rpc.subproj/svc_udp.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
  26  * unrestricted use provided that this legend is included on all tape
  27  * media and as a part of the software program in whole or part.  Users
  28  * may copy or modify Sun RPC without charge, but are not authorized
  29  * to license or distribute it to anyone else except as part of a product or
  30  * program developed by the user.
  31  *
  32  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  33  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  34  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  35  *
  36  * Sun RPC is provided with no support and without any obligation on the
  37  * part of Sun Microsystems, Inc. to assist in its use, correction,
  38  * modification or enhancement.
  39  *
  40  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  41  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  42  * OR ANY PART THEREOF.
  43  *
  44  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  45  * or profits or other special, indirect and consequential damages, even if
  46  * Sun has been advised of the possibility of such damages.
  47  *
  48  * Sun Microsystems, Inc.
  49  * 2550 Garcia Avenue
  50  * Mountain View, California  94043
  51  */
  52
  53 #if defined(LIBC_SCCS) && !defined(lint)
  54 /*static char *sccsid = "from: @(#)svc_udp.c 1.24 87/08/11 Copyr 1984 Sun Micro";*/
  55 /*static char *sccsid = "from: @(#)svc_udp.c    2.2 88/07/29 4.0 RPCSRC";*/
  56 static char *rcsid = "$Id: svc_udp.c,v 1.2 1999/10/14 21:56:54 wsanchez Exp $";
  57 #endif
  58
  59 /*
  60  * svc_udp.c,
  61  * Server side for UDP/IP based RPC.  (Does some caching in the hopes of
  62  * achieving execute-at-most-once semantics.)
  63  *
  64  * Copyright (C) 1984, Sun Microsystems, Inc.
  65  */
  66
  67 #include <stdio.h>
  68 #include <stdlib.h>
  69 #include <rpc/rpc.h>
  70 #include <sys/socket.h>
  71 #include <errno.h>
  72
  73
  74 #define rpc_buffer(xprt) ((xprt)->xp_p1)
  75 #define MAX(a, b)     ((a > b) ? a : b)
  76
  77 static bool_t           svcudp_recv();
  78 static bool_t           svcudp_reply();
  79 static enum xprt_stat   svcudp_stat();
  80 static bool_t           svcudp_getargs();
  81 static bool_t           svcudp_freeargs();
  82 static void             svcudp_destroy();
  83
  84 static struct xp_ops svcudp_op = {
  85         svcudp_recv,
  86         svcudp_stat,
  87         svcudp_getargs,
  88         svcudp_reply,
  89         svcudp_freeargs,
  90         svcudp_destroy
  91 };
  92
  93 extern int errno;
  94
  95 /*
  96  * kept in xprt->xp_p2
  97  */
  98 struct svcudp_data {
  99         u_int   su_iosz;        /* byte size of send.recv buffer */
 100         u_long  su_xid;         /* transaction id */
 101         XDR     su_xdrs;        /* XDR handle */
 102         char    su_verfbody[MAX_AUTH_BYTES];    /* verifier body */
 103         char *  su_cache;       /* cached data, NULL if no cache */
 104 };
 105 #define su_data(xprt)   ((struct svcudp_data *)(xprt->xp_p2))
 106
 107 /*
 108  * Usage:
 109  *      xprt = svcudp_create(sock);
 110  *
 111  * If sock<0 then a socket is created, else sock is used.
 112  * If the socket, sock is not bound to a port then svcudp_create
 113  * binds it to an arbitrary port.  In any (successful) case,
 114  * xprt->xp_sock is the registered socket number and xprt->xp_port is the
 115  * associated port number.
 116  * Once *xprt is initialized, it is registered as a transporter;
 117  * see (svc.h, xprt_register).
 118  * The routines returns NULL if a problem occurred.
