xref: /netbsd/usr.sbin/ypbind/ypbind.c (revision bf9ec67e)
1 /*	$NetBSD: ypbind.c,v 1.46 2001/02/19 23:22:50 cgd Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993 Theo de Raadt <deraadt@fsa.ca>
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
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by Theo de Raadt.
18  * 4. The name of the author may not be used to endorse or promote
19  *    products derived from this software without specific prior written
20  *    permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
23  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
24  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
26  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef LINT
37 __RCSID("$NetBSD: ypbind.c,v 1.46 2001/02/19 23:22:50 cgd Exp $");
38 #endif
39 
40 #include <sys/param.h>
41 #include <sys/types.h>
42 #include <sys/ioctl.h>
43 #include <sys/signal.h>
44 #include <sys/socket.h>
45 #include <sys/file.h>
46 #include <sys/uio.h>
47 #include <sys/syslog.h>
48 #include <sys/stat.h>
49 #include <fcntl.h>
50 #include <limits.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <errno.h>
54 #include <syslog.h>
55 #if __STDC__
56 #include <stdarg.h>
57 #else
58 #include <varargs.h>
59 #endif
60 #include <ctype.h>
61 #include <dirent.h>
62 #include <netdb.h>
63 #include <string.h>
64 #include <err.h>
65 #include <rpc/rpc.h>
66 #include <rpc/xdr.h>
67 #include <net/if.h>
68 #include <arpa/inet.h>
69 #include <rpc/pmap_clnt.h>
70 #include <rpc/pmap_prot.h>
71 #include <rpc/pmap_rmt.h>
72 #include <unistd.h>
73 #include <util.h>
74 #include <rpcsvc/yp_prot.h>
75 #include <rpcsvc/ypclnt.h>
76 #include <ifaddrs.h>
77 
78 #include "pathnames.h"
79 
80 #ifndef O_SHLOCK
81 #define O_SHLOCK 0
82 #endif
83 
84 #define BUFSIZE		1400
85 
86 #define YPSERVERSSUFF	".ypservers"
87 #define BINDINGDIR	(_PATH_VAR_YP "binding")
88 
89 struct _dom_binding {
90 	struct _dom_binding *dom_pnext;
91 	char dom_domain[YPMAXDOMAIN + 1];
92 	struct sockaddr_in dom_server_addr;
93 	unsigned short int dom_server_port;
94 	int dom_socket;
95 	CLIENT *dom_client;
96 	long dom_vers;
97 	time_t dom_check_t;
98 	time_t dom_ask_t;
99 	int dom_lockfd;
100 	int dom_alive;
101 	u_int32_t dom_xid;
102 };
103 
104 static char *domainname;
105 
106 static struct _dom_binding *ypbindlist;
107 static int check;
108 
109 typedef enum {
110 	YPBIND_DIRECT, YPBIND_BROADCAST, YPBIND_SETLOCAL, YPBIND_SETALL
111 } ypbind_mode_t;
112 
113 ypbind_mode_t ypbindmode;
114 
115 /*
116  * If ypbindmode is YPBIND_SETLOCAL or YPBIND_SETALL, this indicates
117  * whether or not we've been "ypset".  If we haven't, we behave like
118  * YPBIND_BROADCAST.  If we have, we behave like YPBIND_DIRECT.
119  */
120 int been_ypset;
121 
122 #ifdef DEBUG
123 static int debug;
124 #endif
125 
126 static int insecure;
127 static int rpcsock, pingsock;
128 static struct rmtcallargs rmtca;
129 static struct rmtcallres rmtcr;
130 static bool_t rmtcr_outval;
131 static u_long rmtcr_port;
132 static SVCXPRT *udptransp, *tcptransp;
133 
134 int	_yp_invalid_domain __P((const char *));		/* from libc */
135 int	main __P((int, char *[]));
136 
137 static void usage __P((void));
138 static void yp_log __P((int, const char *, ...))
139 	__attribute__((__format__(__printf__, 2, 3)));
140 static struct _dom_binding *makebinding __P((const char *));
141 static int makelock __P((struct _dom_binding *));
142 static void removelock __P((struct _dom_binding *));
143 static void *ypbindproc_null_2 __P((SVCXPRT *, void *));
144 static void *ypbindproc_domain_2 __P((SVCXPRT *, void *));
145 static void *ypbindproc_setdom_2 __P((SVCXPRT *, void *));
146 static void ypbindprog_2 __P((struct svc_req *, SVCXPRT *));
147 static void checkwork __P((void));
148 static int ping __P((struct _dom_binding *));
149 static int nag_servers __P((struct _dom_binding *));
150 static enum clnt_stat handle_replies __P((void));
151 static enum clnt_stat handle_ping __P((void));
152 static void rpc_received __P((char *, struct sockaddr_in *, int));
153 static struct _dom_binding *xid2ypdb __P((u_int32_t));
154 static u_int32_t unique_xid __P((struct _dom_binding *));
155 static int broadcast __P((char *, int));
156 static int direct __P((char *, int));
157 static int direct_set __P((char *, int, struct _dom_binding *));
158 
159 static void
160 usage()
161 {
162 	char *opt = "";
163 #ifdef DEBUG
164 	opt = " [-d]";
165 #endif
166 
167 	(void)fprintf(stderr,
168 	    "Usage: %s [-broadcast] [-insecure] [-ypset] [-ypsetme] %s\n",
169 	    getprogname(), opt);
170 	exit(1);
171 }
172 
173 static void
174 #if __STDC__
175 yp_log(int pri, const char *fmt, ...)
