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
  54 #ifdef IP_RECVERR
  55 #include <errqueue.h>
  56 #include <sys/uio.h>
  57 #endif
  58
  59 extern bool_t xdr_opaque_auth (XDR *, struct opaque_auth *);
  60 extern u_long _create_xid (void);
  61
  62 /*
  63  * UDP bases client side rpc operations
  64  */
  65 static enum clnt_stat clntudp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  66                                     xdrproc_t, caddr_t, struct timeval);
  67 static void clntudp_abort (void);
  68 static void clntudp_geterr (CLIENT *, struct rpc_err *);
  69 static bool_t clntudp_freeres (CLIENT *, xdrproc_t, caddr_t);
  70 static bool_t clntudp_control (CLIENT *, int, char *);
  71 static void clntudp_destroy (CLIENT *);
  72
  73 static struct clnt_ops udp_ops =
  74 {
  75   clntudp_call,
  76   clntudp_abort,
  77   clntudp_geterr,
  78   clntudp_freeres,
  79   clntudp_destroy,
  80   clntudp_control
  81 };
  82
  83 /*
  84  * Private data kept per client handle
  85  */
  86 struct cu_data
  87   {
  88     int cu_sock;
  89     bool_t cu_closeit;
  90     struct sockaddr_in cu_raddr;
  91     int cu_rlen;
  92     struct timeval cu_wait;
  93     struct timeval cu_total;
  94     struct rpc_err cu_error;
  95     XDR cu_outxdrs;
  96     u_int cu_xdrpos;
  97     u_int cu_sendsz;
  98     char *cu_outbuf;
  99     u_int cu_recvsz;
 100     char cu_inbuf[1];
 101   };
 102
 103 /*
 104  * Create a UDP based client handle.
 105  * If *sockp<0, *sockp is set to a newly created UPD socket.
 106  * If raddr->sin_port is 0 a binder on the remote machine
 107  * is consulted for the correct port number.
 108  * NB: It is the clients responsibility to close *sockp.
 109  * NB: The rpch->cl_auth is initialized to null authentication.
 110  *     Caller may wish to set this something more useful.
 111  *
 112  * wait is the amount of time used between retransmitting a call if
 113  * no response has been heard; retransmission occurs until the actual
 114  * rpc call times out.
 115  *
 116  * sendsz and recvsz are the maximum allowable packet sizes that can be
 117  * sent and received.
 118  */
 119 CLIENT *
 120 clntudp_bufcreate (struct sockaddr_in *raddr, u_long program, u_long version,
 121                    struct timeval wait, int *sockp, u_int sendsz,
 122                    u_int recvsz)
 123 {
 124   CLIENT *cl;
 125   struct cu_data *cu = NULL;
 126   struct rpc_msg call_msg;
 127
 128   cl = (CLIENT *) mem_alloc (sizeof (CLIENT));
 129   if (cl == NULL)
 130     {
 131       struct rpc_createerr *ce = &get_rpc_createerr ();
 132       (void) fprintf (stderr, _("clntudp_create: out of memory\n"));
 133       ce->cf_stat = RPC_SYSTEMERROR;
 134       ce->cf_error.re_errno = errno;
 135       goto fooy;
 136     }
 137   sendsz = ((sendsz + 3) / 4) * 4;
 138   recvsz = ((recvsz + 3) / 4) * 4;
 139   cu = (struct cu_data *) mem_alloc (sizeof (*cu) + sendsz + recvsz);
 140   if (cu == NULL)
 141     {
 142       struct rpc_createerr *ce = &get_rpc_createerr ();
 143       (void) fprintf (stderr, _("clntudp_create: out of memory\n"));
 144       ce->cf_stat = RPC_SYSTEMERROR;
 145       ce->cf_error.re_errno = errno;
 146       goto fooy;
 147     }
 148   cu->cu_outbuf = &cu->cu_inbuf[recvsz];
 149
 150   if (raddr->sin_port == 0)
 151     {
 152       u_short port;
 153       if ((port =
 154            pmap_getport (raddr, program, version, IPPROTO_UDP)) == 0)
 155         {
 156           goto fooy;
 157         }
 158       raddr->sin_port = htons (port);
