sunrpc/clnt_tcp.c

   1 /*
   2  * clnt_tcp.c, Implements a TCP/IP based, client side RPC.
   3  *
   4  * Copyright (c) 2010, Oracle America, 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 the "Oracle America, 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 #include <wchar.h>
  57
  58 extern u_long _create_xid (void);
  59
  60 #define MCALL_MSG_SIZE 24
  61
  62 struct ct_data
  63   {
  64     int ct_sock;
  65     bool_t ct_closeit;
  66     struct timeval ct_wait;
  67     bool_t ct_waitset;          /* wait set by clnt_control? */
  68     struct sockaddr_in ct_addr;
  69     struct rpc_err ct_error;
  70     char ct_mcall[MCALL_MSG_SIZE];      /* marshalled callmsg */
  71     u_int ct_mpos;              /* pos after marshal */
  72     XDR ct_xdrs;
  73   };
  74
  75 static int readtcp (char *, char *, int);
  76 static int writetcp (char *, char *, int);
  77
  78 static enum clnt_stat clnttcp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  79                                     xdrproc_t, caddr_t, struct timeval);
  80 static void clnttcp_abort (void);
  81 static void clnttcp_geterr (CLIENT *, struct rpc_err *);
  82 static bool_t clnttcp_freeres (CLIENT *, xdrproc_t, caddr_t);
  83 static bool_t clnttcp_control (CLIENT *, int, char *);
  84 static void clnttcp_destroy (CLIENT *);
  85
  86 static const struct clnt_ops tcp_ops =
  87 {
  88   clnttcp_call,
  89   clnttcp_abort,
  90   clnttcp_geterr,
  91   clnttcp_freeres,
  92   clnttcp_destroy,
  93   clnttcp_control
  94 };
  95
  96 /*
  97  * Create a client handle for a tcp/ip connection.
  98  * If *sockp<0, *sockp is set to a newly created TCP socket and it is
  99  * connected to raddr.  If *sockp non-negative then
 100  * raddr is ignored.  The rpc/tcp package does buffering
 101  * similar to stdio, so the client must pick send and receive buffer sizes,];
 102  * 0 => use the default.
 103  * If raddr->sin_port is 0, then a binder on the remote machine is
 104  * consulted for the right port number.
 105  * NB: *sockp is copied into a private area.
 106  * NB: It is the clients responsibility to close *sockp.
 107  * NB: The rpch->cl_auth is set null authentication.  Caller may wish to set this
 108  * something more useful.
 109  */
 110 CLIENT *
 111 clnttcp_create (struct sockaddr_in *raddr, u_long prog, u_long vers,
 112                 int *sockp, u_int sendsz, u_int recvsz)
 113 {
 114   CLIENT *h;
 115   struct ct_data *ct;
 116   struct rpc_msg call_msg;
 117
 118   h = (CLIENT *) mem_alloc (sizeof (*h));
 119   ct = (struct ct_data *) mem_alloc (sizeof (*ct));
 120   if (h == NULL || ct == NULL)
 121     {
 122       struct rpc_createerr *ce = &get_rpc_createerr ();
 123       (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
 124       ce->cf_stat = RPC_SYSTEMERROR;
 125       ce->cf_error.re_errno = ENOMEM;
 126       goto fooy;
 127     }
 128
 129   /*
 130    * If no port number given ask the pmap for one
 131    */
 132   if (raddr->sin_port == 0)
 133     {
 134       u_short port;
 135       if ((port = pmap_getport (raddr, prog, vers, IPPROTO_TCP)) == 0)
 136         {
 137           mem_free ((caddr_t) ct, sizeof (struct ct_data));
 138           mem_free ((caddr_t) h, sizeof (CLIENT));
 139           return ((CLIENT *) NULL);
 140         }
 141       raddr->sin_port = htons (port);
 142     }
 143
 144   /*
 145    * If no socket given, open one
 146    */
 147   if (*sockp < 0)
 148     {
 149       *sockp = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
 150       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 151       if ((*sockp < 0)
 152           || (__connect (*sockp, (struct sockaddr *) raddr,
 153                          sizeof (*raddr)) < 0))
 154         {
 155           struct rpc_createerr *ce = &get_rpc_createerr ();
 156           ce->cf_stat = RPC_SYSTEMERROR;
 157           ce->cf_error.re_errno = errno;
 158           if (*sockp >= 0)
 159             (void) __close (*sockp);
 160           goto fooy;
 161         }
 162       ct->ct_closeit = TRUE;
 163     }
 164   else
 165     {
 166       ct->ct_closeit = FALSE;
 167     }
 168
 169   /*
 170    * Set up private data struct
 171    */
 172   ct->ct_sock = *sockp;
 173   ct->ct_wait.tv_usec = 0;
 174   ct->ct_waitset = FALSE;
 175   ct->ct_addr = *raddr;
 176
 177   /*
 178    * Initialize call message
 179    */
 180   call_msg.rm_xid = _create_xid ();
 181   call_msg.rm_direction = CALL;
 182   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 183   call_msg.rm_call.cb_prog = prog;
 184   call_msg.rm_call.cb_vers = vers;
 185
 186   /*
 187    * pre-serialize the static part of the call msg and stash it away
 188    */
 189   xdrmem_create (&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE, XDR_ENCODE);
 190   if (!xdr_callhdr (&(ct->ct_xdrs), &call_msg))
 191     {
 192       if (ct->ct_closeit)
 193         {
 194           (void) __close (*sockp);
 195         }
 196       goto fooy;
 197     }
 198   ct->ct_mpos = XDR_GETPOS (&(ct->ct_xdrs));
 199   XDR_DESTROY (&(ct->ct_xdrs));
 200
 201   /*
 202    * Create a client handle which uses xdrrec for serialization
 203    * and authnone for authentication.
