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 #include <ifaddrs.h>
  54 #ifdef USE_IN_LIBIO
  55 # include <wchar.h>
  56 #endif
  57
  58 #ifdef IP_RECVERR
  59 #include <errqueue.h>
  60 #include <sys/uio.h>
  61 #endif
  62
  63 extern bool_t xdr_opaque_auth (XDR *, struct opaque_auth *);
  64 extern u_long _create_xid (void);
  65
  66 /*
  67  * UDP bases client side rpc operations
  68  */
  69 static enum clnt_stat clntudp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  70                                     xdrproc_t, caddr_t, struct timeval);
  71 static void clntudp_abort (void);
  72 static void clntudp_geterr (CLIENT *, struct rpc_err *);
  73 static bool_t clntudp_freeres (CLIENT *, xdrproc_t, caddr_t);
  74 static bool_t clntudp_control (CLIENT *, int, char *);
  75 static void clntudp_destroy (CLIENT *);
  76
  77 static const struct clnt_ops udp_ops =
  78 {
  79   clntudp_call,
  80   clntudp_abort,
  81   clntudp_geterr,
  82   clntudp_freeres,
  83   clntudp_destroy,
  84   clntudp_control
  85 };
  86
  87 /*
  88  * Private data kept per client handle
  89  */
  90 struct cu_data
  91   {
  92     int cu_sock;
  93     bool_t cu_closeit;
  94     struct sockaddr_in cu_raddr;
  95     int cu_rlen;
  96     struct timeval cu_wait;
  97     struct timeval cu_total;
  98     struct rpc_err cu_error;
  99     XDR cu_outxdrs;
 100     u_int cu_xdrpos;
 101     u_int cu_sendsz;
 102     char *cu_outbuf;
 103     u_int cu_recvsz;
 104     char cu_inbuf[1];
 105   };
 106
 107 /*
 108  * Create a UDP based client handle.
 109  * If *sockp<0, *sockp is set to a newly created UPD socket.
 110  * If raddr->sin_port is 0 a binder on the remote machine
 111  * is consulted for the correct port number.
 112  * NB: It is the clients responsibility to close *sockp.
 113  * NB: The rpch->cl_auth is initialized to null authentication.
 114  *     Caller may wish to set this something more useful.
 115  *
 116  * wait is the amount of time used between retransmitting a call if
 117  * no response has been heard; retransmission occurs until the actual
 118  * rpc call times out.
 119  *
 120  * sendsz and recvsz are the maximum allowable packet sizes that can be
 121  * sent and received.
 122  */
 123 CLIENT *
 124 clntudp_bufcreate (struct sockaddr_in *raddr, u_long program, u_long version,
 125                    struct timeval wait, int *sockp, u_int sendsz,
 126                    u_int recvsz)
 127 {
 128   CLIENT *cl;
 129   struct cu_data *cu = NULL;
 130   struct rpc_msg call_msg;
 131
 132   cl = (CLIENT *) mem_alloc (sizeof (CLIENT));
 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 (cl == NULL || cu == NULL)
 137     {
 138       struct rpc_createerr *ce = &get_rpc_createerr ();
 139       (void) __fxprintf (NULL, "%s", _("clntudp_create: out of memory\n"));
 140       ce->cf_stat = RPC_SYSTEMERROR;
 141       ce->cf_error.re_errno = ENOMEM;
 142       goto fooy;
 143     }
 144   cu->cu_outbuf = &cu->cu_inbuf[recvsz];
 145
 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 = (struct clnt_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 = _create_xid ();
 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   INTUSE(xdrmem_create) (&(cu->cu_outxdrs), cu->cu_outbuf, sendsz, XDR_ENCODE);
 171   if (!INTUSE(xdr_callhdr) (&(cu->cu_outxdrs), &call_msg))
 172     {
 173       goto fooy;
 174     }
 175   cu->cu_xdrpos = XDR_GETPOS (&(cu->cu_outxdrs));
 176   if (*sockp < 0)
 177     {
 178       int dontblock = 1;
 179
 180       *sockp = __socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 181       if (*sockp < 0)
 182         {
 183           struct rpc_createerr *ce = &get_rpc_createerr ();
 184           ce->cf_stat = RPC_SYSTEMERROR;
 185           ce->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 #ifdef IP_RECVERR
 193       {
 194         int on = 1;
 195         __setsockopt (*sockp, SOL_IP, IP_RECVERR, &on, sizeof(on));
 196       }
 197 #endif
 198       cu->cu_closeit = TRUE;
 199     }
 200   else
