xref: /illumos-gate/usr/src/lib/libnsl/rpc/clnt_generic.c (revision a07094369b21309434206d9b3601d162693466fc)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  */
27 
28 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
29 /* All Rights Reserved */
30 /*
31  * Portions of this source code were derived from Berkeley
32  * 4.3 BSD under license from the Regents of the University of
33  * California.
34  */
35 
36 #pragma ident	"%Z%%M%	%I%	%E% SMI"
37 
38 #include "mt.h"
39 #include "rpc_mt.h"
40 #include <stdio.h>
41 #include <errno.h>
42 #include <unistd.h>
43 #include <stdlib.h>
44 #include <rpc/rpc.h>
45 #include <rpc/nettype.h>
46 #include <netdir.h>
47 #include <string.h>
48 #include <syslog.h>
49 
50 extern int __td_setnodelay(int);
51 extern bool_t __rpc_is_local_host(const char *);
52 extern bool_t __rpc_try_doors(const char *, bool_t *);
53 extern CLIENT *_clnt_vc_create_timed(int, struct netbuf *, rpcprog_t,
54 			rpcvers_t, uint_t, uint_t, const struct timeval *);
55 
56 CLIENT *_clnt_tli_create_timed(int, const struct netconfig *, struct netbuf *,
57 		rpcprog_t, rpcvers_t, uint_t, uint_t, const struct timeval *);
58 
59 #ifndef NETIDLEN
60 #define	NETIDLEN 32
61 #endif
62 
63 /*
64  * Generic client creation with version checking the value of
65  * vers_out is set to the highest server supported value
66  * vers_low <= vers_out <= vers_high  AND an error results
67  * if this can not be done.
68  *
69  * It calls clnt_create_vers_timed() with a NULL value for the timeout
70  * pointer, which indicates that the default timeout should be used.
71  */
72 CLIENT *
73 clnt_create_vers(const char *hostname, const rpcprog_t prog,
74 	rpcvers_t *vers_out, const rpcvers_t vers_low,
75 	const rpcvers_t vers_high, const char *nettype)
76 {
77 	return (clnt_create_vers_timed(hostname, prog, vers_out, vers_low,
78 				vers_high, nettype, NULL));
79 }
80 
81 /*
82  * This routine has the same definition as clnt_create_vers(),
83  * except it takes an additional timeout parameter - a pointer to
84  * a timeval structure.  A NULL value for the pointer indicates
85  * that the default timeout value should be used.
86  */
87 CLIENT *
88 clnt_create_vers_timed(const char *hostname, const rpcprog_t prog,
89     rpcvers_t *vers_out, const rpcvers_t vers_low, const rpcvers_t vers_high,
90     const char *nettype, const struct timeval *tp)
91 {
92 	CLIENT *clnt;
93 	struct timeval to;
94 	enum clnt_stat rpc_stat;
95 	struct rpc_err rpcerr;
96 	rpcvers_t v_low, v_high;
97 
98 	clnt = clnt_create_timed(hostname, prog, vers_high, nettype, tp);
99 	if (clnt == NULL)
100 		return (NULL);
101 	if (tp == NULL) {
102 		to.tv_sec = 10;
103 		to.tv_usec = 0;
104 	} else
105 		to = *tp;
106 
107 	rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
108 			NULL, (xdrproc_t)xdr_void, NULL, to);
109 	if (rpc_stat == RPC_SUCCESS) {
110 		*vers_out = vers_high;
111 		return (clnt);
112 	}
113 	v_low = vers_low;
114 	v_high = vers_high;
115 	while (rpc_stat == RPC_PROGVERSMISMATCH && v_high > v_low) {
116 		unsigned int minvers, maxvers;
117 
118 		clnt_geterr(clnt, &rpcerr);
119 		minvers = rpcerr.re_vers.low;
120 		maxvers = rpcerr.re_vers.high;
121 		if (maxvers < v_high)
122 			v_high = maxvers;
123 		else
124 			v_high--;
125 		if (minvers > v_low)
126 			v_low = minvers;
127 		if (v_low > v_high) {
128 			goto error;
129 		}
130 		CLNT_CONTROL(clnt, CLSET_VERS, (char *)&v_high);
131 		rpc_stat = clnt_call(clnt, NULLPROC, (xdrproc_t)xdr_void,
132 				NULL, (xdrproc_t)xdr_void,
133 				NULL, to);
134 		if (rpc_stat == RPC_SUCCESS) {
135 			*vers_out = v_high;
136 			return (clnt);
137 		}
138 	}
139 	clnt_geterr(clnt, &rpcerr);
140 
141 error:
142 	rpc_createerr.cf_stat = rpc_stat;
143 	rpc_createerr.cf_error = rpcerr;
144 	clnt_destroy(clnt);
145 	return (NULL);
146 }
147 
148 /*
149  * Top level client creation routine.
