1/*
2 * Copyright (c) 1992/3 Theo de Raadt <deraadt@fsa.ca>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote
14 *    products derived from this software without specific prior written
15 *    permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
18 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD$");
32
33#include <sys/param.h>
34#include <sys/types.h>
35#include <sys/wait.h>
36#include <sys/ioctl.h>
37#include <sys/mman.h>
38#include <sys/signal.h>
39#include <sys/socket.h>
40#include <sys/file.h>
41#include <sys/fcntl.h>
42#include <sys/stat.h>
43#include <sys/uio.h>
44#include <ctype.h>
45#include <dirent.h>
46#include <err.h>
47#include <errno.h>
48#include <netdb.h>
49#include <signal.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <syslog.h>
54#include <unistd.h>
55#include <rpc/rpc.h>
56#include <rpc/xdr.h>
57#include <net/if.h>
58#include <netinet/in.h>
59#include <arpa/inet.h>
60#include <rpc/pmap_clnt.h>
61#include <rpc/pmap_prot.h>
62#include <rpc/pmap_rmt.h>
63#include <rpc/rpc_com.h>
64#include <rpcsvc/yp.h>
65#include <rpcsvc/ypclnt.h>
66#include "yp_ping.h"
67
68#ifndef BINDINGDIR
69#define BINDINGDIR "/var/yp/binding"
70#endif
71
72#ifndef YPBINDLOCK
73#define YPBINDLOCK "/var/run/ypbind.lock"
74#endif
75
76struct _dom_binding {
77	struct _dom_binding *dom_pnext;
78	char dom_domain[YPMAXDOMAIN + 1];
79	struct sockaddr_in dom_server_addr;
80	long int dom_vers;
81	int dom_lockfd;
82	int dom_alive;
83	int dom_broadcast_pid;
84	int dom_pipe_fds[2];
85	int dom_default;
86};
87
88#define READFD ypdb->dom_pipe_fds[0]
89#define WRITEFD ypdb->dom_pipe_fds[1]
90#define BROADFD broad_domain->dom_pipe_fds[1]
91
92extern bool_t xdr_domainname(), xdr_ypbind_resp();
93extern bool_t xdr_ypreq_key(), xdr_ypresp_val();
94extern bool_t xdr_ypbind_setdom();
95
96void	checkwork(void);
97void	*ypbindproc_null_2_yp(SVCXPRT *, void *, CLIENT *);
98void	*ypbindproc_setdom_2_yp(SVCXPRT *, struct ypbind_setdom *, CLIENT *);
99void	rpc_received(char *, struct sockaddr_in *, int);
100void	broadcast(struct _dom_binding *);
101int	ping(struct _dom_binding *);
102int	tell_parent(char *, struct sockaddr_in *);
103void	handle_children(struct _dom_binding *);
104void	reaper(int);
105void	terminate(int);
106void	yp_restricted_mode(char *);
107int	verify(struct in_addr);
108
109char *domain_name;
110struct _dom_binding *ypbindlist;
111static struct _dom_binding *broad_domain;
112
113#define YPSET_NO	0
114#define YPSET_LOCAL	1
115#define YPSET_ALL	2
116int ypsetmode = YPSET_NO;
117int ypsecuremode = 0;
118int ppid;
119
120#define NOT_RESPONDING_HYSTERESIS 10
121static int not_responding_count = 0;
122
123/*
124 * Special restricted mode variables: when in restricted mode, only the
125 * specified restricted_domain will be bound, and only the servers listed
126 * in restricted_addrs will be used for binding.
