1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1983, 1993 The Regents of the University of California.
5 * Copyright (c) 2013 Mariusz Zaborski <oshogbo@FreeBSD.org>
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#include <sys/param.h>
34#include <sys/capsicum.h>
35#include <sys/ioctl.h>
36#include <sys/procdesc.h>
37#include <sys/socket.h>
38#include <sys/stat.h>
39#include <sys/signal.h>
40#include <sys/sysctl.h>
41#include <sys/wait.h>
42
43#include <net/if.h>
44#include <net/if_dl.h>
45#include <net/route.h>
46#include <netinet/in.h>
47#include <arpa/inet.h>
48#include <protocols/rwhod.h>
49
50#include <ctype.h>
51#include <capsicum_helpers.h>
52#include <err.h>
53#include <errno.h>
54#include <fcntl.h>
55#include <grp.h>
56#include <netdb.h>
57#include <paths.h>
58#include <pwd.h>
59#include <stdio.h>
60#include <stdlib.h>
61#include <string.h>
62#include <syslog.h>
63#include <timeconv.h>
64#include <utmpx.h>
65#include <unistd.h>
66
67#define	UNPRIV_USER		"daemon"
68#define	UNPRIV_GROUP		"daemon"
69
70#define NO_MULTICAST		0	  /* multicast modes */
71#define PER_INTERFACE_MULTICAST	1
72#define SCOPED_MULTICAST	2
73
74#define MAX_MULTICAST_SCOPE	32	  /* "site-wide", by convention */
75
76#define INADDR_WHOD_GROUP (u_long)0xe0000103      /* 224.0.1.3 */
77						  /* (belongs in protocols/rwhod.h) */
78
79int	insecure_mode;
80int	quiet_mode;
81int	iff_flag = IFF_POINTOPOINT;
82int	multicast_mode = NO_MULTICAST;
83int	multicast_scope;
84struct	sockaddr_in multicast_addr =
85	{ sizeof(multicast_addr), AF_INET, 0, { 0 }, { 0 } };
86
87/*
88 * Sleep interval. Don't forget to change the down time check in ruptime
89 * if this is changed.
90 */
91#define SL_INTERVAL (3 * 60)
92
93char	myname[MAXHOSTNAMELEN];
94
95/*
96 * We communicate with each neighbor in a list constructed at the time we're
97 * started up.  Neighbors are currently directly connected via a hardware
98 * interface.
99 */
100struct	neighbor {
101	struct	neighbor *n_next;
102	char		 *n_name;		/* interface name */
103	struct	sockaddr *n_addr;		/* who to send to */
104	int		  n_addrlen;		/* size of address */
105	int		  n_flags;		/* should forward?, interface flags */
106};
107
108struct	neighbor *neighbors;
109struct	whod mywd;
110struct	servent	*sp;
111int	s;
112int	fdp;
113pid_t	pid_child_receiver;
114
115#define	WHDRSIZE	(int)(sizeof(mywd) - sizeof(mywd.wd_we))
116
117int	configure(int so);
118void	getboottime(int signo __unused);
119void	receiver_process(void);
120void	rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo);
121void	run_as(uid_t *uid, gid_t *gid);
122void	quit(const char *msg);
123void	sender_process(void);
124int	verify(char *name, int maxlen);
125static void usage(void) __dead2;
126
127#ifdef DEBUG
128char	*interval(int time, char *updown);
129void	Sendto(int s, const void *buf, size_t cc, int flags,
130	    const struct sockaddr *to, int tolen);
131#define	 sendto Sendto
132#endif
133
134/*
135 * This version of Berkeley's rwhod has been modified to use IP multicast
136 * datagrams, under control of a new command-line option:
137 *
138 *	rwhod -m	causes rwhod to use IP multicast (instead of
139 *			broadcast or unicast) on all interfaces that have
140 *			the IFF_MULTICAST flag set in their "ifnet" structs
141 *			(excluding the loopback interface).  The multicast
142 *			reports are sent with a time-to-live of 1, to prevent
143 *			forwarding beyond the directly-connected subnet(s).
144 *
145 *	rwhod -m <ttl>	causes rwhod to send IP multicast datagrams with a
146 *			time-to-live of <ttl>, via a SINGLE interface rather
147 *			than all interfaces.  <ttl> must be between 0 and
148 *			MAX_MULTICAST_SCOPE, defined below.  Note that "-m 1"
149 *			is different than "-m", in that "-m 1" specifies
150 *			transmission on one interface only.
