xref: /netbsd-src/lib/libc/rpc/svc.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: svc.c,v 1.39 2015/11/13 15:22:12 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2010, Oracle America, Inc.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are
8  * met:
9  *
10  *     * Redistributions of source code must retain the above copyright
11  *       notice, this list of conditions and the following disclaimer.
12  *     * Redistributions in binary form must reproduce the above
13  *       copyright notice, this list of conditions and the following
14  *       disclaimer in the documentation and/or other materials
15  *       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
21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 #if defined(LIBC_SCCS) && !defined(lint)
36 #if 0
37 static char *sccsid = "@(#)svc.c 1.44 88/02/08 Copyr 1984 Sun Micro";
38 static char *sccsid = "@(#)svc.c	2.4 88/08/11 4.0 RPCSRC";
39 #else
40 __RCSID("$NetBSD: svc.c,v 1.39 2015/11/13 15:22:12 christos Exp $");
41 #endif
42 #endif
43 
44 /*
45  * svc.c, Server-side remote procedure call interface.
46  *
47  * There are two sets of procedures here.  The xprt routines are
48  * for handling transport handles.  The svc routines handle the
49  * list of service routines.
50  *
51  * Copyright (C) 1984, Sun Microsystems, Inc.
52  */
53 
54 #include "namespace.h"
55 #include "reentrant.h"
56 #include <sys/types.h>
57 #include <sys/poll.h>
58 #include <assert.h>
59 #include <errno.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <err.h>
63 
64 #include <rpc/rpc.h>
65 #ifdef PORTMAP
66 #include <rpc/pmap_clnt.h>
67 #endif
68 
69 #include "svc_fdset.h"
70 #include "rpc_internal.h"
71 
72 #ifdef __weak_alias
73 __weak_alias(svc_getreq,_svc_getreq)
74 __weak_alias(svc_getreqset,_svc_getreqset)
75 __weak_alias(svc_getreq_common,_svc_getreq_common)
76 __weak_alias(svc_register,_svc_register)
77 __weak_alias(svc_reg,_svc_reg)
78 __weak_alias(svc_unreg,_svc_unreg)
79 __weak_alias(svc_sendreply,_svc_sendreply)
80 __weak_alias(svc_unregister,_svc_unregister)
81 __weak_alias(svcerr_auth,_svcerr_auth)
82 __weak_alias(svcerr_decode,_svcerr_decode)
83 __weak_alias(svcerr_noproc,_svcerr_noproc)
84 __weak_alias(svcerr_noprog,_svcerr_noprog)
85 __weak_alias(svcerr_progvers,_svcerr_progvers)
86 __weak_alias(svcerr_systemerr,_svcerr_systemerr)
87 __weak_alias(svcerr_weakauth,_svcerr_weakauth)
88 __weak_alias(xprt_register,_xprt_register)
89 __weak_alias(xprt_unregister,_xprt_unregister)
90 __weak_alias(rpc_control,_rpc_control)
91 #endif
92 
93 /* __svc_xports[-1] is reserved for raw */
94 SVCXPRT **__svc_xports;
95 int __svc_maxxports;
96 int __svc_maxrec;
97 
98 #define	RQCRED_SIZE	400		/* this size is excessive */
99 
100 #define SVC_VERSQUIET 0x0001		/* keep quiet about vers mismatch */
101 #define version_keepquiet(xp) ((u_long)(xp)->xp_p3 & SVC_VERSQUIET)
102 
103 #define max(a, b) (a > b ? a : b)
104 
105 /*
106  * The services list
107  * Each entry represents a set of procedures (an rpc program).
108  * The dispatch routine takes request structs and runs the
109  * apropriate procedure.
