xref: /openbsd/usr.sbin/portmap/portmap.c (revision 7b36286a)
1 /*	$OpenBSD: portmap.c,v 1.36 2006/03/18 00:40:14 dhill Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1997 Theo de Raadt (OpenBSD). All rights reserved.
5  * Copyright (c) 1990 The Regents of the University of California.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 char copyright[] =
35 "@(#) Copyright (c) 1990 The Regents of the University of California.\n\
36  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "from: @(#)portmap.c	5.4 (Berkeley) 4/19/91";
42 #else
43 static char rcsid[] = "$OpenBSD: portmap.c,v 1.36 2006/03/18 00:40:14 dhill Exp $";
44 #endif
45 #endif /* not lint */
46 
47 /*
48 @(#)portmap.c	2.3 88/08/11 4.0 RPCSRC
49 static char sccsid[] = "@(#)portmap.c 1.32 87/08/06 Copyr 1984 Sun Micro";
50 */
51 
52 /*
53  * portmap.c, Implements the program,version to port number mapping for
54  * rpc.
55  */
56 
57 /*
58  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
59  * unrestricted use provided that this legend is included on all tape
60  * media and as a part of the software program in whole or part.  Users
61  * may copy or modify Sun RPC without charge, but are not authorized
62  * to license or distribute it to anyone else except as part of a product or
63  * program developed by the user.
64  *
65  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
66  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
67  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
68  *
69  * Sun RPC is provided with no support and without any obligation on the
70  * part of Sun Microsystems, Inc. to assist in its use, correction,
71  * modification or enhancement.
72  *
73  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
74  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
75  * OR ANY PART THEREOF.
76  *
77  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
78  * or profits or other special, indirect and consequential damages, even if
79  * Sun has been advised of the possibility of such damages.
80  *
81  * Sun Microsystems, Inc.
82  * 2550 Garcia Avenue
83  * Mountain View, California  94043
84  */
85 
86 #include <sys/types.h>
87 #include <sys/socket.h>
88 #include <sys/ioctl.h>
89 #include <sys/wait.h>
90 #include <sys/resource.h>
91 
92 #include <rpcsvc/nfs_prot.h>
93 #include <arpa/inet.h>
94 #include <rpc/rpc.h>
95 #include <rpc/pmap_prot.h>
96 
97 #include <signal.h>
98 #include <stdio.h>
99 #include <stdlib.h>
100 #include <string.h>
101 #include <syslog.h>
102 #include <unistd.h>
103 #include <netdb.h>
104 #include <pwd.h>
105 #include <errno.h>
106 
107 void reg_service(struct svc_req *, SVCXPRT *);
108 void reap(int);
109 void callit(struct svc_req *, SVCXPRT *);
110 int check_callit(struct sockaddr_in *, u_long, u_long);
111 struct pmaplist *find_service(u_long, u_long, u_long);
112 
113 struct pmaplist *pmaplist;
114 int debugging = 0;
115 
116 SVCXPRT *ludpxprt, *ltcpxprt;
117 
118 int
119 main(int argc, char *argv[])
120 {
121 	int sock, lsock, c, on = 1, len = sizeof(struct sockaddr_in);
122 	struct sockaddr_in addr, laddr;
123 	struct pmaplist *pml;
124 	struct passwd *pw;
125 	SVCXPRT *xprt;
126 
127 	while ((c = getopt(argc, argv, "d")) != -1) {
128 		switch (c) {
129 
130 		case 'd':
131 			debugging = 1;
132 			break;
133 
134 		default:
135 			(void) fprintf(stderr, "usage: %s [-d]\n", argv[0]);
136 			exit(1);
137 		}
138 	}
139 
140 	if (!debugging && daemon(0, 0)) {
141 		(void) fprintf(stderr, "portmap: fork: %s", strerror(errno));
142 		exit(1);
143 	}
144 
145 	openlog("portmap", LOG_NDELAY | (debugging ? LOG_PID | LOG_PERROR : LOG_PID),
146 	    LOG_DAEMON);
147 
148 	bzero((char *)&addr, sizeof addr);
149 	addr.sin_addr.s_addr = 0;
150 	addr.sin_family = AF_INET;
151 	addr.sin_addr.s_addr = htonl(INADDR_ANY);
152 	addr.sin_port = htons(PMAPPORT);
153 
154 	bzero((char *)&laddr, sizeof laddr);
155 	laddr.sin_addr.s_addr = 0;
156 	laddr.sin_family = AF_INET;
157 	laddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
158 	laddr.sin_port = htons(PMAPPORT);
159 
160 	if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
161 		syslog(LOG_ERR, "cannot create udp socket: %m");
162 		exit(1);
163 	}
164 	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
165 	if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
166 		syslog(LOG_ERR, "cannot bind udp: %m");
167 		exit(1);
168 	}
169 
170 	if ((xprt = svcudp_create(sock)) == (SVCXPRT *)NULL) {
171 		syslog(LOG_ERR, "couldn't do udp_create");
172 		exit(1);
173 	}
174 
175 	if ((lsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
176 		syslog(LOG_ERR, "cannot create udp socket: %m");
177 		exit(1);
178 	}
179 	setsockopt(lsock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
180 	if (bind(lsock, (struct sockaddr *)&laddr, len) != 0) {
181 		syslog(LOG_ERR, "cannot bind local udp: %m");
182 		exit(1);
183 	}
184 
185 	if ((ludpxprt = svcudp_create(lsock)) == (SVCXPRT *)NULL) {
186 		syslog(LOG_ERR, "couldn't do udp_create");
187 		exit(1);
188 	}
189 
190 	/* make an entry for ourself */
191 	pml = (struct pmaplist *)malloc((u_int)sizeof(struct pmaplist));
192 	if (pml == NULL) {
193 		syslog(LOG_ERR, "out of memory");
194 		exit(1);
195 	}
196 	pml->pml_next = 0;
197 	pml->pml_map.pm_prog = PMAPPROG;
198 	pml->pml_map.pm_vers = PMAPVERS;
199 	pml->pml_map.pm_prot = IPPROTO_UDP;
200 	pml->pml_map.pm_port = PMAPPORT;
201 	pmaplist = pml;
202 
203 	if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
204 		syslog(LOG_ERR, "cannot create tcp socket: %m");
205 		exit(1);
206 	}
207 	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
208 	if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
209 		syslog(LOG_ERR, "cannot bind tcp: %m");
210 		exit(1);
211 	}
212 	if ((xprt = svctcp_create(sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE))
213 	    == (SVCXPRT *)NULL) {
214 		syslog(LOG_ERR, "couldn't do tcp_create");
215 		exit(1);
216 	}
217 
218 	if ((lsock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
219 		syslog(LOG_ERR, "cannot create tcp socket: %m");
220 		exit(1);
221 	}
222 	setsockopt(lsock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
223 	if (bind(lsock, (struct sockaddr *)&laddr, len) != 0) {
224 		syslog(LOG_ERR, "cannot bind tcp: %m");
225 		exit(1);
226 	}
227 	if ((ltcpxprt = svctcp_create(lsock, RPCSMALLMSGSIZE,
228 	    RPCSMALLMSGSIZE)) == (SVCXPRT *)NULL) {
229 		syslog(LOG_ERR, "couldn't do tcp_create");
230 		exit(1);
231 	}
232 
233 	/* make an entry for ourself */
234 	pml = (struct pmaplist *)malloc((u_int)sizeof(struct pmaplist));
235 	if (pml == NULL) {
236 		syslog(LOG_ERR, "out of memory");
237 		exit(1);
238 	}
239 	pml->pml_map.pm_prog = PMAPPROG;