151 *
152 * When "-m" is used without a <ttl> argument, the program accepts multicast
153 * rwhod reports from all multicast-capable interfaces.  If a <ttl> argument
154 * is given, it accepts multicast reports from only one interface, the one
155 * on which reports are sent (which may be controlled via the host's routing
156 * table).  Regardless of the "-m" option, the program accepts broadcast or
157 * unicast reports from all interfaces.  Thus, this program will hear the
158 * reports of old, non-multicasting rwhods, but, if multicasting is used,
159 * those old rwhods won't hear the reports generated by this program.
160 *
161 *                  -- Steve Deering, Stanford University, February 1989
162 */
163int
164main(int argc, char *argv[])
165{
166	int on;
167	char *cp;
168	struct sockaddr_in soin;
169	uid_t unpriv_uid;
170	gid_t unpriv_gid;
171
172	on = 1;
173	if (getuid())
174		errx(1, "not super user");
175
176	run_as(&unpriv_uid, &unpriv_gid);
177
178	argv++;
179	argc--;
180	while (argc > 0 && *argv[0] == '-') {
181		if (strcmp(*argv, "-m") == 0) {
182			if (argc > 1 && isdigit(*(argv + 1)[0])) {
183				argv++;
184				argc--;
185				multicast_mode  = SCOPED_MULTICAST;
186				multicast_scope = atoi(*argv);
187				if (multicast_scope > MAX_MULTICAST_SCOPE) {
188					errx(1, "ttl must not exceed %u",
189					    MAX_MULTICAST_SCOPE);
190				}
191			} else {
192				multicast_mode = PER_INTERFACE_MULTICAST;
193			}
194		} else if (strcmp(*argv, "-i") == 0) {
195			insecure_mode = 1;
196		} else if (strcmp(*argv, "-l") == 0) {
197			quiet_mode = 1;
198		} else if (strcmp(*argv, "-p") == 0) {
199			iff_flag = 0;
200		} else {
201			usage();
202		}
203		argv++;
204		argc--;
205	}
206	if (argc > 0)
207		usage();
208#ifndef DEBUG
209	daemon(1, 0);
210#endif
211	(void) signal(SIGHUP, getboottime);
212	openlog("rwhod", LOG_PID | LOG_NDELAY, LOG_DAEMON);
213	sp = getservbyname("who", "udp");
214	if (sp == NULL) {
215		syslog(LOG_ERR, "who/udp: unknown service");
216		exit(1);
217	}
218	if (chdir(_PATH_RWHODIR) < 0) {
219		syslog(LOG_ERR, "%s: %m", _PATH_RWHODIR);
220		exit(1);
221	}
222	/*
223	 * Establish host name as returned by system.
224	 */
225	if (gethostname(myname, sizeof(myname) - 1) < 0) {
226		syslog(LOG_ERR, "gethostname: %m");
227		exit(1);
228	}
229	if ((cp = strchr(myname, '.')) != NULL)
230		*cp = '\0';
231	strlcpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname));
232	getboottime(0);
233	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
234		syslog(LOG_ERR, "socket: %m");
235		exit(1);
236	}
237	if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) {
238		syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
239		exit(1);
240	}
241	memset(&soin, 0, sizeof(soin));
242	soin.sin_len = sizeof(soin);
243	soin.sin_family = AF_INET;
244	soin.sin_port = sp->s_port;
245	if (bind(s, (struct sockaddr *)&soin, sizeof(soin)) < 0) {
246		syslog(LOG_ERR, "bind: %m");
247		exit(1);
248	}
249	if (setgid(unpriv_gid) != 0) {
250		syslog(LOG_ERR, "setgid: %m");
251		exit(1);
252	}
253	if (setgroups(1, &unpriv_gid) != 0) {	/* XXX BOGUS groups[0] = egid */
254		syslog(LOG_ERR, "setgroups: %m");
255		exit(1);
256	}
257	if (setuid(unpriv_uid) != 0) {
258		syslog(LOG_ERR, "setuid: %m");
259		exit(1);
260	}
261	if (!configure(s))
262		exit(1);
263	if (!quiet_mode) {
264		pid_child_receiver = pdfork(&fdp, 0);
265		if (pid_child_receiver == 0) {
266			receiver_process();
267		} else if (pid_child_receiver > 0) {
268			sender_process();
269		} else if (pid_child_receiver == -1) {
270			if (errno == ENOSYS) {
271				syslog(LOG_ERR,
272				    "The pdfork(2) system call is not available - kernel too old.");
273			} else {
274				syslog(LOG_ERR, "pdfork: %m");
275			}
276			exit(1);
277		}
278	} else {
279		receiver_process();
280	}
281}
282
283static void
284usage(void)
285{
286
287	fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
288	exit(1);
289}
290
291void
292run_as(uid_t *uid, gid_t *gid)
293{
294	struct passwd *pw;
295	struct group *gr;
296
297	pw = getpwnam(UNPRIV_USER);
298	if (pw == NULL) {
299		syslog(LOG_ERR, "getpwnam(%s): %m", UNPRIV_USER);
300		exit(1);
301	}
302	*uid = pw->pw_uid;
303
304	gr = getgrnam(UNPRIV_GROUP);
305	if (gr == NULL) {
306		syslog(LOG_ERR, "getgrnam(%s): %m", UNPRIV_GROUP);
307		exit(1);
308	}
309	*gid = gr->gr_gid;
310}
311
312/*
313 * Check out host name for unprintables
314 * and other funnies before allowing a file
315 * to be created.  Sorry, but blanks aren't allowed.
