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 0
  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 #define __FORCE_GLIBC
  41 #include <features.h>
  42
  43 #include <stdio.h>
  44 #include <unistd.h>
  45 #include <rpc/rpc.h>
  46 #include <rpc/xdr.h>
  47 #include <rpc/clnt.h>
  48 #include <poll.h>
  49 #include <sys/socket.h>
  50 #include <sys/ioctl.h>
  51 #include <netdb.h>
  52 #include <errno.h>
  53 #include <rpc/pmap_clnt.h>
  54 #include <net/if.h>
  55 #ifdef USE_IN_LIBIO
  56 # include <wchar.h>
  57 #endif
  58
  59 #ifdef IP_RECVERR
  60 #include "errqueue.h"
  61 #include <sys/uio.h>
  62 #endif
  63
  64 /* CMSG_NXTHDR is using it */
  65
  66
  67 extern u_long _create_xid (void) attribute_hidden;
  68
  69 /*
  70  * UDP bases client side rpc operations
  71  */
  72 static enum clnt_stat clntudp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  73                                     xdrproc_t, caddr_t, struct timeval);
  74 static void clntudp_abort (void);
  75 static void clntudp_geterr (CLIENT *, struct rpc_err *);
  76 static bool_t clntudp_freeres (CLIENT *, xdrproc_t, caddr_t);
  77 static bool_t clntudp_control (CLIENT *, int, char *);
  78 static void clntudp_destroy (CLIENT *);
  79
  80 static const struct clnt_ops udp_ops =
  81 {
  82   clntudp_call,
  83   clntudp_abort,
  84   clntudp_geterr,
  85   clntudp_freeres,
  86   clntudp_destroy,
  87   clntudp_control
  88 };
  89
  90 /*
  91  * Private data kept per client handle
  92  */
  93 struct cu_data
  94   {
  95     int cu_sock;
  96     bool_t cu_closeit;
  97     struct sockaddr_in cu_raddr;
  98     int cu_rlen;
  99     struct timeval cu_wait;
 100     struct timeval cu_total;
 101     struct rpc_err cu_error;
 102     XDR cu_outxdrs;
 103     u_int cu_xdrpos;
 104     u_int cu_sendsz;
 105     char *cu_outbuf;
 106     u_int cu_recvsz;
 107     char cu_inbuf[1];
 108   };
 109
 110 /*
 111  * Create a UDP based client handle.
 112  * If *sockp<0, *sockp is set to a newly created UPD socket.
 113  * If raddr->sin_port is 0 a binder on the remote machine
 114  * is consulted for the correct port number.
 115  * NB: It is the clients responsibility to close *sockp.
 116  * NB: The rpch->cl_auth is initialized to null authentication.
 117  *     Caller may wish to set this something more useful.
 118  *
 119  * wait is the amount of time used between retransmitting a call if
 120  * no response has been heard; retransmission occurs until the actual
 121  * rpc call times out.
 122  *
 123  * sendsz and recvsz are the maximum allowable packet sizes that can be
 124  * sent and received.
