xref: /freebsd/lib/libc/rpc/svc.c (revision cacdd70cc751fb68dec4b86c5e5b8c969b6e26ef)
1 /*	$NetBSD: svc.c,v 1.21 2000/07/06 03:10:35 christos Exp $	*/
2 
3 /*
4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5  * unrestricted use provided that this legend is included on all tape
6  * media and as a part of the software program in whole or part.  Users
7  * may copy or modify Sun RPC without charge, but are not authorized
8  * to license or distribute it to anyone else except as part of a product or
9  * program developed by the user.
10  *
11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14  *
15  * Sun RPC is provided with no support and without any obligation on the
16  * part of Sun Microsystems, Inc. to assist in its use, correction,
17  * modification or enhancement.
18  *
19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21  * OR ANY PART THEREOF.
22  *
23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24  * or profits or other special, indirect and consequential damages, even if
25  * Sun has been advised of the possibility of such damages.
26  *
27  * Sun Microsystems, Inc.
28  * 2550 Garcia Avenue
29  * Mountain View, California  94043
30  */
31 
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char *sccsid2 = "@(#)svc.c 1.44 88/02/08 Copyr 1984 Sun Micro";
34 static char *sccsid = "@(#)svc.c	2.4 88/08/11 4.0 RPCSRC";
35 #endif
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 /*
40  * svc.c, Server-side remote procedure call interface.
41  *
42  * There are two sets of procedures here.  The xprt routines are
43  * for handling transport handles.  The svc routines handle the
44  * list of service routines.
45  *
46  * Copyright (C) 1984, Sun Microsystems, Inc.
47  */
48 
49 #include "namespace.h"
50 #include "reentrant.h"
51 #include <sys/types.h>
52 #include <sys/poll.h>
53 #include <assert.h>
54 #include <errno.h>
55 #include <stdlib.h>
56 #include <string.h>
57 
58 #include <rpc/rpc.h>
59 #ifdef PORTMAP
60 #include <rpc/pmap_clnt.h>
61 #endif				/* PORTMAP */
62 #include "un-namespace.h"
63 
64 #include "rpc_com.h"
65 #include "mt_misc.h"
66 
67 #define	RQCRED_SIZE	400		/* this size is excessive */
68 
69 #define SVC_VERSQUIET 0x0001		/* keep quiet about vers mismatch */
70 #define version_keepquiet(xp) (SVC_EXT(xp)->xp_flags & SVC_VERSQUIET)
71 
72 #define max(a, b) (a > b ? a : b)
73 
74 /*
75  * The services list
76  * Each entry represents a set of procedures (an rpc program).
77  * The dispatch routine takes request structs and runs the
78  * apropriate procedure.
79  */
80 static struct svc_callout {
81 	struct svc_callout *sc_next;
82 	rpcprog_t	    sc_prog;
83 	rpcvers_t	    sc_vers;
84 	char		   *sc_netid;
85 	void		    (*sc_dispatch)(struct svc_req *, SVCXPRT *);
86 } *svc_head;
87 
88 static struct svc_callout *svc_find(rpcprog_t, rpcvers_t,
89     struct svc_callout **, char *);
90 static void __xprt_do_unregister (SVCXPRT *xprt, bool_t dolock);
91 
92 /* ***************  SVCXPRT related stuff **************** */
93 
94 /*
95  * Activate a transport handle.
96  */
97 void
98 xprt_register(xprt)
99 	SVCXPRT *xprt;
100 {
101 	int sock;
102 
103 	assert(xprt != NULL);
104 
105 	sock = xprt->xp_fd;
106 
107 	rwlock_wrlock(&svc_fd_lock);
108 	if (__svc_xports == NULL) {
109 		__svc_xports = (SVCXPRT **)
110 			mem_alloc(FD_SETSIZE * sizeof(SVCXPRT *));
111 		if (__svc_xports == NULL)
112 			return;
113 		memset(__svc_xports, '\0', FD_SETSIZE * sizeof(SVCXPRT *));
114 	}
115 	if (sock < FD_SETSIZE) {
116 		__svc_xports[sock] = xprt;
117 		FD_SET(sock, &svc_fdset);
118 		svc_maxfd = max(svc_maxfd, sock);
119 	}
120 	rwlock_unlock(&svc_fd_lock);
121 }
122 
123 void
124 xprt_unregister(SVCXPRT *xprt)
125 {
126 	__xprt_do_unregister(xprt, TRUE);
127 }
128 
129 void
130 __xprt_unregister_unlocked(SVCXPRT *xprt)
131 {
132 	__xprt_do_unregister(xprt, FALSE);
133 }
134 
135 /*
136  * De-activate a transport handle.
