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 1.17 2005/05/22 17:09:53 liamfoy 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 WITH_ERRNO 1 /* Write to syslog with errno (%m) */
102 #define WITHOUT_ERRNO 0 /* Write to syslog without errno */
104 #define NO_MULTICAST 0 /* multicast modes */
105 #define PER_INTERFACE_MULTICAST 1
106 #define SCOPED_MULTICAST 2
108 #define MAX_MULTICAST_SCOPE 32 /* "site-wide", by convention */
110 #define INADDR_WHOD_GROUP (u_long)0xe0000103 /* 224.0.1.3 */
111 /* (belongs in protocols/rwhod.h) */
115 int iff_flag = IFF_POINTOPOINT;
116 int multicast_mode = NO_MULTICAST;
118 struct sockaddr_in multicast_addr;
121 * Alarm interval. Don't forget to change the down time check in ruptime
122 * if this is changed.
124 #define AL_INTERVAL (3 * 60)
126 char myname[MAXHOSTNAMELEN];
129 * We communicate with each neighbor in a list constructed at the time we're
130 * started up. Neighbors are currently directly connected via a hardware
134 struct neighbor *n_next;
135 char *n_name; /* interface name */
136 struct sockaddr *n_addr; /* who to send to */
137 int n_addrlen; /* size of address */
138 int n_flags; /* should forward?, interface flags */
141 struct neighbor *neighbors;
145 volatile sig_atomic_t got_sigalrm, got_sighup;
147 #define WHDRSIZE (sizeof(mywd) - sizeof(mywd.wd_we))
149 void run_as(uid_t *, gid_t *);
151 void getboottime(void);
154 void quit(const char *, int);
155 void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
156 int verify(char *, int);
157 static void usage(void);
160 char *interval(int, const char *);
161 ssize_t Sendto(int, const void *, size_t, int,
162 const struct sockaddr *, int);
164 #define Sendto sendto
168 main(int argc, char *argv[])
170 struct sockaddr_in from;
172 char path[64], *ep, *cp;
174 struct sockaddr_in m_sin;
180 errx(1, "not super user");
182 run_as(&unpriv_uid, &unpriv_gid);
185 while (argc > 0 && *argv[0] == '-') {
186 if (strcmp(*argv, "-m") == 0) {
187 if (argc > 1 && *(argv + 1)[0] != '-') {
188 /* Argument has been given */
190 multicast_mode = SCOPED_MULTICAST;
191 tmp = strtol(*argv, &ep, 10);
192 if (*ep != '\0' || tmp < INT_MIN || tmp > INT_MAX)
193 errx(1, "invalid ttl: %s", *argv);
194 multicast_scope = (int)tmp;
195 if (multicast_scope > MAX_MULTICAST_SCOPE)
196 errx(1, "ttl must not exceed %u",
197 MAX_MULTICAST_SCOPE);
199 else multicast_mode = PER_INTERFACE_MULTICAST;
201 else if (strcmp(*argv, "-i") == 0)
203 else if (strcmp(*argv, "-l") == 0)
205 else if (strcmp(*argv, "-p") == 0)
216 signal(SIGHUP, onsignal);
217 openlog("rwhod", LOG_PID, LOG_DAEMON);
218 sp = getservbyname("who", "udp");
220 quit("udp/who: unknown service", WITHOUT_ERRNO);
222 if (chdir(_PATH_RWHODIR) < 0)
223 quit(_PATH_RWHODIR, WITH_ERRNO);
226 * Establish host name as returned by system.
