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 #ifdef USE_IN_LIBIO
  49 # include <wchar.h>
  50 # include <libio/iolibio.h>
  51 #endif
  52
  53 /*
  54  * Ops vector for TCP/IP based rpc service handle
  55  */
  56 static bool_t svctcp_recv (SVCXPRT *, struct rpc_msg *);
  57 static enum xprt_stat svctcp_stat (SVCXPRT *);
  58 static bool_t svctcp_getargs (SVCXPRT *, xdrproc_t, caddr_t);
  59 static bool_t svctcp_reply (SVCXPRT *, struct rpc_msg *);
  60 static bool_t svctcp_freeargs (SVCXPRT *, xdrproc_t, caddr_t);
  61 static void svctcp_destroy (SVCXPRT *);
  62
  63 static const struct xp_ops svctcp_op =
  64 {
  65   svctcp_recv,
  66   svctcp_stat,
  67   svctcp_getargs,
  68   svctcp_reply,
  69   svctcp_freeargs,
  70   svctcp_destroy
  71 };
  72
  73 /*
  74  * Ops vector for TCP/IP rendezvous handler
  75  */
  76 static bool_t rendezvous_request (SVCXPRT *, struct rpc_msg *);
  77 static enum xprt_stat rendezvous_stat (SVCXPRT *);
  78 static void svctcp_rendezvous_abort (void) __attribute__ ((__noreturn__));
  79
  80 /* This function makes sure abort() relocation goes through PLT
  81    and thus can be lazy bound.  */
  82 static void
  83 svctcp_rendezvous_abort (void)
  84 {
  85   abort ();
  86 };
  87
  88 static const struct xp_ops svctcp_rendezvous_op =
  89 {
  90   rendezvous_request,
  91   rendezvous_stat,
  92   (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) svctcp_rendezvous_abort,
  93   (bool_t (*) (SVCXPRT *, struct rpc_msg *)) svctcp_rendezvous_abort,
  94   (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) svctcp_rendezvous_abort,
  95   svctcp_destroy
  96 };
  97
  98 static int readtcp (char*, char *, int);
  99 static int writetcp (char *, char *, int);
 100 static SVCXPRT *makefd_xprt (int, u_int, u_int) internal_function;
 101
 102 struct tcp_rendezvous
 103   {                             /* kept in xprt->xp_p1 */
 104     u_int sendsize;
 105     u_int recvsize;
 106   };
 107
 108 struct tcp_conn
 109   {                             /* kept in xprt->xp_p1 */
 110     enum xprt_stat strm_stat;
 111     u_long x_id;
 112     XDR xdrs;
 113     char verf_body[MAX_AUTH_BYTES];
 114   };
 115
 116 /*
 117  * Usage:
 118  *      xprt = svctcp_create(sock, send_buf_size, recv_buf_size);
 119  *
 120  * Creates, registers, and returns a (rpc) tcp based transporter.
 121  * Once *xprt is initialized, it is registered as a transporter
 122  * see (svc.h, xprt_register).  This routine returns
 123  * a NULL if a problem occurred.
 124  *
 125  * If sock<0 then a socket is created, else sock is used.
 126  * If the socket, sock is not bound to a port then svctcp_create
 127  * binds it to an arbitrary port.  The routine then starts a tcp
 128  * listener on the socket's associated port.  In any (successful) case,
 129  * xprt->xp_sock is the registered socket number and xprt->xp_port is the
 130  * associated port number.
 131  *
 132  * Since tcp streams do buffered io similar to stdio, the caller can specify
 133  * how big the send and receive buffers are via the second and third parms;
 134  * 0 => use the system default.
