xref: /freebsd/lib/libc/rpc/clnt_generic.c (revision dc36d6f9bb1753f3808552f3afd30eda9a7b206a)
1 /*	$NetBSD: clnt_generic.c,v 1.18 2000/07/06 03:10:34 christos Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (c) 2010, Oracle America, Inc.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions are met:
11  * - Redistributions of source code must retain the above copyright notice,
12  *   this list of conditions and the following disclaimer.
13  * - Redistributions in binary form must reproduce the above copyright notice,
14  *   this list of conditions and the following disclaimer in the documentation
15  *   and/or other materials 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 "AS IS"
21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1986-1996,1998 by Sun Microsystems, Inc.
35  * All rights reserved.
36  */
37 #include "namespace.h"
38 #include "reentrant.h"
39 #include <sys/types.h>
40 #include <sys/fcntl.h>
41 #include <sys/socket.h>
42 #include <netinet/in.h>
43 #include <netinet/tcp.h>
44 #include <stdio.h>
45 #include <errno.h>
46 #include <netdb.h>
47 #include <syslog.h>
48 #include <rpc/rpc.h>
49 #include <rpc/nettype.h>
50 #include <string.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 #include "un-namespace.h"
54 #include "rpc_com.h"
55 
56 extern bool_t __rpc_is_local_host(const char *);
57 int __rpc_raise_fd(int);
58 
59 #ifndef NETIDLEN
60 #define	NETIDLEN 32
61 #endif
62 
63 
64 /*
65  * Generic client creation with version checking the value of
66  * vers_out is set to the highest server supported value
67  * vers_low <= vers_out <= vers_high  AND an error results
68  * if this can not be done.
69  *
70  * It calls clnt_create_vers_timed() with a NULL value for the timeout
71  * pointer, which indicates that the default timeout should be used.
72  */
73 CLIENT *
clnt_create_vers(const char * hostname,rpcprog_t prog,rpcvers_t * vers_out,rpcvers_t vers_low,rpcvers_t vers_high,const char * nettype)74 clnt_create_vers(const char *hostname, rpcprog_t prog, rpcvers_t *vers_out,
75 	rpcvers_t vers_low, rpcvers_t vers_high, const char *nettype)
76 {
77 
78 	return (clnt_create_vers_timed(hostname, prog, vers_out, vers_low,
79 				vers_high, nettype, NULL));
80 }
81 
82 /*
83  * This the routine has the same definition as clnt_create_vers(),
84  * except it takes an additional timeout parameter - a pointer to
85  * a timeval structure.  A NULL value for the pointer indicates
86  * that the default timeout value should be used.
87  */
88 CLIENT *
clnt_create_vers_timed(const char * hostname,rpcprog_t prog,rpcvers_t * vers_out,rpcvers_t vers_low,rpcvers_t vers_high,const char * nettype,const struct timeval * tp)89 clnt_create_vers_timed(const char *hostname, rpcprog_t prog,
90     rpcvers_t *vers_out, rpcvers_t vers_low, rpcvers_t vers_high,
91     const char *nettype, const struct timeval *tp)
92 {
93 	CLIENT *clnt;
94 	struct timeval to;
95 	enum clnt_stat rpc_stat;
96 	struct rpc_err rpcerr;
97 
98 	clnt = clnt_create_timed(hostname, prog, vers_high, nettype, tp);
99 	if (clnt == NULL) {
100 		return (NULL);
101 	}
102 	to.tv_sec = 10;
103 	to.tv_usec = 0;
104 	rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
105 			(char *)NULL, (xdrproc_t)xdr_void, (char *)NULL, to);
106 	if (rpc_stat == RPC_SUCCESS) {
107 		*vers_out = vers_high;
108 		return (clnt);
109 	}
110 	while (rpc_stat == RPC_PROGVERSMISMATCH && vers_high > vers_low) {
111 		unsigned int minvers, maxvers;
112 
113 		clnt_geterr(clnt, &rpcerr);
114 		minvers = rpcerr.re_vers.low;
115 		maxvers = rpcerr.re_vers.high;
116 		if (maxvers < vers_high)
117 			vers_high = maxvers;
118 		else
119 			vers_high--;
120 		if (minvers > vers_low)
121 			vers_low = minvers;
122 		if (vers_low > vers_high) {
123 			goto error;
124 		}
125 		CLNT_CONTROL(clnt, CLSET_VERS, (char *)&vers_high);
126 		rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
127 				(char *)NULL, (xdrproc_t)xdr_void,
128 				(char *)NULL, to);
129 		if (rpc_stat == RPC_SUCCESS) {
130 			*vers_out = vers_high;
131 			return (clnt);
132 		}
133 	}
134 	clnt_geterr(clnt, &rpcerr);
135 
136 error:
137 	rpc_createerr.cf_stat = rpc_stat;
138 	rpc_createerr.cf_error = rpcerr;
139 	clnt_destroy(clnt);
140 	return (NULL);
141 }
142 
143 /*
144  * Top level client creation routine.