 119  */
 120 SVCXPRT *
 121 svcudp_bufcreate(sock, sendsz, recvsz)
 122         register int sock;
 123         u_int sendsz, recvsz;
 124 {
 125         bool_t madesock = FALSE;
 126         register SVCXPRT *xprt;
 127         register struct svcudp_data *su;
 128         struct sockaddr_in addr;
 129         int len = sizeof(struct sockaddr_in);
 130
 131         if (sock == RPC_ANYSOCK) {
 132                 if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
 133                         perror("svcudp_create: socket creation problem");
 134                         return ((SVCXPRT *)NULL);
 135                 }
 136                 madesock = TRUE;
 137         }
 138         bzero((char *)&addr, sizeof (addr));
 139         addr.sin_family = AF_INET;
 140         if (bindresvport(sock, &addr)) {
 141                 addr.sin_port = 0;
 142                 (void)bind(sock, (struct sockaddr *)&addr, len);
 143         }
 144         if (getsockname(sock, (struct sockaddr *)&addr, &len) != 0) {
 145                 perror("svcudp_create - cannot getsockname");
 146                 if (madesock)
 147                         (void)close(sock);
 148                 return ((SVCXPRT *)NULL);
 149         }
 150         xprt = (SVCXPRT *)mem_alloc(sizeof(SVCXPRT));
 151         if (xprt == NULL) {
 152                 (void)fprintf(stderr, "svcudp_create: out of memory\n");
 153                 return (NULL);
 154         }
 155         su = (struct svcudp_data *)mem_alloc(sizeof(*su));
 156         if (su == NULL) {
 157                 (void)fprintf(stderr, "svcudp_create: out of memory\n");
 158                 return (NULL);
 159         }
 160         su->su_iosz = ((MAX(sendsz, recvsz) + 3) / 4) * 4;
 161         if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL) {
 162                 (void)fprintf(stderr, "svcudp_create: out of memory\n");
 163                 return (NULL);
 164         }
 165         xdrmem_create(
 166             &(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_DECODE);
 167         su->su_cache = NULL;
 168         xprt->xp_p2 = (caddr_t)su;
 169         xprt->xp_verf.oa_base = su->su_verfbody;
 170         xprt->xp_ops = &svcudp_op;
 171         xprt->xp_port = ntohs(addr.sin_port);
 172         xprt->xp_sock = sock;
 173         xprt_register(xprt);
 174         return (xprt);
 175 }
 176
 177 SVCXPRT *
 178 svcudp_create(sock)
 179         int sock;
 180 {
 181
 182         return(svcudp_bufcreate(sock, UDPMSGSIZE, UDPMSGSIZE));
 183 }
 184
 185 static enum xprt_stat
 186 svcudp_stat(xprt)
 187         SVCXPRT *xprt;
 188 {
 189
 190         return (XPRT_IDLE);
 191 }
 192
 193 static bool_t
 194 svcudp_recv(xprt, msg)
 195         register SVCXPRT *xprt;
 196         struct rpc_msg *msg;
 197 {
 198         register struct svcudp_data *su = su_data(xprt);
 199         register XDR *xdrs = &(su->su_xdrs);
 200         register int rlen;
 201         char *reply;
 202         u_long replylen;
 203         static int cache_get();
 204
 205     again:
 206         xprt->xp_addrlen = sizeof(struct sockaddr_in);
 207         rlen = recvfrom(xprt->xp_sock, rpc_buffer(xprt), (int) su->su_iosz,
 208             0, (struct sockaddr *)&(xprt->xp_raddr), &(xprt->xp_addrlen));
 209         if (rlen == -1 && errno == EINTR)
 210                 goto again;
 211         if (rlen < 4*sizeof(u_long))
 212                 return (FALSE);
 213         xdrs->x_op = XDR_DECODE;
 214         XDR_SETPOS(xdrs, 0);
 215         if (! xdr_callmsg(xdrs, msg))
 216                 return (FALSE);
 217         su->su_xid = msg->rm_xid;
 218         if (su->su_cache != NULL) {
 219                 if (cache_get(xprt, msg, &reply, &replylen)) {
 220                         (void) sendto(xprt->xp_sock, reply, (int) replylen, 0,
 221                           (struct sockaddr *) &xprt->xp_raddr, xprt->xp_addrlen);
 222                         return (TRUE);
 223                 }
 224         }
 225         return (TRUE);
 226 }
 227
 228 static bool_t
 229 svcudp_reply(xprt, msg)
 230         register SVCXPRT *xprt;
 231         struct rpc_msg *msg;