240 	pml->pml_map.pm_vers = PMAPVERS;
241 	pml->pml_map.pm_prot = IPPROTO_TCP;
242 	pml->pml_map.pm_port = PMAPPORT;
243 	pml->pml_next = pmaplist;
244 	pmaplist = pml;
245 
246 	pw = getpwnam("_portmap");
247 	if (!pw)
248 		pw = getpwnam("nobody");
249 	if (chroot("/var/empty") == -1) {
250 		syslog(LOG_ERR, "cannot chdir to /var/empty.");
251 		exit(1);
252 	}
253 	chdir("/");
254 	if (pw) {
255 		if (setgroups(1, &pw->pw_gid) == -1 ||
256 		    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1 ||
257 		    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) {
258 			syslog(LOG_ERR, "revoke privs: %s", strerror(errno));
259 			exit(1);
260 		}
261 	}
262 	endpwent();
263 
264 	if (svc_register(xprt, PMAPPROG, PMAPVERS, reg_service, FALSE) == 0) {
265 		syslog(LOG_ERR, "svc_register failed.");
266 		exit(1);
267 	}
268 
269 	(void)signal(SIGCHLD, reap);
270 	svc_run();
271 	syslog(LOG_ERR, "svc_run returned unexpectedly");
272 	abort();
273 }
274 
275 #ifndef lint
276 /* need to override perror calls in rpc library */
277 void
278 perror(const char *what)
279 {
280 
281 	syslog(LOG_ERR, "%s: %m", what);
282 }
283 #endif
284 
285 struct pmaplist *
286 find_service(u_long prog, u_long vers, u_long prot)
287 {
288 	struct pmaplist *hit = NULL;
289 	struct pmaplist *pml;
290 
291 	for (pml = pmaplist; pml != NULL; pml = pml->pml_next) {
292 		if ((pml->pml_map.pm_prog != prog) ||
293 		    (pml->pml_map.pm_prot != prot))
294 			continue;
295 		hit = pml;
296 		if (pml->pml_map.pm_vers == vers)
297 			break;
298 	}
299 	return (hit);
300 }
301 
302 /*
303  * 1 OK, 0 not
304  */
305 void
306 reg_service(struct svc_req *rqstp, SVCXPRT *xprt)
307 {
308 	struct pmap reg;
309 	struct pmaplist *pml, *prevpml, *fnd;
310 	struct sockaddr_in *fromsin;
311 	long ans = 0, port;
312 	caddr_t t;
313 
314 	fromsin = svc_getcaller(xprt);
315 
316 	if (debugging)
317 		(void) fprintf(stderr, "server: about to do a switch\n");
318 	switch (rqstp->rq_proc) {
319 
320 	case PMAPPROC_NULL:
321 		/*
322 		 * Null proc call
323 		 */
324 		if (!svc_sendreply(xprt, xdr_void, (caddr_t)0) && debugging) {
325 			abort();
326 		}
327 		break;
328 
329 	case PMAPPROC_SET:
330 		/*
331 		 * Set a program,version to port mapping
332 		 */
333 		if (xprt != ltcpxprt && xprt != ludpxprt) {
334 			syslog(LOG_WARNING,
335 			    "non-local set attempt (might be from %s)",
336 			    inet_ntoa(fromsin->sin_addr));
337 			svcerr_noproc(xprt);
338 			return;
339 		}
340 		if (!svc_getargs(xprt, xdr_pmap, (caddr_t)&reg)) {
341 			svcerr_decode(xprt);
342 			break;
343 		}
344 
345 		/*
346 		 * check to see if already used
347 		 * find_service returns a hit even if
348 		 * the versions don't match, so check for it
349 		 */
350 		fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
351 		if (fnd && fnd->pml_map.pm_vers == reg.pm_vers) {
352 			if (fnd->pml_map.pm_port == reg.pm_port)
353 				ans = 1;
354 			goto done;
355 		}
356 
357 		if (debugging)
358 			printf("set: prog %lu vers %lu port %lu\n",
359 			    reg.pm_prog, reg.pm_vers, reg.pm_port);
360 
361 		if (reg.pm_port & ~0xffff)
362 			goto done;
363 
364 		/*
365 		 * only permit localhost root to create
366 		 * mappings pointing at sensitive ports
367 		 */
368 		if ((reg.pm_port < IPPORT_RESERVED ||
369 		    reg.pm_port == NFS_PORT) &&
