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