 201     {
 202       cu->cu_closeit = FALSE;
 203     }
 204   cu->cu_sock = *sockp;
 205   cl->cl_auth = INTUSE(authnone_create) ();
 206   return cl;
 207 fooy:
 208   if (cu)
 209     mem_free ((caddr_t) cu, sizeof (*cu) + sendsz + recvsz);
 210   if (cl)
 211     mem_free ((caddr_t) cl, sizeof (CLIENT));
 212   return (CLIENT *) NULL;
 213 }
 214 INTDEF (clntudp_bufcreate)
 215
 216 CLIENT *
 217 clntudp_create (raddr, program, version, wait, sockp)
 218      struct sockaddr_in *raddr;
 219      u_long program;
 220      u_long version;
 221      struct timeval wait;
 222      int *sockp;
 223 {
 224   return INTUSE(clntudp_bufcreate) (raddr, program, version, wait, sockp,
 225                                     UDPMSGSIZE, UDPMSGSIZE);
 226 }
 227 INTDEF (clntudp_create)
 228
 229 static int
 230 is_network_up (int sock)
 231 {
 232   struct ifaddrs *ifa;
 233
 234   if (getifaddrs (&ifa) != 0)
 235     return 0;
 236
 237   struct ifaddrs *run = ifa;
 238   while (run != NULL)
 239     {
 240       if ((run->ifa_flags & IFF_UP) != 0
 241           && run->ifa_addr != NULL
 242           && run->ifa_addr->sa_family == AF_INET)
 243         break;
 244
 245       run = run->ifa_next;
 246     }
 247
 248   freeifaddrs (ifa);
 249
 250   return run != NULL;
 251 }
 252
 253 static enum clnt_stat
 254 clntudp_call (cl, proc, xargs, argsp, xresults, resultsp, utimeout)
 255      CLIENT *cl;        /* client handle */
 256      u_long proc;               /* procedure number */
 257      xdrproc_t xargs;           /* xdr routine for args */
 258      caddr_t argsp;             /* pointer to args */
 259      xdrproc_t xresults;        /* xdr routine for results */
 260      caddr_t resultsp;          /* pointer to results */
 261      struct timeval utimeout;   /* seconds to wait before giving up */
 262 {
 263   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 264   XDR *xdrs;
 265   int outlen = 0;
 266   int inlen;
 267   socklen_t fromlen;
 268   struct pollfd fd;
 269   int milliseconds = (cu->cu_wait.tv_sec * 1000) +
 270     (cu->cu_wait.tv_usec / 1000);
 271   struct sockaddr_in from;
 272   struct rpc_msg reply_msg;
 273   XDR reply_xdrs;
 274   struct timeval time_waited;
 275   bool_t ok;
 276   int nrefreshes = 2;           /* number of times to refresh cred */
 277   struct timeval timeout;
 278   int anyup;                    /* any network interface up */
 279
 280   if (cu->cu_total.tv_usec == -1)
 281     {
 282       timeout = utimeout;       /* use supplied timeout */
 283     }
 284   else
 285     {
 286       timeout = cu->cu_total;   /* use default timeout */
 287     }
 288
 289   time_waited.tv_sec = 0;
 290   time_waited.tv_usec = 0;
 291 call_again:
 292   xdrs = &(cu->cu_outxdrs);
 293   if (xargs == NULL)
 294     goto get_reply;
 295   xdrs->x_op = XDR_ENCODE;
 296   XDR_SETPOS (xdrs, cu->cu_xdrpos);
 297   /*
 298    * the transaction is the first thing in the out buffer
 299    */
 300   (*(uint32_t *) (cu->cu_outbuf))++;
 301   if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 302       (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||
 303       (!(*xargs) (xdrs, argsp)))
 304     return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
 305   outlen = (int) XDR_GETPOS (xdrs);
 306
 307 send_again:
 308   if (__sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,
 309                 (struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)
 310       != outlen)
 311     {
 312       cu->cu_error.re_errno = errno;
 313       return (cu->cu_error.re_status = RPC_CANTSEND);
 314     }
 315
 316   /*
 317    * Hack to provide rpc-based message passing
 318    */
 319   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 320     {
 321       return (cu->cu_error.re_status = RPC_TIMEDOUT);
 322     }
 323  get_reply:
 324   /*
 325    * sub-optimal code appears here because we have
 326    * some clock time to spare while the packets are in flight.
 327    * (We assume that this is actually only executed once.)
