sunrpc/clnt_tcp.c

   1 /* @(#)clnt_tcp.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_tcp.c 1.37 87/10/05 Copyr 1984 Sun Micro";
  32 #endif
  33
  34 /*
  35  * clnt_tcp.c, Implements a TCP/IP based, client side RPC.
  36  *
  37  * Copyright (C) 1984, Sun Microsystems, Inc.
  38  *
  39  * TCP based RPC supports 'batched calls'.
  40  * A sequence of calls may be batched-up in a send buffer.  The rpc call
  41  * return immediately to the client even though the call was not necessarily
  42  * sent.  The batching occurs if the results' xdr routine is NULL (0) AND
  43  * the rpc timeout value is zero (see clnt.h, rpc).
  44  *
  45  * Clients should NOT casually batch calls that in fact return results; that is,
  46  * the server side should be aware that a call is batched and not produce any
  47  * return message.  Batched calls that produce many result messages can
  48  * deadlock (netlock) the client and the server....
  49  *
  50  * Now go hang yourself.
  51  */
  52
  53 #include <netdb.h>
  54 #include <errno.h>
  55 #include <stdio.h>
  56 #include <unistd.h>
  57 #include <rpc/rpc.h>
  58 #include <sys/socket.h>
  59 #include <rpc/pmap_clnt.h>
  60
  61 extern bool_t xdr_opaque_auth (XDR *, struct opaque_auth *);
  62
  63 #define MCALL_MSG_SIZE 24
  64
  65 struct ct_data
  66   {
  67     int ct_sock;
  68     bool_t ct_closeit;
  69     struct timeval ct_wait;
  70     bool_t ct_waitset;          /* wait set by clnt_control? */
  71     struct sockaddr_in ct_addr;
  72     struct rpc_err ct_error;
  73     char ct_mcall[MCALL_MSG_SIZE];      /* marshalled callmsg */
  74     u_int ct_mpos;              /* pos after marshal */
  75     XDR ct_xdrs;
  76   };
  77
  78 static int readtcp (char *, char *, int);
  79 static int writetcp (char *, char *, int);
  80
  81 static enum clnt_stat clnttcp_call (CLIENT *, u_long, xdrproc_t, caddr_t,
  82                                     xdrproc_t, caddr_t, struct timeval);
  83 static void clnttcp_abort (void);
  84 static void clnttcp_geterr (CLIENT *, struct rpc_err *);
  85 static bool_t clnttcp_freeres (CLIENT *, xdrproc_t, caddr_t);
  86 static bool_t clnttcp_control (CLIENT *, int, char *);
  87 static void clnttcp_destroy (CLIENT *);
  88
  89 static struct clnt_ops tcp_ops =
  90 {
  91   clnttcp_call,
  92   clnttcp_abort,
  93   clnttcp_geterr,
  94   clnttcp_freeres,
  95   clnttcp_destroy,
  96   clnttcp_control
  97 };
  98
  99 /*
 100  * Create a client handle for a tcp/ip connection.
 101  * If *sockp<0, *sockp is set to a newly created TCP socket and it is
 102  * connected to raddr.  If *sockp non-negative then
 103  * raddr is ignored.  The rpc/tcp package does buffering
 104  * similar to stdio, so the client must pick send and receive buffer sizes,];
 105  * 0 => use the default.
 106  * If raddr->sin_port is 0, then a binder on the remote machine is
 107  * consulted for the right port number.
 108  * NB: *sockp is copied into a private area.
 109  * NB: It is the clients responsibility to close *sockp.
 110  * NB: The rpch->cl_auth is set null authentication.  Caller may wish to set this
 111  * something more useful.