176 #else
177 yp_log(pri, fmt, va_alist)
178 	int pri;
179 	char *fmt;
180 	va_dcl
181 #endif
182 {
183 	va_list ap;
184 
185 #if __STDC__
186 	va_start(ap, fmt);
187 #else
188 	va_start(ap);
189 #endif
190 
191 #if defined(DEBUG)
192 	if (debug)
193 		vfprintf(stderr, fmt, ap);
194 	else
195 #endif
196 		vsyslog(pri, fmt, ap);
197 	va_end(ap);
198 }
199 
200 static struct _dom_binding *
201 makebinding(dm)
202 	const char *dm;
203 {
204 	struct _dom_binding *ypdb;
205 
206 	if ((ypdb = (struct _dom_binding *)malloc(sizeof *ypdb)) == NULL) {
207 		yp_log(LOG_ERR, "makebinding");
208 		exit(1);
209 	}
210 
211 	(void)memset(ypdb, 0, sizeof *ypdb);
212 	(void)strncpy(ypdb->dom_domain, dm, sizeof ypdb->dom_domain);
213 	ypdb->dom_domain[sizeof(ypdb->dom_domain) - 1] = '\0';
214 	return ypdb;
215 }
216 
217 static int
218 makelock(ypdb)
219 	struct _dom_binding *ypdb;
220 {
221 	int fd;
222 	char path[MAXPATHLEN];
223 
224 	(void)snprintf(path, sizeof(path), "%s/%s.%ld", BINDINGDIR,
225 	    ypdb->dom_domain, ypdb->dom_vers);
226 
227 	if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
228 		(void)mkdir(BINDINGDIR, 0755);
229 		if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
230 			return -1;
231 	}
232 
233 #if O_SHLOCK == 0
234 	(void)flock(fd, LOCK_SH);
235 #endif
236 	return fd;
237 }
238 
239 static void
240 removelock(ypdb)
241 	struct _dom_binding *ypdb;
242 {
243 	char path[MAXPATHLEN];
244 
245 	(void)snprintf(path, sizeof(path), "%s/%s.%ld",
246 	    BINDINGDIR, ypdb->dom_domain, ypdb->dom_vers);
247 	(void)unlink(path);
248 }
249 
250 static void *
251 ypbindproc_null_2(transp, argp)
252 	SVCXPRT *transp;
253 	void *argp;
254 {
255 	static char res;
256 
257 #ifdef DEBUG
258 	if (debug)
259 		printf("ypbindproc_null_2\n");
260 #endif
261 	(void)memset(&res, 0, sizeof(res));
262 	return (void *)&res;
263 }
264 
265 static void *
266 ypbindproc_domain_2(transp, argp)
267 	SVCXPRT *transp;
268 	void *argp;
269 {
270 	static struct ypbind_resp res;
271 	struct _dom_binding *ypdb;
272 	char *arg = *(char **) argp;
273 	time_t now;
274 	int count;
275 
276 #ifdef DEBUG
277 	if (debug)
278 		printf("ypbindproc_domain_2 %s\n", arg);
279 #endif
280 	if (_yp_invalid_domain(arg))
281 		return NULL;
282 
283 	(void)memset(&res, 0, sizeof res);
284 	res.ypbind_status = YPBIND_FAIL_VAL;
285 
286 	for (count = 0, ypdb = ypbindlist;
287 	    ypdb != NULL;
288 	    ypdb = ypdb->dom_pnext, count++) {
289 		if (count > 100)
290 			return NULL;		/* prevent denial of service */
291 		if (!strcmp(ypdb->dom_domain, arg))
292 			break;
293 	}
294 
295 	if (ypdb == NULL) {
296 		ypdb = makebinding(arg);
297 		ypdb->dom_vers = YPVERS;
298 		ypdb->dom_alive = 0;
299 		ypdb->dom_lockfd = -1;
300 		removelock(ypdb);
301 		ypdb->dom_xid = unique_xid(ypdb);
302 		ypdb->dom_pnext = ypbindlist;
303 		ypbindlist = ypdb;
304 		check++;
305 #ifdef DEBUG
306 		if (debug)
307 			printf("unknown domain %s\n", arg);
308 #endif
309 		return NULL;
310 	}
311 
312 	if (ypdb->dom_alive == 0) {
313 #ifdef DEBUG
314 		if (debug)
315 			printf("dead domain %s\n", arg);
316 #endif
317 		return NULL;
318 	}
319 
320 #ifdef HEURISTIC
321 	time(&now);
322 	if (now < ypdb->dom_ask_t + 5) {
323 		/*
324 		 * Hmm. More than 2 requests in 5 seconds have indicated
325 		 * that my binding is possibly incorrect.
326 		 * Ok, do an immediate poll of the server.