228 if (gethostname(myname, sizeof(myname)) < 0)
229 quit("gethostname", WITH_ERRNO);
231 if ((cp = strchr(myname, '.')) != NULL)
233 strlcpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname));
234 utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
236 quit(_PATH_UTMP, WITH_ERRNO);
239 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
240 quit("socket", WITH_ERRNO);
242 if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0)
243 quit("setsockopt SO_BROADCAST", WITH_ERRNO);
245 memset(&m_sin, 0, sizeof(m_sin));
246 m_sin.sin_len = sizeof(m_sin);
247 m_sin.sin_family = AF_INET;
248 m_sin.sin_port = sp->s_port;
249 if (bind(s, (struct sockaddr *)&m_sin, sizeof(m_sin)) < 0)
250 quit("bind", WITH_ERRNO);
253 setgroups(1, &unpriv_gid); /* XXX BOGUS groups[0] = egid */
258 signal(SIGALRM, onsignal);
264 socklen_t len = sizeof(from);
266 if (got_sigalrm == 1) {
270 else if (got_sighup == 1) {
275 cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0,
276 (struct sockaddr *)&from, &len);
280 if (errno == EINTR) {
281 if (got_sigalrm == 1) {
285 else if (got_sighup == 1) {
290 syslog(LOG_WARNING, "recv: %m");
294 if (from.sin_port != sp->s_port && !insecure_mode) {
295 syslog(LOG_WARNING, "%d: bad source port from %s",
296 ntohs(from.sin_port), inet_ntoa(from.sin_addr));
299 if (cc < (int)WHDRSIZE) {
300 syslog(LOG_WARNING, "short packet from %s",
301 inet_ntoa(from.sin_addr));
304 if (wd.wd_vers != WHODVERSION)
306 if (wd.wd_type != WHODTYPE_STATUS)
308 if (!verify(wd.wd_hostname, sizeof wd.wd_hostname)) {
309 syslog(LOG_WARNING, "malformed host name from %s",
310 inet_ntoa(from.sin_addr));
313 snprintf(path, sizeof path, "whod.%s", wd.wd_hostname);
315 * Rather than truncating and growing the file each time,
316 * use ftruncate if size is less than previous size.
318 whod = open(path, O_WRONLY | O_CREAT, 0644);
320 syslog(LOG_WARNING, "%s: %m", path);
323 #if ENDIAN != BIG_ENDIAN
325 int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
328 /* undo header byte swapping before writing to file */
329 wd.wd_sendtime = ntohl(wd.wd_sendtime);
330 for (i = 0; i < 3; i++)
331 wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
332 wd.wd_boottime = ntohl(wd.wd_boottime);
334 for (i = 0; i < n; i++) {
335 we->we_idle = ntohl(we->we_idle);
336 we->we_utmp.out_time =
337 ntohl(we->we_utmp.out_time);
342 time((time_t *)&wd.wd_recvtime);
343 write(whod, (char *)&wd, cc);
344 if (fstat(whod, &st) < 0 || st.st_size > cc)
353 fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
358 run_as(uid_t *uid, gid_t *gid)
363 pw = getpwnam(UNPRIV_USER);
365 quit("getpwnam(daemon)", WITH_ERRNO);
369 gr = getgrnam(UNPRIV_GROUP);
371 quit("getgrnam(daemon)", WITH_ERRNO);
377 * Check out host name for unprintables
378 * and other funnies before allowing a file
379 * to be created. Sorry, but blanks aren't allowed.
382 verify(char *name, int maxlen)
386 while (*name && size < maxlen - 1) {
387 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
398 if (signo == SIGALRM)
414 struct whoent *we = mywd.wd_we, *wlast;
422 if (alarmcount % 10 == 0)
426 if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
427 utmptime = stb.st_mtime;
428 if (stb.st_size > utmpsize) {
429 utmpsize = stb.st_size + 10 * sizeof(struct utmp);
431 utmp = (struct utmp *)realloc(utmp, utmpsize);
433 utmp = (struct utmp *)malloc(utmpsize);
435 syslog(LOG_WARNING, "malloc failed: %m");
440 lseek(utmpf, (off_t)0, L_SET);
441 cc = read(utmpf, (char *)utmp, stb.st_size);
443 syslog(LOG_ERR, "read(%s): %m", _PATH_UTMP);
446 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
447 utmpent = cc / sizeof(struct utmp);
448 for (i = 0; i < utmpent; i++)
449 if (utmp[i].ut_name[0]) {
450 memcpy(we->we_utmp.out_line, utmp[i].ut_line,
451 sizeof(utmp[i].ut_line));
452 memcpy(we->we_utmp.out_name, utmp[i].ut_name,
453 sizeof(utmp[i].ut_name));
454 we->we_utmp.out_time = htonl(utmp[i].ut_time);
459 utmpent = we - mywd.wd_we;
463 * The test on utmpent looks silly---after all, if no one is
464 * logged on, why worry about efficiency?---but is useful on
465 * (e.g.) compute servers.