137  */
138 static void
139 __xprt_do_unregister(xprt, dolock)
140 	SVCXPRT *xprt;
141 	bool_t dolock;
142 {
143 	int sock;
144 
145 	assert(xprt != NULL);
146 
147 	sock = xprt->xp_fd;
148 
149 	if (dolock)
150 		rwlock_wrlock(&svc_fd_lock);
151 	if ((sock < FD_SETSIZE) && (__svc_xports[sock] == xprt)) {
152 		__svc_xports[sock] = NULL;
153 		FD_CLR(sock, &svc_fdset);
154 		if (sock >= svc_maxfd) {
155 			for (svc_maxfd--; svc_maxfd>=0; svc_maxfd--)
156 				if (__svc_xports[svc_maxfd])
157 					break;
158 		}
159 	}
160 	if (dolock)
161 		rwlock_unlock(&svc_fd_lock);
162 }
163 
164 /*
165  * Add a service program to the callout list.
166  * The dispatch routine will be called when a rpc request for this
167  * program number comes in.
168  */
169 bool_t
170 svc_reg(xprt, prog, vers, dispatch, nconf)
171 	SVCXPRT *xprt;
172 	const rpcprog_t prog;
173 	const rpcvers_t vers;
174 	void (*dispatch)(struct svc_req *, SVCXPRT *);
175 	const struct netconfig *nconf;
176 {
177 	bool_t dummy;
178 	struct svc_callout *prev;
179 	struct svc_callout *s;
180 	struct netconfig *tnconf;
181 	char *netid = NULL;
182 	int flag = 0;
183 
184 /* VARIABLES PROTECTED BY svc_lock: s, prev, svc_head */
185 
186 	if (xprt->xp_netid) {
187 		netid = strdup(xprt->xp_netid);
188 		flag = 1;
189 	} else if (nconf && nconf->nc_netid) {
190 		netid = strdup(nconf->nc_netid);
191 		flag = 1;
192 	} else if ((tnconf = __rpcgettp(xprt->xp_fd)) != NULL) {
193 		netid = strdup(tnconf->nc_netid);
194 		flag = 1;
195 		freenetconfigent(tnconf);
196 	} /* must have been created with svc_raw_create */
197 	if ((netid == NULL) && (flag == 1)) {
198 		return (FALSE);
199 	}
200 
201 	rwlock_wrlock(&svc_lock);
202 	if ((s = svc_find(prog, vers, &prev, netid)) != NULL) {
203 		if (netid)
204 			free(netid);
205 		if (s->sc_dispatch == dispatch)
206 			goto rpcb_it; /* he is registering another xptr */
207 		rwlock_unlock(&svc_lock);
208 		return (FALSE);
209 	}
210 	s = mem_alloc(sizeof (struct svc_callout));
211 	if (s == NULL) {
212 		if (netid)
213 			free(netid);
214 		rwlock_unlock(&svc_lock);
215 		return (FALSE);
216 	}
217 
218 	s->sc_prog = prog;
219 	s->sc_vers = vers;
220 	s->sc_dispatch = dispatch;
221 	s->sc_netid = netid;
222 	s->sc_next = svc_head;
223 	svc_head = s;
224 
225 	if ((xprt->xp_netid == NULL) && (flag == 1) && netid)
226 		((SVCXPRT *) xprt)->xp_netid = strdup(netid);
227 
228 rpcb_it:
229 	rwlock_unlock(&svc_lock);
230 	/* now register the information with the local binder service */
231 	if (nconf) {
232 		/*LINTED const castaway*/
233 		dummy = rpcb_set(prog, vers, (struct netconfig *) nconf,
234 		&((SVCXPRT *) xprt)->xp_ltaddr);
235 		return (dummy);
236 	}
237 	return (TRUE);
238 }
239 
240 /*
241  * Remove a service program from the callout list.