 112  */
 113 CLIENT *
 114 clnttcp_create (struct sockaddr_in *raddr, u_long prog, u_long vers,
 115                 int *sockp, u_int sendsz, u_int recvsz)
 116 {
 117   CLIENT *h;
 118   struct ct_data *ct = (struct ct_data *) mem_alloc (sizeof (*ct));
 119   struct timeval now;
 120   struct rpc_msg call_msg;
 121
 122   h = (CLIENT *) mem_alloc (sizeof (*h));
 123   if (h == NULL)
 124     {
 125       (void) fprintf (stderr, _("clnttcp_create: out of memory\n"));
 126       rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 127       rpc_createerr.cf_error.re_errno = errno;
 128       goto fooy;
 129     }
 130   /*  ct = (struct ct_data *) mem_alloc (sizeof (*ct)); */
 131   if (ct == NULL)
 132     {
 133       (void) fprintf (stderr, _("clnttcp_create: out of memory\n"));
 134       rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 135       rpc_createerr.cf_error.re_errno = errno;
 136       goto fooy;
 137     }
 138
 139   /*
 140    * If no port number given ask the pmap for one
 141    */
 142   if (raddr->sin_port == 0)
 143     {
 144       u_short port;
 145       if ((port = pmap_getport (raddr, prog, vers, IPPROTO_TCP)) == 0)
 146         {
 147           mem_free ((caddr_t) ct, sizeof (struct ct_data));
 148           mem_free ((caddr_t) h, sizeof (CLIENT));
 149           return ((CLIENT *) NULL);
 150         }
 151       raddr->sin_port = htons (port);
 152     }
 153
 154   /*
 155    * If no socket given, open one
 156    */
 157   if (*sockp < 0)
 158     {
 159       *sockp = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
 160       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 161       if ((*sockp < 0)
 162           || (connect (*sockp, (struct sockaddr *) raddr,
 163                        sizeof (*raddr)) < 0))
 164         {
 165           rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 166           rpc_createerr.cf_error.re_errno = errno;
 167           if (*sockp >= 0)
 168             (void) close (*sockp);
 169           goto fooy;
 170         }
 171       ct->ct_closeit = TRUE;
 172     }
 173   else
 174     {
 175       ct->ct_closeit = FALSE;
 176     }
 177
 178   /*
 179    * Set up private data struct
 180    */
 181   ct->ct_sock = *sockp;
 182   ct->ct_wait.tv_usec = 0;
 183   ct->ct_waitset = FALSE;
 184   ct->ct_addr = *raddr;
 185
 186   /*
 187    * Initialize call message
 188    */
 189   (void) gettimeofday (&now, (struct timezone *) 0);
 190   call_msg.rm_xid = getpid () ^ now.tv_sec ^ now.tv_usec;
 191   call_msg.rm_direction = CALL;
 192   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 193   call_msg.rm_call.cb_prog = prog;
 194   call_msg.rm_call.cb_vers = vers;
 195
 196   /*
 197    * pre-serialize the static part of the call msg and stash it away
 198    */
 199   xdrmem_create (&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE,
 200                  XDR_ENCODE);
 201   if (!xdr_callhdr (&(ct->ct_xdrs), &call_msg))
 202     {
 203       if (ct->ct_closeit)
 204         {
 205           (void) close (*sockp);
 206         }
 207       goto fooy;
 208     }
 209   ct->ct_mpos = XDR_GETPOS (&(ct->ct_xdrs));
 210   XDR_DESTROY (&(ct->ct_xdrs));
 211
 212   /*
 213    * Create a client handle which uses xdrrec for serialization
 214    * and authnone for authentication.