 204    */
 205   xdrrec_create (&(ct->ct_xdrs), sendsz, recvsz,
 206                  (caddr_t) ct, readtcp, writetcp);
 207   h->cl_ops = (struct clnt_ops *) &tcp_ops;
 208   h->cl_private = (caddr_t) ct;
 209   h->cl_auth = authnone_create ();
 210   return h;
 211
 212 fooy:
 213   /*
 214    * Something goofed, free stuff and barf
 215    */
 216   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 217   mem_free ((caddr_t) h, sizeof (CLIENT));
 218   return ((CLIENT *) NULL);
 219 }
 220 #ifdef EXPORT_RPC_SYMBOLS
 221 libc_hidden_def (clnttcp_create)
 222 #else
 223 libc_hidden_nolink (clnttcp_create, GLIBC_2_0)
 224 #endif
 225
 226 static enum clnt_stat
 227 clnttcp_call (h, proc, xdr_args, args_ptr, xdr_results, results_ptr, timeout)
 228      CLIENT *h;
 229      u_long proc;
 230      xdrproc_t xdr_args;
 231      caddr_t args_ptr;
 232      xdrproc_t xdr_results;
 233      caddr_t results_ptr;
 234      struct timeval timeout;
 235 {
 236   struct ct_data *ct = (struct ct_data *) h->cl_private;
 237   XDR *xdrs = &(ct->ct_xdrs);
 238   struct rpc_msg reply_msg;
 239   u_long x_id;
 240   u_int32_t *msg_x_id = (u_int32_t *) (ct->ct_mcall);   /* yuk */
 241   bool_t shipnow;
 242   int refreshes = 2;
 243
 244   if (!ct->ct_waitset)
 245     {
 246       ct->ct_wait = timeout;
 247     }
 248
 249   shipnow =
 250     (xdr_results == (xdrproc_t) 0 && ct->ct_wait.tv_sec == 0
 251      && ct->ct_wait.tv_usec == 0) ? FALSE : TRUE;
 252
 253 call_again:
 254   xdrs->x_op = XDR_ENCODE;
 255   ct->ct_error.re_status = RPC_SUCCESS;
 256   x_id = ntohl (--(*msg_x_id));
 257   if ((!XDR_PUTBYTES (xdrs, ct->ct_mcall, ct->ct_mpos)) ||
 258       (!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 259       (!AUTH_MARSHALL (h->cl_auth, xdrs)) ||
 260       (!(*xdr_args) (xdrs, args_ptr)))
 261     {
 262       if (ct->ct_error.re_status == RPC_SUCCESS)
 263         ct->ct_error.re_status = RPC_CANTENCODEARGS;
 264       (void) xdrrec_endofrecord (xdrs, TRUE);
 265       return (ct->ct_error.re_status);
 266     }
 267   if (!xdrrec_endofrecord (xdrs, shipnow))
 268     return ct->ct_error.re_status = RPC_CANTSEND;
 269   if (!shipnow)
 270     return RPC_SUCCESS;
 271   /*
 272    * Hack to provide rpc-based message passing
 273    */
 274   if (ct->ct_wait.tv_sec == 0 && ct->ct_wait.tv_usec == 0)
 275     {
 276       return ct->ct_error.re_status = RPC_TIMEDOUT;
 277     }
 278
 279
 280   /*
 281    * Keep receiving until we get a valid transaction id
 282    */
 283   xdrs->x_op = XDR_DECODE;
 284   while (TRUE)
 285     {
 286       reply_msg.acpted_rply.ar_verf = _null_auth;
 287       reply_msg.acpted_rply.ar_results.where = NULL;
 288       reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
 289       if (!xdrrec_skiprecord (xdrs))
 290         return (ct->ct_error.re_status);
 291       /* now decode and validate the response header */
 292       if (!xdr_replymsg (xdrs, &reply_msg))
 293         {
 294           if (ct->ct_error.re_status == RPC_SUCCESS)
 295             continue;
 296           return ct->ct_error.re_status;
 297         }
 298       if ((u_int32_t) reply_msg.rm_xid == (u_int32_t) x_id)
 299         break;
 300     }
 301
 302   /*
 303    * process header
 304    */
 305   _seterr_reply (&reply_msg, &(ct->ct_error));
 306   if (ct->ct_error.re_status == RPC_SUCCESS)
 307     {
 308       if (!AUTH_VALIDATE (h->cl_auth, &reply_msg.acpted_rply.ar_verf))
 309         {
 310           ct->ct_error.re_status = RPC_AUTHERROR;
 311           ct->ct_error.re_why = AUTH_INVALIDRESP;
 312         }
 313       else if (!(*xdr_results) (xdrs, results_ptr))
 314         {
 315           if (ct->ct_error.re_status == RPC_SUCCESS)
 316             ct->ct_error.re_status = RPC_CANTDECODERES;
 317         }
 318       /* free verifier ... */
 319       if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 320         {
 321           xdrs->x_op = XDR_FREE;
