1/*
2 * svc.h, Server-side remote procedure call interface.
3 *
4 * Copyright (C) 2012-2021 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 * <https://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
81enum xprt_stat {
82 XPRT_DIED,
83 XPRT_MOREREQS,
84 XPRT_IDLE
85};
86
87/*
88 * Server side transport handle
89 */
90typedef struct SVCXPRT SVCXPRT;
91struct 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 */
164struct 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
175typedef 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 */
188extern 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 */
199extern void svc_unregister (rpcprog_t __prog, rpcvers_t __vers) __THROW;
200
201/*
202 * Transport registration.
203 *
204 * xprt_register(xprt)
205 * SVCXPRT *xprt;
206 */
207extern void xprt_register (SVCXPRT *__xprt) __THROW;
208
209/*
210 * Transport un-register
211 *
212 * xprt_unregister(xprt)
213 * SVCXPRT *xprt;
214 */
215extern 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
244extern bool_t svc_sendreply (SVCXPRT *__xprt, xdrproc_t __xdr_results,
245 caddr_t __xdr_location) __THROW;
246
247extern void svcerr_decode (SVCXPRT *__xprt) __THROW;
248
249extern void svcerr_weakauth (SVCXPRT *__xprt) __THROW;
250
251extern void svcerr_noproc (SVCXPRT *__xprt) __THROW;
252
253extern void svcerr_progvers (SVCXPRT *__xprt, rpcvers_t __low_vers,
254 rpcvers_t __high_vers) __THROW;
255
256extern void svcerr_auth (SVCXPRT *__xprt, enum auth_stat __why) __THROW;
257
258extern void svcerr_noprog (SVCXPRT *__xprt) __THROW;
259
260extern 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
278extern struct pollfd *svc_pollfd;
279extern int svc_max_pollfd;
280extern 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 */
287extern void svc_getreq (int __rdfds) __THROW;
288extern void svc_getreq_common (const int __fd) __THROW;
289extern void svc_getreqset (fd_set *__readfds) __THROW;
290extern void svc_getreq_poll (struct pollfd *, const int) __THROW;
291extern void svc_exit (void) __THROW;
292extern 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 */
306extern SVCXPRT *svcraw_create (void) __THROW;
307
308/*
309 * Udp based rpc.
310 */
311extern SVCXPRT *svcudp_create (int __sock) __THROW;
312extern SVCXPRT *svcudp_bufcreate (int __sock, u_int __sendsz, u_int __recvsz)
313 __THROW;
314
315/*
316 * Tcp based rpc.
317 */
318extern SVCXPRT *svctcp_create (int __sock, u_int __sendsize, u_int __recvsize)
319 __THROW;
320
321/*
322 * FD based rpc.
323 */
324extern SVCXPRT *svcfd_create (int __sock, u_int __sendsize, u_int __recvsize)
325 __THROW;
326
327/*
328 * Unix based rpc.
329 */
330extern 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 */
337