 215    */
 216   xdrrec_create (&(ct->ct_xdrs), sendsz, recvsz,
 217                  (caddr_t) ct, readtcp, writetcp);
 218   h->cl_ops = &tcp_ops;
 219   h->cl_private = (caddr_t) ct;
 220   h->cl_auth = authnone_create ();
 221   return h;
 222
 223 fooy:
 224   /*
 225    * Something goofed, free stuff and barf
 226    */
 227   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 228   mem_free ((caddr_t) h, sizeof (CLIENT));
 229   return ((CLIENT *) NULL);
 230 }
 231
 232 static enum clnt_stat
 233 clnttcp_call (h, proc, xdr_args, args_ptr, xdr_results, results_ptr, timeout)
 234      CLIENT *h;
 235      u_long proc;
 236      xdrproc_t xdr_args;
 237      caddr_t args_ptr;
 238      xdrproc_t xdr_results;
 239      caddr_t results_ptr;
 240      struct timeval timeout;
 241 {
 242   struct ct_data *ct = (struct ct_data *) h->cl_private;
 243   XDR *xdrs = &(ct->ct_xdrs);
 244   struct rpc_msg reply_msg;
 245   u_long x_id;
 246   u_int32_t *msg_x_id = (u_int32_t *) (ct->ct_mcall);   /* yuk */
 247   bool_t shipnow;
 248   int refreshes = 2;
 249
 250   if (!ct->ct_waitset)
 251     {
 252       ct->ct_wait = timeout;
 253     }
 254
 255   shipnow =
 256     (xdr_results == (xdrproc_t) 0 && timeout.tv_sec == 0
 257      && timeout.tv_usec == 0) ? FALSE : TRUE;
 258
 259 call_again:
 260   xdrs->x_op = XDR_ENCODE;
 261   ct->ct_error.re_status = RPC_SUCCESS;
 262   x_id = ntohl (--(*msg_x_id));
 263   if ((!XDR_PUTBYTES (xdrs, ct->ct_mcall, ct->ct_mpos)) ||
 264       (!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 265       (!AUTH_MARSHALL (h->cl_auth, xdrs)) ||
 266       (!(*xdr_args) (xdrs, args_ptr)))
 267     {
 268       if (ct->ct_error.re_status == RPC_SUCCESS)
 269         ct->ct_error.re_status = RPC_CANTENCODEARGS;
 270       (void) xdrrec_endofrecord (xdrs, TRUE);
 271       return (ct->ct_error.re_status);
 272     }
 273   if (!xdrrec_endofrecord (xdrs, shipnow))
 274     return ct->ct_error.re_status = RPC_CANTSEND;
 275   if (!shipnow)
 276     return RPC_SUCCESS;
 277   /*
 278    * Hack to provide rpc-based message passing
 279    */
 280   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 281     {
 282       return ct->ct_error.re_status = RPC_TIMEDOUT;
 283     }
 284
 285
 286   /*
 287    * Keep receiving until we get a valid transaction id
 288    */
 289   xdrs->x_op = XDR_DECODE;
 290   while (TRUE)
 291     {
 292       reply_msg.acpted_rply.ar_verf = _null_auth;
 293       reply_msg.acpted_rply.ar_results.where = NULL;
 294       reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
 295       if (!xdrrec_skiprecord (xdrs))
 296         return (ct->ct_error.re_status);
 297       /* now decode and validate the response header */
 298       if (!xdr_replymsg (xdrs, &reply_msg))
 299         {
 300           if (ct->ct_error.re_status == RPC_SUCCESS)
 301             continue;
 302           return ct->ct_error.re_status;
 303         }
 304       if (reply_msg.rm_xid == x_id)
 305         break;
 306     }
 307
 308   /*
 309    * process header
 310    */
 311   _seterr_reply (&reply_msg, &(ct->ct_error));
 312   if (ct->ct_error.re_status == RPC_SUCCESS)
 313     {
 314       if (!AUTH_VALIDATE (h->cl_auth, &reply_msg.acpted_rply.ar_verf))
 315         {
 316           ct->ct_error.re_status = RPC_AUTHERROR;
 317           ct->ct_error.re_why = AUTH_INVALIDRESP;
 318         }
 319       else if (!(*xdr_results) (xdrs, results_ptr))
 320         {
 321           if (ct->ct_error.re_status == RPC_SUCCESS)
 322             ct->ct_error.re_status = RPC_CANTDECODERES;
 323         }
 324       /* free verifier ... */
 325       if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 326         {
 327           xdrs->x_op = XDR_FREE;
 328           (void) xdr_opaque_auth (xdrs, &(reply_msg.acpted_rply.ar_verf));
 329         }
 330     }                           /* end successful completion */
 331   else
 332     {
 333       /* maybe our credentials need to be refreshed ... */