110  */
111 static struct svc_callout {
112 	struct svc_callout *sc_next;
113 	rpcprog_t	    sc_prog;
114 	rpcvers_t	    sc_vers;
115 	char		   *sc_netid;
116 	void		    (*sc_dispatch)(struct svc_req *, SVCXPRT *);
117 } *svc_head;
118 
119 #ifdef _REENTRANT
120 extern rwlock_t svc_lock;
121 extern rwlock_t svc_fd_lock;
122 #endif
123 
124 static struct svc_callout *svc_find(rpcprog_t, rpcvers_t,
125 					 struct svc_callout **, char *);
126 static void __xprt_do_unregister(SVCXPRT *xprt, bool_t dolock);
127 
128 /* ***************  SVCXPRT related stuff **************** */
129 
130 static bool_t
131 xprt_alloc(int sock)
132 {
133 	int oldmaxxports, newmaxxports;
134 	SVCXPRT **oldxports, **newxports;
135 
136 	if (++sock < 0)
137 		return FALSE;
138 
139 	newmaxxports = svc_fdset_getsize(sock);
140 	if (newmaxxports == -1)
141 		return FALSE;
142 
143 	if (__svc_xports != NULL && newmaxxports < __svc_maxxports)
144 		return TRUE;
145 
146 	oldxports = __svc_xports;
147 	oldmaxxports = __svc_maxxports;
148 	if (oldxports != NULL) {
149 		/* revert saving [-1] slot */
150 		--oldxports;
151 		++oldmaxxports;
152 	}
153 
154 	/* reserve an extra slot for [-1] */
155 	newmaxxports++;
156 	newxports = realloc(oldxports, newmaxxports * sizeof(SVCXPRT *));
157 	if (newxports == NULL) {
158 		warn("%s: out of memory", __func__);
159 		return FALSE;
160 	}
161 
162 	memset(&newxports[oldmaxxports], 0,
163 	    (newmaxxports - oldmaxxports) * sizeof(SVCXPRT *));
164 
165 	/* save one slot for [-1] */
166 	__svc_xports = newxports + 1;
167 	__svc_maxxports = newmaxxports - 1;
168 
169 	return TRUE;
170 }
171 
172 /*
173  * Activate a transport handle.
174  */
175 bool_t
176 xprt_register(SVCXPRT *xprt)
177 {
178 	int sock;
179 
180 	_DIAGASSERT(xprt != NULL);
181 
182 	rwlock_wrlock(&svc_fd_lock);
183 	sock = xprt->xp_fd;
184 
185 	if (!xprt_alloc(sock))
186 		goto out;
187 
188 	__svc_xports[sock] = xprt;
189 	if (sock != -1) {
190 		if (svc_fdset_set(sock) == -1)
191 			return FALSE;
192 	}
193 	rwlock_unlock(&svc_fd_lock);
194 	return (TRUE);
195 
196 out:
197 	rwlock_unlock(&svc_fd_lock);
198 	return (FALSE);
199 }
200 
201 void
202 xprt_unregister(SVCXPRT *xprt)
203 {
204 	__xprt_do_unregister(xprt, TRUE);
205 }
206 
207 void
208 __xprt_unregister_unlocked(SVCXPRT *xprt)
209 {
210 	__xprt_do_unregister(xprt, FALSE);
211 }
212 
213 /*
214  * De-activate a transport handle.
215  */
216 static void
217 __xprt_do_unregister(SVCXPRT *xprt, bool_t dolock)
218 {
219 	int sock, *fdmax;
220 
221 	_DIAGASSERT(xprt != NULL);
222 
223 	if (dolock)
224 		rwlock_wrlock(&svc_fd_lock);
225 
226 	sock = xprt->xp_fd;
227 	if (sock >= __svc_maxxports || __svc_xports[sock] != xprt)
228 		goto out;
229 
230 	__svc_xports[sock] = NULL;
231 	if (sock == -1)
232 		goto out;
233 	fdmax = svc_fdset_getmax();
234 	if (fdmax == NULL || sock < *fdmax)
235 		goto clr;
236 
237 	for ((*fdmax)--; *fdmax >= 0; (*fdmax)--)
238 		if (__svc_xports[*fdmax])
239 			break;
240 clr:
241 	svc_fdset_clr(sock);
242 out:
243 	if (dolock)
244 		rwlock_unlock(&svc_fd_lock);
245 }
246 
247 /*
248  * Add a service program to the callout list.
