xref: /freebsd/lib/libc/rpc/clnt_generic.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
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 /* #ident	"@(#)clnt_generic.c	1.40	99/04/21 SMI" */
34 
35 #if defined(LIBC_SCCS) && !defined(lint)
36 static char *sccsid2 = "from: @(#)clnt_generic.c 1.4 87/08/11 (C) 1987 SMI";
37 static char *sccsid = "from: @(#)clnt_generic.c	2.2 88/08/01 4.0 RPCSRC";
38 #endif
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 /*
43  * Copyright (c) 1986-1996,1998 by Sun Microsystems, Inc.
44  * All rights reserved.
45  */
46 #include "namespace.h"
47 #include "reentrant.h"
48 #include <sys/types.h>
49 #include <sys/fcntl.h>
50 #include <sys/socket.h>
51 #include <netinet/in.h>
52 #include <netinet/tcp.h>
53 #include <stdio.h>
54 #include <errno.h>
55 #include <netdb.h>
56 #include <syslog.h>
57 #include <rpc/rpc.h>
58 #include <rpc/nettype.h>
59 #include <string.h>
60 #include <stdlib.h>
61 #include <unistd.h>
62 #include "un-namespace.h"
63 #include "rpc_com.h"
64 
65 extern bool_t __rpc_is_local_host(const char *);
66 int __rpc_raise_fd(int);
67 
68 #ifndef NETIDLEN
69 #define	NETIDLEN 32
70 #endif
71 
72 
73 /*
74  * Generic client creation with version checking the value of
75  * vers_out is set to the highest server supported value
76  * vers_low <= vers_out <= vers_high  AND an error results
77  * if this can not be done.
78  *
79  * It calls clnt_create_vers_timed() with a NULL value for the timeout
80  * pointer, which indicates that the default timeout should be used.
81  */
82 CLIENT *
83 clnt_create_vers(const char *hostname, rpcprog_t prog, rpcvers_t *vers_out,
84 	rpcvers_t vers_low, rpcvers_t vers_high, const char *nettype)
85 {
86 
87 	return (clnt_create_vers_timed(hostname, prog, vers_out, vers_low,
88 				vers_high, nettype, NULL));
89 }
90 
91 /*
92  * This the routine has the same definition as clnt_create_vers(),
93  * except it takes an additional timeout parameter - a pointer to
94  * a timeval structure.  A NULL value for the pointer indicates
95  * that the default timeout value should be used.
96  */
97 CLIENT *
98 clnt_create_vers_timed(const char *hostname, rpcprog_t prog,
99     rpcvers_t *vers_out, rpcvers_t vers_low, rpcvers_t vers_high,
100     const char *nettype, const struct timeval *tp)
101 {
102 	CLIENT *clnt;
103 	struct timeval to;
104 	enum clnt_stat rpc_stat;
105 	struct rpc_err rpcerr;
106 
107 	clnt = clnt_create_timed(hostname, prog, vers_high, nettype, tp);
108 	if (clnt == NULL) {
109 		return (NULL);
110 	}
111 	to.tv_sec = 10;
112 	to.tv_usec = 0;
113 	rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
114 			(char *)NULL, (xdrproc_t)xdr_void, (char *)NULL, to);
115 	if (rpc_stat == RPC_SUCCESS) {
116 		*vers_out = vers_high;
117 		return (clnt);
118 	}
119 	while (rpc_stat == RPC_PROGVERSMISMATCH && vers_high > vers_low) {
120 		unsigned int minvers, maxvers;
121 
122 		clnt_geterr(clnt, &rpcerr);
123 		minvers = rpcerr.re_vers.low;
124 		maxvers = rpcerr.re_vers.high;
125 		if (maxvers < vers_high)
126 			vers_high = maxvers;
127 		else
128 			vers_high--;
129 		if (minvers > vers_low)
130 			vers_low = minvers;
131 		if (vers_low > vers_high) {
132 			goto error;
133 		}
134 		CLNT_CONTROL(clnt, CLSET_VERS, (char *)&vers_high);
135 		rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
136 				(char *)NULL, (xdrproc_t)xdr_void,
137 				(char *)NULL, to);
138 		if (rpc_stat == RPC_SUCCESS) {
139 			*vers_out = vers_high;
140 			return (clnt);
141 		}
142 	}
143 	clnt_geterr(clnt, &rpcerr);
144 
145 error:
146 	rpc_createerr.cf_stat = rpc_stat;
147 	rpc_createerr.cf_error = rpcerr;
148 	clnt_destroy(clnt);
149 	return (NULL);
150 }
151 
152 /*
153  * Top level client creation routine.