 135  */
 136 SVCXPRT *
 137 svctcp_create (int sock, u_int sendsize, u_int recvsize)
 138 {
 139   bool_t madesock = FALSE;
 140   SVCXPRT *xprt;
 141   struct tcp_rendezvous *r;
 142   struct sockaddr_in addr;
 143   socklen_t len = sizeof (struct sockaddr_in);
 144
 145   if (sock == RPC_ANYSOCK)
 146     {
 147       if ((sock = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
 148         {
 149           perror (_("svc_tcp.c - tcp socket creation problem"));
 150           return (SVCXPRT *) NULL;
 151         }
 152       madesock = TRUE;
 153     }
 154   __bzero ((char *) &addr, sizeof (addr));
 155   addr.sin_family = AF_INET;
 156   if (bindresvport (sock, &addr))
 157     {
 158       addr.sin_port = 0;
 159       (void) __bind (sock, (struct sockaddr *) &addr, len);
 160     }
 161   if ((__getsockname (sock, (struct sockaddr *) &addr, &len) != 0) ||
 162       (__listen (sock, SOMAXCONN) != 0))
 163     {
 164       perror (_("svc_tcp.c - cannot getsockname or listen"));
 165       if (madesock)
 166         (void) __close (sock);
 167       return (SVCXPRT *) NULL;
 168     }
 169   r = (struct tcp_rendezvous *) mem_alloc (sizeof (*r));
 170   xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
 171   if (r == NULL || xprt == NULL)
 172     {
 173       (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
 174       mem_free (r, sizeof (*r));
 175       mem_free (xprt, sizeof (SVCXPRT));
 176       return NULL;
 177     }
 178   r->sendsize = sendsize;
 179   r->recvsize = recvsize;
 180   xprt->xp_p2 = NULL;
 181   xprt->xp_p1 = (caddr_t) r;
 182   xprt->xp_verf = _null_auth;
 183   xprt->xp_ops = &svctcp_rendezvous_op;
 184   xprt->xp_port = ntohs (addr.sin_port);
 185   xprt->xp_sock = sock;
 186   xprt_register (xprt);
 187   return xprt;
 188 }
 189 #ifdef EXPORT_RPC_SYMBOLS
 190 libc_hidden_def (svctcp_create)
 191 #else
 192 libc_hidden_nolink (svctcp_create, GLIBC_2_0)
 193 #endif
 194
 195 /*
 196  * Like svtcp_create(), except the routine takes any *open* UNIX file
 197  * descriptor as its first input.
 198  */
 199 SVCXPRT *
 200 svcfd_create (int fd, u_int sendsize, u_int recvsize)
 201 {
 202   return makefd_xprt (fd, sendsize, recvsize);
 203 }
 204 libc_hidden_nolink (svcfd_create, GLIBC_2_0)
 205
 206 static SVCXPRT *
 207 internal_function
 208 makefd_xprt (int fd, u_int sendsize, u_int recvsize)
 209 {
 210   SVCXPRT *xprt;
 211   struct tcp_conn *cd;
 212
 213   xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
 214   cd = (struct tcp_conn *) mem_alloc (sizeof (struct tcp_conn));
 215   if (xprt == (SVCXPRT *) NULL || cd == NULL)
 216     {
 217       (void) __fxprintf (NULL, "%s: %s", "svc_tcp: makefd_xprt",
 218                          _("out of memory\n"));
 219       mem_free (xprt, sizeof (SVCXPRT));
 220       mem_free (cd, sizeof (struct tcp_conn));
 221       return NULL;
 222     }
 223   cd->strm_stat = XPRT_IDLE;
 224   xdrrec_create (&(cd->xdrs), sendsize, recvsize,
 225                  (caddr_t) xprt, readtcp, writetcp);
 226   xprt->xp_p2 = NULL;
 227   xprt->xp_p1 = (caddr_t) cd;
 228   xprt->xp_verf.oa_base = cd->verf_body;
 229   xprt->xp_addrlen = 0;
 230   xprt->xp_ops = &svctcp_op;    /* truly deals with calls */
 231   xprt->xp_port = 0;            /* this is a connection, not a rendezvouser */
 232   xprt->xp_sock = fd;
 233   xprt_register (xprt);
 234   return xprt;
 235 }
 236
 237 static bool_t
 238 rendezvous_request (SVCXPRT *xprt, struct rpc_msg *errmsg)
 239 {
 240   int sock;
 241   struct tcp_rendezvous *r;
 242   struct sockaddr_in addr;
 243   socklen_t len;
 244
 245   r = (struct tcp_rendezvous *) xprt->xp_p1;
 246 again:
 247   len = sizeof (struct sockaddr_in);
 248   if ((sock = accept (xprt->xp_sock, (struct sockaddr *) &addr, &len)) < 0)
 249     {
 250       if (errno == EINTR)
 251         goto again;
 252       return FALSE;
 253     }
 254   /*
 255    * make a new transporter (re-uses xprt)
 256    */
 257   xprt = makefd_xprt (sock, r->sendsize, r->recvsize);
 258   memcpy (&xprt->xp_raddr, &addr, sizeof (addr));
 259   xprt->xp_addrlen = len;
 260   return FALSE;         /* there is never an rpc msg to be processed */
 261 }
 262
 263 static enum xprt_stat
 264 rendezvous_stat (SVCXPRT *xprt)
 265 {
 266   return XPRT_IDLE;
 267 }
 268
 269 static void
 270 svctcp_destroy (SVCXPRT *xprt)
 271 {
 272   struct tcp_conn *cd = (struct tcp_conn *) xprt->xp_p1;
 273
 274   xprt_unregister (xprt);
 275   (void) __close (xprt->xp_sock);
 276   if (xprt->xp_port != 0)
 277     {
 278       /* a rendezvouser socket */
 279       xprt->xp_port = 0;
 280     }
 281   else
 282     {
 283       /* an actual connection socket */
 284       XDR_DESTROY (&(cd->xdrs));
 285     }
 286   mem_free ((caddr_t) cd, sizeof (struct tcp_conn));
 287   mem_free ((caddr_t) xprt, sizeof (SVCXPRT));
 288 }
 289
 290
 291 /*
 292  * reads data from the tcp connection.