 125  */
 126 CLIENT *
 127 clntudp_bufcreate (struct sockaddr_in *raddr, u_long program, u_long version,
 128                    struct timeval wait, int *sockp, u_int sendsz,
 129                    u_int recvsz)
 130 {
 131   CLIENT *cl;
 132   struct cu_data *cu = NULL;
 133   struct rpc_msg call_msg;
 134
 135   cl = (CLIENT *) mem_alloc (sizeof (CLIENT));
 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 (cl == NULL || cu == NULL)
 140     {
 141       struct rpc_createerr *ce = &get_rpc_createerr ();
 142 #ifdef USE_IN_LIBIO
 143       if (_IO_fwide (stderr, 0) > 0)
 144         (void) fwprintf (stderr, L"%s",
 145                            _("clntudp_create: out of memory\n"));
 146       else
 147 #endif
 148         (void) fputs (_("clntudp_create: out of memory\n"), stderr);
 149       ce->cf_stat = RPC_SYSTEMERROR;
 150       ce->cf_error.re_errno = ENOMEM;
 151       goto fooy;
 152     }
 153   cu->cu_outbuf = &cu->cu_inbuf[recvsz];
 154
 155   if (raddr->sin_port == 0)
 156     {
 157       u_short port;
 158       if ((port =
 159            pmap_getport (raddr, program, version, IPPROTO_UDP)) == 0)
 160         {
 161           goto fooy;
 162         }
 163       raddr->sin_port = htons (port);
 164     }
 165   cl->cl_ops = &udp_ops;
 166   cl->cl_private = (caddr_t) cu;
 167   cu->cu_raddr = *raddr;
 168   cu->cu_rlen = sizeof (cu->cu_raddr);
 169   cu->cu_wait = wait;
 170   cu->cu_total.tv_sec = -1;
 171   cu->cu_total.tv_usec = -1;
 172   cu->cu_sendsz = sendsz;
 173   cu->cu_recvsz = recvsz;
 174   call_msg.rm_xid = _create_xid ();
 175   call_msg.rm_direction = CALL;
 176   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 177   call_msg.rm_call.cb_prog = program;
 178   call_msg.rm_call.cb_vers = version;
 179   xdrmem_create (&(cu->cu_outxdrs), cu->cu_outbuf,
 180                  sendsz, XDR_ENCODE);
 181   if (!xdr_callhdr (&(cu->cu_outxdrs), &call_msg))
 182     {
 183       goto fooy;
 184     }
 185   cu->cu_xdrpos = XDR_GETPOS (&(cu->cu_outxdrs));
 186   if (*sockp < 0)
 187     {
 188       int dontblock = 1;
 189
 190       *sockp = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 191       if (*sockp < 0)
 192         {
 193           struct rpc_createerr *ce = &get_rpc_createerr ();
 194           ce->cf_stat = RPC_SYSTEMERROR;
 195           ce->cf_error.re_errno = errno;
 196           goto fooy;
 197         }
 198       /* attempt to bind to prov port */
 199       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 200       /* the sockets rpc controls are non-blocking */
 201       (void) ioctl (*sockp, FIONBIO, (char *) &dontblock);
 202 #ifdef IP_RECVERR
 203       {
 204         int on = 1;
 205         setsockopt(*sockp, SOL_IP, IP_RECVERR, &on, sizeof(on));
 206       }
 207 #endif
 208       cu->cu_closeit = TRUE;
 209     }
 210   else
 211     {
 212       cu->cu_closeit = FALSE;
 213     }
 214   cu->cu_sock = *sockp;
 215   cl->cl_auth = authnone_create ();
 216   return cl;
 217 fooy:
 218   if (cu)
 219     mem_free ((caddr_t) cu, sizeof (*cu) + sendsz + recvsz);
 220   if (cl)
 221     mem_free ((caddr_t) cl, sizeof (CLIENT));
 222   return (CLIENT *) NULL;
 223 }
 224 libc_hidden_def(clntudp_bufcreate)
 225
 226 CLIENT *
 227 clntudp_create (struct sockaddr_in *raddr, u_long program, u_long version, struct timeval wait, int *sockp)
 228 {
 229
 230   return clntudp_bufcreate (raddr, program, version, wait, sockp,
 231                             UDPMSGSIZE, UDPMSGSIZE);
 232 }
 233 libc_hidden_def(clntudp_create)
 234
 235 static int
 236 is_network_up (int sock)
 237 {
 238   struct ifconf ifc;
 239   char buf[UDPMSGSIZE];
 240   struct ifreq ifreq, *ifr;
 241   int n;
 242
 243   ifc.ifc_len = sizeof (buf);
 244   ifc.ifc_buf = buf;
 245   if (ioctl(sock, SIOCGIFCONF, (char *) &ifc) == 0)
 246     {
 247       ifr = ifc.ifc_req;
 248       for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; n--, ifr++)
 249         {
 250           ifreq = *ifr;
 251           if (ioctl (sock, SIOCGIFFLAGS, (char *) &ifreq) < 0)
 252             break;
 253
 254           if ((ifreq.ifr_flags & IFF_UP)
