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 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 #ifdef USE_IN_LIBIO
 140       if (_IO_fwide (stderr, 0) > 0)
 141         (void) __fwprintf (stderr, L"%s",
 142                            _("clntudp_create: out of memory\n"));
 143       else
 144 #endif
 145         (void) fputs (_("clntudp_create: out of memory\n"), stderr);
 146       ce->cf_stat = RPC_SYSTEMERROR;
 147       ce->cf_error.re_errno = ENOMEM;
 148       goto fooy;
 149     }
 150   cu->cu_outbuf = &cu->cu_inbuf[recvsz];
 151
 152   if (raddr->sin_port == 0)
 153     {
 154       u_short port;
 155       if ((port =
 156            pmap_getport (raddr, program, version, IPPROTO_UDP)) == 0)
 157         {
 158           goto fooy;
 159         }
 160       raddr->sin_port = htons (port);
 161     }
 162   cl->cl_ops = &udp_ops;
 163   cl->cl_private = (caddr_t) cu;
 164   cu->cu_raddr = *raddr;
 165   cu->cu_rlen = sizeof (cu->cu_raddr);
 166   cu->cu_wait = wait;
 167   cu->cu_total.tv_sec = -1;
 168   cu->cu_total.tv_usec = -1;
 169   cu->cu_sendsz = sendsz;
 170   cu->cu_recvsz = recvsz;
 171   call_msg.rm_xid = _create_xid ();
 172   call_msg.rm_direction = CALL;
 173   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 174   call_msg.rm_call.cb_prog = program;
 175   call_msg.rm_call.cb_vers = version;
 176   INTUSE(xdrmem_create) (&(cu->cu_outxdrs), cu->cu_outbuf, sendsz, XDR_ENCODE);
 177   if (!INTUSE(xdr_callhdr) (&(cu->cu_outxdrs), &call_msg))
 178     {
 179       goto fooy;
 180     }
 181   cu->cu_xdrpos = XDR_GETPOS (&(cu->cu_outxdrs));
 182   if (*sockp < 0)
 183     {
 184       int dontblock = 1;
 185
 186       *sockp = __socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 187       if (*sockp < 0)
 188         {
 189           struct rpc_createerr *ce = &get_rpc_createerr ();
 190           ce->cf_stat = RPC_SYSTEMERROR;
 191           ce->cf_error.re_errno = errno;
 192           goto fooy;
 193         }
 194       /* attempt to bind to prov port */
 195       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 196       /* the sockets rpc controls are non-blocking */
 197       (void) __ioctl (*sockp, FIONBIO, (char *) &dontblock);
 198 #ifdef IP_RECVERR
 199       {
 200         int on = 1;
 201         __setsockopt (*sockp, SOL_IP, IP_RECVERR, &on, sizeof(on));
 202       }
 203 #endif
 204       cu->cu_closeit = TRUE;
 205     }
 206   else
 207     {
 208       cu->cu_closeit = FALSE;
 209     }
 210   cu->cu_sock = *sockp;
 211   cl->cl_auth = INTUSE(authnone_create) ();
 212   return cl;
 213 fooy:
 214   if (cu)
 215     mem_free ((caddr_t) cu, sizeof (*cu) + sendsz + recvsz);
 216   if (cl)
 217     mem_free ((caddr_t) cl, sizeof (CLIENT));
 218   return (CLIENT *) NULL;
 219 }
 220 INTDEF (clntudp_bufcreate)
 221
 222 CLIENT *
 223 clntudp_create (raddr, program, version, wait, sockp)
 224      struct sockaddr_in *raddr;
 225      u_long program;
 226      u_long version;
 227      struct timeval wait;
 228      int *sockp;
 229 {
 230   return INTUSE(clntudp_bufcreate) (raddr, program, version, wait, sockp,
 231                                     UDPMSGSIZE, UDPMSGSIZE);
 232 }
 233 INTDEF (clntudp_create)
 234
 235 static int
 236 is_network_up (int sock)
 237 {
 238   struct ifaddrs *ifa;
 239
 240   if (getifaddrs (&ifa) != 0)
 241     return 0;
 242
 243   struct ifaddrs *run = ifa;
 244   while (run != NULL)
 245     {
 246       if ((run->ifa_flags & IFF_UP) != 0
 247           && run->ifa_addr != NULL
 248           && run->ifa_addr->sa_family == AF_INET)
 249         break;
 250
 251       run = run->ifa_next;
 252     }
 253
 254   freeifaddrs (ifa);
 255
 256   return run != NULL;
 257 }
 258
 259 static enum clnt_stat
 260 clntudp_call (cl, proc, xargs, argsp, xresults, resultsp, utimeout)
 261      CLIENT *cl;        /* client handle */
