sunrpc/rpc/svc.h

   1 /*
   2  * svc.h, Server-side remote procedure call interface.
   3  *
   4  * Copyright (C) 2012-2016 Free Software Foundation, Inc.
   5  * This file is part of the GNU C Library.
   6  *
   7  * The GNU C Library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * The GNU C Library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with the GNU C Library; if not, see
  19  * <http://www.gnu.org/licenses/>.
  20  *
  21  * Copyright (c) 2010, Oracle America, Inc.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions are
  25  * met:
  26  *
  27  *     * Redistributions of source code must retain the above copyright
  28  *       notice, this list of conditions and the following disclaimer.
  29  *     * Redistributions in binary form must reproduce the above
  30  *       copyright notice, this list of conditions and the following
  31  *       disclaimer in the documentation and/or other materials
  32  *       provided with the distribution.
  33  *     * Neither the name of the "Oracle America, Inc." nor the names of its
  34  *       contributors may be used to endorse or promote products derived
  35  *       from this software without specific prior written permission.
  36  *
  37  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  38  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  39  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  40  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  41  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  42  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  43  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  44  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  45  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  46  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  47  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  48  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  49  */
  50
  51 #ifndef _RPC_SVC_H
  52 #define _RPC_SVC_H 1
  53
  54 #include <features.h>
  55 #include <rpc/rpc_msg.h>
  56
  57 __BEGIN_DECLS
  58
  59 /*
  60  * This interface must manage two items concerning remote procedure calling:
  61  *
  62  * 1) An arbitrary number of transport connections upon which rpc requests
  63  * are received.  The two most notable transports are TCP and UDP;  they are
  64  * created and registered by routines in svc_tcp.c and svc_udp.c, respectively;
  65  * they in turn call xprt_register and xprt_unregister.
  66  *
  67  * 2) An arbitrary number of locally registered services.  Services are
  68  * described by the following four data: program number, version number,
  69  * "service dispatch" function, a transport handle, and a boolean that
  70  * indicates whether or not the exported program should be registered with a
  71  * local binder service;  if true the program's number and version and the
  72  * port number from the transport handle are registered with the binder.
  73  * These data are registered with the rpc svc system via svc_register.
  74  *
  75  * A service's dispatch function is called whenever an rpc request comes in
  76  * on a transport.  The request's program and version numbers must match
  77  * those of the registered service.  The dispatch function is passed two
  78  * parameters, struct svc_req * and SVCXPRT *, defined below.
  79  */
  80
  81 enum xprt_stat {
  82         XPRT_DIED,
  83         XPRT_MOREREQS,
  84         XPRT_IDLE
  85 };
  86
  87 /*
  88  * Server side transport handle
  89  */
  90 typedef struct SVCXPRT SVCXPRT;
  91 struct SVCXPRT {
  92   int xp_sock;
  93   u_short xp_port;              /* associated port number */
  94   const struct xp_ops {
  95     bool_t      (*xp_recv) (SVCXPRT *__xprt, struct rpc_msg *__msg);
  96                                 /* receive incoming requests */
  97     enum xprt_stat (*xp_stat) (SVCXPRT *__xprt);
  98                                 /* get transport status */
  99     bool_t      (*xp_getargs) (SVCXPRT *__xprt, xdrproc_t __xdr_args,
 100                                caddr_t __args_ptr); /* get arguments */
 101     bool_t      (*xp_reply) (SVCXPRT *__xprt, struct rpc_msg *__msg);
 102                                 /* send reply */
 103     bool_t      (*xp_freeargs) (SVCXPRT *__xprt, xdrproc_t __xdr_args,
 104                                 caddr_t __args_ptr);
 105                                 /* free mem allocated for args */
 106     void        (*xp_destroy) (SVCXPRT *__xprt);
 107                                 /* destroy this struct */
 108   } *xp_ops;