 255               && ifr->ifr_addr.sa_family == AF_INET)
 256             return 1;
 257         }
 258     }
 259   return 0;
 260 }
 261
 262 static enum clnt_stat
 263 clntudp_call (
 264      CLIENT *cl,        /* client handle */
 265      u_long proc,               /* procedure number */
 266      xdrproc_t xargs,           /* xdr routine for args */
 267      caddr_t argsp,             /* pointer to args */
 268      xdrproc_t xresults,        /* xdr routine for results */
 269      caddr_t resultsp,          /* pointer to results */
 270      struct timeval utimeout    /* seconds to wait before giving up */)
 271 {
 272   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 273   XDR *xdrs;
 274   int outlen = 0;
 275   int inlen;
 276   socklen_t fromlen;
 277   struct pollfd fd;
 278   int milliseconds = (cu->cu_wait.tv_sec * 1000) +
 279     (cu->cu_wait.tv_usec / 1000);
 280   struct sockaddr_in from;
 281   struct rpc_msg reply_msg;
 282   XDR reply_xdrs;
 283   struct timeval time_waited;
 284   bool_t ok;
 285   int nrefreshes = 2;           /* number of times to refresh cred */
 286   struct timeval timeout;
 287   int anyup;                    /* any network interface up */
 288
 289   if (cu->cu_total.tv_usec == -1)
 290     {
 291       timeout = utimeout;       /* use supplied timeout */
 292     }
 293   else
 294     {
 295       timeout = cu->cu_total;   /* use default timeout */
 296     }
 297
 298   time_waited.tv_sec = 0;
 299   time_waited.tv_usec = 0;
 300 call_again:
 301   xdrs = &(cu->cu_outxdrs);
 302   if (xargs == NULL)
 303     goto get_reply;
 304   xdrs->x_op = XDR_ENCODE;
 305   XDR_SETPOS (xdrs, cu->cu_xdrpos);
 306   /*
 307    * the transaction is the first thing in the out buffer
 308    */
 309   (*(uint32_t *) (cu->cu_outbuf))++;
 310   if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 311       (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||
 312       (!(*xargs) (xdrs, argsp)))
 313     return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
 314   outlen = (int) XDR_GETPOS (xdrs);
 315
 316 send_again:
 317   if (sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,
 318               (struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)
 319       != outlen)
 320     {
 321       cu->cu_error.re_errno = errno;
 322       return (cu->cu_error.re_status = RPC_CANTSEND);
 323     }
 324
 325   /*
 326    * Hack to provide rpc-based message passing
 327    */
 328   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 329     {
 330       return (cu->cu_error.re_status = RPC_TIMEDOUT);
 331     }
 332  get_reply:
 333   /*
 334    * sub-optimal code appears here because we have
 335    * some clock time to spare while the packets are in flight.
 336    * (We assume that this is actually only executed once.)
 337    */
 338   reply_msg.acpted_rply.ar_verf = _null_auth;
 339   reply_msg.acpted_rply.ar_results.where = resultsp;
 340   reply_msg.acpted_rply.ar_results.proc = xresults;
 341   fd.fd = cu->cu_sock;
 342   fd.events = POLLIN;
 343   anyup = 0;
 344   for (;;)
 345     {
 346       switch (poll (&fd, 1, milliseconds))
 347         {
 348
 349         case 0:
 350           if (anyup == 0)
 351             {
 352               anyup = is_network_up (cu->cu_sock);
 353               if (!anyup)
 354                 return (cu->cu_error.re_status = RPC_CANTRECV);
 355             }
 356
 357           time_waited.tv_sec += cu->cu_wait.tv_sec;
 358           time_waited.tv_usec += cu->cu_wait.tv_usec;
 359           while (time_waited.tv_usec >= 1000000)
 360             {
 361               time_waited.tv_sec++;
 362               time_waited.tv_usec -= 1000000;
 363             }
 364           if ((time_waited.tv_sec < timeout.tv_sec) ||
 365               ((time_waited.tv_sec == timeout.tv_sec) &&
 366                (time_waited.tv_usec < timeout.tv_usec)))
 367             goto send_again;
 368           return (cu->cu_error.re_status = RPC_TIMEDOUT);
 369
 370           /*
 371            * buggy in other cases because time_waited is not being
 372            * updated.
