rpc.subproj/svc_udp.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
  27  * unrestricted use provided that this legend is included on all tape
  28  * media and as a part of the software program in whole or part.  Users
  29  * may copy or modify Sun RPC without charge, but are not authorized
  30  * to license or distribute it to anyone else except as part of a product or
  31  * program developed by the user.
  32  *
  33  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  34  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  35  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  36  *
  37  * Sun RPC is provided with no support and without any obligation on the
  38  * part of Sun Microsystems, Inc. to assist in its use, correction,
  39  * modification or enhancement.
  40  *
  41  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  42  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  43  * OR ANY PART THEREOF.
  44  *
  45  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  46  * or profits or other special, indirect and consequential damages, even if
  47  * Sun has been advised of the possibility of such damages.
  48  *
  49  * Sun Microsystems, Inc.
  50  * 2550 Garcia Avenue
  51  * Mountain View, California  94043
  52  */
  53
  54 #if defined(LIBC_SCCS) && !defined(lint)
  55 /*static char *sccsid = "from: @(#)svc_udp.c 1.24 87/08/11 Copyr 1984 Sun Micro";*/
  56 /*static char *sccsid = "from: @(#)svc_udp.c    2.2 88/07/29 4.0 RPCSRC";*/
  57 static char *rcsid = "$Id: svc_udp.c,v 1.3 2002/02/19 20:36:25 epeyton Exp $";
  58 #endif
  59
  60 /*
  61  * svc_udp.c,
  62  * Server side for UDP/IP based RPC.  (Does some caching in the hopes of
  63  * achieving execute-at-most-once semantics.)
  64  *
  65  * Copyright (C) 1984, Sun Microsystems, Inc.
  66  */
  67
  68 #include <stdio.h>
  69 #include <stdlib.h>
  70 #include <string.h>
  71 #include <unistd.h>
  72 #include <rpc/rpc.h>
  73 #include <sys/socket.h>
  74 #include <errno.h>
  75
  76 extern int              bindresvport();
  77
  78 #define rpc_buffer(xprt) ((xprt)->xp_p1)
  79
  80 static bool_t           svcudp_recv();
  81 static bool_t           svcudp_reply();
  82 static enum xprt_stat   svcudp_stat();
  83 static bool_t           svcudp_getargs();
  84 static bool_t           svcudp_freeargs();
  85 static void             svcudp_destroy();
  86
  87 static struct xp_ops svcudp_op = {
  88         svcudp_recv,
  89         svcudp_stat,
  90         svcudp_getargs,
  91         svcudp_reply,
  92         svcudp_freeargs,
  93         svcudp_destroy
  94 };
  95
  96 extern int errno;
  97
  98 /*
  99  * kept in xprt->xp_p2
 100  */
 101 struct svcudp_data {
 102         u_int   su_iosz;        /* byte size of send.recv buffer */
 103         u_long  su_xid;         /* transaction id */
 104         XDR     su_xdrs;        /* XDR handle */
 105         char    su_verfbody[MAX_AUTH_BYTES];    /* verifier body */
 106         char *  su_cache;       /* cached data, NULL if no cache */
 107 };
 108 #define su_data(xprt)   ((struct svcudp_data *)(xprt->xp_p2))
 109
 110 /*
 111  * Usage:
 112  *      xprt = svcudp_create(sock);
 113  *
 114  * If sock<0 then a socket is created, else sock is used.
 115  * If the socket, sock is not bound to a port then svcudp_create
 116  * binds it to an arbitrary port.  In any (successful) case,
 117  * xprt->xp_sock is the registered socket number and xprt->xp_port is the
 118  * associated port number.
 119  * Once *xprt is initialized, it is registered as a transporter;
 120  * see (svc.h, xprt_register).
 121  * The routines returns NULL if a problem occurred.