316 */
317int
318verify(char *name, int maxlen)
319{
320	int size;
321
322	size = 0;
323	while (*name != '\0' && size < maxlen - 1) {
324		if (!isascii((unsigned char)*name) ||
325		    !(isalnum((unsigned char)*name) ||
326		    ispunct((unsigned char)*name))) {
327			return (0);
328		}
329		name++;
330		size++;
331	}
332	*name = '\0';
333	return (size > 0);
334}
335
336void
337receiver_process(void)
338{
339	struct sockaddr_in from;
340	struct stat st;
341	cap_rights_t rights;
342	char path[64];
343	int dirfd;
344	struct whod wd;
345	socklen_t len;
346	int cc, whod;
347	time_t t;
348
349	len = sizeof(from);
350	dirfd = open(".", O_RDONLY | O_DIRECTORY);
351	if (dirfd < 0) {
352		syslog(LOG_WARNING, "%s: %m", _PATH_RWHODIR);
353		exit(1);
354	}
355	cap_rights_init(&rights, CAP_CREATE, CAP_FSTAT, CAP_FTRUNCATE,
356	    CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
357	if (caph_rights_limit(dirfd, &rights) < 0) {
358		syslog(LOG_WARNING, "cap_rights_limit: %m");
359		exit(1);
360	}
361	if (caph_enter() < 0) {
362		syslog(LOG_ERR, "cap_enter: %m");
363		exit(1);
364	}
365	for (;;) {
366		cc = recvfrom(s, &wd, sizeof(wd), 0, (struct sockaddr *)&from,
367		    &len);
368		if (cc <= 0) {
369			if (cc < 0 && errno != EINTR)
370				syslog(LOG_WARNING, "recv: %m");
371			continue;
372		}
373		if (from.sin_port != sp->s_port && !insecure_mode) {
374			syslog(LOG_WARNING, "%d: bad source port from %s",
375			    ntohs(from.sin_port), inet_ntoa(from.sin_addr));
376			continue;
377		}
378		if (cc < WHDRSIZE) {
379			syslog(LOG_WARNING, "short packet from %s",
380			    inet_ntoa(from.sin_addr));
381			continue;
382		}
383		if (wd.wd_vers != WHODVERSION)
384			continue;
385		if (wd.wd_type != WHODTYPE_STATUS)
386			continue;
387		if (!verify(wd.wd_hostname, sizeof(wd.wd_hostname))) {
388			syslog(LOG_WARNING, "malformed host name from %s",
389			    inet_ntoa(from.sin_addr));
390			continue;
391		}
392		(void) snprintf(path, sizeof(path), "whod.%s", wd.wd_hostname);
393		/*
394		 * Rather than truncating and growing the file each time,
395		 * use ftruncate if size is less than previous size.