127 */
128#define RESTRICTED_SERVERS 10
129int yp_restricted = 0;
130int yp_manycast = 0;
131struct in_addr restricted_addrs[RESTRICTED_SERVERS];
132
133/* No more than MAX_CHILDREN child broadcasters at a time. */
134#ifndef MAX_CHILDREN
135#define MAX_CHILDREN 5
136#endif
137/* No more than MAX_DOMAINS simultaneous domains */
138#ifndef MAX_DOMAINS
139#define MAX_DOMAINS 200
140#endif
141/* RPC timeout value */
142#ifndef FAIL_THRESHOLD
143#define FAIL_THRESHOLD 20
144#endif
145
146/* Number of times to fish for a response froma particular set of hosts */
147#ifndef MAX_RETRIES
148#define MAX_RETRIES 30
149#endif
150
151int retries = 0;
152int children = 0;
153int domains = 0;
154int yplockfd;
155fd_set fdsr;
156
157SVCXPRT *udptransp, *tcptransp;
158
159void *
160ypbindproc_null_2_yp(SVCXPRT *transp, void *argp, CLIENT *clnt)
161{
162	static char res;
163
164	bzero(&res, sizeof(res));
165	return &res;
166}
167
168struct ypbind_resp *
169ypbindproc_domain_2_yp(SVCXPRT *transp, domainname *argp, CLIENT *clnt)
170{
171	static struct ypbind_resp res;
172	struct _dom_binding *ypdb;
173	char path[MAXPATHLEN];
174
175	bzero(&res, sizeof res);
176	res.ypbind_status = YPBIND_FAIL_VAL;
177	res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV;
178
179	if (strchr(*argp, '/')) {
180		syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
181rejecting.", *argp);
182		return(&res);
183	}
184
185	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
186		if (strcmp(ypdb->dom_domain, *argp) == 0)
187			break;
188		}
189
190	if (ypdb == NULL) {
191		if (yp_restricted) {
192			syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp);
193			return (&res);
194		}
195
196		if (domains >= MAX_DOMAINS) {
197			syslog(LOG_WARNING, "domain limit (%d) exceeded",
198							MAX_DOMAINS);
199			res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
200			return (&res);
201		}
202		if (strlen(*argp) > YPMAXDOMAIN) {
203			syslog(LOG_WARNING, "domain %s too long", *argp);
204			res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
205			return (&res);
206		}
207		ypdb = malloc(sizeof *ypdb);
208		if (ypdb == NULL) {
209			syslog(LOG_WARNING, "malloc: %m");
210			res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
211			return (&res);
212		}
213		bzero(ypdb, sizeof *ypdb);
214		strlcpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain);
215		ypdb->dom_vers = YPVERS;
216		ypdb->dom_alive = 0;
217		ypdb->dom_default = 0;
218		ypdb->dom_lockfd = -1;
219		sprintf(path, "%s/%s.%ld", BINDINGDIR,
220					ypdb->dom_domain, ypdb->dom_vers);
221		unlink(path);
222		ypdb->dom_pnext = ypbindlist;
223		ypbindlist = ypdb;
224		domains++;
225	}
226
227	if (ping(ypdb)) {
228		return (&res);
229	}
230
231	res.ypbind_status = YPBIND_SUCC_VAL;
232	res.ypbind_resp_u.ypbind_error = 0; /* Success */
233	*(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr =
234		ypdb->dom_server_addr.sin_addr.s_addr;
235	*(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port =
236		ypdb->dom_server_addr.sin_port;
237	/*printf("domain %s at %s/%d\n", ypdb->dom_domain,
238		inet_ntoa(ypdb->dom_server_addr.sin_addr),
239		ntohs(ypdb->dom_server_addr.sin_port));*/
240	return (&res);
241}
242
243void *
244ypbindproc_setdom_2_yp(SVCXPRT *transp, ypbind_setdom *argp, CLIENT *clnt)
245{
246	struct sockaddr_in *fromsin, bindsin;
247	static char		*result = NULL;
248
249	if (strchr(argp->ypsetdom_domain, '/')) {
250		syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
251rejecting.", argp->ypsetdom_domain);
252		return(NULL);
253	}
254	fromsin = svc_getcaller(transp);
255
256	switch (ypsetmode) {