 122  */
 123 SVCXPRT *
 124 svcudp_bufcreate(sock, sendsz, recvsz)
 125         register int sock;
 126         u_int sendsz, recvsz;
 127 {
 128         bool_t madesock = FALSE;
 129         register SVCXPRT *xprt;
 130         register struct svcudp_data *su;
 131         struct sockaddr_in addr;
 132         int len = sizeof(struct sockaddr_in);
 133
 134         if (sock == RPC_ANYSOCK) {
 135                 if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
 136                         perror("svcudp_create: socket creation problem");
 137                         return ((SVCXPRT *)NULL);
 138                 }
 139                 madesock = TRUE;
 140         }
 141         bzero((char *)&addr, sizeof (addr));
 142         addr.sin_family = AF_INET;
 143         if (bindresvport(sock, &addr)) {
 144                 addr.sin_port = 0;
 145                 (void)bind(sock, (struct sockaddr *)&addr, len);
 146         }
 147         if (getsockname(sock, (struct sockaddr *)&addr, &len) != 0) {
 148                 perror("svcudp_create - cannot getsockname");
 149                 if (madesock)
 150                         (void)close(sock);
 151                 return ((SVCXPRT *)NULL);
 152         }
 153         xprt = (SVCXPRT *)mem_alloc(sizeof(SVCXPRT));
 154         if (xprt == NULL) {
 155                 (void)fprintf(stderr, "svcudp_create: out of memory\n");
 156                 return (NULL);
 157         }
 158         su = (struct svcudp_data *)mem_alloc(sizeof(*su));
 159         if (su == NULL) {
 160                 (void)fprintf(stderr, "svcudp_create: out of memory\n");
 161                 return (NULL);
 162         }
 163         su->su_iosz = ((MAX(sendsz, recvsz) + 3) / 4) * 4;
 164         if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL) {
 165                 (void)fprintf(stderr, "svcudp_create: out of memory\n");
 166                 return (NULL);
 167         }
 168         xdrmem_create(
 169             &(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_DECODE);
 170         su->su_cache = NULL;
 171         xprt->xp_p2 = (caddr_t)su;
 172         xprt->xp_verf.oa_base = su->su_verfbody;
 173         xprt->xp_ops = &svcudp_op;
 174         xprt->xp_port = ntohs(addr.sin_port);
 175         xprt->xp_sock = sock;
 176         xprt_register(xprt);
 177         return (xprt);
 178 }
 179
 180 SVCXPRT *
 181 svcudp_create(sock)
 182         int sock;
 183 {
 184
 185         return(svcudp_bufcreate(sock, UDPMSGSIZE, UDPMSGSIZE));
 186 }
 187
 188 static enum xprt_stat
 189 svcudp_stat(xprt)
 190         SVCXPRT *xprt;
 191 {
 192
 193         return (XPRT_IDLE);
 194 }
 195
 196 static bool_t
 197 svcudp_recv(xprt, msg)
 198         register SVCXPRT *xprt;
 199         struct rpc_msg *msg;
 200 {
 201         register struct svcudp_data *su = su_data(xprt);
 202         register XDR *xdrs = &(su->su_xdrs);
 203         register int rlen;
 204         char *reply;
 205         u_long replylen;
 206         static int cache_get();
 207
 208     again:
 209         xprt->xp_addrlen = sizeof(struct sockaddr_in);
 210         rlen = recvfrom(xprt->xp_sock, rpc_buffer(xprt), (int) su->su_iosz,
 211             0, (struct sockaddr *)&(xprt->xp_raddr), &(xprt->xp_addrlen));
 212         if (rlen == -1 && errno == EINTR)
 213                 goto again;
 214         if (rlen < 4*sizeof(u_long))
 215                 return (FALSE);
 216         xdrs->x_op = XDR_DECODE;
 217         XDR_SETPOS(xdrs, 0);
 218         if (! xdr_callmsg(xdrs, msg))
 219                 return (FALSE);
 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_sock, reply, (int) replylen, 0,
 224                           (struct sockaddr *) &xprt->xp_raddr, xprt->xp_addrlen);
 225                         return (TRUE);
 226                 }
 227         }
 228         return (TRUE);
 229 }
 230
 231 static bool_t
 232 svcudp_reply(xprt, msg)
 233         register SVCXPRT *xprt;
 234         struct rpc_msg *msg;
 235 {
 236         register struct svcudp_data *su = su_data(xprt);
