sunrpc/svc_tcp.c

   1 /*
   2  * svc_tcp.c, Server side for TCP/IP based 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  * Actually implements two flavors of transporter -
  34  * a tcp rendezvouser (a listener and connection establisher)
  35  * and a record/tcp stream.
  36  */
  37
  38 #include <stdio.h>
  39 #include <unistd.h>
  40 #include <string.h>
  41 #include <libintl.h>
  42 #include <rpc/rpc.h>
  43 #include <sys/socket.h>
  44 #include <sys/poll.h>
  45 #include <errno.h>
  46 #include <stdlib.h>
  47
  48 #include <wchar.h>
  49 #include <libio/iolibio.h>
  50
  51 /*
  52  * Ops vector for TCP/IP based rpc service handle
  53  */
  54 static bool_t svctcp_recv (SVCXPRT *, struct rpc_msg *);
  55 static enum xprt_stat svctcp_stat (SVCXPRT *);
  56 static bool_t svctcp_getargs (SVCXPRT *, xdrproc_t, caddr_t);
  57 static bool_t svctcp_reply (SVCXPRT *, struct rpc_msg *);
  58 static bool_t svctcp_freeargs (SVCXPRT *, xdrproc_t, caddr_t);
  59 static void svctcp_destroy (SVCXPRT *);
  60
  61 static const struct xp_ops svctcp_op =
  62 {
  63   svctcp_recv,
  64   svctcp_stat,
  65   svctcp_getargs,
  66   svctcp_reply,
  67   svctcp_freeargs,
  68   svctcp_destroy
  69 };
  70
  71 /*
  72  * Ops vector for TCP/IP rendezvous handler
  73  */
  74 static bool_t rendezvous_request (SVCXPRT *, struct rpc_msg *);
  75 static enum xprt_stat rendezvous_stat (SVCXPRT *);
  76 static void svctcp_rendezvous_abort (void) __attribute__ ((__noreturn__));
  77
  78 /* This function makes sure abort() relocation goes through PLT
  79    and thus can be lazy bound.  */
  80 static void
  81 svctcp_rendezvous_abort (void)
  82 {
  83   abort ();
  84 };
  85
  86 static const struct xp_ops svctcp_rendezvous_op =
  87 {
  88   rendezvous_request,
  89   rendezvous_stat,
  90   (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) svctcp_rendezvous_abort,
  91   (bool_t (*) (SVCXPRT *, struct rpc_msg *)) svctcp_rendezvous_abort,
  92   (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) svctcp_rendezvous_abort,
  93   svctcp_destroy
  94 };
  95
  96 static int readtcp (char*, char *, int);
  97 static int writetcp (char *, char *, int);
  98 static SVCXPRT *makefd_xprt (int, u_int, u_int) internal_function;
  99
 100 struct tcp_rendezvous
 101   {                             /* kept in xprt->xp_p1 */
 102     u_int sendsize;
 103     u_int recvsize;
 104   };
 105
 106 struct tcp_conn
 107   {                             /* kept in xprt->xp_p1 */
 108     enum xprt_stat strm_stat;
 109     u_long x_id;
 110     XDR xdrs;
 111     char verf_body[MAX_AUTH_BYTES];
 112   };
 113
 114 /*
 115  * Usage:
 116  *      xprt = svctcp_create(sock, send_buf_size, recv_buf_size);
 117  *
 118  * Creates, registers, and returns a (rpc) tcp based transporter.
 119  * Once *xprt is initialized, it is registered as a transporter
 120  * see (svc.h, xprt_register).  This routine returns
 121  * a NULL if a problem occurred.
 122  *
 123  * If sock<0 then a socket is created, else sock is used.
 124  * If the socket, sock is not bound to a port then svctcp_create
 125  * binds it to an arbitrary port.  The routine then starts a tcp
 126  * listener on the socket's associated port.  In any (successful) case,
 127  * xprt->xp_sock is the registered socket number and xprt->xp_port is the
 128  * associated port number.
 129  *
 130  * Since tcp streams do buffered io similar to stdio, the caller can specify
 131  * how big the send and receive buffers are via the second and third parms;
 132  * 0 => use the system default.
