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 <rpc/rpc.h>
  43 #include <rpc/xdr.h>
  44 #include <rpc/clnt.h>
  45 #include <sys/socket.h>
  46 #include <sys/ioctl.h>
  47 #include <netdb.h>
  48 #include <errno.h>
  49 #include <rpc/pmap_clnt.h>
  50
  51 extern bool_t xdr_opaque_auth (XDR *, struct opaque_auth *);
  52
  53 /*
  54  * UDP bases client side rpc operations
  55  */
  56 static enum clnt_stat clntudp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  57                                     xdrproc_t, caddr_t, struct timeval);
  58 static void clntudp_abort (void);
  59 static void clntudp_geterr (CLIENT *, struct rpc_err *);
  60 static bool_t clntudp_freeres (CLIENT *, xdrproc_t, caddr_t);
  61 static bool_t clntudp_control (CLIENT *, int, char *);
  62 static void clntudp_destroy (CLIENT *);
  63
  64 static struct clnt_ops udp_ops =
  65 {
  66   clntudp_call,
  67   clntudp_abort,
  68   clntudp_geterr,
  69   clntudp_freeres,
  70   clntudp_destroy,
  71   clntudp_control
  72 };
  73
  74 /*
  75  * Private data kept per client handle
  76  */
  77 struct cu_data
  78   {
  79     int cu_sock;
  80     bool_t cu_closeit;
  81     struct sockaddr_in cu_raddr;
  82     int cu_rlen;
  83     struct timeval cu_wait;
  84     struct timeval cu_total;
  85     struct rpc_err cu_error;
  86     XDR cu_outxdrs;
  87     u_int cu_xdrpos;
  88     u_int cu_sendsz;
  89     char *cu_outbuf;
  90     u_int cu_recvsz;
  91     char cu_inbuf[1];
  92   };
  93
  94 /*
  95  * Create a UDP based client handle.
  96  * If *sockp<0, *sockp is set to a newly created UPD socket.
  97  * If raddr->sin_port is 0 a binder on the remote machine
  98  * is consulted for the correct port number.
  99  * NB: It is the clients responsibility to close *sockp.
 100  * NB: The rpch->cl_auth is initialized to null authentication.
 101  *     Caller may wish to set this something more useful.
 102  *
 103  * wait is the amount of time used between retransmitting a call if
 104  * no response has been heard; retransmission occurs until the actual
 105  * rpc call times out.
 106  *
 107  * sendsz and recvsz are the maximum allowable packet sizes that can be
 108  * sent and received.
 109  */
 110 CLIENT *
 111 clntudp_bufcreate (raddr, program, version, wait, sockp, sendsz, recvsz)
 112      struct sockaddr_in *raddr;
 113      u_long program;
 114      u_long version;
 115      struct timeval wait;
 116      int *sockp;
 117      u_int sendsz;
 118      u_int recvsz;
 119 {
 120   CLIENT *cl;
 121   struct cu_data *cu = NULL;
 122   struct timeval now;
 123   struct rpc_msg call_msg;
 124
 125   cl = (CLIENT *) mem_alloc (sizeof (CLIENT));
 126   if (cl == NULL)
 127     {
 128       (void) fprintf (stderr, _("clntudp_create: out of memory\n"));
 129       rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 130       rpc_createerr.cf_error.re_errno = errno;
 131       goto fooy;
 132     }
 133   sendsz = ((sendsz + 3) / 4) * 4;
 134   recvsz = ((recvsz + 3) / 4) * 4;
 135   cu = (struct cu_data *) mem_alloc (sizeof (*cu) + sendsz + recvsz);
 136   if (cu == NULL)
 137     {
 138       (void) fprintf (stderr, _("clntudp_create: out of memory\n"));
 139       rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 140       rpc_createerr.cf_error.re_errno = errno;