 237         register XDR *xdrs = &(su->su_xdrs);
 238         register int slen;
 239         register bool_t stat = FALSE;
 240         static void cache_set();
 241
 242         xdrs->x_op = XDR_ENCODE;
 243         XDR_SETPOS(xdrs, 0);
 244         msg->rm_xid = su->su_xid;
 245         if (xdr_replymsg(xdrs, msg)) {
 246                 slen = (int)XDR_GETPOS(xdrs);
 247                 if (sendto(xprt->xp_sock, rpc_buffer(xprt), slen, 0,
 248                     (struct sockaddr *)&(xprt->xp_raddr), xprt->xp_addrlen)
 249                     == slen) {
 250                         stat = TRUE;
 251                         if (su->su_cache && slen >= 0) {
 252                                 cache_set(xprt, (u_long) slen);
 253                         }
 254                 }
 255         }
 256         return (stat);
 257 }
 258
 259 static bool_t
 260 svcudp_getargs(xprt, xdr_args, args_ptr)
 261         SVCXPRT *xprt;
 262         xdrproc_t xdr_args;
 263         caddr_t args_ptr;
 264 {
 265
 266         return ((*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr));
 267 }
 268
 269 static bool_t
 270 svcudp_freeargs(xprt, xdr_args, args_ptr)
 271         SVCXPRT *xprt;
 272         xdrproc_t xdr_args;
 273         caddr_t args_ptr;
 274 {
 275         register XDR *xdrs = &(su_data(xprt)->su_xdrs);
 276
 277         xdrs->x_op = XDR_FREE;
 278         return ((*xdr_args)(xdrs, args_ptr));
 279 }
 280
 281 static void
 282 svcudp_destroy(xprt)
 283         register SVCXPRT *xprt;
 284 {
 285         register struct svcudp_data *su = su_data(xprt);
 286
 287         xprt_unregister(xprt);
 288         (void)close(xprt->xp_sock);
 289         XDR_DESTROY(&(su->su_xdrs));
 290         mem_free(rpc_buffer(xprt), su->su_iosz);
 291         mem_free((caddr_t)su, sizeof(struct svcudp_data));
 292         mem_free((caddr_t)xprt, sizeof(SVCXPRT));
 293 }
 294
 295
 296 /***********this could be a separate file*********************/
 297
 298 /*
 299  * Fifo cache for udp server
 300  * Copies pointers to reply buffers into fifo cache
 301  * Buffers are sent again if retransmissions are detected.
 302  */
 303
 304 #define SPARSENESS 4    /* 75% sparse */
 305
 306 #define CACHE_PERROR(msg)       \
 307         (void) fprintf(stderr,"%s\n", msg)
 308
 309 #define ALLOC(type, size)       \
 310         (type *) mem_alloc((unsigned) (sizeof(type) * (size)))
 311
 312 #define BZERO(addr, type, size)  \
 313         bzero((char *) addr, sizeof(type) * (int) (size))
 314
 315 /*
 316  * An entry in the cache
 317  */
 318 typedef struct cache_node *cache_ptr;
 319 struct cache_node {
 320         /*
 321          * Index into cache is xid, proc, vers, prog and address
 322          */
 323         u_long cache_xid;
 324         u_long cache_proc;
 325         u_long cache_vers;
 326         u_long cache_prog;
 327         struct sockaddr_in cache_addr;
 328         /*
 329          * The cached reply and length
 330          */
 331         char * cache_reply;
 332         u_long cache_replylen;
 333         /*
 334          * Next node on the list, if there is a collision
 335          */
 336         cache_ptr cache_next;
 337 };
 338
 339
 340
 341 /*
 342  * The entire cache
 343  */
 344 struct udp_cache {
 345         u_long uc_size;         /* size of cache */
 346         cache_ptr *uc_entries;  /* hash table of entries in cache */
 347         cache_ptr *uc_fifo;     /* fifo list of entries in cache */
 348         u_long uc_nextvictim;   /* points to next victim in fifo list */
 349         u_long uc_prog;         /* saved program number */
 350         u_long uc_vers;         /* saved version number */
 351         u_long uc_proc;         /* saved procedure number */
 352         struct sockaddr_in uc_addr; /* saved caller's address */
 353 };
 354
 355
 356 /*
 357  * the hashing function
 358  */
 359 #define CACHE_LOC(transp, xid)  \
 360  (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))
 361
 362
 363 /*
 364  * Enable use of the cache.
 365  * Note: there is no disable.
