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 1.3 2002/02/19 20:36:25 epeyton 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 <string.h>
  70 #include <unistd.h>
  71 #include <rpc/rpc.h>
  72 #include <sys/socket.h>
  73 #include <errno.h>
  74
  75 extern int              bindresvport();
  76
  77 #define rpc_buffer(xprt) ((xprt)->xp_p1)
  78
  79 static bool_t           svcudp_recv();
  80 static bool_t           svcudp_reply();
  81 static enum xprt_stat   svcudp_stat();
  82 static bool_t           svcudp_getargs();
  83 static bool_t           svcudp_freeargs();
  84 static void             svcudp_destroy();
  85
  86 static struct xp_ops svcudp_op = {
  87         svcudp_recv,
  88         svcudp_stat,
  89         svcudp_getargs,
  90         svcudp_reply,
  91         svcudp_freeargs,
  92         svcudp_destroy
  93 };
  94
  95 extern int errno;
  96
  97 /*
  98  * kept in xprt->xp_p2
  99  */
 100 struct svcudp_data {
 101         u_int   su_iosz;        /* byte size of send.recv buffer */
 102         u_long  su_xid;         /* transaction id */
 103         XDR     su_xdrs;        /* XDR handle */
 104         char    su_verfbody[MAX_AUTH_BYTES];    /* verifier body */
 105         char *  su_cache;       /* cached data, NULL if no cache */
 106 };
 107 #define su_data(xprt)   ((struct svcudp_data *)(xprt->xp_p2))
 108
 109 /*
 110  * Usage:
 111  *      xprt = svcudp_create(sock);
 112  *
 113  * If sock<0 then a socket is created, else sock is used.
 114  * If the socket, sock is not bound to a port then svcudp_create
 115  * binds it to an arbitrary port.  In any (successful) case,
 116  * xprt->xp_sock is the registered socket number and xprt->xp_port is the
 117  * associated port number.
 118  * Once *xprt is initialized, it is registered as a transporter;
 119  * see (svc.h, xprt_register).
 120  * The routines returns NULL if a problem occurred.
 121  */
 122 SVCXPRT *
 123 svcudp_bufcreate(sock, sendsz, recvsz)
 124         register int sock;
 125         u_int sendsz, recvsz;
 126 {
 127         bool_t madesock = FALSE;
 128         register SVCXPRT *xprt;
 129         register struct svcudp_data *su;
 130         struct sockaddr_in addr;
 131         int len = sizeof(struct sockaddr_in);
 132
 133         if (sock == RPC_ANYSOCK) {
 134                 if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
 135                         perror("svcudp_create: socket creation problem");
 136                         return ((SVCXPRT *)NULL);
 137                 }
 138                 madesock = TRUE;
 139         }
 140         bzero((char *)&addr, sizeof (addr));
 141         addr.sin_family = AF_INET;
 142         if (bindresvport(sock, &addr)) {
 143                 addr.sin_port = 0;
 144                 (void)bind(sock, (struct sockaddr *)&addr, len);
 145         }
 146         if (getsockname(sock, (struct sockaddr *)&addr, &len) != 0) {
 147                 perror("svcudp_create - cannot getsockname");
 148                 if (madesock)
 149                         (void)close(sock);
 150                 return ((SVCXPRT *)NULL);
 151         }
 152         xprt = (SVCXPRT *)mem_alloc(sizeof(SVCXPRT));
 153         if (xprt == NULL) {
 154                 (void)fprintf(stderr, "svcudp_create: out of memory\n");
 155                 return (NULL);
 156         }
 157         su = (struct svcudp_data *)mem_alloc(sizeof(*su));
 158         if (su == NULL) {
 159                 (void)fprintf(stderr, "svcudp_create: out of memory\n");
 160                 return (NULL);
 161         }
 162         su->su_iosz = ((MAX(sendsz, recvsz) + 3) / 4) * 4;
 163         if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL) {
 164                 (void)fprintf(stderr, "svcudp_create: out of memory\n");
 165                 return (NULL);
 166         }
 167         xdrmem_create(
 168             &(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_DECODE);
 169         su->su_cache = NULL;
 170         xprt->xp_p2 = (caddr_t)su;
 171         xprt->xp_verf.oa_base = su->su_verfbody;
 172         xprt->xp_ops = &svcudp_op;
