1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  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 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY 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#ifndef lint
31static const char copyright[] =
32"@(#) Copyright (c) 1983, 1993\n\
33	The Regents of the University of California.  All rights reserved.\n";
34#endif /* not lint */
35
36#if 0
37#ifndef lint
38static char sccsid[] = "@(#)rwhod.c	8.1 (Berkeley) 6/6/93";
39#endif /* not lint */
40#endif
41
42#include <sys/cdefs.h>
43__FBSDID("$FreeBSD: src/usr.sbin/rwhod/rwhod.c,v 1.23 2005/06/03 17:38:33 ssouhlal Exp $");
44
45#include <sys/param.h>
46#include <sys/socket.h>
47#include <sys/stat.h>
48#include <sys/signal.h>
49#include <sys/ioctl.h>
50#include <sys/sysctl.h>
51
52#include <net/if.h>
53#include <net/if_dl.h>
54#include <netinet/in.h>
55#include <arpa/inet.h>
56#include <protocols/rwhod.h>
57
58#include <ctype.h>
59#include <err.h>
60#include <errno.h>
61#include <fcntl.h>
62#include <netdb.h>
63#include <paths.h>
64#include <stdio.h>
65#include <stdlib.h>
66#include <string.h>
67#include <syslog.h>
68#include <timeconv.h>
69#include <unistd.h>
70#ifdef __APPLE__
71#include <utmpx.h>
72#include <net/route.h>
73#else
74#include <utmp.h>
75#endif
76#include <pwd.h>
77#include <grp.h>
78
79/*
80 * This version of Berkeley's rwhod has been modified to use IP multicast
81 * datagrams, under control of a new command-line option:
82 *
83 *	rwhod -m	causes rwhod to use IP multicast (instead of
84 *			broadcast or unicast) on all interfaces that have
85 *			the IFF_MULTICAST flag set in their "ifnet" structs
86 *			(excluding the loopback interface).  The multicast
87 *			reports are sent with a time-to-live of 1, to prevent
88 *			forwarding beyond the directly-connected subnet(s).
89 *
90 *	rwhod -m <ttl>	causes rwhod to send IP multicast datagrams with a
91 *			time-to-live of <ttl>, via a SINGLE interface rather
92 *			than all interfaces.  <ttl> must be between 0 and
93 *			MAX_MULTICAST_SCOPE, defined below.  Note that "-m 1"
94 *			is different than "-m", in that "-m 1" specifies
95 *			transmission on one interface only.
96 *
97 * When "-m" is used without a <ttl> argument, the program accepts multicast
98 * rwhod reports from all multicast-capable interfaces.  If a <ttl> argument
99 * is given, it accepts multicast reports from only one interface, the one
100 * on which reports are sent (which may be controlled via the host's routing
101 * table).  Regardless of the "-m" option, the program accepts broadcast or
102 * unicast reports from all interfaces.  Thus, this program will hear the
103 * reports of old, non-multicasting rwhods, but, if multicasting is used,
104 * those old rwhods won't hear the reports generated by this program.
105 *
106 *                  -- Steve Deering, Stanford University, February 1989
107 */
108
109#define	UNPRIV_USER		"daemon"
110#define	UNPRIV_GROUP		"daemon"
111
112#define NO_MULTICAST		0	  /* multicast modes */
113#define PER_INTERFACE_MULTICAST	1
114#define SCOPED_MULTICAST	2
115
116#define MAX_MULTICAST_SCOPE	32	  /* "site-wide", by convention */
117
118#define INADDR_WHOD_GROUP (u_long)0xe0000103      /* 224.0.1.3 */
119					  /* (belongs in protocols/rwhod.h) */
120
121int			insecure_mode;
122int			quiet_mode;
123int			iff_flag = IFF_POINTOPOINT;
124int			multicast_mode  = NO_MULTICAST;
125int			multicast_scope;
126struct sockaddr_in	multicast_addr  =
127	{ sizeof multicast_addr, AF_INET, 0, { 0 }, { 0 } };
128
129/*
130 * Alarm interval. Don't forget to change the down time check in ruptime
131 * if this is changed.
132 */
133#define AL_INTERVAL (3 * 60)
134
135char	myname[MAXHOSTNAMELEN];
136
137/*
138 * We communicate with each neighbor in a list constructed at the time we're
139 * started up.  Neighbors are currently directly connected via a hardware
140 * interface.
