xref: /freebsd/lib/libc/rpc/svc.c (revision a9e8641da961bcf3d24afc85fd657f2083a872a2)
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 static struct svc_callout *svc_find(rpcprog_t, rpcvers_t,
88     struct svc_callout **, char *);
89 static void __xprt_do_unregister (SVCXPRT *xprt, bool_t dolock);
90 
91 /* ***************  SVCXPRT related stuff **************** */
92 
93 /*
94  * Activate a transport handle.
95  */
96 void
97 xprt_register(xprt)
98 	SVCXPRT *xprt;
99 {
100 	int sock;
101 
102 	assert(xprt != NULL);
103 
104 	sock = xprt->xp_fd;
105 
106 	rwlock_wrlock(&svc_fd_lock);
107 	if (__svc_xports == NULL) {
108 		__svc_xports = (SVCXPRT **)
109 			mem_alloc(FD_SETSIZE * sizeof(SVCXPRT *));
110 		if (__svc_xports == NULL) {
111 			rwlock_unlock(&svc_fd_lock);
112 			return;
113 		}
114 		memset(__svc_xports, '\0', FD_SETSIZE * sizeof(SVCXPRT *));
115 	}
116 	if (sock < FD_SETSIZE) {
117 		__svc_xports[sock] = xprt;
118 		FD_SET(sock, &svc_fdset);
119 		svc_maxfd = max(svc_maxfd, sock);
120 	}
121 	rwlock_unlock(&svc_fd_lock);
122 }
123 
124 void
125 xprt_unregister(SVCXPRT *xprt)
126 {
127 	__xprt_do_unregister(xprt, TRUE);
128 }
129 
130 void
131 __xprt_unregister_unlocked(SVCXPRT *xprt)
132 {
133 	__xprt_do_unregister(xprt, FALSE);
134 }
135 
136 /*
137  * De-activate a transport handle.
138  */
139 static void
140 __xprt_do_unregister(xprt, dolock)
141 	SVCXPRT *xprt;
142 	bool_t dolock;
143 {
144 	int sock;
145 
146 	assert(xprt != NULL);
147 
148 	sock = xprt->xp_fd;
149 
150 	if (dolock)
151 		rwlock_wrlock(&svc_fd_lock);
152 	if ((sock < FD_SETSIZE) && (__svc_xports[sock] == xprt)) {
153 		__svc_xports[sock] = NULL;
154 		FD_CLR(sock, &svc_fdset);
155 		if (sock >= svc_maxfd) {
156 			for (svc_maxfd--; svc_maxfd>=0; svc_maxfd--)
157 				if (__svc_xports[svc_maxfd])
158 					break;
159 		}
160 	}
161 	if (dolock)
162 		rwlock_unlock(&svc_fd_lock);
163 }
164 
165 /*
166  * Add a service program to the callout list.
167  * The dispatch routine will be called when a rpc request for this
168  * program number comes in.
