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 1.5 2004/10/13 00:24:07 jkh 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 <sys/param.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 int cache_get();
 197 static void cache_set();
 198
 199 static bool_t
 200 svcudp_recv(xprt, msg)
 201         register SVCXPRT *xprt;
 202         struct rpc_msg *msg;
 203 {
 204         register struct svcudp_data *su = su_data(xprt);
 205         register XDR *xdrs = &(su->su_xdrs);
 206         register int rlen;
 207         char *reply;
 208         u_long replylen;
 209
 210     again:
 211         xprt->xp_addrlen = sizeof(struct sockaddr_in);
 212         rlen = recvfrom(xprt->xp_sock, rpc_buffer(xprt), (int) su->su_iosz,
 213             0, (struct sockaddr *)&(xprt->xp_raddr), &(xprt->xp_addrlen));
 214         if (rlen == -1 && errno == EINTR)
 215                 goto again;
 216         if (rlen < 4*sizeof(u_long))
 217                 return (FALSE);
 218         xdrs->x_op = XDR_DECODE;
 219         XDR_SETPOS(xdrs, 0);
 220         if (! xdr_callmsg(xdrs, msg))
 221                 return (FALSE);
 222         su->su_xid = msg->rm_xid;
 223         if (su->su_cache != NULL) {
 224                 if (cache_get(xprt, msg, &reply, &replylen)) {
 225                         (void) sendto(xprt->xp_sock, reply, (int) replylen, 0,
 226                           (struct sockaddr *) &xprt->xp_raddr, xprt->xp_addrlen);
 227                         return (TRUE);
 228                 }
 229         }
 230         return (TRUE);
 231 }
 232
 233 static bool_t
 234 svcudp_reply(xprt, msg)
 235         register SVCXPRT *xprt;
 236         struct rpc_msg *msg;
 237 {
 238         register struct svcudp_data *su = su_data(xprt);
 239         register XDR *xdrs = &(su->su_xdrs);
 240         register int slen;
 241         register bool_t stat = FALSE;
 242
 243         xdrs->x_op = XDR_ENCODE;
 244         XDR_SETPOS(xdrs, 0);
 245         msg->rm_xid = su->su_xid;
 246         if (xdr_replymsg(xdrs, msg)) {
 247                 slen = (int)XDR_GETPOS(xdrs);
 248                 if (sendto(xprt->xp_sock, rpc_buffer(xprt), slen, 0,
 249                     (struct sockaddr *)&(xprt->xp_raddr), xprt->xp_addrlen)
 250                     == slen) {
 251                         stat = TRUE;
 252                         if (su->su_cache && slen >= 0) {
 253                                 cache_set(xprt, (u_long) slen);
 254                         }
 255                 }
 256         }
 257         return (stat);
 258 }
 259
 260 static bool_t
 261 svcudp_getargs(xprt, xdr_args, args_ptr)
 262         SVCXPRT *xprt;
 263         xdrproc_t xdr_args;
 264         caddr_t args_ptr;
 265 {
 266
 267         return ((*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr));
 268 }
 269
 270 static bool_t
 271 svcudp_freeargs(xprt, xdr_args, args_ptr)
 272         SVCXPRT *xprt;
 273         xdrproc_t xdr_args;
 274         caddr_t args_ptr;
 275 {
 276         register XDR *xdrs = &(su_data(xprt)->su_xdrs);
 277
 278         xdrs->x_op = XDR_FREE;
 279         return ((*xdr_args)(xdrs, args_ptr));
 280 }
 281
 282 static void
 283 svcudp_destroy(xprt)
 284         register SVCXPRT *xprt;
 285 {
 286         register struct svcudp_data *su = su_data(xprt);
 287
 288         xprt_unregister(xprt);
 289         (void)close(xprt->xp_sock);
 290         XDR_DESTROY(&(su->su_xdrs));
 291         mem_free(rpc_buffer(xprt), su->su_iosz);
 292         mem_free((caddr_t)su, sizeof(struct svcudp_data));
 293         mem_free((caddr_t)xprt, sizeof(SVCXPRT));
 294 }
 295
 296
 297 /***********this could be a separate file*********************/
 298
 299 /*
 300  * Fifo cache for udp server
 301  * Copies pointers to reply buffers into fifo cache
 302  * Buffers are sent again if retransmissions are detected.