145  * Generic client creation: takes (servers name, program-number, nettype) and
146  * returns client handle. Default options are set, which the user can
147  * change using the rpc equivalent of _ioctl()'s.
148  *
149  * It tries for all the netids in that particular class of netid until
150  * it succeeds.
151  * XXX The error message in the case of failure will be the one
152  * pertaining to the last create error.
153  *
154  * It calls clnt_create_timed() with the default timeout.
155  */
156 CLIENT *
clnt_create(const char * hostname,rpcprog_t prog,rpcvers_t vers,const char * nettype)157 clnt_create(const char *hostname, rpcprog_t prog, rpcvers_t vers,
158     const char *nettype)
159 {
160 
161 	return (clnt_create_timed(hostname, prog, vers, nettype, NULL));
162 }
163 
164 /*
165  * This the routine has the same definition as clnt_create(),
166  * except it takes an additional timeout parameter - a pointer to
167  * a timeval structure.  A NULL value for the pointer indicates
168  * that the default timeout value should be used.
169  *
170  * This function calls clnt_tp_create_timed().
171  */
172 CLIENT *
clnt_create_timed(const char * hostname,rpcprog_t prog,rpcvers_t vers,const char * netclass,const struct timeval * tp)173 clnt_create_timed(const char *hostname, rpcprog_t prog, rpcvers_t vers,
174     const char *netclass, const struct timeval *tp)
175 {
176 	struct netconfig *nconf;
177 	CLIENT *clnt = NULL;
178 	void *handle;
179 	enum clnt_stat	save_cf_stat = RPC_SUCCESS;
180 	struct rpc_err	save_cf_error;
181 	char nettype_array[NETIDLEN];
182 	char *nettype = &nettype_array[0];
183 
184 	if (netclass == NULL)
185 		nettype = NULL;
186 	else {
187 		size_t len = strlen(netclass);
188 		if (len >= sizeof (nettype_array)) {
189 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
190 			return (NULL);
191 		}
192 		strcpy(nettype, netclass);
193 	}
194 
195 	if ((handle = __rpc_setconf((char *)nettype)) == NULL) {
196 		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
197 		return (NULL);
198 	}
199 	rpc_createerr.cf_stat = RPC_SUCCESS;
200 	while (clnt == NULL) {
201 		if ((nconf = __rpc_getconf(handle)) == NULL) {
202 			if (rpc_createerr.cf_stat == RPC_SUCCESS)
203 				rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
204 			break;
205 		}
206 #ifdef CLNT_DEBUG
207 		printf("trying netid %s\n", nconf->nc_netid);
208 #endif
209 		clnt = clnt_tp_create_timed(hostname, prog, vers, nconf, tp);
210 		if (clnt)
211 			break;
212 		else
213 			/*
214 			 *	Since we didn't get a name-to-address
215 			 *	translation failure here, we remember
216 			 *	this particular error.  The object of
217 			 *	this is to enable us to return to the
218 			 *	caller a more-specific error than the
219 			 *	unhelpful ``Name to address translation
220 			 *	failed'' which might well occur if we
221 			 *	merely returned the last error (because
222 			 *	the local loopbacks are typically the
223 			 *	last ones in /etc/netconfig and the most
224 			 *	likely to be unable to translate a host
225 			 *	name).  We also check for a more
226 			 *	meaningful error than ``unknown host
227 			 *	name'' for the same reasons.