467 if (utmpent && chdir(_PATH_DEV)) {
468 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
473 for (i = 0; i < utmpent; i++) {
474 if (stat(we->we_utmp.out_line, &stb) >= 0)
475 we->we_idle = htonl(now - stb.st_atime);
478 getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
479 for (i = 0; i < 3; i++)
480 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
481 cc = (char *)we - (char *)&mywd;
482 mywd.wd_sendtime = htonl(time(0));
483 mywd.wd_vers = WHODVERSION;
484 mywd.wd_type = WHODTYPE_STATUS;
485 if (multicast_mode == SCOPED_MULTICAST) {
486 Sendto(s, (char *)&mywd, cc, 0,
487 (struct sockaddr *)&multicast_addr,
488 sizeof(multicast_addr));
490 else for (np = neighbors; np != NULL; np = np->n_next) {
491 if (multicast_mode == PER_INTERFACE_MULTICAST &&
492 np->n_flags & IFF_MULTICAST) {
494 * Select the outgoing interface for the multicast.
496 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
497 &(((struct sockaddr_in *)np->n_addr)->sin_addr),
498 sizeof(struct in_addr)) < 0) {
499 quit("setsockopt IP_MULTICAST_IF", WITH_ERRNO);
501 Sendto(s, (char *)&mywd, cc, 0,
502 (struct sockaddr *)&multicast_addr,
503 sizeof(multicast_addr));
504 } else Sendto(s, (char *)&mywd, cc, 0,
505 np->n_addr, np->n_addrlen);
507 if (utmpent && chdir(_PATH_RWHODIR)) {
508 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
523 mib[1] = KERN_BOOTTIME;
525 if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1)
526 quit("cannot get boottime", WITH_ERRNO);
528 mywd.wd_boottime = htonl(tm.tv_sec);
532 * If wrterrno == WITH_ERRNO, we will print
533 * errno. If not, we leave errno out.
536 quit(const char *msg, int wrterrno)
539 syslog(LOG_ERR, "%s: %m", msg);
541 syslog(LOG_ERR, "%s", msg);
546 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
547 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
550 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
555 memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
556 for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
557 if ((rtinfo->rti_addrs & (1 << i)) == 0)
559 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
565 * Figure out device configuration and select
566 * networks which deserve status information.
569 configure(int c_sock)
572 struct if_msghdr *ifm;
573 struct ifa_msghdr *ifam;
574 struct sockaddr_dl *sdl;
576 int mib[6], flags = 0, len;
577 char *buf, *lim, *next;
578 struct rt_addrinfo info;
580 if (multicast_mode != NO_MULTICAST) {
581 multicast_addr.sin_len = sizeof(multicast_addr);
582 multicast_addr.sin_family = AF_INET;
583 multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP);
584 multicast_addr.sin_port = sp->s_port;
587 if (multicast_mode == SCOPED_MULTICAST) {
591 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
592 mreq.imr_interface.s_addr = htonl(INADDR_ANY);
593 if (setsockopt(c_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
594 &mreq, sizeof(mreq)) < 0) {
596 "setsockopt IP_ADD_MEMBERSHIP: %m");
599 ttl = multicast_scope;
600 if (setsockopt(c_sock, IPPROTO_IP, IP_MULTICAST_TTL,
601 &ttl, sizeof(ttl)) < 0) {
603 "setsockopt IP_MULTICAST_TTL: %m");
613 mib[4] = NET_RT_IFLIST;
615 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
616 quit("route-sysctl-estimate", WITH_ERRNO);
617 if ((buf = malloc(needed)) == NULL)
618 quit("malloc", WITH_ERRNO);
619 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
620 quit("actual retrieval of interface table", WITH_ERRNO);
623 sdl = NULL; /* XXX just to keep gcc -Wall happy */
624 for (next = buf; next < lim; next += ifm->ifm_msglen) {
625 ifm = (struct if_msghdr *)next;
626 if (ifm->ifm_type == RTM_IFINFO) {
627 sdl = (struct sockaddr_dl *)(ifm + 1);
628 flags = ifm->ifm_flags;
631 if ((flags & IFF_UP) == 0 ||
632 (flags & (((multicast_mode == PER_INTERFACE_MULTICAST) ?