 232 {
 233         register struct svcudp_data *su = su_data(xprt);
 234         register XDR *xdrs = &(su->su_xdrs);
 235         register int slen;
 236         register bool_t stat = FALSE;
 237         static void cache_set();
 238
 239         xdrs->x_op = XDR_ENCODE;
 240         XDR_SETPOS(xdrs, 0);
 241         msg->rm_xid = su->su_xid;
 242         if (xdr_replymsg(xdrs, msg)) {
 243                 slen = (int)XDR_GETPOS(xdrs);
 244                 if (sendto(xprt->xp_sock, rpc_buffer(xprt), slen, 0,
 245                     (struct sockaddr *)&(xprt->xp_raddr), xprt->xp_addrlen)
 246                     == slen) {
 247                         stat = TRUE;
 248                         if (su->su_cache && slen >= 0) {
 249                                 cache_set(xprt, (u_long) slen);
 250                         }
 251                 }
 252         }
 253         return (stat);
 254 }
 255
 256 static bool_t
 257 svcudp_getargs(xprt, xdr_args, args_ptr)
 258         SVCXPRT *xprt;
 259         xdrproc_t xdr_args;
 260         caddr_t args_ptr;
 261 {
 262
 263         return ((*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr));
 264 }
 265
 266 static bool_t
 267 svcudp_freeargs(xprt, xdr_args, args_ptr)
 268         SVCXPRT *xprt;
 269         xdrproc_t xdr_args;
 270         caddr_t args_ptr;
 271 {
 272         register XDR *xdrs = &(su_data(xprt)->su_xdrs);
 273
 274         xdrs->x_op = XDR_FREE;
 275         return ((*xdr_args)(xdrs, args_ptr));
 276 }
 277
 278 static void
 279 svcudp_destroy(xprt)
 280         register SVCXPRT *xprt;
 281 {
 282         register struct svcudp_data *su = su_data(xprt);
 283
 284         xprt_unregister(xprt);
 285         (void)close(xprt->xp_sock);
 286         XDR_DESTROY(&(su->su_xdrs));
 287         mem_free(rpc_buffer(xprt), su->su_iosz);
 288         mem_free((caddr_t)su, sizeof(struct svcudp_data));
 289         mem_free((caddr_t)xprt, sizeof(SVCXPRT));
 290 }
 291
 292
 293 /***********this could be a separate file*********************/
 294
 295 /*
 296  * Fifo cache for udp server
 297  * Copies pointers to reply buffers into fifo cache
 298  * Buffers are sent again if retransmissions are detected.
 299  */
 300
 301 #define SPARSENESS 4    /* 75% sparse */
 302
 303 #define CACHE_PERROR(msg)       \
 304         (void) fprintf(stderr,"%s\n", msg)
 305
 306 #define ALLOC(type, size)       \
 307         (type *) mem_alloc((unsigned) (sizeof(type) * (size)))
 308
 309 #define BZERO(addr, type, size)  \
 310         bzero((char *) addr, sizeof(type) * (int) (size))
 311
 312 /*
 313  * An entry in the cache
 314  */
 315 typedef struct cache_node *cache_ptr;
 316 struct cache_node {
 317         /*
 318          * Index into cache is xid, proc, vers, prog and address
 319          */
 320         u_long cache_xid;
 321         u_long cache_proc;
 322         u_long cache_vers;
 323         u_long cache_prog;
 324         struct sockaddr_in cache_addr;
 325         /*
 326          * The cached reply and length
 327          */
 328         char * cache_reply;
 329         u_long cache_replylen;
 330         /*
 331          * Next node on the list, if there is a collision
 332          */
 333         cache_ptr cache_next;
 334 };
 335
 336
 337
 338 /*
 339  * The entire cache
 340  */
 341 struct udp_cache {
 342         u_long uc_size;         /* size of cache */
 343         cache_ptr *uc_entries;  /* hash table of entries in cache */
 344         cache_ptr *uc_fifo;     /* fifo list of entries in cache */
 345         u_long uc_nextvictim;   /* points to next victim in fifo list */
 346         u_long uc_prog;         /* saved program number */
 347         u_long uc_vers;         /* saved version number */
 348         u_long uc_proc;         /* saved procedure number */
 349         struct sockaddr_in uc_addr; /* saved caller's address */
 350 };
 351
 352
 353 /*
 354  * the hashing function
 355  */
 356 #define CACHE_LOC(transp, xid)  \
 357  (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))
 358
 359
 360 /*
 361  * Enable use of the cache.
 362  * Note: there is no disable.