 109   int           xp_addrlen;      /* length of remote address */
 110   struct sockaddr_in xp_raddr;   /* remote address */
 111   struct opaque_auth xp_verf;    /* raw response verifier */
 112   caddr_t               xp_p1;           /* private */
 113   caddr_t               xp_p2;           /* private */
 114   char          xp_pad [256];   /* padding, internal use */
 115 };
 116
 117 /*
 118  *  Approved way of getting address of caller
 119  */
 120 #define svc_getcaller(x) (&(x)->xp_raddr)
 121
 122 /*
 123  * Operations defined on an SVCXPRT handle
 124  *
 125  * SVCXPRT              *xprt;
 126  * struct rpc_msg       *msg;
 127  * xdrproc_t             xargs;
 128  * caddr_t               argsp;
 129  */
 130 #define SVC_RECV(xprt, msg)                             \
 131         (*(xprt)->xp_ops->xp_recv)((xprt), (msg))
 132 #define svc_recv(xprt, msg)                             \
 133         (*(xprt)->xp_ops->xp_recv)((xprt), (msg))
 134
 135 #define SVC_STAT(xprt)                                  \
 136         (*(xprt)->xp_ops->xp_stat)(xprt)
 137 #define svc_stat(xprt)                                  \
 138         (*(xprt)->xp_ops->xp_stat)(xprt)
 139
 140 #define SVC_GETARGS(xprt, xargs, argsp)                 \
 141         (*(xprt)->xp_ops->xp_getargs)((xprt), (xargs), (argsp))
 142 #define svc_getargs(xprt, xargs, argsp)                 \
 143         (*(xprt)->xp_ops->xp_getargs)((xprt), (xargs), (argsp))
 144
 145 #define SVC_REPLY(xprt, msg)                            \
 146         (*(xprt)->xp_ops->xp_reply) ((xprt), (msg))
 147 #define svc_reply(xprt, msg)                            \
 148         (*(xprt)->xp_ops->xp_reply) ((xprt), (msg))
 149
 150 #define SVC_FREEARGS(xprt, xargs, argsp)                \
 151         (*(xprt)->xp_ops->xp_freeargs)((xprt), (xargs), (argsp))
 152 #define svc_freeargs(xprt, xargs, argsp)                \
 153         (*(xprt)->xp_ops->xp_freeargs)((xprt), (xargs), (argsp))
 154
 155 #define SVC_DESTROY(xprt)                               \
 156         (*(xprt)->xp_ops->xp_destroy)(xprt)
 157 #define svc_destroy(xprt)                               \
 158         (*(xprt)->xp_ops->xp_destroy)(xprt)
 159
 160
 161 /*
 162  * Service request
 163  */
 164 struct svc_req {
 165   rpcprog_t rq_prog;            /* service program number */
 166   rpcvers_t rq_vers;            /* service protocol version */
 167   rpcproc_t rq_proc;            /* the desired procedure */
 168   struct opaque_auth rq_cred;   /* raw creds from the wire */
 169   caddr_t rq_clntcred;          /* read only cooked cred */
 170   SVCXPRT *rq_xprt;             /* associated transport */
 171 };
 172
 173 #ifndef __DISPATCH_FN_T
 174 #define __DISPATCH_FN_T
 175 typedef void (*__dispatch_fn_t) (struct svc_req*, SVCXPRT*);
 176 #endif
 177
 178 /*
 179  * Service registration
 180  *
 181  * svc_register(xprt, prog, vers, dispatch, protocol)
 182  *      SVCXPRT *xprt;
 183  *      rpcprog_t prog;
 184  *      rpcvers_t vers;
 185  *      void (*dispatch)(struct svc_req*, SVCXPRT*);
 186  *      rpcprot_t protocol;  like TCP or UDP, zero means do not register
 187  */
 188 extern bool_t svc_register (SVCXPRT *__xprt, rpcprog_t __prog,
 189                             rpcvers_t __vers, __dispatch_fn_t __dispatch,
 190                             rpcprot_t __protocol) __THROW;
 191
 192 /*
 193  * Service un-registration
 194  *
 195  * svc_unregister(prog, vers)
 196  *      rpcprog_t prog;
 197  *      rpcvers_t vers;
 198  */
 199 extern void svc_unregister (rpcprog_t __prog, rpcvers_t __vers) __THROW;
 200
 201 /*
 202  * Transport registration.
 203  *
 204  * xprt_register(xprt)
 205  *      SVCXPRT *xprt;
 206  */
 207 extern void xprt_register (SVCXPRT *__xprt) __THROW;
 208
 209 /*
 210  * Transport un-register
 211  *
 212  * xprt_unregister(xprt)
 213  *      SVCXPRT *xprt;
 214  */
 215 extern void xprt_unregister (SVCXPRT *__xprt) __THROW;
 216
 217
 218 /*
 219  * When the service routine is called, it must first check to see if it
 220  * knows about the procedure;  if not, it should call svcerr_noproc
 221  * and return.  If so, it should deserialize its arguments via
 222  * SVC_GETARGS (defined above).  If the deserialization does not work,
 223  * svcerr_decode should be called followed by a return.  Successful
 224  * decoding of the arguments should be followed the execution of the
 225  * procedure's code and a call to svc_sendreply.
 226  *
 227  * Also, if the service refuses to execute the procedure due to too-
 228  * weak authentication parameters, svcerr_weakauth should be called.
