xref: /freebsd/lib/libc/rpc/svc.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1 /*	$NetBSD: svc.c,v 1.21 2000/07/06 03:10:35 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2009, Sun Microsystems, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are met:
9  * - Redistributions of source code must retain the above copyright notice,
10  *   this list of conditions and the following disclaimer.
11  * - Redistributions in binary form must reproduce the above copyright notice,
12  *   this list of conditions and the following disclaimer in the documentation
13  *   and/or other materials provided with the distribution.
14  * - Neither the name of Sun Microsystems, Inc. nor the names of its
15  *   contributors may be used to endorse or promote products derived
16  *   from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #if defined(LIBC_SCCS) && !defined(lint)
32 static char *sccsid2 = "@(#)svc.c 1.44 88/02/08 Copyr 1984 Sun Micro";
33 static char *sccsid = "@(#)svc.c	2.4 88/08/11 4.0 RPCSRC";
34 #endif
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 /*
39  * svc.c, Server-side remote procedure call interface.
40  *
41  * There are two sets of procedures here.  The xprt routines are
42  * for handling transport handles.  The svc routines handle the
43  * list of service routines.
44  *
45  * Copyright (C) 1984, Sun Microsystems, Inc.
46  */
47 
48 #include "namespace.h"
49 #include "reentrant.h"
50 #include <sys/types.h>
51 #include <sys/poll.h>
52 #include <assert.h>
53 #include <errno.h>
54 #include <stdlib.h>
55 #include <string.h>
56 
57 #include <rpc/rpc.h>
58 #ifdef PORTMAP
59 #include <rpc/pmap_clnt.h>
60 #endif				/* PORTMAP */
61 #include "un-namespace.h"
62 
63 #include "rpc_com.h"
64 #include "mt_misc.h"
65 
66 #define	RQCRED_SIZE	400		/* this size is excessive */
67 
68 #define SVC_VERSQUIET 0x0001		/* keep quiet about vers mismatch */
69 #define version_keepquiet(xp) (SVC_EXT(xp)->xp_flags & SVC_VERSQUIET)
70 
71 #define max(a, b) (a > b ? a : b)
72 
73 /*
74  * The services list
75  * Each entry represents a set of procedures (an rpc program).
76  * The dispatch routine takes request structs and runs the
77  * apropriate procedure.
78  */
79 static struct svc_callout {
80 	struct svc_callout *sc_next;
81 	rpcprog_t	    sc_prog;
82 	rpcvers_t	    sc_vers;
83 	char		   *sc_netid;
84 	void		    (*sc_dispatch)(struct svc_req *, SVCXPRT *);
85 } *svc_head;
86 
87 SVCXPRT **__svc_xports;
88 int __svc_maxrec;
89 
90 static struct svc_callout *svc_find(rpcprog_t, rpcvers_t,
91     struct svc_callout **, char *);
92 static void __xprt_do_unregister (SVCXPRT *xprt, bool_t dolock);
93 
94 /* ***************  SVCXPRT related stuff **************** */
95 
96 /*
97  * Activate a transport handle.
98  */
99 void
100 xprt_register(xprt)
101 	SVCXPRT *xprt;
102 {
103 	int sock;
104 
105 	assert(xprt != NULL);
106 
107 	sock = xprt->xp_fd;
108 
109 	rwlock_wrlock(&svc_fd_lock);
110 	if (__svc_xports == NULL) {
111 		__svc_xports = (SVCXPRT **)
112 			mem_alloc(FD_SETSIZE * sizeof(SVCXPRT *));
113 		if (__svc_xports == NULL) {
114 			rwlock_unlock(&svc_fd_lock);
115 			return;
116 		}
117 		memset(__svc_xports, '\0', FD_SETSIZE * sizeof(SVCXPRT *));
118 	}
119 	if (sock < FD_SETSIZE) {
120 		__svc_xports[sock] = xprt;
121 		FD_SET(sock, &svc_fdset);
122 		svc_maxfd = max(svc_maxfd, sock);
123 	}
124 	rwlock_unlock(&svc_fd_lock);
125 }
126 
127 void
128 xprt_unregister(SVCXPRT *xprt)
129 {
130 	__xprt_do_unregister(xprt, TRUE);
131 }
132 
133 void
134 __xprt_unregister_unlocked(SVCXPRT *xprt)
135 {
136 	__xprt_do_unregister(xprt, FALSE);
137 }
138 
139 /*
140  * De-activate a transport handle.