169  */
170 bool_t
171 svc_reg(xprt, prog, vers, dispatch, nconf)
172 	SVCXPRT *xprt;
173 	const rpcprog_t prog;
174 	const rpcvers_t vers;
175 	void (*dispatch)(struct svc_req *, SVCXPRT *);
176 	const struct netconfig *nconf;
177 {
178 	bool_t dummy;
179 	struct svc_callout *prev;
180 	struct svc_callout *s;
181 	struct netconfig *tnconf;
182 	char *netid = NULL;
183 	int flag = 0;
184 
185 /* VARIABLES PROTECTED BY svc_lock: s, prev, svc_head */
186 
187 	if (xprt->xp_netid) {
188 		netid = strdup(xprt->xp_netid);
189 		flag = 1;
190 	} else if (nconf && nconf->nc_netid) {
191 		netid = strdup(nconf->nc_netid);
192 		flag = 1;
193 	} else if ((tnconf = __rpcgettp(xprt->xp_fd)) != NULL) {
194 		netid = strdup(tnconf->nc_netid);
195 		flag = 1;
196 		freenetconfigent(tnconf);
197 	} /* must have been created with svc_raw_create */
198 	if ((netid == NULL) && (flag == 1)) {
199 		return (FALSE);
200 	}
201 
202 	rwlock_wrlock(&svc_lock);
203 	if ((s = svc_find(prog, vers, &prev, netid)) != NULL) {
204 		if (netid)
205 			free(netid);
206 		if (s->sc_dispatch == dispatch)
207 			goto rpcb_it; /* he is registering another xptr */
208 		rwlock_unlock(&svc_lock);
209 		return (FALSE);
210 	}
211 	s = mem_alloc(sizeof (struct svc_callout));
212 	if (s == NULL) {
213 		if (netid)
214 			free(netid);
215 		rwlock_unlock(&svc_lock);
216 		return (FALSE);
217 	}
218 
219 	s->sc_prog = prog;
220 	s->sc_vers = vers;
221 	s->sc_dispatch = dispatch;
222 	s->sc_netid = netid;
223 	s->sc_next = svc_head;
224 	svc_head = s;
225 
226 	if ((xprt->xp_netid == NULL) && (flag == 1) && netid)
227 		((SVCXPRT *) xprt)->xp_netid = strdup(netid);
228 
229 rpcb_it:
230 	rwlock_unlock(&svc_lock);
231 	/* now register the information with the local binder service */
232 	if (nconf) {
233 		/*LINTED const castaway*/
234 		dummy = rpcb_set(prog, vers, (struct netconfig *) nconf,
235 		&((SVCXPRT *) xprt)->xp_ltaddr);
236 		return (dummy);
237 	}
238 	return (TRUE);
239 }
240 
241 /*
242  * Remove a service program from the callout list.
243  */
244 void
245 svc_unreg(prog, vers)
246 	const rpcprog_t prog;
247 	const rpcvers_t vers;
248 {
249 	struct svc_callout *prev;
250 	struct svc_callout *s;
251 
252 	/* unregister the information anyway */
253 	(void) rpcb_unset(prog, vers, NULL);
254 	rwlock_wrlock(&svc_lock);
255 	while ((s = svc_find(prog, vers, &prev, NULL)) != NULL) {
256 		if (prev == NULL) {
257 			svc_head = s->sc_next;
258 		} else {
259 			prev->sc_next = s->sc_next;
260 		}
261 		s->sc_next = NULL;
262 		if (s->sc_netid)
263 			mem_free(s->sc_netid, sizeof (s->sc_netid) + 1);
264 		mem_free(s, sizeof (struct svc_callout));
265 	}
266 	rwlock_unlock(&svc_lock);
267 }
268 
269 /* ********************** CALLOUT list related stuff ************* */
270 
271 #ifdef PORTMAP
272 /*
273  * Add a service program to the callout list.
274  * The dispatch routine will be called when a rpc request for this
275  * program number comes in.
276  */
277 bool_t
278 svc_register(xprt, prog, vers, dispatch, protocol)
279 	SVCXPRT *xprt;
280 	u_long prog;
281 	u_long vers;
282 	void (*dispatch)(struct svc_req *, SVCXPRT *);
283 	int protocol;
284 {
285 	struct svc_callout *prev;
286 	struct svc_callout *s;
287 
288 	assert(xprt != NULL);
289 	assert(dispatch != NULL);
290 
291 	if ((s = svc_find((rpcprog_t)prog, (rpcvers_t)vers, &prev, NULL)) !=
292 	    NULL) {
293 		if (s->sc_dispatch == dispatch)
294 			goto pmap_it;  /* he is registering another xptr */
295 		return (FALSE);
296 	}
297 	s = mem_alloc(sizeof(struct svc_callout));
298 	if (s == NULL) {
299 		return (FALSE);
300 	}
301 	s->sc_prog = (rpcprog_t)prog;
302 	s->sc_vers = (rpcvers_t)vers;
303 	s->sc_dispatch = dispatch;
304 	s->sc_next = svc_head;
305 	svc_head = s;
306 pmap_it:
307 	/* now register the information with the local binder service */
308 	if (protocol) {
309 		return (pmap_set(prog, vers, protocol, xprt->xp_port));
310 	}
311 	return (TRUE);
312 }
313 
314 /*
315  * Remove a service program from the callout list.