 303  */
 304
 305 #define SPARSENESS 4    /* 75% sparse */
 306
 307 #define CACHE_PERROR(msg)       \
 308         (void) fprintf(stderr,"%s\n", msg)
 309
 310 #define ALLOC(type, size)       \
 311         (type *) mem_alloc((unsigned) (sizeof(type) * (size)))
 312
 313 #define BZERO(addr, type, size)  \
 314         bzero((char *) addr, sizeof(type) * (int) (size))
 315
 316 /*
 317  * An entry in the cache
 318  */
 319 typedef struct cache_node *cache_ptr;
 320 struct cache_node {
 321         /*
 322          * Index into cache is xid, proc, vers, prog and address
 323          */
 324         u_long cache_xid;
 325         u_long cache_proc;
 326         u_long cache_vers;
 327         u_long cache_prog;
 328         struct sockaddr_in cache_addr;
 329         /*
 330          * The cached reply and length
 331          */
 332         char * cache_reply;
 333         u_long cache_replylen;
 334         /*
 335          * Next node on the list, if there is a collision
 336          */
 337         cache_ptr cache_next;
 338 };
 339
 340
 341
 342 /*
 343  * The entire cache
 344  */
 345 struct udp_cache {
 346         u_long uc_size;         /* size of cache */
 347         cache_ptr *uc_entries;  /* hash table of entries in cache */
 348         cache_ptr *uc_fifo;     /* fifo list of entries in cache */
 349         u_long uc_nextvictim;   /* points to next victim in fifo list */
 350         u_long uc_prog;         /* saved program number */
 351         u_long uc_vers;         /* saved version number */
 352         u_long uc_proc;         /* saved procedure number */
 353         struct sockaddr_in uc_addr; /* saved caller's address */
 354 };
 355
 356
 357 /*
 358  * the hashing function
 359  */
 360 #define CACHE_LOC(transp, xid)  \
 361  (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))
 362
 363
 364 /*
 365  * Enable use of the cache.
 366  * Note: there is no disable.
 367  */
 368 int
 369 svcudp_enablecache(transp, size)
 370         SVCXPRT *transp;
 371         u_long size;
 372 {
 373         struct svcudp_data *su = su_data(transp);
 374         struct udp_cache *uc;
 375
 376         if (su->su_cache != NULL) {
 377                 CACHE_PERROR("enablecache: cache already enabled");
 378                 return(0);
 379         }
 380         uc = ALLOC(struct udp_cache, 1);
 381         if (uc == NULL) {
 382                 CACHE_PERROR("enablecache: could not allocate cache");
 383                 return(0);
 384         }
 385         uc->uc_size = size;
 386         uc->uc_nextvictim = 0;
 387         uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
 388         if (uc->uc_entries == NULL) {
 389                 CACHE_PERROR("enablecache: could not allocate cache data");
 390                 return(0);
 391         }
 392         BZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
 393         uc->uc_fifo = ALLOC(cache_ptr, size);
 394         if (uc->uc_fifo == NULL) {
 395                 CACHE_PERROR("enablecache: could not allocate cache fifo");
 396                 return(0);
 397         }
 398         BZERO(uc->uc_fifo, cache_ptr, size);
 399         su->su_cache = (char *) uc;
 400         return(1);
 401 }
 402
 403
 404 /*
 405  * Set an entry in the cache
 406  */
 407 static void
 408 cache_set(xprt, replylen)
 409         SVCXPRT *xprt;
 410         u_long replylen;
 411 {
 412         register cache_ptr victim;
 413         register cache_ptr *vicp;
 414         register struct svcudp_data *su = su_data(xprt);
 415         struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 416         u_int loc;
 417         char *newbuf;
 418