 159     }
 160   cl->cl_ops = &udp_ops;
 161   cl->cl_private = (caddr_t) cu;
 162   cu->cu_raddr = *raddr;
 163   cu->cu_rlen = sizeof (cu->cu_raddr);
 164   cu->cu_wait = wait;
 165   cu->cu_total.tv_sec = -1;
 166   cu->cu_total.tv_usec = -1;
 167   cu->cu_sendsz = sendsz;
 168   cu->cu_recvsz = recvsz;
 169   call_msg.rm_xid = _create_xid ();
 170   call_msg.rm_direction = CALL;
 171   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 172   call_msg.rm_call.cb_prog = program;
 173   call_msg.rm_call.cb_vers = version;
 174   xdrmem_create (&(cu->cu_outxdrs), cu->cu_outbuf,
 175                  sendsz, XDR_ENCODE);
 176   if (!xdr_callhdr (&(cu->cu_outxdrs), &call_msg))
 177     {
 178       goto fooy;
 179     }
 180   cu->cu_xdrpos = XDR_GETPOS (&(cu->cu_outxdrs));
 181   if (*sockp < 0)
 182     {
 183       int dontblock = 1;
 184
 185       *sockp = __socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 186       if (*sockp < 0)
 187         {
 188           struct rpc_createerr *ce = &get_rpc_createerr ();
 189           ce->cf_stat = RPC_SYSTEMERROR;
 190           ce->cf_error.re_errno = errno;
 191           goto fooy;
 192         }
 193       /* attempt to bind to prov port */
 194       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 195       /* the sockets rpc controls are non-blocking */
 196       (void) __ioctl (*sockp, FIONBIO, (char *) &dontblock);
 197 #ifdef IP_RECVERR
 198       {
 199         int on = 1;
 200         setsockopt(*sockp, SOL_IP, IP_RECVERR, &on, sizeof(on));
 201       }
 202 #endif
 203       cu->cu_closeit = TRUE;
 204     }
 205   else
 206     {
 207       cu->cu_closeit = FALSE;
 208     }
 209   cu->cu_sock = *sockp;
 210   cl->cl_auth = authnone_create ();
 211   return cl;
 212 fooy:
 213   if (cu)
 214     mem_free ((caddr_t) cu, sizeof (*cu) + sendsz + recvsz);
 215   if (cl)
 216     mem_free ((caddr_t) cl, sizeof (CLIENT));
 217   return (CLIENT *) NULL;
 218 }
 219
 220 CLIENT *
 221 clntudp_create (raddr, program, version, wait, sockp)
 222      struct sockaddr_in *raddr;
 223      u_long program;
 224      u_long version;
 225      struct timeval wait;
 226      int *sockp;
 227 {
 228
 229   return clntudp_bufcreate (raddr, program, version, wait, sockp,
 230                             UDPMSGSIZE, UDPMSGSIZE);
 231 }
 232
 233 static int
 234 is_network_up (int sock)
 235 {
 236   struct ifconf ifc;
 237   char buf[UDPMSGSIZE];
 238   struct ifreq ifreq, *ifr;
 239   int n;
 240
 241   ifc.ifc_len = sizeof (buf);
 242   ifc.ifc_buf = buf;
 243   if (__ioctl(sock, SIOCGIFCONF, (char *) &ifc) == 0)
 244     {
 245       ifr = ifc.ifc_req;
 246       for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; n--, ifr++)
 247         {
 248           ifreq = *ifr;
 249           if (__ioctl (sock, SIOCGIFFLAGS, (char *) &ifreq) < 0)
 250             break;
 251
 252           if ((ifreq.ifr_flags & IFF_UP)
 253               && ifr->ifr_addr.sa_family == AF_INET)
 254             return 1;
 255         }
 256     }
 257   return 0;
 258 }
 259
 260 static enum clnt_stat
 261 clntudp_call (cl, proc, xargs, argsp, xresults, resultsp, utimeout)
 262      CLIENT *cl;        /* client handle */
 263      u_long proc;               /* procedure number */
 264      xdrproc_t xargs;           /* xdr routine for args */
 265      caddr_t argsp;             /* pointer to args */
 266      xdrproc_t xresults;        /* xdr routine for results */
 267      caddr_t resultsp;          /* pointer to results */