257	case YPSET_LOCAL:
258		if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
259			svcerr_noprog(transp);
260			return(NULL);
261		}
262		break;
263	case YPSET_ALL:
264		break;
265	case YPSET_NO:
266	default:
267		svcerr_noprog(transp);
268		return(NULL);
269	}
270
271	if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
272		svcerr_noprog(transp);
273		return(NULL);
274	}
275
276	if (argp->ypsetdom_vers != YPVERS) {
277		svcerr_noprog(transp);
278		return(NULL);
279	}
280
281	bzero(&bindsin, sizeof bindsin);
282	bindsin.sin_family = AF_INET;
283	bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr;
284	bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port;
285	rpc_received(argp->ypsetdom_domain, &bindsin, 1);
286
287	return((void *) &result);
288}
289
290void
291ypbindprog_2(struct svc_req *rqstp, register SVCXPRT *transp)
292{
293	union {
294		domainname ypbindproc_domain_2_arg;
295		struct ypbind_setdom ypbindproc_setdom_2_arg;
296	} argument;
297	struct authunix_parms *creds;
298	char *result;
299	bool_t (*xdr_argument)(), (*xdr_result)();
300	char *(*local)();
301
302	switch (rqstp->rq_proc) {
303	case YPBINDPROC_NULL:
304		xdr_argument = xdr_void;
305		xdr_result = xdr_void;
306		local = (char *(*)()) ypbindproc_null_2_yp;
307		break;
308
309	case YPBINDPROC_DOMAIN:
310		xdr_argument = xdr_domainname;
311		xdr_result = xdr_ypbind_resp;
312		local = (char *(*)()) ypbindproc_domain_2_yp;
313		break;
314
315	case YPBINDPROC_SETDOM:
316		switch (rqstp->rq_cred.oa_flavor) {
317		case AUTH_UNIX:
318			creds = (struct authunix_parms *)rqstp->rq_clntcred;
319			if (creds->aup_uid != 0) {
320				svcerr_auth(transp, AUTH_BADCRED);
321				return;
322			}
323			break;
324		default:
325			svcerr_auth(transp, AUTH_TOOWEAK);
326			return;
327		}
328
329		xdr_argument = xdr_ypbind_setdom;
330		xdr_result = xdr_void;
331		local = (char *(*)()) ypbindproc_setdom_2_yp;
332		break;
333
334	default:
335		svcerr_noproc(transp);
336		return;
337	}
338	bzero(&argument, sizeof(argument));
339	if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) {
340		svcerr_decode(transp);
341		return;
342	}
343	result = (*local)(transp, &argument, rqstp);
344	if (result != NULL &&
345	    !svc_sendreply(transp, (xdrproc_t)xdr_result, result)) {
346		svcerr_systemerr(transp);
347	}
348	return;
349}
350
351/* Jack the reaper */
352void
353reaper(int sig)
354{
355	int st;
356
357	while (wait3(&st, WNOHANG, NULL) > 0)
358		children--;
359}
360
361void
362terminate(int sig)
363{
364	struct _dom_binding *ypdb;
365	char path[MAXPATHLEN];
366
367	if (ppid != getpid())
368		exit(0);
369
370	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
371		close(ypdb->dom_lockfd);
372		if (ypdb->dom_broadcast_pid)
373			kill(ypdb->dom_broadcast_pid, SIGINT);
374		sprintf(path, "%s/%s.%ld", BINDINGDIR,
375			ypdb->dom_domain, ypdb->dom_vers);
376		unlink(path);
377	}
378	close(yplockfd);
379	unlink(YPBINDLOCK);
380	pmap_unset(YPBINDPROG, YPBINDVERS);
381	exit(0);
382}
383
384int
385main(int argc, char *argv[])
386{
387	struct timeval tv;
388	int i;
389	DIR *dird;
390	struct dirent *dirp;
391	struct _dom_binding *ypdb, *next;
392
393	/* Check that another ypbind isn't already running. */
394	if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1)
395		err(1, "%s", YPBINDLOCK);
396
397	if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK)
398		errx(1, "another ypbind is already running. Aborting");
399
400	/* XXX domainname will be overridden if we use restricted mode */
401	yp_get_default_domain(&domain_name);
402	if (domain_name[0] == '\0')
403		errx(1, "domainname not set. Aborting");
