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/poll.h>
  59 #include <sys/socket.h>
  60 #include <rpc/pmap_clnt.h>
  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 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 = (struct ct_data *) mem_alloc (sizeof (*ct));
 118   struct timeval now;
 119   struct rpc_msg call_msg;
 120
 121   h = (CLIENT *) mem_alloc (sizeof (*h));
 122   if (h == NULL)
 123     {
 124       (void) fprintf (stderr, _("clnttcp_create: out of memory\n"));
 125       rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 126       rpc_createerr.cf_error.re_errno = errno;
 127       goto fooy;
 128     }
 129   /*  ct = (struct ct_data *) mem_alloc (sizeof (*ct)); */
 130   if (ct == NULL)
 131     {
 132       (void) fprintf (stderr, _("clnttcp_create: out of memory\n"));
 133       rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 134       rpc_createerr.cf_error.re_errno = errno;
 135       goto fooy;
 136     }
 137
 138   /*
 139    * If no port number given ask the pmap for one
 140    */
 141   if (raddr->sin_port == 0)
 142     {
 143       u_short port;
 144       if ((port = pmap_getport (raddr, prog, vers, IPPROTO_TCP)) == 0)
 145         {
 146           mem_free ((caddr_t) ct, sizeof (struct ct_data));
 147           mem_free ((caddr_t) h, sizeof (CLIENT));
 148           return ((CLIENT *) NULL);
 149         }
 150       raddr->sin_port = htons (port);
 151     }
 152
 153   /*
 154    * If no socket given, open one
 155    */
 156   if (*sockp < 0)
 157     {
 158       *sockp = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
 159       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 160       if ((*sockp < 0)
 161           || (__connect (*sockp, (struct sockaddr *) raddr,
 162                          sizeof (*raddr)) < 0))
 163         {
 164           rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 165           rpc_createerr.cf_error.re_errno = errno;
 166           if (*sockp >= 0)
 167             (void) __close (*sockp);
 168           goto fooy;
 169         }
 170       ct->ct_closeit = TRUE;
 171     }
 172   else
 173     {
 174       ct->ct_closeit = FALSE;
 175     }
 176
 177   /*
 178    * Set up private data struct
 179    */
 180   ct->ct_sock = *sockp;
 181   ct->ct_wait.tv_usec = 0;
 182   ct->ct_waitset = FALSE;
 183   ct->ct_addr = *raddr;
 184
 185   /*
 186    * Initialize call message
 187    */
 188   (void) __gettimeofday (&now, (struct timezone *) 0);
 189   call_msg.rm_xid = __getpid () ^ now.tv_sec ^ now.tv_usec;
 190   call_msg.rm_direction = CALL;
 191   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 192   call_msg.rm_call.cb_prog = prog;
 193   call_msg.rm_call.cb_vers = vers;
 194
 195   /*
 196    * pre-serialize the static part of the call msg and stash it away
 197    */
 198   xdrmem_create (&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE,
 199                  XDR_ENCODE);
 200   if (!xdr_callhdr (&(ct->ct_xdrs), &call_msg))
 201     {
 202       if (ct->ct_closeit)
 203         {
 204           (void) __close (*sockp);
 205         }
 206       goto fooy;
 207     }
 208   ct->ct_mpos = XDR_GETPOS (&(ct->ct_xdrs));
 209   XDR_DESTROY (&(ct->ct_xdrs));
 210
 211   /*
 212    * Create a client handle which uses xdrrec for serialization
 213    * and authnone for authentication.
 214    */
 215   xdrrec_create (&(ct->ct_xdrs), sendsz, recvsz,
 216                  (caddr_t) ct, readtcp, writetcp);
 217   h->cl_ops = &tcp_ops;
 218   h->cl_private = (caddr_t) ct;
 219   h->cl_auth = authnone_create ();
 220   return h;
 221
 222 fooy:
 223   /*
 224    * Something goofed, free stuff and barf
 225    */
 226   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 227   mem_free ((caddr_t) h, sizeof (CLIENT));
 228   return ((CLIENT *) NULL);
 229 }
 230
 231 static enum clnt_stat
 232 clnttcp_call (h, proc, xdr_args, args_ptr, xdr_results, results_ptr, timeout)
 233      CLIENT *h;
 234      u_long proc;
 235      xdrproc_t xdr_args;
 236      caddr_t args_ptr;
 237      xdrproc_t xdr_results;
 238      caddr_t results_ptr;
 239      struct timeval timeout;
 240 {
 241   struct ct_data *ct = (struct ct_data *) h->cl_private;
 242   XDR *xdrs = &(ct->ct_xdrs);
 243   struct rpc_msg reply_msg;
 244   u_long x_id;
 245   u_int32_t *msg_x_id = (u_int32_t *) (ct->ct_mcall);   /* yuk */
 246   bool_t shipnow;
 247   int refreshes = 2;
 248
 249   if (!ct->ct_waitset)
 250     {
 251       ct->ct_wait = timeout;
 252     }
 253
 254   shipnow =