 262      u_long proc;               /* procedure number */
 263      xdrproc_t xargs;           /* xdr routine for args */
 264      caddr_t argsp;             /* pointer to args */
 265      xdrproc_t xresults;        /* xdr routine for results */
 266      caddr_t resultsp;          /* pointer to results */
 267      struct timeval utimeout;   /* seconds to wait before giving up */
 268 {
 269   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 270   XDR *xdrs;
 271   int outlen = 0;
 272   int inlen;
 273   socklen_t fromlen;
 274   struct pollfd fd;
 275   int milliseconds = (cu->cu_wait.tv_sec * 1000) +
 276     (cu->cu_wait.tv_usec / 1000);
 277   struct sockaddr_in from;
 278   struct rpc_msg reply_msg;
 279   XDR reply_xdrs;
 280   struct timeval time_waited;
 281   bool_t ok;
 282   int nrefreshes = 2;           /* number of times to refresh cred */
 283   struct timeval timeout;
 284   int anyup;                    /* any network interface up */
 285
 286   if (cu->cu_total.tv_usec == -1)
 287     {
 288       timeout = utimeout;       /* use supplied timeout */
 289     }
 290   else
 291     {
 292       timeout = cu->cu_total;   /* use default timeout */
 293     }
 294
 295   time_waited.tv_sec = 0;
 296   time_waited.tv_usec = 0;
 297 call_again:
 298   xdrs = &(cu->cu_outxdrs);
 299   if (xargs == NULL)
 300     goto get_reply;
 301   xdrs->x_op = XDR_ENCODE;
 302   XDR_SETPOS (xdrs, cu->cu_xdrpos);
 303   /*
 304    * the transaction is the first thing in the out buffer
 305    */
 306   (*(uint32_t *) (cu->cu_outbuf))++;
 307   if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 308       (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||
 309       (!(*xargs) (xdrs, argsp)))
 310     return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
 311   outlen = (int) XDR_GETPOS (xdrs);
 312
 313 send_again:
 314   if (__sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,
 315                 (struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)
 316       != outlen)
 317     {
 318       cu->cu_error.re_errno = errno;
 319       return (cu->cu_error.re_status = RPC_CANTSEND);
 320     }
 321
 322   /*
 323    * Hack to provide rpc-based message passing
 324    */
 325   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 326     {
 327       return (cu->cu_error.re_status = RPC_TIMEDOUT);
 328     }
 329  get_reply:
 330   /*
 331    * sub-optimal code appears here because we have
 332    * some clock time to spare while the packets are in flight.
 333    * (We assume that this is actually only executed once.)
 334    */
 335   reply_msg.acpted_rply.ar_verf = _null_auth;
 336   reply_msg.acpted_rply.ar_results.where = resultsp;
 337   reply_msg.acpted_rply.ar_results.proc = xresults;
 338   fd.fd = cu->cu_sock;
 339   fd.events = POLLIN;
 340   anyup = 0;
 341   for (;;)
 342     {
 343       switch (__poll (&fd, 1, milliseconds))
 344         {
 345
 346         case 0:
 347           if (anyup == 0)
 348             {
 349               anyup = is_network_up (cu->cu_sock);
 350               if (!anyup)
 351                 return (cu->cu_error.re_status = RPC_CANTRECV);
 352             }
 353
 354           time_waited.tv_sec += cu->cu_wait.tv_sec;
 355           time_waited.tv_usec += cu->cu_wait.tv_usec;
 356           while (time_waited.tv_usec >= 1000000)
 357             {
 358               time_waited.tv_sec++;
 359               time_waited.tv_usec -= 1000000;
 360             }
 361           if ((time_waited.tv_sec < timeout.tv_sec) ||
 362               ((time_waited.tv_sec == timeout.tv_sec) &&
 363                (time_waited.tv_usec < timeout.tv_usec)))
 364             goto send_again;
 365           return (cu->cu_error.re_status = RPC_TIMEDOUT);
 366
 367           /*
 368            * buggy in other cases because time_waited is not being
 369            * updated.