 268      struct timeval utimeout;   /* seconds to wait before giving up */
 269 {
 270   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 271   XDR *xdrs;
 272   int outlen = 0;
 273   int inlen;
 274   socklen_t fromlen;
 275   struct pollfd fd;
 276   int milliseconds = (cu->cu_wait.tv_sec * 1000) +
 277     (cu->cu_wait.tv_usec / 1000);
 278   struct sockaddr_in from;
 279   struct rpc_msg reply_msg;
 280   XDR reply_xdrs;
 281   struct timeval time_waited;
 282   bool_t ok;
 283   int nrefreshes = 2;           /* number of times to refresh cred */
 284   struct timeval timeout;
 285   int anyup;                    /* any network interface up */
 286
 287   if (cu->cu_total.tv_usec == -1)
 288     {
 289       timeout = utimeout;       /* use supplied timeout */
 290     }
 291   else
 292     {
 293       timeout = cu->cu_total;   /* use default timeout */
 294     }
 295
 296   time_waited.tv_sec = 0;
 297   time_waited.tv_usec = 0;
 298 call_again:
 299   xdrs = &(cu->cu_outxdrs);
 300   if (xargs == NULL)
 301     goto get_reply;
 302   xdrs->x_op = XDR_ENCODE;
 303   XDR_SETPOS (xdrs, cu->cu_xdrpos);
 304   /*
 305    * the transaction is the first thing in the out buffer
 306    */
 307   (*(uint32_t *) (cu->cu_outbuf))++;
 308   if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 309       (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||
 310       (!(*xargs) (xdrs, argsp)))
 311     return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
 312   outlen = (int) XDR_GETPOS (xdrs);
 313
 314 send_again:
 315   if (sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,
 316               (struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)
 317       != outlen)
 318     {
 319       cu->cu_error.re_errno = errno;
 320       return (cu->cu_error.re_status = RPC_CANTSEND);
 321     }
 322
 323   /*
 324    * Hack to provide rpc-based message passing
 325    */
 326   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 327     {
 328       return (cu->cu_error.re_status = RPC_TIMEDOUT);
 329     }
 330  get_reply:
 331   /*
 332    * sub-optimal code appears here because we have
 333    * some clock time to spare while the packets are in flight.
 334    * (We assume that this is actually only executed once.)
 335    */
 336   reply_msg.acpted_rply.ar_verf = _null_auth;
 337   reply_msg.acpted_rply.ar_results.where = resultsp;
 338   reply_msg.acpted_rply.ar_results.proc = xresults;
 339   fd.fd = cu->cu_sock;
 340   fd.events = POLLIN;
 341   anyup = 0;
 342   for (;;)
 343     {
 344       switch (__poll (&fd, 1, milliseconds))
 345         {
 346
 347         case 0:
 348           if (anyup == 0)
 349             {
 350               anyup = is_network_up (cu->cu_sock);
 351               if (!anyup)
 352                 return (cu->cu_error.re_status = RPC_CANTRECV);
 353             }
 354
 355           time_waited.tv_sec += cu->cu_wait.tv_sec;
 356           time_waited.tv_usec += cu->cu_wait.tv_usec;
 357           while (time_waited.tv_usec >= 1000000)
 358             {
 359               time_waited.tv_sec++;
 360               time_waited.tv_usec -= 1000000;
 361             }
 362           if ((time_waited.tv_sec < timeout.tv_sec) ||
 363               ((time_waited.tv_sec == timeout.tv_sec) &&
 364                (time_waited.tv_usec < timeout.tv_usec)))
 365             goto send_again;
 366           return (cu->cu_error.re_status = RPC_TIMEDOUT);
 367
 368           /*
 369            * buggy in other cases because time_waited is not being
 370            * updated.