150  * Generic client creation: takes (servers name, program-number, nettype) and
151  * returns client handle. Default options are set, which the user can
152  * change using the rpc equivalent of ioctl()'s.
153  *
154  * It tries for all the netids in that particular class of netid until
155  * it succeeds.
156  * XXX The error message in the case of failure will be the one
157  * pertaining to the last create error.
158  *
159  * It calls clnt_create_timed() with the default timeout.
160  */
161 CLIENT *
162 clnt_create(const char *hostname, const rpcprog_t prog, const rpcvers_t vers,
163     const char *nettype)
164 {
165 	return (clnt_create_timed(hostname, prog, vers, nettype, NULL));
166 }
167 
168 /*
169  * This the routine has the same definition as clnt_create(),
170  * except it takes an additional timeout parameter - a pointer to
171  * a timeval structure.  A NULL value for the pointer indicates
172  * that the default timeout value should be used.
173  *
174  * This function calls clnt_tp_create_timed().
175  */
176 CLIENT *
177 clnt_create_timed(const char *hostname, const rpcprog_t prog,
178     const rpcvers_t vers, const char *netclass, const struct timeval *tp)
179 {
180 	struct netconfig *nconf;
181 	CLIENT *clnt = NULL;
182 	void *handle;
183 	enum clnt_stat	save_cf_stat = RPC_SUCCESS;
184 	struct rpc_err	save_cf_error;
185 	char nettype_array[NETIDLEN];
186 	char *nettype = &nettype_array[0];
187 	bool_t try_others;
188 
189 	if (netclass == NULL)
190 		nettype = NULL;
191 	else {
192 		size_t len = strlen(netclass);
193 		if (len >= sizeof (nettype_array)) {
194 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
195 			return (NULL);
196 		}
197 		(void) strcpy(nettype, netclass);
198 	}
199 
200 	/*
201 	 * Check to see if a rendezvous over doors should be attempted.
202 	 */
203 	if (__rpc_try_doors(nettype, &try_others)) {
204 		/*
205 		 * Make sure this is the local host.
206 		 */
207 		if (__rpc_is_local_host(hostname)) {
208 			if ((clnt = clnt_door_create(prog, vers, 0)) != NULL)
209 				return (clnt);
210 			else {
211 				if (rpc_createerr.cf_stat == RPC_SYSTEMERROR)
212 					return (NULL);
213 				save_cf_stat = rpc_createerr.cf_stat;
214 				save_cf_error = rpc_createerr.cf_error;
215 			}
216 		} else {
217 			save_cf_stat = rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
218 		}
219 	}
220 	if (!try_others)
221 		return (NULL);
222 
223 	if ((handle = __rpc_setconf((char *)nettype)) == NULL) {
224 		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
225 		return (NULL);
226 	}
227 	rpc_createerr.cf_stat = RPC_SUCCESS;
228 	while (clnt == NULL) {
229 		if ((nconf = __rpc_getconf(handle)) == NULL) {
230 			if (rpc_createerr.cf_stat == RPC_SUCCESS)
231 				rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
232 			break;
233 		}
234 		clnt = clnt_tp_create_timed(hostname, prog, vers, nconf, tp);
235 		if (clnt)
236 			break;
237 		else {
238 			/*
239 			 *	Since we didn't get a name-to-address
240 			 *	translation failure here, we remember
241 			 *	this particular error.  The object of
242 			 *	this is to enable us to return to the
243 			 *	caller a more-specific error than the
244 			 *	unhelpful ``Name to address translation
245 			 *	failed'' which might well occur if we
246 			 *	merely returned the last error (because
247 			 *	the local loopbacks are typically the
248 			 *	last ones in /etc/netconfig and the most
249 			 *	likely to be unable to translate a host
250 			 *	name).  We also check for a more
251 			 *	meaningful error than ``unknown host
252 			 *	name'' for the same reasons.