 363  */
 364 svcudp_enablecache(transp, size)
 365         SVCXPRT *transp;
 366         u_long size;
 367 {
 368         struct svcudp_data *su = su_data(transp);
 369         struct udp_cache *uc;
 370
 371         if (su->su_cache != NULL) {
 372                 CACHE_PERROR("enablecache: cache already enabled");
 373                 return(0);
 374         }
 375         uc = ALLOC(struct udp_cache, 1);
 376         if (uc == NULL) {
 377                 CACHE_PERROR("enablecache: could not allocate cache");
 378                 return(0);
 379         }
 380         uc->uc_size = size;
 381         uc->uc_nextvictim = 0;
 382         uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
 383         if (uc->uc_entries == NULL) {
 384                 CACHE_PERROR("enablecache: could not allocate cache data");
 385                 return(0);
 386         }
 387         BZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
 388         uc->uc_fifo = ALLOC(cache_ptr, size);
 389         if (uc->uc_fifo == NULL) {
 390                 CACHE_PERROR("enablecache: could not allocate cache fifo");
 391                 return(0);
 392         }
 393         BZERO(uc->uc_fifo, cache_ptr, size);
 394         su->su_cache = (char *) uc;
 395         return(1);
 396 }
 397
 398
 399 /*
 400  * Set an entry in the cache
 401  */
 402 static void
 403 cache_set(xprt, replylen)
 404         SVCXPRT *xprt;
 405         u_long replylen;
 406 {
 407         register cache_ptr victim;
 408         register cache_ptr *vicp;
 409         register struct svcudp_data *su = su_data(xprt);
 410         struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 411         u_int loc;
 412         char *newbuf;
 413
 414         /*
 415          * Find space for the new entry, either by
 416          * reusing an old entry, or by mallocing a new one
 417          */
 418         victim = uc->uc_fifo[uc->uc_nextvictim];
 419         if (victim != NULL) {
 420                 loc = CACHE_LOC(xprt, victim->cache_xid);
 421                 for (vicp = &uc->uc_entries[loc];
 422                   *vicp != NULL && *vicp != victim;
 423                   vicp = &(*vicp)->cache_next)
 424                                 ;
 425                 if (*vicp == NULL) {
 426                         CACHE_PERROR("cache_set: victim not found");
 427                         return;
 428                 }
 429                 *vicp = victim->cache_next;     /* remote from cache */
 430                 newbuf = victim->cache_reply;
 431         } else {
 432                 victim = ALLOC(struct cache_node, 1);
 433                 if (victim == NULL) {
 434                         CACHE_PERROR("cache_set: victim alloc failed");
 435                         return;
 436                 }
 437                 newbuf = mem_alloc(su->su_iosz);
 438                 if (newbuf == NULL) {
 439                         CACHE_PERROR("cache_set: could not allocate new rpc_buffer");
 440                         return;
 441                 }
 442         }
 443
 444         /*
 445          * Store it away
 446          */
 447         victim->cache_replylen = replylen;
 448         victim->cache_reply = rpc_buffer(xprt);
 449         rpc_buffer(xprt) = newbuf;
 450         xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_ENCODE);
 451         victim->cache_xid = su->su_xid;
 452         victim->cache_proc = uc->uc_proc;
 453         victim->cache_vers = uc->uc_vers;
 454         victim->cache_prog = uc->uc_prog;
 455         victim->cache_addr = uc->uc_addr;
 456         loc = CACHE_LOC(xprt, victim->cache_xid);
 457         victim->cache_next = uc->uc_entries[loc];
 458         uc->uc_entries[loc] = victim;
 459         uc->uc_fifo[uc->uc_nextvictim++] = victim;
 460         uc->uc_nextvictim %= uc->uc_size;
 461 }
 462
 463 /*
 464  * Try to get an entry from the cache
 465  * return 1 if found, 0 if not found
 466  */
 467 static
 468 cache_get(xprt, msg, replyp, replylenp)
 469         SVCXPRT *xprt;
 470         struct rpc_msg *msg;
 471         char **replyp;
 472         u_long *replylenp;
 473 {
 474         u_int loc;
 475         register cache_ptr ent;
 476         register struct svcudp_data *su = su_data(xprt);
 477         register struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 478
 479 #       define EQADDR(a1, a2)   (bcmp((char*)&a1, (char*)&a2, sizeof(a1)) == 0)
 480
 481         loc = CACHE_LOC(xprt, su->su_xid);
 482         for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
 483                 if (ent->cache_xid == su->su_xid &&
 484                   ent->cache_proc == uc->uc_proc &&
 485                   ent->cache_vers == uc->uc_vers &&
 486                   ent->cache_prog == uc->uc_prog &&
 487                   EQADDR(ent->cache_addr, uc->uc_addr)) {
 488                         *replyp = ent->cache_reply;
 489                         *replylenp = ent->cache_replylen;
 490                         return(1);
 491                 }
 492         }
 493         /*
 494          * Failed to find entry
 495          * Remember a few things so we can do a set later
 496          */
 497         uc->uc_proc = msg->rm_call.cb_proc;
 498         uc->uc_vers = msg->rm_call.cb_vers;
 499         uc->uc_prog = msg->rm_call.cb_prog;
 500         uc->uc_addr = xprt->xp_raddr;
 501         return(0);
 502 }
 503