396		 */
397		whod = openat(dirfd, path, O_WRONLY | O_CREAT, 0644);
398		if (whod < 0) {
399			syslog(LOG_WARNING, "%s: %m", path);
400			continue;
401		}
402		cap_rights_init(&rights, CAP_FSTAT, CAP_FTRUNCATE, CAP_WRITE);
403		if (caph_rights_limit(whod, &rights) < 0) {
404			syslog(LOG_WARNING, "cap_rights_limit: %m");
405			exit(1);
406		}
407#if ENDIAN != BIG_ENDIAN
408		{
409			struct whoent *we;
410			int i, n;
411
412			n = (cc - WHDRSIZE) / sizeof(struct whoent);
413			/* undo header byte swapping before writing to file */
414			wd.wd_sendtime = ntohl(wd.wd_sendtime);
415			for (i = 0; i < 3; i++)
416				wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
417			wd.wd_boottime = ntohl(wd.wd_boottime);
418			we = wd.wd_we;
419			for (i = 0; i < n; i++) {
420				we->we_idle = ntohl(we->we_idle);
421				we->we_utmp.out_time =
422				    ntohl(we->we_utmp.out_time);
423				we++;
424			}
425		}
426#endif
427		(void) time(&t);
428		wd.wd_recvtime = _time_to_int(t);
429		(void) write(whod, (char *)&wd, cc);
430		if (fstat(whod, &st) < 0 || st.st_size > cc)
431			ftruncate(whod, cc);
432		(void) close(whod);
433	}
434	(void) close(dirfd);
435}
436
437void
438sender_process(void)
439{
440	int sendcount;
441	double avenrun[3];
442	time_t now;
443	int i, cc, status;
444	struct utmpx *ut;
445	struct stat stb;
446	struct neighbor *np;
447	struct whoent *we, *wend;
448
449	sendcount = 0;
450	for (;;) {
451		we = mywd.wd_we;
452		now = time(NULL);
453		if (sendcount % 10 == 0)
454			getboottime(0);
455		sendcount++;
456		wend = &mywd.wd_we[1024 / sizeof(struct whoent)];
457		setutxent();
458		while ((ut = getutxent()) != NULL && we < wend) {
459			if (ut->ut_type != USER_PROCESS)
460				continue;
461			strncpy(we->we_utmp.out_line, ut->ut_line,
462			    sizeof(we->we_utmp.out_line));
463			strncpy(we->we_utmp.out_name, ut->ut_user,
464			    sizeof(we->we_utmp.out_name));
465			we->we_utmp.out_time =
466			    htonl(_time_to_time32(ut->ut_tv.tv_sec));
467			we++;
468		}
469		endutxent();
470
471		if (chdir(_PATH_DEV) < 0) {
472			syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
473			exit(1);
474		}
475		wend = we;
476		for (we = mywd.wd_we; we < wend; we++) {
477			if (stat(we->we_utmp.out_line, &stb) >= 0)
478				we->we_idle = htonl(now - stb.st_atime);
479		}
480		(void) getloadavg(avenrun,
481		    nitems(avenrun));
482		for (i = 0; i < 3; i++)
483			mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
484		cc = (char *)wend - (char *)&mywd;
485		mywd.wd_sendtime = htonl(_time_to_time32(time(NULL)));
486		mywd.wd_vers = WHODVERSION;
487		mywd.wd_type = WHODTYPE_STATUS;
488		if (multicast_mode == SCOPED_MULTICAST) {
489			(void) sendto(s, (char *)&mywd, cc, 0,
490			    (struct sockaddr *)&multicast_addr,
491			    sizeof(multicast_addr));
492		} else {
493			for (np = neighbors; np != NULL; np = np->n_next) {
494				if (multicast_mode == PER_INTERFACE_MULTICAST &&
495				    (np->n_flags & IFF_MULTICAST) != 0) {
496					/*
497					 * Select the outgoing interface for the
498					 * multicast.