253 			 */
254 			if (rpc_createerr.cf_stat == RPC_SYSTEMERROR) {
255 				syslog(LOG_ERR, "clnt_create_timed: "
256 					"RPC_SYSTEMERROR.");
257 				break;
258 			}
259 
260 			if (rpc_createerr.cf_stat != RPC_N2AXLATEFAILURE &&
261 			    rpc_createerr.cf_stat != RPC_UNKNOWNHOST) {
262 				save_cf_stat = rpc_createerr.cf_stat;
263 				save_cf_error = rpc_createerr.cf_error;
264 			}
265 		}
266 	}
267 
268 	/*
269 	 *	Attempt to return an error more specific than ``Name to address
270 	 *	translation failed'' or ``unknown host name''
271 	 */
272 	if ((rpc_createerr.cf_stat == RPC_N2AXLATEFAILURE ||
273 				rpc_createerr.cf_stat == RPC_UNKNOWNHOST) &&
274 					(save_cf_stat != RPC_SUCCESS)) {
275 		rpc_createerr.cf_stat = save_cf_stat;
276 		rpc_createerr.cf_error = save_cf_error;
277 	}
278 	__rpc_endconf(handle);
279 	return (clnt);
280 }
281 
282 /*
283  * Create a client handle for a well known service or a specific port on
284  * host. This routine bypasses rpcbind and can be use to construct a client
285  * handle to services that are not registered with rpcbind or where the remote
286  * rpcbind is not available, e.g., the remote rpcbind port is blocked by a
287  * firewall. We construct a client handle and then ping the service's NULL
288  * proc to see that the service is really available. If the caller supplies
289  * a non zero port number, the service name is ignored and the port will be
290  * used. A non-zero port number limits the protocol family to inet or inet6.
291  */
292 
293 CLIENT *
294 clnt_create_service_timed(const char *host, const char *service,
295 			const rpcprog_t prog, const rpcvers_t vers,
296 			const ushort_t port, const char *netclass,
297 			const struct timeval *tmout)
298 {
299 	int fd;
300 	void *handle;
301 	CLIENT *clnt = NULL;
302 	struct netconfig *nconf;
303 	struct nd_hostserv hs;
304 	struct nd_addrlist *raddrs;
305 	struct t_bind *tbind = NULL;
306 	struct timeval to;
307 	char nettype_array[NETIDLEN];
308 	char *nettype = &nettype_array[0];
309 	char *hostname, *serv;
310 	bool_t try_others;
311 	extern int __rpc_minfd;
312 
313 
314 	/*
315 	 * handle const of netclass
316 	 */
317 	if (netclass == NULL)
318 		nettype = NULL;
319 	else {
320 		size_t len = strlen(netclass);
321 		if (len >= sizeof (nettype_array)) {
322 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
323 			return (NULL);
324 		}
325 		(void) strcpy(nettype, netclass);
326 	}
327 
328 	if (tmout == NULL) {
329 		to.tv_sec = 10;
330 		to.tv_usec = 0;
331 	} else
332 		to = *tmout;
333 
334 	if ((handle = __rpc_setconf(nettype)) == NULL) {
335 		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
336 		return (NULL);
337 	}
338 
339 	/*
340 	 * Sinct host, and service are const
341 	 */
342 	if (host == NULL || (hostname = strdup(host)) == NULL) {
343 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
344 		rpc_createerr.cf_error.re_errno = (host ? errno : EINVAL);
345 		rpc_createerr.cf_error.re_terrno = 0;
346 		return (NULL);
347 	}
348 
349 	if (service == NULL)
350 		serv = NULL;
351 	else if ((serv = strdup(service ? service : "")) == NULL) {
352 		free(hostname);
353 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
354 		rpc_createerr.cf_error.re_errno = errno;
355 		rpc_createerr.cf_error.re_terrno = 0;
356 		return (NULL);
357 	}
358 
359 	hs.h_host = hostname;
360 	hs.h_serv = port ? NULL : serv;
361 
362 	/*
363 	 * Check to see if a rendezvous over doors should be attempted.
