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 #include <shlib-compat.h>
  58
  59 extern u_long _create_xid (void);
  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 const 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;
 117   struct rpc_msg call_msg;
 118
 119   h = (CLIENT *) mem_alloc (sizeof (*h));
 120   ct = (struct ct_data *) mem_alloc (sizeof (*ct));
 121   if (h == NULL || ct == NULL)
 122     {
 123       struct rpc_createerr *ce = &get_rpc_createerr ();
 124       (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
 125       ce->cf_stat = RPC_SYSTEMERROR;
 126       ce->cf_error.re_errno = ENOMEM;
 127       goto fooy;
 128     }
 129
 130   /*
 131    * If no port number given ask the pmap for one
 132    */
 133   if (raddr->sin_port == 0)
 134     {
 135       u_short port;
 136       if ((port = pmap_getport (raddr, prog, vers, IPPROTO_TCP)) == 0)
 137         {
 138           mem_free ((caddr_t) ct, sizeof (struct ct_data));
 139           mem_free ((caddr_t) h, sizeof (CLIENT));
 140           return ((CLIENT *) NULL);
 141         }
 142       raddr->sin_port = htons (port);
 143     }
 144
 145   /*
 146    * If no socket given, open one
 147    */
 148   if (*sockp < 0)
 149     {
 150       *sockp = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
 151       (void) bindresvport (*sockp, (struct sockaddr_in *) 0);
 152       if ((*sockp < 0)
 153           || (__connect (*sockp, (struct sockaddr *) raddr,
 154                          sizeof (*raddr)) < 0))
 155         {
 156           struct rpc_createerr *ce = &get_rpc_createerr ();
 157           ce->cf_stat = RPC_SYSTEMERROR;
 158           ce->cf_error.re_errno = errno;
 159           if (*sockp >= 0)
 160             (void) __close (*sockp);
 161           goto fooy;
 162         }
 163       ct->ct_closeit = TRUE;
 164     }
 165   else
 166     {
 167       ct->ct_closeit = FALSE;
 168     }
 169
 170   /*
 171    * Set up private data struct
 172    */
 173   ct->ct_sock = *sockp;
 174   ct->ct_wait.tv_usec = 0;
 175   ct->ct_waitset = FALSE;
 176   ct->ct_addr = *raddr;
 177
 178   /*
 179    * Initialize call message
 180    */
 181   call_msg.rm_xid = _create_xid ();
 182   call_msg.rm_direction = CALL;
 183   call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 184   call_msg.rm_call.cb_prog = prog;
 185   call_msg.rm_call.cb_vers = vers;
 186
 187   /*
 188    * pre-serialize the static part of the call msg and stash it away
 189    */
 190   xdrmem_create (&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE, XDR_ENCODE);
 191   if (!xdr_callhdr (&(ct->ct_xdrs), &call_msg))
 192     {
 193       if (ct->ct_closeit)
 194         {
 195           (void) __close (*sockp);
 196         }
 197       goto fooy;
 198     }
 199   ct->ct_mpos = XDR_GETPOS (&(ct->ct_xdrs));
 200   XDR_DESTROY (&(ct->ct_xdrs));
 201
 202   /*
 203    * Create a client handle which uses xdrrec for serialization
 204    * and authnone for authentication.