327 		 */
328 		if (ypdb->dom_check_t >= now) {
329 			/* don't flood it */
330 			ypdb->dom_check_t = 0;
331 			check++;
332 		}
333 	}
334 	ypdb->dom_ask_t = now;
335 #endif
336 
337 	res.ypbind_status = YPBIND_SUCC_VAL;
338 	res.ypbind_respbody.ypbind_bindinfo.ypbind_binding_addr.s_addr =
339 		ypdb->dom_server_addr.sin_addr.s_addr;
340 	res.ypbind_respbody.ypbind_bindinfo.ypbind_binding_port =
341 		ypdb->dom_server_port;
342 #ifdef DEBUG
343 	if (debug)
344 		printf("domain %s at %s/%d\n", ypdb->dom_domain,
345 		    inet_ntoa(ypdb->dom_server_addr.sin_addr),
346 		    ntohs(ypdb->dom_server_addr.sin_port));
347 #endif
348 	return &res;
349 }
350 
351 static void *
352 ypbindproc_setdom_2(transp, argp)
353 	SVCXPRT *transp;
354 	void *argp;
355 {
356 	struct ypbind_setdom *sd = argp;
357 	struct sockaddr_in *fromsin, bindsin;
358 	static bool_t res;
359 
360 #ifdef DEBUG
361 	if (debug)
362 		printf("ypbindproc_setdom_2 %s\n", inet_ntoa(bindsin.sin_addr));
363 #endif
364 	(void)memset(&res, 0, sizeof(res));
365 	fromsin = svc_getcaller(transp);
366 
367 	switch (ypbindmode) {
368 	case YPBIND_SETLOCAL:
369 		if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
370 #ifdef DEBUG
371 			if (debug)
372 				printf("ypset from %s denied\n",
373 				    inet_ntoa(fromsin->sin_addr));
374 #endif
375 			return NULL;
376 		}
377 		/* FALLTHROUGH */
378 
379 	case YPBIND_SETALL:
380 		been_ypset = 1;
381 		break;
382 
383 	case YPBIND_DIRECT:
384 	case YPBIND_BROADCAST:
385 	default:
386 #ifdef DEBUG
387 		if (debug)
388 			printf("ypset denied\n");
389 #endif
390 		return NULL;
391 	}
392 
393 	if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
394 #ifdef DEBUG
395 		if (debug)
396 			printf("ypset from unprivileged port denied\n");
397 #endif
398 		return &res;
399 	}
400 
401 	if (sd->ypsetdom_vers != YPVERS) {
402 #ifdef DEBUG
403 		if (debug)
404 			printf("ypset with wrong version denied\n");
405 #endif
406 		return &res;
407 	}
408 
409 	(void)memset(&bindsin, 0, sizeof bindsin);
410 	bindsin.sin_family = AF_INET;
411 	bindsin.sin_len = sizeof(bindsin);
412 	bindsin.sin_addr = sd->ypsetdom_addr;
413 	bindsin.sin_port = sd->ypsetdom_port;
414 	rpc_received(sd->ypsetdom_domain, &bindsin, 1);
415 
416 #ifdef DEBUG
417 	if (debug)
418 		printf("ypset to %s succeeded\n", inet_ntoa(bindsin.sin_addr));
419 #endif
420 	res = 1;
421 	return &res;
422 }
423 
424 static void
425 ypbindprog_2(rqstp, transp)
426 	struct svc_req *rqstp;
427 	register SVCXPRT *transp;
428 {
429 	union {
430 		char ypbindproc_domain_2_arg[YPMAXDOMAIN + 1];
431 		struct ypbind_setdom ypbindproc_setdom_2_arg;
432 	} argument;
433 	struct authunix_parms *creds;
434 	char *result;
435 	xdrproc_t xdr_argument, xdr_result;
436 	void *(*local) __P((SVCXPRT *, void *));
437 
438 	switch (rqstp->rq_proc) {
439 	case YPBINDPROC_NULL:
440 		xdr_argument = xdr_void;
441 		xdr_result = xdr_void;
442 		local = ypbindproc_null_2;
443 		break;
444 
445 	case YPBINDPROC_DOMAIN:
446 		xdr_argument = xdr_ypdomain_wrap_string;
447 		xdr_result = xdr_ypbind_resp;
448 		local = ypbindproc_domain_2;
449 		break;
450 
451 	case YPBINDPROC_SETDOM:
452 		switch (rqstp->rq_cred.oa_flavor) {
453 		case AUTH_UNIX:
454 			creds = (struct authunix_parms *)rqstp->rq_clntcred;
455 			if (creds->aup_uid != 0) {
456 				svcerr_auth(transp, AUTH_BADCRED);
457 				return;
458 			}
459 			break;
460 		default:
461 			svcerr_auth(transp, AUTH_TOOWEAK);
462 			return;
463 		}
464 
465 		xdr_argument = xdr_ypbind_setdom;
466 		xdr_result = xdr_void;
467 		local = ypbindproc_setdom_2;
468 		break;
469 
470 	default:
471 		svcerr_noproc(transp);
472 		return;
473 	}
474 	(void)memset(&argument, 0, sizeof(argument));
475 	if (!svc_getargs(transp, xdr_argument, (caddr_t)&argument)) {
476 		svcerr_decode(transp);
477 		return;
478 	}
479 	result = (*local)(transp, &argument);
480 	if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
481 		svcerr_systemerr(transp);
482 	}
483 	return;
484 }
485 
486 int
487 main(argc, argv)
488 	int argc;
489 	char *argv[];
490 {
491 	struct timeval tv;
492 	fd_set fdsr;
493 	int width, lockfd;
494 	int evil = 0, one;
495 	char pathname[MAXPATHLEN];
496 	struct stat st;
497 
498 	yp_get_default_domain(&domainname);
499 	if (domainname[0] == '\0')
500 		errx(1, "Domainname not set. Aborting.");
501 
502 	/*
503 	 * Per traditional ypbind(8) semantics, if a ypservers
504 	 * file does not exist, we default to broadcast mode.
505 	 * If the file does exist, we default to direct mode.
506 	 * Note that we can still override direct mode by passing
507 	 * the -broadcast flag.
