sunrpc/svc_udp6.c

   1 /* @(#)svc_udp.c        2.2 88/07/29 4.0 RPCSRC */
   2 /*
   3  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   4  * unrestricted use provided that this legend is included on all tape
   5  * media and as a part of the software program in whole or part.  Users
   6  * may copy or modify Sun RPC without charge, but are not authorized
   7  * to license or distribute it to anyone else except as part of a product or
   8  * program developed by the user.
   9  *
  10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  13  *
  14  * Sun RPC is provided with no support and without any obligation on the
  15  * part of Sun Microsystems, Inc. to assist in its use, correction,
  16  * modification or enhancement.
  17  *
  18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  20  * OR ANY PART THEREOF.
  21  *
  22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  23  * or profits or other special, indirect and consequential damages, even if
  24  * Sun has been advised of the possibility of such damages.
  25  *
  26  * Sun Microsystems, Inc.
  27  * 2550 Garcia Avenue
  28  * Mountain View, California  94043
  29  */
  30 #if !defined(lint) && defined(SCCSIDS)
  31 static char sccsid[] = "@(#)svc_udp.c 1.24 87/08/11 Copyr 1984 Sun Micro";
  32 #endif
  33
  34 /*
  35  * svc_udp.c,
  36  * Server side for UDP/IP based RPC.  (Does some caching in the hopes of
  37  * achieving execute-at-most-once semantics.)
  38  *
  39  * Copyright (C) 1984, Sun Microsystems, Inc.
  40  */
  41
  42 #include <stdio.h>
  43 #include <unistd.h>
  44 #include <string.h>
  45 #include <libintl.h>
  46 #include <rpc/rpc.h>
  47 #include <sys/socket.h>
  48 #include <errno.h>
  49
  50 #ifdef USE_IN_LIBIO
  51 # include <libio/iolibio.h>
  52 # define fputs(s, f) _IO_fputs (s, f)
  53 #endif
  54
  55 #define rpc_buffer(xprt) ((xprt)->xp_p1)
  56 #ifndef MAX
  57 #define MAX(a, b)     ((a > b) ? a : b)
  58 #endif
  59
  60 static bool_t svcudp6_recv (SVCXPRT *, struct rpc_msg *);
  61 static bool_t svcudp6_reply (SVCXPRT *, struct rpc_msg *);
  62 static enum xprt_stat svcudp6_stat (SVCXPRT *);
  63 static bool_t svcudp6_getargs (SVCXPRT *, xdrproc_t, caddr_t);
  64 static bool_t svcudp6_freeargs (SVCXPRT *, xdrproc_t, caddr_t);
  65 static void svcudp6_destroy (SVCXPRT *);
  66
  67 static const struct xp_ops svcudp6_op =
  68 {
  69   svcudp6_recv,
  70   svcudp6_stat,
  71   svcudp6_getargs,
  72   svcudp6_reply,
  73   svcudp6_freeargs,
  74   svcudp6_destroy
  75 };
  76
  77 static int cache_get (SVCXPRT *, struct rpc_msg *, char **replyp,
  78                       u_long *replylenp);
  79 static void cache_set (SVCXPRT *xprt, u_long replylen);
  80
  81 /*
  82  * kept in xprt->xp_p2
  83  */
  84 struct svcudp_data
  85   {
  86     u_int su_iosz;              /* byte size of send.recv buffer */
  87     u_long su_xid;              /* transaction id */
  88     XDR su_xdrs;                /* XDR handle */
  89     char su_verfbody[MAX_AUTH_BYTES];   /* verifier body */
  90     char *su_cache;             /* cached data, NULL if no cache */
  91   };
  92 #define su_data(xprt)   ((struct svcudp_data *)(xprt->xp_p2))
  93
  94 /*
  95  * Usage:
  96  *      xprt = svcudp_create(sock);
  97  *
  98  * If sock<0 then a socket is created, else sock is used.
  99  * If the socket, sock is not bound to a port then svcudp_create
 100  * binds it to an arbitrary port.  In any (successful) case,
 101  * xprt->xp_sock is the registered socket number and xprt->xp_port is the
 102  * associated port number.
 103  * Once *xprt is initialized, it is registered as a transporter;
 104  * see (svc.h, xprt_register).
 105  * The routines returns NULL if a problem occurred.