370 		    htons(fromsin->sin_port) >= IPPORT_RESERVED) {
371 			syslog(LOG_WARNING,
372 			    "resvport set attempt by non-root");
373 			goto done;
374 		}
375 
376 		/*
377 		 * add to END of list
378 		 */
379 		pml = (struct pmaplist *)malloc(sizeof(struct pmaplist));
380 		if (pml == NULL) {
381 			syslog(LOG_ERR, "out of memory");
382 			svcerr_systemerr(xprt);
383 			return;
384 		}
385 
386 		pml->pml_map = reg;
387 		pml->pml_next = 0;
388 		if (pmaplist == 0) {
389 			pmaplist = pml;
390 		} else {
391 			for (fnd = pmaplist; fnd->pml_next != 0;
392 			    fnd = fnd->pml_next);
393 			fnd->pml_next = pml;
394 		}
395 		ans = 1;
396 	done:
397 		if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
398 		    debugging) {
399 			(void) fprintf(stderr, "svc_sendreply\n");
400 			abort();
401 		}
402 		break;
403 
404 	case PMAPPROC_UNSET:
405 		/*
406 		 * Remove a program,version to port mapping.
407 		 */
408 		if (xprt != ltcpxprt && xprt != ludpxprt) {
409 			syslog(LOG_WARNING,
410 			    "non-local unset attempt (might be from %s)",
411 			    inet_ntoa(fromsin->sin_addr));
412 			svcerr_noproc(xprt);
413 			return;
414 		}
415 		if (!svc_getargs(xprt, xdr_pmap, (caddr_t)&reg)) {
416 			svcerr_decode(xprt);
417 			break;
418 		}
419 		for (prevpml = NULL, pml = pmaplist; pml != NULL; ) {
420 			if ((pml->pml_map.pm_prog != reg.pm_prog) ||
421 			    (pml->pml_map.pm_vers != reg.pm_vers)) {
422 				/* both pml & prevpml move forwards */
423 				prevpml = pml;
424 				pml = pml->pml_next;
425 				continue;
426 			}
427 			if ((pml->pml_map.pm_port < IPPORT_RESERVED ||
428 			    pml->pml_map.pm_port == NFS_PORT) &&
429 			    htons(fromsin->sin_port) >= IPPORT_RESERVED) {
430 				syslog(LOG_WARNING,
431 				    "resvport unset attempt by non-root");
432 				break;
433 			}
434 
435 			/* found it; pml moves forward, prevpml stays */
436 			ans = 1;
437 			t = (caddr_t)pml;
438 			pml = pml->pml_next;
439 			if (prevpml == NULL)
440 				pmaplist = pml;
441 			else
442 				prevpml->pml_next = pml;
443 			free(t);
444 		}
445 		if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
446 		    debugging) {
447 			fprintf(stderr, "svc_sendreply\n");
448 			abort();
449 		}
450 		break;
451 
452 	case PMAPPROC_GETPORT:
453 		/*
454 		 * Lookup the mapping for a program,version and return its port
455 		 */
456 		if (!svc_getargs(xprt, xdr_pmap, (caddr_t)&reg)) {
457 			svcerr_decode(xprt);
458 			break;
459 		}
460 		fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
461 		if (fnd)
462 			port = fnd->pml_map.pm_port;
463 		else
464 			port = 0;
465 		if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&port)) &&
466 		    debugging) {
467 			fprintf(stderr, "svc_sendreply\n");
468 			abort();
469 		}
470 		break;
471 
472 	case PMAPPROC_DUMP:
473 		/*
474 		 * Return the current set of mapped program,version
475 		 */
476 		if (!svc_getargs(xprt, xdr_void, NULL)) {
477 			svcerr_decode(xprt);
478 			break;
479 		}
480 		if (!svc_sendreply(xprt, xdr_pmaplist, (caddr_t)&pmaplist) &&
481 		    debugging) {
482 			fprintf(stderr, "svc_sendreply\n");
483 			abort();
484 		}
485 		break;
486 
487 	case PMAPPROC_CALLIT:
488 		/*
489 		 * Calls a procedure on the local machine.  If the requested
490 		 * procedure is not registered this procedure does not return
491 		 * error information!!