242  */
243 void
244 svc_unreg(prog, vers)
245 	const rpcprog_t prog;
246 	const rpcvers_t vers;
247 {
248 	struct svc_callout *prev;
249 	struct svc_callout *s;
250 
251 	/* unregister the information anyway */
252 	(void) rpcb_unset(prog, vers, NULL);
253 	rwlock_wrlock(&svc_lock);
254 	while ((s = svc_find(prog, vers, &prev, NULL)) != NULL) {
255 		if (prev == NULL) {
256 			svc_head = s->sc_next;
257 		} else {
258 			prev->sc_next = s->sc_next;
259 		}
260 		s->sc_next = NULL;
261 		if (s->sc_netid)
262 			mem_free(s->sc_netid, sizeof (s->sc_netid) + 1);
263 		mem_free(s, sizeof (struct svc_callout));
264 	}
265 	rwlock_unlock(&svc_lock);
266 }
267 
268 /* ********************** CALLOUT list related stuff ************* */
269 
270 #ifdef PORTMAP
271 /*
272  * Add a service program to the callout list.
273  * The dispatch routine will be called when a rpc request for this
274  * program number comes in.
275  */
276 bool_t
277 svc_register(xprt, prog, vers, dispatch, protocol)
278 	SVCXPRT *xprt;
279 	u_long prog;
280 	u_long vers;
281 	void (*dispatch)(struct svc_req *, SVCXPRT *);
282 	int protocol;
283 {
284 	struct svc_callout *prev;
285 	struct svc_callout *s;
286 
287 	assert(xprt != NULL);
288 	assert(dispatch != NULL);
289 
290 	if ((s = svc_find((rpcprog_t)prog, (rpcvers_t)vers, &prev, NULL)) !=
291 	    NULL) {
292 		if (s->sc_dispatch == dispatch)
293 			goto pmap_it;  /* he is registering another xptr */
294 		return (FALSE);
295 	}
296 	s = mem_alloc(sizeof(struct svc_callout));
297 	if (s == NULL) {
298 		return (FALSE);
299 	}
300 	s->sc_prog = (rpcprog_t)prog;
301 	s->sc_vers = (rpcvers_t)vers;
302 	s->sc_dispatch = dispatch;
303 	s->sc_next = svc_head;
304 	svc_head = s;
305 pmap_it:
306 	/* now register the information with the local binder service */
307 	if (protocol) {
308 		return (pmap_set(prog, vers, protocol, xprt->xp_port));
309 	}
310 	return (TRUE);
311 }
312 
313 /*
314  * Remove a service program from the callout list.
315  */
316 void
317 svc_unregister(prog, vers)
318 	u_long prog;
319 	u_long vers;
320 {
321 	struct svc_callout *prev;
322 	struct svc_callout *s;
323 
324 	if ((s = svc_find((rpcprog_t)prog, (rpcvers_t)vers, &prev, NULL)) ==
325 	    NULL)
326 		return;
327 	if (prev == NULL) {
328 		svc_head = s->sc_next;
329 	} else {
330 		prev->sc_next = s->sc_next;
331 	}
332 	s->sc_next = NULL;
333 	mem_free(s, sizeof(struct svc_callout));
334 	/* now unregister the information with the local binder service */
335 	(void)pmap_unset(prog, vers);
336 }
337 #endif				/* PORTMAP */
338 
339 /*
340  * Search the callout list for a program number, return the callout
341  * struct.
342  */
343 static struct svc_callout *
344 svc_find(prog, vers, prev, netid)
345 	rpcprog_t prog;
346 	rpcvers_t vers;
347 	struct svc_callout **prev;
348 	char *netid;
349 {
350 	struct svc_callout *s, *p;
351 
352 	assert(prev != NULL);
353 
354 	p = NULL;
355 	for (s = svc_head; s != NULL; s = s->sc_next) {
356 		if (((s->sc_prog == prog) && (s->sc_vers == vers)) &&
357 		    ((netid == NULL) || (s->sc_netid == NULL) ||
358 		    (strcmp(netid, s->sc_netid) == 0)))
359 			break;
360 		p = s;
361 	}
362 	*prev = p;
363 	return (s);
364 }
365 
366 /* ******************* REPLY GENERATION ROUTINES  ************ */
367 
368 /*
369  * Send a reply to an rpc request
370  */
371 bool_t
372 svc_sendreply(xprt, xdr_results, xdr_location)
373 	SVCXPRT *xprt;
374 	xdrproc_t xdr_results;
375 	void * xdr_location;
376 {
377 	struct rpc_msg rply;
378 
379 	assert(xprt != NULL);
380 
381 	rply.rm_direction = REPLY;
382 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
383 	rply.acpted_rply.ar_verf = xprt->xp_verf;
384 	rply.acpted_rply.ar_stat = SUCCESS;
385 	rply.acpted_rply.ar_results.where = xdr_location;
386 	rply.acpted_rply.ar_results.proc = xdr_results;
