xref: /freebsd/lib/libc/rpc/clnt_generic.c (revision ec994981447e8a974426660b5071bc405280af73)
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 /*
41  * Copyright (c) 1986-1996,1998 by Sun Microsystems, Inc.
42  * All rights reserved.
43  */
44 #include "namespace.h"
45 #include "reentrant.h"
46 #include <sys/types.h>
47 #include <sys/fcntl.h>
48 #include <sys/socket.h>
49 #include <netinet/in.h>
50 #include <netinet/tcp.h>
51 #include <stdio.h>
52 #include <errno.h>
53 #include <netdb.h>
54 #include <syslog.h>
55 #include <rpc/rpc.h>
56 #include <rpc/nettype.h>
57 #include <string.h>
58 #include <stdlib.h>
59 #include <unistd.h>
60 #include "un-namespace.h"
61 #include "rpc_com.h"
62 
63 extern bool_t __rpc_is_local_host(const char *);
64 int __rpc_raise_fd(int);
65 
66 #ifndef NETIDLEN
67 #define	NETIDLEN 32
68 #endif
69 
70 
71 /*
72  * Generic client creation with version checking the value of
73  * vers_out is set to the highest server supported value
74  * vers_low <= vers_out <= vers_high  AND an error results
75  * if this can not be done.
76  *
77  * It calls clnt_create_vers_timed() with a NULL value for the timeout
78  * pointer, which indicates that the default timeout should be used.
79  */
80 CLIENT *
81 clnt_create_vers(const char *hostname, rpcprog_t prog, rpcvers_t *vers_out,
82 	rpcvers_t vers_low, rpcvers_t vers_high, const char *nettype)
83 {
84 
85 	return (clnt_create_vers_timed(hostname, prog, vers_out, vers_low,
86 				vers_high, nettype, NULL));
87 }
88 
89 /*
90  * This the routine has the same definition as clnt_create_vers(),
91  * except it takes an additional timeout parameter - a pointer to
92  * a timeval structure.  A NULL value for the pointer indicates
93  * that the default timeout value should be used.
94  */
95 CLIENT *
96 clnt_create_vers_timed(const char *hostname, rpcprog_t prog,
97     rpcvers_t *vers_out, rpcvers_t vers_low, rpcvers_t vers_high,
98     const char *nettype, const struct timeval *tp)
99 {
100 	CLIENT *clnt;
101 	struct timeval to;
102 	enum clnt_stat rpc_stat;
103 	struct rpc_err rpcerr;
104 
105 	clnt = clnt_create_timed(hostname, prog, vers_high, nettype, tp);
106 	if (clnt == NULL) {
107 		return (NULL);
108 	}
109 	to.tv_sec = 10;
110 	to.tv_usec = 0;
111 	rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
112 			(char *)NULL, (xdrproc_t)xdr_void, (char *)NULL, to);
113 	if (rpc_stat == RPC_SUCCESS) {
114 		*vers_out = vers_high;
115 		return (clnt);
116 	}
117 	while (rpc_stat == RPC_PROGVERSMISMATCH && vers_high > vers_low) {
118 		unsigned int minvers, maxvers;
119 
120 		clnt_geterr(clnt, &rpcerr);
121 		minvers = rpcerr.re_vers.low;
122 		maxvers = rpcerr.re_vers.high;
123 		if (maxvers < vers_high)
124 			vers_high = maxvers;
125 		else
126 			vers_high--;
127 		if (minvers > vers_low)
128 			vers_low = minvers;
129 		if (vers_low > vers_high) {
130 			goto error;
131 		}
132 		CLNT_CONTROL(clnt, CLSET_VERS, (char *)&vers_high);
133 		rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
134 				(char *)NULL, (xdrproc_t)xdr_void,
135 				(char *)NULL, to);
136 		if (rpc_stat == RPC_SUCCESS) {
137 			*vers_out = vers_high;
138 			return (clnt);
139 		}
140 	}
141 	clnt_geterr(clnt, &rpcerr);
142 
143 error:
144 	rpc_createerr.cf_stat = rpc_stat;
145 	rpc_createerr.cf_error = rpcerr;
146 	clnt_destroy(clnt);
147 	return (NULL);
148 }
149 
150 /*
151  * Top level client creation routine.