404
405	for (i = 1; i<argc; i++) {
406		if (strcmp("-ypset", argv[i]) == 0)
407			ypsetmode = YPSET_ALL;
408		else if (strcmp("-ypsetme", argv[i]) == 0)
409		        ypsetmode = YPSET_LOCAL;
410		else if (strcmp("-s", argv[i]) == 0)
411		        ypsecuremode++;
412		else if (strcmp("-S", argv[i]) == 0 && argc > i)
413			yp_restricted_mode(argv[++i]);
414		else if (strcmp("-m", argv[i]) == 0)
415			yp_manycast++;
416		else
417			errx(1, "unknown option: %s", argv[i]);
418	}
419
420	if (strlen(domain_name) > YPMAXDOMAIN)
421		warnx("truncating domain name %s", domain_name);
422
423	/* blow away everything in BINDINGDIR (if it exists) */
424
425	if ((dird = opendir(BINDINGDIR)) != NULL) {
426		char path[MAXPATHLEN];
427		while ((dirp = readdir(dird)) != NULL)
428			if (strcmp(dirp->d_name, ".") &&
429			    strcmp(dirp->d_name, "..")) {
430				sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
431				unlink(path);
432			}
433		closedir(dird);
434	}
435
436#ifdef DAEMON
437	if (daemon(0,0))
438		err(1, "fork");
439#endif
440
441	pmap_unset(YPBINDPROG, YPBINDVERS);
442
443	udptransp = svcudp_create(RPC_ANYSOCK);
444	if (udptransp == NULL)
445		errx(1, "cannot create udp service");
446	if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
447	    IPPROTO_UDP))
448		errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
449
450	tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
451	if (tcptransp == NULL)
452		errx(1, "cannot create tcp service");
453
454	if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
455	    IPPROTO_TCP))
456		errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
457
458	/* build initial domain binding, make it "unsuccessful" */
459	ypbindlist = malloc(sizeof *ypbindlist);
460	if (ypbindlist == NULL)
461		errx(1, "malloc");
462	bzero(ypbindlist, sizeof *ypbindlist);
463	strlcpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
464	ypbindlist->dom_vers = YPVERS;
465	ypbindlist->dom_alive = 0;
466	ypbindlist->dom_lockfd = -1;
467	ypbindlist->dom_default = 1;
468	domains++;
469
470	signal(SIGCHLD, reaper);
471	signal(SIGTERM, terminate);
472
473	ppid = getpid(); /* Remember who we are. */
474
475	openlog(argv[0], LOG_PID, LOG_DAEMON);
476
477	if (madvise(NULL, 0, MADV_PROTECT) != 0)
478		syslog(LOG_WARNING, "madvise(): %m");
479
480	/* Kick off the default domain */
481	broadcast(ypbindlist);
482
483	while (1) {
484		fdsr = svc_fdset;
485
486		tv.tv_sec = 60;
487		tv.tv_usec = 0;
488
489		switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
490		case 0:
491			checkwork();
492			break;
493		case -1:
494			if (errno != EINTR)
495				syslog(LOG_WARNING, "select: %m");
496			break;
497		default:
498			for (ypdb = ypbindlist; ypdb; ypdb = next) {
499				next = ypdb->dom_pnext;
500				if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
501					handle_children(ypdb);
502					if (children == (MAX_CHILDREN - 1))
503						checkwork();
504				}
505			}
506			svc_getreqset(&fdsr);
507			break;
508		}
509	}
510
511	/* NOTREACHED */
512	exit(1);
513}
514
515void
516checkwork(void)
517{
518	struct _dom_binding *ypdb;
519
520	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
521		ping(ypdb);
522}
523
524/* The clnt_broadcast() callback mechanism sucks. */
525
526/*
527 * Receive results from broadcaster. Don't worry about passing
528 * bogus info to rpc_received() -- it can handle it. Note that we
529 * must be sure to invalidate the dom_pipe_fds descriptors here:
530 * since descriptors can be re-used, we have to make sure we
531 * don't mistake one of the RPC descriptors for one of the pipes.