249  * The dispatch routine will be called when a rpc request for this
250  * program number comes in.
251  */
252 bool_t
253 svc_reg(SVCXPRT *xprt, const rpcprog_t prog, const rpcvers_t vers,
254 	void (*dispatch)(struct svc_req *, SVCXPRT *),
255 	const struct netconfig *nconf)
256 {
257 	bool_t dummy;
258 	struct svc_callout *prev;
259 	struct svc_callout *s;
260 	struct netconfig *tnconf;
261 	char *netid = NULL;
262 	int flag = 0;
263 
264 	_DIAGASSERT(xprt != NULL);
265 	/* XXX: dispatch may be NULL ??? */
266 
267 /* VARIABLES PROTECTED BY svc_lock: s, prev, svc_head */
268 
269 	if (xprt->xp_netid) {
270 		netid = strdup(xprt->xp_netid);
271 		flag = 1;
272 	} else if (nconf && nconf->nc_netid) {
273 		netid = strdup(nconf->nc_netid);
274 		flag = 1;
275 	} else if ((tnconf = __rpcgettp(xprt->xp_fd)) != NULL) {
276 		netid = strdup(tnconf->nc_netid);
277 		flag = 1;
278 		freenetconfigent(tnconf);
279 	} /* must have been created with svc_raw_create */
280 	if ((netid == NULL) && (flag == 1)) {
281 		return (FALSE);
282 	}
283 
284 	rwlock_wrlock(&svc_lock);
285 	if ((s = svc_find(prog, vers, &prev, netid)) != NULL) {
286 		if (netid)
287 			free(netid);
288 		if (s->sc_dispatch == dispatch)
289 			goto rpcb_it; /* he is registering another xptr */
290 		rwlock_unlock(&svc_lock);
291 		return (FALSE);
292 	}
293 	s = mem_alloc(sizeof (struct svc_callout));
294 	if (s == NULL) {
295 		if (netid)
296 			free(netid);
297 		rwlock_unlock(&svc_lock);
298 		return (FALSE);
299 	}
300 
301 	if ((xprt->xp_netid == NULL) && (flag == 1) && netid)
302 		if ((((SVCXPRT *) xprt)->xp_netid = strdup(netid)) == NULL) {
303 			warn("svc_reg");
304 			mem_free(s, sizeof(struct svc_callout));
305 			rwlock_unlock(&svc_lock);
306 			return FALSE;
307 		}
308 
309 	s->sc_prog = prog;
310 	s->sc_vers = vers;
311 	s->sc_dispatch = dispatch;
312 	s->sc_netid = netid;
313 	s->sc_next = svc_head;
314 	svc_head = s;
315 
316 rpcb_it:
317 	rwlock_unlock(&svc_lock);
318 	/* now register the information with the local binder service */
319 	if (nconf) {
320 		dummy = rpcb_set(prog, vers, __UNCONST(nconf),
321 		&((SVCXPRT *) xprt)->xp_ltaddr);
322 		return (dummy);
323 	}
324 	return (TRUE);
325 }
326 
327 /*
328  * Remove a service program from the callout list.
329  */
330 void
331 svc_unreg(const rpcprog_t prog, const rpcvers_t vers)
332 {
333 	struct svc_callout *prev;
334 	struct svc_callout *s;
335 
336 	/* unregister the information anyway */
337 	(void) rpcb_unset(prog, vers, NULL);
338 	rwlock_wrlock(&svc_lock);
339 	while ((s = svc_find(prog, vers, &prev, NULL)) != NULL) {
340 		if (prev == NULL) {
341 			svc_head = s->sc_next;
342 		} else {
343 			prev->sc_next = s->sc_next;
344 		}
345 		s->sc_next = NULL;
346 		if (s->sc_netid)
347 			mem_free(s->sc_netid, sizeof (s->sc_netid) + 1);
348 		mem_free(s, sizeof (struct svc_callout));
349 	}
350 	rwlock_unlock(&svc_lock);
351 }
352 
353 /* ********************** CALLOUT list related stuff ************* */
354 
355 #ifdef PORTMAP
356 /*
357  * Add a service program to the callout list.