141  */
142 static void
143 __xprt_do_unregister(xprt, dolock)
144 	SVCXPRT *xprt;
145 	bool_t dolock;
146 {
147 	int sock;
148 
149 	assert(xprt != NULL);
150 
151 	sock = xprt->xp_fd;
152 
153 	if (dolock)
154 		rwlock_wrlock(&svc_fd_lock);
155 	if ((sock < FD_SETSIZE) && (__svc_xports[sock] == xprt)) {
156 		__svc_xports[sock] = NULL;
157 		FD_CLR(sock, &svc_fdset);
158 		if (sock >= svc_maxfd) {
159 			for (svc_maxfd--; svc_maxfd>=0; svc_maxfd--)
160 				if (__svc_xports[svc_maxfd])
161 					break;
162 		}
163 	}
164 	if (dolock)
165 		rwlock_unlock(&svc_fd_lock);
166 }
167 
168 /*
169  * Add a service program to the callout list.
170  * The dispatch routine will be called when a rpc request for this
171  * program number comes in.
172  */
173 bool_t
174 svc_reg(xprt, prog, vers, dispatch, nconf)
175 	SVCXPRT *xprt;
176 	const rpcprog_t prog;
177 	const rpcvers_t vers;
178 	void (*dispatch)(struct svc_req *, SVCXPRT *);
179 	const struct netconfig *nconf;
180 {
181 	bool_t dummy;
182 	struct svc_callout *prev;
183 	struct svc_callout *s;
184 	struct netconfig *tnconf;
185 	char *netid = NULL;
186 	int flag = 0;
187 
188 /* VARIABLES PROTECTED BY svc_lock: s, prev, svc_head */
189 
190 	if (xprt->xp_netid) {
191 		netid = strdup(xprt->xp_netid);
192 		flag = 1;
193 	} else if (nconf && nconf->nc_netid) {
194 		netid = strdup(nconf->nc_netid);
195 		flag = 1;
196 	} else if ((tnconf = __rpcgettp(xprt->xp_fd)) != NULL) {
197 		netid = strdup(tnconf->nc_netid);
198 		flag = 1;
199 		freenetconfigent(tnconf);
200 	} /* must have been created with svc_raw_create */
201 	if ((netid == NULL) && (flag == 1)) {
202 		return (FALSE);
203 	}
204 
205 	rwlock_wrlock(&svc_lock);
206 	if ((s = svc_find(prog, vers, &prev, netid)) != NULL) {
207 		if (netid)
208 			free(netid);
209 		if (s->sc_dispatch == dispatch)
210 			goto rpcb_it; /* he is registering another xptr */
211 		rwlock_unlock(&svc_lock);
212 		return (FALSE);
213 	}
214 	s = mem_alloc(sizeof (struct svc_callout));
215 	if (s == NULL) {
216 		if (netid)
217 			free(netid);
218 		rwlock_unlock(&svc_lock);
219 		return (FALSE);
220 	}
221 
222 	s->sc_prog = prog;
223 	s->sc_vers = vers;
224 	s->sc_dispatch = dispatch;
225 	s->sc_netid = netid;
226 	s->sc_next = svc_head;
227 	svc_head = s;
228 
229 	if ((xprt->xp_netid == NULL) && (flag == 1) && netid)
230 		((SVCXPRT *) xprt)->xp_netid = strdup(netid);
231 
232 rpcb_it:
233 	rwlock_unlock(&svc_lock);
234 	/* now register the information with the local binder service */
235 	if (nconf) {
236 		/*LINTED const castaway*/
237 		dummy = rpcb_set(prog, vers, (struct netconfig *) nconf,
238 		&((SVCXPRT *) xprt)->xp_ltaddr);
239 		return (dummy);
240 	}
241 	return (TRUE);
242 }
243 
244 /*
245  * Remove a service program from the callout list.
246  */
247 void
248 svc_unreg(prog, vers)
249 	const rpcprog_t prog;
250 	const rpcvers_t vers;
251 {
252 	struct svc_callout *prev;
253 	struct svc_callout *s;
254 
255 	/* unregister the information anyway */
256 	(void) rpcb_unset(prog, vers, NULL);
257 	rwlock_wrlock(&svc_lock);
258 	while ((s = svc_find(prog, vers, &prev, NULL)) != NULL) {
259 		if (prev == NULL) {
260 			svc_head = s->sc_next;
261 		} else {
262 			prev->sc_next = s->sc_next;
263 		}
264 		s->sc_next = NULL;
265 		if (s->sc_netid)
266 			mem_free(s->sc_netid, sizeof (s->sc_netid) + 1);
267 		mem_free(s, sizeof (struct svc_callout));
268 	}
269 	rwlock_unlock(&svc_lock);
270 }
271 
272 /* ********************** CALLOUT list related stuff ************* */
273 
274 #ifdef PORTMAP
275 /*
276  * Add a service program to the callout list.
