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 #ifdef USE_IN_LIBIO
  54 # include <wchar.h>
  55 #endif
  56
  57 #ifdef IP_RECVERR
  58 #include <errqueue.h>
  59 #include <sys/uio.h>
  60 #endif
  61
  62 extern bool_t xdr_opaque_auth (XDR *, struct opaque_auth *);
  63 extern u_long _create_xid (void);
  64
  65 /*
  66  * UDP bases client side rpc operations
  67  */
  68 static enum clnt_stat clntudp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  69                                     xdrproc_t, caddr_t, struct timeval);
  70 static void clntudp_abort (void);
  71 static void clntudp_geterr (CLIENT *, struct rpc_err *);
  72 static bool_t clntudp_freeres (CLIENT *, xdrproc_t, caddr_t);
  73 static bool_t clntudp_control (CLIENT *, int, char *);
  74 static void clntudp_destroy (CLIENT *);
  75
  76 static struct clnt_ops udp_ops =
  77 {
  78   clntudp_call,
  79   clntudp_abort,
  80   clntudp_geterr,
  81   clntudp_freeres,
  82   clntudp_destroy,
  83   clntudp_control
  84 };
  85
  86 /*
  87  * Private data kept per client handle
  88  */
  89 struct cu_data
  90   {
  91     int cu_sock;
  92     bool_t cu_closeit;
  93     struct sockaddr_in cu_raddr;
  94     int cu_rlen;
  95     struct timeval cu_wait;
  96     struct timeval cu_total;
  97     struct rpc_err cu_error;
  98     XDR cu_outxdrs;
  99     u_int cu_xdrpos;
 100     u_int cu_sendsz;
 101     char *cu_outbuf;
 102     u_int cu_recvsz;
 103     char cu_inbuf[1];
 104   };
 105
 106 /*
 107  * Create a UDP based client handle.
 108  * If *sockp<0, *sockp is set to a newly created UPD socket.
 109  * If raddr->sin_port is 0 a binder on the remote machine
 110  * is consulted for the correct port number.
 111  * NB: It is the clients responsibility to close *sockp.
 112  * NB: The rpch->cl_auth is initialized to null authentication.
 113  *     Caller may wish to set this something more useful.
 114  *
 115  * wait is the amount of time used between retransmitting a call if
 116  * no response has been heard; retransmission occurs until the actual
 117  * rpc call times out.
 118  *
 119  * sendsz and recvsz are the maximum allowable packet sizes that can be
 120  * sent and received.
 121  */
 122 CLIENT *
 123 clntudp_bufcreate (struct sockaddr_in *raddr, u_long program, u_long version,
 124                    struct timeval wait, int *sockp, u_int sendsz,
 125                    u_int recvsz)
 126 {
 127   CLIENT *cl;
 128   struct cu_data *cu = NULL;
 129   struct rpc_msg call_msg;
 130
 131   cl = (CLIENT *) mem_alloc (sizeof (CLIENT));
 132   sendsz = ((sendsz + 3) / 4) * 4;
 133   recvsz = ((recvsz + 3) / 4) * 4;
 134   cu = (struct cu_data *) mem_alloc (sizeof (*cu) + sendsz + recvsz);
 135   if (cl == NULL || cu == NULL)
 136     {
 137       struct rpc_createerr *ce = &get_rpc_createerr ();
 138 #ifdef USE_IN_LIBIO
 139       if (_IO_fwide (stderr, 0) > 0)
 140         (void) __fwprintf (stderr, L"%s",
 141                            _("clntudp_create: out of memory\n"));
 142       else
 143 #endif
 144         (void) fputs (_("clntudp_create: out of memory\n"), stderr);
 145       ce->cf_stat = RPC_SYSTEMERROR;
 146       ce->cf_error.re_errno = ENOMEM;
 147       goto fooy;
 148     }
 149   cu->cu_outbuf = &cu->cu_inbuf[recvsz];
 150
 151   if (raddr->sin_port == 0)
 152     {
 153       u_short port;
 154       if ((port =
 155            pmap_getport (raddr, program, version, IPPROTO_UDP)) == 0)
 156         {
 157           goto fooy;
 158         }
 159       raddr->sin_port = htons (port);
 160     }
 161   cl->cl_ops = &udp_ops;
 162   cl->cl_private = (caddr_t) cu;
 163   cu->cu_raddr = *raddr;
 164   cu->cu_rlen = sizeof (cu->cu_raddr);
 165   cu->cu_wait = wait;
 166   cu->cu_total.tv_sec = -1;
 167   cu->cu_total.tv_usec = -1;
 168   cu->cu_sendsz = sendsz;
 169   cu->cu_recvsz = recvsz;
 170   call_msg.rm_xid = _create_xid ();
 171   call_msg.rm_direction = CALL;
 172   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 173   call_msg.rm_call.cb_prog = program;
 174   call_msg.rm_call.cb_vers = version;
