2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * @(#) Copyright (c) 1983, 1993 The Regents of the University of California. All rights reserved.
34 * @(#)rwhod.c 8.1 (Berkeley) 6/6/93
35 * $FreeBSD: src/usr.sbin/rwhod/rwhod.c,v 1.13.2.2 2000/12/23 15:28:12 iedowse Exp $
36 * $DragonFly: src/usr.sbin/rwhod/rwhod.c,v 1.6 2004/12/18 22:48:14 swildner Exp $
39 #include <sys/param.h>
40 #include <sys/socket.h>
42 #include <sys/signal.h>
43 #include <sys/ioctl.h>
44 #include <sys/sysctl.h>
47 #include <net/if_dl.h>
48 #include <net/route.h>
49 #include <netinet/in.h>
50 #include <arpa/inet.h>
51 #include <protocols/rwhod.h>
69 * This version of Berkeley's rwhod has been modified to use IP multicast
70 * datagrams, under control of a new command-line option:
72 * rwhod -m causes rwhod to use IP multicast (instead of
73 * broadcast or unicast) on all interfaces that have
74 * the IFF_MULTICAST flag set in their "ifnet" structs
75 * (excluding the loopback interface). The multicast
76 * reports are sent with a time-to-live of 1, to prevent
77 * forwarding beyond the directly-connected subnet(s).
79 * rwhod -m <ttl> causes rwhod to send IP multicast datagrams with a
80 * time-to-live of <ttl>, via a SINGLE interface rather
81 * than all interfaces. <ttl> must be between 0 and
82 * MAX_MULTICAST_SCOPE, defined below. Note that "-m 1"
83 * is different than "-m", in that "-m 1" specifies
84 * transmission on one interface only.
86 * When "-m" is used without a <ttl> argument, the program accepts multicast
87 * rwhod reports from all multicast-capable interfaces. If a <ttl> argument
88 * is given, it accepts multicast reports from only one interface, the one
89 * on which reports are sent (which may be controlled via the host's routing
90 * table). Regardless of the "-m" option, the program accepts broadcast or
91 * unicast reports from all interfaces. Thus, this program will hear the
92 * reports of old, non-multicasting rwhods, but, if multicasting is used,
93 * those old rwhods won't hear the reports generated by this program.
95 * -- Steve Deering, Stanford University, February 1989
98 #define UNPRIV_USER "daemon"
99 #define UNPRIV_GROUP "daemon"
101 #define NO_MULTICAST 0 /* multicast modes */
102 #define PER_INTERFACE_MULTICAST 1
103 #define SCOPED_MULTICAST 2
105 #define MAX_MULTICAST_SCOPE 32 /* "site-wide", by convention */
107 #define INADDR_WHOD_GROUP (u_long)0xe0000103 /* 224.0.1.3 */
108 /* (belongs in protocols/rwhod.h) */
112 int iff_flag = IFF_POINTOPOINT;
113 int multicast_mode = NO_MULTICAST;
115 struct sockaddr_in multicast_addr = { sizeof multicast_addr, AF_INET };
118 * Alarm interval. Don't forget to change the down time check in ruptime
119 * if this is changed.
121 #define AL_INTERVAL (3 * 60)
123 char myname[MAXHOSTNAMELEN];
126 * We communicate with each neighbor in a list constructed at the time we're
127 * started up. Neighbors are currently directly connected via a hardware
131 struct neighbor *n_next;
132 char *n_name; /* interface name */
133 struct sockaddr *n_addr; /* who to send to */
134 int n_addrlen; /* size of address */
135 int n_flags; /* should forward?, interface flags */
138 struct neighbor *neighbors;
143 #define WHDRSIZE (sizeof(mywd) - sizeof(mywd.wd_we))
145 void run_as(uid_t *, gid_t *);
147 void getboottime(int);
150 void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
151 int verify(char *, int);
152 static void usage(void);
154 char *interval(int, char *);
155 void Sendto(int, const void *, size_t, int,
156 const struct sockaddr *, int);
157 #define sendto Sendto
161 main(int argc, char *argv[])
163 struct sockaddr_in from;
168 struct sockaddr_in sin;
173 errx(1, "not super user");
175 run_as(&unpriv_uid, &unpriv_gid);
178 while (argc > 0 && *argv[0] == '-') {
179 if (strcmp(*argv, "-m") == 0) {
180 if (argc > 1 && isdigit(*(argv + 1)[0])) {
182 multicast_mode = SCOPED_MULTICAST;
183 multicast_scope = atoi(*argv);
184 if (multicast_scope > MAX_MULTICAST_SCOPE)
185 errx(1, "ttl must not exceed %u",
186 MAX_MULTICAST_SCOPE);
188 else multicast_mode = PER_INTERFACE_MULTICAST;
190 else if (strcmp(*argv, "-i") == 0)
192 else if (strcmp(*argv, "-l") == 0)
194 else if (strcmp(*argv, "-p") == 0)
205 signal(SIGHUP, getboottime);
206 openlog("rwhod", LOG_PID, LOG_DAEMON);
207 sp = getservbyname("who", "udp");
209 syslog(LOG_ERR, "udp/who: unknown service");
212 if (chdir(_PATH_RWHODIR) < 0) {
213 syslog(LOG_ERR, "%s: %m", _PATH_RWHODIR);
217 * Establish host name as returned by system.
