sunrpc/clnt_tcp.c

   1 /*
   2  * clnt_tcp.c, Implements a TCP/IP based, client side RPC.
   3  *
   4  * Copyright (C) 1984, Sun Microsystems, Inc.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met:
   9  *
  10  *     * Redistributions of source code must retain the above copyright
  11  *       notice, this list of conditions and the following disclaimer.
  12  *     * Redistributions in binary form must reproduce the above
  13  *       copyright notice, this list of conditions and the following
  14  *       disclaimer in the documentation and/or other materials
  15  *       provided with the distribution.
  16  *     * Neither the name of Sun Microsystems, Inc. nor the names of its
  17  *       contributors may be used to endorse or promote products derived
  18  *       from this software without specific prior written permission.
  19  *
  20  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  23  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  24  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  25  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  27  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  29  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  30  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  *
  33  * TCP based RPC supports 'batched calls'.
  34  * A sequence of calls may be batched-up in a send buffer.  The rpc call
  35  * return immediately to the client even though the call was not necessarily
  36  * sent.  The batching occurs if the results' xdr routine is NULL (0) AND
  37  * the rpc timeout value is zero (see clnt.h, rpc).
  38  *
  39  * Clients should NOT casually batch calls that in fact return results; that is,
  40  * the server side should be aware that a call is batched and not produce any
  41  * return message.  Batched calls that produce many result messages can
  42  * deadlock (netlock) the client and the server....
  43  *
  44  * Now go hang yourself.
  45  */
  46
  47 #include <netdb.h>
  48 #include <errno.h>
  49 #include <stdio.h>
  50 #include <unistd.h>
  51 #include <libintl.h>
  52 #include <rpc/rpc.h>
  53 #include <sys/poll.h>
  54 #include <sys/socket.h>
  55 #include <rpc/pmap_clnt.h>
  56 #ifdef USE_IN_LIBIO
  57 # include <wchar.h>
  58 #endif
  59
  60 extern u_long _create_xid (void);
  61
  62 #define MCALL_MSG_SIZE 24
  63
  64 struct ct_data
  65   {
  66     int ct_sock;
  67     bool_t ct_closeit;
  68     struct timeval ct_wait;
  69     bool_t ct_waitset;          /* wait set by clnt_control? */
  70     struct sockaddr_in ct_addr;
  71     struct rpc_err ct_error;
  72     char ct_mcall[MCALL_MSG_SIZE];      /* marshalled callmsg */
  73     u_int ct_mpos;              /* pos after marshal */
  74     XDR ct_xdrs;
  75   };
  76
  77 static int readtcp (char *, char *, int);
  78 static int writetcp (char *, char *, int);
  79
  80 static enum clnt_stat clnttcp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  81                                     xdrproc_t, caddr_t, struct timeval);
  82 static void clnttcp_abort (void);
  83 static void clnttcp_geterr (CLIENT *, struct rpc_err *);
  84 static bool_t clnttcp_freeres (CLIENT *, xdrproc_t, caddr_t);
  85 static bool_t clnttcp_control (CLIENT *, int, char *);
  86 static void clnttcp_destroy (CLIENT *);
  87
  88 static const struct clnt_ops tcp_ops =
  89 {
  90   clnttcp_call,
  91   clnttcp_abort,
  92   clnttcp_geterr,
  93   clnttcp_freeres,
  94   clnttcp_destroy,
  95   clnttcp_control
  96 };
  97
  98 /*
  99  * Create a client handle for a tcp/ip connection.
 100  * If *sockp<0, *sockp is set to a newly created TCP socket and it is
 101  * connected to raddr.  If *sockp non-negative then
 102  * raddr is ignored.  The rpc/tcp package does buffering
 103  * similar to stdio, so the client must pick send and receive buffer sizes,];
 104  * 0 => use the default.
 105  * If raddr->sin_port is 0, then a binder on the remote machine is
 106  * consulted for the right port number.