 205    */
 206   xdrrec_create (&(ct->ct_xdrs), sendsz, recvsz,
 207                  (caddr_t) ct, readtcp, writetcp);
 208   h->cl_ops = (struct clnt_ops *) &tcp_ops;
 209   h->cl_private = (caddr_t) ct;
 210   h->cl_auth = authnone_create ();
 211   return h;
 212
 213 fooy:
 214   /*
 215    * Something goofed, free stuff and barf
 216    */
 217   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 218   mem_free ((caddr_t) h, sizeof (CLIENT));
 219   return ((CLIENT *) NULL);
 220 }
 221 #ifdef EXPORT_RPC_SYMBOLS
 222 libc_hidden_def (clnttcp_create)
 223 #else
 224 libc_hidden_nolink_sunrpc (clnttcp_create, GLIBC_2_0)
 225 #endif
 226
 227 static enum clnt_stat
 228 clnttcp_call (CLIENT *h, u_long proc, xdrproc_t xdr_args, caddr_t args_ptr,
 229               xdrproc_t xdr_results, caddr_t results_ptr,
 230               struct timeval timeout)
 231 {
 232   struct ct_data *ct = (struct ct_data *) h->cl_private;
 233   XDR *xdrs = &(ct->ct_xdrs);
 234   struct rpc_msg reply_msg;
 235   u_long x_id;
 236   u_int32_t *msg_x_id = (u_int32_t *) (ct->ct_mcall);   /* yuk */
 237   bool_t shipnow;
 238   int refreshes = 2;
 239
 240   if (!ct->ct_waitset)
 241     {
 242       ct->ct_wait = timeout;
 243     }
 244
 245   shipnow =
 246     (xdr_results == (xdrproc_t) 0 && ct->ct_wait.tv_sec == 0
 247      && ct->ct_wait.tv_usec == 0) ? FALSE : TRUE;
 248
 249 call_again:
 250   xdrs->x_op = XDR_ENCODE;
 251   ct->ct_error.re_status = RPC_SUCCESS;
 252   x_id = ntohl (--(*msg_x_id));
 253   if ((!XDR_PUTBYTES (xdrs, ct->ct_mcall, ct->ct_mpos)) ||
 254       (!XDR_PUTLONG (xdrs, (long *) &proc)) ||
 255       (!AUTH_MARSHALL (h->cl_auth, xdrs)) ||
 256       (!(*xdr_args) (xdrs, args_ptr)))
 257     {
 258       if (ct->ct_error.re_status == RPC_SUCCESS)
 259         ct->ct_error.re_status = RPC_CANTENCODEARGS;
 260       (void) xdrrec_endofrecord (xdrs, TRUE);
 261       return (ct->ct_error.re_status);
 262     }
 263   if (!xdrrec_endofrecord (xdrs, shipnow))
 264     return ct->ct_error.re_status = RPC_CANTSEND;
 265   if (!shipnow)
 266     return RPC_SUCCESS;
 267   /*
 268    * Hack to provide rpc-based message passing
 269    */
 270   if (ct->ct_wait.tv_sec == 0 && ct->ct_wait.tv_usec == 0)
 271     {
 272       return ct->ct_error.re_status = RPC_TIMEDOUT;
 273     }
 274
 275
 276   /*
 277    * Keep receiving until we get a valid transaction id
 278    */
 279   xdrs->x_op = XDR_DECODE;
 280   while (TRUE)
 281     {
 282       reply_msg.acpted_rply.ar_verf = _null_auth;
 283       reply_msg.acpted_rply.ar_results.where = NULL;
 284       reply_msg.acpted_rply.ar_results.proc = (xdrproc_t)xdr_void;
 285       if (!xdrrec_skiprecord (xdrs))
 286         return (ct->ct_error.re_status);
 287       /* now decode and validate the response header */
 288       if (!xdr_replymsg (xdrs, &reply_msg))
 289         {
 290           if (ct->ct_error.re_status == RPC_SUCCESS)
