xref: /netbsd-src/lib/libc/rpc/svc_simple.c (revision 85f5e301f5b0e5c7695c7222d16769f8f55f6aeb)
1 /*	$NetBSD: svc_simple.c,v 1.34 2024/01/23 17:24:38 christos Exp $	*/
2 
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 /*
34  * Copyright (c) 1986-1991 by Sun Microsystems Inc.
35  */
36 
37 /* #pragma ident	"@(#)svc_simple.c	1.18	94/04/24 SMI" */
38 
39 /*
40  * svc_simple.c
41  * Simplified front end to rpc.
42  */
43 
44 /*
45  * This interface creates a virtual listener for all the services
46  * started thru rpc_reg(). It listens on the same endpoint for
47  * all the services and then executes the corresponding service
48  * for the given prognum and procnum.
49  */
50 
51 #include <sys/cdefs.h>
52 #if defined(LIBC_SCCS) && !defined(lint)
53 __RCSID("$NetBSD: svc_simple.c,v 1.34 2024/01/23 17:24:38 christos Exp $");
54 #endif
55 
56 #include "namespace.h"
57 #include "reentrant.h"
58 #include <sys/types.h>
59 #include <rpc/rpc.h>
60 #include <rpc/nettype.h>
61 #include <assert.h>
62 #include <err.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 
67 #include "rpc_internal.h"
68 
69 #ifdef __weak_alias
70 __weak_alias(rpc_reg,_rpc_reg)
71 #endif
72 
73 static void universal(struct svc_req *, SVCXPRT *);
74 
75 static struct proglst {
76 	char *(*p_progname)(char *);
77 	rpcprog_t p_prognum;
78 	rpcvers_t p_versnum;
79 	rpcproc_t p_procnum;
80 	SVCXPRT *p_transp;
81 	char *p_netid;
82 	char *p_xdrbuf;
83 	int p_recvsz;
84 	xdrproc_t p_inproc, p_outproc;
85 	struct proglst *p_nxt;
86 } *proglst;
87 
88 static const char __reg_err1[] = "can't find appropriate transport";
89 static const char __reg_err2[] = "can't get protocol info";
90 static const char __reg_err3[] = "unsupported transport size";
91 static const char __no_mem_str[] = "out of memory";
92 
93 /*
94  * For simplified, easy to use kind of rpc interfaces.
95  * nettype indicates the type of transport on which the service will be
96  * listening. Used for conservation of the system resource. Only one
97  * handle is created for all the services (actually one of each netid)
98  * and same xdrbuf is used for same netid. The size of the arguments
99  * is also limited by the recvsize for that transport, even if it is
100  * a COTS transport. This may be wrong, but for cases like these, they
101  * should not use the simplified interfaces like this.
102  */
103 
104 int
rpc_reg(rpcprog_t prognum,rpcvers_t versnum,rpcproc_t procnum,char * (* progname)(char *),xdrproc_t inproc,xdrproc_t outproc,char * nettype)105 rpc_reg(
106 	rpcprog_t prognum,		/* program number */
107 	rpcvers_t versnum,		/* version number */
108 	rpcproc_t procnum,		/* procedure number */
109 	char *(*progname)(char *),	/* Server routine */
110 	xdrproc_t inproc,		/* in XDR procedure */
111 	xdrproc_t outproc,		/* out XDR procedure */
112 	char *nettype)			/* nettype */
113 {
114 	struct netconfig *nconf;
115 	int done = FALSE;
116 	void *handle;
117 
118 	if (procnum == NULLPROC) {
119 		warnx("%s: can't reassign procedure number %u", __func__,
120 		    NULLPROC);
121 		return (-1);
122 	}
123 
124 	if (nettype == NULL)
125 		nettype = __UNCONST("netpath");	/* The default behavior */
126 	if ((handle = __rpc_setconf(nettype)) == NULL) {
127 		warnx("%s: %s", __func__, __reg_err1);
128 		return (-1);
129 	}
130 /* VARIABLES PROTECTED BY proglst_lock: proglst */
131 	mutex_lock(&proglst_lock);
132 	while ((nconf = __rpc_getconf(handle)) != NULL) {
133 		struct proglst *pl;
134 		SVCXPRT *svcxprt;
135 		int madenow;
136 		u_int recvsz;
137 		char *xdrbuf;
138 		char *netid;
139 
140 		madenow = FALSE;
141 		svcxprt = NULL;
142 		recvsz = 0;
143 		xdrbuf = NULL;
144 		netid = NULL;
145 		for (pl = proglst; pl; pl = pl->p_nxt)
146 			if (strcmp(pl->p_netid, nconf->nc_netid) == 0) {
147 				svcxprt = pl->p_transp;
148 				xdrbuf = pl->p_xdrbuf;
149 				recvsz = pl->p_recvsz;
150 				netid = pl->p_netid;
151 				break;
152 			}
153 
154 		if (svcxprt == NULL) {
155 			struct __rpc_sockinfo si;
156 
157 			svcxprt = svc_tli_create(RPC_ANYFD, nconf, NULL, 0, 0);
158 			if (svcxprt == NULL)
159 				continue;
160 			if (!__rpc_fd2sockinfo(svcxprt->xp_fd, &si)) {
161 				warnx("%s: %s", __func__, __reg_err2);
162 				SVC_DESTROY(svcxprt);
163 				continue;
164 			}
165 			recvsz = __rpc_get_t_size(si.si_af, si.si_proto, 0);
166 			if (recvsz == 0) {
167 				warnx("%s: %s", __func__, __reg_err3);
168 				SVC_DESTROY(svcxprt);