 366  */
 367 int
 368 svcudp_enablecache(transp, size)
 369         SVCXPRT *transp;
 370         u_long size;
 371 {
 372         struct svcudp_data *su = su_data(transp);
 373         struct udp_cache *uc;
 374
 375         if (su->su_cache != NULL) {
 376                 CACHE_PERROR("enablecache: cache already enabled");
 377                 return(0);
 378         }
 379         uc = ALLOC(struct udp_cache, 1);
 380         if (uc == NULL) {
 381                 CACHE_PERROR("enablecache: could not allocate cache");
 382                 return(0);
 383         }
 384         uc->uc_size = size;
 385         uc->uc_nextvictim = 0;
 386         uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
 387         if (uc->uc_entries == NULL) {
 388                 CACHE_PERROR("enablecache: could not allocate cache data");
 389                 return(0);
 390         }
 391         BZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
 392         uc->uc_fifo = ALLOC(cache_ptr, size);
 393         if (uc->uc_fifo == NULL) {
 394                 CACHE_PERROR("enablecache: could not allocate cache fifo");
 395                 return(0);
 396         }
 397         BZERO(uc->uc_fifo, cache_ptr, size);
 398         su->su_cache = (char *) uc;
 399         return(1);
 400 }
 401
 402
 403 /*
 404  * Set an entry in the cache
 405  */
 406 static void
 407 cache_set(xprt, replylen)
 408         SVCXPRT *xprt;
 409         u_long replylen;
 410 {
 411         register cache_ptr victim;
 412         register cache_ptr *vicp;
 413         register struct svcudp_data *su = su_data(xprt);
 414         struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 415         u_int loc;
 416         char *newbuf;
 417
 418         /*
 419          * Find space for the new entry, either by
 420          * reusing an old entry, or by mallocing a new one
 421          */
 422         victim = uc->uc_fifo[uc->uc_nextvictim];
 423         if (victim != NULL) {
 424                 loc = CACHE_LOC(xprt, victim->cache_xid);
 425                 for (vicp = &uc->uc_entries[loc];
 426                   *vicp != NULL && *vicp != victim;
 427                   vicp = &(*vicp)->cache_next)
 428                                 ;
 429                 if (*vicp == NULL) {
 430                         CACHE_PERROR("cache_set: victim not found");
 431                         return;
 432                 }
 433                 *vicp = victim->cache_next;     /* remote from cache */
 434                 newbuf = victim->cache_reply;
 435         } else {
 436                 victim = ALLOC(struct cache_node, 1);
 437                 if (victim == NULL) {
 438                         CACHE_PERROR("cache_set: victim alloc failed");
 439                         return;
 440                 }
 441                 newbuf = mem_alloc(su->su_iosz);
 442                 if (newbuf == NULL) {
 443                         CACHE_PERROR("cache_set: could not allocate new rpc_buffer");
 444                         return;
 445                 }
 446         }
 447
 448         /*
 449          * Store it away
 450          */
 451         victim->cache_replylen = replylen;
 452         victim->cache_reply = rpc_buffer(xprt);
 453         rpc_buffer(xprt) = newbuf;
 454         xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_ENCODE);
 455         victim->cache_xid = su->su_xid;
 456         victim->cache_proc = uc->uc_proc;
 457         victim->cache_vers = uc->uc_vers;
 458         victim->cache_prog = uc->uc_prog;
 459         victim->cache_addr = uc->uc_addr;
 460         loc = CACHE_LOC(xprt, victim->cache_xid);
 461         victim->cache_next = uc->uc_entries[loc];
 462         uc->uc_entries[loc] = victim;
 463         uc->uc_fifo[uc->uc_nextvictim++] = victim;
 464         uc->uc_nextvictim %= uc->uc_size;
 465 }
 466
 467 /*
 468  * Try to get an entry from the cache
 469  * return 1 if found, 0 if not found
 470  */
 471 static int
 472 cache_get(xprt, msg, replyp, replylenp)
 473         SVCXPRT *xprt;
 474         struct rpc_msg *msg;
 475         char **replyp;
 476         u_long *replylenp;
 477 {
 478         u_int loc;
 479         register cache_ptr ent;
 480         register struct svcudp_data *su = su_data(xprt);
 481         register struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 482
 483 #       define EQADDR(a1, a2)   (bcmp((char*)&a1, (char*)&a2, sizeof(a1)) == 0)
 484
 485         loc = CACHE_LOC(xprt, su->su_xid);
 486         for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
 487                 if (ent->cache_xid == su->su_xid &&
 488                   ent->cache_proc == uc->uc_proc &&
 489                   ent->cache_vers == uc->uc_vers &&
 490                   ent->cache_prog == uc->uc_prog &&
 491                   EQADDR(ent->cache_addr, uc->uc_addr)) {
 492                         *replyp = ent->cache_reply;
 493                         *replylenp = ent->cache_replylen;
 494                         return(1);
 495                 }
 496         }
 497         /*
 498          * Failed to find entry
 499          * Remember a few things so we can do a set later
 500          */
 501         uc->uc_proc = msg->rm_call.cb_proc;
 502         uc->uc_vers = msg->rm_call.cb_vers;
 503         uc->uc_prog = msg->rm_call.cb_prog;
 504         uc->uc_addr = xprt->xp_raddr;
 505         return(0);
 506 }
 507