532 * What's weird is that forgetting to invalidate the pipe descriptors
533 * doesn't always result in an error (otherwise I would have caught
534 * the mistake much sooner), even though logically it should.
535 */
536void
537handle_children(struct _dom_binding *ypdb)
538{
539	char buf[YPMAXDOMAIN + 1];
540	struct sockaddr_in addr;
541	int d = 0, a = 0;
542	struct _dom_binding *y, *prev = NULL;
543	char path[MAXPATHLEN];
544
545	if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
546		syslog(LOG_WARNING, "could not read from child: %m");
547
548	if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
549		syslog(LOG_WARNING, "could not read from child: %m");
550
551	close(READFD);
552	FD_CLR(READFD, &fdsr);
553	FD_CLR(READFD, &svc_fdset);
554	READFD = WRITEFD = -1;
555	if (d > 0 && a > 0)
556		rpc_received(buf, &addr, 0);
557	else {
558		for (y = ypbindlist; y; y = y->dom_pnext) {
559			if (y == ypdb)
560				break;
561			prev = y;
562		}
563		switch (ypdb->dom_default) {
564		case 0:
565			if (prev == NULL)
566				ypbindlist = y->dom_pnext;
567			else
568				prev->dom_pnext = y->dom_pnext;
569			sprintf(path, "%s/%s.%ld", BINDINGDIR,
570				ypdb->dom_domain, YPVERS);
571			close(ypdb->dom_lockfd);
572			unlink(path);
573			free(ypdb);
574			domains--;
575			return;
576		case 1:
577			ypdb->dom_broadcast_pid = 0;
578			ypdb->dom_alive = 0;
579			broadcast(ypdb);
580			return;
581		default:
582			break;
583		}
584	}
585
586	return;
587}
588
589/*
590 * Send our dying words back to our parent before we perish.
591 */
592int
593tell_parent(char *dom, struct sockaddr_in *addr)
594{
595	char buf[YPMAXDOMAIN + 1];
596	struct timeval timeout;
597	fd_set fds;
598
599	timeout.tv_sec = 5;
600	timeout.tv_usec = 0;
601
602	sprintf(buf, "%s", broad_domain->dom_domain);
603	if (write(BROADFD, &buf, sizeof(buf)) < 0)
604		return(1);
605
606	/*
607	 * Stay in sync with parent: wait for it to read our first
608	 * message before sending the second.
609	 */
610
611	FD_ZERO(&fds);
612	FD_SET(BROADFD, &fds);
613	if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1)
614		return(1);
615	if (FD_ISSET(BROADFD, &fds)) {
616		if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0)
617			return(1);
618	} else {
619		return(1);
620	}
621
622	close(BROADFD);
623	return (0);
624}
625
626bool_t broadcast_result(out, addr)
627bool_t *out;
628struct sockaddr_in *addr;
629{
630	if (retries >= MAX_RETRIES) {
631		bzero(addr, sizeof(struct sockaddr_in));
632		if (tell_parent(broad_domain->dom_domain, addr))
633			syslog(LOG_WARNING, "lost connection to parent");
634		return (TRUE);
635	}
636
637	if (yp_restricted && verify(addr->sin_addr)) {
638		retries++;
639		syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr));
640		return (FALSE);
641	} else {
642		if (tell_parent(broad_domain->dom_domain, addr))
643			syslog(LOG_WARNING, "lost connection to parent");
644		return (TRUE);
645	}
646}
647
648/*
649 * The right way to send RPC broadcasts.