 371            */
 372         case -1:
 373           if (errno == EINTR)
 374             continue;
 375           cu->cu_error.re_errno = errno;
 376           return (cu->cu_error.re_status = RPC_CANTRECV);
 377         }
 378 #ifdef IP_RECVERR
 379       if (fd.revents & POLLERR)
 380         {
 381           struct msghdr msg;
 382           struct cmsghdr *cmsg;
 383           struct sock_extended_err *e;
 384           struct sockaddr_in err_addr;
 385           struct iovec iov;
 386           char *cbuf = (char *) alloca (outlen + 256);
 387           int ret;
 388
 389           iov.iov_base = cbuf + 256;
 390           iov.iov_len = outlen;
 391           msg.msg_name = (void *) &err_addr;
 392           msg.msg_namelen = sizeof (err_addr);
 393           msg.msg_iov = &iov;
 394           msg.msg_iovlen = 1;
 395           msg.msg_flags = 0;
 396           msg.msg_control = cbuf;
 397           msg.msg_controllen = 256;
 398           ret = recvmsg (cu->cu_sock, &msg, MSG_ERRQUEUE);
 399           if (ret >= 0
 400               && memcmp (cbuf + 256, cu->cu_outbuf, ret) == 0
 401               && (msg.msg_flags & MSG_ERRQUEUE)
 402               && ((msg.msg_namelen == 0
 403                    && ret >= 12)
 404                   || (msg.msg_namelen == sizeof (err_addr)
 405                       && err_addr.sin_family == AF_INET
 406                       && memcmp (&err_addr.sin_addr, &cu->cu_raddr.sin_addr,
 407                                  sizeof (err_addr.sin_addr)) == 0
 408                       && err_addr.sin_port == cu->cu_raddr.sin_port)))
 409             for (cmsg = CMSG_FIRSTHDR (&msg); cmsg;
 410                  cmsg = CMSG_NXTHDR (&msg, cmsg))
 411               if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
 412                 {
 413                   e = (struct sock_extended_err *) CMSG_DATA(cmsg);
 414                   cu->cu_error.re_errno = e->ee_errno;
 415                   return (cu->cu_error.re_status = RPC_CANTRECV);
 416                 }
 417         }
 418 #endif
 419       do
 420         {
 421           fromlen = sizeof (struct sockaddr);
 422           inlen = recvfrom (cu->cu_sock, cu->cu_inbuf,
 423                             (int) cu->cu_recvsz, 0,
 424                             (struct sockaddr *) &from, &fromlen);
 425         }
 426       while (inlen < 0 && errno == EINTR);
 427       if (inlen < 0)
 428         {
 429           if (errno == EWOULDBLOCK)
 430             continue;
 431           cu->cu_error.re_errno = errno;
 432           return (cu->cu_error.re_status = RPC_CANTRECV);
 433         }
 434       if (inlen < 4)
 435         continue;
 436
 437       /* see if reply transaction id matches sent id.
 438         Don't do this if we only wait for a replay */
 439       if (xargs != NULL
 440           && (*((u_int32_t *) (cu->cu_inbuf))
 441               != *((u_int32_t *) (cu->cu_outbuf))))
 442         continue;
 443       /* we now assume we have the proper reply */
 444       break;
 445     }
 446
 447   /*
 448    * now decode and validate the response
 449    */
 450   xdrmem_create (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);
 451   ok = xdr_replymsg (&reply_xdrs, &reply_msg);
 452   /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
 453   if (ok)
 454     {
 455       _seterr_reply (&reply_msg, &(cu->cu_error));
 456       if (cu->cu_error.re_status == RPC_SUCCESS)
 457         {
 458           if (!AUTH_VALIDATE (cl->cl_auth,
 459                               &reply_msg.acpted_rply.ar_verf))
 460             {
 461               cu->cu_error.re_status = RPC_AUTHERROR;
 462               cu->cu_error.re_why = AUTH_INVALIDRESP;
 463             }
 464           if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 465             {
 466               xdrs->x_op = XDR_FREE;
 467               (void) xdr_opaque_auth (xdrs,
 468                                       &(reply_msg.acpted_rply.ar_verf));
 469             }
 470         }                       /* end successful completion */
 471       else
 472         {
 473           /* maybe our credentials need to be refreshed ... */
 474           if (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))