508 	 */
509 	snprintf(pathname, sizeof(pathname), "%s/%s%s", BINDINGDIR,
510 	    domainname, YPSERVERSSUFF);
511 	if (stat(pathname, &st) < 0) {
512 #ifdef DEBUG
513 		if (debug)
514 			fprintf(stderr,
515 			    "%s does not exist, defaulting to broadcast\n",
516 			    pathname);
517 #endif
518 		ypbindmode = YPBIND_BROADCAST;
519 	} else
520 		ypbindmode = YPBIND_DIRECT;
521 
522 	while (--argc) {
523 		++argv;
524 		if (!strcmp("-insecure", *argv))
525 			insecure = 1;
526 		else if (!strcmp("-ypset", *argv))
527 			ypbindmode = YPBIND_SETALL;
528 		else if (!strcmp("-ypsetme", *argv))
529 			ypbindmode = YPBIND_SETLOCAL;
530 		else if (!strcmp("-broadcast", *argv))
531 			ypbindmode = YPBIND_BROADCAST;
532 #ifdef DEBUG
533 		else if (!strcmp("-d", *argv))
534 			debug++;
535 #endif
536 		else
537 			usage();
538 	}
539 
540 	/* initialise syslog */
541 	openlog("ypbind", LOG_PERROR | LOG_PID, LOG_DAEMON);
542 
543 	/* blow away everything in BINDINGDIR */
544 
545 	lockfd = open(_PATH_YPBIND_LOCK, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644);
546 	if (lockfd == -1)
547 		err(1, "Cannot create %s", _PATH_YPBIND_LOCK);
548 
549 #if O_SHLOCK == 0
550 	(void)flock(lockfd, LOCK_SH);
551 #endif
552 
553 	(void)pmap_unset(YPBINDPROG, YPBINDVERS);
554 
555 	udptransp = svcudp_create(RPC_ANYSOCK);
556 	if (udptransp == NULL)
557 		errx(1, "Cannot create udp service.");
558 
559 	if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
560 	    IPPROTO_UDP))
561 		errx(1, "Unable to register (YPBINDPROG, YPBINDVERS, udp).");
562 
563 	tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
564 	if (tcptransp == NULL)
565 		errx(1, "Cannot create tcp service.");
566 
567 	if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
568 	    IPPROTO_TCP))
569 		errx(1, "Unable to register (YPBINDPROG, YPBINDVERS, tcp).");
570 
571 	/* XXX use SOCK_STREAM for direct queries? */
572 	if ((rpcsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
573 		err(1, "rpc socket");
574 	if ((pingsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
575 		err(1, "ping socket");
576 
577 	(void)fcntl(rpcsock, F_SETFL, fcntl(rpcsock, F_GETFL, 0) | FNDELAY);
578 	(void)fcntl(pingsock, F_SETFL, fcntl(pingsock, F_GETFL, 0) | FNDELAY);
579 
580 	one = 1;
581 	(void)setsockopt(rpcsock, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one));
582 	rmtca.prog = YPPROG;
583 	rmtca.vers = YPVERS;
584 	rmtca.proc = YPPROC_DOMAIN_NONACK;
585 	rmtca.xdr_args = NULL;		/* set at call time */
586 	rmtca.args_ptr = NULL;		/* set at call time */
587 	rmtcr.port_ptr = &rmtcr_port;
588 	rmtcr.xdr_results = xdr_bool;
589 	rmtcr.results_ptr = (caddr_t)&rmtcr_outval;
590 
591 	if (_yp_invalid_domain(domainname))
592 		errx(1, "bad domainname: %s", domainname);
593 
594 	/* build initial domain binding, make it "unsuccessful" */
595 	ypbindlist = makebinding(domainname);
596 	ypbindlist->dom_vers = YPVERS;
597 	ypbindlist->dom_alive = 0;
598 	ypbindlist->dom_lockfd = -1;
599 	removelock(ypbindlist);
600 
601 	checkwork();
602 
603 	width = svc_maxfd;
604 	if (rpcsock > width)
605 		width = rpcsock;
606 	if (pingsock > width)
607 		width = pingsock;
608 	width++;
609 
610 	for (;;) {
611 		fdsr = svc_fdset;
612 		FD_SET(rpcsock, &fdsr);
613 		FD_SET(pingsock, &fdsr);
614 		tv.tv_sec = 1;
615 		tv.tv_usec = 0;
616 
617 		switch (select(width, &fdsr, NULL, NULL, &tv)) {
618 		case 0:
619 			checkwork();
620 			break;
621 		case -1:
622 			yp_log(LOG_WARNING, "select: %m");
623 			break;
624 		default:
625 			if (FD_ISSET(rpcsock, &fdsr))
626 				handle_replies();
627 			if (FD_ISSET(pingsock, &fdsr))
628 				handle_ping();
629 			svc_getreqset(&fdsr);
630 			if (check)
631 				checkwork();
632 			break;
633 		}
634 
635 		if (!evil && ypbindlist->dom_alive) {
636 			evil = 1;
637 #ifdef DEBUG
638 			if (!debug)
639 #endif
640 				daemon(0, 0);
641 			pidfile(NULL);
642 		}
643 	}
644 }
645 
646 /*
647  * State transition is done like this:
648  *
649  * STATE	EVENT		ACTION			NEWSTATE	TIMEOUT
650  * no binding	timeout		broadcast 		no binding	5 sec
651  * no binding	answer		--			binding		60 sec