152  * Generic client creation: takes (servers name, program-number, nettype) and
153  * returns client handle. Default options are set, which the user can
154  * change using the rpc equivalent of _ioctl()'s.
155  *
156  * It tries for all the netids in that particular class of netid until
157  * it succeeds.
158  * XXX The error message in the case of failure will be the one
159  * pertaining to the last create error.
160  *
161  * It calls clnt_create_timed() with the default timeout.
162  */
163 CLIENT *
164 clnt_create(const char *hostname, rpcprog_t prog, rpcvers_t vers,
165     const char *nettype)
166 {
167 
168 	return (clnt_create_timed(hostname, prog, vers, nettype, NULL));
169 }
170 
171 /*
172  * This the routine has the same definition as clnt_create(),
173  * except it takes an additional timeout parameter - a pointer to
174  * a timeval structure.  A NULL value for the pointer indicates
175  * that the default timeout value should be used.
176  *
177  * This function calls clnt_tp_create_timed().
178  */
179 CLIENT *
180 clnt_create_timed(const char *hostname, rpcprog_t prog, rpcvers_t vers,
181     const char *netclass, const struct timeval *tp)
182 {
183 	struct netconfig *nconf;
184 	CLIENT *clnt = NULL;
185 	void *handle;
186 	enum clnt_stat	save_cf_stat = RPC_SUCCESS;
187 	struct rpc_err	save_cf_error;
188 	char nettype_array[NETIDLEN];
189 	char *nettype = &nettype_array[0];
190 
191 	if (netclass == NULL)
192 		nettype = NULL;
193 	else {
194 		size_t len = strlen(netclass);
195 		if (len >= sizeof (nettype_array)) {
196 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
197 			return (NULL);
198 		}
199 		strcpy(nettype, netclass);
200 	}
201 
202 	if ((handle = __rpc_setconf((char *)nettype)) == NULL) {
203 		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
204 		return (NULL);
205 	}
206 	rpc_createerr.cf_stat = RPC_SUCCESS;
207 	while (clnt == NULL) {
208 		if ((nconf = __rpc_getconf(handle)) == NULL) {
209 			if (rpc_createerr.cf_stat == RPC_SUCCESS)
210 				rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
211 			break;
212 		}
213 #ifdef CLNT_DEBUG
214 		printf("trying netid %s\n", nconf->nc_netid);
215 #endif
216 		clnt = clnt_tp_create_timed(hostname, prog, vers, nconf, tp);
217 		if (clnt)
218 			break;
219 		else
220 			/*
221 			 *	Since we didn't get a name-to-address
222 			 *	translation failure here, we remember
223 			 *	this particular error.  The object of
224 			 *	this is to enable us to return to the
225 			 *	caller a more-specific error than the
226 			 *	unhelpful ``Name to address translation
227 			 *	failed'' which might well occur if we
228 			 *	merely returned the last error (because
229 			 *	the local loopbacks are typically the
230 			 *	last ones in /etc/netconfig and the most
231 			 *	likely to be unable to translate a host
232 			 *	name).  We also check for a more
233 			 *	meaningful error than ``unknown host
234 			 *	name'' for the same reasons.