 107  * NB: *sockp is copied into a private area.
 108  * NB: It is the clients responsibility to close *sockp.
 109  * NB: The rpch->cl_auth is set null authentication.  Caller may wish to set this
 110  * something more useful.
 111  */
 112 CLIENT *
 113 clnttcp_create (struct sockaddr_in *raddr, u_long prog, u_long vers,
 114                 int *sockp, u_int sendsz, u_int recvsz)
 115 {
 116   CLIENT *h;
 117   struct ct_data *ct;
 118   struct rpc_msg call_msg;
 119
 120   h = (CLIENT *) mem_alloc (sizeof (*h));
 121   ct = (struct ct_data *) mem_alloc (sizeof (*ct));
 122   if (h == NULL || ct == NULL)
 123     {
 124       struct rpc_createerr *ce = &get_rpc_createerr ();
 125       (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
 126       ce->cf_stat = RPC_SYSTEMERROR;
 127       ce->cf_error.re_errno = ENOMEM;
 128       goto fooy;
 129     }
 130
 131   /*
 132    * If no port number given ask the pmap for one
 133    */
 134   if (raddr->sin_port == 0)
 135     {
 136       u_short port;
 137       if ((port = pmap_getport (raddr, prog, vers, IPPROTO_TCP)) == 0)
 138         {
 139           mem_free ((caddr_t) ct, sizeof (struct ct_data));
 140           mem_free ((caddr_t) h, sizeof (CLIENT));
 141           return ((CLIENT *) NULL);
 142         }
 143       raddr->sin_port = htons (port);
 144     }
 145
 146   /*
 147    * If no socket given, open one
 148    */
 149   if (*sockp < 0)
 150     {
 151       *sockp = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
 152       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 153       if ((*sockp < 0)
 154           || (__connect (*sockp, (struct sockaddr *) raddr,
 155                          sizeof (*raddr)) < 0))
 156         {
 157           struct rpc_createerr *ce = &get_rpc_createerr ();
 158           ce->cf_stat = RPC_SYSTEMERROR;
 159           ce->cf_error.re_errno = errno;
 160           if (*sockp >= 0)
 161             (void) __close (*sockp);
 162           goto fooy;
 163         }
 164       ct->ct_closeit = TRUE;
 165     }
 166   else
 167     {
 168       ct->ct_closeit = FALSE;
 169     }
 170
 171   /*
 172    * Set up private data struct
 173    */
 174   ct->ct_sock = *sockp;
 175   ct->ct_wait.tv_usec = 0;
 176   ct->ct_waitset = FALSE;
 177   ct->ct_addr = *raddr;
 178
 179   /*
 180    * Initialize call message
 181    */
 182   call_msg.rm_xid = _create_xid ();
 183   call_msg.rm_direction = CALL;
 184   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 185   call_msg.rm_call.cb_prog = prog;
 186   call_msg.rm_call.cb_vers = vers;
 187
 188   /*
 189    * pre-serialize the static part of the call msg and stash it away
 190    */
 191   INTUSE(xdrmem_create) (&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE,
 192                          XDR_ENCODE);
 193   if (!INTUSE(xdr_callhdr) (&(ct->ct_xdrs), &call_msg))
 194     {
 195       if (ct->ct_closeit)
 196         {
 197           (void) __close (*sockp);
 198         }
 199       goto fooy;
 200     }
 201   ct->ct_mpos = XDR_GETPOS (&(ct->ct_xdrs));
 202   XDR_DESTROY (&(ct->ct_xdrs));
 203
 204   /*
 205    * Create a client handle which uses xdrrec for serialization
 206    * and authnone for authentication.