 175   xdrmem_create (&(cu->cu_outxdrs), cu->cu_outbuf,
 176                  sendsz, XDR_ENCODE);
 177   if (!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 = 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
 221 CLIENT *
 222 clntudp_create (raddr, program, version, wait, sockp)
 223      struct sockaddr_in *raddr;
 224      u_long program;
 225      u_long version;
 226      struct timeval wait;
 227      int *sockp;
 228 {
 229
 230   return clntudp_bufcreate (raddr, program, version, wait, sockp,
 231                             UDPMSGSIZE, UDPMSGSIZE);
 232 }
 233
 234 static int
 235 is_network_up (int sock)
 236 {
 237   struct ifconf ifc;
 238   char buf[UDPMSGSIZE];
 239   struct ifreq ifreq, *ifr;
 240   int n;
 241
 242   ifc.ifc_len = sizeof (buf);
 243   ifc.ifc_buf = buf;
 244   if (__ioctl(sock, SIOCGIFCONF, (char *) &ifc) == 0)
 245     {
 246       ifr = ifc.ifc_req;
 247       for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; n--, ifr++)
 248         {
 249           ifreq = *ifr;
 250           if (__ioctl (sock, SIOCGIFFLAGS, (char *) &ifreq) < 0)
 251             break;
 252
 253           if ((ifreq.ifr_flags & IFF_UP)
 254               && ifr->ifr_addr.sa_family == AF_INET)
 255             return 1;
 256         }
 257     }
 258   return 0;
 259 }
 260
 261 static enum clnt_stat
 262 clntudp_call (cl, proc, xargs, argsp, xresults, resultsp, utimeout)
 263      CLIENT *cl;        /* client handle */
 264      u_long proc;               /* procedure number */
 265      xdrproc_t xargs;           /* xdr routine for args */
 266      caddr_t argsp;             /* pointer to args */
 267      xdrproc_t xresults;        /* xdr routine for results */
 268      caddr_t resultsp;          /* pointer to results */
 269      struct timeval utimeout;   /* seconds to wait before giving up */
 270 {
 271   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 272   XDR *xdrs;
 273   int outlen = 0;
 274   int inlen;
 275   socklen_t fromlen;
 276   struct pollfd fd;
 277   int milliseconds = (cu->cu_wait.tv_sec * 1000) +
 278     (cu->cu_wait.tv_usec / 1000);
 279   struct sockaddr_in from;
 280   struct rpc_msg reply_msg;
 281   XDR reply_xdrs;
 282   struct timeval time_waited;
 283   bool_t ok;
 284   int nrefreshes = 2;           /* number of times to refresh cred */
 285   struct timeval timeout;
 286   int anyup;                    /* any network interface up */
 287
 288   if (cu->cu_total.tv_usec == -1)
 289     {
 290       timeout = utimeout;       /* use supplied timeout */
 291     }
 292   else
 293     {
 294       timeout = cu->cu_total;   /* use default timeout */
 295     }
 296
 297   time_waited.tv_sec = 0;
 298   time_waited.tv_usec = 0;
 299 call_again:
 300   xdrs = &(cu->cu_outxdrs);
 301   if (xargs == NULL)
 302     goto get_reply;
 303   xdrs->x_op = XDR_ENCODE;
 304   XDR_SETPOS (xdrs, cu->cu_xdrpos);
 305   /*
 306    * the transaction is the first thing in the out buffer
 307    */
 308   (*(uint32_t *) (cu->cu_outbuf))++;
 309   if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 310       (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||
 311       (!(*xargs) (xdrs, argsp)))
 312     return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
 313   outlen = (int) XDR_GETPOS (xdrs);
 314
 315 send_again:
 316   if (sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,
 317               (struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)
 318       != outlen)
 319     {
 320       cu->cu_error.re_errno = errno;
 321       return (cu->cu_error.re_status = RPC_CANTSEND);
 322     }
 323
 324   /*
 325    * Hack to provide rpc-based message passing
 326    */
 327   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 328     {
 329       return (cu->cu_error.re_status = RPC_TIMEDOUT);
 330     }
 331  get_reply:
 332   /*
 333    * sub-optimal code appears here because we have
 334    * some clock time to spare while the packets are in flight.
 335    * (We assume that this is actually only executed once.)