 229  * Note: do not confuse access-control failure with weak authentication!
 230  *
 231  * NB: In pure implementations of rpc, the caller always waits for a reply
 232  * msg.  This message is sent when svc_sendreply is called.
 233  * Therefore pure service implementations should always call
 234  * svc_sendreply even if the function logically returns void;  use
 235  * xdr.h - xdr_void for the xdr routine.  HOWEVER, tcp based rpc allows
 236  * for the abuse of pure rpc via batched calling or pipelining.  In the
 237  * case of a batched call, svc_sendreply should NOT be called since
 238  * this would send a return message, which is what batching tries to avoid.
 239  * It is the service/protocol writer's responsibility to know which calls are
 240  * batched and which are not.  Warning: responding to batch calls may
 241  * deadlock the caller and server processes!
 242  */
 243
 244 extern bool_t   svc_sendreply (SVCXPRT *__xprt, xdrproc_t __xdr_results,
 245                                caddr_t __xdr_location) __THROW;
 246
 247 extern void     svcerr_decode (SVCXPRT *__xprt) __THROW;
 248
 249 extern void     svcerr_weakauth (SVCXPRT *__xprt) __THROW;
 250
 251 extern void     svcerr_noproc (SVCXPRT *__xprt) __THROW;
 252
 253 extern void     svcerr_progvers (SVCXPRT *__xprt, rpcvers_t __low_vers,
 254                                  rpcvers_t __high_vers) __THROW;
 255
 256 extern void     svcerr_auth (SVCXPRT *__xprt, enum auth_stat __why) __THROW;
 257
 258 extern void     svcerr_noprog (SVCXPRT *__xprt) __THROW;
 259
 260 extern void     svcerr_systemerr (SVCXPRT *__xprt) __THROW;
 261
 262 /*
 263  * Lowest level dispatching -OR- who owns this process anyway.
 264  * Somebody has to wait for incoming requests and then call the correct
 265  * service routine.  The routine svc_run does infinite waiting; i.e.,
 266  * svc_run never returns.
 267  * Since another (coexistent) package may wish to selectively wait for
 268  * incoming calls or other events outside of the rpc architecture, the
 269  * routine svc_getreq is provided.  It must be passed readfds, the
 270  * "in-place" results of a select system call (see select, section 2).
 271  */
 272
 273 /*
 274  * Global keeper of rpc service descriptors in use
 275  * dynamic; must be inspected before each call to select
 276  */
 277
 278 extern struct pollfd *svc_pollfd;
 279 extern int svc_max_pollfd;
 280 extern fd_set svc_fdset;
 281 #define svc_fds svc_fdset.fds_bits[0]   /* compatibility */
 282
 283 /*
 284  * a small program implemented by the svc_rpc implementation itself;
 285  * also see clnt.h for protocol numbers.
 286  */
 287 extern void svc_getreq (int __rdfds) __THROW;
 288 extern void svc_getreq_common (const int __fd) __THROW;
 289 extern void svc_getreqset (fd_set *__readfds) __THROW;
 290 extern void svc_getreq_poll (struct pollfd *, const int) __THROW;
 291 extern void svc_exit (void) __THROW;
 292 extern void svc_run (void) __THROW;
 293
 294 /*
 295  * Socket to use on svcxxx_create call to get default socket
 296  */
 297 #define RPC_ANYSOCK     -1
 298
 299 /*
 300  * These are the existing service side transport implementations
 301  */
 302
 303 /*
 304  * Memory based rpc for testing and timing.
 305  */
 306 extern SVCXPRT *svcraw_create (void) __THROW;
 307
 308 /*
 309  * Udp based rpc.
 310  */
 311 extern SVCXPRT *svcudp_create (int __sock) __THROW;
 312 extern SVCXPRT *svcudp_bufcreate (int __sock, u_int __sendsz, u_int __recvsz)
 313      __THROW;
 314
 315 /*
 316  * Tcp based rpc.
 317  */
 318 extern SVCXPRT *svctcp_create (int __sock, u_int __sendsize, u_int __recvsize)
 319      __THROW;
 320
 321 /*
 322  * FD based rpc.
 323  */
 324 extern SVCXPRT *svcfd_create (int __sock, u_int __sendsize, u_int __recvsize)
 325      __THROW;
 326
 327 /*
 328  * Unix based rpc.
 329  */
 330 extern SVCXPRT *svcunix_create (int __sock, u_int __sendsize, u_int __recvsize,
 331                                 char *__path) __THROW;
 332
 333
 334 __END_DECLS
 335
 336 #endif /* rpc/svc.h */