650 * Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast()
651 * blocks while waiting for replies, so we have to fork off separate
652 * broadcaster processes that do the waiting and then transmit their
653 * results back to the parent for processing. We also have to remember
654 * to save the name of the domain we're trying to bind in a global
655 * variable since clnt_broadcast() provides no way to pass things to
656 * the 'eachresult' callback function.
657 */
658void
659broadcast(struct _dom_binding *ypdb)
660{
661	bool_t out = FALSE;
662	enum clnt_stat stat;
663
664	if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
665		return;
666
667	if (pipe(ypdb->dom_pipe_fds) < 0) {
668		syslog(LOG_WARNING, "pipe: %m");
669		return;
670	}
671
672	if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr) {
673		if (not_responding_count++ >= NOT_RESPONDING_HYSTERESIS) {
674			not_responding_count = NOT_RESPONDING_HYSTERESIS;
675			syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
676			    inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
677		}
678	}
679
680	broad_domain = ypdb;
681	flock(ypdb->dom_lockfd, LOCK_UN);
682
683	switch ((ypdb->dom_broadcast_pid = fork())) {
684	case 0:
685		close(READFD);
686		signal(SIGCHLD, SIG_DFL);
687		signal(SIGTERM, SIG_DFL);
688		break;
689	case -1:
690		syslog(LOG_WARNING, "fork: %m");
691		close(READFD);
692		close(WRITEFD);
693		return;
694	default:
695		close(WRITEFD);
696		FD_SET(READFD, &svc_fdset);
697		children++;
698		return;
699	}
700
701	/* Release all locks before doing anything else. */
702	while (ypbindlist) {
703		close(ypbindlist->dom_lockfd);
704		ypbindlist = ypbindlist->dom_pnext;
705	}
706	close(yplockfd);
707
708	/*
709	 * Special 'many-cast' behavior. If we're in restricted mode,
710	 * we have a list of possible server addresses to try. What
711	 * we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
712	 * procedure and time the replies. Whoever replies fastest
713	 * gets to be our server. Note that this is not a broadcast
714	 * operation: we transmit uni-cast datagrams only.
715	 */
716	if (yp_restricted && yp_manycast) {
717		short			port;
718		int			i;
719		struct sockaddr_in	sin;
720
721		i = __yp_ping(restricted_addrs, yp_restricted,
722				ypdb->dom_domain, &port);
723		if (i == -1) {
724			bzero(&ypdb->dom_server_addr,
725			    sizeof(struct sockaddr_in));
726			if (tell_parent(ypdb->dom_domain,
727				&ypdb->dom_server_addr))
728			syslog(LOG_WARNING, "lost connection to parent");
729		} else {
730			bzero(&sin, sizeof(struct sockaddr_in));
731			bcopy(&restricted_addrs[i],
732			    &sin.sin_addr, sizeof(struct in_addr));
733			sin.sin_family = AF_INET;
734			sin.sin_port = port;
735			if (tell_parent(broad_domain->dom_domain, &sin))
736				syslog(LOG_WARNING,
737					"lost connection to parent");
738		}
739		_exit(0);
740	}
741
742	retries = 0;
743
744	{
745		char *ptr;
746
747		ptr = ypdb->dom_domain;
748		stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
749	    		(xdrproc_t)xdr_domainname, &ptr,
750		        (xdrproc_t)xdr_bool, &out,
751	    		(resultproc_t)broadcast_result);
752	}
753
754	if (stat != RPC_SUCCESS) {
755		bzero(&ypdb->dom_server_addr,
756		    sizeof(struct sockaddr_in));
757		if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
758			syslog(LOG_WARNING, "lost connection to parent");
759	}
760
761	_exit(0);
762}
763
764/*
765 * The right way to check if a server is alive.