 336    */
 337   reply_msg.acpted_rply.ar_verf = _null_auth;
 338   reply_msg.acpted_rply.ar_results.where = resultsp;
 339   reply_msg.acpted_rply.ar_results.proc = xresults;
 340   fd.fd = cu->cu_sock;
 341   fd.events = POLLIN;
 342   anyup = 0;
 343   for (;;)
 344     {
 345       switch (__poll (&fd, 1, milliseconds))
 346         {
 347
 348         case 0:
 349           if (anyup == 0)
 350             {
 351               anyup = is_network_up (cu->cu_sock);
 352               if (!anyup)
 353                 return (cu->cu_error.re_status = RPC_CANTRECV);
 354             }
 355
 356           time_waited.tv_sec += cu->cu_wait.tv_sec;
 357           time_waited.tv_usec += cu->cu_wait.tv_usec;
 358           while (time_waited.tv_usec >= 1000000)
 359             {
 360               time_waited.tv_sec++;
 361               time_waited.tv_usec -= 1000000;
 362             }
 363           if ((time_waited.tv_sec < timeout.tv_sec) ||
 364               ((time_waited.tv_sec == timeout.tv_sec) &&
 365                (time_waited.tv_usec < timeout.tv_usec)))
 366             goto send_again;
 367           return (cu->cu_error.re_status = RPC_TIMEDOUT);
 368
 369           /*
 370            * buggy in other cases because time_waited is not being
 371            * updated.
 372            */
 373         case -1:
 374           if (errno == EINTR)
 375             continue;
 376           cu->cu_error.re_errno = errno;
 377           return (cu->cu_error.re_status = RPC_CANTRECV);
 378         }
 379 #ifdef IP_RECVERR
 380       if (fd.revents & POLLERR)
 381         {
 382           struct msghdr msg;
 383           struct cmsghdr *cmsg;
 384           struct sock_extended_err *e;
 385           struct sockaddr_in err_addr;
 386           struct iovec iov;
 387           char *cbuf = (char *) alloca (outlen + 256);
 388           int ret;
 389
 390           iov.iov_base = cbuf + 256;
 391           iov.iov_len = outlen;
 392           msg.msg_name = (void *) &err_addr;
 393           msg.msg_namelen = sizeof (err_addr);
 394           msg.msg_iov = &iov;
 395           msg.msg_iovlen = 1;
 396           msg.msg_flags = 0;
 397           msg.msg_control = cbuf;
 398           msg.msg_controllen = 256;
 399           ret = recvmsg (cu->cu_sock, &msg, MSG_ERRQUEUE);
 400           if (ret >= 0
 401               && memcmp (cbuf + 256, cu->cu_outbuf, ret) == 0
 402               && (msg.msg_flags & MSG_ERRQUEUE)
 403               && ((msg.msg_namelen == 0
 404                    && ret >= 12)
 405                   || (msg.msg_namelen == sizeof (err_addr)
 406                       && err_addr.sin_family == AF_INET
 407                       && memcmp (&err_addr.sin_addr, &cu->cu_raddr.sin_addr,
 408                                  sizeof (err_addr.sin_addr)) == 0
 409                       && err_addr.sin_port == cu->cu_raddr.sin_port)))
 410             for (cmsg = CMSG_FIRSTHDR (&msg); cmsg;
 411                  cmsg = CMSG_NXTHDR (&msg, cmsg))
 412               if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
 413                 {
 414                   e = (struct sock_extended_err *) CMSG_DATA(cmsg);
 415                   cu->cu_error.re_errno = e->ee_errno;
 416                   return (cu->cu_error.re_status = RPC_CANTRECV);
 417                 }
 418         }
 419 #endif
 420       do
 421         {
 422           fromlen = sizeof (struct sockaddr);
 423           inlen = recvfrom (cu->cu_sock, cu->cu_inbuf,
 424                             (int) cu->cu_recvsz, 0,
 425                             (struct sockaddr *) &from, &fromlen);
 426         }
 427       while (inlen < 0 && errno == EINTR);
 428       if (inlen < 0)
 429         {
 430           if (errno == EWOULDBLOCK)
 431             continue;
 432           cu->cu_error.re_errno = errno;
 433           return (cu->cu_error.re_status = RPC_CANTRECV);
 434         }
 435       if (inlen < 4)
 436         continue;
 437
 438       /* see if reply transaction id matches sent id.