141 */
142struct	neighbor {
143	struct	neighbor *n_next;
144	char	*n_name;		/* interface name */
145	struct	sockaddr *n_addr;		/* who to send to */
146	int	n_addrlen;		/* size of address */
147	int	n_flags;		/* should forward?, interface flags */
148};
149
150struct	neighbor *neighbors;
151struct	whod mywd;
152struct	servent *sp;
153int	s, utmpf;
154
155#define	WHDRSIZE	(int)(sizeof(mywd) - sizeof(mywd.wd_we))
156
157void	 run_as(uid_t *, gid_t *);
158int	 configure(int);
159void	 getboottime(int);
160void	 onalrm(int);
161void	 quit(const char *);
162void	 rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
163int	 verify(char *, int);
164static void usage(void);
165#ifdef DEBUG
166char	*interval(int, char *);
167void	 Sendto(int, const void *, size_t, int, const struct sockaddr *, int);
168#define	 sendto Sendto
169#endif
170
171int
172main(int argc, char *argv[])
173{
174	struct sockaddr_in from;
175	struct stat st;
176	char path[64];
177	int on = 1;
178	char *cp;
179	struct sockaddr_in soin;
180	uid_t unpriv_uid;
181	gid_t unpriv_gid;
182
183	if (getuid())
184		errx(1, "not super user");
185
186	run_as(&unpriv_uid, &unpriv_gid);
187
188	argv++; argc--;
189	while (argc > 0 && *argv[0] == '-') {
190		if (strcmp(*argv, "-m") == 0) {
191			if (argc > 1 && isdigit(*(argv + 1)[0])) {
192				argv++, argc--;
193				multicast_mode  = SCOPED_MULTICAST;
194				multicast_scope = atoi(*argv);
195				if (multicast_scope > MAX_MULTICAST_SCOPE)
196					errx(1, "ttl must not exceed %u",
197					MAX_MULTICAST_SCOPE);
198			}
199			else multicast_mode = PER_INTERFACE_MULTICAST;
200		}
201		else if (strcmp(*argv, "-i") == 0)
202			insecure_mode = 1;
203		else if (strcmp(*argv, "-l") == 0)
204			quiet_mode = 1;
205		else if (strcmp(*argv, "-p") == 0)
206			iff_flag = 0;
207		else
208			usage();
209		argv++, argc--;
210	}
211	if (argc > 0)
212		usage();
213#ifndef DEBUG
214	daemon(1, 0);
215#endif
216	(void) signal(SIGHUP, getboottime);
217	openlog("rwhod", LOG_PID, LOG_DAEMON);
218	sp = getservbyname("who", "udp");
219	if (sp == NULL) {
220		syslog(LOG_ERR, "who/udp: unknown service");
221		exit(1);
222	}
223	if (chdir(_PATH_RWHODIR) < 0) {
224		syslog(LOG_ERR, "%s: %m", _PATH_RWHODIR);
225		exit(1);
226	}
227	/*
228	 * Establish host name as returned by system.
229	 */
230	if (gethostname(myname, sizeof(myname) - 1) < 0) {
231		syslog(LOG_ERR, "gethostname: %m");
232		exit(1);
233	}
234	if ((cp = index(myname, '.')) != NULL)
235		*cp = '\0';
236	strncpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname) - 1);
237	mywd.wd_hostname[sizeof(mywd.wd_hostname) - 1] = '\0';
238#ifdef __APPLE__
239	utmpf = open(_PATH_UTMPX, O_RDONLY|O_CREAT, 0644);
240#else
241	utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
242#endif
243	if (utmpf < 0) {
244#ifdef __APPLE__
245		syslog(LOG_ERR, "%s: %m", _PATH_UTMPX);
246#else
247		syslog(LOG_ERR, "%s: %m", _PATH_UTMP);
248#endif
249		exit(1);
250	}
251	getboottime(0);
252	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
253		syslog(LOG_ERR, "socket: %m");
254		exit(1);
255	}
256	if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) {
257		syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
258		exit(1);
259	}