 291             continue;
 292           return ct->ct_error.re_status;
 293         }
 294       if ((u_int32_t) reply_msg.rm_xid == (u_int32_t) x_id)
 295         break;
 296     }
 297
 298   /*
 299    * process header
 300    */
 301   _seterr_reply (&reply_msg, &(ct->ct_error));
 302   if (ct->ct_error.re_status == RPC_SUCCESS)
 303     {
 304       if (!AUTH_VALIDATE (h->cl_auth, &reply_msg.acpted_rply.ar_verf))
 305         {
 306           ct->ct_error.re_status = RPC_AUTHERROR;
 307           ct->ct_error.re_why = AUTH_INVALIDRESP;
 308         }
 309       else if (!(*xdr_results) (xdrs, results_ptr))
 310         {
 311           if (ct->ct_error.re_status == RPC_SUCCESS)
 312             ct->ct_error.re_status = RPC_CANTDECODERES;
 313         }
 314       /* free verifier ... */
 315       if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)
 316         {
 317           xdrs->x_op = XDR_FREE;
 318           (void) xdr_opaque_auth (xdrs, &(reply_msg.acpted_rply.ar_verf));
 319         }
 320     }                           /* end successful completion */
 321   else
 322     {
 323       /* maybe our credentials need to be refreshed ... */
 324       if (refreshes-- && AUTH_REFRESH (h->cl_auth))
 325         goto call_again;
 326     }                           /* end of unsuccessful completion */
 327   return ct->ct_error.re_status;
 328 }
 329
 330 static void
 331 clnttcp_geterr (CLIENT *h, struct rpc_err *errp)
 332 {
 333   struct ct_data *ct =
 334   (struct ct_data *) h->cl_private;
 335
 336   *errp = ct->ct_error;
 337 }
 338
 339 static bool_t
 340 clnttcp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 341 {
 342   struct ct_data *ct = (struct ct_data *) cl->cl_private;
 343   XDR *xdrs = &(ct->ct_xdrs);
 344
 345   xdrs->x_op = XDR_FREE;
 346   return (*xdr_res) (xdrs, res_ptr);
 347 }
 348
 349 static void
 350 clnttcp_abort (void)
 351 {
 352 }
 353
 354 static bool_t
 355 clnttcp_control (CLIENT *cl, int request, char *info)
 356 {
 357   struct ct_data *ct = (struct ct_data *) cl->cl_private;
 358   u_long ul;
 359   u_int32_t ui32;
 360
 361
 362   switch (request)
 363     {
 364     case CLSET_FD_CLOSE:
 365       ct->ct_closeit = TRUE;
 366       break;
 367     case CLSET_FD_NCLOSE:
 368       ct->ct_closeit = FALSE;
 369       break;
 370     case CLSET_TIMEOUT:
 371       ct->ct_wait = *(struct timeval *) info;
 372       ct->ct_waitset = TRUE;
 373       break;
 374     case CLGET_TIMEOUT:
 375       *(struct timeval *) info = ct->ct_wait;
 376       break;
 377     case CLGET_SERVER_ADDR:
 378       *(struct sockaddr_in *) info = ct->ct_addr;
 379       break;
 380     case CLGET_FD:
 381       *(int *)info = ct->ct_sock;
 382       break;
 383     case CLGET_XID:
 384       /*
 385        * use the knowledge that xid is the
 386        * first element in the call structure *.
