libc/inet/rpc/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 #include <stdio.h>
  41 #include <unistd.h>
  42 #include "rpc_private.h"
  43 #include <rpc/xdr.h>
  44 #include <rpc/clnt.h>
  45 #include <sys/poll.h>
  46 #include <sys/socket.h>
  47 #include <sys/ioctl.h>
  48 #include <netdb.h>
  49 #include <errno.h>
  50 #include <rpc/pmap_clnt.h>
  51 #include <net/if.h>
  52
  53 #ifdef IP_RECVERR
  54 #include "errqueue.h"
  55 #include <sys/uio.h>
  56 #endif
  57
  58 /*
  59  * UDP bases client side rpc operations
  60  */
  61 static enum clnt_stat clntudp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  62                                     xdrproc_t, caddr_t, struct timeval);
  63 static void clntudp_abort (void);
  64 static void clntudp_geterr (CLIENT *, struct rpc_err *);
  65 static bool_t clntudp_freeres (CLIENT *, xdrproc_t, caddr_t);
  66 static bool_t clntudp_control (CLIENT *, int, char *);
  67 static void clntudp_destroy (CLIENT *);
  68
  69 static const struct clnt_ops udp_ops =
  70 {
  71   clntudp_call,
  72   clntudp_abort,
  73   clntudp_geterr,
  74   clntudp_freeres,
  75   clntudp_destroy,
  76   clntudp_control
  77 };
  78
  79 /*
  80  * Private data kept per client handle
  81  */
  82 struct cu_data
  83   {
  84     int cu_sock;
  85     bool_t cu_closeit;
  86     struct sockaddr_in cu_raddr;
  87     int cu_rlen;
  88     struct timeval cu_wait;
  89     struct timeval cu_total;
  90     struct rpc_err cu_error;
  91     XDR cu_outxdrs;
  92     u_int cu_xdrpos;
  93     u_int cu_sendsz;
  94     char *cu_outbuf;
  95     u_int cu_recvsz;
  96     char cu_inbuf[1];
  97   };
  98
  99 /*
 100  * Create a UDP based client handle.
 101  * If *sockp<0, *sockp is set to a newly created UPD socket.
 102  * If raddr->sin_port is 0 a binder on the remote machine
 103  * is consulted for the correct port number.
 104  * NB: It is the clients responsibility to close *sockp.
 105  * NB: The rpch->cl_auth is initialized to null authentication.
 106  *     Caller may wish to set this something more useful.
 107  *
 108  * _wait is the amount of time used between retransmitting a call if
 109  * no response has been heard; retransmission occurs until the actual
 110  * rpc call times out.
 111  *
 112  * sendsz and recvsz are the maximum allowable packet sizes that can be
 113  * sent and received.
 114  */
 115 CLIENT *
 116 clntudp_bufcreate (struct sockaddr_in *raddr, u_long program, u_long version,
 117                    struct timeval _wait, int *sockp, u_int sendsz,
 118                    u_int recvsz)
 119 {
 120   CLIENT *cl;
 121   struct cu_data *cu = NULL;
 122   struct rpc_msg call_msg;
 123
 124   cl = (CLIENT *) mem_alloc (sizeof (CLIENT));
 125   sendsz = ((sendsz + 3) / 4) * 4;
 126   recvsz = ((recvsz + 3) / 4) * 4;
 127   cu = (struct cu_data *) mem_alloc (sizeof (*cu) + sendsz + recvsz);
 128   if (cl == NULL || cu == NULL)
 129     {
 130       struct rpc_createerr *ce = &get_rpc_createerr ();
 131       (void) fputs (_("clntudp_create: out of memory\n"), stderr);
 132       ce->cf_stat = RPC_SYSTEMERROR;
 133       ce->cf_error.re_errno = ENOMEM;
 134       goto fooy;
 135     }
 136   cu->cu_outbuf = &cu->cu_inbuf[recvsz];
 137
 138   if (raddr->sin_port == 0)
 139     {
 140       u_short port;
 141       if ((port =
 142            pmap_getport (raddr, program, version, IPPROTO_UDP)) == 0)
 143         {
 144           goto fooy;
 145         }
 146       raddr->sin_port = htons (port);
 147     }
 148   cl->cl_ops = &udp_ops;
 149   cl->cl_private = (caddr_t) cu;
 150   cu->cu_raddr = *raddr;
 151   cu->cu_rlen = sizeof (cu->cu_raddr);
 152   cu->cu_wait = _wait;
 153   cu->cu_total.tv_sec = -1;
 154   cu->cu_total.tv_usec = -1;
 155   cu->cu_sendsz = sendsz;
 156   cu->cu_recvsz = recvsz;
 157   call_msg.rm_xid = _create_xid ();
 158   call_msg.rm_direction = CALL;
 159   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 160   call_msg.rm_call.cb_prog = program;
 161   call_msg.rm_call.cb_vers = version;
 162   xdrmem_create (&(cu->cu_outxdrs), cu->cu_outbuf,
 163                  sendsz, XDR_ENCODE);
 164   if (!xdr_callhdr (&(cu->cu_outxdrs), &call_msg))
 165     {
 166       goto fooy;
 167     }
 168   cu->cu_xdrpos = XDR_GETPOS (&(cu->cu_outxdrs));
 169   if (*sockp < 0)
 170     {
 171       int dontblock = 1;
 172
 173       *sockp = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 174       if (*sockp < 0)
 175         {
 176           struct rpc_createerr *ce = &get_rpc_createerr ();
 177           ce->cf_stat = RPC_SYSTEMERROR;