228 			 */
229 			if (rpc_createerr.cf_stat != RPC_N2AXLATEFAILURE &&
230 			    rpc_createerr.cf_stat != RPC_UNKNOWNHOST) {
231 				save_cf_stat = rpc_createerr.cf_stat;
232 				save_cf_error = rpc_createerr.cf_error;
233 			}
234 	}
235 
236 	/*
237 	 *	Attempt to return an error more specific than ``Name to address
238 	 *	translation failed'' or ``unknown host name''
239 	 */
240 	if ((rpc_createerr.cf_stat == RPC_N2AXLATEFAILURE ||
241 				rpc_createerr.cf_stat == RPC_UNKNOWNHOST) &&
242 					(save_cf_stat != RPC_SUCCESS)) {
243 		rpc_createerr.cf_stat = save_cf_stat;
244 		rpc_createerr.cf_error = save_cf_error;
245 	}
246 	__rpc_endconf(handle);
247 	return (clnt);
248 }
249 
250 /*
251  * Generic client creation: takes (servers name, program-number, netconf) and
252  * returns client handle. Default options are set, which the user can
253  * change using the rpc equivalent of _ioctl()'s : clnt_control()
254  * It finds out the server address from rpcbind and calls clnt_tli_create().
255  *
256  * It calls clnt_tp_create_timed() with the default timeout.
257  */
258 CLIENT *
clnt_tp_create(const char * hostname,rpcprog_t prog,rpcvers_t vers,const struct netconfig * nconf)259 clnt_tp_create(const char *hostname, rpcprog_t prog, rpcvers_t vers,
260     const struct netconfig *nconf)
261 {
262 
263 	return (clnt_tp_create_timed(hostname, prog, vers, nconf, NULL));
264 }
265 
266 /*
267  * This has the same definition as clnt_tp_create(), except it
268  * takes an additional parameter - a pointer to a timeval structure.
269  * A NULL value for the timeout pointer indicates that the default
270  * value for the timeout should be used.
271  */
272 CLIENT *
clnt_tp_create_timed(const char * hostname,rpcprog_t prog,rpcvers_t vers,const struct netconfig * nconf,const struct timeval * tp)273 clnt_tp_create_timed(const char *hostname, rpcprog_t prog, rpcvers_t vers,
274     const struct netconfig *nconf, const struct timeval *tp)
275 {
276 	struct netbuf *svcaddr;			/* servers address */
277 	CLIENT *cl = NULL;			/* client handle */
278 
279 	if (nconf == NULL) {
280 		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
281 		return (NULL);
282 	}
283 
284 	/*
285 	 * Get the address of the server
286 	 */
287 	if ((svcaddr = __rpcb_findaddr_timed(prog, vers,
288 			(struct netconfig *)nconf, (char *)hostname,
289 			&cl, (struct timeval *)tp)) == NULL) {
290 		/* appropriate error number is set by rpcbind libraries */
291 		return (NULL);
292 	}
293 	if (cl == NULL) {
294 		cl = clnt_tli_create(RPC_ANYFD, nconf, svcaddr,
295 					prog, vers, 0, 0);
296 	} else {
297 		/* Reuse the CLIENT handle and change the appropriate fields */
298 		if (CLNT_CONTROL(cl, CLSET_SVC_ADDR, (void *)svcaddr) == TRUE) {
299 			if (cl->cl_netid == NULL)
300 				cl->cl_netid = strdup(nconf->nc_netid);
301 			if (cl->cl_tp == NULL)
302 				cl->cl_tp = strdup(nconf->nc_device);
303 			(void) CLNT_CONTROL(cl, CLSET_PROG, (void *)&prog);
304 			(void) CLNT_CONTROL(cl, CLSET_VERS, (void *)&vers);
305 		} else {
306 			CLNT_DESTROY(cl);
307 			cl = clnt_tli_create(RPC_ANYFD, nconf, svcaddr,
308 					prog, vers, 0, 0);
309 		}
310 	}
311 	free(svcaddr->buf);
312 	free(svcaddr);
313 	return (cl);
314 }
315 
316 /*
317  * Generic client creation:  returns client handle.
318  * Default options are set, which the user can
319  * change using the rpc equivalent of _ioctl()'s : clnt_control().
320  * If fd is RPC_ANYFD, it will be opened using nconf.
321  * It will be bound if not so.
322  * If sizes are 0; appropriate defaults will be chosen.