260	memset(&soin, 0, sizeof(soin));
261	soin.sin_len = sizeof(soin);
262	soin.sin_family = AF_INET;
263	soin.sin_port = sp->s_port;
264	if (bind(s, (struct sockaddr *)&soin, sizeof(soin)) < 0) {
265		syslog(LOG_ERR, "bind: %m");
266		exit(1);
267	}
268	setgid(unpriv_gid);
269	setgroups(1, &unpriv_gid);	/* XXX BOGUS groups[0] = egid */
270	setuid(unpriv_uid);
271	if (!configure(s))
272		exit(1);
273	if (!quiet_mode) {
274		signal(SIGALRM, onalrm);
275		onalrm(0);
276	}
277	for (;;) {
278		struct whod wd;
279		socklen_t len = sizeof(from);
280		int cc, whod;
281		time_t t;
282
283		cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0,
284			(struct sockaddr *)&from, &len);
285		if (cc <= 0) {
286			if (cc < 0 && errno != EINTR)
287				syslog(LOG_WARNING, "recv: %m");
288			continue;
289		}
290		if (from.sin_port != sp->s_port && !insecure_mode) {
291			syslog(LOG_WARNING, "%d: bad source port from %s",
292			    ntohs(from.sin_port), inet_ntoa(from.sin_addr));
293			continue;
294		}
295		if (cc < WHDRSIZE) {
296			syslog(LOG_WARNING, "short packet from %s",
297			    inet_ntoa(from.sin_addr));
298			continue;
299		}
300		if (wd.wd_vers != WHODVERSION)
301			continue;
302		if (wd.wd_type != WHODTYPE_STATUS)
303			continue;
304		if (!verify(wd.wd_hostname, sizeof wd.wd_hostname)) {
305			syslog(LOG_WARNING, "malformed host name from %s",
306			    inet_ntoa(from.sin_addr));
307			continue;
308		}
309		(void) snprintf(path, sizeof path, "whod.%s", wd.wd_hostname);
310		/*
311		 * Rather than truncating and growing the file each time,
312		 * use ftruncate if size is less than previous size.
313		 */
314		whod = open(path, O_WRONLY | O_CREAT, 0644);
315		if (whod < 0) {
316			syslog(LOG_WARNING, "%s: %m", path);
317			continue;
318		}
319#if ENDIAN != BIG_ENDIAN
320		{
321			int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
322			struct whoent *we;
323
324			/* undo header byte swapping before writing to file */
325			wd.wd_sendtime = ntohl(wd.wd_sendtime);
326			for (i = 0; i < 3; i++)
327				wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
328			wd.wd_boottime = ntohl(wd.wd_boottime);
329			we = wd.wd_we;
330			for (i = 0; i < n; i++) {
331				we->we_idle = ntohl(we->we_idle);
332				we->we_utmp.out_time =
333				    ntohl(we->we_utmp.out_time);
334				we++;
335			}
336		}
337#endif
338		(void) time(&t);
339		wd.wd_recvtime = _time_to_int(t);
340		(void) write(whod, (char *)&wd, cc);
341		if (fstat(whod, &st) < 0 || st.st_size > cc)
342			ftruncate(whod, cc);
343		(void) close(whod);
344	}
345}
346
347static void
348usage()
349{
350	fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
351	exit(1);
352}
353
354void
355run_as(uid, gid)
356	uid_t *uid;
357	gid_t *gid;
358{
359	struct passwd *pw;
360	struct group *gr;
361
362	pw = getpwnam(UNPRIV_USER);
363	if (!pw) {
364		syslog(LOG_ERR, "getpwnam(%s): %m", UNPRIV_USER);
365		exit(1);
366	}
367	*uid = pw->pw_uid;
368
369	gr = getgrnam(UNPRIV_GROUP);
370	if (!gr) {
371		syslog(LOG_ERR, "getgrnam(%s): %m", UNPRIV_GROUP);
372		exit(1);
373	}
374	*gid = gr->gr_gid;
375}
376
377/*
378 * Check out host name for unprintables
379 * and other funnies before allowing a file
380 * to be created.  Sorry, but blanks aren't allowed.