652  * binding	timeout		ping server		checking	5 sec
653  * checking	timeout		ping server + broadcast	checking	5 sec
654  * checking	answer		--			binding		60 sec
655  */
656 void
657 checkwork()
658 {
659 	struct _dom_binding *ypdb;
660 	time_t t;
661 
662 	check = 0;
663 
664 	time(&t);
665 	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
666 		if (ypdb->dom_check_t < t) {
667 			if (ypdb->dom_alive == 1)
668 				ping(ypdb);
669 			else
670 				nag_servers(ypdb);
671 			time(&t);
672 			ypdb->dom_check_t = t + 5;
673 		}
674 	}
675 }
676 
677 int
678 ping(ypdb)
679 	struct _dom_binding *ypdb;
680 {
681 	char *dom = ypdb->dom_domain;
682 	struct rpc_msg msg;
683 	char buf[BUFSIZE];
684 	enum clnt_stat st;
685 	int outlen;
686 	AUTH *rpcua;
687 	XDR xdr;
688 
689 	(void)memset(&xdr, 0, sizeof xdr);
690 	(void)memset(&msg, 0, sizeof msg);
691 
692 	rpcua = authunix_create_default();
693 	if (rpcua == NULL) {
694 #ifdef DEBUG
695 		if (debug)
696 			printf("cannot get unix auth\n");
697 #endif
698 		return RPC_SYSTEMERROR;
699 	}
700 
701 	msg.rm_direction = CALL;
702 	msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
703 	msg.rm_call.cb_prog = YPPROG;
704 	msg.rm_call.cb_vers = YPVERS;
705 	msg.rm_call.cb_proc = YPPROC_DOMAIN_NONACK;
706 	msg.rm_call.cb_cred = rpcua->ah_cred;
707 	msg.rm_call.cb_verf = rpcua->ah_verf;
708 
709 	msg.rm_xid = ypdb->dom_xid;
710 	xdrmem_create(&xdr, buf, sizeof buf, XDR_ENCODE);
711 	if (!xdr_callmsg(&xdr, &msg)) {
712 		st = RPC_CANTENCODEARGS;
713 		AUTH_DESTROY(rpcua);
714 		return st;
715 	}
716 	if (!xdr_ypdomain_wrap_string(&xdr, &dom)) {
717 		st = RPC_CANTENCODEARGS;
718 		AUTH_DESTROY(rpcua);
719 		return st;
720 	}
721 	outlen = (int)xdr_getpos(&xdr);
722 	xdr_destroy(&xdr);
723 	if (outlen < 1) {
724 		st = RPC_CANTENCODEARGS;
725 		AUTH_DESTROY(rpcua);
726 		return st;
727 	}
728 	AUTH_DESTROY(rpcua);
729 
730 	ypdb->dom_alive = 2;
731 	if (sendto(pingsock, buf, outlen, 0,
732 		   (struct sockaddr *)&ypdb->dom_server_addr,
733 		   sizeof ypdb->dom_server_addr) == -1)
734 		yp_log(LOG_WARNING, "ping: sendto: %m");
735 	return 0;
736 
737 }
738 
739 static int
740 nag_servers(ypdb)
741 	struct _dom_binding *ypdb;
742 {
743 	char *dom = ypdb->dom_domain;
744 	struct rpc_msg msg;
745 	char buf[BUFSIZE];
746 	enum clnt_stat st;
747 	int outlen;
748 	AUTH *rpcua;
749 	XDR xdr;
750 
751 	rmtca.xdr_args = xdr_ypdomain_wrap_string;
752 	rmtca.args_ptr = (char *)&dom;
753 
754 	(void)memset(&xdr, 0, sizeof xdr);
755 	(void)memset(&msg, 0, sizeof msg);
756 
757 	rpcua = authunix_create_default();
758 	if (rpcua == NULL) {
759 #ifdef DEBUG
760 		if (debug)
761 			printf("cannot get unix auth\n");
762 #endif
763 		return RPC_SYSTEMERROR;
764 	}
765 	msg.rm_direction = CALL;
766 	msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
767 	msg.rm_call.cb_prog = PMAPPROG;
768 	msg.rm_call.cb_vers = PMAPVERS;
769 	msg.rm_call.cb_proc = PMAPPROC_CALLIT;
770 	msg.rm_call.cb_cred = rpcua->ah_cred;
771 	msg.rm_call.cb_verf = rpcua->ah_verf;
772 
773 	msg.rm_xid = ypdb->dom_xid;
774 	xdrmem_create(&xdr, buf, sizeof buf, XDR_ENCODE);
775 	if (!xdr_callmsg(&xdr, &msg)) {
776 		st = RPC_CANTENCODEARGS;
777 		AUTH_DESTROY(rpcua);
778 		return st;
779 	}
780 	if (!xdr_rmtcall_args(&xdr, &rmtca)) {
781 		st = RPC_CANTENCODEARGS;
782 		AUTH_DESTROY(rpcua);
783 		return st;
784 	}
785 	outlen = (int)xdr_getpos(&xdr);
786 	xdr_destroy(&xdr);
787 	if (outlen < 1) {
788 		st = RPC_CANTENCODEARGS;
789 		AUTH_DESTROY(rpcua);
790 		return st;
791 	}
792 	AUTH_DESTROY(rpcua);
793 
794 	if (ypdb->dom_lockfd != -1) {
795 		(void)close(ypdb->dom_lockfd);
796 		ypdb->dom_lockfd = -1;
797 		removelock(ypdb);
798 	}
799 
800 	if (ypdb->dom_alive == 2) {
801 		/*
802 		 * This resolves the following situation:
803 		 * ypserver on other subnet was once bound,
804 		 * but rebooted and is now using a different port
805 		 */
806 		struct sockaddr_in bindsin;
807 
808 		memset(&bindsin, 0, sizeof bindsin);
809 		bindsin.sin_family = AF_INET;
810 		bindsin.sin_len = sizeof(bindsin);
811 		bindsin.sin_port = htons(PMAPPORT);