 141       goto fooy;
 142     }
 143   cu->cu_outbuf = &cu->cu_inbuf[recvsz];
 144
 145   (void) gettimeofday (&now, (struct timezone *) 0);
 146   if (raddr->sin_port == 0)
 147     {
 148       u_short port;
 149       if ((port =
 150            pmap_getport (raddr, program, version, IPPROTO_UDP)) == 0)
 151         {
 152           goto fooy;
 153         }
 154       raddr->sin_port = htons (port);
 155     }
 156   cl->cl_ops = &udp_ops;
 157   cl->cl_private = (caddr_t) cu;
 158   cu->cu_raddr = *raddr;
 159   cu->cu_rlen = sizeof (cu->cu_raddr);
 160   cu->cu_wait = wait;
 161   cu->cu_total.tv_sec = -1;
 162   cu->cu_total.tv_usec = -1;
 163   cu->cu_sendsz = sendsz;
 164   cu->cu_recvsz = recvsz;
 165   call_msg.rm_xid = getpid () ^ now.tv_sec ^ now.tv_usec;
 166   call_msg.rm_direction = CALL;
 167   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 168   call_msg.rm_call.cb_prog = program;
 169   call_msg.rm_call.cb_vers = version;
 170   xdrmem_create (&(cu->cu_outxdrs), cu->cu_outbuf,
 171                  sendsz, XDR_ENCODE);
 172   if (!xdr_callhdr (&(cu->cu_outxdrs), &call_msg))
 173     {
 174       goto fooy;
 175     }
 176   cu->cu_xdrpos = XDR_GETPOS (&(cu->cu_outxdrs));
 177   if (*sockp < 0)
 178     {
 179       int dontblock = 1;
 180
 181       *sockp = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 182       if (*sockp < 0)
 183         {
 184           rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 185           rpc_createerr.cf_error.re_errno = errno;
 186           goto fooy;
 187         }
 188       /* attempt to bind to prov port */
 189       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 190       /* the sockets rpc controls are non-blocking */
 191       (void) ioctl (*sockp, FIONBIO, (char *) &dontblock);
 192       cu->cu_closeit = TRUE;
 193     }
 194   else
 195     {
 196       cu->cu_closeit = FALSE;
 197     }
 198   cu->cu_sock = *sockp;
 199   cl->cl_auth = authnone_create ();
 200   return cl;
 201 fooy:
 202   if (cu)
 203     mem_free ((caddr_t) cu, sizeof (*cu) + sendsz + recvsz);
 204   if (cl)
 205     mem_free ((caddr_t) cl, sizeof (CLIENT));
 206   return (CLIENT *) NULL;
 207 }
 208
 209 CLIENT *
 210 clntudp_create (raddr, program, version, wait, sockp)
 211      struct sockaddr_in *raddr;
 212      u_long program;
 213      u_long version;
 214      struct timeval wait;
 215      int *sockp;
 216 {
 217
 218   return clntudp_bufcreate (raddr, program, version, wait, sockp,
 219                             UDPMSGSIZE, UDPMSGSIZE);
 220 }
 221
 222 static enum clnt_stat
 223 clntudp_call (cl, proc, xargs, argsp, xresults, resultsp, utimeout)
 224      CLIENT *cl;        /* client handle */
 225      u_long proc;               /* procedure number */
 226      xdrproc_t xargs;           /* xdr routine for args */
 227      caddr_t argsp;             /* pointer to args */
 228      xdrproc_t xresults;        /* xdr routine for results */
 229      caddr_t resultsp;          /* pointer to results */
 230      struct timeval utimeout;   /* seconds to wait before giving up */
 231 {
 232   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 233   XDR *xdrs;
 234   int outlen = 0;
 235   int inlen;
 236   size_t fromlen;
 237 #ifdef FD_SETSIZE