 207    */
 208   INTUSE(xdrrec_create) (&(ct->ct_xdrs), sendsz, recvsz,
 209                          (caddr_t) ct, readtcp, writetcp);
 210   h->cl_ops = (struct clnt_ops *) &tcp_ops;
 211   h->cl_private = (caddr_t) ct;
 212   h->cl_auth = INTUSE(authnone_create) ();
 213   return h;
 214
 215 fooy:
 216   /*
 217    * Something goofed, free stuff and barf
 218    */
 219   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 220   mem_free ((caddr_t) h, sizeof (CLIENT));
 221   return ((CLIENT *) NULL);
 222 }
 223 INTDEF (clnttcp_create)
 224
 225 static enum clnt_stat
 226 clnttcp_call (h, proc, xdr_args, args_ptr, xdr_results, results_ptr, timeout)
 227      CLIENT *h;
 228      u_long proc;
 229      xdrproc_t xdr_args;
 230      caddr_t args_ptr;
 231      xdrproc_t xdr_results;
 232      caddr_t results_ptr;
 233      struct timeval timeout;
 234 {
 235   struct ct_data *ct = (struct ct_data *) h->cl_private;
 236   XDR *xdrs = &(ct->ct_xdrs);
 237   struct rpc_msg reply_msg;
 238   u_long x_id;
 239   u_int32_t *msg_x_id = (u_int32_t *) (ct->ct_mcall);   /* yuk */
 240   bool_t shipnow;
 241   int refreshes = 2;
 242
 243   if (!ct->ct_waitset)
 244     {
 245       ct->ct_wait = timeout;
 246     }
 247
 248   shipnow =
 249     (xdr_results == (xdrproc_t) 0 && ct->ct_wait.tv_sec == 0
 250      && ct->ct_wait.tv_usec == 0) ? FALSE : TRUE;
 251
 252 call_again:
 253   xdrs->x_op = XDR_ENCODE;
 254   ct->ct_error.re_status = RPC_SUCCESS;
 255   x_id = ntohl (--(*msg_x_id));
 256   if ((!XDR_PUTBYTES (xdrs, ct->ct_mcall, ct->ct_mpos)) ||
 257       (!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 258       (!AUTH_MARSHALL (h->cl_auth, xdrs)) ||
 259       (!(*xdr_args) (xdrs, args_ptr)))
 260     {
 261       if (ct->ct_error.re_status == RPC_SUCCESS)
 262         ct->ct_error.re_status = RPC_CANTENCODEARGS;
 263       (void) INTUSE(xdrrec_endofrecord) (xdrs, TRUE);
 264       return (ct->ct_error.re_status);
 265     }
 266   if (!INTUSE(xdrrec_endofrecord) (xdrs, shipnow))
 267     return ct->ct_error.re_status = RPC_CANTSEND;
 268   if (!shipnow)
 269     return RPC_SUCCESS;
 270   /*
 271    * Hack to provide rpc-based message passing
 272    */
 273   if (ct->ct_wait.tv_sec == 0 && ct->ct_wait.tv_usec == 0)
 274     {
 275       return ct->ct_error.re_status = RPC_TIMEDOUT;
 276     }
 277
 278
 279   /*
 280    * Keep receiving until we get a valid transaction id
 281    */
 282   xdrs->x_op = XDR_DECODE;
 283   while (TRUE)
 284     {
 285       reply_msg.acpted_rply.ar_verf = _null_auth;
 286       reply_msg.acpted_rply.ar_results.where = NULL;
 287       reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)INTUSE(xdr_void);
 288       if (!INTUSE(xdrrec_skiprecord) (xdrs))
 289         return (ct->ct_error.re_status);
 290       /* now decode and validate the response header */
 291       if (!INTUSE(xdr_replymsg) (xdrs, &reply_msg))
 292         {
 293           if (ct->ct_error.re_status == RPC_SUCCESS)