219 if (gethostname(myname, sizeof(myname) - 1) < 0) {
220 syslog(LOG_ERR, "gethostname: %m");
223 if ((cp = strchr(myname, '.')) != NULL)
225 strncpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname) - 1);
226 mywd.wd_hostname[sizeof(mywd.wd_hostname) - 1] = '\0';
227 utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
229 syslog(LOG_ERR, "%s: %m", _PATH_UTMP);
233 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
234 syslog(LOG_ERR, "socket: %m");
237 if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) {
238 syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
241 memset(&sin, 0, sizeof(sin));
242 sin.sin_len = sizeof(sin);
243 sin.sin_family = AF_INET;
244 sin.sin_port = sp->s_port;
245 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
246 syslog(LOG_ERR, "bind: %m");
250 setgroups(1, &unpriv_gid); /* XXX BOGUS groups[0] = egid */
255 signal(SIGALRM, onalrm);
260 int cc, whod, len = sizeof(from);
262 cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0,
263 (struct sockaddr *)&from, &len);
265 if (cc < 0 && errno != EINTR)
266 syslog(LOG_WARNING, "recv: %m");
269 if (from.sin_port != sp->s_port && !insecure_mode) {
270 syslog(LOG_WARNING, "%d: bad source port from %s",
271 ntohs(from.sin_port), inet_ntoa(from.sin_addr));
275 syslog(LOG_WARNING, "short packet from %s",
276 inet_ntoa(from.sin_addr));
279 if (wd.wd_vers != WHODVERSION)
281 if (wd.wd_type != WHODTYPE_STATUS)
283 if (!verify(wd.wd_hostname, sizeof wd.wd_hostname)) {
284 syslog(LOG_WARNING, "malformed host name from %s",
285 inet_ntoa(from.sin_addr));
288 snprintf(path, sizeof path, "whod.%s", wd.wd_hostname);
290 * Rather than truncating and growing the file each time,
291 * use ftruncate if size is less than previous size.
293 whod = open(path, O_WRONLY | O_CREAT, 0644);
295 syslog(LOG_WARNING, "%s: %m", path);
298 #if ENDIAN != BIG_ENDIAN
300 int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
303 /* undo header byte swapping before writing to file */
304 wd.wd_sendtime = ntohl(wd.wd_sendtime);
305 for (i = 0; i < 3; i++)
306 wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
307 wd.wd_boottime = ntohl(wd.wd_boottime);
309 for (i = 0; i < n; i++) {
310 we->we_idle = ntohl(we->we_idle);
311 we->we_utmp.out_time =
312 ntohl(we->we_utmp.out_time);
317 time((time_t *)&wd.wd_recvtime);
318 write(whod, (char *)&wd, cc);
319 if (fstat(whod, &st) < 0 || st.st_size > cc)
329 fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
334 run_as(uid_t *uid, gid_t *gid)
339 pw = getpwnam(UNPRIV_USER);
341 syslog(LOG_ERR, "getpwnam(%s): %m", UNPRIV_USER);
346 gr = getgrnam(UNPRIV_GROUP);
348 syslog(LOG_ERR, "getgrnam(%s): %m", UNPRIV_GROUP);
355 * Check out host name for unprintables
356 * and other funnies before allowing a file
357 * to be created. Sorry, but blanks aren't allowed.