323  */
324 CLIENT *
clnt_tli_create(int fd,const struct netconfig * nconf,struct netbuf * svcaddr,rpcprog_t prog,rpcvers_t vers,uint sendsz,uint recvsz)325 clnt_tli_create(int fd, const struct netconfig *nconf,
326 	struct netbuf *svcaddr, rpcprog_t prog, rpcvers_t vers,
327 	uint sendsz, uint recvsz)
328 {
329 	CLIENT *cl;			/* client handle */
330 	bool_t madefd = FALSE;		/* whether fd opened here */
331 	long servtype;
332 	int one = 1;
333 	struct __rpc_sockinfo si;
334 	extern int __rpc_minfd;
335 
336 	if (fd == RPC_ANYFD) {
337 		if (nconf == NULL) {
338 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
339 			return (NULL);
340 		}
341 
342 		fd = __rpc_nconf2fd(nconf);
343 
344 		if (fd == -1)
345 			goto err;
346 		if (fd < __rpc_minfd)
347 			fd = __rpc_raise_fd(fd);
348 		madefd = TRUE;
349 		servtype = nconf->nc_semantics;
350 		if (!__rpc_fd2sockinfo(fd, &si))
351 			goto err;
352 		bindresvport(fd, NULL);
353 	} else {
354 		if (!__rpc_fd2sockinfo(fd, &si))
355 			goto err;
356 		servtype = __rpc_socktype2seman(si.si_socktype);
357 		if (servtype == -1) {
358 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
359 			return (NULL);
360 		}
361 	}
362 
363 	if (si.si_af != ((struct sockaddr *)svcaddr->buf)->sa_family) {
364 		rpc_createerr.cf_stat = RPC_UNKNOWNHOST;	/* XXX */
365 		goto err1;
366 	}
367 
368 	switch (servtype) {
369 	case NC_TPI_COTS:
370 		cl = clnt_vc_create(fd, svcaddr, prog, vers, sendsz, recvsz);
371 		break;
372 	case NC_TPI_COTS_ORD:
373 		if (nconf && ((strcmp(nconf->nc_protofmly, "inet") == 0))) {
374 			_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one,
375 			    sizeof (one));
376 		}
377 		cl = clnt_vc_create(fd, svcaddr, prog, vers, sendsz, recvsz);
378 		break;
379 	case NC_TPI_CLTS:
380 		cl = clnt_dg_create(fd, svcaddr, prog, vers, sendsz, recvsz);
381 		break;
382 	default:
383 		goto err;
384 	}
385 
386 	if (cl == NULL)
387 		goto err1; /* borrow errors from clnt_dg/vc creates */
388 	if (nconf) {
389 		cl->cl_netid = strdup(nconf->nc_netid);
390 		cl->cl_tp = strdup(nconf->nc_device);
391 	} else {
392 		cl->cl_netid = "";
393 		cl->cl_tp = "";
394 	}
395 	if (madefd) {
396 		(void) CLNT_CONTROL(cl, CLSET_FD_CLOSE, NULL);
397 /*		(void) CLNT_CONTROL(cl, CLSET_POP_TIMOD, NULL);  */
398 	}
399 
400 	return (cl);
401 
402 err:
403 	rpc_createerr.cf_stat = RPC_SYSTEMERROR;
404 	rpc_createerr.cf_error.re_errno = errno;
405 err1:	if (madefd)
406 		(void)_close(fd);
407 	return (NULL);
408 }
409 
410 /*
411  *  To avoid conflicts with the "magic" file descriptors (0, 1, and 2),
412  *  we try to not use them.  The __rpc_raise_fd() routine will dup
413  *  a descriptor to a higher value.  If we fail to do it, we continue
414  *  to use the old one (and hope for the best).
415  */
416 int __rpc_minfd = 3;
417 
418 int
__rpc_raise_fd(int fd)419 __rpc_raise_fd(int fd)
420 {
421 	int nfd;
422 
423 	if (fd >= __rpc_minfd)
424 		return (fd);
425 
426 	if ((nfd = _fcntl(fd, F_DUPFD, __rpc_minfd)) == -1)
427 		return (fd);
428 
429 	if (_fsync(nfd) == -1) {
430 		_close(nfd);
431 		return (fd);
432 	}
433 
434 	if (_close(fd) == -1) {
435 		/* this is okay, we will syslog an error, then use the new fd */
436 		(void) syslog(LOG_ERR,
437 			"could not close() fd %d; mem & fd leak", fd);
438 	}
439 
440 	return (nfd);
441 }
442