 294             continue;
 295           return ct->ct_error.re_status;
 296         }
 297       if ((u_int32_t) reply_msg.rm_xid == (u_int32_t) x_id)
 298         break;
 299     }
 300
 301   /*
 302    * process header
 303    */
 304   _seterr_reply (&reply_msg, &(ct->ct_error));
 305   if (ct->ct_error.re_status == RPC_SUCCESS)
 306     {
 307       if (!AUTH_VALIDATE (h->cl_auth, &reply_msg.acpted_rply.ar_verf))
 308         {
 309           ct->ct_error.re_status = RPC_AUTHERROR;
 310           ct->ct_error.re_why = AUTH_INVALIDRESP;
 311         }
 312       else if (!(*xdr_results) (xdrs, results_ptr))
 313         {
 314           if (ct->ct_error.re_status == RPC_SUCCESS)
 315             ct->ct_error.re_status = RPC_CANTDECODERES;
 316         }
 317       /* free verifier ... */
 318       if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 319         {
 320           xdrs->x_op = XDR_FREE;
 321           (void) INTUSE(xdr_opaque_auth) (xdrs,
 322                                           &(reply_msg.acpted_rply.ar_verf));
 323         }
 324     }                           /* end successful completion */
 325   else
 326     {
 327       /* maybe our credentials need to be refreshed ... */
 328       if (refreshes-- && AUTH_REFRESH (h->cl_auth))
 329         goto call_again;
 330     }                           /* end of unsuccessful completion */
 331   return ct->ct_error.re_status;
 332 }
 333
 334 static void
 335 clnttcp_geterr (h, errp)
 336      CLIENT *h;
 337      struct rpc_err *errp;
 338 {
 339   struct ct_data *ct =
 340   (struct ct_data *) h->cl_private;
 341
 342   *errp = ct->ct_error;
 343 }
 344
 345 static bool_t
 346 clnttcp_freeres (cl, xdr_res, res_ptr)
 347      CLIENT *cl;
 348      xdrproc_t xdr_res;
 349      caddr_t res_ptr;
 350 {
 351   struct ct_data *ct = (struct ct_data *) cl->cl_private;
 352   XDR *xdrs = &(ct->ct_xdrs);
 353
 354   xdrs->x_op = XDR_FREE;
 355   return (*xdr_res) (xdrs, res_ptr);
 356 }
 357
 358 static void
 359 clnttcp_abort ()
 360 {
 361 }
 362
 363 static bool_t
 364 clnttcp_control (CLIENT *cl, int request, char *info)
 365 {
 366   struct ct_data *ct = (struct ct_data *) cl->cl_private;
 367
 368
 369   switch (request)
 370     {
 371     case CLSET_FD_CLOSE:
 372       ct->ct_closeit = TRUE;
 373       break;
 374     case CLSET_FD_NCLOSE:
 375       ct->ct_closeit = FALSE;
 376       break;
 377     case CLSET_TIMEOUT:
 378       ct->ct_wait = *(struct timeval *) info;
 379       ct->ct_waitset = TRUE;
 380       break;
 381     case CLGET_TIMEOUT:
 382       *(struct timeval *) info = ct->ct_wait;
 383       break;
 384     case CLGET_SERVER_ADDR:
 385       *(struct sockaddr_in *) info = ct->ct_addr;
 386       break;
 387     case CLGET_FD:
 388       *(int *)info = ct->ct_sock;
 389       break;
 390     case CLGET_XID:
 391       /*
 392        * use the knowledge that xid is the
 393        * first element in the call structure *.