 419         /*
 420          * Find space for the new entry, either by
 421          * reusing an old entry, or by mallocing a new one
 422          */
 423         victim = uc->uc_fifo[uc->uc_nextvictim];
 424         if (victim != NULL) {
 425                 loc = CACHE_LOC(xprt, victim->cache_xid);
 426                 for (vicp = &uc->uc_entries[loc];
 427                   *vicp != NULL && *vicp != victim;
 428                   vicp = &(*vicp)->cache_next)
 429                                 ;
 430                 if (*vicp == NULL) {
 431                         CACHE_PERROR("cache_set: victim not found");
 432                         return;
 433                 }
 434                 *vicp = victim->cache_next;     /* remote from cache */
 435                 newbuf = victim->cache_reply;
 436         } else {
 437                 victim = ALLOC(struct cache_node, 1);
 438                 if (victim == NULL) {
 439                         CACHE_PERROR("cache_set: victim alloc failed");
 440                         return;
 441                 }
 442                 newbuf = mem_alloc(su->su_iosz);
 443                 if (newbuf == NULL) {
 444                         CACHE_PERROR("cache_set: could not allocate new rpc_buffer");
 445                         return;
 446                 }
 447         }
 448
 449         /*
 450          * Store it away
 451          */
 452         victim->cache_replylen = replylen;
 453         victim->cache_reply = rpc_buffer(xprt);
 454         rpc_buffer(xprt) = newbuf;
 455         xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_ENCODE);
 456         victim->cache_xid = su->su_xid;
 457         victim->cache_proc = uc->uc_proc;
 458         victim->cache_vers = uc->uc_vers;
 459         victim->cache_prog = uc->uc_prog;
 460         victim->cache_addr = uc->uc_addr;
 461         loc = CACHE_LOC(xprt, victim->cache_xid);
 462         victim->cache_next = uc->uc_entries[loc];
 463         uc->uc_entries[loc] = victim;
 464         uc->uc_fifo[uc->uc_nextvictim++] = victim;
 465         uc->uc_nextvictim %= uc->uc_size;
 466 }
 467
 468 /*
 469  * Try to get an entry from the cache
 470  * return 1 if found, 0 if not found
 471  */
 472 static int
 473 cache_get(xprt, msg, replyp, replylenp)
 474         SVCXPRT *xprt;
 475         struct rpc_msg *msg;
 476         char **replyp;
 477         u_long *replylenp;
 478 {
 479         u_int loc;
 480         register cache_ptr ent;
 481         register struct svcudp_data *su = su_data(xprt);
 482         register struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 483
 484 #       define EQADDR(a1, a2)   (bcmp((char*)&a1, (char*)&a2, sizeof(a1)) == 0)
 485
 486         loc = CACHE_LOC(xprt, su->su_xid);
 487         for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
 488                 if (ent->cache_xid == su->su_xid &&
 489                   ent->cache_proc == uc->uc_proc &&
 490                   ent->cache_vers == uc->uc_vers &&
 491                   ent->cache_prog == uc->uc_prog &&
 492                   EQADDR(ent->cache_addr, uc->uc_addr)) {
 493                         *replyp = ent->cache_reply;
 494                         *replylenp = ent->cache_replylen;
 495                         return(1);
 496                 }
 497         }
 498         /*
 499          * Failed to find entry
 500          * Remember a few things so we can do a set later
 501          */
 502         uc->uc_proc = msg->rm_call.cb_proc;
 503         uc->uc_vers = msg->rm_call.cb_vers;
 504         uc->uc_prog = msg->rm_call.cb_prog;
 505         uc->uc_addr = xprt->xp_raddr;
 506         return(0);
 507 }
 508