235 			 */
236 			if (rpc_createerr.cf_stat != RPC_N2AXLATEFAILURE &&
237 			    rpc_createerr.cf_stat != RPC_UNKNOWNHOST) {
238 				save_cf_stat = rpc_createerr.cf_stat;
239 				save_cf_error = rpc_createerr.cf_error;
240 			}
241 	}
242 
243 	/*
244 	 *	Attempt to return an error more specific than ``Name to address
245 	 *	translation failed'' or ``unknown host name''
246 	 */
247 	if ((rpc_createerr.cf_stat == RPC_N2AXLATEFAILURE ||
248 				rpc_createerr.cf_stat == RPC_UNKNOWNHOST) &&
249 					(save_cf_stat != RPC_SUCCESS)) {
250 		rpc_createerr.cf_stat = save_cf_stat;
251 		rpc_createerr.cf_error = save_cf_error;
252 	}
253 	__rpc_endconf(handle);
254 	return (clnt);
255 }
256 
257 /*
258  * Generic client creation: takes (servers name, program-number, netconf) and
259  * returns client handle. Default options are set, which the user can
260  * change using the rpc equivalent of _ioctl()'s : clnt_control()
261  * It finds out the server address from rpcbind and calls clnt_tli_create().
262  *
263  * It calls clnt_tp_create_timed() with the default timeout.
264  */
265 CLIENT *
266 clnt_tp_create(const char *hostname, rpcprog_t prog, rpcvers_t vers,
267     const struct netconfig *nconf)
268 {
269 
270 	return (clnt_tp_create_timed(hostname, prog, vers, nconf, NULL));
271 }
272 
273 /*
274  * This has the same definition as clnt_tp_create(), except it
275  * takes an additional parameter - a pointer to a timeval structure.
276  * A NULL value for the timeout pointer indicates that the default
277  * value for the timeout should be used.
278  */
279 CLIENT *
280 clnt_tp_create_timed(const char *hostname, rpcprog_t prog, rpcvers_t vers,
281     const struct netconfig *nconf, const struct timeval *tp)
282 {
283 	struct netbuf *svcaddr;			/* servers address */
284 	CLIENT *cl = NULL;			/* client handle */
285 
286 	if (nconf == NULL) {
287 		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
288 		return (NULL);
289 	}
290 
291 	/*
292 	 * Get the address of the server
293 	 */
294 	if ((svcaddr = __rpcb_findaddr_timed(prog, vers,
295 			(struct netconfig *)nconf, (char *)hostname,
296 			&cl, (struct timeval *)tp)) == NULL) {
297 		/* appropriate error number is set by rpcbind libraries */
298 		return (NULL);
299 	}
300 	if (cl == NULL) {
301 		cl = clnt_tli_create(RPC_ANYFD, nconf, svcaddr,
302 					prog, vers, 0, 0);
303 	} else {
304 		/* Reuse the CLIENT handle and change the appropriate fields */
305 		if (CLNT_CONTROL(cl, CLSET_SVC_ADDR, (void *)svcaddr) == TRUE) {
306 			if (cl->cl_netid == NULL)
307 				cl->cl_netid = strdup(nconf->nc_netid);
308 			if (cl->cl_tp == NULL)
309 				cl->cl_tp = strdup(nconf->nc_device);
310 			(void) CLNT_CONTROL(cl, CLSET_PROG, (void *)&prog);
311 			(void) CLNT_CONTROL(cl, CLSET_VERS, (void *)&vers);
312 		} else {
313 			CLNT_DESTROY(cl);
314 			cl = clnt_tli_create(RPC_ANYFD, nconf, svcaddr,
315 					prog, vers, 0, 0);
316 		}
317 	}
318 	free(svcaddr->buf);
319 	free(svcaddr);
320 	return (cl);
321 }
322 
323 /*
324  * Generic client creation:  returns client handle.
325  * Default options are set, which the user can
326  * change using the rpc equivalent of _ioctl()'s : clnt_control().
327  * If fd is RPC_ANYFD, it will be opened using nconf.
328  * It will be bound if not so.
329  * If sizes are 0; appropriate defaults will be chosen.
