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