387 	return (SVC_REPLY(xprt, &rply));
388 }
389 
390 /*
391  * No procedure error reply
392  */
393 void
394 svcerr_noproc(xprt)
395 	SVCXPRT *xprt;
396 {
397 	struct rpc_msg rply;
398 
399 	assert(xprt != NULL);
400 
401 	rply.rm_direction = REPLY;
402 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
403 	rply.acpted_rply.ar_verf = xprt->xp_verf;
404 	rply.acpted_rply.ar_stat = PROC_UNAVAIL;
405 	SVC_REPLY(xprt, &rply);
406 }
407 
408 /*
409  * Can't decode args error reply
410  */
411 void
412 svcerr_decode(xprt)
413 	SVCXPRT *xprt;
414 {
415 	struct rpc_msg rply;
416 
417 	assert(xprt != NULL);
418 
419 	rply.rm_direction = REPLY;
420 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
421 	rply.acpted_rply.ar_verf = xprt->xp_verf;
422 	rply.acpted_rply.ar_stat = GARBAGE_ARGS;
423 	SVC_REPLY(xprt, &rply);
424 }
425 
426 /*
427  * Some system error
428  */
429 void
430 svcerr_systemerr(xprt)
431 	SVCXPRT *xprt;
432 {
433 	struct rpc_msg rply;
434 
435 	assert(xprt != NULL);
436 
437 	rply.rm_direction = REPLY;
438 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
439 	rply.acpted_rply.ar_verf = xprt->xp_verf;
440 	rply.acpted_rply.ar_stat = SYSTEM_ERR;
441 	SVC_REPLY(xprt, &rply);
442 }
443 
444 #if 0
445 /*
446  * Tell RPC package to not complain about version errors to the client.	 This
447  * is useful when revving broadcast protocols that sit on a fixed address.
448  * There is really one (or should be only one) example of this kind of
449  * protocol: the portmapper (or rpc binder).
450  */
451 void
452 __svc_versquiet_on(xprt)
453 	SVCXPRT *xprt;
454 {
455 
456 	SVC_EXT(xprt)->xp_flags |= SVC_VERSQUIET;
457 }
458 
459 void
460 __svc_versquiet_off(xprt)
461 	SVCXPRT *xprt;
462 {
463 
464 	SVC_EXT(xprt)->xp_flags &= ~SVC_VERSQUIET;
465 }
466 
467 void
468 svc_versquiet(xprt)
469 	SVCXPRT *xprt;
470 {
471 	__svc_versquiet_on(xprt);
472 }
473 
474 int
475 __svc_versquiet_get(xprt)
476 	SVCXPRT *xprt;
477 {
478 
479 	return (SVC_EXT(xprt)->xp_flags & SVC_VERSQUIET);
480 }
481 #endif
482 
483 /*
484  * Authentication error reply
485  */
486 void
487 svcerr_auth(xprt, why)
488 	SVCXPRT *xprt;
489 	enum auth_stat why;
490 {
491 	struct rpc_msg rply;
492 
493 	assert(xprt != NULL);
494 
495 	rply.rm_direction = REPLY;
496 	rply.rm_reply.rp_stat = MSG_DENIED;
497 	rply.rjcted_rply.rj_stat = AUTH_ERROR;
498 	rply.rjcted_rply.rj_why = why;
499 	SVC_REPLY(xprt, &rply);
500 }
501 
502 /*
503  * Auth too weak error reply
504  */
505 void
506 svcerr_weakauth(xprt)
507 	SVCXPRT *xprt;
508 {
509 
510 	assert(xprt != NULL);
511 
512 	svcerr_auth(xprt, AUTH_TOOWEAK);
513 }
514 
515 /*
516  * Program unavailable error reply
517  */
518 void
519 svcerr_noprog(xprt)
520 	SVCXPRT *xprt;
521 {
522 	struct rpc_msg rply;
523 
524 	assert(xprt != NULL);
525 
526 	rply.rm_direction = REPLY;
527 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
528 	rply.acpted_rply.ar_verf = xprt->xp_verf;
529 	rply.acpted_rply.ar_stat = PROG_UNAVAIL;
530 	SVC_REPLY(xprt, &rply);
531 }
532 
533 /*
534  * Program version mismatch error reply
535  */
536 void
537 svcerr_progvers(xprt, low_vers, high_vers)
538 	SVCXPRT *xprt;
539 	rpcvers_t low_vers;
540 	rpcvers_t high_vers;
541 {
542 	struct rpc_msg rply;
543 
544 	assert(xprt != NULL);
545 
546 	rply.rm_direction = REPLY;
547 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
548 	rply.acpted_rply.ar_verf = xprt->xp_verf;
549 	rply.acpted_rply.ar_stat = PROG_MISMATCH;
550 	rply.acpted_rply.ar_vers.low = (u_int32_t)low_vers;
551 	rply.acpted_rply.ar_vers.high = (u_int32_t)high_vers;
552 	SVC_REPLY(xprt, &rply);
553 }
554 
555 /*
556  * Allocate a new server transport structure. All fields are
557  * initialized to zero and xp_p3 is initialized to point at an
558  * extension structure to hold various flags and authentication
559  * parameters.