 255     (xdr_results == (xdrproc_t) 0 && timeout.tv_sec == 0
 256      && timeout.tv_usec == 0) ? FALSE : TRUE;
 257
 258 call_again:
 259   xdrs->x_op = XDR_ENCODE;
 260   ct->ct_error.re_status = RPC_SUCCESS;
 261   x_id = ntohl (--(*msg_x_id));
 262   if ((!XDR_PUTBYTES (xdrs, ct->ct_mcall, ct->ct_mpos)) ||
 263       (!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 264       (!AUTH_MARSHALL (h->cl_auth, xdrs)) ||
 265       (!(*xdr_args) (xdrs, args_ptr)))
 266     {
 267       if (ct->ct_error.re_status == RPC_SUCCESS)
 268         ct->ct_error.re_status = RPC_CANTENCODEARGS;
 269       (void) xdrrec_endofrecord (xdrs, TRUE);
 270       return (ct->ct_error.re_status);
 271     }
 272   if (!xdrrec_endofrecord (xdrs, shipnow))
 273     return ct->ct_error.re_status = RPC_CANTSEND;
 274   if (!shipnow)
 275     return RPC_SUCCESS;
 276   /*
 277    * Hack to provide rpc-based message passing
 278    */
 279   if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
 280     {
 281       return ct->ct_error.re_status = RPC_TIMEDOUT;
 282     }
 283
 284
 285   /*
 286    * Keep receiving until we get a valid transaction id
 287    */
 288   xdrs->x_op = XDR_DECODE;
 289   while (TRUE)
 290     {
 291       reply_msg.acpted_rply.ar_verf = _null_auth;
 292       reply_msg.acpted_rply.ar_results.where = NULL;
 293       reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
 294       if (!xdrrec_skiprecord (xdrs))
 295         return (ct->ct_error.re_status);
 296       /* now decode and validate the response header */
 297       if (!xdr_replymsg (xdrs, &reply_msg))
 298         {
 299           if (ct->ct_error.re_status == RPC_SUCCESS)
 300             continue;
 301           return ct->ct_error.re_status;
 302         }
 303       if (reply_msg.rm_xid == x_id)
 304         break;
 305     }
 306
 307   /*
 308    * process header
 309    */
 310   _seterr_reply (&reply_msg, &(ct->ct_error));
 311   if (ct->ct_error.re_status == RPC_SUCCESS)
 312     {
 313       if (!AUTH_VALIDATE (h->cl_auth, &reply_msg.acpted_rply.ar_verf))
 314         {
 315           ct->ct_error.re_status = RPC_AUTHERROR;
 316           ct->ct_error.re_why = AUTH_INVALIDRESP;
 317         }
 318       else if (!(*xdr_results) (xdrs, results_ptr))
 319         {
 320           if (ct->ct_error.re_status == RPC_SUCCESS)
 321             ct->ct_error.re_status = RPC_CANTDECODERES;
 322         }
 323       /* free verifier ... */
 324       if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 325         {
 326           xdrs->x_op = XDR_FREE;
 327           (void) xdr_opaque_auth (xdrs, &(reply_msg.acpted_rply.ar_verf));
 328         }
 329     }                           /* end successful completion */
 330   else
 331     {
 332       /* maybe our credentials need to be refreshed ... */
 333       if (refreshes-- && AUTH_REFRESH (h->cl_auth))
 334         goto call_again;
 335     }                           /* end of unsuccessful completion */
 336   return ct->ct_error.re_status;
 337 }
 338
 339 static void
 340 clnttcp_geterr (h, errp)
 341      CLIENT *h;
 342      struct rpc_err *errp;
 343 {
 344   struct ct_data *ct =
 345   (struct ct_data *) h->cl_private;
 346
 347   *errp = ct->ct_error;
 348 }
 349
 350 static bool_t
 351 clnttcp_freeres (cl, xdr_res, res_ptr)
 352      CLIENT *cl;
 353      xdrproc_t xdr_res;
 354      caddr_t res_ptr;
 355 {
 356   struct ct_data *ct = (struct ct_data *) cl->cl_private;
 357   XDR *xdrs = &(ct->ct_xdrs);
 358
 359   xdrs->x_op = XDR_FREE;
 360   return (*xdr_res) (xdrs, res_ptr);
 361 }
 362
 363 static void
 364 clnttcp_abort ()
 365 {
 366 }
 367
 368 static bool_t
 369 clnttcp_control (CLIENT *cl, int request, char *info)
 370 {
 371   struct ct_data *ct = (struct ct_data *) cl->cl_private;
 372
 373
 374   switch (request)
 375     {
 376     case CLSET_FD_CLOSE:
 377       ct->ct_closeit = TRUE;
 378       break;
 379     case CLSET_FD_NCLOSE:
 380       ct->ct_closeit = FALSE;
 381       break;
 382     case CLSET_TIMEOUT:
 383       ct->ct_wait = *(struct timeval *) info;
 384       ct->ct_waitset = TRUE;
 385       break;
 386     case CLGET_TIMEOUT:
 387       *(struct timeval *) info = ct->ct_wait;
 388       break;
 389     case CLGET_SERVER_ADDR:
 390       *(struct sockaddr_in *) info = ct->ct_addr;
 391       break;
 392     case CLGET_FD:
 393       *(int *)info = ct->ct_sock;
 394       break;
 395     case CLGET_XID:
 396       /*
 397        * use the knowledge that xid is the
 398        * first element in the call structure *.