381 */
382int
383verify(name, maxlen)
384	register char *name;
385	register int   maxlen;
386{
387	register int size = 0;
388
389	while (*name && size < maxlen - 1) {
390		if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
391			return (0);
392		name++, size++;
393	}
394	*name = '\0';
395	return (size > 0);
396}
397
398int	utmptime;
399int	utmpent;
400int	utmpsize = 0;
401#ifndef __APPLE__
402struct	utmp *utmp;
403#endif
404int	alarmcount;
405
406void
407onalrm(signo)
408	int signo __unused;
409{
410	register struct neighbor *np;
411	register struct whoent *we = mywd.wd_we, *wlast;
412	register int i;
413	struct stat stb;
414	double avenrun[3];
415	time_t now;
416	int cc;
417#ifdef __APPLE__
418	struct utmpx *u;
419#endif
420
421	now = time(NULL);
422	if (alarmcount % 10 == 0)
423		getboottime(0);
424	alarmcount++;
425	(void) fstat(utmpf, &stb);
426	if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
427		utmptime = stb.st_mtime;
428#ifdef __APPLE__
429		utmpsize = stb.st_size > utmpsize;
430		wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
431		utmpent = 0;
432		setutxent();
433		while ((u = getutxent()) != NULL)
434			if (u->ut_user[0] && u->ut_type == USER_PROCESS) {
435				memcpy(we->we_utmp.out_line, u->ut_line,
436				   sizeof(we->we_utmp.out_line));
437				memcpy(we->we_utmp.out_name, u->ut_user,
438				   sizeof(we->we_utmp.out_name));
439				we->we_utmp.out_time = htonl(u->ut_tv.tv_sec);
440				if (++we > wlast)
441					break;
442			}
443		endutxent();
444#else
445		if (stb.st_size > utmpsize) {
446			utmpsize = stb.st_size + 10 * sizeof(struct utmp);
447			utmp = (struct utmp *)reallocf(utmp, utmpsize);
448			if (utmp == NULL) {
449				syslog(LOG_WARNING, "malloc failed");
450				utmpsize = 0;
451				goto done;
452			}
453		}
454		(void) lseek(utmpf, (off_t)0, L_SET);
455		cc = read(utmpf, (char *)utmp, stb.st_size);
456		if (cc < 0) {
457			syslog(LOG_ERR, "read(%s): %m", _PATH_UTMP);
458			goto done;
459		}
460		wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
461		utmpent = cc / sizeof(struct utmp);
462		for (i = 0; i < utmpent; i++)
463			if (utmp[i].ut_name[0]) {
464				memcpy(we->we_utmp.out_line, utmp[i].ut_line,
465				   sizeof(utmp[i].ut_line));
466				memcpy(we->we_utmp.out_name, utmp[i].ut_name,
467				   sizeof(utmp[i].ut_name));
468				we->we_utmp.out_time = htonl(utmp[i].ut_time);
469				if (we >= wlast)
470					break;
471				we++;
472			}
473#endif
474		utmpent = we - mywd.wd_we;
475	}
476
477	/*
478	 * The test on utmpent looks silly---after all, if no one is
479	 * logged on, why worry about efficiency?---but is useful on
480	 * (e.g.) compute servers.
481	 */
482	if (utmpent && chdir(_PATH_DEV)) {
483		syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
484		exit(1);
485	}
486	we = mywd.wd_we;
487	for (i = 0; i < utmpent; i++) {
488		if (stat(we->we_utmp.out_line, &stb) >= 0)
489			we->we_idle = htonl(now - stb.st_atime);
490		we++;
491	}
492	(void)getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
493	for (i = 0; i < 3; i++)
494		mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
495	cc = (char *)we - (char *)&mywd;
496	mywd.wd_sendtime = htonl(_time_to_time32(time(NULL)));
497	mywd.wd_vers = WHODVERSION;
498	mywd.wd_type = WHODTYPE_STATUS;
499	if (multicast_mode == SCOPED_MULTICAST) {
500		(void) sendto(s, (char *)&mywd, cc, 0,
501				(struct sockaddr *)&multicast_addr,
502				sizeof(multicast_addr));
503	}
504	else for (np = neighbors; np != NULL; np = np->n_next) {
505		if (multicast_mode == PER_INTERFACE_MULTICAST &&
506		    np->n_flags & IFF_MULTICAST) {
507			/*
508			 * Select the outgoing interface for the multicast.