560  */
561 SVCXPRT *
562 svc_xprt_alloc()
563 {
564 	SVCXPRT *xprt;
565 	SVCXPRT_EXT *ext;
566 
567 	xprt = mem_alloc(sizeof(SVCXPRT));
568 	memset(xprt, 0, sizeof(SVCXPRT));
569 	ext = mem_alloc(sizeof(SVCXPRT_EXT));
570 	memset(ext, 0, sizeof(SVCXPRT_EXT));
571 	xprt->xp_p3 = ext;
572 
573 	return (xprt);
574 }
575 
576 /*
577  * Free a server transport structure.
578  */
579 void
580 svc_xprt_free(xprt)
581 	SVCXPRT *xprt;
582 {
583 
584 	mem_free(xprt->xp_p3, sizeof(SVCXPRT_EXT));
585 	mem_free(xprt, sizeof(SVCXPRT));
586 }
587 
588 /* ******************* SERVER INPUT STUFF ******************* */
589 
590 /*
591  * Get server side input from some transport.
592  *
593  * Statement of authentication parameters management:
594  * This function owns and manages all authentication parameters, specifically
595  * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
596  * the "cooked" credentials (rqst->rq_clntcred).
597  * However, this function does not know the structure of the cooked
598  * credentials, so it make the following assumptions:
599  *   a) the structure is contiguous (no pointers), and
600  *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
601  * In all events, all three parameters are freed upon exit from this routine.
602  * The storage is trivially management on the call stack in user land, but
603  * is mallocated in kernel land.
604  */
605 
606 void
607 svc_getreq(rdfds)
608 	int rdfds;
609 {
610 	fd_set readfds;
611 
612 	FD_ZERO(&readfds);
613 	readfds.fds_bits[0] = rdfds;
614 	svc_getreqset(&readfds);
615 }
616 
617 void
618 svc_getreqset(readfds)
619 	fd_set *readfds;
620 {
621 	int bit, fd;
622 	fd_mask mask, *maskp;
623 	int sock;
624 
625 	assert(readfds != NULL);
626 
627 	maskp = readfds->fds_bits;
628 	for (sock = 0; sock < FD_SETSIZE; sock += NFDBITS) {
629 	    for (mask = *maskp++; (bit = ffs(mask)) != 0;
630 		mask ^= (1 << (bit - 1))) {
631 		/* sock has input waiting */
632 		fd = sock + bit - 1;
633 		svc_getreq_common(fd);
634 	    }
635 	}
636 }
637 
638 void
639 svc_getreq_common(fd)
640 	int fd;
641 {
642 	SVCXPRT *xprt;
643 	struct svc_req r;
644 	struct rpc_msg msg;
645 	int prog_found;
646 	rpcvers_t low_vers;
647 	rpcvers_t high_vers;
648 	enum xprt_stat stat;
649 	char cred_area[2*MAX_AUTH_BYTES + RQCRED_SIZE];
650 
651 	msg.rm_call.cb_cred.oa_base = cred_area;
652 	msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
653 	r.rq_clntcred = &(cred_area[2*MAX_AUTH_BYTES]);
654 
655 	rwlock_rdlock(&svc_fd_lock);
656 	xprt = __svc_xports[fd];
657 	rwlock_unlock(&svc_fd_lock);
658 	if (xprt == NULL)
659 		/* But do we control sock? */
660 		return;
661 	/* now receive msgs from xprtprt (support batch calls) */
662 	do {
663 		if (SVC_RECV(xprt, &msg)) {
664 
665 			/* now find the exported program and call it */
666 			struct svc_callout *s;
667 			enum auth_stat why;
668 
669 			r.rq_xprt = xprt;
670 			r.rq_prog = msg.rm_call.cb_prog;
671 			r.rq_vers = msg.rm_call.cb_vers;
672 			r.rq_proc = msg.rm_call.cb_proc;
673 			r.rq_cred = msg.rm_call.cb_cred;
674 			/* first authenticate the message */
675 			if ((why = _authenticate(&r, &msg)) != AUTH_OK) {
676 				/*
677 				 * RPCSEC_GSS uses this return code
678 				 * for requests that form part of its
679 				 * context establishment protocol and
680 				 * should not be dispatched to the
681 				 * application.