 173         xprt->xp_port = ntohs(addr.sin_port);
 174         xprt->xp_sock = sock;
 175         xprt_register(xprt);
 176         return (xprt);
 177 }
 178
 179 SVCXPRT *
 180 svcudp_create(sock)
 181         int sock;
 182 {
 183
 184         return(svcudp_bufcreate(sock, UDPMSGSIZE, UDPMSGSIZE));
 185 }
 186
 187 static enum xprt_stat
 188 svcudp_stat(xprt)
 189         SVCXPRT *xprt;
 190 {
 191
 192         return (XPRT_IDLE);
 193 }
 194
 195 static bool_t
 196 svcudp_recv(xprt, msg)
 197         register SVCXPRT *xprt;
 198         struct rpc_msg *msg;
 199 {
 200         register struct svcudp_data *su = su_data(xprt);
 201         register XDR *xdrs = &(su->su_xdrs);
 202         register int rlen;
 203         char *reply;
 204         u_long replylen;
 205         static int cache_get();
 206
 207     again:
 208         xprt->xp_addrlen = sizeof(struct sockaddr_in);
 209         rlen = recvfrom(xprt->xp_sock, rpc_buffer(xprt), (int) su->su_iosz,
 210             0, (struct sockaddr *)&(xprt->xp_raddr), &(xprt->xp_addrlen));
 211         if (rlen == -1 && errno == EINTR)
 212                 goto again;
 213         if (rlen < 4*sizeof(u_long))
 214                 return (FALSE);
 215         xdrs->x_op = XDR_DECODE;
 216         XDR_SETPOS(xdrs, 0);
 217         if (! xdr_callmsg(xdrs, msg))
 218                 return (FALSE);
 219         su->su_xid = msg->rm_xid;
 220         if (su->su_cache != NULL) {
 221                 if (cache_get(xprt, msg, &reply, &replylen)) {
 222                         (void) sendto(xprt->xp_sock, reply, (int) replylen, 0,
 223                           (struct sockaddr *) &xprt->xp_raddr, xprt->xp_addrlen);
 224                         return (TRUE);
 225                 }
 226         }
 227         return (TRUE);
 228 }
 229
 230 static bool_t
 231 svcudp_reply(xprt, msg)
 232         register SVCXPRT *xprt;
 233         struct rpc_msg *msg;
 234 {
 235         register struct svcudp_data *su = su_data(xprt);
 236         register XDR *xdrs = &(su->su_xdrs);
 237         register int slen;
 238         register bool_t stat = FALSE;
 239         static void cache_set();
 240
 241         xdrs->x_op = XDR_ENCODE;
 242         XDR_SETPOS(xdrs, 0);
 243         msg->rm_xid = su->su_xid;
 244         if (xdr_replymsg(xdrs, msg)) {
 245                 slen = (int)XDR_GETPOS(xdrs);
 246                 if (sendto(xprt->xp_sock, rpc_buffer(xprt), slen, 0,
 247                     (struct sockaddr *)&(xprt->xp_raddr), xprt->xp_addrlen)
 248                     == slen) {
 249                         stat = TRUE;
 250                         if (su->su_cache && slen >= 0) {
 251                                 cache_set(xprt, (u_long) slen);
 252                         }
 253                 }
 254         }
 255         return (stat);
 256 }
 257
 258 static bool_t
 259 svcudp_getargs(xprt, xdr_args, args_ptr)
 260         SVCXPRT *xprt;
 261         xdrproc_t xdr_args;
 262         caddr_t args_ptr;
 263 {
 264
 265         return ((*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr));
 266 }
 267
 268 static bool_t
 269 svcudp_freeargs(xprt, xdr_args, args_ptr)
 270         SVCXPRT *xprt;
 271         xdrproc_t xdr_args;
 272         caddr_t args_ptr;
 273 {
 274         register XDR *xdrs = &(su_data(xprt)->su_xdrs);
 275
 276         xdrs->x_op = XDR_FREE;
 277         return ((*xdr_args)(xdrs, args_ptr));
 278 }
 279
 280 static void
 281 svcudp_destroy(xprt)
 282         register SVCXPRT *xprt;
 283 {
 284         register struct svcudp_data *su = su_data(xprt);
 285
 286         xprt_unregister(xprt);
 287         (void)close(xprt->xp_sock);
 288         XDR_DESTROY(&(su->su_xdrs));
 289         mem_free(rpc_buffer(xprt), su->su_iosz);
 290         mem_free((caddr_t)su, sizeof(struct svcudp_data));
 291         mem_free((caddr_t)xprt, sizeof(SVCXPRT));
 292 }
 293
 294
 295 /***********this could be a separate file*********************/
 296
 297 /*
 298  * Fifo cache for udp server
 299  * Copies pointers to reply buffers into fifo cache
 300  * Buffers are sent again if retransmissions are detected.