 178           ce->cf_error.re_errno = errno;
 179           goto fooy;
 180         }
 181       /* attempt to bind to prov port */
 182       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 183       /* the sockets rpc controls are non-blocking */
 184       (void) ioctl (*sockp, FIONBIO, (char *) &dontblock);
 185 #ifdef IP_RECVERR
 186       {
 187         int on = 1;
 188         setsockopt(*sockp, SOL_IP, IP_RECVERR, &on, sizeof(on));
 189       }
 190 #endif
 191       cu->cu_closeit = TRUE;
 192     }
 193   else
 194     {
 195       cu->cu_closeit = FALSE;
 196     }
 197   cu->cu_sock = *sockp;
 198   cl->cl_auth = authnone_create ();
 199   return cl;
 200 fooy:
 201   if (cu)
 202     mem_free ((caddr_t) cu, sizeof (*cu) + sendsz + recvsz);
 203   if (cl)
 204     mem_free ((caddr_t) cl, sizeof (CLIENT));
 205   return (CLIENT *) NULL;
 206 }
 207 libc_hidden_def(clntudp_bufcreate)
 208
 209 CLIENT *
 210 clntudp_create (struct sockaddr_in *raddr, u_long program, u_long version, struct timeval _wait, int *sockp)
 211 {
 212
 213   return clntudp_bufcreate (raddr, program, version, _wait, sockp,
 214                             UDPMSGSIZE, UDPMSGSIZE);
 215 }
 216 libc_hidden_def(clntudp_create)
 217
 218 static int
 219 is_network_up (int sock)
 220 {
 221   struct ifconf ifc;
 222   char buf[UDPMSGSIZE];
 223   struct ifreq ifreq, *ifr;
 224   int n;
 225
 226   ifc.ifc_len = sizeof (buf);
 227   ifc.ifc_buf = buf;
 228   if (ioctl(sock, SIOCGIFCONF, (char *) &ifc) == 0)
 229     {
 230       ifr = ifc.ifc_req;
 231       for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; n--, ifr++)
 232         {
 233           ifreq = *ifr;
 234           if (ioctl (sock, SIOCGIFFLAGS, (char *) &ifreq) < 0)
 235             break;
 236
 237           if ((ifreq.ifr_flags & IFF_UP)
 238               && ifr->ifr_addr.sa_family == AF_INET)
 239             return 1;
 240         }
 241     }
 242   return 0;
 243 }
 244
 245 static enum clnt_stat
 246 clntudp_call (
 247      CLIENT *cl,        /* client handle */
 248      u_long proc,               /* procedure number */
 249      xdrproc_t xargs,           /* xdr routine for args */
 250      caddr_t argsp,             /* pointer to args */
 251      xdrproc_t xresults,        /* xdr routine for results */
 252      caddr_t resultsp,          /* pointer to results */
 253      struct timeval utimeout    /* seconds to wait before giving up */)
 254 {
 255   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 256   XDR *xdrs;
 257   int outlen = 0;
 258   int inlen;
 259   socklen_t fromlen;
 260   struct pollfd fd;
 261   int milliseconds = (cu->cu_wait.tv_sec * 1000) +
 262     (cu->cu_wait.tv_usec / 1000);
 263   struct sockaddr_in from;
 264   struct rpc_msg reply_msg;
 265   XDR reply_xdrs;
 266   struct timeval time_waited;
 267   bool_t ok;
 268   int nrefreshes = 2;           /* number of times to refresh cred */
 269   struct timeval timeout;
 270   int anyup;                    /* any network interface up */
 271
 272   if (cu->cu_total.tv_usec == -1)
 273     {
 274       timeout = utimeout;       /* use supplied timeout */
 275     }
 276   else
 277     {
 278       timeout = cu->cu_total;   /* use default timeout */
 279     }
 280
 281   time_waited.tv_sec = 0;
 282   time_waited.tv_usec = 0;
 283 call_again:
 284   xdrs = &(cu->cu_outxdrs);
 285   if (xargs == NULL)
 286     goto get_reply;
 287   xdrs->x_op = XDR_ENCODE;
 288   XDR_SETPOS (xdrs, cu->cu_xdrpos);
 289   /*
 290    * the transaction is the first thing in the out buffer
 291    */
 292   (*(uint32_t *) (cu->cu_outbuf))++;
 293   if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 294       (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||
 295       (!(*xargs) (xdrs, argsp)))
 296     return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
 297   outlen = (int) XDR_GETPOS (xdrs);
 298
 299 send_again:
 300   if (sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,
 301               (struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)
 302       != outlen)
 303     {
 304       cu->cu_error.re_errno = errno;
 305       return (cu->cu_error.re_status = RPC_CANTSEND);
 306     }
 307
 308   /*
 309    * Hack to provide rpc-based message passing
 310    */
 311   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 312     {
 313       return (cu->cu_error.re_status = RPC_TIMEDOUT);
 314     }
 315  get_reply:
 316   /*
 317    * sub-optimal code appears here because we have
 318    * some clock time to spare while the packets are in flight.