766 * Attempt to get a client handle pointing to the server and send a
767 * YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
768 * we invalidate this binding entry and send out a broadcast to try to
769 * establish a new binding. Note that we treat non-default domains
770 * specially: once bound, we keep tabs on our server, but if it
771 * goes away and fails to respond after one round of broadcasting, we
772 * abandon it until a client specifically references it again. We make
773 * every effort to keep our default domain bound, however, since we
774 * need it to keep the system on its feet.
775 */
776int
777ping(struct _dom_binding *ypdb)
778{
779	bool_t out;
780	struct timeval interval, timeout;
781	enum clnt_stat stat;
782	int rpcsock = RPC_ANYSOCK;
783	CLIENT *client_handle;
784
785	interval.tv_sec = FAIL_THRESHOLD;
786	interval.tv_usec = 0;
787	timeout.tv_sec = FAIL_THRESHOLD;
788	timeout.tv_usec = 0;
789
790	if (ypdb->dom_broadcast_pid)
791		return(1);
792
793	if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
794		YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
795		RPCSMALLMSGSIZE)) == (CLIENT *)NULL) {
796		/* Can't get a handle: we're dead. */
797		ypdb->dom_alive = 0;
798		ypdb->dom_vers = -1;
799		broadcast(ypdb);
800		return(1);
801	}
802
803	{
804		char *ptr;
805
806		ptr = ypdb->dom_domain;
807
808		stat = clnt_call(client_handle, YPPROC_DOMAIN,
809		    (xdrproc_t)xdr_domainname, &ptr,
810		    (xdrproc_t)xdr_bool, &out, timeout);
811		if (stat != RPC_SUCCESS || out == FALSE) {
812			ypdb->dom_alive = 0;
813			ypdb->dom_vers = -1;
814			clnt_destroy(client_handle);
815			broadcast(ypdb);
816			return(1);
817		}
818	}
819
820	clnt_destroy(client_handle);
821	return(0);
822}
823
824void
825rpc_received(char *dom, struct sockaddr_in *raddrp, int force)
826{
827	struct _dom_binding *ypdb, *prev = NULL;
828	struct iovec iov[2];
829	struct ypbind_resp ybr;
830	char path[MAXPATHLEN];
831	int fd;
832
833	/*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
834	       ntohs(raddrp->sin_port), dom);*/
835
836	if (dom == NULL)
837		return;
838
839	for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
840		if (strcmp(ypdb->dom_domain, dom) == 0)
841			break;
842		prev = ypdb;
843	}
844
845	if (ypdb && force) {
846		if (ypdb->dom_broadcast_pid) {
847			kill(ypdb->dom_broadcast_pid, SIGINT);
848			close(READFD);
849			FD_CLR(READFD, &fdsr);
850			FD_CLR(READFD, &svc_fdset);
851			READFD = WRITEFD = -1;
852		}
853	}
854
855	/* if in secure mode, check originating port number */
856	if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
857	    syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
858		   inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
859		   dom);
860	    if (ypdb != NULL) {
861		ypdb->dom_broadcast_pid = 0;
862		ypdb->dom_alive = 0;
863	    }
864	    return;
865	}
866
867	if (raddrp->sin_addr.s_addr == (long)0) {
868		switch (ypdb->dom_default) {
869		case 0:
870			if (prev == NULL)
871				ypbindlist = ypdb->dom_pnext;
872			else
873				prev->dom_pnext = ypdb->dom_pnext;
874			sprintf(path, "%s/%s.%ld", BINDINGDIR,
875				ypdb->dom_domain, YPVERS);
876			close(ypdb->dom_lockfd);
877			unlink(path);
878			free(ypdb);
879			domains--;
880			return;
881		case 1:
882			ypdb->dom_broadcast_pid = 0;
883			ypdb->dom_alive = 0;
884			broadcast(ypdb);
885			return;
886		default:
887			break;
888		}