 301  */
 302
 303 #define SPARSENESS 4    /* 75% sparse */
 304
 305 #define CACHE_PERROR(msg)       \
 306         (void) fprintf(stderr,"%s\n", msg)
 307
 308 #define ALLOC(type, size)       \
 309         (type *) mem_alloc((unsigned) (sizeof(type) * (size)))
 310
 311 #define BZERO(addr, type, size)  \
 312         bzero((char *) addr, sizeof(type) * (int) (size))
 313
 314 /*
 315  * An entry in the cache
 316  */
 317 typedef struct cache_node *cache_ptr;
 318 struct cache_node {
 319         /*
 320          * Index into cache is xid, proc, vers, prog and address
 321          */
 322         u_long cache_xid;
 323         u_long cache_proc;
 324         u_long cache_vers;
 325         u_long cache_prog;
 326         struct sockaddr_in cache_addr;
 327         /*
 328          * The cached reply and length
 329          */
 330         char * cache_reply;
 331         u_long cache_replylen;
 332         /*
 333          * Next node on the list, if there is a collision
 334          */
 335         cache_ptr cache_next;
 336 };
 337
 338
 339
 340 /*
 341  * The entire cache
 342  */
 343 struct udp_cache {
 344         u_long uc_size;         /* size of cache */
 345         cache_ptr *uc_entries;  /* hash table of entries in cache */
 346         cache_ptr *uc_fifo;     /* fifo list of entries in cache */
 347         u_long uc_nextvictim;   /* points to next victim in fifo list */
 348         u_long uc_prog;         /* saved program number */
 349         u_long uc_vers;         /* saved version number */
 350         u_long uc_proc;         /* saved procedure number */
 351         struct sockaddr_in uc_addr; /* saved caller's address */
 352 };
 353
 354
 355 /*
 356  * the hashing function
 357  */
 358 #define CACHE_LOC(transp, xid)  \
 359  (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))
 360
 361
 362 /*
 363  * Enable use of the cache.
 364  * Note: there is no disable.