 319    * (We assume that this is actually only executed once.)
 320    */
 321   reply_msg.acpted_rply.ar_verf = _null_auth;
 322   reply_msg.acpted_rply.ar_results.where = resultsp;
 323   reply_msg.acpted_rply.ar_results.proc = xresults;
 324   fd.fd = cu->cu_sock;
 325   fd.events = POLLIN;
 326   anyup = 0;
 327   for (;;)
 328     {
 329       switch (poll (&fd, 1, milliseconds))
 330         {
 331
 332         case 0:
 333           if (anyup == 0)
 334             {
 335               anyup = is_network_up (cu->cu_sock);
 336               if (!anyup)
 337                 return (cu->cu_error.re_status = RPC_CANTRECV);
 338             }
 339
 340           time_waited.tv_sec += cu->cu_wait.tv_sec;
 341           time_waited.tv_usec += cu->cu_wait.tv_usec;
 342           while (time_waited.tv_usec >= 1000000)
 343             {
 344               time_waited.tv_sec++;
 345               time_waited.tv_usec -= 1000000;
 346             }
 347           if ((time_waited.tv_sec < timeout.tv_sec) ||
 348               ((time_waited.tv_sec == timeout.tv_sec) &&
 349                (time_waited.tv_usec < timeout.tv_usec)))
 350             goto send_again;
 351           return (cu->cu_error.re_status = RPC_TIMEDOUT);
 352
 353           /*
 354            * buggy in other cases because time_waited is not being
 355            * updated.
 356            */
 357         case -1:
 358           if (errno == EINTR)
 359             continue;
 360           cu->cu_error.re_errno = errno;
 361           return (cu->cu_error.re_status = RPC_CANTRECV);
 362         }
 363 #ifdef IP_RECVERR
 364       if (fd.revents & POLLERR)
 365         {
 366           struct msghdr msg;
 367           struct cmsghdr *cmsg;
 368           struct sock_extended_err *e;
 369           struct sockaddr_in err_addr;
 370           struct iovec iov;
 371           char *cbuf = malloc (outlen + 256);
 372           int ret;
 373
 374           if (cbuf == NULL)
 375             {
 376               cu->cu_error.re_errno = errno;
 377               return (cu->cu_error.re_status = RPC_CANTRECV);
 378             }
 379
 380           iov.iov_base = cbuf + 256;
 381           iov.iov_len = outlen;
 382           msg.msg_name = (void *) &err_addr;
 383           msg.msg_namelen = sizeof (err_addr);
 384           msg.msg_iov = &iov;
 385           msg.msg_iovlen = 1;
 386           msg.msg_flags = 0;
 387           msg.msg_control = cbuf;
 388           msg.msg_controllen = 256;
 389           ret = recvmsg (cu->cu_sock, &msg, MSG_ERRQUEUE);
 390           if (ret >= 0
 391               && memcmp (cbuf + 256, cu->cu_outbuf, ret) == 0
 392               && (msg.msg_flags & MSG_ERRQUEUE)
 393               && ((msg.msg_namelen == 0
 394                    && ret >= 12)
 395                   || (msg.msg_namelen == sizeof (err_addr)
 396                       && err_addr.sin_family == AF_INET
 397                       && memcmp (&err_addr.sin_addr, &cu->cu_raddr.sin_addr,
 398                                  sizeof (err_addr.sin_addr)) == 0
 399                       && err_addr.sin_port == cu->cu_raddr.sin_port)))
 400             for (cmsg = CMSG_FIRSTHDR (&msg); cmsg;
 401                  cmsg = CMSG_NXTHDR (&msg, cmsg))
 402               if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
 403                 {
 404                   free (cbuf);
 405                   e = (struct sock_extended_err *) CMSG_DATA(cmsg);
 406                   cu->cu_error.re_errno = e->ee_errno;
 407                   return (cu->cu_error.re_status = RPC_CANTRECV);
 408                 }
 409           free (cbuf);
 410         }
 411 #endif
 412       do
 413         {
 414           fromlen = sizeof (struct sockaddr);
 415           inlen = recvfrom (cu->cu_sock, cu->cu_inbuf,
 416                             (int) cu->cu_recvsz, 0,
 417                             (struct sockaddr *) &from, &fromlen);
 418         }
 419       while (inlen < 0 && errno == EINTR);
 420       if (inlen < 0)
 421         {
 422           if (errno == EWOULDBLOCK)
 423             continue;
 424           cu->cu_error.re_errno = errno;
 425           return (cu->cu_error.re_status = RPC_CANTRECV);
 426         }
 427       if (inlen < 4)
 428         continue;
 429
 430       /* see if reply transaction id matches sent id.