 106  */
 107 SVCXPRT *
 108 svcudp6_bufcreate (sock, sendsz, recvsz)
 109      int sock;
 110      u_int sendsz, recvsz;
 111 {
 112   bool_t madesock = FALSE;
 113   SVCXPRT *xprt;
 114   struct svcudp_data *su;
 115   struct sockaddr_in6 addr;
 116   socklen_t len = sizeof (struct sockaddr_in6);
 117
 118   if (sock == RPC_ANYSOCK)
 119     {
 120       if ((sock = __socket (AF_INET6, SOCK_DGRAM, IPPROTO_UDP)) < 0)
 121         {
 122           perror (_("svcudp_create: socket creation problem"));
 123           return (SVCXPRT *) NULL;
 124         }
 125       madesock = TRUE;
 126     }
 127   __bzero ((char *) &addr, sizeof (addr));
 128   addr.sin6_family = AF_INET6;
 129   if (bindresvport6 (sock, &addr))
 130     {
 131       addr.sin6_port = 0;
 132       (void) bind (sock, (struct sockaddr *) &addr, len);
 133     }
 134   if (getsockname (sock, (struct sockaddr *) &addr, &len) != 0)
 135     {
 136       perror (_("svcudp_create - cannot getsockname"));
 137       if (madesock)
 138         (void) __close (sock);
 139       return (SVCXPRT *) NULL;
 140     }
 141   xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
 142   if (xprt == NULL)
 143     {
 144       (void) fputs (_("svcudp_create: out of memory\n"), stderr);
 145       return NULL;
 146     }
 147   su = (struct svcudp_data *) mem_alloc (sizeof (*su));
 148   if (su == NULL)
 149     {
 150       (void) fputs (_("svcudp_create: out of memory\n"), stderr);
 151       return NULL;
 152     }
 153   su->su_iosz = ((MAX (sendsz, recvsz) + 3) / 4) * 4;
 154   if ((rpc_buffer (xprt) = mem_alloc (su->su_iosz)) == NULL)
 155     {
 156       (void) fputs (_("svcudp_create: out of memory\n"), stderr);
 157       return NULL;
 158     }
 159   xdrmem_create (&(su->su_xdrs), rpc_buffer (xprt), su->su_iosz, XDR_DECODE);
 160   su->su_cache = NULL;
 161   xprt->xp_p2 = (caddr_t) su;
 162   xprt->xp_verf.oa_base = su->su_verfbody;
 163   xprt->xp_ops = &svcudp6_op;
 164   xprt->xp_port = ntohs (addr.sin6_port);
 165   xprt->xp_sock = sock;
 166   xprt_register (xprt);
 167   return xprt;
 168 }
 169
 170 SVCXPRT *
 171 svcudp6_create (sock)
 172      int sock;
 173 {
 174
 175   return svcudp6_bufcreate (sock, UDPMSGSIZE, UDPMSGSIZE);
 176 }
 177
 178 static enum xprt_stat
 179 svcudp6_stat (xprt)
 180      SVCXPRT *xprt;
 181 {
 182
 183   return XPRT_IDLE;
 184 }
 185
 186 static bool_t
 187 svcudp6_recv (xprt, msg)
 188      SVCXPRT *xprt;
 189      struct rpc_msg *msg;
 190 {
 191   struct svcudp_data *su = su_data (xprt);
 192   XDR *xdrs = &(su->su_xdrs);
 193   int rlen;
 194   char *reply;
 195   u_long replylen;
 196   socklen_t len;
 197
 198 again:
 199   /* FIXME -- should xp_addrlen be a size_t?  */
 200   len = (socklen_t) sizeof(struct sockaddr_in6);
 201   rlen = recvfrom (xprt->xp_sock, rpc_buffer (xprt), (int) su->su_iosz, 0,
 202                    (struct sockaddr *) &(xprt->xp_raddr), &len);
 203   xprt->xp_addrlen = len;
 204   if (rlen == -1 && errno == EINTR)
 205     goto again;
 206   if (rlen < 16)                /* < 4 32-bit ints? */
 207     return FALSE;
 208   xdrs->x_op = XDR_DECODE;
 209   XDR_SETPOS (xdrs, 0);
 210   if (!xdr_callmsg (xdrs, msg))
 211     return FALSE;
 212   su->su_xid = msg->rm_xid;
 213   if (su->su_cache != NULL)
 214     {
 215       if (cache_get (xprt, msg, &reply, &replylen))
 216         {
 217           (void) sendto (xprt->xp_sock, reply, (int) replylen, 0,
 218                          (struct sockaddr *) &xprt->xp_raddr, len);