316  */
317 void
318 svc_unregister(prog, vers)
319 	u_long prog;
320 	u_long vers;
321 {
322 	struct svc_callout *prev;
323 	struct svc_callout *s;
324 
325 	if ((s = svc_find((rpcprog_t)prog, (rpcvers_t)vers, &prev, NULL)) ==
326 	    NULL)
327 		return;
328 	if (prev == NULL) {
329 		svc_head = s->sc_next;
330 	} else {
331 		prev->sc_next = s->sc_next;
332 	}
333 	s->sc_next = NULL;
334 	mem_free(s, sizeof(struct svc_callout));
335 	/* now unregister the information with the local binder service */
336 	(void)pmap_unset(prog, vers);
337 }
338 #endif				/* PORTMAP */
339 
340 /*
341  * Search the callout list for a program number, return the callout
342  * struct.
343  */
344 static struct svc_callout *
345 svc_find(prog, vers, prev, netid)
346 	rpcprog_t prog;
347 	rpcvers_t vers;
348 	struct svc_callout **prev;
349 	char *netid;
350 {
351 	struct svc_callout *s, *p;
352 
353 	assert(prev != NULL);
354 
355 	p = NULL;
356 	for (s = svc_head; s != NULL; s = s->sc_next) {
357 		if (((s->sc_prog == prog) && (s->sc_vers == vers)) &&
358 		    ((netid == NULL) || (s->sc_netid == NULL) ||
359 		    (strcmp(netid, s->sc_netid) == 0)))
360 			break;
361 		p = s;
362 	}
363 	*prev = p;
364 	return (s);
365 }
366 
367 /* ******************* REPLY GENERATION ROUTINES  ************ */
368 
369 /*
370  * Send a reply to an rpc request
371  */
372 bool_t
373 svc_sendreply(xprt, xdr_results, xdr_location)
374 	SVCXPRT *xprt;
375 	xdrproc_t xdr_results;
376 	void * xdr_location;
377 {
378 	struct rpc_msg rply;
379 
380 	assert(xprt != NULL);
381 
382 	rply.rm_direction = REPLY;
383 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
384 	rply.acpted_rply.ar_verf = xprt->xp_verf;
385 	rply.acpted_rply.ar_stat = SUCCESS;
386 	rply.acpted_rply.ar_results.where = xdr_location;
387 	rply.acpted_rply.ar_results.proc = xdr_results;
388 	return (SVC_REPLY(xprt, &rply));
389 }
390 
391 /*
392  * No procedure error reply
393  */
394 void
395 svcerr_noproc(xprt)
396 	SVCXPRT *xprt;
397 {
398 	struct rpc_msg rply;
399 
400 	assert(xprt != NULL);
401 
402 	rply.rm_direction = REPLY;
403 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
404 	rply.acpted_rply.ar_verf = xprt->xp_verf;
405 	rply.acpted_rply.ar_stat = PROC_UNAVAIL;
406 	SVC_REPLY(xprt, &rply);
407 }
408 
409 /*
410  * Can't decode args error reply
411  */
412 void
413 svcerr_decode(xprt)
414 	SVCXPRT *xprt;
415 {
416 	struct rpc_msg rply;
417 
418 	assert(xprt != NULL);
419 
420 	rply.rm_direction = REPLY;
421 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
422 	rply.acpted_rply.ar_verf = xprt->xp_verf;
423 	rply.acpted_rply.ar_stat = GARBAGE_ARGS;
424 	SVC_REPLY(xprt, &rply);
425 }
426 
427 /*
428  * Some system error
429  */
430 void
431 svcerr_systemerr(xprt)
432 	SVCXPRT *xprt;
433 {
434 	struct rpc_msg rply;
435 
436 	assert(xprt != NULL);
437 
438 	rply.rm_direction = REPLY;
439 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
440 	rply.acpted_rply.ar_verf = xprt->xp_verf;
441 	rply.acpted_rply.ar_stat = SYSTEM_ERR;
442 	SVC_REPLY(xprt, &rply);
443 }
444 
445 #if 0
446 /*
447  * Tell RPC package to not complain about version errors to the client.	 This
448  * is useful when revving broadcast protocols that sit on a fixed address.