889	}
890
891	if (ypdb == NULL) {
892		if (force == 0)
893			return;
894		if (strlen(dom) > YPMAXDOMAIN) {
895			syslog(LOG_WARNING, "domain %s too long", dom);
896			return;
897		}
898		ypdb = malloc(sizeof *ypdb);
899		if (ypdb == NULL) {
900			syslog(LOG_WARNING, "malloc: %m");
901			return;
902		}
903		bzero(ypdb, sizeof *ypdb);
904		strlcpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
905		ypdb->dom_lockfd = -1;
906		ypdb->dom_default = 0;
907		ypdb->dom_pnext = ypbindlist;
908		ypbindlist = ypdb;
909	}
910
911	/* We've recovered from a crash: inform the world. */
912	if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr) {
913		if (not_responding_count >= NOT_RESPONDING_HYSTERESIS) {
914			not_responding_count = 0;
915			syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
916			    inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
917		}
918	}
919
920	bcopy(raddrp, &ypdb->dom_server_addr,
921		sizeof ypdb->dom_server_addr);
922
923	ypdb->dom_vers = YPVERS;
924	ypdb->dom_alive = 1;
925	ypdb->dom_broadcast_pid = 0;
926
927	if (ypdb->dom_lockfd != -1)
928		close(ypdb->dom_lockfd);
929
930	sprintf(path, "%s/%s.%ld", BINDINGDIR,
931		ypdb->dom_domain, ypdb->dom_vers);
932#ifdef O_SHLOCK
933	if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
934		(void)mkdir(BINDINGDIR, 0755);
935		if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
936			return;
937	}
938#else
939	if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
940		(void)mkdir(BINDINGDIR, 0755);
941		if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
942			return;
943	}
944	flock(fd, LOCK_SH);
945#endif
946
947	/*
948	 * ok, if BINDINGDIR exists, and we can create the binding file,
949	 * then write to it..
950	 */
951	ypdb->dom_lockfd = fd;
952
953	iov[0].iov_base = (char *)&(udptransp->xp_port);
954	iov[0].iov_len = sizeof udptransp->xp_port;
955	iov[1].iov_base = (char *)&ybr;
956	iov[1].iov_len = sizeof ybr;
957
958	bzero(&ybr, sizeof ybr);
959	ybr.ypbind_status = YPBIND_SUCC_VAL;
960	*(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
961	*(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
962
963	if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
964		syslog(LOG_WARNING, "write: %m");
965		close(ypdb->dom_lockfd);
966		ypdb->dom_lockfd = -1;
967		return;
968	}
969}
970
971/*
972 * Check address against list of allowed servers. Return 0 if okay,
973 * 1 if not matched.
974 */
975int
976verify(struct in_addr addr)
977{
978	int i;
979
980	for (i = 0; i < RESTRICTED_SERVERS; i++)
981		if (!bcmp(&addr, &restricted_addrs[i], sizeof(struct in_addr)))
982			return(0);
983
984	return(1);
985}
986
987/*
988 * Try to set restricted mode. We default to normal mode if we can't
989 * resolve the specified hostnames.
990 */
991void
992yp_restricted_mode(char *args)
993{
994	struct hostent *h;
995	int i = 0;
996	char *s;
997
998	/* Find the restricted domain. */
999	if ((s = strsep(&args, ",")) == NULL)
1000		return;
1001	domain_name = s;
1002
1003	/* Get the addresses of the servers. */
1004	while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
1005		if ((h = gethostbyname(s)) == NULL)
1006			return;
1007		bcopy (h->h_addr_list[0], &restricted_addrs[i],
1008		    sizeof(struct in_addr));
1009		i++;
1010	}
1011
1012	/* ypset and ypsetme not allowed with restricted mode */
1013	ypsetmode = YPSET_NO;
1014
1015	yp_restricted = i;
1016	return;
1017}
1018