 370            */
 371         case -1:
 372           if (errno == EINTR)
 373             continue;
 374           cu->cu_error.re_errno = errno;
 375           return (cu->cu_error.re_status = RPC_CANTRECV);
 376         }
 377 #ifdef IP_RECVERR
 378       if (fd.revents & POLLERR)
 379         {
 380           struct msghdr msg;
 381           struct cmsghdr *cmsg;
 382           struct sock_extended_err *e;
 383           struct sockaddr_in err_addr;
 384           struct iovec iov;
 385           char *cbuf = (char *) alloca (outlen + 256);
 386           int ret;
 387
 388           iov.iov_base = cbuf + 256;
 389           iov.iov_len = outlen;
 390           msg.msg_name = (void *) &err_addr;
 391           msg.msg_namelen = sizeof (err_addr);
 392           msg.msg_iov = &iov;
 393           msg.msg_iovlen = 1;
 394           msg.msg_flags = 0;
 395           msg.msg_control = cbuf;
 396           msg.msg_controllen = 256;
 397           ret = __recvmsg (cu->cu_sock, &msg, MSG_ERRQUEUE);
 398           if (ret >= 0
 399               && memcmp (cbuf + 256, cu->cu_outbuf, ret) == 0
 400               && (msg.msg_flags & MSG_ERRQUEUE)
 401               && ((msg.msg_namelen == 0
 402                    && ret >= 12)
 403                   || (msg.msg_namelen == sizeof (err_addr)
 404                       && err_addr.sin_family == AF_INET
 405                       && memcmp (&err_addr.sin_addr, &cu->cu_raddr.sin_addr,
 406                                  sizeof (err_addr.sin_addr)) == 0
 407                       && err_addr.sin_port == cu->cu_raddr.sin_port)))
 408             for (cmsg = CMSG_FIRSTHDR (&msg); cmsg;
 409                  cmsg = CMSG_NXTHDR (&msg, cmsg))
 410               if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
 411                 {
 412                   e = (struct sock_extended_err *) CMSG_DATA(cmsg);
 413                   cu->cu_error.re_errno = e->ee_errno;
 414                   return (cu->cu_error.re_status = RPC_CANTRECV);
 415                 }
 416         }
 417 #endif
 418       do
 419         {
 420           fromlen = sizeof (struct sockaddr);
 421           inlen = __recvfrom (cu->cu_sock, cu->cu_inbuf,
 422                               (int) cu->cu_recvsz, 0,
 423                               (struct sockaddr *) &from, &fromlen);
 424         }
 425       while (inlen < 0 && errno == EINTR);
 426       if (inlen < 0)
 427         {
 428           if (errno == EWOULDBLOCK)
 429             continue;
 430           cu->cu_error.re_errno = errno;
 431           return (cu->cu_error.re_status = RPC_CANTRECV);
 432         }
 433       if (inlen < 4)
 434         continue;
 435
 436       /* see if reply transaction id matches sent id.
 437         Don't do this if we only wait for a replay */
 438       if (xargs != NULL
 439           && (*((u_int32_t *) (cu->cu_inbuf))
 440               != *((u_int32_t *) (cu->cu_outbuf))))
 441         continue;
 442       /* we now assume we have the proper reply */
 443       break;
 444     }
 445
 446   /*
 447    * now decode and validate the response
 448    */
 449   INTUSE(xdrmem_create) (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);
 450   ok = INTUSE(xdr_replymsg) (&reply_xdrs, &reply_msg);
 451   /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
 452   if (ok)
 453     {
 454       _seterr_reply (&reply_msg, &(cu->cu_error));
 455       if (cu->cu_error.re_status == RPC_SUCCESS)
 456         {
 457           if (!AUTH_VALIDATE (cl->cl_auth,
 458                               &reply_msg.acpted_rply.ar_verf))
 459             {
 460               cu->cu_error.re_status = RPC_AUTHERROR;
 461               cu->cu_error.re_why = AUTH_INVALIDRESP;
 462             }
 463           if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 464             {
 465               xdrs->x_op = XDR_FREE;
 466               (void) INTUSE(xdr_opaque_auth) (xdrs,
 467                                               &(reply_msg.acpted_rply.ar_verf));
 468             }
 469         }                       /* end successful completion */
 470       else
 471         {
 472           /* maybe our credentials need to be refreshed ... */