449  * There is really one (or should be only one) example of this kind of
450  * protocol: the portmapper (or rpc binder).
451  */
452 void
453 __svc_versquiet_on(xprt)
454 	SVCXPRT *xprt;
455 {
456 
457 	SVC_EXT(xprt)->xp_flags |= SVC_VERSQUIET;
458 }
459 
460 void
461 __svc_versquiet_off(xprt)
462 	SVCXPRT *xprt;
463 {
464 
465 	SVC_EXT(xprt)->xp_flags &= ~SVC_VERSQUIET;
466 }
467 
468 void
469 svc_versquiet(xprt)
470 	SVCXPRT *xprt;
471 {
472 	__svc_versquiet_on(xprt);
473 }
474 
475 int
476 __svc_versquiet_get(xprt)
477 	SVCXPRT *xprt;
478 {
479 
480 	return (SVC_EXT(xprt)->xp_flags & SVC_VERSQUIET);
481 }
482 #endif
483 
484 /*
485  * Authentication error reply
486  */
487 void
488 svcerr_auth(xprt, why)
489 	SVCXPRT *xprt;
490 	enum auth_stat why;
491 {
492 	struct rpc_msg rply;
493 
494 	assert(xprt != NULL);
495 
496 	rply.rm_direction = REPLY;
497 	rply.rm_reply.rp_stat = MSG_DENIED;
498 	rply.rjcted_rply.rj_stat = AUTH_ERROR;
499 	rply.rjcted_rply.rj_why = why;
500 	SVC_REPLY(xprt, &rply);
501 }
502 
503 /*
504  * Auth too weak error reply
505  */
506 void
507 svcerr_weakauth(xprt)
508 	SVCXPRT *xprt;
509 {
510 
511 	assert(xprt != NULL);
512 
513 	svcerr_auth(xprt, AUTH_TOOWEAK);
514 }
515 
516 /*
517  * Program unavailable error reply
518  */
519 void
520 svcerr_noprog(xprt)
521 	SVCXPRT *xprt;
522 {
523 	struct rpc_msg rply;
524 
525 	assert(xprt != NULL);
526 
527 	rply.rm_direction = REPLY;
528 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
529 	rply.acpted_rply.ar_verf = xprt->xp_verf;
530 	rply.acpted_rply.ar_stat = PROG_UNAVAIL;
531 	SVC_REPLY(xprt, &rply);
532 }
533 
534 /*
535  * Program version mismatch error reply
536  */
537 void
538 svcerr_progvers(xprt, low_vers, high_vers)
539 	SVCXPRT *xprt;
540 	rpcvers_t low_vers;
541 	rpcvers_t high_vers;
542 {
543 	struct rpc_msg rply;
544 
545 	assert(xprt != NULL);
546 
547 	rply.rm_direction = REPLY;
548 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
549 	rply.acpted_rply.ar_verf = xprt->xp_verf;
550 	rply.acpted_rply.ar_stat = PROG_MISMATCH;
551 	rply.acpted_rply.ar_vers.low = (u_int32_t)low_vers;
552 	rply.acpted_rply.ar_vers.high = (u_int32_t)high_vers;
553 	SVC_REPLY(xprt, &rply);
554 }
555 
556 /*
557  * Allocate a new server transport structure. All fields are
558  * initialized to zero and xp_p3 is initialized to point at an
559  * extension structure to hold various flags and authentication
560  * parameters.