 238   fd_set readfds;
 239   fd_set mask;
 240 #else
 241   int readfds;
 242   int mask;
 243 #endif /* def FD_SETSIZE */
 244   struct sockaddr_in from;
 245   struct rpc_msg reply_msg;
 246   XDR reply_xdrs;
 247   struct timeval time_waited;
 248   bool_t ok;
 249   int nrefreshes = 2;           /* number of times to refresh cred */
 250   struct timeval timeout;
 251
 252   if (cu->cu_total.tv_usec == -1)
 253     {
 254       timeout = utimeout;       /* use supplied timeout */
 255     }
 256   else
 257     {
 258       timeout = cu->cu_total;   /* use default timeout */
 259     }
 260
 261   time_waited.tv_sec = 0;
 262   time_waited.tv_usec = 0;
 263 call_again:
 264   xdrs = &(cu->cu_outxdrs);
 265   if (xargs == NULL)
 266     goto get_reply;
 267   xdrs->x_op = XDR_ENCODE;
 268   XDR_SETPOS (xdrs, cu->cu_xdrpos);
 269   /*
 270    * the transaction is the first thing in the out buffer
 271    */
 272   (*(u_short *) (cu->cu_outbuf))++;
 273   if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 274       (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||
 275       (!(*xargs) (xdrs, argsp)))
 276     return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
 277   outlen = (int) XDR_GETPOS (xdrs);
 278
 279 send_again:
 280   if (sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,
 281               (struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)
 282       != outlen)
 283     {
 284       cu->cu_error.re_errno = errno;
 285       return (cu->cu_error.re_status = RPC_CANTSEND);
 286     }
 287
 288   /*
 289    * Hack to provide rpc-based message passing
 290    */
 291   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 292     {
 293       return (cu->cu_error.re_status = RPC_TIMEDOUT);
 294     }
 295  get_reply:
 296   /*
 297    * sub-optimal code appears here because we have
 298    * some clock time to spare while the packets are in flight.
 299    * (We assume that this is actually only executed once.)
 300    */
 301   reply_msg.acpted_rply.ar_verf = _null_auth;
 302   reply_msg.acpted_rply.ar_results.where = resultsp;
 303   reply_msg.acpted_rply.ar_results.proc = xresults;
 304 #ifdef FD_SETSIZE
 305   FD_ZERO (&mask);
 306   FD_SET (cu->cu_sock, &mask);
 307 #else
 308   mask = 1 << cu->cu_sock;
 309 #endif /* def FD_SETSIZE */
 310   for (;;)
 311     {
 312       struct timeval timeout = cu->cu_wait;
 313       readfds = mask;
 314       switch (select (_rpc_dtablesize (), &readfds, (fd_set*) NULL,
 315                       (fd_set*) NULL, &timeout))
 316         {
 317
 318         case 0:
 319           time_waited.tv_sec += cu->cu_wait.tv_sec;
 320           time_waited.tv_usec += cu->cu_wait.tv_usec;
 321           while (time_waited.tv_usec >= 1000000)
 322             {
 323               time_waited.tv_sec++;
 324               time_waited.tv_usec -= 1000000;
 325             }
 326           if ((time_waited.tv_sec < timeout.tv_sec) ||
 327               ((time_waited.tv_sec == timeout.tv_sec) &&
 328                (time_waited.tv_usec < timeout.tv_usec)))
 329             goto send_again;
 330           return (cu->cu_error.re_status = RPC_TIMEDOUT);
 331
 332           /*
 333            * buggy in other cases because time_waited is not being
 334            * updated.