364 	 */
365 	if (__rpc_try_doors(nettype, &try_others)) {
366 		/*
367 		 * Make sure this is the local host.
368 		 */
369 		if (__rpc_is_local_host(hostname)) {
370 			if ((clnt = clnt_door_create(prog, vers, 0)) != NULL)
371 				goto done;
372 			else if (rpc_createerr.cf_stat == RPC_SYSTEMERROR)
373 				goto done;
374 		} else {
375 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
376 		}
377 	}
378 	if (!try_others)
379 		goto done;
380 
381 	rpc_createerr.cf_stat = RPC_SUCCESS;
382 	while (clnt == NULL) {
383 		tbind = NULL;
384 		if ((nconf = __rpc_getconf(handle)) == NULL) {
385 			if (rpc_createerr.cf_stat == RPC_SUCCESS)
386 				rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
387 			break;
388 		}
389 
390 		if (port) {
391 			if (strcmp(nconf->nc_protofmly, NC_INET) != 0 &&
392 			    strcmp(nconf->nc_protofmly, NC_INET6) != 0)
393 				continue;
394 		}
395 
396 		if ((fd = t_open(nconf->nc_device, O_RDWR, NULL)) < 0) {
397 			rpc_createerr.cf_stat = RPC_TLIERROR;
398 			rpc_createerr.cf_error.re_errno = errno;
399 			rpc_createerr.cf_error.re_terrno = t_errno;
400 			continue;
401 		}
402 
403 		if (fd < __rpc_minfd)
404 			fd = __rpc_raise_fd(fd);
405 
406 		/* LINTED pointer cast */
407 		if ((tbind = (struct t_bind *)t_alloc(fd, T_BIND, T_ADDR))
408 		    == NULL) {
409 			(void) t_close(fd);
410 			rpc_createerr.cf_stat = RPC_TLIERROR;
411 			rpc_createerr.cf_error.re_errno = errno;
412 			rpc_createerr.cf_error.re_terrno = t_errno;
413 			continue;
414 		}
415 
416 		if (netdir_getbyname(nconf, &hs, &raddrs) != ND_OK) {
417 			if (rpc_createerr.cf_stat == RPC_SUCCESS)
418 				rpc_createerr.cf_stat = RPC_UNKNOWNHOST;
419 			if (tbind)
420 				(void) t_free((char *)tbind, T_BIND);
421 			(void) t_close(fd);
422 			continue;
423 		}
424 		(void) memcpy(tbind->addr.buf, raddrs->n_addrs->buf,
425 		    raddrs->n_addrs->len);
426 		tbind->addr.len = raddrs->n_addrs->len;
427 		netdir_free((void *)raddrs, ND_ADDRLIST);
428 
429 		if (port) {
430 			if (strcmp(nconf->nc_protofmly, NC_INET) == NULL)
431 				/* LINTED pointer alignment */
432 				((struct sockaddr_in *)
433 				tbind->addr.buf)->sin_port = htons(port);
434 			else if (strcmp(nconf->nc_protofmly, NC_INET6) == NULL)
435 				/* LINTED pointer alignment */
436 				((struct sockaddr_in6 *)
437 				tbind->addr.buf)->sin6_port = htons(port);
438 		}
439 
440 		clnt = _clnt_tli_create_timed(fd, nconf, &tbind->addr,
441 					    prog, vers, 0, 0, &to);
442 
443 		if (clnt == NULL) {
444 			if (tbind)
445 				(void) t_free((char *)tbind, T_BIND);
446 			(void) t_close(fd);
447 			continue;
448 		}
449 
450 		(void) CLNT_CONTROL(clnt, CLSET_FD_CLOSE, NULL);
451 
452 		/*
453 		 * Check if we can reach the server with this clnt handle
454 		 * Other clnt_create calls do a ping by contacting the
455 		 * remote rpcbind, here will just try to execute the service's
456 		 * NULL proc.