 431         Don't do this if we only wait for a replay */
 432       if (xargs != NULL
 433           && (*((u_int32_t *) (cu->cu_inbuf))
 434               != *((u_int32_t *) (cu->cu_outbuf))))
 435         continue;
 436       /* we now assume we have the proper reply */
 437       break;
 438     }
 439
 440   /*
 441    * now decode and validate the response
 442    */
 443   xdrmem_create (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);
 444   ok = xdr_replymsg (&reply_xdrs, &reply_msg);
 445   /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
 446   if (ok)
 447     {
 448       _seterr_reply (&reply_msg, &(cu->cu_error));
 449       if (cu->cu_error.re_status == RPC_SUCCESS)
 450         {
 451           if (!AUTH_VALIDATE (cl->cl_auth,
 452                               &reply_msg.acpted_rply.ar_verf))
 453             {
 454               cu->cu_error.re_status = RPC_AUTHERROR;
 455               cu->cu_error.re_why = AUTH_INVALIDRESP;
 456             }
 457           if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 458             {
 459               xdrs->x_op = XDR_FREE;
 460               (void) xdr_opaque_auth (xdrs,
 461                                       &(reply_msg.acpted_rply.ar_verf));
 462             }
 463         }                       /* end successful completion */
 464       else
 465         {
 466           /* maybe our credentials need to be refreshed ... */
 467           if (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))
 468             {
 469               nrefreshes--;
 470               goto call_again;
 471             }
 472         }                       /* end of unsuccessful completion */
 473     }                           /* end of valid reply message */
 474   else
 475     {
 476       cu->cu_error.re_status = RPC_CANTDECODERES;
 477     }
 478   return cu->cu_error.re_status;
 479 }
 480
 481 static void
 482 clntudp_geterr (CLIENT *cl, struct rpc_err *errp)
 483 {
 484   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 485
 486   *errp = cu->cu_error;
 487 }
 488
 489
 490 static bool_t
 491 clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 492 {
 493   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 494   XDR *xdrs = &(cu->cu_outxdrs);
 495
 496   xdrs->x_op = XDR_FREE;
 497   return (*xdr_res) (xdrs, res_ptr);
 498 }
 499
 500 static void
 501 clntudp_abort (void)
 502 {
 503 }
 504
 505 static bool_t
 506 clntudp_control (CLIENT *cl, int request, char *info)
 507 {
 508   struct cu_data *cu = (struct cu_data *) cl->cl_private;
 509
 510   switch (request)
 511     {
 512     case CLSET_FD_CLOSE:
 513       cu->cu_closeit = TRUE;
 514       break;
 515     case CLSET_FD_NCLOSE:
 516       cu->cu_closeit = FALSE;
 517       break;
 518     case CLSET_TIMEOUT:
 519       cu->cu_total = *(struct timeval *) info;
 520       break;
 521     case CLGET_TIMEOUT:
 522       *(struct timeval *) info = cu->cu_total;
 523       break;
 524     case CLSET_RETRY_TIMEOUT:
 525       cu->cu_wait = *(struct timeval *) info;
 526       break;
 527     case CLGET_RETRY_TIMEOUT:
 528       *(struct timeval *) info = cu->cu_wait;
 529       break;
 530     case CLGET_SERVER_ADDR:
 531       *(struct sockaddr_in *) info = cu->cu_raddr;
 532       break;
 533     case CLGET_FD:
 534       *(int *)info = cu->cu_sock;
 535       break;
 536     case CLGET_XID:
 537       /*
 538        * use the knowledge that xid is the
 539        * first element in the call structure *.
 540        * This will get the xid of the PREVIOUS call
 541        */
 542       *(u_long *)info = ntohl(*(u_long *)cu->cu_outbuf);
 543       break;
 544     case CLSET_XID:
 545       /* This will set the xid of the NEXT call */
 546       *(u_long *)cu->cu_outbuf =  htonl(*(u_long *)info - 1);
 547       /* decrement by 1 as clntudp_call() increments once */
 548       break;
 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 }