sunrpc/clnt_udp.c

   1 /* @(#)clnt_udp.c       2.2 88/08/01 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[] = "@(#)clnt_udp.c 1.39 87/08/11 Copyr 1984 Sun Micro";
  32 #endif
  33
  34 /*
  35  * clnt_udp.c, Implements a UDP/IP based, client side RPC.
  36  *
  37  * Copyright (C) 1984, Sun Microsystems, Inc.
  38  */
  39
  40 #include <stdio.h>
  41 #include <unistd.h>
  42 #include <libintl.h>
  43 #include <rpc/rpc.h>
  44 #include <rpc/xdr.h>
  45 #include <rpc/clnt.h>
  46 #include <sys/poll.h>
  47 #include <sys/socket.h>
  48 #include <sys/ioctl.h>
  49 #include <netdb.h>
  50 #include <errno.h>
  51 #include <rpc/pmap_clnt.h>
  52 #include <net/if.h>
  53
  54 extern bool_t xdr_opaque_auth (XDR *, struct opaque_auth *);
  55 extern u_long _create_xid (void);
  56
  57 /*
  58  * UDP bases client side rpc operations
  59  */
  60 static enum clnt_stat clntudp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  61                                     xdrproc_t, caddr_t, struct timeval);
  62 static void clntudp_abort (void);
  63 static void clntudp_geterr (CLIENT *, struct rpc_err *);
  64 static bool_t clntudp_freeres (CLIENT *, xdrproc_t, caddr_t);
  65 static bool_t clntudp_control (CLIENT *, int, char *);
  66 static void clntudp_destroy (CLIENT *);
  67
  68 static struct clnt_ops udp_ops =
  69 {
  70   clntudp_call,
  71   clntudp_abort,
  72   clntudp_geterr,
  73   clntudp_freeres,
  74   clntudp_destroy,
  75   clntudp_control
  76 };
  77
  78 /*
  79  * Private data kept per client handle
  80  */
  81 struct cu_data
  82   {
  83     int cu_sock;
  84     bool_t cu_closeit;
  85     struct sockaddr_in cu_raddr;
  86     int cu_rlen;
  87     struct timeval cu_wait;
  88     struct timeval cu_total;
  89     struct rpc_err cu_error;
  90     XDR cu_outxdrs;
  91     u_int cu_xdrpos;
  92     u_int cu_sendsz;
  93     char *cu_outbuf;
  94     u_int cu_recvsz;
  95     char cu_inbuf[1];
  96   };
  97
  98 /*
  99  * Create a UDP based client handle.
 100  * If *sockp<0, *sockp is set to a newly created UPD socket.
 101  * If raddr->sin_port is 0 a binder on the remote machine
 102  * is consulted for the correct port number.
 103  * NB: It is the clients responsibility to close *sockp.
 104  * NB: The rpch->cl_auth is initialized to null authentication.
 105  *     Caller may wish to set this something more useful.
 106  *
 107  * wait is the amount of time used between retransmitting a call if
 108  * no response has been heard; retransmission occurs until the actual
 109  * rpc call times out.
 110  *
 111  * sendsz and recvsz are the maximum allowable packet sizes that can be
 112  * sent and received.
 113  */
 114 CLIENT *
 115 clntudp_bufcreate (struct sockaddr_in *raddr, u_long program, u_long version,
 116                    struct timeval wait, int *sockp, u_int sendsz,
 117                    u_int recvsz)
 118 {
 119   CLIENT *cl;
 120   struct cu_data *cu = NULL;
 121   struct rpc_msg call_msg;
 122
 123   cl = (CLIENT *) mem_alloc (sizeof (CLIENT));
 124   if (cl == NULL)
 125     {
 126       (void) fprintf (stderr, _("clntudp_create: out of memory\n"));
 127       rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 128       rpc_createerr.cf_error.re_errno = errno;
 129       goto fooy;
 130     }
 131   sendsz = ((sendsz + 3) / 4) * 4;
 132   recvsz = ((recvsz + 3) / 4) * 4;
 133   cu = (struct cu_data *) mem_alloc (sizeof (*cu) + sendsz + recvsz);
 134   if (cu == NULL)
 135     {
 136       (void) fprintf (stderr, _("clntudp_create: out of memory\n"));
 137       rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 138       rpc_createerr.cf_error.re_errno = errno;
 139       goto fooy;
 140     }
 141   cu->cu_outbuf = &cu->cu_inbuf[recvsz];
 142
 143   if (raddr->sin_port == 0)
 144     {
 145       u_short port;
 146       if ((port =
 147            pmap_getport (raddr, program, version, IPPROTO_UDP)) == 0)
 148         {
 149           goto fooy;
 150         }
 151       raddr->sin_port = htons (port);
 152     }
 153   cl->cl_ops = &udp_ops;
 154   cl->cl_private = (caddr_t) cu;
 155   cu->cu_raddr = *raddr;
 156   cu->cu_rlen = sizeof (cu->cu_raddr);
 157   cu->cu_wait = wait;
 158   cu->cu_total.tv_sec = -1;
 159   cu->cu_total.tv_usec = -1;
 160   cu->cu_sendsz = sendsz;
 161   cu->cu_recvsz = recvsz;
 162   call_msg.rm_xid = _create_xid ();
 163   call_msg.rm_direction = CALL;
 164   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 165   call_msg.rm_call.cb_prog = program;
 166   call_msg.rm_call.cb_vers = version;
 167   xdrmem_create (&(cu->cu_outxdrs), cu->cu_outbuf,
 168                  sendsz, XDR_ENCODE);
 169   if (!xdr_callhdr (&(cu->cu_outxdrs), &call_msg))
 170     {
 171       goto fooy;
 172     }
 173   cu->cu_xdrpos = XDR_GETPOS (&(cu->cu_outxdrs));