812 		bindsin.sin_addr = ypdb->dom_server_addr.sin_addr;
813 
814 		if (sendto(rpcsock, buf, outlen, 0, (struct sockaddr *)&bindsin,
815 			   sizeof bindsin) == -1)
816 			yp_log(LOG_WARNING, "broadcast: sendto: %m");
817 	}
818 
819 	switch (ypbindmode) {
820 	case YPBIND_SETALL:
821 	case YPBIND_SETLOCAL:
822 		if (been_ypset)
823 			return direct_set(buf, outlen, ypdb);
824 		/* FALLTHROUGH */
825 
826 	case YPBIND_BROADCAST:
827 		return broadcast(buf, outlen);
828 
829 	case YPBIND_DIRECT:
830 		return direct(buf, outlen);
831 	}
832 
833 	return -1;
834 }
835 
836 static int
837 broadcast(buf, outlen)
838 	char *buf;
839 	int outlen;
840 {
841 	struct ifaddrs *ifap, *ifa;
842 	struct sockaddr_in bindsin;
843 	struct in_addr in;
844 
845 	memset(&bindsin, 0, sizeof bindsin);
846 	bindsin.sin_family = AF_INET;
847 	bindsin.sin_len = sizeof(bindsin);
848 	bindsin.sin_port = htons(PMAPPORT);
849 
850 	if (getifaddrs(&ifap) != 0) {
851 		yp_log(LOG_WARNING, "broadcast: getifaddrs: %m");
852 		return (-1);
853 	}
854 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
855 		if (ifa->ifa_addr->sa_family != AF_INET)
856 			continue;
857 		if ((ifa->ifa_flags & IFF_UP) == 0)
858 			continue;
859 
860 		switch (ifa->ifa_flags & (IFF_LOOPBACK | IFF_BROADCAST)) {
861 		case IFF_BROADCAST:
862 			if (!ifa->ifa_broadaddr)
863 				continue;
864 			if (ifa->ifa_broadaddr->sa_family != AF_INET)
865 				continue;
866 			in = ((struct sockaddr_in *)ifa->ifa_broadaddr)->sin_addr;
867 			break;
868 		case IFF_LOOPBACK:
869 			in = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
870 			break;
871 		default:
872 			continue;
873 		}
874 
875 		bindsin.sin_addr = in;
876 		if (sendto(rpcsock, buf, outlen, 0, (struct sockaddr *)&bindsin,
877 			   bindsin.sin_len) == -1)
878 			yp_log(LOG_WARNING, "broadcast: sendto: %m");
879 	}
880 	freeifaddrs(ifap);
881 	return (0);
882 }
883 
884 static int
885 direct(buf, outlen)
886 	char *buf;
887 	int outlen;
888 {
889 	static FILE *df;
890 	static char ypservers_path[MAXPATHLEN];
891 	char line[_POSIX2_LINE_MAX];
892 	char *p;
893 	struct hostent *hp;
894 	struct sockaddr_in bindsin;
895 	int i, count = 0;
896 
897 	if (df)
898 		rewind(df);
899 	else {
900 		snprintf(ypservers_path, sizeof(ypservers_path),
901 		    "%s/%s%s", BINDINGDIR, domainname, YPSERVERSSUFF);
902 		df = fopen(ypservers_path, "r");
903 		if (df == NULL) {
904 			yp_log(LOG_ERR, "%s: ", ypservers_path);
905 			exit(1);
906 		}
907 	}
908 
909 	memset(&bindsin, 0, sizeof bindsin);
910 	bindsin.sin_family = AF_INET;
911 	bindsin.sin_len = sizeof(bindsin);
912 	bindsin.sin_port = htons(PMAPPORT);
913 
914 	while(fgets(line, sizeof(line), df) != NULL) {
915 		/* skip lines that are too big */
916 		p = strchr(line, '\n');
917 		if (p == NULL) {
918 			int c;
919 
920 			while ((c = getc(df)) != '\n' && c != EOF)
921 				;
922 			continue;
923 		}
924 		*p = '\0';
925 		p = line;
926 		while (isspace(*p))
927 			p++;
928 		if (*p == '#')
929 			continue;
930 		hp = gethostbyname(p);
931 		if (!hp) {
932 			yp_log(LOG_WARNING, "%s: %s", p, hstrerror(h_errno));
933 			continue;
934 		}
935 		/* step through all addresses in case first is unavailable */
936 		for (i = 0; hp->h_addr_list[i]; i++) {
937 			memmove(&bindsin.sin_addr, hp->h_addr_list[0],
938 			    hp->h_length);
939 			if (sendto(rpcsock, buf, outlen, 0,
940 			    (struct sockaddr *)&bindsin, sizeof bindsin) < 0) {
941 				yp_log(LOG_WARNING, "direct: sendto: %m");
942 				continue;
943 			} else
944 				count++;
945 		}
946 	}
947 	if (!count) {
948 		yp_log(LOG_WARNING, "no contactable servers found in %s",
949 		    ypservers_path);
950 		return -1;
951 	}
952 	return 0;
953 }
954 
955 static int
956 direct_set(buf, outlen, ypdb)
957 	char *buf;
958 	int outlen;
959 	struct _dom_binding *ypdb;
960 {
961 	struct sockaddr_in bindsin;
962 	char path[MAXPATHLEN];
963 	struct iovec iov[2];
964 	struct ypbind_resp ybr;
965 	SVCXPRT dummy_svc;
966 	int fd, bytes;
967 
968 	/*
969 	 * Gack, we lose if binding file went away.  We reset
970 	 * "been_set" if this happens, otherwise we'll never
971 	 * bind again.