 334       if (refreshes-- && AUTH_REFRESH (h->cl_auth))
 335         goto call_again;
 336     }                           /* end of unsuccessful completion */
 337   return ct->ct_error.re_status;
 338 }
 339
 340 static void
 341 clnttcp_geterr (h, errp)
 342      CLIENT *h;
 343      struct rpc_err *errp;
 344 {
 345   struct ct_data *ct =
 346   (struct ct_data *) h->cl_private;
 347
 348   *errp = ct->ct_error;
 349 }
 350
 351 static bool_t
 352 clnttcp_freeres (cl, xdr_res, res_ptr)
 353      CLIENT *cl;
 354      xdrproc_t xdr_res;
 355      caddr_t res_ptr;
 356 {
 357   struct ct_data *ct = (struct ct_data *) cl->cl_private;
 358   XDR *xdrs = &(ct->ct_xdrs);
 359
 360   xdrs->x_op = XDR_FREE;
 361   return (*xdr_res) (xdrs, res_ptr);
 362 }
 363
 364 static void
 365 clnttcp_abort ()
 366 {
 367 }
 368
 369 static bool_t
 370 clnttcp_control (cl, request, info)
 371      CLIENT *cl;
 372      int request;
 373      char *info;
 374 {
 375   struct ct_data *ct = (struct ct_data *) cl->cl_private;
 376
 377   switch (request)
 378     {
 379     case CLSET_TIMEOUT:
 380       ct->ct_wait = *(struct timeval *) info;
 381       ct->ct_waitset = TRUE;
 382       break;
 383     case CLGET_TIMEOUT:
 384       *(struct timeval *) info = ct->ct_wait;
 385       break;
 386     case CLGET_SERVER_ADDR:
 387       *(struct sockaddr_in *) info = ct->ct_addr;
 388       break;
 389     default:
 390       return FALSE;
 391     }
 392   return TRUE;
 393 }
 394
 395
 396 static void
 397 clnttcp_destroy (CLIENT *h)
 398 {
 399   struct ct_data *ct =
 400   (struct ct_data *) h->cl_private;
 401
 402   if (ct->ct_closeit)
 403     {
 404       (void) close (ct->ct_sock);
 405     }
 406   XDR_DESTROY (&(ct->ct_xdrs));
 407   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 408   mem_free ((caddr_t) h, sizeof (CLIENT));
 409 }
 410
 411 /*
 412  * Interface between xdr serializer and tcp connection.
 413  * Behaves like the system calls, read & write, but keeps some error state
 414  * around for the rpc level.
 415  */
 416 static int
 417 readtcp (char *ctptr, char *buf, int len)
 418 {
 419   struct ct_data *ct = (struct ct_data *)ctptr;
 420 #ifdef FD_SETSIZE
 421   fd_set mask;
 422   fd_set readfds;
 423
 424   if (len == 0)
 425     return 0;
 426   FD_ZERO (&mask);
 427   FD_SET (ct->ct_sock, &mask);
 428 #else
 429   int mask = 1 << (ct->ct_sock);
 430   int readfds;
 431
 432   if (len == 0)
 433     return 0;
 434
 435 #endif /* def FD_SETSIZE */
 436   while (TRUE)
 437     {
 438       struct timeval timeout = ct->ct_wait;
 439       readfds = mask;
 440       switch (select (_rpc_dtablesize (), &readfds, (fd_set*)NULL,
 441                       (fd_set*)NULL, &timeout))
 442         {
 443         case 0:
 444           ct->ct_error.re_status = RPC_TIMEDOUT;
 445           return -1;
 446
 447         case -1:
 448           if (errno == EINTR)
 449             continue;
 450           ct->ct_error.re_status = RPC_CANTRECV;
 451           ct->ct_error.re_errno = errno;
 452           return -1;
 453         }
 454       break;
 455     }
 456   switch (len = read (ct->ct_sock, buf, len))
 457     {
 458
 459     case 0:
 460       /* premature eof */
 461       ct->ct_error.re_errno = ECONNRESET;
 462       ct->ct_error.re_status = RPC_CANTRECV;
 463       len = -1;                 /* it's really an error */
 464       break;
 465
 466     case -1:
 467       ct->ct_error.re_errno = errno;
 468       ct->ct_error.re_status = RPC_CANTRECV;
 469       break;
 470     }
 471   return len;
 472 }
 473
 474 static int
 475 writetcp (char *ctptr, char *buf, int len)
 476 {
 477   int i, cnt;
 478   struct ct_data *ct = (struct ct_data*)ctptr;
 479
 480   for (cnt = len; cnt > 0; cnt -= i, buf += i)
 481     {
 482       if ((i = write (ct->ct_sock, buf, cnt)) == -1)
 483         {
 484           ct->ct_error.re_errno = errno;
 485           ct->ct_error.re_status = RPC_CANTSEND;
 486           return -1;
 487         }
 488     }
 489   return len;
 490 }