 174   if (*sockp < 0)
 175     {
 176       int dontblock = 1;
 177
 178       *sockp = __socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 179       if (*sockp < 0)
 180         {
 181           rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 182           rpc_createerr.cf_error.re_errno = errno;
 183           goto fooy;
 184         }
 185       /* attempt to bind to prov port */
 186       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 187       /* the sockets rpc controls are non-blocking */
 188       (void) __ioctl (*sockp, FIONBIO, (char *) &dontblock);
 189       cu->cu_closeit = TRUE;
 190     }
 191   else
 192     {
 193       cu->cu_closeit = FALSE;
 194     }
 195   cu->cu_sock = *sockp;
 196   cl->cl_auth = authnone_create ();
 197   return cl;
 198 fooy:
 199   if (cu)
 200     mem_free ((caddr_t) cu, sizeof (*cu) + sendsz + recvsz);
 201   if (cl)
 202     mem_free ((caddr_t) cl, sizeof (CLIENT));
 203   return (CLIENT *) NULL;
 204 }
 205
 206 CLIENT *
 207 clntudp_create (raddr, program, version, wait, sockp)
 208      struct sockaddr_in *raddr;
 209      u_long program;
 210      u_long version;
 211      struct timeval wait;
 212      int *sockp;
 213 {
 214
 215   return clntudp_bufcreate (raddr, program, version, wait, sockp,
 216                             UDPMSGSIZE, UDPMSGSIZE);
 217 }
 218
 219 static int
 220 is_network_up (int sock)
 221 {
 222   struct ifconf ifc;
 223   char buf[UDPMSGSIZE];
 224   struct ifreq ifreq, *ifr;
 225   int n;
 226
 227   ifc.ifc_len = sizeof (buf);
 228   ifc.ifc_buf = buf;
 229   if (__ioctl(sock, SIOCGIFCONF, (char *) &ifc) == 0)
 230     {
 231       ifr = ifc.ifc_req;
 232       for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; n--, ifr++)
 233         {
 234           ifreq = *ifr;
 235           if (__ioctl (sock, SIOCGIFFLAGS, (char *) &ifreq) < 0)
 236             break;
 237
 238           if ((ifreq.ifr_flags & IFF_UP)
 239               && ifr->ifr_addr.sa_family == AF_INET)
 240             return 1;
 241         }
 242     }
 243   return 0;
 244 }
 245
 246 static enum clnt_stat
 247 clntudp_call (cl, proc, xargs, argsp, xresults, resultsp, utimeout)
 248      CLIENT *cl;        /* client handle */
 249      u_long proc;               /* procedure number */
 250      xdrproc_t xargs;           /* xdr routine for args */
 251      caddr_t argsp;             /* pointer to args */
 252      xdrproc_t xresults;        /* xdr routine for results */
 253      caddr_t resultsp;          /* pointer to results */
 254      struct timeval utimeout;   /* seconds to wait before giving up */
 255 {
 256   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 257   XDR *xdrs;
 258   int outlen = 0;
 259   int inlen;
 260   socklen_t fromlen;
 261   struct pollfd fd;
 262   int milliseconds = (cu->cu_wait.tv_sec * 1000) +
 263     (cu->cu_wait.tv_usec / 1000);
 264   struct sockaddr_in from;
 265   struct rpc_msg reply_msg;
 266   XDR reply_xdrs;
 267   struct timeval time_waited;
 268   bool_t ok;
 269   int nrefreshes = 2;           /* number of times to refresh cred */
 270   struct timeval timeout;
 271   int anyup;                    /* any network interface up */
 272
 273   if (cu->cu_total.tv_usec == -1)
 274     {
 275       timeout = utimeout;       /* use supplied timeout */
 276     }
 277   else
 278     {
 279       timeout = cu->cu_total;   /* use default timeout */
 280     }
 281
 282   time_waited.tv_sec = 0;
 283   time_waited.tv_usec = 0;
 284 call_again:
 285   xdrs = &(cu->cu_outxdrs);
 286   if (xargs == NULL)
 287     goto get_reply;
 288   xdrs->x_op = XDR_ENCODE;
 289   XDR_SETPOS (xdrs, cu->cu_xdrpos);
 290   /*
 291    * the transaction is the first thing in the out buffer
 292    */
 293   (*(uint32_t *) (cu->cu_outbuf))++;
 294   if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 295       (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||
 296       (!(*xargs) (xdrs, argsp)))
 297     return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
 298   outlen = (int) XDR_GETPOS (xdrs);
 299
 300 send_again:
 301   if (sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,
 302               (struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)
 303       != outlen)
 304     {
 305       cu->cu_error.re_errno = errno;
 306       return (cu->cu_error.re_status = RPC_CANTSEND);
 307     }
 308
 309   /*
 310    * Hack to provide rpc-based message passing
 311    */
 312   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 313     {
 314       return (cu->cu_error.re_status = RPC_TIMEDOUT);
 315     }
 316  get_reply:
 317   /*
 318    * sub-optimal code appears here because we have
 319    * some clock time to spare while the packets are in flight.