 133  */
 134 SVCXPRT *
 135 svctcp_create (int sock, u_int sendsize, u_int recvsize)
 136 {
 137   bool_t madesock = FALSE;
 138   SVCXPRT *xprt;
 139   struct tcp_rendezvous *r;
 140   struct sockaddr_in addr;
 141   socklen_t len = sizeof (struct sockaddr_in);
 142
 143   if (sock == RPC_ANYSOCK)
 144     {
 145       if ((sock = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
 146         {
 147           perror (_("svc_tcp.c - tcp socket creation problem"));
 148           return (SVCXPRT *) NULL;
 149         }
 150       madesock = TRUE;
 151     }
 152   __bzero ((char *) &addr, sizeof (addr));
 153   addr.sin_family = AF_INET;
 154   if (bindresvport (sock, &addr))
 155     {
 156       addr.sin_port = 0;
 157       (void) __bind (sock, (struct sockaddr *) &addr, len);
 158     }
 159   if ((__getsockname (sock, (struct sockaddr *) &addr, &len) != 0) ||
 160       (__listen (sock, SOMAXCONN) != 0))
 161     {
 162       perror (_("svc_tcp.c - cannot getsockname or listen"));
 163       if (madesock)
 164         (void) __close (sock);
 165       return (SVCXPRT *) NULL;
 166     }
 167   r = (struct tcp_rendezvous *) mem_alloc (sizeof (*r));
 168   xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
 169   if (r == NULL || xprt == NULL)
 170     {
 171       (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
 172       mem_free (r, sizeof (*r));
 173       mem_free (xprt, sizeof (SVCXPRT));
 174       return NULL;
 175     }
 176   r->sendsize = sendsize;
 177   r->recvsize = recvsize;
 178   xprt->xp_p2 = NULL;
 179   xprt->xp_p1 = (caddr_t) r;
 180   xprt->xp_verf = _null_auth;
 181   xprt->xp_ops = &svctcp_rendezvous_op;
 182   xprt->xp_port = ntohs (addr.sin_port);
 183   xprt->xp_sock = sock;
 184   xprt_register (xprt);
 185   return xprt;
 186 }
 187 #ifdef EXPORT_RPC_SYMBOLS
 188 libc_hidden_def (svctcp_create)
 189 #else
 190 libc_hidden_nolink_sunrpc (svctcp_create, GLIBC_2_0)
 191 #endif
 192
 193 /*
 194  * Like svtcp_create(), except the routine takes any *open* UNIX file
 195  * descriptor as its first input.
 196  */
 197 SVCXPRT *
 198 svcfd_create (int fd, u_int sendsize, u_int recvsize)
 199 {
 200   return makefd_xprt (fd, sendsize, recvsize);
 201 }
 202 libc_hidden_nolink_sunrpc (svcfd_create, GLIBC_2_0)
 203
 204 static SVCXPRT *
 205 internal_function
 206 makefd_xprt (int fd, u_int sendsize, u_int recvsize)
 207 {
 208   SVCXPRT *xprt;
 209   struct tcp_conn *cd;
 210
 211   xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
 212   cd = (struct tcp_conn *) mem_alloc (sizeof (struct tcp_conn));
 213   if (xprt == (SVCXPRT *) NULL || cd == NULL)
 214     {
 215       (void) __fxprintf (NULL, "%s: %s", "svc_tcp: makefd_xprt",
 216                          _("out of memory\n"));
 217       mem_free (xprt, sizeof (SVCXPRT));
 218       mem_free (cd, sizeof (struct tcp_conn));
 219       return NULL;
 220     }
 221   cd->strm_stat = XPRT_IDLE;
 222   xdrrec_create (&(cd->xdrs), sendsize, recvsize,
 223                  (caddr_t) xprt, readtcp, writetcp);
 224   xprt->xp_p2 = NULL;
 225   xprt->xp_p1 = (caddr_t) cd;
 226   xprt->xp_verf.oa_base = cd->verf_body;
 227   xprt->xp_addrlen = 0;
 228   xprt->xp_ops = &svctcp_op;    /* truly deals with calls */
 229   xprt->xp_port = 0;            /* this is a connection, not a rendezvouser */
 230   xprt->xp_sock = fd;
 231   xprt_register (xprt);
 232   return xprt;
 233 }
 234
 235 static bool_t
 236 rendezvous_request (SVCXPRT *xprt, struct rpc_msg *errmsg)
 237 {
 238   int sock;
 239   struct tcp_rendezvous *r;
 240   struct sockaddr_in addr;
 241   socklen_t len;
 242
 243   r = (struct tcp_rendezvous *) xprt->xp_p1;
 244 again:
 245   len = sizeof (struct sockaddr_in);
 246   if ((sock = accept (xprt->xp_sock, (struct sockaddr *) &addr, &len)) < 0)
 247     {
 248       if (errno == EINTR)
 249         goto again;
 250       return FALSE;
 251     }
 252   /*
 253    * make a new transporter (re-uses xprt)
 254    */
 255   xprt = makefd_xprt (sock, r->sendsize, r->recvsize);
 256   memcpy (&xprt->xp_raddr, &addr, sizeof (addr));
 257   xprt->xp_addrlen = len;
 258   return FALSE;         /* there is never an rpc msg to be processed */
 259 }
 260
 261 static enum xprt_stat
 262 rendezvous_stat (SVCXPRT *xprt)
 263 {
 264   return XPRT_IDLE;
 265 }
 266
 267 static void
 268 svctcp_destroy (SVCXPRT *xprt)
 269 {
 270   struct tcp_conn *cd = (struct tcp_conn *) xprt->xp_p1;
 271
 272   xprt_unregister (xprt);
 273   (void) __close (xprt->xp_sock);
 274   if (xprt->xp_port != 0)
 275     {
 276       /* a rendezvouser socket */
 277       xprt->xp_port = 0;
 278     }
 279   else
 280     {
 281       /* an actual connection socket */
 282       XDR_DESTROY (&(cd->xdrs));
 283     }
 284   mem_free ((caddr_t) cd, sizeof (struct tcp_conn));
 285   mem_free ((caddr_t) xprt, sizeof (SVCXPRT));
 286 }
 287
 288
 289 /*
 290  * reads data from the tcp connection.