 365  */
 366 int
 367 svcudp_enablecache(transp, size)
 368         SVCXPRT *transp;
 369         u_long size;
 370 {
 371         struct svcudp_data *su = su_data(transp);
 372         struct udp_cache *uc;
 373
 374         if (su->su_cache != NULL) {
 375                 CACHE_PERROR("enablecache: cache already enabled");
 376                 return(0);
 377         }
 378         uc = ALLOC(struct udp_cache, 1);
 379         if (uc == NULL) {
 380                 CACHE_PERROR("enablecache: could not allocate cache");
 381                 return(0);
 382         }
 383         uc->uc_size = size;
 384         uc->uc_nextvictim = 0;
 385         uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
 386         if (uc->uc_entries == NULL) {
 387                 CACHE_PERROR("enablecache: could not allocate cache data");
 388                 return(0);
 389         }
 390         BZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
 391         uc->uc_fifo = ALLOC(cache_ptr, size);
 392         if (uc->uc_fifo == NULL) {
 393                 CACHE_PERROR("enablecache: could not allocate cache fifo");
 394                 return(0);
 395         }
 396         BZERO(uc->uc_fifo, cache_ptr, size);
 397         su->su_cache = (char *) uc;
 398         return(1);
 399 }
 400
 401
 402 /*
 403  * Set an entry in the cache
 404  */
 405 static void
 406 cache_set(xprt, replylen)
 407         SVCXPRT *xprt;
 408         u_long replylen;
 409 {
 410         register cache_ptr victim;
 411         register cache_ptr *vicp;
 412         register struct svcudp_data *su = su_data(xprt);
 413         struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 414         u_int loc;
 415         char *newbuf;
 416
 417         /*
 418          * Find space for the new entry, either by
 419          * reusing an old entry, or by mallocing a new one
 420          */
 421         victim = uc->uc_fifo[uc->uc_nextvictim];
 422         if (victim != NULL) {
 423                 loc = CACHE_LOC(xprt, victim->cache_xid);
 424                 for (vicp = &uc->uc_entries[loc];
 425                   *vicp != NULL && *vicp != victim;
 426                   vicp = &(*vicp)->cache_next)
 427                                 ;
 428                 if (*vicp == NULL) {
 429                         CACHE_PERROR("cache_set: victim not found");
 430                         return;
 431                 }
 432                 *vicp = victim->cache_next;     /* remote from cache */
 433                 newbuf = victim->cache_reply;
 434         } else {
 435                 victim = ALLOC(struct cache_node, 1);
 436                 if (victim == NULL) {
 437                         CACHE_PERROR("cache_set: victim alloc failed");
 438                         return;
 439                 }
 440                 newbuf = mem_alloc(su->su_iosz);
 441                 if (newbuf == NULL) {
 442                         CACHE_PERROR("cache_set: could not allocate new rpc_buffer");
 443                         return;
 444                 }
 445         }
 446
 447         /*
 448          * Store it away
 449          */
 450         victim->cache_replylen = replylen;
 451         victim->cache_reply = rpc_buffer(xprt);
 452         rpc_buffer(xprt) = newbuf;
 453         xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_ENCODE);
 454         victim->cache_xid = su->su_xid;
 455         victim->cache_proc = uc->uc_proc;
 456         victim->cache_vers = uc->uc_vers;
 457         victim->cache_prog = uc->uc_prog;
 458         victim->cache_addr = uc->uc_addr;
 459         loc = CACHE_LOC(xprt, victim->cache_xid);
 460         victim->cache_next = uc->uc_entries[loc];
 461         uc->uc_entries[loc] = victim;
 462         uc->uc_fifo[uc->uc_nextvictim++] = victim;
 463         uc->uc_nextvictim %= uc->uc_size;
 464 }
 465
 466 /*
 467  * Try to get an entry from the cache
 468  * return 1 if found, 0 if not found
 469  */
 470 static int
 471 cache_get(xprt, msg, replyp, replylenp)
 472         SVCXPRT *xprt;
 473         struct rpc_msg *msg;
 474         char **replyp;
 475         u_long *replylenp;
 476 {
 477         u_int loc;
 478         register cache_ptr ent;
 479         register struct svcudp_data *su = su_data(xprt);
 480         register struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 481
 482 #       define EQADDR(a1, a2)   (bcmp((char*)&a1, (char*)&a2, sizeof(a1)) == 0)
 483
 484         loc = CACHE_LOC(xprt, su->su_xid);
 485         for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
 486                 if (ent->cache_xid == su->su_xid &&
 487                   ent->cache_proc == uc->uc_proc &&
 488                   ent->cache_vers == uc->uc_vers &&
 489                   ent->cache_prog == uc->uc_prog &&
 490                   EQADDR(ent->cache_addr, uc->uc_addr)) {
 491                         *replyp = ent->cache_reply;
 492                         *replylenp = ent->cache_replylen;
 493                         return(1);
 494                 }
 495         }
 496         /*
 497          * Failed to find entry
 498          * Remember a few things so we can do a set later
 499          */
 500         uc->uc_proc = msg->rm_call.cb_proc;
 501         uc->uc_vers = msg->rm_call.cb_vers;
 502         uc->uc_prog = msg->rm_call.cb_prog;
 503         uc->uc_addr = xprt->xp_raddr;
 504         return(0);
 505 }
 506