 473           if (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))
 474             {
 475               nrefreshes--;
 476               goto call_again;
 477             }
 478         }                       /* end of unsuccessful completion */
 479     }                           /* end of valid reply message */
 480   else
 481     {
 482       cu->cu_error.re_status = RPC_CANTDECODERES;
 483     }
 484   return cu->cu_error.re_status;
 485 }
 486
 487 static void
 488 clntudp_geterr (CLIENT *cl, struct rpc_err *errp)
 489 {
 490   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 491
 492   *errp = cu->cu_error;
 493 }
 494
 495
 496 static bool_t
 497 clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 498 {
 499   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 500   XDR *xdrs = &(cu->cu_outxdrs);
 501
 502   xdrs->x_op = XDR_FREE;
 503   return (*xdr_res) (xdrs, res_ptr);
 504 }
 505
 506 static void
 507 clntudp_abort (void)
 508 {
 509 }
 510
 511 static bool_t
 512 clntudp_control (CLIENT *cl, int request, char *info)
 513 {
 514   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 515
 516   switch (request)
 517     {
 518     case CLSET_FD_CLOSE:
 519       cu->cu_closeit = TRUE;
 520       break;
 521     case CLSET_FD_NCLOSE:
 522       cu->cu_closeit = FALSE;
 523       break;
 524     case CLSET_TIMEOUT:
 525       cu->cu_total = *(struct timeval *) info;
 526       break;
 527     case CLGET_TIMEOUT:
 528       *(struct timeval *) info = cu->cu_total;
 529       break;
 530     case CLSET_RETRY_TIMEOUT:
 531       cu->cu_wait = *(struct timeval *) info;
 532       break;
 533     case CLGET_RETRY_TIMEOUT:
 534       *(struct timeval *) info = cu->cu_wait;
 535       break;
 536     case CLGET_SERVER_ADDR:
 537       *(struct sockaddr_in *) info = cu->cu_raddr;
 538       break;
 539     case CLGET_FD:
 540       *(int *)info = cu->cu_sock;
 541       break;
 542     case CLGET_XID:
 543       /*
 544        * use the knowledge that xid is the
 545        * first element in the call structure *.
 546        * This will get the xid of the PREVIOUS call
 547        */
 548       *(u_long *)info = ntohl(*(u_long *)cu->cu_outbuf);
 549       break;
 550     case CLSET_XID:
 551       /* This will set the xid of the NEXT call */
 552       *(u_long *)cu->cu_outbuf =  htonl(*(u_long *)info - 1);
 553       /* decrement by 1 as clntudp_call() increments once */
 554     case CLGET_VERS:
 555       /*
 556        * This RELIES on the information that, in the call body,
 557        * the version number field is the fifth field from the
 558        * begining of the RPC header. MUST be changed if the
 559        * call_struct is changed
 560        */
 561       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 562                                           4 * BYTES_PER_XDR_UNIT));
 563       break;
 564     case CLSET_VERS:
 565       *(u_long *)(cu->cu_outbuf + 4 * BYTES_PER_XDR_UNIT)
 566         = htonl(*(u_long *)info);
 567       break;
 568     case CLGET_PROG:
 569       /*
 570        * This RELIES on the information that, in the call body,
 571        * the program number field is the  field from the
 572        * begining of the RPC header. MUST be changed if the
 573        * call_struct is changed
 574        */
 575       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 576                                           3 * BYTES_PER_XDR_UNIT));
 577       break;
 578     case CLSET_PROG:
 579       *(u_long *)(cu->cu_outbuf + 3 * BYTES_PER_XDR_UNIT)
 580         = htonl(*(u_long *)info);
 581       break;
 582     /* The following are only possible with TI-RPC */
 583     case CLGET_SVC_ADDR:
 584     case CLSET_SVC_ADDR:
 585     case CLSET_PUSH_TIMOD:
 586     case CLSET_POP_TIMOD:
 587     default:
 588       return FALSE;
 589     }
 590   return TRUE;
 591 }
 592
 593 static void
 594 clntudp_destroy (CLIENT *cl)
 595 {
 596   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 597
 598   if (cu->cu_closeit)
 599     {
 600       (void) __close (cu->cu_sock);
 601     }
 602   XDR_DESTROY (&(cu->cu_outxdrs));
 603   mem_free ((caddr_t) cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
 604   mem_free ((caddr_t) cl, sizeof (CLIENT));
 605 }