358  * The dispatch routine will be called when a rpc request for this
359  * program number comes in.
360  */
361 bool_t
362 svc_register(SVCXPRT *xprt, u_long prog, u_long vers,
363 	void (*dispatch)(struct svc_req *, SVCXPRT *), int protocol)
364 {
365 	struct svc_callout *prev;
366 	struct svc_callout *s;
367 
368 	_DIAGASSERT(xprt != NULL);
369 	_DIAGASSERT(dispatch != NULL);
370 
371 	if ((s = svc_find((rpcprog_t)prog, (rpcvers_t)vers, &prev, NULL)) !=
372 	    NULL) {
373 		if (s->sc_dispatch == dispatch)
374 			goto pmap_it;  /* he is registering another xptr */
375 		return (FALSE);
376 	}
377 	s = mem_alloc(sizeof(struct svc_callout));
378 	if (s == NULL) {
379 		return (FALSE);
380 	}
381 	s->sc_prog = (rpcprog_t)prog;
382 	s->sc_vers = (rpcvers_t)vers;
383 	s->sc_dispatch = dispatch;
384 	s->sc_next = svc_head;
385 	svc_head = s;
386 pmap_it:
387 	/* now register the information with the local binder service */
388 	if (protocol) {
389 		return (pmap_set(prog, vers, protocol, xprt->xp_port));
390 	}
391 	return (TRUE);
392 }
393 
394 /*
395  * Remove a service program from the callout list.
396  */
397 void
398 svc_unregister(u_long prog, u_long vers)
399 {
400 	struct svc_callout *prev;
401 	struct svc_callout *s;
402 
403 	if ((s = svc_find((rpcprog_t)prog, (rpcvers_t)vers, &prev, NULL)) ==
404 	    NULL)
405 		return;
406 	if (prev == NULL) {
407 		svc_head = s->sc_next;
408 	} else {
409 		prev->sc_next = s->sc_next;
410 	}
411 	s->sc_next = NULL;
412 	mem_free(s, sizeof(struct svc_callout));
413 	/* now unregister the information with the local binder service */
414 	(void)pmap_unset(prog, vers);
415 }
416 #endif /* PORTMAP */
417 
418 /*
419  * Search the callout list for a program number, return the callout
420  * struct.
421  */
422 static struct svc_callout *
423 svc_find(rpcprog_t prog, rpcvers_t vers, struct svc_callout **prev, char *netid)
424 {
425 	struct svc_callout *s, *p;
426 
427 	_DIAGASSERT(prev != NULL);
428 	/* netid is handled below */
429 
430 	p = NULL;
431 	for (s = svc_head; s != NULL; s = s->sc_next) {
432 		if (((s->sc_prog == prog) && (s->sc_vers == vers)) &&
433 		    ((netid == NULL) || (s->sc_netid == NULL) ||
434 		    (strcmp(netid, s->sc_netid) == 0)))
435 			break;
436 		p = s;
437 	}
438 	*prev = p;
439 	return (s);
440 }
441 
442 /* ******************* REPLY GENERATION ROUTINES  ************ */
443 
444 /*
445  * Send a reply to an rpc request
446  */
447 bool_t
448 svc_sendreply(SVCXPRT *xprt, xdrproc_t xdr_results, const char *xdr_location)
449 {
450 	struct rpc_msg rply;
451 
452 	_DIAGASSERT(xprt != NULL);
453 
454 	rply.rm_direction = REPLY;
455 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
456 	rply.acpted_rply.ar_verf = xprt->xp_verf;
457 	rply.acpted_rply.ar_stat = SUCCESS;
458 	rply.acpted_rply.ar_results.where = xdr_location;
459 	rply.acpted_rply.ar_results.proc = xdr_results;
460 	return (SVC_REPLY(xprt, &rply));
461 }
462 
463 /*
464  * No procedure error reply
465  */
466 void
467 svcerr_noproc(SVCXPRT *xprt)
468 {
469 	struct rpc_msg rply;
470 
471 	_DIAGASSERT(xprt != NULL);
472 
473 	rply.rm_direction = REPLY;
474 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
475 	rply.acpted_rply.ar_verf = xprt->xp_verf;
476 	rply.acpted_rply.ar_stat = PROC_UNAVAIL;
477 	SVC_REPLY(xprt, &rply);
478 }
479 
480 /*
481  * Can't decode args error reply