 291  * any error is fatal and the connection is closed.
 292  * (And a read of zero bytes is a half closed stream => error.)
 293  */
 294 static int
 295 readtcp (char *xprtptr, char *buf, int len)
 296 {
 297   SVCXPRT *xprt = (SVCXPRT *)xprtptr;
 298   int sock = xprt->xp_sock;
 299   int milliseconds = 35 * 1000;
 300   struct pollfd pollfd;
 301
 302   do
 303     {
 304       pollfd.fd = sock;
 305       pollfd.events = POLLIN;
 306       switch (__poll (&pollfd, 1, milliseconds))
 307         {
 308         case -1:
 309           if (errno == EINTR)
 310             continue;
 311           /*FALLTHROUGH*/
 312         case 0:
 313           goto fatal_err;
 314         default:
 315           if ((pollfd.revents & POLLERR) || (pollfd.revents & POLLHUP)
 316               || (pollfd.revents & POLLNVAL))
 317             goto fatal_err;
 318           break;
 319         }
 320     }
 321   while ((pollfd.revents & POLLIN) == 0);
 322
 323   if ((len = __read (sock, buf, len)) > 0)
 324     return len;
 325
 326  fatal_err:
 327   ((struct tcp_conn *) (xprt->xp_p1))->strm_stat = XPRT_DIED;
 328   return -1;
 329 }
 330
 331 /*
 332  * writes data to the tcp connection.
 333  * Any error is fatal and the connection is closed.
 334  */
 335 static int
 336 writetcp (char *xprtptr, char * buf, int len)
 337 {
 338   SVCXPRT *xprt = (SVCXPRT *)xprtptr;
 339   int i, cnt;
 340
 341   for (cnt = len; cnt > 0; cnt -= i, buf += i)
 342     {
 343       if ((i = __write (xprt->xp_sock, buf, cnt)) < 0)
 344         {
 345           ((struct tcp_conn *) (xprt->xp_p1))->strm_stat = XPRT_DIED;
 346           return -1;
 347         }
 348     }
 349   return len;
 350 }
 351
 352 static enum xprt_stat
 353 svctcp_stat (SVCXPRT *xprt)
 354 {
 355   struct tcp_conn *cd =
 356   (struct tcp_conn *) (xprt->xp_p1);
 357
 358   if (cd->strm_stat == XPRT_DIED)
 359     return XPRT_DIED;
 360   if (!xdrrec_eof (&(cd->xdrs)))
 361     return XPRT_MOREREQS;
 362   return XPRT_IDLE;
 363 }
 364
 365 static bool_t
 366 svctcp_recv (SVCXPRT *xprt, struct rpc_msg *msg)
 367 {
 368   struct tcp_conn *cd = (struct tcp_conn *) (xprt->xp_p1);
 369   XDR *xdrs = &(cd->xdrs);
 370
 371   xdrs->x_op = XDR_DECODE;
 372   (void) xdrrec_skiprecord (xdrs);
 373   if (xdr_callmsg (xdrs, msg))
 374     {
 375       cd->x_id = msg->rm_xid;
 376       return TRUE;
 377     }
 378   cd->strm_stat = XPRT_DIED;    /* XXXX */
 379   return FALSE;
 380 }
 381
 382 static bool_t
 383 svctcp_getargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
 384 {
 385   return ((*xdr_args) (&(((struct tcp_conn *)
 386                           (xprt->xp_p1))->xdrs), args_ptr));
 387 }
 388
 389 static bool_t
 390 svctcp_freeargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
 391 {
 392   XDR *xdrs = &(((struct tcp_conn *) (xprt->xp_p1))->xdrs);
 393
 394   xdrs->x_op = XDR_FREE;
 395   return ((*xdr_args) (xdrs, args_ptr));
 396 }
 397
 398 static bool_t
 399 svctcp_reply (SVCXPRT *xprt, struct rpc_msg *msg)
 400 {
 401   struct tcp_conn *cd = (struct tcp_conn *) (xprt->xp_p1);
 402   XDR *xdrs = &(cd->xdrs);
 403   bool_t stat;
 404
 405   xdrs->x_op = XDR_ENCODE;
 406   msg->rm_xid = cd->x_id;
 407   stat = xdr_replymsg (xdrs, msg);
 408   (void) xdrrec_endofrecord (xdrs, TRUE);
 409   return stat;
 410 }