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