482  */
483 void
484 svcerr_decode(SVCXPRT *xprt)
485 {
486 	struct rpc_msg rply;
487 
488 	_DIAGASSERT(xprt != NULL);
489 
490 	rply.rm_direction = REPLY;
491 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
492 	rply.acpted_rply.ar_verf = xprt->xp_verf;
493 	rply.acpted_rply.ar_stat = GARBAGE_ARGS;
494 	SVC_REPLY(xprt, &rply);
495 }
496 
497 /*
498  * Some system error
499  */
500 void
501 svcerr_systemerr(SVCXPRT *xprt)
502 {
503 	struct rpc_msg rply;
504 
505 	_DIAGASSERT(xprt != NULL);
506 
507 	rply.rm_direction = REPLY;
508 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
509 	rply.acpted_rply.ar_verf = xprt->xp_verf;
510 	rply.acpted_rply.ar_stat = SYSTEM_ERR;
511 	SVC_REPLY(xprt, &rply);
512 }
513 
514 #if 0
515 /*
516  * Tell RPC package to not complain about version errors to the client.	 This
517  * is useful when revving broadcast protocols that sit on a fixed address.
518  * There is really one (or should be only one) example of this kind of
519  * protocol: the portmapper (or rpc binder).
520  */
521 void
522 __svc_versquiet_on(SVCXPRT *xprt)
523 {
524 	u_long	tmp;
525 
526 	_DIAGASSERT(xprt != NULL);
527 
528 	tmp = ((u_long) xprt->xp_p3) | SVC_VERSQUIET;
529 	xprt->xp_p3 = (caddr_t) tmp;
530 }
531 
532 void
533 __svc_versquiet_off(SVCXPRT *xprt)
534 {
535 	u_long	tmp;
536 
537 	_DIAGASSERT(xprt != NULL);
538 
539 	tmp = ((u_long) xprt->xp_p3) & ~SVC_VERSQUIET;
540 	xprt->xp_p3 = (caddr_t) tmp;
541 }
542 
543 void
544 svc_versquiet(SVCXPRT *xprt)
545 {
546 	__svc_versquiet_on(xprt);
547 }
548 
549 int
550 __svc_versquiet_get(SVCXPRT *xprt)
551 {
552 
553 	_DIAGASSERT(xprt != NULL);
554 
555 	return ((int) xprt->xp_p3) & SVC_VERSQUIET;
556 }
557 #endif
558 
559 /*
560  * Authentication error reply
561  */
562 void
563 svcerr_auth(SVCXPRT *xprt, enum auth_stat why)
564 {
565 	struct rpc_msg rply;
566 
567 	_DIAGASSERT(xprt != NULL);
568 
569 	rply.rm_direction = REPLY;
570 	rply.rm_reply.rp_stat = MSG_DENIED;
571 	rply.rjcted_rply.rj_stat = AUTH_ERROR;
572 	rply.rjcted_rply.rj_why = why;
573 	SVC_REPLY(xprt, &rply);
574 }
575 
576 /*
577  * Auth too weak error reply
578  */
579 void
580 svcerr_weakauth(SVCXPRT *xprt)
581 {
582 
583 	_DIAGASSERT(xprt != NULL);
584 
585 	svcerr_auth(xprt, AUTH_TOOWEAK);
586 }
587 
588 /*
589  * Program unavailable error reply
590  */
591 void
592 svcerr_noprog(SVCXPRT *xprt)
593 {
594 	struct rpc_msg rply;
595 
596 	_DIAGASSERT(xprt != NULL);
597 
598 	rply.rm_direction = REPLY;
599 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
600 	rply.acpted_rply.ar_verf = xprt->xp_verf;
601 	rply.acpted_rply.ar_stat = PROG_UNAVAIL;
602 	SVC_REPLY(xprt, &rply);
603 }
604 
605 /*
606  * Program version mismatch error reply
607  */
608 void
609 svcerr_progvers(SVCXPRT *xprt, rpcvers_t low_vers, rpcvers_t high_vers)
610 {
611 	struct rpc_msg rply;
612 
613 	_DIAGASSERT(xprt != NULL);
614 
615 	rply.rm_direction = REPLY;
616 	rply.rm_reply.rp_stat = MSG_ACCEPTED;
617 	rply.acpted_rply.ar_verf = xprt->xp_verf;
618 	rply.acpted_rply.ar_stat = PROG_MISMATCH;
619 	rply.acpted_rply.ar_vers.low = (u_int32_t)low_vers;
620 	rply.acpted_rply.ar_vers.high = (u_int32_t)high_vers;
621 	SVC_REPLY(xprt, &rply);
622 }
623 
624 /* ******************* SERVER INPUT STUFF ******************* */
625 
626 /*
627  * Get server side input from some transport.