492 		 * This procedure is only supported on rpc/udp and calls via
493 		 * rpc/udp.  It passes null authentication parameters.
494 		 */
495 		callit(rqstp, xprt);
496 		break;
497 
498 	default:
499 		svcerr_noproc(xprt);
500 		break;
501 	}
502 }
503 
504 
505 /*
506  * Stuff for the rmtcall service
507  */
508 #define ARGSIZE 9000
509 
510 struct encap_parms {
511 	u_int arglen;
512 	char *args;
513 };
514 
515 static bool_t
516 xdr_encap_parms(XDR *xdrs, struct encap_parms *epp)
517 {
518 
519 	return (xdr_bytes(xdrs, &(epp->args), &(epp->arglen), ARGSIZE));
520 }
521 
522 struct rmtcallargs {
523 	u_long	rmt_prog;
524 	u_long	rmt_vers;
525 	u_long	rmt_port;
526 	u_long	rmt_proc;
527 	struct encap_parms rmt_args;
528 };
529 
530 static bool_t
531 xdr_rmtcall_args(XDR *xdrs, struct rmtcallargs *cap)
532 {
533 
534 	/* does not get a port number */
535 	if (xdr_u_long(xdrs, &(cap->rmt_prog)) &&
536 	    xdr_u_long(xdrs, &(cap->rmt_vers)) &&
537 	    xdr_u_long(xdrs, &(cap->rmt_proc))) {
538 		return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
539 	}
540 	return (FALSE);
541 }
542 
543 static bool_t
544 xdr_rmtcall_result(XDR *xdrs, struct rmtcallargs *cap)
545 {
546 	if (xdr_u_long(xdrs, &(cap->rmt_port)))
547 		return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
548 	return (FALSE);
549 }
550 
551 /*
552  * only worries about the struct encap_parms part of struct rmtcallargs.
553  * The arglen must already be set!!
554  */
555 static bool_t
556 xdr_opaque_parms(XDR *xdrs, struct rmtcallargs *cap)
557 {
558 
559 	return (xdr_opaque(xdrs, cap->rmt_args.args, cap->rmt_args.arglen));
560 }
561 
562 /*
563  * This routine finds and sets the length of incoming opaque paraters
564  * and then calls xdr_opaque_parms.
565  */
566 static bool_t
567 xdr_len_opaque_parms(XDR *xdrs, struct rmtcallargs *cap)
568 {
569 	u_int beginpos, lowpos, highpos, currpos, pos;
570 
571 	beginpos = lowpos = pos = xdr_getpos(xdrs);
572 	highpos = lowpos + ARGSIZE;
573 	while ((int)(highpos - lowpos) >= 0) {
574 		currpos = (lowpos + highpos) / 2;
575 		if (xdr_setpos(xdrs, currpos)) {
576 			pos = currpos;
577 			lowpos = currpos + 1;
578 		} else {
579 			highpos = currpos - 1;
580 		}
581 	}
582 	xdr_setpos(xdrs, beginpos);
583 	cap->rmt_args.arglen = pos - beginpos;
584 	return (xdr_opaque_parms(xdrs, cap));
585 }
586 
587 /*
588  * Call a remote procedure service
589  * This procedure is very quiet when things go wrong.
590  * The proc is written to support broadcast rpc.  In the broadcast case,
591  * a machine should shut-up instead of complain, less the requestor be
592  * overrun with complaints at the expense of not hearing a valid reply ...
593  *
594  * This now forks so that the program & process that it calls can call
595  * back to the portmapper.