360 verify(char *name, int maxlen)
364 while (*name && size < maxlen - 1) {
365 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
383 struct whoent *we = mywd.wd_we, *wlast;
391 if (alarmcount % 10 == 0)
395 if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
396 utmptime = stb.st_mtime;
397 if (stb.st_size > utmpsize) {
398 utmpsize = stb.st_size + 10 * sizeof(struct utmp);
400 utmp = (struct utmp *)realloc(utmp, utmpsize);
402 utmp = (struct utmp *)malloc(utmpsize);
404 syslog(LOG_WARNING, "malloc failed");
409 lseek(utmpf, (off_t)0, L_SET);
410 cc = read(utmpf, (char *)utmp, stb.st_size);
412 syslog(LOG_ERR, "read(%s): %m", _PATH_UTMP);
415 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
416 utmpent = cc / sizeof(struct utmp);
417 for (i = 0; i < utmpent; i++)
418 if (utmp[i].ut_name[0]) {
419 memcpy(we->we_utmp.out_line, utmp[i].ut_line,
420 sizeof(utmp[i].ut_line));
421 memcpy(we->we_utmp.out_name, utmp[i].ut_name,
422 sizeof(utmp[i].ut_name));
423 we->we_utmp.out_time = htonl(utmp[i].ut_time);
428 utmpent = we - mywd.wd_we;
432 * The test on utmpent looks silly---after all, if no one is
433 * logged on, why worry about efficiency?---but is useful on
434 * (e.g.) compute servers.
436 if (utmpent && chdir(_PATH_DEV)) {
437 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
441 for (i = 0; i < utmpent; i++) {
442 if (stat(we->we_utmp.out_line, &stb) >= 0)
443 we->we_idle = htonl(now - stb.st_atime);
446 getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
447 for (i = 0; i < 3; i++)
448 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
449 cc = (char *)we - (char *)&mywd;
450 mywd.wd_sendtime = htonl(time(0));
451 mywd.wd_vers = WHODVERSION;
452 mywd.wd_type = WHODTYPE_STATUS;
453 if (multicast_mode == SCOPED_MULTICAST) {
454 sendto(s, (char *)&mywd, cc, 0,
455 (struct sockaddr *)&multicast_addr,
456 sizeof(multicast_addr));
458 else for (np = neighbors; np != NULL; np = np->n_next) {
459 if (multicast_mode == PER_INTERFACE_MULTICAST &&
460 np->n_flags & IFF_MULTICAST) {
462 * Select the outgoing interface for the multicast.
464 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
465 &(((struct sockaddr_in *)np->n_addr)->sin_addr),
466 sizeof(struct in_addr)) < 0) {
468 "setsockopt IP_MULTICAST_IF: %m");
471 sendto(s, (char *)&mywd, cc, 0,
472 (struct sockaddr *)&multicast_addr,
473 sizeof(multicast_addr));
474 } else sendto(s, (char *)&mywd, cc, 0,
475 np->n_addr, np->n_addrlen);
477 if (utmpent && chdir(_PATH_RWHODIR)) {
478 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
486 getboottime(int signo)
493 mib[1] = KERN_BOOTTIME;
495 if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1) {
496 syslog(LOG_ERR, "cannot get boottime: %m");
499 mywd.wd_boottime = htonl(tm.tv_sec);
506 syslog(LOG_ERR, "%s", msg);
511 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
512 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
515 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
520 memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
521 for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
522 if ((rtinfo->rti_addrs & (1 << i)) == 0)
524 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
530 * Figure out device configuration and select
531 * networks which deserve status information.