 293  * any error is fatal and the connection is closed.
 294  * (And a read of zero bytes is a half closed stream => error.)
 295  */
 296 static int
 297 readtcp (char *xprtptr, char *buf, int len)
 298 {
 299   SVCXPRT *xprt = (SVCXPRT *)xprtptr;
 300   int sock = xprt->xp_sock;
 301   int milliseconds = 35 * 1000;
 302   struct pollfd pollfd;
 303
 304   do
 305     {
 306       pollfd.fd = sock;
 307       pollfd.events = POLLIN;
 308       switch (__poll (&pollfd, 1, milliseconds))
 309         {
 310         case -1:
 311           if (errno == EINTR)
 312             continue;
 313           /*FALLTHROUGH*/
 314         case 0:
 315           goto fatal_err;
 316         default:
 317           if ((pollfd.revents & POLLERR) || (pollfd.revents & POLLHUP)
 318               || (pollfd.revents & POLLNVAL))
 319             goto fatal_err;
 320           break;
 321         }
 322     }
 323   while ((pollfd.revents & POLLIN) == 0);
 324
 325   if ((len = __read (sock, buf, len)) > 0)
 326     return len;
 327
 328  fatal_err:
 329   ((struct tcp_conn *) (xprt->xp_p1))->strm_stat = XPRT_DIED;
 330   return -1;
 331 }
 332
 333 /*
 334  * writes data to the tcp connection.
 335  * Any error is fatal and the connection is closed.
 336  */
 337 static int
 338 writetcp (char *xprtptr, char * buf, int len)
 339 {
 340   SVCXPRT *xprt = (SVCXPRT *)xprtptr;
 341   int i, cnt;
 342
 343   for (cnt = len; cnt > 0; cnt -= i, buf += i)
 344     {
 345       if ((i = __write (xprt->xp_sock, buf, cnt)) < 0)
 346         {
 347           ((struct tcp_conn *) (xprt->xp_p1))->strm_stat = XPRT_DIED;
 348           return -1;
 349         }
 350     }
 351   return len;
 352 }
 353
 354 static enum xprt_stat
 355 svctcp_stat (SVCXPRT *xprt)
 356 {
 357   struct tcp_conn *cd =
 358   (struct tcp_conn *) (xprt->xp_p1);
 359
 360   if (cd->strm_stat == XPRT_DIED)
 361     return XPRT_DIED;
 362   if (!xdrrec_eof (&(cd->xdrs)))
 363     return XPRT_MOREREQS;
 364   return XPRT_IDLE;
 365 }
 366
 367 static bool_t
 368 svctcp_recv (SVCXPRT *xprt, struct rpc_msg *msg)
 369 {
 370   struct tcp_conn *cd = (struct tcp_conn *) (xprt->xp_p1);
 371   XDR *xdrs = &(cd->xdrs);
 372
 373   xdrs->x_op = XDR_DECODE;
 374   (void) xdrrec_skiprecord (xdrs);
 375   if (xdr_callmsg (xdrs, msg))
 376     {
 377       cd->x_id = msg->rm_xid;
 378       return TRUE;
 379     }
 380   cd->strm_stat = XPRT_DIED;    /* XXXX */
 381   return FALSE;
 382 }
 383
 384 static bool_t
 385 svctcp_getargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
 386 {
 387   return ((*xdr_args) (&(((struct tcp_conn *)
 388                           (xprt->xp_p1))->xdrs), args_ptr));
 389 }
 390
 391 static bool_t
 392 svctcp_freeargs (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
 393 {
 394   XDR *xdrs = &(((struct tcp_conn *) (xprt->xp_p1))->xdrs);
 395
 396   xdrs->x_op = XDR_FREE;
 397   return ((*xdr_args) (xdrs, args_ptr));
 398 }
 399
 400 static bool_t
 401 svctcp_reply (SVCXPRT *xprt, struct rpc_msg *msg)
 402 {
 403   struct tcp_conn *cd = (struct tcp_conn *) (xprt->xp_p1);
 404   XDR *xdrs = &(cd->xdrs);
 405   bool_t stat;
 406
 407   xdrs->x_op = XDR_ENCODE;
 408   msg->rm_xid = cd->x_id;
 409   stat = xdr_replymsg (xdrs, msg);
 410   (void) xdrrec_endofrecord (xdrs, TRUE);
 411   return stat;
 412 }