277  * The dispatch routine will be called when a rpc request for this
278  * program number comes in.
279  */
280 bool_t
281 svc_register(xprt, prog, vers, dispatch, protocol)
282 	SVCXPRT *xprt;
283 	u_long prog;
284 	u_long vers;
285 	void (*dispatch)(struct svc_req *, SVCXPRT *);
286 	int protocol;
287 {
288 	struct svc_callout *prev;
289 	struct svc_callout *s;
290 
291 	assert(xprt != NULL);
292 	assert(dispatch != NULL);
293 
294 	if ((s = svc_find((rpcprog_t)prog, (rpcvers_t)vers, &prev, NULL)) !=
295 	    NULL) {
296 		if (s->sc_dispatch == dispatch)
297 			goto pmap_it;  /* he is registering another xptr */
298 		return (FALSE);
299 	}
300 	s = mem_alloc(sizeof(struct svc_callout));
301 	if (s == NULL) {
302 		return (FALSE);
303 	}
304 	s->sc_prog = (rpcprog_t)prog;
305 	s->sc_vers = (rpcvers_t)vers;
306 	s->sc_dispatch = dispatch;
307 	s->sc_next = svc_head;
308 	svc_head = s;
309 pmap_it:
310 	/* now register the information with the local binder service */
311 	if (protocol) {
312 		return (pmap_set(prog, vers, protocol, xprt->xp_port));
313 	}
314 	return (TRUE);
315 }
316 
317 /*
318  * Remove a service program from the callout list.
319  */
320 void
321 svc_unregister(prog, vers)
322 	u_long prog;
323 	u_long vers;
324 {
325 	struct svc_callout *prev;
326 	struct svc_callout *s;
327 
328 	if ((s = svc_find((rpcprog_t)prog, (rpcvers_t)vers, &prev, NULL)) ==
329 	    NULL)
330 		return;
331 	if (prev == NULL) {
332 		svc_head = s->sc_next;
333 	} else {
334 		prev->sc_next = s->sc_next;
335 	}
336 	s->sc_next = NULL;
337 	mem_free(s, sizeof(struct svc_callout));
338 	/* now unregister the information with the local binder service */
339 	(void)pmap_unset(prog, vers);
340 }
341 #endif				/* PORTMAP */
342 
343 /*
344  * Search the callout list for a program number, return the callout
345  * struct.
346  */
347 static struct svc_callout *
348 svc_find(prog, vers, prev, netid)
349 	rpcprog_t prog;
350 	rpcvers_t vers;
351 	struct svc_callout **prev;
352 	char *netid;
353 {
354 	struct svc_callout *s, *p;
355 
356 	assert(prev != NULL);
357 
358 	p = NULL;
359 	for (s = svc_head; s != NULL; s = s->sc_next) {
360 		if (((s->sc_prog == prog) && (s->sc_vers == vers)) &&
361 		    ((netid == NULL) || (s->sc_netid == NULL) ||
362 		    (strcmp(netid, s->sc_netid) == 0)))
363 			break;
364 		p = s;
365 	}
366 	*prev = p;
367 	return (s);
368 }
369 
370 /* ******************* REPLY GENERATION ROUTINES  ************ */
371 
372 /*
373  * Send a reply to an rpc request
374  */
375 bool_t
376 svc_sendreply(xprt, xdr_results, xdr_location)
377 	SVCXPRT *xprt;
378 	xdrproc_t xdr_results;
379 	void * xdr_location;
380 {
381 	struct rpc_msg rply;
382 
383 	assert(xprt != NULL);
384 
385 	rply.rm_direction = REPLY;
386 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
387 	rply.acpted_rply.ar_verf = xprt->xp_verf;
388 	rply.acpted_rply.ar_stat = SUCCESS;
389 	rply.acpted_rply.ar_results.where = xdr_location;
390 	rply.acpted_rply.ar_results.proc = xdr_results;
391 	return (SVC_REPLY(xprt, &rply));
392 }
393 
394 /*
395  * No procedure error reply
396  */
397 void
398 svcerr_noproc(xprt)
399 	SVCXPRT *xprt;
400 {
401 	struct rpc_msg rply;
402 
403 	assert(xprt != NULL);
404 
405 	rply.rm_direction = REPLY;
406 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
407 	rply.acpted_rply.ar_verf = xprt->xp_verf;
408 	rply.acpted_rply.ar_stat = PROC_UNAVAIL;