561  */
562 SVCXPRT *
563 svc_xprt_alloc()
564 {
565 	SVCXPRT *xprt;
566 	SVCXPRT_EXT *ext;
567 
568 	xprt = mem_alloc(sizeof(SVCXPRT));
569 	if (xprt == NULL)
570 		return (NULL);
571 	memset(xprt, 0, sizeof(SVCXPRT));
572 	ext = mem_alloc(sizeof(SVCXPRT_EXT));
573 	if (ext == NULL) {
574 		mem_free(xprt, sizeof(SVCXPRT));
575 		return (NULL);
576 	}
577 	memset(ext, 0, sizeof(SVCXPRT_EXT));
578 	xprt->xp_p3 = ext;
579 	ext->xp_auth.svc_ah_ops = &svc_auth_null_ops;
580 
581 	return (xprt);
582 }
583 
584 /*
585  * Free a server transport structure.
586  */
587 void
588 svc_xprt_free(xprt)
589 	SVCXPRT *xprt;
590 {
591 
592 	mem_free(xprt->xp_p3, sizeof(SVCXPRT_EXT));
593 	mem_free(xprt, sizeof(SVCXPRT));
594 }
595 
596 /* ******************* SERVER INPUT STUFF ******************* */
597 
598 /*
599  * Get server side input from some transport.
600  *
601  * Statement of authentication parameters management:
602  * This function owns and manages all authentication parameters, specifically
603  * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
604  * the "cooked" credentials (rqst->rq_clntcred).
605  * However, this function does not know the structure of the cooked
606  * credentials, so it make the following assumptions:
607  *   a) the structure is contiguous (no pointers), and
608  *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
609  * In all events, all three parameters are freed upon exit from this routine.
610  * The storage is trivially management on the call stack in user land, but
611  * is mallocated in kernel land.
612  */
613 
614 void
615 svc_getreq(rdfds)
616 	int rdfds;
617 {
618 	fd_set readfds;
619 
620 	FD_ZERO(&readfds);
621 	readfds.fds_bits[0] = rdfds;
622 	svc_getreqset(&readfds);
623 }
624 
625 void
626 svc_getreqset(readfds)
627 	fd_set *readfds;
628 {
629 	int bit, fd;
630 	fd_mask mask, *maskp;
631 	int sock;
632 
633 	assert(readfds != NULL);
634 
635 	maskp = readfds->fds_bits;
636 	for (sock = 0; sock < FD_SETSIZE; sock += NFDBITS) {
637 	    for (mask = *maskp++; (bit = ffsl(mask)) != 0;
638 		mask ^= (1ul << (bit - 1))) {
639 		/* sock has input waiting */
640 		fd = sock + bit - 1;
641 		svc_getreq_common(fd);
642 	    }
643 	}
644 }
645 
646 void
647 svc_getreq_common(fd)
648 	int fd;
649 {
650 	SVCXPRT *xprt;
651 	struct svc_req r;
652 	struct rpc_msg msg;
653 	int prog_found;
654 	rpcvers_t low_vers;
655 	rpcvers_t high_vers;
656 	enum xprt_stat stat;
657 	char cred_area[2*MAX_AUTH_BYTES + RQCRED_SIZE];
658 
659 	msg.rm_call.cb_cred.oa_base = cred_area;
660 	msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
661 	r.rq_clntcred = &(cred_area[2*MAX_AUTH_BYTES]);
662 
663 	rwlock_rdlock(&svc_fd_lock);
664 	xprt = __svc_xports[fd];
665 	rwlock_unlock(&svc_fd_lock);
666 	if (xprt == NULL)
667 		/* But do we control sock? */
668 		return;
669 	/* now receive msgs from xprtprt (support batch calls) */
670 	do {
671 		if (SVC_RECV(xprt, &msg)) {
672 
673 			/* now find the exported program and call it */
674 			struct svc_callout *s;
675 			enum auth_stat why;
676 
677 			r.rq_xprt = xprt;
678 			r.rq_prog = msg.rm_call.cb_prog;
679 			r.rq_vers = msg.rm_call.cb_vers;
680 			r.rq_proc = msg.rm_call.cb_proc;
681 			r.rq_cred = msg.rm_call.cb_cred;
682 			/* first authenticate the message */
683 			if ((why = _authenticate(&r, &msg)) != AUTH_OK) {
684 				/*
685 				 * RPCSEC_GSS uses this return code
686 				 * for requests that form part of its
687 				 * context establishment protocol and
688 				 * should not be dispatched to the
689 				 * application.