 373            */
 374         case -1:
 375           if (errno == EINTR)
 376             continue;
 377           cu->cu_error.re_errno = errno;
 378           return (cu->cu_error.re_status = RPC_CANTRECV);
 379         }
 380 #ifdef IP_RECVERR
 381       if (fd.revents & POLLERR)
 382         {
 383           struct msghdr msg;
 384           struct cmsghdr *cmsg;
 385           struct sock_extended_err *e;
 386           struct sockaddr_in err_addr;
 387           struct iovec iov;
 388           char *cbuf = (char *) alloca (outlen + 256);
 389           int ret;
 390
 391           iov.iov_base = cbuf + 256;
 392           iov.iov_len = outlen;
 393           msg.msg_name = (void *) &err_addr;
 394           msg.msg_namelen = sizeof (err_addr);
 395           msg.msg_iov = &iov;
 396           msg.msg_iovlen = 1;
 397           msg.msg_flags = 0;
 398           msg.msg_control = cbuf;
 399           msg.msg_controllen = 256;
 400           ret = recvmsg (cu->cu_sock, &msg, MSG_ERRQUEUE);
 401           if (ret >= 0
 402               && memcmp (cbuf + 256, cu->cu_outbuf, ret) == 0
 403               && (msg.msg_flags & MSG_ERRQUEUE)
 404               && ((msg.msg_namelen == 0
 405                    && ret >= 12)
 406                   || (msg.msg_namelen == sizeof (err_addr)
 407                       && err_addr.sin_family == AF_INET
 408                       && memcmp (&err_addr.sin_addr, &cu->cu_raddr.sin_addr,
 409                                  sizeof (err_addr.sin_addr)) == 0
 410                       && err_addr.sin_port == cu->cu_raddr.sin_port)))
 411             for (cmsg = CMSG_FIRSTHDR (&msg); cmsg;
 412                  cmsg = CMSG_NXTHDR (&msg, cmsg))
 413               if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
 414                 {
 415                   e = (struct sock_extended_err *) CMSG_DATA(cmsg);
 416                   cu->cu_error.re_errno = e->ee_errno;
 417                   return (cu->cu_error.re_status = RPC_CANTRECV);
 418                 }
 419         }
 420 #endif
 421       do
 422         {
 423           fromlen = sizeof (struct sockaddr);
 424           inlen = recvfrom (cu->cu_sock, cu->cu_inbuf,
 425                             (int) cu->cu_recvsz, 0,
 426                             (struct sockaddr *) &from, &fromlen);
 427         }
 428       while (inlen < 0 && errno == EINTR);
 429       if (inlen < 0)
 430         {
 431           if (errno == EWOULDBLOCK)
 432             continue;
 433           cu->cu_error.re_errno = errno;
 434           return (cu->cu_error.re_status = RPC_CANTRECV);
 435         }
 436       if (inlen < 4)
 437         continue;
 438
 439       /* see if reply transaction id matches sent id.
 440         Don't do this if we only wait for a replay */
 441       if (xargs != NULL
 442           && (*((u_int32_t *) (cu->cu_inbuf))
 443               != *((u_int32_t *) (cu->cu_outbuf))))
 444         continue;
 445       /* we now assume we have the proper reply */
 446       break;
 447     }
 448
 449   /*
 450    * now decode and validate the response
 451    */
 452   xdrmem_create (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);
 453   ok = xdr_replymsg (&reply_xdrs, &reply_msg);
 454   /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
 455   if (ok)
 456     {
 457       _seterr_reply (&reply_msg, &(cu->cu_error));
 458       if (cu->cu_error.re_status == RPC_SUCCESS)
 459         {
 460           if (!AUTH_VALIDATE (cl->cl_auth,
 461                               &reply_msg.acpted_rply.ar_verf))
 462             {
 463               cu->cu_error.re_status = RPC_AUTHERROR;
 464               cu->cu_error.re_why = AUTH_INVALIDRESP;
 465             }
 466           if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 467             {
 468               xdrs->x_op = XDR_FREE;
 469               (void) xdr_opaque_auth (xdrs,
 470                                       &(reply_msg.acpted_rply.ar_verf));
 471             }
 472         }                       /* end successful completion */
 473       else
 474         {
 475           /* maybe our credentials need to be refreshed ... */
 476           if (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))