409 	SVC_REPLY(xprt, &rply);
410 }
411 
412 /*
413  * Can't decode args error reply
414  */
415 void
416 svcerr_decode(xprt)
417 	SVCXPRT *xprt;
418 {
419 	struct rpc_msg rply;
420 
421 	assert(xprt != NULL);
422 
423 	rply.rm_direction = REPLY;
424 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
425 	rply.acpted_rply.ar_verf = xprt->xp_verf;
426 	rply.acpted_rply.ar_stat = GARBAGE_ARGS;
427 	SVC_REPLY(xprt, &rply);
428 }
429 
430 /*
431  * Some system error
432  */
433 void
434 svcerr_systemerr(xprt)
435 	SVCXPRT *xprt;
436 {
437 	struct rpc_msg rply;
438 
439 	assert(xprt != NULL);
440 
441 	rply.rm_direction = REPLY;
442 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
443 	rply.acpted_rply.ar_verf = xprt->xp_verf;
444 	rply.acpted_rply.ar_stat = SYSTEM_ERR;
445 	SVC_REPLY(xprt, &rply);
446 }
447 
448 #if 0
449 /*
450  * Tell RPC package to not complain about version errors to the client.	 This
451  * is useful when revving broadcast protocols that sit on a fixed address.
452  * There is really one (or should be only one) example of this kind of
453  * protocol: the portmapper (or rpc binder).
454  */
455 void
456 __svc_versquiet_on(xprt)
457 	SVCXPRT *xprt;
458 {
459 
460 	SVC_EXT(xprt)->xp_flags |= SVC_VERSQUIET;
461 }
462 
463 void
464 __svc_versquiet_off(xprt)
465 	SVCXPRT *xprt;
466 {
467 
468 	SVC_EXT(xprt)->xp_flags &= ~SVC_VERSQUIET;
469 }
470 
471 void
472 svc_versquiet(xprt)
473 	SVCXPRT *xprt;
474 {
475 	__svc_versquiet_on(xprt);
476 }
477 
478 int
479 __svc_versquiet_get(xprt)
480 	SVCXPRT *xprt;
481 {
482 
483 	return (SVC_EXT(xprt)->xp_flags & SVC_VERSQUIET);
484 }
485 #endif
486 
487 /*
488  * Authentication error reply
489  */
490 void
491 svcerr_auth(xprt, why)
492 	SVCXPRT *xprt;
493 	enum auth_stat why;
494 {
495 	struct rpc_msg rply;
496 
497 	assert(xprt != NULL);
498 
499 	rply.rm_direction = REPLY;
500 	rply.rm_reply.rp_stat = MSG_DENIED;
501 	rply.rjcted_rply.rj_stat = AUTH_ERROR;
502 	rply.rjcted_rply.rj_why = why;
503 	SVC_REPLY(xprt, &rply);
504 }
505 
506 /*
507  * Auth too weak error reply
508  */
509 void
510 svcerr_weakauth(xprt)
511 	SVCXPRT *xprt;
512 {
513 
514 	assert(xprt != NULL);
515 
516 	svcerr_auth(xprt, AUTH_TOOWEAK);
517 }
518 
519 /*
520  * Program unavailable error reply
521  */
522 void
523 svcerr_noprog(xprt)
524 	SVCXPRT *xprt;
525 {
526 	struct rpc_msg rply;
527 
528 	assert(xprt != NULL);
529 
530 	rply.rm_direction = REPLY;
531 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
532 	rply.acpted_rply.ar_verf = xprt->xp_verf;
533 	rply.acpted_rply.ar_stat = PROG_UNAVAIL;
534 	SVC_REPLY(xprt, &rply);
535 }
536 
537 /*
538  * Program version mismatch error reply
539  */
540 void
541 svcerr_progvers(xprt, low_vers, high_vers)
542 	SVCXPRT *xprt;
543 	rpcvers_t low_vers;
544 	rpcvers_t high_vers;
545 {
546 	struct rpc_msg rply;
547 
548 	assert(xprt != NULL);
549 
550 	rply.rm_direction = REPLY;
551 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
552 	rply.acpted_rply.ar_verf = xprt->xp_verf;
553 	rply.acpted_rply.ar_stat = PROG_MISMATCH;
554 	rply.acpted_rply.ar_vers.low = (u_int32_t)low_vers;
555 	rply.acpted_rply.ar_vers.high = (u_int32_t)high_vers;
556 	SVC_REPLY(xprt, &rply);
557 }
558 
559 /*
560  * Allocate a new server transport structure. All fields are
561  * initialized to zero and xp_p3 is initialized to point at an
562  * extension structure to hold various flags and authentication
563  * parameters.