972 	 */
973 	snprintf(path, sizeof(path), "%s/%s.%ld", BINDINGDIR,
974 	    ypdb->dom_domain, ypdb->dom_vers);
975 
976 	if ((fd = open(path, O_SHLOCK|O_RDONLY, 0644)) == -1) {
977 		yp_log(LOG_WARNING, "%s: %m", path);
978 		been_ypset = 0;
979 		return -1;
980 	}
981 
982 #if O_SHLOCK == 0
983 	(void)flock(fd, LOCK_SH);
984 #endif
985 
986 	/* Read the binding file... */
987 	iov[0].iov_base = (caddr_t)&(dummy_svc.xp_port);
988 	iov[0].iov_len = sizeof(dummy_svc.xp_port);
989 	iov[1].iov_base = (caddr_t)&ybr;
990 	iov[1].iov_len = sizeof(ybr);
991 	bytes = readv(fd, iov, 2);
992 	(void)close(fd);
993 	if (bytes != (iov[0].iov_len + iov[1].iov_len)) {
994 		/* Binding file corrupt? */
995 		yp_log(LOG_WARNING, "%s: %m", path);
996 		been_ypset = 0;
997 		return -1;
998 	}
999 
1000 	bindsin.sin_addr =
1001 	    ybr.ypbind_respbody.ypbind_bindinfo.ypbind_binding_addr;
1002 
1003 	if (sendto(rpcsock, buf, outlen, 0, (struct sockaddr *)&bindsin,
1004 	    sizeof(bindsin)) < 0) {
1005 		yp_log(LOG_WARNING, "direct_set: sendto: %m");
1006 		return -1;
1007 	}
1008 
1009 	return 0;
1010 }
1011 
1012 static enum clnt_stat
1013 handle_replies()
1014 {
1015 	char buf[BUFSIZE];
1016 	int fromlen, inlen;
1017 	struct _dom_binding *ypdb;
1018 	struct sockaddr_in raddr;
1019 	struct rpc_msg msg;
1020 	XDR xdr;
1021 
1022 recv_again:
1023 	(void)memset(&xdr, 0, sizeof(xdr));
1024 	(void)memset(&msg, 0, sizeof(msg));
1025 	msg.acpted_rply.ar_verf = _null_auth;
1026 	msg.acpted_rply.ar_results.where = (caddr_t)&rmtcr;
1027 	msg.acpted_rply.ar_results.proc = xdr_rmtcallres;
1028 
1029 try_again:
1030 	fromlen = sizeof(struct sockaddr);
1031 	inlen = recvfrom(rpcsock, buf, sizeof buf, 0,
1032 		(struct sockaddr *)&raddr, &fromlen);
1033 	if (inlen < 0) {
1034 		if (errno == EINTR)
1035 			goto try_again;
1036 		return RPC_CANTRECV;
1037 	}
1038 	if (inlen < sizeof(u_int32_t))
1039 		goto recv_again;
1040 
1041 	/*
1042 	 * see if reply transaction id matches sent id.
1043 	 * If so, decode the results.
1044 	 */
1045 	xdrmem_create(&xdr, buf, (u_int)inlen, XDR_DECODE);
1046 	if (xdr_replymsg(&xdr, &msg)) {
1047 		if ((msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
1048 		    (msg.acpted_rply.ar_stat == SUCCESS)) {
1049 			raddr.sin_port = htons((u_short)rmtcr_port);
1050 			ypdb = xid2ypdb(msg.rm_xid);
1051 			if (ypdb != NULL)
1052 				rpc_received(ypdb->dom_domain, &raddr, 0);
1053 		}
1054 	}
1055 	xdr.x_op = XDR_FREE;
1056 	msg.acpted_rply.ar_results.proc = xdr_void;
1057 	xdr_destroy(&xdr);
1058 
1059 	return RPC_SUCCESS;
1060 }
1061 
1062 static enum clnt_stat
1063 handle_ping()
1064 {
1065 	char buf[BUFSIZE];
1066 	int fromlen, inlen;
1067 	struct _dom_binding *ypdb;
1068 	struct sockaddr_in raddr;
1069 	struct rpc_msg msg;
1070 	XDR xdr;
1071 	bool_t res;
1072 
1073 recv_again:
1074 	(void)memset(&xdr, 0, sizeof(xdr));
1075 	(void)memset(&msg, 0, sizeof(msg));
1076 	msg.acpted_rply.ar_verf = _null_auth;
1077 	msg.acpted_rply.ar_results.where = (caddr_t)&res;
1078 	msg.acpted_rply.ar_results.proc = xdr_bool;
1079 
1080 try_again:
1081 	fromlen = sizeof (struct sockaddr);
1082 	inlen = recvfrom(pingsock, buf, sizeof buf, 0,
1083 		(struct sockaddr *)&raddr, &fromlen);
1084 	if (inlen < 0) {
1085 		if (errno == EINTR)
1086 			goto try_again;
1087 		return RPC_CANTRECV;
1088 	}
1089 	if (inlen < sizeof(u_int32_t))
1090 		goto recv_again;
1091 
1092 	/*
1093 	 * see if reply transaction id matches sent id.