 320    * (We assume that this is actually only executed once.)
 321    */
 322   reply_msg.acpted_rply.ar_verf = _null_auth;
 323   reply_msg.acpted_rply.ar_results.where = resultsp;
 324   reply_msg.acpted_rply.ar_results.proc = xresults;
 325   fd.fd = cu->cu_sock;
 326   fd.events = POLLIN;
 327   anyup = 0;
 328   for (;;)
 329     {
 330       switch (__poll (&fd, 1, milliseconds))
 331         {
 332
 333         case 0:
 334           if (anyup == 0)
 335             {
 336               anyup = is_network_up (cu->cu_sock);
 337               if (!anyup)
 338                 return (cu->cu_error.re_status = RPC_CANTRECV);
 339             }
 340
 341           time_waited.tv_sec += cu->cu_wait.tv_sec;
 342           time_waited.tv_usec += cu->cu_wait.tv_usec;
 343           while (time_waited.tv_usec >= 1000000)
 344             {
 345               time_waited.tv_sec++;
 346               time_waited.tv_usec -= 1000000;
 347             }
 348           if ((time_waited.tv_sec < timeout.tv_sec) ||
 349               ((time_waited.tv_sec == timeout.tv_sec) &&
 350                (time_waited.tv_usec < timeout.tv_usec)))
 351             goto send_again;
 352           return (cu->cu_error.re_status = RPC_TIMEDOUT);
 353
 354           /*
 355            * buggy in other cases because time_waited is not being
 356            * updated.
 357            */
 358         case -1:
 359           if (errno == EINTR)
 360             continue;
 361           cu->cu_error.re_errno = errno;
 362           return (cu->cu_error.re_status = RPC_CANTRECV);
 363         }
 364       do
 365         {
 366           fromlen = sizeof (struct sockaddr);
 367           inlen = recvfrom (cu->cu_sock, cu->cu_inbuf,
 368                             (int) cu->cu_recvsz, 0,
 369                             (struct sockaddr *) &from, &fromlen);
 370         }
 371       while (inlen < 0 && errno == EINTR);
 372       if (inlen < 0)
 373         {
 374           if (errno == EWOULDBLOCK)
 375             continue;
 376           cu->cu_error.re_errno = errno;
 377           return (cu->cu_error.re_status = RPC_CANTRECV);
 378         }
 379       if (inlen < 4)
 380         continue;
 381
 382       /* see if reply transaction id matches sent id.