628  *
629  * Statement of authentication parameters management:
630  * This function owns and manages all authentication parameters, specifically
631  * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
632  * the "cooked" credentials (rqst->rq_clntcred).
633  * However, this function does not know the structure of the cooked
634  * credentials, so it make the following assumptions:
635  *   a) the structure is contiguous (no pointers), and
636  *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
637  * In all events, all three parameters are freed upon exit from this routine.
638  * The storage is trivially management on the call stack in user land, but
639  * is mallocated in kernel land.
640  */
641 
642 void
643 svc_getreq(int rdfds)
644 {
645 	fd_set *readfds = svc_fdset_copy(NULL);
646 	if (readfds == NULL)
647 		return;
648 
649 	readfds->fds_bits[0] = (unsigned int)rdfds;
650 	svc_getreqset(readfds);
651 	free(readfds);
652 }
653 
654 void
655 svc_getreqset2(fd_set *readfds, int maxsize)
656 {
657 	uint32_t mask, *maskp;
658 	int sock, bit, fd;
659 
660 	_DIAGASSERT(readfds != NULL);
661 
662 	maskp = readfds->fds_bits;
663 	for (sock = 0; sock < maxsize; sock += NFDBITS) {
664 	    for (mask = *maskp++; (bit = ffs((int)mask)) != 0;
665 		mask ^= (1 << (bit - 1))) {
666 		/* sock has input waiting */
667 		fd = sock + bit - 1;
668 		svc_getreq_common(fd);
669 	    }
670 	}
671 }
672 
673 void
674 svc_getreqset(fd_set *readfds)
675 {
676 	svc_getreqset2(readfds, FD_SETSIZE);
677 }
678 
679 void
680 svc_getreq_common(int fd)
681 {
682 	SVCXPRT *xprt;
683 	struct svc_req r;
684 	struct rpc_msg msg;
685 	int prog_found;
686 	rpcvers_t low_vers;
687 	rpcvers_t high_vers;
688 	enum xprt_stat stat;
689 	char cred_area[2*MAX_AUTH_BYTES + RQCRED_SIZE];
690 
691 	msg.rm_call.cb_cred.oa_base = cred_area;
692 	msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
693 	r.rq_clntcred = &(cred_area[2*MAX_AUTH_BYTES]);
694 
695 	rwlock_rdlock(&svc_fd_lock);
696 	xprt = __svc_xports[fd];
697 	rwlock_unlock(&svc_fd_lock);
698 	if (xprt == NULL)
699 		/* But do we control sock? */
700 		return;
701 	/* now receive msgs from xprtprt (support batch calls) */
702 	do {
703 		if (SVC_RECV(xprt, &msg)) {
704 
705 			/* now find the exported program and call it */
706 			struct svc_callout *s;
707 			enum auth_stat why;
708 
709 			r.rq_xprt = xprt;
710 			r.rq_prog = msg.rm_call.cb_prog;
711 			r.rq_vers = msg.rm_call.cb_vers;
712 			r.rq_proc = msg.rm_call.cb_proc;
713 			r.rq_cred = msg.rm_call.cb_cred;
714 			/* first authenticate the message */
715 			if ((why = _authenticate(&r, &msg)) != AUTH_OK) {
716 				svcerr_auth(xprt, why);
717 				goto call_done;
718 			}