457 		 */
458 
459 		rpc_createerr.cf_stat = clnt_call(clnt, NULLPROC,
460 						xdr_void, 0, xdr_void, 0, to);
461 
462 		rpc_createerr.cf_error.re_errno = rpc_callerr.re_status;
463 		rpc_createerr.cf_error.re_terrno = 0;
464 
465 		if (rpc_createerr.cf_stat != RPC_SUCCESS) {
466 			clnt_destroy(clnt);
467 			clnt = NULL;
468 			if (tbind)
469 				(void) t_free((char *)tbind, T_BIND);
470 			continue;
471 		} else
472 			break;
473 	}
474 
475 	__rpc_endconf(handle);
476 	if (tbind)
477 		(void) t_free((char *)tbind, T_BIND);
478 
479 done:
480 	if (hostname)
481 		free(hostname);
482 	if (serv)
483 		free(serv);
484 
485 	return (clnt);
486 }
487 
488 /*
489  * Generic client creation: takes (servers name, program-number, netconf) and
490  * returns client handle. Default options are set, which the user can
491  * change using the rpc equivalent of ioctl()'s : clnt_control()
492  * It finds out the server address from rpcbind and calls clnt_tli_create().
493  *
494  * It calls clnt_tp_create_timed() with the default timeout.
495  */
496 CLIENT *
497 clnt_tp_create(const char *hostname, const rpcprog_t prog, const rpcvers_t vers,
498     const struct netconfig *nconf)
499 {
500 	return (clnt_tp_create_timed(hostname, prog, vers, nconf, NULL));
501 }
502 
503 /*
504  * This has the same definition as clnt_tp_create(), except it
505  * takes an additional parameter - a pointer to a timeval structure.
506  * A NULL value for the timeout pointer indicates that the default
507  * value for the timeout should be used.
508  */
509 CLIENT *
510 clnt_tp_create_timed(const char *hostname, const rpcprog_t prog,
511     const rpcvers_t vers, const struct netconfig *nconf,
512     const struct timeval *tp)
513 {
514 	struct netbuf *svcaddr;			/* servers address */
515 	CLIENT *cl = NULL;			/* client handle */
516 	extern struct netbuf *__rpcb_findaddr_timed(rpcprog_t, rpcvers_t,
517 	    struct netconfig *, char *, CLIENT **, struct timeval *);
518 
519 	if (nconf == NULL) {
520 		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
521 		return (NULL);
522 	}
523 
524 	/*
525 	 * Get the address of the server
526 	 */
527 	if ((svcaddr = __rpcb_findaddr_timed(prog, vers,
528 			(struct netconfig *)nconf, (char *)hostname,
529 			&cl, (struct timeval *)tp)) == NULL) {
530 		/* appropriate error number is set by rpcbind libraries */
531 		return (NULL);
532 	}
533 	if (cl == NULL) {
534 		cl = _clnt_tli_create_timed(RPC_ANYFD, nconf, svcaddr,
535 					prog, vers, 0, 0, tp);
536 	} else {
537 		/* Reuse the CLIENT handle and change the appropriate fields */
538 		if (CLNT_CONTROL(cl, CLSET_SVC_ADDR, (void *)svcaddr) == TRUE) {
539 			if (cl->cl_netid == NULL) {
540 				cl->cl_netid = strdup(nconf->nc_netid);
541 				if (cl->cl_netid == NULL) {
542 					netdir_free((char *)svcaddr, ND_ADDR);
543 					rpc_createerr.cf_stat = RPC_SYSTEMERROR;
544 					syslog(LOG_ERR,
545 						"clnt_tp_create_timed: "
546 						"strdup failed.");
547 					return (NULL);
548 				}
549 			}
550 			if (cl->cl_tp == NULL) {
551 				cl->cl_tp = strdup(nconf->nc_device);
552 				if (cl->cl_tp == NULL) {
553 					netdir_free((char *)svcaddr, ND_ADDR);
554 					if (cl->cl_netid)
555 						free(cl->cl_netid);
556 					rpc_createerr.cf_stat = RPC_SYSTEMERROR;
557 					syslog(LOG_ERR,
558 						"clnt_tp_create_timed: "
559 						"strdup failed.");
560 					return (NULL);
561 				}
562 			}
563 			(void) CLNT_CONTROL(cl, CLSET_PROG, (void *)&prog);
564 			(void) CLNT_CONTROL(cl, CLSET_VERS, (void *)&vers);
565 		} else {
566 			CLNT_DESTROY(cl);
567 			cl = _clnt_tli_create_timed(RPC_ANYFD, nconf, svcaddr,
568 					prog, vers, 0, 0, tp);
569 		}
570 	}
571 	netdir_free((char *)svcaddr, ND_ADDR);
572 	return (cl);
573 }
574 
575 /*
576  * Generic client creation:  returns client handle.