154  * Generic client creation: takes (servers name, program-number, nettype) and
155  * returns client handle. Default options are set, which the user can
156  * change using the rpc equivalent of _ioctl()'s.
157  *
158  * It tries for all the netids in that particular class of netid until
159  * it succeeds.
160  * XXX The error message in the case of failure will be the one
161  * pertaining to the last create error.
162  *
163  * It calls clnt_create_timed() with the default timeout.
164  */
165 CLIENT *
166 clnt_create(const char *hostname, rpcprog_t prog, rpcvers_t vers,
167     const char *nettype)
168 {
169 
170 	return (clnt_create_timed(hostname, prog, vers, nettype, NULL));
171 }
172 
173 /*
174  * This the routine has the same definition as clnt_create(),
175  * except it takes an additional timeout parameter - a pointer to
176  * a timeval structure.  A NULL value for the pointer indicates
177  * that the default timeout value should be used.
178  *
179  * This function calls clnt_tp_create_timed().
180  */
181 CLIENT *
182 clnt_create_timed(const char *hostname, rpcprog_t prog, rpcvers_t vers,
183     const char *netclass, const struct timeval *tp)
184 {
185 	struct netconfig *nconf;
186 	CLIENT *clnt = NULL;
187 	void *handle;
188 	enum clnt_stat	save_cf_stat = RPC_SUCCESS;
189 	struct rpc_err	save_cf_error;
190 	char nettype_array[NETIDLEN];
191 	char *nettype = &nettype_array[0];
192 
193 	if (netclass == NULL)
194 		nettype = NULL;
195 	else {
196 		size_t len = strlen(netclass);
197 		if (len >= sizeof (nettype_array)) {
198 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
199 			return (NULL);
200 		}
201 		strcpy(nettype, netclass);
202 	}
203 
204 	if ((handle = __rpc_setconf((char *)nettype)) == NULL) {
205 		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
206 		return (NULL);
207 	}
208 	rpc_createerr.cf_stat = RPC_SUCCESS;
209 	while (clnt == NULL) {
210 		if ((nconf = __rpc_getconf(handle)) == NULL) {
211 			if (rpc_createerr.cf_stat == RPC_SUCCESS)
212 				rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
213 			break;
214 		}
215 #ifdef CLNT_DEBUG
216 		printf("trying netid %s\n", nconf->nc_netid);
217 #endif
218 		clnt = clnt_tp_create_timed(hostname, prog, vers, nconf, tp);
219 		if (clnt)
220 			break;
221 		else
222 			/*
223 			 *	Since we didn't get a name-to-address
224 			 *	translation failure here, we remember
225 			 *	this particular error.  The object of
226 			 *	this is to enable us to return to the
227 			 *	caller a more-specific error than the
228 			 *	unhelpful ``Name to address translation
229 			 *	failed'' which might well occur if we
230 			 *	merely returned the last error (because
231 			 *	the local loopbacks are typically the
232 			 *	last ones in /etc/netconfig and the most
233 			 *	likely to be unable to translate a host
234 			 *	name).  We also check for a more
235 			 *	meaningful error than ``unknown host
236 			 *	name'' for the same reasons.