564  */
565 SVCXPRT *
566 svc_xprt_alloc()
567 {
568 	SVCXPRT *xprt;
569 	SVCXPRT_EXT *ext;
570 
571 	xprt = mem_alloc(sizeof(SVCXPRT));
572 	if (xprt == NULL)
573 		return (NULL);
574 	memset(xprt, 0, sizeof(SVCXPRT));
575 	ext = mem_alloc(sizeof(SVCXPRT_EXT));
576 	if (ext == NULL) {
577 		mem_free(xprt, sizeof(SVCXPRT));
578 		return (NULL);
579 	}
580 	memset(ext, 0, sizeof(SVCXPRT_EXT));
581 	xprt->xp_p3 = ext;
582 	ext->xp_auth.svc_ah_ops = &svc_auth_null_ops;
583 
584 	return (xprt);
585 }
586 
587 /*
588  * Free a server transport structure.
589  */
590 void
591 svc_xprt_free(xprt)
592 	SVCXPRT *xprt;
593 {
594 
595 	mem_free(xprt->xp_p3, sizeof(SVCXPRT_EXT));
596 	mem_free(xprt, sizeof(SVCXPRT));
597 }
598 
599 /* ******************* SERVER INPUT STUFF ******************* */
600 
601 /*
602  * Get server side input from some transport.
603  *
604  * Statement of authentication parameters management:
605  * This function owns and manages all authentication parameters, specifically
606  * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
607  * the "cooked" credentials (rqst->rq_clntcred).
608  * However, this function does not know the structure of the cooked
609  * credentials, so it make the following assumptions:
610  *   a) the structure is contiguous (no pointers), and
611  *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
612  * In all events, all three parameters are freed upon exit from this routine.
613  * The storage is trivially management on the call stack in user land, but
614  * is mallocated in kernel land.
615  */
616 
617 void
618 svc_getreq(rdfds)
619 	int rdfds;
620 {
621 	fd_set readfds;
622 
623 	FD_ZERO(&readfds);
624 	readfds.fds_bits[0] = rdfds;
625 	svc_getreqset(&readfds);
626 }
627 
628 void
629 svc_getreqset(readfds)
630 	fd_set *readfds;
631 {
632 	int bit, fd;
633 	fd_mask mask, *maskp;
634 	int sock;
635 
636 	assert(readfds != NULL);
637 
638 	maskp = readfds->fds_bits;
639 	for (sock = 0; sock < FD_SETSIZE; sock += NFDBITS) {
640 	    for (mask = *maskp++; (bit = ffsl(mask)) != 0;
641 		mask ^= (1ul << (bit - 1))) {
642 		/* sock has input waiting */
643 		fd = sock + bit - 1;
644 		svc_getreq_common(fd);
645 	    }
646 	}
647 }
648 
649 void
650 svc_getreq_common(fd)
651 	int fd;
652 {
653 	SVCXPRT *xprt;
654 	struct svc_req r;
655 	struct rpc_msg msg;
656 	int prog_found;
657 	rpcvers_t low_vers;
658 	rpcvers_t high_vers;
659 	enum xprt_stat stat;
660 	char cred_area[2*MAX_AUTH_BYTES + RQCRED_SIZE];
661 
662 	msg.rm_call.cb_cred.oa_base = cred_area;
663 	msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
664 	r.rq_clntcred = &(cred_area[2*MAX_AUTH_BYTES]);
665 
666 	rwlock_rdlock(&svc_fd_lock);
667 	xprt = __svc_xports[fd];
668 	rwlock_unlock(&svc_fd_lock);
669 	if (xprt == NULL)
670 		/* But do we control sock? */
671 		return;
672 	/* now receive msgs from xprtprt (support batch calls) */
673 	do {
674 		if (SVC_RECV(xprt, &msg)) {
675 
676 			/* now find the exported program and call it */
677 			struct svc_callout *s;
678 			enum auth_stat why;
679 
680 			r.rq_xprt = xprt;
681 			r.rq_prog = msg.rm_call.cb_prog;
682 			r.rq_vers = msg.rm_call.cb_vers;
683 			r.rq_proc = msg.rm_call.cb_proc;
684 			r.rq_cred = msg.rm_call.cb_cred;
685 			/* first authenticate the message */
686 			if ((why = _authenticate(&r, &msg)) != AUTH_OK) {
687 				/*
688 				 * RPCSEC_GSS uses this return code
689 				 * for requests that form part of its
690 				 * context establishment protocol and
691 				 * should not be dispatched to the
692 				 * application.