 219           return TRUE;
 220         }
 221     }
 222   return TRUE;
 223 }
 224
 225 static bool_t
 226 svcudp6_reply (xprt, msg)
 227      SVCXPRT *xprt;
 228      struct rpc_msg *msg;
 229 {
 230   struct svcudp_data *su = su_data (xprt);
 231   XDR *xdrs = &(su->su_xdrs);
 232   int slen;
 233   bool_t stat = FALSE;
 234
 235   xdrs->x_op = XDR_ENCODE;
 236   XDR_SETPOS (xdrs, 0);
 237   msg->rm_xid = su->su_xid;
 238   if (xdr_replymsg (xdrs, msg))
 239     {
 240       slen = (int) XDR_GETPOS (xdrs);
 241       if (sendto (xprt->xp_sock, rpc_buffer (xprt), slen, 0,
 242                   (struct sockaddr *) &(xprt->xp_raddr), xprt->xp_addrlen)
 243           == slen)
 244         {
 245           stat = TRUE;
 246           if (su->su_cache && slen >= 0)
 247             {
 248               cache_set (xprt, (u_long) slen);
 249             }
 250         }
 251     }
 252   return stat;
 253 }
 254
 255 static bool_t
 256 svcudp6_getargs (xprt, xdr_args, args_ptr)
 257      SVCXPRT *xprt;
 258      xdrproc_t xdr_args;
 259      caddr_t args_ptr;
 260 {
 261
 262   return (*xdr_args) (&(su_data (xprt)->su_xdrs), args_ptr);
 263 }
 264
 265 static bool_t
 266 svcudp6_freeargs (xprt, xdr_args, args_ptr)
 267      SVCXPRT *xprt;
 268      xdrproc_t xdr_args;
 269      caddr_t args_ptr;
 270 {
 271   XDR *xdrs = &(su_data (xprt)->su_xdrs);
 272
 273   xdrs->x_op = XDR_FREE;
 274   return (*xdr_args) (xdrs, args_ptr);
 275 }
 276
 277 static void
 278 svcudp6_destroy (xprt)
 279      SVCXPRT *xprt;
 280 {
 281   struct svcudp_data *su = su_data (xprt);
 282
 283   xprt_unregister (xprt);
 284   (void) __close (xprt->xp_sock);
 285   XDR_DESTROY (&(su->su_xdrs));
 286   mem_free (rpc_buffer (xprt), su->su_iosz);
 287   mem_free ((caddr_t) su, sizeof (struct svcudp_data));
 288   mem_free ((caddr_t) xprt, sizeof (SVCXPRT));
 289 }
 290
 291
 292 /***********this could be a separate file*********************/
 293
 294 /*
 295  * Fifo cache for udp server
 296  * Copies pointers to reply buffers into fifo cache
 297  * Buffers are sent again if retransmissions are detected.
 298  */
 299
 300 #define SPARSENESS 4            /* 75% sparse */
 301
 302 #define CACHE_PERROR(msg)       \
 303         (void) fprintf(stderr,"%s\n", msg)
 304
 305 #define ALLOC(type, size)       \
 306         (type *) mem_alloc((unsigned) (sizeof(type) * (size)))
 307
 308 #define BZERO(addr, type, size)  \
 309         __bzero((char *) addr, sizeof(type) * (int) (size))
 310
 311 /*
 312  * An entry in the cache
 313  */
 314 typedef struct cache_node *cache_ptr;
 315 struct cache_node
 316   {
 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_in6 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   {
 343     u_long uc_size;             /* size of cache */
 344     cache_ptr *uc_entries;      /* hash table of entries in cache */
 345     cache_ptr *uc_fifo;         /* fifo list of entries in cache */
 346     u_long uc_nextvictim;       /* points to next victim in fifo list */
 347     u_long uc_prog;             /* saved program number */
 348     u_long uc_vers;             /* saved version number */
 349     u_long uc_proc;             /* saved procedure number */
 350     struct sockaddr_in6 uc_addr;        /* saved caller's address */
 351   };
 352
 353
 354 /*
 355  * the hashing function
 356  */
 357 #define CACHE_LOC(transp, xid)  \
 358  (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))
 359
 360
 361 /*
 362  * Enable use of the cache.