690 				 */
691 				if (why != RPCSEC_GSS_NODISPATCH)
692 					svcerr_auth(xprt, why);
693 				goto call_done;
694 			}
695 			/* now match message with a registered service*/
696 			prog_found = FALSE;
697 			low_vers = (rpcvers_t) -1L;
698 			high_vers = (rpcvers_t) 0L;
699 			for (s = svc_head; s != NULL; s = s->sc_next) {
700 				if (s->sc_prog == r.rq_prog) {
701 					if (s->sc_vers == r.rq_vers) {
702 						(*s->sc_dispatch)(&r, xprt);
703 						goto call_done;
704 					}  /* found correct version */
705 					prog_found = TRUE;
706 					if (s->sc_vers < low_vers)
707 						low_vers = s->sc_vers;
708 					if (s->sc_vers > high_vers)
709 						high_vers = s->sc_vers;
710 				}   /* found correct program */
711 			}
712 			/*
713 			 * if we got here, the program or version
714 			 * is not served ...
715 			 */
716 			if (prog_found)
717 				svcerr_progvers(xprt, low_vers, high_vers);
718 			else
719 				svcerr_noprog(xprt);
720 			/* Fall through to ... */
721 		}
722 		/*
723 		 * Check if the xprt has been disconnected in a
724 		 * recursive call in the service dispatch routine.
725 		 * If so, then break.
726 		 */
727 		rwlock_rdlock(&svc_fd_lock);
728 		if (xprt != __svc_xports[fd]) {
729 			rwlock_unlock(&svc_fd_lock);
730 			break;
731 		}
732 		rwlock_unlock(&svc_fd_lock);
733 call_done:
734 		if ((stat = SVC_STAT(xprt)) == XPRT_DIED){
735 			SVC_DESTROY(xprt);
736 			break;
737 		}
738 	} while (stat == XPRT_MOREREQS);
739 }
740 
741 
742 void
743 svc_getreq_poll(pfdp, pollretval)
744 	struct pollfd	*pfdp;
745 	int	pollretval;
746 {
747 	int i;
748 	int fds_found;
749 
750 	for (i = fds_found = 0; fds_found < pollretval; i++) {
751 		struct pollfd *p = &pfdp[i];
752 
753 		if (p->revents) {
754 			/* fd has input waiting */
755 			fds_found++;
756 			/*
757 			 *	We assume that this function is only called
758 			 *	via someone _select()ing from svc_fdset or
759 			 *	_poll()ing from svc_pollset[].  Thus it's safe
760 			 *	to handle the POLLNVAL event by simply turning
761 			 *	the corresponding bit off in svc_fdset.  The
762 			 *	svc_pollset[] array is derived from svc_fdset
763 			 *	and so will also be updated eventually.
764 			 *
765 			 *	XXX Should we do an xprt_unregister() instead?
766 			 */
767 			if (p->revents & POLLNVAL) {
768 				rwlock_wrlock(&svc_fd_lock);
769 				FD_CLR(p->fd, &svc_fdset);
770 				rwlock_unlock(&svc_fd_lock);
771 			} else
772 				svc_getreq_common(p->fd);
773 		}
774 	}
775 }
776 
777 bool_t
778 rpc_control(int what, void *arg)
779 {
780 	int val;
781 
782 	switch (what) {
783 	case RPC_SVC_CONNMAXREC_SET:
784 		val = *(int *)arg;
785 		if (val <= 0)
786 			return FALSE;
787 		__svc_maxrec = val;
788 		return TRUE;
789 	case RPC_SVC_CONNMAXREC_GET:
790 		*(int *)arg = __svc_maxrec;
791 		return TRUE;
792 	default:
793 		break;
794 	}
795 	return FALSE;
796 }
797