693 				 */
694 				if (why != RPCSEC_GSS_NODISPATCH)
695 					svcerr_auth(xprt, why);
696 				goto call_done;
697 			}
698 			/* now match message with a registered service*/
699 			prog_found = FALSE;
700 			low_vers = (rpcvers_t) -1L;
701 			high_vers = (rpcvers_t) 0L;
702 			for (s = svc_head; s != NULL; s = s->sc_next) {
703 				if (s->sc_prog == r.rq_prog) {
704 					if (s->sc_vers == r.rq_vers) {
705 						(*s->sc_dispatch)(&r, xprt);
706 						goto call_done;
707 					}  /* found correct version */
708 					prog_found = TRUE;
709 					if (s->sc_vers < low_vers)
710 						low_vers = s->sc_vers;
711 					if (s->sc_vers > high_vers)
712 						high_vers = s->sc_vers;
713 				}   /* found correct program */
714 			}
715 			/*
716 			 * if we got here, the program or version
717 			 * is not served ...
718 			 */
719 			if (prog_found)
720 				svcerr_progvers(xprt, low_vers, high_vers);
721 			else
722 				svcerr_noprog(xprt);
723 			/* Fall through to ... */
724 		}
725 		/*
726 		 * Check if the xprt has been disconnected in a
727 		 * recursive call in the service dispatch routine.
728 		 * If so, then break.
729 		 */
730 		rwlock_rdlock(&svc_fd_lock);
731 		if (xprt != __svc_xports[fd]) {
732 			rwlock_unlock(&svc_fd_lock);
733 			break;
734 		}
735 		rwlock_unlock(&svc_fd_lock);
736 call_done:
737 		if ((stat = SVC_STAT(xprt)) == XPRT_DIED){
738 			SVC_DESTROY(xprt);
739 			break;
740 		}
741 	} while (stat == XPRT_MOREREQS);
742 }
743 
744 
745 void
746 svc_getreq_poll(pfdp, pollretval)
747 	struct pollfd	*pfdp;
748 	int	pollretval;
749 {
750 	int i;
751 	int fds_found;
752 
753 	for (i = fds_found = 0; fds_found < pollretval; i++) {
754 		struct pollfd *p = &pfdp[i];
755 
756 		if (p->revents) {
757 			/* fd has input waiting */
758 			fds_found++;
759 			/*
760 			 *	We assume that this function is only called
761 			 *	via someone _select()ing from svc_fdset or
762 			 *	_poll()ing from svc_pollset[].  Thus it's safe
763 			 *	to handle the POLLNVAL event by simply turning
764 			 *	the corresponding bit off in svc_fdset.  The
765 			 *	svc_pollset[] array is derived from svc_fdset
766 			 *	and so will also be updated eventually.
767 			 *
768 			 *	XXX Should we do an xprt_unregister() instead?
769 			 */
770 			if (p->revents & POLLNVAL) {
771 				rwlock_wrlock(&svc_fd_lock);
772 				FD_CLR(p->fd, &svc_fdset);
773 				rwlock_unlock(&svc_fd_lock);
774 			} else
775 				svc_getreq_common(p->fd);
776 		}
777 	}
778 }
779 
780 bool_t
781 rpc_control(int what, void *arg)
782 {
783 	int val;
784 
785 	switch (what) {
786 	case RPC_SVC_CONNMAXREC_SET:
787 		val = *(int *)arg;
788 		if (val <= 0)
789 			return FALSE;
790 		__svc_maxrec = val;
791 		return TRUE;
792 	case RPC_SVC_CONNMAXREC_GET:
793 		*(int *)arg = __svc_maxrec;
794 		return TRUE;
795 	default:
796 		break;
797 	}
798 	return FALSE;
799 }
800