 363  * Note: there is no disable.
 364  */
 365 int
 366 svcudp6_enablecache (SVCXPRT *transp, 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     {
 373       CACHE_PERROR (_("enablecache: cache already enabled"));
 374       return 0;
 375     }
 376   uc = ALLOC (struct udp_cache, 1);
 377   if (uc == NULL)
 378     {
 379       CACHE_PERROR (_("enablecache: could not allocate cache"));
 380       return 0;
 381     }
 382   uc->uc_size = size;
 383   uc->uc_nextvictim = 0;
 384   uc->uc_entries = ALLOC (cache_ptr, size * SPARSENESS);
 385   if (uc->uc_entries == NULL)
 386     {
 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     {
 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 (SVCXPRT *xprt, u_long replylen)
 408 {
 409   cache_ptr victim;
 410   cache_ptr *vicp;
 411   struct svcudp_data *su = su_data (xprt);
 412   struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 413   u_int loc;
 414   char *newbuf;
 415
 416   /*
 417    * Find space for the new entry, either by
 418    * reusing an old entry, or by mallocing a new one
 419    */
 420   victim = uc->uc_fifo[uc->uc_nextvictim];
 421   if (victim != NULL)
 422     {
 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         {
 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     }
 436   else
 437     {
 438       victim = ALLOC (struct cache_node, 1);
 439       if (victim == NULL)
 440         {
 441           CACHE_PERROR (_("cache_set: victim alloc failed"));
 442           return;
 443         }
 444       newbuf = mem_alloc (su->su_iosz);
 445       if (newbuf == NULL)
 446         {
 447           CACHE_PERROR (_("cache_set: could not allocate new rpc_buffer"));
 448           return;
 449         }
 450     }
 451
 452   /*
 453    * Store it away
 454    */
 455   victim->cache_replylen = replylen;
 456   victim->cache_reply = rpc_buffer (xprt);
 457   rpc_buffer (xprt) = newbuf;
 458   xdrmem_create (&(su->su_xdrs), rpc_buffer (xprt), su->su_iosz, XDR_ENCODE);
 459   victim->cache_xid = su->su_xid;
 460   victim->cache_proc = uc->uc_proc;
 461   victim->cache_vers = uc->uc_vers;
 462   victim->cache_prog = uc->uc_prog;
 463   victim->cache_addr = uc->uc_addr;
 464   loc = CACHE_LOC (xprt, victim->cache_xid);
 465   victim->cache_next = uc->uc_entries[loc];
 466   uc->uc_entries[loc] = victim;
 467   uc->uc_fifo[uc->uc_nextvictim++] = victim;
 468   uc->uc_nextvictim %= uc->uc_size;
 469 }
 470
 471 /*
 472  * Try to get an entry from the cache
 473  * return 1 if found, 0 if not found
 474  */
 475 static int
 476 cache_get (xprt, msg, replyp, replylenp)
 477      SVCXPRT *xprt;
 478      struct rpc_msg *msg;
 479      char **replyp;
 480      u_long *replylenp;
 481 {
 482   u_int loc;
 483   cache_ptr ent;
 484   struct svcudp_data *su = su_data (xprt);
 485   struct udp_cache *uc = (struct udp_cache *) su->su_cache;
 486
 487 #define EQADDR(a1, a2)  (memcmp((char*)&a1, (char*)&a2, sizeof(a1)) == 0)
 488
 489   loc = CACHE_LOC (xprt, su->su_xid);
 490   for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next)
 491     {
 492       if (ent->cache_xid == su->su_xid &&
 493           ent->cache_proc == uc->uc_proc &&
 494           ent->cache_vers == uc->uc_vers &&
 495           ent->cache_prog == uc->uc_prog &&
 496           EQADDR (ent->cache_addr, uc->uc_addr))
 497         {
 498           *replyp = ent->cache_reply;
 499           *replylenp = ent->cache_replylen;
 500           return 1;
 501         }
 502     }
 503   /*
 504    * Failed to find entry
 505    * Remember a few things so we can do a set later
 506    */
 507   uc->uc_proc = msg->rm_call.cb_proc;
 508   uc->uc_vers = msg->rm_call.cb_vers;
 509   uc->uc_prog = msg->rm_call.cb_prog;
 510   memcpy (&uc->uc_addr, &xprt->xp_raddr, sizeof (uc->uc_addr));
 511   return 0;
 512 }