537 struct if_msghdr *ifm;
538 struct ifa_msghdr *ifam;
539 struct sockaddr_dl *sdl;
541 int mib[6], flags = 0, len;
542 char *buf, *lim, *next;
543 struct rt_addrinfo info;
545 if (multicast_mode != NO_MULTICAST) {
546 multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP);
547 multicast_addr.sin_port = sp->s_port;
550 if (multicast_mode == SCOPED_MULTICAST) {
554 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
555 mreq.imr_interface.s_addr = htonl(INADDR_ANY);
556 if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
557 &mreq, sizeof(mreq)) < 0) {
559 "setsockopt IP_ADD_MEMBERSHIP: %m");
562 ttl = multicast_scope;
563 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL,
564 &ttl, sizeof(ttl)) < 0) {
566 "setsockopt IP_MULTICAST_TTL: %m");
576 mib[4] = NET_RT_IFLIST;
578 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
579 quit("route-sysctl-estimate");
580 if ((buf = malloc(needed)) == NULL)
582 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
583 quit("actual retrieval of interface table");
586 sdl = NULL; /* XXX just to keep gcc -Wall happy */
587 for (next = buf; next < lim; next += ifm->ifm_msglen) {
588 ifm = (struct if_msghdr *)next;
589 if (ifm->ifm_type == RTM_IFINFO) {
590 sdl = (struct sockaddr_dl *)(ifm + 1);
591 flags = ifm->ifm_flags;
594 if ((flags & IFF_UP) == 0 ||
595 (flags & (((multicast_mode == PER_INTERFACE_MULTICAST) ?
597 IFF_BROADCAST|iff_flag)) == 0)
599 if (ifm->ifm_type != RTM_NEWADDR)
600 quit("out of sync parsing NET_RT_IFLIST");
601 ifam = (struct ifa_msghdr *)ifm;
602 info.rti_addrs = ifam->ifam_addrs;
603 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
605 /* gag, wish we could get rid of Internet dependencies */
606 #define dstaddr info.rti_info[RTAX_BRD]
607 #define ifaddr info.rti_info[RTAX_IFA]
608 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
609 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
610 if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
612 PORT_SA(dstaddr) = sp->s_port;
613 for (np = neighbors; np != NULL; np = np->n_next)
614 if (memcmp(sdl->sdl_data, np->n_name,
615 sdl->sdl_nlen) == 0 &&
616 IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
620 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
621 np = (struct neighbor *)malloc(len);
623 quit("malloc of neighbor structure");
626 np->n_addr = (struct sockaddr *)(np + 1);
627 np->n_addrlen = dstaddr->sa_len;
628 np->n_name = np->n_addrlen + (char *)np->n_addr;
629 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
630 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
631 if (multicast_mode == PER_INTERFACE_MULTICAST &&
632 (flags & IFF_MULTICAST) &&
633 !(flags & IFF_LOOPBACK)) {
636 memcpy((char *)np->n_addr, (char *)ifaddr,
638 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
639 mreq.imr_interface.s_addr =
640 ((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr;
641 if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
642 &mreq, sizeof(mreq)) < 0) {
644 "setsockopt IP_ADD_MEMBERSHIP: %m");
646 /* Fall back to broadcast on this if. */
647 np->n_flags &= ~IFF_MULTICAST;
654 np->n_next = neighbors;
663 Sendto(int s, const void *buf, size_t cc, int flags,
664 const struct sockaddr *to, int tolen)
666 struct whod *w = (struct whod *)buf;
668 struct sockaddr_in *sin = (struct sockaddr_in *)to;
670 printf("sendto %x.%d\n", ntohl(sin->sin_addr.s_addr),
671 ntohs(sin->sin_port));
672 printf("hostname %s %s\n", w->wd_hostname,
673 interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), " up"));
674 printf("load %4.2f, %4.2f, %4.2f\n",
675 ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
676 ntohl(w->wd_loadav[2]) / 100.0);
678 for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
679 time_t t = ntohl(we->we_utmp.out_time);
680 printf("%-8.8s %s:%s %.12s",
681 we->we_utmp.out_name,
682 w->wd_hostname, we->we_utmp.out_line,
684 we->we_idle = ntohl(we->we_idle) / 60;
686 if (we->we_idle >= 100*60)
687 we->we_idle = 100*60 - 1;
688 if (we->we_idle >= 60)
689 printf(" %2d", we->we_idle / 60);
692 printf(":%02d", we->we_idle % 60);
699 interval(int time, char *updown)
701 static char resbuf[32];
702 int days, hours, minutes;
704 if (time < 0 || time > 3*30*24*60*60) {
705 sprintf(resbuf, " %s ??:??", updown);
708 minutes = (time + 59) / 60; /* round to minutes */
709 hours = minutes / 60; minutes %= 60;
710 days = hours / 24; hours %= 24;
712 sprintf(resbuf, "%s %2d+%02d:%02d",
713 updown, days, hours, minutes);
715 sprintf(resbuf, "%s %2d:%02d",
716 updown, hours, minutes);