 328    */
 329   reply_msg.acpted_rply.ar_verf = _null_auth;
 330   reply_msg.acpted_rply.ar_results.where = resultsp;
 331   reply_msg.acpted_rply.ar_results.proc = xresults;
 332   fd.fd = cu->cu_sock;
 333   fd.events = POLLIN;
 334   anyup = 0;
 335   for (;;)
 336     {
 337       switch (__poll (&fd, 1, milliseconds))
 338         {
 339
 340         case 0:
 341           if (anyup == 0)
 342             {
 343               anyup = is_network_up (cu->cu_sock);
 344               if (!anyup)
 345                 return (cu->cu_error.re_status = RPC_CANTRECV);
 346             }
 347
 348           time_waited.tv_sec += cu->cu_wait.tv_sec;
 349           time_waited.tv_usec += cu->cu_wait.tv_usec;
 350           while (time_waited.tv_usec >= 1000000)
 351             {
 352               time_waited.tv_sec++;
 353               time_waited.tv_usec -= 1000000;
 354             }
 355           if ((time_waited.tv_sec < timeout.tv_sec) ||
 356               ((time_waited.tv_sec == timeout.tv_sec) &&
 357                (time_waited.tv_usec < timeout.tv_usec)))
 358             goto send_again;
 359           return (cu->cu_error.re_status = RPC_TIMEDOUT);
 360
 361           /*
 362            * buggy in other cases because time_waited is not being
 363            * updated.
 364            */
 365         case -1:
 366           if (errno == EINTR)
 367             continue;
 368           cu->cu_error.re_errno = errno;
 369           return (cu->cu_error.re_status = RPC_CANTRECV);
 370         }
 371 #ifdef IP_RECVERR
 372       if (fd.revents & POLLERR)
 373         {
 374           struct msghdr msg;
 375           struct cmsghdr *cmsg;
 376           struct sock_extended_err *e;
 377           struct sockaddr_in err_addr;
 378           struct iovec iov;
 379           char *cbuf = (char *) alloca (outlen + 256);
 380           int ret;
 381
 382           iov.iov_base = cbuf + 256;
 383           iov.iov_len = outlen;
 384           msg.msg_name = (void *) &err_addr;
 385           msg.msg_namelen = sizeof (err_addr);
 386           msg.msg_iov = &iov;
 387           msg.msg_iovlen = 1;
 388           msg.msg_flags = 0;
 389           msg.msg_control = cbuf;
 390           msg.msg_controllen = 256;
 391           ret = __recvmsg (cu->cu_sock, &msg, MSG_ERRQUEUE);
 392           if (ret >= 0
 393               && memcmp (cbuf + 256, cu->cu_outbuf, ret) == 0
 394               && (msg.msg_flags & MSG_ERRQUEUE)
 395               && ((msg.msg_namelen == 0
 396                    && ret >= 12)
 397                   || (msg.msg_namelen == sizeof (err_addr)
 398                       && err_addr.sin_family == AF_INET
 399                       && memcmp (&err_addr.sin_addr, &cu->cu_raddr.sin_addr,
 400                                  sizeof (err_addr.sin_addr)) == 0
 401                       && err_addr.sin_port == cu->cu_raddr.sin_port)))
 402             for (cmsg = CMSG_FIRSTHDR (&msg); cmsg;
 403                  cmsg = CMSG_NXTHDR (&msg, cmsg))
 404               if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
 405                 {
 406                   e = (struct sock_extended_err *) CMSG_DATA(cmsg);
 407                   cu->cu_error.re_errno = e->ee_errno;
 408                   return (cu->cu_error.re_status = RPC_CANTRECV);
 409                 }
 410         }
 411 #endif
 412       do
 413         {
 414           fromlen = sizeof (struct sockaddr);
 415           inlen = __recvfrom (cu->cu_sock, cu->cu_inbuf,
 416                               (int) cu->cu_recvsz, 0,
 417                               (struct sockaddr *) &from, &fromlen);
 418         }
 419       while (inlen < 0 && errno == EINTR);
 420       if (inlen < 0)
 421         {
 422           if (errno == EWOULDBLOCK)
 423             continue;
 424           cu->cu_error.re_errno = errno;
 425           return (cu->cu_error.re_status = RPC_CANTRECV);
 426         }
 427       if (inlen < 4)
 428         continue;
 429
 430       /* see if reply transaction id matches sent id.