 439         Don't do this if we only wait for a replay */
 440       if (xargs != NULL
 441           && (*((u_int32_t *) (cu->cu_inbuf))
 442               != *((u_int32_t *) (cu->cu_outbuf))))
 443         continue;
 444       /* we now assume we have the proper reply */
 445       break;
 446     }
 447
 448   /*
 449    * now decode and validate the response
 450    */
 451   xdrmem_create (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);
 452   ok = xdr_replymsg (&reply_xdrs, &reply_msg);
 453   /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
 454   if (ok)
 455     {
 456       _seterr_reply (&reply_msg, &(cu->cu_error));
 457       if (cu->cu_error.re_status == RPC_SUCCESS)
 458         {
 459           if (!AUTH_VALIDATE (cl->cl_auth,
 460                               &reply_msg.acpted_rply.ar_verf))
 461             {
 462               cu->cu_error.re_status = RPC_AUTHERROR;
 463               cu->cu_error.re_why = AUTH_INVALIDRESP;
 464             }
 465           if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 466             {
 467               xdrs->x_op = XDR_FREE;
 468               (void) xdr_opaque_auth (xdrs,
 469                                       &(reply_msg.acpted_rply.ar_verf));
 470             }
 471         }                       /* end successful completion */
 472       else
 473         {
 474           /* maybe our credentials need to be refreshed ... */
 475           if (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))
 476             {
 477               nrefreshes--;
 478               goto call_again;
 479             }
 480         }                       /* end of unsuccessful completion */
 481     }                           /* end of valid reply message */
 482   else
 483     {
 484       cu->cu_error.re_status = RPC_CANTDECODERES;
 485     }
 486   return cu->cu_error.re_status;
 487 }
 488
 489 static void
 490 clntudp_geterr (CLIENT *cl, struct rpc_err *errp)
 491 {
 492   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 493
 494   *errp = cu->cu_error;
 495 }
 496
 497
 498 static bool_t
 499 clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 500 {
 501   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 502   XDR *xdrs = &(cu->cu_outxdrs);
 503
 504   xdrs->x_op = XDR_FREE;
 505   return (*xdr_res) (xdrs, res_ptr);
 506 }
 507
 508 static void
 509 clntudp_abort (void)
 510 {
 511 }
 512
 513 static bool_t
 514 clntudp_control (CLIENT *cl, int request, char *info)
 515 {
 516   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 517
 518   switch (request)
 519     {
 520     case CLSET_FD_CLOSE:
 521       cu->cu_closeit = TRUE;
 522       break;
 523     case CLSET_FD_NCLOSE:
 524       cu->cu_closeit = FALSE;
 525       break;
 526     case CLSET_TIMEOUT:
 527       cu->cu_total = *(struct timeval *) info;
 528       break;
 529     case CLGET_TIMEOUT:
 530       *(struct timeval *) info = cu->cu_total;
 531       break;
 532     case CLSET_RETRY_TIMEOUT:
 533       cu->cu_wait = *(struct timeval *) info;
 534       break;
 535     case CLGET_RETRY_TIMEOUT:
 536       *(struct timeval *) info = cu->cu_wait;
 537       break;
 538     case CLGET_SERVER_ADDR:
 539       *(struct sockaddr_in *) info = cu->cu_raddr;
 540       break;
 541     case CLGET_FD:
 542       *(int *)info = cu->cu_sock;
 543       break;
 544     case CLGET_XID:
 545       /*
 546        * use the knowledge that xid is the
 547        * first element in the call structure *.
 548        * This will get the xid of the PREVIOUS call
 549        */
 550       *(u_long *)info = ntohl(*(u_long *)cu->cu_outbuf);
 551       break;
 552     case CLSET_XID:
 553       /* This will set the xid of the NEXT call */
 554       *(u_long *)cu->cu_outbuf =  htonl(*(u_long *)info - 1);
 555       /* decrement by 1 as clntudp_call() increments once */
 556     case CLGET_VERS:
 557       /*
 558        * This RELIES on the information that, in the call body,
 559        * the version number field is the fifth field from the
 560        * begining of the RPC header. MUST be changed if the
 561        * call_struct is changed
 562        */
 563       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 564                                           4 * BYTES_PER_XDR_UNIT));
 565       break;
 566     case CLSET_VERS:
 567       *(u_long *)(cu->cu_outbuf + 4 * BYTES_PER_XDR_UNIT)
 568         = htonl(*(u_long *)info);
 569       break;
 570     case CLGET_PROG:
 571       /*
 572        * This RELIES on the information that, in the call body,
 573        * the program number field is the  field from the
 574        * begining of the RPC header. MUST be changed if the
 575        * call_struct is changed
 576        */
 577       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 578                                           3 * BYTES_PER_XDR_UNIT));
 579       break;
 580     case CLSET_PROG:
 581       *(u_long *)(cu->cu_outbuf + 3 * BYTES_PER_XDR_UNIT)
 582         = htonl(*(u_long *)info);
 583       break;
 584     /* The following are only possible with TI-RPC */
 585     case CLGET_SVC_ADDR:
 586     case CLSET_SVC_ADDR:
 587     case CLSET_PUSH_TIMOD:
 588     case CLSET_POP_TIMOD:
 589     default:
 590       return FALSE;
 591     }
 592   return TRUE;
 593 }
 594
 595 static void
 596 clntudp_destroy (CLIENT *cl)
 597 {
 598   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 599
 600   if (cu->cu_closeit)
 601     {
 602       (void) __close (cu->cu_sock);
 603     }
 604   XDR_DESTROY (&(cu->cu_outxdrs));
 605   mem_free ((caddr_t) cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
 606   mem_free ((caddr_t) cl, sizeof (CLIENT));
 607 }