719 			/* now match message with a registered service*/
720 			prog_found = FALSE;
721 			low_vers = (rpcvers_t) -1L;
722 			high_vers = (rpcvers_t) 0L;
723 			for (s = svc_head; s != NULL; s = s->sc_next) {
724 				if (s->sc_prog == r.rq_prog) {
725 					if (s->sc_vers == r.rq_vers) {
726 						(*s->sc_dispatch)(&r, xprt);
727 						goto call_done;
728 					}  /* found correct version */
729 					prog_found = TRUE;
730 					if (s->sc_vers < low_vers)
731 						low_vers = s->sc_vers;
732 					if (s->sc_vers > high_vers)
733 						high_vers = s->sc_vers;
734 				}   /* found correct program */
735 			}
736 			/*
737 			 * if we got here, the program or version
738 			 * is not served ...
739 			 */
740 			if (prog_found)
741 				svcerr_progvers(xprt, low_vers, high_vers);
742 			else
743 				 svcerr_noprog(xprt);
744 			/* Fall through to ... */
745 		}
746 		/*
747 		 * Check if the xprt has been disconnected in a
748 		 * recursive call in the service dispatch routine.
749 		 * If so, then break.
750 		 */
751 		rwlock_rdlock(&svc_fd_lock);
752 		if (xprt != __svc_xports[fd]) {
753 			rwlock_unlock(&svc_fd_lock);
754 			break;
755 		}
756 		rwlock_unlock(&svc_fd_lock);
757 call_done:
758 		if ((stat = SVC_STAT(xprt)) == XPRT_DIED){
759 			SVC_DESTROY(xprt);
760 			break;
761 		}
762 	} while (stat == XPRT_MOREREQS);
763 }
764 
765 
766 void
767 svc_getreq_poll(struct pollfd *pfdp, int pollretval)
768 {
769 	int i;
770 	int fds_found;
771 
772 	_DIAGASSERT(pfdp != NULL);
773 
774 	for (i = fds_found = 0; fds_found < pollretval; i++) {
775 		struct pollfd *p = &pfdp[i];
776 
777 		if (p->revents) {
778 			/* fd has input waiting */
779 			fds_found++;
780 			/*
781 			 *	We assume that this function is only called
782 			 *	via someone select()ing from svc_fdset or
783 			 *	pollts()ing from svc_pollset[].  Thus it's safe
784 			 *	to handle the POLLNVAL event by simply turning
785 			 *	the corresponding bit off in the fdset.  The
786 			 *	svc_pollset[] array is derived from svc_fdset
787 			 *	and so will also be updated eventually.
788 			 *
789 			 *	XXX Should we do an xprt_unregister() instead?
790 			 */
791 			if (p->revents & POLLNVAL) {
792 				rwlock_wrlock(&svc_fd_lock);
793 				svc_fdset_clr(p->fd);
794 				rwlock_unlock(&svc_fd_lock);
795 			} else
796 				svc_getreq_common(p->fd);
797 		}
798 	}
799 }
800 
801 bool_t
802 rpc_control(int what, void *arg)
803 {
804 	int val;
805 
806 	switch (what) {
807 	case RPC_SVC_CONNMAXREC_SET:
808 		val = *(int *)arg;
809 		if (val <= 0)
810 			return FALSE;
811 		__svc_maxrec = val;
812 		return TRUE;
813 	case RPC_SVC_CONNMAXREC_GET:
814 		*(int *)arg = __svc_maxrec;
815 		return TRUE;
816 	default:
817 		break;
818 	}
819 	return FALSE;
820 }
821