 399        * This will get the xid of the PREVIOUS call
 400        */
 401       *(u_long *)info = ntohl (*(u_long *)ct->ct_mcall);
 402       break;
 403     case CLSET_XID:
 404       /* This will set the xid of the NEXT call */
 405       *(u_long *)ct->ct_mcall =  htonl (*(u_long *)info - 1);
 406       /* decrement by 1 as clnttcp_call() increments once */
 407     case CLGET_VERS:
 408       /*
 409        * This RELIES on the information that, in the call body,
 410        * the version number field is the fifth field from the
 411        * begining of the RPC header. MUST be changed if the
 412        * call_struct is changed
 413        */
 414       *(u_long *)info = ntohl (*(u_long *)(ct->ct_mcall +
 415                                            4 * BYTES_PER_XDR_UNIT));
 416       break;
 417     case CLSET_VERS:
 418       *(u_long *)(ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT)
 419         = htonl (*(u_long *)info);
 420       break;
 421     case CLGET_PROG:
 422       /*
 423        * This RELIES on the information that, in the call body,
 424        * the program number field is the  field from the
 425        * begining of the RPC header. MUST be changed if the
 426        * call_struct is changed
 427        */
 428       *(u_long *)info = ntohl(*(u_long *)(ct->ct_mcall +
 429                                           3 * BYTES_PER_XDR_UNIT));
 430       break;
 431     case CLSET_PROG:
 432       *(u_long *)(ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT)
 433         = htonl(*(u_long *)info);
 434       break;
 435     /* The following are only possible with TI-RPC */
 436     case CLGET_RETRY_TIMEOUT:
 437     case CLSET_RETRY_TIMEOUT:
 438     case CLGET_SVC_ADDR:
 439     case CLSET_SVC_ADDR:
 440     case CLSET_PUSH_TIMOD:
 441     case CLSET_POP_TIMOD:
 442     default:
 443       return FALSE;
 444     }
 445   return TRUE;
 446 }
 447
 448
 449 static void
 450 clnttcp_destroy (CLIENT *h)
 451 {
 452   struct ct_data *ct =
 453   (struct ct_data *) h->cl_private;
 454
 455   if (ct->ct_closeit)
 456     {
 457       (void) __close (ct->ct_sock);
 458     }
 459   XDR_DESTROY (&(ct->ct_xdrs));
 460   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 461   mem_free ((caddr_t) h, sizeof (CLIENT));
 462 }
 463
 464 /*
 465  * Interface between xdr serializer and tcp connection.
 466  * Behaves like the system calls, read & write, but keeps some error state
 467  * around for the rpc level.
 468  */
 469 static int
 470 readtcp (char *ctptr, char *buf, int len)
 471 {
 472   struct ct_data *ct = (struct ct_data *)ctptr;
 473   struct pollfd fd;
 474   int milliseconds = (ct->ct_wait.tv_sec * 1000) +
 475     (ct->ct_wait.tv_usec / 1000);
 476
 477   if (len == 0)
 478     return 0;
 479
 480   fd.fd = ct->ct_sock;
 481   fd.events = POLLIN;
 482   while (TRUE)
 483     {
 484       switch (__poll(&fd, 1, milliseconds))
 485         {
 486         case 0:
 487           ct->ct_error.re_status = RPC_TIMEDOUT;
 488           return -1;
 489
 490         case -1:
 491           if (errno == EINTR)
 492             continue;
 493           ct->ct_error.re_status = RPC_CANTRECV;
 494           ct->ct_error.re_errno = errno;
 495           return -1;
 496         }
 497       break;
 498     }
 499   switch (len = __read (ct->ct_sock, buf, len))
 500     {
 501
 502     case 0:
 503       /* premature eof */
 504       ct->ct_error.re_errno = ECONNRESET;
 505       ct->ct_error.re_status = RPC_CANTRECV;
 506       len = -1;                 /* it's really an error */
 507       break;
 508
 509     case -1:
 510       ct->ct_error.re_errno = errno;
 511       ct->ct_error.re_status = RPC_CANTRECV;
 512       break;
 513     }
 514   return len;
 515 }
 516
 517 static int
 518 writetcp (char *ctptr, char *buf, int len)
 519 {
 520   int i, cnt;
 521   struct ct_data *ct = (struct ct_data*)ctptr;
 522
 523   for (cnt = len; cnt > 0; cnt -= i, buf += i)
 524     {
 525       if ((i = __write (ct->ct_sock, buf, cnt)) == -1)
 526         {
 527           ct->ct_error.re_errno = errno;
 528           ct->ct_error.re_status = RPC_CANTSEND;
 529           return -1;
 530         }
 531     }
 532   return len;
 533 }