682 				 */
683 				if (why != RPCSEC_GSS_NODISPATCH)
684 					svcerr_auth(xprt, why);
685 				goto call_done;
686 			}
687 			/* now match message with a registered service*/
688 			prog_found = FALSE;
689 			low_vers = (rpcvers_t) -1L;
690 			high_vers = (rpcvers_t) 0L;
691 			for (s = svc_head; s != NULL; s = s->sc_next) {
692 				if (s->sc_prog == r.rq_prog) {
693 					if (s->sc_vers == r.rq_vers) {
694 						(*s->sc_dispatch)(&r, xprt);
695 						goto call_done;
696 					}  /* found correct version */
697 					prog_found = TRUE;
698 					if (s->sc_vers < low_vers)
699 						low_vers = s->sc_vers;
700 					if (s->sc_vers > high_vers)
701 						high_vers = s->sc_vers;
702 				}   /* found correct program */
703 			}
704 			/*
705 			 * if we got here, the program or version
706 			 * is not served ...
707 			 */
708 			if (prog_found)
709 				svcerr_progvers(xprt, low_vers, high_vers);
710 			else
711 				svcerr_noprog(xprt);
712 			/* Fall through to ... */
713 		}
714 		/*
715 		 * Check if the xprt has been disconnected in a
716 		 * recursive call in the service dispatch routine.
717 		 * If so, then break.
718 		 */
719 		rwlock_rdlock(&svc_fd_lock);
720 		if (xprt != __svc_xports[fd]) {
721 			rwlock_unlock(&svc_fd_lock);
722 			break;
723 		}
724 		rwlock_unlock(&svc_fd_lock);
725 call_done:
726 		if ((stat = SVC_STAT(xprt)) == XPRT_DIED){
727 			SVC_DESTROY(xprt);
728 			break;
729 		}
730 	} while (stat == XPRT_MOREREQS);
731 }
732 
733 
734 void
735 svc_getreq_poll(pfdp, pollretval)
736 	struct pollfd	*pfdp;
737 	int	pollretval;
738 {
739 	int i;
740 	int fds_found;
741 
742 	for (i = fds_found = 0; fds_found < pollretval; i++) {
743 		struct pollfd *p = &pfdp[i];
744 
745 		if (p->revents) {
746 			/* fd has input waiting */
747 			fds_found++;
748 			/*
749 			 *	We assume that this function is only called
750 			 *	via someone _select()ing from svc_fdset or
751 			 *	_poll()ing from svc_pollset[].  Thus it's safe
752 			 *	to handle the POLLNVAL event by simply turning
753 			 *	the corresponding bit off in svc_fdset.  The
754 			 *	svc_pollset[] array is derived from svc_fdset
755 			 *	and so will also be updated eventually.
756 			 *
757 			 *	XXX Should we do an xprt_unregister() instead?
758 			 */
759 			if (p->revents & POLLNVAL) {
760 				rwlock_wrlock(&svc_fd_lock);
761 				FD_CLR(p->fd, &svc_fdset);
762 				rwlock_unlock(&svc_fd_lock);
763 			} else
764 				svc_getreq_common(p->fd);
765 		}
766 	}
767 }
768 
769 bool_t
770 rpc_control(int what, void *arg)
771 {
772 	int val;
773 
774 	switch (what) {
775 	case RPC_SVC_CONNMAXREC_SET:
776 		val = *(int *)arg;
777 		if (val <= 0)
778 			return FALSE;
779 		__svc_maxrec = val;
780 		return TRUE;
781 	case RPC_SVC_CONNMAXREC_GET:
782 		*(int *)arg = __svc_maxrec;
783 		return TRUE;
784 	default:
785 		break;
786 	}
787 	return FALSE;
788 }
789