577  * Default options are set, which the user can
578  * change using the rpc equivalent of ioctl()'s : clnt_control().
579  * If fd is RPC_ANYFD, it will be opened using nconf.
580  * It will be bound if not so.
581  * If sizes are 0; appropriate defaults will be chosen.
582  */
583 CLIENT *
584 clnt_tli_create(const int fd, const struct netconfig *nconf,
585     struct netbuf *svcaddr, const rpcprog_t prog, const rpcvers_t vers,
586     const uint_t sendsz, const uint_t recvsz)
587 {
588 	return (_clnt_tli_create_timed(fd, nconf, svcaddr, prog, vers, sendsz,
589 		recvsz, NULL));
590 }
591 
592 /*
593  * This has the same definition as clnt_tli_create(), except it
594  * takes an additional parameter - a pointer to a timeval structure.
595  *
596  * Not a public interface. This is for clnt_create_timed,
597  * clnt_create_vers_times, clnt_tp_create_timed to pass down  the
598  * timeout value to COTS creation routine.
599  * (for bug 4049792: clnt_create_timed does not time out)
600  */
601 CLIENT *
602 _clnt_tli_create_timed(int fd, const struct netconfig *nconf,
603 	struct netbuf *svcaddr, rpcprog_t prog, rpcvers_t vers, uint_t sendsz,
604 	uint_t recvsz, const struct timeval *tp)
605 {
606 	CLIENT *cl;			/* client handle */
607 	struct t_info tinfo;		/* transport info */
608 	bool_t madefd;			/* whether fd opened here */
609 	t_scalar_t servtype;
610 	int retval;
611 	extern int __rpc_minfd;
612 
613 	if (fd == RPC_ANYFD) {
614 		if (nconf == NULL) {
615 			rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
616 			return (NULL);
617 		}
618 
619 		fd = t_open(nconf->nc_device, O_RDWR, NULL);
620 		if (fd == -1)
621 			goto err;
622 		if (fd < __rpc_minfd)
623 			fd = __rpc_raise_fd(fd);
624 		madefd = TRUE;
625 		if (t_bind(fd, NULL, NULL) == -1)
626 			goto err;
627 		switch (nconf->nc_semantics) {
628 		case NC_TPI_CLTS:
629 			servtype = T_CLTS;
630 			break;
631 		case NC_TPI_COTS:
632 			servtype = T_COTS;
633 			break;
634 		case NC_TPI_COTS_ORD:
635 			servtype = T_COTS_ORD;
636 			break;
637 		default:
638 			if (t_getinfo(fd, &tinfo) == -1)
639 				goto err;
640 			servtype = tinfo.servtype;
641 			break;
642 		}
643 	} else {
644 		int state;		/* Current state of provider */
645 
646 		/*
647 		 * Sync the opened fd.