509			 */
510			if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
511			    &(((struct sockaddr_in *)np->n_addr)->sin_addr),
512			    sizeof(struct in_addr)) < 0) {
513				syslog(LOG_ERR,
514					"setsockopt IP_MULTICAST_IF: %m");
515				exit(1);
516			}
517			(void) sendto(s, (char *)&mywd, cc, 0,
518				(struct sockaddr *)&multicast_addr,
519				sizeof(multicast_addr));
520		} else (void) sendto(s, (char *)&mywd, cc, 0,
521					np->n_addr, np->n_addrlen);
522	}
523	if (utmpent && chdir(_PATH_RWHODIR)) {
524		syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
525		exit(1);
526	}
527#ifndef __APPLE__
528done:
529#endif
530	(void) alarm(AL_INTERVAL);
531}
532
533void
534getboottime(signo)
535	int signo __unused;
536{
537	int mib[2];
538	size_t size;
539	struct timeval tm;
540
541	mib[0] = CTL_KERN;
542	mib[1] = KERN_BOOTTIME;
543	size = sizeof(tm);
544	if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1) {
545		syslog(LOG_ERR, "cannot get boottime: %m");
546		exit(1);
547	}
548	mywd.wd_boottime = htonl(_time_to_time32(tm.tv_sec));
549}
550
551void
552quit(msg)
553	const char *msg;
554{
555	syslog(LOG_ERR, "%s", msg);
556	exit(1);
557}
558
559#ifdef __APPLE__
560/*
561 * This macro returns the size of a struct sockaddr when passed
562 * through a routing socket. Basically we round up sa_len to
563 * a multiple of sizeof(long), with a minimum of sizeof(long).
564 * The check for a NULL pointer is just a convenience, probably never used.
565 * The case sa_len == 0 should only apply to empty structures.
566 */
567#define SA_SIZE(sa)												\
568	(	(!(sa) || ((struct sockaddr *)(sa))->sa_len == 0) ?		\
569		sizeof(long)		:									\
570		1 + ( (((struct sockaddr *)(sa))->sa_len - 1) | (sizeof(long) - 1) ) )
571#endif
572
573void
574rt_xaddrs(cp, cplim, rtinfo)
575	register caddr_t cp, cplim;
576	register struct rt_addrinfo *rtinfo;
577{
578	register struct sockaddr *sa;
579	register int i;
580
581	memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
582	for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
583		if ((rtinfo->rti_addrs & (1 << i)) == 0)
584			continue;
585		rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
586		cp += SA_SIZE(sa);
587	}
588}
589
590/*
591 * Figure out device configuration and select
592 * networks which deserve status information.
593 */
594int
595configure(so)
596	int so;
597{
598	register struct neighbor *np;
599	register struct if_msghdr *ifm;
600	register struct ifa_msghdr *ifam;
601	struct sockaddr_dl *sdl;
602	size_t needed;
603	int mib[6], flags = 0, len;
604	char *buf, *lim, *next;
605	struct rt_addrinfo info;
606
607	if (multicast_mode != NO_MULTICAST) {
608		multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP);
609		multicast_addr.sin_port = sp->s_port;
610	}
611
612	if (multicast_mode == SCOPED_MULTICAST) {
613		struct ip_mreq mreq;
614		unsigned char ttl;
615
616		mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
617		mreq.imr_interface.s_addr = htonl(INADDR_ANY);
618		if (setsockopt(so, IPPROTO_IP, IP_ADD_MEMBERSHIP,
619					&mreq, sizeof(mreq)) < 0) {
620			syslog(LOG_ERR,
621				"setsockopt IP_ADD_MEMBERSHIP: %m");
622			return(0);
623		}
624		ttl = multicast_scope;
625		if (setsockopt(so, IPPROTO_IP, IP_MULTICAST_TTL,
626					&ttl, sizeof(ttl)) < 0) {
627			syslog(LOG_ERR,
628				"setsockopt IP_MULTICAST_TTL: %m");
629			return(0);
630		}
631		return(1);
632	}
633
634	mib[0] = CTL_NET;
635	mib[1] = PF_ROUTE;
636	mib[2] = 0;
637	mib[3] = AF_INET;
638	mib[4] = NET_RT_IFLIST;
639	mib[5] = 0;
640	if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
641		quit("route-sysctl-estimate");
642	if ((buf = malloc(needed)) == NULL)
643		quit("malloc");
644	if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
645		quit("actual retrieval of interface table");
646	lim = buf + needed;
647
648	sdl = NULL;		/* XXX just to keep gcc -Wall happy */
649	for (next = buf; next < lim; next += ifm->ifm_msglen) {
650		ifm = (struct if_msghdr *)next;
651		if (ifm->ifm_type == RTM_IFINFO) {
652			sdl = (struct sockaddr_dl *)(ifm + 1);
653			flags = ifm->ifm_flags;
654			continue;
655		}
656		if ((flags & IFF_UP) == 0 ||
657		    (flags & (((multicast_mode == PER_INTERFACE_MULTICAST) ?