 477             {
 478               nrefreshes--;
 479               goto call_again;
 480             }
 481         }                       /* end of unsuccessful completion */
 482     }                           /* end of valid reply message */
 483   else
 484     {
 485       cu->cu_error.re_status = RPC_CANTDECODERES;
 486     }
 487   return cu->cu_error.re_status;
 488 }
 489
 490 static void
 491 clntudp_geterr (CLIENT *cl, struct rpc_err *errp)
 492 {
 493   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 494
 495   *errp = cu->cu_error;
 496 }
 497
 498
 499 static bool_t
 500 clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 501 {
 502   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 503   XDR *xdrs = &(cu->cu_outxdrs);
 504
 505   xdrs->x_op = XDR_FREE;
 506   return (*xdr_res) (xdrs, res_ptr);
 507 }
 508
 509 static void
 510 clntudp_abort (void)
 511 {
 512 }
 513
 514 static bool_t
 515 clntudp_control (CLIENT *cl, int request, char *info)
 516 {
 517   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 518
 519   switch (request)
 520     {
 521     case CLSET_FD_CLOSE:
 522       cu->cu_closeit = TRUE;
 523       break;
 524     case CLSET_FD_NCLOSE:
 525       cu->cu_closeit = FALSE;
 526       break;
 527     case CLSET_TIMEOUT:
 528       cu->cu_total = *(struct timeval *) info;
 529       break;
 530     case CLGET_TIMEOUT:
 531       *(struct timeval *) info = cu->cu_total;
 532       break;
 533     case CLSET_RETRY_TIMEOUT:
 534       cu->cu_wait = *(struct timeval *) info;
 535       break;
 536     case CLGET_RETRY_TIMEOUT:
 537       *(struct timeval *) info = cu->cu_wait;
 538       break;
 539     case CLGET_SERVER_ADDR:
 540       *(struct sockaddr_in *) info = cu->cu_raddr;
 541       break;
 542     case CLGET_FD:
 543       *(int *)info = cu->cu_sock;
 544       break;
 545     case CLGET_XID:
 546       /*
 547        * use the knowledge that xid is the
 548        * first element in the call structure *.
 549        * This will get the xid of the PREVIOUS call
 550        */
 551       *(u_long *)info = ntohl(*(u_long *)cu->cu_outbuf);
 552       break;
 553     case CLSET_XID:
 554       /* This will set the xid of the NEXT call */
 555       *(u_long *)cu->cu_outbuf =  htonl(*(u_long *)info - 1);
 556       /* decrement by 1 as clntudp_call() increments once */
 557     case CLGET_VERS:
 558       /*
 559        * This RELIES on the information that, in the call body,
 560        * the version number field is the fifth field from the
 561        * begining of the RPC header. MUST be changed if the
 562        * call_struct is changed
 563        */
 564       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 565                                           4 * BYTES_PER_XDR_UNIT));
 566       break;
 567     case CLSET_VERS:
 568       *(u_long *)(cu->cu_outbuf + 4 * BYTES_PER_XDR_UNIT)
 569         = htonl(*(u_long *)info);
 570       break;
 571     case CLGET_PROG:
 572       /*
 573        * This RELIES on the information that, in the call body,
 574        * the program number field is the  field from the
 575        * begining of the RPC header. MUST be changed if the
 576        * call_struct is changed
 577        */
 578       *(u_long *)info = ntohl(*(u_long *)(cu->cu_outbuf +
 579                                           3 * BYTES_PER_XDR_UNIT));
 580       break;
 581     case CLSET_PROG:
 582       *(u_long *)(cu->cu_outbuf + 3 * BYTES_PER_XDR_UNIT)
 583         = htonl(*(u_long *)info);
 584       break;
 585     /* The following are only possible with TI-RPC */
 586     case CLGET_SVC_ADDR:
 587     case CLSET_SVC_ADDR:
 588     case CLSET_PUSH_TIMOD:
 589     case CLSET_POP_TIMOD:
 590     default:
 591       return FALSE;
 592     }
 593   return TRUE;
 594 }
 595
 596 static void
 597 clntudp_destroy (CLIENT *cl)
 598 {
 599   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 600
 601   if (cu->cu_closeit)
 602     {
 603       (void) close (cu->cu_sock);
 604     }
 605   XDR_DESTROY (&(cu->cu_outxdrs));
 606   mem_free ((caddr_t) cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
 607   mem_free ((caddr_t) cl, sizeof (CLIENT));
 608 }