 383         Don't do this if we only wait for a replay */
 384       if (xargs != NULL
 385           && (*((u_int32_t *) (cu->cu_inbuf))
 386               != *((u_int32_t *) (cu->cu_outbuf))))
 387         continue;
 388       /* we now assume we have the proper reply */
 389       break;
 390     }
 391
 392   /*
 393    * now decode and validate the response
 394    */
 395   xdrmem_create (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);
 396   ok = xdr_replymsg (&reply_xdrs, &reply_msg);
 397   /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
 398   if (ok)
 399     {
 400       _seterr_reply (&reply_msg, &(cu->cu_error));
 401       if (cu->cu_error.re_status == RPC_SUCCESS)
 402         {
 403           if (!AUTH_VALIDATE (cl->cl_auth,
 404                               &reply_msg.acpted_rply.ar_verf))
 405             {
 406               cu->cu_error.re_status = RPC_AUTHERROR;
 407               cu->cu_error.re_why = AUTH_INVALIDRESP;
 408             }
 409           if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 410             {
 411               xdrs->x_op = XDR_FREE;
 412               (void) xdr_opaque_auth (xdrs,
 413                                       &(reply_msg.acpted_rply.ar_verf));
 414             }
 415         }                       /* end successful completion */
 416       else
 417         {
 418           /* maybe our credentials need to be refreshed ... */
 419           if (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))
 420             {
 421               nrefreshes--;
 422               goto call_again;
 423             }
 424         }                       /* end of unsuccessful completion */
 425     }                           /* end of valid reply message */
 426   else
 427     {
 428       cu->cu_error.re_status = RPC_CANTDECODERES;
 429     }
 430   return cu->cu_error.re_status;
 431 }
 432
 433 static void
 434 clntudp_geterr (CLIENT *cl, struct rpc_err *errp)
 435 {
 436   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 437
 438   *errp = cu->cu_error;
 439 }
 440
 441
 442 static bool_t
 443 clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 444 {
 445   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 446   XDR *xdrs = &(cu->cu_outxdrs);
 447
 448   xdrs->x_op = XDR_FREE;
 449   return (*xdr_res) (xdrs, res_ptr);
 450 }
 451
 452 static void
 453 clntudp_abort (void)
 454 {
 455 }
 456
 457 static bool_t
 458 clntudp_control (CLIENT *cl, int request, char *info)
 459 {
 460   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 461
 462   switch (request)
 463     {
 464     case CLSET_FD_CLOSE:
 465       cu->cu_closeit = TRUE;
 466       break;
 467     case CLSET_FD_NCLOSE:
 468       cu->cu_closeit = FALSE;
 469       break;
 470     case CLSET_TIMEOUT:
 471       cu->cu_total = *(struct timeval *) info;
 472       break;
 473     case CLGET_TIMEOUT:
 474       *(struct timeval *) info = cu->cu_total;
 475       break;
 476     case CLSET_RETRY_TIMEOUT:
 477       cu->cu_wait = *(struct timeval *) info;
 478       break;
 479     case CLGET_RETRY_TIMEOUT:
 480       *(struct timeval *) info = cu->cu_wait;
 481       break;
 482     case CLGET_SERVER_ADDR:
 483       *(struct sockaddr_in *) info = cu->cu_raddr;
 484       break;
 485     case CLGET_FD:
 486       *(int *)info = cu->cu_sock;
 487       break;
 488     case CLGET_XID:
 489       /*
 490        * use the knowledge that xid is the
 491        * first element in the call structure *.
 492        * This will get the xid of the PREVIOUS call
 493        */
 494       *(u_long *)info = ntohl(*(u_long *)cu->cu_outbuf);
 495       break;
 496     case CLSET_XID:
 497       /* This will set the xid of the NEXT call */
 498       *(u_long *)cu->cu_outbuf =  htonl(*(u_long *)info - 1);
 499       /* decrement by 1 as clntudp_call() increments once */
 500     case CLGET_VERS:
 501       /*
 502        * This RELIES on the information that, in the call body,
 503        * the version number field is the fifth field from the
 504        * begining of the RPC header. MUST be changed if the
 505        * call_struct is changed
 506        */
 507       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 508                                           4 * BYTES_PER_XDR_UNIT));
 509       break;
 510     case CLSET_VERS:
 511       *(u_long *)(cu->cu_outbuf + 4 * BYTES_PER_XDR_UNIT)
 512         = htonl(*(u_long *)info);
 513       break;
 514     case CLGET_PROG:
 515       /*
 516        * This RELIES on the information that, in the call body,
 517        * the program number field is the  field from the
 518        * begining of the RPC header. MUST be changed if the
 519        * call_struct is changed
 520        */
 521       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 522                                           3 * BYTES_PER_XDR_UNIT));
 523       break;
 524     case CLSET_PROG:
 525       *(u_long *)(cu->cu_outbuf + 3 * BYTES_PER_XDR_UNIT)
 526         = htonl(*(u_long *)info);
 527       break;
 528     /* The following are only possible with TI-RPC */
 529     case CLGET_SVC_ADDR:
 530     case CLSET_SVC_ADDR:
 531     case CLSET_PUSH_TIMOD:
 532     case CLSET_POP_TIMOD:
 533     default:
 534       return FALSE;
 535     }
 536   return TRUE;
 537 }
 538
 539 static void
 540 clntudp_destroy (CLIENT *cl)
 541 {
 542   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 543
 544   if (cu->cu_closeit)
 545     {
 546       (void) __close (cu->cu_sock);
 547     }
 548   XDR_DESTROY (&(cu->cu_outxdrs));
 549   mem_free ((caddr_t) cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
 550   mem_free ((caddr_t) cl, sizeof (CLIENT));
 551 }