658				IFF_MULTICAST : 0) |
659				IFF_BROADCAST|iff_flag)) == 0)
660			continue;
661		if (ifm->ifm_type != RTM_NEWADDR)
662			quit("out of sync parsing NET_RT_IFLIST");
663		ifam = (struct ifa_msghdr *)ifm;
664		info.rti_addrs = ifam->ifam_addrs;
665		rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
666			&info);
667		/* gag, wish we could get rid of Internet dependencies */
668#define dstaddr	info.rti_info[RTAX_BRD]
669#define ifaddr info.rti_info[RTAX_IFA]
670#define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
671#define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
672		if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
673			continue;
674		PORT_SA(dstaddr) = sp->s_port;
675		for (np = neighbors; np != NULL; np = np->n_next)
676			if (memcmp(sdl->sdl_data, np->n_name,
677				   sdl->sdl_nlen) == 0 &&
678			    IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
679				break;
680		if (np != NULL)
681			continue;
682		len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
683		np = (struct neighbor *)malloc(len);
684		if (np == NULL)
685			quit("malloc of neighbor structure");
686		memset(np, 0, len);
687		np->n_flags = flags;
688		np->n_addr = (struct sockaddr *)(np + 1);
689		np->n_addrlen = dstaddr->sa_len;
690		np->n_name = np->n_addrlen + (char *)np->n_addr;
691		memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
692		memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
693		if (multicast_mode == PER_INTERFACE_MULTICAST &&
694		    (flags & IFF_MULTICAST) &&
695		   !(flags & IFF_LOOPBACK)) {
696			struct ip_mreq mreq;
697
698			memcpy((char *)np->n_addr, (char *)ifaddr,
699				np->n_addrlen);
700			mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
701			mreq.imr_interface.s_addr =
702			  ((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr;
703			if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
704						&mreq, sizeof(mreq)) < 0) {
705				syslog(LOG_ERR,
706				    "setsockopt IP_ADD_MEMBERSHIP: %m");
707#if 0
708				/* Fall back to broadcast on this if. */
709				np->n_flags &= ~IFF_MULTICAST;
710#else
711				free((char *)np);
712				continue;
713#endif
714			}
715		}
716		np->n_next = neighbors;
717		neighbors = np;
718	}
719	free(buf);
720	return (1);
721}
722
723#ifdef DEBUG
724void
725Sendto(s, buf, cc, flags, to, tolen)
726	int s;
727	const void *buf;
728	size_t cc;
729	int flags;
730	const struct sockaddr *to;
731	int tolen;
732{
733	register struct whod *w = (struct whod *)buf;
734	register struct whoent *we;
735	struct sockaddr_in *sin = (struct sockaddr_in *)to;
736
737	printf("sendto %x.%d\n", ntohl(sin->sin_addr.s_addr),
738				 ntohs(sin->sin_port));
739	printf("hostname %s %s\n", w->wd_hostname,
740	   interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), "  up"));
741	printf("load %4.2f, %4.2f, %4.2f\n",
742	    ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
743	    ntohl(w->wd_loadav[2]) / 100.0);
744	cc -= WHDRSIZE;
745	for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
746		time_t t = _time32_to_time(ntohl(we->we_utmp.out_time));
747		printf("%-8.8s %s:%s %.12s",
748			we->we_utmp.out_name,
749			w->wd_hostname, we->we_utmp.out_line,
750			ctime(&t)+4);
751		we->we_idle = ntohl(we->we_idle) / 60;
752		if (we->we_idle) {
753			if (we->we_idle >= 100*60)
754				we->we_idle = 100*60 - 1;
755			if (we->we_idle >= 60)
756				printf(" %2d", we->we_idle / 60);
757			else
758				printf("   ");
759			printf(":%02d", we->we_idle % 60);
760		}
761		printf("\n");
762	}
763}
764
765char *
766interval(time, updown)
767	int time;
768	char *updown;
769{
770	static char resbuf[32];
771	int days, hours, minutes;
772
773	if (time < 0 || time > 3*30*24*60*60) {
774		(void) sprintf(resbuf, "   %s ??:??", updown);
775		return (resbuf);
776	}
777	minutes = (time + 59) / 60;		/* round to minutes */
778	hours = minutes / 60; minutes %= 60;
779	days = hours / 24; hours %= 24;
780	if (days)
781		(void) sprintf(resbuf, "%s %2d+%02d:%02d",
782		    updown, days, hours, minutes);
783	else
784		(void) sprintf(resbuf, "%s    %2d:%02d",
785		    updown, hours, minutes);
786	return (resbuf);
787}
788#endif
789