 387        * This will get the xid of the PREVIOUS call
 388        */
 389       memcpy (&ui32, ct->ct_mcall, sizeof (ui32));
 390       ul = ntohl (ui32);
 391       memcpy (info, &ul, sizeof (ul));
 392       break;
 393     case CLSET_XID:
 394       /* This will set the xid of the NEXT call */
 395       memcpy (&ul, info, sizeof (ul));
 396       ui32 = htonl (ul - 1);
 397       memcpy (ct->ct_mcall, &ui32, sizeof (ui32));
 398       /* decrement by 1 as clnttcp_call() increments once */
 399       break;
 400     case CLGET_VERS:
 401       /*
 402        * This RELIES on the information that, in the call body,
 403        * the version number field is the fifth field from the
 404        * beginning of the RPC header. MUST be changed if the
 405        * call_struct is changed
 406        */
 407       memcpy (&ui32, ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT, sizeof (ui32));
 408       ul = ntohl (ui32);
 409       memcpy (info, &ul, sizeof (ul));
 410       break;
 411     case CLSET_VERS:
 412       memcpy (&ul, info, sizeof (ul));
 413       ui32 = htonl (ul);
 414       memcpy (ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT, &ui32, sizeof (ui32));
 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        * beginning of the RPC header. MUST be changed if the
 421        * call_struct is changed
 422        */
 423       memcpy (&ui32, ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT, sizeof (ui32));
 424       ul = ntohl (ui32);
 425       memcpy (info, &ul, sizeof (ul));
 426       break;
 427     case CLSET_PROG:
 428       memcpy (&ul, info, sizeof (ul));
 429       ui32 = htonl (ul);
 430       memcpy (ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT, &ui32, sizeof (ui32));
 431       break;
 432     /* The following are only possible with TI-RPC */
 433     case CLGET_RETRY_TIMEOUT:
 434     case CLSET_RETRY_TIMEOUT:
 435     case CLGET_SVC_ADDR:
 436     case CLSET_SVC_ADDR:
 437     case CLSET_PUSH_TIMOD:
 438     case CLSET_POP_TIMOD:
 439     default:
 440       return FALSE;
 441     }
 442   return TRUE;
 443 }
 444
 445
 446 static void
 447 clnttcp_destroy (CLIENT *h)
 448 {
 449   struct ct_data *ct =
 450   (struct ct_data *) h->cl_private;
 451
 452   if (ct->ct_closeit)
 453     {
 454       (void) __close (ct->ct_sock);
 455     }
 456   XDR_DESTROY (&(ct->ct_xdrs));
 457   mem_free ((caddr_t) ct, sizeof (struct ct_data));
 458   mem_free ((caddr_t) h, sizeof (CLIENT));
 459 }
 460
 461 /*
 462  * Interface between xdr serializer and tcp connection.
 463  * Behaves like the system calls, read & write, but keeps some error state
 464  * around for the rpc level.
 465  */
 466 static int
 467 readtcp (char *ctptr, char *buf, int len)
 468 {
 469   struct ct_data *ct = (struct ct_data *)ctptr;
 470   struct pollfd fd;
 471   int milliseconds = (ct->ct_wait.tv_sec * 1000) +
 472     (ct->ct_wait.tv_usec / 1000);
 473
 474   if (len == 0)
 475     return 0;
 476
 477   fd.fd = ct->ct_sock;
 478   fd.events = POLLIN;
 479   while (TRUE)
 480     {
 481       switch (__poll(&fd, 1, milliseconds))
 482         {
 483         case 0:
 484           ct->ct_error.re_status = RPC_TIMEDOUT;
 485           return -1;
 486
 487         case -1:
 488           if (errno == EINTR)
 489             continue;
 490           ct->ct_error.re_status = RPC_CANTRECV;
 491           ct->ct_error.re_errno = errno;
 492           return -1;
 493         }
 494       break;
 495     }
 496   switch (len = __read (ct->ct_sock, buf, len))
 497     {
 498
 499     case 0:
 500       /* premature eof */
 501       ct->ct_error.re_errno = ECONNRESET;
 502       ct->ct_error.re_status = RPC_CANTRECV;
 503       len = -1;                 /* it's really an error */
 504       break;
 505
 506     case -1:
 507       ct->ct_error.re_errno = errno;
 508       ct->ct_error.re_status = RPC_CANTRECV;
 509       break;
 510     }
 511   return len;
 512 }
 513
 514 static int
 515 writetcp (char *ctptr, char *buf, int len)
 516 {
 517   int i, cnt;
 518   struct ct_data *ct = (struct ct_data*)ctptr;
 519
 520   for (cnt = len; cnt > 0; cnt -= i, buf += i)
 521     {
 522       if ((i = __write (ct->ct_sock, buf, cnt)) == -1)
 523         {
 524           ct->ct_error.re_errno = errno;
 525           ct->ct_error.re_status = RPC_CANTSEND;
 526           return -1;
 527         }
 528     }
 529   return len;
 530 }