237 			 */
238 			if (rpc_createerr.cf_stat != RPC_N2AXLATEFAILURE &&
239 			    rpc_createerr.cf_stat != RPC_UNKNOWNHOST) {
240 				save_cf_stat = rpc_createerr.cf_stat;
241 				save_cf_error = rpc_createerr.cf_error;
242 			}
243 	}
244 
245 	/*
246 	 *	Attempt to return an error more specific than ``Name to address
247 	 *	translation failed'' or ``unknown host name''
248 	 */
249 	if ((rpc_createerr.cf_stat == RPC_N2AXLATEFAILURE ||
250 				rpc_createerr.cf_stat == RPC_UNKNOWNHOST) &&
251 					(save_cf_stat != RPC_SUCCESS)) {
252 		rpc_createerr.cf_stat = save_cf_stat;
253 		rpc_createerr.cf_error = save_cf_error;
254 	}
255 	__rpc_endconf(handle);
256 	return (clnt);
257 }
258 
259 /*
260  * Generic client creation: takes (servers name, program-number, netconf) and
261  * returns client handle. Default options are set, which the user can
262  * change using the rpc equivalent of _ioctl()'s : clnt_control()
263  * It finds out the server address from rpcbind and calls clnt_tli_create().
264  *
265  * It calls clnt_tp_create_timed() with the default timeout.
266  */
267 CLIENT *
268 clnt_tp_create(const char *hostname, rpcprog_t prog, rpcvers_t vers,
269     const struct netconfig *nconf)
270 {
271 
272 	return (clnt_tp_create_timed(hostname, prog, vers, nconf, NULL));
273 }
274 
275 /*
276  * This has the same definition as clnt_tp_create(), except it
277  * takes an additional parameter - a pointer to a timeval structure.
278  * A NULL value for the timeout pointer indicates that the default
279  * value for the timeout should be used.
280  */
281 CLIENT *
282 clnt_tp_create_timed(const char *hostname, rpcprog_t prog, rpcvers_t vers,
283     const struct netconfig *nconf, const struct timeval *tp)
284 {
285 	struct netbuf *svcaddr;			/* servers address */
286 	CLIENT *cl = NULL;			/* client handle */
287 
288 	if (nconf == NULL) {
289 		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
290 		return (NULL);
291 	}
292 
293 	/*
294 	 * Get the address of the server
295 	 */
296 	if ((svcaddr = __rpcb_findaddr_timed(prog, vers,
297 			(struct netconfig *)nconf, (char *)hostname,
298 			&cl, (struct timeval *)tp)) == NULL) {
299 		/* appropriate error number is set by rpcbind libraries */
300 		return (NULL);
301 	}
302 	if (cl == NULL) {
303 		cl = clnt_tli_create(RPC_ANYFD, nconf, svcaddr,
304 					prog, vers, 0, 0);
305 	} else {
306 		/* Reuse the CLIENT handle and change the appropriate fields */
307 		if (CLNT_CONTROL(cl, CLSET_SVC_ADDR, (void *)svcaddr) == TRUE) {
308 			if (cl->cl_netid == NULL)
309 				cl->cl_netid = strdup(nconf->nc_netid);
310 			if (cl->cl_tp == NULL)
311 				cl->cl_tp = strdup(nconf->nc_device);
312 			(void) CLNT_CONTROL(cl, CLSET_PROG, (void *)&prog);
313 			(void) CLNT_CONTROL(cl, CLSET_VERS, (void *)&vers);
314 		} else {
315 			CLNT_DESTROY(cl);
316 			cl = clnt_tli_create(RPC_ANYFD, nconf, svcaddr,
317 					prog, vers, 0, 0);
318 		}
319 	}
320 	free(svcaddr->buf);
321 	free(svcaddr);
322 	return (cl);
323 }
324 
325 /*
326  * Generic client creation:  returns client handle.
327  * Default options are set, which the user can
328  * change using the rpc equivalent of _ioctl()'s : clnt_control().
329  * If fd is RPC_ANYFD, it will be opened using nconf.
330  * It will be bound if not so.
331  * If sizes are 0; appropriate defaults will be chosen.