634 IFF_BROADCAST|iff_flag)) == 0)
636 if (ifm->ifm_type != RTM_NEWADDR)
637 quit("out of sync parsing NET_RT_IFLIST", WITHOUT_ERRNO);
638 ifam = (struct ifa_msghdr *)ifm;
639 info.rti_addrs = ifam->ifam_addrs;
640 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
642 /* gag, wish we could get rid of Internet dependencies */
643 #define dstaddr info.rti_info[RTAX_BRD]
644 #define ifaddr info.rti_info[RTAX_IFA]
645 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
646 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
647 if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
649 PORT_SA(dstaddr) = sp->s_port;
650 for (np = neighbors; np != NULL; np = np->n_next)
651 if (memcmp(sdl->sdl_data, np->n_name,
652 sdl->sdl_nlen) == 0 &&
653 IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
657 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
658 np = (struct neighbor *)malloc(len);
660 quit("malloc of neighbor structure", WITH_ERRNO);
663 np->n_addr = (struct sockaddr *)(np + 1);
664 np->n_addrlen = dstaddr->sa_len;
665 np->n_name = np->n_addrlen + (char *)np->n_addr;
666 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
667 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
668 if (multicast_mode == PER_INTERFACE_MULTICAST &&
669 (flags & IFF_MULTICAST) &&
670 !(flags & IFF_LOOPBACK)) {
673 memcpy((char *)np->n_addr, (char *)ifaddr,
675 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
676 mreq.imr_interface.s_addr =
677 ((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr;
678 if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
679 &mreq, sizeof(mreq)) < 0) {
681 "setsockopt IP_ADD_MEMBERSHIP: %m");
683 /* Fall back to broadcast on this if. */
684 np->n_flags &= ~IFF_MULTICAST;
691 np->n_next = neighbors;
700 Sendto(int s_debug, const void *buf, size_t cc, int flags,
701 const struct sockaddr *to, int tolen)
703 const struct whod *w = (const struct whod *)buf;
704 const struct whoent *we;
705 const struct sockaddr_in *sock_in = (const struct sockaddr_in *)to;
709 ret = sendto(s_debug, buf, cc, flags, to, tolen);
711 printf("sendto %x.%d\n", ntohl(sock_in->sin_addr.s_addr),
712 ntohs(sock_in->sin_port));
713 printf("hostname %s %s\n", w->wd_hostname,
714 interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), " up"));
715 printf("load %4.2f, %4.2f, %4.2f\n",
716 ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
717 ntohl(w->wd_loadav[2]) / 100.0);
719 for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
720 time_t t = ntohl(we->we_utmp.out_time);
721 idle_time = we->we_idle;
722 printf("%-8.8s %s:%s %.12s",
723 we->we_utmp.out_name,
724 w->wd_hostname, we->we_utmp.out_line,
726 idle_time = ntohl(we->we_idle) / 60;
728 if (idle_time >= 100*60)
729 idle_time = 100*60 - 1;
731 printf(" %2d", idle_time / 60);
734 printf(":%02d", idle_time % 60);
742 interval(int inter_time, const char *updown)
744 static char resbuf[32];
745 int days, hours, minutes;
747 if (inter_time < 0 || inter_time > 3*30*24*60*60) {
748 snprintf(resbuf, sizeof(resbuf), " %s ??:??", updown);
751 minutes = (inter_time + 59) / 60; /* round to minutes */
752 hours = minutes / 60; minutes %= 60;
753 days = hours / 24; hours %= 24;
755 snprintf(resbuf, sizeof(resbuf), "%s %2d+%02d:%02d",
756 updown, days, hours, minutes);
758 snprintf(resbuf, sizeof(resbuf), "%s %2d:%02d",
759 updown, hours, minutes);