 394        * This will get the xid of the PREVIOUS call
 395        */
 396       *(u_long *)info = ntohl (*(u_long *)ct->ct_mcall);
 397       break;
 398     case CLSET_XID:
 399       /* This will set the xid of the NEXT call */
 400       *(u_long *)ct->ct_mcall =  htonl (*(u_long *)info - 1);
 401       /* decrement by 1 as clnttcp_call() increments once */
 402     case CLGET_VERS:
 403       /*
 404        * This RELIES on the information that, in the call body,
 405        * the version number field is the fifth field from the
 406        * begining of the RPC header. MUST be changed if the
 407        * call_struct is changed
 408        */
 409       *(u_long *)info = ntohl (*(u_long *)(ct->ct_mcall +
 410                                            4 * BYTES_PER_XDR_UNIT));
 411       break;
 412     case CLSET_VERS:
 413       *(u_long *)(ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT)
 414         = htonl (*(u_long *)info);
 415       break;
 416     case CLGET_PROG:
 417       /*
 418        * This RELIES on the information that, in the call body,
 419        * the program number field is the  field from the
 420        * begining of the RPC header. MUST be changed if the
 421        * call_struct is changed
 422        */
 423       *(u_long *)info = ntohl(*(u_long *)(ct->ct_mcall +
 424                                           3 * BYTES_PER_XDR_UNIT));
 425       break;
 426     case CLSET_PROG:
 427       *(u_long *)(ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT)
 428         = htonl(*(u_long *)info);
 429       break;
 430     /* The following are only possible with TI-RPC */
 431     case CLGET_RETRY_TIMEOUT:
 432     case CLSET_RETRY_TIMEOUT:
 433     case CLGET_SVC_ADDR:
 434     case CLSET_SVC_ADDR:
 435     case CLSET_PUSH_TIMOD:
 436     case CLSET_POP_TIMOD:
 437     default:
 438       return FALSE;
 439     }
 440   return TRUE;
 441 }
 442
 443
 444 static void
 445 clnttcp_destroy (CLIENT *h)
 446 {
 447   struct ct_data *ct =
 448   (struct ct_data *) h->cl_private;
 449
 450   if (ct->ct_closeit)
 451     {
 452       (void) __close (ct->ct_sock);
 453     }
 454   XDR_DESTROY (&(ct->ct_xdrs));
 455   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 456   mem_free ((caddr_t) h, sizeof (CLIENT));
 457 }
 458
 459 /*
 460  * Interface between xdr serializer and tcp connection.
 461  * Behaves like the system calls, read & write, but keeps some error state
 462  * around for the rpc level.
 463  */
 464 static int
 465 readtcp (char *ctptr, char *buf, int len)
 466 {
 467   struct ct_data *ct = (struct ct_data *)ctptr;
 468   struct pollfd fd;
 469   int milliseconds = (ct->ct_wait.tv_sec * 1000) +
 470     (ct->ct_wait.tv_usec / 1000);
 471
 472   if (len == 0)
 473     return 0;
 474
 475   fd.fd = ct->ct_sock;
 476   fd.events = POLLIN;
 477   while (TRUE)
 478     {
 479       switch (__poll(&fd, 1, milliseconds))
 480         {
 481         case 0:
 482           ct->ct_error.re_status = RPC_TIMEDOUT;
 483           return -1;
 484
 485         case -1:
 486           if (errno == EINTR)
 487             continue;
 488           ct->ct_error.re_status = RPC_CANTRECV;
 489           ct->ct_error.re_errno = errno;
 490           return -1;
 491         }
 492       break;
 493     }
 494   switch (len = __read (ct->ct_sock, buf, len))
 495     {
 496
 497     case 0:
 498       /* premature eof */
 499       ct->ct_error.re_errno = ECONNRESET;
 500       ct->ct_error.re_status = RPC_CANTRECV;
 501       len = -1;                 /* it's really an error */
 502       break;
 503
 504     case -1:
 505       ct->ct_error.re_errno = errno;
 506       ct->ct_error.re_status = RPC_CANTRECV;
 507       break;
 508     }
 509   return len;
 510 }
 511
 512 static int
 513 writetcp (char *ctptr, char *buf, int len)
 514 {
 515   int i, cnt;
 516   struct ct_data *ct = (struct ct_data*)ctptr;
 517
 518   for (cnt = len; cnt > 0; cnt -= i, buf += i)
 519     {
 520       if ((i = __write (ct->ct_sock, buf, cnt)) == -1)
 521         {
 522           ct->ct_error.re_errno = errno;
 523           ct->ct_error.re_status = RPC_CANTSEND;
 524           return -1;
 525         }
 526     }
 527   return len;
 528 }