 475             {
 476               nrefreshes--;
 477               goto call_again;
 478             }
 479         }                       /* end of unsuccessful completion */
 480     }                           /* end of valid reply message */
 481   else
 482     {
 483       cu->cu_error.re_status = RPC_CANTDECODERES;
 484     }
 485   return cu->cu_error.re_status;
 486 }
 487
 488 static void
 489 clntudp_geterr (CLIENT *cl, struct rpc_err *errp)
 490 {
 491   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 492
 493   *errp = cu->cu_error;
 494 }
 495
 496
 497 static bool_t
 498 clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 499 {
 500   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 501   XDR *xdrs = &(cu->cu_outxdrs);
 502
 503   xdrs->x_op = XDR_FREE;
 504   return (*xdr_res) (xdrs, res_ptr);
 505 }
 506
 507 static void
 508 clntudp_abort (void)
 509 {
 510 }
 511
 512 static bool_t
 513 clntudp_control (CLIENT *cl, int request, char *info)
 514 {
 515   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 516
 517   switch (request)
 518     {
 519     case CLSET_FD_CLOSE:
 520       cu->cu_closeit = TRUE;
 521       break;
 522     case CLSET_FD_NCLOSE:
 523       cu->cu_closeit = FALSE;
 524       break;
 525     case CLSET_TIMEOUT:
 526       cu->cu_total = *(struct timeval *) info;
 527       break;
 528     case CLGET_TIMEOUT:
 529       *(struct timeval *) info = cu->cu_total;
 530       break;
 531     case CLSET_RETRY_TIMEOUT:
 532       cu->cu_wait = *(struct timeval *) info;
 533       break;
 534     case CLGET_RETRY_TIMEOUT:
 535       *(struct timeval *) info = cu->cu_wait;
 536       break;
 537     case CLGET_SERVER_ADDR:
 538       *(struct sockaddr_in *) info = cu->cu_raddr;
 539       break;
 540     case CLGET_FD:
 541       *(int *)info = cu->cu_sock;
 542       break;
 543     case CLGET_XID:
 544       /*
 545        * use the knowledge that xid is the
 546        * first element in the call structure *.
 547        * This will get the xid of the PREVIOUS call
 548        */
 549       *(u_long *)info = ntohl(*(u_long *)cu->cu_outbuf);
 550       break;
 551     case CLSET_XID:
 552       /* This will set the xid of the NEXT call */
 553       *(u_long *)cu->cu_outbuf =  htonl(*(u_long *)info - 1);
 554       /* decrement by 1 as clntudp_call() increments once */
 555     case CLGET_VERS:
 556       /*
 557        * This RELIES on the information that, in the call body,
 558        * the version number field is the fifth field from the
 559        * begining of the RPC header. MUST be changed if the
 560        * call_struct is changed
 561        */
 562       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 563                                           4 * BYTES_PER_XDR_UNIT));
 564       break;
 565     case CLSET_VERS:
 566       *(u_long *)(cu->cu_outbuf + 4 * BYTES_PER_XDR_UNIT)
 567         = htonl(*(u_long *)info);
 568       break;
 569     case CLGET_PROG:
 570       /*
 571        * This RELIES on the information that, in the call body,
 572        * the program number field is the  field from the
 573        * begining of the RPC header. MUST be changed if the
 574        * call_struct is changed
 575        */
 576       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 577                                           3 * BYTES_PER_XDR_UNIT));
 578       break;
 579     case CLSET_PROG:
 580       *(u_long *)(cu->cu_outbuf + 3 * BYTES_PER_XDR_UNIT)
 581         = htonl(*(u_long *)info);
 582       break;
 583     /* The following are only possible with TI-RPC */
 584     case CLGET_SVC_ADDR:
 585     case CLSET_SVC_ADDR:
 586     case CLSET_PUSH_TIMOD:
 587     case CLSET_POP_TIMOD:
 588     default:
 589       return FALSE;
 590     }
 591   return TRUE;
 592 }
 593
 594 static void
 595 clntudp_destroy (CLIENT *cl)
 596 {
 597   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 598
 599   if (cu->cu_closeit)
 600     {
 601       (void) __close (cu->cu_sock);
 602     }
 603   XDR_DESTROY (&(cu->cu_outxdrs));
 604   mem_free ((caddr_t) cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
 605   mem_free ((caddr_t) cl, sizeof (CLIENT));
 606 }