1094 	 * If so, decode the results.
1095 	 */
1096 	xdrmem_create(&xdr, buf, (u_int)inlen, XDR_DECODE);
1097 	if (xdr_replymsg(&xdr, &msg)) {
1098 		if ((msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
1099 		    (msg.acpted_rply.ar_stat == SUCCESS)) {
1100 			ypdb = xid2ypdb(msg.rm_xid);
1101 			if (ypdb != NULL)
1102 				rpc_received(ypdb->dom_domain, &raddr, 0);
1103 		}
1104 	}
1105 	xdr.x_op = XDR_FREE;
1106 	msg.acpted_rply.ar_results.proc = xdr_void;
1107 	xdr_destroy(&xdr);
1108 
1109 	return RPC_SUCCESS;
1110 }
1111 
1112 /*
1113  * LOOPBACK IS MORE IMPORTANT: PUT IN HACK
1114  */
1115 void
1116 rpc_received(dom, raddrp, force)
1117 	char *dom;
1118 	struct sockaddr_in *raddrp;
1119 	int force;
1120 {
1121 	struct _dom_binding *ypdb;
1122 	struct iovec iov[2];
1123 	struct ypbind_resp ybr;
1124 	int fd;
1125 
1126 #ifdef DEBUG
1127 	if (debug)
1128 		printf("returned from %s about %s\n",
1129 		    inet_ntoa(raddrp->sin_addr), dom);
1130 #endif
1131 
1132 	if (dom == NULL)
1133 		return;
1134 
1135 	if (_yp_invalid_domain(dom))
1136 		return;
1137 
1138 		/* don't support insecure servers by default */
1139 	if (!insecure && ntohs(raddrp->sin_port) >= IPPORT_RESERVED)
1140 		return;
1141 
1142 	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
1143 		if (!strcmp(ypdb->dom_domain, dom))
1144 			break;
1145 
1146 	if (ypdb == NULL) {
1147 		if (force == 0)
1148 			return;
1149 		ypdb = makebinding(dom);
1150 		ypdb->dom_lockfd = -1;
1151 		ypdb->dom_pnext = ypbindlist;
1152 		ypbindlist = ypdb;
1153 	}
1154 
1155 	/* soft update, alive */
1156 	if (ypdb->dom_alive == 1 && force == 0) {
1157 		if (!memcmp(&ypdb->dom_server_addr, raddrp,
1158 			    sizeof ypdb->dom_server_addr)) {
1159 			ypdb->dom_alive = 1;
1160 			/* recheck binding in 60 sec */
1161 			ypdb->dom_check_t = time(NULL) + 60;
1162 		}
1163 		return;
1164 	}
1165 
1166 	(void)memcpy(&ypdb->dom_server_addr, raddrp,
1167 	    sizeof ypdb->dom_server_addr);
1168 	/* recheck binding in 60 seconds */
1169 	ypdb->dom_check_t = time(NULL) + 60;
1170 	ypdb->dom_vers = YPVERS;
1171 	ypdb->dom_alive = 1;
1172 
1173 	if (ypdb->dom_lockfd != -1)
1174 		(void)close(ypdb->dom_lockfd);
1175 
1176 	if ((fd = makelock(ypdb)) == -1)
1177 		return;
1178 
1179 	/*
1180 	 * ok, if BINDINGDIR exists, and we can create the binding file,
1181 	 * then write to it..
1182 	 */
1183 	ypdb->dom_lockfd = fd;
1184 
1185 	iov[0].iov_base = (caddr_t)&(udptransp->xp_port);
1186 	iov[0].iov_len = sizeof udptransp->xp_port;
1187 	iov[1].iov_base = (caddr_t)&ybr;
1188 	iov[1].iov_len = sizeof ybr;
1189 
1190 	(void)memset(&ybr, 0, sizeof ybr);
1191 	ybr.ypbind_status = YPBIND_SUCC_VAL;
1192 	ybr.ypbind_respbody.ypbind_bindinfo.ypbind_binding_addr =
1193 	    raddrp->sin_addr;
1194 	ybr.ypbind_respbody.ypbind_bindinfo.ypbind_binding_port =
1195 	    raddrp->sin_port;
1196 
1197 	if (writev(ypdb->dom_lockfd, iov, 2) !=
1198 	    iov[0].iov_len + iov[1].iov_len) {
1199 		yp_log(LOG_WARNING, "writev: %m");
1200 		(void)close(ypdb->dom_lockfd);
1201 		removelock(ypdb);
1202 		ypdb->dom_lockfd = -1;
1203 	}
1204 }
1205 
1206 static struct _dom_binding *
1207 xid2ypdb(xid)
1208 	u_int32_t xid;
1209 {
1210 	struct _dom_binding *ypdb;
1211 
1212 	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
1213 		if (ypdb->dom_xid == xid)
1214 			break;
1215 	return (ypdb);
1216 }
1217 
1218 static u_int32_t
1219 unique_xid(ypdb)
1220 	struct _dom_binding *ypdb;
1221 {
1222 	u_int32_t tmp_xid;
1223 
1224 	tmp_xid = (u_int32_t)(((u_long)ypdb) & 0xffffffff);
1225 	while (xid2ypdb(tmp_xid) != NULL)
1226 		tmp_xid++;
1227 
1228 	return tmp_xid;
1229 }
1230