596  */
597 void
598 callit(struct svc_req *rqstp, SVCXPRT *xprt)
599 {
600 	struct rmtcallargs a;
601 	struct pmaplist *pml;
602 	u_short port;
603 	struct sockaddr_in me;
604 	pid_t pid;
605 	int so = -1, dontblock = 1;
606 	CLIENT *client;
607 	struct authunix_parms *au = (struct authunix_parms *)rqstp->rq_clntcred;
608 	struct timeval timeout;
609 	char buf[ARGSIZE];
610 
611 	timeout.tv_sec = 5;
612 	timeout.tv_usec = 0;
613 	a.rmt_args.args = buf;
614 	if (!svc_getargs(xprt, xdr_rmtcall_args, (caddr_t)&a))
615 		return;
616 	if (!check_callit(svc_getcaller(xprt), a.rmt_prog, a.rmt_proc))
617 		return;
618 	if ((pml = find_service(a.rmt_prog, a.rmt_vers,
619 	    (u_long)IPPROTO_UDP)) == NULL)
620 		return;
621 
622 	/*
623 	 * fork a child to do the work.  Parent immediately returns.
624 	 * Child exits upon completion.
625 	 */
626 	if ((pid = fork()) != 0) {
627 		if (pid == -1)
628 			syslog(LOG_ERR, "CALLIT (prog %lu): fork: %m",
629 			    a.rmt_prog);
630 		return;
631 	}
632 	port = pml->pml_map.pm_port;
633 	get_myaddress(&me);
634 	me.sin_port = htons(port);
635 
636 	/* Avoid implicit binding to reserved port by clntudp_create() */
637 	so = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
638 	if (so == -1)
639 		exit(1);
640 	if (ioctl(so, FIONBIO, &dontblock) == -1)
641 		exit(1);
642 
643 	client = clntudp_create(&me, a.rmt_prog, a.rmt_vers, timeout, &so);
644 	if (client != (CLIENT *)NULL) {
645 		if (rqstp->rq_cred.oa_flavor == AUTH_UNIX)
646 			client->cl_auth = authunix_create(au->aup_machname,
647 			    au->aup_uid, au->aup_gid, au->aup_len, au->aup_gids);
648 		a.rmt_port = (u_long)port;
649 		if (clnt_call(client, a.rmt_proc, xdr_opaque_parms, &a,
650 		    xdr_len_opaque_parms, &a, timeout) == RPC_SUCCESS)
651 			svc_sendreply(xprt, xdr_rmtcall_result, (caddr_t)&a);
652 		AUTH_DESTROY(client->cl_auth);
653 		clnt_destroy(client);
654 	}
655 	(void)close(so);
656 	exit(0);
657 }
658 
659 /* ARGSUSED */
660 void
661 reap(int signo)
662 {
663 	int save_errno = errno;
664 
665 	while (wait3(NULL, WNOHANG, NULL) > 0)
666 		;
667 	errno = save_errno;
668 }
669 
670 #define	NFSPROG			((u_long) 100003)
671 #define	MOUNTPROG		((u_long) 100005)
672 #define	YPXPROG			((u_long) 100069)
673 #define	YPPROG			((u_long) 100004)
674 #define	YPPROC_DOMAIN_NONACK	((u_long) 2)
675 #define	MOUNTPROC_MNT		((u_long) 1)
676 #define XXXPROC_NOP		((u_long) 0)
677 
678 int
679 check_callit(struct sockaddr_in *addr, u_long prog, u_long aproc)
680 {
681 	if ((prog == PMAPPROG && aproc != XXXPROC_NOP) ||
682 	    (prog == NFSPROG && aproc != XXXPROC_NOP) ||
683 	    (prog == YPXPROG && aproc != XXXPROC_NOP) ||
684 	    (prog == MOUNTPROG && aproc == MOUNTPROC_MNT) ||
685 	    (prog == YPPROG && aproc != YPPROC_DOMAIN_NONACK)) {
686 		syslog(LOG_WARNING,
687 		    "callit prog %d aproc %d (might be from %s)",
688 		    (int)prog, (int)aproc, inet_ntoa(addr->sin_addr));
689 		return (FALSE);
690 	}
691 	return (TRUE);
692 }
693