 431         Don't do this if we only wait for a replay */
 432       if (xargs != NULL
 433           && (*((u_int32_t *) (cu->cu_inbuf))
 434               != *((u_int32_t *) (cu->cu_outbuf))))
 435         continue;
 436       /* we now assume we have the proper reply */
 437       break;
 438     }
 439
 440   /*
 441    * now decode and validate the response
 442    */
 443   INTUSE(xdrmem_create) (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);
 444   ok = INTUSE(xdr_replymsg) (&reply_xdrs, &reply_msg);
 445   /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
 446   if (ok)
 447     {
 448       _seterr_reply (&reply_msg, &(cu->cu_error));
 449       if (cu->cu_error.re_status == RPC_SUCCESS)
 450         {
 451           if (!AUTH_VALIDATE (cl->cl_auth,
 452                               &reply_msg.acpted_rply.ar_verf))
 453             {
 454               cu->cu_error.re_status = RPC_AUTHERROR;
 455               cu->cu_error.re_why = AUTH_INVALIDRESP;
 456             }
 457           if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 458             {
 459               xdrs->x_op = XDR_FREE;
 460               (void) INTUSE(xdr_opaque_auth) (xdrs,
 461                                               &(reply_msg.acpted_rply.ar_verf));
 462             }
 463         }                       /* end successful completion */
 464       else
 465         {
 466           /* maybe our credentials need to be refreshed ... */
 467           if (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))
 468             {
 469               nrefreshes--;
 470               goto call_again;
 471             }
 472         }                       /* end of unsuccessful completion */
 473     }                           /* end of valid reply message */
 474   else
 475     {
 476       cu->cu_error.re_status = RPC_CANTDECODERES;
 477     }
 478   return cu->cu_error.re_status;
 479 }
 480
 481 static void
 482 clntudp_geterr (CLIENT *cl, struct rpc_err *errp)
 483 {
 484   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 485
 486   *errp = cu->cu_error;
 487 }
 488
 489
 490 static bool_t
 491 clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 492 {
 493   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 494   XDR *xdrs = &(cu->cu_outxdrs);
 495
 496   xdrs->x_op = XDR_FREE;
 497   return (*xdr_res) (xdrs, res_ptr);
 498 }
 499
 500 static void
 501 clntudp_abort (void)
 502 {
 503 }
 504
 505 static bool_t
 506 clntudp_control (CLIENT *cl, int request, char *info)
 507 {
 508   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 509
 510   switch (request)
 511     {
 512     case CLSET_FD_CLOSE:
 513       cu->cu_closeit = TRUE;
 514       break;
 515     case CLSET_FD_NCLOSE:
 516       cu->cu_closeit = FALSE;
 517       break;
 518     case CLSET_TIMEOUT:
 519       cu->cu_total = *(struct timeval *) info;
 520       break;
 521     case CLGET_TIMEOUT:
 522       *(struct timeval *) info = cu->cu_total;
 523       break;
 524     case CLSET_RETRY_TIMEOUT:
 525       cu->cu_wait = *(struct timeval *) info;
 526       break;
 527     case CLGET_RETRY_TIMEOUT:
 528       *(struct timeval *) info = cu->cu_wait;
 529       break;
 530     case CLGET_SERVER_ADDR:
 531       *(struct sockaddr_in *) info = cu->cu_raddr;
 532       break;
 533     case CLGET_FD:
 534       *(int *)info = cu->cu_sock;
 535       break;
 536     case CLGET_XID:
 537       /*
 538        * use the knowledge that xid is the
 539        * first element in the call structure *.
 540        * This will get the xid of the PREVIOUS call
 541        */
 542       *(u_long *)info = ntohl(*(u_long *)cu->cu_outbuf);
 543       break;
 544     case CLSET_XID:
 545       /* This will set the xid of the NEXT call */
 546       *(u_long *)cu->cu_outbuf =  htonl(*(u_long *)info - 1);
 547       /* decrement by 1 as clntudp_call() increments once */
 548     case CLGET_VERS:
 549       /*
 550        * This RELIES on the information that, in the call body,
 551        * the version number field is the fifth field from the
 552        * begining of the RPC header. MUST be changed if the
 553        * call_struct is changed
 554        */
 555       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 556                                           4 * BYTES_PER_XDR_UNIT));
 557       break;
 558     case CLSET_VERS:
 559       *(u_long *)(cu->cu_outbuf + 4 * BYTES_PER_XDR_UNIT)
 560         = htonl(*(u_long *)info);
 561       break;
 562     case CLGET_PROG:
 563       /*
 564        * This RELIES on the information that, in the call body,
 565        * the program number field is the  field from the
 566        * begining of the RPC header. MUST be changed if the
 567        * call_struct is changed
 568        */
 569       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 570                                           3 * BYTES_PER_XDR_UNIT));
 571       break;
 572     case CLSET_PROG:
 573       *(u_long *)(cu->cu_outbuf + 3 * BYTES_PER_XDR_UNIT)
 574         = htonl(*(u_long *)info);
 575       break;
 576     /* The following are only possible with TI-RPC */
 577     case CLGET_SVC_ADDR:
 578     case CLSET_SVC_ADDR:
 579     case CLSET_PUSH_TIMOD:
 580     case CLSET_POP_TIMOD:
 581     default:
 582       return FALSE;
 583     }
 584   return TRUE;
 585 }
 586
 587 static void
 588 clntudp_destroy (CLIENT *cl)
 589 {
 590   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 591
 592   if (cu->cu_closeit)
 593     {
 594       (void) __close (cu->cu_sock);
 595     }
 596   XDR_DESTROY (&(cu->cu_outxdrs));
 597   mem_free ((caddr_t) cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
 598   mem_free ((caddr_t) cl, sizeof (CLIENT));
 599 }