 335            */
 336         case -1:
 337           if (errno == EINTR)
 338             continue;
 339           cu->cu_error.re_errno = errno;
 340           return (cu->cu_error.re_status = RPC_CANTRECV);
 341         }
 342       do
 343         {
 344           fromlen = sizeof (struct sockaddr);
 345           inlen = recvfrom (cu->cu_sock, cu->cu_inbuf,
 346                             (int) cu->cu_recvsz, 0,
 347                             (struct sockaddr *) &from, &fromlen);
 348         }
 349       while (inlen < 0 && errno == EINTR);
 350       if (inlen < 0)
 351         {
 352           if (errno == EWOULDBLOCK)
 353             continue;
 354           cu->cu_error.re_errno = errno;
 355           return (cu->cu_error.re_status = RPC_CANTRECV);
 356         }
 357       if (inlen < 4)
 358         continue;
 359       /* see if reply transaction id matches sent id */
 360       if (*((u_int32_t *) (cu->cu_inbuf)) != *((u_int32_t *) (cu->cu_outbuf)))
 361         continue;
 362       /* we now assume we have the proper reply */
 363       break;
 364     }
 365
 366   /*
 367    * now decode and validate the response
 368    */
 369   xdrmem_create (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);
 370   ok = xdr_replymsg (&reply_xdrs, &reply_msg);
 371   /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
 372   if (ok)
 373     {
 374       _seterr_reply (&reply_msg, &(cu->cu_error));
 375       if (cu->cu_error.re_status == RPC_SUCCESS)
 376         {
 377           if (!AUTH_VALIDATE (cl->cl_auth,
 378                               &reply_msg.acpted_rply.ar_verf))
 379             {
 380               cu->cu_error.re_status = RPC_AUTHERROR;
 381               cu->cu_error.re_why = AUTH_INVALIDRESP;
 382             }
 383           if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 384             {
 385               xdrs->x_op = XDR_FREE;
 386               (void) xdr_opaque_auth (xdrs,
 387                                       &(reply_msg.acpted_rply.ar_verf));
 388             }
 389         }                       /* end successful completion */
 390       else
 391         {
 392           /* maybe our credentials need to be refreshed ... */
 393           if (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))
 394             {
 395               nrefreshes--;
 396               goto call_again;
 397             }
 398         }                       /* end of unsuccessful completion */
 399     }                           /* end of valid reply message */
 400   else
 401     {
 402       cu->cu_error.re_status = RPC_CANTDECODERES;
 403     }
 404   return cu->cu_error.re_status;
 405 }
 406
 407 static void
 408 clntudp_geterr (CLIENT *cl, struct rpc_err *errp)
 409 {
 410   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 411
 412   *errp = cu->cu_error;
 413 }
 414
 415
 416 static bool_t
 417 clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 418 {
 419   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 420   XDR *xdrs = &(cu->cu_outxdrs);
 421
 422   xdrs->x_op = XDR_FREE;
 423   return (*xdr_res) (xdrs, res_ptr);
 424 }
 425
 426 static void
 427 clntudp_abort (void)
 428 {
 429 }
 430
 431 static bool_t
 432 clntudp_control (CLIENT *cl, int request, char *info)
 433 {
 434   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 435
 436   switch (request)
 437     {
 438     case CLSET_TIMEOUT:
 439       cu->cu_total = *(struct timeval *) info;
 440       break;
 441     case CLGET_TIMEOUT:
 442       *(struct timeval *) info = cu->cu_total;
 443       break;
 444     case CLSET_RETRY_TIMEOUT:
 445       cu->cu_wait = *(struct timeval *) info;
 446       break;
 447     case CLGET_RETRY_TIMEOUT:
 448       *(struct timeval *) info = cu->cu_wait;
 449       break;
 450     case CLGET_SERVER_ADDR:
 451       *(struct sockaddr_in *) info = cu->cu_raddr;
 452       break;
 453     default:
 454       return FALSE;
 455     }
 456   return TRUE;
 457 }
 458
 459 static void
 460 clntudp_destroy (CLIENT *cl)
 461 {
 462   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 463
 464   if (cu->cu_closeit)
 465     {
 466       (void) close (cu->cu_sock);
 467     }
 468   XDR_DESTROY (&(cu->cu_outxdrs));
 469   mem_free ((caddr_t) cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
 470   mem_free ((caddr_t) cl, sizeof (CLIENT));
 471 }