169 				continue;
170 			}
171 			if (((xdrbuf = mem_alloc((size_t)recvsz)) == NULL) ||
172 				((netid = strdup(nconf->nc_netid)) == NULL)) {
173 				warnx("%s: %s", __func__, __no_mem_str);
174 				if (xdrbuf != NULL)
175 					free(xdrbuf);
176 				if (netid != NULL)
177 					free(netid);
178 				SVC_DESTROY(svcxprt);
179 				break;
180 			}
181 			madenow = TRUE;
182 		}
183 		/*
184 		 * Check if this (program, version, netid) had already been
185 		 * registered.  The check may save a few RPC calls to rpcbind
186 		 */
187 		for (pl = proglst; pl; pl = pl->p_nxt)
188 			if ((pl->p_prognum == prognum) &&
189 				(pl->p_versnum == versnum) &&
190 				(strcmp(pl->p_netid, netid) == 0))
191 				break;
192 		if (pl == NULL) { /* Not yet */
193 			(void) rpcb_unset(prognum, versnum, nconf);
194 		} else {
195 			/* so that svc_reg does not call rpcb_set() */
196 			nconf = NULL;
197 		}
198 
199 		if (!svc_reg(svcxprt, prognum, versnum, universal, nconf)) {
200 			warnx("%s: couldn't register prog %u vers %u for %s",
201 			    __func__, (unsigned)prognum,
202 			    (unsigned)versnum, netid);
203 			if (madenow) {
204 				SVC_DESTROY(svcxprt);
205 				free(xdrbuf);
206 				free(netid);
207 			}
208 			continue;
209 		}
210 
211 		pl = malloc(sizeof(*pl));
212 		if (pl == NULL) {
213 			warn("%s: %s", __func__, __no_mem_str);
214 			if (madenow) {
215 				SVC_DESTROY(svcxprt);
216 				free(xdrbuf);
217 				free(netid);
218 			}
219 			break;
220 		}
221 		pl->p_progname = progname;
222 		pl->p_prognum = prognum;
223 		pl->p_versnum = versnum;
224 		pl->p_procnum = procnum;
225 		pl->p_inproc = inproc;
226 		pl->p_outproc = outproc;
227 		pl->p_transp = svcxprt;
228 		pl->p_xdrbuf = xdrbuf;
229 		pl->p_recvsz = recvsz;
230 		pl->p_netid = netid;
231 		pl->p_nxt = proglst;
232 		proglst = pl;
233 		done = TRUE;
234 	}
235 	__rpc_endconf(handle);
236 	mutex_unlock(&proglst_lock);
237 
238 	if (done == FALSE) {
239 		warnx("%s: can't find suitable transport for %s",
240 		    __func__, nettype);
241 		return (-1);
242 	}
243 	return (0);
244 }
245 
246 /*
247  * The universal handler for the services registered using registerrpc.
248  * It handles both the connectionless and the connection oriented cases.
249  */
250 
251 static void
universal(struct svc_req * rqstp,SVCXPRT * transp)252 universal(struct svc_req *rqstp, SVCXPRT *transp)
253 {
254 	rpcprog_t prog;
255 	rpcvers_t vers;
256 	rpcproc_t proc;
257 	char *outdata;
258 	char *xdrbuf;
259 	struct proglst *pl;
260 
261 	_DIAGASSERT(rqstp != NULL);
262 	_DIAGASSERT(transp != NULL);
263 
264 	/*
265 	 * enforce "procnum 0 is echo" convention
266 	 */
267 	if (rqstp->rq_proc == NULLPROC) {
268 		if (svc_sendreply(transp, (xdrproc_t) xdr_void, NULL) ==
269 		    FALSE) {
270 			warnx("%s: svc_sendreply failed", __func__);
271 		}
272 		return;
273 	}
274 	prog = rqstp->rq_prog;
275 	vers = rqstp->rq_vers;
276 	proc = rqstp->rq_proc;
277 	mutex_lock(&proglst_lock);
278 	for (pl = proglst; pl; pl = pl->p_nxt)
279 		if (pl->p_prognum == prog && pl->p_procnum == proc &&
280 			pl->p_versnum == vers &&
281 			(strcmp(pl->p_netid, transp->xp_netid) == 0)) {
282 			/* decode arguments into a CLEAN buffer */
283 			xdrbuf = pl->p_xdrbuf;
284 			/* Zero the arguments: reqd ! */
285 			(void) memset(xdrbuf, 0, (size_t)pl->p_recvsz);
286 			/*
287 			 * Assuming that sizeof (xdrbuf) would be enough
288 			 * for the arguments; if not then the program
289 			 * may bomb. BEWARE!
290 			 */
291 			if (!svc_getargs(transp, pl->p_inproc, xdrbuf)) {
292 				svcerr_decode(transp);
293 				mutex_unlock(&proglst_lock);
294 				return;
295 			}
296 			outdata = (*(pl->p_progname))(xdrbuf);
297 			if (outdata == NULL &&
298 				pl->p_outproc != (xdrproc_t) xdr_void){
299 				/* there was an error */
300 				mutex_unlock(&proglst_lock);
301 				return;
302 			}
303 			if (!svc_sendreply(transp, pl->p_outproc, outdata)) {
304 				warnx("%s: trouble replying to prog %u vers %u",
305 				    __func__, (unsigned)prog, (unsigned)vers);
306 				mutex_unlock(&proglst_lock);
307 				return;
308 			}
309 			/* free the decoded arguments */
310 			(void) svc_freeargs(transp, pl->p_inproc, xdrbuf);
311 			mutex_unlock(&proglst_lock);
312 			return;
313 		}
314 	mutex_unlock(&proglst_lock);
315 	/* This should never happen */
316 	warnx("%s: never registered prog %u vers %u", __func__,
317 	    (unsigned)prog, (unsigned)vers);
318 	return;
319 }
320