vers; 506 victim->cache_prog = uc->uc_prog; 507 victim->cache_addr = xprt->xp_rtaddr; 508 victim->cache_addr.buf = ALLOC(char, xprt->xp_rtaddr.len); 509 memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf, 510 (size_t)xprt->xp_rtaddr.len); 511 loc = CACHE_LOC(xprt, victim->cache_xid); 512 victim->cache_next = uc->uc_entries[loc]; 513 uc->uc_entries[loc] = victim; 514 uc->uc_fifo[uc->uc_nextvictim++] = victim; 515 uc->uc_nextvictim %= uc->uc_size; 516 mutex_unlock(&dupreq_lock); 517 } 518 519 /* 520 * Try to get an entry from the cache 521 * return 1 if found, 0 if not found and set the stage for cache_set() 522 */ 523 static int 524 cache_get(SVCXPRT *xprt, struct rpc_msg *msg, char **replyp, size_t *replylenp) 525 { 526 u_int loc; 527 cache_ptr ent; 528 struct svc_dg_data *su = su_data(xprt); 529 struct cl_cache *uc = (struct cl_cache *) su->su_cache; 530 #ifdef RPC_CACHE_DEBUG 531 struct netconfig *nconf; 532 char *uaddr; 533 #endif 534 535 mutex_lock(&dupreq_lock); 536 loc = CACHE_LOC(xprt, su->su_xid); 537 for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) { 538 if (ent->cache_xid == su->su_xid && 539 ent->cache_proc == msg->rm_call.cb_proc && 540 ent->cache_vers == msg->rm_call.cb_vers && 541 ent->cache_prog == msg->rm_call.cb_prog && 542 ent->cache_addr.len == xprt->xp_rtaddr.len && 543 (memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf, 544 xprt->xp_rtaddr.len) == 0)) { 545 #ifdef RPC_CACHE_DEBUG 546 if (nconf = getnetconfigent(xprt->xp_netid)) { 547 uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr); 548 freenetconfigent(nconf); 549 printf( 550 "cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n", 551 su->su_xid, msg->rm_call.cb_prog, 552 msg->rm_call.cb_vers, 553 msg->rm_call.cb_proc, uaddr); 554 free(uaddr); 555 } 556 #endif 557 *replyp = ent->cache_reply; 558 *replylenp = ent->cache_replylen; 559 mutex_unlock(&dupreq_lock); 560 return (1); 561 } 562 } 563 /* 564 * Failed to find entry 565 * Remember a few things so we can do a set later 566 */ 567 uc->uc_proc = msg->rm_call.cb_proc; 568 uc->uc_vers = msg->rm_call.cb_vers; 569 uc->uc_prog = msg->rm_call.cb_prog; 570 mutex_unlock(&dupreq_lock); 571 return (0); 572 } 573