499					 */
500					if (setsockopt(s, IPPROTO_IP,
501					    IP_MULTICAST_IF,
502					    &(((struct sockaddr_in *)np->n_addr)->sin_addr),
503					    sizeof(struct in_addr)) < 0) {
504						syslog(LOG_ERR,
505						    "setsockopt IP_MULTICAST_IF: %m");
506						exit(1);
507					}
508					(void) sendto(s, (char *)&mywd, cc, 0,
509					    (struct sockaddr *)&multicast_addr,
510					    sizeof(multicast_addr));
511				} else {
512					(void) sendto(s, (char *)&mywd, cc, 0,
513					    np->n_addr, np->n_addrlen);
514				}
515			}
516		}
517		if (chdir(_PATH_RWHODIR) < 0) {
518			syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
519			exit(1);
520		}
521		if (waitpid(pid_child_receiver, &status, WNOHANG) ==
522		    pid_child_receiver) {
523			break;
524		}
525		sleep(SL_INTERVAL);
526	}
527}
528
529void
530getboottime(int signo __unused)
531{
532	int mib[2];
533	size_t size;
534	struct timeval tm;
535
536	mib[0] = CTL_KERN;
537	mib[1] = KERN_BOOTTIME;
538	size = sizeof(tm);
539	if (sysctl(mib, nitems(mib), &tm, &size, NULL, 0) == -1) {
540		syslog(LOG_ERR, "cannot get boottime: %m");
541		exit(1);
542	}
543	mywd.wd_boottime = htonl(_time_to_time32(tm.tv_sec));
544}
545
546void
547quit(const char *msg)
548{
549
550	syslog(LOG_ERR, "%s", msg);
551	exit(1);
552}
553
554void
555rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
556{
557	struct sockaddr *sa;
558	int i;
559
560	memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
561	for (i = 0; i < RTAX_MAX && cp < cplim; i++) {
562		if ((rtinfo->rti_addrs & (1 << i)) == 0)
563			continue;
564		sa = (struct sockaddr *)cp;
565		rtinfo->rti_info[i] = sa;
566		cp += SA_SIZE(sa);
567	}
568}
569
570/*
571 * Figure out device configuration and select
572 * networks which deserve status information.
573 */
574int
575configure(int so)
576{
577	struct neighbor *np;
578	struct if_msghdr *ifm;
579	struct ifa_msghdr *ifam;
580	struct sockaddr_dl *sdl;
581	size_t needed;
582	int mib[6], flags, lflags, len;
583	char *buf, *lim, *next;
584	struct rt_addrinfo info;
585
586	flags = 0;
587	if (multicast_mode != NO_MULTICAST) {
588		multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP);
589		multicast_addr.sin_port = sp->s_port;
590	}
591
592	if (multicast_mode == SCOPED_MULTICAST) {
593		struct ip_mreq mreq;
594		unsigned char ttl;
595
596		mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
597		mreq.imr_interface.s_addr = htonl(INADDR_ANY);
598		if (setsockopt(so, IPPROTO_IP, IP_ADD_MEMBERSHIP,
599		    &mreq, sizeof(mreq)) < 0) {
600			syslog(LOG_ERR,
601			    "setsockopt IP_ADD_MEMBERSHIP: %m");
602			return (0);
603		}
604		ttl = multicast_scope;
605		if (setsockopt(so, IPPROTO_IP, IP_MULTICAST_TTL, &ttl,
606		    sizeof(ttl)) < 0) {
607			syslog(LOG_ERR,
608			    "setsockopt IP_MULTICAST_TTL: %m");
609			return (0);
610		}
611		return (1);
612	}
613
614	mib[0] = CTL_NET;
615	mib[1] = PF_ROUTE;
616	mib[2] = 0;
617	mib[3] = AF_INET;
618	mib[4] = NET_RT_IFLIST;
619	mib[5] = 0;
620	if (sysctl(mib, nitems(mib), NULL, &needed, NULL, 0) < 0)
621		quit("route-sysctl-estimate");
622	if ((buf = malloc(needed)) == NULL)
623		quit("malloc");
624	if (sysctl(mib, nitems(mib), buf, &needed, NULL, 0) < 0)
625		quit("actual retrieval of interface table");
626	lim = buf + needed;
627
628	sdl = NULL;		/* XXX just to keep gcc -Wall happy */
629	for (next = buf; next < lim; next += ifm->ifm_msglen) {
630		ifm = (struct if_msghdr *)next;
631		if (ifm->ifm_type == RTM_IFINFO) {
632			sdl = (struct sockaddr_dl *)(ifm + 1);
633			flags = ifm->ifm_flags;
634			continue;
635		}
636		if ((flags & IFF_UP) == 0)
637			continue;
638		lflags = IFF_BROADCAST | iff_flag;
639		if (multicast_mode == PER_INTERFACE_MULTICAST)
640			lflags |= IFF_MULTICAST;
641		if ((flags & lflags) == 0)
642			continue;
643		if (ifm->ifm_type != RTM_NEWADDR)
644			quit("out of sync parsing NET_RT_IFLIST");
645		ifam = (struct ifa_msghdr *)ifm;