 322           (void) xdr_opaque_auth (xdrs, &(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       break;
 403     case CLGET_VERS:
 404       /*
 405        * This RELIES on the information that, in the call body,
 406        * the version number field is the fifth field from the
 407        * begining of the RPC header. MUST be changed if the
 408        * call_struct is changed
 409        */
 410       *(u_long *)info = ntohl (*(u_long *)(ct->ct_mcall +
 411                                            4 * BYTES_PER_XDR_UNIT));
 412       break;
 413     case CLSET_VERS:
 414       *(u_long *)(ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT)
 415         = htonl (*(u_long *)info);
 416       break;
 417     case CLGET_PROG:
 418       /*
 419        * This RELIES on the information that, in the call body,
 420        * the program number field is the  field from the
 421        * begining of the RPC header. MUST be changed if the
 422        * call_struct is changed
 423        */
 424       *(u_long *)info = ntohl(*(u_long *)(ct->ct_mcall +
 425                                           3 * BYTES_PER_XDR_UNIT));
 426       break;
 427     case CLSET_PROG:
 428       *(u_long *)(ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT)
 429         = htonl(*(u_long *)info);
 430       break;
 431     /* The following are only possible with TI-RPC */
 432     case CLGET_RETRY_TIMEOUT:
 433     case CLSET_RETRY_TIMEOUT:
 434     case CLGET_SVC_ADDR:
 435     case CLSET_SVC_ADDR:
 436     case CLSET_PUSH_TIMOD:
 437     case CLSET_POP_TIMOD:
 438     default:
 439       return FALSE;
 440     }
 441   return TRUE;
 442 }
 443
 444
 445 static void
 446 clnttcp_destroy (CLIENT *h)
 447 {
 448   struct ct_data *ct =
 449   (struct ct_data *) h->cl_private;
 450
 451   if (ct->ct_closeit)
 452     {
 453       (void) __close (ct->ct_sock);
 454     }
 455   XDR_DESTROY (&(ct->ct_xdrs));
 456   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 457   mem_free ((caddr_t) h, sizeof (CLIENT));
 458 }
 459
 460 /*
 461  * Interface between xdr serializer and tcp connection.
 462  * Behaves like the system calls, read & write, but keeps some error state
 463  * around for the rpc level.
 464  */
 465 static int
 466 readtcp (char *ctptr, char *buf, int len)
 467 {
 468   struct ct_data *ct = (struct ct_data *)ctptr;
 469   struct pollfd fd;
 470   int milliseconds = (ct->ct_wait.tv_sec * 1000) +
 471     (ct->ct_wait.tv_usec / 1000);
 472
 473   if (len == 0)
 474     return 0;
 475
 476   fd.fd = ct->ct_sock;
 477   fd.events = POLLIN;
 478   while (TRUE)
 479     {
 480       switch (__poll(&fd, 1, milliseconds))
 481         {
 482         case 0:
 483           ct->ct_error.re_status = RPC_TIMEDOUT;
 484           return -1;
 485
 486         case -1:
 487           if (errno == EINTR)
 488             continue;
 489           ct->ct_error.re_status = RPC_CANTRECV;
 490           ct->ct_error.re_errno = errno;
 491           return -1;
 492         }
 493       break;
 494     }
 495   switch (len = __read (ct->ct_sock, buf, len))
 496     {
 497
 498     case 0:
 499       /* premature eof */
 500       ct->ct_error.re_errno = ECONNRESET;
 501       ct->ct_error.re_status = RPC_CANTRECV;
 502       len = -1;                 /* it's really an error */
 503       break;
 504
 505     case -1:
 506       ct->ct_error.re_errno = errno;
 507       ct->ct_error.re_status = RPC_CANTRECV;
 508       break;
 509     }
 510   return len;
 511 }
 512
 513 static int
 514 writetcp (char *ctptr, char *buf, int len)
 515 {
 516   int i, cnt;
 517   struct ct_data *ct = (struct ct_data*)ctptr;
 518
 519   for (cnt = len; cnt > 0; cnt -= i, buf += i)
 520     {
 521       if ((i = __write (ct->ct_sock, buf, cnt)) == -1)
 522         {
 523           ct->ct_error.re_errno = errno;
 524           ct->ct_error.re_status = RPC_CANTSEND;
 525           return -1;
 526         }
 527     }
 528   return len;
 529 }