332  */
333 CLIENT *
334 clnt_tli_create(int fd, const struct netconfig *nconf,
335 	struct netbuf *svcaddr, rpcprog_t prog, rpcvers_t vers,
336 	uint sendsz, uint recvsz)
337 {
338 	CLIENT *cl;			/* client handle */
339 	bool_t madefd = FALSE;		/* whether fd opened here */
340 	long servtype;
341 	int one = 1;
342 	struct __rpc_sockinfo si;
343 	extern int __rpc_minfd;
344 
345 	if (fd == RPC_ANYFD) {
346 		if (nconf == NULL) {
347 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
348 			return (NULL);
349 		}
350 
351 		fd = __rpc_nconf2fd(nconf);
352 
353 		if (fd == -1)
354 			goto err;
355 		if (fd < __rpc_minfd)
356 			fd = __rpc_raise_fd(fd);
357 		madefd = TRUE;
358 		servtype = nconf->nc_semantics;
359 		if (!__rpc_fd2sockinfo(fd, &si))
360 			goto err;
361 		bindresvport(fd, NULL);
362 	} else {
363 		if (!__rpc_fd2sockinfo(fd, &si))
364 			goto err;
365 		servtype = __rpc_socktype2seman(si.si_socktype);
366 		if (servtype == -1) {
367 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
368 			return (NULL);
369 		}
370 	}
371 
372 	if (si.si_af != ((struct sockaddr *)svcaddr->buf)->sa_family) {
373 		rpc_createerr.cf_stat = RPC_UNKNOWNHOST;	/* XXX */
374 		goto err1;
375 	}
376 
377 	switch (servtype) {
378 	case NC_TPI_COTS:
379 		cl = clnt_vc_create(fd, svcaddr, prog, vers, sendsz, recvsz);
380 		break;
381 	case NC_TPI_COTS_ORD:
382 		if (nconf && ((strcmp(nconf->nc_protofmly, "inet") == 0))) {
383 			_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one,
384 			    sizeof (one));
385 		}
386 		cl = clnt_vc_create(fd, svcaddr, prog, vers, sendsz, recvsz);
387 		break;
388 	case NC_TPI_CLTS:
389 		cl = clnt_dg_create(fd, svcaddr, prog, vers, sendsz, recvsz);
390 		break;
391 	default:
392 		goto err;
393 	}
394 
395 	if (cl == NULL)
396 		goto err1; /* borrow errors from clnt_dg/vc creates */
397 	if (nconf) {
398 		cl->cl_netid = strdup(nconf->nc_netid);
399 		cl->cl_tp = strdup(nconf->nc_device);
400 	} else {
401 		cl->cl_netid = "";
402 		cl->cl_tp = "";
403 	}
404 	if (madefd) {
405 		(void) CLNT_CONTROL(cl, CLSET_FD_CLOSE, NULL);
406 /*		(void) CLNT_CONTROL(cl, CLSET_POP_TIMOD, NULL);  */
407 	}
408 
409 	return (cl);
410 
411 err:
412 	rpc_createerr.cf_stat = RPC_SYSTEMERROR;
413 	rpc_createerr.cf_error.re_errno = errno;
414 err1:	if (madefd)
415 		(void)_close(fd);
416 	return (NULL);
417 }
418 
419 /*
420  *  To avoid conflicts with the "magic" file descriptors (0, 1, and 2),
421  *  we try to not use them.  The __rpc_raise_fd() routine will dup
422  *  a descriptor to a higher value.  If we fail to do it, we continue
423  *  to use the old one (and hope for the best).
424  */
425 int __rpc_minfd = 3;
426 
427 int
428 __rpc_raise_fd(int fd)
429 {
430 	int nfd;
431 
432 	if (fd >= __rpc_minfd)
433 		return (fd);
434 
435 	if ((nfd = _fcntl(fd, F_DUPFD, __rpc_minfd)) == -1)
436 		return (fd);
437 
438 	if (_fsync(nfd) == -1) {
439 		_close(nfd);
440 		return (fd);
441 	}
442 
443 	if (_close(fd) == -1) {
444 		/* this is okay, we will syslog an error, then use the new fd */
445 		(void) syslog(LOG_ERR,
446 			"could not close() fd %d; mem & fd leak", fd);
447 	}
448 
449 	return (nfd);
450 }
451