330  */
331 CLIENT *
332 clnt_tli_create(int fd, const struct netconfig *nconf,
333 	struct netbuf *svcaddr, rpcprog_t prog, rpcvers_t vers,
334 	uint sendsz, uint recvsz)
335 {
336 	CLIENT *cl;			/* client handle */
337 	bool_t madefd = FALSE;		/* whether fd opened here */
338 	long servtype;
339 	int one = 1;
340 	struct __rpc_sockinfo si;
341 	extern int __rpc_minfd;
342 
343 	if (fd == RPC_ANYFD) {
344 		if (nconf == NULL) {
345 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
346 			return (NULL);
347 		}
348 
349 		fd = __rpc_nconf2fd(nconf);
350 
351 		if (fd == -1)
352 			goto err;
353 		if (fd < __rpc_minfd)
354 			fd = __rpc_raise_fd(fd);
355 		madefd = TRUE;
356 		servtype = nconf->nc_semantics;
357 		if (!__rpc_fd2sockinfo(fd, &si))
358 			goto err;
359 		bindresvport(fd, NULL);
360 	} else {
361 		if (!__rpc_fd2sockinfo(fd, &si))
362 			goto err;
363 		servtype = __rpc_socktype2seman(si.si_socktype);
364 		if (servtype == -1) {
365 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
366 			return (NULL);
367 		}
368 	}
369 
370 	if (si.si_af != ((struct sockaddr *)svcaddr->buf)->sa_family) {
371 		rpc_createerr.cf_stat = RPC_UNKNOWNHOST;	/* XXX */
372 		goto err1;
373 	}
374 
375 	switch (servtype) {
376 	case NC_TPI_COTS:
377 		cl = clnt_vc_create(fd, svcaddr, prog, vers, sendsz, recvsz);
378 		break;
379 	case NC_TPI_COTS_ORD:
380 		if (nconf && ((strcmp(nconf->nc_protofmly, "inet") == 0))) {
381 			_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one,
382 			    sizeof (one));
383 		}
384 		cl = clnt_vc_create(fd, svcaddr, prog, vers, sendsz, recvsz);
385 		break;
386 	case NC_TPI_CLTS:
387 		cl = clnt_dg_create(fd, svcaddr, prog, vers, sendsz, recvsz);
388 		break;
389 	default:
390 		goto err;
391 	}
392 
393 	if (cl == NULL)
394 		goto err1; /* borrow errors from clnt_dg/vc creates */
395 	if (nconf) {
396 		cl->cl_netid = strdup(nconf->nc_netid);
397 		cl->cl_tp = strdup(nconf->nc_device);
398 	} else {
399 		cl->cl_netid = "";
400 		cl->cl_tp = "";
401 	}
402 	if (madefd) {
403 		(void) CLNT_CONTROL(cl, CLSET_FD_CLOSE, NULL);
404 /*		(void) CLNT_CONTROL(cl, CLSET_POP_TIMOD, NULL);  */
405 	}
406 
407 	return (cl);
408 
409 err:
410 	rpc_createerr.cf_stat = RPC_SYSTEMERROR;
411 	rpc_createerr.cf_error.re_errno = errno;
412 err1:	if (madefd)
413 		(void)_close(fd);
414 	return (NULL);
415 }
416 
417 /*
418  *  To avoid conflicts with the "magic" file descriptors (0, 1, and 2),
419  *  we try to not use them.  The __rpc_raise_fd() routine will dup
420  *  a descriptor to a higher value.  If we fail to do it, we continue
421  *  to use the old one (and hope for the best).
422  */
423 int __rpc_minfd = 3;
424 
425 int
426 __rpc_raise_fd(int fd)
427 {
428 	int nfd;
429 
430 	if (fd >= __rpc_minfd)
431 		return (fd);
432 
433 	if ((nfd = _fcntl(fd, F_DUPFD, __rpc_minfd)) == -1)
434 		return (fd);
435 
436 	if (_fsync(nfd) == -1) {
437 		_close(nfd);
438 		return (fd);
439 	}
440 
441 	if (_close(fd) == -1) {
442 		/* this is okay, we will syslog an error, then use the new fd */
443 		(void) syslog(LOG_ERR,
444 			"could not close() fd %d; mem & fd leak", fd);
445 	}
446 
447 	return (nfd);
448 }
449