648 		 * Check whether bound or not, else bind it
649 		 */
650 		if (((state = t_sync(fd)) == -1) ||
651 		    ((state == T_UNBND) && (t_bind(fd, NULL, NULL) == -1)) ||
652 		    (t_getinfo(fd, &tinfo) == -1))
653 			goto err;
654 		servtype = tinfo.servtype;
655 		madefd = FALSE;
656 	}
657 
658 	switch (servtype) {
659 	case T_COTS:
660 		cl = _clnt_vc_create_timed(fd, svcaddr, prog, vers, sendsz,
661 				recvsz, tp);
662 		break;
663 	case T_COTS_ORD:
664 		if (nconf && ((strcmp(nconf->nc_protofmly, NC_INET) == 0) ||
665 		    (strcmp(nconf->nc_protofmly, NC_INET6) == 0))) {
666 			retval =  __td_setnodelay(fd);
667 			if (retval == -1)
668 				goto err;
669 		}
670 		cl = _clnt_vc_create_timed(fd, svcaddr, prog, vers, sendsz,
671 			recvsz, tp);
672 		break;
673 	case T_CLTS:
674 		cl = clnt_dg_create(fd, svcaddr, prog, vers, sendsz, recvsz);
675 		break;
676 	default:
677 		goto err;
678 	}
679 
680 	if (cl == NULL)
681 		goto err1; /* borrow errors from clnt_dg/vc creates */
682 	if (nconf) {
683 		cl->cl_netid = strdup(nconf->nc_netid);
684 		if (cl->cl_netid == NULL) {
685 			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
686 			rpc_createerr.cf_error.re_errno = errno;
687 			rpc_createerr.cf_error.re_terrno = 0;
688 			syslog(LOG_ERR,
689 				"clnt_tli_create: strdup failed");
690 			goto err1;
691 		}
692 		cl->cl_tp = strdup(nconf->nc_device);
693 		if (cl->cl_tp == NULL) {
694 			if (cl->cl_netid)
695 				free(cl->cl_netid);
696 			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
697 			rpc_createerr.cf_error.re_errno = errno;
698 			rpc_createerr.cf_error.re_terrno = 0;
699 			syslog(LOG_ERR,
700 				"clnt_tli_create: strdup failed");
701 			goto err1;
702 		}
703 	} else {
704 		struct netconfig *nc;
705 
706 		if ((nc = __rpcfd_to_nconf(fd, servtype)) != NULL) {
707 			if (nc->nc_netid) {
708 				cl->cl_netid = strdup(nc->nc_netid);
709 				if (cl->cl_netid == NULL) {
710 					rpc_createerr.cf_stat = RPC_SYSTEMERROR;
711 					rpc_createerr.cf_error.re_errno = errno;
712 					rpc_createerr.cf_error.re_terrno = 0;
713 					syslog(LOG_ERR,
714 						"clnt_tli_create: "
715 						"strdup failed");
716 					goto err1;
717 				}
718 			}
719 			if (nc->nc_device) {
720 				cl->cl_tp = strdup(nc->nc_device);
721 				if (cl->cl_tp == NULL) {
722 					if (cl->cl_netid)
723 						free(cl->cl_netid);
724 					rpc_createerr.cf_stat = RPC_SYSTEMERROR;
725 					rpc_createerr.cf_error.re_errno = errno;
726 					rpc_createerr.cf_error.re_terrno = 0;
727 					syslog(LOG_ERR,
728 						"clnt_tli_create: "
729 						"strdup failed");
730 					goto err1;
731 				}
732 			}
733 			freenetconfigent(nc);
734 		}
735 		if (cl->cl_netid == NULL)
736 			cl->cl_netid = "";
737 		if (cl->cl_tp == NULL)
738 			cl->cl_tp = "";
739 	}
740 	if (madefd) {
741 		(void) CLNT_CONTROL(cl, CLSET_FD_CLOSE, NULL);
742 /*		(void) CLNT_CONTROL(cl, CLSET_POP_TIMOD, NULL);  */
743 	};
744 
745 	return (cl);
746 
747 err:
748 	rpc_createerr.cf_stat = RPC_TLIERROR;
749 	rpc_createerr.cf_error.re_errno = errno;
750 	rpc_createerr.cf_error.re_terrno = t_errno;
751 err1:	if (madefd)
752 		(void) t_close(fd);
753 	return (NULL);
754 }
755 
756 /*
757  *  To avoid conflicts with the "magic" file descriptors (0, 1, and 2),
758  *  we try to not use them.  The __rpc_raise_fd() routine will dup
759  *  a descriptor to a higher value.  If we fail to do it, we continue
760  *  to use the old one (and hope for the best).
761  */
762 int __rpc_minfd = 3;
763 
764 int
765 __rpc_raise_fd(int fd)
766 {
767 	int nfd;
768 
769 	if (fd >= __rpc_minfd)
770 		return (fd);
771 
772 	if ((nfd = fcntl(fd, F_DUPFD, __rpc_minfd)) == -1)
773 		return (fd);
774 
775 	if (t_sync(nfd) == -1) {
776 		(void) close(nfd);
777 		return (fd);
778 	}
779 
780 	if (t_close(fd) == -1) {
781 		/* this is okay, we will syslog an error, then use the new fd */
782 		(void) syslog(LOG_ERR,
783 			"could not t_close() fd %d; mem & fd leak", fd);
784 	}
785 
786 	return (nfd);
787 }
788