646		info.rti_addrs = ifam->ifam_addrs;
647		rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
648		    &info);
649		/* gag, wish we could get rid of Internet dependencies */
650#define	dstaddr		info.rti_info[RTAX_BRD]
651#define	ifaddr		info.rti_info[RTAX_IFA]
652#define	IPADDR_SA(x)	((struct sockaddr_in *)(x))->sin_addr.s_addr
653#define	PORT_SA(x)	((struct sockaddr_in *)(x))->sin_port
654		if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
655			continue;
656		PORT_SA(dstaddr) = sp->s_port;
657		for (np = neighbors; np != NULL; np = np->n_next) {
658			if (memcmp(sdl->sdl_data, np->n_name,
659			    sdl->sdl_nlen) == 0 &&
660			    IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr)) {
661				break;
662			}
663		}
664		if (np != NULL)
665			continue;
666		len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
667		np = malloc(len);
668		if (np == NULL)
669			quit("malloc of neighbor structure");
670		memset(np, 0, len);
671		np->n_flags = flags;
672		np->n_addr = (struct sockaddr *)(np + 1);
673		np->n_addrlen = dstaddr->sa_len;
674		np->n_name = np->n_addrlen + (char *)np->n_addr;
675		memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
676		memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
677		if (multicast_mode == PER_INTERFACE_MULTICAST &&
678		    (flags & IFF_MULTICAST) != 0 &&
679		    (flags & IFF_LOOPBACK) == 0) {
680			struct ip_mreq mreq;
681
682			memcpy((char *)np->n_addr, (char *)ifaddr,
683			    np->n_addrlen);
684			mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
685			mreq.imr_interface.s_addr =
686			    ((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr;
687			if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
688			    &mreq, sizeof(mreq)) < 0) {
689				syslog(LOG_ERR,
690				    "setsockopt IP_ADD_MEMBERSHIP: %m");
691#if 0
692				/* Fall back to broadcast on this if. */
693				np->n_flags &= ~IFF_MULTICAST;
694#else
695				free(np);
696				continue;
697#endif
698			}
699		}
700		np->n_next = neighbors;
701		neighbors = np;
702	}
703	free(buf);
704	return (1);
705}
706
707#ifdef DEBUG
708void
709Sendto(int s, const void *buf, size_t cc, int flags, const struct sockaddr *to,
710    int tolen)
711{
712	struct whod *w;
713	struct whoent *we;
714	struct sockaddr_in *sin;
715
716	w = (struct whod *)buf;
717	sin = (struct sockaddr_in *)to;
718	printf("sendto %x.%d\n", ntohl(sin->sin_addr.s_addr),
719	    ntohs(sin->sin_port));
720	printf("hostname %s %s\n", w->wd_hostname,
721	    interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), "  up"));
722	printf("load %4.2f, %4.2f, %4.2f\n",
723	    ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
724	    ntohl(w->wd_loadav[2]) / 100.0);
725	cc -= WHDRSIZE;
726	for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
727		time_t t = _time32_to_time(ntohl(we->we_utmp.out_time));
728
729		printf("%-8.8s %s:%s %.12s", we->we_utmp.out_name,
730		    w->wd_hostname, we->we_utmp.out_line, ctime(&t) + 4);
731		we->we_idle = ntohl(we->we_idle) / 60;
732		if (we->we_idle != 0) {
733			if (we->we_idle >= 100 * 60)
734				we->we_idle = 100 * 60 - 1;
735			if (we->we_idle >= 60)
736				printf(" %2d", we->we_idle / 60);
737			else
738				printf("   ");
739			printf(":%02d", we->we_idle % 60);
740		}
741		printf("\n");
742	}
743}
744
745char *
746interval(int time, char *updown)
747{
748	static char resbuf[32];
749	int days, hours, minutes;
750
751	if (time < 0 || time > 3 * 30 * 24 * 60 * 60) {
752		(void) sprintf(resbuf, "   %s ??:??", updown);
753		return (resbuf);
754	}
755	minutes = (time + 59) / 60;		/* round to minutes */
756	hours = minutes / 60;
757	minutes %= 60;
758	days = hours / 24;
759	hours %= 24;
760	if (days > 0) {
761		(void) sprintf(resbuf, "%s %2d+%02d:%02d",
762		    updown, days, hours, minutes);
763	} else {
764		(void) sprintf(resbuf, "%s    %2d:%02d",
765		    updown, hours, minutes);
766	}
767	return (resbuf);
768}
769#endif
770